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Sample records for affect physical properties

  1. Physical and chemical properties of industrial mineral oils affecting lubrication

    SciTech Connect

    Godfrey, D.; Herguth, W.R.

    1996-02-01

    The lubricating properties of mineral oils, and contaminants which affect those properties, are discussed. A contaminant is any material not in the original fresh oil, whether it is generated within the system or ingested. 5 refs.

  2. Hydration kinetics and physical properties of split chickpea as affected by soaking temperature and time.

    PubMed

    Johnny, Saeed; Razavi, Seyed M A; Khodaei, Diako

    2015-12-01

    In this study, some physical properties (principal dimensions, mean diameters, sphericity, area, density and electrical conductivity) of split chickpea were measured as function of soaking time (up to 360 min) and temperature (25-65 °C). Initially, the water absorption rate was high and then it showed a progressive decrease at all temperatures, whereas solid loss exhibited a power function of temperature (P < 0.05). The Peleg model was predicted well the kinetic of split chickpea soaking. No significant difference (P < 0.05) was observed in Peleg rate constant (K1) and Peleg capacity constant (K2) at all temperatures except for K1 at 25 °C. The discrepancy for K1 was in relation to permeability characteristics of split chickpea at temperature of 25 °C. As temperature increased from 25 to 65 °C, the K1 value decreased from 0.04620 to 0.00945 g h(-1), whereas the K2 value increased from 0.08597 to 0.11320 g(-1). Plot for K1 exhibited a slope changes around 45 °C corresponding to gelatinization temperature of split chickpeas. The effect of temperature and time on physical properties of split chickpea during soaking was monitored by regression equations. It was concluded that physical properties of split chickpea affected by its water absorption especially at higher temperatures.

  3. Deacetylation affects the physical properties and bioactivity of acemannan, an extracted polysaccharide from Aloe vera.

    PubMed

    Chokboribal, Jaroenporn; Tachaboonyakiat, Wanpen; Sangvanich, Polkit; Ruangpornvisuti, Vithaya; Jettanacheawchankit, Suwimon; Thunyakitpisal, Pasutha

    2015-11-20

    Acemannan, an acetylated polymannose from Aloe vera, induces tissue repair. We investigated the role of acemannan's acetyl-groups on its physical and biological properties. Deacetylated acemannan (DeAcAM) was prepared and characterized. The physical properties and microscopic structure of DeAcAM were evaluated using water solubility, contact angle, X-ray diffraction, and scanning-electron microscopy. The activity of DeAcAM on cell proliferation and gene expression were assessed. Acemannan and DeAcAM structures were simulated and the acemannan tetramer diad and its completely deacetylated structure were also determined. Increased acemannan deacetylation reduced its water solubility and hydrophilicity. Complete deacetylation altered acemannan's conformation to a partial crystal structure. The bioactivity of acemannan was reduced corresponding to its deacetylation. Acemannan induced cell proliferation, and VEGF and Collagen I expression; however, 100% DeAcAM did not. The simulated structures of the acemannan diad and the completely deacetylated diad were different. We conclude acetyl-groups affect acemannan's structure and physical/biological properties.

  4. Deacetylation affects the physical properties and bioactivity of acemannan, an extracted polysaccharide from Aloe vera.

    PubMed

    Chokboribal, Jaroenporn; Tachaboonyakiat, Wanpen; Sangvanich, Polkit; Ruangpornvisuti, Vithaya; Jettanacheawchankit, Suwimon; Thunyakitpisal, Pasutha

    2015-11-20

    Acemannan, an acetylated polymannose from Aloe vera, induces tissue repair. We investigated the role of acemannan's acetyl-groups on its physical and biological properties. Deacetylated acemannan (DeAcAM) was prepared and characterized. The physical properties and microscopic structure of DeAcAM were evaluated using water solubility, contact angle, X-ray diffraction, and scanning-electron microscopy. The activity of DeAcAM on cell proliferation and gene expression were assessed. Acemannan and DeAcAM structures were simulated and the acemannan tetramer diad and its completely deacetylated structure were also determined. Increased acemannan deacetylation reduced its water solubility and hydrophilicity. Complete deacetylation altered acemannan's conformation to a partial crystal structure. The bioactivity of acemannan was reduced corresponding to its deacetylation. Acemannan induced cell proliferation, and VEGF and Collagen I expression; however, 100% DeAcAM did not. The simulated structures of the acemannan diad and the completely deacetylated diad were different. We conclude acetyl-groups affect acemannan's structure and physical/biological properties. PMID:26344314

  5. Soil physical and hydrological properties as affected by long-term addition of various organic amendments

    NASA Astrophysics Data System (ADS)

    Eden, Marie; Völkel, Jörg; Mercier, Vincent; Labat, Christophe; Houot, Sabine

    2014-05-01

    The use of organic residues as soil amendments in agriculture not only reduces the amount of waste needing to be disposed of; it may also lead to improvements in soil properties, including physical and hydrological ones. The present study examines a long-term experiment called "Qualiagro", run jointly by INRA and Veolia Environment in Feucherolles, France (near Paris). It was initiated in 1998 on a loess-derived silt loam (787 g/kg silt, 152 g/kg clay) and includes ten treatments: four types of organic amendments and a control (CNT) each at two levels of mineral nitrogen (N) addition: minimal (Nmin) and optimal (Nopt). The amendments include three types of compost and farmyard manure (FYM), which were applied every other year at a rate of ca. 4 t carbon ha-1. The composts include municipal solid waste compost (MSW), co-compost of green wastes and sewage sludge (GWS), and biowaste compost (BIO). The plots are arranged in a randomized block design and have a size of 450 m²; each treatment is replicated four times (total of 40 plots). Ca. 15 years after the start of the experiment soil organic carbon (OC) had continuously increased in the amended plots, while it remained stable or decreased in the control plots. This compost- or manure-induced increase in OC plays a key role, affecting numerous dependant soil properties like bulk density, porosity and water retention. The water holding capacity (WHC) of a soil is of particular interest to farmers in terms of water supply for plants, but also indicates soil quality and functionality. Addition of OC may affect WHC in different ways: carbon-induced aggregation may increase larger-pore volume and hence WHC at the wet end while increased surface areas may lead to an increased retention of water at the dry end. Consequently it is difficult to predict (e.g. with pedotransfer functions) the impact on the amount of water available for plants (PAW), which was experimentally determined for the soils, along with the entire range

  6. The interplay between physical and chemical properties of protein films affects their bioactivity.

    PubMed

    Grover, Chloe N; Farndale, Richard W; Best, Serena M; Cameron, Ruth E

    2012-09-01

    Although mechanical properties, roughness, and receptor molecule expression have all been shown to influence the cellular reactivity of collagen-based biomaterials, their relative contribution, in a given system remains unclear. Here, we study films containing combinations of collagen, gelatin, and soluble and insoluble elastin, crosslinking of which results in altered film stiffness and roughness. Collagen and gelatin have similar amino acid sequences but altered cell-binding sites. We studied cell response with both C2C12 myoblast cells (which possess RGD-recognizing integrins α(V)β(3) and α(5)β(1)) and C2C12-α2+ cells (which, in addition, express the collagen-binding integrin α(2)β(1)) to establish the effect of altering the available binding sites on cell adhesion and spreading on films. Systematically altering the composition, crosslinking and cell type, allows us to deconvolute the effects of physical parameters and available binding sites on the cell reactivity of films in this system. Collagen-based films were rougher and stiffer and supported lower cell surface coverage than gelatin-based films. Additionally, C2C12-α2+ cells showed preferential attachment to collagen-based films compared with C2C12 cells, but no significant difference was seen using gelatin-based films. The cell count and surface coverage were found to decrease significantly on all films after crosslinking (Coll XL coverage = 2-6%, Gel XL coverage = 20-32%), but cell area and aspect ratio on collagen films were affected to a greater extent than on gelatin films. The results show that, in this system, the composition, and more significantly, crosslinking, of films affects the cell reactivity to a greater extent than their stiffness or roughness.

  7. Ozone gas affects the physical and chemical properties of wheat (Triticum aestivum L.) starch

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ozone can oxidize hydroxyl groups present at C2, C3, and C6 positions on the starch molecule and affect its physicochemical properties. In this experiment, bread wheat flour and isolated wheat starch were treated with ozone gas (1,500 ppm, gas flow rate 2.5 L/minutes) for 45 minutes and 30 minutes, ...

  8. Salt matters: How salt affects the rheological and physical properties of gelatine for analogue modelling

    NASA Astrophysics Data System (ADS)

    Brizzi, S.; Funiciello, F.; Corbi, F.; Di Giuseppe, E.; Mojoli, G.

    2016-06-01

    Gelatine is extensively used as analogue material for the easiness to tune its physical and rheological properties. The addition of salt to gelatine is generally adopted to increase the density of the material, improving the scaling of the models. However, the way the addition of salt changes the rheological properties of gelatine is generally underestimated. Here, we investigate both rheological and physical properties (i.e., density and transparency) of type A pig-skin 2.5 wt.% gelatine at T = 10 °C as a function of salt concentration, cNaCl, and ageing time. We established a standard preparation recipe and measuring protocol, yielding to uniform samples with reproducible behaviour. Rheometric measurements show that the presence of salt weakens the gelatine structure, with a decrease of both material rigidity and viscosity as cNaCl increases. Salted gelatine behaviour moves from viscoelastic to dominantly elastic as the ageing time increases. Density and cloudiness also increase with cNaCl. Finally, we present results from subduction interplate seismicity models performed with pure and salted gelatines, showing that the modified material may improve the modelling performance and open new perspectives in experimental tectonics.

  9. Do the physical properties of occlusal-indicating media affect muscle activity [EMG) during use?

    PubMed

    Forrester, Stephanie E; Pain, Matthew T G; Presswood, Ron; Toy, Andy

    2009-06-01

    Four occlusal marking media (Parkell film, articulating silk, articulating paper and T-Scan foil) were tested to assess whether they affected neuromuscular function during occlusal marking events. Muscle activity of the anterior temporalis (TA) and superficial masseter (MS) muscles were obtained from surface EMG measurements during a slow closure to occlusion followed immediately by a forceful bite and a maximum clench onto each of the various occlusal indicating media. Muscle activity during the whole period of activation and immediately following onset were investigated. Significant differences in neuromuscular function between the occlusal marking media were observed, particularly between the Parkell film and articulating silk as opposed to the articulating paper and the T-Scan foil. The Parkell film and articulating silk gave neuromuscular function very similar to that of natural dentition occlusal contact, while the articulating paper and T-Scan foil showed similarities to occluding onto cotton rolls as previously reported (1). These results suggest that both the thickness and plasticity of the indicating media affect neuromuscular function during occlusion.

  10. Physical-Mechanical Properties of Nitrodopes Affected by Ultra-Violet Radiation

    PubMed Central

    Cakić, Suzana; Raskovic, Ljiljana; Lačnjevac, Časlav; Rajkovic, Milos; Barać, Miroljub; Stojanovic, Miodrag

    2007-01-01

    The FTIR spectroscopy has been employed in this research work to monitor the process of nitrodope photodegradation, by measuring surfaces of bands typical of a nitro group. Nitric esters are subject to degradation, which is reflected on a quantitative ratio of the surfaces of the IR bands that originate from the nitric ester. The obtained results show that the length of the UV rays' activity on the samples over the time periods of 240, 480 and 960 minutes directly affects the spectrum appearance of the same sample before and after the irradiation. The longer the action time of the UV rays and the higher a mass percentage of nitrocellulose in the nitrodope is, the smaller the bands' surfaces become, i.e. the level of degradation is higher. In order to confirm the degradation of nitrodope, the degree of crosslinking has also been examined by determining the König hardness and also the mean viscosity molar mass has been defined repeatedly applying the capillary viscosimetry method.

  11. Drying Characteristics and Physical and Nutritional Properties of Shrimp Meat as Affected by Different Traditional Drying Techniques.

    PubMed

    Akonor, P T; Ofori, H; Dziedzoave, N T; Kortei, N K

    2016-01-01

    The influence of different drying methods on physical and nutritional properties of shrimp meat was investigated in this study. Peeled shrimps were dried separately using an air-oven dryer and a tunnel solar dryer. The drying profile of shrimp meat was determined in the two drying systems by monitoring moisture loss over the drying period. Changes in color, proximate composition, and rehydration capacity were assessed. The rate of moisture removal during solar drying was faster than the air-oven drying. The development of red color during drying was comparable among the two methods, but solar-dried shrimps appeared darker (L (⁎) = 47.4) than the air-oven-dried (L (⁎) = 49.0). Chemical analysis indicated that protein and fat made up nearly 20% and 2% (wb) of the shrimp meat, respectively. Protein and ash content of shrimp meat dried under the two dryer types were comparable but fat was significantly (p < 0.05) higher in oven-dried meat (2.1%), compared to solar-dried meat (1.5%). Although rehydration behavior of shrimp from the two drying systems followed a similar pattern, solar-dried shrimp absorbed moisture more rapidly. The results have demonstrated that different approaches to drying may affect the physical and nutritional quality of shrimp meat differently.

  12. Drying Characteristics and Physical and Nutritional Properties of Shrimp Meat as Affected by Different Traditional Drying Techniques.

    PubMed

    Akonor, P T; Ofori, H; Dziedzoave, N T; Kortei, N K

    2016-01-01

    The influence of different drying methods on physical and nutritional properties of shrimp meat was investigated in this study. Peeled shrimps were dried separately using an air-oven dryer and a tunnel solar dryer. The drying profile of shrimp meat was determined in the two drying systems by monitoring moisture loss over the drying period. Changes in color, proximate composition, and rehydration capacity were assessed. The rate of moisture removal during solar drying was faster than the air-oven drying. The development of red color during drying was comparable among the two methods, but solar-dried shrimps appeared darker (L (⁎) = 47.4) than the air-oven-dried (L (⁎) = 49.0). Chemical analysis indicated that protein and fat made up nearly 20% and 2% (wb) of the shrimp meat, respectively. Protein and ash content of shrimp meat dried under the two dryer types were comparable but fat was significantly (p < 0.05) higher in oven-dried meat (2.1%), compared to solar-dried meat (1.5%). Although rehydration behavior of shrimp from the two drying systems followed a similar pattern, solar-dried shrimp absorbed moisture more rapidly. The results have demonstrated that different approaches to drying may affect the physical and nutritional quality of shrimp meat differently. PMID:27034924

  13. Drying Characteristics and Physical and Nutritional Properties of Shrimp Meat as Affected by Different Traditional Drying Techniques

    PubMed Central

    Ofori, H.; Dziedzoave, N. T.; Kortei, N. K.

    2016-01-01

    The influence of different drying methods on physical and nutritional properties of shrimp meat was investigated in this study. Peeled shrimps were dried separately using an air-oven dryer and a tunnel solar dryer. The drying profile of shrimp meat was determined in the two drying systems by monitoring moisture loss over the drying period. Changes in color, proximate composition, and rehydration capacity were assessed. The rate of moisture removal during solar drying was faster than the air-oven drying. The development of red color during drying was comparable among the two methods, but solar-dried shrimps appeared darker (L⁎ = 47.4) than the air-oven-dried (L⁎ = 49.0). Chemical analysis indicated that protein and fat made up nearly 20% and 2% (wb) of the shrimp meat, respectively. Protein and ash content of shrimp meat dried under the two dryer types were comparable but fat was significantly (p < 0.05) higher in oven-dried meat (2.1%), compared to solar-dried meat (1.5%). Although rehydration behavior of shrimp from the two drying systems followed a similar pattern, solar-dried shrimp absorbed moisture more rapidly. The results have demonstrated that different approaches to drying may affect the physical and nutritional quality of shrimp meat differently. PMID:27034924

  14. The Tripartite Virions of the Brome Mosaic Virus Have Distinct Physical Properties That Affect the Timing of the Infection Process

    PubMed Central

    Vaughan, Robert; Tragesser, Brady; Ni, Peng; Ma, Xiang; Dragnea, Bogdan

    2014-01-01

    ABSTRACT The three subsets of virions that comprise the Brome mosaic virus (BMV) were previously thought to be indistinguishable. This work tested the hypothesis that distinct capsid-RNA interactions in the BMV virions allow different rates of viral RNA release. Several results support distinct interactions between the capsid and the BMV genomic RNAs. First, the deletion of the first eight residues of the BMV coat protein (CP) resulted in the RNA1-containing particles having altered morphologies, while those containing RNA2 were unaffected. Second, subsets of the BMV particles separated by density gradients into a pool enriched for RNA1 (B1) and for RNA2 and RNA3/4 (B2.3/4) were found to have different physiochemical properties. Compared to the B2.3/4 particles, the B1 particles were more sensitive to protease digestion and had greater resistivity to nanoindentation by atomic force microscopy and increased susceptibility to nuclease digestion. Mapping studies showed that portions of the arginine-rich N-terminal tail of the CP could interact with RNA1. Mutational analysis in the putative RNA1-contacting residues severely reduced encapsidation of BMV RNA1 without affecting the encapsidation of RNA2. Finally, during infection of plants, the more easily released RNA1 accumulated to higher levels early in the infection. IMPORTANCE Viruses with genomes packaged in distinct virions could theoretically release the genomes at different times to regulate the timing of gene expression. Using an RNA virus composed of three particles, we demonstrated that the RNA in one of the virions is released more easily than the other two in vitro. The differential RNA release is due to distinct interactions between the viral capsid protein and the RNAs. The ease of RNA release is also correlated with the more rapid accumulation of that RNA in infected plants. Our study identified a novel role for capsid-RNA interactions in the regulation of a viral infection. PMID:24672042

  15. Physical Properties of Polymers

    NASA Astrophysics Data System (ADS)

    Mark, James; Ngai, Kia; Graessley, William; Mandelkern, Leo; Samulski, Edward; Koenig, Jack; Wignall, George

    2004-04-01

    This thoroughly revised and updated third edition is written by seven well-known authorities in the polymer science community. Each author contributes a chapter which reflects his own interests and expertise in the physical states and associated properties of polymers. Second Edition published by the American Chemical Society Hb (1993): 0-841-22505-2

  16. [PHYSICAL PROPERTIES OF PLASTER BANDAGES].

    PubMed

    Antabak, Anko; Barisić, Branimir; Andabak, Matej; Bradić, Lucija; Brajcinović, Melita; Haramina, Tatjana; Haluzan, Damir; Fuchs, Nino; Durkovir, Selena; Curković, Selena; Luetić, Tomislav; Sisko, Jerko; Prlić, Ivica

    2015-01-01

    The physical properties of plaster bandages are a very important factor in achieving the basic functions of immobilization (maintaining bone fragments in the best possible position), which directly affects the speed and quality of fracture healing. This paper compares the differences between the physical properties of plaster bandages (mass, specific weight, drying rate, elasticity and strength) and records the differences in plaster modeling of fast bonding 10 cm wide plaster bandages, from three different manufacturers: Safix plus (Hartmann, Germany), Cellona (Lohman Rauscher, Austria) and Gipsan (Ivo Lola Ribar ltd., Croatia). Plaster tiles from ten layers of plaster, dimension 10 x 10 cm were made. The total number of tiles from each manufacturer was 48. The water temperature of 22 °C was used for the first 24 tiles and 34 'C was used for the remainder. The average specific weight of the original packaging was: Cellona (0.52 g/cm3), Gipsan (0.50 g/cm3), Safix plus (0.38 g/cm3). Three days after plaster tile modeling an average specific weight of the tiles was: Gipsan (1.15 g/cm3), Safix plus (1.00 g/cm3), Cellona (1.10 g/cm3). The average humidity of 50% for Safix plus and Cellona plaster tiles was recorded 18 hours after modeling, while for the Gipsan plaster tiles, this humidity value was seen after 48 hours. On the third day after plaster modeling the average humidity of the plaster tiles was 30% for Gipsan, 24% for Safix and 16% for Cellona. Cellona plaster tiles made with 34 °C water achieved the highest elasticity (11.75±3.18 MPa), and Gipsan plaster tiles made with 22 °C had the lowest (7.21±0.9 MPa). Cellona plaster tiles made with 34 °C water showed maximum material strength (4390±838 MPa), and Gipsan plaster tiles made with 22 °C water showed the lowest material strength (771±367 MPa). The rigidity and strength of Cellona and Gipsan plaster are higher in tiles made in warmer water, and for Safix plus are higher in tiles made in cooler water

  17. Dynamic molecular crystals with switchable physical properties.

    PubMed

    Sato, Osamu

    2016-06-21

    The development of molecular materials whose physical properties can be controlled by external stimuli - such as light, electric field, temperature, and pressure - has recently attracted much attention owing to their potential applications in molecular devices. There are a number of ways to alter the physical properties of crystalline materials. These include the modulation of the spin and redox states of the crystal's components, or the incorporation within the crystalline lattice of tunable molecules that exhibit stimuli-induced changes in their molecular structure. A switching behaviour can also be induced by changing the molecular orientation of the crystal's components, even in cases where the overall molecular structure is not affected. Controlling intermolecular interactions within a molecular material is also an effective tool to modulate its physical properties. This Review discusses recent advances in the development of such stimuli-responsive, switchable crystalline compounds - referred to here as dynamic molecular crystals - and suggests how different approaches can serve to prepare functional materials. PMID:27325090

  18. Cesium Eluate Physical Property Determination

    SciTech Connect

    Baich, M.A.

    2001-02-13

    Two bench-scale process simulations of the proposed cesium eluate evaporation process of concentrating eluate produced in the Hanford Site Waste Treatment Plant were conducted. The primary objective of these experiments was to determine the physical properties and the saturation concentration of the eluate evaporator bottoms while producing condensate approximately 0.50 molar HN03.

  19. Physical properties of evaporite minerals

    USGS Publications Warehouse

    Robertson, Eugene C.

    1962-01-01

    The data in the following tables were abstracted from measurements of physical properties of evaporite minerals or of equivalent synthetic compounds. The compounds considered are the halide and sulfate salts which supposedly precipitated from evaporating ocean water and which form very extensive and thick "rock salt" beds. These beds are composed almost entirely of NaCl. In places where the beds are deeply buried and where fractures occur in the overlying rocks, the salt is plastically extruded upward as in a pipe to form the "salt domes". Most of the tables are for NaCl, both the natural (halite) and the synthetic salt, polycrystalline and single crystals. These measurements have been collected for use 1) in studies on storage of radioactive wastes in salt domes or beds, 2) in calculations concerned with nuclear tests in salt domes and beds, and 3) in studies of phenomena in salt of geologic interest. Rather than an exhaustive compilation of physical property measurements, there tables represent a summary of data from accessible sources. As limitations of time have presented making a more systematic and comprehensive selection, the data given may seem arbitrarily chosen. Some of the data listed are old, and newer, more accurate data are undoubtedly available. Halite (an synthetic NaCl) has been very thoroughly studied because of its relatively simple and highly symmetrical crystal structure, its easy availability naturally or synthetically, both in single crystals and polycrystalline, its useful and scientifically interesting properties, and its role as a compound of almost purely ionic bonding. The measurements of NaCl in the tables, however, represent only a small part of the total number of observations; discrimination was necessary to keep the size of the tabulations manageable. The physical properties of the evaporite minerals other than halite and sylvite have received only desultory attention of experiementalists, and appear in only a few tables. The

  20. Chemical and physical properties affecting strontium distribution coefficients of surficial-sediment samples at the Idaho National Engineering and Environmental Laboratory, Idaho

    USGS Publications Warehouse

    Liszewski, M.J.; Rosentreter, J.J.; Miller, Karl E.; Bartholomay, R.C.

    2000-01-01

    The U.S. Geological Survey and Idaho State University, in cooperation with the U.S. Department of Energy, conducted a study to determine strontium distribution coefficients (K(d)s) of surficial sediments at the Idaho National Engineering and Environmental Laboratory (INEEL). Batch experiments using synthesized aqueous solutions were used to determine K(d)s, which describe the distribution of a solute between the solution and solid phase, of 20 surficial-sediment samples from the INEEL. The K(d)s for the 20 surficial-sediment samples ranged from 36 to 275 ml/g. Many properties of both the synthesized aqueous solutions and sediments used in the experiments also were determined. Solution properties determined were initial and equilibrium concentrations of calcium, magnesium, and strontium, pH and specific conductance, and initial concentrations of potassium and sodium. Sediment properties determined were grain-size distribution, bulk mineralogy, whole-rock major-oxide and strontium and barium concentrations, and Brunauer-Emmett-Teller (BET) surface area. Solution and sediment properties were correlated with strontium K(d)s of the 20 surficial sediments using Pearson correlation coefficients. Solution properties with the strongest correlations with strontium K(d)s were equilibrium pH and equilibrium calcium concentration correlation coefficients, 0.6598 and -0.6518, respectively. Sediment properties with the strongest correlations with strontium K(d)s were manganese oxide (MnO), BET surface area, and the >4.75-mm-grain-size fraction correlation coefficients, 0.7054, 0.7022, and -0.6660, respectively. Effects of solution properties on strontium K(d)s were interpreted as being due to competition among similarly charged and sized cations in solution for strontium-sorption sites; effects of sediment properties on strontium K(d)s were interpreted as being surface-area related. Multivariate analyses of these solution and sediment properties resulted in r2 values of 0

  1. Teaching Affective Qualities in Physical Education

    ERIC Educational Resources Information Center

    Heidorn, Brent; Welch, Mindy M.

    2010-01-01

    Physical educators at all levels have observed learners in a school-based physical education setting as well as physical activity or sport settings outside of organized school curricula demonstrating behaviors deemed inappropriate or inconsistent with professional standards. Because sport is such a public, social, and international phenomenon,…

  2. Changes in the electro-physical properties of MCT epitaxial films affected by a plasma volume discharge induced by an avalanche beam in atmospheric-pressure air

    NASA Astrophysics Data System (ADS)

    Grigoryev, D. V.; Voitsekhovskii, A. V.; Lozovoy, K. A.; Tarasenko, V. F.; Shulepov, M. A.

    2015-11-01

    In this paper the influence of the plasma volume discharge of nanosecond duration formed in a non-uniform electric field at atmospheric pressure on samples of epitaxial films HgCdTe (MCT) films are discussed. The experimental data show that the action of pulses of nanosecond volume discharge in air at atmospheric pressure leads to changes in the electrophysical properties of MCT epitaxial films due to formation of a near-surface high- conductivity layer of the n-type conduction. The preliminary results show that it is possible to use such actions in the development of technologies for the controlled change of the properties of MCT.

  3. Regenerator matrix physical property data

    NASA Technical Reports Server (NTRS)

    Fucinari, C. A.

    1980-01-01

    Among several cellular ceramic structures manufactured by various suppliers for regenerator application in a gas turbine engine, three have the best potential for achieving durability and performance objectives for use in gas turbines, Stirling engines, and waste heat recovery systems: (1) an aluminum-silicate sinusoidal flow passage made from a corrugated wate paper process; (2) an extruded isosceles triangle flow passage; and (3) a second generation matrix incorporating a square flow passage formed by an embossing process. Key physical and thermal property data for these configurations presented include: heat transfer and pressure drop characteristics, compressive strength, tensile strength and elasticity, thermal expansion characteristics, chanical attack, and thermal stability.

  4. Physical Properties of Bright Comets

    NASA Astrophysics Data System (ADS)

    Pittichová, J.; Meech, K. J.

    2002-09-01

    We will show preliminary results from a program of long-term observation of the dust coma activity of bright comets. One and half years of observation of 32 selected comets in B, V, R, I filters are used for the study of the physical properties and the dust activity of their comae at a range of heliocentric distances from 0.99 to 8.61 AU. This enables us to compare the activity of different cometary nuclei at similar solar radiation conditions. As shown in the Table, the selected comets belong to different cometary populations from the point of view of their active age (near parabolic orbits versus short-period orbits, outbursts of brightness, disruption of nuclei) and orbital parameters (the eccentricity from 0.04 to 1.01 AU, the perihelion distance from 0.34 to 8.24 AU). The knowledge of physical properties of cometary nuclei and coma are very important to our understanding of the environment in the outer solar system during the era of formation. The comet dataset of 1128 images will enable us to study thermal evolution of the small dust particles, their dynamical parameters and size distribution as a function of time and grain size at different heliocentric distances. Our future goal is to model the near-nucleus particle region using a Finston-Probstein dust model. Since our observations are still in progress at this time we will present only preliminary results of brightness and color changes for several selected bright comets.

  5. Morphology and physical properties of soil material in cryogenic cracks of permafrost-affected meadow-chernozemic soils of the Trans-Baikal Region

    NASA Astrophysics Data System (ADS)

    Tsybenov, Yu. B.; Chimitdorzhieva, G. D.; Chimitdorzhieva, E. O.; Egorova, R. A.; Mil'kheev, E. Yu.; Davydova, T. V.; Korsunova, Ts. D.-Ts.

    2016-08-01

    Meadow-chernozemic soils (Turbic Chernozems Molliglossic) in the western Trans-Baikal Region are dissected by large cryogenic cracks penetrating to the depth of 100-120 cm and filled with humified material. The depth of humus pockets is 50-80 cm, and their width in the upper part is 50-90 cm. The lower boundary of most of the humus pockets lies at the depth of 60-70 cm. The development of cryogenic cracks proceeded due to their penetration into the frozen ground, which is evidenced by their sharply narrowing lower part. The fraction of physical clay (<0.01 mm) constitutes a considerable part of the material filling the cracks, which explains the significant humus content in this material. The contents of humus and adsorbed bases sharply decrease down through the soil profile in the soil mass between the cracks and remain relatively stable in the material filling the cracks. The soil mass in humus pockets is less compact that that in the background soil mass at the same depth, which is explained by the higher humus content in the pockets. Humified soil material in the pockets is also characterized by a higher porosity and, hence, higher water permeability than the surrounding soil mass.

  6. Psychometric properties of the Affect Phobia Test.

    PubMed

    Frankl, My; Philips, Björn; Berggraf, Lene; Ulvenes, Pål; Johansson, Robert; Wennberg, Peter

    2016-10-01

    The aim of this study was to make the first evaluation of the psychometric properties of the Affect Phobia Test, using the Swedish translation - a test developed to screen the ability to experience, express and regulate emotions. Data was collected from a clinical sample (N = 82) of patients with depression and/or anxiety participating in randomized controlled trial of Internet-based affect-focused treatment, and a university student sample (N = 197). The internal consistency for the total score was satisfactory (Clinical sample α = 0.88/Student sample α = 0.84) as well as for all the affective domains, except Anger/Assertion (α = 0.44/0.36), Sadness/Grief (α = 0.24/0.46) and Attachment/Closeness (α = 0.67/0.69). Test retest reliability was satisfactory (ICC > 0.77) for the total score and for all the affective domains except for Sadness/Grief (ICC = 0.04). The exploratory factor analysis resulted in a six-factor solution and did only moderately match the test's original affective domains. An empirical cut-off between the clinical and the university student sample were calculated and yielded a cut-off of 72 points. As expected, the Affect Phobia test showed negative significant correlations in the clinical group with measures on depression (rxy  = -0.229; p < 0.01) and anxiety (rxy  = -0.315; p < 0.05). The conclusion is that the psychometric properties are satisfactory for the total score of the Affect Phobia Test but not for some of the test's affective domains. Consequently the domains should not be used as subscales. The test can discriminate between individuals who seek help for psychological problems and those who do not. PMID:27461917

  7. Psychometric properties of the Affect Phobia Test.

    PubMed

    Frankl, My; Philips, Björn; Berggraf, Lene; Ulvenes, Pål; Johansson, Robert; Wennberg, Peter

    2016-10-01

    The aim of this study was to make the first evaluation of the psychometric properties of the Affect Phobia Test, using the Swedish translation - a test developed to screen the ability to experience, express and regulate emotions. Data was collected from a clinical sample (N = 82) of patients with depression and/or anxiety participating in randomized controlled trial of Internet-based affect-focused treatment, and a university student sample (N = 197). The internal consistency for the total score was satisfactory (Clinical sample α = 0.88/Student sample α = 0.84) as well as for all the affective domains, except Anger/Assertion (α = 0.44/0.36), Sadness/Grief (α = 0.24/0.46) and Attachment/Closeness (α = 0.67/0.69). Test retest reliability was satisfactory (ICC > 0.77) for the total score and for all the affective domains except for Sadness/Grief (ICC = 0.04). The exploratory factor analysis resulted in a six-factor solution and did only moderately match the test's original affective domains. An empirical cut-off between the clinical and the university student sample were calculated and yielded a cut-off of 72 points. As expected, the Affect Phobia test showed negative significant correlations in the clinical group with measures on depression (rxy  = -0.229; p < 0.01) and anxiety (rxy  = -0.315; p < 0.05). The conclusion is that the psychometric properties are satisfactory for the total score of the Affect Phobia Test but not for some of the test's affective domains. Consequently the domains should not be used as subscales. The test can discriminate between individuals who seek help for psychological problems and those who do not.

