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1

Nano Waterproofing  

NSDL National Science Digital Library

This lesson focuses on how nanotechnology has impacted the design and engineering of many everyday items from paint to fabrics. Learners explore the hydrophobic effect and how similar properties can be introduced by reengineering products at the nano level. Learners work in teams to develop a waterproof material and compare their results with nano waterproof materials developed recently by engineers and scientists.

Ieee

2013-07-30

2

Waterproofing Materials for Masonry.  

National Technical Information Service (NTIS)

The initial effectiveness and durability characteristics of fifty-five clear masonry waterproofing materials were evaluated using laboratory tests. This report contains the results of initial performance tests including water absorption, water vapor trans...

E. J. Clark P. G. Campbell G. Frohnsdorff

1975-01-01

3

Simplified Waterproofing of Aerogels  

NASA Technical Reports Server (NTRS)

A relatively simple silanization process has been developed for waterproofing or rewaterproofing aerogels, xerogels, and aerogel/tile composites, and other, similar low-density, highly microporous materials. Such materials are potentially attractive for a variety of applications especially for thermal-insulation panels that are required to be thin and lightweight. Unfortunately, such materials are also hydrophilic and tend to collapse after adsorbing water from the air. Hence, an effective means of waterproofing is necessary to enable practical exploitation of aerogels and the like. Older processes for waterproofing aerogels are time-consuming, labor-intensive, and expensive, relative to the present process. Each of the older processes includes a number of different chemical treatment steps, and some include the use of toxic halogenated surface-modifying compounds, pressures as high as hundreds of atmospheres, and/or temperatures as high as 1,000 C.

Hsu, Ming-Ta S.; Chen, Timothy S.; White, Susan; Rasky, Daniel J.

2003-01-01

4

Waterproofing Agents for Silica Tiles  

NASA Technical Reports Server (NTRS)

Waterproofing agent methyltrimethoxysilane applied to silica thermal insulation tiles in simple vapor-deposition process. Other waterproofing agents in same series include methylsiloxane and hexamethyldisilazane. Originally developed for insulating tiles for spacecraft, agents also find uses in roofing tiles, insulation for buildings or solar-energy systems, or solar reflectors.

Nakano, H. N.; Izu, Y. D.; Yoshioka, E. N.

1985-01-01

5

Method for Waterproofing Ceramic Materials  

NASA Technical Reports Server (NTRS)

Hygroscopic ceramic materials which are difficult to waterproof with a silane, substituted silane or silazane waterproofing agent, such as an alumina containing fibrous, flexible and porous, fibrous ceramic insulation used on a reentry space vehicle, are rendered easy to waterproof if the interior porous surface of the ceramic is first coated with a thin coating of silica. The silica coating is achieved by coating the interior surface of the ceramic with a silica precursor converting the precursor to silica either in-situ or by oxidative pyrolysis and then applying the waterproofing agent to the silica coated ceramic. The silica precursor comprises almost any suitable silicon containing material such as a silane, silicone, siloxane, silazane and the like applied by solution, vapor deposition and the like. If the waterproofing is removed by e.g., burning, the silica remains and the ceramic is easily rewaterproofed. An alumina containing TABI insulation which absorbs more that five times its weight of water, absorbs less than 10 wt. % water after being waterproofed according to the method of the invention.

Cagliostro, Domenick E. (Inventor); Hsu, Ming-Ta S. (Inventor)

1998-01-01

6

Aerogel Composites: Strong and Waterproof  

NASA Technical Reports Server (NTRS)

Aerogels are exotic materials having superior thermal and physical properties with great potential for both space and industrial uses. Although aerogels are excellent low-density insulators with unique acoustic and optical properties, their commercialization potential is currently limited by moisture absorption, fragility, and cost. This paper describes useful, easily scaled-up solutions to the first two of these three problems. The waterproofing and water-repellent method described here is a cheaper and simpler improvement over previous permanent methods.

White, Susan; Hsu, Ming-ta; Arnold, James O. (Technical Monitor)

1999-01-01

7

Organopolysiloxane Waterproofing Treatment for Porous Ceramics  

NASA Technical Reports Server (NTRS)

Rigid and flexible porous ceramics, including thermal insulation of a type used on space vehicles, are waterproofed by a treatment which comprises applying an aqueous solution of an organopolysiloxane water-proofing agent having reactive silanol groups to the surface of the ceramic and then heating the treated ceramic to form a waterproofed ceramic. The organopolysiloxane is formed by the hydrolysis and partial condensation of di- and trialkoxyfunctional alkylalkoxysilanes having 1-10 carbon atom hydrocarbyl groups.

Leiser, Daniel B. (Inventor); Cagliostro, Domenick E. (Inventor); Hsu, Ming-ta S. (Inventor); Chen, Timothy S. (Inventor)

1998-01-01

8

Waterproofing Nanostructured Aerogel-Ceramic Fiber Composites  

NASA Technical Reports Server (NTRS)

Aerogels are nanoporous materials which can be used to enhance the transport properties of ceramic fiber materials, to exploit their unique properties such as high porosity, large surface area, low density and low thermal conductivity. Numerous applications have been investigated. major obstacle to commercialization is that the structure of aerogels collapses due to the adsorption of water. simple and relatively cheap process has been developed to waterproof silica, alumina and alumina-silica and carbon aerogels and composites incorporating them. Previous waterproofing methods are short lived or expensive and time consuming.

White, Susan; Hsu, Ming Ta; Arnold, Jim (Technical Monitor)

2001-01-01

9

Improvements in Waterproofing Membranes by Modifying Bitumen with Thermoplastic Polymer.  

National Technical Information Service (NTIS)

Waterproofing of roofs with impermeable membranes based on bitumen modified with high modulus materials is widely employed. The mechanical and viscoelastic behavior of bitumen, either at low or at high temperatures, are appreciably improved by addition of...

S. Piazza A. Arcozzi F. Balestrazzi C. Verga S. D. Milanese

1982-01-01

10

Ftir Instrumentation to Monitor Vapors from Shuttle Tile Waterproofing Materials.  

National Technical Information Service (NTIS)

The Space Shuttle Thermal Protection System (TPS) tiles and blankets are waterproofed using DimethylEthoxySilane (DMEX) in the Orbiter Processing Facilities (OPF). DMES has a Threshold Limit Value (TLV) for exposure of personnel to vapor concentration in ...

1995-01-01

11

Evaluation for waterproof ear protectors in swimmers.  

PubMed

The middle ear cavity is exposed and vulnerable to waterborne infection in patients with grommets, perforated tympanic membranes and after radical mastoidectomy. Patients suffering from chronic otitis externa and those receiving radiotherapy to the head and neck also have an increased susceptibility to such infections. Many advocate the use of waterproof ear protectors in such patients when swimming. The choice of a suitable ear protector is complicated as many are now available commercially. This study was therefore designed to evaluate the degree of protection afforded by seven different ear protectors in a group of six swimmers. A very sensitive, original method of water detection was devised incorporating a pH indicator strip. The results showed conclusively that cotton wool coated in paraffin jelly BPC was the most effective method of ear protection and was found to be comfortable and easy to use. Other methods, including custom-made silicone rubber plugs, were not adequate in sealing the external auditory canal and are considerably more expensive. PMID:2614235

Robinson, A C

1989-12-01

12

Possible Concepts for Waterproofing of Norwegian TBM Railway Tunnels  

NASA Astrophysics Data System (ADS)

The aim of this paper is to evaluate and compare the durability, life expectancy and maintenance needs of traditional Norwegian waterproofing concepts to the generally more rigid waterproofing concepts seen in other European countries. The focus will be on solutions for future Norwegian tunnel boring machine railway tunnels. Experiences from operation of newer and older tunnels with different waterproofing concepts have been gathered and analyzed. In the light of functional requirements for Norwegian rail tunnels, some preliminary conclusions about suitable concepts are drawn. Norwegian concepts such as polyethylene panels and lightweight concrete segments with membrane are ruled out. European concepts involving double shell draining systems (inner shell of cast concrete with membrane) and single shell undrained systems (waterproof concrete segments) are generally evaluated as favorable. Sprayable membranes and waterproof/insulating shotcrete are welcomed innovations, but more research is needed to verify their reliability and cost effectiveness compared to the typical European concepts. Increasing traffic and reliance on public transport systems in Norway result in high demand for durable and cost effective solutions.

Dammyr, Øyvind; Nilsen, Bjørn; Thuro, Kurosch; Grøndal, Jørn

2014-05-01

13

Waterproof Silicone Coatings of Thermal Insulation and Vaporization Method  

NASA Technical Reports Server (NTRS)

Thermal insulation composed of porous ceramic material can be waterproofed by producing a thin silicone film on the surface of the insulation by exposing it to volatile silicone precursors at ambient conditions. When the silicone precursor reactants are multi-functional siloxanes or silanes containing alkenes or alkynes carbon groups higher molecular weight films can be produced. Catalyst are usually required for the silicone precursors to react at room temperature to form the films. The catalyst are particularly useful in the single component system e.g. dimethylethoxysilane (DNMS) to accelerate the reaction and decrease the time to waterproof and protect the insulation. In comparison to other methods, the chemical vapor technique assures better control over the quantity and location of the film being deposited on the ceramic insulation to improve the waterproof coating.

Cagliostro, Domenick E. (Inventor)

1999-01-01

14

Waterproof versus cotton cast liners: a randomized, prospective comparison.  

PubMed

Casting injured extremities can cause complications (eg, itching, odor, rashes, skin maceration), many of which are associated with the inability to wash the extremity because of water retention and slow drying of conventional cast liners. A waterproof cast liner allows casts to become wet and perhaps improves hygiene and comfort. Fifty-nine patients (age, > or = 10 years) with upper or lower extremity injuries were randomized to a waterproof-liner group (n = 29) or a cotton-liner group (n = 30). Both groups had casts made of fiberglass tape. At each clinic visit, patients and physicians completed questionnaires evaluating comfort and skin condition, respectively. The waterproof-liner group had better scores for itch (P = .008), discomfort (P < .001), irritation (P = .002), overall patient score (P = .012), and overall physician score (P = .049). PMID:16610379

Haley, Chad A; DeJong, E Schuyler; Ward, John A; Kragh, John F

2006-03-01

15

Efficient, environmentally acceptable method for waterproofing insulation material  

NASA Technical Reports Server (NTRS)

A process of waterproofing alumina-rich or silica-rich fibrous thermal insulation material, the process including the steps of: (a) providing an alumina-rich or a silica-rich fibrous material; (b) providing a waterproofing solution including: (1) a carrier solvent selected from the group consisting of aliphatic alcohols having from 1C to 6C, water, and mixtures thereof; and (2) an alkoxysilane defined by the formula R.sub.4-x -Si-(O-R').sub.x where x is 1-3 and R is selected from the group consisting of alkyl groups having from 1C to 10C, hydrogen, or fluorocarbon groups having from 1F to 15F; and where O-R' is an alkoxy group having from 1C to 5C, or a mixture of alkoxysilanes defined by the above formula R.sub.4-x -Si-(O-R').sub.x ; and optionally (3) modifiers including acids, such as acetic acid or nitric acid, or bases, such as ammonium hydroxide, RNH.sub.2, R.sub.2 NH, or R.sub.3 N, or MOH, where R is selected from the group consisting of alkyl groups having from 1C to 10C or hydrogen, and where M=Na, Li, or K; (c) contacting the fibrous material with the waterproofing solution for a sufficient amount of time to waterproof the fibrous material; and (d) curing the coated fibrous material to render it sufficiently waterproof. A chemical solution for waterproofing alumina-rich or silica-rich fibrous thermal insulation materials, the solution including: (a) a carrier solvent selected from the group consisting of aliphatic alcohols having from 1C to 6C, water, and mixtures thereof; and (b) an alkoxysilane defined by the formula R.sub.4-x -Si-(O-R').sub.x where x is 1-3 and R is selected from the group consisting of alkyl groups having from 1C to 10C, hydrogen, or fluorocarbon groups having from 1F to 15F; and where O-R' is an alkoxy group having from 1C to 5C, or a mixture of alkoxysilanes defined by the above formula R.sub.4-x -Si-(O-R').sub.x ; and optionally (c) modifiers including acids, such as acetic acid or nitric acid, or bases, such as ammonium hydroxide, RNH.sub.2, R.sub.2 NH, or R.sub.3 N, or MOH, where R is selected from the group consisting of alkyl groups having from 1C to 10C or hydrogen, and where M=Na, Li, or K.

Blohowiak, Kay Y. (Inventor); Krienke, Kenneth A. (Inventor); Olli, Larry K. (Inventor); Newquist, Charles W. (Inventor)

2000-01-01

16

FTIR instrumentation to monitor vapors from Shuttle tile waterproofing materials  

NASA Astrophysics Data System (ADS)

The Space Shuttle Thermal Protection System (TPS) tiles and blankets are waterproofed using DimethylEthoxySilane (DMEX) in the Orbiter Processing Facilities (OPF). DMES has a Threshold Limit Value (TLV) for exposure of personnel to vapor concentration in air of 0.5 ppm. The OPF high bay cannot be opened for normal work after a waterproofing operation until the DMES concentration is verified by measurement to be below the TLV. On several occasions the high bay has been kept closed for up to 8 hours following waterproofing operations due to high DMES measurements. In addition, the Miran 203 and Miran 1 BX infrared analyzers calibrated at different wavelengths gave different readings under the same conditions. There was reason to believe that some of the high DMES concentration readings were caused by interference form water and ethanol vapors. The Toxic Vapor Detection Laboratory (TVDL) was asked to test the existing DMES instruments and identify the best qualified instrument. In addition the TVDL was requested to develop instrumentation to ensure the OPF high bay could be opened safely as soon as possible after a waterproofing operation. A Fourier Transform Infrared (FTIR) spectrophotometer instrument developed for an earlier project was reprogrammed to measure DMES vapor along with ethanol, water, and several common solvent vapors. The FTIR was then used to perform a series of laboratory and field tests to evaluate the performance of the single wavelength IR instruments in use. The results demonstrated that the single wavelength IR instruments did respond to ethanol and water vapors, more or less depending on the analytical IR wavelength selected. The FTIR was able to separate the responses to DMES, water and ethanol, and give consistent readings for the DMES vapor concentration. The FTIR was then deployed to the OPF to monitor real waterproofing operations. The FTIR was also used to measure the time for DMES to evaporate from TPS tile under a range of humidity conditions in controlled laboratory tests. The combination of laboratory and field tests with the FTIR instrument demonstrated superior sensitivity, ability to reject interference from water and ethanol vapors, ruggedness to be transported from the lab to the OPF and set up without special procedures or degradation of performance. The multiple component vapor analysis algorithm was developed at KSC and incorporates automatic baseline correction and shape fitting of the spectra. The analysis for DMES, TetraMethylDiSiloxane (TMDS), ethanol, methanol, isopropanol, and baseline parameters uses 161 points per sample at 4 cm(exp -1) resolution, and processes an eight scan sample every ten seconds. The standard deviation of the measurements is 0.013 ppm and the upper linear limit is 125 ppm DMES. waterproofing operations. &The design and building of the 'DMES Carts' were accomplished in Fiscal year 1995.

Mattson, C. B.; Schwindt, C. J.

1995-11-01

17

FTIR instrumentation to monitor vapors from Shuttle tile waterproofing materials  

NASA Technical Reports Server (NTRS)

The Space Shuttle Thermal Protection System (TPS) tiles and blankets are waterproofed using DimethylEthoxySilane (DMEX) in the Orbiter Processing Facilities (OPF). DMES has a Threshold Limit Value (TLV) for exposure of personnel to vapor concentration in air of 0.5 ppm. The OPF high bay cannot be opened for normal work after a waterproofing operation until the DMES concentration is verified by measurement to be below the TLV. On several occasions the high bay has been kept closed for up to 8 hours following waterproofing operations due to high DMES measurements. In addition, the Miran 203 and Miran 1 BX infrared analyzers calibrated at different wavelengths gave different readings under the same conditions. There was reason to believe that some of the high DMES concentration readings were caused by interference form water and ethanol vapors. The Toxic Vapor Detection Laboratory (TVDL) was asked to test the existing DMES instruments and identify the best qualified instrument. In addition the TVDL was requested to develop instrumentation to ensure the OPF high bay could be opened safely as soon as possible after a waterproofing operation. A Fourier Transform Infrared (FTIR) spectrophotometer instrument developed for an earlier project was reprogrammed to measure DMES vapor along with ethanol, water, and several common solvent vapors. The FTIR was then used to perform a series of laboratory and field tests to evaluate the performance of the single wavelength IR instruments in use. The results demonstrated that the single wavelength IR instruments did respond to ethanol and water vapors, more or less depending on the analytical IR wavelength selected. The FTIR was able to separate the responses to DMES, water and ethanol, and give consistent readings for the DMES vapor concentration. The FTIR was then deployed to the OPF to monitor real waterproofing operations. The FTIR was also used to measure the time for DMES to evaporate from TPS tile under a range of humidity conditions in controlled laboratory tests. The combination of laboratory and field tests with the FTIR instrument demonstrated superior sensitivity, ability to reject interference from water and ethanol vapors, ruggedness to be transported from the lab to the OPF and set up without special procedures or degradation of performance. The multiple component vapor analysis algorithm was developed at KSC and incorporates automatic baseline correction and shape fitting of the spectra. The analysis for DMES, TetraMethylDiSiloxane (TMDS), ethanol, methanol, isopropanol, and baseline parameters uses 161 points per sample at 4 cm(exp -1) resolution, and processes an eight scan sample every ten seconds. The standard deviation of the measurements is 0.013 ppm and the upper linear limit is 125 ppm DMES. Based on successful demonstration of capabilities we produced three mobile instrument carts to be used in each OPF to support future waterproofing operations. The design and building of the 'DMES Carts' were accomplished in Fiscal year 1995.

Mattson, C. B.; Schwindt, C. J.

1995-01-01

18

A Theory of Wood Waterproofing by Complexes of Metal Oxides with Lignin Structural Units.  

National Technical Information Service (NTIS)

The effect of various metallic oxides and hydroxides on wood waterproofing was investigated. The waterproofing effect was attributed to the type of complexes formed by the metallic oxide with the guaiacol units of the lignin network of wood. The type of s...

H. Kubel A. Pizzi

1981-01-01

19

The fatty acyl-CoA reductase Waterproof mediates airway clearance in Drosophila.  

PubMed

The transition from a liquid to a gas filled tubular network is the prerequisite for normal function of vertebrate lungs and invertebrate tracheal systems. However, the mechanisms underlying the process of gas filling remain obscure. Here we show that waterproof, encoding a fatty acyl-CoA reductase (FAR), is essential for the gas filling of the tracheal tubes during Drosophila embryogenesis, and does not affect branch network formation or key tracheal maturation processes. However, electron microscopic analysis reveals that in waterproof mutant embryos the formation of the outermost tracheal cuticle sublayer, the envelope, is disrupted and the hydrophobic tracheal coating is damaged. Genetic and gain-of-function experiments indicate a non-cell-autonomous waterproof function for the beginning of the tracheal gas filling process. Interestingly, Waterproof reduces very long chain fatty acids of 24 and 26 carbon atoms to fatty alcohols. Thus, we propose that Waterproof plays a key role in tracheal gas filling by providing very long chain fatty alcohols that serve as potential substrates for wax ester synthesis or related hydrophobic substances that ultimately coat the inner lining of the trachea. The hydrophobicity in turn reduces the tensile strength of the liquid inside the trachea, leading to the formation of a gas bubble, the focal point for subsequent gas filling. Waterproof represents the first enzyme described to date that is necessary for tracheal gas filling without affecting branch morphology. Considering its conservation throughout evolution, Waterproof orthologues may play a similar role in the vertebrate lung. PMID:24183938

Jaspers, Martin H J; Pflanz, Ralf; Riedel, Dietmar; Kawelke, Steffen; Feussner, Ivo; Schuh, Reinhard

2014-01-01

20

Waterproofing and Strengthening Volcanic Tuff in Waste Repositories  

SciTech Connect

Waste repositories from surface trenches and shafts at Los Alamos to drilled tunnels at Yucca Mountain are being built in volcanic Tuff, a soft compacted material that is permeable to water and air. US Department of Energy documents on repository design identify the primary design goal of 'preventing water from reaching the waste canisters, dissolving the canisters and carrying the radioactive waste particles away from the repository'. Designers expect to achieve this by use of multiple barriers along with careful placement of the repository both well above the water table and well above the ground level in a mountain. Though repositories are located in areas that have a historically dry climate to minimize the impact of rainfall infiltration, global warming phenomena may have the potential to alter regional climate patterns - potentially leading to higher infiltration rates. Conventional methods of sealing fractures within volcanic tuff may not be sufficiently robust or long lived to isolate a repository shaft from water for the required duration. A new grouting technology based on molten wax shows significant promise for producing the kind of long term sealing performance required. Molten wax is capable of permeating a significant distance through volcanic tuff, as well as sealing fractures by permeation that is thermally dependent instead of chemically or time dependent. The wax wicks into and saturates tuff even if no fractures are present, but penetrates and fills only the heated area. Heated portions of the rock fill like a vessel. The taffy-like wax has been shown to waterproof the tuff, and significantly increase its resistance to fracture. This wax was used in 2004 for grouting of buried radioactive beryllium waste at the Idaho National Laboratory, chiefly to stop the water based corrosion reactions of the waste. The thermoplastic material contains no water and does not dry out or change with age. Recent studies indicate that this kind of wax material may be inherently resistant to bio-degradation. (authors)

Carter, E.E.; Carter, P.E. [Technologies Co, Texas (United States); Cooper, D.C. [Ph.D. Idaho National Laboratory, Idaho Falls, ID (United States)

2008-07-01

21

Effect of Waterproofing Admixtures on the Flexural Strength and Corrosion Resistance of Concrete  

NASA Astrophysics Data System (ADS)

This paper deals about the flexural strength and corrosion behaviour of concrete using waterproofing admixtures. The effect of waterproofing admixtures on the corrosion behaviour of RCC specimen has been studied by conducting accelerated corrosion test. To identify the effect of corrosion in pull out strength, corrosion process was induced by means of accelerated corrosion procedure. To accelerate the reinforcement corrosion, direct electric current was impressed on the rebar embedded in the specimen using a DC power supply system that has a facility to adjust voltage. The addition of waterproofing admixtures also shows the improvement in the flexural strength of concrete has been studied by conducting flexural strength tests on the concrete prism specimen of size 100 × 100 × 500 mm with and without admixtures for various dosages and various curing periods of 7 and 28 days. The results showed that the presence of waterproofing admixtures always improves the corrosion resistance and thus increases the strength of concrete due to the hydrophobic action of waterproofing admixtures.

Geetha, A.; Perumal, P.

2012-02-01

22

Application of new concept waterproofing in Xiang'an undersea tunnel, China  

NASA Astrophysics Data System (ADS)

As a kind of transportation mode for crossing channels, undersea tunnel has incomparable advantages for its directness, convenience, fastness, insusceptibility to weather conditions, and smaller influences on environments. In recent years, with the development of undersea tunnel construction, the design and construction technologies have been greatly enhanced. The first undersea tunnel in China has just been built. Waterproofing is the key technique of undersea tunneling. A new concept of waterproofing scheme of grouting, sealing, draining and divided sections was adopted in the construction of the tunnel based on the researches, the in-situ geological features, the astuteness of the current technology, and the cost of construction. The structural details of the sealing and draining system are introduced to illustrate the salient features of the new waterproofing technique. It is hoped that experiences described in the paper can offer guidance for the construction of the extensive undersea tunnels in the coming years.

Chen, Tie-lin; Zhang, Ding-li; Zeng, Chao; Ying, Guo-gang

2013-03-01

23

Waterproof Anti-Explosive Powders for Coal Mines  

NASA Astrophysics Data System (ADS)

Limestone powder characterized by hydrophobic properties is used as an anti-explosive agent in coal mining industry. Unfortunately, the standard method of producing such powder by milling limestone with stearic acid is practically unprofitable in many modernized quarries and plants, and sometimes literally impossible due to the introduction of technological changes and implementation of modern mills. Then new methods of hydrophobization of limestone surfaces ought be searched. In the work two methods hydrophobization: from the stearic acid vapour phase and from silicone solutions are proposed. Lime dust from the Czatkowice Quarry of Lime was used as a raw material during investigations. It is a good agent for research because it is possible to compare the properties of samples modified in this work to the properties of anti-explosive lime powder (Polish Standard, 1994) used in mining industry in Poland. The first technique of limestone powder hydrophobization was carried out in an apparatus of own design (Vogt, 2008, 2011), and it consisted in free sedimentation of the powder layer dispersed by stearic acid vapour in powder counter current flow. The second way of modification consisted in mixing in the evaporating dish substrates: limestone powder and dope - silicone solution - Sarsil® H-15 (Vogt & Opali?ski, 2009; Vogt & Ho?ownia, 2010). Evaluation of properties so-obtained waterproof powders was carried out according to the Polish Standard, as well as using original powder determination ways, with the Powder Characteristic Tester (Index tables, Tablets & Capsules, 2005). Moreover water vapour adsorption isotherms were obtained and the thermal decomposition of powder was made. All modified samples acquired the hydrophobic character. Therefore we can state that the both proposed methods of hydrophobization of the limestone powder are useful. The parameters obtained with the use of Powder Characteristics Tester enable us to make a characterization of limestone properties not only as a water resistant material but also from the cohesion point of view. On the base of TG, DTG or DTA and EGA curves for all investigated materials was stated that the character of the thermal decomposition of modified samples is the same as this one for raw powder, what is profitable for application of hydrophobized powders as an anti-explosive agent. W górnictwie w?gla kamiennego u?ywany jest hydrofobowy py? wapienny jako substancja stosowana w systemie zabezpiecze? przeciwwybuchowych (Cybulski, 2004). Niestety, dotychczasowy sposób wy- twarzania takiego produktu polegaj?cy na wspó?mieleniu kamienia wapiennego z kwasem stearynowym staje si? praktycznie niemo?liwy do stosowania w nowoczesnych zak?adach np. kamienio?omy. Sytuacja taka jest wynikiem wprowadzania zmian technologicznych, g?ównie zwi?zanych z wymian? starych konstrukcji m?ynów na nowe urz?dzenia. Tym samym istnieje potrzeba poszukiwania nowych metod hydrofobizacji powierzchni py?ów wapiennych. W pracy omówiono dwie nowe metody hydrofobizacji py?u wapiennego: za pomoc? par kwasu stearynowego oraz roztworu silikonowego - Sarsil® H-15. Podczas bada? u?ywano surowego py?u wapiennego pochodz?cego z Kopalni Kamienia Wapiennego w Czatkowicach. Materia? ten jest dobrym materia?em do bada? gdy? istnieje mo?liwo?? porównywania w?a?ciwo?ci materia?ów hydrofobowych otrzymanych w pracy z w?a?ciwo?ciami handlowego py?u przeciwwybuchowego (Polska Norma, 1994), u?ywanego w polskich kopalniach. Pierwszy sposób hydrofobizacji py?u wapiennego, polegaj?cy na swobodnym opadaniu py?u wapiennego w oparach kwasu stearynowego przep?ywaj?cych w przeciwpr?dzie, przeprowadzono w aparacie w?asnej konstrukcji (Vogt, 2008, 2011). Aparat gwarantuje dobry kontakt modyfikatora z ziarnami py?u. Py? opadaj?c, nie napotyka ?adnych przeszkód ulega? rozproszeniu, a wprowadzony w stanie parowym kwas stearynowy mo?e swobodnie osiada? na jego powierzchni zewn?trznej oraz penetrowa? w g??b porów, blokuj?c je dla wilgoci. Drugi sposób hydrofo

Buczek, Bronis?aw; Vogt, El?bieta

2014-03-01

24

RADON DIFFUSION COPEFFICIENT - A MATERIAL PROPERTY DETERMINING THE APPLICABILITY OF WATERPROOF MEMBRANES AS RADON BARRIERS  

Microsoft Academic Search

Barrier properties of various waterproofing materials against radon were studied by means of the radon diffusion coefficient. Method for the determination of this material property used in the Czech Republic is presented. Results of radon diffusion coefficients measurements in more than 300 insulating materials are summarized. We have found out that great differences exist in diffusion properties because the diffusion

Martin Jiránek

25

Waterproofness Results for the Surface Treatment of Heavy-Duty Leather for Adhesion Enhancement  

Microsoft Academic Search

This article presents further work undertaken in respect to the use of specific primers for adhesion on leather surfaces. This research focused on the use of photoreactive reagents and silane networks as primers and investigated their roles in seam strength and resistance against water ingress. A specific waterproof test was undertaken on treated samples in accordance with EN ISO 5403:2002.

Catalin Fotea; Claudius DSilva; Sean Spear

2007-01-01

26

Science and technology of building seals, sealants, glazing, and waterproofing: Seventh volume  

Microsoft Academic Search

This book captures papers from the Charles J. Parise Seventh Symposium on the Science and Technology of Building Seals. Sealants, Glazing, and Waterproofing. The overriding theme behind the papers is durability. This topic is fundamental to all users and specifiers of sealants. The first set of papers in this book addresses the topic of stress and fatigue. Joint designs vary

Klosowski

1998-01-01

27

Transient altitude-induced compartment syndrome associated with fiberglass casts using waterproof cast padding.  

PubMed

Changes in aircraft cabin pressure and its interplay with a fixed diameter fiberglass cylindrical cast and the closed air cells in waterproof cast padding may cause a transient altitude-induced compartment syndrome. In this case series, 2 patients reported transient compartment syndromes that resolved with aircraft decent. As proof of concept, this work displays photographic and video evidence showing the difference in air cell volume from experimental data in a vacuum chamber as well as real-world volume changes at cruise altitude in a commercial airliner. Transient altitude-induced compartment syndromes associated with fiberglass casts using waterproof cast padding are real and surgeons and patients should be advised of this potentially devastating complication. PMID:23431541

Kadzielski, John; Bae, Donald S

2013-01-01

28

Fire ants self-assemble into waterproof rafts to survive floods.  

PubMed

Why does a single fire ant Solenopsis invicta struggle in water, whereas a group can float effortlessly for days? We use time-lapse photography to investigate how fire ants S. invicta link their bodies together to build waterproof rafts. Although water repellency in nature has been previously viewed as a static material property of plant leaves and insect cuticles, we here demonstrate a self-assembled hydrophobic surface. We find that ants can considerably enhance their water repellency by linking their bodies together, a process analogous to the weaving of a waterproof fabric. We present a model for the rate of raft construction based on observations of ant trajectories atop the raft. Central to the construction process is the trapping of ants at the raft edge by their neighbors, suggesting that some "cooperative" behaviors may rely upon coercion. PMID:21518911

Mlot, Nathan J; Tovey, Craig A; Hu, David L

2011-05-10

29

Science and technology of building seals, sealants, glazing, and waterproofing: Fifth volume  

SciTech Connect

The current proceedings provide reviews of technological advances and the most recent developments in the domain of significant importance to both researchers and practitioners in the sealant industry. This would include, for instance, those involved in test method and product development research and practitioners having expertise in the areas of building joint seal and waterproofing design, specification, application, failure diagnosis, maintenance and repair, and other related domains. This volume contains eighteen contributions covering a wide spectrum of areas related to the science and technology of sealants and waterproofing and cognate systems. The papers have been organized into six categories: joint design and sealant selection: joint sealant failures; design, evaluation, and application of structural silicone glazing sealants; aesthetic performance; recent advances in adhesion testing; and studies related to the long-term performance and aging of sealants and gaskets. Papers have been processed separately for inclusion on the data base.

Lacasse, M.A. [ed.

1996-12-31

30

Elevated waterproof access floor system and method of making the same  

NASA Technical Reports Server (NTRS)

An elevated waterproof access floor system having subfloor channels or compartments for power lines, gas lines or the like is adapted such that it can be opened and subsequently resealed without destroying the waterproofing and without destroying its aesthetic appearance. A multiplicity of tiles are supported on a support grid, and a flooring sheet is supported on the tiles. Attachment means are provided to prevent lateral but not vertical movement of the flooring sheet with respect to the tiles so that the flooring sheet can be lifted off the tiles, but when the flooring sheet is supported on the tiles, no lateral slipping will occur. The flooring sheet is made of a heat resealable material, so that it can be cut away in sections, and the tiles therebelow lifted off, to provide access to subfloor compartments.

Cohen, Marc M. (inventor)

1987-01-01

31

Waterproof and translucent wings at the same time: problems and solutions in butterflies  

Microsoft Academic Search

Although the colour of butterflies attracts the most attention, the waterproofing properties of their wings are also extremely\\u000a interesting. Most butterfly wings are considered “super-hydrophobic” because the contact angle (CA) with a water drop exceeds\\u000a 150°. Usually, butterfly wings are covered with strongly overlapping scales; however, in the case of transparent or translucent\\u000a wings, scale cover is reduced; thus, the

Pablo Perez Goodwyn; Yasunori Maezono; Naoe Hosoda; Kenji Fujisaki

2009-01-01

32

Loads on Sprayed Waterproof Tunnel Linings in Jointed Hard Rock: A Study Based on Norwegian Cases  

NASA Astrophysics Data System (ADS)

A composite tunnel lining system based on a sprayed waterproofing membrane combined with sprayed concrete is currently being considered for future Norwegian rail and road tunnels. Possible loading of the tunnel linings caused by water pressure is being investigated. This tunnel lining system consists of a waterproof membrane which, during application on the sprayed concrete lining, bonds mechanically to the sprayed concrete on either side. Hence, a continuous, sealing, and non-draining structure from the rock mass to the interior tunnel surface is formed in the walls and crown. Experiences from some successful recent projects with this lining system in Europe are reviewed. However, these experiences are not directly comparable to the Scandinavian hard rock tunnel lining approach, which utilizes a relatively thin sprayed and irregular concrete layer for permanent lining. When considering the sprayed membrane and sprayed concrete composite lining concept, introducing a partially sealing and undrained element in the lining, the experiences with the traditionally used lining systems in Norway need to be reconsidered and fully understood. A review of several hard rock tunnels with adverse conditions, in which the tunnel lining has been subject to load monitoring, shows that only very small loads in the tunnel linings occur. Recent investigations with in situ water pressure testing, including two sites with the composite sprayed membrane in a partially drained waterproof tunnel lining, are discussed. In a case with a cavern located in a hydraulically saturated rock mass subjected to approximately 8 bar hydrostatic pressure, a negative pressure gradient towards the tunnel lining has been measured. The investigation results from the Norwegian test sites indicate that no significant loading of the tunnel lining takes place in a hydraulically saturated rock when applying this composite waterproof tunnel lining in parts of the tunnel perimeter.

Holter, Karl Gunnar

2014-05-01

33

Ultrastructural organization of avian stratum corneum lipids as the basis for facultative cutaneous waterproofing.  

PubMed

The ultrastructure of naked neck epidermis from the ostrich (Struthio camelus) and ventral apterium from watered, and water-deprived, Zebra finches (Taeniopygia [Poephila] guttata castanotis) is presented. The form and distribution of the fully differentiated products of the lipid-enriched multigranular bodies are compared in biopsies post-fixed with osmium tetroxide or ruthenium tetroxide. The fine structure of ostrich epidermis suggests it is a relatively poor barrier to cutaneous water loss (CWL). The fine structure from watered, and 16-hr water-deprived Zebra finches, considered in conjunction with measurements of CWL, confirms previous reports of "facultative waterproofing," and emphasizes the rapidity of tissue response to dehydration. The seemingly counterintuitive facts that one xerophilic avian species, the ostrich, lacks a "good barrier" to CWL, whereas another, the Zebra finch, is capable of forming a good barrier, but does not always express this capability, are discussed. An explanation of these data in comparison to mammals centers on the dual roles of the integument of homeotherms in thermoregulation and conserving body water. It is concluded that birds, whose homeothermic control depends so much on CWL, cannot possess a permanent "good barrier," as such would compromise the heat loss mechanism. Facultative waterproofing (also documented in lizards) protects the organism against sudden reductions in water availability. In birds, and probably in snakes and lizards, facultative waterproofing involves qualitative changes in epidermal cell differentiation. Possible control mechanisms are discussed. PMID:8568904

Menon, G K; Maderson, P F; Drewes, R C; Baptista, L F; Price, L F; Elias, P M

1996-01-01

34

Basic principles for the development of a common standardised method for determining the radon diffusion coefficient in waterproofing materials.  

PubMed

Paper presents the principles for unified test methods for determining the radon diffusion coefficient in waterproof materials in order to increase the accuracy, repeatability and reproducibility of the results. We consider this very important, because an assessment of the radon diffusion coefficient is required by several national technical standards when waterproofing acts as a radon-proof membrane. The requirements for key parameters for one test method performed under non-stationary conditions and for two methods performed under stationary conditions are described in this paper. PMID:22245288

Jiránek, Martin; Rovenská, Kate?ina

2012-04-01

35

Toxicity study of dimethylethoxysilane (DMSES), the waterproofing agent for the Orbiter heat protective system  

NASA Technical Reports Server (NTRS)

DMES, a volatile liquid, is used by NASA to waterproof the Orbiter thermal protective system. During waterproofing operations at the Oribter Processing Facility at KSC, workers could be exposed to DMES vapor. To assess the toxicity of DMES, acute and subchronic (2-week and 13-week) inhalation studies were conducted with rats. Studies were also conducted to assess the potential of DMES. Inhalation exposure concentrations ranged from 40 ppm to 4000 ppm. No mortality was observed during the studies. Exposures to 2100 ppm produced narcosis and ataxia. Post-exposure recovery from these CNS effects was rapid (less than 1 hr). These effects were concentration-dependent and relatively independent of exposure length. Exposure to 3000 ppm for 2 weeks (5 h/d, 5 d/wk) produced testicular toxicity. The 13-week study yielded similar results. Results from the genotoxicity assays (in vivo/in vitro unscheduled DNA synthesis in rat primary heptaocytes, chromosomal aberrations in rat bone marrow cells; reverse gene mutation in Salmonella typhimurium; and forward mutation in Chinese hamster culture cells) were negative. These studies indicated that DMES is mildly to moderately toxic but not a multagen.

Lam, Chiu-Wing; James, John T.; Dodd, Darol; Stuart, Bruce; Rothenberg, Simon; Kershaw, Mary Ann; Thilagar, A.

1993-01-01

36

Does long term exposure to radon gas influence the properties of polymeric waterproof materials?  

NASA Astrophysics Data System (ADS)

The technical state of buildings and the quality of the indoor environment depend on the quality of the waterproofing course and on the properties of the insulating materials that are applied, in particular on their durability, long-term functional reliability and resistance to corrosive effects of the subsoil. Underground water chemistry and soil bacteria are well-known corrosive agents. Our investigations indicate that the ageing process of waterproof materials can be significantly accelerated by alpha particles emitted by radon and radon progenies which are present in soil gas. Materials commonly available on the building market, e.g. LDPE and HDPE of various densities, PVC, TPO (thermoplastic polyolefin), PP (polypropylene) and EPDM were selected for our experimental study. The preliminary results for 3-year exposure to radon gas show a decrease in tensile strength to 60%, elongation to 80% and hardness to 95% for samples based on PE. The diffusion coefficient of radon for samples based on PVC decreased to 20% of the initial value after 1-year exposure to radon and soil bacteria.

Navratilova Rovenska, Katerina; Jiranek, Martin; Kokes, Pavel; Wasserbauer, Richard; Kacmarikova, Veronika

2014-01-01

37

Radon diffusion coefficients in 360 waterproof materials of different chemical composition.  

PubMed

This paper summarises the results of radon diffusion coefficient measurements in 360 common waterproof materials available throughout Europe. The materials were grouped into 26 categories according to their chemical composition. It was found that the diffusion coefficients of materials used for protecting houses against radon vary within eight orders from 10(-15) to 10(-8) m(2) s(-1). The lowest values were obtained for bitumen membranes with an Al carrier film and for ethylene vinyl acetate membranes. The highest radon diffusion coefficient values were discovered for sodium bentonite membranes, rubber membranes made of ethylene propylene diene monomer and polymer cement coatings. The radon diffusion coefficients for waterproofings widely used for protecting houses, i.e. flexible polyvinyl chloride, high-, low-density polyethylene, polypropylene and bitumen membranes, vary in the range from 3 × 10(-12) to 3 × 10(-11) m(2) s(-1). Tests were performed which confirmed that the radon diffusion coefficient is also an effective tool for verifying the air-tightness of joints. PMID:21450700

Jiránek, M; Kotrbatá, M

2011-05-01

38

Science and technology of building seals, sealants, glazing, and waterproofing: Seventh volume  

SciTech Connect

This book captures papers from the Charles J. Parise Seventh Symposium on the Science and Technology of Building Seals. Sealants, Glazing, and Waterproofing. The overriding theme behind the papers is durability. This topic is fundamental to all users and specifiers of sealants. The first set of papers in this book addresses the topic of stress and fatigue. Joint designs vary from the square section to exaggerated hour-glass shapes. The joint designs are factors in the longevity of a sealant in the joint. The available work on accelerated weathering tests and how that relates to the damage caused by real weathering is summarized. Acrylic latex sealants can come in many qualities and some can be formulated to have properties that approach and in some cases match some of the chemically curing sealants. The unique sealant applications in roofs and doing the old fashion listing of the performance needed for each application is addressed. Destruction of a joint can be more than a failed sealant. It can be a fine sealant in a joint that is picked clean by birds. Destruction of weather protection offered by sealant, the diagnosis of the cause and solutions, especially in EIFS systems, was discussed in several papers. The esthetic concerns of fluid migration from sealants and sealant staining potential were addressed. Relative to sealant testing, the paper of work done at V.P.I. on adhesion testing is a landmark paper. Papers on finite element analysis are presented. These show where the stress concentration starts and maximizes in various joint designs and provides the basis for better joint design and better joint geometry. There is a concluding series of papers that address the adhesion of waterproofing membranes; firestopping from a latex viewpoint; polysulfide sealants for chemical containment; and a final paper looks at the myriad of places sealants are used in modern buildings and spaceframe structures.

Klosowski, J.M. [ed.

1998-12-31

39

Health Hazard Evaluation Report: HEAT-2008-0058-3108, Aduddell Restoration and Waterproofing, Inc., Arlington, Virginia, April 2010. Crystalline Silica and Isocyanate Exposures during Parking Garage Repair.  

