text:
Light Emitting Concrete
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Download your Full Reports for Light Emitting Concrete
Light transmitting concrete (LiTraCon), also known as translucent concrete, is the brightest building material development in recent years; it is one of the newest, most functional and revolutionary elements in green construction materials.
Originally developed by Hungarian architect, Aron Losonczi, in 2001, light permitting concrete is produced by embedding 4% to 5% optical glass fibers (by volume) into the concrete mixture. Having a small size, the fibers blend into concrete and become a component of the material similar to small pieces of aggregate. Light-transmitting concrete could reach a compressive strength of 50 MPa.
Besides the architectural and interior design appeal, light-transmitting concrete is used in floors, pavements, heat insulation, and load bearing structures. Even though there are limited examples of translucent concrete currently in use, some of the future potential applications under consideration for implementation include:
Translucent concrete inserts on front doors of homes, allowing the resident to see when there is a person standing outside.
Translucent concrete walls on restaurants, clubs, and other establishments to reveal how many patrons are inside.
Ceilings of any large office building or commercial structure incorporating translucent concrete would reduce lighting costs during daylight hours.
Lane markers in roadways could incorporate various colors in the translucent concrete, allowing for dynamic adjustments when required by traffic fluctuations.
Sidewalks poured with translucent concrete could be made with lighting underneath, creating lit walkways which would enhance safety, and also encourage foot travel where previously avoided at night.
The use of translucent concrete in an outer wall of an indoor stairwell would provide illumination in a power outage, resulting in enhanced safety.
Speed bumps in parking lots and driveways could be illuminated from below, making them more visible and therefore more effective.
Subways using this material could be illuminated with daylight.
Greater day lighting means less electrical lighting, less energy use, less cost, less energy-related emissions. Last but not least, "LiTraCon" matches conventional concrete in terms of strength, insulation, and sustainability.
On the other hand, the product's high cost due to expensive raw material and unavailability for in situ casting represent some of the main drawbacks. The complex manufacturing process of this product eliminates the possibility of using it on site: light transmission is directly related to proper alignment of fibers; any deviation from the application technique would result in ordinary concrete.
There is no doubt that Losonczi's invention is a breakthrough in the construction world; so far countries such as Sweden, Hungary, Germany, France, USA, and China have tried this technology. The most recent realized projects are in Hungary: partition walls in a private Villa, a cinema new logo plate, and an open air statue.
As this technology grows, more people will see its potential and more new exciting applications will appear in everyday use. "LiTraCon" is yet to be seen in Lebanon.


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Kanpur: Killed girl after sexual assault, accused taken for lever for spiritual practice
Uttar Pradesh Of Kanpur On the night of Diwali, a seven-year-old girl was brutally murdered and took out her liver.
Both the accused first kidnapped the girl and sexually assaulted her and then killed her.
It is being told that a relative of the accused had given him money and asked him to bring the baby's lever for tantra Sadhana. This incident is of Kanpur Rural.
Come, let us know the whole news.
Four people arrested in the case so far
Police said that the relatives of the accused were married about 20 years ago, but no child has been born yet.
During this time, someone told them under tantric practice that if they eat a baby's liver, they can have a baby. The couple paid Rs 1,500 for the crime of both the accused.
Police have arrested both the accused and a relative couple in this case.
1,500 were given to the accused for work
Kanpur Rural Superintendent of Police (SP) Brijesh Kumar Srivastava said that Rs 1,500 was given to both the accused. He bought liquor with this money.
The accused told the police that they sexually assaulted the girl and strangled her to death. He then made an incision in her abdomen and tried to take out her limbs.
In the post-mortem report, the injury and shock on the child's limbs have been cited as the cause of death.
The girl was seduced and taken into the forest by accused-DIG
Giving information about the incident, DIG Preetinder Singh of Kanpur Nagar said that the girl went missing while playing outside her house on the night of Diwali. Locals and police searched for him, but he was not found.
The next morning the dead body of the girl was found in a forest near the village. Later, it was learned that two youths from the neighborhood seduced the girl on the pretext of feeding chips and sexually assaulted her.
The accused confessed during the interrogation
SP Srivastava said that an FIR has been registered against the accused under sections 302 (murder) and 201 (attempt to erase evidence) of the Indian Penal Code.
Against them Gangrape A case has also been registered under the Section of S and POCSO. Both have confessed to the crime during interrogation.
Both of them told the police that their uncle had given them money to fetch the dead body.
Case will be heard in fast track court
Srivastava said that the uncle of the accused believed that eating the baby's liver could produce a child for his wife. For this both of them murdered the girl and took the lever. The baby's parts have not been recovered yet.
Chief Minister of Uttar Pradesh Yogi Adityanath Mourning the incident, has announced a compensation of five lakh to the victim's family. He said that the case would be heard in fast track court.

redpajama_set_name: RedPajamaCommonCrawl


Lately winged stamps have become the crowd favorite. They simply need to be coated with eyeliner and stamped in the right spot. You cannot ask for an easier solution. This method saves up on time and effort. There are also variety of stamps available and diy methods to create your own stamps. Get to stampin'!
Who knew taping your eyes would become the secret to perfect wings?
These days stickers aren't only glowing stars and cartoon figures.Thanks to innovative makeup creators we now have Eyeliner Stickers! These stickers come in a pack of 5 or 10. They are usually the same or different design. Pick your favourite, place it on your eyelid, apply a damp cloth to wet the sticker and there you have it. Freshly applied eyeliner and zero effort!
Running late? Or need a quick eyeliner for a last minute date? Stencils are the perfect solution for you. Stencils are reusable and extremely easy to handle.
Just place the stencil according to the instructions and start applying eyeliner or eyeshadow in the given area. Once you remove the stencils you will be left with the perfect winged eyeliner.
If you've had enough practice to go freehand with the winged liner, we commend you. But beware of smudges and wipe aways. Make sure you have your earbuds handy.
Earbuds dipped in makeup remover act as perfect tools clean and create a perfect wing by wiping away the mistakes. This prevents you from having to wipe off your entire eyeliner.
Concealer is usually used to cover up spots and dark circles on your face but it is also extremely helpful to cleanup and perfect your winged eyeliner.
Simply apply your eyeliner and grab a small and flat brush to apply the concealer. Swipe it right next to the eyeliner wing to create a clean and perfectionist look. You're set to conquer the day!


Do you have great customer service skills? Interested in an opportunity to work some part time hours and earn extra money? We have a client in Northern Massachusetts who is looking for a Receptionist who can help cover on an as needed basis while their current receptionist needs to be out or while they have company functions. This is a growing company in the area that has a friendly work environment. Hours are typically 8: 00AM to 4: 00PM or 1/2 days from 12: 30PM to 4: 00PM. Would need to train from 9-1 for 2-5 days prior. Client is looking to have coverage on going and would like to find a candidate as soon as possible.


text:
Window on Eurasia: Kremlin Personnel Changes Point to Closer Ties between Regime and Patriarchate
Vienna, April 23 – The retirement of two senior Russian officials, one who had been involved with religious affairs since Soviet times and a second who earlier had clashed with the Moscow Patriarchate, opens the way for a further tightening of relations between President Dmitry Medvedev and the Russian Orthodox Church.
These latest developments continue a trend that Medvedev and especially his wife have pushed since he came to office, but they are especially important because they open the way for steps, like the introduction of a new national holiday on the Baptism of Kievan Rus, that will exacerbate relations between Moscow and followers of other faiths, including Islam.
In an article in today's "Nezavisimaya gazeta," Elina Bilevskaya points to the retirement of two senior Kremlin officials as an indication that "the Kremlin is seeking new models of interrelations with religious organizations" in general and with the Russian Orthodox Church in particular (www.ng.ru/politics/2010-04-23/3_rpc.html).
In both cases, the journalist says, the "formal" explanation was that the two had reached retirement age, but she argues that most observers think far more is in fact involved. The first of the two, Aleksandr Kudryavtsev, the referent for internal policy, had primary responsibility who oversaw the presidential Council on Interrelations with Religious Organizations.
Kudryavtsev was involved with religious affairs since Soviet times. From 1988 to 1990, he worked in the Council on Religious Affairs of the RSFSR Council of Ministers. Then, he supervised the registration of religious communities in the justice ministry and headed the department for humanitarian policy and social ties of the Presidential Administration.
In all these positions, he was committed to the idea of the complete separation of church and state and to the notion that the state should treat all religions equally, positions that inevitably brought him into conflict with the Moscow Patriarchate which, especially under Kirill, has sought to raise the status of Russian Orthodoxy to something more than primus inter pares.
The second departure is that of Andrey Sebentsov, who until recently was the White House's responsible secretary for the commission questions of religious organizations and who has been at odds with the Moscow Patriarchate since at least 1997 when he opposed federal legislation that would have legalized Kirill's concept of the four "traditional" religions of Russia.
Worse, from the point of view of many in the Orthodox hierarchy, Bilevskaya continues, Sebentsov is "considered as a supporter of broad democratic views concerning the relationship of the state with religious organizations," something that protects non-Orthodox groups but that undermines the Patriarchate's sense of primacy.
A source in the government said that he "did not exclude" that these retirements could be "connected with the search for innovative ideas in the development of dialogue between the state and religious organizations," all the more so because "innovation" is all the rage in that sector along with all others.
But a source in the Kremlin itself told "Nezavisimaya gazeta" that there was more to this. Medvedev, he indicated, currently views "the question of relations of the state with religious organizations" as a "priority" matter. Consequently, personnel changes in this area likely point to policy shifts as well.
Aleksey Makarkin, the deputy head of the Moscow Center of Political Technologies, agrees. He suggested to "Nezavisimaya gazeta" that "the retirements of Kudryavtsev and Sebentsov could be connected with the activity of Kirill, the Patriarch of Moscow and All Russia."
Both of those sent into retirement, he said, were "supporters of a model which presupposed that the state relates to all spiritual communities in the same way without giving supremacy to any one of them." That clearly did not and does not please the leaders of the Russian Orthodox Church.
And Makarkin suggested that "cooperation [by the government] with the Russian Orthodox Church will be strengthened," a reward for the Patriarchate's support of the government during the crisis and its success in preventing splits by "extreme conservatives" whose views might threaten popular unrest.
Such cooperation, not surprisingly, will please the Orthodox but only at the cost of offending other religious groups. An indication of that danger was on view this week. On Wednesday, the Duma passed on first reading a government-proposed measure that would make July 28 the Day of the Baptism of Rus (www.pravo.ru/news/view/28759/).
A backer of the measure, Sergey Markov, said that the Baptism of Kievan Rus was "the most important moment in the history of Russia" and that the celebration of this event which took place in 988 will promote the rapprochement of Russia and Ukraine, whose capital by tradition was the site of this event.
But one deputy, Just Russia's Semen Bagdasarov, suggested that this latest indication of a rapprochement between Moscow and Orthodoxy not only contradicts the Russian Constitution which mandates separation of church and state but could generate serious problems, including instability, in a country, "more than 20 percent" of whose population is Muslim.
Posted by Paul Goble at 4:57 PM