  8. What physics does affect the MRI threshold

    SciTech Connect

    Ilgisonis, V. I.; Lakhin, V. P.; Khalzov, I. V.; Smolyakov, A. I.

    2010-06-16

    Several physical effects, which can considerably decrease the magnetorotational instability (MRI) threshold are discussed. First, we show that MRI features are changed significantly in non-uniform magnetic field. Second, the buoyancy effect is shown to can be destabilizing for azimuthal flow of a resistive plasma. Third, we demonstrate that the rotating fluid may be unstable with respect to non-axisymmetric modes at much lower rotation velocities than with respect to usual symmetric modes.

  9. What Is Beautiful Feels Good: Affective Reactions to Physical Attractiveness.

    ERIC Educational Resources Information Center

    Carducci, Bernardo J.; Ogan, Tamra A.

    Previous research has consistently demonstrated that variations in physical attractiveness elicit different evaluative and behavioral responses. To assess differences in affective responses to variations in physical attractiveness and the affect of sex on those responses, 76 college students (31 male and 45 female) viewed colored slides of an…

  10. Physical properties and mantle dynamics

    SciTech Connect

    Shankland, T.J.; Johnson, P.A.; McCall, K.R.

    1997-11-01

    This is the final report of a three-year, Laboratory Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). Because planetary interiors are remote, laboratory methods and associated theory are an essential step for interpreting geophysical measurements in terms of quantities that are needed for understanding Earth--temperature, composition, stress state, history, and hazards. One objective is the study of minerals and rocks as materials using experimental methods; another is to develop new methods, as in high pressure research, codes for computation in rock/soil physics, or nuclear-based analysis. Accomplishments include developing a single-crystal x-ray diffraction apparatus with application to materials at extremely high pressure and temperature; P-V-T equations of state and seismic velocity measurements for understanding the composition of Earth`s outer 1,000 km; creating computational tools to explain complex stress-strain histories of rocks; and measuring tungsten/thorium ratios W/Th that agree with the hypothesis that Earth accreted heterogeneously. Work performed in this project applies to geosciences, geothermal energy, mineral and rock properties, seismic detection, and isotope dating.

  11. The mechanical microenvironment in cancer: How physics affects tumours.

    PubMed

    Nagelkerke, Anika; Bussink, Johan; Rowan, Alan E; Span, Paul N

    2015-12-01

    The tumour microenvironment contributes greatly to the response of tumour cells. It consists of chemical gradients, for example of oxygen and nutrients. However, a physical environment is also present. Apart from chemical input, cells also receive physical signals. Tumours display unique mechanical properties: they are a lot stiffer than normal tissue. This may be either a cause or a consequence of cancer, but literature suggests it has a major impact on tumour cells as will be described in this review. The mechanical microenvironment may cause malignant transformation, possibly through activation of oncogenic pathways and inhibition of tumour suppressor genes. In addition, the mechanical microenvironment may promote tumour progression by influencing processes such as epithelial-to-mesenchymal transition, enhancing cell survival through autophagy, but also affects sensitivity of tumour cells to therapeutics. Furthermore, multiple intracellular signalling pathways prove sensitive to the mechanical properties of the microenvironment. It appears the increased stiffness is unlikely to be caused by increased stiffness of the tumour cells themselves. However, there are indications that tumours display a higher cell density, making them more rigid. In addition, increased matrix deposition in the tumour, as well as increased interstitial fluid pressure may account for the increased stiffness of tumours. Overall, tumour mechanics are significantly different from normal tissue. Therefore, this feature should be further explored for use in cancer prevention, detection and treatment.

  12. Physical parameters affecting living cells in space

    NASA Astrophysics Data System (ADS)

    Langbein, Dieter

    The question is posed: Why does a living cell react to the absence of gravity? What sensors may it have? Does it note pressure, sedimentation, convection, or other parameters? If somewhere in a liquid volume sodium ions are replaced by potassium ions, the density of the liquid changes locally: the heavier regions sink, the lighter regions rise. This may contribute to species transport, to the metabolism. Under microgravity this mechanism is strongly reduced. On the other hand, other reasons for convection like thermal and solutal interface convection are left. Do they affect species transport? Another important effect of gravity is the hydrostatic pressure. On the macroscopic side, the pressure between our head and feet changes by 0.35 atmospheres. On the microscopic level the hydrostatic pressure on the upper half of a cell membrane is lower than on the lower half. This, by affecting the ion transport through the membrane, may change the surrounding electric potential. It has been suggested to be one of the reasons for graviperception. Following the discussion of these and other effects possibly important in life sciences in space, an order of magnitude analysis of the residual accelerations tolerable during experiments in materials sciences is outlined. In the field of life sciences only rough estimates are available at present.

  13. Physical Properties of Supraglacial Debris on Mars

    NASA Astrophysics Data System (ADS)

    Baker, D. M. H.; Carter, L. M.

    2016-09-01

    The thickness and physical properties of surface debris preserving glacial ice in the mid-latitudes of Mars is assessed using crater morphology and radar sounding data. We suggest that this debris layer is much thicker than has been hypothesized.

  14. Effects of current physical activity on affective response to exercise: physical and social-cognitive mechanisms.

    PubMed

    Magnan, Renee E; Kwan, Bethany M; Bryan, Angela D

    2013-01-01

    Affective responses during exercise are often important determinants of exercise initiation and maintenance. Current physical activity may be one individual difference that is associated with the degree to which individuals have positive (or negative) affective experiences during exercise. The objective of this study was to explore physical and cognitive explanations of the relationship between current activity status (more versus less active) and affective response during a 30-minute bout of moderate-intensity exercise. Participants reported their current level of physical activity, exercise self-efficacy and affect during a 30-minute bout of moderate-intensity exercise. More active individuals experienced higher levels of positive affect and tranquillity and lower levels of negative affect and fatigue during exercise. Multivariate models for each affective state indicated separate processes through which physical activity may be associated with changes in affect during exercise. These models indicate that affect experienced during physical activity is related to the current activity level and these relationships can be partially explained by the physical and cognitive factors explored in this study. Recommendations for future research to elucidate whether positive affective response to physical activity improves as a function of becoming more active over time are discussed.

  15. Physical properties of cumin and caraway seeds

    NASA Astrophysics Data System (ADS)

    Zare, D.; Bakhshipour, A.; Chen, G.

    2013-12-01

    Physical properties of cumin and caraway seeds were measured and compared at constant moisture content of 7.5% w.b. The average thousand mass of grain, mean length, mean width, mean thickness, equivalent diameter, geometric mean diameter, surface area, volume, sphericity, aspect ratio, true density, bulk density and porosity were measured for cumin and caraway. There are significant differences (p<0.01) in most physical properties of cumin and caraway, except porosity and sphericity

  16. Synthesis and physical properties of pennycress estolides and esters

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A new series of pennycress (Thlasphi arvense L.) based free-acid estolides was synthesized by an acid-catalyzed condensation reaction, followed by an esterification reaction to produce the 2-ethylhexyl (2-EH) esters of the initial estolides. The physical properties of the estolides are highly affect...

  17. Physical Properties of Craters on Asteroid (21) Lutetia

    NASA Astrophysics Data System (ADS)

    Vincent, J.-B.; Marchi, S.; Besse, S.; Böhnhardt, H.; Sierks, H.; A'Hearn, M.; Angrilli, F.; Barbieri, C.; Barucci, A.; Cremonese, G.; da Deppo, V.; Davidsson, B.; Debei, S.; de Cecco, M.; Fornasier, S.; Fulle, M.; Groussin, O.; Gutierrez, P.; Hviid, S. F.; Ip, W.-H.; Keller, H. U.; Kramm, J. R.; Knollenberg, J.; Koschny, D.; Kuehrt, E.; Kueppers, M.; Lamy, P.; Lara, L. M.; Lazzarin, M.; Lopez-Moreno, J. J.; Magrin, S.; Marzari, F.; Massironi, M.; Michalik, H.; Naletto, G.; Rickman, H.; Rodrigo, R.; Sabau, L.; Thomas, N.; Wenzel, K.-P.

    2011-03-01

    This abstract presents the physical properties of craters derived from the measurement of depth/diameter ratios on asteroid (21) Lutetia. We show how the d/D ratio varies in different regions and how it can be used to better understand the processes that affected the surface.

  18. The trinucleons: Physical observables and model properties

    SciTech Connect

    Gibson, B.F.

    1992-01-01

    Our progress in understanding the properties of {sup 3}H and {sup 3}He in terms of a nonrelativistic Hamiltonian picture employing realistic nuclear forces is reviewed. Trinucleon model properties are summarized for a number of contemporary force models, and predictions for physical observables are presented. Disagreement between theoretical model results and experimental results are highlighted.

  19. The trinucleons: Physical observables and model properties

    SciTech Connect

    Gibson, B.F.

    1992-05-01

    Our progress in understanding the properties of {sup 3}H and {sup 3}He in terms of a nonrelativistic Hamiltonian picture employing realistic nuclear forces is reviewed. Trinucleon model properties are summarized for a number of contemporary force models, and predictions for physical observables are presented. Disagreement between theoretical model results and experimental results are highlighted.

  20. Structure and physical properties of silkworm cocoons

    PubMed Central

    Chen, Fujia; Porter, David; Vollrath, Fritz

    2012-01-01

    Silkworm cocoons have evolved a wide range of different structures and combinations of physical and chemical properties in order to cope with different threats and environmental conditions. We present our observations and measurements on 25 diverse types of cocoons in a first attempt to correlate physical properties with the structure and morphology of the cocoons. These two architectural parameters appear to be far more important than the material properties of the silk fibres themselves. We consider tensile and compressive mechanical properties and gas permeation of the cocoon walls, and in each case identify mechanisms or models that relate these properties to cocoon structure, usually based upon non-woven fibre composites. These properties are of relevance also for synthetic non-woven composite materials and our studies will help formulate bio-inspired design principles for new materials. PMID:22552916

  1. Gender Differences in Introductory University Physics Performance: The Influence of High School Physics Preparation and Affect

    NASA Astrophysics Data System (ADS)

    Hazari, Zahra

    2006-12-01

    The attrition of females studying physics after high school has been a continuing concern for the physics education community. If females are well prepared, feel confident, and do well in introductory college physics, they may be inclined to study physics further. This quantitative study uses HLM to identify factors from high school physics preparation (content, pedagogy, and assessment) and the affective domain that predict female and male performance in introductory college physics. The study includes controls for student demographic and academic background characteristics, and the final dataset consists of 1973 surveys from 54 introductory college physics classes. The results highlight high school physics and affective experiences that differentially predict female and male performance. These experiences include: learning requirements, computer graphing/analysis, long written problems, everyday world examples, community projects cumulative tests/quizzes, father's encouragement, family's belief that science leads to a better career, and the length of time students believe that high school physics would help in university physics. There were also experiences that similarly predict female and male performance. The results paint a dynamic picture of the factors from high school physics and the affective domain that influence the future physics performance of females and males. The implication is that there are many aspects to the teaching of physics in high school that, although widely used and thought to be effective, need reform in their implementation in order to be fully beneficial to females and/or males in college.

  2. Physical Properties of Centaur Objects

    NASA Technical Reports Server (NTRS)

    Cruikshank, Dale P.; DeVincenzi, Donald L. (Technical Monitor)

    2001-01-01

    Centaurs are objects in unstable orbits that cross the orbits of the giant planets. They are presumed to be recent additions to the planetary zone of the Solar System, having been dynamically perturbed from the Kulper Disk by the gravitational action of Neptune. Telescopic observations of Centaurs are important because they give us a view of the composition (and in some cases cometary activity) of large bodies that are normally to far from the Sun to be studied in detail. This paper reports on physical observations, primarily through spectroscopy, of the compositions of a small number of Centaurs that have been studied to date. In particular, the composition of 5145 Pholus is reviewed, following the published work of Crulkshank et al., in which compositional models that fit the spectrum well included H2O ice, the organic solid Titan tholin, a light hydrocarbon ice (e.g., CH3OH), the silicate mineral olivine, and amorphous carbon. The Centaur 1997 CU(26) shows evidence for H2O ice, but nothing else is yet identified.

  3. Physical properties of hydrate-bearing sediments

    NASA Astrophysics Data System (ADS)

    Waite, W. F.; Santamarina, J. C.; Cortes, D. D.; Dugan, B.; Espinoza, D. N.; Germaine, J.; Jang, J.; Jung, J. W.; Kneafsey, T. J.; Shin, H.; Soga, K.; Winters, W. J.; Yun, T.-S.

    2009-12-01

    Methane gas hydrates, crystalline inclusion compounds formed from methane and water, are found in marine continental margin and permafrost sediments worldwide. This article reviews the current understanding of phenomena involved in gas hydrate formation and the physical properties of hydrate-bearing sediments. Formation phenomena include pore-scale habit, solubility, spatial variability, and host sediment aggregate properties. Physical properties include thermal properties, permeability, electrical conductivity and permittivity, small-strain elastic P and S wave velocities, shear strength, and volume changes resulting from hydrate dissociation. The magnitudes and interdependencies of these properties are critically important for predicting and quantifying macroscale responses of hydrate-bearing sediments to changes in mechanical, thermal, or chemical boundary conditions. These predictions are vital for mitigating borehole, local, and regional slope stability hazards; optimizing recovery techniques for extracting methane from hydrate-bearing sediments or sequestering carbon dioxide in gas hydrate; and evaluating the role of gas hydrate in the global carbon cycle.

  4. Physical Properties of Gas Hydrates: A Review

    DOE PAGES

    Gabitto, Jorge F.; Tsouris, Costas

    2010-01-01

    Memore » thane gas hydrates in sediments have been studied by several investigators as a possible future energy resource. Recent hydrate reserves have been estimated at approximately 10 16   m 3 of methane gas worldwide at standard temperature and pressure conditions. In situ dissociation of natural gas hydrate is necessary in order to commercially exploit the resource from the natural-gas-hydrate-bearing sediment. The presence of gas hydrates in sediments dramatically alters some of the normal physical properties of the sediment. These changes can be detected by field measurements and by down-hole logs. An understanding of the physical properties of hydrate-bearing sediments is necessary for interpretation of geophysical data collected in field settings, borehole, and slope stability analyses; reservoir simulation; and production models. This work reviews information available in literature related to the physical properties of sediments containing gas hydrates. A brief review of the physical properties of bulk gas hydrates is included. Detection methods, morphology, and relevant physical properties of gas-hydrate-bearing sediments are also discussed.« less

  5. Physical Properties of Gas Hydrates: A Review

    SciTech Connect

    Gabitto, Jorge; Tsouris, Costas

    2010-01-01

    Methane gas hydrates in sediments have been studied by several investigators as a possible future energy resource. Recent hydrate reserves have been estimated at approximately 1016?m3 of methane gas worldwide at standard temperature and pressure conditions. In situ dissociation of natural gas hydrate is necessary in order to commercially exploit the resource from the natural-gas-hydrate-bearing sediment. The presence of gas hydrates in sediments dramatically alters some of the normal physical properties of the sediment. These changes can be detected by field measurements and by down-hole logs. An understanding of the physical properties of hydrate-bearing sediments is necessary for interpretation of geophysical data collected in field settings, borehole, and slope stability analyses; reservoir simulation; and production models. This work reviews information available in literature related to the physical properties of sediments containing gas hydrates. A brief review of the physical properties of bulk gas hydrates is included. Detection methods, morphology, and relevant physical properties of gas-hydrate-bearing sediments are also discussed.

  6. Physical properties of molten carbonate electrolyte

    SciTech Connect

    Kojima, T.; Yanagida, M.; Tanimoto, K.

    1996-12-31

    Recently many kinds of compositions of molten carbonate electrolyte have been applied to molten carbonate fuel cell in order to avoid the several problems such as corrosion of separator plate and NiO cathode dissolution. Many researchers recognize that the addition of alkaline earth (Ca, Sr, and Ba) carbonate to Li{sub 2}CO{sub 3}-Na{sub 2}CO{sub 3} and Li{sub 2}CO{sub 3}-K{sub 2}CO{sub 3} eutectic electrolytes is effective to avoid these problems. On the other hand, one of the corrosion products, CrO{sub 4}{sup 2-} ion is found to dissolve into electrolyte and accumulated during the long-term MCFC operations. This would affect the performance of MCFC. There, however, are little known data of physical properties of molten carbonate containing alkaline earth carbonates and CrO{sub 4}{sup 2-}. We report the measured and accumulated data for these molten carbonate of electrical conductivity and surface tension to select favorable composition of molten carbonate electrolytes.

  7. Physical and Psychological Decrements Affecting Reading in the Aged.

    ERIC Educational Resources Information Center

    Wilson, Molly M.

    While reading has been recognized as a potentially useful and enjoyable pastime for the elderly, physical and psychological decrements affect the ability of the elderly to read. As the eyes age, near-point tasks become more difficult. In addition to reduced sensory intake, perceptual changes occur. The central nervous system slows, and data travel…

  8. Aerosol physical properties from satellite horizon inversion

    NASA Technical Reports Server (NTRS)

    Gray, C. R.; Malchow, H. L.; Merritt, D. C.; Var, R. E.; Whitney, C. K.

    1973-01-01

    The feasibility is investigated of determining the physical properties of aerosols globally in the altitude region of 10 to 100 km from a satellite horizon scanning experiment. The investigation utilizes a horizon inversion technique previously developed and extended. Aerosol physical properties such as number density, size distribution, and the real and imaginary components of the index of refraction are demonstrated to be invertible in the aerosol size ranges (0.01-0.1 microns), (0.1-1.0 microns), (1.0-10 microns). Extensions of previously developed radiative transfer models and recursive inversion algorithms are displayed.

  9. Physical properties of cytoplasmic intermediate filaments.

    PubMed

    Block, Johanna; Schroeder, Viktor; Pawelzyk, Paul; Willenbacher, Norbert; Köster, Sarah

    2015-11-01

    Intermediate filaments (IFs) constitute a sophisticated filament system in the cytoplasm of eukaryotes. They form bundles and networks with adapted viscoelastic properties and are strongly interconnected with the other filament types, microfilaments and microtubules. IFs are cell type specific and apart from biochemical functions, they act as mechanical entities to provide stability and resilience to cells and tissues. We review the physical properties of these abundant structural proteins including both in vitro studies and cell experiments. IFs are hierarchical structures and their physical properties seem to a large part be encoded in the very specific architecture of the biopolymers. Thus, we begin our review by presenting the assembly mechanism, followed by the mechanical properties of individual filaments, network and structure formation due to electrostatic interactions, and eventually the mechanics of in vitro and cellular networks. This article is part of a Special Issue entitled: Mechanobiology.

  10. Physical Properties of Cometary Nucleus Candidates

    NASA Technical Reports Server (NTRS)

    Jewitt, David; Hillman, John (Technical Monitor)

    2003-01-01

    In this proposal we aim to study the physical properties of the Centaurs and the dead comets, these being the precursors to, and the remnants from, the active cometary nuclei. The nuclei themselves are very difficult to study, because of the contaminating effects of near-nucleus coma. Systematic investigation of the nuclei both before they enter the zone of strong sublimation and after they have depleted their near-surface volatiles should neatly bracket the properties of these objects, revealing evolutionary effects.

  11. Tillage system affects microbiological properties of soil

    NASA Astrophysics Data System (ADS)

    Delgado, A.; de Santiago, A.; Avilés, M.; Perea, F.

    2012-04-01

    Soil tillage significantly affects organic carbon accumulation, microbial biomass, and subsequently enzymatic activity in surface soil. Microbial activity in soil is a crucial parameter contributing to soil functioning, and thus a basic quality factor for soil. Since enzymes remain soil after excretion by living or disintegrating cells, shifts in their activities reflect long-term fluctuations in microbial biomass. In order to study the effects of no-till on biochemical and microbiological properties in comparison to conventional tillage in a representative soil from South Spain, an experiment was conducted since 1982 on the experimental farm of the Institute of Agriculture and Fisheries Research of Andalusia (IFAPA) in Carmona, SW Spain (37o24'07''N, 5o35'10''W). The soil at the experimental site was a very fine, montomorillonitic, thermic Chromic Haploxerert (Soil Survey Staff, 2010). A randomized complete block design involving three replications and the following two tillage treatments was performed: (i) Conventional tillage, which involved mouldboard plowing to a depth of 50 cm in the summer (once every three years), followed by field cultivation to a depth of 15 cm before sowing; crop residues being burnt, (ii) No tillage, which involved controlling weeds before sowing by spraying glyphosate and sowing directly into the crop residue from the previous year by using a planter with double-disk openers. For all tillage treatments, the crop rotation (annual crops) consisted of winter wheat, sunflower, and legumes (pea, chickpea, or faba bean, depending on the year), which were grown under rainfed conditions. Enzymatic activities (ß-glucosidase, dehydrogenase, aryl-sulphatase, acid phosphatase, and urease), soil microbial biomass by total viable cells number by acridine orange direct count, the density of cultivable groups of bacteria and fungi by dilution plating on semi-selective media, the physiological profiles of the microbial communities by BiologR, and the

  12. Microstructures, percolation thresholds, and rock physical properties

    NASA Astrophysics Data System (ADS)

    Guéguen, Y.; Chelidze, T.; Le Ravalec, M.

    1997-09-01

    The physical properties (transport properties and mechanical properties) of porous/cracked rocks are mainly functions of their microstructure. In this connection the problem of critical (threshold) porosity for transport, elasticity and mechanical strength is especially important. Two dominant mathematical formalisms — effective medium theory (EMT) and percolation theory — pretend to give answers to this problem. Some of the EMT models do not predict any threshold (differential effective medium). Other EMT models (self-consistent models) do predict thresholds, but it is shown that these thresholds are fictitious and result from an extension of a theory beyond its limit of validity. The failure of EMT methods at high pores/crack concentrations is the result of clustering effects. The appropriate formalism to correctly describe the phenomenon of clustering of pores and cracks and the behaviour of a system close to its critical porosity is percolation theory. Percolation thresholds can be predicted in that case from classical site or bond percolation on regular or random lattices. The threshold values depend on the density and average size of pores/cracks so that porosity is not sufficient in general to characterize the threshold for a specific physical property. The general term 'critical porosity' should thus be used with caution and it is preferable to specify which property is concerned and what kind of microstructure is present. This term can be more safely used for a population of rocks which have an identical average shape of pores/cracks and for a given physical property.

  13. Food properties affecting the digestion and absorption of carbohydrates.

    PubMed

    Björck, I; Granfeldt, Y; Liljeberg, H; Tovar, J; Asp, N G

    1994-03-01

    Carbohydrate foods differ considerably in their effects on postprandial glucose and insulin responses. Qualitative differences among starchy foods are particularly intriguing because of the dominance of starch in human diets. This paper focuses on food properties in cereal (eg, pasta, bread, Arepas, and porridge) and legume products (eg, red kidney beans and lentils) that affect metabolic responses to starch. Studies in healthy subjects have found that postprandial blood glucose and insulin responses are greatly affected by food structure. Any process that disrupts the physical or botanical structure of food ingredients will increase the plasma glucose and insulin responses. The glycemic responses to bread products were reduced by the use of ingredients with an intact botanical or physical structure or a high amylose content or by enrichment with viscous dietary fiber. However, the important of a moderate increase in the amylose-amylopectin ratio and the naturally occurring levels of viscous cereal fiber is less clear. The rate of starch digestion in vitro was shown to be a key determinant of metabolic responses to most products. Assuming the sample preparation mimics chewing, in vitro enzymic procedures can be used to facilitate ranking. One such procedure, based on chewed rather than artificially disintegrated products, was recently developed and correlates well with glycemic and insulinemic indices for several starchy foods. PMID:8116553

  14. Effects of physical properties on thermo-fluids cavitating flows

    NASA Astrophysics Data System (ADS)

    Chen, T. R.; Wang, G. Y.; Huang, B.; Li, D. Q.; Ma, X. J.; Li, X. L.

    2015-12-01

    The aims of this paper are to study the thermo-fluid cavitating flows and to evaluate the effects of physical properties on cavitation behaviours. The Favre-averaged Navier-Stokes equations with the energy equation are applied to numerically investigate the liquid nitrogen cavitating flows around a NASA hydrofoil. Meanwhile, the thermodynamic parameter Σ is used to assess the thermodynamic effects on cavitating flows. The results indicate that the thermodynamic effects on the thermo-fluid cavitating flows significantly affect the cavitation behaviours, including pressure and temperature distribution, the variation of physical properties, and cavity structures. The thermodynamic effects can be evaluated by physical properties under the same free-stream conditions. The global sensitivity analysis of liquid nitrogen suggests that ρv, Cl and L significantly influence temperature drop and cavity structure in the existing numerical framework, while pv plays the dominant role when these properties vary with temperature. The liquid viscosity μl slightly affects the flow structure via changing the Reynolds number Re equivalently, however, it hardly affects the temperature distribution.

  15. Waste Feed Evaporation Physical Properties Modeling

    SciTech Connect

    Daniel, W.E.

    2003-08-25

    This document describes the waste feed evaporator modeling work done in the Waste Feed Evaporation and Physical Properties Modeling test specification and in support of the Hanford River Protection Project (RPP) Waste Treatment Plant (WTP) project. A private database (ZEOLITE) was developed and used in this work in order to include the behavior of aluminosilicates such a NAS-gel in the OLI/ESP simulations, in addition to the development of the mathematical models. Mathematical models were developed that describe certain physical properties in the Hanford RPP-WTP waste feed evaporator process (FEP). In particular, models were developed for the feed stream to the first ultra-filtration step characterizing its heat capacity, thermal conductivity, and viscosity, as well as the density of the evaporator contents. The scope of the task was expanded to include the volume reduction factor across the waste feed evaporator (total evaporator feed volume/evaporator bottoms volume). All the physical properties were modeled as functions of the waste feed composition, temperature, and the high level waste recycle volumetric flow rate relative to that of the waste feed. The goal for the mathematical models was to predict the physical property to predicted simulation value. The simulation model approximating the FEP process used to develop the correlations was relatively complex, and not possible to duplicate within the scope of the bench scale evaporation experiments. Therefore, simulants were made of 13 design points (a subset of the points used in the model fits) using the compositions of the ultra-filtration feed streams as predicted by the simulation model. The chemistry and physical properties of the supernate (the modeled stream) as predicted by the simulation were compared with the analytical results of experimental simulant work as a method of validating the simulation software.

  16. Physical and mechanical properties of hemp seed

    NASA Astrophysics Data System (ADS)

    Taheri-Garavand, A.; Nassiri, A.; Gharibzahedi, S.

    2012-04-01

    The current study was conducted to investigate the effect of moisture content on the post-harvest physical and mechanical properties of hemp seed in the range of 5.39 to 27.12% d.b. Results showed that the effect of moisture content on the most physical properties of the grain was significant (P<0.05). The results of mechanical tests demonstrated that the effect of loading rate on the mechanical properties of hemp seed was not significant. However, the moisture content effect on rupture force and energy was significant (P<0.01). The lowest value of rupture force was obtained at the highest loading rate (3mm min-1)and in the moisture content of 27.12% d.b. Moreover, the interaction effects of loading rate and moisture content on the rupture force and energy of hemp seed were significant (P<0.05).

  17. Factors Affecting the Textural Properties of Pork

    ERIC Educational Resources Information Center

    Holmer, Sean Frederick

    2009-01-01

    Research concerning rate and extent of tenderization has focused on beef or lamb. However, it is critical to understand these processes in pork, especially as retailers move towards minimally processed or non-enhanced product. The objectives of this experiment were to evaluate the textural properties of pork (firmness and tenderness) by examining…

  18. Physical Properties of Hanford Transuranic Waste

    SciTech Connect

    Berg, John C.

    2010-03-25

    The research described herein was undertaken to provide needed physical property descriptions of the Hanford transuranic tank sludges under conditions that might exist during retrieval, treatment, packaging and transportation for disposal. The work addressed the development of a fundamental understanding of the types of systems represented by these sludge suspensions through correlation of the macroscopic rheological properties with particle interactions occurring at the colloidal scale in the various liquid media. The results of the work have advanced existing understanding of the sedimentation and aggregation properties of complex colloidal suspensions. Bench scale models were investigated with respect to their structural, colloidal and rheological properties that should be useful for the development and optimization of techniques to process the wastes at various DOE sites.

  19. Physical properties of the planet Mercury

    NASA Technical Reports Server (NTRS)

    Clark, Pamela E.

    1988-01-01

    The global physical properties of Mercury are summarized with attention given to its figure and orbital parameters. The combination of properties suggests that Mercury has an extensive iron-rich core, possibly with a still-functioning dynamo, which is 42 percent of the interior by volume. Mercury's three major axes are comparable in size, indicating that the planet is a triaxial ellipsoid rather than an oblate spheroid. In terms of the domination of its surface by an intermediate plains terrane, it is more Venus- or Mars-like; however, due to the presence of a large metallic magnetic core, its interior may be more earth-like.

  20. Population properties affect inbreeding avoidance in moose.

    PubMed

    Herfindal, Ivar; Haanes, Hallvard; Røed, Knut H; Solberg, Erling J; Markussen, Stine S; Heim, Morten; Sæther, Bernt-Erik

    2014-12-01

    Mechanisms reducing inbreeding are thought to have evolved owing to fitness costs of breeding with close relatives. In small and isolated populations, or populations with skewed age- or sex distributions, mate choice becomes limited, and inbreeding avoidance mechanisms ineffective. We used a unique individual-based dataset on moose from a small island in Norway to assess whether inbreeding avoidance was related to population structure and size, expecting inbreeding avoidance to be greater in years with larger populations and even adult sex ratios. The probability that a potential mating event was realized was negatively related to the inbreeding coefficient of the potential offspring, with a stronger relationship in years with a higher proportion or number of males in the population. Thus, adult sex ratio and population size affect the degree of inbreeding avoidance. Consequently, conservation managers should aim for sex ratios that facilitate inbreeding avoidance, especially in small and isolated populations.