National Technical Information Service (NTIS)

On November 30, 2007, NIOSH received a request from managers at Aduddell Restoration and Waterproofing, Inc. for an HHE at the Ballston Mall Parking Garage in Arlington, Virginia. The managers wanted to know if the employees were adequately protected agai...

A. Adebayo C. Achutan F. Nourian

2010-01-01

40

The effect on the radon diffusion coefficient of long-term exposure of waterproof membranes to various degradation agents.  

PubMed

Waterproofing, usually made of bitumen or polymers with various additives, is used to protect buildings mainly against dampness, but also against radon transported from the soil beneath the building. The radon diffusion coefficient is a material property which is considered to be strongly influenced by the inner structure (chemical composition, crystallinity) of a measured sample. We have used this parameter together with measurements of mechanical properties (hardness, tensile strength, elongation at break, etc.) and FTIR spectroscopy has been used in order to describe the changes in material properties induced by long-term degradation. This paper summarizes the results of radon diffusion coefficient measurements of waterproof materials exposed to radon, soil bacteria, high temperature and combinations of these factors. We have discovered changes as high as 83 % have been discovered compared to virgin samples. PMID:24748486

Navrátilová Rovenská, Katerina

2014-07-01

41

Radon diffusion coefficient measurement in waterproofings--a review of methods and an analysis of differences in results.  

PubMed

This paper summarizes information about 16 measuring methods for determining the radon diffusion coefficient of waterproofing materials. We have found that the differences in results for identical membranes, which can be as high as two orders of magnitude, can mainly be attributed to insufficient duration of the tests, insufficient radon concentration to which the samples are exposed, and the use of steady state calculation procedures for data measured under non-steady state conditions. PMID:22285061

Rovenská, Kate?ina; Jiránek, Martin

2012-04-01

42

Ovarian dual oxidase (Duox) activity is essential for insect eggshell hardening and waterproofing.  

PubMed

In insects, eggshell hardening involves cross-linking of chorion proteins via their tyrosine residues. This process is catalyzed by peroxidases at the expense of H2O2 and confers physical and biological protection to the developing embryo. Here, working with Rhodnius prolixus, the insect vector of Chagas disease, we show that an ovary dual oxidase (Duox), a NADPH oxidase, is the source of the H2O2 that supports dityrosine-mediated protein cross-linking and eggshell hardening. RNAi silencing of Duox activity decreased H2O2 generation followed by a failure in embryo development caused by a reduced resistance to water loss, which, in turn, caused embryos to dry out following oviposition. Phenotypes of Duox-silenced eggs were reversed by incubation in a water-saturated atmosphere, simultaneous silencing of the Duox and catalase genes, or H2O2 injection into the female hemocoel. Taken together, our results show that Duox-generated H2O2 fuels egg chorion hardening and that this process plays an essential role during eggshell waterproofing. PMID:24174530

Dias, Felipe A; Gandara, Ana Caroline P; Queiroz-Barros, Fernanda G; Oliveira, Raquel L L; Sorgine, Marcos H F; Braz, Glória R C; Oliveira, Pedro L

2013-12-01

43

Identification et Proprietes de Bitumes Modifies ou Non pour Chapes d'Etancheite (Research on the Problem of Remedying the Intrinsic Causes of Deterioration in Waterproofing Courses in Mastic Asphalt).  

National Technical Information Service (NTIS)

The study is a contribution to the problem of remedying the intrinsic causes of deterioration observed in certain waterproofing courses in mastic asphalt, particularly those which are intended as substrates for relatively horizontal layers (bridge decks a...

F. Choquet

1985-01-01

44

High-power direct green laser oscillation of 598 mW in Pr(3+)-doped waterproof fluoroaluminate glass fiber excited by two-polarization-combined GaN laser diodes.  

PubMed

We demonstrated a high-power and highly efficient Pr-doped waterproof fluoride glass fiber laser at 522.2 nm excited by two-polarization-combined GaN laser diodes and achieved a subwatt output power of 598 mW and slope efficiency of 43.0%. This system will enable us to make a vivid laser display, a photocoagulation laser for eye surgery, a color confocal scanning laser microscope, and an effective laser for material processing. Direct visible ultrashort pulse generation is also expected. PMID:21593907

Nakanishi, Jun; Horiuchi, Yuya; Yamada, Tsuyoshi; Ishii, Osamu; Yamazaki, Masaaki; Yoshida, Minoru; Fujimoto, Yasushi

2011-05-15

45

Waterproof active paper via laser surface micropatterning of magnetic nanoparticles.  

PubMed

Paper is one of the oldest and most abundant materials known to man. Recently, there has been a considerable interest in creating paper devices by combining paper with other functional materials. In this letter, we demonstrate a simple fabrication technique to create water-resistant ferro-patterns on wax paper using CO(2) laser ablation. A resolution of about 100 ?m is achieved which is mostly limited by the cellulose fiber size (~50 ?m) in the wax paper and can be improved by using a smaller cellulose matrix. Laser ablation results in modification of surface morphology and chemistry, leading to a change in surface energy. We also present a 2D model for ferrofluid deposition relating the size of the pattern to the amount of ferroparticles deposited on the surface. Finally, a paper gripper is presented to demonstrate advantages of our technique, which allows microscale patterning and machining in a single step. PMID:22939525

Chitnis, G; Ziaie, B

2012-09-26

46

Science and technology of building seals, sealants, glazing, and waterproofing: Sixth volume  

SciTech Connect

This publication contains ten peer-reviewed papers on structural silicone glazing (SSG), sealant design, and recent sealant research. Collectively, these papers help answer some recent questions in sealant technology and provide the foundation for additional research and ASTM standards development. Papers have been processed separately for inclusion on the database.

Myers, J.C. [ed.

1996-12-31

47

Effectiveness of Waterproof, Breathable Handwear in a Cold Environment. (Reannouncement with New Availability Information).  

National Technical Information Service (NTIS)

Cooling of the hands has been implicated as a cause for reduced endurance time, loss of manual dexterity and general discomfort during cold exposure. An extended exposure to cold-wet weather can result in rapid cooling of the extremities from the conducti...

T. L. Endrusick W. R. Santee L. A. Blanchard R. R. Gonzalez

1990-01-01

48

Waterproof Manado: Life must be safe and secure, not only today but also in the future!  

Microsoft Academic Search

Manado City is growing, its population is increasing. This demands the city to grow outside its borders and even into the sea by using land reclamation. Introducing new challenges or making challenges bigger, which are already present. Not only growth is present in the city, going forward and becoming better and better is an on-going fight for cities. The city

R. V. Slijk; L. W. Schadee; P. P. Knook; G. L. S. Van der Salm; P. D. Notenboom

2011-01-01

49

Drosophila melanogaster Acetyl-CoA-carboxylase sustains a fatty acid-dependent remote signal to waterproof the respiratory system.  

PubMed

Fatty acid (FA) metabolism plays a central role in body homeostasis and related diseases. Thus, FA metabolic enzymes are attractive targets for drug therapy. Mouse studies on Acetyl-coenzymeA-carboxylase (ACC), the rate-limiting enzyme for FA synthesis, have highlighted its homeostatic role in liver and adipose tissue. We took advantage of the powerful genetics of Drosophila melanogaster to investigate the role of the unique Drosophila ACC homologue in the fat body and the oenocytes. The fat body accomplishes hepatic and storage functions, whereas the oenocytes are proposed to produce the cuticular lipids and to contribute to the hepatic function. RNA-interfering disruption of ACC in the fat body does not affect viability but does result in a dramatic reduction in triglyceride storage and a concurrent increase in glycogen accumulation. These metabolic perturbations further highlight the role of triglyceride and glycogen storage in controlling circulatory sugar levels, thereby validating Drosophila as a relevant model to explore the tissue-specific function of FA metabolic enzymes. In contrast, ACC disruption in the oenocytes through RNA-interference or tissue-targeted mutation induces lethality, as does oenocyte ablation. Surprisingly, this lethality is associated with a failure in the watertightness of the spiracles-the organs controlling the entry of air into the trachea. At the cellular level, we have observed that, in defective spiracles, lipids fail to transfer from the spiracular gland to the point of air entry. This phenotype is caused by disrupted synthesis of a putative very-long-chain-FA (VLCFA) within the oenocytes, which ultimately results in a lethal anoxic issue. Preventing liquid entry into respiratory systems is a universal issue for air-breathing animals. Here, we have shown that, in Drosophila, this process is controlled by a putative VLCFA produced within the oenocytes. PMID:22956916

Parvy, Jean-Philippe; Napal, Laura; Rubin, Thomas; Poidevin, Mickael; Perrin, Laurent; Wicker-Thomas, Claude; Montagne, Jacques

2012-01-01

50

46 CFR 160.052-8 - Marking.  

Code of Federal Regulations, 2010 CFR

...Buoyant Vest, Unicellular Plastic Foam, Adult and Child ...information clearly marked in waterproof lettering that can be read... (Lot No.) (b) Waterproof marking. Marking for buoyant vests shall be sufficiently waterproof so that after 72 hours...

2010-10-01

51

46 CFR 160.052-8 - Marking.  

Code of Federal Regulations, 2010 CFR

...Buoyant Vest, Unicellular Plastic Foam, Adult and Child ...information clearly marked in waterproof lettering that can be read... (Lot No.) (b) Waterproof marking. Marking for buoyant vests shall be sufficiently waterproof so that after 72 hours...

2009-10-01

52

46 CFR 160.021-3 - Materials, workmanship, construction and performance requirements.  

Code of Federal Regulations, 2012 CFR

...alternate waterproofing of the signal by means of a water-resistant coating on the signal plus packaging in a sealed plastic waterproof bag satisfactory to the Commandant. (d) Performance. Signals shall meet all the inspection and test...

2012-10-01

53

46 CFR 160.037-3 - Materials, workmanship, construction, and performance requirements.  

Code of Federal Regulations, 2012 CFR

...alternate waterproofing of the signal by means of a water-resistant coating on the signal plus packaging in a sealed plastic waterproof bag satisfactory to the Commandant. (d) Performance. Signals shall meet all the inspection and test...

2012-10-01

54

46 CFR 160.049-6 - Marking.  

Code of Federal Regulations, 2010 CFR

... Specification for a Buoyant Cushion Plastic Foam § 160.049-6 Marking. ...following information clearly marked in waterproof lettering: (1) In letters that...buoyant cushions shall be sufficiently waterproof so that after 72 hours...

2009-10-01

55

46 CFR 160.049-6 - Marking.  

Code of Federal Regulations, 2010 CFR

... Specification for a Buoyant Cushion Plastic Foam § 160.049-6 Marking. ...following information clearly marked in waterproof lettering: (1) In letters that...buoyant cushions shall be sufficiently waterproof so that after 72 hours...

2010-10-01

56

46 CFR 160.037-3 - Materials, workmanship, construction, and performance requirements.  

Code of Federal Regulations, 2010 CFR

...alternate waterproofing of the signal by means of a water-resistant coating on the signal plus packaging in a sealed plastic waterproof bag satisfactory to the Commandant. (d) Performance. Signals shall meet all the inspection and test...

2010-10-01

57

46 CFR 160.021-3 - Materials, workmanship, construction and performance requirements.  

Code of Federal Regulations, 2011 CFR

...alternate waterproofing of the signal by means of a water-resistant coating on the signal plus packaging in a sealed plastic waterproof bag satisfactory to the Commandant. (d) Performance. Signals shall meet all the inspection and test...

2011-10-01

58

46 CFR 160.021-3 - Materials, workmanship, construction and performance requirements.  

Code of Federal Regulations, 2010 CFR

...alternate waterproofing of the signal by means of a water-resistant coating on the signal plus packaging in a sealed plastic waterproof bag satisfactory to the Commandant. (d) Performance. Signals shall meet all the inspection and test...

2010-10-01

59

46 CFR 160.037-3 - Materials, workmanship, construction, and performance requirements.  

Code of Federal Regulations, 2011 CFR

...alternate waterproofing of the signal by means of a water-resistant coating on the signal plus packaging in a sealed plastic waterproof bag satisfactory to the Commandant. (d) Performance. Signals shall meet all the inspection and test...

2011-10-01

60

46 CFR 160.053-5 - Marking.  

Code of Federal Regulations, 2010 CFR

... Work Vests, Unicellular Plastic Foam § 160.053-5 Marking...information clearly printed in waterproof lettering that can be read...there shall be stenciled in waterproof ink in letters not less than...tags shall be sufficiently waterproof so that after 48...

2010-10-01

61

46 CFR 160.053-5 - Marking.  

Code of Federal Regulations, 2010 CFR

... Work Vests, Unicellular Plastic Foam § 160.053-5 Marking...information clearly printed in waterproof lettering that can be read...there shall be stenciled in waterproof ink in letters not less than...tags shall be sufficiently waterproof so that after 48...

2009-10-01

62

Water-Repellency Probe  

NASA Technical Reports Server (NTRS)

Instrument yielding presence or absence of waterproofing agent at any given depth in blanket developed. In original application, blankets in question part of space shuttle thermal protection system. Instrument utilized to determine extent of waterproofing "burnout" due to re-entry heating and adverse environment exposure.

Rosen, Charles D.; Mitchell, Shirley M.; Jolly, Stanley R.; Jackson, Richard G.; Fleming, Scott T.; Roberts, William J.; Bell, Daniel R., III

1996-01-01

63

10 CFR 32.103 - Schedule D-prototype tests for ice detection devices containing strontium-90.  

Code of Federal Regulations, 2010 CFR

...subjected to shock test as set forth in § 32.101(d). (d) Hermetic seal and waterproof test. On completion of all...centimeters. The amount of strontium-90 in the water used in the hermetic seal and waterproof test prescribed in paragraph (d)...

2009-01-01

64

40 CFR Table 1 to Subpart C - VOC Content Limits by Product Category  

Code of Federal Regulations, 2010 CFR

...Construction and panel 40 General purpose 10 Structural waterproof 15 Insecticides: Crawling bug 40 Flea and tick 25 Flying bug 35 Foggers 45 Lawn and Garden 20 Laundry prewash: Aerosols/solids 22 All other...

2010-07-01

65

40 CFR Table 1 to Subpart C - VOC Content Limits by Product Category  

Code of Federal Regulations, 2010 CFR

...Construction and panel 40 General purpose 10 Structural waterproof 15 Insecticides: Crawling bug 40 Flea and tick 25 Flying bug 35 Foggers 45 Lawn and Garden 20 Laundry prewash: Aerosols/solids 22 All other...

2009-07-01

66

Bituminous Heat Insulating Materials.  

National Technical Information Service (NTIS)

The project envisages energy savings in the heating of civil and industrial buildings with the use of improved insulating materials, e.g. waterproofed against humidity and water vapor and protected against the attack of polluting agents in the atmosphere,...

L. Bocchi V. Castagnetta

1986-01-01

67

Get A Kit: Gather Emergency Supplies  

MedlinePLUS

... radio (NOAA Weather Radio, if possible) Extra batteries First aid kit Medications (7-day supply), other medical supplies, and ... and medical records stored in a waterproof container. First aid kit with a pet first aid book. Sturdy leash, ...

68

Wireless telemetry system for floating bodies  

NASA Technical Reports Server (NTRS)

Unit includes rugged waterproof cables and equipment containers, low power, sturdy antenna construction, and easy equipment setup and serviceability. Accuracy and reliability of entire measurement system were not sacrificed.

Fain, L. T.; Cribb, H. E.

1974-01-01

69

46 CFR 160.064-4 - Marking.  

Code of Federal Regulations, 2013 CFR

...buoyant device must have the following information clearly marked in waterproof lettering: (1) For devices to be worn: (Type II or Type III) Personal Flotation Device. Inspected and tested in accordance with U.S. Coast Guard...

2013-10-01

70

46 CFR 160.047-6 - Marking.  

Code of Federal Regulations, 2013 CFR

...vest must have the following information clearly marked in waterproof lettering that can be read at a distance of 2 feet: Type II Personal Flotation Device. Inspected and tested in accordance with U.S. Coast Guard regulations. (Kapok...

2013-10-01

71

Components of skin  

MedlinePLUS Videos and Cool Tools

... skin layers from the outside environment and contains cells that make keratin, a substance that waterproofs and strengthens the skin. The epidermis also has cells that contain melanin, the dark pigment that gives ...

72

Interface Modeling for Electro-Osmosis in Subgrade Structures.  

National Technical Information Service (NTIS)

Conventional waterproofing techniques for below grade structures are ineffective, expensive and short lived. Electro-Osmotic Pulse technology is an alternative technique to controlling moisture movement in porous medium. A research study was undertaken to...

S. W. Morefield M. K. McInerney V. F. Hock O. S. Marshall P. G. Malone

2004-01-01

73

Chemical Stabilization and Physicochemical Properties of Soils.  

National Technical Information Service (NTIS)

The major conclusion resulting from the waterproofer phase of the study was that Arquad 2 HT significantly improved the shear strength of granular materials containing small amounts of clay. The following conclusions were reached concerning the water vapo...

T. Demirel

1966-01-01

74

Director's Discretionary Fund Report for Fiscal Year 1996.  

National Technical Information Service (NTIS)

Topics covered include: Waterproofing the Space Shuttle tiles, thermal protection system for Reusable Launch Vehicles, computer modeling of the thermal conductivity of cometary ice, effects of ozone depletion and ultraviolet radiation on plants, a novel t...

1997-01-01

75

Fabrication Process of Blocks of Radioactive Wastes Encapsulated in Cement and Resistant to Leaching and Salt Solutions.  

National Technical Information Service (NTIS)

Waterproof additives are claimed to decrease water penetration through the cement such as silicone resins, latex emulsions or organic aluminium salts, avoiding leaching of radioactive wastes. (ERA citation 14:021761)

H. Holtz

1987-01-01

76

Repairing Your Flooded Home  

MedlinePLUS

... connection, clean the joint, and apply pipe joint compound or pipe tape (available at hardware stores) on ... with plastic or rubberized sheeting or special waterproofing compounds. Openings such as doors, windows, sewer lines, and ...

77

46 CFR 161.013-9 - Independent power source.  

Code of Federal Regulations, 2013 CFR

...is rechargeable, it must have a waterproof recharger designed for marine use. (c) If the independent power source requires external water to form an electrolyte, it must operate in sea water and fresh...

2013-10-01

78

46 CFR 161.006-4 - Requirements.  

Code of Federal Regulations, 2010 CFR

...equivalent, of a size not less than No. 16 AWG. At the point where the cable enters the searchlight, a waterproof entrance bushing with packing gland and cord grip shall be provided. (e) Lamp and socket. The motor lifeboat searchlight...

2009-10-01

79

46 CFR 161.006-4 - Requirements.  

Code of Federal Regulations, 2010 CFR

...equivalent, of a size not less than No. 16 AWG. At the point where the cable enters the searchlight, a waterproof entrance bushing with packing gland and cord grip shall be provided. (e) Lamp and socket. The motor lifeboat searchlight...

2010-10-01

80

Shingle system  

DOEpatents

A barrier, such as a PV module, is secured to a base by a support to create a shingle assembly with a venting region defined between the barrier and base for temperature regulation. Water resistant junctions may be formed between the bases of adjacent shingle assemblies of an array of shingle assemblies. The base may include an insulation layer underlying a water barrier. The base may also include a waterproofing element; the width and height of the barrier may be shorter than the width and height of the waterproofing element.

Dinwoodie, Thomas L. (Piedmont, CA) [Piedmont, CA

2008-02-12

81

Fluid-tight enclosure for geophone and cable  

Microsoft Academic Search

Positive waterproof seals are formed by clamping a flexible header between a metal top plate and the metal housing of a geophone enclosure. The ends of the cable are fed into conical-shaped supports of the flexible header through holes in a nylon stress ring and knotted. The bottom of the stress ring is forced against an annular lip, which clamps

McNeel

1976-01-01

82

NMR studies of molecular structure in fruit cuticle polyesters  

Microsoft Academic Search

The cuticle of higher plants functions primarily as a protective barrier for the leaves and fruits, controlling microbial attack as well as the diffusion of water and chemicals from the outside environment. Its major chemical constituents are waxes (for waterproofing) and cutin (a structural support polymer). However, the insolubility of cutin has hampered investigations of its covalent structure and domain

Xiuhua Fang; Feng Qiu; Bin Yan; Hsin Wang; Andrew J. Mort; Ruth E. Stark

2001-01-01

83

UROPYGIAL GLAND SIZE AND AVIAN HABITAT  

Microsoft Academic Search

The physiological role of the uropygial gland is still controversial. Certain authors state that its function could be closely connected to the hydrophobic properties of its secretion, that may be essential for plumage waterproofing. Therefore, it could be hypothesized that the degree of this gland's develop- ment should be greater in aquatic birds than in terrestrial species. In order to

Diego Montalti; Alfredo Salibián

84

46 CFR 160.061-3 - Design and construction.  

Code of Federal Regulations, 2010 CFR

...be prepared in pamphlet form, approximately 21/2 inches by 41/2 inches on parchment paper, in waterproof ink, with printing on one side of the paper only. The booklet shall contain a complete description of how and under what...

2009-10-01

85

46 CFR 160.061-3 - Design and construction.  

Code of Federal Regulations, 2010 CFR

...be prepared in pamphlet form, approximately 21/2 inches by 41/2 inches on parchment paper, in waterproof ink, with printing on one side of the paper only. The booklet shall contain a complete description of how and under what...

2010-10-01

86

New system for bathing bedridden patients  

NASA Technical Reports Server (NTRS)

Multihead shower facility can be used with minimal patient handling. Waterproof curtain allows patient to bathe with his head out of shower. He can move completely inside shower to wash his face and hair. Main advantage of shower system is time saved in giving bath.

Greenleaf, J. E.; Staley, R. A.; Payne, P. A.

1973-01-01

87

46 CFR 160.061-3 - Design and construction.  

Code of Federal Regulations, 2013 CFR

...prepared in pamphlet form, approximately 21/2 inches by 41/2 inches on parchment paper, in waterproof ink, with printing on one side of the paper only. The booklet shall contain a complete description of how and under what...

2013-10-01

88

Defeating the Drips.  

ERIC Educational Resources Information Center

Discusses a holistic approach to preventing moisture penetration of exterior walls in modular school buildings. The problem of roof leaks in modular structures is examined as are approaches to water management, roof waterproofing, the problem of condensation, and the design of heating, ventilation, and air conditioning systems as it affects water…

Moss, Lincoln

2000-01-01

89

49 CFR 178.521 - Standards for paper bags.  

Code of Federal Regulations, 2012 CFR

...waterproof ply or barrier, such as double-tarred kraft paper, plastics-coated kraft paper, plastics film bonded to the inner surface of the bag, or one or more inner plastics liners, must also be placed next to the substance. Seams...

2012-10-01

90

3-D Wizardry: Design in Papier-Mache, Plaster, and Foam.  

ERIC Educational Resources Information Center

Papier-mache, plaster, and foam are inexpensive and versatile media for 3-dimensional classroom and studio art experiences. They can be used equally well by elementary, high school, or college students. Each medium has its own characteristic. Papier-mache is pliable but dries into a hard, firm surface that can be waterproofed. Plaster can be…

Wolfe, George

91

Genetic Control of Cuticle Formation During Embryonic Development of Drosophila melanogaster  

Microsoft Academic Search

The embryonic cuticle of Drosophila melanogaster is deposited by the epidermal epithelium during stage 16 of development. This tough, waterproof layer is essential for maintaining the structural integrity of the larval body. We have characterized mutations in a set of genes required for proper deposition and\\/or morphogenesis of the cuticle. Zygotic disruption of any one of these genes results in

Stephen Ostrowski; Herman A. Dierick; Amy Bejsovec

92

49 CFR 173.185 - Lithium cells and batteries.  

Code of Federal Regulations, 2013 CFR

...batteries must be further packed in a strong outer packaging. The cells or batteries...section, and the equipment is packed in a strong outer packaging that is waterproof or...against short circuits and packed in a strong outer packaging conforming to the...

2013-10-01

93

The Vicenza Wearable Artificial Kidney for Peritoneal Dialysis (ViWAK PD)  

Microsoft Academic Search

Background: The study describes the structure and operational characteristics of a new wearable system for continuous ambulatory peritoneal dialysis (CAPD) for chronic kidney disease patients. Methods: We designed a wearable system consisting of: (1) a double lumen peritoneal catheter; (2) a dialysate outflow line; (3) a miniaturized rotary pump; (4) a circuit for dialysate regeneration featuring a waterproof container with

Claudio Ronco; Luciano Fecondini

2007-01-01

94

Design of an applied optical fiber process tomography system  

Microsoft Academic Search

In this paper, a novel optical fiber process tomography (OFPT) probe is developed; in which, eight optical fiber sensor units are uniformly distributed around the cylindrical container. Each unit comprises three optical fiber collimators, one photo detector and one optical window. The window is specially designed to make the light pass through and the container waterproof. All devices in the

Chunsheng Yan; Jing Zhong; Yanbiao Liao; Shurong Lai; Min Zhang; Dewen Gao

2005-01-01

95

Coatings for mullite insulation  

NASA Technical Reports Server (NTRS)

Series of coatings provides hard, impermeable, waterproof layer. Inclusion of color oxides imparts high emittance to surface. Refractory fillers investigated include TiO2, BaO.ZrO2, SrO.TiO2 ziron, spodumene, petalite, and kryptonite. Colorants include Cr2O3, NiO, and CoO.

Bolinger, P. N.; Rauch, H. W., Sr.

1976-01-01

96

Making a Canoe-Paddle.  

ERIC Educational Resources Information Center

Instructions on making a canoe paddle include types of wood to consider, choices of tools, how to determine paddle length, various designs, blade dimensions, smoothing, waterproofing, and storage. Explains how every aspect of the design is influenced by upper body strength, paddling experience, and personal preference. (TD)

Stevens, Rob

1996-01-01

97

Acute Pulmonary Toxicity Linked to Use of a Leather Protector  

Microsoft Academic Search

Leather protectors are used extensively for waterproofing leather garments. Inhalation exposure to this type of product is usually considered a benign incident. We report two cases of acute pulmonary toxicity associated with the use of a new leather protector recently introduced to the Canadian market. Emergency physicians must be aware of the potential acute toxicity of new leather protectors.[Laliberté M,

Martin Laliberté; Guy Sanfaçon; René Blais

1995-01-01

98

46 CFR 160.050-4 - Construction and workmanship.  

Code of Federal Regulations, 2010 CFR

...Specification for a Buoy, Life Ring, Unicellular Plastic § 160.050-4 Construction and workmanship...securely cemented to the buoy with a suitable waterproof adhesive which is compatible with the unicellular plastic used in the buoy body. The ends...

2009-10-01

99

46 CFR 160.050-4 - Construction and workmanship.  

Code of Federal Regulations, 2010 CFR

...Specification for a Buoy, Life Ring, Unicellular Plastic § 160.050-4 Construction and workmanship...securely cemented to the buoy with a suitable waterproof adhesive which is compatible with the unicellular plastic used in the buoy body. The ends...

2010-10-01

100

49 CFR 178.521 - Standards for paper bags.  

Code of Federal Regulations, 2011 CFR

...waterproof ply or barrier, such as double-tarred kraft paper, plastics-coated kraft paper, plastics film bonded to the inner surface of the bag, or one or more inner plastics liners, must also be placed next to the substance. Seams...

2011-10-01

101

49 CFR 178.521 - Standards for paper bags.  

Code of Federal Regulations, 2010 CFR

...waterproof ply or barrier, such as double-tarred kraft paper, plastics-coated kraft paper, plastics film bonded to the inner surface of the bag, or one or more inner plastics liners, must also be placed next to the substance. Seams...

2010-10-01

102

Physical and geotechnical properties of clay phyllites  

Microsoft Academic Search

An experimental programme is presented with the aim of characterising – from physical, microstructural and geotechnical perspectives – the main properties of compacted clay phyllites. These clay phyllites are widely used as waterproofing material for roofs in the Alpujarra (Andalusia, Spain), as sealing liners in irrigation ponds, and as core material of small earthen zoned dams. An exhaustive physical-characterisation programme

E. Garzón; P. J. Sánchez-Soto; E. Romero

2010-01-01

103

Marker and pen graffiti cleaning on diverse calcareous stones by different laser techniques  

Microsoft Academic Search

Industries nowadays continuously produce new types of inks for markers and pens, so new different graffiti appear . In this paper laser cleaning tests on 41 new marker and pen types ( fluorescent, permanent, water-based, acrylic tempera, metallic paint, waterproof inks ), applied into laboratory on different litho- type samples (Chianca, Travertino di Roma, Tufo Carparo fine grain, Sabbie), typical

S. E. Andriani; I. M. Catalano; G. Daurelio; A. Albanese

2007-01-01

104

Impact of air intrusion on the wind uplift performance of fully bonded roofing assemblies  

Microsoft Academic Search

Wind performance investigation is critical in the design of durable roofing assemblies. In North America, mainly two types of low slope roofs, conventional and inverted, are in practice depending on the placement of the membrane in the assembly. As part of the conventional low-sloped roofs, in a fully bonded assembly (FBA) the insulation is mechanically attached and waterproof membrane is

A. Baskaran; S. Molleti

2009-01-01

105

Hide And Seek GPS And Geocaching In The Classroom  

ERIC Educational Resources Information Center

In short, geocaching is a high-tech, worldwide treasure hunt (geocaches can now be found in more than 180 countries) where a person hides a cache for others to find. Generally, the cache is some type of waterproof container that contains a log book and an assortment of goodies, such as lottery tickets, toys, photo books for cachers to fill with…

Lary, Lynn M.

2004-01-01

106

Underwater Weapon System Having a Rotatable Gun.  

National Technical Information Service (NTIS)

This patent application discloses an underwater weapon system having a rotating gun system mounted in a vehicle housing. The gun system includes a gun and ammunition sealed within a waterproof housing with the gun muzzle protruding from the housing. The g...

T. J. Gieseke

2003-01-01

107

NEW TEACHER WELCOME PACK: ELEMENTARY SCHOOL  

NSDL National Science Digital Library

Assortment of "Best-Selling" books for Elementary School Teachers. Pack includes the following books. Picture Perfect Science, Exemplary Science Grades K-4, Uncovering Student Ideas in Science, Volume 1, Using Science Notebooks, and Everyday Science Mysteries. Books are packed into a waterproof, nylon briefcase with handle and shoulder strap. Front flap of briefcase is printed with the NSTA logo.

1900-01-01

108

Characterization of structural byzantine mortars by thermogravimetric analysis  

Microsoft Academic Search

The mortars and `cocciopesto' plasters were largely used in the historic buildings, as waterproof coverings and in the preparation of mortars, especially in horizontal structures. In recent years, the necessity of restoration interventions with materials which are compatible with the masonry structure requires a detailed study on these materials. In this study, the composition of a significative number of mortars

A Bakolas; G Biscontin; A Moropoulou; E Zendri

1998-01-01

109

Trials of the Manufacture and Machine Laying of Mastic Asphalt.  

National Technical Information Service (NTIS)

A series of trials was undertaken to investigate: the manufacture of mastic asphalt on a conventional rolled-asphalt mixing plant with an additional dryer, and the machine-laying of mastic asphalt. Both waterproofing-grade mastic asphalt and paving-grade ...

D. H. Mathews B. W. Ferne

1970-01-01

110

O/W microemulsion as a vehicle for sunscreens.  

PubMed

In recent years, transparent dispersions or diluted milks have been used as sunscreens. These products contain water-soluble sunscreen agents, and quite frequently are washed away from the skin. However, O/W microemulsions are now being prepared as transparent vehicles for sunscreens. They are waterproof, nonsticky, and easily spreadable. The microemulsions are prepared by using pseudoternary diagrams, by combining lipids with surfactant blends and a polar phase. Soya lecithin and decylpolyglucose produce transparent systems with the lowest percentage of surfactants. These microemulsions contain 4-methylbenzilidene camphor or octylmethoxycinnamate as sunscreen agents. Cyclomethicone, menthol, and allantoin give products a good skin feel, and stearyl methicone gives the waterproof effect. These systems show a Newtonian flux. Little permeation of the sunscreens' trough lipophilic and hydrophilic membrane is evidenced. PMID:14605687

Carlotti, M Eugenia; Gallarate, Marina; Rossatto, Valeria

2003-01-01

111

The behavior of pre-rusted steel in concrete  

SciTech Connect

This paper explores the possibility of an effective protection for precorroded steel by effect of the high alkalinity of the encasing mortar (by itself or in combination with the action of sodium nitrite). Application of a waterproof coating on the mortar surface was evaluated for this purpose. The behavior of clean steel electrodes and in three different pre-corrosion grades was characterized from periodic measurements of the corrosion potential (E{sub corr}) and polarization resistance (R{sub p}). Neither mortar alkalinity alone nor in combination with the effect of nitride ions was found to passivate the reinforcements in the two higher corrosion grades over 2 years of exposure in an atmosphere of a high relative humidity. Also, immersion of the specimens in a 5% NaNO{sub 2} solution was found not to passivate steel undergoing active corrosion. The effectiveness of the waterproofing treatment for diminishing reinforcement corrosion was found to rely heavily on timely application.

Gonzalez, J.A.; Bautista, A.; Feliu, S. [Centro Nacional de Investigaciones Metalurgicas, Madrid (Spain)] [Centro Nacional de Investigaciones Metalurgicas, Madrid (Spain); Ramirez, E. [Pontificia Universidad Catolica, Lima (Peru)] [Pontificia Universidad Catolica, Lima (Peru)

1996-03-01

112

A lichen protected by a super-hydrophobic and breathable structure.  

PubMed

A species of lichen, Lecanora conizaeoides, is shown to be super-hydrophobic. It uses a combination of hydrophobic compounds and multi-layered roughness to shed water effectively. This is combined with gas channels to produce a biological analogue of a waterproof, breathable garment. The particular lichen grows mostly during wet seasons and is unusually resistant to acid rain [Hauck, M., 2003. The Bryologist 106(2), 257-269; Honegger, R., 1998. Lichenologist 30(3),193-212]. The waterproof, breathable surface allows this lichen to photosynthesise when other species are covered with a layer of water. In addition, rainwater runs off the surface of the organism, reducing its intake of water from above and probably contributing to its resistance to acid rain. PMID:16434121

Shirtcliffe, Neil J; Brian Pyatt, F; Newton, Michael I; McHale, Glen

2006-11-01

113

Use of epoxy compounds in structural elements and insulation in the Kislogubsk tidal power station  

Microsoft Academic Search

Conclusions  \\u000a \\u000a \\u000a \\u000a 1. \\u000a \\u000a Epoxy foam heat-and-water insulation and epoxy-pitch waterproofing have been found to be suitable for structures in regions\\u000a with a severe climate, and in particular for tidal power stations built by the floating method.\\u000a \\u000a \\u000a \\u000a \\u000a 2. \\u000a \\u000a Industrial experience in the construction of the Kislogubsk tidal power station has shown the advantages of using epoxy plastic\\u000a solutions for constructing waterproofing seams

L. A. Igonin; P. A. Pshenitsyn; V. I. Sakharov

1971-01-01

114

Characterization of Glossy1 -homologous genes in rice involved in leaf wax accumulation and drought resistance  

Microsoft Academic Search

The outermost surfaces of plants are covered with an epicuticular wax layer that provides a primary waterproof barrier and\\u000a protection against different environmental stresses. Glossy 1 (GL1) is one of the reported genes controlling wax synthesis. This study analyzed GL1-homologous genes in Oryza sativa and characterized the key members of this family involved in wax synthesis and stress resistance. Sequence

Mohammad Asadul Islam; Hao Du; Jing Ning; Haiyan Ye; Lizhong Xiong

2009-01-01

115

Smart temperature-controlled water vapor permeable polyurethane film  

Microsoft Academic Search

Aim of this study was to develop a temperature-controlled polyurethane (PU) film for the application in film coated clothes. The PU film should be a smart one that can control its water vapor permeability (WVP) through temperature change. The study was carried out by increasing the water vapor permeability of various breathable\\/waterproof PU films through variations of their hard-to-soft-segment ratio,

Chia-Yen Lin; Ken-Hsuan Liao; Cheng-Feng Su; Chao-Hui Kuo; Kuo-Huang Hsieh

2007-01-01

116

Condition Assessment Survey (CAS) Program. Deficiency standards and inspections methods manual: Volume 1, 0.01 Foundations and footings  

SciTech Connect

General information is presented for asset determinant factor/CAS repair codes/CAS cost factors; guide sheet tool & material listing; testing methods; inspection frequency; standard system design life tables; system work breakdown structure; and general system/material data. Deficiency standards and inspection methods are given for footings - spread/strip/grade beams; foundation walls; foundation dampproofing/waterproofing; excavation/backfill/ and piles & caissons.

Not Available

1993-05-01

117

The Sensor Fish: Measuring Fish Passage in Severe Hydraulic Conditions  

SciTech Connect

This article describes PNNL's efforts to develop the Sensor Fish, a waterproof sensor package that travels thru the turbines of spillways of hydroelectric dam to collect pressure and acceleration data on the conditions experienced by live salmon smolts during dam passage. Sensor Fish development is sponsored by the DOE Advanced Hydropower Turbine Survival Program. The article also gave two recent examples of Sensor Fish use: turbine passage at a McNary Kaplan turbine and spill passage in topspill at Rock Island Dam.

Carlson, Thomas J. (BATTELLE (PACIFIC NW LAB)); Duncan, Joanne P. (BATTELLE (PACIFIC NW LAB)); Gilbride, Theresa L. (BATTELLE (PACIFIC NW LAB))

2003-05-28

118

NEW TEACHER WELCOME PACK: HIGH SCHOOL  

NSDL National Science Digital Library

Assortment of "Best Selling" books for High School Science Teachers. Pack includes the following books. Investigating Safely, Science Educator's Guide to Laboratory Assessment, How to Write to Learn Science, Science as Inquiry in the Secondary Setting, and The Biologist's Handbook. Books are packed into a waterproof, nylon briefcase with handle and shoulder strap. Front flap of briefcase is printed with the NSTA logo. Includes free sample of the journal, The Science Teacher .

1900-01-01

119

NEW TEACHER WELCOME PACK: MIDDLE SCHOOL  

NSDL National Science Digital Library

Assortment of "Best Selling" books for Middle School Science Teachers. Pack includes the following books. Help! I'm Teaching Middle School Science, Exemplary Science Grades 5-8, Uncovering Student Ideas in Science, Volume 2, Doing Good Science in Middle School, Stop Faking It: Force and Motion. Books are packed into a waterproof, nylon briefcase with handle and shoulder strap. Front flap of briefcase is printed with the NSTA logo. Includes a free sample of the journal, Science Scope .

1900-01-01

120

Online dynamic measurement of saturation-capillary pressure relation in sandy medium under water level fluctuation  

Microsoft Academic Search

An online dynamic method based on electrical conductivity probe, tensiometer and datataker was presented to measure saturation-capillary\\u000a pressure (S-p) relation in water-light nonaqueous phase liquid (LNAPL) two-phase sandy medium under water level fluctuation. Three-electrode\\u000a electrical conductivity probe (ECP) was used to measure water saturation. Hydrophobic tensiometer was obtained by spraying\\u000a waterproof material to the ceramic cup of commercially available hydrophilic

Yan Li; Jin-feng Zhou; Jun Xu; M. Kamon

2010-01-01

121

Development and characterization of poly ethyl metha acrylate–iron oxide(III) based hydrophobic liquid nanocomposite films  

Microsoft Academic Search

Select applications of hydrophobic nanocomposites include preparation of robust self-cleaning surfaces, water-repellent glass surfaces, and waterproofing textiles. Various nanocomposites have been reported in the literature; however, the relationship between the nanocomposite surface morphology and its hydrophobicity needs to be understood better. In the present work Fe2O3 nanoparticles and poly ethyl metha acrylate (PEMA) were used in varying proportions to obtain

Munish Kumar Sharma; Sandip Roy; Kartic Chandra Khilar

2009-01-01

122

BotEC: Weight of Gold  

NSDL National Science Digital Library

Question Let's suppose that you have a shoe box full of water (the box is waterproof, of course). The shoe box weighs about 9 kg (19.8 pounds). Suppose you emptied the box and filled it completely with rock (little or no air space). How much would it weigh? Let's empty the box again and fill it completely with pure gold. How much would the box weigh now?

Tewksbury, Barb

123

Rewaterproofing Chemical For Use With Silicones  

NASA Technical Reports Server (NTRS)

Agent restores impermeability without degrading silicone adhesives and substructures. Dimethylethoxysilane (DMES) found to rewaterproof tiles and composite panels internally without harming materials that underlie them. Replaces hexamethyldisilazane (HMDS) as postmission rewaterproofing agent for tiles of thermal-protection system on Space Shuttle. Much of original waterproofing lost during rigors of launch and reentry. Potential terrestrial application includes composite materials in such structures as bridges and submarines.

Hill, William L.; Mitchell, Shirley M.; Massey, Howard S.

1990-01-01

124

Ingrown toenail treated with cotton collodion insert.  

PubMed

Separating the distal anterior tip and lateral edges of an ingrown toenail from the adjacent soft tissue with a wisp of absorbent cotton coated with collodion gives immediate relief of pain and provides a firm runway for further growth of the nail. The collodion coating fixes the cotton in place, waterproofs, and permits bathing. This simple office method was successfully used on 86 private patients. It is not applicable in patients with infected acute paronychia. PMID:2037270

Ilfeld, F W

1991-04-01

125

Design of Intelligent Water Vision System  

Microsoft Academic Search

This paper proposes intelligent Water Vision System(IWVS) that can analyze and process the vision underwater by filming various underwater environments with multi-directional underwater camera that is specifically waterproofed. The existing underwater camera filming method had the weakness in acquiring only one side of vision with single-directional under water camera. Thus this the paper proposed a system in which vision data

Tae-Kwan Jang; Eun-Ju Kim; Dae-Kyeong Kim; Ye-Seul Han; Yoon-Soo Seo; Hyun-Sik Cho; Byung-Soo Lee

2010-01-01

126

Water loss and nitrogen excretion in sharp-nosed reed frogs (Hyperolius nasutus: anura, Hyperoliidae).  

