Image Aerogelbrick.jpg 200px thumb right A 2.5 kg brick is supported by a piece of aerogel with a mass of only 2 grams. Aerogel is a Manufacturing synthetic porous material derived from a gel , in which ... low density ref Name GuinnessRecord cite web title Guinness Records Names JPL s Aerogel World s Lightest ... styrofoam to the touch. Aerogel was first created by Samuel Stephens Kistler in 1931, as a result ... is on a piece of aerogel which is suspended over a bunsen burner . Aerogel has excellent insulating ... from gels. Pressing softly on an aerogel typically does not leave a mark pressing .... Silica aerogel is especially good because silica is also a poor conductor of heat a metallic aerogel, on the other hand, would be less effective . They are good convective inhibitors because air cannot circulate through the lattice. Carbon aerogel is a good radiative insulator because carbon ... nature, aerogel feels dry and acts as a strong desiccant . Persons handling aerogel for extended ... because it allows the use of a water jet cutter . Types Silica Image Aerogel nasa.jpg thumb Peter Tsou with a sample of aerogel at Jet Propulsion Laboratory , California Institute of Technology Silica aerogel is the most common type of aerogel and the most extensively studied and used. It is a silica based substance, derived from silica gel . The lowest density aerogel is a silica nanofoam at 1 mg cm sup 3 sup , ref name terms http www.llnl.gov IPandC technology profile aerogel Terms index.php ... aerogel of 1.9 mg cm sup 3 sup . ref name llnl03 cite web url http www.llnl.gov str October03 NewsOctober03.html title Lab s aerogel sets world record publisher LLNL Science & Technology Review ... 334 issue 6058 pages 962 ref Silica aerogel strongly absorbs infrared radiation. It allows the construction ... point is 1,473 K 1,200 C or 2,192 F . By 2011, silica aerogel held 15 entries in Guinness World ... woven paper made of carbon fiber s, impregnated with resorcinol formaldehyde aerogel, and pyrolisis ... more details
Orphan date December 2011 Ultralight materials are solids with a density of less than 10 mg cm sup 3 sup , including silica aerogel s, carbon nanotube aerogel s, metallic foam s, polymeric foam s, and metallic microlattice s. The density of air is about 1.275 mg cm sup 3 sup , which means that the air in the pores contributes significantly to the density of the material. References cite article title Ultralight Metallic Microlattices author TA Schaedler, AJ Jacobsen, A Torrents, AE Sorensen, J Lian, JR Greer, L Valdevit, WB Carter journal Science date 18 November 2011 volume 334 number 6058 pages 962 965 doi 10.1126 science.1211649 Category Materials technology stub date December 2011 simple Ultralight material ... more details
Image Aerogel nasa.jpg thumb 250px Peter Tsou with a sample of aerogel Peter Tsou is a principal science staff member at the Jet Propulsion Laboratory JPL of the California Institute of Technology , where he has worked for the past 34 years. ref name nasa bio cite web url http stardust.jpl.nasa.gov news bio ptsou.html title Bios Dr. Peter Tsou publisher NASA accessdate 2006 05 11 ref Dr. Tsou s area of focus is utilizing aerogel for space exploration. http www.smc.edu forms news.asp?Q 51&T News&P 1 Dr. Tsou is a Principal Investigator PI for a number of Shuttle and Mir missions, and is responsible for inventing the technique of intact capture of hypervelocity particles. In addition, his work revolutionized the use of silica aerogel for space missions. He is most famous for his work involving ... Silica Aerogel for Particle Extraction , 36th LPSC, 2307, 2005. Tsou, P., Cosmic Dust Intact Capture Experiment , STAIF 99, 1999. Tsou, P., Hypervelocity Capture of Meteoroids in Aerogel , ASPCS Vol ... mission. Working with scientists at Lawrence Livermore National Laboratory , he made the aerogel ... publisher Discover ref He has also introduced the use of aerogel as one of the capture media and flight qualified variable density aerogel for space flight. He is the principal investigator for a series of Shuttle Sample Return Experiments and Mir Sample Return Experiment with silica aerogel he ... in aerogel. Dr. Tsou was responsible for inventing an integrated aerogel thermal structural ... Dr. Tsou has donated several samples of aerogel for display at JPL s museum, located on their main ... donated a piece of aerogel to the Kirkpatrick Science & Air Space Museum, also known as the Omniplex ... files misc stardust.pdf In 2009, Dr. Tsou donated a sample of space grade aerogel to Santa ... state 4.5 billion years ago. Concerning the Stardust project Citation needed date February 2007 Aerogel ... forms news.asp?Q 51&T News&P 1 ...aerogel has many unique properties that are very suitable for space ... more details