  1. Gender differences in introductory university physics performance: The influence of high school physics preparation and affect

    NASA Astrophysics Data System (ADS)

    Hazari, Zahra Sana

    The attrition of females studying physics after high school is a concern to the science education community. Most undergraduate science programs require introductory physics coursework. Thus, success in introductory physics is necessary for students to progress to higher levels of science study. Success also influences attitudes; if females are well-prepared, feel confident, and do well in introductory physics, they may be inclined to study physics further. This quantitative study using multilevel modeling focused on determining factors from high school physics preparation (content, pedagogy, and assessment) and the affective domain that influenced female and male performance in introductory university physics. The study controlled for some university/course level characteristics as well as student demographic and academic background characteristics. The data consisted of 1973 surveys from 54 introductory physics courses within 35 universities across the US. The results highlight high school physics and affective experiences that differentially influenced female and male performance. These experiences include: learning requirements, computer graphing/analysis, long written problems, everyday world examples, community projects, cumulative tests/quizzes, father's encouragement, family's belief that science leads to a better career, and the length of time students believed that high school physics would help in university physics. There were also experiences that had a similar influence on female and male performance. Positively related to performance were: covering fewer topics for longer periods of time, the history of physics as a recurring topic, physics-related videos, and test/quiz questions that involved calculations and/or were drawn from standardized tests. Negatively related to performance were: student-designed projects, reading/discussing labs the day before performing them, microcomputer based laboratories, discussion after demonstrations, and family

  2. F-Canyon Sludge Physical Properties

    SciTech Connect

    Poirier, M. R.; Hansen, P. R.; Fink, S. D.

    2005-08-22

    The Site Deactivation and Decommissioning (SDD) Organization is evaluating options to disposition the 800 underground tanks (including removal of the sludge heels from these tanks). To support this effort, D&D requested assistance from Savannah River National Laboratory (SRNL) personnel to determine the pertinent physical properties to effectively mobilize the sludge from these tanks (Tanks 804, 808, and 809). SDD provided SRNL with samples of the sludge from Tanks 804, 808, and 809. The authors measured the following physical properties for each tank: particle settling rate, shear strength (i.e., settled solids yield stress), slurry rheology (i.e., yield stress and consistency), total solids concentration in the sludge, soluble solids concentration of the sludge, sludge density, and particle size distribution.

  3. Substrate properties affect collective cell motion

    NASA Astrophysics Data System (ADS)

    Pegoraro, Adrian; Guo, Ming; Ehrlicher, Allen; Weitz, David

    2013-03-01

    When cells move collectively, cooperative motion, which is characterized by long range correlations in cell movement, is necessary for migration. This collective cell motion is influenced by cell-cell interactions as well as by cell-substrate coupling. Furthermore, on soft substrates it is possible for cells to mechanically couple over long distances through the substrate itself. By changing the properties of the substrate, it is possible to decouple some of these contributions and better understand the role they play in collective cell motion. We vary both the substrate stiffness and adhesion protein concentration and find changes in the collective cell motion of the cells despite only small differences in total cell density and average cell size in the confluent layers. We test these changes on polyacrylamide and PDMS substrates as well as on structured substrates made of PDMS posts that prevent mechanical coupling through the substrate while still allowing stiffness to be varied.

  4. Polyaniline: Factors affecting conductivity and mechanical properties

    SciTech Connect

    Scherr, E.M.

    1993-01-01

    The main objectives of this study were: (a) to study electronic and mechanical properties of films of the conducting polymer, polyaniline, in the doped and undoped emeraldine oxidation state, (b) to study how the electronic and mechanical properties were modified through mechanical stretch-orientation of the films, (c) to study the effect of water vapor on the conductivity of stretched protonic acid doped films, (d) to observe changes in tensile strength and Young's modulus when selected plasticizers were introduced into the films, (e) to observe, using UV/Vis spectroscopy, the effect that neutral salts in the doping media have on the doping level of thin, optically transparent films of polyaniline, (f) to use thin, optically transparent films to spectroscopically study (by UV/Vis) hysteresis in the doping and undoping behavior of polyaniline. The significant results and conclusions are: (a) mechanical stretch-orientation of polyaniline increased the tensile strength of emeraldine base films, (b) the conductivity of doped films of polyaniline was increased approximately two orders of magnitude by stretch-orientation (four-fold elongation) from [approximately]5 S/cm to [approximately]90 S/cm, (c) an increase in the relative percent crystallinity (by x-ray diffraction) upon stretch-orientation of emeraldine base films, (d) the removal of water vapor was found to decrease the conductivity of stretched emeraldine, (e) both tensile strength and Young's modulus are decreased by the introduction of plasticizers and [open quotes]dopant plasticizers[close quotes] into the films, (f) no loss in conductivity was observed due to the addition of plasticizers, (g) the presence of neutral salts in the doping media increased the doping level of thin films of polyaniline, (h) observed hysteresis upon doping and undoping thin polyaniline films is due to irreversible morphological changes that take place in polyaniline upon doping and undoping.

  5. Physical properties of Dowell Chemical Seal Ring

    SciTech Connect

    Benny, H.L.

    1985-07-01

    This document outlines the tests, procedures, and results of an evaluation program for Dowell's Chemical Seal Ring.'' The testing reported here deals with the physical properties of density, compression, tensile strength, elongation, and a push-out/bond strength test. Dowell's Chemical Seal Ring'' is proposed as a gasket-like seal between grout layers in the annulus around the Exploratory Shaft steel liner. 4 refs., 1 fig., 4 tabs.

  6. Chemical and Physical Properties of Tantalum Powder

    NASA Astrophysics Data System (ADS)

    Purushotham, Y.; Balaji, T.; Kumar, Arbind; Govindaiah, R.; Sharma, M. K.; Sethi, V. C.; Prakash, T. L.

    The present work is intended to produce capacitor grade Tantalum powder by sodium reduction of potassium tantalum fluoride prepared from an indigenous ore source. The powder has been characterized for its chemical and physical properties, and compared with the commercially available powders. It is found that indigenous powder has higher impurity levels which could, however, be reduced to acceptance limits. The average particle size is within the prescribed limits.

  7. Chirality: a relational geometric-physical property.

    PubMed

    Gerlach, Hans

    2013-11-01

    The definition of the term chirality by Lord Kelvin in 1893 and 1904 is analyzed by taking crystallography at that time into account. This shows clearly that chirality is a relational geometric-physical property, i.e., two relations between isometric objects are possible: homochiral or heterochiral. In scientific articles the relational term chirality is often mistaken for the two valued measure for the individual (absolute) sense of chirality, an arbitrary attributive term.

  8. Physical and biological properties of Bazna waters

    PubMed Central

    TRÂMBIŢAŞ, DAN

    2013-01-01

    The healing properties of Bazna waters and their therapeutic indications have been well known since the 18th century. The objective of the present study was to characterize these waters from physical and biological points of view, and to further analyze the nitrogen compounds, especially NH4+. The following physical parameters of the water were analyzed: density (g/cm3), electric resistivity (Ω·m), electric conductivity (cm−1o−1), salinity, The pH analysis of the biological component was performed on samples from 4 basins. Nitrogen compounds were dosed in the form of ammonium ion (NH4+). The physical and chemical proprieties are similar across the basins. Flora and fauna biological components were identified. Ammonium ions were identified in large quantities, but this did not lead to hygienicaly unclean waters. PMID:26527972

  9. Are physicians' ratings of pain affected by patients' physical attractiveness?

    PubMed

    Hadjistavropoulos, H D; Ross, M A; von Baeyer, C L

    1990-01-01

    The degree to which physical attractiveness and nonverbal expressions of pain influence physicians' perceptions of pain was investigated. Photographs of eight female university students were represented in four experimental conditions created by the manipulation of cosmetics, hairstyles, and facial expressions: (a) attractive-no pain, (b) attractive-pain, (c) unattractive-no pain, and (d) unattractive-pain. Each photograph was accompanied by a brief description of the patient's pain problem that was standard across conditions. Medical residents (N = 60) viewed the photographs and rated each patient's pain, distress, negative affective experience, health, personality, blame for the situation, and the physician's own solicitude for the patient. The results showed that physicians' ratings of pain were influenced both by attractiveness of patients and by nonverbal expressions of pain. Unattractive patients, and patients who were expressing pain, were perceived as experiencing more pain, distress, and negative affective experiences than attractive patients and patients who were not expressing pain. Unattractive patients also received higher ratings of solicitude on the doctor's part and lower ratings of health than attractive patients. Physician's assessments of pain appear to be influenced by the physical attractiveness of the patient. PMID:2367884

  10. Are physicians' ratings of pain affected by patients' physical attractiveness?

    PubMed

    Hadjistavropoulos, H D; Ross, M A; von Baeyer, C L

    1990-01-01

    The degree to which physical attractiveness and nonverbal expressions of pain influence physicians' perceptions of pain was investigated. Photographs of eight female university students were represented in four experimental conditions created by the manipulation of cosmetics, hairstyles, and facial expressions: (a) attractive-no pain, (b) attractive-pain, (c) unattractive-no pain, and (d) unattractive-pain. Each photograph was accompanied by a brief description of the patient's pain problem that was standard across conditions. Medical residents (N = 60) viewed the photographs and rated each patient's pain, distress, negative affective experience, health, personality, blame for the situation, and the physician's own solicitude for the patient. The results showed that physicians' ratings of pain were influenced both by attractiveness of patients and by nonverbal expressions of pain. Unattractive patients, and patients who were expressing pain, were perceived as experiencing more pain, distress, and negative affective experiences than attractive patients and patients who were not expressing pain. Unattractive patients also received higher ratings of solicitude on the doctor's part and lower ratings of health than attractive patients. Physician's assessments of pain appear to be influenced by the physical attractiveness of the patient.

  11. Physical properties of the Uranian satellites

    NASA Technical Reports Server (NTRS)

    Brown, Robert H.; Johnson, Torrence V.; Synnott, Stephen; Anderson, John D.; Jacobson, Robert A.; Dermott, Stanley F.; Thomas, Peter C.

    1991-01-01

    Data regarding the Uranian satellites' radii, masses, mean density, and, consequently, their internal structures obtained from the Voyager encounter are analyzed. Topics covered are the sizes, shapes, topography, masses, densities, and models of the internal structures of the five major satellites. The sizes and shapes of the 10 small satellites discovered by Voyager 2 are discussed. The physical properties of the large satellites of Uranus are compared to those other satellites in the outer solar system, particularly those of Jupiter and Saturn, and the implications that these comparisons have for understanding the origin and evolution of the satellites of Uranus are discussed.

  12. F antigen. II. Chemical and physical properties.

    PubMed

    Utzinger, R

    1975-01-01

    Physical and chemical properties of the liver-specific F antigen suggested a model for the labile quarternary structure of the protein. The native molecule showed a size slightly larger than 60,000 dalton (d), which was reduced to about 40,000 d under acidic conditions. Breaking of hydrogen bonds by chaotropic treatment resulted in the release of components of 30,000, 7,000 and 2,000 d. The smallest component was split to fragments of about 1,000 d by the reducing action of sulfhydryl compounds.

  13. Physical Properties of Synthetic Resin Materials

    NASA Technical Reports Server (NTRS)

    Fishbein, Meyer

    1939-01-01

    A study was made to determine the physical properties of synthetic resins having paper, canvas, and linen reinforcements, and of laminated wood impregnated with a resin varnish. The results show that commercial resins have moduli of elasticity that are too low for structural considerations. Nevertheless, there do exist plastics that have favorable mechanical properties and, with further development, it should be possible to produce resin products that compare favorably with the light-metal alloys. The results obtained from tests on Compound 1840, resin-impregnated wood, show that this material can stand on its own merit by virtue of a compressive strength four times that of the natural wood. This increase in compressive strength was accomplished with an increase of density to a value slightly below three times the normal value and corrected one of the most serious defects of the natural product.

  14. Physical Properties of the Glycoprotein Mucin

    NASA Astrophysics Data System (ADS)

    Matthews, Garrett; Davis, William; Superfine, Richard; Boucher, Richard

    2003-03-01

    Epithelial cell surfaces are covered by a protective gel known as mucus. The physiological function of this gel depends on its rheological properties, and these properties are largely derived from the secreted glycoprotein mucin. The genetic disease Cystic Fibrosis (CF) is characterized by the adhesion of thick, viscous mucus on these tissues. In the lungs, this results in the interruption of mucus transport thus compromising the first line of defense against pathogens in these tissues. In order to restore the flow of tracheobronchial mucus out of the body, knowledge of the molecular and physical properties of mucin and mucin solutions would be greatly beneficial. The present model for these molecules is that of a long linear strand consisting of highly glycosylated regions linked by cystein-rich globular regions. It is thought that the globular regions may interact either through intermolecular disulfide bonds or through hydrophobic interactions. It has also been speculated that the glycosylated regions may have lectin-like interactions. In the present work, single mucin molecules were imaged at high resolution using atomic force microscopy (AFM). Phase mode imaging was used to map the interactions between functionalized AFM tips and the molecular topography. Additionally, using force-distance curves with the AFM, the adhesion between mucin bound tips and cell surface glycocalyx and glycocalyx-like model surfaces, was measured. And, finally, the viscoelastic properties of mucin solutions were measured using the recently developed technique, single particle tracking microrheology. A model is being developed that will incorporate the properties of mucins beginning at the single molecule and ending with the bulk viscoelastic properties.

  15. HYDRAULIC AND PHYSICAL PROPERTIES OF MCU SALTSTONE

    SciTech Connect

    Dixon, K; Mark Phifer, M

    2008-03-19

    The Saltstone Disposal Facility (SDF), located in the Z-Area of the Savannah River Site (SRS), is used for the disposal of low-level radioactive salt solution. The SDF currently contains two vaults: Vault 1 (6 cells) and Vault 4 (12 cells). Additional disposal cells are currently in the design phase. The individual cells of the saltstone facility are filled with saltstone., Saltstone is produced by mixing the low-level radioactive salt solution, with blast furnace slag, fly ash, and cement or lime to form a dense, micro-porous, monolithic, low-level radioactive waste form. The saltstone is pumped into the disposal cells where it subsequently solidifies. Significant effort has been undertaken to accurately model the movement of water and contaminants through the facility. Key to this effort is an accurate understanding of the hydraulic and physical properties of the solidified saltstone. To date, limited testing has been conducted to characterize the saltstone. The primary focus of this task was to estimate the hydraulic and physical properties of MCU (Modular Caustic Side Solvent Extraction Unit) saltstone relative to two permeating fluids. These fluids included simulated groundwater equilibrated with vault concrete and simulated saltstone pore fluid. Samples of the MCU saltstone were prepared by the Savannah River National Laboratory (SRNL) and allowed to cure for twenty eight days prior to testing. These samples included two three-inch diameter by six inch long mold samples and three one-inch diameter by twelve inch long mold samples.

  16. Some physical properties of naturally irradiated fluorite

    USGS Publications Warehouse

    Berman, Robert

    1955-01-01

    Five samples of purple fluorite found in association with radioactive, materials, and a synthetic colorless control sample were studied and compared.  Before and after heating, observations were made on specific gravity, index of refraction, unit-cell size, breadth of X-ray diffraction lines, and fluorescence.  The purple samples became colorless on heating above 175° C.  During the process, observations were made on color, thermoluminescence, and differential thermal analysis curves.  There were strong correlations between the various physical properties, and it was found possible to arrange the samples in order of increasing difference in their physical properties from the control sample. This order apparently represents increasing structural damage by radiation; if so, it correlates with decreasing specific gravity, increasing index of refraction, broadening of X-ray lines, and increasingly strong exothermic reactions on annealing. The differences between the samples in index of refraction and X-ray pattern are largely eliminated on annealing.  Annealing begins at 1750 C; thermoluminescence at lower temperatures is due to electrons escaping from the metastable potential traps, not the destruction of those traps which takes place on annealing.

  17. Physical properties of soils in Rostov agglomeration

    NASA Astrophysics Data System (ADS)

    Gorbov, S. N.; Bezuglova, O. S.; Abrosimov, K. N.; Skvortsova, E. B.; Tagiverdiev, S. S.; Morozov, I. V.

    2016-08-01

    Physical properties of natural and anthropogenically transformed soils of Rostov agglomeration were examined. The data obtained by conventional methods and new approaches to the study of soil physical properties (in particular, tomographic study of soil monoliths) were used for comparing the soils of different functional zones of the urban area. For urban territories in the steppe zone, a comparison of humus-accumulative horizons (A, Asod, Ap, and buried [A] horizons) made it possible to trace tendencies of changes in surface soils under different anthropogenic impacts and in the buried and sealed soils. The microtomographic study demonstrated differences in the bulk density and aggregation of urban soils from different functional zones. The A horizon in the forest-park zone is characterized by good aggregation and high porosity, whereas buried humus-accumulative horizons of anthropogenically transformed soils are characterized by poor aggregation and low porosity. The traditional parameters of soil structure and texture also proved to be informative for the identification of urban pedogenesis.

  18. Physical Properties of Fractured Porous Media

    NASA Astrophysics Data System (ADS)

    Mohammed, T. E.; Schmitt, D. R.

    2015-12-01

    The effect of fractures on the physical properties of porous media is of considerable interest to oil and gas exploration as well as enhanced geothermal systems and carbon capture and storage. This work represents an attempt to study the effect fractures have on multiple physical properties of rocks. An experimental technique to make simultaneous electric and ultrasonic measurements on cylindrical core plugs is developed. Aluminum end caps are mounted with ultrasonic transducers to transmit pules along the axis of the cylinder while non-polarizing electrodes are mounted on the sides of the core to make complex conductivity measurements perpendicular to the cylinder axis. Electrical measurements are made by applying a sinusoidal voltage across the measurement circuit that consist of a resister and the sample in series. The magnitude and phase of the signal across the sample is recorded relative to the input signal across a range of frequencies. Synthetic rock analogs are constructed using sintered glass beads with fractures imbedded in them. The fracture location, size and orientation are controlled and each fractured specimen has an unfractured counterpart. Porosity, Permeability, electrical conductivity and ultrasonic velocity measurements are conducted on each sample with the complex electrical conductivities recorded at frequencies from 10hz to 1 Mhz. These measurements allow us to examine the changes induced by these mesoscale fractures on the embedding porous medium. Of particular interest is the effect of fracture orientation on electrical conductivity of the rock. Seismic anisotropy caused by fractures is a well understood phenomenon with many rock physics models dedicated to its understanding. The effect of fractures on electrical conductivity is less well understood with electrical anisotropy scarcely investigated in the literature. None the less, using electrical conductivity to characterize fractures can add an extra constraint to characterization based

  19. Coupled model of physical and biological processes affecting maize pollination

    NASA Astrophysics Data System (ADS)

    Arritt, R.; Westgate, M.; Riese, J.; Falk, M.; Takle, E.

    2003-04-01

    Controversy over the use of genetically modified (GM) crops has led to increased interest in evaluating and controlling the potential for inadvertent outcrossing in open-pollinated crops such as maize. In response to this problem we have developed a Lagrangian model of pollen dispersion as a component of a coupled end-to-end (anther to ear) physical-biological model of maize pollination. The Lagrangian method is adopted because of its generality and flexibility: first, the method readily accommodates flow fields of arbitrary complexity; second, each element of the material being transported can be identified by its source, time of release, or other properties of interest. The latter allows pollen viability to be estimated as a function of such factors as travel time, temperature, and relative humidity, so that the physical effects of airflow and turbulence on pollen dispersion can be considered together with the biological aspects of pollen release and viability. Predicted dispersion of pollen compares well both to observations and to results from a simpler Gaussian plume model. Ability of the Lagrangian model to handle complex air flows is demonstrated by application to pollen dispersion in the vicinity of an agricultural shelter belt. We also show results indicating that pollen viability can be quantified by an "aging function" that accounts for temperature, humidity, and time of exposure.

  20. Determining Physical Properties of the Cell Cortex.

    PubMed

    Saha, Arnab; Nishikawa, Masatoshi; Behrndt, Martin; Heisenberg, Carl-Philipp; Jülicher, Frank; Grill, Stephan W

    2016-03-29

    Actin and myosin assemble into a thin layer of a highly dynamic network underneath the membrane of eukaryotic cells. This network generates the forces that drive cell- and tissue-scale morphogenetic processes. The effective material properties of this active network determine large-scale deformations and other morphogenetic events. For example, the characteristic time of stress relaxation (the Maxwell time τM) in the actomyosin sets the timescale of large-scale deformation of the cortex. Similarly, the characteristic length of stress propagation (the hydrodynamic length λ) sets the length scale of slow deformations, and a large hydrodynamic length is a prerequisite for long-ranged cortical flows. Here we introduce a method to determine physical parameters of the actomyosin cortical layer in vivo directly from laser ablation experiments. For this we investigate the cortical response to laser ablation in the one-cell-stage Caenorhabditis elegans embryo and in the gastrulating zebrafish embryo. These responses can be interpreted using a coarse-grained physical description of the cortex in terms of a two-dimensional thin film of an active viscoelastic gel. To determine the Maxwell time τM, the hydrodynamic length λ, the ratio of active stress ζΔμ, and per-area friction γ, we evaluated the response to laser ablation in two different ways: by quantifying flow and density fields as a function of space and time, and by determining the time evolution of the shape of the ablated region. Importantly, both methods provide best-fit physical parameters that are in close agreement with each other and that are similar to previous estimates in the two systems. Our method provides an accurate and robust means for measuring physical parameters of the actomyosin cortical layer. It can be useful for investigations of actomyosin mechanics at the cellular-scale, but also for providing insights into the active mechanics processes that govern tissue-scale morphogenesis. PMID

  1. Physical Properties of Thin Film Semiconducting Materials

    NASA Astrophysics Data System (ADS)

    Bouras, N.; Djebbouri, M.; Outemzabet, R.; Sali, S.; Zerrouki, H.; Zouaoui, A.; Kesri, N.

    2005-10-01

    The physics and chemistry of semiconducting materials is a continuous question of debate. We can find a large stock of well-known properties but at the same time, many things are not understood. In recent years, porous silicon (PS-Si), diselenide of copper and indium (CuInSe2 or CIS) and metal oxide semiconductors like tin oxide (SnO2) and zinc oxide (ZnO) have been subjected to extensive studies because of the rising interest their potential applications in fields such as electronic components, solar panels, catalysis, gas sensors, in biocompatible materials, in Li-based batteries, in new generation of MOSFETS. Bulk structure and surface and interface properties play important roles in all of these applications. A deeper understanding of these fundamental properties would impact largely on technological application performances. In our laboratory, thin films of undoped and antimony-doped films of tin oxide have been deposited by chemical vapor deposition. Spray pyrolysis was used for ZnO. CIS was prepared by flash evaporation or close-space vapor transport. Some of the deposition parameters have been varied, such as substrate temperature, time of deposition (or anodization), and molar concentration of bath preparation. For some samples, thermal annealing was carried out under oxygen (or air), under nitrogen gas and under vacuum. Deposition and post-deposition parameters are known to strongly influence film structure and electrical resistivity. We investigated the influence of film thickness and thermal annealing on structural optical and electrical properties of the films. Examination of SnO2 by x-ray diffraction showed that the main films are polycrystalline with rutile structure. The x-ray spectra of ZnO indicated a hexagonal wurtzite structure. Characterizations of CIS films with compositional analysis, x-ray diffraction, scanning microscopy, spectrophotometry, and photoluminescence were carried out.

  2. Physical Properties of the Uranian Satellites

    NASA Technical Reports Server (NTRS)

    Brown, R. H.

    1984-01-01

    Recent work on the satellites of Uranus revealed many of their basic physical properties. Radiometric measurements showed that the Ariel, Umbriel, Titania and Oberon have diameters which range from 1630 to 1110 km and albedos which range from 0.30 to 0.18. Spectrophotometric observations of Miranda suggest that it may have the highest albedo of the known Uranian satellites and a diameter of about 500 km. Near-infrared measurements show that Ariel, Titania and Oberon have the largest known opposition surges. All five known satellites of Uranus have surfaces which are composed of water ice contaminated with small amounts of dark material. The dark material on the surfaces of Ariel, Umbriel, Titania and Oberon is spectrally bland and has spectral similarities to carbon black, charcoal, carbonaceous chondritic material and other dark, spectrally neutral materials. Recent density determinations suggest that there may be large density differences among Ariel, Umbriel, Titania and Oberon, with density increasing with distance from Uranus.

  3. Physical properties of the Uranian satellites

    SciTech Connect

    Brown, R.H.

    1984-10-01

    Recent work on the satellites of Uranus revealed many of their basic physical properties. Radiometric measurements showed that the Ariel, Umbriel, Titania and Oberon have diameters which range from 1630 to 1110 km and albedos which range from 0.30 to 0.18. Spectrophotometric observations of Miranda suggest that it may have the highest albedo of the known Uranian satellites and a diameter of about 500 km. Near-infrared measurements show that Ariel, Titania and Oberon have the largest known opposition surges. All five known satellites of Uranus have surfaces which are composed of water ice contaminated with small amounts of dark material. The dark material on the surfaces of Ariel, Umbriel, Titania and Oberon is spectrally bland and has spectral similarities to carbon black, charcoal, carbonaceous chondritic material and other dark, spectrally neutral materials. Recent density determinations suggest that there may be large density differences among Ariel, Umbriel, Titania and Oberon, with density increasing with distance from Uranus.

  4. Physical Properties of Hanford Transuranic Waste Sludge

    SciTech Connect

    Poloski, A.; Berg, Dr.

    2003-06-01

    Since the start of this project in March of 2004 two main goals have been achieved. First, the laboratory facilities of the Center for Surfaces, Polymers and Colloids (SPC) at the University of Washington have been updated with the purchase and installation of two state-of-the-art analysis tools. Second, a study of the sedimentation behavior of high density colloidal solids in complex media has been performed. The results of this study were presented at the 78th ACS Colloid and Surface Science Symposium at Yale University in New Haven, CT, and have been submitted for publication to the Journal of Colloid and Interface Science. Both the new equipment and the results of the initial study will help to gain insight into the physical properties of Hanford transuranic waste sludge.

  5. Physical Factors Affecting Outflow Facility Measurements in Mice

    PubMed Central

    Boussommier-Calleja, Alexandra; Li, Guorong; Wilson, Amanda; Ziskind, Tal; Scinteie, Oana Elena; Ashpole, Nicole E.; Sherwood, Joseph M.; Farsiu, Sina; Challa, Pratap; Gonzalez, Pedro; Downs, J. Crawford; Ethier, C. Ross; Stamer, W. Daniel; Overby, Darryl R.

    2015-01-01

    Purpose Mice are commonly used to study conventional outflow physiology. This study examined how physical factors (hydration, temperature, and anterior chamber [AC] deepening) influence ocular perfusion measurements in mice. Methods Outflow facility (C) and pressure-independent outflow (Fu) were assessed by multilevel constant pressure perfusion of enucleated eyes from C57BL/6 mice. To examine the effect of hydration, seven eyes were perfused at room temperature, either immersed to the limbus in saline and covered with wet tissue paper or exposed to room air. Temperature effects were examined in 12 eyes immersed in saline at 20°C or 35°C. Anterior chamber deepening was examined in 10 eyes with the cannula tip placed in the anterior versus posterior chamber (PC). Posterior bowing of the iris (AC deepening) was visualized by three-dimensional histology in perfusion-fixed C57BL/6 eyes and by spectral-domain optical coherence tomography in living CD1 mice. Results Exposure to room air did not significantly affect C, but led to a nonzero Fu that was significantly reduced upon immersion in saline. Increasing temperature from 20°C to 35°C increased C by 2.5-fold, more than could be explained by viscosity changes alone (1.4-fold). Perfusion via the AC, but not the PC, led to posterior iris bowing and increased outflow. Conclusions Insufficient hydration contributes to the appearance of pressure-independent outflow in enucleated mouse eyes. Despite the large lens, AC deepening may artifactually increase outflow in mice. Temperature-dependent metabolic processes appear to influence conventional outflow regulation. Physical factors should be carefully controlled in any outflow studies involving mice. PMID:26720486

  6. Percolation and Physical Properties of Rock Salt

    NASA Astrophysics Data System (ADS)

    Ghanbarzadeh, S.; Hesse, M. A.; Prodanovic, M.

    2015-12-01

    Textural equilibrium controls the distribution of the liquid phase in many naturally occurring porous materials such as partially molten rocks and alloys, salt-brine and ice-water systems. In these materials, pore geometry evolves to minimize the solid-liquid interfacial energy while maintaining a constant dihedral angle, θ, at solid-liquid contact lines. A characteristic of texturally equilibrated porous media, in the absence of deformation, is that the pore network percolates at any porosity for θ<60° while a percolation threshold exists for θ>60°. However, in ductile polycrystalline materials including rock salt, the balance between surface tension and ductile deformation controls the percolation of fluid pockets along grain corners and edges. Here we show sufficiently rapid deformation can overcome this threshold by elongating and connecting isolated pores by examining a large number of accessible salt samples from deep water Gulf of Mexico. We first confirm the percolation threshold in static laboratory experiments on synthetic salt samples with X-ray microtomography. We then provide field evidence on existence of interconnected pore space in rock salt in extremely low porosities, significantly below the static percolation threshold. Scaling arguments suggest that strain rates in salt are sufficient to overcome surface tension and may allow percolation. We also present the first level-set computations of three-dimensional texturally equilibrated melt networks in realistic rock fabrics. The resulting pore space is used to obtain the effective physical properties of rock, effective electrical conductivity and mechanical properties, with a novel numerical model.

  7. Physical and chemical properties of radionuclide therapy.

    PubMed

    Wessels, B W; Meares, C F

    2000-04-01

    As more radionuclide therapies move from laboratory feasibility studies into clinical reality, it becomes increasingly important for the labeling chemistry to produce consistently a stable radiopharmaceutical that remains intact under the challenge of human catabolism. Similarly, once proof of principle is established to bring a radionuclide conjugate into clinical therapy trials, dosimetric estimates should be made to select the appropriate radionuclide properties, which are based on animal-specific or patient-specific pharmacokinetics and match a set of specific clinical endpoints. These properties may include the radionuclide physical half-life, radiolabeled conjugate biological uptake and clearance, product-specific activity, range and type of emissions, and resultant effects on tumor and normal tissue cellular survival. The immunologist and labeling chemist have now produced a variety of strategies that have potential to increase the therapeutic ratio (tumor-to-normal tissue dose ratio). The advent of normal tissue clearing agents, fragmented or chimerized carriers to improve targeting, and the method of bispecific or two-step and three-step targeting agents has increased the need for realistic modeling of the carrier in vivo to guide prospectively the competitive development of these radiopharmaceuticals. In this article, examples have been taken from the literature to elucidate the benchmark of success that careful experimental design has fostered to bring these agents into clinical practice by creative and logical methodologies.

  8. Physical Property Comparison of Ordinary Chondrite Classes

    NASA Astrophysics Data System (ADS)

    Ostrowski, Daniel; Bryson, Kathryn L.

    2016-10-01

    Measurements of the physical properties of meteorites are essential in helping to determine the physical characteristics of the parent asteroids. Studying of physical properties can provide fundamental information to understand meteoroid behavior in the atmosphere and determine methods to deflect potentially hazardous asteroids. Initial focus of our study is on ordinary chondrites, since they are over 70% of the meteorites.To date we have measured the density (bulk and grain), porosity, thermal emissivity, and acoustic velocity of 7 ordinary chondrites (Tamdakht, Chelyabinsk, and multiple Antarctic meteorites). Each meteorite is first scanned using a 3D laser scanner to determine bulk density. For the other tests 1.5cm cubes are studied. Grain density is determined using gas pycnometer using nitrogen gas. Acoustic velocity, longitudinal and shear wave, are measured using an Olympus 45-MG in single element mode. Thermal emissivity is measured from 20°C up to atmospheric entry temperatures, and is based on average measurements over the wavelength range of 8 to 14μm.Tamdakht's bulk density is that of an average H Chondrite (3-4 g/cm3), while it has a low longitudinal velocity of 3540 m/s compared to the normal rage for H chondrites at 3529-6660 m/s. The velocity is consistent across all three axes in the sample. One possibility is an internal fracture, where part of has been seen on the surface of one of the test cubes. Chelyabinsk and the studied Antarctic meteorites have lower bulk and higher grain densities yielding above average porosities. Tamdakht is on the high end of the emissivity range for H chondrites and Chelyabinsk is on the high end for LL chondrites. Emissivity ranges from 0.985-0.995 at 20°C for the ordinary chondrites studied. Heated samples emissivity decreases slightly, 0.045, from initial 20°C measurement. Between 40-200°C, the emissivity stays fairly constant after decrease from room temperature. BTN 00304 has the highest average over the

  9. Physical properties of Michigan Antrim Shale

    SciTech Connect

    Hockings, W.A.