If you're looking for low maintenance living in a wonderful community while being close to shops, dining and having an easy commute, you have found the perfect home! This townhouse style condo has 2 bedrooms, 2 1/2 bathrooms and has a great, open floor plan with a large kitchen, dining and living room plus a 1/2 bath downstairs. Upstairs, you will find two great size Master Suites with en-Suite bathrooms! This home also features an attached, one car garage, laminate flooring in the dining room, a skylight, front and rear porches, perfect for early morning coffee or a quiet evening. The rear porch is screened in and there are no direct rear neighbors so you can overlook the beautiful HOA maintained landscaping and oak trees! The kitchen is spacious and has enough room for a movable island, breakfast table or extra storage space. The storage space throughout this condo isn't lacking either! Not only is this a great home but it is nestled in a wonderful, gated community. The community amenities are a clubhouse with a seating area and kitchen, multiple pools, hot tub, gym, recreation room and you have private community access to Lake Orienta! There is also a community dock for fishing and relaxing, a boat ramp and boat/kayak/canoe storage! This home and community has so much to offer, you will love living here! Don't miss out on this lovely home!
I was searching for a Property and found this listing (MLS® #O5749021). Please send me more information regarding 641 Maple Oak Cir #121, Altamonte Springs, FL, 32701. Thank you!
I'd like to request a showing of 641 Maple Oak Cir #121, Altamonte Springs, FL, 32701 (MLS® #O5749021). Thank you!
641 Maple Oak Cir #121 is located in the Oak Harbour Sec 4 neighborhood in Altamonte Springs, FL. This residential property for sale is currently being offered at $185,000. Built in 1990 this 2 bedroom, 3.00 bathroom Central Florida residential property has been listed on RealtyInOrlando.com for 11 days. 641 Maple Oak Cir #121 is priced at $114 Per Square Foot, and is situated on 0.04 acres of land. Homeowner association fees in Oak Harbour Sec 4 are $349 per month. Please contact your local Realtor® for more information on 641 Maple Oak Cir #121, Altamonte Springs, Florida 32701. Property Listing Reference: MLS number: O5749021.


Fish Habitat | Artificial Fish Habitat | Honey Hole Dock Dropper — Pond King, Inc.
If you want to boost the vertical fishing around your dock, The Honey Hole Dock Dropper is for you!
This hanging, artificial fish structure provides vertical habitat for suspending fish at varying depths. Combine the Dock Dropper with the Honey Hole Canopy and you'll turn your dock into a mega structure for fish.
Long-lasting and safe for the environment, The Honey Hole Dock Dropper is made of High Density Polyethylene (HDPE). With dual color variation flexible leaves, the Dock Dropper replicates the structural complexity and dynamic movement of natural cover but without the degradation or decay of natural cover.
The Honey Hole Dock Dropper ships free in the continental U.S.
The Honey Hole Dock Dropper requires no assembly—just a quick installation!
The Honey Hole Dock Dropper should be attached to the side of your dock in a spot where the water is at least 15 feet deep.
Simply shackle the cable around an attachment point, like a vertical post or dock cleat, and drop the rest into the water. The chain at the end provides the weight to sink the habitat vertically, directly beneath your attachment point.
Why is fish habitat so important? Fish like cover. They either go to it to feed, or they go to it to avoid being eaten. Submerged vegetation is valuable as habitat for predatory species like Bass or Crappie and for forage species like Bluegill. Pond King's fish biologists designed the Honey Hole product line to augment or replace naturally occurring aquatic vegetation to attract game fish (the fish that use cover as ambush to help them feed) and protect forage fish. Our artificial fish habitat is designed for pond and lake owners to help with fish population management.
Is the Honey Hole Artificial Fish Habitat environmentally safe? All the Honey Hole artificial fish habitat is made of High Density Polyethylene (HDPE) and is designed to be assembled without any toxic glues or adhesives, so yes it is safe for the environment. In fact, given that it doesn't degrade overtime and minimizes the number of lures snagged that land on the bottom of the lake or pond, some might even say our artificial fish habitat is good for the environment.
Is it hard to install the Honey Hole Artificial Habitat? Absolutely not! The Honey Hole, and the Honey Hole Reed, Brush and Grass can just be tossed into the water from your boat or the shore. You just drop the Dock Dropper from your dock (as the name implies), secure it to your deck and you are good to go. The Honey Hole Canopy requires just a little more effort; you just have to attach it to a weight (not included), and then drop it the water.
For more information, please visit our Artificial Fish Habitat FAQ page.


Sir Samuel Sandys, who died on August 18 1623, and his wife who died in 1629, are both buried in Wickhamford. The Peerage of England, published in 1779, has the following description.
Sir Samuel, and his lady, who died in 1629, are both buried at Wickhamford, and on the North side of the chancel, have a double monument of alabaster, supported by five pillars of touch-stone; where lieth the portraiture of an armed knight, with his hands lifted up in a prayer posture, and at his feet a griffin. By his side lays his Lady, Her hands joined in prayer; at her feet, on a wreath argent and azure, a harpy's head arm'd mane and beard, Or. Over these arms, on an escutcheon, Or, a fess dancette between three cross croslets fitchee, gules, quartering party per fess, gules and azure, a tower of castle argent. On a tablet, near the monument, were the following inscriptions, viz.
Here, in Hopes of a Joyful Resurrection, resteth the Body of Sir Samuel Sandys, Knt. Eldest son to that famous Prelate, Edwin Archbishop of York; for Piety, and excellent Endowments of his Mind, deservedly justly to be remembered by Posterity; especially for his singular Wisdom, Integrity, and Industry, in the Affairs of the Commonwealth, of whom the great and frequent Assemblies of Parliament were approving Witnesses. Being also to this County, that challengeth his birth, a principal Ornament. He changed this Life for a better, in his Climacterical Year (a Year for the most Part fatal to excellent Men) having almost attained to 63. The Wife of his Youth, and his Age, was Mercey, descended of the ancient Family of the Culpeppers, and the only Daughter of her Mother; a wife and prudent Woman, who, together with her Husband, was a great Advancer of her Family; with whom he lived 36 Years, in exemplary Concord; and had by her eleven Children, all of them (an extraordinary Blessing) at his Death surviving; But she having honourably interred her Husband, together with her eldest Son, Sir Edwin Sandys, a Young Gentleman of great Virtues, who hardly 21 Days outlived his Father; a most sorrowful Widow, and Mother, erected this monument to their Memories, as a lasting Testimony of her Love and Affection; and hath commanded her Children, after her Death, to inter her by Body of her dear Husband; that so her Ashes may be mingled with his, from whom, in her Life, her Desires and Affections were inseparable, which is since accordingly accomplished; for she having piously breathed out her Soul unto God, here resteth in Peace, and assured Expectation of the second Coming of our Lord and Saviour, Jesus Christ.
This tablet is no longer in the Church and may have been removed in 1841. A plaque over the chancel arch records that in that year Arthur Lord Sandys of Ombersley Court "Restored and Beautified" the Church and the Family Monuments.
A book on the Sandys family published in 1930 makes mention of the tablet being in the church, but the author may have been quoting from the 1779 book?
There is plaque at the foot of the tombs which is now blank and may at one time have carried an inscription, but it is too small to have been inscribed with the amount of detail above.
Blank plaque at foot of tomb which may once have carried an inscription.
Long shot of the Sandys tombs to show the position of the blank tablet.
It is now thought that the pillars and canopy were part of the restoration of 1841, but the 1779 book refers to the five pillars being there at that time, but of "touch-stone". This material is what? Are the present pillars replacements, from 1841? Given the details below, this seems very likely.
The date given above for the death of Sir Samuel is 18th August 1623. The parish Burial Register gives the date of his burial as 20th August 1623. His son was buried on 9th September 1623, according to the Burial Register, so the mention of them dying 21 days apart would be correct.
But the present inscription above Sir Samuel's tomb states that he died on 2nd September 1626, aged 63 and that above Sir Edwin states that he died on 23rd September 1626. These are obviously incorrect and must have been put there in 1841.
The description of a "harpy's head" at Mercy's feet, explains the beast that looks like a goat.