Orphan date January 2011 Unreferenced auto yes date December 2009 Silicon alkoxides are a group of alkoxide s, chemical compound s of silicon and an alcohol , with the formula Silicon Oxygen alkyl R sub 4 sub . Silicon alkoxides are an important precursor for manufacture of silica based aerogel s. DEFAULTSORT Silicon Alkoxide Category Alkoxides Category Silicate esters organic compound stub ... more details
. ref name Aerogel FAQs cite web url http www.connectexpress.com ips aerogel faq.html title Aerogel FAQs accessdate 2010 04 04 last Stone first Mike date 1999 archiveurl http web.archive.org web 20080324135004 connectexpress.com ips aerogel faq.html archivedate 2008 03 24 ref Whether these experiments ... Company in the early 1940s to start developing granular silica aerogel products under the trademark ... of Utah in 1952. He died in 1975, shortly before the resurgence of interest in aerogel ... more details
aerogel might look like. The focus movie can be viewed in the Stardust Search Tutorial with the virtual ... collector on the Russian space station Mir and tracks of submicrometre dust particles shot into aerogel ... more details
Refimprove date March 2010 Nanogel is a brand of aerogel Building insulation insulation mainly used in building products and oil and gas industries. It is sometimes called frozen smoke . It is made by Cabot Corporation , which has a plant in Frankfurt , Germany . It is an aerogel that consists of 95 air, in nano sized pores that inhibit heat transfer through the aerogel . Made in grades from Opacity optics opaque to translucent , it can be adapted to different environments. Properties include High porosity Highly porous structure provides high reinforcement and matting efficiency at low concentrations Flowability Excellent flow properties Friability Under intense dispersion conditions, particles are reduced to sub micrometer sizes, leading to superior reinforcement Hydrophobic surface Particles repel water but can be wetted by oleophilic substances such as oils Open porosity Pores are open to each other within the structure Particle size Available in a wide range of particle sizes Surface treatment Surface groups are chemically anchored to the silica skeleton and thus are stable over a wide range of temperatures and pH Nanogel in Skylighting Nanogel is increasingly being used in skylights and daylighting systems. It helps to retain the natural light while doubling the insulation. ref http www.duo gard.com nanogel ref It is non toxic, non combustible, reduces glare, lowers noise levels and reduces HVAC loads. Although the added insulation saves energy costs, and depending on the climate may be cost effective in the long run, the initial cost may be prohibitive for lower budget projects. References references External links http www.nanogel.com Official Site of Nanogel http www.daylightspec.com nanogel Exclusive Nanogel Distributors in North America Category Aerogels Category Brand name materials pl Nano el ... more details
Orphan date November 2006 Polyimide foam is a foam designed by NASA , manufactured by Inspec Foams Evonik Foams, Inc. in Magnolia, Arkansas , and marketed under the name Solimide. Its primary purposes are as an insulator such as for rocket fuel s and acoustic damper. NASA engineered the product to have relatively low outgassing a problem in vacuum and aboard spacecraft , desirable thermal and acoustic performance, as well as uniformity during distribution and application. Typical uses of the foam include ducting, duct piping insulation, structural components, and strengthening of hollow components while remaining lightweight. See also aerogel Polyimide ferroelectret External links http www.sti.nasa.gov tto spinoff1998 t3.htm Brief NASA article on Solimide http www.evonikfoams.com Evonik Foams public website DEFAULTSORT Polyimide Foam Category Foams ... more details