    1980-08-01

    The physical properties of approximately 225 core samples and 700 samples of well cuttings from the Antrim Shale formation in the Michigan Basin were measured. The properties included density, porosity, permeability, pore size distribution, specific surface, and thermal expansion. Measurements were made before and after roasting in air and in nitrogen. In general the properties showed little variation with depth or location within the sampling area. The average porosity was about 8 percent of which approximately one-half consisted of closed pores. The porosity increased by about a factor of two after roasting at 500/sup 0/C. The permeability was found to be very low, averaging about 0.008 millidarcies. Permeability was higher in the direction parallel to the bedding planes than in the direction perpendicular to the planes. After roasting at 500/sup 0/C the permeability increased by about a factor of ten. Measurements while heating from 20 to 225/sup 0/C showed only minor variations in permeability with temperature. The specific surface area of the shale is low, averaging about 0.5 square meters per gram. The pore size distribution is bimodal with most of the pore volume in the size ranges of 0.01 to 0.1 and 10 to 100 micrometers. The shale expands about one percent perpendicular to bedding and 0.2 percent parallel to bedding when heated to 500/sup 0/C. The average expansion coefficient is 0.0025 percent per /sup 0/C on heating and 0.0010 on cooling. Peaks in the heating curve occur at about 25/sup 0/C and 450/sup 0/C.

  10. Acoustic Imaging of Snowpack Physical Properties

    NASA Astrophysics Data System (ADS)

    Kinar, N. J.; Pomeroy, J. W.

    2011-12-01

    Measurements of snowpack depth, density, structure and temperature have often been conducted by the use of snowpits and invasive measurement devices. Previous research has shown that acoustic waves passing through snow are capable of measuring these properties. An experimental observation device (SAS2, System for the Acoustic Sounding of Snow) was used to autonomously send audible sound waves into the top of the snowpack and to receive and process the waves reflected from the interior and bottom of the snowpack. A loudspeaker and microphone array separated by an offset distance was suspended in the air above the surface of the snowpack. Sound waves produced from a loudspeaker as frequency-swept sequences and maximum length sequences were used as source signals. Up to 24 microphones measured the audible signal from the snowpack. The signal-to-noise ratio was compared between sequences in the presence of environmental noise contributed by wind and reflections from vegetation. Beamforming algorithms were used to reject spurious reflections and to compensate for movement of the sensor assembly during the time of data collection. A custom-designed circuit with digital signal processing hardware implemented an inversion algorithm to relate the reflected sound wave data to snowpack physical properties and to create a two-dimensional image of snowpack stratigraphy. The low power consumption circuit was powered by batteries and through WiFi and Bluetooth interfaces enabled the display of processed data on a mobile device. Acoustic observations were logged to an SD card after each measurement. The SAS2 system was deployed at remote field locations in the Rocky Mountains of Alberta, Canada. Acoustic snow properties data was compared with data collected from gravimetric sampling, thermocouple arrays, radiometers and snowpit observations of density, stratigraphy and crystal structure. Aspects for further research and limitations of the acoustic sensing system are also discussed.

  11. High Strength Stainless Steel Properties that Affect Resistance Welding

    SciTech Connect

    Kanne, W.R.

    2001-08-01

    This report discusses results of a study on selected high strength stainless steel alloy properties that affect resistance welding. The austenitic alloys A-286, JBK-75 (Modified A-286), 21-6-9, 22-13-5, 316 and 304L were investigated and compared. The former two are age hardenable, and the latter four obtain their strength through work hardening. Properties investigated include corrosion and its relationship to chemical cleaning, the effects of heat treatment on strength and surface condition, and the effect of mechanical properties on strength and weldability.

  12. The Relationship of Freshmen's Physics Achievement and Their Related Affective Characteristics

    ERIC Educational Resources Information Center

    Gungor, Almer (Abak); Eryilmaz, Ali; Fakioglu, Turgut

    2007-01-01

    The purpose of this study was to determine the best-fitting structural equation model between the freshmen's physics achievement and selected affective characteristics related to physics. These characteristics are students' situational interest in physics, personal interest in physics, aspiring extra activities related to physics, importance of…

  13. Physical properties of defined lipopolysaccharide salts.

    PubMed

    Coughlin, R T; Haug, A; McGroarty, E J

    1983-04-12

    The electron spin resonance probes 5-doxylstearate and 4-(dodecyldimethylammonio)-1-oxy-2,2,6,6-tetramethylpiperidine bromide were used to characterize the fluidity of the acyl chain and head-group regions, respectively, of defined salts of lipopolysaccharide (LPS) from Escherichia coli K12. The removal of the weakly bound divalent cations from native LPS by electrodialysis and their replacement by sodium had little effect on the midpoint of the lipid-phase transition or on head-group mobility. In contrast, lipopolysaccharide acyl chain mobility increased following electrodialysis. The replacement of most of the remaining cations with sodium resulted in a further dramatic increase in mobility in both the polar and nonpolar regions of lipopolysaccharide. Head-group mobility of the sodium salt of LPS was shown to be reduced with the addition of divalent cations. Furthermore, evidence is presented which suggests that low magnesium concentrations may induce phase separations in the sodium salt. The magnesium salt of lipopolysaccharide closely resembled the native form in both head-group and acyl chain mobility although the cation charge to phosphorus ratio in the magnesium salt was greater than that detected in the native isolate. Analyses of other lipopolysaccharide salts support our hypothesis that many of the observed differences in the physical and pathological properties of lipopolysaccharide salts may simply be explained by the degree of charge neutralization. PMID:6303400

  14. Does Physics Teaching Affect Gender-based Science Anxiety?

    ERIC Educational Resources Information Center

    Udo, M. K.; Ramsey, G. P.; Reynolds-Alpert, S.; Mallow, J. V.

    2001-01-01

    Presents the results of a study designed to measure the level of science anxiety in students enrolled in physics courses at Loyola University in Chicago. The leading factors contributing to science anxiety include nonscience anxiety and gender. Concludes that the teaching of an introductory physics course can reduce acute levels of science…

  15. Negative Experiences in Physical Education and Sport: How Much Do They Affect Physical Activity Participation Later in Life?

    ERIC Educational Resources Information Center

    Cardinal, Bradley J.; Yan, Zi; Cardinal, Marita K.

    2013-01-01

    People's feelings toward physical activity are often influenced by memories of their childhood experiences in physical education and sport. Unfortunately, many adults remember negative experiences, which may affect their desire to maintain a physically active lifestyle. A survey that asked 293 students about recollections from their childhood…

  16. Affective Learning Profiles in Compulsory High School Physical Education: An Instructional Communication Perspective

    ERIC Educational Resources Information Center

    Webster, Collin A.; Mindrila, Diana; Weaver, Glenn

    2013-01-01

    Affective learning is a major focus of the national K-12 physical education (PE) content standards (National Association for Sport and Physical Education [NASPE, 2004]). Understanding how students might fit into different affective learning subgroups would help extend affective learning theory in PE and suggest possible intervention strategies for…

  17. A study of factors affecting indoor radon properties.

    PubMed

    Yu, K N; Young, E C; Li, K C

    1996-08-01

    The factors affecting indoor radon properties in Hong Kong have been studied, including the radon concentration, the total potential alpha energy concentration of radon progeny, the equilibrium factor, and the fraction of unattached radon progeny. These factors fall into three categories, namely, (1) the building characteristics, including cooling method, age of the buildings, wall coverings and floor coverings; (2) the location of sites, including nearby environments, geological materials of the area, and the elevation of the sites; and (3) the meteorological parameters, including rainfall, relative humidity, pressure, temperature, and wind speeds. For category (1), only the ventilation is found to affect the indoor radon properties. For category (2), only the nearby environments have effects. For category (3), the rainfall and temperature are found to have significant effects.

  18. A study of factors affecting indoor radon properties

    SciTech Connect

    Yu, K.N.; Young, E.C.M.; Li, K.C.

    1996-08-01

    The factors affecting indoor radon properties in Hong Kong have been studied, including the radon concentration, the total potential alpha energy concentration of radon progeny, the equilibrium factor, and the fraction of unattached radon progeny. These factors fall into three categories, namely, (1) the building characteristics, including cooling method, age of the buildings, wall coverings and floor coverings; (2) the location of sites, including nearby environments, geological materials of the area, and the elevation of the sites; and (3) the meteorological parameters, including rainfall, relative humidity, pressure, temperature, and wind speeds. For category (1), only the ventilation is found to affect the indoor radon properties. For category (2), only the nearby environments have effects. For category (3), the rainfall and temperature are found to have significant effects. 15 refs., 1 fig., 5 tabs.

  19. Affective and Physical Changes Associated with Oral Contraceptive Use.

    ERIC Educational Resources Information Center

    Wiener, Alane L.; And Others

    Although investigations of the physiological effects of oral contraceptives suggest that affective changes may accompany their use, empirical documentation of these effects has not been consistent. This study examined physiological and affective changes accompanying use of a low-dosage oral contraceptive while controlling for possible expectancy…

  20. Factors Affecting Junior High School Students' Interest in Physics

    NASA Astrophysics Data System (ADS)

    Trumper, Ricardo

    2006-03-01

    We report the results of a study on students' interest in physics at the end of their compulsory schooling in Israel carried out in the framework of the ROSE Project. Factors studied were their opinions about science classes, their out-of-school experiences in physics, and their attitudes toward science and technology. Students' overall interest in physics was "neutral" (neither positive nor negative), with boys showing a higher interest than girls. We found a strong correlation between students' "neutral" interest in physics and their negative opinions about science classes. These findings raise serious questions about the implementation of changes made in the Israeli science curriculum in primary and junior high school, especially if the goal is to prepare the young generation for life in a scientific-technological era. A more in-depth analysis of the results led us to formulate curricular, behavioral, and organizational changes needed to reach this goal.

  1. 40 CFR 716.50 - Reporting physical and chemical properties.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Reporting physical and chemical... chemical properties. Studies of physical and chemical properties must be reported under this subpart if...) Degradation by chemical mechanisms—hydrolytic, reductive, and oxidative. (j) Degradation by...

  2. Physical Activity Affects Brain Integrity in HIV + Individuals

    PubMed Central

    Ortega, Mario; Baker, Laurie M.; Vaida, Florin; Paul, Robert; Basco, Brian; Ances, Beau M.

    2015-01-01

    Prior research has suggested benefits of aerobic physical activity (PA) on cognition and brain volumes in HIV uninfected (HIV−) individuals, however, few studies have explored the relationships between PA and brain integrity (cognition and structural brain volumes) in HIV-infected (HIV +) individuals. Seventy HIV + individuals underwent neuropsychological testing, structural neuroimaging, laboratory tests, and completed a PA questionnaire, recalling participation in walking, running, and jogging activities over the last year. A PA engagement score of weekly metabolic equivalent (MET) hr of activity was calculated using a compendium of PAs. HIV + individuals were classified as physically active (any energy expended above resting expenditure, n = 22) or sedentary (n = 48). Comparisons of neuropsychological performance, grouped by executive and motor domains, and brain volumes were completed between groups. Physically active and sedentary HIV + individuals had similar demographic and laboratory values, but the active group had higher education (14.0 vs. 12.6 years, p = .034). Physically active HIV + individuals performed better on executive (p = .040, unadjusted; p = .043, adjusted) but not motor function (p = .17). In addition, among the physically active group the amount of physical activity (METs) positively correlated with executive (Pearson’s r = 0.45, p = 0.035) but not motor (r = 0.21; p = .35) performance. In adjusted analyses the physically active HIV + individuals had larger putamen volumes (p = .019). A positive relationship exists between PA and brain integrity in HIV + individuals. Results from the present study emphasize the importance to conduct longitudinal interventional investigation to determine if PA improves brain integrity in HIV + individuals. PMID:26581799

  3. Introduction to physical properties and elasticity models: Chapter 20

    USGS Publications Warehouse

    Dvorkin, Jack; Helgerud, Michael B.; Waite, William F.; Kirby, Stephen H.; Nur, Amos

    2003-01-01

    Estimating the in situ methane hydrate volume from seismic surveys requires knowledge of the rock physics relations between wave speeds and elastic moduli in hydrate/sediment mixtures. The elastic moduli of hydrate/sediment mixtures depend on the elastic properties of the individual sedimentary particles and the manner in which they are arranged. In this chapter, we present some rock physics data currently available from literature. The unreferenced values in Table I were not measured directly, but were derived from other values in Tables I and II using standard relationships between elastic properties for homogeneous, isotropic material. These derivations allow us to extend the list of physical property estimates, but at the expense of introducing uncertainties due to combining property values measured under different physical conditions. This is most apparent in the case of structure II (sII) hydrate for which very few physical properties have been measured under identical conditions.

  4. Associations between positive and negative affect and 12-month physical disorders in a national sample.

    PubMed

    Weiser, Eric B

    2012-06-01

    Associations between positive and negative affect and a range of 12-month physical disorders were investigated in the Midlife Development in the United States Survey, a nationally representative sample of 3,032 adults ages 25-74. These associations were examined, controlling for relevant sociodemographic and psychiatric covariates. High positive affect was associated with decreased risk of physical disorders, whereas high negative affect was associated with increased risk. However, associations between positive affect and physical disorders were partially attenuated following adjustment for concurrent negative affect. Additionally, high affect balance was associated with decreased risk of physical disorders before and after adjustments. These findings underscore the relevance of affective disposition in health status, suggesting that both positive and negative affect may serve as viable health risk parameters.

  5. Patterns and determinants of wood physical and mechanical properties across major tree species in China.

    PubMed

    Zhu, JiangLing; Shi, Yue; Fang, LeQi; Liu, XingE; Ji, ChengJun

    2015-06-01

    The physical and mechanical properties of wood affect the growth and development of trees, and also act as the main criteria when determining wood usage. Our understanding on patterns and controls of wood physical and mechanical properties could provide benefits for forestry management and bases for wood application and forest tree breeding. However, current studies on wood properties mainly focus on wood density and ignore other wood physical properties. In this study, we established a comprehensive database of wood physical properties across major tree species in China. Based on this database, we explored spatial patterns and driving factors of wood properties across major tree species in China. Our results showed that (i) compared with wood density, air-dried density, tangential shrinkage coefficient and resilience provide more accuracy and higher explanation power when used as the evaluation index of wood physical properties. (ii) Among life form, climatic and edaphic variables, life form is the dominant factor shaping spatial patterns of wood physical properties, climatic factors the next, and edaphic factors have the least effects, suggesting that the effects of climatic factors on spatial variations of wood properties are indirectly induced by their effects on species distribution.

  6. Some physical properties of tabletted seed of Garcinia kola (HECKEL).

    PubMed

    Onunkwo, G C; Egeonu, H C; Adikwu, M U; Ojile, J E; Olowosulu, A K

    2004-06-01

    The formulation of Garcinia kola seeds into tablet dosage form and evaluation of some physical properties of the tablets are presented. A chemical assay was conducted on the dry, powdered seeds as well as the crude aqueous extract of the seeds. The dry powdered seeds contain 0.003% of flavonoids while the crude extract contained 0.007% of flavonoids based on rutin used as the standard. The powdered material (50 mg) and crude extract (10 mg) were formulated into tablets using the wet granulation method. Named binders were evaluated in these formulations. The various tablet parameters were evaluated, namely: weight variation, thickness and diameter, hardness, friability, disintegration time, dissolution profile and content uniformity. The results indicated that the tablets had good disintegration time, dissolution and hardness/friability profiles. Tablets formulated with starch had the best disintegration properties but were consequently very friable. Tablets formulated from 10 mg of the crude extract needed a larger proportion of diluents, which affected the tablet properties.

  7. How Molecular Structure Affects Mechanical Properties of an Advanced Polymer

    NASA Technical Reports Server (NTRS)

    Nicholson, Lee M.; Whitley, Karen S.; Gates, Thomas S.; Hinkley, Jeffrey A.

    2000-01-01

    density was performed over a range of temperatures below the glass transition temperature. The physical characterization, elastic properties and notched tensile strength all as a function of molecular weight and test temperature were determined. For the uncrosslinked SI material, it was shown that notched tensile strength is a strong function of both temperature and molecular weight, whereas stiffness is only a strong function of temperature. For the crosslinked PETI-SI material, it was shown that the effect of crosslinking significantly enhances the mechanical performance of the low molecular weight material; comparable to that exhibited by the high molecular weight material.

  8. How sensory properties of foods affect human feeding behavior.

    PubMed

    Rolls, B J; Rowe, E A; Rolls, E T

    1982-09-01

    The sensory properties of food which can lead to a decrease in the pleasantness of that food after it is eaten, and to enhanced food intake if that property of the food is changed by successive presentation of different foods, were investigated. After eating chocolates of one color the pleasantness of the taste of the eaten color declined more than of the non-eaten colors, although these chocolates differed only in appearance. The presentation of a variety of colors of chocolates, either simultaneously or successively, did not affect food intake compared with consumption of the subject's favorite color. Changes in the shape of food (which affects both appearance and mouth feel) were introduced by offering subjects three successive courses consisting of different shapes of pasta. Changes in shape led to a specific decrease in the pleasantness of the shape eaten and to a significant enhancement (14%) of food intake when three shapes were offered compared with intake of the subject's favorite shape. Changes in just the flavor of food (i.e., cream cheese sandwiches flavored with salt, or with the non-nutritive flavoring agents lemon and saccharin, or curry) led to a significant enhancement (15%) of food intake when all three flavors were presented successively compared with intake of the favorite. The experiments elucidate some of the properties of food which are involved in sensory specific satiety, and which determine the amount of food eaten. PMID:7178247

  9. Biochar physico-chemical properties as affected by environmental exposure.

    PubMed

    Sorrenti, Giovambattista; Masiello, Caroline A; Dugan, Brandon; Toselli, Moreno

    2016-09-01

    To best use biochar as a sustainable soil management and carbon (C) sequestration technique, we must understand the effect of environmental exposure on its physical and chemical properties because they likely vary with time. These properties play an important role in biochar's environmental behavior and delivery of ecosystem services. We measured biochar before amendment and four years after amendment to a commercial nectarine orchard at rates of 5, 15 and 30tha(-1). We combined two pycnometry techniques to measure skeletal (ρs) and envelope (ρe) density and to estimate the total pore volume of biochar particles. We also examined imbibition, which can provide information about soil hydraulic conductivity. Finally, we investigated the chemical properties, surface, inner layers atomic composition and C1s bonding state of biochar fragments through X-ray photoelectron spectroscopy (XPS). Ageing increased biochar skeletal density and reduced the water imbibition rate within fragments as a consequence of partial pore clogging. However, porosity and the volume of water stored in particles remained unchanged. Exposure reduced biochar pH, EC, and total C, but enhanced total N, nitrate-N, and ammonium-N. X-ray photoelectron spectroscopy analyses showed an increase of O, Si, N, Na, Al, Ca, Mn, and Fe surface (0-5nm) atomic composition (at%) and a reduction of C and K in aged particles, confirming the interactions of biochar with soil inorganic and organic phases. Oxidation of aged biochar fragments occurred mainly in the particle surface, and progressively decreased down to 75nm. Biochar surface chemistry changes included the development of carbonyl and carboxylate functional groups, again mainly on the particle surface. However, changes were noticeable down to 75nm, while no significant changes were measured in the deepest layer, up to 110nm. Results show unequivocal shifts in biochar physical and chemical properties/characteristics over short (~years) timescales. PMID

  10. Biochar physico-chemical properties as affected by environmental exposure.

    PubMed

    Sorrenti, Giovambattista; Masiello, Caroline A; Dugan, Brandon; Toselli, Moreno

    2016-09-01

    To best use biochar as a sustainable soil management and carbon (C) sequestration technique, we must understand the effect of environmental exposure on its physical and chemical properties because they likely vary with time. These properties play an important role in biochar's environmental behavior and delivery of ecosystem services. We measured biochar before amendment and four years after amendment to a commercial nectarine orchard at rates of 5, 15 and 30tha(-1). We combined two pycnometry techniques to measure skeletal (ρs) and envelope (ρe) density and to estimate the total pore volume of biochar particles. We also examined imbibition, which can provide information about soil hydraulic conductivity. Finally, we investigated the chemical properties, surface, inner layers atomic composition and C1s bonding state of biochar fragments through X-ray photoelectron spectroscopy (XPS). Ageing increased biochar skeletal density and reduced the water imbibition rate within fragments as a consequence of partial pore clogging. However, porosity and the volume of water stored in particles remained unchanged. Exposure reduced biochar pH, EC, and total C, but enhanced total N, nitrate-N, and ammonium-N. X-ray photoelectron spectroscopy analyses showed an increase of O, Si, N, Na, Al, Ca, Mn, and Fe surface (0-5nm) atomic composition (at%) and a reduction of C and K in aged particles, confirming the interactions of biochar with soil inorganic and organic phases. Oxidation of aged biochar fragments occurred mainly in the particle surface, and progressively decreased down to 75nm. Biochar surface chemistry changes included the development of carbonyl and carboxylate functional groups, again mainly on the particle surface. However, changes were noticeable down to 75nm, while no significant changes were measured in the deepest layer, up to 110nm. Results show unequivocal shifts in biochar physical and chemical properties/characteristics over short (~years) timescales.

  11. Mechanical and physical properties of plasma-sprayed stabilized zirconia

    NASA Technical Reports Server (NTRS)

    Siemers, P. A.; Mehan, R. L.

    1983-01-01

    Physical and mechanical properties were determined for plasma-sprayed MgO- or Y2O3-stabilized ZrO2 thermal barrier coatings. Properties were determined for the ceramic coating in both the freestanding condition and as-bonded to a metal substrate. The properties of the NiCrAlY bond coating were also investigated.

  12. Emergent Properties of Patch Shapes Affect Edge Permeability to Animals

    PubMed Central

    Nams, Vilis O.

    2011-01-01

    Animal travel between habitat patches affects populations, communities and ecosystems. There are three levels of organization of edge properties, and each of these can affect animals. At the lowest level are the different habitats on each side of an edge, then there is the edge itself, and finally, at the highest level of organization, is the geometry or structure of the edge. This study used computer simulations to (1) find out whether effects of edge shapes on animal behavior can arise as emergent properties solely due to reactions to edges in general, without the animals reacting to the shapes of the edges, and to (2) generate predictions to allow field and experimental studies to test mechanisms of edge shape response. Individual animals were modeled traveling inside a habitat patch that had different kinds of edge shapes (convex, concave and straight). When animals responded edges of patches, this created an emergent property of responding to the shape of the edge. The response was mostly to absolute width of the shapes, and not the narrowness of them. When animals were attracted to edges, then they tended to collect in convexities and disperse from concavities, and the opposite happened when animals avoided edges. Most of the responses occurred within a distance of 40% of the perceptual range from the tip of the shapes. Predictions were produced for directionality at various locations and combinations of treatments, to be used for testing edge behavior mechanisms. These results suggest that edge shapes tend to either concentrate or disperse animals, simply because the animals are either attracted to or avoid edges, with an effect as great as 3 times the normal density. Thus edge shape could affect processes like pollination, seed predation and dispersal and predator abundance. PMID:21747965

  13. Determinants affecting physical activity levels in animal models

    NASA Technical Reports Server (NTRS)

    Tou, Janet C L.; Wade, Charles E.

    2002-01-01

    Weight control is dependent on energy balance. Reduced energy expenditure (EE) associated with decreased physical activity is suggested to be a major underlying cause in the increasing prevalence of weight gain and obesity. Therefore, a better understanding of the biological determinants involved in the regulation of physical activity is essential. To facilitate interpretation in humans, it is helpful to consider the evidence from animal studies. This review focuses on animal studies examining the biological determinants influencing activity and potential implications to human. It appears that physical activity is influenced by a number of parameters. However, regardless of the parameter involved, body weight appears to play an underlying role in the regulation of activity. Furthermore, the regulation of activity associated with body weight appears to occur only after the animal achieves a critical weight. This suggests that activity levels are a consequence rather than a contributor to weight control. However, the existence of an inverse weight-activity relationship remains inconclusive. Confounding the results are the multifactorial nature of physical activity and the lack of appropriate measuring devices. Furthermore, many determinants of body weight are closely interlocked, making it difficult to determine whether a single, combination, or interaction of factors is important for the regulation of activity. For example, diet-induced obesity, aging, lesions to the ventral medial hypothalamus, and genetics all produce hypoactivity. Providing a better understanding of the biological determinants involved in the regulation of activity has important implications for the development of strategies for the prevention of weight gain leading to obesity and subsequent morbidity and mortality in the human population.

  14. Determinants Affecting Physical Activity Levels In Animal Models

    NASA Technical Reports Server (NTRS)

    Tou, Janet C. L.; Wade, Charles E.; Dalton, Bonnie P. (Technical Monitor)

    2001-01-01

    Weight control is dependent on energy balance. Reduced energy expenditure (EE) associated with decreased physical activity is suggested to be a major underlying cause in the increasing prevalence of weight gain and obesity. Therefore, a better understanding of the biological determinants involved in the regulation of physical activity is essential. To facilitate interpretation in humans, it is helpful to consider the evidence from animal studies. This review focuses on animal studies examining the biological determinants influencing activity and potential implications to human. It appears that physical activity is influenced by a number of parameters. However, regardless of the parameter involved, body weight appears to play all underlying role in the regulation of activity. Furthermore, the regulation of activity associated with body weight appears to occur only after the animal achieves a critical weight. This suggests that activity levels are a consequence rather than a contributor to weight control. However, the existence of an inverse weight-activity relationship remains inconclusive. Confounding the results are the multi-factorial nature of physical activity and the lack of appropriate measuring devices. Furthermore, many determinants of body weight are closely interlocked making it difficult to determine whether a single, combination or interaction of factors is important for the regulation of activity. For example, diet-induced obesity, aging, lesions to tile ventral medial hypothalamus and genetics all produce hypoactivity. Providing a better understanding of the biological determinants involved in the regulation of activity has important implications for the development of strategies for the prevention of weight gain leading to obesity and subsequent morbidity and mortality in the human population.

  15. Biochemical basis of physical properties of respiratory tract secretions.

    PubMed

    Lopez-Vidriero, M T

    1987-01-01

    The physical properties of respiratory tract secretion (RTS) play a prominent rôle in the non-specific defence mechanisms of the lung. Viscosity and elasticity, that is flow and deformation, are only two of the physical properties of RTS. Spinability, pourability, adhesiveness and tackiness are starting to be recognised as physical properties of RTS and its is likely that they may be relevant in the pathogenesis of airways obstruction. RTS is a gel, which consists of a cross-linked polymer network dispersed in a liquid solvent. The polymeric structure of the epithelial glycoprotein can be explained in terms of covalent (disulphide) linkages and/or physical entanglement between glycoproteins subunits. Other constituents of RTS such as proteins, lipids, ions and water can influence the physical properties of RTS. PMID:3322857

  16. Biochemical basis of physical properties of respiratory tract secretions.

    PubMed

    Lopez-Vidriero, M T

    1987-01-01

    The physical properties of respiratory tract secretion (RTS) play a prominent rôle in the non-specific defence mechanisms of the lung. Viscosity and elasticity, that is flow and deformation, are only two of the physical properties of RTS. Spinability, pourability, adhesiveness and tackiness are starting to be recognised as physical properties of RTS and its is likely that they may be relevant in the pathogenesis of airways obstruction. RTS is a gel, which consists of a cross-linked polymer network dispersed in a liquid solvent. The polymeric structure of the epithelial glycoprotein can be explained in terms of covalent (disulphide) linkages and/or physical entanglement between glycoproteins subunits. Other constituents of RTS such as proteins, lipids, ions and water can influence the physical properties of RTS.

  17. Do Stretch Durations Affect Muscle Mechanical and Neurophysiological Properties?

    PubMed

    Opplert, J; Genty, J-B; Babault, N

    2016-08-01

    The aim of the study was to determine whether stretching durations influence acute changes of mechanical and neurophysiological properties of plantar flexor muscles. Plantar flexors of 10 active males were stretched in passive conditions on an isokinetic dynamometer. Different durations of static stretching were tested in 5 randomly ordered experimental trials (1, 2, 3, 4 and 10×30-s). Fascicle stiffness index, evoked contractile properties and spinal excitability (Hmax/Mmax) were examined before (PRE), immediately after (POST0) and 5 min after (POST5) stretching. No stretch duration effect was recorded for any variable. Moreover, whatever the stretching duration, stiffness index, peak twitch torque and rate of force development were significantly lower at POST0 and POST5 as compared to PRE (P<0.05). Electromechanical delay was longer at POST0 and POST5 as compared to PRE (P<0.05). Whatever the stretch duration, no significant changes of Hmax/Mmax ratio were recorded. In conclusion, 30 s of static stretching to maximum tolerated discomfort is sufficient enough to alter mechanical properties of plantar flexor muscles, but 10×30 s does not significantly affect these properties further. Stretching does not impair spinal excitability. PMID:27191211

  18. Physical and mechanical properties of icebergs

    SciTech Connect

    Gammon, P.H.; Bobby, W.; Gagnon, R.E.; Russell, W.E.

    1983-05-01

    Physical and mechanical characteristics of iceberg ice were studied from samples collected near the shores of eastern Newfoundland. Although the physical characteristics show considerable diversity, iceberg ice has some common features and is generally porous, lacks significant concentrations of dissolved materials, contains internal cracks and has an irregular interlocking grain structure. A review of mechanical testing of ice was carried out and an experimental setup was devised to reduce effects of improper contact between specimen and loading apparatus. Uniaxial compressive strength for iceberg ice was determined and compared with that for lake ice. The strength of iceberg ice was higher than that of lake ice but Young's Modulus for lake ice was higher.

  19. Silicified structures affect leaf optical properties in grasses and sedge.

    PubMed

    Klančnik, Katja; Vogel-Mikuš, Katarina; Gaberščik, Alenka

    2014-01-01

    Silicon (Si) is an important structural element that can accumulate at high concentrations in grasses and sedges, and therefore Si structures might affect the optical properties of the leaves. To better understand the role of Si in light/leaf interactions in species rich in Si, we examined the total Si and silica phytoliths, the biochemical and morphological leaf properties, and the reflectance and transmittance spectra in grasses (Phragmites australis, Phalaris arundinacea, Molinia caerulea, Deschampsia cespitosa) and sedge (Carex elata). We show that these grasses contain >1% phytoliths per dry mass, while the sedge contains only 0.4%. The data reveal the variable leaf structures of these species and significant differences in the amount of Si and phytoliths between developing and mature leaves within each species and between grasses and sedge, with little difference seen among the grass species. Redundancy analysis shows the significant roles of the different near-surface silicified leaf structures (e.g., prickle hairs, cuticle, epidermis), phytoliths and Si contents, which explain the majority of the reflectance and transmittance spectra variability. The amount of explained variance differs between mature and developing leaves. The transmittance spectra are also significantly affected by chlorophyll a content and calcium levels in the leaf tissue.