Are you looking for a family tradition that would help you show gratitude this time of the year? Maybe something you can even do at dinner time. This Gratitude table runner is for you and so easy to create.
I took a table runner that I had in my kitchen. It was plain tan color. I am sure you can find one like it at any home decor store.
Then, I used felt to create turkeys.
I just free handed it all. But there are patterns online.
I found mine at a craft store but you can also find online.
Line up your turkeys and glue down but leave the top open.
I placed my sticks in just to make sure that I could make them look like a feather. Then, I glued down the sides a little more so that the sticks stay in better. Feather them out.
On the center stick, I wrote gratitude and have that one higher than the others.
For the other 4, each week until Thanksgiving, as a family pull one stick out and write 1 thing you are grateful for.
4 weeks and 4 sticks. One for each family member.
You can do this at dinner time and talk about what each other wrote as a family. Pick a night of the week and share your gratitude.
Another great thing about this table runner activity is that kids big and small can do it and they will love making their own turkey and writing on their sticks. Then, expressing their feelings of gratitude opens the door up for communication that is so important to do as a family.
Thanksgiving has become my favorite holiday. I think because it is just about family, love and being grateful. There aren't many distractions that day other than food and if you are a member of my family, the Dallas Cowboys, but ultimately it is about time spent with those you love.
This time of the year is perfect for sharing what you love and what you are thankful for. The whole point of this season is to share, love and to give!
At The CSI Project, we live to create, to share and to inspire all year long but we won't let this time of year pass us by without sharing even more!
We are grateful for you, dear readers!
Oh, I just love this so! What a wonderful, meaningful, and adorable craft for Thanksgiving! We will be trying this one, and I'll be featuring your project this week at Heathered Nest for Think & Make Thursday 🙂 Thanks for sharing it!
What a cute idea, and a great way to discuss all we can be grateful for! Thanks for sharing this post with us as Merry Monday! Tweeted!
What a great project for kids to create. I love this idea and would be great to add to the kids Thanksgiving table with their names on them.


Christmas is a season of self-expression in Layla and Kevin Palmer's 1950 cottage. You never know when Layla will get out her craft supplies to embellish a stocking or change decorations. "I'm so Gemini—one year I'm totally into this, and the next year I'm doing that," she says.


text:
Lincoln and Marti Turned in Their Graves
Embracing tyrants doesn't raise their standards. To the contrary -- it lowers the standards of those who embrace them.
Case and point is an oped today by a Cuban-American businessman, Mike Fernandez, in Univision's online portal.
In short, Fernandez argues: If given the choice between free speech, multi-party elections and being a "cuentapropista", the Cuban people would choose being a "cuentapropista."
Of course, we'd argue: Let's ask them in an open, democratic process. (Never mind that Fernandez doesn't realize his entire premise is an oxymoron.)
Elecciones para que?
He claims to already know the answer because he's asked them "at street corners in Havana."
Fernandez is part of a handful of Cuban-American businessmen who joined President Obama during his recent trip to Havana. According to The Miami Herald, they were "helping the Cuban people" by hanging out with Castro's apparatchiks at the military-owned Hotel Saratoga. There, they enjoyed "a feast of delicacies most Cubans can only dream of: smoked salmon, prosciutto, dates, figs, four types of soft cheeses."
These businessmen like to use "cuentapropismo" as a scapegoat. But U.S. law doesn't impede transactions with "cuentapropistas" -- it's Castro that limits their freedom. What they are lobbying for is the U.S. Congress to lift sanctions on business with Castro's state monopolies, fully equipped with slave labor, stolen properties, et al.
They discard that freedom and democracy didn't stem from capitalism. It's the other way around.
They ignore that The Wealth of Nations didn't precede The Magna Carta. It's the other way around.
They forget that they were successful due to the freedom and democracy that Americans enjoy. That our freedoms and democracy aren't secondary to making a profit. That they would not have made their profits without freedom and democracy.
This is precisely why business groups are losing the American people. It's why fringe candidates have amassed such large followings. They have subjugated America's freedom-first agenda to one of profits-first.
Fernandez admits that economic engagement hasn't resulted in rights and freedoms for the people of China and Vietnam, but that we should instead recognize the "progress" there. Progress akin to Mussolini making the trains run on time, we presume.
But here's the kicker:
In this latest effort to relegate freedom and democracy, Fernandez summons the leadership of Abraham Lincoln and Jose Marti.
Lincoln and Marti must have turned in their graves.
Abraham Lincoln didn't relegate the freedom of slaves to Northern manufacturer's desire to purchase cheap cotton from Southern plantation owners. To the contrary.
Jose Marti didn't relegate the freedom of the Cuban people to Spain's mercantilism and the business interests of the merchant "criollos" that enabled it. To the contrary.
And neither Lincoln or Marti believed that the way to end slavery and colonialism was to embrace and forgive its perpetrators, particularly as they continued oppressing its people.
Fernandez doesn't seem to know much about Abraham Lincoln. But during his time, Lincoln clearly knew men like Fernandez, whom he shamed:
"On the question of liberty, as a principle, we are not what we have been. When we were the political slaves of King George, and wanted to be free, we called the maxim that 'all men are created equal' a self evident truth; but now when we have grown fat, and have lost all dread of being slaves ourselves, we have become so greedy to be masters that we call the same maxim 'a self evident lie.'"
-- August 15, 1855, Letter to George Robertson


In our fast-paced secular world, God and theology are second-class citizens. Money, politics, sports, and science seem better suited to the hard realities of our world. As the church steeple has been eclipsed by the skyscraper as the centerpiece of the urban landscape, so has the divine realm been set aside in favor of more immediate human experience. One sad consequence of this shift is the loss of spiritual and theological bearings, most clearly evident in our inability to understand or speak about such things. If the old way of viewing the universe no longer works, something else has to replace it.
The Powers That Be reclaims the divine realm as central to human existence by offering new ways of understanding our world in theological terms. Walter Wink reformulates ancient concepts, such as God and the devil, heaven and hell, angels and demons, principalities and powers, in light of our modern experience. He helps us see heaven and hell, sin and salvation, and the powers that shape our lives as tangible parts of our day-to-day experience, rather than as mysterious phantoms. Based on his reading of the Bible and analysis of the world around him, Wink creates a whole new language for talking about and to God. Equipped with this fresh world view, we can embark on a new relationship with God and our world into the next millennium.


text:
Q: Open new HTML page in the same tab via Javascript I have tried a half dozen ways to open a page in the same tab upon clicking a button and none of them work on FireFox or Edge:
window.location ="advance.html";

nothing happens
window.location ="/advance.html";

nothing happens
window.location.href ="advance.html";

nothing happens
window.location.href ="/advance.html";

nothing happens
window.open("advance.html", _self);

nothing happens
window.open("advance.html");

opens page in new tab
Been working on it for an hour trying every suggestion and nothing works.
What am I missing here?
EDIT:
Since people are asking for the context (I know the username and password are in plain text, I'm just trying to get this part working first):
<script language="javascript">
    function goHome()
    {
        window.location = 'index.html';
    };

    function login(form)
    {
        if(form.company.value == "advance" && form.password.value == "1234")
        {
            window.location.href ="advance.html";
        }
        else if(form.company.value == "" || form.password.value == "")
        {
        }
        else
        {
            alert("Incorrect Usename/Password combination please try again.");
            form.password.value = "";
        }
    }

A: I've actually figured this out by experimenting because the MDN documentation wasn't clear on this, but it seems window.location uses full paths with protocol, but accepts relative paths that begin with . or .. and absolute site paths that begin with /.
This means your second and fourth examples actually work.
window.location = "/advance.html";

If that's not working for you, then the error might be elsewhere, or browsers are inconsistent (which would surprise me since this is an old feature).