orphan date January 2010 A chalcogel or properly metal chalcogenide aerogel is an aerogel made from chalcogen s the column of elements on the periodic table beginning with oxygen such as sulfur and selenium, with cadmium, tellurium, platinum, and other elements. ref cite web title Heavy Metal Filter Made Largely from Air url http www.sciam.com article.cfm?chanId sa003&articleId 044B7489 E7F2 99DF 3433709C76B127DF date 2007 07 26 author Biello, David publisher Scientific American ref Research is ongoing, and metals less expensive than platinum have also been used in its creation. Chalcogels preferentially absorb heavy metals, ref S. Bag et al. http www.sciencemag.org cgi content full 317 5837 490 Porous Semiconducting Gels and Aerogels from Chalcogenide Clusters . Science 2007 07 27 Vol. 317. no. 5837, pp. 490 493, DOI 10.1126 science.1142535 ref showing promise in absorbing pollutants mercury, lead, and cadmium from water. ref Carmichael, Mary. http www.newsweek.com id 32528 First Prize for Weird A bizarre substance, like frozen smoke, may clean up rivers, run cell phones and power spaceships. Newsweek International, 2007 08 13. Retrieved on 2007 08 05. ref In addition, scientists have made one that is claimed to be twice as effective at desulfurization as any current methods. This is a very impressive feat, particularly because until the discovery of chalcogels properties, scientists were beginning to consider desulfurization an optimized process. ref cite web title New Sponge like Material Can Remove Mercury From Water, Separate Hydrogen From Other Gases And Pull Sulfur Out Of Crude Oil url http www.sciencedaily.com releases 2009 05 090517143341.htm date 2009 05 17 publisher ScienceDaily ref Semiconducting metal chalcogenide aerogels, first demonstrated by Professor Stephanie Brock at Wayne State University , show great promise for use in chemical sensors, solar cells, and photoelectrolysis of water. References Reflist External links http www.aerogel.org ?p 560 Detailed ... more details
, deployed on the Mir space station for 18 months during 1996 1997, used aerogel to capture interplanetary ... aerogel 99 of which is empty space which has about 1 1000 of the density of glass. This permits ... and the samples themselves. Aerogel main Aerogel Image Particle captured in aerogel.jpg thumb right 200px A particle captured in aerogelAerogel is a silicon silicon based , porous, solid with a sponge like structure in which 99.8 of its volume is composed of empty space. Aerogel has about 1 1000 of the density of glass. An aerogel was implemented for use with the Stardust spacecraft because ... alter its chemical composition , and perhaps vaporize it completely. Since the aerogel is mostly ... scale, the particles do not merely pass through the aerogel completely. Instead, they slow to a stop and then are embedded within it. The Stardust spacecraft has a tennis racket shaped collector with aerogel ... to Earth. One thing that makes aerogel a good choice for missions such as Stardust is that it is quite ... Stardust Aerogel Stardust website on aerogel technology. http www.jaxa.jp missions projects ... more details
for example is a type of aerogel which floats in the air after being filled with nitrogen. ref name ... hydride . Aerogel holds or held the Guiness World Record for the lightest solid or to be more accurate ... ref Aerogel is mostly air because its structure is like that of a highly vacuous sponge . ref http ... advantage of this, SEAgel , in the same family as aerogel but made from agar , can be filled with nitrogen ... more details
A desiccant is a substance that absorbs water. It is most commonly used to remove humidity that would normally degrade or even destroy products sensitive to moisture. see also desiccant List of desiccants Activated alumina Aerogel Benzophenone Bentonite Bentonite clay Calcium chloride Calcium hydride Calcium sulfate Cobalt II chloride Copper II sulfate Lithium chloride Lithium hydride Lithium bromide Magnesium Magnesium sulfate Magnesium perchlorate Molecular sieve NaK , a sodium potassium alloy Phosphorus pentachloride Phosphorus pentoxide Potassium Potassium carbonate Silica gel Sodium Sodium chlorate Sodium chloride Sodium hydride Sodium hydroxide Sodium sulfate Sodium benzophenone Sucrose Sulfuric Acid External links http www.mallbaker.com techlib documents americas 3045.html Desiccant Selection Guide http www.merck chemicals.com is bin INTERSHOP.enfinity WFS Merck International Site en US USD ViewProductDetail Attachments?ProductUUID 0Y.b.s1ORWYAAAEWCLMW4z8f&PortalCatalogUUID Uc6b.s1LfzAAAAEW6tYfVhTl&SelectedDocumentType Bro ankerBrochures Drying agents brochure from Merck http www.sud chemie.com scmcms web content.jsp?nodeId 3944&lang en Education Center Category Desiccants Category Chemistry lists Desiccants pt Anexo Lista de dessecantes nl Lijst van droogmiddelen ... more details