  20. PHYSICAL PROPERTY MEASUREMENTS OF LABORATORY PREPARED SALTSTONE GROUT

    SciTech Connect

    Hansen, E.; Cozzi, A.; Edwards, T.

    2014-05-05

    were essentially the same for the salt grout without admixture. When Daratard 17 was added, the Bingham Plastic yield stress increased for the 10 minute mix. The simulant salt used in this task had similar physical properties of the Tank 50 3Q13 salt grout and is recommended for future use, if the salt solution in Tank 50 does not change. The design basis physical properties used to size the pumps and mixers at SPF were obtained from DPST-85-312. The grouts characterized in this report are bounded by the design basis density and Bingham Plastic yield stress. The opposite is true for the plastic viscosity. Steady state pressure drop calculations were performed for the design basis values using the flow rate for the clean cap and salt grouts and they bound the pressure drop of the grouts characterized in this report. A comparison of the lab prepared samples to PI ProcessBook data, specifically average pressure drop, indicate that the lab prepared samples are more viscous in nature than what is processed in the facility. This difference could be due to the applied shear rates which could be lower in the lab as compared to the facility and that fact the SPF added flush water, making this comparison more difficult. A perfunctory review of the PI ProcessBook data was discussed. It may be possible that the frequency that the distributed control system alters the grout pump speed to maintain grout hopper volume can negatively affect the efficiency of the grout pump.

  1. Mechanical Properties of Heat Affected Zone of High Strength Steels

    NASA Astrophysics Data System (ADS)

    Sefcikova, K.; Brtnik, T.; Dolejs, J.; Keltamaki, K.; Topilla, R.

    2015-11-01

    High Strength Steels became more popular as a construction material during last decade because of their increased availability and affordability. On the other hand, even though general use of Advanced High Strength Steels (AHSS) is expanding, the wide utilization is limited because of insufficient information about their behaviour in structures. The most widely used technique for joining steels is fusion welding. The welding process has an influence not only on the welded connection but on the area near this connection, the so-called heat affected zone, as well. For that reason it is very important to be able to determine the properties in the heat affected zone (HAZ). This area of investigation is being continuously developed in dependence on significant progress in material production, especially regarding new types of steels available. There are currently several types of AHSS on the world market. Two most widely used processes for AHSS production are Thermo-Mechanically Controlled Processing (TMCP) and Quenching in connection with Tempering. In the presented study, TMCP and QC steels grade S960 were investigated. The study is focused on the changes of strength, ductility, hardness and impact strength in heat affected zone based on the used amount of heat input.

  2. Does UV irradiation affect polymer properties relevant to tissue engineering?

    NASA Astrophysics Data System (ADS)

    Fischbach, Claudia; Tessmar, Jörg; Lucke, Andrea; Schnell, Edith; Schmeer, Georg; Blunk, Torsten; Göpferich, Achim

    2001-10-01

    For most tissue engineering approaches aiming at the repair or generation of living tissues the interaction of cells and polymeric biomaterials is of paramount importance. Prior to contact with cells or tissues, biomaterials have to be sterilized. However, many sterilization procedures such as steam autoclave or heat sterilization are known to strongly affect polymer properties. UV irradiation is used as an alternative sterilization method in many tissue engineering laboratories on a routine basis, however, potential alterations of polymer properties have not been extensively considered. In this study we investigated the effects of UV irradiation on spin-cast films made from biodegradable poly( D, L-lactic acid)-poly(ethylene glycol)-monomethyl ether diblock copolymers (Me.PEG-PLA) which have recently been developed for controlled cell-biomaterial interaction. After 2 h of UV irradiation, which is sufficient for sterilization, no alterations in cell adhesion to polymer films were detected, as demonstrated with 3T3-L1 preadipocytes. This correlated with unchanged film topography and molecular weight distribution. However, extended UV irradiation for 5-24 h elicited drastic responses regarding Me.PEG-PLA polymer properties and interactions with biological elements: Large increases in unspecific protein adsorption and subsequent cell adhesion were observed. Changes in polymer surface properties could be correlated with the observed alterations in cell/protein-polymer interactions. Atomic force microscopy analysis of polymer films revealed a marked "smoothing" of the polymer surface after UV irradiation. Investigations using GPC, 1H-NMR, mass spectrometry, and a PEG-specific colorimetric assay demonstrated that polymer film composition was time-dependently affected by exposure to UV irradiation, i.e., that large amounts of PEG were lost from the copolymer surface. The data indicate that sterilization using UV irradiation for 2 h is an appropriate technique for the

  3. Do Non-Collagenous Proteins Affect Skeletal Mechanical Properties?

    PubMed Central

    Morgan, Stacyann; Poundarik, Atharva A.; Vashishth, Deepak

    2015-01-01

    The remarkable mechanical behavior of bone is attributed to its complex nanocomposite structure that, in addition to mineral and collagen, comprises a variety of non-collagenous matrix proteins or NCPs. Traditionally, NCPs have been studied as signaling molecules in biological processes including bone formation, resorption and turnover. Limited attention has been given to their role in determining the mechanical properties of bone. Recent studies have highlighted that NCPs can indeed be lost or modified with aging, diseases and drug therapies. Homozygous and heterozygous mice models of key NCP provide a useful approach to determine the impact of NCPs on bone morphology as well as matrix quality, and to carry out detailed mechanical analysis for elucidating the pathway by which NCPs can affect the mechanical properties of bone. In this article, we present a systematic analysis of a large cohort of NCPs on bone’s structural and material hierarchy, and identify three principal pathways by which they determine bone’s mechanical properties. These pathways include alterations of bone morphological parameters crucial for bone’s structural competency, bone quality changes in key matrix parameters (mineral and collagen), and a direct role as load bearing structural proteins. PMID:26048282

  4. Do Non-collagenous Proteins Affect Skeletal Mechanical Properties?

    PubMed

    Morgan, Stacyann; Poundarik, Atharva A; Vashishth, Deepak

    2015-09-01

    The remarkable mechanical behavior of bone is attributed to its complex nanocomposite structure that, in addition to mineral and collagen, comprises a variety of non-collagenous matrix proteins or NCPs. Traditionally, NCPs have been studied as signaling molecules in biological processes including bone formation, resorption, and turnover. Limited attention has been given to their role in determining the mechanical properties of bone. Recent studies have highlighted that NCPs can indeed be lost or modified with aging, diseases, and drug therapies. Homozygous and heterozygous mice models of key NCP provide a useful approach to determine the impact of NCPs on bone morphology as well as matrix quality, and to carry out detailed mechanical analysis for elucidating the pathway by which NCPs can affect the mechanical properties of bone. In this article, we present a systematic analysis of a large cohort of NCPs on bone's structural and material hierarchy, and identify three principal pathways by which they determine bone's mechanical properties. These pathways include alterations of bone morphological parameters crucial for bone's structural competency, bone quality changes in key matrix parameters (mineral and collagen), and a direct role as load-bearing structural proteins.

  5. Prediction of Solvent Physical Properties using the Hierarchical Clustering Method

    EPA Science Inventory

    Recently a QSAR (Quantitative Structure Activity Relationship) method, the hierarchical clustering method, was developed to estimate acute toxicity values for large, diverse datasets. This methodology has now been applied to the estimate solvent physical properties including sur...

  6. A Comparison of Video-Based and Interaction-Based Affect Detectors in Physics Playground

    ERIC Educational Resources Information Center

    Kai, Shiming; Paquette, Luc; Baker, Ryan S.; Bosch, Nigel; D'Mello, Sidney; Ocumpaugh, Jaclyn; Shute, Valerie; Ventura, Matthew

    2015-01-01

    Increased attention to the relationships between affect and learning has led to the development of machine-learned models that are able to identify students' affective states in computerized learning environments. Data for these affect detectors have been collected from multiple modalities including physical sensors, dialogue logs, and logs of…

  7. Predicting Soil Biological and Physical Properties Using Hydrological Properties

    NASA Astrophysics Data System (ADS)

    Geiger, L.; Hofmockel, K.; Kaleita, A.; Hargreaves, S.

    2012-12-01

    Soil biological and chemical properties vary at different spatial scales, which make predicting processes associated with these properties difficult. However, soil biological and chemical properties are important to fertility and ecosystem functioning. In this study, we used a Self Organizing Map (SOM) to determine whether soil hydrological characteristics can be used to characterize the distribution of a suite of soil biological and chemical properties. From a row crop field in south-central Iowa, we generated 36 sampling locations via a SOM, which were grouped into three categories according to hydrological properties by the SOM. Soil samples were then analyzed for microbial biomass, carbon and nitrogen mineralization potential, and organic and inorganic pools of carbon and nitrogen. We found that sampling locations in category 1 (potholes and toe slopes) had greater microbial biomass, total carbon, total nitrogen, and extractable organic carbon than compared locations in the two well-drained categories. Nitrogen and carbon mineralization and inorganic nitrogen pools did not differ significantly among the categories. These results demonstrate that hydrological characteristics can be used to predict relatively stable biological and chemical soil properties. However, prediction of nitrogen and carbon fluxes remains a challenge.

  8. Physical processes affecting the sedimentary environments of Long Island Sound

    USGS Publications Warehouse

    Signell, R.P.; Knebel, H. J.; List, J.H.; Farris, A.S.; ,

    1997-01-01

    A modeling study was undertaken to simulate the bottom tidal-, wave-, and wind-driven currents in Long Island Sound in order to provide a general physical oceanographic framework for understanding the characteristics and distribution of seafloor sedimentary environments. Tidal currents are important in the funnel-shaped eastern part of the Sound, where a strong gradient of tidal-current speed was found. This current gradient parallels the general westward progression of sedimentary environments from erosion or non-deposition, through bedload transport and sediment sorting, to fine-grained deposition. Wave-driven currents, meanwhile, appear to be important along the shallow margins of the basin, explaining the occurrence of relatively coarse sediments in regions where tidal currents alone are not strong enough to move sediment. Finally, westerly wind events are shown to locally enhance bottom currents along the axial depression of the sound, providing a possible explanation for the relatively coarse sediments found in the depression despite tide- and wave-induced currents below the threshold of sediment movement. The strong correlation between the near-bottom current intensity based on the model results and the sediment response as indicated by the distribution of sedimentary environments provides a framework for predicting the long-term effects of anthropogenic activities.

  9. Microwave techniques for physical property measurements

    NASA Technical Reports Server (NTRS)

    Barmatz, M.

    1993-01-01

    Industrial processing of metals and ceramics is now being streamlined by the development of theoretical models. High temperature thermophysical properties of these materials are required to successfully apply these theories. Unfortunately, there is insufficient experimental data available for many of these properties, particularly in the molten state. Microwave fields can be used to measure specific heat, thermal diffusivity, thermal conductivity and dielectric constants at high temperatures. We propose to (1) develop a microwave flash method (analogous to the laser flash technique) that can simultaneously measure the thermal diffusivity and specific heat of insulators and semiconductors at high temperatures, (2) an appropriate theory and experimental apparatus to demonstrate the measurement of the specific heat of a metal using a new microwave ac specific heat technique, and (3) experimental methods for noncontact measurement of the real and imaginary dielectric constants.

  10. 4.4 Physical Properties of the Most Important Radionuclides

    NASA Astrophysics Data System (ADS)

    Noßke, D.; Mattsson, S.; Johansson, L.

    This document is part of Subvolume A 'Fundamentals and Data in Radiobiology, Radiation Biophysics, Dosimetry and Medical Radiological Protection' of Volume 7 'Medical Radiological Physics' of Landolt-Börnstein - Group VIII 'Advanced Materials and Technologies'. It contains the Section '4.4 Physical Properties of the Most Important Radionuclides' of the Chapter '4 Dosimetry in Nuclear Medicine Diagnosis and Therapy'.

  11. Psychometric Properties of the Commitment to Physical Activity Scale

    ERIC Educational Resources Information Center

    DeBate, Rita DiGioacchino; Huberty, Jennifer; Pettee, Kelley

    2009-01-01

    Objective: To assess psychometric properties of the Commitment to Physical Activity Scale (CPAS). Methods: Girls in third to fifth grades (n = 932) completed the CPAS before and after a physical activity intervention. Psychometric measures included internal consistency, factor analysis, and concurrent validity. Results: Three CPAS factors emerged:…

  12. Let Students Discover an Important Physical Property of a Slinky

    NASA Astrophysics Data System (ADS)

    Gash, Philip

    2016-10-01

    This paper describes a simple experiment that lets first-year physics and engineering students discover an important physical property of a Slinky. The restoring force for the fundamental oscillation frequency is provided only by those coils between the support and the Slinky center of mass.

  13. Let Students Discover an Important Physical Property of a Slinky

    ERIC Educational Resources Information Center

    Gash, Philip

    2016-01-01

    This paper describes a simple experiment that lets first-year physics and engineering students discover an important physical property of a Slinky. The restoring force for the fundamental oscillation frequency is provided only by those coils between the support and the Slinky center of mass.

  14. Synthesis and Physical Properties of Liquid Crystals: An Interdisciplinary Experiment

    ERIC Educational Resources Information Center

    Van Hecke, Gerald R.; Karukstis, Kerry K.; Hanhan Li; Hendargo, Hansford C.; Cosand, Andrew J.; Fox, Marja M.

    2005-01-01

    A study involves multiple chemistry and physics concepts applied to a state of matter that has biological relevance. An experiment involving the synthesis and physical properties of liquid crystals illustrates the interdisciplinary nature of liquid crystal research and the practical devices derived from such research.

  15. Optimization of Rei-mullite Physical Properties

    NASA Technical Reports Server (NTRS)

    Tanzilli, R. A.; Musikant, S.; Bolinger, P. N.; Brazel, J. P.

    1973-01-01

    Micromechanical and thermal modeling studies prove that ceramic fiber mullite materials is the only system capable of shuttle thermal protection to 1644 K. Hafnia pigmentated mullite surface coatings meet both orbital and reentry thermal radiative requirements for reuse without refurbishment. Thermal and mechanical models show growths potentials associated with the mullite system for a factor of 2 improvement in mechanical properties, and a factor of 2 to 3 reduction in thermal conductivity.

  16. Symmetry and causality properties of physical fields

    PubMed Central

    Jakobsen, H. P.; Ørsted, B.; Segal, I. E.; Speh, B.; Vergne, M.

    1978-01-01

    Representations of groups of causality-preserving transformations on locally Minkowskian space-times, by actions on classes of wave functions of designated transformation properties, are analyzed, in extension of the conventional theoretical treatment of free relativistic particles. In particular, the constraints of positivity of the energy and finiteness of propagation velocity are developed, and the concept of mass is explored, within the indicated framework. PMID:16592512

  17. Physical exercise affects attentional orienting behavior through noradrenergic mechanisms.

    PubMed

    Robinson, Andrea M; Buttolph, Thomas; Green, John T; Bucci, David J

    2015-06-01

    Spontaneously hypertensive rats (SHRs), a commonly used animal model of attention-deficit/hyperactivity disorder, exhibit little habituation of the orienting response to repeated presentations of a nonreinforced visual stimulus. However, SHRs that have access to a running wheel for 5, 10, or 21 days exhibit robust habituation that is indistinguishable from normo-active rats. Two days of exercise, in comparison, is not sufficient to affect habituation. Here we tested the hypothesis that the effect of exercise on orienting behavior in SHRs is mediated by changes in noradrenergic function. In Experiment 1, we found that 5, 10, or 21 days of access to a running wheel, but not 2 days, significantly reduced levels of the norepinephrine transporter in medial prefrontal cortex. In Experiment 2, we tested for a causal relationship between changes in noradrenergic function and orienting behavior by blocking noradrenergic receptors during exercise. Rats that received propranolol (beta adrenergic/noradrenergic receptor blocker) during 10 days of exercise failed to exhibit an exercise-induced reduction in orienting behavior. The results inform a growing literature regarding the effects of exercise on behavior and the potential use of exercise as a treatment for mental disorders. PMID:26030434

  18. Physical exercise affects attentional orienting behavior through noradrenergic mechanisms.

    PubMed

    Robinson, Andrea M; Buttolph, Thomas; Green, John T; Bucci, David J

    2015-06-01

    Spontaneously hypertensive rats (SHRs), a commonly used animal model of attention-deficit/hyperactivity disorder, exhibit little habituation of the orienting response to repeated presentations of a nonreinforced visual stimulus. However, SHRs that have access to a running wheel for 5, 10, or 21 days exhibit robust habituation that is indistinguishable from normo-active rats. Two days of exercise, in comparison, is not sufficient to affect habituation. Here we tested the hypothesis that the effect of exercise on orienting behavior in SHRs is mediated by changes in noradrenergic function. In Experiment 1, we found that 5, 10, or 21 days of access to a running wheel, but not 2 days, significantly reduced levels of the norepinephrine transporter in medial prefrontal cortex. In Experiment 2, we tested for a causal relationship between changes in noradrenergic function and orienting behavior by blocking noradrenergic receptors during exercise. Rats that received propranolol (beta adrenergic/noradrenergic receptor blocker) during 10 days of exercise failed to exhibit an exercise-induced reduction in orienting behavior. The results inform a growing literature regarding the effects of exercise on behavior and the potential use of exercise as a treatment for mental disorders.

  19. Physical Exercise Affects Attentional Orienting Behavior through Noradrenergic Mechanisms

    PubMed Central

    Robinson, Andrea M.; Buttolph, Thomas; Green, John T.; Bucci, David J.

    2015-01-01

    Spontaneously Hypertensive Rats (SHRs), a commonly-used animal model of ADHD, exhibit little habituation of the orienting response to repeated presentations of a non-reinforced visual stimulus. However, SHRs that have access to a running wheel for 5, 10, or 21 days exhibit robust habituation that is indistinguishable from normo-active rats. Two days of exercise, in comparison, was not sufficient to affect habituation. Here we tested the hypothesis that the effect of exercise on orienting behavior in SHRs is mediated by changes in noradrenergic function. In Experiment 1, we found that 5, 10, or 21 days of access to a running wheel, but not 2 days, significantly reduced levels of the norepinephrine transporter (NET) in medial prefrontal cortex. In Experiment 2, we tested for a causal relationship between changes in noradrenergic function and orienting behavior by blocking noradrenergic receptors during exercise. Rats that received propranolol (beta adrenergic/noradrenergic receptor blocker) during 10 days of exercise failed to exhibit an exercise-induced reduction in orienting behavior. The results inform a growing literature regarding the effects of exercise on behavior and the potential use of exercise as a treatment for mental disorders. PMID:26030434

  20. Powdered materials, products, and coating: Finely disperse cemented carbides WC-Ni. II. Physical properties

    SciTech Connect

    Sverdel, V.V.; Shatov, A.V.; Yurchuk, N.A.

    1994-09-01

    A change of the conditions of sintering of ceneted carbides will lead to a change in the completeness and speed of the sintering process forming the structure of the material. Changes in structure affect the mechanical and physical properties. Investigations were performed on tungsten carbides and nickel systems.

  1. Soil carbon dioxide fluxes in relation to physical properties as influenced by management practices

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Among greenhouse gases, carbon dioxide (CO2) is one of the most significant contributors to regional and global warming as well as climatic change. However, CO2 flux from the soil surface to the atmosphere can be affected by modifications in soil physical properties resulting from changes in land ma...

  2. Physical, chemical and kinetic factors affecting prion infectivity

    PubMed Central

    Properzi, Francesca; Badhan, Anjna; Klier, Steffi; Schmidt, Christian; Klöhn, Peter C.; Wadsworth, Jonathan D. F.; Clarke, Anthony R.; Jackson, Graham S.; Collinge, John

    2016-01-01

    ABSTRACT The mouse-adapted scrapie prion strain RML is one of the most widely used in prion research. The introduction of a cell culture-based assay of RML prions, the scrapie cell assay (SCA) allows more rapid and precise prion titration. A semi-automated version of this assay (ASCA) was applied to explore a range of conditions that might influence the infectivity and properties of RML prions. These include resistance to freeze-thaw procedures; stability to endogenous proteases in brain homogenate despite prolonged exposure to varying temperatures; distribution of infective material between pellet and supernatant after centrifugation, the effect of reducing agents and the influence of detergent additives on the efficiency of infection. Apparent infectivity is increased significantly by interaction with cationic detergents. Importantly, we have also elucidated the relationship between the duration of exposure of cells to RML prions and the transmission of infection. We established that the infection process following contact of cells with RML prions is rapid and followed an exponential time course, implying a single rate-limiting process. PMID:27282252

  3. Ferric Phosphate Hydroxide Microstructures Affect Their Magnetic Properties.

    PubMed

    Zhao, Junhong; Zhang, Youjuan; Run, Zhen; Li, Pengwei; Guo, Qifei; Pang, Huan

    2015-06-01

    Uniformly sized and shape-controlled nanoparticles are important due to their applications in catalysis, electrochemistry, ion exchange, molecular adsorption, and electronics. Several ferric phosphate hydroxide (Fe4(OH)3(PO4)3) microstructures were successfully prepared under hydrothermal conditions. Using controlled variations in the reaction conditions, such as reaction time, temperature, and amount of hexadecyltrimethylammonium bromide (CTAB), the crystals can be grown as almost perfect hyperbranched microcrystals at 180 °C (without CTAB) or relatively monodisperse particles at 220 °C (with CTAB). The large hyperbranched structure of Fe4(OH)3(PO4)3 with a size of ∼19 μm forms with the "fractal growth rule" and shows many branches. More importantly, the magnetic properties of these materials are directly correlated to their size and micro/nanostructure morphology. Interestingly, the blocking temperature (T B) shows a dependence on size and shape, and a smaller size resulted in a lower T B. These crystals are good examples that prove that physical and chemical properties of nano/microstructured materials are related to their structures, and the precise control of the morphology of such functional materials could allow for the control of their performance.

  4. Physics teachers' perspectives on factors that affect urban physics participation and accessibility

    NASA Astrophysics Data System (ADS)

    Kelly, Angela M.

    2013-06-01

    The accessibility of secondary physics in U.S. urban school districts is a complex issue. Many schools do not offer a physics option, and for those that do, access is often restricted by various school policies and priorities that do not promote physics participation for all. To analyze this problem in greater depth, I adopted a qualitative phenomenological methodology to explore urban physics teachers’ views on school- and district-based conditions that may marginalize traditionally underrepresented students. Teachers from three large urban districts shared concerns and suggestions regarding administrative commitment, student preparedness for physics, reform initiatives and testing mandates, promoting physics enrollments, and implementing high quality instruction. Data from interviews and focus groups provided contextual insights into ways in which physics study may be improved and encouraged for urban youth. Teachers believed expanding access could be facilitated with differentiated levels of physics, incorporating mathematical applications with multiple representations, educating students and counselors on the ramifications of choosing or not choosing elective sciences, well-designed grant-funded initiatives, and flexibility with prerequisites and science course sequencing. Teachers experienced frustration with standardized testing, lack of curricular autonomy, shifting administrative directives, and top-down reforms that did not incorporate their feedback in the decision-making processes. Data from this study revealed that physics teacher networks, often housed at local universities, have been a key resource for establishing supportive professional communities to share best practices that may influence school-based reforms that promote physics participation in urban schools.

  5. Can programmed or self-selected physical activity affect physical fitness of adolescents?

    PubMed

    Neto, Cláudio F; Neto, Gabriel R; Araújo, Adenilson T; Sousa, Maria S C; Sousa, Juliana B C; Batista, Gilmário R; Reis, Victor M M R

    2014-09-29

    The aim of this study was to verify the effects of programmed and self-selected physical activities on the physical fitness of adolescents. High school adolescents, aged between 15 and 17 years, were divided into two experimental groups: a) a self-selected physical activity group (PAS) with 55 students (aged 15.7 ± 0.7 years), who performed physical activities with self-selected rhythm at the following sports: basketball, volleyball, handball, futsal and swimming; and b) a physical fitness training group (PFT) with 53 students (aged 16.0 ± 0.7 years), who performed programmed physical fitness exercises. Both types of activity were developed during 60 min classes. To assess physical fitness the PROESP-BR protocol was used. The statistical analysis was performed by repeated measures ANOVA. The measurements of pre and post-tests showed significantly different values after PFT in: 9 minute running test, medicine ball throw, horizontal jump, abdominal endurance, running speed and flexibility. After PAS differences were detected in abdominal endurance, agility, running speed and flexibility. The intervention with programmed physical activity promoted more changes in the physical abilities; however, in the self-selected program, agility was improved probably because of the practice of sports. Therefore, physical education teachers can use PFT to improve cardiorespiratory fitness and power of lower and upper limbs and PAS to improve agility of high school adolescents.

  6. Nanoscale chemical interaction enhances the physical properties of bioglass composites.

    PubMed

    Ravarian, Roya; Zhong, Xia; Barbeck, Mike; Ghanaati, Shahram; Kirkpatrick, Charles James; Murphy, Ciara M; Schindeler, Aaron; Chrzanowski, Wojciech; Dehghani, Fariba

    2013-10-22

    Bioglasses are favorable biomaterials for bone tissue engineering; however, their applications are limited due to their brittleness. In addition, the early failure in the interface is a common problem of composites of bioglass and a polymer with high mechanical strength. This effect is due to the phase separation, nonhomogeneous mixture, nonuniform mechanical strength, and different degradation properties of two compounds. To address these issues, in this study a nanoscale interaction between poly(methyl methacrylate) (PMMA) and bioactive glass was formed via silane coupling agent (3-trimethoxysilyl)propyl methacrylate (MPMA). A monolith was produced at optimum composition from this hybrid by the sol-gel method at 50 °C with a rapid gelation time (<50 min) that possessed superior physicochemical properties compared to pure bioglass and physical mixture. For instance, the Young's modulus of bioglass was decreased 40-fold and the dissolution rate of silica was retarded 1.5-fold by integration of PMMA. Prolonged dissolution of silica fosters bone integration due to the continuous dissolution of bioactive silica. The primary osteoblast cells were well anchored and cell migration was observed on the surface of the hybrid. The in vivo studies in mice demonstrated that the integrity of the hybrids was maintained in subcutaneous implantation. They induced mainly a mononuclear phagocytic tissue reaction with a low level of inflammation, while bioglass provoked a tissue reaction with TRAP-positive multinucleated giant cells. These results demonstrated that the presence of a nanoscale interaction between bioglass and PMMA affects the properties of bioglass and broadens its potential applications for bone replacement.

  7. Emergent membrane-affecting properties of BSA-gold nanoparticleconstructs

    NASA Astrophysics Data System (ADS)

    Lystvet, Sina M.; Volden, Sondre; Yasuda, Masahiro; Halskau, Øyvind, Jr.; Glomm, Wilhelm R.

    2011-04-01

    By adsorbing bovine serum albumin (BSA) on gold nanoparticles (Aunps) with diameters 30 nm and 80 nm, different degrees of protein unfolding were obtained. Adsorption and adlayer conformation were characterized by UV-vis spectroscopy, ζ-potential measurements, steady-state and time-resolved fluorescence. The unfolding was also studied using 1-anilino-8-naphthalene sulfonate (ANS) as an extrinsic probe, showing that BSA unfolds more on 80 nm Aunp than on 30 nm Aunp. Langmuir monolayer studies using two distinct methods of introducing the BSA and BSA-Aunp constructs accompanied with Brewster Angle Microscopy (BAM) and Digital Video Microscope (DVM) imaging demonstrated that BSA-Aunp constructs induce film miscibility with l-α-phosphatidylethanolamine not seen for BSA or Aunp alone. The changes induced by partial unfolding clearly give better film-penetration ability, as well as disruption of liquid crystalline domains in the film, thereby inducing film miscibility. Gold or protein only does not possess the nanoscale film-affecting properties of the protein-goldconstructs, and as such the surface-active and miscibility-affecting characteristics of the BSA-Aunp represent emergent qualities.

  8. Do Physical Activity Facilities near Schools Affect Physical Activity in High School Girls?

    PubMed Central

    Trilk, Jennifer L.; Ward, Dianne S.; Dowda, Marsha; Pfeiffer, Karin A.; Porter, Dwayne E.; Hibbert, James; Pate, Russell R.

    2011-01-01

    Objective To investigate associations between the number of physical activity facilities within walking distance of school and physical activity behavior in 12th grade girls during after-school hours. Methods Girls (N=1394) from 22 schools completed a self-report to determine physical activity after 3:00 pm. The number of physical activity facilities within a 0.75-mile buffer of the school was counted with a Geographic Information System. Associations between the number of facilities and girls’ physical activity were examined using linear mixed-model analysis of variance. Results Overall, girls who attended schools with ≥ 5 facilities within the buffer reported more physical activity per day than girls in schools with < 5 facilities. In addition, girls who attended rural schools with ≥ 5 facilities reported ~12% more physical activity per day than girls who attended rural schools with < 5 facilities. No difference existed for girls in urban/suburban schools with ≥ 5 vs. < 5 facilities. Conclusion When school siting decisions are made, the number of physical activity facilities surrounding the school should be considered to encourage physical activity in 12th grade girls. PMID:21334248

  9. Modelling the historical changes in physical soil properties caused by wind erosion process

    NASA Astrophysics Data System (ADS)

    Lackóová, Lenka

    2016-04-01

    Soil physical properties could be significantly affected by land degradation processes. Spatial variation modelling of physical soil properties in time is important in areas where wind erosion occurs regularly. The objectives of this study were to determine the changes of spatial variability of sand, silt and clay % contents in selected area in Slovakia over 45 years using topsoil physical properties at European scale (using LUCAS topsoil) and historical Complex Soil Survey Data. The Complex Soil Survey was made in the period 1960-1970 for the whole of the Slovak Republic, using a unified methodology to build an important soil properties database including physical topsoil properties. Spatial model distribution using regression kriging algorithm created by Soil Science and Conservation Research Institute was used for comparison with LUCAS topsoil particle size distribution datasets and their derived products of clay, sand and silt % content. The results of this study will show the effects of wind erosion in long time scale. Continual total mass removal during wind erosion can produce dramatic changes in the texture of the soil surface. Fine particles are removed, which tend to concentrate sand as erosion continues. Wind erosion physically removes the most fertile portion of the soil which may lead to lower productivity or destroying the characteristics of topsoil beneficial to plant growth. Historical changes of physical soil properties are discussed in this study.

  10. Effects of Vermicompost and Water Treatment Residuals on Soil Physical Properties and Wheat Yield

    NASA Astrophysics Data System (ADS)

    Ibrahim, Mahmoud M.; Mahmoud, Essawy K.; Ibrahim, Doaa A.

    2015-04-01

    The application of vermicompost and water treatment residuals to improve the physical properties in the salt affected soils is a promising technology to meet the requirements of high plant growth and cost-effective reclamation. Therefore, the aim of this study was to investigate the effect of vermicompost and its mixtures with water treatment residuals on selected physical properties of saline sodic soil and on wheat yield. The treatments were vermicompost, water treatment residuals, vermicompost + water treatment residuals (1:1 and 2:1 wet weight ratio) at levels of 5 and 10 g dry weight kg-1 dry soil. The considered physical properties included aggregate stability, mean weight diameter, pore size distribution and dry bulk density. The addition of vermicompost and water treatment residuals had significant positive effects on the studied soil physical properties, and improved the grain yield of wheat. The treatment of (2 vermicompost + 1 water treatment residuals) at level of 5 g kg-1 soil gave the best grain yield. Combination of vermicompost and water treatment residuals improved the water treatment residuals efficiency in ameliorating the soil physical properties, and could be considered as an ameliorating material for the reclamation of salt affected soils.