PubMed

Sharp-nosed African reed frogs, Hyperolius nasutus Gunther, are small (0.4 g) hyperoliids which have minimal rates of evaporative water loss (4.5 mg g-1 h-1; 0.3 mg cm-2 h-1) that are only 1/10 to 1/20 that of a typical frog, Hylaregilla, of comparable size (171 mg g-1 h-1, 4.8 mg cm-2 h-1). The surface-area-specific resistance to water flux of H. nasutus dorsal skin (96-257 sec cm-1) is similar to that of other 'waterproof' frogs (300-400), of cocooned frogs (40-500), and of desert reptiles (200-1400). However, H. nasutus can greatly increase the rate of evaporative water loss during radiative heat stress by mucous gland discharge, and by exposing the ventral skin. Urea is the principal nitrogenous waste product of H. nasutus and uric acid comprises less than 1% of the total nitrogen excretion for both H. nasutus and H. regilla. Other 'waterproof' frogs, in contrast, are uricotelic. Lethal dehydration requires less than two weeks in H. nasutus, despite its low surface-area-specific rate of water loss, because of its small size and concomitantly high surface-to-volume ratio. The rate of urea accumulation during dehydration was 23 mM g-1 day-1, which is sufficiently low that urea accumulation would not be lethal before the frog had succumbed to dehydrational death. Consequently, there appears to be little or no selective advantage for uricotely in small 'waterproof' frogs, such as H. nasutus. PMID:7086345

Withers, P C; Hillman, S S; Drewes, R C; Sokol, O M

1982-04-01

127

Integrated residential photovoltaic array development  

NASA Technical Reports Server (NTRS)

The design details of an optimized integrated residential photovoltaic module/array are presented. This selected design features a waterproofing and mounting scheme which was devised to simplify the installation procedures by the avoidance of complex gasketed or caulked joints, while still maintaining a high confidence that the watertight integrity of the integral roofing surface will be achieved for the design lifetime of the system. The production and installation costs for the selected module/array design are reported for a range of annual production rates as a function of the cost of solar cells.

Shepard, N. F., Jr.

1981-01-01

128

Modular hydro dam approach to the economic development of ultra low-head hydropower  

NASA Astrophysics Data System (ADS)

The potential for developing economical new ultra low head sites using an innovative concept known as the modular hydro dam (MHD) were explored. This concept, combines the benefits of shop fabrication and installation of equipment in truck transportable, waterproof power modules, with prefabricated gate sections that can be located between the power modules. The technical, economic, environmental, and institutional feasibility of the MHD concept are examined. Capital and operating costs are estimated. It is concluded that the potential for power generation at ultralow head sites justifies the development of the MHD concept.

Broome, K. R.

1981-06-01

129

Superhydrophobic Materials Technology-PVC Bonding Techniques  

SciTech Connect

The purpose of the technology maturation project was to develop an enhanced application technique for applying diatomaceous earth with pinned polysiloxane oil to PVC pipes and materials. The oil infiltration technique is applied as a spray of diluted oil in a solvent onto the superhydrophobic diatomaceous earth substrate. This makes the surface take on the following characteristics: • wet?cleanable • anti?biofouling • waterproof • anti?corrosion. The project involved obtaining input and supplies from VeloxFlow and the development of successful techniques that would quickly result in a commercial license agreement with VeloxFlow and other companies that use PVC materials in a variety of other fields of use.

Hunter, Scott R. [Oak Ridge National Laboratory; Efird, Marty [VeloxFlow, LLC

2013-05-03

130

Disappearing Statues  

NSDL National Science Digital Library

In this activity (on page 8), learners model how marble statues and buildings are affected by acid rain. Antacid tablets made with calcium carbonate are used to represent marble (also made from calcium carbonate), and vinegar is used to represent acid rain. Learners observe the effect of adding water to one tablet and vinegar to another. The tablets can be made into slightly more realistic models by drawing on them with a pencil, or rubber stamping a design with waterproof ink. This activity could be used in connection with lessons on pollution and acid rain, or lessons on art and architecture.

Society, American C.

2008-01-01

131

Sources and transport of silicone NVR  

NASA Technical Reports Server (NTRS)

The retrieved LDEF had varying amounts of visible contamination films (brown stains) at many locations. FTIR spectra of heavy film deposits at vents and of optical windows from tray E5 indicated methyl silicone and silica in the contaminant films. Two possible sources of the methyl silicone are DC-710 phenyl methyl silicone in the shuttle-bay-liner beta cloth, and the shuttle tile waterproofing silane. It is concluded that much of the silicon and silica contamination came from ground operations and the orbiter.

Harvey, Gale A.

1992-01-01

132

Flood Resilient Technological Products  

NASA Astrophysics Data System (ADS)

As a consequence of the paradigm shift of the EU water policy (Directive 2007/60/EC, EC 2003) from defense to living with flood, floods shall be faced in the future through resilient solutions, seeking to improve the permanence of flood protection, and getting thus beyond traditional temporary and human-relying solutions. But the fact is that nowadays "Flood Resilient (FRe) Building Technological Products" is an undefined concept, and concerned FRe solutions cannot be even easily identified. "FRe Building Technological materials" is a wide term involving a wide and heterogeneous range of solutions. There is an interest in offering an identification and classification of the referred products, since it will be useful for stakeholders and populations at flood risk for adopting the most adequate protections when facing floods. Thus, a previous schematic classification would enable us at least to identify most of them and to figure out autonomous FRe Technological Products categories subject all of them to intense industrial innovative processes. The flood resilience enhancement of a given element requires providing it enough water-repelling capacity, and different flood resilient solutions can be sorted out: barriers, waterproofing and anticorrosive. Barriers are palliative solutions that can be obtained either from traditional materials, or from technological ones, offering their very low weight and high maneuverability. Belonging barriers and waterproofing systems to industrial branches clearly different, from a conceptual point of view, waterproofing material may complement barriers, and even be considered as autonomous barriers in some cases. Actually, they do not only complement barriers by their application to barriers' singular weak points, like anchors, joints, but on the other hand, waterproofing systems can be applied to enhance the flood resilience of new building, as preventive measure. Anticorrosive systems do belong to a clearly different category because their function do not consist in repelling water, but in preventing damages caused by the watery contact. Finally, others preventive flood resilient technologies could also be considered, since forecasting, near-casting and warning alert are solutions getting more and more involved in flood resilience strategies.

Diez Gonzalez, J. J.; Monnot, J. V.; Marquez Paniagua, P.; Pámpanas, P.; Paz Abuín, S.; Prendes, P.; Videra, O.; U. P. M. Smartest Team

2012-04-01

133

Development of Air Speed Nozzles  

NASA Technical Reports Server (NTRS)

Report describes the development of a suitable speed nozzle for the first few thousand airplanes made by the United States during the recent war in Europe, and to furnish a basis for more mature instruments in the future. Requirements for the project were to provide a suitable pressure collector for aircraft speed meters and to develop a speed nozzle which would be waterproof, powerful, unaffected by slight pitch and yaw, rugged and easy to manufacture, and uniform in structure and reading, so as not to require individual calibration.

Zahm, A F

1920-01-01

134

Just Add Water!  

NSDL National Science Digital Library

This activity gives students a look at the rugged terrain of the ocean floor. Using modeling clay, students create a landform model complete with mountain ridges, plateaus, rivers, and canyons in a large waterproof pan. Then they pour in blue-tinted water to see that the ocean is simply flooded land with many of the same landforms found above water. The activity includes an extension that has students explore the heights of various underwater formations with a topological map of the ocean floor and then compare them to the heights of buildings or landforms.

135

Composite Riflescope  

NASA Technical Reports Server (NTRS)

Bushnell Division of Bausch & Lomb's Armor-Sight riflescope combines the company's world-renowned optics with a graphite composite (Graphlon VI) developed for space applications. The riflescope is 10 percent lighter than aluminum scopes, and, because its thermal expansion coefficient is near zero, optical distortion from heat and cold extremes is eliminated. It is fogproof and waterproof; advanced multicoated optics provide maximum light transmission to brighten target ranges. Bushnell was assisted by NIAC/USC in searching for technical information on graphic composites and in overcoming difficulties with bonding and porosity.

1989-01-01

136

Give Me Some Skin: A Hands-On Science Activity Integrating Racial Sensitivity  

NSDL National Science Digital Library

What's the largest, fastest growing, organ in the human body? It's the tough, elastic, flexible, and waterproof covering that helps protect other organs and body parts from such things as germs, heat, cold, and sunlight--skin, of course! This life science activity engages middle school students in an exploration of the structure, function, and variety of skin. They "construct" skin layer by layer using simple materials such as felt, foam padding, yarn, and vinyl in various skin tones. This activity provides an opportunity to discuss racial diversity and to show students that skin color is, quite literally, only skin deep.

Houtz, Lynne E.; Quinn, Thomas H.

2003-02-01

137

Fire Resistant, Moisture Barrier Membrane  

NASA Technical Reports Server (NTRS)

A waterproof and breathable, fire-resistant laminate is provided for use in tents, garments, shoes, and covers, especially in industrial, military and emergency situations. The laminate permits water vapor evaporation while simultaneously preventing liquid water penetration. Further, the laminate is fire-resistant and significantly reduces the danger of toxic compound production when exposed to flame or other high heat source. The laminate may be applied to a variety of substrates and is comprised of a silicone rubber and plurality of fire-resistant, inherently thermally-stable polyimide particles.

St.Clair, Terry L. (Inventor)

2000-01-01

138

Fire Resistant, Moisture Barrier Membrane  

NASA Technical Reports Server (NTRS)

A waterproof and breathable, fire-resistant laminate is provided for use in tents, garments, shoes, and covers, especially in industrial, military and emergency situations. The laminate permits water vapor evaporation while simultaneously preventing liquid water penetration. Further, the laminate is fire-resistant and significantly reduces the danger of toxic compound production when exposed to flame or other high heat source. The laminate may be applied to a variety of substrates and is comprised of a silicone rubber and plurality of fire-resistant, inherently thermally-stable polyimide particles.

St.Clair, Terry L. (Inventor)

1998-01-01

139

PCB concentrations in Pere Marquette River and Muskegon River watersheds, 2002  

USGS Publications Warehouse

Polychlorinated biphenyl compounds (PCBs) are a class of209 individual compounds (known as congeners) for which there are no known natural sources. PCBs are carcinogenic and bioaccumulative compounds. For over 40 years, PCBs were manufactured in the United States. The flame resistant property of PCBs made them ideal chemicals for use as flame-retardants, and as coolants and lubricants in transformers and other electrical equipment. PCBs were also used in heating coils, carbonless paper, degreasers, varnishes, lacquers, waterproofing material, and cereal boxes. In addition, they were frequently used in the manufacturing of plastics, adhesives, and paints.

Fogarty, Lisa R.

2005-01-01

140

Microfabricated environmental barrier using ZnO nanowire on metal mesh  

NASA Astrophysics Data System (ADS)

In this study, a waterproof environmental barrier for microsensor package has been developed using metal mesh covered with zinc oxide (ZnO) nanowire. A near superhydrophobic surface with two-dimensional array of holes has been fabricated by hydrothermal growth of ZnO nanowire on an off-the-shelf steel use stainless (SUS) mesh. For a twill-woven SUS wire mesh having wire thickness of 30 µm and gap of 33 µm, a maximum contact angle of 160.40° and a minimum contact angle hysteresis of 15.23° have been achieved using ZnO nanowire grown on the wire surface and further deposition of FC film. The mesh was able to withstand a maximum water pressure of 2,459.8 Pa. The measured height of ZnO nanowire was approximately 2-3 µm. The fabricated SUS mesh covered with ZnO nanowire has been assembled with a microphone package, and waterproof characteristics have been measured by cyclic dipping test at various water levels. For a microphone package having two acoustic ports on top and bottom covered with fabricated mesh, no visible change in acoustic characteristics has been observed up to 1,372.9 Pa of water pressure. Total volume of the package was 6.8 × 9.8 × 1.9 mm3.

Shin, Young-Min; Lee, Seung-Ki; Lee, Joo-Yong; Kim, Jun-Ho; Park, Jae-Hyoung; Ji, Chang-Hyeon

2013-12-01

141

An instrument for measuring bacterial penetration through fabrics used for barrier clothing.  

PubMed Central

A new instrument has been designed to measure the penetration by rubbing of bacteria from cloth contaminated in the nursing of burn patients through fabrics designed for barrier garments. Most fabrics tested dry reduced the transfer of bacteria from the source cloth to about 10%, irrespective of the results of air filter tests, which agrees with mock nursing results. When the fabrics were tested against a wet surface, the transfer of bacteria rapidly reached 100% if the fabrics had a high wettability, but was slower for fabrics with a low wettability. Through closely woven waterproofed cotton, transfer was 5--25%, but increased three- to four-fold after ten launderings, in line with the water absorption. Transfer through plastic-laminated material was less than 1%. The results suggest that barrier garments should be made either of plastic or of recently waterproofed closely woven cotton at points of contact between nurse and patient where the clothes may be wetted by bacteria-containing wound secretions. Images Plate 1

RansjA?, U.; Hambraeus, A.

1979-01-01

142

Make a Watershed Model  

NSDL National Science Digital Library

Students will create a three-dimensional model from a two-dimensional topographic map. They will use the model to trace the path that a water droplet takes across the watershed and into the watercourse, and will describe the relationship between the physical features of the watershed and the location of human activities. Resources needed vary, depending on the kind of model that is to be build, but may include: a topographic map of the local watershed, tracing paper, tempera paints, paint brushes, cutting knife or saw, plaster of Paris or paper maché, plasticene or other waterproofing, and corrugated cardboard, plywood or other media from which to cut layers representing each of the contour intervals. This activity is part of the Ground Truth Studies Teacher Handbook, which provides more than 20 activities to build student understanding of global change and remote sensing, and includes background chapters for teachers, glossary, and appendices. Resources needed vary, depending on the kind of model that is to be build, but may include: a topographic map of the local watershed, tracing paper, tempera paints, paint brushes, cutting knife or saw, plaster of Paris or paper maché, plasticene or other waterproofing, and corrugated cardboard, plywood or other media from which to cut layers representing each of the contour intervals.

143

Constructing earth sheltered housing with concrete  

SciTech Connect

This manual provides a state - of - the - art review of the design and construction of an earth - sheltered house using cast - in - place concrete, precast concrete, and concrete masonry. Based on a literature survey, theoretical work, and discussions with researchers and engineers in the concrete industry, the text is designed for use by architects, engineers, and homebuilders. The features of concrete construction that are current accepted practice for the concrete products discussed are shown to be applicable with reasonable care to building a safe, dry, and comfortable earth - sheltered house. The main considerations underlying the recommendations were the use of the earth's mass and passive solar effects to minimize energy needs, the structural capacity of the separate concrete products and their construction methods, and drainage principles and waterproofing details. Shelter ranging from those with at least 2 feet of earth cover to those with an uncovered roof of usual construction are included. To be considered an earth - sheltered residential building, at least half of the exterior wall and roof area that is in direct contact with the conditioned living space must be sheltered from the environment by earth berm or earthfill. Siting considerations, the fundamentals of passive solar heating, planning considerations, and structural considerations are discussed. Detailed guidelines are provided on concrete masonry construction, joint details in walls and floors, waterproofing, formwork and form removal, concrete construction practices, concrete masonry, and surface finishes. Numerous illustrations, tables, and a list of 32 references are provided. (Author abstract modified).

Spears, R.E.

1981-01-01

144

The Ancient Wood of the Acqualadrone Rostrum: A Materials History Through GC-MS and Sulfur X-ray Absorption Spectroscopy  

PubMed Central

In 2008 the rostrum from an ancient warship was recovered from the Mediterranean near Acqualadrone, Sicily. To establish its provenance and condition, samples of black and brown rostrum wood were examined using sulfur K-edge x-ray absorption spectroscopy (XAS) and GC-MS. GC-MS of pyrolytic volatiles yielded only guaiacyl derivatives, indicating construction from pinewood. A derivatized extract of black wood yielded forms of abietic acid and sandaracopimaric acid consistent with pine pitch waterproofing. Numerical fits to the sulfur K-edge XAS spectra showed that about 65% of the endogenous sulfur consisted of thiols and disulfides. Elemental sulfur was about 2% and 7% in black and brown wood, respectively, while pyritic sulfur was about 12% and 6%. About 2% of the sulfur in both wood types was modeled as trimethylsulfonium, possibly reflecting biogenic dimethylsulfonio-propionate. High valent sulfur was exclusively represented by sulfate esters, consistent with bacterial sulfotransferase activity. Traces of chloride were detected, but no free sulfate ion. In summary, the rostrum was manufactured of pine wood and subsequently waterproofed with pine pitch. The subsequent 2300 years included battle, foundering, and marine burial followed by anoxia, bacterial colonization, sulfate reduction, and mobilization of transition metals, which produced pyrite and copious appended sulfur functionality.

Frank, Patrick; Caruso, Francesco; Caponetti, Eugenio

2012-01-01

145

Analysis of yellow ``fat'' deposits on Inuit boots  

NASA Astrophysics Data System (ADS)

Irregular residues of a yellow deposit that was assumed to be seal fat used for waterproofing were observed in the creases of the outer surface of a pair of Inuit boots from Arctic Canada. A sample of this deposit detached from one of these areas on these boots was examined initially by FT-Raman microscopy, from which interesting and rather surprising results demanded further analysis using FT-IR and GC-MS. The non-destructive Raman spectroscopic analysis yielded spectra which indicated the presence of a tree resin from the Pinaceae sp. The Raman spectra were also characteristic of a well-preserved keratotic protein and indicative of adherent skin. Subsequent FT-IR spectroscopic analysis supported the attribution of a Pinaceae resin to the yellow deposit. GC-MS analysis of the same deposits identified the presence of pimaric, sandaracopimaric, dehydroabietic and abietic acids, all indicative of an aged Pinaceae resin. These results confirmed that the Inuit people had access to tree resins which they probably used as a waterproofing agent.

Edwards, Howell G. M.; Stern, Ben; Burgio, Lucia; Kite, Marion

2009-08-01

146

A pilot study on the refinement of acute inhalation toxicity studies: the isolated perfused rat lung as a screening tool for surface-active substances.  

PubMed

New surface-active agents in waterproofing sprays are frequently tested for acute inhalation toxicity in vivo according to OECD Test Guideline 403. In order to refine and reduce the number of acute inhalation tests performed, we propose a screening test that uses isolated lungs. The test consists of the exposure of isolated, ventilated and perfused rat lungs, to aerosolised formulations of waterproofing agents (mass median aerodynamic diameter = 1?m), and on-line monitoring of respiratory parameters and gross pathology analysis. A pilot evaluation of the isolated perfused rat lung model for use in a screening test was carried out by blind testing 12 surface-active substances. The results obtained compared well with data available from in vivo acute inhalation studies. Substances that triggered harmful effects, such as impaired lung compliance and atelectasis of the isolated perfused lung, were also found to cause changes in respiratory parameters, some of which would be severe enough to lead to death in in vivo tests with rats. The changes in respiratory parameters suggest that the mode-of-action is associated with impairment of the surfactant layer. Therefore, pre-testing in the isolated perfused rat lung allows the identification of surface-active substances with the potential for causing acute inhalation toxicity. PMID:23067301

Fischer, Monika; Koch, Wolfgang; Windt, Horst; Dasenbrock, Clemens

2012-09-01

147

Ancient wood of the Acqualadrone rostrum: materials history through gas chromatography/mass spectrometry and sulfur X-ray absorption spectroscopy.  

PubMed

In 2008 the rostrum from an ancient warship was recovered from the Mediterranean near Acqualadrone, Sicily. To establish its provenance and condition, samples of black and brown rostrum wood were examined using sulfur K-edge X-ray absorption spectroscopy (XAS) and gas chromatography/mass spectrometry (GC/MS). GC/MS of pyrolytic volatiles yielded only guaiacyl derivatives, indicating construction from pinewood. A derivatized extract of black wood yielded forms of abietic acid and sandaracopimaric acid consistent with pine pitch waterproofing. Numerical fits to the sulfur K-edge XAS spectra showed that about 65% of the endogenous sulfur consisted of thiols and disulfides. Elemental sulfur was about 2% and 7% in black and brown wood, respectively, while pyritic sulfur was about 12% and 6%. About 2% of the sulfur in both wood types was modeled as trimethylsulfonium, possibly reflecting biogenic (dimethylsulfonio)propionate. High-valent sulfur was exclusively represented by sulfate esters, consistent with bacterial sulfotransferase activity. Traces of chloride were detected, but no free sulfate ion. In summary, the rostrum was manufactured of pine wood and subsequently waterproofed with pine pitch. The subsequent 2300 years included battle, foundering, and marine burial followed by anoxia, bacterial colonization, sulfate reduction, and mobilization of transition metals, which produced pyrite and copious appended sulfur functionality. PMID:22545724

Frank, Patrick; Caruso, Francesco; Caponetti, Eugenio

2012-05-15

148

Body wiping behaviors associated with cutaneous lipids in hylid tree frogs of Florida.  

PubMed

Body wiping behavior, integumentary secretions and rates of evaporative water loss (EWL) were examined in six species of Florida tree frogs (Anura: Hylidae). Additionally, morphology of the integument and dermal glands were compared among these and one other Florida tree frog (Hyla andersonii), an arid-adapted tree frog (Phyllomedusa hypochondrialis), and a highly aquatic frog (Rana utricularia). An extra-epidermal layer of lipid and mucus, presumably secreted from dermal granular glands, was detected on the skin of all Florida hylid frogs examined. Distinct body wiping behaviors were observed in the hylid frogs, but these were less complex than those described previously in phyllomedusine frogs, which occupy arid habitats, secrete lipids onto their skin, and are regarded as relatively 'waterproof'. Florida hylids occupy seasonally arid habitats and appear to have reduced rates of EWL. The suite of traits we observed in these frogs have been previously documented in a rhacophorid tree frog from seasonally arid regions of India and likely represent an evolutionary convergent response to periodic dehydration stress. The presence of lipids that are spread by simple wiping behaviors to form an extra-epidermal water barrier may represent an early stage of the more advanced adaptations described in more waterproof arboreal frogs. PMID:15914658

Barbeau, Tamatha R; Lillywhite, Harvey B

2005-06-01

149

A vision-based tool for the control of hydraulic structures in sewer systems  

NASA Astrophysics Data System (ADS)

During rain events, the total amount of the wastewater/storm-water mixture cannot be treated in the wastewater treatment plant; the overflowed water goes directly into the environment (lakes, rivers, streams) via devices called combined sewers overflows (CSOs). This water is untreated and is recognized as an important source of pollution. In most cases, the quantity of overflowed water is unknown due to high hydraulic turbulences during rain events; this quantity is often significant. For this reason, the monitoring of the water flow and the water level is of crucial environmental importance. Robust monitoring of sewer systems is a challenging task to achieve. Indeed, the environment inside sewers systems is inherently harsh and hostile: constant humidity of 100%, fast and large water level changes, corrosive atmosphere, presence of gas, difficult access, solid debris inside the flow. A flow monitoring based on traditional probes placed inside the water (such as Doppler flow meter) is difficult to conduct because of the solid material transported by the flow. Probes placed outside the flow such as ultrasonic water level probes are often used; however the measurement is generally done on only one particular point. Experience has shown that the water level in CSOs during rain events is far from being constant due to hydraulic turbulences. Thus, such probes output uncertain information. Moreover, a check of the data reliability is impossible to achieve. The HydroPix system proposes a novel approach to the monitoring of sewers based on video images, without contact with the water flow. The goal of this system is to provide a monitoring tool for wastewater system managers (end-users). The hardware was chosen in order to suit the harsh conditions of sewers system: Cameras are 100% waterproof and corrosion-resistant; Infra-red LED illumination systems are used (waterproof, low power consumption); A waterproof case contains the registration and communication system. The monitoring software has the following requirements: visual analysis of particular hydraulic behavior, automatic vision-based flow measurements, automatic alarm system for particular events (overflows, risk of flooding, etc), database for data management (images, events, measurements, etc.), ability to be controlled remotely. The software is implemented in modular server/client architecture under LabVIEW development system. We have conducted conclusive in situ tests in various sewers configurations (CSOs, storm-water sewerage, WWTP); they have shown the ability of the HydroPix to perform accurate monitoring of hydraulic structures. Visual information demonstrated a better understanding of the flow behavior in complex and difficult environment.

Nguyen, L.; Sage, D.; Kayal, S.; Jeanbourquin, D.; Rossi, L.

2009-04-01

150

Preparation of porous super-hydrophobic and super-oleophilic polyvinyl chloride surface with corrosion resistance property  

NASA Astrophysics Data System (ADS)

Porous super-hydrophobic polyvinyl chloride (PVC) surfaces were obtained via a facile solvent/non-solvent coating process without introducing compounds with low surface energy. The microstructure, wetting behavior, and corrosion resistance of resultant super-hydrophobic PVC coatings were investigated in relation to the effects of dosage of glacial acetic acid and the temperature of drying the mixed PVC solution spread over glass slide substrate. As-prepared PVC coatings had porous microstructure, and the one obtained at a glacial acetic acid to tetrahydrofuran volume ratio of 2.5:10.0 and under a drying temperature of 17 °C had a water contact angle of 150 ± 1.5°, showing super-hydrophobicity. In the meantime, it possessed very small contact angles for liquid paraffin and diiodomethane and good corrosion resistance against acid and alkali corrosive mediums, showing promising applications in self-cleaning, waterproof for outer wall of building, seawater resistant coating, and efficient separation of oil and water.

Kang, Yingke; Wang, Jinyan; Yang, Guangbin; Xiong, Xiujuan; Chen, Xinhua; Yu, Laigui; Zhang, Pingyu

2011-11-01

151

Rad Pole Cam Development  

SciTech Connect

The RadPoleCam was developed to provide Department Of Energy (DOE) first responders the capability to assess the radiological and visual condition of remote or inaccessible locations. Real time gamma isotopic identification is provided to the first responder in the form of audio feedback (i.e. spoken through head phones) from a gamma detector mounted on a collapsible pole that can extend from 1 to 9 meters (6 to 29 feet). Simultaneously, selectable direct and side looking visual images are provided from the 5cm (2in) diameter, waterproof probe tip. The lightweight, self contained, ruggedized, system will provide a rapidly deployable field system for visual and radiological search and assessment of confined spaces and extended reach locations.

Heckendorn, F. M.; Odell, D. M. C; Harpring, L. J.; Peterson, K. D.

2005-10-05

152

THROUGH-THE-EARTH (TTE) COMMUNICATIONS SYSTEM AND THE IN-MINE POWER LINE (IMPL) COMMUNICATIONS SYSTEM  

SciTech Connect

Work has progressed on both subsystems: the Through-the-Earth (TTE) Communications system and the In-Mine Power Line (IMPL) Communications system. The TTE system: The system was fabricated and repackaged as an industrial product enclosed in a commercial rugged, waterproof housing suitable for installation in mines. Features were added to the system to appeal to the preferences of different mine managers. Arrangements were made with NIOSH to install the system in the Lake Lynn underground mine for evaluation and demonstration to potential users. The IMPL system: Voice compression was successfully implemented and incorporated into the laboratory model. Compressed voice was transmitted through a power line, expanded at the receiving end, and received with high clarity.

Zvi H. Meiksin

2002-01-01

153

A kinetic analysis of evaporative water loss barriers.  

PubMed

A simple kinetic analysis of evaporation solves a number of current theoretical conflicts and provides a much needed insight into waterproofing barriers. Although the saturation deficit law approximates the gradient across a free water surface, it is not necessarily applicable when a barrier is present. Any gaseous diffusion barrier reduces water loss by increasing condensation at the interface, whereas a hydrophobic barrier reduces both vaporization and condensation. Hydrophilic barriers may decrease vaporization without inhibiting condensation but are ineffective when fully hydrated. A general model is derived for steady state water loss across a biological barrier consisting of a mosaic of hydrophilic and hydrophobic bonds. These principles are applied to organisms inhabiting temporally heterogeneous environments. PMID:3796002

Damstra, K S

1986-08-21

154

A convenient first aid kit for chemical and biological agents and for radiation exposure.  

PubMed

The chemical and biological warfare agents are extremely toxic in nature. They act rapidly even in very small quantities and death may occur in minutes. Hence, physical and medical protection must be provided immediately to save life or avoid serious injury. A first aid kit has thus been developed for providing immediate relief from chemical and biological warfare agents (FAKCBW) with the objective of easy detection, personal decontamination, antidote for chemical warfare agents (like nerve agents, sulphur mustard, phosgene, cyanide, radiation exposure and bacterial agents), along with basic medication aid for pain, fever and inflammation. The kit box also includes a user friendly handbook with a simple standard operating procedure. In addition, the kit is rugged to withstand normal jerks, vibration and is water-proof. PMID:23029921

Vijayaraghavan, R; Bhaskar, A S B; Gautam, Anshoo; Gopalan, N; Singh, A K; Singh, Beer; Flora, S J S

2012-05-01

155

A method of extracellular recording of neuronal activity in swimming mice.  

PubMed

The design of a removable miniature microdrive-headstage waterproof assembly for extracellular recordings of single unit activity with high-impedance electrodes in swimming mice is presented. The assembly provides perfect protection of the critical components and electric contacts from water. Neuronal activity may be recorded even if the animal is diving and swimming under the water surface. The advantages of this construction include simple installation and removal of the electrodes, rapid attachment of the assembly to the animal's skull, and rapid removal after recording. The device provides precise vertical positioning of the electrode without rotation or lateral shift, stable recordings of single units for several hours and the possibility to change the penetration track many times in the same animal. The assembly weight is less than 160mg. This work is the first successful attempt to record neuronal activity in mice performing spatial task in water maze. PMID:17669505

Korshunov, Victor A; Averkin, Robert G

2007-09-30

156

Stable low-loss optical nanofibres embedded in hydrophobic aerogel.  

PubMed

Nanofibres, optical fibres narrower than the wavelength of light, degrade in hours on exposure to air. We show that encapsulation in hydrophobic silica aerogel (refractive index 1.05) provides protection and stability (over 2 months) without sacrificing low attenuation, strong confinement and accessible evanescent field. The measured attenuation was <0.03 dB/mm, over 10 × lower than reported with other encapsulants. This enables many nanofibre applications based on their extreme small size and strong external evanescent field, such as optical sensors, nonlinear optics, nanofibre circuits and high-Q resonators. The aerogel is more than a waterproof box, it is a completely-compatible gas-permeable material in intimate contact with the nanofibre and hydrophobic on both the macroscopic and molecular scales. Its benefits are illustrated by experiments on gas sensing (exploiting the aerogel's porosity) and supercontinuum generation (exploiting its ultra-low index). PMID:21263617

Xiao, Limin; Grogan, M D W; Wadsworth, W J; England, R; Birks, T A

2011-01-17

157

[Basic studies of ultrasound surgery. VIII. Experimental animal studies of power ultrasound surgery of the swine pancreas].  

PubMed

The technique of the power ultrasound was tested in vitro and in vivo in 20 porcine pancreas. Simultaneous temperature measurements and laboratory tests do not produce any restriction. Enzymatic disorders were provable adequate to the clinical course. The ultrasonic effect guarantees a nearly riskless dissection in the layer. Joining processes, by adding Ligament-FIMOMED, produced a waterproof occlusion of parenchymal wounds. The cross-section of the pancreas with the pancreatic duct was sealed sufficiently. Also the jointed pancreato-jejunostomy remained sufficient. The reaction of the pancreatic parenchyma to the power ultrasound was small. A scarred metaplasia evolved immediately at the adhesive as a chronic atrophic interstitial pancreatitis. Only in case of occlusion of the pancreatic duct this alteration comprehended the whole pancreas. PMID:2623913

Nowotny, K; Fritzsch, G; Füssel, J; Vetter, J; Wehner, W; Ludwig, P; Kühnert, R; Morgenstern, R; Daniel, P

1989-01-01

158

The application of conductive polymer nano emulsion in printing ink  

NASA Astrophysics Data System (ADS)

In order to achieve the acquirement of flexible displayer, such as e-paper and touch screen, and to reduce the cost of conductive printing ink, the application of conductive polymer in printing ink is studied, and conductive flexible layer is acquired. The effect of N, N-dimethylformamide, glycerol, deionizer water, and pH value on the performance of water-based nano conductive polymer ink is studied by the second doping of conductive polymer nano suspension. The effect of various polymers on the conductivity of printing ink is researched by adding various polymer resins. At last, printing performance of the conductive polymer ink is tested by some printing methods, such as screen, and offset printing. Conductive printing layer which can be compared with the traditional conductive ink in the conductivity is acquired and the conductive layer is waterproof.

Li, Luhai; Mo, Linxin; Yi, Fang; Xin, Zhiqing; Tang, Xiaojun

2009-07-01

159

Green Roofs: Federal Energy Management Program (FEMP) Federal Technology Alert  

SciTech Connect

In a ''green roof,'' a layer of vegetation (e.g., a roof garden) covers the surface of a roof to provide shade, cooler indoor and outdoor temperatures, and effective storm-water management to reduce runoff. The main components are waterproofing, soil, and plants. There are two basic kinds: intensive and extensive. An intensive green roof often features large shrubs and trees, and it can be expensive to install and maintain. An extensive green roof features shallow soil and low-growing, horizontally spreading plants that can thrive in the alpine conditions of many rooftops. These plants do not require a lot of water or soil, and they can tolerate a significant amount of exposure to the sun and wind. This Federal Technology Alert focuses on the benefits, design, and implementation of extensive green roofs and includes criteria for their use on federal facilities.

Scholz-Barth, K.; Tanner, S.

2004-09-01

160

Field-deployable monitors for volatile organic compounds in air. (Essential capabilities of a portable gas chromatograph)  

SciTech Connect

Volatile organic compounds in ambient air are usually estimated by trapping them from air or collecting whole air samples and returning them to a laboratory for analysis by gas chromatography using selective detection. Immediate data can be obtained, and sampling errors minimized, by analyzing with a field-deployable instrument at the time samples are collected. Portable gas chromatographs are available, but they don't fully meet the need for quick, high-quality data under field conditions. Shortcomings include insensitive detectors, non-selective detectors, poor resolution, retention time drift, maladroit data processing schemes, excessive energy consumption, and vulnerability to weather. Improved waterproofing, temperature regulation, and energy efficiency are particularly crucial to true field-deployability. Mass spectrometric detection, high-speed chromatography, polycapillary chromatography, and peak modulation may lead to useful enhancements in future.

Berkley, R.E.

1993-01-01

161

Underwater manipulator  

DOEpatents

Self-contained, waterproof, water-submersible, remote-controlled apparatus is described for manipulating a device, such as an ultrasonic transducer for measuring crack propagation on an underwater specimen undergoing shock testing. The subject manipulator includes metal bellows for transmittal of angular motions without the use of rotating shaft seals or O-rings. Inside the manipulator, a first stepper motor controls angular movement. In the preferred embodiment, the bellows permit the first stepper motor to move an ultrasonic transducer [plus minus]45 degrees in a first plane and a second bellows permit a second stepper motor to move the transducer [plus minus]10 degrees in a second plane orthogonal to the first. In addition, an XY motor-driven table provides XY motion.

Schrum, P.B.; Cohen, G.H.

1993-04-20

162

Development and characterization of CPI surface insulation  

NASA Technical Reports Server (NTRS)

A new type of reusable surface material that could find application as a component of the thermal protection system of the space shuttle orbiter is discussed. These materials consist of 20-30% dense closed cell high emittance glass ceramic foams formulated by sintering an intimate mixture of fly ash cenospheres with 4-12 wt % cobalt oxide. These unique ceramic foams exhibit: (1) High mechanical strengths; (2) no need for waterproof coating due to the non-interconnecting cell network; (3) high emissivities; (4) ability to withstand space shuttle thermal environments with no loss of reuse capability; and (5) a machinable ceramic with capability of maintaining the close tolerances required of an integrated heat shield system.

Tobin, A.; Feldman, C.; Reichman, J.; Russak, M.; Varisco, A.

1973-01-01

163

The testing of balloon fabrics  

NASA Technical Reports Server (NTRS)

Report describes methods and materials used in waterproofing and fireproofing airplane fabrics using dopes. The determination of the probable life of a balloon fabric in service by experimental means is of great value in choosing the most suitable fabrics for a given purpose and in pointing the way to improvements in compounding and construction. The usefulness of exposure to the weather for this purpose has been amply demonstrated. Various attempts have been made to reproduce by artificial means the conditions promoting deterioration in service, but without marked success. Exposure to the weather remains the most satisfactory method for this purpose, and a consideration of the characteristics of such tests is therefore important. This report presents the results of a typical series of exposure tests made in 1917.

Edwards, Junius David; Moore, Irwin L

1920-01-01

164

The application of PCMMcs and SiC by commercially direct dual-complex coating on textile polymer  

NASA Astrophysics Data System (ADS)

To enhance the thermal insulation effect, waterproof/breathable fabrics were directly top dual-coated by the dry coating method with ceramic materials (silicon carbide, SiC). The fabric was base coated by the wet coating method with 5 wt% phase-change material microcapsules (PCMMcs) and tested for the emission of far-infrared (FIR) radiation. With increasing SiC content, the fabric altered some of the physical properties by increasing the FIR emissivity, emission power, water vapor transmission rate (WVTR) and heat release capacity. Scanning electron microscopy (SEM) analysis revealed the presence of the PCMMcs and SiC particles at the cross-section and surface of the coating, respectively, which exhibited a rugged and blocky shape. The results indicated that SiC addition did not affect the water entry pressure (WEP) in the fabric structure, but did alter the following physical properties: WVTR, interactions between the macromolecule chains and the susceptibility to humidity.

Koo, Kang; Choe, Jongdeok; Park, Youngmi

2009-07-01

165

A novel wearable apnea dive computer for continuous plethysmographic monitoring of oxygen saturation and heart rate.  

PubMed

We describe the development of a novel wrist-mounted apnea dive computer. The device is able to measure and display transcutaneous oxygen saturation, heart rate, plethysmographic pulse waveform, depth, time and temperature during breath-hold dives. All measurements are stored in an external memory chip. The data-processing software reads from the chip and writes the processed data into a comma-separated values file which can be analysed by applications such as Microsoft Excel™ or Open Office™. The housing is waterproof and pressure-resistant to more than 20 bar (2.026 MPa) (breath-hold divers have already exceeded 200 metres' sea water depth). It is compact, lightweight, has low power requirements and is easy to use. PMID:23111837

Kuch, Benjamin; Koss, Bernhard; Dujic, Zeljko; Buttazzo, Giorgio; Sieber, Arne

2010-03-01

166

Pelletizing/reslurrying as a means of distributing and firing clean coal. Final report  

SciTech Connect

Battelle-Columbus and Amax Research & Development conducted a program to develop a process to transport, handle, store, and utilize ultra-fine, ultra-clean (UFUC) coals. The primary objective was to devise a cost-effective method, based on conventional pelletization techniques, to transform the sludge-like filter cake produced in advanced flotation cleaning processes into a product which could be used like lump coal. A secondary objective was the production of a pellet which could be readily converted into a coal water fuel (CWF) because the UFUC coal would ultimately be used as CWF. The resulting product would be a hard, waterproof pellet which could be easily reduced to small particle sizes and formulated with water into a liquid fuel.

Conkle, H.N.

1992-09-29

167

Pelletizing/reslurrying as a means of distributing and firing clean coal  

SciTech Connect

Battelle-Columbus and Amax Research Development conducted a program to develop a process to transport, handle, store, and utilize ultra-fine, ultra-clean (UFUC) coals. The primary objective was to devise a cost-effective method, based on conventional pelletization techniques, to transform the sludge-like filter cake produced in advanced flotation cleaning processes into a product which could be used like lump coal. A secondary objective was the production of a pellet which could be readily converted into a coal water fuel (CWF) because the UFUC coal would ultimately be used as CWF. The resulting product would be a hard, waterproof pellet which could be easily reduced to small particle sizes and formulated with water into a liquid fuel.

Conkle, H.N.

1992-09-29

168

Invisible photonic printing: computer designing graphics, UV printing and shown by a magnetic field.  

PubMed

Invisible photonic printing, an emerging printing technique, is particularly useful for steganography and watermarking for anti-counterfeiting purposes. However, many challenges exist in order to realize this technique. Herein, we describe a novel photonic printing strategy targeting to overcome these challenges and realize fast and convenient fabrication of invisible photonic prints with good tenability and reproducibility. With this novel photonic printing technique, a variety of graphics with brilliant colors can be perfectly hidden in a soft and waterproof photonic-paper. The showing and hiding of the latent photonic prints are instantaneous with magnet as the only required instrument. In addition, this strategy has excellent practicality and allows end-user control of the structural design utilizing simple software on a PC. PMID:23508071

Hu, Haibo; Tang, Jian; Zhong, Hao; Xi, Zheng; Chen, Changle; Chen, Qianwang

2013-01-01

169

Development of processing techniques for advanced thermal protection materials. Annual progress report, 1 June 1994-31 May 1995  

SciTech Connect

The main purpose of this work has been in the development and characterization of materials for high temperature applications. Thermal Protection Systems (TPS) are constantly being tested, and evaluated for increased thermal shock resistance, high temperature dimensional stability, and tolerance to environmental effects. Materials development was carried out through the use of many different instruments and methods, ranging from extensive elemental analysis to physical attributes testing. The six main focus areas include: (1) protective coatings for carbon/carbon composites; (2) TPS material characterization; (3) improved waterproofing for TPS; (4) modified ceramic insulation for bone implants; (5) improved durability ceramic insulation blankets; and (6) ultra-high temperature ceramics. This report describes the progress made in these research areas during this contract period.

Selvaduray, G.S.

1995-06-01

170

Surface contamination of titanium by abrading treatment.  