A: Do not use submit, use the button like this:
<input type="button" onclick="login(this.form)" value="login">

function login(form) {
   if (form.company.value == "advance" && form.password.value == "1234")
   {
      window.open("advance.html", "_top");
   }
}

A: I think the problem is in your window.open("advance.html", _self);. You have to quote the "_self". window.open("advance.html", "_self"); this code should work.
Also you can use location parameter in it. Like `location.assign("advance.html"). It will open it in a new window.

redpajama_set_name: RedPajamaStackExchange


text:
Journal of Applied Meteorology and Climatology
Field experiment description
Vegetation and fuel
Instrument and data description
Data preprocessing
Image-flow analysis
Sample sequence of images
Statistical maxima
Spread rates
Other sequences
Albini, F. A. 1993. Dynamics and modeling of vegetation fires: Observations. Fire in the Environment: The Ecological, Atmospheric, and Climatic Importance of Vegetation Fires, P. J. Crutzen and J. G. Goldhammer, Eds., John Wiley and Sons, 39–52.
Albini, F. A. 1993. Dynamics and modeling of vegetation fires: Observations. Fire in the Environment: The Ecological, Atmospheric, and Climatic Importance of Vegetation Fires, P. J. Crutzen and J. G. Goldhammer, Eds., John Wiley and Sons, 39–52.)| false
Albini, F. A. and B. J. Stocks. 1986. Predicted and observed rates of spread of crown fires in immature jack pine. Combust. Sci. Technol 48:65–76.
Albini, F. A. and B. J. Stocks. 1986. Predicted and observed rates of spread of crown fires in immature jack pine. Combust. Sci. Technol 48:65–76.)| false
Bab-Hadiashar, A. and D. Suter. 1998. Robust optic flow computation. Int. J. Comput. Vision 29:59–77.
Bab-Hadiashar, A. and D. Suter. 1998. Robust optic flow computation. Int. J. Comput. Vision 29:59–77.)| false
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Image of extreme fire behavior (forward burst) obtained during the ICFME (photo courtesy of the Canadian Forest Service)
(a) Terrain with locations of Caribou Peak (imager location) and location of the data cross sections (i.e., the image plane) of sequences 1–5. The thick contour shows the FROSTFIRE burn perimeter. (b) Local terrain with locations of surface stations (courtesy of Larry Hinzman, University of Alaska, Fairbanks). (c) Typical black spruce distribution during blacklining on 8 Jul 1999 near station C4 [see (b)] (photo courtesy of U.S. Department of Agriculture Forest Service Research)
Weather variables recorded at CPCRW stations CPEAK and CRREL. Legends contain the measurement height (data courtesy of Larry Hinzman and John Gallagher, University of Alaska, Fairbanks)
Fire climbing ridge, viewed from Caribou Peak, at two times during sequence 5. East is to the left of the image, and west is to the right
Temperature images at six times relative to the beginning of sequence 5: 1.85, 4.00, 9.77, and 41.37 s, from top to bottom. The grayscale image data correspond to temperatures of the range 500° (black)–800°C (white), as shown in the temperature scale to the left of each image. The fire is traveling from left to right. Because of deinterlacing, the vertical scale is compressed; the image area is 195 m × 205 m
Sequence of images obtained from image-flow analysis (with calculated vectors) during sequence 5. This image corresponds to the dark line in Fig. 2a. (East is to the left.) Shaded contours show the temperature detected by the infrared imager. The vectors show the calculated flow velocities. Every eighth point in the x direction and every fourth point in the z direction are plotted
Motions for sequence 5 calculated from image-flow analysis. The velocity parallel to the slope is shown. Negative values are surrounded by contour lines and are also filled according to the shading bar shown
Velocity statistics for domainwide maximum and minimum for sequence 5: (a) w (vertical velocity) component, (b) extrema for the (derived) velocity component parallel to the slope, and (c) the maximum air speed. Actual calculated maximum values are shown in gray; black lines show expected extrema that are ±5 std dev from the imagewide mean statistical values
Average vertical profiles (averages taken at constant height above ground level) of (a) vertical velocity (m s−1), (b) temperature perturbation from ambient (°C), (c) sensible heat flux (MW m−2), and (d) speed (m s−1) for sequence 5
Wind vectors derived through image-flow analysis of sequence 3 at four times: (a) 12.1, (b) 12.783, (c) 12.917, and (d) 13.067 s. Shaded contours show the temperature detected by the infrared imager. Every eighth point in the x direction and every fourth point in the z direction are plotted
Wind vectors derived through image-flow analysis of sequence 2 at two times: (a) 32.833 and (b) 33.067 s. Shaded contours show the temperature detected by the infrared imager. Every eighth point in the x direction and every fourth point in the z direction are plotted
Infrared Imagery of Crown-Fire Dynamics during FROSTFIRE
Janice Coena, Shankar Mahalingamb, and John Dailyc
a National Center for Atmospheric Research,* Boulder, Colorado
| b University of California, Riverside, Riverside, California
| c University of Colorado at Boulder, Boulder, Colorado
https://doi.org/10.1175/1520-0450(2004)043<1241:IIOCDD>2.0.CO;2
A thorough understanding of crown-fire dynamics requires a clear picture of the three-dimensional winds in and near the fire, including the flaming combustion zone and the convective updrafts produced by the fire. These observations and analyses present a unique high-spatial-resolution and high-temporal-resolution perspective of the motions within crown fires propagating up a forested 20° slope under light winds of 3 m s−1 during the FROSTFIRE experiment in interior Alaska. The purpose of this work is to calculate combustion-zone winds and examine mechanisms for the rapid propagation of crown fires. An infrared imager was used to detect high-temperature regions produced by incandescent soot particles in and near the fire and to produce a sequence of high-frequency (60 Hz), high-resolution (0.375 m × 0.8 m) two-dimensional images of temperature. An image-flow-analysis technique was applied to these data to derive wind fields in the image plane. Maximum updrafts of 32–60 m s−1 accompany maximum downdrafts of 18–30 m s−1. Horizontal wind speeds of 12–28 m s−1 show strong inflow into the base of the convective updrafts and imply recirculation of air and incomplete combustion products from the fire. Motions were more complex than a single large convective plume or many buoyant tree-scale plumes rising separately. Instead, repeated examples of narrow flaming fingers, representing a scale larger than individual trees, initially burst upslope along the ground for tens of meters at speeds up to 28–48 m s−1 before turning upward. These bursts exceeded ambient environmental winds, those considered to be driving the fire, by a factor of 10 and were low enough to propagate the crown fire actively by both igniting and preheating/ drying canopy fuel ahead of the fire. Average spread rates were 0.75–1.11 m s−1, with a peak 10-s spread rate of 1.26 m s−1. This powerful, dynamic mechanism of fire spread could explain firefighter reports of being overtaken by "fireballs."
Corresponding author address: Janice Coen, National Center for Atmospheric Research, P.O. Box 3000, Boulder, CO 80307-3000. janicec@ncar.ucar.edu
Wildland fire exhibits a vast range of fire behavior, from smoldering ground fires, to quickly spreading grass fires, to flaming crown fires running through tree canopies. Crowning is an example of extreme fire behavior and is important from a fire management perspective because it represents an intensity of wildfire behavior that ordinarily precludes, or at least severely limits, direct suppression until conditions subside. Crown-fire spread rates can vary widely (0–3.1 m s−1, faster in mountainous terrain or when environmental winds are strong—Rothermel 1991; 0.131–0.455 m s−1 on flat ground with ambient winds ranging from 10 to 16 km h−1—Albini and Stocks 1986). Bessie and Johnson (1995) attribute most of this variability to weather factors rather than variability in fuel. Crown fires can spread at several times the rate of surface fires (Rothermel 1983, 1991) and can spot (i.e., can loft burning embers ahead of the fire to ignite new fires), leading to control problems at natural and anthropogenic fuel breaks. Predictability is difficult because such fires often affect their atmospheric environment, behaving erratically and sometimes dangerously (National Wildfire Coordinating Group 1994).
Some specific examples of this erratic behavior have been recorded in the International Crown Fire Modelling Experiment (ICFME), during which balls of fire were photographed bursting forward from a prescribed crown fire burning through a plot of boreal forest (Fig. 1), and in the Wildland Fire Experiment (WiFE), during which a research aircraft captured infrared imagery of a finger of flame that appeared, from the overhead perspective, to shoot 100 m from the fire line at a speed estimated at 50 m s−1 (Radke et al. 2000) before collapsing. From this perspective, Radke et al. could not determine the burst's height above ground or determine unambiguously whether the path was forward or upward, although a second instrument on the aircraft confirmed that at least part of the burst left a trail of burning fuel on the ground, suggesting it was close to the surface. The mechanisms for this behavior are not understood well because few detailed observations of the motions inside crown fires have been made, visible imagery is often obscured by smoke, the phenomenon changes in fractions of a second, and coupled atmosphere–fire models (Clark et al. 1996a,b, 2004; Coen et al. 2001; Linn et al. 2002) are just beginning to replicate the phenomena that result from the complex interactions between a fire and its atmospheric environment.
A good understanding of fire behavior requires a clear picture of the three-dimensional winds in and near the fire, including the flaming combustion zone and the convective motions produced by the fire. These motions determine the convergence pattern superimposed upon the surface winds, which in turn direct and propagate the fire, produce the persistence and ubiquity of the "universal fire shape" (Albini 1993; Coen et al. 2001), and lead to the complex, nonlinear dynamics exemplified by fire whirls and the previously mentioned forward bursts. Clark et al. (1999) developed image-flow-analysis methods to analyze infrared imager data and to study the very small temporal and spatial scales of motion in the prescribed crown fires set in boreal forest plots during ICFME. They found that updrafts between 10 and 30 m s−1, downdrafts between 10 and 20 m s−1, and horizontal motions between 5 and 15 m s−1 frequently occurred throughout the fire. The analysis also revealed pairs of counterrotating convective updrafts, rotating such that air between the towers blew forward, downwind in the direction of fire spread. They theorized that as these vertically oriented vortices tilt together, their combined motion causes the vortices to tip forward at a sharp angle, forming a hairpin-shaped vortex that causes a turbulent burst. This technique has also been applied in a laboratory setting to study motions within fire plumes (Zhou et al. 2003).