Nanofoams are a class of nanostructured, porous medium porous materials , foam s, containing a significant population of pores with diameters less than 100 nanometer nm . Aerogel s are one example of nanofoam. Metal Nanofoams In 2006, Dr. Bryce Tappan at Los Alamos National Laboratory discovered a technique for producing metal nanofoams by igniting pellets of energetic metal bis tetrazolato amine complexes. Nanofoams of iron , cobalt , nickel , copper , silver , and palladium have been prepared through this technique. These materials exhibit densities as low as 11 mg cm sup 3 sup , and surface areas as high as 258 m sup 2 sup g. These foams are effective catalysts and are being investigated for other applications. ref http www.rdmag.com ShowPR.aspx?PUBCODE 014&ACCT 1400000100&ISSUE 0509&RELTYPE R100&PRODCODE 00000000&PRODLETT AO&CommonCount 0 R&D magazine 100 Awards . Access date Aug. 26, 2008. ref See also Nanoporous Nanoporous material Ceramic foam Metal foam References Reflist added above categories infobox footers by script assisted edit Category Nanomaterials Category Foams Category Gels chemistry stub it Nanoschiuma ar ... more details
by 3 . Artificial muscles and giant strokes by MWNT aerogel sheets Highly ordered free standing aerogel sheets of MWNTs can be realized by simply drawing the sheet from the sidewalls of CVD grown ... minute to get 3 5 cm wide aerogel sheets of aligned MWNTs which have exceptional mechanical ... year 2005 doi 10.1126 science.1115311 pmid 16109875 ref The aerogel sheets have a density of 1.5 ... is decreased to 50 nm by liquid based densification to decrease the volume. The aerogel ... is remained. Having aerogel sheets of MWNTs, UT researchers fabricated actuators with giant strokes ... 1578 year 2009 doi 10.1126 science.1168312 title Giant Stroke, Superelastic Carbon Nanotube Aerogel ... of electrolyte solution and temperature robustness of the aerogel sheet in inert ambient makes ... more details
Friability or friable is the ability of a solid substance to be reduced to smaller pieces with little effort. The opposite of friable is indurated. Often, substances designated as being hazardous, such as asbestos or crystal line Silicon dioxide silica are referred to as being friable if they are present in such a State of matter state that it is possible for small particles to easily become dislodged, thus enabling them to become respirable able to enter human lung s , posing a health hazard. A friable substance is any substance that can be reduced to fibres or finer particles by the action of a small pressure or friction on its mass , such as inadvertently brushing up against the substance. The term could also apply to any material that exhibits these properties. Examples include but are not limited to Typically Ionic bond ionically Chemical bond bound substances 1 kg Litre L density Clumps of dried clay Chalk Rock geology Stone Tablet s Cracker food Crackers Perlite Mineral wool Mineral fibres Polyurethane foam Aerogel Some forms of cancer , such as atrial myxoma Tougher substances, such as concrete may also be mechanically ground down and reduced to finely divided mineral dust. However, such substances are not generally considered friable because of the degree of difficulty involved in breaking the substance s chemical bonds through mechanical means. Some substances, such as polyurethane foams, can increase in friability with exposure to ultraviolet radiation such as is present in sunlight . Friable and indurated are terms used commonly in soft rock geology , especially with sandstone s, mudstone s and shale s to describe how well held together or cemented the rock is. The term friable is also used to describe tumors in medicine, with tumors that are easily torn apart having a higher risk of malignancy and metastasis. See also Asbestos abatement External links http www.epa.gov region4 air asbestos asbmatl.htm EPA Treatise On Friable Asbestos http www.hse.gov.uk ... more details
Nanogel usually refers to a nanoparticle composed of a crosslinked hydrophilic polymer network hydrogel . Nanogels are most often composed of synthetic polymers ref http stbb.nichd.nih.gov pdf nanostruc hybrid hydrogels.pdf ref or biopolymers which are chemically or physically crosslinked. ref http onlinelibrary.wiley.com doi 10.1002 anie.200900441 abstract ref Nanogels are usually in the tens to hundreds of nanometers in diameter. Like hydrogels, the pores in nanogels can be filled with small molecules or macromolecules , ref http www.ncbi.nlm.nih.gov pubmed 17408798 ref and their properties, such as swelling, degradation, and chemical functionality, can be controlled. ref http pubs.acs.org doi abs 10.1021 ma049199g ref Applications Potential applications of nanogels include drug delivery agents, nanoactuators, and sensors. ref http books.google.com books?id nHlyFdd2B5QC&lpg PA137&ots K4JKvPjyt3&dq nanogel 20omar 20fisher&pg PA137 v onepage&q&f false ref ref http onlinelibrary.wiley.com