PubMed

This study investigated the contamination of abraded Ti surfaces. Using a polishing machine, specimens were abraded with waterproof SiC grit papers under water cooling. The abraded surfaces were examined using element analysis, X-ray diffraction, and hardness tests. Contaminant deposits with dimensions reaching about 30 microns were observed throughout the surface. In these deposits, Ti was apparently reduced by about 10% and replaced by Si and O. The chemical bond state of the Si was similar to that of SiC or a titanium silicide. The O was solute in Ti, which increased the surface hardness. The contaminant deposits were amorphous or very thin. The contamination of Ti, the extent of which was related to hardness, resulted from a reaction with abrasives. PMID:8940534

Miyakawa, O; Watanabe, K; Okawa, S; Kanatani, M; Nakano, S; Kobayashi, M

1996-06-01

171

Modular, multi-level groundwater sampler  

DOEpatents

Apparatus for taking a multiple of samples of groundwater or pressure measurements from a well simultaneously. The apparatus comprises a series of chambers arranged in an axial array, each of which is dimensioned to fit into a perforated well casing and leave a small gap between the well casing and the exterior of the chamber. Seals at each end of the container define the limits to the axial portion of the well to be sampled. A submersible pump in each chamber pumps the groundwater that passes through the well casing perforations into the gap from the gap to the surface for analysis. The power lines and hoses for the chambers farther down the array pass through each chamber above them in the array. The seals are solid, water-proof, non-reactive, resilient disks supported to engage the inside surface of the well casing. Because of the modular design, the apparatus provides flexibility for use in a variety of well configurations.

Nichols, Ralph L. (812 Plantation Point Dr., N. Augusta, SC 29841); Widdowson, Mark A. (4204 Havana Ct., Columbia, SC 29206); Mullinex, Harry (10 Cardross La., Columbia, SC 29209); Orne, William H. (12 Martha Ct., Sumter, SC 29150); Looney, Brian B. (1135 Ridgemont Dr., Aiken, SC 29803)

1994-01-01

172

Integrated residential photovoltaic array development. Quarterly report No. 2  

SciTech Connect

The results of a selection process to define the conceptual design of an optimum integrated residential photovoltaic module array are discussed. Three basic module design concepts have been analyzed with respect to both production and installation costs. The results of this evaluation have been used to synthesize a fourth design which incorporates the best features of these initial concepts to produce a module/array design approach which offers the promise of a substantial reduction in the installed cost of a residential array. A unique waterproofing and mounting scheme has been used to reduce the cost of installing an integral array while still maintaining a high probability that the installed array will be watertight for the design lifetime of the system. This recommended concept will also permit the array to be mounted as a direct or stand-off installation with no changes to the module design.

Shepard, N.F. Jr.

1981-05-18

173

Use of autologous platelet rich fibrin in urethracutaneous fistula repair: preliminary report.  

PubMed

Urethrocutaneous fistula (UCF) is one of the most common complications occurring after hypospadias repair. Despite the surgical advancement in hypospadias, multiple failed fistula closures are commonly referred to paediatric urologists. Although several techniques have been described to interpose a waterproof layer between urethral and skin closures, occurrence of urethrocutaneous fistula cannot be eliminated completely. In addition to several local tissue grafts, autologous and homologous fibrin sealants are used to prevent UCF. Platelet rich fibrin (PRF) is known as an autologous source of growth factors obtained from the sera of the patient. PRF supports collagen synthesis and tissue repair and accelerates wound healing. We aimed to present our initial experience about the use of autologous PRF in a 3-year-old boy with a UCF after hypospadias repair. PMID:22568526

Soyer, Tutku; Çakmak, Murat; Aslan, Mustafa K; ?enyücel, Mine F; Kisa, Üçler

2013-06-01

174

Director's Discretionary Fund Report for Fiscal Year 1996  

NASA Technical Reports Server (NTRS)

Topics covered include: Waterproofing the Space Shuttle tiles, thermal protection system for Reusable Launch Vehicles, computer modeling of the thermal conductivity of cometary ice, effects of ozone depletion and ultraviolet radiation on plants, a novel telemetric biosensor to monitor blood pH on-line, ion mobility in polymer electrolytes for lithium-polymer batteries, a microwave-pumped far infrared photoconductor, and a new method for measuring cloud liquid vapor using near infrared remote sensing. Also included: laser-spectroscopic instrument for turbulence measurement, remote sensing of aircraft contrails using a field portable imaging interferometer, development of a silicon-micromachined gas chromatography system for determination of planetary surface composition, planar Doppler velocimetry, chaos in interstellar chemistry, and a limited pressure cycle engine for high-speed output.

1997-01-01

175

Underwater manipulator  

DOEpatents

Self-contained, waterproof, water-submersible, remote-controlled apparatus is provided for manipulating a device, such as an ultrasonic transducer for measuring crack propagation on an underwater specimen undergoing shock testing. The subject manipulator includes metal bellows for transmittal of angular motions without the use of rotating shaft seals or O-rings. Inside the manipulator, a first stepper motor controls angular movement. In the preferred embodiment, the bellows permit the first stepper motor to move an ultrasonic transducer .+-.45 degrees in a first plane and a second bellows permit a second stepper motor to move the transducer .+-.10 degrees in a second plane orthogonal to the first. In addition, an XY motor-driven table provides XY motion.

Schrum, Phillip B. (Clairton, PA); Cohen, George H. (Pittsburgh, PA)

1993-01-01

176

Integrated residential photovoltaic array development  

NASA Technical Reports Server (NTRS)

Three basic module design concepts were analyzed with respect to both production and installation costs. The results of this evaluation were used to synthesize a fourth design which incorporates the best features of these initial concepts to produce a module/array design approach which offers the promise of a substantial reduction in the installed cost of a residential array. A unique waterproofing and mounting scheme was used to reduce the cost of installing an integral array while still maintaining a high probability that the installed array will be watertight for the design lifetime of the system. This recommended concept will also permit the array to be mounted as a direct or stand-off installation with no changes to the module design.

Shepard, N. F., Jr.

1981-01-01

177

The NAVI-2: A ruggedized portable radiation analyzer  

SciTech Connect

The NAVI-2 is a rugged, lightweight, and waterproof portable radiation analyzer developed by the Advanced Nuclear Technology group at Los Alamos National Laboratory. It was originally developed for a specific application: performing confirmatory measurements on plutonium removed from dismantled nuclear weapons as part of the O`Leary-Mikhailov mutual reciprocal inspections agreement. Since that time the hardware has stabilized into a mature package while several additional software packages have been developed. Now, in addition to the original software for performing confirmatory measurements, software is available that will allow the NAVI-2 to be used for scanning of extended sources, searching for hidden sources, and monitoring of items in a portal monitoring sense. This report will provide hardware and software details for owners and users of the NAVI-2.

Murray, W.S.; Butterfield, K.B.; Frankle, C.M.

1996-01-01

178

Cold water survival suits for aircrew.  

PubMed

Laboratory and sea trials were used to compare the effectiveness of three aircrew exposure garments--the British Mark 10, the United States CWU 21/P, and the Canadian U.VIC. Thermofloat jacket. The first two are waterproof coveralls, whereas the third is a neoprene-lined jacket designed on the basis of the "wet suit" concept. Rectal and skin temperatures, electrocardiograms and other variables were measured while subjects, wearing the suits, were immersed in water at temperatures of 70 degrees C and 10.5 degrees C. The three garments were found to be similar in the degree of thermal protection provided, but the Thermofloat jacket appeared superior in other ways and has the greater potential for development. A previously unreported observation was a marked reduction in core cooling rate after the expected linear fall in core temperature. This has possible implications in the conduct of research in this field. PMID:518448

White, G R; Roth, N J

1979-10-01

179

Development of processing techniques for advanced thermal protection materials  

NASA Technical Reports Server (NTRS)

The main purpose of this work has been in the development and characterization of materials for high temperature applications. Thermal Protection Systems (TPS) are constantly being tested, and evaluated for increased thermal shock resistance, high temperature dimensional stability, and tolerance to environmental effects. Materials development was carried out through the use of many different instruments and methods, ranging from extensive elemental analysis to physical attributes testing. The six main focus areas include: (1) protective coatings for carbon/carbon composites; (2) TPS material characterization; (3) improved waterproofing for TPS; (4) modified ceramic insulation for bone implants; (5) improved durability ceramic insulation blankets; and (6) ultra-high temperature ceramics. This report describes the progress made in these research areas during this contract period.

Selvaduray, Guna S.

1995-01-01

180

Visible fiber lasers excited by GaN laser diodes  

NASA Astrophysics Data System (ADS)

This paper describes and discusses visible fiber lasers that are excited by GaN laser diodes. One of the attractive points of visible light is that the human eye is sensitive to it between 400 and 700 nm, and therefore we can see applications in display technology. Of course, many other applications exist. First, we briefly review previously developed visible lasers in the gas, liquid, and solid-state phases and describe the history of primary solid-state visible laser research by focusing on rare-earth doped fluoride media, including glasses and crystals, to clarify the differences and the merits of primary solid-state visible lasers. We also demonstrate over 1 W operation of a Pr:WPFG fiber laser due to high-power GaN laser diodes and low-loss optical fibers (0.1 dB/m) made by waterproof fluoride glasses. This new optical fiber glass is based on an AlF3 system fluoride glass, and its waterproof property is much better than the well known fluoride glass of ZBLAN. The configuration of primary visible fiber lasers promises highly efficient, cost-effective, and simple laser systems and will realize visible lasers with photon beam quality and quantity, such as high-power CW or tunable laser systems, compact ultraviolet lasers, and low-cost ultra-short pulse laser systems. We believe that primary visible fiber lasers, especially those excited by GaN laser diodes, will be effective tools for creating the next generation of research and light sources.

Fujimoto, Yasushi; Nakanishi, Jun; Yamada, Tsuyoshi; Ishii, Osamu; Yamazaki, Masaaki

2013-07-01

181

Airborne nanoparticle concentrations in the manufacturing of polytetrafluoroethylene (PTFE) apparel.  

PubMed

One form of waterproof, breathable apparel is manufactured from polytetrafluoroethylene (PTFE) membrane laminated fabric using a specific process to seal seams that have been sewn with traditional techniques. The sealing process involves applying waterproof tape to the seam by feeding the seam through two rollers while applying hot air (600 °C). This study addressed the potential for exposure to particulate matter from this sealing process by characterizing airborne particles in a facility that produces more than 1000 lightweight PTFE rain jackets per day. Aerosol concentrations throughout the facility were mapped, breathing zone concentrations were measured, and hoods used to ventilate the seam sealing operation were evaluated. The geometric mean (GM) particle number concentrations were substantially greater in the sewing and sealing areas (67,000 and 188,000 particles cm?³)) compared with that measured in the office area (12,100 particles cm?³). Respirable mass concentrations were negligible throughout the facility (GM = 0.002 mg m?³) in the sewing and sealing areas). The particles exiting the final discharge of the facility's ventilation system were dominated by nanoparticles (number median diameter = 25 nm; geometric standard deviation of 1.39). The breathing zone particle number concentrations of the workers who sealed the sewn seams were highly variable and significantly greater when sealing seams than when conducting other tasks (p < 0.0001). The sealing workers' breathing zone concentrations ranged from 147,000 particles cm?³ to 798,000 particles cm?³, and their seam responsibility significantly influenced their breathing zone concentrations (p = 0.03). The finding that particle number concentrations were approximately equal outside the hood and inside the local exhaust duct indicated poor effectiveness of the canopy hoods used to ventilate sealing operations. PMID:21347955

Vosburgh, Donna J H; Boysen, Dane A; Oleson, Jacob J; Peters, Thomas M

2011-03-01

182

Preparation and evaluation of colon adhesive pellets of 5-aminosalicylic acid.  

PubMed

Oral modified-release delivery systems, such as bio-adhesive one, enable drug delivery to affected regions and minimize the side effects by reducing the systemic absorption. Our aim was to develop colon adhesive pellets of 5-aminosalicylic acid (5-ASA) for the treatment of ulcerative colitis. The core of the pellet was formulated from bioadhesive agents, Carbomer 940 and hydroxypropyl cellulose (HPC), by extrusion/spheronization method and coated with Surelease(®) as inner layer for waterproof and with Eudragit(®) S100 as outer layer for pH control. The rat model of ulcerative colitis was used to evaluate the efficiency of our loaded pellets as a drug carrier. Microcrystalline cellulose 101 (PH 301) was found to be the best agent for pellet core. The ratio of CP940 to HPC should be kept as (1:1) to achieve high bioadhesion. When the amount of Surelease(®) was from 16% to 20% and of Eudragit(®) S100 was 28%, the dissolution profiles of coated pellets revealed no drug release in the artificial gastric fluid (pH 1.0) within 2h and less than 10% was released in phosphate buffer (pH 6.0) within 2h whereas complete dissolution was observed in colonic fluid of pH 7.4 for 20h. The animal experiment showed that 5-ASA loaded colon adhesive pellets had optimal therapeutic effect. We showed a novel approach to prepare effective bioadhesive pellets as colon targeted drug delivery system. PMID:24746693

Xu, Meixia; Sun, Minjie; Qiao, Hongzhi; Ping, Qineng; Elamin, Eltayeb Suliman

2014-07-01

183

Benchmarking numerical predictions with force and moment measurements on slender, supercavitating bodies  

SciTech Connect

High-speed water-entry is a very complex, dynamic process. As a first attempt at modeling the process, a numerical solution was developed at Sandia National Laboratories for predicting the forces and moments acting on a body with a steady supercavity, that is, a cavity which extends beyond the base of the body. The solution is limited to supercavities on slender, axisymmetric bodies at small angles of attack. Limited data were available with which to benchmark the axial force predictions at zero angle of attack. Even less data were available with which to benchmark the pitching moment and normal force predictions at nonzero angles of attack. A water tunnel test was conducted to obtain force and moment data on a slender shape. This test produced limited data because of waterproofing problems with the balance. A new balance was designed and a second water tunnel test was conducted at Tracor Hydronautics, Inc. This paper describes the numerical solution, the experimental equipment and test procedures, and the results of the second test. 8 refs., 11 figs.

Hailey, C.E.; Clark, E.L.; Cole, J.K.

1991-01-01

184

A Wireless Sensor Network Field Study: Network Development, Installation, and Measurement Results  

NASA Astrophysics Data System (ADS)

The sustainable condition of our freshwater resources partially depends on our understanding of the natural system in which it is cycled. Exploring the status and trends of soil moisture and transpiration can help improve estimates (including flux and storage components) of water budgets on a regional-scale. As a part of this effort, a multi-node wireless network measuring sap flow, soil water content and soil water potential has been deployed in a forested and hill-sloped region in western Pennsylvania. The results of this study are presented in three components. The first is comprised of the issues faced with the development of the node mesh and its evolution to a stable network through the dense vegetation and variable topography. This component includes a comparison of mote battery life, especially over network bottlenecks, and signal transmission statistics, including parenting analysis and data packet loss. The second component examines the design and installation of the sensor nodes. Due to the frequent occurrences of precipitation, water intrusion was a major concern. This is exemplified in the water-proofing techniques used in the box design which enclosed sensors and other vulnerable electronics. The final component reviews the data collected from the network and the different techniques used for processing the measurements. A power saving scheme is tested for removing low mote battery power attenuation in the transmitted data. The results for the soil moisture and sap flow measurements are compared with data collected by a local weather station.

Davis, T. W.; Kuo, C.; van Hemmen, H.; Aouni, A.; Ferriss, E.; Liang, Y.; Liang, X.

2010-12-01

185

Use of PTFE membrane for in-situ gas phase extraction from natural waters  

NASA Astrophysics Data System (ADS)

The extraction of the dissolved gas phase in natural waters is a delicate operation which can frequently invalidate the analytical data. Several methodologies were developed in order to separate the dissolved gaseous phase from water. They can be divided in two main groups: the extraction laboratory technique (ELT) (Mazor, 1977; Sugisaki & Taki, 1987; Andrews et al.,1989; Holt et al. 1995; Capasso & Inguaggiato, 1998) and the extraction field technique (EFT) (Tonani, 1971; Chiodini, 1996). Recently, new EFT method have been developed using PDMS membrane, (Sanford et al., 1996; Jacinthe & Groffman, 2001). We perform a method based on semi-permeable polymeric membrane PTFE (waterproof and permeable to the gases).The sampling device consists of a PTFE tube, sealed at one end, and connected to a glass vessel. The evacuated system is plunged in the natural water for one or more days. During this time the dissolved gases flows inside the system. The equilibrium is reached after 10 days, but a theoretical model was developed to recalculate the partial pressure of each gas species, from not equilibrated gas sample. The recalculation model was developed combining Mass Balance with "Diffusion-Solution Model", the best model to describe the gas permeation through the PTFE membrane. The recalculation model was experimentally validated by several laboratory tests and compared with ELT methods. The new method was applied in groundwater of Vulcano Island, and allows us to carry out chemical and isotopic data of dissolved gas phase from a same gas sample

de Gregorio, S.; Gurrieri, S.; Valenza, M.

2003-12-01

186

Large thermal protection system panel  

NASA Technical Reports Server (NTRS)

A protective panel for a reusable launch vehicle provides enhanced moisture protection, simplified maintenance, and increased temperature resistance. The protective panel includes an outer ceramic matrix composite (CMC) panel, and an insulative bag assembly coupled to the outer CMC panel for isolating the launch vehicle from elevated temperatures and moisture. A standoff attachment system attaches the outer CMC panel and the bag assembly to the primary structure of the launch vehicle. The insulative bag assembly includes a foil bag having a first opening shrink fitted to the outer CMC panel such that the first opening and the outer CMC panel form a water tight seal at temperatures below a desired temperature threshold. Fibrous insulation is contained within the foil bag for protecting the launch vehicle from elevated temperatures. The insulative bag assembly further includes a back panel coupled to a second opening of the foil bag such that the fibrous insulation is encapsulated by the back panel, the foil bag, and the outer CMC panel. The use of a CMC material for the outer panel in conjunction with the insulative bag assembly eliminates the need for waterproofing processes, and ultimately allows for more efficient reentry profiles.

Myers, Franklin K. (Inventor); Weinberg, David J. (Inventor); Tran, Tu T. (Inventor)

2003-01-01

187

Feather mites and birds: an interaction mediated by uropygial gland size?  

PubMed

Feather mites (Arachnida: Acari: Astigmata) feed mainly on secretions of the uropygial gland of birds. Here, we use analyses corrected for phylogeny and body size to show that there is a positive correlation between the size of this gland and mite abundance in passerine birds at an interspecific level during the breeding season, suggesting that the gland mediates interactions between mites and birds. As predicted on the basis of hypothesized waterproofing and antibiotic functions of uropygial gland secretions, riparian/marsh bird species had larger glands and higher mite loads than birds living in less mesic terrestrial environments. An unexpected pattern was a steeper relationship between mite load and gland size in migratory birds than in residents. If moderate mite loads are beneficial to a host but high loads detrimental, this could create complex selection regimes in which gland size influences mite load and vice versa. Mites may exert selective pressures on gland size of their hosts that has resulted in smaller glands among migratory bird species, suggesting that smaller glands may have evolved in these birds to attenuate a possible detrimental effect of feather mites when present in large numbers. PMID:18028353

Galván, I; Barba, E; Piculo, R; Cantó, J L; Cortés, V; Monrós, J S; Atiénzar, F; Proctor, H

2008-01-01

188

Short-chain carboxylic acids from gray catbird (Dumetella carolinensis) uropygial secretions vary with testosterone levels and photoperiod.  

PubMed

The uropygial gland of birds produces secretions that are important in maintaining the health and structural integrity of feathers. Non-volatile components of uropygial secretions are believed to serve a number of functions including waterproofing and conditioning the feathers. Volatile components have been characterized in fewer species, but are particularly interesting because of their potential importance in olfactory interactions within and across species. We used solid-phase microextraction headspace sampling with gas chromatography-mass spectrometry to detect and identify volatiles in uropygial secretions of gray catbirds (Dumetella carolinensis), a North American migratory bird. We consistently detected the following carboxylic acids: acetic, propanoic, 2-methylpropanoic, butanoic, and 3-methylbutanoic. We tested for the effect of lengthened photoperiod and/or exogenous testosterone on volatile signal strength and found a negative effect of lengthened photoperiod on the signal strength of propanoic, 2-methylpropanoic, and butanoic acids, suggesting a trade-off between their production and heightened night-time activity associated with lengthened photoperiod. Signal strength of propanoic and 2-methylpropanoic acids was lower in birds treated with exogenous testosterone than in birds treated with placebos. Sex did not affect signal strength of any of the volatile compounds. PMID:20346408

Whelan, Rebecca J; Levin, Tera C; Owen, Jennifer C; Garvin, Mary C

2010-07-01

189

Macrophyte monitoring along the Trentino side of the Lake Garda  

NASA Astrophysics Data System (ADS)

Macrophytes, that grow along the Trentino shorezone of the Lake Garda, were sampled and mapped during summer 2010. The sampling protocol foresees a lake bottom survey until the depth of 15 using GPS system, for identifying sampling sites and transects, waterproof camcorder, batiscope and a rake. The proof of 13/14 meters is the internal limit for macrophyte development. The area between 6 and 13/14 meters was surveyed with a robot camcorder placed on a boat of the fireworks brigade of Trento. This boat was used to track the 14 km of the shorezone of the Trentino part of the Lake Garda. The investigation result is a survey of a wide carex prairie that has no interruption all along the lake perimeter. An inflatable boat was used to inspect the shorezone using a batiscope. The macrophyte samples were collected using a rake. The number of mapped sites is 15, transects are 15 and identified 18 different species. During 2011, in conjunction with the flight MIVIS within the EULAKES project, the macrophyte distribution was confirmed and further inspection was carried out for sampling and classifying caracee. Among the species collected, Chara globularis was present in all sites sampled, while sites 0 and 12, corresponding respectively to local reserve Val Gola and the bay of Torbole, showed the highest biodiversity among sites, with 11 species collected of the 18 total. Within each site, higher number of species were collected between 2 and 5 meters depth's.

Pellegrini, Giovanna; Monauni, Catia; Fedrizzi, Fabio; Laura, Fravezzi; Paola, Testa; Silvia, Costaraoss; Mario, Mazzurana; Gaetano, Patti; Barbara, Zennaro

2013-04-01

190

Tethered acoustic doppler current profiler platforms for measuring streamflow  

USGS Publications Warehouse

The U.S. Geological Survey tested and refined tethered-platform designs for measuring streamflow. Platform specifications were developed, radio-modem telemetry of acoustic Doppler current profiler (ADCP) data and potential platform-hull sources were investigated, and hulls were tested and evaluated. Different platforms, which included a variety of hull configurations, were tested for drag and stability at the U.S. Geological Survey tow tank and at a field site below a reservoir. The testing indicated that, although any of the designs could be used under certain conditions, trimaran designs provided the best all-around performance under a range of conditions. The trimaran designs housed the ADCP in the center hull; this resulted in lower drag than the catamaran designs and retained the stability advantage of catamarans over monohull designs. Waterproof radio modems that operate at 900 megahertz were used to communicate wirelessly with instruments at high baud rates. A tethered-platform design with a tri-maran hull and 900-megahertz radio modems is now commercially available. Continued field use has resulted in U.S. Geological Survey procedures for making tethered-platform discharge measurements, including methods for tethered-boat deployment, moving-bed tests, and measurement of edge distances.

Rehmel, Michael S.; Stewart, James A.; Morlock, Scott E.

2003-01-01

191

Specification of epidermal cell fate in plant shoots.  

PubMed

Land plants have evolved a single layer of epidermal cells, which are characterized by mostly anticlinal cell division patterns, formation of a waterproof coat called cuticle, and unique cell types such as stomatal guard cells and trichomes. The shoot epidermis plays important roles not only to protect plants from dehydration and pathogens but also to ensure their proper organogenesis and growth control. Extensive molecular genetic studies in Arabidopsis and maize have identified a number of genes that are required for epidermal cell differentiation. However, the mechanism that specifies shoot epidermal cell fate during plant organogenesis remains largely unknown. Particularly, little is known regarding positional information that should restrict epidermal cell fate to the outermost cell layer of the developing organs. Recent studies suggested that certain members of the HD-ZIP class IV homeobox genes are possible master regulators of shoot epidermal cell fate. Here, we summarize the roles of the regulatory genes that are involved in epidermal cell fate specification and discuss the possible mechanisms that limit the expression and/or activity of the master transcriptional regulators to the outermost cell layer in plant shoots. PMID:24616724

Takada, Shinobu; Iida, Hiroyuki

2014-01-01

192

Ex situ reconstitution of the plant biopolyester suberin as a film.  

PubMed

Biopolymers often have unique properties of considerable interest as a basis for new materials. It is however not evident how to extract them from plants without destroying their chemical skeleton and inherent properties. Here we report the ex situ reconstitution of the biopolyester suberin as a new waterproof and antimicrobial material. In plant cell walls, suberin, a cross-linked network of aromatic and aliphatic monomers, builds up a hydrophobic protective and antimicrobial barrier. Recently we succeeded in extracting suberin from the plant cell wall using the ionic liquid cholinium hexanoate. During extraction the native three-dimensional structure of suberin was partially preserved. In this study, we demonstrate that this preservation is the key for its ex situ reconstitution. Without any chemical additives or purification, the suberin composing macromolecules undergo self-association on the casting surface forming a film. Suberin films obtained show barrier properties similar to those of the suberin barrier in plants, including a potentially broad bactericidal effect. PMID:24670155

Garcia, Helga; Ferreira, Rui; Martins, Celso; Sousa, Andreia F; Freire, Carmen S R; Silvestre, Armando J D; Kunz, Werner; Rebelo, Luís Paulo N; Silva Pereira, Cristina

2014-05-12

193

Thermal ecology on an exposed algal reef: infrared imagery a rapid tool to survey temperature at local spatial scales  

NASA Astrophysics Data System (ADS)

We tested the feasibility of infra-red (IR) thermography as a tool to survey in situ temperatures in intertidal habitats. We employed this method to describe aspects of thermal ecology for an exposed algal reef in the tropics (O`ahu, Hawai`i). In addition, we compared temperatures of the surrounding habitat as determined by IR thermography and traditional waterproof loggers. Images of reef organisms (6 macroalgae, 9 molluscs, 1 anthozoan, and 2 echinoderms), loggers, and landscapes were taken during two diurnal low tides. Analysis of IR thermographs revealed remarkable thermal complexity on a narrow tropical shore, as habitats ranged from 18.1 to 38.3°C and surfaces of organisms that ranged from 21.1 to 33.2°C. The near 20°C difference between abiotic habitats and the mosaic of temperatures experienced by reef organisms across the shore are similar to findings from temperate studies using specialized longterm loggers. Further, IR thermography captured rapid temperature fluctuations that were related to tidal height and cross-correlated to wave action. Finally, we gathered evidence that tidal species were associated with particular temperature ranges and that two species possess morphological characteristics that limit thermal stress. Loggers provided similar results as thermography but lack the ability to resolve variation in fine-scale spatial and temporal patterns. Our results support the utility of IR thermography in exploring thermal ecology, and demonstrate the steps needed to calibrate data leading to establishment of baseline conditions in a changing and heterogeneous environment.

Cox, T. E.; Smith, C. M.

2011-12-01

194

Effect of nano BaCO3 on pyrolytic reaction of phenol-formaldehyde resin  

NASA Astrophysics Data System (ADS)

Phenol-formaldehyde resin is used as the most adhesive to produce waterproof plant-based composite. However, this product contains phenol and formaldehyde which can be easily released to pollute air and water. Based on the single-factor method, the effect of nano BaCO3 on situabtion of pyrolytic reaction of PF resin was studied by Py-GC/MS. There were components including carbon dioxide, D,.alpha.-tocopherol, 1,3-bis(trimethylsilyl) benzene, phenol from PF resin in 590(see manuscript) He gas. However, the 17 compounds including phenol, 2-methyl-, phenol, carbon dioxide, p-xylene, toluene, phenol, 2-ethyl-, phenol, 2,3-dimethyl-, benzene, 1,2,3-trimethyl-, etc were identified by Py-GC/MS after PF/BaCO3 composite was pyrolyzed in 590(see manuscript) He gas, and phenol and phenol derivants were found in the compounds. The result showed that nano BaCO3 could effectively delay the pyrolysis of PF resin.

Zhang, Xu; Ma, Qing-Zhi; Zhang, Zhong-Feng; Peng, Wan-Xi; Zhang, Ming-Long

2009-07-01

195

Genetic control of cuticle formation during embryonic development of Drosophila melanogaster.  

PubMed

The embryonic cuticle of Drosophila melanogaster is deposited by the epidermal epithelium during stage 16 of development. This tough, waterproof layer is essential for maintaining the structural integrity of the larval body. We have characterized mutations in a set of genes required for proper deposition and/or morphogenesis of the cuticle. Zygotic disruption of any one of these genes results in embryonic lethality. Mutant embryos are hyperactive within the eggshell, resulting in a high proportion reversed within the eggshell (the "retroactive" phenotype), and all show poor cuticle integrity when embryos are mechanically devitellinized. This last property results in embryonic cuticle preparations that appear grossly inflated compared to wild-type cuticles (the "blimp" phenotype). We find that one of these genes, krotzkopf verkehrt (kkv), encodes the Drosophila chitin synthase enzyme and that a closely linked gene, knickkopf (knk), encodes a novel protein that shows genetic interaction with the Drosophila E-cadherin, shotgun. We also demonstrate that two other known mutants, grainy head (grh) and retroactive (rtv), show the blimp phenotype when devitellinized, and we describe a new mutation, called zeppelin (zep), that shows the blimp phenotype but does not produce defects in the head cuticle as the other mutations do. PMID:12019232

Ostrowski, Stephen; Dierick, Herman A; Bejsovec, Amy

2002-05-01

196

Genetic control of cuticle formation during embryonic development of Drosophila melanogaster.  

PubMed Central

The embryonic cuticle of Drosophila melanogaster is deposited by the epidermal epithelium during stage 16 of development. This tough, waterproof layer is essential for maintaining the structural integrity of the larval body. We have characterized mutations in a set of genes required for proper deposition and/or morphogenesis of the cuticle. Zygotic disruption of any one of these genes results in embryonic lethality. Mutant embryos are hyperactive within the eggshell, resulting in a high proportion reversed within the eggshell (the "retroactive" phenotype), and all show poor cuticle integrity when embryos are mechanically devitellinized. This last property results in embryonic cuticle preparations that appear grossly inflated compared to wild-type cuticles (the "blimp" phenotype). We find that one of these genes, krotzkopf verkehrt (kkv), encodes the Drosophila chitin synthase enzyme and that a closely linked gene, knickkopf (knk), encodes a novel protein that shows genetic interaction with the Drosophila E-cadherin, shotgun. We also demonstrate that two other known mutants, grainy head (grh) and retroactive (rtv), show the blimp phenotype when devitellinized, and we describe a new mutation, called zeppelin (zep), that shows the blimp phenotype but does not produce defects in the head cuticle as the other mutations do.

Ostrowski, Stephen; Dierick, Herman A; Bejsovec, Amy

2002-01-01

197

Coastal Changes in Temperature and Salinity Observed during Hurricane Isaac Recorded and Downloaded by NASA DRIFTERs Moored in Heron Bay and at Half Moon Island, Louisiana  

NASA Technical Reports Server (NTRS)

Major changes in salinity (approx.14 ppt.) and temperature (approx.40C) were continuously registered by two prototype NASA DRIFTERs, surface moored floaters, that NASA's Applied Science and Technology Project Office (ASTPO) has developed. The DRIFTER floating sensor module is equipped with an Arduino open-source electronics prototyping platform and programming language (http://www.arduino.cc), a GPS (Global Positioning System) module with antenna, a cell phone SIM (Subscriber Identity Module) card and a cellular antenna which is used to transmit data, and a probe to measure temperature and conductivity (from which salinity can be derived). The DRIFTER is powered by a solar cell panel and all the electronic components are mounted and sealed in [ waterproof encasement. Position and measurement data are transmitted via short message service (SMS) messaging to a Twitter site (DRIFTER 002@NASADRIFTER_002 and DRIFTER 004@NASADRIFTER_004), which provides a live feed. These data are the imported into a Google spreadsheet where conductivity is converted to salinity, and graphed in real-time. The spreadsheet data will be imported into a webpage maintained by ASTPO, where it will be displayed available for dO\\\\1lload.

Kalcic, Maria; Iturriaga, Rodolfo H.; Kuper, Philip D.; O'Neal, Stanford Duane; Underwood, Lauren; Fletcher, Rose

2012-01-01

198

Radioactive contamination incidents involving protective clothing  

SciTech Connect

The study focuses on incidents at Department of Energy (DOE) facilities involving the migration of radioactive contaminants through protective clothing. The authors analyzed 68 occurrence reports for the following factors: (1) type of work; (2) working conditions; (3) type of anti-contamination (anti-C) material; (4) area of body or clothing contaminated; and (5) nature of spread of contamination. A majority of reports identified strenuous work activities such as maintenance, construction, or decontamination and decommissioning (D&D) projects. The reports also indicated adverse working conditions that included hot and humid or cramped work environments. The type of anti-C clothing most often identified was cotton or water-resistant, disposable clothing. Most of the reports also indicated contaminants migrating through perspiration-soaked areas, typically in the knees and forearms. On the basis of their survey, the authors recommend the use of improved engineering controls and resilient, breathable, waterproof protective clothing for work in hot, humid, or damp areas where the possibility of prolonged contact with contamination cannot be easily avoided or controlled.

Reichelt, R.; Clay, M.; Eichorst, J.

1996-10-01

199

CFD Lagrangian Modeling of Water Droplet Transport for ISS Hygiene Activity Application  

NASA Technical Reports Server (NTRS)

The goal of this study was to assess the impacts of free water propagation in the Waste and Hygiene Compartment (WHC) installed in Node 3. Free water can be generated inside the WHC in small quantities due to crew hygiene activity. To mitigate potential impact of free water in Node 3 cabin the WHC doorway is enclosed by a waterproof bump-out, Kabin, with openings at the top and bottom. At the overhead side of the rack, there is a screen that prevents large drops of water from exiting. However, as the avionics fan in the WHC causes airflow toward the deck side of the rack, small quantities of free water may exit at the bottom of the Kabin. A Computational Fluid Dynamics (CFD) analysis of Node 3 cabin airflow enable identifying the paths of water transport. To simulate the droplet transport the Lagrangian discrete phase approach was used. Various initial droplet distributions were considered in the study. The droplet diameter was varied in the range of 5-20 mm. The results of the computations showed that most of the drops fall to the rack surface not far from the WHC curtain.

Son, Chang H.

2013-01-01

200

Long-term dry immersion: review and prospects.  

PubMed

Dry immersion, which is a ground-based model of prolonged conditions of microgravity, is widely used in Russia but is less well known elsewhere. Dry immersion involves immersing the subject in thermoneutral water covered with an elastic waterproof fabric. As a result, the immersed subject, who is freely suspended in the water mass, remains dry. For a relatively short duration, the model can faithfully reproduce most physiological effects of actual microgravity, including centralization of body fluids, support unloading, and hypokinesia. Unlike bed rest, dry immersion provides a unique opportunity to study the physiological effects of the lack of a supporting structure for the body (a phenomenon we call 'supportlessness'). In this review, we attempt to provide a detailed description of dry immersion. The main sections of the paper discuss the changes induced by long-term dry immersion in the neuromuscular and sensorimotor systems, fluid-electrolyte regulation, the cardiovascular system, metabolism, blood and immunity, respiration, and thermoregulation. The long-term effects of dry immersion are compared with those of bed rest and actual space flight. The actual and potential uses of dry immersion are discussed in the context of fundamental studies and applications for medical support during space flight and terrestrial health care. PMID:21161267

Navasiolava, Nastassia M; Custaud, Marc-Antoine; Tomilovskaya, Elena S; Larina, Irina M; Mano, Tadaaki; Gauquelin-Koch, Guillemette; Gharib, Claude; Kozlovskaya, Inesa B

2011-07-01

201

Detection of water content inhomogeneities in a dike model using invasive GPR guided wave sounding and TRIME-TDR® technique  

NASA Astrophysics Data System (ADS)

Guided wave sounding (GWS), an invasive application of ground-penetrating radar (GPR), and time domain reflectometry with intelligible micro elements (TRIME-TDR®) were used to investigate the distribution of volumetric water content (VWC) in a dike model under controlled conditions in order to detect possible dike damage. The dike model, which was constructed with soil of the texture class loamy sand, was flooded at different levels of water between 0.3 and 1.25 m high from a waterproof baseline. The two techniques were applied to retrieve VWC information from the same location at the crest of the dike model. Both techniques assessed reflection data from the lower end of a metal probe lowered through a common access borehole and successfully detected a water content inhomogeneity in the model at a depth of about 0.6 m from the crest. Comparison of the colocated VWC measurements from the two techniques showed almost identical trends with a root mean square deviation of 0.018 m3 m-3. GWS, however, showed a much higher depth resolution than TRIME-TDR®. Accompanying analytical and numerical modelling show that GWS sounding should be applicable to water content exploration in existing, 10-20 m deep boreholes.

Preko, Kwasi; Wilhelm, Helmut

2012-06-01

202

Comparison of invasive and non-invasive electromagnetic methods in soil water content estimation of a dike model  

NASA Astrophysics Data System (ADS)

Water infiltration through a dike model under controlled flooding and drainage conditions was investigated using the gravimetric soil water sampling technique and electromagnetic techniques, in particular ground penetrating radar (GPR) applied in different forms, time domain reflectometry with intelligent microelements (TRIME-TDR) and spatial-time domain reflectometry (S-TDR). The experiments were conducted on the model in two phases. In the first phase, the model was flooded with varying water levels between 0 and 1.25 m above the waterproof base of the model. In the second phase, the characteristics of the temporal water content changes were investigated over a period of 65 days as the flood water drained off from the 1.25 m level. The dike model was constructed with soil of the texture class loamy sand. The aim of the experiment was to investigate whether GPR-based invasive and non-invasive methods were able to quantitatively observe and correctly monitor temporal changes in the volumetric water content (VWC) within embankment dams. The VWC values from the various techniques corresponded very well, especially with low VWC values. A comparison with the VWC of gravimetric soil water sampling showed a satisfactory reproducibility. Characteristic discrepancies were recorded with higher values of the VWC. Under saturated conditions only the invasive methods were able to produce reasonable values of the VWC. After the release of the highest flood level, the drainage phase could be characterized by two invasive methods based on the TDR and GPR techniques.

Preko, Kwasi; Scheuermann, Alexander; Wilhelm, Helmut

2009-06-01

203

Preparation and mechanism of ultra-lightweight ceramics produced from sewage sludge.  

PubMed

The preparation, characterization, preheating mechanism and bloating mechanism of ultra-lightweight ceramics (ULWC) manufactured by dehydrated sewage sludge (DSS) and clay were studied. Three experiments were designed to investigate the addition of DSS, the effect of preheating treatment and sintering treatment, respectively, and then the optimum conditions for preparing ULWC were determined. Chemical components, especially ratios of carbon content to iron oxide content (C/Fe-ratios), were used to explain the preheating mechanism; physical forces (surface tension and bloating force) combined with C/Fe-ratios were used to explain the bloating mechanism. The characterizations (physical properties, microstructure properties and toxic metal leaching properties) of ULWC that were prepared under the optimum conditions were tested. The results showed that the optimum addition of DSS was 20-30 wt.%, and the pellets which preheated at 400 degrees C for 20 min and sintered at 1150 degrees C for 10 min were beneficial to produce ULWC. Property tests of ULWC showed that ULWC was light (with a bulk density of 330.80 kg m(-3)), waterproof (with a water absorption of 5.30 wt.%), nontoxic (contents of toxic metal leaching test were all below the detection limit) and suitable for practical civil engineering. PMID:19945788

Qi, Yuanfeng; Yue, Qinyan; Han, Shuxin; Yue, Min; Gao, Baoyu; Yu, Hui; Shao, Tian

2010-04-15

204

LWA demonstration applications using Illinois coal gasification slag: Phase 2. Technical report, September 1--November 30, 1993  

SciTech Connect

The objectives of this program are to demonstrate the feasibility of producing ultra-lightweight aggregates (ULWA) from solid residues (slag) generated during the gasification of Illinois coals, and to test the products as substitutes for conventional aggregates produced by pyroprocessing of perlite ores. In Phase 1 of this project, Praxis developed a pilotscale production technique and produced a large batch of expanded aggregates from an Illinois coal slag feed. The Phase 2 work focuses on characterization and applications-oriented testing of the expanded slag products as substitutes for conventional ULWAs. Target applications include high-volume uses such as loose fill insulation, insulating concrete, lightweight precast products (blocks), waterproof wallboard, rooftiles, and filtration media. The precast products will be subjected to performance and characterization testing in conjunction with a commercial manufacturer of such products in order to obtain input from a potential user. The production of value-added products from slag will eliminate a solid waste and possibly enhance the overall gasification process economics, especially when the avoided costs of disposal are taken into consideration.

Choudhry, V. [Praxis Engineers, Inc., Milpitas, CA (United States); Steck, P. [Harvey Cement Products, Inc. (United States)

1993-12-31

205

Integrated Microbatteries for Implantable Medical Devices  

NASA Technical Reports Server (NTRS)

Integrated microbatteries have been proposed to satisfy an anticipated need for long-life, low-rate primary batteries, having volumes less than 1 mm3, to power electronic circuitry in implantable medical devices. In one contemplated application, such a battery would be incorporated into a tubular hearing-aid device to be installed against an eardrum. This device is based on existing tube structures that have already been approved by the FDA for use in human ears. As shown in the figure, the battery would comprise a single cell at one end of the implantable tube. A small volume of Li-based primary battery cathode material would be compacted and inserted in the tube near one end, followed by a thin porous separator, followed by a pressed powder of a Li-containing alloy. Current-collecting wires would be inserted, with suitably positioned insulators to prevent a short circuit. The battery would contain a liquid electrolyte consisting of a Li-based salt in an appropriate solvent. Hermetic seals would be created by plugging both ends with a waterproof polymer followed by deposition of parylene.