Here, infrared imagery obtained during the FROSTFIRE experiment is analyzed, during which time prescribed fires were set in the boreal forest of the Caribou– Poker Creeks Research Watershed (CPCRW) Long-Term Ecological Research Program site in the Alaskan interior. Section 2 describes the FROSTFIRE experiment, the fire environment variables, and the fires. Section 3 describes the instrument used, the techniques for gathering and processing these data, and the image-flow-analysis method used to analyze these data. Section 4 describes our analysis of crown-fire runs to investigate crown-fire properties and propagation. The analysis shows bursts along the surface comparable to the magnitudes found by Radke et al. (2000), with wind velocities and sensible heat fluxes that represent extremes among atmospheric processes. Moreover, in this case these extreme velocities cannot be attributed to strong environmental winds. These results are discussed in section 5.
FROSTFIRE was a landscape-scale research project conducted in the boreal forest of interior Alaska that focused on the long-term ecological effects of fire. The research goals of FROSTFIRE were to understand the role of wildfire in Alaska and to develop an improved understanding of boreal feedbacks to climate. The setting was the CPCRW Long-Term Ecological Research Program site, a 104-km2 basin approximately 40 km northeast of Fairbanks, near the town of Chatanika (65°10′N, 147°30′W). Within the 1050-ha perimeter, during the experiment, prescribed fires mimicking natural conditions burned 430 ha of mostly black spruce, leaving the hardwoods standing. Major burning occurred over 3 days (8–10 July 1999) while conditions were within the window of prescribed burning conditions, followed by several days of smoldering. For more details, see Hinzman et al. (2003) and Fastie et al. (2003).
CPCRW is located in the Yukon–Tanana uplands in interior Alaska. Located between the Brooks and Alaska Ranges, CPCRW is part of a large area of rolling forested hills covered by boreal forest. Ridge elevations range from 450 to 900 m, with rises of 150–500 m above the adjacent valleys. The topography in the area of the FROSTFIRE burn is shown in Figs. 2a and 2b. The dominant terrain features within the prescribed burn perimeter are Caribou Peak (773 m MSL) and Helmer's Ridge (630 m MSL), between which Little Poker Creek flows.
CPCRW is a permafrost-dominated watershed that contains the major forest types of the Alaskan boreal forest. Three primary types characterized the vegetation in the burn area. The first is closed and open coniferous forests of black spruce (Picea mariana; Fig. 2c). This highly flammable vegetation is the climax vegetation type on north slopes in the research area. They grow tall and thin, rarely exceeding 15 m in height or 0.25 m in diameter, and one-half of the trees in a stand may be less than 0.05 m in diameter. Based upon photos of the burn area, the treetops in the data field of view were approximately 10 m above ground and spaced closely together, with stems often only 2 m apart. Black spruce are not fire resistant—branches close to the ground and thin bark combine to make them particularly vulnerable to fire—and thus fire spread freely throughout the black spruce in this experiment. The remainder of the site was dominated by closed hardwood forests of paper birch (Betula paperifera) and quaking aspen (Populus tremuloides) on south-facing slopes, boggy sphagnum– dominated wetlands along the stream, and caribou moss (Cladonia rangifernia) on exposed ground. Dwarf tree scrub and tall scrub grow in the valley bottom and on some ridgelines.
Fuel loads given in the FROSTFIRE burn plan (Wilmore et al. 1998) were estimated using an aerial photo series and previously published data from other sites (Dymess et al. 1989). Based on these works, Wilmore et al. (1998) estimated that aerial biomass totaled approximately 5.16 kg m−2 and the forest floor totaled 12.3 kg m−2 in the black spruce stands. Above-ground biomass for the aspen and birch was estimated at 5.60 kg m−2. Forest floor necromass was estimated as 7.85– 10.8 kg m−2 for the birch and aspen stands.
The weather conditions recorded at two surface stations at CPCRW during the burn period are shown (Fig. 3). The data at the Caribou Peak (CPEAK) station represent exposed mountaintop conditions unaffected by the fire. The Cold Regions Research and Engineering Laboratory (CRREL) station was located at the mouth of the valley between Caribou Peak and Helmer's Ridge, about 1 km downstream from the fires (see Fig. 2b). The conditions at midday on 10 July 1999 in the area of the fire were approximately 20°–25°C, with 30% relative humidity and winds from the northeast at 2–4 m s−1. The flows were upslope as the ground began warming in the sun.
A 10-m-wide fire line was cut and brush was removed from the entire perimeter of the FROSTFIRE burn site, and then it was blacklined (all vegetation was burned by hand torches down to mineral soil) before the prescribed fire. Burning occurred over a 3-day period from 8 to 10 July 1999, followed by several days of smoldering. The experiment was designed to vary fire intensity across the watershed to span the entire range of burn intensities observed in boreal forest. After 1.5 days of blacklining, interior aerial ignition began at approximately 1900 LST 9 July with "ping-pong" ignition (small spheres containing potassium permanganate were injected with ethylene glycol and jettisoned from the helicopter before the chemicals reacted thermally to produce a flame) and terra torching (a giant drip torch, fueled by a drum of gelled gasoline and suspended from a helicopter, emitted a steady stream of burning fuel globs) and ended at approximately 2100 LST when the relative humidity became too high and the fuels resisted ignition. These ignitions subsided overnight.
The 10 July operational plan called for more firing, and, as of 1100 LST, only small fires were smoldering from the previous night's ignitions. Then, as the solar heating increased, the northeasterly wind increased, fanning the smoldering fires in the lowest part of the valley, spreading these fires toward the top of Helmer's Ridge (see Fig. 4). Stands of black spruce flared up and fire spread rapidly upslope in running crown fires. At a position 2.6–3.2 km across the valley from the fire, data of several crown-fire periods of varying intensity ranging from smoldering fires to running crown fires were recorded on 9–10 July. Although the fires on 10 July were originally manually ignited, they were not guided by humans. Thus they evolved as natural fires. Burning continued throughout 10 July, with smoldering until 15 July when rains finally extinguished the fire. About 1/3 of the possible acreage burned during FROSTFIRE, mostly in the black spruce–dominated areas, whereas the hardwoods (birch and aspen) and the wetter valley did not burn under these wind, humidity, and fuel moisture conditions (Hinzman et al. 2003).
Infrared imagers are one of the few instruments that can penetrate the smoke of fire to reveal motions within the flaming combustion zone and intense convective column with high temporal and spatial resolution. The instrument used for these observations is an Inframetrics, Inc., (now FLIR Systems, Inc.) ThermaCAM PM380: a digital, high-resolution infrared imager. The ThermaCAM incorporates a 256 × 256 element platinum silicide focal plane array recording over the 3.4– 5.0-μm wavelength range, which provides a sensing range between −10° and 1500°C. Spectral filters extend the measurement range to accommodate high-temperature targets above 450°C. The instrument has a 12-bit (4096 levels) measurement dynamic range over one of several temperature ranges selected by the user. The instrument's maximum sensitivity of 0.1°C can be achieved when the user sets a narrow temperature detection range. Instrument accuracy was specified to be ±2°C. A self-contained Sterling cooler is used to reach cryogenic temperatures (i.e., no external, bulky nitrogen cooling unit is required). Algorithms within the imager attempt to account for the gaseous medium between the subject and the imager. Although the imager had a 17° × 16° field of view, a 4° × 4.2° telephoto lens was added, and so at a range of 2800 m, for example, each reprocessed pixel ultimately represented an area of 0.376 m × 0.845 m. This model of the instrument does not have digital output but internally converts the 12-bit digital data to an analog video signal. By detecting the radiant energy in this wavelength band and applying the user-set value of emissivity (an estimate, as discussed later), the imager estimates the radiating object's temperature and creates two-dimensional video images of hot, swirling air mixed with products of combustion in the fire, detailing their size, structure, and temperature.
At a position approximately 200 m southwest of Caribou Peak, about 400–500 m above and 2.6–3.2 km across the valley from the fire, several crown-fire periods of varying intensity, ranging from smoldering fires to running crown fires, were recorded. Mounted on a tripod, the infrared imager had an unobstructed view of several fire sequences, either as fires climbed a ridge from left to right, giving an opportunity to study fire spread, or as fire climbed toward the peak traveling away from the observation station, giving a perspective along the width of the fire (see Fig. 2a and Table 1). For an overview of this and other radiometric instruments present at the Caribou Peak site, see Daily et al. (1999).
When collecting data, the user sets the target's emissivity, the distance to the target, and the atmospheric temperature and relative humidity. The user can select one of several temperature ranges on the imager and the span of temperatures within this range. The luminance measured by the camera (lumens) is converted by the instrument to temperature (degrees Celsius) using a fit to a factory-provided calibration curve [shown in Clark et al. (1999)]. When viewing fires, it is assumed that the targets are incandescent condensed particles of incomplete combustion (i.e., soot particles) in a shallow, warped, constantly changing image plane in the first few meters of depth of the combustion zone and that the gas phase is effectively transparent. If the flame is thick (>1 m) and luminous, it is common to assume essentially blackbody (emissivity ∼ 1) behavior (Drysdale 1998); thus, the emissivity was set to 0.95. Variation in emissivity over the target area captured in the image is neglected. Although the target's true emissivity can only be estimated, an error in estimating this parameter affects the measured temperature slightly but not the winds inferred from these data (which are based upon gradients of this property) and, therefore, not the conclusions based on the analysis.
The 60-Hz analog black-and-white video signal from the infrared imager is recorded to a standard VHS videocassette recorder at 30 frames per second, although these data are later temporally split (see section 3c) to produce 60 frames per second. Although a higher-resolution SVHS recorder is now used, the authors do not know of currently available portable recording devices that can further improve this step of the process for this instrument.