doi 10.1002 anie.200900441 abstract ref Polyethylene glycol polyethylenimine PEG PEI nanogels have been used to deliver anti cancer compounds into cells. ref http www.ingentaconnect.com content asp jnn 2008 00000008 00000005 art00017 ref A highly hydrophilic fluorescent nanogel thermometer makes it possible to measure temperatures to within 0.5 C within cells. The cell absorbs water when colder and squeezes the water out as its internal temperature rises the relative quantity of water masks or exposes the fluorescence of the nanogel. ref http www.pubs.acs.org doi abs 10.1021 ja807714j ref A nanogel composed of protein molecules in solution can be used to stop bleeding, even in severe gashes. The proteins self assemble on the nanoscale into a biodegradable gel that can stop bleeding in a few seconds. ref http www.impactlab.com 2006 10 11 nano gel used to stop bleeding ref Nanogels are not to be confused with Nanogel insulation Nanogel aerogel , a lightweight thermal insulator. Refere ... more details
usually prohibits its use in commercial buildings. Aerogel Silica Aerogel insulation has the lowest ... manufactures Aerogel pipe sections, it is possible to wrap Aerogel blanket around pipework, allowing it to function as pipe insulation. The usage of Aerogel for pipe insulation is currently limited ... more details
impacts at over 1000 miles per hour, even into aerogel, were believed to be terminal for any known ... less than 6.5 km s such that non destructive capture of comet dust is possible using an aerogel ... collector uses aerogel , a low density, inert, microporous, silica based substance, to capture ... File Stardust Coletor 2.png right thumb 100px Stardust capsule with aerogel collector deployed Comet and interstellar particles are collected in ultra low density aerogel . The tennis racket sized collector tray contains ninety blocks of aerogel, providing more than 1,000 square centimeters of surface ... is used in which 99.8 percent of the volume is empty space. Aerogel is 1,000 times less dense than glass , another silicon based solid. When a particle hits the aerogel, it becomes buried in the material, creating a long track, up to 200 times the length of the grain. The aerogel was packed in an aluminum ... as it passed Earth in 2006. To analyze the aerogel for interstellar dust, one million photographs ... Sample processing File Aerogel labtest.jpg thumb 100px alt Visible dust grains in the aerogel collector Visible dust grains in the aerogel collector. File Particle captured in aerogel.jpg thumb 100px alt Visible track and particle in aerogel Visible track and particle in aerogel. The sample ... microscopic specks of dust were embedded in aerogel collector. Ten particles were found to be at least ... found in the samples returned methylamine and ethylamine was found in the aerogel but was not associated ... Bruce Hudson found a track labeled I1043,1,30 among the many images of the aerogel that may contain ... more details
. Capacitive Deionization of NaCI and NaNO3 Solutions with Carbon Aerogel Electrodes, J. Electrochem ... water using carbon aerogel based capacitive deionization technology, Water Research 42 2605 2617. br ... more details
SEAgel Safe Emulsion Agar gel is one of a class of high tech foam materials known as aerogel s. It is an excellent Thermal insulation thermal insulator and among the least dense solids known. SEAgel was invented by Robert Morrison at the Lawrence Livermore National Laboratory in 1992. SEAgel is made of agar , a carbohydrate material that comes from kelp and red algae , and contains from one and a half to fifty milligrams of material per cubic centimeter of solid in other words, it has a density of 1.5 50 mg cm sup 3 sup . SEAgel can be made lighter than air using hydrogen causing it to float or hang in the air. It insulates against temperature, noise, and electrical current. SEAgel is also completely biodegradable, as it is made entirely of biological material and can even be eaten. ref http www.youtube.com watch?v HoCAxS4vqwQ Discovery Channel ref Initially, SEAgel starts out as a gelatin like mixture of agar and water. After it is Freeze drying freeze dried to remove the water, it is left as a honeycomb of dried agar filled with air, with cell sizes two to three micrometers 2 3 m in diameter. SEAgel can have many different uses. Laboratory scientists use SEAgel as targets for x ray laser experiments because it can be Doping semiconductor doped with other materials, such as selenium . In order to eliminate the volatile hydrodynamics that occur when a solid density target explodes before it reaches the density required for laser lasing , scientists are trying to develop an x ray laser target with a density that is less than the critical density of laser light 4 10 sup 21 sup electrons cm sup 3 sup for 0.53 m light . SEAgel can help them achieve a more uniform Plasma physics plasma , which will ultimately improve the quality of the x ray laser beam. SEAgel could also be used as food packaging or the encapsulating material of timed release medical pills, as it is safe to digest. SEAgel could also replace Ochroma pyramidale balsa wood to insulate supertanker s and to provide ... more details