Whitacre, Jay; West, William

2008-01-01

206

Canonical notch signaling functions as a commitment switch in the epidermal lineage  

PubMed Central

Mammalian epidermis consists of a basal layer of proliferative progenitors that gives rise to multiple differentiating layers to provide a waterproof envelope covering the skin surface. To accomplish this, progenitor cells must detach from the basal layer, move upward, and execute a terminal differentiation program consisting of three distinct stages: spinous, granular layer, and stratum corneum. Notch signaling has been implicated in late stages of differentiation, but the commitment switch remains unknown. Here we show with loss and gain-of-function studies that active Notch intracellular domain (NICD) and its obligate canonical signaling partner RBP-J act at the basal/suprabasal juncture to induce spinous and down-regulate basal fate. Spinous layers are absent in RBP-J conditional null epidermis and expanded when Notch1 signaling is elevated transgenically in epidermis. We show that RBP-J is essential for mediating both spinous gene activation and basal gene repression. In contrast, the NICD/RBP-J target gene Hes1 is expressed in spinous layers and mediates spinous gene induction but not basal gene repression. These data uncover an early role for RBP-J and Notch in commitment of epidermal cells to terminally differentiate and reveal that spinous gene induction is mediated by a Hes1-dependent mechanism, while basal gene repression occurs independently of Hes1.

Lowry, William E.; Pasolli, H. Amalia; Fuchs, Elaine

2006-01-01

207

Design of Inorganic Water Repellent Coatings for Thermal Protection Insulation on an Aerospace Vehicle  

NASA Technical Reports Server (NTRS)

In this report, thin film deposition of one of the model candidate materials for use as water repellent coating on the thermal protection systems (TPS) of an aerospace vehicle was investigated. The material tested was boron nitride (BN), the water-repellent properties of which was detailed in our other investigation. Two different methods, chemical vapor deposition (CVD) and pulsed laser deposition (PLD), were used to prepare the BN films on a fused quartz substrate (one of the components of thermal protection systems on aerospace vehicles). The deposited films were characterized by a variety of techniques including X-ray diffraction, X-ray photoelectron spectroscopy, and scanning electron microscopy. The BN films were observed to be amorphous in nature, and a CVD-deposited film yielded a contact angle of 60 degrees with water, similar to the pellet BN samples investigated previously. This demonstrates that it is possible to use the bulk sample wetting properties as a guideline to determine the candidate waterproofing material for the TPS.

Fuerstenau, D. W.; Ravikumar, R.

1997-01-01

208

Shuttle antenna radome technology test program. Volume 2: Development of S-band antenna interface design  

NASA Technical Reports Server (NTRS)

The effects of the Thermal Protection Subsystem (TPS) contamination on the space shuttle orbiter S band quad antenna due to multiple mission buildup are discussed. A test fixture was designed, fabricated and exposed to ten cycles of simulated ground and flight environments. Radiation pattern and impedance tests were performed to measure the effects of the contaminates. The degradation in antenna performance was attributed to the silicone waterproofing in the TPS tiles rather than exposure to the contaminating sources used in the test program. Validation of the accuracy of an analytical thermal model is discussed. Thermal vacuum tests with a test fixture and a representative S band quad antenna were conducted to evaluate the predictions of the analytical thermal model for two orbital heating conditions and entry from each orbit. The results show that the accuracy of predicting the test fixture thermal responses is largely dependent on the ability to define the boundary and ambient conditions. When the test conditions were accurately included in the analytical model, the predictions were in excellent agreement with measurements.

Kuhlman, E. A.; Baranowski, L. C.

1977-01-01

209

The "Double-Pulley" Technique for Arthroscopic Fixation of Partial Articular-Side Bony Avulsion of the Supraspinatus Tendon: A Rare Case of Bony PASTA Lesion  

PubMed Central

We report the use of the double-pulley technique for arthroscopic fixation of the bony PASTA (partial articular surface tendon avulsion) lesion. Arthroscopic examination documented a 15-mm-long and 8-mm-wide comminuted bony avulsion with 2 main fragments. Two double-loaded suture anchors were placed with a transtendinous technique at the anterior and posterior edges of the lesion respecting the tendon insertion to the avulsed fragment. The medial sutures were retrieved through the intact supraspinatus tendon medially to the fracture. The sutures were initially coupled in a double-pulley configuration generating 2 sutures oriented from anterior to posterior; then a simple suture for each anchor oriented from medial to lateral was obtained. At the end of the procedure, the adequacy of reduction and stability of the fragments were confirmed. At 2 months from surgery, radiographic healing of the fracture was noted and integrity of the supraspinatus tendon insertion to the footprint was confirmed by arthro–magnetic resonance imaging, with full recovery of daily activities and complete active range of motion confirmed at 6 and 12 months. The double-pulley technique allows optimal reduction of bony fragments and reconstruction of normal footprint anatomy even in comminuted fractures. Moreover, it creates a waterproof reduction of the fragments, protecting the fracture site from synovial fluid.

Murena, Luigi; Canton, Gianluca; Falvo, Daniele A.; Genovese, Eugenio A.; Surace, Michele F.; Cherubino, Paolo

2012-01-01

210

QSAR classification models for the screening of the endocrine-disrupting activity of perfluorinated compounds.  

PubMed

Perfluorinated compounds (PFCs) are a class of emerging pollutants still widely used in different materials as non-adhesives, waterproof fabrics, fire-fighting foams, etc. Their toxic effects include potential for endocrine-disrupting activity, but the amount of experimental data available for these pollutants is limited. The use of predictive strategies such as quantitative structure-activity relationships (QSARs) is recommended under the REACH regulation, to fill data gaps and to screen and prioritize chemicals for further experimentation, with a consequent reduction of costs and number of tested animals. In this study, local classification models for PFCs were developed to predict their T4-TTR (thyroxin-transthyretin) competing potency. The best models were selected by maximizing the sensitivity and external predictive ability. These models, characterized by robustness, good predictive power and a defined applicability domain, were applied to predict the activity of 33 other PFCs of environmental concern. Finally, classification models recently published by our research group for T4-TTR binding of brominated flame retardants and for estrogenic and anti-androgenic activity were applied to the studied perfluorinated chemicals to compare results and to further evaluate the potential for these PFCs to cause endocrine disruption. PMID:22352429

Kovarich, S; Papa, E; Li, J; Gramatica, P

2012-01-01

211

Use of high-resolution mass spectrometry to identify precursors and biodegradation products of perfluorinated and polyfluorinated compounds in end-user products.  

PubMed

Structural identification of perfluoroalkyl and polyfluoroalkyl substances found in end-user products and their biodegradation products was performed using ultra-high resolution mass spectrometry. Little attention has so far been paid to the environmental burden of perfluorooctane sulfonate and perfluorooctanoic acid from compounds with a molar mass of ~2,000. Analysis of end-user waterproofing and stain repellent products revealed the presence of numerous ions with molar masses ranging from 1,000 to 2,000 and complex mass spectra. Ultra-high resolution mass spectrometry determined the accurate mass of the observed ions, allowing the cleavage position and fragment structure to be determined. The precursor structures were determined based on reconstitution of the retrieved fragments. Products of fluorochemical manufacturers before voluntary regulation comprised compounds with plural perfluorooctyl chains. In the current product lines, compounds comprising perfluorobutyl chains were detected. Biodegradation tests using activated sludge revealed that biodegradation products consistent with those reported previously were generated even from complex end-user products. For example, the biodegradation test revealed the formation of N-ethyl perfluorooctane sulfonamido acetic acid and various fluorotelomer acids in the samples. The results of the present study suggest that the environmental burden of these compounds should be reevaluated. PMID:24828983

Yamamoto, Atsushi; Hisatomi, Hirotaka; Ando, Tomoshige; Takemine, Shusuke; Terao, Tomoko; Tojo, Toshiki; Yagi, Masahiro; Ono, Daisuke; Kawasaki, Hideya; Arakawa, Ryuichi

2014-07-01

212

Isotopic characterization of the Precambrian carbonate aquifers under the city of Bangui (Central African Republic)  

NASA Astrophysics Data System (ADS)

The city of Bangui, the capital of the Central African Republic, is located on the right bank of the Ubangi River which is the northernmost tributary of the Congo River. From its foundation in 1889 this city has always suffered from serious problems of water management. This is related to the specificity of the site configuration (steep hills surrounding a large swampy flat valley poorly drained) and to the urbanisation process responsible for the waterproofing of soils and the associated increased runoff processes under tropical humid condition.This paper presents the results of a geochemical and isotopic survey carried out in 2011 aiming at evaluating the type and chemical quality of the groundwater resources of the Bangui region. By combining geological, hydrogeochemical and isotopic data it appears that the underground of Bangui seems favourable to the development of a secured and sustainable water supply from groundwater provided that the conditions of exploitation would be constrained by the local authorities. The deep fractured (and locally kastified) Precambrian carbonate aquifers known as Bimbo and Fatima formations are identified as target resources considering the relatively good quality of the resource from the chemical point of view, and the semi-confined structure of the aquifer preventing the mixing with shallow aquifers already strongly impacted by domestic and industrial pollutions.

Huneau, Frederic; Djebebe-Ndjiguim, Chantal-Laure; Foto, Eric; Ito, Mari; Celle-Jeanton, Helene; Garel, Emilie; Mabingui, Joseph

2013-04-01

213

NASA Tech Briefs, September 2003  

NASA Technical Reports Server (NTRS)

Topics include: Oxygen-Partial-Pressure Sensor for Aircraft Oxygen Mask; Three-Dimensional Venturi Sensor for Measuring Extreme Winds; Swarms of Micron-Sized Sensors; Monitoring Volcanoes by Use of Air-Dropped Sensor Packages; Capacitive Sensors for Measuring Masses of Cryogenic Fluids; UHF Microstrip Antenna Array for Synthetic- Aperture Radar; Multimode Broad-Band Patch Antennas; 164-GHz MMIC HEMT Frequency Doubler; GPS Position and Heading Circuitry for Ships; Software for Managing Parametric Studies; Software Aids Visualization of Computed Unsteady Flow; Software for Testing Electroactive Structural Components; Advanced Software for Analysis of High-Speed Rolling-Element Bearings; Web Program for Development of GUIs for Cluster Computers; XML-Based Generator of C++ Code for Integration With GUIs; Oxide Protective Coats for Ir/Re Rocket Combustion Chambers; Simplified Waterproofing of Aerogels; Improved Thermal-Insulation Systems for Low Temperatures; Device for Automated Cutting and Transfer of Plant Shoots; Extension of Liouville Formalism to Postinstability Dynamics; Advances in Thrust-Based Emergency Control of an Airplane; Ultrasonic/Sonic Mechanisms for Drilling and Coring; Exercise Device Would Exert Selectable Constant Resistance; Improved Apparatus for Measuring Distance Between Axles; Six Classes of Diffraction-Based Optoelectronic Instruments; Modernizing Fortran 77 Legacy Codes; Active State Model for Autonomous Systems; Shields for Enhanced Protection Against High-Speed Debris; Scaling of Two-Phase Flows to Partial-Earth Gravity; Neutral-Axis Springs for Thin-Wall Integral Boom Hinges.

2003-01-01

214

A Feasibility Study of Wearable Activity Monitors for Pre-Adolescent School-Age Children  

PubMed Central

Introduction Understanding physical activity is key in the fight against childhood obesity. The objective of this study was to examine the feasibility of using certain wearable devices to measure physical activity among children. Methods A qualitative study was conducted with 25 children aged 7 to 10 years to assess acceptability and compliance of wearable activity devices in this age group. During March through August 2012, children participated in a 4-week study of 3 accelerometer models and a heart rate monitor. Children were asked to use a different device each week for 7 consecutive days. Children and their parents completed structured interviews after using each device; they also completed a final exit interview. Results The wrist-worn Polar Active was the device most preferred by children and was associated with the highest level of compliance. Devices that are comfortable to wear, fit properly, have engaging features, and are waterproof increase feasibility and are associated with higher levels of compliance. Conclusion The wrist-worn device was the most feasible for measuring physical activity among children aged 7 to 10 years. These findings will inform researchers in selecting tools for measuring children’s physical activity.

Van Loan, Marta; German, J. Bruce

2014-01-01

215

Could the Health Decline of Prehistoric California Indians be Related to Exposure to Polycyclic Aromatic Hydrocarbons (PAHs) from Natural Bitumen?  

PubMed Central

Background: The negative health effects of polycyclic aromatic hydrocarbons (PAHs) are well established for modern human populations but have so far not been studied in prehistoric contexts. PAHs are the main component of fossil bitumen, a naturally occurring material used by past societies such as the Chumash Indians in California as an adhesive, as a waterproofing agent, and for medicinal purposes. The rich archaeological and ethnohistoric record of the coastal Chumash suggests that they were exposed to multiple uptake pathways of bituminous PAHs, including direct contact, fume inhalation, and oral uptake from contaminated water and seafood. Objectives: We investigated the possibility that PAHs from natural bitumen compromised the health of the prehistoric Chumash Indians in California. Conclusions: Exposure of the ancient Chumash Indians to toxic PAHs appears to have gradually increased across a period of 7,500 years because of an increased use of bitumen in the Chumash technology, together with a dietary shift toward PAH-contaminated marine food. Skeletal analysis indicates a concurrent population health decline that may be related to PAH uptake. However, establishing such a connection is virtually impossible without knowing the actual exposure levels experienced by these populations. Future methodological research may provide techniques for determining PAH levels in ancient skeletal material, which would open new avenues for research on the health of prehistoric populations and on the long-term effects of human PAH exposure.

Sholts, Sabrina B.; Erlandson, Jon M.; Gjerdrum, Thor; Westerholm, Roger

2011-01-01

216

Lightweight, Miniature Inertial Measurement System  

NASA Technical Reports Server (NTRS)

A miniature, lighter-weight, and highly accurate inertial navigation system (INS) is coupled with GPS receivers to provide stable and highly accurate positioning, attitude, and inertial measurements while being subjected to highly dynamic maneuvers. In contrast to conventional methods that use extensive, groundbased, real-time tracking and control units that are expensive, large, and require excessive amounts of power to operate, this method focuses on the development of an estimator that makes use of a low-cost, miniature accelerometer array fused with traditional measurement systems and GPS. Through the use of a position tracking estimation algorithm, onboard accelerometers are numerically integrated and transformed using attitude information to obtain an estimate of position in the inertial frame. Position and velocity estimates are subject to drift due to accelerometer sensor bias and high vibration over time, and so require the integration with GPS information using a Kalman filter to provide highly accurate and reliable inertial tracking estimations. The method implemented here uses the local gravitational field vector. Upon determining the location of the local gravitational field vector relative to two consecutive sensors, the orientation of the device may then be estimated, and the attitude determined. Improved attitude estimates further enhance the inertial position estimates. The device can be powered either by batteries, or by the power source onboard its target platforms. A DB9 port provides the I/O to external systems, and the device is designed to be mounted in a waterproof case for all-weather conditions.

Tang, Liang; Crassidis, Agamemnon

2012-01-01

217

[Action proposals to Japanese Neurological Society from Fukushima Medical University: based on our three years' experiences].  

PubMed

In this paper, I make several proposals of what Japanese Neurological Society is able to do or should do in preparing future disaster in Japan. I mention several points separately.Patient education: Patients usually try to visit their hospital as soon as possible for the safety, especially in Japan. Is it true? The traffic jams actually blocked this action in March 11, 2011, which made more serious problems in some patients. We should ask them to prepare matters necessary for staying at home at least for a week when no medical emergency is present.Disaster prevention training: We should make a list of hospitals which accept emergent patients at disaster. We should have some methods of communication still active at disaster (internet, satellite phone) and make society network for communication and patient transportation. How to transfer required drugs to patients is another issue we should consider.Name tag: We sometimes treated unidentified patients in the disaster because the name tag or reference papers was gone or not specified to a certain patient. It is due to great mechanical power of injury or rains. For not detached from the patient and waterproofed, I recommend writing the patient's name on the chest with a permanent marker used in the triathlon when transferring the patients to other hospitals or other places. PMID:24291912

Ugawa, Yoshikazu

2013-01-01

218

Mechanical model testing of rebreathing potential in infant bedding materials  

PubMed Central

Rebreathing of expired air may be a lethal hazard for prone sleeping infants. This paper describes a mechanical model to simulate infant breathing, and examines the effects of bedding on exhaled air retention. Under simulated rebreathing conditions, the model allows the monitoring of raised carbon dioxide (CO2) inside an artificial lung-trachea system. Resulting levels of CO2 (although probably exaggerated in the mechanical model compared with an infant, due to the model's fixed breathing rate and volume) suggest that common bedding materials vary widely in inherent rebreathing potential. In face down tests, maximum airway CO2 ranged from less than 5% on sheets and waterproof mattresses to over 25% on sheepskins, bean bag cushions, and some pillows and comforters. Concentrations of CO2 decreased with increasing head angle of the doll, away from the face down position. Recreations of 29infant death scenes also showed large CO2 increases on some bedding materials, suggesting these infants could have died while rebreathing.??

Carleton, J.; Donoghue, A.; Porter, W.

1998-01-01

219

Biocides used in building materials and their leaching behavior to sewer systems.  

PubMed

There is increasing concern about diffuse pollution of aquatic systems by biocides used in urban areas. We investigated sources and pathways of biocides significant for the pollution of storm water runoff. Main sources seem to be building envelopes, i.e. facades (paints, plasters) and roof sealing membranes. First results from a defined urban catchment drained by a separated sewer system without any agricultural activities reveal a substantial occurrence. Even after the first flush, concentrations of terbutryn, carbendazim, mecoprop as well as Irgarol 1051 and its metabolite exceeded the Swiss water quality standard of 0.1 microg/L. In laboratory experiments, leaching of mecoprop used as a root protection agent in bitumen sheets for roof waterproofing was determined. The concentrations differed in 16 different sheets two orders of magnitude, depending on the product composition. Using optimized products, it is expected to be the most efficient and sustainable way to reduce the environmental impact. To understand transport dynamics and environmental risk, further storm water events will be analyzed. Based on the ongoing project URBIC, first measures will be proposed to limit the release to surface and ground water. PMID:18075180

Burkhardt, M; Kupper, T; Hean, S; Haag, R; Schmid, P; Kohler, M; Boller, M

2007-01-01

220

Development of Small-Scale Submersible PIV System  

NASA Astrophysics Data System (ADS)

A low-cost, small-scale submersible Particle Imaging Velocimetry (PIV) device has been developed to characterize unsteady flow in natural environments. PIV systems provide high accuracy, non intrusive, planar flow measurements of velocity and vorticity. Since this device is intended for the field, it is designed to be portable. This is accomplished using a powerful handheld laser, beam chopper, microprocessor, and the proper lenses, in conjunction with a one mega pixel CCD video camera. The system consists of two connected waterproof cases; one housing the camera and the other the laser/chopper system. The apparatus is fully self-contained and can be operated using a laptop computer on shore or on a floating platform. The system is also unique in that it was developed for under 8000 USD. The PIV device was tested in a small creek in Michigan. Eddy diameter, circulation, orientation, and convective velocity were characterized. The design of a submersible PIV system like this one will lead to a better characterization of naturally occurring flows and a greater understanding of what conditions aquatic life find acceptable. This knowledge will prove most useful in river and shoreline restoration, as well as in the design of new coastal management plans to alleviate human impact on coastal regions.

Clarke, Jenna; Cotel, Aline; Tritico, Hans

2006-11-01

221

CFD Model of Water Droplet Transport for ISS Hygiene Activity  

NASA Technical Reports Server (NTRS)

The goal of the study is to assess the impacts of free water propagation in the Waste and Hygiene Compartment (WHC). Free water can be generated inside the WHC in small quantities due to crew hygiene activity. To mitigate potential impact of free water in Node 3 cabin the WHC doorway is enclosed by a waterproof bump-out, Kabin, with openings at the top and bottom. At the overhead side of the rack, there is a screen that prevents large drops of water from exiting. However, as the avionics fan in the WHC causes airflow toward the deck side of the rack, small quantities of free water may exit at the bottom of the Kabin. A Computational Fluid Dynamics (CFD) analysis of Node 3 cabin airflow made possible to identify the paths of water transport. The Node 3 airflow was computed for several ventilation scenarios. To simulate the droplet transport the Lagrangian discrete phase approach was used. Various initial droplet distributions were considered in the study. The droplet diameter was varied in the range of 2-20 mm. The results of the computations showed that most of the drops fall to the rack surface not far from the WHC curtain. The probability of the droplet transport to the adjacent rack surface with electronic equipment was predicted.

Son, Chang H.

2011-01-01

222

Marker and pen graffiti cleaning on diverse calcareous stones by different laser techniques  

NASA Astrophysics Data System (ADS)

Industries nowadays continuously produce new types of inks for markers and pens, so new different graffiti appear . In this paper laser cleaning tests on 41 new marker and pen types ( fluorescent, permanent, water-based, acrylic tempera, metallic paint, waterproof inks ), applied into laboratory on different litho- type samples (Chianca, Travertino di Roma, Tufo Carparo fine grain, Sabbie), typical stones employed in much more monuments in Puglia and Italian architectures were carried out. The same ones, were exposed for twelve months to outdoor ageing, subject to sunshine, rain, wind, IR and UV solar radiations. Ablation experiments and tests by using different cleaning techniques, each one in Dry and Wet condition (classic technique, Daurelio technique 1 and Daurelio technique 2 and others new techniques) and two different Nd:YAG laser systems (Palladio by QUANTA SYSTEM and SMART CLEAN II by EL.EN.), were adopted. The experimental modes, N-Mode (1064nm - 150, 300 and 500 ?s pulse duration), Q-Switch (1064nm - 8 ns pulse duration) and SFR (Short Free Running - 1064 nm - 40 to 110?s pulse duration) were tested on each marked stones. It was found that according to the different ink types and stone substrate, Q-Switch laser cleaning ablation with optimized laser technique are the best solution to marker an pen graffiti removal. The work is still in progress.

Andriani, S. E.; Catalano, I. M.; Daurelio, G.; Albanese, A.

2007-05-01

223

Preparation of hydrophobic organic aeorgels  

DOEpatents

Synthetic methods for the preparation of hydrophobic organics aerogels. One method involves the sol-gel polymerization of 1,3-dimethoxybenzene or 1,3,5-trimethoxybenzene with formaldehyde in non-aqueous solvents. Using a procedure analogous to the preparation of resorcinol-formaldehyde (RF) aerogels, this approach generates wet gels that can be dried using either supercritical solvent extraction to generate the new organic aerogels or air dried to produce an xerogel. Other methods involve the sol-gel polymerization of 1,3,5 trihydroxy benzene (phloroglucinol) or 1,3 dihydroxy benzene (resorcinol) and various aldehydes in non-aqueous solvents. These methods use a procedure analogous to the one-step base and two-step base/acid catalyzed polycondensation of phloroglucinol and formaldehyde, but the base catalyst used is triethylamine. These methods can be applied to a variety of other sol-gel precursors and solvent systems. These hydrophobic organics aerogels have numerous application potentials in the field of material absorbers and water-proof insulation.

Baumann, Theodore F. (Tracy, CA); Satcher, Jr., Joe H. (Patterson, CA); Gash, Alexander E. (Livermore, CA)

2007-11-06

224

Can Preening Contribute to Influenza A Virus Infection in Wild Waterbirds?  

PubMed Central

Wild aquatic birds in the Orders Anseriformes and Charadriiformes are the main reservoir hosts perpetuating the genetic pool of all influenza A viruses, including pandemic viruses. High viral loads in feces of infected birds permit a fecal-oral route of transmission. Numerous studies have reported the isolation of avian influenza viruses (AIVs) from surface water at aquatic bird habitats. These isolations indicate aquatic environments have an important role in the transmission of AIV among wild aquatic birds. However, the progressive dilution of infectious feces in water could decrease the likelihood of virus/host interactions. To evaluate whether alternate mechanisms facilitate AIV transmission in aquatic bird populations, we investigated whether the preen oil gland secretions by which all aquatic birds make their feathers waterproof could support a natural mechanism that concentrates AIVs from water onto birds' bodies, thus, representing a possible source of infection by preening activity. We consistently detected both viral RNA and infectious AIVs on swabs of preened feathers of 345 wild mallards by using reverse transcription–polymerase chain reaction (RT-PCR) and virus-isolation (VI) assays. Additionally, in two laboratory experiments using a quantitative real-time (qR) RT-PCR assay, we demonstrated that feather samples (n?=?5) and cotton swabs (n?=?24) experimentally impregnated with preen oil, when soaked in AIV-contaminated waters, attracted and concentrated AIVs on their surfaces. The data presented herein provide information that expands our understanding of AIV ecology in the wild bird reservoir system.

Delogu, Mauro; De Marco, Maria A.; Di Trani, Livia; Raffini, Elisabetta; Cotti, Claudia; Puzelli, Simona; Ostanello, Fabio; Webster, Robert G.; Cassone, Antonio; Donatelli, Isabella

2010-01-01

225

Automatic front-crawl temporal phase detection using adaptive filtering of inertial signals.  

PubMed

This study introduces a novel approach for automatic temporal phase detection and inter-arm coordination estimation in front-crawl swimming using inertial measurement units (IMUs). We examined the validity of our method by comparison against a video-based system. Three waterproofed IMUs (composed of 3D accelerometer, 3D gyroscope) were placed on both forearms and the sacrum of the swimmer. We used two underwater video cameras in side and frontal views as our reference system. Two independent operators performed the video analysis. To test our methodology, seven well-trained swimmers performed three 300 m trials in a 50 m indoor pool. Each trial was in a different coordination mode quantified by the index of coordination. We detected different phases of the arm stroke by employing orientation estimation techniques and a new adaptive change detection algorithm on inertial signals. The difference of 0.2 ± 3.9% between our estimation and video-based system in assessment of the index of coordination was comparable to experienced operators' difference (1.1 ± 3.6%). The 95% limits of agreement of the difference between the two systems in estimation of the temporal phases were always less than 7.9% of the cycle duration. The inertial system offers an automatic easy-to-use system with timely feedback for the study of swimming. PMID:23560703

Dadashi, Farzin; Crettenand, Florent; Millet, Grégoire P; Seifert, Ludovic; Komar, John; Aminian, Kamiar

2013-01-01

226

Modular hydro dam approach to the economic development of ultra low-head hydropower  

SciTech Connect

The solution to developing economical ultra low-head (10 ft. -6 ft., 3m-2m hydrpower lies in being able to reduce equipment and construction costs at new dams to less than $4000/KW, while maintaining an operating efficiency of 80% or more. The purpose of this investigation was to explore the potential for developing economical new ultra low-head sites using an innovative concept known as the Modular Hydro Dam (MHD). This concept, combines the benefits of shop fabrication and installation of equipment in truck transportable, waterproof power modules, with prefabricated gate sections that can be located between the power modules. Lateral support to withstand the static head pressure is provided by an upstream tension cable system anchored at each bank. Foundation design for vertical support varies with subsurface conditions. The technical, economic, environmental, and institutional feasibility of the MHD concept were examined. The module selected contains an axial-flow type turbine, rated at 300 kW under a 10-ft head, a generator driven by a belt drive, vertical intake gate, and electrical control system and switchgear. Capital and operating costs are estimated. It is concluded that the US potential for power generation at ultralow-head sites justifies the development of the MHD concept, and that a full scale demonstration of the concept could be completed by 1986. (LCL)

Broome, K.R.

1981-01-01

227

Overexpression of Arabidopsis ECERIFERUM1 promotes wax very-long-chain alkane biosynthesis and influences plant response to biotic and abiotic stresses.  

PubMed

Land plant aerial organs are covered by a hydrophobic layer called the cuticle that serves as a waterproof barrier protecting plants against desiccation, ultraviolet radiation, and pathogens. Cuticle consists of a cutin matrix as well as cuticular waxes in which very-long-chain (VLC) alkanes are the major components, representing up to 70% of the total wax content in Arabidopsis (Arabidopsis thaliana) leaves. However, despite its major involvement in cuticle formation, the alkane-forming pathway is still largely unknown. To address this deficiency, we report here the characterization of the Arabidopsis ECERIFERUM1 (CER1) gene predicted to encode an enzyme involved in alkane biosynthesis. Analysis of CER1 expression showed that CER1 is specifically expressed in the epidermis of aerial organs and coexpressed with other genes of the alkane-forming pathway. Modification of CER1 expression in transgenic plants specifically affects VLC alkane biosynthesis: waxes of TDNA insertional mutant alleles are devoid of VLC alkanes and derivatives, whereas CER1 overexpression dramatically increases the production of the odd-carbon-numbered alkanes together with a substantial accumulation of iso-branched alkanes. We also showed that CER1 expression is induced by osmotic stresses and regulated by abscisic acid. Furthermore, CER1-overexpressing plants showed reduced cuticle permeability together with reduced soil water deficit susceptibility. However, CER1 overexpression increased susceptibility to bacterial and fungal pathogens. Taken together, these results demonstrate that CER1 controls alkane biosynthesis and is highly linked to responses to biotic and abiotic stresses. PMID:21386033

Bourdenx, Brice; Bernard, Amélie; Domergue, Frédéric; Pascal, Stéphanie; Léger, Amandine; Roby, Dominique; Pervent, Marjorie; Vile, Denis; Haslam, Richard P; Napier, Johnathan A; Lessire, René; Joubès, Jérôme

2011-05-01

228

Reconstitution of plant alkane biosynthesis in yeast demonstrates that Arabidopsis ECERIFERUM1 and ECERIFERUM3 are core components of a very-long-chain alkane synthesis complex.  

PubMed

In land plants, very-long-chain (VLC) alkanes are major components of cuticular waxes that cover aerial organs, mainly acting as a waterproof barrier to prevent nonstomatal water loss. Although thoroughly investigated, plant alkane synthesis remains largely undiscovered. The Arabidopsis thaliana ECERIFERUM1 (CER1) protein has been recognized as an essential element of wax alkane synthesis; nevertheless, its function remains elusive. In this study, a screen for CER1 physical interaction partners was performed. The screen revealed that CER1 interacts with the wax-associated protein ECERIFERUM3 (CER3) and endoplasmic reticulum-localized cytochrome b5 isoforms (CYTB5s). The functional relevance of these interactions was assayed through an iterative approach using yeast as a heterologous expression system. In a yeast strain manipulated to produce VLC acyl-CoAs, a strict CER1 and CER3 coexpression resulted in VLC alkane synthesis. The additional presence of CYTB5s was found to enhance CER1/CER3 alkane production. Site-directed mutagenesis showed that CER1 His clusters are essential for alkane synthesis, whereas those of CER3 are not, suggesting that CYTB5s are specific CER1 cofactors. Collectively, our study reports the identification of plant alkane synthesis enzymatic components and supports a new model for alkane production in which CER1 interacts with both CER3 and CYTB5 to catalyze the redox-dependent synthesis of VLC alkanes from VLC acyl-CoAs. PMID:22773744

Bernard, Amélie; Domergue, Frédéric; Pascal, Stéphanie; Jetter, Reinhard; Renne, Charlotte; Faure, Jean-Denis; Haslam, Richard P; Napier, Johnathan A; Lessire, René; Joubès, Jérôme

2012-07-01

229

Assessment of the state of urban ecosystems on the basis of remote sensing data  

NASA Astrophysics Data System (ADS)

The results of the soil-ecological monitoring of the Novovladykino (Moscow) key site are presented. The monitoring included the interpretation of aerospace information collected in 2000 and 2010, terrestrial route observations, and mapping of the key site. The data obtained confirm the possibility to use the remote sensing information in the investigation of urban ecosystems and to recognize the arboreal vegetation, shrubs, and lawn grass in images. The approximate identification of the tree species; the assessment of the state of the green belts and the natural, anthropogenic, and technogenic soils and their complexes; the identification of the overcompacted, mechanically destroyed, and sealed soils under the waterproof and permeable surface horizons are also possible. The determination of the species composition of the trees in small groups, the poor state of the individual trees and small groves, and the causes of the changes in the state of the green belts and polluted areas turned out to be impossible. Additional field and laboratory investigations were performed in order to verify and refine information obtained from the satellite images.

Gorokhova, I. N.; Borisochkina, T. I.; Shishkonakova, E. A.

2013-04-01

230

Detailed tests and specifications of the new microbarometer MB3  

NASA Astrophysics Data System (ADS)

To solve the unaddressed issue of remote calibration of infrasound stations and some needs for temporary deployment, CEA developed a new microbarometer called MB3. The goal was to propose a sensor as reliable and robust as the worldwide deployed reference sensor MB2005, with a self-noise 10 dB under the Low noise model on the whole IS bandwidth. The core of the sensor is an aneroid capsule coupled to a magnet & coil transducer. A secondary coil wrapped with the main one ensures remote calibration. Two versions are available. The analog one MB3a, is compatible with usual digitizers while the MB3d is digital, embedding a low consumption high performance ADC, a low drift GPS timing board and a 1 GB data storage memory. This last version is especially suitable for temporary measurement required by scientific studies. Experiments showed the MB3 ability to measure very low frequency signals down to 24 hours. Environment testing was performed with success: Operating temperature, Waterproofness, Shock/fall, Transportation, EMC compliancy…

Denis, Stephane; Nief, Guillaume; Baptiste Le Blanc, Jean; Larsonnier, Franck; Bosca, Laurent; Guillois, Francis

2014-05-01

231

Tubularized Penile-Flap Urethroplasty Using a Fasciocutaneous Random Pedicled Flap for Recurrent Anterior Urethral Stricture  

PubMed Central

This report describes the use of a tubularized random flap for the curative treatment of recurrent anterior urethral stricture. Under the condition of pendulous lithotomy and suprapubic cystostomy, the urethral stricture was removed via a midline ventral penile incision followed by elevation of the flap and insertion of an 18-Fr catheter. Subcutaneous buried interrupted sutures were used to reapproximate the waterproof tubularized neourethra and to coapt with the neourethra and each stump of the urethra, first proximally and then distally. The defect of the penile shaft was covered by advancement of the surrounding scrotal flap. The indwelling catheter was maintained for 21 days. A 9 month postoperative cystoscopy showed no flap necrosis, no mechanical stricture, and no hair growth on the lumen of the neourethra. The patient showed no voiding discomfort 6 months after the operation. The advantages of this procedure are the lack of need for microsurgery, shortening of admission, the use of only spinal anesthesia (no general anesthesia), and a relatively short operative time. The tubularized unilateral penile fasciocutaneous flap should be considered an option for initial flap urethroplasty as a curative technique.

Lee, Byung Kwon

2012-01-01

232

Tubularized penile-flap urethroplasty using a fasciocutaneous random pedicled flap for recurrent anterior urethral stricture.  

PubMed

This report describes the use of a tubularized random flap for the curative treatment of recurrent anterior urethral stricture. Under the condition of pendulous lithotomy and suprapubic cystostomy, the urethral stricture was removed via a midline ventral penile incision followed by elevation of the flap and insertion of an 18-Fr catheter. Subcutaneous buried interrupted sutures were used to reapproximate the waterproof tubularized neourethra and to coapt with the neourethra and each stump of the urethra, first proximally and then distally. The defect of the penile shaft was covered by advancement of the surrounding scrotal flap. The indwelling catheter was maintained for 21 days. A 9 month postoperative cystoscopy showed no flap necrosis, no mechanical stricture, and no hair growth on the lumen of the neourethra. The patient showed no voiding discomfort 6 months after the operation. The advantages of this procedure are the lack of need for microsurgery, shortening of admission, the use of only spinal anesthesia (no general anesthesia), and a relatively short operative time. The tubularized unilateral penile fasciocutaneous flap should be considered an option for initial flap urethroplasty as a curative technique. PMID:22783537

Lee, Yong Jig; Lee, Byung Kwon

2012-05-01

233

Evaluation of reusable surface insulation for space shuttle over a range of heat-transfer rate and surface temperature  

NASA Technical Reports Server (NTRS)

Reusable surface insulation materials, which were developed as heat shields for the space shuttle, were tested over a range of conditions including heat-transfer rates between 160 and 620 kW/sq m. The lowest of these heating rates was in a range predicted for the space shuttle during reentry, and the highest was more than twice the predicted entry heating on shuttle areas where reusable surface insulation would be used. Individual specimens were tested repeatedly at increasingly severe conditions to determine the maximum heating rate and temperature capability. A silica-base material experienced only minimal degradation during repeated tests which included conditions twice as severe as predicted shuttle entry and withstood cumulative exposures three times longer than the best mullite material. Mullite-base materials cracked and experienced incipient melting at conditions within the range predicted for shuttle entry. Neither silica nor mullite materials consistently survived the test series with unbroken waterproof surfaces. Surface temperatures for a silica and a mullite material followed a trend expected for noncatalytic surfaces, whereas surface temperatures for a second mullite material appeared to follow a trend expected for a catalytic surface.

Chapman, A. J.

1973-01-01

234

Segmented, elongated, expandable, 4-season, double-walled, low-cost, rigid extruded plastic panel structures  

US Patent & Trademark Office Database

Low-cost, semi-permanent rigid-wall modular longhouse-type, peaked-roof structures, stadium-shaped (in plan view), made of light-weight, water-proof cellular extruded plastic sheet material die cut into blanks that are easily portable, quickly field erectable and dismountable by unskilled workers for a wide variety of uses. Two semi-circular end portions are spaced apart and joined by multiple segments of straight wall and roof modules, the length depending only on the number of intermediate segments. Blanks are easily folded on site into double-walled, bolt-together, modular wall and roof panels. Only four basic panel configurations are needed to form all structural elements. Multiple modular structures may be grouped to form larger compound structures with individual ones assigned to individual persons or dedicated work space usages: disaster shelters, sleeping, gathering, storage, hygiene, medical treatment, schooling, entertainment, goods manufacture, cooking, eating, herding, etc. Double-wall modules provide inter-stitial space for cold-weather insulation and passive ventilation in hot environments.

2013-02-26

235

A comparison of standard methods for measuring water vapour permeability of fabrics  

NASA Astrophysics Data System (ADS)

It is difficult for outdoor apparel manufacturers to interpret the technical information provided by fabric suppliers concerning fabric 'breathability' properties because different methods and test conditions are used. In addition, fabrics with hydrophilic components change their properties under different humidity conditions. The purpose of this study was to measure the water vapour permeability and evaporative resistance of 26 different waterproof, windproof and breathable shell fabrics using five standard test methods. The water vapour transmission rate (WVTR) was measured using the ASTM E 96 upright and inverted cup tests with water, the JIS L 1099 desiccant inverted cup test and the new ASTM F 2298 standard using the dynamic moisture permeation cell (DMPC). The evaporative resistance was measured using the ISO 11092 sweating hot plate test. The WVTRs were consistently highest when measured with the desiccant inverted cup, followed by the inverted cup, DMPC and upright cup. The upright cup was significantly correlated with the DMPC (0.97), and the desiccant inverted cup was correlated to the sweating hot plate (-0.91).

McCullough, Elizabeth A.; Kwon, Myoungsook; Shim, Huensup

2003-08-01

236

Comparative analysis of cutaneous evaporative water loss in frogs demonstrates correlation with ecological habits.  

PubMed

Most frog species show little resistance to evaporative water loss (EWL), but some arboreal species are known to have very high resistances. We measured EWL and cutaneous resistance to evaporation (Rc) in 25 species of frogs from northern Australia, including 17 species in the family Hylidae, six species in the Myobatrachidae, and one each in the Bufonidae and the Microhylidae. These species display a variety of ecological habits, including aquatic, terrestrial, and arboreal specialisations, with the complete range of habits displayed within just the one hylid genus, Litoria. The 25 species measured in this study have resistances that range from Rc=0 to 63.1. These include low values indistinguishable from a free water surface to high values typical of "waterproof" anuran species. There was a strong correlation between ecological habit and Rc, even taking phylogenetic relationships into account; arboreal species had the highest resistance, aquatic species tended to have little or no resistance, and terrestrial species tended to have resistance between those of arboreal and aquatic frogs. For one species, Litoria rubella, we found no significant changes in EWL along a 1,500-km aridity gradient. This study represents the strongest evidence to date of a link between ecological habits and cutaneous resistance to water loss among species of frogs. PMID:16052451

Young, Jeanne E; Christian, Keith A; Donnellan, Stephen; Tracy, Christopher R; Parry, David

2005-01-01

237

Study on antireflective coatings of PbTe/PbSnTe heterojunction infrared detectors  

NASA Astrophysics Data System (ADS)

ZnS antireflective coatings and passivation layer are developed on self-made PbTe/PbSnTe heterojunction infrared detectors and following experiments have been finished: WaterProof properties of ZnS coatings; Anti-reflective properties of PbSnTe materials and their detectors with ZnS coatings, respectively; ageing and stability tests of the PbSnTe detectors with ZnS coatings. All experimental results are excellent: The typical detectivity (D*) of PbSnTe detector is 2.83×1010 cmHz1/2W-1. (with peak wavelength ?p=9.8 ?m and cut-off wavelength ?c=11.7 ?m). Average detectivity of the PbSnTe detector with ZnS anti-reflective coatings is increased by 45%. Ageing tests indicated that the PbSnTe detectors with ZnS coatings have still high stabilities after several years. They are used successfully in medical infrared imaging systems and other applications.

Shuxing, Gong

1990-11-01

238

Specification of epidermal cell fate in plant shoots  

PubMed Central

Land plants have evolved a single layer of epidermal cells, which are characterized by mostly anticlinal cell division patterns, formation of a waterproof coat called cuticle, and unique cell types such as stomatal guard cells and trichomes. The shoot epidermis plays important roles not only to protect plants from dehydration and pathogens but also to ensure their proper organogenesis and growth control. Extensive molecular genetic studies in Arabidopsis and maize have identified a number of genes that are required for epidermal cell differentiation. However, the mechanism that specifies shoot epidermal cell fate during plant organogenesis remains largely unknown. Particularly, little is known regarding positional information that should restrict epidermal cell fate to the outermost cell layer of the developing organs. Recent studies suggested that certain members of the HD-ZIP class IV homeobox genes are possible master regulators of shoot epidermal cell fate. Here, we summarize the roles of the regulatory genes that are involved in epidermal cell fate specification and discuss the possible mechanisms that limit the expression and/or activity of the master transcriptional regulators to the outermost cell layer in plant shoots.