  11. Changes of physical properties in multiferroic phase transitions.

    PubMed

    Litvin, Daniel B

    2014-07-01

    The physical property coefficients that arise in a phase transition which are zero in the high-symmetry phase and nonzero in the low-symmetry phase are called spontaneous coefficients. For all 1601 Aizu species of phase transitions, matrices have been constructed which show the nonzero coefficients of a wide variety of magnetic and nonmagnetic physical properties including toroidal property coefficients in the high-symmetry phase and their corresponding spontaneous coefficients in the low-symmetry phase. It is also shown that these spontaneous coefficients provide for the distinction of and switching between nonferroelastic domain pairs. PMID:25970196

  12. The importance of physical activity and sleep for affect on stressful days: Two intensive longitudinal studies.

    PubMed

    Flueckiger, Lavinia; Lieb, Roselind; Meyer, Andrea H; Witthauer, Cornelia; Mata, Jutta

    2016-06-01

    We investigated the potential stress-buffering effect of 3 health behaviors-physical activity, sleep quality, and snacking-on affect in the context of everyday life in young adults. In 2 intensive longitudinal studies with up to 65 assessment days over an entire academic year, students (Study 1, N = 292; Study 2, N = 304) reported stress intensity, sleep quality, physical activity, snacking, and positive and negative affect. Data were analyzed using multilevel regression analyses. Stress and positive affect were negatively associated; stress and negative affect were positively associated. The more physically active than usual a person was on a given day, the weaker the association between stress and positive affect (Study 1) and negative affect (Studies 1 and 2). The better than usual a person's sleep quality had been during the previous night, the weaker the association between stress and positive affect (Studies 1 and 2) and negative affect (Study 2). The association between daily stress and positive or negative affect did not differ as a function of daily snacking (Studies 1 and 2). On stressful days, increasing physical activity or ensuring high sleep quality may buffer adverse effects of stress on affect in young adults. These findings suggest potential targets for health-promotion and stress-prevention programs, which could help reduce the negative impact of stress in young adults. (PsycINFO Database Record

  13. Physical and Chemical Properties of Modified Nanodiamonds

    NASA Astrophysics Data System (ADS)

    Puzyr, A. P.; Bondar, V. S.; Bukayemsky, A. A.; Selyutin, G. E.; Kargin, V. F.

    A unique technology of nanodiamond surface modification is suggested which allows to separation of commercial nanodiamond powders into two fractions (F1 and F2), each possessing absolutely new properties as compared to the initial powder. Fl and F2 differ in size characteristics. Initial and modified nanodiamonds contain iron impurities and two types of nondiamond carbon. The color of the powders and hydrosols does not correlate with the content of non-diamond carbon. According to the EPR data, modified nanodiamonds possess a high level of diamond matrix shielding, and the extracted fractions differ in width of the basic transition area and in the SHF energy adsorption ratio. Due to this, Fl can be applied as precursors for CVD growth of nanocrystalline diamond and as field electron emission tips.

  14. Rock physics properties of some lunar samples

    NASA Technical Reports Server (NTRS)

    Warren, N.; Trice, R.; Anderson, O. L.; Soga, N.

    1973-01-01

    Linear strains and acoustic velocity data for lunar samples under uniaxial and hydrostatic loading are presented. Elastic properties are presented for 60335,20; 15555,68; 15498,23; and 12063,97. Internal friction data are summarized for a number of artificial lunar glasses with compositions similar to lunar rocks 12009, 12012, 14305, 15021, and 15555. Zero porosity model-rock moduli are calculated for a number of lunar model-rocks, with mineralogies similar to Apollo 12, 14, and 16 rocks. Model-rock calculations indicate that rock types in the troctolitic composition range may provide reasonable modeling of the lunar upper mantle. Model calculations involving pore crack effects are compatible with a strong dependence of rock moduli on pore strain, and therefore of rock velocities on nonhydrostatic loading. The high velocity of rocks under uniaxial loading appears to be compatible with, and may aid in, interpretation of near-surface velocity profiles observed in the active seismic experiment.

  15. Physical Properties of Asteroid (1917) Cuyo

    NASA Astrophysics Data System (ADS)

    Rożek, A.; Lowry, S. C.; Duddy, S. R.; Snodgrass, C.; Weissman, P. R.; Wolters, S. D.; Fitzsimmons, A.; Green, S. F.; Hicks, M. D.; Rozitis, B.

    2013-09-01

    Asteroid (1917) Cuyo is a Near-Earth Asteroid (NEA) from the Amor group. It is orbitting the Sun on a highly elongated orbit with semimajor axis 2.15 AU and eccentricity 0.504. At a low delta-V (8.6 kms-1) it could be a potential target for future spacecraft missions. Radar observations indicated a slight elongation of the object with a "breadth ratio" of the asteroid's mean cross section estimated to be 1.14 [7]. Further studies showed its rotation period to be 2.6905 ± 0.0007h [11], and it was classified as 'Sr' type in the Bus-DeMeo taxonomy [8]. Cuyo was observed as part of our ESO Large Programme. The programme includes ongoing optical photometric monitoring of selected NEAs, thermal-IR observations, and optical-NIR spectroscopy. Among the principal aims of the programme are the physical characterisation of NEAs, shape modelling, and search for YORP-induced changes in rotation periods. Here we present our latest results and analysis from our observational monitoring of (1917) Cuyo. We are conducting a broad study of this asteroid, including optical photometry and spectroscopy, and thermal-IR observations. This work is ongoing and we shall present our latest results at the meeting.

  16. Seven types of nonsexual romantic physical affection among Brigham young university students.

    PubMed

    Gulledge, Andrew K; Stahmann, Robert F; Wilson, Colwick M

    2004-10-01

    College students from Brigham Young University (N= 186; 68 men, 118 women, M age=22.7 yr., SD=3.5) completed a survey regarding nonsexual, romantic physical affection-defined as any touch intended to arouse feelings of love in the giver or the recipient. Respondents included both dating and married individuals, although this was not specified on the questionnaire. This descriptive study reports the mean, median, mode, and standard deviation for each of the seven physical affection types: backrubs/massages, caressing/stroking, cuddling/holding, holding hands, hugging, kissing on the face, and kissing on the lips. Grouped frequency distributions further describe the amounts of each type of physical affection. Although physical affection has been underrepresented in the literature, studies have shown it to be associated with relationship satisfaction, partner satisfaction, psychological intimacy, feeling understood, the development of attachment bonds, modulating cardiovascular arousal, and easier conflict resolution. PMID:15587229

  17. Physical transport properties of marine microplastic pollution

    NASA Astrophysics Data System (ADS)

    Ballent, A.; Purser, A.; Mendes, P. de Jesus; Pando, S.; Thomsen, L.

    2012-12-01

    Given the complexity of quantitative collection, knowledge of the distribution of microplastic pollution in many regions of the world ocean is patchy, both spatially and temporally, especially for the subsurface environment. However, with knowledge of typical hydrodynamic behavior of waste plastic material, models predicting the dispersal of pelagic and benthic plastics from land sources into the ocean are possible. Here we investigate three aspects of plastic distribution and transport in European waters. Firstly, we assess patterns in the distribution of plastics found in fluvial strandlines of the North Sea and how distribution may be related to flow velocities and distance from source. Second, we model transport of non-buoyant preproduction pellets in the Nazaré Canyon of Portugal using the MOHID system after assessing the density, settling velocity, critical and depositional shear stress characteristics of such waste plastics. Thirdly, we investigate the effect of surface turbulences and high pressures on a range of marine plastic debris categories (various densities, degradation states and shapes tested) in an experimental water column simulator tank and pressure laboratory. Plastics deposited on North Sea strandlines varied greatly spatially, as a function of material composition and distance from source. Model outputs indicated that such dense production pellets are likely transported up and down canyon as a function of tidal forces, with only very minor net down canyon movement. Behaviour of plastic fragments under turbulence varied greatly, with the dimensions of the material, as well as density, playing major determining roles. Pressure was shown to affect hydrodynamic behaviours of only low density foam plastics at pressures ≥ 60 bar.

  18. Maternal nutrient restriction affects properties of skeletal muscle in offspring

    PubMed Central

    Zhu, Mei J; Ford, Stephen P; Means, Warrie J; Hess, Bret W; Nathanielsz, Peter W; Du, Min

    2006-01-01

    Maternal nutrient restriction (NR) affects fetal development with long-term consequences on postnatal health of offspring, including predisposition to obesity and diabetes. Most studies have been conducted in fetuses in late gestation, and little information is available on the persistent impact of NR from early to mid-gestation on properties of offspring skeletal muscle, which was the aim of this study. Pregnant ewes were subjected to 50% NR from day 28–78 of gestation and allowed to deliver. The longissimus dorsi muscle was sampled from 8-month-old offspring. Maternal NR during early to mid-gestation decreased the number of myofibres in the offspring and increased the ratio of myosin IIb to other isoforms by 17.6 ± 4.9% (P < 0.05) compared with offspring of ad libitum fed ewes. Activity of carnitine palmitoyltransferase-1, a key enzyme controlling fatty acid oxidation, was reduced by 24.7 ± 4.5% (P < 0.05) in skeletal muscle of offspring of NR ewes and would contribute to increased fat accumulation observed in offspring of NR ewes. Intramuscular triglyceride content (IMTG) was increased in skeletal muscle of NR lambs, a finding which may be linked to predisposition to diabetes in offspring of NR mothers, since enhanced IMTG predisposes to insulin resistance in skeletal muscle. Proteomic analysis by two-dimensional gel electrophoresis demonstrated downregulation of several catabolic enzymes in 8-month-old offspring of NR ewes. These data demonstrate that the early to mid-gestation period is important for skeletal muscle development. Impaired muscle development during this stage of gestation affects the number and composition of fibres in offspring which may lead to long-term physiological consequences, including predisposition to obesity and diabetes. PMID:16763001

  19. SAPHYR: the Swiss Atlas of PHYsical properties of Rocks

    NASA Astrophysics Data System (ADS)

    Wenning, Q. C.; Zappone, A. S.; Kissling, E.

    2015-12-01

    The Swiss Atlas of PHYsical properties of Rocks (SAPHYR) is a multi-year project, aiming to compile a comprehensive data set on physical properties of rocks exposed in Switzerland and surrounding areas. The ultimate goal of SAPHYR is to make these data accessible to an open and wide public, such as industrial, engineering, land and resource planning companies, as well as academic institutions. Since the early sixties worldwide geophysicists, petrologists, and engineers, focused their work on laboratory measurements of rocks physical properties, and their relations with microstructures, mineralogical compositions and other rock parameters, in the effort to constrain the geological interpretation of geophysical surveys. In combination with efforts to investigate deep structure of the continental crust by controlled source seismology, laboratories capable to reproduce pressure and temperature conditions to depth of 50km and more collected measurements of various parameters on a wide variety of rock types. In recent years, the increasing interest on non-traditional energy supply, (deep geothermal energy, shale gas) and CO2 storage renovated the interests in physical characterization of the deep underground. The idea to organize those laboratory data into a geographically referenced database (GIS) is supported by the Swiss Commission for Geophysics. The data refer to density and porosity, seismic, magnetic, thermal properties, permeability and electrical properties. An effort has been placed on collecting samples and measuring the physical properties of lithologies that are poorly documented in literature. The phase of laboratory measurements is still in progress. At present SAPHYR focuses towards developing a 3-D physical properties model of the Swiss subsurface, using the structure of the exposed geology, boreholes data and seismic surveys, combined with lab determined pressure and temperature derivatives. An early version of the final product is presented here.

  20. Physical Properties of Hanford Transuranic Waste Sludge

    SciTech Connect

    Berg, John C.

    2005-06-01

    Equipment that was purchased in the abbreviated year 1 of this project has been used during year 2 to study the fundamental behavior of materials that simulate the behavior of the Hanford transuranic waste sludge. Two significant results have been found, and each has been submitted for publication. Both studies found non-DLVO behavior in simulant systems. These separate but related studies were performed concurrently. It was previously shown in Rassat et al.'s report Physical and Liquid Chemical Simulant Formulations for Transuranic Wastes in Hanford Single-Shell Tanks that colloidal clays behave similarly to transuranic waste sludge (PNNL-14333, National Technical Information Service, U.S. Dept. of Commerce). Rassat et al. also discussed the pH and salt content of actual waste materials. It was shown that these materials exist at high pHs, generally above 10, and at high salt content, approximately 1.5 M from a mixture of different salts. A type of clay commonly studied, due to its uniformity, is a synthetic hectorite, Laponite. Therefore the work performed over the course of the last year was done mainly using suspensions of Laponite at high pH and involving high salt concentrations. One study was titled ''Relating Clay Rheology to Colloidal Parameters''. It has been submitted to the Journal of Colloid and INterface Science and is currently in the review process. The idea was to gain the ability to use measurable quantities to predict the flow behavior of clay systems, which should be similar to transuranic waste sludge. Leong et al. had previously shown that the yield stress of colloidal slurries of titania and alumina could be predicted, given the measurement of the accessible parameter zeta potential (Leong YK et al. J Chem Soc Faraday Trans, 19 (1993) 2473). Colloidal clays have a fundamentally different morphology and surface charge distribution than the spheroidal, uniformly charged colloids previously studied. This study was therefore performed in order to

  1. Physical properties of Southern infrared dark clouds

    NASA Astrophysics Data System (ADS)

    Vasyunina, T.; Linz, H.; Henning, Th.; Stecklum, B.; Klose, S.; Nyman, L.-Å.

    2009-05-01

    Context: What are the mechanisms by which massive stars form? What are the initial conditions for these processes? It is commonly assumed that cold and dense Infrared Dark Clouds (IRDCs) represent the birth-sites of massive stars. Therefore, these clouds have been receiving an increasing amount of attention, and their analysis offers the opportunity to tackle the afore mentioned questions. Aims: To enlarge the sample of well-characterised IRDCs in the southern hemisphere, where ALMA will play a major role in the near future, we have developed a program to study the gas and dust of southern infrared dark clouds. The present paper attempts to characterize the continuum properties of this sample of IRDCs. Methods: We cross-correlated 1.2 mm continuum data from SIMBA bolometer array mounted on SEST telescope with Spitzer/GLIMPSE images to establish the connection between emission sources at millimeter wavelengths and the IRDCs that we observe at 8 μm in absorption against the bright PAH background. Analysing the dust emission and extinction enables us to determine the masses and column densities, which are important quantities in characterizing the initial conditions of massive star formation. We also evaluated the limitations of the emission and extinction methods. Results: The morphology of the 1.2 mm continuum emission is in all cases in close agreement with the mid-infrared extinction. The total masses of the IRDCs were found to range from 150 to 1150 M_⊙ (emission data) and from 300 to 1750 M_⊙ (extinction data). We derived peak column densities of between 0.9 and 4.6 × 1022 cm-2 (emission data) and 2.1 and 5.4 × 1022 cm-2 (extinction data). We demonstrate that the extinction method is unreliable at very high extinction values (and column densities) beyond AV values of roughly 75 mag according to the Weingartner & Draine (2001) extinction relation RV = 5.5 model B (around 200 mag when following the common Mathis (1990, ApJ, 548, 296) extinction calibration

  2. Germination conditions affect physicochemical properties of germinated brown rice flour.

    PubMed

    Charoenthaikij, Phantipha; Jangchud, Kamolwan; Jangchud, Anuvat; Piyachomkwan, Kuakoon; Tungtrakul, Patcharee; Prinyawiwatkul, Witoon

    2009-01-01

    Germinated brown rice has been reported to be nutritious due to increased free gamma-aminobutyric acid (GABA). The physicochemical properties of brown rice (BR) and glutinous brown rice (GNBR) after germination as affected by different steeping times (24, 36, 48, and 72 h depending on the rice variety) and pHs of steeping water (3, 5, 7, and as-is) were determined and compared to those of the nongerminated one (control). As the steeping time increased or pH of steeping water decreased, germinated brown rice flours (GBRF) from both BR and GNBR had greater reducing sugar, free GABA and alpha-amylase activity; while the total starch and viscosity were lower than their respective controls. GBRFs from both BR and GNBR prepared after 24-h steeping time at pH 3 contained a high content of free GABA at 32.70 and 30.69 mg/100 g flour, respectively. The peak viscosity of GBRF obtained from both BR and GNBR (7.42 to 228.22 and 4.42 to 58.67 RVU, respectively) was significantly lower than that of their controls (255.46 and 190.17 RVU, respectively). The principal component analysis indicated that the important variables for discriminating among GBRFs, explained by the first 2 components at 89.82% of total explained variance, were the pasting profiles, alpha-amylase activity, and free GABA. PMID:20492098

  3. Effect of composition on physical properties of food powders

    NASA Astrophysics Data System (ADS)

    Szulc, Karolina; Lenart, Andrzej

    2016-04-01

    The paper presents an influence of raw material composition and technological process applied on selected physical properties of food powders. Powdered multi-component nutrients were subjected to the process of mixing, agglomeration, coating, and drying. Wetting liquids ie water and a 15% water lactose solution, were used in agglomeration and coating. The analyzed food powders were characterized by differentiated physical properties, including especially: particle size, bulk density, wettability, and dispersibility. The raw material composition of the studied nutrients exerted a statistically significant influence on their physical properties. Agglomeration as well as coating of food powders caused a significant increase in particle size, decreased bulk density, increased apparent density and porosity, and deterioration in flowability in comparison with non-agglomerated nutrients.

  4. Investigating correlation between legal and physical property: possibilities and constraints

    NASA Astrophysics Data System (ADS)

    Dimopoulou, E.; Kitsakis, D.; Tsiliakou, E.

    2015-06-01

    Contemporary urban environment is characterized by complexity and mixed use of space, in which overlapping land parcels and different RRRs (Rights, Restrictions and Responsibilities) are frequent phenomena. Internationally, real property legislation either focuses on surface property or has introduced individual 3D real property units. The former approach merely accommodates issues related to subdivision, expropriation and transactions on part of the real property above or below surface, while the latter provides for defining and registering 3D real property units. National laws require two-dimensional real property descriptions and only a limited number of jurisdictions provide for threedimensional data presentation and recording. International awareness on 3D Cadastre may be apparent through the proposals for transition of existing cadastral systems to 3D along with legal amendments improving national 3D Cadastre legislation. Concurrently the use of appropriate data sources and the correct depiction of 3D property units' boundaries and spatial relationships need to be addressed. Spatial relations and constraints amongst real world objects could be modeled geometrically and topologically utilizing numerous modeling tools, e.g. CityGML, BIM and further sophisticated 3D software or by adapting international standards, e.g. LADM. A direct correlation between legal and physical property should be based on consistent geometry between physical and legal space, improving the accuracy that legal spaces' volumes or locations are defined. To address these issues, this paper investigates correlation possibilities and constraints between legal and physical space of typical 3D property cases. These cases comprise buildings or their interior spaces with mixed use, as well as complex structures described by explicit facade patterns, generated by procedural or by BIM ready 3D models. The 3D models presented are evaluated, regarding compliancy to physical or legal reality.

  5. GLYCOLIC ACID PHYSICAL PROPERTIES, IMPURITIES, AND RADIATION EFFECTS ASSESSMENT

    SciTech Connect

    Pickenheim, B.; Bibler, N.

    2010-06-08

    The DWPF is pursuing alternative reductants/flowsheets to increase attainment to meet closure commitment dates. In fiscal year 2009, SRNL evaluated several options and recommended the further assessment of the nitric/formic/glycolic acid flowsheet. SRNL is currently performing testing with this flowsheet to support the DWPF down-select of alternate reductants. As part of the evaluation, SRNL was requested to determine the physical properties of formic and glycolic acid blends. Blends of formic acid in glycolic acid were prepared and their physical properties tested. Increasing amounts of glycolic acid led to increases in blend density, viscosity and surface tension as compared to the 90 wt% formic acid that is currently used at DWPF. These increases are small, however, and are not expected to present any difficulties in terms of processing. The effect of sulfur impurities in technical grade glycolic acid was studied for its impact on DWPF glass quality. While the glycolic acid specification allows for more sulfate than the current formic acid specification, the ultimate impact is expected to be on the order of 0.03 wt% sulfur in glass. Note that lower sulfur content glycolic acid could likely be procured at some increased cost if deemed necessary. A paper study on the effects of radiation on glycolic acid was performed. The analysis indicates that substitution of glycolic acid for formic acid would not increase the radiolytic production rate of H{sub 2} and cause an adverse effect in the SRAT or SME process. It has been cited that glycolic acid solutions that are depleted of O{sub 2} when subjected to large radiation doses produced considerable quantities of a non-diffusive polymeric material. Considering a constant air purge is maintained in the SRAT and the solution is continuously mixed, oxygen depletion seems unlikely, however, if this polymer is formed in the SRAT solution, the rheology of the solution may be affected and pumping of the solution may be

  6. GLYCOLIC ACID PHYSICAL PROPERTIES, IMPURITIES, AND RADIATION EFFECTS ASSESSMENT

    SciTech Connect

    Lambert, D.; Pickenheim, B.; Hay, M.

    2011-06-20

    The Defense Waste Processing Facility (DWPF) is pursuing alternative reductants/flowsheets to increase attainment to meet closure commitment dates. In fiscal year 2009, SRNL evaluated several options and recommended the further assessment of the nitric/formic/glycolic acid flowsheet. SRNL is currently performing testing with this flowsheet to support the DWPF down-select of alternate reductants. As part of the evaluation, SRNL was requested to determine the physical properties of formic and glycolic acid blends. Blends of formic acid in glycolic acid were prepared and their physical properties tested. Increasing amounts of glycolic acid led to increases in blend density, viscosity and surface tension as compared to the 90 wt% formic acid that is currently used at DWPF. These increases are small, however, and are not expected to present any difficulties in terms of processing. The effect of sulfur impurities in technical grade glycolic acid was studied for its impact on DWPF glass quality. While the glycolic acid specification allows for more sulfate than the current formic acid specification, the ultimate impact is expected to be on the order of 0.03 wt% sulfur in glass. Note that lower sulfur content glycolic acid could likely be procured at some increased cost if deemed necessary. A paper study on the effects of radiation on glycolic acid was performed. The analysis indicates that substitution of glycolic acid for formic acid would not increase the radiolytic production rate of H{sub 2} and cause an adverse effect in the SRAT or SME process. It has been cited that glycolic acid solutions that are depleted of O{sub 2} when subjected to large radiation doses produced considerable quantities of a non-diffusive polymeric material. Considering a constant air purge is maintained in the SRAT and the solution is continuously mixed, oxygen depletion seems unlikely, however, if this polymer is formed in the SRAT solution, the rheology of the solution may be affected and

  7. Physical properties about metal matrix FGM of molybdenum and copper

    SciTech Connect

    Nakano, Kouichi; Nishida, Shinichi

    1995-11-01

    Metal matrix composites (MMC) have been made trials to produce by a lot of fabrication processes such as the powder metallurgical method, the plasma spraying, the diffusion bonding, the physical vapor deposition method, the hot isostatic pressing (HIP) etc. In the most cases of these processes, dissimilar materials are combined or bonded directly. The various physical properties are discontinuous at the bonded interface of the dissimilar materials. In order to overcome the problem, functionally gradient materials (FGM) have been considered recently, and have attracted the authors. Its compositions are prepared so that physical properties continuously vary across the bond interface of the dissimilar metals. In this study, a FGM is produced by a new process based on HIP. Copper and molybdenum, which are distinct in the thermo-physical property to each other, are the constitutents for the FGM. This composition have been confirmed by absorbed electron and characteristics X-ray images of each mixed layer for FGM to be uniform or continuous. The following items have been investigated and compared with the linear law of mixture rule: Vickers hardness, thermal expansion, and thermal conductivity at a one-dimensional non-steady state. Those physical properties have been identified to depend on the mixing ratios of copper and molybdenum. Pretty good agreements have been obtained between the experimental data and the calculated values according to the linear law of mixture rule.

  8. Use of ultrasound to monitor physical properties of soybean oil

    NASA Astrophysics Data System (ADS)

    Baêsso, R. M.; Oliveira, P. A.; Morais, G. C.; Alvarenga, A. V.; Costa-Félix, R. P. B.

    2016-07-01

    The study of the monitoring physical properties of soybean oil was performed. The pulse-echo method allowed measuring the density and viscosity of the oil in real time and accurately. The physical property values were related to the acoustic time of flight ratio, dimensionless parameter that can be obtained from any reference. In our case, we used the time of flight at 20°C as reference and a fixed distance between the transducer and the reflector. Ultrasonic monitoring technique employed here has shown promising in the analysis of edible oils.

  9. Aerosol physical properties in the stratosphere (APPS) radiometer design

    NASA Technical Reports Server (NTRS)

    Gray, C. R.; Woodin, E. A.; Anderson, T. J.; Magee, R. J.; Karthas, G. W.

    1977-01-01

    The measurement concepts and radiometer design developed to obtain earth-limb spectral radiance measurements for the Aerosol Physical Properties in the Stratosphere (APPS) measurement program are presented. The measurements made by a radiometer of this design can be inverted to yield vertical profiles of Rayleigh scatterers, ozone, nitrogen dioxide, aerosol extinction, and aerosol physical properties, including a Junge size-distribution parameter, and a real and imaginary index of refraction. The radiometer design provides the capacity for remote sensing of stratospheric constituents from space on platforms such as the space shuttle and satellites, and therefore provides for global measurements on a daily basis.

  10. Plant diversity and root traits benefit physical properties key to soil function in grasslands.

    PubMed

    Gould, Iain J; Quinton, John N; Weigelt, Alexandra; De Deyn, Gerlinde B; Bardgett, Richard D

    2016-09-01

    Plant diversity loss impairs ecosystem functioning, including important effects on soil. Most studies that have explored plant diversity effects belowground, however, have largely focused on biological processes. As such, our understanding of how plant diversity impacts the soil physical environment remains limited, despite the fundamental role soil physical structure plays in ensuring soil function and ecosystem service provision. Here, in both a glasshouse and a long-term field study, we show that high plant diversity in grassland systems increases soil aggregate stability, a vital structural property of soil, and that root traits play a major role in determining diversity effects. We also reveal that the presence of particular plant species within mixed communities affects an even wider range of soil physical processes, including hydrology and soil strength regimes. Our results indicate that alongside well-documented effects on ecosystem functioning, plant diversity and root traits also benefit essential soil physical properties.

  11. Plant diversity and root traits benefit physical properties key to soil function in grasslands.

    PubMed

    Gould, Iain J; Quinton, John N; Weigelt, Alexandra; De Deyn, Gerlinde B; Bardgett, Richard D

    2016-09-01

    Plant diversity loss impairs ecosystem functioning, including important effects on soil. Most studies that have explored plant diversity effects belowground, however, have largely focused on biological processes. As such, our understanding of how plant diversity impacts the soil physical environment remains limited, despite the fundamental role soil physical structure plays in ensuring soil function and ecosystem service provision. Here, in both a glasshouse and a long-term field study, we show that high plant diversity in grassland systems increases soil aggregate stability, a vital structural property of soil, and that root traits play a major role in determining diversity effects. We also reveal that the presence of particular plant species within mixed communities affects an even wider range of soil physical processes, including hydrology and soil strength regimes. Our results indicate that alongside well-documented effects on ecosystem functioning, plant diversity and root traits also benefit essential soil physical properties. PMID:27459206

  12. Spatial variability of snow physical properties across northwestern Greenland

    NASA Astrophysics Data System (ADS)

    Courville, Z.; Polashenski, C.; Dibb, J. E.; Domine, F.

    2013-12-01

    In the late spring and early summer of 2013, researchers on the SAGE (Sunlight Absorption on the Greenland ice sheet Experiment) Traverse, embarked on a 4000 km ground traverse across northwestern Greenland in an attempt to quantify spatial variability of snow chemistry, snow physical properties, and snow reflectance. The field team targeted sites first visited by Carl Benson during his series of traverses from 1952 to 1955 as part of his pioneering work to characterize the Greenland Ice Sheet. This route now represents a rapidly changing and variable area of Greenland, as the route passes through several of the ice sheet facies first delimited by Benson. Along the traverse, the SAGE field team made ground-based albedo measurements using a hand-held spectroradiometer and collected snow physical property samples to determine snow specific surface area (SSA) from shallow, 2m pits. In addition, snow density and stratigraphy were measured. Snow layers in the near-surface and at the previous season's melt layer were targeted for sampling. Here we present preliminary snow physical property results from the upper portion of the snow pits and relate these to surface albedo data collected over the route. Further measurements of snow properties in the 2012 melt layer will be analyzed to assess the potential role of snow chemical (see Dibb et al. for a discussion of chemical analysis) and physical property driven albedo feedbacks could have played in contributing to that event. Route of 2013 SAGE Traverse in northwestern Greenland.

  13. Reconciling the Orbital and Physical Properties of the Martian Moons

    NASA Astrophysics Data System (ADS)

    Ronnet, T.; Vernazza, P.; Mousis, O.; Brugger, B.; Beck, P.; Devouard, B.; Witasse, O.; Cipriani, F.

    2016-09-01

    The origin of Phobos and Deimos is still an open question. Currently, none of the three proposed scenarios for their origin (intact capture of two distinct outer solar system small bodies, co-accretion with Mars, and accretion within an impact-generated disk) are able to reconcile their orbital and physical properties. Here we investigate the expected mineralogical composition and size of the grains from which the moons once accreted assuming they formed within an impact-generated accretion disk. A comparison of our results with the present-day spectral properties of the moons allows us to conclude that their building blocks cannot originate from a magma phase, thus preventing their formation in the innermost part of the disk. Instead, gas-to-solid condensation of the building blocks in the outer part of an extended gaseous disk is found as a possible formation mechanism as it does allow reproducing both the spectral and physical properties of the moons. Such a scenario may finally reconcile their orbital and physical properties, alleviating the need to invoke an unlikely capture scenario to explain their physical properties.

  14. Drive for thinness, affect regulation and physical activity in eating disorders: a daily life study.

    PubMed

    Vansteelandt, Kristof; Rijmen, Frank; Pieters, Guido; Probst, Michel; Vanderlinden, Johan

    2007-08-01

    Using Ecological Momentary Assessment, the within patient associations between drive for thinness, emotional states, momentary urge to be physically active and physical activity were studied in 32 inpatients with an eating disorder. Participants received an electronic device and had to indicate at nine random times a day during 1 week their momentary drive for thinness, positive and negative emotional states and their urge to be physically active and physical activity. Multilevel analyses indicated that patients with higher mean levels for urge to be physically active were characterized by lower body mass index (BMI) and chronically negative affect whereas patients with higher mean levels for physical activity were characterized by lower BMI and higher dispositions for drive for thinness. In addition, within patient relations between drive for thinness and urge to be physically active were moderated by BMI and chronically negative affect whereas within patient relations between drive for thinness and physical activity were moderated by BMI. Finally, also positive emotional states were significantly associated with physical activity within patients. By using a daily process design, characteristics of physical activity were revealed that have not been identified with assessment methods that have a lower time resolution.