This analog imagery is digitized and recorded as eight-bit (256 levels) uncompressed digital data on an Accom, Inc., 2Xtreme CCIR601 videodisc array and are deinterlaced based on some simple assumptions, giving effectively 60 frames of data per second. Interlaced video signals consist of two video fields, each containing the odd or even lines of the image. During the image-capture process, cameras output the odd lines at one time and then, 33 ms later, output the even lines, which are combined into one image. This procedure creates a temporal shift between the odd and even lines that must be addressed for data analysis of rapidly changing fields. For data analysis, the images are deinterlaced to their original state; that is, odd and even horizontal lines are split into two temporally aligned files (720 × 243 pixels) that are assumed to be separated by a time interval of 1/60th of a second. Assumptions are that the image subject has not changed substantially in the 1/60th of a second required to capture the image and that the image height represented by the vertical pixel height of each scanned line can be doubled (because every other line has been removed) to reconstitute the image's original dimension. These Quantel, Inc., National Television System Committee (NTSC) images (a professional digital video standard with nonsquare pixels) are resampled to convert to an image with square pixels [red–green– blue (RGB) format], and the images' luminance field is converted to readable 1-byte binary files that are then analyzed.
Although this instrument (Inframetrics PM-380) does not have digital output, other versions (such as the SC-1000, with 12-bit serial digital output) do; data from them could be recorded directly in digital format, eliminating some of this process. At this time, however, most digital recording devices limit the immense volume of data by relying on compression schemes that lose data quality; these schemes are not suitable because of the errors introduced into the data. Other digital recording devices that circumvent this compression method by limiting the data flow with lower frame rates are also undesirable because they decrease the data's temporal resolution. We continue to seek to improve this process but are limited until a similar instrument with digital output can be recorded on a portable digital recorder with no compression.
The data produced by the infrared imager are the temperature of the graybody in the image plane. To extract more information beyond the evolution of temperature, one must make further assumptions and apply analysis algorithms, described next.
Gradient-based image-flow-analysis methods were used to extract fire wind estimates from the temporal and spatial evolution of the temperature field. These techniques are a variant of Verri et al. (1990), incorporating details described in detail in Clark et al. (1999). The broad purposes of this analysis technique are to calculate combustion-zone winds and fire spread rates, to study crown-fire dynamics, and to derive statistics of fire winds (magnitude, and temporal and spatial scales of motions) that can be used to understand crown-fire dynamics, to assess modeling requirements, and to validate coupled atmosphere–fire models (Clark et al. 1996a,b, 2004; Linn et al. 2002). Other techniques that are likely to produce better accuracy have been benchmarked (Bab-Hadiashar and Suter 1998; Farnebäck 2001, 2002; Wang and Suter 2003).
These methods have two steps. The first step is image registration, which includes extracting motions of the observation platform (such as the swaying of a tower; aircraft roll, yaw, and pitch changes; wind buffeting; and deliberate movement of the camera), if any (none was required for these observations), and georeferencing the images; the second step is image-flow analysis, which involves describing the motion in the image plane as a composite of the five elementary motions from Helmholtz's theorem for deformable objects. These motions include two components of translation, rotation, expansion, and two orthogonal components of shear, but, as in the Clark et al. (1999) procedure, only the two translation components are considered so as to limit the complexity. The governing equation for image flow is
where f represents the measured temperature, u and w are the horizontal (x direction) and vertical (z direction) components of the wind velocity, time is indicated by t, and the subscripts indicate first-order partial differentiation with respect to the subscript variable. Basic assumptions in this method are that 1) f is approximately conserved (i.e., local features can be followed) for short periods (i.e., about seven frames, or 0.1 s), 2) the combustion zone has high emissivity (∼1.0), 3) the infrared imager detects incandescent condensed soot particles that trace the air motion, 4) the motion is on a distorted two-dimensional surface, and 5) the data can be fit to simple kinds of motions such as translation.
Taking the gradient of (1) gives the following matrix equation:
the determinant det of which is
fxxfzzf2xz (3)
If |det| is relatively large, that is, there is sufficient structure to the flow, then solutions for u and w can be found. Details of the solution of (3) can be found in Clark et al. (1999). In summary, (3) is solved using a least squares method in which transformations (such as our two-component translation, but which more generally would also include rotation and stretching) are given polynomial fits. A temperature threshold of 40°C over the lowest temperature of the selected temperature range was chosen subjectively to eliminate the small, random noise introduced during calculations (primarily through algebra of calculated gradients over small differences). One difference from Clark et al. (1999) is that local minimizations are performed over local patches of data (7 × 7 pixels) around each pixel instead of over the entire field.
Five periods of crown-fire propagation during 9–10 July 1999 (listed in Table 1) are analyzed. These range in duration from 1 to 5 min; data recording was broken off either because the fire subsided or because it traveled across the field of view and exited, requiring that the imager be reaimed. Nevertheless, even the 1-min sequences are long enough to capture representative behavior that reveals dynamics within the fires. The orientation of the imager with respect to the fires is important—the geometry on sequence 5 is unique and ideal: the forward spread was across our two-dimensional cross section. In other sequences, the fire was directly ahead (sequence 1), traveling away from us, or at some angle up the hill (sequence 2), making interpretation of the three-dimensional motions more ambiguous.
Figure 5 shows temperature images from sequence 5 (temperature range 500°–800°C; 2.8 km away from imager). With 520 × 243 eight-bit (256 level) data pixels in the reprocessed image, each pixel represents an area with dimensions 0.376 m × 0.845 m with temperature increments of 1.17°C, providing exceptional resolution for analyzing the motions within the flaming combustion zone. The high temporal resolution of the data is necessary, because significant changes in the images occur within a fraction of a second.
The high-temperature regions identify the flaming combustion of an envelope of volatile gases released by pyrolyzing surface fuel and individual trees. These gases are not instantly consumed, and pockets may be transported some distance before entrainment with environmental air produces the stoichiometric conditions needed for combustion. Although one must be cautious in interpreting the temperature data because of the assumptions made about emissivity, the temperatures are well within the range expected for combustion in diffusion flames. The imager detects infrared radiation from intermediate combustion particles and particles of incomplete combustion (such as soot) until they mix and cool enough to be outside the selected detection temperature range. The outline of treetops (dark, cool region) can be discerned at the base of the flaming combustion, although individual trees are spaced slightly closer than the resolution can show. This outline of treetops, calculated as the highest vertical point at which the temperature is not raised over ambient, was followed over time to identify the ridgeline in the infrared data. The terrain slope was approximately 20° and is used in later sections to calculate the velocities parallel to the surface.
The images show a crown fire traveling upslope from left to right. Some features are apparent. Although the crown fire is pyrolyzing and igniting the gases from individual trees, the convective heat from several trees rapidly loses the scale of individual trees (approximately 1–5 m apart) and agglomerates into many larger-than-individual-tree-scale convective plumes. Although buoyant, these elements do not simply rise vertically, but shoot some distance parallel to the slope before buoyancy forces take over and the plume rises much more vertically, tilted in the downwind direction (here, left to right). The fire's spread upslope is not smooth but is characterized by a sequence of these bursts of flame. A more quantitative analysis of these motions is presented in sections 4b and 4c.
The air velocities in and near the fire cannot be regarded as an external force directing the fire, but are themselves partly driven by the fire and are an intrinsic part of the dynamics of fire propagation. For example, the vertical velocity and its vertical gradient influence the surface convergence pattern and, thus, the small-scale fire-induced winds that drive the fire. Vertical velocities are important both as an indication of the fire's intensity and because they are used to calculate the fluxes and transport of sensible heat and emissions. They also influence how high and, therefore, how far spotting embers are lofted. The image-flow analysis technique described in section 3d was used to analyze the sequence of temperature data and to determine atmospheric motions in and around the fire. Both Cartesian velocities and velocities that are parallel and normal to the slope will be presented.
Figure 6 shows the air velocities at the same times as the IR grayscale data images of Fig. 5. A 1-2-1 spatial filter has been applied to the data, and a threshold of 40°C over the bottom of the temperature range (i.e., all temperatures below this value were set to the threshold) was used in the velocity calculations to eliminate the erroneously large, noisy velocities that would be calculated away from the main features where there is a relatively weak feature amid the noise.
Under a weak westerly upslope wind that is partially ambient and probably modified by the fire itself because of the strong forcing nearby, the plumes do not immediately rise vertically, but shoot tens of meters parallel to the slope before buoyancy forces take over, after which time the plumes rise more vertically. Although this analysis readily reveals the updrafts created by the fire, it captures only some of the necessary downward transport of air into the rear of the updraft base. When it does so, this air must already contain warm, radiating particles from the fire in order to be detected by the imager—transport of clear air is not detected.
More physically relevant than the horizontal wind component is the wind component along the slope. This component was obtained by calculating the dot product of the total wind vector with the gradient slope, which in sequence 5 is 20°. Although the strongest atmospheric winds overall are located in the rising convective plume several tens of meters above the ground, Fig. 7 shows how close the forward bursts described earlier are to the ground. In this sequence, velocity components parallel to the surface of 10 m s−1 are routine, with frequent bursts of 25 m s−1. Peak surges of 30 m s−1 are detectable less than 15 m above the base of the detectable fire.