Takada, Shinobu; Iida, Hiroyuki

2014-01-01

239

Revisions included in HUD Intermediate Minimum Property Standards Supplement 4930. 2, 1977 edition: solar heating and domestic hot-water systems  

SciTech Connect

This addendum to a 1977 HUD publication contains revisions and additions to the existing intermediate minimum property standards supplment for solar heating and cooling systems. Building design revisions cover fire protection, penetrations, and roof coverings. Changes to guidelines for materials, such as those for thermal and ultraviolet stability and moisture resistance, are detailed. Flash points of toxic and combustive fluids, chemical and physical compatibility, and flame spread and resistance of insulation materials are also explained. Construction standards were revised for hail loads; waterproofing insulated exterior storage containers, pipes, and ducts; and for passive systems. Standards also were revised for power-operated protection, dust and dirt prevention, and chimney and vent heights. Radiation temperature, draft control, and thermal energy storage and loss standards were deleted. Other standards for insulation values for thermal devices, lighting protection, and sealing and testing air distribution systems were added. Appended materials contain revisions to calculation procedures for determining the thermal performance of active, solar space heating, and domestic hot water systems. A revised materials list for properties of typical cover materials, absorptive coatings, thermal storage unit containers, and heat-transfer liquids is provided. Revisions to acceptable engineering practice standards are also included.

Not Available

1984-04-01

240

Design and preparation of ethyl cellulose microcapsules of gadopentetate dimeglumine for neutron-capture therapy using the Wurster process.  

PubMed

Microcapsules of hygroscopic, highly water-soluble gadopentetate dimeglumine (Gd-DTPA-DM) for use in preliminary in vivo experiments for neutron-capture therapy were designed. They were prepared with such properties as a particle size small enough to be suspended and injected through a syringe, a negligible release of Gd-DTPA-DM, and a high drug content by means of the Wurster process, a spray coating method using a spouted bed with a draft tube. They were composed of lactose cores of 53-63 microm, an undercoat of ethyl cellulose (EC) and polyvinylpyrrolidone (PVP), a drug-layer of Gd-DTPA-DM, EC and PVP, a waterproof coat and a release-sustaining overcoat of EC and cholesterol (1:1), and a surface treated with hydrogenated egg lecithin. By curing at 110 degrees C for 30 min after mixing with 20% pulverized mannitol powder, the 20% overcoating suppressed the release of Gd-DTPA-DM from 75-106 microm microcapsules to less than 10% for the first 20 min, which was the period required to prepare a suspension, inject it and irradiate the neutron. The microcapsules could be used to confirm that the intracellular presence of Gd is not critical in gadolinium neutron-capture therapy. PMID:8370113

Fukumori, Y; Ichikawa, H; Tokumitsu, H; Miyamoto, M; Jono, K; Kanamori, R; Akine, Y; Tokita, N

1993-06-01

241

Latherin and other biocompatible surfactant proteins.  

PubMed

Horses and other equids are unusual in producing protein-rich sweat for thermoregulation, a major component of which is latherin, a highly surface-active, non-glycosylated protein that is a member of the PLUNC (palate, lung and nasal epithelium clone) family. Latherin produces a significant reduction in water surface tension at low concentrations (?1 mg/ml), and probably acts as a wetting agent to facilitate evaporative cooling through a thick, waterproofed pelt. Latherin binds temporarily to hydrophobic surfaces, and so may also have a disruptive effect on microbial biofilms. It may consequently have a dual role in horse sweat in both evaporative cooling and controlling microbial growth in the pelt that would otherwise be resourced by nutrients in sweat. Latherin is also present at high levels in horse saliva, where its role could be to improve mastication of the fibrous diet of equids, and also to reduce microbial adherence to teeth and oral surfaces. Neutron reflection experiments indicate that latherin adsorbs to the air/water interface, and that the protein undergoes significant conformational change and/or partial unfolding during incorporation into the interfacial layer. PMID:21787340

Kennedy, Malcolm W

2011-08-01

242

Airplane dopes and doping  

NASA Technical Reports Server (NTRS)

Cellulose acetate and cellulose nitrate are the important constituents of airplane dopes in use at the present time, but planes were treated with other materials in the experimental stages of flying. The above compounds belong to the class of colloids and are of value because they produce a shrinking action on the fabric when drying out of solution, rendering it drum tight. Other colloids possessing the same property have been proposed and tried. In the first stages of the development of dope, however, shrinkage was not considered. The fabric was treated merely to render it waterproof. The first airplanes constructed were covered with cotton fabric stretched as tightly as possible over the winds, fuselage, etc., and flying was possible only in fine weather. The necessity of an airplane which would fly under all weather conditions at once became apparent. Then followed experiments with rubberized fabrics, fabrics treated with glue rendered insoluble by formaldehyde or bichromate, fabrics treated with drying and nondrying oils, shellac, casein, etc. It was found that fabrics treated as above lost their tension in damp weather, and the oil from the motor penetrated the proofing material and weakened the fabric. For the most part the film of material lacked durability. Cellulose nitrate lacquers, however were found to be more satisfactory under varying weather conditions, added less weight to the planes, and were easily applied. On the other hand, they were highly inflammable, and oil from the motor penetrated the film of cellulose nitrate, causing the tension of the fabric to be relaxed.

Smith, W H

1919-01-01

243

Flow rate logging seepage meter  

NASA Technical Reports Server (NTRS)

An apparatus for remotely measuring and logging the flow rate of groundwater seepage into surface water bodies. As groundwater seeps into a cavity created by a bottomless housing, it displaces water through an inlet and into a waterproof sealed upper compartment, at which point, the water is collected by a collection bag, which is contained in a bag chamber. A magnet on the collection bag approaches a proximity switch as the collection bag fills, and eventually enables the proximity switch to activate a control circuit. The control circuit then rotates a three-way valve from the collection path to a discharge path, enables a data logger to record the time, and enables a pump, which discharges the water from the collection bag, through the three-way valve and pump, and into the sea. As the collection bag empties, the magnet leaves the proximity of the proximity switch, and the control circuit turns off the pump, resets the valve to provide a collection path, and restarts the collection cycle.

Reay, William G. (Inventor); Walthall, Harry G. (Inventor)

1996-01-01

244

Analysis of streambed temperatures in ephemeral channels to determine streamflow frequency and duration  

USGS Publications Warehouse

Spatial and temporal patterns in streamflow are rarely monitored for ephemeral streams. Flashy, erosive streamflows common in ephemeral channels create a series of operational and maintenance problems, which makes it impractical to deploy a series of gaging stations along ephemeral channels. Streambed temperature is a robust and inexpensive parameter to monitor remotely, leading to the possibility of analyzing temperature patterns to estimate streamflow frequency and duration along ephemeral channels. A simulation model was utilized to examine various atmospheric and hydrological upper boundary conditions compared with a series of hypothetical temperature-monitoring depths within the streambed. Simulation results indicate that streamflow events were distinguished from changing atmospheric conditions with greater certainty using temperatures at shallow depths (e.g., 10-20 cm) as opposed to the streambed surface. Three ephemeral streams in the American Southwest were instrumented to monitor streambed temperature for determining the accuracy of using this approach to ascertain the long-term temporal and spatial extent of streamflow along each stream channel. Streambed temperature data were collected at the surface or at shallow depth along each stream channel, using thermistors encased in waterproof, single-channel data loggers tethered to anchors in the channel. On the basis of comparisons with site information, such as direct field observations and upstream flow records, diurnal temperature variations successfully detected the presence and duration of streamflow for all sites.

Constantz, J.; Stonestrom, D.; Stewart, A. E.; Niswonger, R.; Smith, T. R.

2001-01-01

245

Overexpression of Arabidopsis ECERIFERUM1 Promotes Wax Very-Long-Chain Alkane Biosynthesis and Influences Plant Response to Biotic and Abiotic Stresses1[W  

PubMed Central

Land plant aerial organs are covered by a hydrophobic layer called the cuticle that serves as a waterproof barrier protecting plants against desiccation, ultraviolet radiation, and pathogens. Cuticle consists of a cutin matrix as well as cuticular waxes in which very-long-chain (VLC) alkanes are the major components, representing up to 70% of the total wax content in Arabidopsis (Arabidopsis thaliana) leaves. However, despite its major involvement in cuticle formation, the alkane-forming pathway is still largely unknown. To address this deficiency, we report here the characterization of the Arabidopsis ECERIFERUM1 (CER1) gene predicted to encode an enzyme involved in alkane biosynthesis. Analysis of CER1 expression showed that CER1 is specifically expressed in the epidermis of aerial organs and coexpressed with other genes of the alkane-forming pathway. Modification of CER1 expression in transgenic plants specifically affects VLC alkane biosynthesis: waxes of TDNA insertional mutant alleles are devoid of VLC alkanes and derivatives, whereas CER1 overexpression dramatically increases the production of the odd-carbon-numbered alkanes together with a substantial accumulation of iso-branched alkanes. We also showed that CER1 expression is induced by osmotic stresses and regulated by abscisic acid. Furthermore, CER1-overexpressing plants showed reduced cuticle permeability together with reduced soil water deficit susceptibility. However, CER1 overexpression increased susceptibility to bacterial and fungal pathogens. Taken together, these results demonstrate that CER1 controls alkane biosynthesis and is highly linked to responses to biotic and abiotic stresses.

Bourdenx, Brice; Bernard, Amelie; Domergue, Frederic; Pascal, Stephanie; Leger, Amandine; Roby, Dominique; Pervent, Marjorie; Vile, Denis; Haslam, Richard P.; Napier, Johnathan A.; Lessire, Rene; Joubes, Jerome

2011-01-01

246

Design and construction of a cost effective headstage for simultaneous neural stimulation and recording in the water maze.  

PubMed

Headstage preamplifiers and source followers are commonly used to study neural activity in behavioral neurophysiology experiments. Available commercial products are often expensive, not easily customized, and not submersible. Here we describe a method to design and build a customized, integrated circuit headstage for simultaneous 4-channel neural recording and 2-channel simulation in awake, behaving animals. The headstage is designed using a free, commercially available CAD-type design package, and can be modified easily to accommodate different scales (e.g. to add channels). A customized printed circuit board is built using surface mount resistors, capacitors and operational amplifiers to construct the unity gain source follower circuit. The headstage is made water-proof with a combination of epoxy, parafilm and a synthetic rubber putty. We have successfully used this device to record local field potentials and stimulate different brain regions simultaneously via independent channels in rats swimming in a water maze. The total cost is < $30/unit and can be manufactured readily. PMID:20972415

Shirvalkar, Prasad R; Shapiro, Mathew L

2010-01-01

247

Fabrication of superhydrophobic cellulose-based materials through a solution-immersion process.  

PubMed

An industrial waterproof reagent [(potassium methyl siliconate) (PMS)] was used for fabricating a superhydrophobic surface on a cellulose-based material (cotton fabric or paper) through a solution-immersion method. This method involves a hydrogen bond assembly and a polycondensation process. The silanol, which was formed by a reaction of PMS aqueous solution with CO 2, was assembled on the cellulose molecule surface via hydrogen bond interactions. The polymethylsilsesquioxane coatings were prepared by a polycondensation reaction of the hydroxyl between cellulose and silanol. The superhydrophobic cellulose materials were characterized by FTIR spectroscopy, thermogravimetry, and surface analysis (XPS, FESEM, AFM, and contact angle measurements). Analytical characterization revealed that nanoscale roughness protuberances uniformly covered the surface, thus transforming the cellulose from superhydrophilic to superhydrophobic with a water contact angle of 157 degrees . The superhydrophobic coatings were satisfactory with regard to both chemical and mechanical durability, and because of the transparency of the coatings the native cotton fabric displayed no changes with regard to either morphology or color. The easy availability of the materials and simplicity of this method render it convenient for mass production. PMID:18426232

Li, Shenghai; Zhang, Suobo; Wang, Xianhong

2008-05-20

248

Modular, multi-level groundwater sampler  

DOEpatents

An apparatus is described for taking a multiple of samples of groundwater or pressure measurements from a well simultaneously. The apparatus comprises a series of chambers arranged in an axial array, each of which is dimensioned to fit into a perforated well casing and leave a small gap between the well casing and the exterior of the chamber. Seals at each end of the container define the limits to the axial portion of the well to be sampled. A submersible pump in each chamber pumps the groundwater that passes through the well casing perforations into the gap from the gap to the surface for analysis. The power lines and hoses for the chambers farther down the array pass through each chamber above them in the array. The seals are solid, water-proof, non-reactive, resilient disks supported to engage the inside surface of the well casing. Because of the modular design, the apparatus provides flexibility for use in a variety of well configurations. 3 figures.

Nichols, R.L.; Widdowson, M.A.; Mullinex, H.; Orne, W.H.; Looney, B.B.

1994-03-15

249

Investigations of a large scale eared grebe (Podiceps nigricollis) die-off at the Salton Sea, California in 1992  

USGS Publications Warehouse

An estimated 150,000 Eared Grebes (Podiceps nigricollis) died at the Salton Sea between 16 December 1991 and 21 April 1992. This represented the largest documented mortality event of Eared Grebes at the time and approximately 6% of the North American population. During the die-off, grebes exhibited several uncharacteristic behaviors, such as congregating at freshwater tributaries, repeatedly gulping freshwater, preening excessively, moving onto land, and allowing close approach and/or capture. Avian cholera was diagnosed in Eared Grebes collected along the north and west shoreline of the Sea late in the die-off but not from the majority of the Eared Grebes dying along the south shore. Gross and histological examinations and diagnostic testing for viruses, bacteria, and parasites did not identify the cause of mortality in the majority of Eared Grebes examined from the south shore of the Sea. Liver concentrations of arsenic, chromium, DDE, mercury, selenium, and zinc were elevated in some Eared Grebes, but none of those contaminants exceeded known thresholds for independent lethality. Poisoning by heavy metals, organochlorine, organophosphorus, or carbamate pesticides, avian botulism, and salt were ruled out as the cause of mortality. Hypotheses for the die-off are interactive effects of contaminants, immunosuppression, a yet unidentified biotoxin or pathogen present in the Salton Sea, impairment of feather waterproofing leading to hypothermia, or a unique manifestation of avian cholera that evades laboratory detection.

Meteyer, C. U.; Audet, D. J.; Rocke, T. E.; Radke, W.; Creekmore, L. H.; Duncan, R.

2004-01-01

250

Surprising high hydrophobicity of polymer networks from hydrophilic components.  

PubMed

We report a simple and inexpensive method of fabricating highly hydrophobic novel materials based on interpenetrating networks of polyamide and poly(ethyl cyanoacrylate) hydrophilic components. The process is a single-step solution casting from a common solvent, formic acid, of polyamide and ethyl cyanoacrylate monomers. After casting and subsequent solvent evaporation, the in situ polymerization of ethyl cyanoacrylate monomer forms polyamide-poly(ethyl cyanoacrylate) interpenetrating network films. The interpenetrating networks demonstrate remarkable waterproof properties allowing wettability control by modulating the concentration of the components. In contrast, pure polyamide and poly(ethyl cyanoacrylate) films obtained from formic acid solutions are highly hygroscopic and hydrophilic, respectively. The polymerization of ethyl cyanoacrylate in the presence of polyamide promotes molecular interactions between the components, which reduce the available hydrophilic moieties and render the final material hydrophobic. The wettability, morphology, and thermo-physical properties of the polymeric coatings were characterized. The materials developed in this work take advantage of the properties of both polymers in a single blend and above all, due to their hydrophobic nature and minimal water uptake, can extend the application range of the individual polymers where water repellency is required. PMID:23713478

Attanasio, Agnese; Bayer, Ilker S; Ruffilli, Roberta; Ayadi, Farouk; Athanassiou, Athanassia

2013-06-26

251

Design and Construction of a Cost Effective Headstage for Simultaneous Neural Stimulation and Recording in the Water Maze  

PubMed Central

Headstage preamplifiers and source followers are commonly used to study neural activity in behavioral neurophysiology experiments. Available commercial products are often expensive, not easily customized, and not submersible. Here we describe a method to design and build a customized, integrated circuit headstage for simultaneous 4-channel neural recording and 2-channel simulation in awake, behaving animals. The headstage is designed using a free, commercially available CAD-type design package, and can be modified easily to accommodate different scales (e.g. to add channels). A customized printed circuit board is built using surface mount resistors, capacitors and operational amplifiers to construct the unity gain source follower circuit. The headstage is made water-proof with a combination of epoxy, parafilm and a synthetic rubber putty. We have successfully used this device to record local field potentials and stimulate different brain regions simultaneously via independent channels in rats swimming in a water maze. The total cost is < $30/unit and can be manufactured readily.

Shirvalkar, Prasad R.; Shapiro, Mathew L.

2010-01-01

252

Water depression storage under different tillage conditions: measuring and modelling  

NASA Astrophysics Data System (ADS)

Water storage in surface depressions (DS) is an important process which affects infiltration, runoff and erosion. Since DS is driven by micro relief, in agricultural soils DS is much affected by tillage and by the direction of tillage rows in relation to the main slope. A direct and accurate measurement of DS requires making the soil surface waterproof -soil is very permeable especially under tillage- but preserving all details of the soil roughness including aggregates over the soil surface (micro-roughness). All this is a very laborious and time-consuming task. That is why hydrological and erosion models for DS estimation normally use either empirical relationships based on some roughness index or numerical approaches. The aim of this work was (i) to measure directly in the field the DS of a soil under different tillage conditions and (ii) to assess the performance of existing empirical 2D models and of a numerical 2D algorithm for DS estimation. Three types of tillage classes (mouldbard+roller, roller compacted and chisel) in 2 tillage directions (parallel and perpendicular to the main slope) were assessed in an experimental hillslope (10% slope) which defines then 6 treatments. Experiments were carried out in 12, 1-m2 micro-plots delimited by metal sheets; that is, a pair of repetitions for each treatment. In each plot, soil surface was gently impregnated with a waterproof, white paint but without altering micro-roughness. A known amount of water (stained with a blue dye) was poured all over the surface with a measuring cup. The excess water was captured in a gutter and measured. Soon after finishing the experiment, pictures of the surface was taken in order to analyze water storage pattern (from stained water) by image processing. Besides, longitudinal height profiles were measured using a laser profilemeter. Finally, infiltration rate was measured near the plot using a double ring infiltrometer. For all the treatments, DS ranged from 2 mm to 17 mm. For the same tillage direction, clear differences in DS were observed among tillage types. Besides and as expected, DS much increased (up to 3 times) in those treatments were tillage rows were perpendicular to the main slope. The performance of the models in DS prediction was in general rather limited with deviations from reference values ranging from 45% to over 100%. The results suggest the inadequacy of 2D approaches to depict the complexity of the water surface storage pattern. On the other hand, some tillage operations lead to a rather small DS but with a relative high infiltration rate (up to 3 times that of the non-tilled soil); whereas in others the opposite was true. This fact should be taken into account in hydrological management of agricultural soils.

Giménez, R.; Campo, M. A.; González-Audicana, M.; Álvarez-Mozos, J.; Casalí, J.

2012-04-01

253

"Smart pebble" design for environmental monitoring applications  

NASA Astrophysics Data System (ADS)

Sediment transport, due to primarily the action of water, wind and ice, is one of the most significant geomorphic processes responsible for shaping Earth's surface. It involves entrainment of sediment grains in rivers and estuaries due to the violently fluctuating hydrodynamic forces near the bed. Here an instrumented particle, namely a "smart pebble", is developed to investigate the exact flow conditions under which individual grains may be entrained from the surface of a gravel bed. This could lead in developing a better understanding of the processes involved, while focusing on the response of the particle during a variety of flow entrainment events. The "smart pebble" is a particle instrumented with MEMS sensors appropriate for capturing the hydrodynamic forces a coarse particle might experience during its entrainment from the river bed. A 3-axial gyroscope and accelerometer registers data to a memory card via a microcontroller, embedded in a 3D-printed waterproof hollow spherical particle. The instrumented board is appropriately fit and centred into the shell of the pebble, so as to achieve a nearly uniform distribution of the mass which could otherwise bias its motion. The "smart pebble" is powered by an independent power to ensure autonomy and sufficiently long periods of operation appropriate for deployment in the field. Post-processing and analysis of the acquired data is currently performed offline, using scientific programming software. The performance of the instrumented particle is validated, conducting a series of calibration experiments under well-controlled laboratory conditions. "Smart pebble" allows for a wider range of environmental sensors (e.g. for environmental/pollutant monitoring) to be incorporated so as to extend the range of its application, enabling accurate environmental monitoring which is required to ensure infrastructure resilience and preservation of ecological health.

Valyrakis, Manousos; Pavlovskis, Edgars

2014-05-01

254

A hundred-year-old question: is the moss calyptra covered by a cuticle? A case study of Funaria hygrometrica  

PubMed Central

Background and Aims The maternal gametophytic calyptra is critical for moss sporophyte development and ultimately sporogenesis. The calyptra has been predicted to protect the sporophyte apex, including the undifferentiated sporogenous region and seta meristem, from desiccation. We investigate the hypothesis that this waterproofing ability is due to a waxy cuticle. The idea that moss calyptrae are covered by a cuticle has been present in the literature for over a century, but, until now, neither the presence nor the absence of a cuticle has been documented for any calyptra. Methods The epidermis of the calyptra, leafy gametophyte and sporophyte sporangia of the moss Funaria hygrometrica were examined using scanning and transmission electron microscopy. Thicknesses of individual cuticle layers were quantified and compared statistically. The immunochemistry antibody (LM19) specific for pectins was used to locate cell wall material within the cuticle. Key Results A multi-layered cuticle is present on the calyptra of F. hygrometrica, including layers analogous to the cuticular layer, cell wall projections, electron-lucent and electron-dense cuticle proper observed in vascular plants. The calyptra rostrum has a cuticle that is significantly thicker than the other tissues examined and differs by specialized thickenings of the cuticular layer (cuticular pegs) at the regions of the anticlinal cell walls. This is the first documentation of cuticular pegs in a moss. Conclusions The calyptra and its associated cuticle represent a unique form of maternal care in embryophytes. This organ has the potential to play a critical role in preventing desiccation of immature sporophytes and thereby may have been essential for the evolution of the moss sporophyte.

Budke, Jessica M.; Goffinet, Bernard; Jones, Cynthia S.

2011-01-01

255

Development of polymer concrete vaults for natural gas regulator stations  

SciTech Connect

Vaults for natural gas regulator stations have traditionally been fabricated with steel-reinforced portland cement concrete. Since these vaults are installed below ground level, they are usually coated with a water-proofing material to prevent the ingress of moisture into the vault. In some cases, penetrations for piping that are normally cast into the vault do not line up with the gas lines in the streets. This necessitates off-setting the lines to line up with the penetrations in the vault or breaking out new penetrations which could weaken the structure and/or allow water ingress. By casting the vaults using a new material of construction such as polymer concrete, a longer maintenance free service life is possible because the physical and durability properties of polymer concrete composites are much superior to those of portland cement concrete. The higher strengths of polymer concrete allow the design engineer to reduce the wall, floor, and ceiling thicknesses making the vaults lighter for easier transportation and installation. Penetrations can be cut after casting to match existing street lines, thus making the vault more universal and reducing the number of vaults that are normally in stock. The authors developed a steel-fiber reinforced polymer concrete composite that could be used for regulator vaults. Based on the physical properties of his new composite, vaults were designed to replace the BUG PV-008 and Con Ed GR-6 regulator vaults made of reinforced portland cement concrete. Quarter-scale models of the polymer concrete vaults were tested and the results reaffirmed the reduced wall thickness design. Two sets of vaults, cast by Hardinge Bros., were inspected by representatives of the utilities and BNL (Brookhaven National Laboratory), and were accepted for delivery. 6 refs., 5 figs., 12 tabs.

Fontana, J.J.; Miller, C.A.; Reams, W.; Elling, D.

1990-08-01

256

Development of a semi-permanent mascara technology.  

PubMed

Many women would like their mascara beauty benefits to be available all day, every day. One way to address this desire is through a semi-permanent mascara technology that provides full mascara benefits of long, dark beautiful lashes for multiple days. To date, products promising multi-day benefits have acted more as either 'lash dyes', providing a lash darkening benefit but failing to provide fullness and length, or waterproof mascaras that do not maintain the initial beauty look over multiple days. Here, a formulation approach is described for a mascara product that is designed to be abrasion resistant, flexible and insoluble in soap and water so that the initial beauty look is maintained for multiple days. The new semi-permanent formula technology uses rosinate polymers that have a superior combination of flexibility, abrasion resistance and water and surfactant resistance. Based on principles used by the paint industry for creating durable films, the levels of the polymers and other non-volatile ingredients are balanced such that the product forms a continuous polymer film on the eyelash. Cryo-SEM is used to demonstrate that the new semi-permanent formula technology forms a film different from those formed by current mascara products. A stretch test and rub test are used to demonstrate that the new semi-permanent formula technology has superior flexibility and abrasion resistance to current mascara products. Finally, a multi-day consumer study with daily imaging of the eyes is used to demonstrate the superior wear performance of the new semi-permanent formula technology in actual usage. PMID:21834943

Dempsey, J H; Fabula, A M; Rabe, T E; Lubbers, J M; Ye, M

2012-02-01

257

Diphenylthiourea, a common rubber chemical, is bioactivated to potent skin sensitizers.  

PubMed

Diphenylthiourea (DPTU) is a known skin sensitizer commonly used as a vulcanization accelerator in the production of synthetic rubber, for example, neoprene. The versatile usage of neoprene is due to the multifaceted properties of the material; for example, it is stretchable, waterproof, and chemical- and abrasion-resistant. The wide application of neoprene has resulted in numerous case reports of dermatitis patients allergic to DPTU. The mechanism by which DPTU works as a contact allergen has not been described; thus, the aim of the present study was to investigate if DPTU is a prohapten that can be activated by skin metabolism. The metabolic activation and covalent binding of (14)C-labeled DPTU to proteins were tested using a skinlike cytochrome P450 (P450) cocktail containing the five most abundant P450s found in human skin (CYP1A1, 1B1, 2B6, 2E1, and 3A5) and human liver microsomes. The incubations were carried out in the presence or absence of the metabolite trapping agents glutathione, methoxylamine, and benzylamine. The metabolism mixtures were analyzed by LC-radiochromatography, LC-MS, and LC-MS/MS. DPTU was mainly metabolically activated to reactive sulfoxides resulting in desulfurated adducts in both enzymatic systems used. Also, phenylisothiocyanate and phenylisocyanate were found to be metabolites of DPTU. The sensitizing capacity of the substrate (DPTU) and three metabolites was tested in the murine local lymph node assay. Two out of three metabolites tested were strong skin sensitizers, whereas DPTU itself, as previously known, was negative using this mouse model. In conclusion, DPTU forms highly reactive metabolites upon bioactivation by enzymes present in the skin. These metabolites are able to induce skin sensitization and are probable causes for DPTU allergy. To increase the possibilities of diagnosing contact allergy to DPTU-containing items, we suggest that suitable metabolites of DPTU should be used for screening testing. PMID:21073181

Samuelsson, Kristin; Bergström, Moa Andresen; Jonsson, Charlotte A; Westman, Gunnar; Karlberg, Ann-Therese

2011-01-14

258

Novel Electrodes for Underwater ECG Monitoring.  

PubMed

We have developed hydrophobic electrodes that provide all morphological waveforms without distortion of an ECG signal for both dry and water-immersed conditions. Our electrode is comprised of a mixture of carbon black powder (CB) and polydimethylsiloxane (PDMS). For feasibility testing of the CB/PDMS electrodes, various tests were performed. One of the tests included evaluation of the electrode-to-skin contact impedance for different diameters, thicknesses, and different pressure levels. As expected, the larger the diameter of the electrodes, the lower the impedance and the difference between the large sized CB/PDMS and the similarly-sized Ag/AgCl hydrogel electrodes was at most 200 k?, in favor of the latter. Performance comparison of CB/PDMS electrodes to Ag/AgCl hydrogel electrodes was carried out in three different scenarios: a dry surface, water immersion, and postwater immersion conditions. In the dry condition, no statistical differences were found for both the temporal and spectral indices of the heart rate variability analysis between the CB/PDMS and Ag/AgCl hydrogel (p   > 0.05) electrodes. During water immersion, there was significant ECG amplitude reduction with CB/PDMS electrodes when compared to wet Ag/AgCl electrodes kept dry by their waterproof adhesive tape, but the reduction was not severe enough to obscure the readability of the recordings, and all morphological waveforms of the ECG signal were discernible even when motion artifacts were introduced. When water did not penetrate tape-wrapped Ag/AgCl electrodes, high fidelity ECG signals were observed. However, when water penetrated the Ag/AgCl electrodes, the signal quality degraded to the point where ECG morphological waveforms were not discernible. PMID:24845297

Reyes, Bersain A; Posada-Quintero, Hugo F; Bales, Justin R; Clement, Amanda L; Pins, George D; Swiston, Albert; Riistama, Jarno; Florian, John P; Shykoff, Barbara; Qin, Michael; Chon, Ki H

2014-06-01

259

A fibre optic scintillator dosemeter for absorbed dose measurements of low-energy X-ray-emitting brachytherapy sources.  

PubMed

A newly developed dosemeter using a 0.5 mm diameter x 0.5 mm thick cylindrical plastic scintillator coupled to the end of a fibre optic cable is capable of measuring the absorbed dose rate in water around low-activity, low-energy X-ray emitters typically used in prostate brachytherapy. Recent tests of this dosemeter showed that it is possible to measure the dose rate as a function of distance in water from 2 to 30 mm of a (103)Pd source of air-kerma strength 3.4 U (1 U = 1 microGy m(2) h(-1)), or 97 MBq (2.6 mCi) apparent activity, with good signal-to-noise ratio. The signal-to-noise ratio is only dependent on the integration time and background subtraction. The detector volume is enclosed in optically opaque, nearly water-equivalent materials so that there is no polar response other than that due to the shape of the scintillator volume chosen, in this case cylindrical. The absorbed dose rate very close to commercial brachytherapy sources can be mapped in an automated water phantom, providing a 3-D dose distribution with sub-millimeter spatial resolution. The sensitive volume of the detector is 0.5 mm from the end of the optically opaque waterproof housing, enabling measurements at very close distances to sources. The sensitive detector electronics allow the measurement of very low dose rates, as exist at centimeter distances from these sources. The detector is also applicable to mapping dose distributions from more complex source geometries such as eye applicators for treating macular degeneration. PMID:16782747

Sliski, Alan; Soares, Christopher; Mitch, Michael G

2006-01-01

260

Absorption and thermal study of dental enamel when irradiated with Nd:YAG laser with the aim of caries prevention  

NASA Astrophysics Data System (ADS)

It is widely recognized that Nd:YAG can increase enamel resistance to demineralization; however, the safe parameters and conditions that enable the application of Nd:YAG laser irradiation in vivo are still unknown. The aim of this study was to determine a dye as a photoabsorber for Nd:YAG laser and to verify in vitro a safe condition of Nd:YAG irradiation for caries prevention. Fifty-eight human teeth were selected. In a first morphological study, four dyes (waterproof India ink., iron oxide, caries indicator and coal paste) were tested before Nd:YAG laser irradiation, under two different irradiation conditions: 60 mJ/pulse and 10 Hz (84.9 J/cm2); 80 mJ/pulse and 10 Hz (113.1 J/cm2). In a second study, the enamel surface and pulp chamber temperatures were evaluated during laser irradiations. All dyes produced enamel surface melting, with the exception of the caries indicator, and coal paste was the only dye that could be completely removed. All irradiation conditions produced temperature increases of up to 615.08°C on the enamel surface. Nd:YAG laser irradiation at 60 mJ/pulse, 10 Hz and 84.9 J/cm2 promoted no harmful temperature increase in the pulp chamber (ANOVA, p < 0.05). Among all dyes tested, the coal paste was an efficient photoabsorber for Nd:YAG irradiation, considered feasible for clinical practice. Nd:YAG laser at 84.9 J/cm2 can be indicated as a safe parameter for use in caries prevention.

Boari, H. G. D.; Ana, P. A.; Eduardo, C. P.; Powell, G. L.; Zezell, D. M.

2009-07-01

261

Effects of temperature and humidity on transpiration in adults of the lesser mealworm, Alphitobius diaperinus (Coleoptera: Tenebrionidae).  

PubMed

Measurements of water loss were made on adults of the lesser mealworm, Alphitobius diaperinus, using a recording micro-electrobalance and a programmable heat circulator bath. This species originates in tropical regions and infests poultry houses in temperate countries. Two routes of water loss were examined: the general cuticle and via the spiracles. Temperature and relative humidity of the ambient air substantially affect the cuticular transpiration in adults (fresh body weights from 12 mg to 22 mg). At near 0% R.H., between 20 and 40 degrees C the rate of body water loss gradually increased; on the other hand, the insects gained weight in an atmosphere close to saturation. Above 40 degrees C transpiration flow abruptly increased coinciding with the start of vigorous locomotor activity. This critical point corresponds to the opening of the spiracles from which the water is expelled from the tracheal system.In dead specimens, killed by cyanide or solvent, the water vapour slowly diffused out of the spiracles and, as in atracheate insects, the transpiration curves did not show a peak as the air temperature was increased.The thermostupor point (TSP) occurred as the insects became motionless; the corresponding temperature is significantly affected by atmospheric relative humidity (TSP=47.4+/-0.6 degrees C at c. 0% R.H.; TSP=46.6+/-0.7 degrees C at c. 100% R.H.).The transpiration flow was about four times as fast in specimens treated with solvent as in the individuals (live or cyanide-killed) that had undamaged water-proof cuticle. This species has to cope with a double challenge: (i) to adapt its physiology and ecology to poultry-house conditions which constitutes an extension of its primary habitats, and (ii) to survive over winter; high drought resistance and heat tolerance may constitute a pre-adaptation to conquer anthropogenic air-conditioned sites. PMID:12770283

Salin, C; Vernon, P; Vannier, G

1999-10-01

262

Methodology for calibration and use of heat flux transducers  

NASA Astrophysics Data System (ADS)

The direct assessment of heat flux from the body is a basic measurement in thermal physiology. Heat flux transducers (HFTs) are being used increasingly for that purpose under different environmental conditions. However, questions have been raised regarding the accuracy of the manufacturer's constant of calibration, and also about the effect of the thermal resistance of the device on the true thermal flux from the skin. Two different types of waterproofed HFTs were checked for their calibration using the Rapid-k thermal conductivity instrument. A detailed description of the methodology used during the calibration is given. A model capable of simulating a large range of tissue insulation was used to study the effect of the underlying tissue insulation on the relative error in thermal flux due to the thermal resistance of the HFTs. The data show that the deviation from the true value of thermal flux increases with the reciprocal of the underlying tissue insulation (r = 0.99, p less than 0.001). The underestimation of the heat flux through the skin measured by an HFT is minimal when the device is used on vasoconstricted skin in cool subjects (3 to 13 pct. error), but becomes important when used on warm vasodilated subjects (29 to 35 pct. error), and even more important on metallic skin mannequins (greater than 60 pct. error). In order to optimize the accuracy of the heat flux measurements by HFTs, it is important to recalibrate the HFTs and to correct the heat flux values for the thermal resistance of the HFT when used on vasodilated tissues.

Ducharme, Michel B.; Frim, John

1991-05-01

263

Perfluoroalkyl and polyfluoroalkyl substances (PFASs) in consumer products in Norway - a pilot study.  

PubMed

Perfluoroalkyl and polyfluoroalkyl substances (PFAS) are used in numerous industrial and consumer products because of their special chemical properties, for instance the ability to repel both water and oil. A broad variety of PFAS have been introduced into the Norwegian market through industrial use (e.g. via fire fighting foams and paints) as well as in treated customer products such as textiles and coated paper. Our present knowledge of the exact chemical PFAS compositions in preparations using perfluorinated compounds is limited. This lack of knowledge means that it is difficult to provide an accurate assessment of human exposure to these compounds or to the amount of waste that may contain treated products. It is a growing concern that these potentially harmful compounds can now be found throughout the global environment. Samples of consumer products and preparations were collected in Norway, with supplemental samples from Sweden. In 27 of the 30 analyzed consumer products and preparations a number of polyfluorinated substances that were analyzed were detected but this does not exclude the occurrence of unknown PFAS. Notable was that perfluorooctanesulphonate (PFOS), which has been strictly regulated in Norway since 2007, was found in amounts close to or exceeding the EU regulatory level in 4 of the 30 analyzed products, all within the leather or carpet product groups. High amounts of fluorotelomer alcohols (FTOHs) were found in waterproofing agents, carpets and textiles, consistent with earlier findings by Fiedler et al. (2010). The presence of PFAS in a broad range of consumer products can give rise to a constant diffuse human exposure that might eventually result in harm to humans. PMID:22483730

Herzke, Dorte; Olsson, Elisabeth; Posner, Stefan

2012-08-01

264

A first global production, emission, and environmental inventory for perfluorooctane sulfonate.  

PubMed

This study makes a new estimate of the global historical production for perfluorooctane sulfonyl fluoride (POSF), and then focuses on producing a first estimate of the global historical environmental releases of perfluorooctane sulfonate (PFOS). The total historical worldwide production of POSF was estimated to be 96,000 t (or 122,500 t, including unusable wastes) between 1970-2002, with an estimated global release of 45,250 t to air and water between 1970-2012 from direct (manufacture, use, and consumer products) and indirect (PFOS precursors and/or impurities) sources. Estimates indicate that direct emissions from POSF-derived products are the major source to the environment resulting in releases of 450-2700 t PFOS into wastewater streams, primarily through losses from stain repellent treated carpets, waterproof apparel, and aqueous fire fighting foams. Large uncertainties surround indirect sources and have not yet been estimated due to limited information on environmental degradation, although it can be assumed that some POSF-derived chemicals will degrade to PFOS over time. The properties of PFOS (high water solubility, negligible vapor pressure, and limited sorption to particles) imply it will reside in surface waters, predominantly in oceans. Measured oceanic data suggests approximately 235-1770 t of PFOS currently reside in ocean surface waters, similar to the estimated PFOS releases. Environmental monitoring from the 1970s onward shows strong upward trends in biota, in broad agreement with the estimates of use and emissions made here. Since cessation of POSF production by 3M in 2002, a reduction in some compartments has been observed, although current and future exposure is dependent on emission routes, subsequent transport and degradation. PMID:19238969

Paul, Alexander G; Jones, Kevin C; Sweetman, Andrew J

2009-01-15

265

The eggshell of the cherry fly Rhagoletis cerasi.  

PubMed

One of the major pests in Greek cherry orchards is the cherry fly Rhagoletis cerasi (Diptera: Tephritidae). In order to complete our comparative work on the chorion assembly of other representatives of the fruit flies (e.g. Ceratitis capitata and Dacus oleae) we studied eggshell morphogenesis in the cherry fly. The oocyte is surrounded by several distinct layers which are produced during choriogenesis. The eggshell consists of the vitelline membrane, a fibrous layer of possible water-proofing function, an innermost chorionic layer, endochorionic and exochorionic layers. The endochorion shows a branched configuration with irregular cavities, and the exochorion consists of inner and outer layers for better embryo protection. At the anterior region of the follicle, the hexagonal borders of the follicle cells are created by endochorionic material, covered by both inner and outer exochorion. This area resembles the D. melanogaster chorionic appendages and therefore can serve for plastron respiration. The structural results support the phylogenetic relationships among the tephritids (Rhagoletis is closer to Ceratitis than Dacus). The presence of peroxidase in the endochorion, detected by diaminobenzidine, is consistent with the eggshell hardening at the end of choriogenesis, following the same pattern with the other fruit flies studied so far. Two major chorionic proteins are found both in R. cerasi and in C. capitata and therefore general conclusions can be drawn from this study, concerning the pattern of choriogenesis, which all dipteran insects follow, in order to create a resistant and functional eggshell, and the high conservation of the proteinaceous components of the chorion among species in the order. PMID:18621185

Mouzaki, D G; Margaritis, L H

1991-01-01

266

Surface energy and wettability of spin-coated thin films of lignin isolated from wood.  

PubMed

The surface energy of lignin films spin-coated onto oxidized silicon wafer has been determined from contact angle measurements of different test liquids with varying polar and dispersive components. Three different lignin raw materials were used, a kraft lignin from softwood, along with milled wood lignin from softwood and hardwood. Infrared and (31)P NMR spectroscopy was used to identify any major functional group differences between the lignin samples. No significant difference in the total solid-vapor surface energy for the different lignin films was observed; however, the polar component for the kraft lignin was much greater than for either of the milled wood lignin samples consistent with the presence of carboxyl groups and higher proportion of phenolic hydroxyl groups as shown by quantitative (31)P NMR on the phosphitylated samples. Furthermore, the total surface energy of lignin of 53-56 mJ m(-2) is of a similar magnitude to cellulose, also found in the wood cell wall; however, cellulose has a higher polar component leading to a lower contact angle with water and greater wettability than the milled wood lignin. Although lignin is not hydrophobic according to the strictest definition of a water contact angle greater than 90 degrees, water may only be considered a partially wetting liquid on a lignin surface. This supports the long-held belief that one of the functions of lignin in the wood cell wall is to provide water-proofing to aid in water transport. Furthermore, these results on the solid-vapor surface energy of lignin will provide invaluable insight for many natural and industrial applications including in the design and manufacture of many sustainable products such as paper, fiberboard, and polymer composite blends. PMID:20349913

Notley, Shannon M; Norgren, Magnus

2010-04-20

267

Heterogeneous Films of Ionotropic Hydrogels Fabricated From Delivery Templates of Patterned Paper  

PubMed Central

The use of delivery templates makes it possible to fabricate shaped, millimeter-thick heterogeneously patterned films of ionotropic hydrogels. These structures include 2-D patterns of a polymer cross-linked by different ions (e.g., alginic acid cross-linked with Ca2+ and Fe3+) and patterns of step-gradients in the concentration of a single cross-linking ion. The delivery templates consist of stacked sheets of chromatography paper patterned with hydrophobic barriers (waterproof tape, transparency film, or toner deposited by a color laser printer). Each layer of paper serves as a reservoir for a different solution of cross-linking ions, while the hydrophobic barriers prevent solutions on adjacent sheets from mixing. Holes cut through the sheets expose different solutions of cross-linking ions to the surface of the templates. Films with shaped regions of hydrogels cross-linked by paramagnetic ions can be oriented with a bar magnet. Variations in the concentrations of cations used to cross-link the gel can control the mechanical properties of the film: for single alginate films composed of areas cross-linked with different concentrations of Fe3+, the regions cross-linked with high concentrations of Fe3+ are more rigid than regions cross-linked with low concentrations of Fe3+. The heterogeneous hydrogel films can be used to culture bacteria in various 2-D designs. The pattern of toxic and nontoxic ions used to cross-link the polymer determines the pattern of viable colonies of E. coli within the film.