  15. Momentary Affective States Are Associated with Momentary Volume, Prospective Trends, and Fluctuation of Daily Physical Activity

    PubMed Central

    Kanning, Martina K.; Schoebi, Dominik

    2016-01-01

    Several interventions aiming to enhance physical activity in everyday life showed mixed effects. Affective constructs are thought to potentially support health behavior change. However, little is known about within-subject associations between momentary affect and subsequent physical activity in everyday life. This study analyzed the extent to which three dimensions of affective states (valence, calmness, and energetic arousal) were associated with different components of daily activity trajectories. Sixty-five undergraduates’ students (Age: M = 24.6; SD = 3.2; females: 57%) participated in this study. Physical activity was assessed objectively through accelerometers during 24 h. Affective states assessments were conducted randomly every 45 min using an e-diary with a six-item mood scale that was especially designed for ambulatory assessment. We conducted three-level multi-level analyses to investigate the extent to which momentary affect accounted for momentary volume, prospective trends, and stability vs. fluctuation of physical activity in everyday life. All three affect dimensions were significantly associated with momentary activity volumes and prospective trends over 45 min periods. Physical activity didn’t fluctuate freely, but featured significant autocorrelation across repeated measurements, suggesting some stability of physical activity across 5-min assessments. After adjusting for the autoregressive structure in physical activity assessments, only energetic arousal remained a significant predictor. Feeling energized and awake was associated with an increased momentary volume of activity and initially smaller but gradually growing decreases in subsequent activity within the subsequent 45 min. Although not related to trends in physical activity, higher valence predicted lower stability in physical activity across subsequent 45 min, suggesting more short-term fluctuations in daily activity the more participants reported positive affective valence. The

  16. Situational motivation and perceived intensity: their interaction in predicting changes in positive affect from physical activity.

    PubMed

    Guérin, Eva; Fortier, Michelle S

    2012-01-01

    There is evidence that affective experiences surrounding physical activity can contribute to the proper self-regulation of an active lifestyle. Motivation toward physical activity, as portrayed by self-determination theory, has been linked to positive affect, as has the intensity of physical activity, especially of a preferred nature. The purpose of this experimental study was to examine the interaction between situational motivation and intensity [i.e., ratings of perceived exertion (RPE)] in predicting changes in positive affect following an acute bout of preferred physical activity, namely, running. Fourty-one female runners engaged in a 30-minute self-paced treadmill run in a laboratory context. Situational motivation for running, pre- and post-running positive affect, and RPE were assessed via validated self-report questionnaires. Hierarchical regression analyses revealed a significant interaction effect between RPE and introjection (P < .05) but not between RPE and identified regulation or intrinsic motivation. At low levels of introjection, the influence of RPE on the change in positive affect was considerable, with higher RPE ratings being associated with greater increases in positive affect. The implications of the findings in light of SDT principles as well as the potential contingencies between the regulations and RPE in predicting positive affect among women are discussed.

  17. Situational Motivation and Perceived Intensity: Their Interaction in Predicting Changes in Positive Affect from Physical Activity

    PubMed Central

    Guérin, Eva; Fortier, Michelle S.

    2012-01-01

    There is evidence that affective experiences surrounding physical activity can contribute to the proper self-regulation of an active lifestyle. Motivation toward physical activity, as portrayed by self-determination theory, has been linked to positive affect, as has the intensity of physical activity, especially of a preferred nature. The purpose of this experimental study was to examine the interaction between situational motivation and intensity [i.e., ratings of perceived exertion (RPE)] in predicting changes in positive affect following an acute bout of preferred physical activity, namely, running. Fourty-one female runners engaged in a 30-minute self-paced treadmill run in a laboratory context. Situational motivation for running, pre- and post-running positive affect, and RPE were assessed via validated self-report questionnaires. Hierarchical regression analyses revealed a significant interaction effect between RPE and introjection (P < .05) but not between RPE and identified regulation or intrinsic motivation. At low levels of introjection, the influence of RPE on the change in positive affect was considerable, with higher RPE ratings being associated with greater increases in positive affect. The implications of the findings in light of SDT principles as well as the potential contingencies between the regulations and RPE in predicting positive affect among women are discussed. PMID:22778914

  18. Effects of Tillage, Rotation and Cover Crop on the Physical Properties of a Silt-Loam Soil

    NASA Astrophysics Data System (ADS)

    Haruna, Samuel Idoko; Nkongolo, Nsalambi Vakanda

    2015-04-01

    Soil and crop management practices can affect the physical properties and have a direct impact on soil sustainability and crop performance. The objective of this study was to investigate how soil physical properties were affected by three years of tillage, cover crop and crop rotation treatments in a corn and soybean field. The study was conducted on a Waldron siltyloam soil at Lincoln University of Missouri. Soil physical properties studied were soil bulk density, volumetric and gravimetric water contents, volumetric air content, total pore space, air-filled and water-filled pore space, gas diffusion coefficient and pore tortuosity factor. Results showed significant interactions (p<0.05) between cover crop and crop rotation for bulk density, gravimetric and total pore space in 2013. In addition, cover crop also significantly interacted (p<0.05) with tillage for bulk density and total pore space. All soil physical properties studied were significantly affected by the depth of sampling (p<0.0001), except for bulk density, the pore tortuosity factor and total pore space in 2012, and gravimetric and volumetric in 2013. Overall, soil physical properties were significantly affected by the treatments, with the effects changing from one year to another. Addition of a cover crop improved soil physical properties better in rotation than in monoculture.

  19. How Vision Affects Kinematic Properties of Pantomimed Prehension Movements

    PubMed Central

    Fukui, Takao; Inui, Toshio

    2013-01-01

    When performing the reach-to-grasp movement, fingers open wider than the size of a target object and then stop opening. The recorded peak grip aperture (PGA) is significantly larger when this action is performed without vision during the movement than with vision, presumably due to an error margin that is retained in order to avoid collision with the object. People can also pretend this action based on an internal target representation (i.e., pantomimed prehension), and previous studies have shown that kinematic differences exist between natural and pantomimed prehension. These differences are regarded as a reflection of variations in information processing in the brain through the dorsal and ventral streams. Pantomimed action is thought to be mediated by the ventral stream. This implies that visual information during the movement, which is essential to the dorsal stream, has little effect on the kinematic properties of pantomimed prehension. We investigated whether an online view of the external world affects pantomimed grasping, and more specifically, whether the dorsal stream is involved in its execution. Participants gazed at a target object and were then subjected to a 3-s visual occlusion, during which time the experimenter removed the object. The participants were then required to pretend to make a reach-to-grasp action toward the location where the object had been presented. Two visual conditions (full vision and no vision) were imposed during the pantomimed action by manipulating shutter goggles. The PGA showed significant differences between the two visual conditions, whereas no significant difference was noted for terminal grip aperture, which was recorded at the movement end. This suggests the involvement of the dorsal stream in pantomimed action and implies that pantomimed prehension is a good probe for revealing the mechanism of interaction between the ventral and dorsal streams, which is also linked to embodied cognition. PMID:23404470

  20. Hydrate morphology: Physical properties of sands with patchy hydrate saturation

    USGS Publications Warehouse

    Dai, S.; Santamarina, J.C.; Waite, William F.; Kneafsey, T.J.

    2012-01-01

    The physical properties of gas hydrate-bearing sediments depend on the volume fraction and spatial distribution of the hydrate phase. The host sediment grain size and the state of effective stress determine the hydrate morphology in sediments; this information can be used to significantly constrain estimates of the physical properties of hydrate-bearing sediments, including the coarse-grained sands subjected to high effective stress that are of interest as potential energy resources. Reported data and physical analyses suggest hydrate-bearing sands contain a heterogeneous, patchy hydrate distribution, whereby zones with 100% pore-space hydrate saturation are embedded in hydrate-free sand. Accounting for patchy rather than homogeneous hydrate distribution yields more tightly constrained estimates of physical properties in hydrate-bearing sands and captures observed physical-property dependencies on hydrate saturation. For example, numerical modeling results of sands with patchy saturation agree with experimental observation, showing a transition in stiffness starting near the series bound at low hydrate saturations but moving toward the parallel bound at high hydrate saturations. The hydrate-patch size itself impacts the physical properties of hydrate-bearing sediments; for example, at constant hydrate saturation, we find that conductivity (electrical, hydraulic and thermal) increases as the number of hydrate-saturated patches increases. This increase reflects the larger number of conductive flow paths that exist in specimens with many small hydrate-saturated patches in comparison to specimens in which a few large hydrate saturated patches can block flow over a significant cross-section of the specimen.

  1. Examining the construct validity of affective judgments of physical activity measures.

    PubMed

    Chmielewski, Michael; Sala, Margarita; Tang, Rui; Baldwin, Austin

    2016-09-01

    Affective judgments of physical activity have emerged as important predictors of physical activity and interventions targeting affective judgments are a promising approach to improving regular physical activity. Currently, measures assessing a variety of potentially distinct constructs are treated as interchangeable assessments of affective judgments of physical activity. Moreover, little is known about the construct validity of the purported measures of this construct. We review several components of construct validity; highlighting their importance for health psychology research. Then, we examine the construct validity of a wide variety of affective judgment of physical activity measures in MTurk and student samples. Cronbach's alpha for the included measures was uniformly high; however, several scales contained excessively redundant items that ultimately lessen their construct validity. Moreover, dependability estimates for the majority of measures was poor, indicating high levels of transient measurement error. The included measures significantly predicted levels of physical activity; however, their relative predictive power was strongly associated with their dependability. In general, the affective judgment measures demonstrated poor convergent validity suggesting they are not interchangeable and best viewed as assessing distinct, albeit related, constructs. Another important limitation of these measures is that they exhibited poor discriminant validity from exercise self-efficacy, which represents an important theoretical and empirical issue for the field of health behavior research. Overall, the current findings indicate the available affective judgments of physical activity measures are suboptimal, have considerable construct validity limitations, and thereby prevent the further advancement of science, theory, and intervention development in this promising area of research. (PsycINFO Database Record PMID:27537007

  2. Physical properties of sediment containing methane gas hydrate

    USGS Publications Warehouse

    Winters, W.J.; Waite, W.F.; Mason, D.H.; Gilbert, L.Y.

    2005-01-01

    A study conducted by the US Geological Survey (USGS) on the formation, behavior, and properties of mixtures of gas hydrate and sediment is presented. The results show that the properties of host material influence the type and quantity of hydrates formed. The presence of hydrate during mechanical shear tests affects the measured sediment pore pressure. Sediment shear strength may be increased more than 500 percent by intact hydrate, but greatly weakened if the hydrate dissociates.

  3. Physical property characterization of 183-H Basin sludge

    SciTech Connect

    Biyani, R.K.; Delegard, C.H.

    1995-09-20

    This document describes the characterization of 183-H Basin sludge physical properties, e.g. bulk density of sludge and absorbent, and determination of free liquids. Calcination of crucible-size samples of sludge was also done and the resulting `loss-on-ignition` was compared to the theoretical weight loss based on sludge analysis obtained from Weston Labs.

  4. Mechanical and physical properties of modern boron fibers

    NASA Technical Reports Server (NTRS)

    Dicarlo, J. A.

    1978-01-01

    The results of accurate measurements of the modern boron fiber's Young's modulus, flexural modulus, shear modulus, and Poisson's ratio are reported. Physical property data concerning fiber density, thermal expansion, and resistance obtained during the course of the mechanical studies are also given.

  5. Physical Properties of Meteorite Falls in Relation to Planetary Defense

    NASA Astrophysics Data System (ADS)

    Ostrowski, D.; Sears, D. W. G.; Bryson, K.; Agrawal, P.

    2015-07-01

    NASA ARC has set up a new lab to study a suite of physical properties of all types of meteorite falls. This is aide to the Planetary Defense initiative at Ames in determining how to deflect or the impact outcome of potentially hazardous bodies.

  6. Physical and Chemical Properties of Anthropogenic Aerosols: An overview

    EPA Science Inventory

    A wide variety of anthropogenic sources emit fine aerosols to the atmosphere. The physical and chemical properties of these aerosols are of interest due to their influence on climate, human health, and visibility. Aerosol chemical composition is complex. Combustion aerosols can c...

  7. Characterization of physical and aerodynamic properties of walnuts

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objective of this research was to study the physical and aerodynamic properties of freshly harvested walnuts. Measurements were carried out for three walnut varieties, Tulare, Howard and Chandler cultivated in California, USA. The nuts treated with and without Ethephon were collected from mechan...

  8. IMPROVED PHYSICAL PROPERTIES OF ZEIN USING GLYOXAL AS A CROSSLINKER

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The effect of crosslinkers glyoxal, methylglyoxal and formaldehyde on physical properties of zein films was studied. Zein was solubilized in 90%(v/v) aqueous ethanol and the pH was adjusted with either hydrochloric acid or sodium hydroxide. Crosslinkers were added to 0.3, 1, 3 and 6%(w/w by zein w...

  9. IMPROVED PHYSICAL PROPERTIES OF ZEIN USING GLYOXAL AS A CROSSLINKER

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The effect of crosslinkers glyoxal, methylglyoxal and formaldehyde on physical properties of zein films was studied. Crosslinker concentrations varied from 0.3 to 6% by zein weight. Films crosslinked with glyoxal and formaldehyde showed a significant increase in tensile strength under certain pH c...

  10. Effect of adjuvant physical properties on spray characteristics

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The effects of adjuvant physical properties on spray characteristics were studied. Dynamic surface tension was measured with a Sensa Dyne surface tensiometer 6000 using the maximum bubble pressure method. Viscosity was measured with a Brookfield synchro-lectric viscometer model LVT using a UL adap...

  11. Geology and physical properties of the Monterey Formation, California

    SciTech Connect

    Isaacs, C.M.

    1984-04-01

    Original sediments of the Monterey Formation have diverse compositions reflecting both paleobasin setting (fine detritus) and oceanographic productivity (silica/carbonate). Varying stages of diagenesis, which includes silica phase transformations and dolomitization, have produced fractured reservoirs characterized by a complex array of rock types with a wide range of physical properties.

  12. Physical Properties of Cell Water in Partially Dried Saccharomyces cerevisiae

    PubMed Central

    Koga, Shozo; Echigo, Akira; Nunomura, Kazuko

    1966-01-01

    The equilibrium vapor pressure, the heat of vaporization, the dielectric increment, and the NMR spectra of partially dried cells were studied in Saccharomyces cerevisiae with water contents varying in the range from 25 to 0.8%. The comparative study of those physical properties suggests that physical states of the microbe can be classified into four regions in accordance with the states of the cell water: the solution region, the gel region, the mobile adsorption region, and the localized water region. Much difference in the physiological properties is found between the cells in the solution region and those in the gel region, whereas the pattern changes in physical properties take place when the cells in the gel region are dried to a further extent into the mobile or the localized region. The various modes in the molecular motion of the cell water reflected in those physical properties of the cell seem to give some insight into the biological functions of the molecule in the native as well as the dried states of the cell. PMID:5970569

  13. Physical properties of biological entities: an introduction to the ontology of physics for biology.

    PubMed

    Cook, Daniel L; Bookstein, Fred L; Gennari, John H

    2011-01-01

    As biomedical investigators strive to integrate data and analyses across spatiotemporal scales and biomedical domains, they have recognized the benefits of formalizing languages and terminologies via computational ontologies. Although ontologies for biological entities-molecules, cells, organs-are well-established, there are no principled ontologies of physical properties-energies, volumes, flow rates-of those entities. In this paper, we introduce the Ontology of Physics for Biology (OPB), a reference ontology of classical physics designed for annotating biophysical content of growing repositories of biomedical datasets and analytical models. The OPB's semantic framework, traceable to James Clerk Maxwell, encompasses modern theories of system dynamics and thermodynamics, and is implemented as a computational ontology that references available upper ontologies. In this paper we focus on the OPB classes that are designed for annotating physical properties encoded in biomedical datasets and computational models, and we discuss how the OPB framework will facilitate biomedical knowledge integration.

  14. Acute physical exercise affected processing efficiency in an auditory attention task more than processing effectiveness.

    PubMed

    Dutke, Stephan; Jaitner, Thomas; Berse, Timo; Barenberg, Jonathan

    2014-02-01

    Research on effects of acute physical exercise on performance in a concurrent cognitive task has generated equivocal evidence. Processing efficiency theory predicts that concurrent physical exercise can increase resource requirements for sustaining cognitive performance even when the level of performance is unaffected. This hypothesis was tested in a dual-task experiment. Sixty young adults worked on a primary auditory attention task and a secondary interval production task while cycling on a bicycle ergometer. Physical load (cycling) and cognitive load of the primary task were manipulated. Neither physical nor cognitive load affected primary task performance, but both factors interacted on secondary task performance. Sustaining primary task performance under increased physical and/or cognitive load increased resource consumption as indicated by decreased secondary task performance. Results demonstrated that physical exercise effects on cognition might be underestimated when only single task performance is the focus.

  15. Physical and related sensory properties of a swallowable bolus.

    PubMed

    Loret, C; Walter, M; Pineau, N; Peyron, M A; Hartmann, C; Martin, N

    2011-10-24

    Rheology and water content properties of cereal boluses collected just before swallowing were investigated. No specific physical markers for swallowing were found between subjects. Each subject had his own mastication strategy leading to food boluses with different rheological and water content properties. However, for most of the subjects, similar physical properties were found for food boluses obtained from consumption of different cereals. Results showed that the food boluses from different cereals exhibited gel-like properties being in a range from 14.1 kPa to 21.2 kPa (G'(1 Hz, 0.4%)), when swallowed. The food boluses had a static yield stress varying from 1.3 kPa to 4.3 kPa. Another interesting finding was that the water content of food boluses might be an important marker for swallowing since it was similar for different cereal food boluses (around 50%). This physical property might drive the fluid sensory perception, which could also be a sensory swallowing threshold. PMID:21620879

  16. Physical and mechanical properties of the lunar soil (a review)

    NASA Astrophysics Data System (ADS)

    Slyuta, E. N.

    2014-09-01

    We review the data on the physical and mechanical properties of the lunar soil that were acquired in the direct investigations on the lunar surface carried out in the manned and automatic missions and in the laboratory examination of the lunar samples returned to the Earth. In justice to the American manned program Apollo, we show that a large volume of the data on the properties of the lunar soil was also obtained in the Soviet automatic program Lunokhod and with the automatic space stations Luna-16, -20, and -24 that returned the lunar soil samples to the Earth. We consider all of the main physical and mechanical properties of the lunar soil, such as the granulometric composition, density and porosity, cohesion and adhesion, angle of internal friction, shear strength of loose soil, deformation characteristics (the deformation modulus and Poisson ratio), compressibility, and the bearing capacity, and show the change of some properties versus the depth. In most cases, the analytical dependence of the main parameters is presented, which is required in developing reliable engineering models of the lunar soil. The main physical and mechanical properties are listed in the summarizing table, and the currently available models and simulants of the lunar soil are reviewed.

  17. Physical Properties of Five Brands of K-Files

    PubMed Central

    Izadi, Arash; Shahravan, Arash; Shabani Nejad, Hoda

    2016-01-01

    Introduction: Endodontic K-files are major tools for cleaning and shaping of the root canal systems. As there are various K-files available in Iranian market, the physical properties of the five available brands were investigated to assist the clinician when selecting suitable endodontic K-files according to the intended application. Materials and Methods: Physical properties (including debris creation, machinery defect and corrosion) of the selected K-files were investigated by a scanning electron microscope (SEM) under ×250 magnification. For evaluating the flutes number, a stereomicroscope was used with ×40 magnification. Results: Maximum and minimum debris and corrosion were observed in the Larmrose and Perfect K-files, respectively. Dentsply showed the least machinery defects. Other brands had intermediary properties. In addition, Larmrose K-files showed the maximum flutes number compared to the other brands. Conclusion: According to the results, none of the K-files had the ideal properties. More studies regarding the physical properties of the K-files and their clinical efficacy are suggested. PMID:27141219

  18. Process depending morphology and resulting physical properties of TPU

    SciTech Connect

    Frick, Achim Spadaro, Marcel

    2015-12-17

    Thermoplastic polyurethane (TPU) is a rubber like material with outstanding properties, e.g. for seal applications. TPU basically provides high strength, low frictional behavior and excellent wear resistance. Though, due to segmented structure of TPU, which is composed of hard segments (HSs) and soft segments (SSs), physical properties depend strongly on the morphological arrangement of the phase separated HSs at a certain ratio of HSs to SSs. It is obvious that the TPU deforms differently depending on its bulk morphology. Basically, the morphology can either consist of HSs segregated into small domains, which are well dispersed in the SS matrix or of few strongly phase separated large size HS domains embedded in the SS matrix. The morphology development is hardly ruled by the melt processing conditions of the TPU. Depending on the morphology, TPU provides quite different physical properties with respect to strength, deformation behavior, thermal stability, creep resistance and tribological performance. The paper deals with the influence of important melt processing parameters, such as temperature, pressure and shear conditions, on the resulting physical properties tested by tensile and relaxation experiments. Furthermore the morphology is studied employing differential scanning calorimeter (DSC), transmission light microscopy (TLM), scanning electron beam microscopy (SEM) and transmission electron beam microscopy (TEM) investigations. Correlations between processing conditions and resulting TPU material properties are elaborated. Flow and shear simulations contribute to the understanding of thermal and flow induced morphology development.

  19. Aqueous aerosol SOA formation: impact on aerosol physical properties.

    PubMed

    Woo, Joseph L; Kim, Derek D; Schwier, Allison N; Li, Ruizhi; McNeill, V Faye

    2013-01-01

    Organic chemistry in aerosol water has recently been recognized as a potentially important source of secondary organic aerosol (SOA) material. This SOA material may be surface-active, therefore potentially affecting aerosol heterogeneous activity, ice nucleation, and CCN activity. Aqueous aerosol chemistry has also been shown to be a potential source of light-absorbing products ("brown carbon"). We present results on the formation of secondary organic aerosol material in aerosol water and the associated changes in aerosol physical properties from GAMMA (Gas-Aerosol Model for Mechanism Analysis), a photochemical box model with coupled gas and detailed aqueous aerosol chemistry. The detailed aerosol composition output from GAMMA was coupled with two recently developed modules for predicting a) aerosol surface tension and b) the UV-Vis absorption spectrum of the aerosol, based on our previous laboratory observations. The simulation results suggest that the formation of oligomers and organic acids in bulk aerosol water is unlikely to perturb aerosol surface tension significantly. Isoprene-derived organosulfates are formed in high concentrations in acidic aerosols under low-NO(x) conditions, but more experimental data are needed before the potential impact of these species on aerosol surface tension may be evaluated. Adsorption of surfactants from the gas phase may further suppress aerosol surface tension. Light absorption by aqueous aerosol SOA material is driven by dark glyoxal chemistry and is highest under high-NO(x) conditions, at high relative humidity, in the early morning hours. The wavelength dependence of the predicted absorption spectra is comparable to field observations and the predicted mass absorption efficiencies suggest that aqueous aerosol chemistry can be a significant source of aerosol brown carbon under urban conditions. PMID:24601011

  20. Biomedically relevant chemical and physical properties of coal combustion products.

    PubMed Central

    Fisher, G L

    1983-01-01

    The evaluation of the potential public and occupational health hazards of developing and existing combustion processes requires a detailed understanding of the physical and chemical properties of effluents available for human and environmental exposures. These processes produce complex mixtures of gases and aerosols which may interact synergistically or antagonistically with biological systems. Because of the physicochemical complexity of the effluents, the biomedically relevant properties of these materials must be carefully assessed. Subsequent to release from combustion sources, environmental interactions further complicate assessment of the toxicity of combustion products. This report provides an overview of the biomedically relevant physical and chemical properties of coal fly ash. Coal fly ash is presented as a model complex mixture for health and safety evaluation of combustion processes. PMID:6337824

  1. Gas diffusion and physical property investigations for polar firn

    NASA Astrophysics Data System (ADS)

    Adolph, A. C.; Albert, M. R.

    2012-12-01

    Improved understanding of physical and gas transport properties of firn and their controls on interstitial gas diffusion would inform ice core interpretation and snow/atmosphere exchange processes. In particular, gas diffusivity is relevant in the important calculation of gas age/ice age differences, but extensive direct measurements of gas diffusivity of firn have not been made. This paper describes an investigation that relates gas diffusivity and permeability based on measurements of the physical properties of firn over a wide range of density. Gas diffusivity and permeability measurements were made on a set of homogeneous samples from varying depths between the surface and pore close-off at Summit, Greenland. Microstructural properties were obtained using Micro-CT measurements. Correlations between our findings and firn densification processes are examined.

  2. Physical and Electronic Properties Changed by Aging Plutonium

    SciTech Connect

    Chung, B W; Tobin, J G; Thompson, S R; Ebbinghaus, B B

    2005-03-22

    Plutonium, because of its radioactive nature, ages from the ''inside out'' by means of self-irradiation damage and thus produces Frankel-type defects and defect clusters. The defects resulting from the residual lattice damage and helium in-growth could result in microstructural, electronic, and physical property changes. This paper presents volume, density, and electronic property change observed from both naturally and accelerated aged plutonium alloys. Accelerated alloys are plutonium alloys with a fraction of Pu-238 to accelerate the aging process by approximately 18 times the rate of unaged weapons-grade plutonium. After thirty-five equivalent years of aging on accelerated alloys, the samples have swelled in volume by approximately 0.1% and now exhibit a near linear volume increase due to helium in-growth. We will correlate the physical property changes to the electronic structure of plutonium observed by the resonant photoelectron spectroscopy (RESPES).

  3. Influence of surface and subsurface tillage on soil physical properties and soil/plant relationships of planted loblolly pine

    SciTech Connect

    D. L. Kelting; H. L. Allen

    2000-05-01

    Soil tillage can improve tree survival and growth by reducing competing vegetation, increasing nutrient availability, improving planting quality, and improving soil physical properties. The authors conducted a tillage study with competition control and nutrient amendments to isolate the physical effects of tillage on tree growth. The objectives of this study were to understand: (1) how tillage affects soil physical properties; (2) the relationships between these properties and root growth; (3) linkages between root growth response and aboveground growth; and (4) tillage effects on aboveground growth. Four replicates of a 2x2 factorial combination of surface (disking) and subsurface (subsoiling) were installed on a well-drained, clay-textured subsoil, soil located on the Piedmont of North Carolina. Disking improved soil physical properties (reduced bulk density and increased aeration porosity) in the surface 20-cm of soil. Subsoiling improved soil physical properties at all depths in the planting row, with improvements still noted at 60-cm from the planting row in the surface 10-cm of soil. Rooting patterns followed the changes in soil physical properties. Despite improvements in soil physical properties and changes in rooting patterns, aboveground tree growth was not affected by tillage. The results of this study point to the need for better diagnostics for identifying sites were tillage is appropriate in situations where fertilization and vegetation control are planned. Potential factors to consider are presence and abundance of old root channels, soil shrink/swell capacity, soil structure, presence and depth to root restricting layers, and historical precipitation records.

  4. Direct Comparison of Physical Properties of Bacillus subtilis NCIB 3610 and B-1 Biofilms

    PubMed Central

    Kesel, Sara; Grumbein, Stefan; Gümperlein, Ina; Tallawi, Marwa; Marel, Anna-Kristina

    2016-01-01

    Many bacteria form surface-attached communities known as biofilms. Due to the extreme resistance of these bacterial biofilms to antibiotics and mechanical stresses, biofilms are of growing interest not only in microbiology but also in medicine and industry. Previous studies have determined the extracellular polymeric substances present in the matrix of biofilms formed by Bacillus subtilis NCIB 3610. However, studies on the physical properties of biofilms formed by this strain are just emerging. In particular, quantitative data on the contributions of biofilm matrix biopolymers to these physical properties are lacking. Here, we quantitatively investigated three physical properties of B. subtilis NCIB 3610 biofilms: the surface roughness and stiffness and the bulk viscoelasticity of these biofilms. We show how specific biomolecules constituting the biofilm matrix formed by this strain contribute to those biofilm properties. In particular, we demonstrate that the surface roughness and surface elasticity of 1-day-old NCIB 3610 biofilms are strongly affected by the surface layer protein BslA. For a second strain, B. subtilis B-1, which forms biofilms containing mainly γ-polyglutamate, we found significantly different physical biofilm properties that are also differently affected by the commonly used antibacterial agent ethanol. We show that B-1 biofilms are protected from ethanol-induced changes in the biofilm's stiffness and that this protective effect can be transferred to NCIB 3610 biofilms by the sole addition of γ-polyglutamate to growing NCIB 3610 biofilms. Together, our results demonstrate the importance of specific biofilm matrix components for the distinct physical properties of B. subtilis biofilms. PMID:26873313

  5. PhySIC: a veto supertree method with desirable properties.

    PubMed

    Ranwez, Vincent; Berry, Vincent; Criscuolo, Alexis; Fabre, Pierre-Henri; Guillemot, Sylvain; Scornavacca, Celine; Douzery, Emmanuel J P

    2007-10-01

    This paper focuses on veto supertree methods; i.e., methods that aim at producing a conservative synthesis of the relationships agreed upon by all source trees. We propose desirable properties that a supertree should satisfy in this framework, namely the non-contradiction property (PC) and the induction property (PI). The former requires that the supertree does not contain relationships that contradict one or a combination of the source topologies, whereas the latter requires that all topological information contained in the supertree is present in a source tree or collectively induced by several source trees. We provide simple examples to illustrate their relevance and that allow a comparison with previously advocated properties. We show that these properties can be checked in polynomial time for any given rooted supertree. Moreover, we introduce the PhySIC method (PHYlogenetic Signal with Induction and non-Contradiction). For k input trees spanning a set of n taxa, this method produces a supertree that satisfies the above-mentioned properties in O(kn(3) + n(4)) computing time. The polytomies of the produced supertree are also tagged by labels indicating areas of conflict as well as those with insufficient overlap. As a whole, PhySIC enables the user to quickly summarize consensual information of a set of trees and localize groups of taxa for which the data require consolidation. Lastly, we illustrate the behaviour of PhySIC on primate data sets of various sizes, and propose a supertree covering 95% of all primate extant genera. The PhySIC algorithm is available at http://atgc.lirmm.fr/cgi-bin/PhySIC. PMID:17918032

  6. The Influence of Fuelbed Physical Properties on Biomass Burning Emissions

    NASA Astrophysics Data System (ADS)

    Urbanski, S. P.; Lincoln, E.; Baker, S. P.; Richardson, M.

    2014-12-01

    Emissions from biomass fires can significantly degrade regional air quality and therefore are of major concern to air regulators and land managers in the U.S. and Canada. Accurately estimating emissions from different fire types in various ecosystems is crucial to predicting and mitigating the impact of fires on air quality. The physical properties of ecosystems' fuelbeds can heavily influence the combustion processes (e.g. flaming or smoldering) and the resultant emissions. However, despite recent progress in characterizing the composition of biomass smoke, significant knowledge gaps remain regarding the linkage between basic fuelbed physical properties and emissions. In laboratory experiments we examined the effects of fuelbed properties on combustion efficiency (CE) and emissions for an important fuel component of temperate and boreal forests - conifer needles. The bulk density (BD), depth (DZ), and moisture content (MC) of Ponderosa Pine needle fuelbeds were manipulated in 75 burns for which gas and particle emissions were measured. We found CE was negatively correlated with BD, DZ and MC and that the emission factors of species associated with smoldering combustion processes (CO, CH4, particles) were positively correlated with these fuelbed properties. The study indicates the physical properties of conifer needle fuelbeds have a significant effect on CE and hence emissions. However, many of the emission models used to predict and manage smoke impacts on air quality assume conifer litter burns by flaming combustion with a high CE and correspondingly low emissions of CO, CH4, particles, and organic compounds. Our results suggest emission models underestimate emissions from fires involving a large component of conifer needles. Additionally, our findings indicate that laboratory studies of emissions should carefully control fuelbed physical properties to avoid confounding effects that may obscure the effects being tested and lead to erroneous interpretations.