The analysis cannot precisely identify how deep into the trees and close to the ground these forward-bursting fingers penetrate because intervening treetops partially obscure the view, nor can the analysis show how flow is modified and mitigated by canopy drag. However, it is clear that for some distance these flame-filled fingers are traveling parallel to the ground at heights at which they can propagate the fire by igniting through contact as well as preheating and drying the canopy ahead of the fire, making it easier to ignite. The speed the fingers travel parallel to the slope is an order of magnitude larger than ambient winds measured by nearby surface weather stations, and the motions are far more complex than tilting of a buoyant updraft. These observations suggest that nonlinear interactions are at the heart of propagation in crown fires and transfer some of the vertical momentum created by buoyancy into bursts primarily traveling along the surface before buoyancy forces take over and produce a mostly vertical plume rise.
It can be shown under very general assumptions that the distribution of independent random errors of observation takes on a normal distribution as the number of observations becomes large. A classical normal ("Gaussian") distribution is assumed to represent the distribution of observed values. If the Gaussian distribution were accurate, the probability that the extrema deviate from the mean by more than 5 standard deviations would be 0.000 03%. Figure 8 shows the wind-velocity-component imagewide maxima statistics over sequence 5. Thin lines show the actual maxima of the vertical velocity component (Fig. 8a), and thick lines in each plot represent the mean ±5 standard deviations, which should represent the extrema values in a Gaussian-distributed dataset. Under this assumption, when maxima values fall outside this range, one can assume they are artificially produced outliers overlooked by the analysis scheme. These statistical extrema may be more physically meaningful estimates of maximum velocities.
The vertical velocity statistics show that, even in the more conservative statistical estimates, maximum updrafts of over 60 m s−1 are common in this and the other sequences. The negative vertical velocities in Fig. 8a reflect the downdrafts bringing air into the fire—here consistently reaching peaks over 20 m s−1, a value that is substantially smaller than the peak updrafts. The positive (updraft) maxima showed a pulsing behavior with an almost periodic nature, with distinct peak updrafts occurring approximately every 1.8 s for the first 50 s (3000 frames). This pulsing is also not apparent in the downdraft maxima, presumably because the downdraft maxima location varies much more and is not tied to individual surges. The horizontal wind maximum (not shown) is steadier—the statistically estimated maximum wind speed (at 5 std dev greater than the average) is 22–24 m s−1 throughout the sequence.
The component of the wind parallel to the slope shown in Fig. 8b shows the time history of the maximum of this quantity throughout the domain (thin lines), as well as the statistical estimate of the maximum calculated the same way as was discussed in previous paragraphs. In this fire, this component frequently has peaks of 35–40 m s−1, with some evidence of pulses in the maximum value with time; however, the amplitude of the peaks over the values in between peaks is less exaggerated than in the vertical velocity. Figure 8c shows that the maximum velocity magnitude ranges from 32 to 60 m s−1. The peak speeds are reached in the highest detectable heights of the most dominant updrafts in the image, after heat from individual trees has combined to form an accelerating convective plume.
To summarize the fire's overall effect on the atmosphere, vertical profiles of fields averaged over the domain as a function of time are presented. Ground level is identified as the lowest point in each column that ever experiences a perturbation in temperature above the background field. These profiles allow us to assess the fire's vertical structure and to estimate the height to which it influences the local energetics of the atmosphere.
The profile of vertical velocity for sequence 5 averaged over the domain's width (Fig. 9a) shows that the fire affects the air in its vicinity with an average updraft of at least 0.25 m s−1 for at least 50 m above the fire. The peak updraft is not at the height of the fuel but is at 20–25 m above it, after the individual plumes have merged and accelerated. Near the surface, on average over the image width, the vertical velocity is from −0.25 to −0.5 m s−1, reflecting the recirculation of fire-modified air into the base of the updrafts. These values could be an underestimate, because this detection method misses clear-air downdrafts. During the last third of the sequence, the fire's right flank (the side facing the imager) makes a run along the ridgeline that causes the height of peak velocities to drop.
The temperature perturbation revealed by the imager (Fig. 9b) extends up to approximately 50 m above the base of the fire. Few individual or agglomerated convective plumes extend above this height, either because they have entrained enough air to dilute below the sensible temperature threshold or, more likely, because the air parcels have radiatively cooled below the fixed temperature range (500°–800°C). Although temperature perturbations below 500°C still contribute to the heat flux and are not included in these numbers, analysis of other sequences in lower temperature ranges showed they are limited to a small region around the fire and contribute a small amount of heat relative to that detected in the 500°–800°C range.
Wildfires release extreme amounts of sensible heat, with values orders of magnitude larger than other atmospheric sources such as solar heating. Even though their areal extent is limited, wildfires can substantially alter local atmospheric dynamics and thermodynamic structure and alter flow through scale interactions. The profile of the sensible heat flux Hs was calculated as
HsρcpwT (4)
where cp is the specific heat of dry air at constant pressure, T′ is the measured temperature perturbation, w′ is the vertical velocity perturbation calculated using image-flow analysis, and ρ is density, calculated locally using
where p is pressure, Rd is the gas constant, and Tυ is the virtual temperature. Both cp and ρ are functions of temperature and the chemical composition of the air. Here we have assumed in (5) that the pressure perturbations and water vapor contributions to the variability of density can be neglected (introducing small errors to our results), that the vertical motions outside our detected region are negligible, that air is prevalent in excess, that the variation in cp over this temperature range is negligible, and that the image suitably frames the region of interest but is not so large as to dilute our spatial averages. Because Hs varies greatly in time and space and is primarily used to represent the flux contributed over the fire area, the horizontally averaged vertical profile of Hs as a function of time is presented (Fig. 9c). It is estimated from the imagery that the imager receives radiant energy halfway into the depth of the 10-m trees, thus, the base of our measurements is approximately 5 m above ground level. The horizontally averaged peak sensible heat flux is 0.3–1.2 MW m−2, located 21–25 m above ground, although maximum sensible heat fluxes of 7–11 MW m−2 (with statistical outliers removed using the techniques in section 4c) are found. Smaller negative values of Hs near the ground reflect downdrafts recirculating warm air recently passed through the fire (because the particles in it are still hot and radiating) into the base of convective updrafts. Although this method readily calculates the positive sensible heat flux associated with the upward transport of relatively warm air, it does not account for all of the downward transport of relatively cool air (also a positive contribution to sensible heat flux), because it is likely that some of the air brought down into the base of the fire updraft is clear air that contains no glowing soot particles to be captured by the imager or is air that has cooled outside the prescribed temperature range.
The wind speed magnitude averaged over the domain (Fig. 9d) increases throughout the sequence to a peak of 6 m s−1 at a height of 15–20 m above the bottom of the imaged region (approximately 20–25 m above ground). The height at which this average approaches 0 is about 50 m, suggesting that the kinetic energy of this fire, on average, is contained and released into the atmosphere within this depth, defining a unique zone strongly affected by the fire.
One of the most important aspects of fire behavior is the spread rate—the speed at which the interface between burning and nonburning fuel progresses in a direction normal to the interface. It is difficult to calculate an overall canopy spread rate for this fire because, rather than a smoothly spreading interface, the observations show repeated flame-filled bursts from the fire's core upslope along the treetops. (These ignited patches of treetop ahead of the main fire flared up in intensity as the most dynamically active core of the fire approached.) However, our perspective allowed the calculation of the spread rate in a fire flank oriented toward the imager that surged toward the right of the imagery during this period. This was done by calculating the progression of the leading edge of the 540°C isotherm in our imagery. During 50 s of sequence 5, this front traveled 43 m upslope, giving this feature an average spread rate of 0.75 m s−1. The latter half of this period was more active, with an average spread rate of 1.11 m s−1 (2.48 mi h−1). The maximum over any 10-s period was 1.26 m s−1 (2.82 mi h−1). Although crown fires may travel at a wide range of speeds, these spread rates are substantial, especially considering the comparatively light environmental winds.
Further examples of bursts of flaming fingers in sequences 3 and 2 are shown in Figs. 10 and 11, respectively. In sequence 3, the fire is traveling upslope (into the image toward the upper right) with the well-known universal fire shape, with one very active updraft area at the head (Fig. 10a) sustained by heat brought forward by winds parallel to the flanks. The head intensifies as pockets of air with temperatures of over 500°C are drawn into it and stretched, and a narrow (5 m wide) finger of flame shoots 25 m upslope (Fig. 10b) before turning vertically upward, as shown by the derived velocities (Fig. 10c). The convective finger breaks off (Fig. 10d) into a hot rising thermal before the 1–2-s cycle repeats.
Although sequence 2 exemplifies this same flaming-finger behavior, it manifests in a row of updrafts (a consequence of a line heat source breaking up into convective cells) spread across a broad, wide fire line (a dynamic consequence of a less steep slope, slower winds, weaker updrafts, or less rapid burning), and thus displays a slower spread rate (Coen et al. 2001). In between the updrafts, 10–27 m s−1 downdrafts supply air into the base of the updrafts. A finger on the right side is beginning (Figs. 11a and 11b) as a finger on the left side is breaking off into a thermal.