Bracher, Paul J.; Gupta, Malancha; Mack, Eric T.; Whitesides, George M.

2009-01-01

268

Blue-Violet Laser Modification of Titania Treated Titanium: Antibacterial and Osteo-Inductive Effects  

PubMed Central

Background Many studies on surface modifications of titanium have been performed in an attempt to accelerate osseointegration. Recently, anatase titanium dioxide has been found to act as a photocatalyst that expresses antibiotic properties and exhibits hydrophilicity after ultraviolet exposure. A blue-violet semiconductor laser (BV-LD) has been developed as near-ultraviolet light. The purpose of this study was to investigate the effects of exposure to this BV-LD on surface modifications of titanium with the goal of enhancing osteoconductive and antibacterial properties. Methods The surfaces of pure commercial titanium were polished with #800 waterproof polishing papers and were treated with anatase titania solution. Specimens were exposed using BV-LD (? = 405 nm) or an ultraviolet light-emitting diode (UV-LED, ? = 365 nm) at 6 mW/cm2 for 3 h. The surface modification was evaluated physically and biologically using the following parameters or tests: surface roughness, surface temperature during exposure, X-ray diffraction (XRD) analysis, contact angle, methylene blue degradation tests, adherence of Porphyromonas gingivalis, osteoblast and fibroblast proliferation, and histological examination after implantation in rats. Results No significant changes were found in the surface roughness or XRD profiles after exposure. BV-LD exposure did not raise the surface temperature of titanium. The contact angle was significantly decreased, and methylene blue was significantly degraded. The number of attached P. gingivalis organisms was significantly reduced after BV-LD exposure compared to that in the no exposure group. New bone was observed around exposed specimens in the histological evaluation, and both the bone-to-specimen contact ratio and the new bone area increased significantly in exposed groups. Conclusions This study suggested that exposure of titanium to BV-LD can enhance the osteoconductivity of the titanium surface and induce antibacterial properties, similar to the properties observed following exposure to UV-LED.

Kawano, Takanori; Prananingrum, Widyasri; Ishida, Yuichi; Goto, Takaharu; Naito, Yoshihito; Watanabe, Megumi; Tomotake, Yoritoki; Ichikawa, Tetsuo

2013-01-01

269

Impact of Megacity Shanghai on the Urban Heat-Island Effects over the Downstream City Kunshan  

NASA Astrophysics Data System (ADS)

The impact of upstream urbanization on the enhanced urban heat-island (UHI) effects between Shanghai and Kunshan is investigated by analyzing seven years of surface observations and results from mesoscale model simulations. The observational analysis indicates that, under easterly and westerly winds, the temperature difference between Shanghai and Kunshan increases with wind speed when the wind speed < 5 m s^{-1} . The Weather Research and Forecasting (WRF) numerical model, coupled with a one-layer urban canopy model (UCM), is used to examine the UHI structure and upstream effects by replacing the urban surface of Shanghai and/or Kunshan with cropland. The WRF/UCM modelling system is capable of reproducing the surface temperature and wind field reasonably well. The simulated urban canopy wind speed is a better representation of the near-surface wind speed than is the 10-m wind speed at the centre of Shanghai. Without the urban landscape of Shanghai, the surface air temperature over downstream Kunshan would decrease by 0.2-0.4 ^{circ } C in the afternoon and 0.4-0.6 ^{circ } C in the evening. In the simulation with the urban landscape of Shanghai, a shallow cold layer is found above the UHI, with a minimum temperature of about -0.2 to - 0.5 ^{circ } C during the afternoon hours. Strong horizontal divergence is found in this cold layer. The easterly breeze over Shanghai is strengthened at the surface by strong UHI effects, but weakened at upper levels. With the appearance of the urban landscape specific humidity decreases by 0.5-1 g kg^{-1} within the urban area because of the waterproof property of an urban surface. On the other hand, the upper-level specific humidity is increased because of water vapour transferred by the strong upward vertical motions.

Kang, Han-Qing; Zhu, Bin; Zhu, Tong; Sun, Jia-Li; Ou, Jian-Jun

2014-05-01

270

Groundwater System Investigation of the Cheonggyecheon Watershed Area  

NASA Astrophysics Data System (ADS)

The Cheonggyecheon is an urban stream in the center of the Seoul, Korea. Because of fundamental solution of the deterioration on covering structure and expressway, the Seoul Metropolis decided 'Cheonggyecheon restoration' and began on July 1, 2003. The purpose of the Cheonggyecheon restoration is a plan for the afforestation in Seoul, but the Cheonggyecheon needs more water for the maintenance of flow. The Cheonggyecheon is a disconnected stream because of a urban stream which has many influenced factors such as pumping out, groundwater leakages into subway stations and leaking water from water supply and sewage line. So, the objectives of this study are analyzing influenced factors in the groundwater budget in the Cheonggyecheon watershed and suggesting the amount of input and output water. There are many factors influenced by the infiltration in this study area such as a flow rate of the stream, a thickness of the stream bed, a grain size of the stream bed, and a permeability of a waterproof material after restoration. For investigation of the hydrogeologic parameter in the study area, we perform the hydraulic tests; pumping test, slug test, and infiltration test. Groundwater quality data were collected for an investigation of the origin of groundwater in the study area and the index parameter after restoration. For estimating a level of sensitive factors after restoration construction, we conduct sand tank test and numerical test. In comparison of the results of the sand tank test and the numerical test, we decide the prime control factor of infiltration water in the Cheonggyecheon watershed, and suggest the amount of water budget in this study site.

Choi, D.; Lee, K.; Hyun, Y.; Kim, Y.

2004-12-01

271

Development of a retrofit coal combustor for industrial applications, (Phase 1-A). Technical progress report, July--September 1988  

SciTech Connect

During this past quarter, two tandem-fired pulse combustors were designed to fire at a nominal rate of 3.5 to 5.5 MMBtu/hr under continuation of Phase I work on DOE project DE-AC22-87PC79654. In prior work, MTCI demonstrated the operation of a 1--2 MMBtu/h coal-fired tandem pulse combustor that is intended for small industrial applications. These component tests emphasized verification of key design issues such as combustor coupling, slag rejection, and staged air addition. The current work, which represents an extension of the Phase I effort, focuses on integrated testing of the tandem pulse combustor with a fire-tube boiler, and the addition of a slag quench vessel. A tandem-fired pulse combustion unit designed to fire at a nominal rate of 3.5-5 MMBtu/hr was designed and fabricated. The configuration includes two combustion chambers cast in a single monolith, tailpipes cast separately with annular air preheating capability, and a cyclonic decoupler. Design analysis and evaluations were performed to optimize the system with respect to minimizing heat losses, size, and cost. Heat losses from the combustor and decoupler walls are predicted to be approximately 3 percent. The final designs for the ancillary items (slag quench, tertiary air addition, scrubber and sampling system) were completed and fabrication and installation initiated. A Cleaver-Brooks 150 hp-4 pass boiler was delivered and installed and modifications for interfacing with the retrofit pulse combustor unit completed. A below-ground slag collection pit was excavated to permit direct in-line coupling of the combustor to the boiler and to reduce head-room requirements. The pit is 30 inches deep and lined with waterproof and fireproof siding.

Not Available

1988-10-01

272

Development of a retrofit coal combustor for industrial applications, (Phase 1-A)  

SciTech Connect

During this past quarter, two tandem-fired pulse combustors were designed to fire at a nominal rate of 3.5 to 5.5 MMBtu/hr under continuation of Phase I work on DOE project DE-AC22-87PC79654. In prior work, MTCI demonstrated the operation of a 1--2 MMBtu/h coal-fired tandem pulse combustor that is intended for small industrial applications. These component tests emphasized verification of key design issues such as combustor coupling, slag rejection, and staged air addition. The current work, which represents an extension of the Phase I effort, focuses on integrated testing of the tandem pulse combustor with a fire-tube boiler, and the addition of a slag quench vessel. A tandem-fired pulse combustion unit designed to fire at a nominal rate of 3.5-5 MMBtu/hr was designed and fabricated. The configuration includes two combustion chambers cast in a single monolith, tailpipes cast separately with annular air preheating capability, and a cyclonic decoupler. Design analysis and evaluations were performed to optimize the system with respect to minimizing heat losses, size, and cost. Heat losses from the combustor and decoupler walls are predicted to be approximately 3 percent. The final designs for the ancillary items (slag quench, tertiary air addition, scrubber and sampling system) were completed and fabrication and installation initiated. A Cleaver-Brooks 150 hp-4 pass boiler was delivered and installed and modifications for interfacing with the retrofit pulse combustor unit completed. A below-ground slag collection pit was excavated to permit direct in-line coupling of the combustor to the boiler and to reduce head-room requirements. The pit is 30 inches deep and lined with waterproof and fireproof siding.

Not Available

1988-10-01

273

Latherin: A Surfactant Protein of Horse Sweat and Saliva  

PubMed Central

Horses are unusual in producing protein-rich sweat for thermoregulation, a major component of which is latherin, a highly surface-active, non-glycosylated protein. The amino acid sequence of latherin, determined from cDNA analysis, is highly conserved across four geographically dispersed equid species (horse, zebra, onager, ass), and is similar to a family of proteins only found previously in the oral cavity and associated tissues of mammals. Latherin produces a significant reduction in water surface tension at low concentrations (?1 mg ml?1), and therefore probably acts as a wetting agent to facilitate evaporative cooling through a waterproofed pelt. Neutron reflection experiments indicate that this detergent-like activity is associated with the formation of a dense protein layer, about 10 Å thick, at the air-water interface. However, biophysical characterization (circular dichroism, differential scanning calorimetry) in solution shows that latherin behaves like a typical globular protein, although with unusual intrinsic fluorescence characteristics, suggesting that significant conformational change or unfolding of the protein is required for assembly of the air-water interfacial layer. RT-PCR screening revealed latherin transcripts in horse skin and salivary gland but in no other tissues. Recombinant latherin produced in bacteria was also found to be the target of IgE antibody from horse-allergic subjects. Equids therefore may have adapted an oral/salivary mucosal protein for two purposes peculiar to their lifestyle, namely their need for rapid and efficient heat dissipation and their specialisation for masticating and processing large quantities of dry food material.

Beeley, John G.; Bovell, Douglas L.; Lu, Jian R.; Zhao, Xiubo; Cooper, Alan; Kennedy, Malcolm W.

2009-01-01

274

Rotating Balances Used for Fluid Pump Testing  

NASA Technical Reports Server (NTRS)

Marshall Space Flight Center has developed and demonstrated two direct read force and moment balances for sensing and resolving the hydrodynamic loads on rotating fluid machinery. These rotating balances consist of a series of stainless steel flexures instrumented with semiconductor type, unidirectional strain gauges arranged into six bridges, then sealed and waterproofed, for use fully submerged in degassed water at rotational speeds up to six thousand revolutions per minute. The balances are used to measure the forces and moments due to the onset and presence of cavitation or other hydrodynamic phenomena on subscale replicas of rocket engine turbomachinery, principally axial pumps (inducers) designed specifically to operate in a cavitating environment. The balances are inserted into the drive assembly with power to and signal from the sensors routed through the drive shaft and out through an air-cooled twenty-channel slip ring. High frequency data - balance forces and moments as well as extensive, flush-mounted pressures around the rotating component periphery - are acquired via a high-speed analog to digital data acquisition system while the test rig conditions are varied continuously. The data acquisition and correction process is described, including the in-situ verifications that are performed to quantify and correct for known system effects such as mechanical imbalance, "added mass," buoyancy, mechanical resonance, and electrical bias. Examples of four types of cavitation oscillations for two typical inducers are described in the laboratory (pressure) and rotating (force) frames: 1) attached, symmetric cavitation, 2) rotating cavitation, 3) attached, asymmetric cavitation, and 4) cavitation surge. Rotating and asymmetric cavitation generate a corresponding unbalanced radial force on the rotating assembly while cavitation surge generates an axial force. Attached, symmetric cavitation induces no measurable force. The frequency of the forces can be determined a priori from the pressure environment while the magnitude of the hydrodynamic force is proportional to the pressure unsteadiness.

Skelley, Stephen; Mulder, Andrew

2014-01-01

275

Design and characterization of a piezoelectric sensor for monitoring scour hole evolution  

NASA Astrophysics Data System (ADS)

Scour occurring near bridge piers and abutments jeopardizes the stability and safety of overwater bridges. In fact, bridge scour is responsible for a significant portion of overwater bridge failures in the United States and around the world. As a result, numerous methods have been developed for monitoring bridge scour by measuring scour depth at locations near bridge piers and foundations. Besides visual inspections conducted by trained divers, other technologies include sonar, float-out devices, magnetic sliding collars, tilt sensors, and fiber optics, to name a few. These systems each offer unique advantages, but most of them share fundamental limitations (e.g., high costs, low reliability, limited accuracy, low reliability, etc.) that have limited their implementation in practice. Thus, the goal of this study is to present a low-cost and simple scour depth sensor fabricated using piezoelectric poly(vinylidene fluoride) (PVDF) polymer strips. Unlike current piezoelectric scour sensors that are based on mounting multiple and equidistantly spaced transducers on a rod, the proposed sensor is formed by coating one continuous PVDF film onto a substrate, followed by waterproofing the sensor. The PVDF-based sensor can then be buried in the streambed and at a location where scour depth measurements are desired. When scour occurs and exposes a portion of the PVDF sensor, water flow excites the sensor to cause the generation of a time-varying voltage signal. Since the dynamics of the voltage time history response is related to the exposed length of the sensor, scour depth can be determined. This work presents the design and fabrication of the sensor. Then, the sensor's performance and accuracy is characterized through extensive laboratory testing.

Azhari, Faezeh; Tom, Caroline; Benassini, Joseph; Loh, Kenneth J.; Bombardelli, Fabian A.

2014-03-01

276

Shear bond strength of composite resin to dentin after application of cavity disinfectants - SEM study  

PubMed Central

Aim: The aim was to evaluate the effect of different cavity disinfectants on dentin bond strengths of composite resin applied with two different adhesive systems. Materials and Methods: Two-hundred mandibular molars were sectioned parallel to the occlusal surface to expose dentin in the midcoronal one-third. The dentinal surfaces were polished with waterproof-polishing papers. The specimens were randomly divided into five groups of 40 teeth each as follows: group 1(control) -- specimens were not treated with any cavity disinfectants. Groups 2--5 (experimental groups) -- dentin surfaces were treated with the following cavity disinfectants, respectively; 2% chlorhexidine solution, 0.1% benzalkonium chloride-based disinfectant, 1% chlorhexidine gel, and an iodine potassium iodide/copper sulfate-based disinfectant. The specimens were then randomly divided into two subgroups including 20 teeth each to evaluate the effect of different bonding systems. Dentin bonding systems were applied to the dentin surfaces and the composite buildups were done. After the specimens were stored in an incubator for 24 hours, the shear bond strength was measured at a crosshead speed of 1 mm/min. The specimens were then statistically analyzed. Statistical Analysis Used: One way analysis of variance and Tukey-HSD tests were used. Results: There was no significant difference between chlorhexidine gel and control groups regardless of the type of the bonding agent used (P>0.05). On the other hand, pretreatment with benzalkonium chloride-based, iodine potassium iodide/copper sulfate-based disinfectants or chlorhexidine solutions had a negative effect on the shear bond strength of self-etching bonding systems. Conclusions: The findings of this study suggest that when benzalkonium chloride-based, iodine potassium iodide/copper sulfate-based disinfectants or chlorhexidine solutions are used as a cavity disinfectant, an etch-and-rinse bonding system should be preferred.

Sharma, Vivek; Rampal, Poonam; Kumar, Sukesh

2011-01-01

277

Molecular Structure of Oleic acid  

NSDL National Science Digital Library

A mono-unsaturated fatty acid, oleic acid is a component of almost all natural fats. It is obtained from any of various vegetable and animal oils and fats, particularly the seeds of castor, sunflower, safflower, parsley, soybean, flax, perilla, and celery. A colorless or yellow-to-red oily liquid with a lard-like odor, it solidifies to a crystalline mass at four degrees Celsius. When exposed to air it oxidizes and acquires a yellow to brown color and rancid odor; for this reason it should be kept sealed in a container and away from sunlight. It is almost completely insoluble in water but is soluble in alcohol, benzene chloroform, ether, and fixed and volatile oils. Although oleic acid has a low level of toxicity when absorbed orally, it is mildly irritating to the skin and mucous membranes. It also is combustible. Oleic acid is used as a soap base and in the production of food-grade additives, ointments, cosmetics, fragrance products, polishing compounds, surface coatings, and manufacturing driers. It is used for waterproofing textiles and for thickening lubricating oils. It also is used as a solvent in the manufacture of pharmaceuticals. It contributes to the flavor of foods and is found in sweet cider apples. One of the "good" or unsaturated fatty acids, oleic acid has proven helpful to cell and heart function. It has shown anti-inflammatory effects in the body and has been used to treat arthritis, asthma, allergies, and skin conditions. Its inclusion in the diet has improved cases of diabetes, depression, menopausal problems, obesity, memory and learning disabilities, eye problems, and digestive disorders. It is considered to lower the incidence of cancer (as an antioxidant), multiple sclerosis, and lupus as well.

2003-05-08

278

A novel Multi-Fiber Optode sensor system (MuFO) for monitoring oxygen  

NASA Astrophysics Data System (ADS)

In the marine environment, dissolved oxygen concentrations often vary significantly spatially as well as temporally. Monitoring these variations is essential for our understanding of the biological and chemical processes controlling the oxygen dynamics in water columns and sediments. Such investigations require a high number of measuring points and a high temporal resolution. A Multi-Fiber Optode sensor system (MuFO) was designed to assess these requirements. The MuFO system simultaneously controls 100 fiber optodes enabling continuous monitoring of oxygen in 100 positions within a 5-10m radius. The measurements are based on quenching of an oxygen sensitive luminophore, which is immobilised at the end of each fiber optode. The optical oxygen measurements are based on lifetime-imaging, which are converted into oxygen concentrations using a multipoint calibration. At a constant temperature of 21C, the system overall had a mean accuracy of 1.3%, a precision of 0.2% air saturation, the average 90% response time was 16 seconds and the detection limit was 0.1% air saturation. The MuFO set-up was build into a waterproof titanium casing for marine field applications. The system is battery-powered and has a maximum operational capacity of 15 hours for continuous measurements. The MuFO system was recently used for various research tasks in the marine environment: Mounted on a lander, the in situ MuFO system was used for investigations of oxygen dynamics in marine water columns placing the fiber optodes in a vertical line on a 7m high pole. For studies of oxygen dynamics in marine wetland rhizospheres, the sensing ends of the fiber optodes were covered with a 50cm protective sleeve made from stainless steel tubing, and the sensors were manually pushed into the rhizosphere. For laboratory measurements of sediment oxygen demand, the MuFO system was used to simultaneously monitor the oxygen consumption in multiple sediment slurry incubations. The MuFO system proved to be a useful tool for field studies as well as in the laboratory and the system has multiple applications in marine research. This work was supported by the 7th framework EU-projects SENSEnet and HYPOX.

Koop-Jakobsen, K.; Fischer, J.; Wenzhöfer, F.

2012-04-01

279

Pesticide personal protective clothing.  

PubMed

A fairly large established data base provides information on clothing worn by U.S. and Canadian farmers to work with pesticides, their attitudes and beliefs about pesticide risk, and clothing as a dermal barrier. Very limited similar data are available for farmers in less developed countries. Clearly, farmers perceive the benefits of pesticides to far exceed any risks. While few report poisoning symptoms, most believe that their usual work clothing offers a sufficient pesticide barrier, and few wear special-purpose protective clothing. Gloves of various materials, including cotton and leather, appear to be the major protective clothing item. Although farmers feel that their usual work clothing provides excellent protection, fabric penetration research does not support this. Shirting-weight fabrics offer some limited protection against light spray of field-strenght pesticides. Heavier-weight fabrics, such as denim and twill, are better barriers. With a heavier spray or a spill, usual work clothing does not give sufficient protection. Greater protection can usually be achieved with the use of a fluorocarbon finished fabric, such as Scotchgard or Zepel. Scotchgard can readily be applied at home. A durable-press finish does not appear to improve fabric's pesticide-barrier resistance and some data suggest that it may decrease barrier properties. A second alternative for increased protection is the use of a special-purpose fabric, such as a coated nonwoven or possibly Gore-Tex. Numerous other new "waterproof breathable" fabrics have recently come to the market. Many of these are finished or coated fabrics and one would expect them to be at least somewhat resistant to pesticides. However, they have not been tested. Wearing an additional layer also appears to be another clothing strategy to minimize exposure. Fabric penetration research also shows that pesticide formulation, volume or spray regime, concentration, and active ingredients influence the barrier properties of fabrics. Clothing evaluation studies have shown that protective clothing and coveralls of various materials and designs were effective in reducing exposure. Results of some of these studies suggested that the farmer's typical work clothing was more effective than fabric penetration results suggested. This apparent conflict is not surprising, given the methods used in both types of research. The field studies use pads placed in various areas under the clothing. This method assumes that exposure is uniform over entire body regions. But fluorescent tracer research has shown that this is not a valid assumption (DeJonge et al. 1985; Fenske 1988). Also, the way in which the pads are attached may make a difference, although no research has examined this issue.(ABSTRACT TRUNCATED AT 400 WORDS) PMID:1771275

Branson, D H; Sweeney, M

1991-01-01

280

Characterization of Antimicrobial Substances Produced by Enterococcus faecalis MRR 10-3, Isolated from the Uropygial Gland of the Hoopoe (Upupa epops)  

PubMed Central

The uropygial gland (preen gland) is a holocrine secretory gland situated at the base of the tail in birds which produces a hydrophobic fatty secretion. In certain birds, such as the hoopoe, Upupa epops, the composition of this secretion is influenced by both seasonal and sexual factors, becoming darker and more malodorous in females and in their nestlings during the nesting phase. The secretion is spread throughout the plumage when the bird preens itself, leaving its feathers flexible and waterproof. It is also thought to play a role in defending the bird against predators and parasites. We have isolated from the uropygial secretion of a nestling a bacterium that grows in monospecific culture which we have identified unambiguously by phenotypic and genotypic means as Enterococcus faecalis. The strain in question produces antibacterial substances that are active against all gram-positive bacteria assayed and also against some gram-negative strains. Its peptide nature identifies it as a bacteriocin within the group known as enterocins. Two peptides were purified to homogeneity (MR10A and MR10B), and matrix-assisted laser desorption ionization-time of flight (mass spectrometry) analysis showed masses of 5201.58 and 5207.7 Da, respectively. Amino acid sequencing of both peptides revealed high similarity with enterocin L50A and L50B (L. M. Cintas, P. Casaus, H. Holo, P. E. Hernández, I. F. Nes, and L. S. Håvarstein, J. Bacteriol. 180:1988-1994, 1998). PCR amplification of total DNA from strain MRR10-3 with primers for the L50A/B structural genes and sequencing of the amplified fragment revealed almost identical sequences, except for a single conservative change in residue 38 (Glu?Asp) in MR10A and two changes in residues 9 (Thr?Ala) and 15 (Leu?Phe) in MR10B. This is the first time that the production of bacteriocins by a bacterium isolated from the uropygial gland has been described. The production of these broad-spectrum antibacterial substances by an enterococcal strain living in the uropygial gland may be important to the hygiene of the nest and thus to the health of the eggs and chicks.

Martin-Platero, Antonio M.; Valdivia, Eva; Ruiz-Rodriguez, Magdalena; Soler, Juan J.; Martin-Vivaldi, Manuel; Maqueda, Mercedes; Martinez-Bueno, Manuel

2006-01-01

281

Characterization of antimicrobial substances produced by Enterococcus faecalis MRR 10-3, isolated from the uropygial gland of the hoopoe (Upupa epops).  

PubMed

The uropygial gland (preen gland) is a holocrine secretory gland situated at the base of the tail in birds which produces a hydrophobic fatty secretion. In certain birds, such as the hoopoe, Upupa epops, the composition of this secretion is influenced by both seasonal and sexual factors, becoming darker and more malodorous in females and in their nestlings during the nesting phase. The secretion is spread throughout the plumage when the bird preens itself, leaving its feathers flexible and waterproof. It is also thought to play a role in defending the bird against predators and parasites. We have isolated from the uropygial secretion of a nestling a bacterium that grows in monospecific culture which we have identified unambiguously by phenotypic and genotypic means as Enterococcus faecalis. The strain in question produces antibacterial substances that are active against all gram-positive bacteria assayed and also against some gram-negative strains. Its peptide nature identifies it as a bacteriocin within the group known as enterocins. Two peptides were purified to homogeneity (MR10A and MR10B), and matrix-assisted laser desorption ionization-time of flight (mass spectrometry) analysis showed masses of 5201.58 and 5207.7 Da, respectively. Amino acid sequencing of both peptides revealed high similarity with enterocin L50A and L50B (L. M. Cintas, P. Casaus, H. Holo, P. E. Hernández, I. F. Nes, and L. S. Håvarstein, J. Bacteriol. 180:1988-1994, 1998). PCR amplification of total DNA from strain MRR10-3 with primers for the L50A/B structural genes and sequencing of the amplified fragment revealed almost identical sequences, except for a single conservative change in residue 38 (Glu-->Asp) in MR10A and two changes in residues 9 (Thr-->Ala) and 15 (Leu-->Phe) in MR10B. This is the first time that the production of bacteriocins by a bacterium isolated from the uropygial gland has been described. The production of these broad-spectrum antibacterial substances by an enterococcal strain living in the uropygial gland may be important to the hygiene of the nest and thus to the health of the eggs and chicks. PMID:16751538

Martín-Platero, Antonio M; Valdivia, Eva; Ruíz-Rodríguez, Magdalena; Soler, Juan J; Martín-Vivaldi, Manuel; Maqueda, Mercedes; Martínez-Bueno, Manuel

2006-06-01

282

A tactical, permanent telemetered volcano monitoring station design  

NASA Astrophysics Data System (ADS)

The USGS-USAID Volcano Disaster Assistance Program (VDAP) designs, constructs and installs telemetered volcano-monitoring stations for use in developing countries, at a wide range of latitudes and elevations, weather and environmental conditions. The stations typically house seismometers, GPS and webcams, singly or in combination. They are frequently installed quickly during a volcanic crisis, but are expected to function over the long term as permanent stations. The primary design goal is for a simple, highly portable station that can be installed in less than a day, but not require maintenance until the natural end of battery life, usually 2-5 years. The station consists of a pair of aluminum boxes (43x46x71cm, approx.) placed on the ground facing each other, 2-3m apart, forming the lower part of a metal framework made of 2" pipe to mount solar panels and antennae. Vertical sections of 2" pipe, 3-4m long, are clamped to each end of both the boxes, the lower ends buried into cement-filled holes. This makes 4 masts on a rectangular footprint of 1m X 3-4m. Two horizontal crosspieces of 2" pipe 3-4m long are clamped across the masts. Solar panels are laid across the crosspieces, mounted with 2" angle aluminum extending from the high crosspiece to the low one. Relative height of the crosspieces controls the angle of the solar panels. The crosspieces can be lengthened to increase mounting space for additional solar panels. Inside the aluminum boxes, the radios and electronics are housed in plastic boxes. All external cables are protected by flexible aluminum conduit. Important elements of the design include: -Redundant dual solar power supplies of expandable capacity for loads from 1W to 10W or more. -Robust lightning protection afforded by grounded metal footlockers and framework, and a built-in common grounding point. -Strongly resistant to ice loads. -Waterproof, insect-proof plastic boxes for radios and electronics. -Aluminum boxes are easily fabricated, fit within postal and airline baggage size and weight limitations. -2" pipe can be procured locally, everywhere VDAP has worked. -Clamps for 2" pipe are made of U-bolts that can be readily obtained or procured locally if necessary. This design can be easily replicated and installed by relatively inexperienced and unskilled workers. A USGS Open-File Report detailing the construction is in production.

Lockhart, A. B.; LaFevers, M.; Couchman, M. R.

2012-12-01

283

Development of a Testing Platform for Scaled-Laboratory Studies of Marine Hydrokinetic Devices  

NASA Astrophysics Data System (ADS)

A small-scale platform for testing model hydrokinetic devices in riverine environments has been developed for the hydraulic flume facility (32 ft long, 4 ft wide, 1.5 ft deep) in the Environmental Fluid Mechanics and Hydraulics Laboratory (EFM&H) at Bucknell University. This platform is being used to advance development of marine hydrokinetic technologies by providing scaled-laboratory testing in a controlled environment. The results will provide validation of numerical predictions for device effects on the local substrate. Specifically, the flume is being used to model the effect of an underwater turbine on the sediment transport through its wake flow as it converts hydrokinetic energy to power. A test bed has been designed and assembled to hold sediment of varying size and material, where a single model turbine or an array formation, can be rooted within an erodible bed to conduct scour and erosion studies. Additionally, the facility is equipped with contraction inserts to increase the range of flow speeds available for turbine testing. For accurate flow field measurements the testing platform is instrumented with a Sontek Horizon 16 MHz Micro Acoustic Doppler Velocimeter (ADV) which is used to characterize the mean velocity field of the wake generated by the turbine to correlate the strength of the wake with changes in the sediment bed. Finally, the testing platform includes an HR Wallingford 2D Sediment Bed Profiler with a low-powered laser distance sensor mounted inside a waterproof housing to enable characterization of changes in bed form topology for various turbine performance regimes. The flume is equipped with a track that allows a precision 3D traversing system to position measurement probes along the length, width and depth of the flume. Model turbine performance in terms of torque and power are characterized. This testing platform for laboratory-scaled studies are instrumental in yielding physical measurements of the alteration of sediment caused by variations in flow and wake structures due to the presence of marine hydrokinetic devices. These results will facilitate siting assessment for green energy technologies.

Beninati, M. L.; Volpe, M. A.; Riley, D. R.; Krane, M. H.

2010-12-01

284

Variations on a theme: diversification of cuticular hydrocarbons in a clade of cactophilic Drosophila  

PubMed Central

Background We characterized variation and chemical composition of epicuticular hydrocarbons (CHCs) in the seven species of the Drosophila buzzatii cluster with gas chromatography/mass spectrometry. Despite the critical role of CHCs in providing resistance to desiccation and involvement in communication, such as courtship behavior, mating, and aggregation, few studies have investigated how CHC profiles evolve within and between species in a phylogenetic context. We analyzed quantitative differences in CHC profiles in populations of the D. buzzatii species cluster in order to assess the concordance of CHC differentiation with species divergence. Results Thirty-six CHC components were scored in single fly extracts with carbon chain lengths ranging from C29 to C39, including methyl-branched alkanes, n-alkenes, and alkadienes. Multivariate analysis of variance revealed that CHC amounts were significantly different among all species and canonical discriminant function (CDF) analysis resolved all species into distinct, non-overlapping groups. Significant intraspecific variation was found in different populations of D. serido suggesting that this taxon is comprised of at least two species. We summarized CHC variation using CDF analysis and mapped the first five CHC canonical variates (CVs) onto an independently derived period (per) gene + chromosome inversion + mtDNA COI gene for each sex. We found that the COI sequences were not phylogenetically informative due to introgression between some species, so only per + inversion data were used. Positive phylogenetic signal was observed mainly for CV1 when parsimony methods and the test for serial independence (TFSI) were used. These results changed when no outgroup species were included in the analysis and phylogenetic signal was then observed for female CV3 and/or CV4 and male CV4 and CV5. Finally, removal of divergent populations of D. serido significantly increased the amount of phylogenetic signal as up to four out of five CVs then displayed positive phylogenetic signal. Conclusions CHCs were conserved among species while quantitative differences in CHC profiles between populations and species were statistically significant. Most CHCs were species-, population-, and sex-specific. Mapping CHCs onto an independently derived phylogeny revealed that a significant portion of CHC variation was explained by species' systematic affinities indicating phylogenetic conservatism in the evolution of these hydrocarbon arrays, presumptive waterproofing compounds and courtship signals as in many other drosophilid species.

2011-01-01

285

Direct burial and vault emplacement data quality comparison at Dotson Ranch, New Mexico  

NASA Astrophysics Data System (ADS)

We compare the data quality of two emplacement methods for portable broadband seismic stations, traditional vault and direct burial, using power spectral density analysis to examine temporal trends in noise, the ratio of signal-to-noise for local, regional and teleseismic earthquakes, coherence of both noise and earthquake signal recordings as well as overall data return. Sensor emplacement in the past has been overwhelmingly dominated by traditional vaults requiring more materials, manpower and time. A new technique of directly burying sensors drastically reduces the expense, personnel and time required to install a seismic station. Comparisons between the data quality of vault and direct buried sensors are needed to show that the time and money saved in emplacement does not downgrade the quality of the data collected. Two identical shallow vaults were installed adjacent to two identical direct burial sites at Dotson Ranch in San Antonio, New Mexico, in a deliberately-chosen noisy, wet and generally inhospitable location. These four sites each used a Guralp 3T sensor retrofitted with a waterproof lid and connector. Eight months of data recorded during 2012 from these four sensors are compared in order to determine if the emplacement method has a profound and systematic effect on data quality using several different metrics that mimic the actual use of seismic data in research. A posthole installation with a Nanometrics Trillium 120PH sensor was also installed at the site for a portion of the study and six months of data are included in the analysis. Overall the variability in data quality metrics used in this study is comparable between sites with differing emplacement method as it is between sites with the same emplacement method. Noise in the vaults is higher in amplitude during the transition from spring to summer as compared to the direct burials and is especially evident on the horizontal components at long periods between 20-170 seconds. Diurnal changes in noise levels are similar at all sensors and are likely due to cultural activity and temperature fluctuations. The conclusion from this study is that the shallow vault emplacement method does not provide significant improvement in data quality compared to direct burial emplacement method. Further experiments are underway in a less noisy environment at Poker Flat Research Range in Alaska.

Beaudoin, B. C.; Aderhold, K.; Anderson, K.; Pfeifer, M.; Parker, T.; Miller, P. E.; Slad, G. W.; Reusch, A.

2013-12-01

286

Digital field mapping of the Dingle Peninsular, County Kerry, Ireland  

NASA Astrophysics Data System (ADS)

In September 2011, a team of eight students from the University of Göttingen digitally mapped seven 10 km2 adjoining areas on the western tip of the Dingle Peninsular in County Kerry, Ireland for their M.Sc. mapping projects. The students worked in pairs; each pair was equipped with an outdoor, waterproof, drop-proof touchscreen tablet running Windows and Midland Valley Exploration Ltd's Fieldmove software. They also used paper field-notebooks, cameras and hand compasses. The tablets have built-in GPS, two five-hour batteries, and displays that are designed to work even in bright sunlight. In preparation for the fieldwork, the topographic maps of the area (from 1890!) were scanned, geo-rectified and draped onto the DEM of the area using the Midland Valley's Move software. The geology of the Dingle Peninsular is complex; an inlier of Ordovician rocks that were deformed in the Caledonian Orogeny, are surrounded by Devonian Old Red Sandstone (ORS) units, which were syntectonically deposited as the whole area was folded during the Variscan Orogeny. Consequently the ORS units vary in thickness tremendously and facies often vary laterally. The ORS also contains many unconformities. The area is excellently exposed at the coastline, but it is poor inland because of glacial deposits. As a consequent the students required the software to record bedding planes, cleavages, fold axes and unconformities, as well as standard geological information. The work went well, despite the weather (the post tropical cyclone Katia!). It was far quicker to complete the map compared to working on a paper map, after the students had got used to the software and the tablet controls. The GPS in the tablet was deemed to be inaccurate and locations on the map were ascertained using standard techniques. It was also extremely useful to export tectonic data in the evening for stereonet projection analysis. Each 10 km2 area was mapped at 1:10000 in approx. 2 weeks. Because the tablet requires two hands, it is even more a necessity that the students map in pairs.

Tanner, David; Bense, Frithjof

2014-05-01

287

Corrosion Resistant Cladding by YAG Laser Welding in Underwater Environment  

SciTech Connect

It is known that stress-corrosion cracking (SCC) will occur in nickel-base alloys used in Reactor Pressure Vessel (RPV) and Internals of nuclear power plants. A SCC sensitivity has been evaluated by IHI in each part of RPV and Internals. There are several water level instrumentation nozzles installed in domestic BWR RPV. In water level instrumentation nozzles, 182 type nickel-base alloys were used for the welding joint to RPV. It is estimated the SCC potential is high in this joint because of a higher residual stress than the yield strength (about 400 MPa). This report will describe a preventive maintenance method to these nozzles Heat Affected Zone (HAZ) and welds by a corrosion resistant cladding (CRC) by YAG Laser in underwater environment (without draining a reactor water). There are many kinds of countermeasures for SCC, for example, Induction Heating Stress Improvement (IHSI), Mechanical Stress Improvement Process (MSIP) and so on. A YAG laser CRC is one of them. In this technology a laser beam is used for heat source and irradiated through an optical fiber to a base metal and SCC resistant material is used for welding wires. After cladding the HAZ and welds are coated by the corrosion resistant materials so their surfaces are improved. A CRC by gas tungsten arc welding (GTAW) in an air environment had been developed and already applied to a couple of operating plants (16 Nozzles). This method was of course good but it spent much time to perform because of an installation of some water-proof working boxes to make a TIG-weldability environment. CRC by YAG laser welding in underwater environment has superior features comparing to this conventional TIG method as follows. At the viewpoint of underwater environment, (1) an outage term reduction (no drainage water). (2) a radioactive exposure dose reduction for personnel. At that of YAG laser welding, (1) A narrower HAZ. (2) A smaller distortion. (3) A few cladding layers. A YAG laser CRC test in underwater environment was carried out in the different welding position, horizontal, vertical upward and downward. The soundness of cladding layers (about 3 mm) is confirmed in visual and penetration test, and cross section observation. In the application to the actual plants, it is preferable to reduce the start and end point numbers of beads with which a defect is easy to cause. Therefore a special welding equipment for a YAG laser CRC that could weld continuously was developed. (authors)

Tsutomi Kochi; Toshio Kojima; Suemi Hirata; Ichiro Morita; Katsura Ohwaki [Ishikawajima-Harima Heavy Industries Company Ltd., 1 Shin-Nakaharacho, Isogoku, Yokohama 235-8501 (Japan)

2002-07-01

288

Characterization of a new MOSFET detector configuration for in vivo skin dosimetry  

SciTech Connect

The dose released to the patient skin during a radiotherapy treatment is important when the skin is an organ at risk, or on the contrary, is included in the target volume. Since most treatment planning programs do not predict dose within several millimeters of the body surface, it is important to have a method to verify the skin dose for the patient who is undergoing radiotherapy. A special type of metal oxide semiconductors field-effect transistors (MOSFET) was developed to perform in vivo skin dosimetry for radiotherapy treatments. Water-equivalent depth (WED), both manufacturing and sensor reproducibility, dependence on both field size and angulation of the sensor were investigated using 6 MV photon beams. Patient skin dosimetries were performed during 6 MV total body irradiations (TBI). The resulting WEDs ranged from 0.04 and 0.15 mm (0.09 mm on average). The reproducibility of the sensor response, for doses of 50 cGy, was within {+-}2% (maximum deviation) and improves with increasing sensitivity or dose level. As to the manufacturing reproducibility, it was found to be {+-}0.055 mm. No WED dependence on the field size was verified, but possible variations of this quantity with the field size could be hidden by the assessment uncertainty. The angular dependence, for both phantom-surface and in-air setups, when referred to the mean response, is within {+-}27% until 80 deg. rotations. The results of the performed patient skin dosimetries showed that, normally, our TBI setup was suitable to give skin the prescribed dose, but, for some cases, interventions were necessary: as a consequence the TBI setup was corrected. The water-equivalent depth is, on average, less than the thinnest thermoluminescent dosimeters (TLD). In addition, when compared with TLDs, the skin MOSFETs have significant advantages, like immediate both readout and reuse, as well as the permanent storage of dose. These sensors are also waterproof. The in vivo dosimetries performed prove the importance of verifying the dose to the skin of the patient undergoing radiotherapy.

Scalchi, Paolo; Francescon, Paolo; Rajaguru, Priyadarshini [Department of Medical Physics, San Bortolo Hospital, Vicenza (Italy)

2005-06-15

289

Tribute to R. G. Boutilier: skin colour and body temperature changes in basking Bokermannohyla alvarengai (Bokermann 1956).  