Wiktionarypar gel A gel is a complex solid but fluid substance with liquid like properties. Gel may also refer to In personal care Hair gel , a gel used for setting hair styles Shower gel , a cosmetic body wash Personal lubricant used for sex purpose Hair colouring gel, a form of hair dye In pharmaceutics and physical chemistry Gel capsule gel cap , a gelatinous capsule in which a drug is held Sol gel , a colloidal suspension that can be gelled to form a solid Hydrogel or Aquagel, a water insoluble polymer Xerogel , a dried gel that, when heated, becomes a dense glass Aerogel , a gel that has been dehydrated under supercritical conditions such that the liquid has been replaced with gas In biochemistry Gel electrophoresis , the separation of deoxyribonucleic acid, ribonucleic acid, and protein through an electric charge Polyacrylamide gel , a separation matrix used in electrophoresis of biomolecules, called polyacrylamide gel electrophoresis or PAGE Agarose gel electrophoresis , the separation of usually large organic molecules by size Gel extraction , a technique used to isolate a fragment of intact DNA Gel filtration chromatography , where gel spheres with varying matrix sizes are used to separate proteins in solution with water Gel permeation chromatography , as above, but the proteins are in solution with an organic solvent In entertainment Color gel , a transparent colored material used to shade stage lighting List of The Tribe characters Gel Gel , a fictional character from The Tribe TV series The Tribe 1999 2003 played by Vicky Rodewyk Recurring enemies in The Legend of Zelda series Gel Gel , an enemy from The Legend of Zelda series Gel song , a song by Collective Soul In popular culture Gel bracelets , wristband similar to a large diameter O ring Gel pen , gel inked ballpoint pens Gel conference GEL, or Good Experience Live Other uses G l, a city in Armenia, now called Lichk Gel battery is a rechargeable valve regulated lead acid battery with a gelified elect ... more details
Tony McDonnell is a Professor Emeritus of Planetary and Space Sciences. Specialising in space science and a recognised authority in cosmic dust , he was Professor of Space Sciences at the University of Kent and Professor of Planetary and Space Sciences at the Open University . Space Science Tony McDonnell started his career at the Jodrell Bank Observatory, providing the opportunity for space research, where innovative satellite borne detectors were developed to measure the threat to survival in space environments. They were to be his career speciality. Following a NASA fellowship, he joined the University of Kent in 1967 and, over 30 years, successfully developed the Unit for Space Sciences and Astronomy. His research included analysis of moon rocks from NASA Project Apollo Apollo Programme and USSR Luna missions hypervelocity impacts and specialised facilities experiments during Giotto s flyby of Halleys Comet and interplanetary explorations by the Ulysses spacecraft Ulysses and Galileo spacecraft Galileo probes. Together with Peter Tsou and Donald E. Brownlee Don Brownlee , he was the first to demonstrate the intact capture of space particulates in aerogel , the baseline technique used in the Stardust spacecraft Stardust Mission. He has played a significant role in the UK framework and funding for the exploration of space, including the Rosetta spacecraft Rosetta , Stardust spacecraft Stardust , Cassini Huygens Cassini Huygens missions and the International Space Station facilities. In 1984, the International Astronomical Union named asteroid 9159 McDonnell after him. He is also author of Cosmic Dust , a milestone in Solar System Cosmic Dust Research. In 2000, he and his team moved from the University of Kent to form the UK s largest space team at the Open University and triggered the building of the Planetary and Space Sciences Research Institute. He is now retired and working on a barn renovation in Dordogne , France . A friend has helped. References http stardu ... more details
Encyclopedia
top