These observations and analyses present a unique (high spatial and temporal resolution) perspective into the motions within a crown fire propagating up a forested slope in interior Alaska. The overall picture that emerges from these results is dynamically complex and defies the common notion of one large convective plume or many tree-scale plumes that rise separately, simply accelerating under the force of buoyancy. Instead, the picture that emerges is a sequence of surges of many convective plumes that represent a scale larger than individual trees. These upslope bursts of flame initially have a strong along-ground component that in this situation exceeds ambient environmental winds (the winds generally considered to be "driving" the fire) by a factor of 10. These bursts play an active role in propagating the crown fire and point toward a powerful, dynamic mechanism of fire spread. These observations revealed motions within a crown fire with conservative estimates of maximum updrafts of 32–60 m s−1, maximum downdrafts of 18–30 m s−1, maximum horizontal wind speeds of 12–28 m s−1, and maximum winds parallel to the slope of 28–48 m s−1. Average spread rates for a flank of the fire were 0.75–1.11 m s−1, and the peak spread rate over any 10-s period was 1.26 m s−1. These values exceed the Clark et al. (1999) estimates of updrafts of between 10 and 30 m s−1, downdrafts of 10–20 m s−1, and horizontal flows of 5–15 m s−1 found in a prescribed crown fire in boreal forest in the International Crown Fire Modeling Experiment; however, there the fire was still accelerating from its average spread rate of 0.6 m s−1 as it reached the end of the 150 m × 150 m plot.
Our perspective and subsequent analysis of extreme fire behavior complement the observations of Radke et al. (2000), who first recognized these sudden flame-filled fingers and theorized that they were traveling near enough the ground to ignite the fuel. These fingers are present throughout our data as well, but our view of fires in profile allows us to refine their interpretations. Our analysis shows that the air in plumes initially bursts upslope parallel to the ground (at speeds of 28–48 m s−1), close enough to ignite as well as to preheat and dry canopy fuel ahead of the fire. These observations support reports of "fireballs" or bursts of hot air (and flame) documented by firefighters overrun by crown fires. The flaming fingers next turn upward and accelerate to 50–60 m s−1, rising more vertically but tilted slightly downwind. If stronger environmental winds were bending the plume closer to the ground, even stronger along-ground components might occur. The purpose of the work is not merely to document that strong winds exist near a crown fire, but to shed light on how the atmosphere above the trees responds to and interacts with the tremendous energy of the fire. We emphasize that these phenomena are not explosions. The flames in wildland fires are purely gaseous deflagrations, not detonations, and are unconfined. In a confined deflagration (such as in a typical jet engine), volumetric expansion would strongly accelerate the flow.
These results clarify the mechanism for the rapid spread of crown fires. First, if the convective plume from the fire were merely rising because of buoyancy, such surges along the ground would not exist. The mechanism for rapid crown fire spread has been attributed (Rothermel 1991) to three factors: strong environmental winds (in the case of so-called wind-driven fires), downbursts of wind from convective cells, or momentum feedback from the vertical updraft increasing surface turbulence in the surface winds, resulting in increased radiational heating of surface fuels. None of these explanations is satisfactory here. First, the ambient flow is only 3 m s−1, even though bursts of 20–25 m s−1 were detected within 20 m of the ground (we cannot detect motions immediately next to the surface because it is obscured and the pixel temperature is diluted by trees). Second, no clouds were present to produce downdrafts. The source of the momentum was clearly not these external environmental factors, but instead involved internal forces produced by the fire, including pressure gradients, advective terms, and buoyancy. The third explanation posed by Rothermel (1991) touches upon internal interactions, but the inflow to these extremely strong updrafts over a very narrow depth appears to be very organized and smooth, showing none of the signs of locally increased mixing—these bursts, although turbulent in nature, are coherent features. Other possible processes also can be discounted, such as the role of phase change on the fluid dynamics. Any phase change relating to pyrolysis of fuel is strictly a local effect, with a length scale of tens of centimeters near the solid fuel source, which is almost entirely attached to the ground. (There it is very important, because first vaporized water and then pyrolysis gases are driven rapidly from the solid fuel as it is heated radiatively.) Small amounts of fuel may be lofted by the fire, but they are energetically unimportant.
However, there are limits to this analysis; it cannot precisely identify how deep into the trees and close to the ground these forward-bursting fingers extend, because intervening treetops partially obscure our view, nor can this analysis tell how the flow is influenced by canopy drag.
Some unsettled points remain. This work provides insight into the downdrafts that supply the air that by mass conservation must be entering these convective updrafts. One would expect, from analogies to convective clouds, that intense convective columns would be surrounded by wider but relatively weaker compensating subsidence, yet here strong downdrafts that recirculated fire-modified air into the fire were detected. The phenomenon has implications for combustion reactions, because it could contain pyrolyzed but not ignited gaseous fuel or could reintroduce products of incomplete combustion back into the chemically active zones of the fire. However, because this imaging technique cannot detect clear air in the region of the fire and, with one instrument, is limited to a two-dimensional image plane, it cannot map the full three-dimensional atmospheric motions. This work also implies that, because of the highly nonlinear vortex dynamics, crown-fire behavior parameters such as spread rate are not likely to be parameterized adequately in terms of linear relationships among ambient wind speed, terrain slope, and vegetation characteristics.
We emphasize that the speed of extremely high temperature air near the surface is not based upon ambient wind speeds, but is a result of complex fire–atmosphere dynamics that transfer vertical momentum into surging flow along the surface. Clark et al. (1999) attributed the rapid forward burst of winds in a crown fire to vortex tilting in the sense that the tilted vortices (produced by sharp gradients in buoyancy) come together to form a hairpin shape, such that their combined motion results in tilting forward at a sharp angle, resulting in a turbulent burst. Some understanding of hairpin vortices may be drawn from Meinhardt and Adrian's (1995) discussion of boundary layers, in that repeated hairpin vortices form in shear layers in the overlying rapid flow and are stretched by the shearing action of the boundary layer because the tails remain in the low-speed region of the flow while the heads are entrained in the high-speed region. The vertical stretching, shown by the increase in vertical velocities with height in our data, would account for the high vertical rotation rates reported by Clark et al. (1999) in the counterrotating towers between which one burst reportedly occurred. However, we have also seen these bursts appear from narrow fires with a single updraft at the head.
However, these boundary layer phenomena are not a direct analogy, particularly because they do not involve buoyancy effects. Also, the temperatures in our results saturated the sensible temperature range (capped at 800°C) and so combustion was still occurring—the transport and continued combustion of flammable gaseous pyrolysis products (which, according to our analysis, may also be recirculated into the convective updrafts) continues to release heat even as the buoyant air rises, adding complexity. Another added complexity is that the reaction rates in that process, based upon the knowledge of combustion in diffusion flames, are limited by the mixing rate of the envelope of flammable gases with air, where combustion is limited to the interface where stoichiometric conditions are met. Higher turbulence rates increase the mixing and thus the surface area of this interface (measured by the quantity "flame surface density") and overall heat release rates. Thus, the turbulence characteristics of this dynamic feature influence its strength. This is a difficult problem to study, because it requires modeling at scales that are extremely small for atmospheric models and extremely large for three-dimensional direct numerical simulation models of combustion. Nevertheless, these analyses provide data against which finescale numerical models, such as those of Porterie et al. (2003) and Linn et al. (2002), may be compared.
The domain-averaged quantities perhaps have the most application as an approximation of the net effect of the fire on the atmosphere. For example, the sensible heat flux averaged over the 141-m-long fire domain of sequence 5 gives an approximation for how such a fire might be represented in atmospheric prediction models. Because of the rapid rate at which this vertical heat flux decreases with height, it may be reasonable to approximate the macroscale effect of this fire on the atmosphere as a sensible heat flux of 1.0–1.2 MW m−2 that peaks at 20–25 m above the ground but decays approximately exponentially above that, with an e-folding distance (where the value decreases to e−1 or ∼37% of its value) at 11 m above the maximum. This cannot directly be contrasted with the 0.7–3.0 MW m−2 reported by Clark et al. (1999), because their perspective was from the front such that the fire filled the breadth of the image, whereas our perspective was in profile where the active head of the fire did not span the entire image, and they used ambient density (1.0 g kg−1) in their calculations rather than the local density (calculated as approximately 0.6 g kg−1 here). Nevertheless, the maximum sensible heat fluxes of 7–11 MW m−2 represent an extreme for atmospheric processes, although very limited in extent and frequency.
Support for this work through NSF Grant ATM 0049007 to the University of California, Riverside, is gratefully acknowledged. The National Center for Atmospheric Research is sponsored by the National Science Foundation. We thank Larry Hinzman and John Gallagher at University of Alaska, Fairbanks, for providing the meteorological station data. We particularly thank the Alaska Fire Service for their assistance at the FROSTFIRE site. Comments and suggestions by two anonymous reviewers greatly improved the manuscript.
Citation: Journal of Applied Meteorology 43, 9; 10.1175/1520-0450(2004)043<1241:IIOCDD>2.0.CO;2
Imagery sequences
The National Center for Atmospheric Research is sponsored by the National Science Foundation.
https://journals.ametsoc.org/view/journals/apme/43/9/1520-0450_2004_043_1241_iiocdd_2.0.co_2.xml