PubMed

In amphibians solar basking far from water sources is relatively uncommon since the highly permeable amphibian skin does not represent a significant barrier to the accompanying risk of losing water by evaporation. A South American frog, Bokermannohyla alvarengai (Bokermann 1956), however, spends a significant amount of the day exposed to full sun and relatively high temperatures. The means by which this frog copes with potentially high rates of evaporative water loss and high body temperatures are unknown. Thus, in this study, skin colour changes, body surface temperature, and evaporative water loss rates were examined under a mixture of field and laboratory conditions to ascertain whether changes in skin reflectivity play an important role in this animal's thermal and hydric balance. Field data demonstrated a tight correlation between the lightness of skin colour and frog temperature, with lighter frogs being captured possessing higher body temperatures. Laboratory experiments supported this relationship, revealing that frogs kept in the dark or at lower temperatures (20 degrees C) had darker skin colours, whereas frogs kept in the light or higher temperatures (30 degrees C) had skin colours of a lighter hue. Light exhibited a stronger influence on skin colour than temperature alone, suggesting that colour change is triggered by the increase in incident solar energy and in anticipation of changes in body temperature. This conclusion is corroborated by the observation that cold, darkly coloured frogs placed in the sun rapidly became lighter in colour during the initial warming up period (over the first 5 min), after which they warmed up more slowly and underwent a further, albeit slower, lightening of skin colour. Surprisingly, despite its natural disposition to bask in the sun, this species does not possess a ;waterproof' skin, since its rates of evaporative water loss were not dissimilar from many hylid species that live in arboreal or semi-aquatic environments. The natural history of B. alvarengai is largely unknown and, therefore, it is likely that the herein reported colour change and basking behaviour represent a complex interaction between thermoregulation and water balance with other ecologically relevant functions, such as crypsis. PMID:16547291

Tattersall, Glenn J; Eterovick, Paula C; de Andrade, Denis V

2006-04-01

290

Management of long-term and reversible hysteroscopic sterilization: a novel device with nickel-titanium shape memory alloy  

PubMed Central

Background Female sterilization is the second most commonly used method of contraception in the United States. Female sterilization can now be performed through laparoscopic, abdominal, or hysteroscopic approaches. The hysteroscopic sterilization may be a safer option than sterilization through laparoscopy or laparotomy because it avoids invading the abdominal cavity and undergoing general anaesthesia. Hysteroscopic sterilization mainly includes chemical agents and mechanical devices. Common issues related to the toxicity of the chemical agents used have raised concerns regarding this kind of contraception. The difficulty of the transcervical insertion of such mechanical devices into the fallopian tubes has increased the high incidence of device displacement or dislodgment. At present, Essure® is the only commercially available hysteroscopic sterilization device being used clinically. The system is irreversible and is not effective immediately. Presentation of the hypothesis Our new hysteroscopic sterility system consists of nickel-titanium (NiTi) shape memory alloy and a waterproof membrane. The NiTi alloy is covered with two coatings to avoid toxic Ni release and to prevent stimulation of epithelial tissue growth around the oviducts. Because of the shape memory effect of the NiTi alloy, the device works like an umbrella: it stays collapsed at low temperature before placement and opens by the force of shape memory activated by the body temperature after it is inserted hysteroscopically into the interstitial tubal lumen. The rim of the open device will incise into interstitial myometrium during the process of unfolding. Once the device is fixed, it blocks the tube completely. When the patient no longer wishes for sterilization, the device can be closed by perfusing liquid with low temperature into the uterine cavity, followed by prospective hysteroscopic removal. After the device removal, the fallopian tube will revert to its physiological functions. Testing the hypothesis Currently, experimental and clinical studies are needed to attest the safety, efficiency and reversibility of the novel sterilization device. Implications of the hypothesis If our hypothesis is confirmed, appropriate and reversible contraceptive can be achieved with the device we have designed, which may have significant repercussions for numerous women worldwide.

2014-01-01

291

Energy balance measurements over a small reservoir in Ghana's Upper East Region  

NASA Astrophysics Data System (ADS)

Near the small village of Binaba (10.778927 deg N, 0.464859 deg E), a small irrigation reservoir has been instrumented to measure different parts of the energy balance of this water body. Instruments were placed on, or attached to, a spar platform. This platform consisted of a long PVC pipe, the spar, which is closed at the bottom. On the PVC pipe rests an aluminum frame platform that carries instrumentation and solar power panel. In turn, the platform rests partially on a large inflated tire. At the bottom of the PVC pipe, lead weights and batteries were placed to ensure a very low point of gravity to minimize wave impact on the platform movement. The tire ensures a large second moment of the water plane. The combination of large second momentum of the water plane and small displacement, ensures a high placement of the metacenter. The distance between the point of gravity and the metacenter is relatively long and the weight is large due to the weights and batteries. This ensures that the eigenfrequency of the platform is very low. On the platform, we fixed a WindMaster Pro (sonic anemometer for 3D wind speed and air temperature to perform eddy covariance measurements of sensible heat flux), a NR Lite (net radiometer), and air temperature and relative humidity sensors. Water temperature at different depths was measured with a string of TidbiT's (waterproof temperature sensors and loggers). The platform had a wind vane and the spar could turn freely around its anchor cable to ensure that the anemometer always faced upwind. A compass in the logger completed this setup. First results suggest, as expected, that the sensible heat flux is relatively small with on average 20 W/m2 over the course of a day. Sensible heat flux peaked around midnight at 35 W/m2, when the warm water warmed up the air from the colder surrounding land. The dynamics of heat storage during the daytime and longwave radiation during the night time, are important to calculate the latent heat flux.

van de Giesen, Nick; Ohene Annor, Frank

2013-04-01

292

[Water births and the exposure to HIV].  

PubMed

The risk of a work related HIV-exposure or infection to midwives, or other HCW, in attending waterbirths of (possible unrecognized) HIV-positive women is unknown. Our goal was the quantification of the loss of blood of the childbearing woman after a waterbirth into the waterpool, in taking pool-water-samples of 14 different waterbirths and measuring the hemoglobin in the plasma, and then correlating the mean found loss of blood and the mean quantity of poolwater with a hypothetical HIV-RNA viral load of 10(3)-10(6) copies per milliliters (ml) blood. All attended waterbirths were evaluated with a questionnaire regarding: parity of the child-bearing woman; serostatus for HIV/Hepatitis-B (HBV) and Hepatitis-C (HCV); length of the birth-process; perineum-rupture or not, etc. Questions concerning the HCW in implementing universal precautions like: type of gloves and garment used, if at all; duration of water contact with the hands; existing skin lesions; HBV-vaccination-status; years of professional experiences as a midwife; how many waterbirths attended etc. were also evaluated. The mean calculated loss of blood into the pool was 300 ml, the mean pool-water content 633 liters. With a hypothetical (maximal) HIV-RNA viral load of 10(6) copies per ml blood, we calculated a mean HIV-RNA viral load of 476 copies per ml pool-water. We also found 37% of the interviewed midwives (n = 14) to have skin lesions on hands or fingers; 1 received splashes into her (unprotected) face and 1 was not immunized against HBV. The mean loss of blood of 300 ml into the pool is a relevant amount. The skin-contact of the HCW with the potentially contaminated water is the norm, because of the failure of the type of used gloves. Because of the diluting effect of the poolwater, we estimate the potential risk for a HIV-exposure to intact skin as minimal and, therefore a potential HIV-infection as "low level" and to be unlikely. However, a risk for nosocomial HBV-infection is significantly higher. We recommend wearing long-sleeved gloves, waterproofed garment, and HBV-vaccination to all HCW. PMID:10969581

Colombo, C; Pei, P; Jost, J

2000-06-01

293

Measurement of ionization chamber absorbed dose k{sub Q} factors in megavoltage photon beams  

SciTech Connect

Purpose: Absorbed dose beam quality conversion factors (k{sub Q} factors) were obtained for 27 different types of ionization chamber. The aim was to obtain objective evidence on the performance of a wide range of chambers currently available, and potentially used for reference dosimetry, and to investigate the accuracy of the k{sub Q} calculation algorithm used in the TG-51 protocol. Methods: Measurements were made using the {sup 60}Co irradiator and Elekta Precise linac facilities at the National Research Council of Canada. The objective was to characterize the chambers over the range of energies applicable to TG-51 and determine whether each chamber met the requirements of a reference-class instrument. Chamber settling, leakage current, ion recombination and polarity, and waterproofing sleeve effects were investigated, and absorbed dose calibration coefficients were obtained for {sup 60}Co and 6, 10, and 25 MV photon beams. Only thimble-type chambers were considered in this investigation and were classified into three groups: (i) Reference chambers (''standard''0.6 cm{sup 3} Farmer-type chambers and their derivatives traditionally used for beam output calibration); (ii) scanning chambers (typically 0.1 cm{sup 3} volume chambers used for beam commissioning with 3-D scanning phantoms); and (iii) microchambers (very small volume ion chambers ({<=}0.01 cm{sup 3}) used for small field dosimetry). Results: As might be expected, 0.6 cm{sup 3} thimble chambers showed the most predictable performance and experimental k{sub Q} factors were obtained with a relative uncertainty of 0.1%. The performance of scanning and microchambers was somewhat variable. Some chambers showed very good behavior but others showed anomalous polarity and recombination corrections that are not fully explained at present. For the well-behaved chambers, agreement between measured and calculated k{sub Q} factors was within 0.4%; for some chambers, differences of more than 1% were seen that may be related to the recombination/polarity results. Use of such chambers could result in significant errors in the determination of reference dose in the clinic. Conclusions: Based on the experimental evidence obtained here, specification for a reference-class ionization chamber could be developed that would minimize the error in using a dosimetry protocol with calculated beam quality conversion factors. The experimental k{sub Q} data obtained here for a wide range of thimble chambers can be used when choosing suitable detectors for reference dosimetry and are intended to be used in the upcoming update/addendum to the AAPM TG-51 dosimetry protocol.

McEwen, Malcolm R. [Institute for National Measurement Standards, National Research Council of Canada, Ottawa, Ontario K1A 0R6 (Canada)

2010-05-15

294

Hydraulic description of a flood event with optical remote sensors: a constructive constraint on modelling uncertainties  

NASA Astrophysics Data System (ADS)

The exceptional characteristics of the December 2003 Rhône flood event (particularly high water flows, extent of the affected area, important damages especially in the region of Arles) make it be considered as a reference flood episode of this French river and a very well-known event. During the crisis, the International Charter "Space and Major Disasters" was triggered by the French Civil Protection for the rapid mapping of the flooding using Earth Observation imagery in order to facilitate crisis operations. As a result, more than 60 satellite images covering the flood were acquired over a 10 days period following the peak flow. Using the opportunity provided by this incomparable data coverage, the French Ministry of the Environment ordered a study on the evaluation of remote sensing's potential benefits for flood management. One of the questions asked by the risk managers was: what type of flood information can be provided by the different remote sensing platforms? Elements of response were delivered mainly in the form of a comprehensive compilation of maps and illustrations, displaying the main hydraulic elements (static ones as well as dynamic ones), initially listed and requested by hydrologists (more precisely, by a regional engineering society specialised in hydraulics and hydrology and in charge of a field campaign during the event), observed on different optical images of the flood event having affected the plain between Tarascon (upstream) and Arles (downstream). It is seen that a careful mapping of all flood traces visible on remote sensing event imagery - apparent water, moisture traces, breaches, overflows, stream directions, impermeable boundaries … - delivers a valuable vision of the flood's occurrence combining accuracy and comprehensiveness. In fact, optical imagery offers a detailed vision of the event : moisture traces complete flood traces extent; the observation of draw-off directions through waterproof barriers reveals hydraulic compartments; high resolution optical imagery allow the exhaustive inventory of breaches and overflows; turbidity variations and draw-off give information on stream directions. These facts are of primary interest to help in deriving a firm understanding of the flooding processes, but also comprise a powerful source for the necessary parameterization and/or calibration of hydraulic models. Thus the accuracy of flood extents derived from remote sensing data could, on the one hand, be valuable inputs to historical flood info-bases within overall risk-linked databases, and on the other hand, test the validity of hydrological modelling, while helping to lift equifinality uncertainties. These first investigations highlight that space imagery of events constitutes an unrivalled tool for flood disaster observation. This 2D record is complementary to all field measurements and the integration of "space derived flood products" is valuable for all stages of risk management. This potential of EO optical sensors for flood monitoring is also confirmed in a detailed analysis making a qualitative and quantitative evaluation of the results, confronting ten optical and radar remote sensing platforms with field observations.

Battiston, Stéphanie; Allenbach, Bernard

2010-05-01

295

Modeling Leptospirosis in Trinidad, West Indies: A Waterborne Zoonosis of Increasing Public Health Importance  

NASA Astrophysics Data System (ADS)

Leptospirosis is a waterborne disease which is considered one of the most common and widely spread bacterial zoonosis and a growing global public health problem. Transmission in humans is caused by direct or indirect contact with contaminated water, soil or infected urine, blood or tissue of carrier animals. Because of the similarity with influenza, dengue and viral hepatitis symptoms it is often misdiagnosed with these diseases, but as the leptospirosis progresses, internal organs can be compromised, causing severe syndromes (e.g. Weil's disease), and potentially can cause death. In less developed countries, leptospirosis is often poorly recognized. In humid tropics and subtropics, where this disease has a high impact, climatic and environmental factors, such as rainfall, floods, land cover and their modifications have been frequently related to the occurrence of leptospirosis. In these regions one of the main problems for the study of the role of environmental factors on disease dynamics is the lack of accurate data since, in many cases, data are either unavailable or do not exist at all. Between 1980 and 2005 a total of 12,475 cases of leptospirosis were reported from all Caribbean countries, with 2,370 (19%) of these corresponding to Trinidad and Tobago, where the current average annual incidence rate is 1.84 per 100,000 population based on confirmed cases. In order to explore the underlying spatial variability of leptospirosis occurrence as related to environmental and socio-economic factors, a series of Geographically Weighted Regression (GWR) models were developed. GWR was used to examine the determinants of leptospirosis in the communities of Trinidad using a total of 1,549 reported cases and 250 confirmed cases from 1998 to 2008. MODIS satellite imagery and GIS analysis were used to develop a series of covariables for each community including land cover, vegetation indices, wetness index (ln (?/tan?)), river length per Ha, topography, percentage of free draining soils, percentage of imperfectly draining soils, percentage of impeded draining soils and mean annual rainfall. These covariables together with socio-economic data were used to set up the GWR models. Local model correlation (R^{2}) was 0.78, higher than the global correlation of 0.58 and there was found to be a clear spatial correlation between covariables and leptospirosis cases. Percentage of draining soils and topography were found to be significant (p<0.01 and 0.00) indicating spatial variability in the influence of these factors on the occurrence of leptospirosis in Trinidad communities. Composition of the soils and their lack of drainage may be an important factor influencing leptospirosis occurrence. Leptospires do not have a waterproof membrane therefore for their survival they must remain submersed in water. Previous studies have found leptospires to be associated with soils of high moisture and organic matter content.

Vega, M. C.; Opadeyi, J.

2012-12-01

296

Continuous Measurement of CO2 concentration in Arctic Soil by Small Open-path Type CO2 Sensors  

NASA Astrophysics Data System (ADS)

Permafrost and seasonally thawed Arctic soils in high northern latitudes hold approximately 25 percent of the world's soil organic carbon. The predicted warming of the Arctic, coupled with regional drying, could release much of the carbon now stored in the Arctic soils. Understanding the mechanisms controlling the release of soil organic carbon as CO2 is critical to predicting sensitive Arctic soils will respond to and influence global climate change. However, there are only a few reports of soil respiration, and very few that report continuous respiration rates. The results of chamber measurements give the overall efflux from the surface and emphasize biological and chemical processes and controls. However, they do not measure soil CO2 concentrations. To our knowledge, continuous measurements of soil CO2 concentration has not been previously conducted in the Arctic, and gas diffusivity of Arctic soils that thaw and freeze are poorly known. To obtain a better understanding of the patterns and controls on carbon release from Arctic soils, long-term measurements of soil respiration and an investigation of the underlying processes were undertaken. In this study, continuous measurements of soil CO2 concentration by small open path type infrared gas analyzers in a revegetated Arctic drained lake basin at Barrow Alaska was undertaken. Measurements were conducted from the beginning of soil thaw in summer through the following winter and summer. Changes in soil CO2 concentration during freezing and thawing processes proved especially interesting. Soil CO2 concentration in the organic layer of the drained lake basin was much higher than that of Typic Psamomoturbals soil from heath vegetation cover in Greenland (Elberling and Brandt 2003) throughout the thawing season. Soil CO2 increased with increasing soil temperature and thaw depth reflecting CO2 production in the soil. Soil CO2 concentration was greater in relatively wet soil than in dry soil. Soil CO2 concentration increased as a result of rain, and this phenomenon was especially pronounced in soils that had been relatively dry before the precipitation. Ground surface CO2 concentration increased when the ground was covered with snow. The level of CO2 in the snow pack at our sites was similar to results of Jones et al. (1999) which was measured in the Canadian arctic tundra. CO2 in the snow pack changed with wind speed suggesting that ventilation during wind was important for CO2 exchange between snow and the atmosphere. Soil CO2 concentration increased quickly and significantly with soil freezing. CO2 at 20cm depth exceeded 20 percent in relatively wet soil. The waterproof filter of the sensor encasement, which is reportedly resistant to 200 mbar of pressure, leaked water when the surrounding water froze suggesting that there is a pressure change (more than 200 mbar) in the soil upon freezing. Such pressure would have significant impacts on gas transport and concentration in the soil. The temperature dependency of soil CO2 concentration changed markedly at -1 degree Celsius and there was considerable hysteresis in temperature dependency of soil CO2 concentration at sub-zero temperatures as temperatures raised or fell suggesting that both biological and physical processes affect differently between the freezing and the thawing periods.

Nakamoto, K.; Oechel, W. C.; Lipson, D.

2006-12-01

297

Mathematical numeric models for assessing the groundwater pollution from Sanitary landfills  

NASA Astrophysics Data System (ADS)

Landfills are among the most common sources of pollution in ground water. Their widespread deployment, prolonged usage and the serious damage they cause to all of the elements of the environment are the reasons, which make the study of the problem particularly relevant. Most dangerous of all are the open dumps used until the middle of the twentieth century, from which large amounts of liquid emissions flowed freely (landfill infiltrate). In recent decades, the problem is solved by the construction of sanitary landfills in which they bury waste or solid residue from waste utilization plants. The bottom and the sides of the sanitary landfills are covered with a protective waterproof screen made of clay and polyethylene and the landfill infiltrate is led outside through a drainage system. This method of disposal severely limits any leakage of gas and liquid emissions into the environment and virtually eliminates the possibility of contamination. The main topic in the conducted hydrogeological study was a quantitative assessment of groundwater pollution and the environmental effects of re-landfilling of an old open dump into a new sanitary landfill, following the example of the municipal landfill of Asenovgrad, Bulgaria. The study includes: 1.A set of drilling, geophysical and hydrogeological field and laboratory studies on: -the definition and designation of the spatial limits of the main hydrogeological units; -identification of filtration parameters and migration characteristics of the main hydrogeological units; -clarifying the conditions for the sustentation and drainage of groundwater; -determininng the structure of the filtration field; -identifying and assessing the size and the extent of groundwater contamination from the old open dump . 2.Mathematical numeric models of migration and entry conditions of contaminants below the bottom of the landfill unit, with which the natural protection of the geological environment, the protective effect of the engineering barriers of the sanitary landfill, and the potential risk of contamination of the groundwater were evaluated. The migration of contaminants through the zone of aeration and the engineering barriers are modeled with 2D models, and their potential distribution in groundwater - with 3D models. The models simulate the behavior of highly mobile and less mobile contaminants by the example of chloride and ammonium ions (Cl-and NH4 +).The mechanism of mass transfer is set in its full form: convective transport, accompanied by reversible elimination (sorption), mechanical dispersion (longitudinal and transverse), molecular diffusion and dilution. The concentration of the infiltrating under the bottom of the dump unit pollutants is set to exponentially decreasing function, determined by data from the monitoring. Two-dimensional models are developed using the computer program VS2DTI - v.1.3, and three-dimensional models by Modflow and MT3D-MS.dimensional models by Modflow and MT3D-MS.

Petrov, Vasil; Stoyanov, Nikolay; Sotinev, Petar

2014-05-01

298

Strain gage installation and survivability on geosynthetics used in flexible pavements  

NASA Astrophysics Data System (ADS)

The use of foil type strain gages on geosynthetics is poorly documented. In addition, very few individuals are versed in proper installation techniques or calibration methods. Due to the limited number of knowledgeable technicians there is no information regarding the susceptibility of theses gages to errors in installation by inexperienced installers. Also lacking in the documentation related to the use of foil type strain gages on geosynthetics is the survivability of the gages in field conditions. This research documented procedures for installation, calibration, and survivability used by the project team to instruments a full scale field installation in Marked Tree, AR. This research also addressed sensitivity to installation errors on both geotextile and geogrid. To document the process of gage installation an experienced technician, Mr. Joe Ables, formerly of the UASCE Waterways Experiment Station, was consulted. His techniques were combined with those discovered in related literature and those developed by the research team to develop processes that were adaptable to multiple gage geometries and parent geosynthetics. These processes were described and documented in a step by step manner with accompanying photographs, which should allow virtually anyone with basic electronics knowledge to install these gages properly. Calibration of the various geosynthetic / strain gage combinations was completed using wide width tensile testing on multiple samples of each material. The tensile testing process was documented and analyzed using digital photography to analyze strain on the strain gage itself. Calibration factors for each geosynthtics used in the full scale field testing were developed. In addition, the process was thoroughly documented to allow future researchers to calibrate additional strain gage and geosynthetic combinations. The sensitivity of the strain gages to installation errors was analyzed using wide width tensile testing and digital photography to determine the variability of the data collected from gages with noticeable installation errors as compared to properly installed gages. Induced errors varied based on the parent geosynthetics material, but included excessive and minimal waterproofing, gage rotation, gage shift, excessive and minimal adhesive, and excessive and minimal adhesive impregnation loads. The results of this work indicated that minor errors in geotextile gage installation that are noticeable and preventable by the experienced installer have no statistical significance on the data recorded during the life span of geotextile gages; however the lifespan of the gage may be noticeably shortened by such errors. Geogrid gage installation errors were found to cause statistically significant changes in the data recorded from improper installations. The issue of gage survivability was analyzed using small scale test sections instrumented and loaded similarly to field conditions anticipated during traditional roadway construction. Five methods of protection were tested for both geotextile and geogrid including a sand blanket, inversion, semi-hemispherical PCV sections, neoprene mats, and geosynthetic wick drain. Based on this testing neoprene mats were selected to protect geotextile installed gages, and wick drains were selected to protect geogrid installed gages. These methods resulted in survivability rates of 73% and 100% in the full scale installation respectively. This research and documentation may be used to train technicians to install and calibrate geosynthetic mounted foil type strain gages. In addition, technicians should be able to install gages in the field with a high probability of gage survivability using the protection methods recommended.

Brooks, Jeremy A.

299

Anterior cruciate ligament reconstruction using semitendinosus and gracilis tendons, bone patellar tendon, or quadriceps tendon-graft with press-fit fixation without hardware. A new and innovative procedure.  

PubMed

BONE--PATELLAR TENDON: The "no hardware" technique for ACL reconstruction is a new method that offers many advantages and is straightforward to perform. Its main innovative feature is that it does not require bone-block harvesting from the patella. This reduces donor site morbidity and prevents patellar fractures. The bone tunnels are made using tube harvesters and compaction drilling. This minimizes trauma and obviates the risk of bone necrosis. The articular entrance of the tibial tunnel is completely occupied by the grafts. This prevents a windshield-wiper effect and synovial fluid ingress into the tunnel, and enhances graft incorporation. The fact that no hardware is used with both patellar tendon or hamstring grafts significantly reduces the overall cost of the operation and facilitates revision surgery. The quadriceps tendon is also a very good graft. It is thick and has good biomechanical properties and low donor site morbidity. Its disadvantages are: weakness of quadriceps after the operation, an unsightly scar, and some difficulty in graft harvesting [58]. Also, postoperative MRI is not fraught with the problem of metal artifacts. It is difficult to decide which of the methods currently available for ACL reconstruction is the best because most of them give satisfactory results. In the future, assessments of knee ligament reconstruction techniques should look at long-term stability combined with low complication rates. Ease of revision surgery and low cost should also be taken into consideration, given the large annual volume of knee ligament reconstructions (50,000 in the United States alone) [59]. We believe that our technique addresses most of these issues, and that it constitutes a useful alternative method for ACL reconstruction. SEMITENDINOSUS--GRACILIS: This technique, which was used with 915 patients from June 1998 to February 2002, shows a particularly low rate of postoperative morbidity. The reason is probably to be found in the "waterproofing" of the bone tunnels, which lead to less postoperative bleeding and swelling. No drains were used. Rehabilitation follows the same protocol as used for the reconstruction using patellar tendon grafts (accelerated/functional). As expected, there was no widening of the femoral tunnels and little widening of the tibial tunnels. Interestingly, tibial tunnel enlargement was significantly less in a nonaccelarated rehabilitation group than in the accelerated group [60] without affecting stability. The measured internal torque of the hamstrings, as well as their flexion force, already had returned to normal 12 months postoperatively. In a prospective randomized (unpublished) study comparing this technique with ACL reconstruction with BPT grafts with medial or lateral third with only one bone plug (from the tibial tuberosity, see technique described above), we found no significant difference between both groups in subjective scores, stability, KT-1000 values, Tegner activity score, and IKDC at 1-year follow-up. Only the results of kneeling and knee walking testing were significantly better in the hamstring group [61]. In summary, the advantages of this presented technique are: (1) the knot of the graft is close proximally to the anatomic site of the insertion of the ACL, thus avoiding the Bungee effect.; (2) the press-fit tunnel fixation prevents synovial fluid entering the bone tunnels, windshield-wiper effect, and longitudinal motion within the tunnel; the intensive contact between the bony wall of the tunnel and graft collagen over a long distance without any suture material results in quick and complete graft incorporation; and (3) no fixation material means no hardware problems, facilitates revision surgery, and lowers overall costs. PMID:12735201

Paessler, Hans H; Mastrokalos, Dimitrios S

2003-01-01

300

Surface assessment and modification of concrete using abrasive blasting  

NASA Astrophysics Data System (ADS)

Composite systems are applied to concrete substrates to strengthen and extend the service life. Successful restoration or rehabilitation requires surface preparation prior to the application of the overlay. Surface coatings, waterproofing systems, and other external surface applications also require surface preparation prior to application. Abrasive blast media is often used to clean and uniformly roughen the substrate. The appropriate surface roughness is necessary to facilitate a strong bond between the existing substrate and overlay. Thus, surface modification using abrasive blast media (sand and dry ice), their respective environmental effects, surface roughness characterization prior to and after blasting, and the adhesion between the substrate and overlay are the focus of this dissertation. This dissertation is comprised of an introduction, a literature review, and four chapters, the first of which addresses the environmental effects due to abrasive blasting using sand, water, and dry ice. The assessment considered four response variables: carbon dioxide (CO2) emissions, fuel and energy consumption, and project duration. The results indicated that for sand blasting and water jetting, the primary factor contributing to environmental detriment was CO22 emissions from vehicular traffic near the construction site. The second chapter is an analysis of the International Concrete Repair Institute's (ICRI) concrete surface profiles (CSPs) using 3-D optical profilometry. The primary objective was to evaluate the suitability of approximating the 3-D surface (areal) parameters with those extracted from 2-D (linear) profiles. Four profile directions were considered: two diagonals, and lines parallel and transverse to the longitudinal direction of the mold. For any CSP mold, the estimation of the 3-D surface roughness using a 2-D linear profile resulted in underestimation and overestimation errors exceeding 50%, demonstrating the inadequacy of 2-D linear profiles to approximate the 3-D concrete surface profiles. The errors were reduced when a weighted average of the four linear profiles approximated the corresponding 3-D parameter. The following chapter considers the parametric and sensitivity of concrete surface topography measurements. The weighted average of the four 2-D profiles consistently resulted in underestimation of the corresponding 3-D parameters: the dispersion of surface elevations (Sq) and the roughness (Sa). Results indicated the 3-D parameter, Sq, had the least sensitivity to data point reduction. The final chapter investigated surface modification using dry ice and sand blasting. The overall objective was to evaluate the change in the 3-D surface roughness (Sa) following blasting as functions of mix design and as induced by freeze-thaw cycling, and to compare the results obtained using dry ice with those obtained using sand as the blasting media. In general, sand blasting produced larger changes in Sa compared to dry ice blasting for the concrete mix designs considered. The primary mechanism responsible for altering the surface topography of the concrete was the scaling of the superficial cement paste layer on the exposed surface, which was due to freeze-thaw cycling. The largest relative change in roughness following blasting occurred in the control samples, which had not undergone freeze-thaw cycling.

Millman, Lauren R.

301

Simulating Lahars Using A Rotating Drum  

NASA Astrophysics Data System (ADS)

A large (0.5 m in diameter, 0.15 m wide) rotating drum is used to investigate the erosion and deposition mechanics of lahars. To systematically simulate the conditions occurring in natural mass flows our experimental setup differs from the common rotating drum employed in industrial/engineering studies. Natural materials with their typical friction properties are used, as opposed to the frequently employed spherical glass beads; the drum is completely water-proof, so solid/air and solid/liquid mixtures can be investigated; the drum velocity and acceleration can be precisely controlled using a software interface to a micro-controller, allowing for the study of steady, unsteady and intermediate flow regimes. The drum has a toughened glass door, allowing high-resolution, high-speed video recording of the material inside. Vector maps of the velocities involved in the flows are obtained using particle image velocimetry (PIV). The changes in velocity direction and/or magnitude are used to locate the primary internal boundaries between layers of opposite flow direction, as well as secondary interfaces between shear layers. A range of variables can be measured: thickness and number of layers; the curvature of the free surface; frequency of avalanching; position of the centre of mass of the material; and the velocity profiles of the flowing material. Experiments to date have focussed on dry materials, and have had a fill factor of approximately 0.3. Combining these measured variables allows us to derive additional data of interest, such as mass and momentum flux. It is these fluxes that we propose will allow insight into the erosion/deposition mechanics of a lahar. A number of conclusions can be drawn to date. A primary interface separates flowing and passive region (this interface has been identified in previous studies). As well as the primary interface, the flowing layer separates into individual shear layers, with individual erosion/deposition and flow histories. This complex flow geometry and process of erosion and deposition seen in our high speed videos is more complicated than previously reported in the literature. We identify two layers only in the slowest flows (< 0.5 rad s-1), while faster ones (< 4 rad s-1) include between three and five. As the rotational velocity of the drum increases, the curvature of the free surface increases. In the central part of the drum, the primary interfaces occasionally merges into an elliptical zone rather than a linear shear boundary. Inside this zone is a complete circulation of material. These zones' size and number appears to be a function of the rotational velocity of the drum. These "Neather cells" (as we tentatively name these phenomena) can reach as large as 20 mm in thickness. The centre of mass' deflection from vertical is linearly dependent on rotational velocity, whilst the typical flow regimes as identified by Mellmann [2001] show no influence. The frequency of avalanches increases with velocity up to a critical velocity (approximately 1.1 rad s-1), after which the avalanche frequency remains constant. 1 References J Mellmann. The transverse motion of solids in rotating cylinders-forms of motion and transition behavior. Powder Technology, 118(3):251-270, 2001.

Neather, Adam; Lube, Gert; Jones, Jim; Cronin, Shane

2014-05-01

302

Inducer Hydrodynamic Forces in a Cavitating Environment  

NASA Technical Reports Server (NTRS)

Marshall Space Flight Center has developed and demonstrated a measurement device for sensing and resolving the hydrodynamic loads on fluid machinery. The device - a derivative of the six-component wind tunnel balance - senses the forces and moments on the rotating device through a weakened shaft section instrumented with a series of strain gauges. This rotating balance was designed to directly measure the steady and unsteady hydrodynamic loads on an inducer, thereby defining the amplitude and frequency content associated with operating in various cavitation modes. The rotating balance was calibrated statically using a dead-weight load system in order to generate the 6 x 12 calibration matrix later used to convert measured voltages to engineering units. Structural modeling suggested that the rotating assembly first bending mode would be significantly reduced with the balance s inclusion. This reduction in structural stiffness was later confirmed experimentally with a hammer-impact test. This effect, coupled with the relatively large damping associated with the rotating balance waterproofing material, limited the device s bandwidth to approximately 50 Hertz Other pre-test validations included sensing the test article rotating assembly built-in imbalance for two configurations and directly measuring the assembly mass and buoyancy while submerged under water. Both tests matched predictions and confirmed the device s sensitivity while stationary and rotating. The rotating balance was then demonstrated in a water test of a full-scale Space Shuttle Main Engine high-pressure liquid oxygen pump inducer. Experimental data was collected a scaled operating conditions at three flow coefficients across a range of cavitation numbers for the single inducer geometry and radial clearance. Two distinct cavitation modes were observed symmetric tip vortex cavitation and alternate-blade cavitation. Although previous experimental tests on the same inducer demonstrated two additional cavitation modes at lower inlet pressures, these conditions proved unreachable with the rotating balance installed due to the intense dynamic environment. The sensed radial load was less influenced by flow coefficient than by cavitation number or cavitation mode although the flow coefficient range was relatively narrow. Transition from symmetric tip vortex to alternate-blade cavitation corresponded to changes in both radial load magnitude and radial load orientation relative to the inducer. Sensed moments indicated that the effective load center moved downstream during this change in cavitation mode. An occurrence of "higher+rdex cavitation" was also detected in both the stationary pressures and the rotating balance data although the frequency of the phenomena was well above the reliable bandwidth of the rotating balance. In summary the experimental tests proved both the concept and device s capability despite the limitations and confirmed that hydrodynamically-induced forces and moments develop in response to the unbalanced pressure field, which is, in turn, a product of the cavitation environment.

Skelley, Stephen E.

2004-01-01

303

Acute, 2-week, and 13-week inhalation toxicity studies on dimethylethoxysilane vapor in Fischer 344 rats  

NASA Technical Reports Server (NTRS)

Dimethylethoxysilane (DMES), a volatile liquid, is used by NASA to waterproof the heat-protective silica tiles and blankets on the Space Shuttle. Acute, 2-wk, and 13-wk inhalation exposures to DMES vapor were conducted in male and female Fischer 344 rats. In the acute study, rats were exposed to 4000, 2000, 1000, 500, or 0 (control) ppm DMES for 4 h and observed for 14 days. There were no deaths. Narcosis and ataxia were observed in rats of the two highest concentrations only. These signs disappeared within 1 h following exposure. There were no DMES-related gross or microscopic tissue lesions in rats of all exposure groups. In the 2-wk study, rats were exposed for 6 h/day, 5 days/wk to 3000, 1000, 300, 100, or 0 ppm DMES. During exposure, narcosis was observed in rats of the 3000 and 1000 ppm groups. There was a mild decrease in body weight gain in rats of the 3000 ppm group. A decrease in platelet count, an increase in bile acids, and reduced weights of the thymus, testis, and liver were observed in rats of the 3000 ppm group. Microscopically, hypospermatogenesis and spermatid giant cells were observed in the seminiferous tubules of the testes of rats exposed to 3000 ppm DMES. In the 13-wk study, rats were exposed 6 h/day, 5 days/wk to 2000, 600, 160, 40, or 0 ppm DMES. During exposure, rats of the 2000 ppm group exhibited mild narcosis and loss of startle reflex. Recovery from these central nervous system signs was rapid. Body weights were mildly decreased for rats of the 2000 ppm group. There were no exposure-related effects in hematology, serum chemistry, or urinalysis. Female rats of the 2000 ppm group had delayed estrous cycles (6 days compared to 5 days in control rats). Noteworthy organ weight changes in rats of the 2000 ppm group included decreases in thymus, liver, and testicular weights; however, pathologic lesions were observed in the testes only. Sperm motility, epididymal sperm count, and testicular spermatid count were dramatically reduced. Microscopic lesions included degeneration of the seminiferous tubular cells, pyknosis or absence of germ cells, and hypospermia in the epididymis. Rats of the 600 ppm group had a slight decrease in thymic weight and a transient decrease in body weight. Results of the acute, 2-wk, and 13-wk inhalation studies indicate DMES concentrations of 1000 ppm and higher produce narcosis that rapidly disappears following exposure. Repeated exposure of rats to DMES at either 3000 ppm for 2 wk or 2000 ppm for 13 wk caused testicular atrophy and hypospermia in male rats. Female rats exposed to 2000 ppm for 13 wk had delayed estrous cycles. Toxicological effects in rats of the 600 ppm group were minimal and equivocal. The 160 ppm concentration was a no-observable-effect level (NOEL) for 13 wk of exposure to DMES.

Dodd, D. E.; Stuart, B. O.; Rothenberg, S. J.; Kershaw, M.; Mann, P. C.; James, J. T.; Lam, C. W.

1994-01-01

304

IMPROVED NATURAL GAS STORAGE WELL REMEDIATION  

SciTech Connect

This report summarizes the research conducted during Budget Period One on the project ''Improved Natural Gas Storage Well Remediation''. The project team consisted of Furness-Newburge, Inc., the technology developer; TechSavants, Inc., the technology validator; and Nicor Technologies, Inc., the technology user. The overall objectives for the project were: (1) To develop, fabricate and test prototype laboratory devices using sonication and underwater plasma to remove scale from natural gas storage well piping and perforations; (2) To modify the laboratory devices into units capable of being used downhole; (3) To test the capability of the downhole units to remove scale in an observation well at a natural gas storage field; (4) To modify (if necessary) and field harden the units and then test the units in two pressurized injection/withdrawal gas storage wells; and (5) To prepare the project's final report. This report covers activities addressing objectives 1-3. Prototype laboratory units were developed, fabricated, and tested. Laboratory testing of the sonication technology indicated that low-frequency sonication was more effective than high-frequency (ultrasonication) at removing scale and rust from pipe sections and tubing. Use of a finned horn instead of a smooth horn improves energy dispersal and increases the efficiency of removal. The chemical data confirmed that rust and scale were removed from the pipe. The sonication technology showed significant potential and technical maturity to warrant a field test. The underwater plasma technology showed a potential for more effective scale and rust removal than the sonication technology. Chemical data from these tests also confirmed the removal of rust and scale from pipe sections and tubing. Focusing of the underwater plasma's energy field through the design and fabrication of a parabolic shield will increase the technology's efficiency. Power delivered to the underwater plasma unit by a sparkplug repeatedly was interrupted by sparkplug failure. The lifecycle for the plugs was less than 10 hours. An electrode feed system for delivering continuous power needs to be designed and developed. As a result, further work on the underwater plasma technology was terminated. It needs development of a new sparking system and a redesign of the pulsed power supply system to enable the unit to operate within a well diameter of less than three inches. Both of these needs were beyond the scope of the project. Meanwhile, the laboratory sonication unit was waterproofed and hardened, enabling the unit to be used as a field prototype, operating at temperatures to 350 F and depths of 15,000 feet. The field prototype was extensively tested at a field service company's test facility before taking it to the field site. The field test was run in August 2001 in a Nicor Gas storage field observation well at Pontiac, Illinois. Segmented bond logs, gamma ray neutron logs, water level measurements and water chemistry samples were obtained before and after the downhole demonstration. Fifteen tests were completed in the field. Results from the water chemistry analysis showed an increase in the range of calcium from 1755-1984 mg/l before testing to 3400-4028 mg/l after testing. For magnesium, the range increased from 285-296 mg/l to 461-480 mg/l. The change in pH from a range of 3.11-3.25 to 8.23-8.45 indicated a buffering of the acidic well water, probably due to the increased calcium available for buffering. The segmented bond logs showed no damage to the cement bond in the well and the gamma ray neutron log showed no increase in the amount of hydrocarbons present in the formation where the testing took place. Thus, the gas storage bubble in the aquifer was not compromised. A review of all the field test data collected documents the fact that the application of low-frequency sonication technology definitely removes scale from well pipe. Phase One of this project took sonication technology from the concept stage through a successful ''proof-of-concept'' downhole application in a natural gas storage field

James C. Furness; Donald O. Johnson; Michael L. Wilkey; Lynn Furness; Keith Vanderlee; P. David Paulsen

2001-12-01

305

Use and trade of bitumen in antiquity and prehistory: molecular archaeology reveals secrets of past civilizations  

PubMed Central

Natural asphalt (or bitumen) deposits, oil seepage and liquid oil shows are widespread in the Middle East, especially in the Zagros mountains of Iran. Ancient people from northern Iraq, south-west Iran and the Dead Sea area extensively used this ubiquitous natural resource until the Neolithic period (7000 to 6000 BC). Evidence of earlier use has been recently documented in the Syrian desert near El Kown, where bitumen-coated flint implements, dated to 40,000 BC (Mousterian period), have been unearthed. This discovery at least proves that bitumen was used by Neanderthal populations as hafting material to fix handles to their flint tools. Numerous testimonies, proving the importance of this petroleum-based material in Ancient civilizations, were brought to light by the excavations conducted in the Near East as of the beginning of the century. Bitumen remains show a wide range of uses that can be classified under several headings. First of all, bitumen was largely used in Mesopotamia and Elam as mortar in the construction of palaces (e.g. the Darius Palace in Susa), temples, ziggurats (e.g. the so-called 'Tower of Babel' in Babylon), terraces (e.g. the famous 'Hanging Gardens of Babylon') and exceptionally for roadway coating (e.g. the processional way of Babylon). Since the Neolithic, bitumen served to waterproof containers (baskets, earthenware jars, storage pits), wooden posts, palace grounds (e.g. in Mari and Haradum), reserves of lustral waters, bathrooms, palm roofs, etc. Mats, sarcophagi, coffins and jars, used for funeral practices, were often covered and sealed with bitumen. Reed and wood boats were also caulked with bitumen. Abundant lumps of bituminous mixtures used for that particular purpose have been found in storage rooms of houses at Ra's al-Junayz in Oman. Bitumen was also a widespread adhesive in antiquity and served to repair broken ceramics, fix eyes and horns on statues (e.g. at Tell al-Ubaid around 2500 BC). Beautiful decorations with stones, shells, mother of pearl, on palm trees, cups, ostrich eggs, musical instruments (e.g. the Queen's lyre) and other items, such as rings, jewellery and games, have been excavated from the Royal tombs in Ur. They are on view in the British Museum. With a special enigmatic material, commonly referred to as 'bitumen mastic', the inhabitants of Susa sculpted masterpieces of art which are today exhibited in the Louvre Museum in Paris. This unique collection is presented in a book by Connan and Deschesne (1996). Last, bitumen was also considered as a powerful remedy in medical practice, especially as a disinfectant and insecticide, and was used by the ancient Egyptians to prepare mixtures to embalm the corpses of their dead. Modern analytical techniques, currently applied in the field of petroleum geochemistry, have been adapted to the study of numerous archaeological bituminous mixtures found in excavations. More than 700 bituminous samples have been analysed during the last decade, using gas chromatography alone and gas chromatography coupled with mass spectrometry and isotopic chemistry (carbon and hydrogen mainly). These powerful tools, focused on the detailed analysis of biomarkers in hydrocarbon fractions, were calibrated on various well-known natural sources of bitumen in Iraq, Syria, Iran, Bahrain and Kuwait. These reference studies have made it possible to establish the origins of bitumen from numerous archaeological sites and to document the bitumen trade routes in the Middle East and the Arabo-Persian Gulf. Using a well-documented case history, Tell el 'Oueili (5800 to 3500 BC) in South Mesopotamia, we will illustrate in this paper how these new molecular and isotopic tools can help us to recognize different sources of bitumen and to trace the ancient trade routes through time. These import routes were found to vary with major cultural and political changes in the area under study. A second example, referring to the prehistoric period, describes bitumen traces on flint implements, dated from Mousterian times. This discovery, from the Umm El Tlel excavations nea

Connan, J.

1999-01-01