  7. Factors affecting daily physical activity and physical performance in maintenance dialysis patients.

    PubMed

    Kopple, Joel D; Kim, Jun C; Shapiro, Bryan B; Zhang, Min; Li, Yinan; Porszasz, Janos; Bross, Rachelle; Feroze, Usama; Upreti, Rajeev; Kalantar-Zadeh, Kamyar

    2015-03-01

    Maintenance hemodialysis (MHD) patients display reduced daily physical activity (DPA) and physical performance (PP). Previous studies did not differentiate the effects of kidney failure and MHD treatments from comorbidities as causes for reduced DPA and PP. In relatively healthy MHD patients and normal adults, we evaluated DPA and PP and examined relationships between DPA and PP and possible associations between anxiety or depression and DPA and PP. DPA, 6-minute walk distance (6-MWD), sit-to-stand (STS), and stair-climbing tests were measured in 72 MHD patients (40% diabetics) with limited comorbidities and 39 normal adults of similar age and gender mix. Anxiety and depression were measured by the Beck anxiety and depression inventories. DPA, time-averaged over 7 days, and all 3 PP tests were impaired in MHD patients, to about 60% to 70% of normal values (P < .0001 for each measurement). MHD patients spent more time sleeping or physically inactive (P < .0001) and less time in ≥ moderate activity (P < .0001). Adjusted DPA correlated with 6-MWD but not STS or stair-climbing. Anxiety and depression were identified in 43% and 33% of MHD patients and 2.5% and 5.1% of normals (P < .0001 for each comparison). Most of the impairment in DPA and PP tests were also observed in MHD patients without anxiety or depression. However, MHD patients with both anxiety and depression generally had the most impaired DPA and PP. In MHD patients, higher adjusted anxiety scores were correlated with impaired 6-MWD and STS, whereas adjusted average DPA was negatively correlated with depression (r = -0.33, P = .006) but not anxiety. DPA on the hemodialysis day (P = .01), day after dialysis (P = .03), and day 2 after dialysis (P = .03) each correlated negatively with degree of depression but not with anxiety. MHD patients displayed negative-adjusted correlations between anxiety and 6-MWD (P = .03) and STS (P = .04). In relatively healthy MHD patients, DPA and PP are substantially impaired

  8. Factors affecting the dielectric properties of agricultural and food products

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Dielectric properties of materials are defined, and the major factors that influence these properties of agricultural and food materials, namely, frequency of the applied radio-frequency and microwave electric fields, water content, temperature, and density of the materials are discussed on the bas...

  9. Fractal Scaling of Particle Size Distribution and Relationships with Topsoil Properties Affected by Biological Soil Crusts

    PubMed Central

    Gao, Guang-Lei; Ding, Guo-Dong; Wu, Bin; Zhang, Yu-Qing; Qin, Shu-Gao; Zhao, Yuan-Yuan; Bao, Yan-Feng; Liu, Yun-Dong; Wan, Li; Deng, Ji-Feng

    2014-01-01

    Background Biological soil crusts are common components of desert ecosystem; they cover ground surface and interact with topsoil that contribute to desertification control and degraded land restoration in arid and semiarid regions. Methodology/Principal Findings To distinguish the changes in topsoil affected by biological soil crusts, we compared topsoil properties across three types of successional biological soil crusts (algae, lichens, and mosses crust), as well as the referenced sandland in the Mu Us Desert, Northern China. Relationships between fractal dimensions of soil particle size distribution and selected soil properties were discussed as well. The results indicated that biological soil crusts had significant positive effects on soil physical structure (P<0.05); and soil organic carbon and nutrients showed an upward trend across the successional stages of biological soil crusts. Fractal dimensions ranged from 2.1477 to 2.3032, and significantly linear correlated with selected soil properties (R2 = 0.494∼0.955, P<0.01). Conclusions/Significance Biological soil crusts cause an important increase in soil fertility, and are beneficial to sand fixation, although the process is rather slow. Fractal dimension proves to be a sensitive and useful index for quantifying changes in soil properties that additionally implies desertification. This study will be essential to provide a firm basis for future policy-making on optimal solutions regarding desertification control and assessment, as well as degraded ecosystem restoration in arid and semiarid regions. PMID:24516668

  10. Heavy metals concentration relationship with Perna viridis physical properties in Mengkabong Lagoon, Sabah, Malaysia.

    PubMed

    Abdullah, Noraini; Tair, Rohana; Abdullah, Mohd Harun

    2014-01-01

    Perna viridis (P. viridis) has been identified as a good biological indicator in identifying environmental pollution, especially when there are various types of Heavy Metals Accumulations (HMA) inside its tissue. Based on the potential of P. viridis to accumulate heavy metals and the data on its physical properties, this study proffers to determine the relationships between both properties. The similarities of the physical properties are used to mathematical model their relationships, which included the size (length, width, height) and weight (wet and dry) of P. viridis, whilst the heavy metals are focused on concentrations of Pb, Cu, Cr, Cd and Zn. The concentrations of metal elements are detected by using Flame Atomic Adsorption Spectrometry. Results show that the mean concentration of Pb, Cu, Cr, Cd, Zn, length, width, height, wet weight and dry weight are: 1.12 +/- 1.00, 2.36 +/- 1.65, 2.12 +/- 2.74, 0.44 +/- 0.41 and 16.52 +/- 10.64 mg kg(-1) (dry weight), 105.08 +/- 14.35, 41.64 +/- 4.64, 28.75 +/- 3.92 mm, 14.56 +/- 3.30 and 2.37 +/- 0.86 g, respectively. It is also found out that the relationships between the Heavy Metals Concentrations (HMA) and the physical properties can be represented using Multiple Linear Regressions (MLR) models, relating that the HMA of Zinc has affected significantly the physical growth properties of P. viridis.

  11. Ultrasonic evaluation of the physical and mechanical properties of granites.

    PubMed

    Vasconcelos, G; Lourenço, P B; Alves, C A S; Pamplona, J

    2008-09-01

    Masonry is the oldest building material that survived until today, being used all over the world and being present in the most impressive historical structures as an evidence of spirit of enterprise of ancient cultures. Conservation, rehabilitation and strengthening of the built heritage and protection of human lives are clear demands of modern societies. In this process, the use of nondestructive methods has become much common in the diagnosis of structural integrity of masonry elements. With respect to the evaluation of the stone condition, the ultrasonic pulse velocity is a simple and economical tool. Thus, the central issue of the present paper concerns the evaluation of the suitability of the ultrasonic pulse velocity method for describing the mechanical and physical properties of granites (range size between 0.1-4.0 mm and 0.3-16.5 mm) and for the assessment of its weathering state. The mechanical properties encompass the compressive and tensile strength and modulus of elasticity, and the physical properties include the density and porosity. For this purpose, measurements of the longitudinal ultrasonic pulse velocity with distinct natural frequency of the transducers were carried out on specimens with different size and shape. A discussion of the factors that induce variations on the ultrasonic velocity is also provided. Additionally, statistical correlations between ultrasonic pulse velocity and mechanical and physical properties of granites are presented and discussed. The major output of the work is the confirmation that ultrasonic pulse velocity can be effectively used as a simple and economical nondestructive method for a preliminary prediction of mechanical and physical properties, as well as a tool for the assessment of the weathering changes of granites that occur during the serviceable life. This is of much interest due to the usual difficulties in removing specimens for mechanical characterization. PMID:18471849

  12. Ultrasonic evaluation of the physical and mechanical properties of granites.

    PubMed

    Vasconcelos, G; Lourenço, P B; Alves, C A S; Pamplona, J

    2008-09-01

    Masonry is the oldest building material that survived until today, being used all over the world and being present in the most impressive historical structures as an evidence of spirit of enterprise of ancient cultures. Conservation, rehabilitation and strengthening of the built heritage and protection of human lives are clear demands of modern societies. In this process, the use of nondestructive methods has become much common in the diagnosis of structural integrity of masonry elements. With respect to the evaluation of the stone condition, the ultrasonic pulse velocity is a simple and economical tool. Thus, the central issue of the present paper concerns the evaluation of the suitability of the ultrasonic pulse velocity method for describing the mechanical and physical properties of granites (range size between 0.1-4.0 mm and 0.3-16.5 mm) and for the assessment of its weathering state. The mechanical properties encompass the compressive and tensile strength and modulus of elasticity, and the physical properties include the density and porosity. For this purpose, measurements of the longitudinal ultrasonic pulse velocity with distinct natural frequency of the transducers were carried out on specimens with different size and shape. A discussion of the factors that induce variations on the ultrasonic velocity is also provided. Additionally, statistical correlations between ultrasonic pulse velocity and mechanical and physical properties of granites are presented and discussed. The major output of the work is the confirmation that ultrasonic pulse velocity can be effectively used as a simple and economical nondestructive method for a preliminary prediction of mechanical and physical properties, as well as a tool for the assessment of the weathering changes of granites that occur during the serviceable life. This is of much interest due to the usual difficulties in removing specimens for mechanical characterization.

  13. Affect and achievement goals in physical activity: a meta-analysis.

    PubMed

    Ntoumanis, N; Biddle, S J

    1999-12-01

    Achievement goal orientation theory has been the subject of extensive research in recent years. In view of the importance of identifying the motivational antecedents of affect in physical activity, this study examined through meta-analysis the conflicting evidence regarding the links between different achievement goals and emotions. Using the formulas of Hunter and Schmidt (1), correlations were gathered from 41 independent samples and were corrected for both sampling and measurement errors. The results showed that task orientation and positive affect were moderately-to-highly correlated and in a positive fashion, whereas the relationship between task orientation and negative affect was negative and moderate to small. Both correlations were found to be heterogeneous, and so moderators were sought. The relationships between ego orientation and positive and negative affect were positive but very small, with the former being heterogeneous. Moderators coded were the time frame of affect (independent of context vs. after an athletic event), the physical activity setting (school physical education vs. recreation vs. competitive sport), age (university vs. school students), nationality (British vs. American), nature of negative affect (high vs. low arousal), and the publication status of the studies (published vs. unpublished). Lastly, a subset of the corrected correlations were inserted into a structural equation modelling analysis in order to look concurrently at the relationships among all the variables.

  14. Perceived occupational stress, affective, and physical well-being among telecommunication employees in Greece.

    PubMed

    Lazuras, Lambros; Rodafinos, Angelos; Matsiggos, Georgios; Stamatoulakis, Alexander

    2009-03-01

    The present study examined four potential roles of work-related negative affectivity on the associations between self-reported occupational stress and physical well-being among telecommunication employees in Greece. Participants (764, predominantly male) completed a battery of self-report measures on perceived occupational stress, negative affectivity, and illness symptoms. In line with previous research, negative affectivity exerted a nuisance effect, by inflating the association between reported stressors and illness symptoms, and significantly predicted illness symptoms, over and above the effects of stressors. In addition, negative affectivity influenced reported illness symptom indirectly, through the effects of stressors, and moderated the relationship between interpersonal conflict at work and illness symptoms. The findings suggest that negative affectivity can largely explain and influence in different ways the associations between self-reported stress and physical strain. It is recommended that future studies of occupational stress should control for the effects of negative affectivity, and that health professionals should be cautious of its effects when interpreting relationships between self-reported occupational stress and physical well-being. PMID:19185405

  15. Swiss Atlas of PHYsical properties of Rocks (SAPHYR)

    NASA Astrophysics Data System (ADS)

    Zappone, Alba; Kissling, Eduard

    2015-04-01

    The Swiss Atlas of PHYsical properties of Rocks (SAPHYR), is a multi-year project, funded entirely by Swiss Commission for Geophysics (SGPK), with the aim to compile a comprehensive data set in digital form on physical properties of rocks exposed in Switzerland and surrounding regions. The ultimate goal of SAPHYR is to make these data accessible to an open and wide public including industrial, engineering, land and resource planning companies, as well as academic institutions, or simply people interested in geology. Since the early sixties worldwide many scientists, i.e. geophysicists, petrologists, and engineers, focused their work on laboratory measurements of rocks physical properties, and their relations with microstructures, mineralogical compositions and other rock parameters, in the effort to constrain the geological interpretation of geophysical surveys. Particularly in the years in which seismic reflection and refraction crustal scale projects were investigating the deep structures of the Alps, laboratories capable to reproduce the pressure and temperature ranges of the continental crust were collecting measurements of various rock parameters on a wide variety of lithologies, developing in the meantime more and more sophisticated experimental methodologies. In recent years, the increasing interest of European Countries on non-traditional energy supply, (i.e. Deep Geothermal Energy and shale gas) and CO2 storage renovated the interests in physical characterization of the deep underground. SAPHYR aims to organize all those laboratory data into a geographically referenced database (GIS). The data refer to density, porosity, permeability, and seismic, magnetic, thermal and electric properties. In the past years, effort has been placed on collecting samples and measuring the physical properties of lithologies that were poorly documented in literature. The phase of laboratory measurements is still in progress. Recently, SAPHYR project focused towards developing

  16. Entropy and the Shelf Model: A Quantum Physical Approach to a Physical Property

    ERIC Educational Resources Information Center

    Jungermann, Arnd H.

    2006-01-01

    In contrast to most other thermodynamic data, entropy values are not given in relation to a certain--more or less arbitrarily defined--zero level. They are listed in standard thermodynamic tables as absolute values of specific substances. Therefore these values describe a physical property of the listed substances. One of the main tasks of…

  17. Process Formulations And Curing Conditions That Affect Saltstone Properties

    SciTech Connect

    Reigel, M. M.; Pickenheim, B. R.; Daniel, W. E.

    2012-09-28

    The first objective of this study was to analyze saltstone fresh properties to determine the feasibility of reducing the formulation water to premix (w/p) ratio while varying the amount of extra water and admixtures used during processing at the Saltstone Production Facility (SPF). The second part of this study was to provide information for understanding the impact of curing conditions (cure temperature, relative humidity (RH)) and processing formulation on the performance properties of cured saltstone.

  18. Chemical and Physical Properties of Hi-Cal-2

    NASA Technical Reports Server (NTRS)

    Spakowski, A. E.; Allen, Harrison, Jr.; Caves, Robert M.

    1955-01-01

    As part of the Navy Project Zip to consider various boron-containing materials as possible high-energy fuels, the chemical and physical properties of Hi-Cal-2 prepared by the Callery Chemical Company were evaluated at the NACA Lewis laboratory. Elemental chemical analysis, heat of combustion, vapor pressure and decomposition, freezing point, density, self ignition temperature, flash point, and blow-out velocity were determined for the fuel. Although the precision of measurement of these properties was not equal to that obtained for hydrocarbons, this special release research memorandum was prepared to make the data available as soon as possible.

  19. Effects of amendment of different biochars on soil physical and biological properties related to carbon mineralization

    NASA Astrophysics Data System (ADS)

    Zhang, Renduo; Zhu, Shuzhi; Ouyang, Lei

    2014-05-01

    Biochar addition to soils potentially affects various soil properties, and these effects are dependent on biochars derived from different feedstock materials and pyrolysis processes. The objective of this study was to investigate the effects of amendment of different biochars on soil physical and biological properties. Biochars were produced with dairy manure and woodchip at temperatures of 300, 500, and 700°C, respectively. Each biochar was mixed at 5% (w/w) with a forest soil and the mixture was incubated for 180 days, during which soil physical and biological properties, and soil respiration rates were measured. Results showed that the biochar addition significantly enhanced the formation of soil macroaggregates at the early incubation time. The biochar application significantly reduced soil bulk density, increased the amount of soil organic matter, and stimulated microbial activity and soil respiration rates at the early incubation stage. Biochar applications improved water retention capacity, with stronger effects by biochars produced at higher pyrolysis temperatures. At the same suction, the soil with woodchip biochars possessed higher water content than with the dairy manure biochars. Biochar addition significantly affected the soil physical and biological properties, which resulted in different soil carbon mineralization rates.

  20. Lipid peroxidation affects red blood cells membrane properties in patients with systemic lupus erythematosus.

    PubMed

    Spengler, M I; Svetaz, M J; Leroux, M B; Bertoluzzo, S M; Parente, F M; Bosch, P

    2014-01-01

    Systemic lupus erythematosus (SLE) is an autoimmune, chronic inflammatory, non-organ specific disease with an important morbimortality affecting several organs and systems. Oxidative stress is a well documented mechanism of red blood cells (RBC) mechanical impairment. Free radicals could produced, through lipid peroxidation, physical and chemical alterations in the cellular membrane properties modifying its composition, packing and lipid distribution on the membrane erythrocyte. The aim of the present work is to study the lipid peroxidation in the RBC membrane in SLE patients (n = 42) affecting so far the lipid membrane fluidity and erythrocyte deformability in comparison with healthy controls (n = 52). Malonildialdehyde (MDA) is a subrogate assessing lipidic peroxidation, rigidity index estimating erythrocyte deformability and the anisotropy coefficient estimating lipid membrane fluidity were used. Our results show that MDA values are increased, while erythrocyte deformability and membrane fluidity are significantly decreased in erythrocyte membrane from SLE patients in comparison with normal controls. The association of thiobarbituric acid reactive substances (TBARS) with membrane lipid fluidity and erythrocyte deformability confirms that the damage of membrane properties is produced by lipid peroxidation. PMID:23603321

  1. Unique characterization of lunar samples by physical properties

    NASA Technical Reports Server (NTRS)

    Todd, T.; Richter, D. A.; Simmons, G.; Wang, H.

    1973-01-01

    The measurement of compressional velocity, shear velocity, static compressibility, and thermal expansion of (1) a suite of shocked rocks fron the Ries impact in Germany, (2) a suite of samples cracked by thermal cycling to high temperatures, (3) many terrestrial igneous rocks, and (4) lunar basalts, gabbroic anorthosites, and breccias, indicate that shock metamorphism is the primary cause for values of physical properties of lunar rocks being diffferent from their intrinsic values. Large scale thermal metamorphism, thermal cycling between temperatures of lunar day and night, large thermal gradients, or thermal fatigue could possibly cause minor cracking in the top few centimeters of the lunar regolith, but are probably not important mechanism for extensively changing values of physical properties of lunar rocks.-

  2. Physical and chemical properties of pomegranate fruit accessions from Croatia.

    PubMed

    Radunić, Mira; Jukić Špika, Maja; Goreta Ban, Smiljana; Gadže, Jelena; Díaz-Pérez, Juan Carlos; MacLean, Dan

    2015-06-15

    The objective was to evaluate physical and chemical properties of eight pomegranate accessions (seven cultivars and one wild genotype) collected from the Mediterranean region of Croatia. Accessions showed high variability in fruit weight and size, calyx and peel properties, number of arils per fruit, total aril weight, and aril and juice yield. Variables that define sweet taste, such as low total acidity (TA; 0.37-0.59%), high total soluble solids content (TSS; 12.5-15.0%) and their ratio (TSS/TA) were evaluated, and results generally aligned with sweetness classifications of the fruit. Pomegranate fruit had a high variability in total phenolic content (1985.6-2948.7 mg/L). HPLC-MALDI-TOF/MS analysis showed that accessions with dark red arils had the highest total anthocyanin content, with cyanidin 3-glucoside as the most abundant compound. Principal component analysis revealed great differences in fruit physical characteristics and chemical composition among pomegranate accessions.

  3. Physical and chemical properties of pomegranate fruit accessions from Croatia.

    PubMed

    Radunić, Mira; Jukić Špika, Maja; Goreta Ban, Smiljana; Gadže, Jelena; Díaz-Pérez, Juan Carlos; MacLean, Dan

    2015-06-15

    The objective was to evaluate physical and chemical properties of eight pomegranate accessions (seven cultivars and one wild genotype) collected from the Mediterranean region of Croatia. Accessions showed high variability in fruit weight and size, calyx and peel properties, number of arils per fruit, total aril weight, and aril and juice yield. Variables that define sweet taste, such as low total acidity (TA; 0.37-0.59%), high total soluble solids content (TSS; 12.5-15.0%) and their ratio (TSS/TA) were evaluated, and results generally aligned with sweetness classifications of the fruit. Pomegranate fruit had a high variability in total phenolic content (1985.6-2948.7 mg/L). HPLC-MALDI-TOF/MS analysis showed that accessions with dark red arils had the highest total anthocyanin content, with cyanidin 3-glucoside as the most abundant compound. Principal component analysis revealed great differences in fruit physical characteristics and chemical composition among pomegranate accessions. PMID:25660857

  4. School and Classroom Goal Structures: Effects on Affective Responses in Physical Education

    ERIC Educational Resources Information Center

    Barkoukis, Vassilis; Koidou, Eirini; Tsorbatzoudis, Haralambos; Grouios, George

    2012-01-01

    The current study examined the relative impact of school and classroom goal structures on students' affective responses and the mediating role of motivation. The sample of the study consisted of 368 high school students, who completed measures of school and classroom goal structures, motivational regulations in physical education, boredom, and…

  5. Pretend and Physical Play: Links to Preschoolers' Affective Social Competence

    ERIC Educational Resources Information Center

    Lindsey, Eric W.; Colwell, Malinda J.

    2013-01-01

    This study investigated different forms of pretend and physical play as predictors of preschool children's "affective social competence" (ASC). Data were collected from 122 preschool children (57 boys, 65 girls; 86 European American, 9 African American, 17 Hispanic, and 10 other ethnicity) over a 2-year period. Children participated…

  6. Sociocultural and Motivational Factors Affecting Asian American Females Studying Physics and Engineering in High School

    ERIC Educational Resources Information Center

    Sha, Saliha L.

    2012-01-01

    This quantitative study investigated whether and to what extent the motivational and sociocultural factors affect female Asian American high school physics students' achievement, their intended major in college, and their planned career goals at work fields. A survey of 62 questions, extracted from subscales of AAMAS,STPQ and PSE, were…

  7. Factors Affecting the Link between Physical Discipline and Child Externalizing Problems in Black and White Families

    ERIC Educational Resources Information Center

    Lau, Anna S.; Litrownik, Alan J.; Newton, Rae R.; Black, Maureen M.; Everson, Mark D.

    2006-01-01

    We examined contextual factors that may affect the impact of physical discipline on later child behavior problems among high-risk Black and White families. We examined race, parental warmth, and early child problems as potential moderators of the discipline-behavior problem link. The sample included 442 White and Black children and their…

  8. Structurally imperfect glycine-containing ferroelectrics and their physical properties

    NASA Astrophysics Data System (ADS)

    Khasinevich, N. I.; Chesnokov, E. D.; Tarasevich, E. V.; Rodin, S. V.

    The study is concerned with the effect of substitutional and growth defects on the physical properties of diglycine nitrate crystals, which belong to the triglycine sulfate group of ferroelectric crystals. In particular, experimental data are presented on the temperature dependences of the piezoelectric moduli, elastic compliances, electromechanical coupling coefficients, and electrostriction coefficients of pure and alanine-alloyed crystals. The permittivity and the nuclear spin-lattice relaxation time of the crystals are also determined.

  9. Investigation of physical properties of TiO2 nanolayers

    NASA Astrophysics Data System (ADS)

    Struk, Przemyslaw; Pustelny, Tadeusz

    2015-12-01

    We present applications of titanium dioxide wide bandgap oxide semiconductor and its application in integrated optics devices. The paper is focus on research of physical properties TiO2 such as: spectral transmittance, refractive index, extinction coefficient in the UV-VIS-IR range of light as well as surface topography. In addition we show the numerical calculation and optical characterization of fabricated optical planar waveguide based on TiO2.

  10. Role of physical properties of liquids in cavitation erosion

    NASA Technical Reports Server (NTRS)

    Thiruvengadam, A.

    1974-01-01

    The dependence of erosion rates on the ambient temperature of water is discussed. The assumption that the gas inside the bubble is compressed adiabatically during collapse gives better agreement with experiments than the assumption that the gas is isothermally compressed. Acoustic impedance is an important liquid parameter that governs the erosion intensity in vibratory devices. The investigation reveals that the major physical properties of liquids governing the intensity of erosion include density, sound speed, surface tension, vapor pressure, gas content, and nuclei distribution.

  11. Synthesis and physical properties of some composite systems

    NASA Astrophysics Data System (ADS)

    Pu, Zhengcai

    There are four major parts in this dissertation: (1) investigation of filler-matrix interactions in poly(dimethylsiloxane)/zeolite (PDMS/zeolite) composites, (2) characterization of mechanical and thermal properties of 3-(trimethoxysilyl)propyl methacrylate coated silica (TPM-Si) filled poly(methyl acrylate) (PMA), (3) small angle x-ray scattering studies of chain penetration into cavities of a zeolite in poly(ethyl acrylate)/zeolite (PEA/zeolite) hybrid material, (4) study of hydrolysis kinetics and stability of bis(triethoxysilyl)ethane (BTESE) in water-ethanol solutions by Fourier transform infrared (FTIR) spectroscopy. In the first part of this study, two types of PDMS/zeolite composites with physically or chemically crosslinked networks were prepared through two different approaches: (1) blending hydroxyl-terminated linear PDMS with zeolite and crosslinking PDMS with tetraethylorthosilicate (TEOS); (2) mixing dichlorodimethylsilane with zeolite, and then hydrolyzing and polymerizing the dichlorodimethylsilane with water. The physical properties of the resulting composites, including mechanical properties, swelling properties, and small angle X-ray (SAXS), were measured and compared. It was shown that the PDMS/zeolite composites having PDMS networks differently crosslinked behave differently in many aspects. In the second part of the study, composites of PMA and of TPM-Si with randomly dispersed, regularly dispersed, and aggregated silica were prepared by blending methyl acrylate and TPM-Si, followed by free radical polymerization. Simple tension properties, equibiaxial extension properties, dynamic mechanical properties, and differential scanning calorimetry (DSC) properties of the resulting composites were investigated. It was shown that well-defined relationships exist between the physical properties of the composites and the preparation processes. In the third part of this study, small angle X-ray scattering (SAXS) intensities of PEA/zeolite hybrids were

  12. [The effect of physical properties of chitosan on cell activity and on its mechanics property].

    PubMed

    Tian, Shengli; Ye, Zhiyi

    2012-12-01

    Chitosan is a natural biopolymer and is made up of D-glucosamine subunits linked by beta-(1,4) glycosidic bond. In recent years, the application of chitosan has attracted more and more attention because of its good biological function in cell biology. The properties of chitosan-based biomaterial are attributed to the physical properties and chemical composition of chitosan. The author of this paper summarized recent related studies and progresses of the influence of physical properties of chitosan on cell activity and cell mechanics property at home and abroad. The findings show that most studies mainly focused on the influence of chitosan and cell activity, while few were on cell mechanics property. The related studies of the influence of chitosan on cell will contribute to the explanation for the mechanism of the interaction between chitosan and cell, and provide the theoretical support for the further study.

  13. Physical Properties of Biological Entities: An Introduction to the Ontology of Physics for Biology

    PubMed Central

    Cook, Daniel L.; Bookstein, Fred L.; Gennari, John H.

    2011-01-01

    As biomedical investigators strive to integrate data and analyses across spatiotemporal scales and biomedical domains, they have recognized the benefits of formalizing languages and terminologies via computational ontologies. Although ontologies for biological entities—molecules, cells, organs—are well-established, there are no principled ontologies of physical properties—energies, volumes, flow rates—of those entities. In this paper, we introduce the Ontology of Physics for Biology (OPB), a reference ontology of classical physics designed for annotating biophysical content of growing repositories of biomedical datasets and analytical models. The OPB's semantic framework, traceable to James Clerk Maxwell, encompasses modern theories of system dynamics and thermodynamics, and is implemented as a computational ontology that references available upper ontologies. In this paper we focus on the OPB classes that are designed for annotating physical properties encoded in biomedical datasets and computational models, and we discuss how the OPB framework will facilitate biomedical knowledge integration. PMID:22216106

  14. Relationship between physical properties and sensory attributes of carbonated beverages.

    PubMed

    Kappes, S M; Schmidt, S J; Lee, S-Y

    2007-01-01

    Bulk sweeteners provide functional properties in beverages, including sweet taste, bulking, bitter masking, structure, and mouthfeel. Diet beverages come closer to the taste of regular beverages using a blend of high-intensity sweeteners; however, some properties, including bulking, structure, and mouthfeel, remain significantly different. Relating physical properties to sensory characteristics is an important step in understanding why mouthfeel differences are apparent in beverages sweetened with alternative sweeteners compared to bulk sweeteners. The objectives of this research were to (1) measure sweetener profile, Brix, refractive index, viscosity, a(w), carbonation, titratable acidity, and pH of commercial carbonated beverages; and (2) correlate the physical property measurements to descriptive analysis of the beverages. Correlation analysis, partial least squares, canonical correlation analysis, and cluster analysis were used to analyze the data. Brix, viscosity, and sweet taste were highly correlated among one another and were all negatively correlated to a(w). Carbonated and decarbonated pH were highly correlated to each other and were both negatively correlated to mouthcoating. Numbing, burn, bite, and carbonation were highly correlated to total acidity, citric acid, and ascorbic acid and negatively correlated to phosphoric acid. The mouthfeel difference between diet and regular lemon/lime carbonated beverages is small and may be related to overall differences between flavor, acid, and sweetener types and usage levels. This research is significant because it demonstrates the use of both sensory attributes and physical properties to identify types of ingredients and levels that may decrease the mouthfeel perception differences between regular and diet carbonated beverages, which could consequently lead to higher acceptance of diet beverages by the consumers of regular. PMID:17995891

  15. Characterization of the physical properties for solid granular materials

    SciTech Connect

    Tucker, Jonathan R.; Shadle, Lawrence J.; Guenther, Chris; Benyahia, Sofiane; Mei, Joseph S.; Banta, Larry

    2012-01-01

    Accurate prediction of the behavior of a system is strongly governed by the components within that system. For multiphase systems incorporating solid powder-like particles, there are many different physical properties which need to be known to some level of accuracy for proper design, modeling, or data analysis. In the past, the material properties were determined initially as a secondary part of the study or design. In an attempt to provide results with the least level of uncertainty, a procedure was developed and implemented to provide consistent analysis of several different types of materials. The properties that were characterized included particle sizing and size distributions, shape analysis, density (particle, skeletal and bulk), minimum fluidization velocities, void fractions, particle porosity, and assignment within the Geldart Classification. In the methods used for this experiment, a novel form of the Ergun equation was used to determine the bulk void fractions and particle density. Materials of known properties were initially characterized to validate the accuracy and methodology, prior to testing materials of unknown properties. The procedures used yielded valid and accurate results, with a high level of repeatability. A database of these materials has been developed to assist in model validation efforts and future designs. It is also anticipated that further development of these procedures wil be expanded increasing the properties included in the database.

  16. CONTINUOSLY STIRRED TANK REACTOR PARAMETERS THAT AFFECT SLUDGE BATCH 6 SIMULANT PROPERTIES

    SciTech Connect

    Newell, J.; Lambert, D.; Stone, M.; Fernandez, A.

    2010-05-28

    ). Precipitated MnO{sub 2} is combined with metal nitrates and fed into the CSTR. The metals are precipitated by a caustic NaOH stream. The rates at which these streams are added allows for pH adjustment of the mixture. A graphical representation of this process is given in Figure 1. In using the CSTR method for developing simulant, there are various parameters that can be adjusted in order to effectuate a physical change in the resulting simulant: pH, temperature, mixing speed, and flow rate. How will changing these parameters affect the physical properties of the sludge simulant? The ability to determine which parameter affects a particular property could allow one to develop a simulant that would better match the physical characteristics of HLW sludge.

  17. Neural evidence that human emotions share core affective properties.

    PubMed

    Wilson-Mendenhall, Christine D; Barrett, Lisa Feldman; Barsalou, Lawrence W

    2013-06-01

    Research on the "emotional brain" remains centered around the idea that emotions like fear, happiness, and sadness result from specialized and distinct neural circuitry. Accumulating behavioral and physiological evidence suggests, instead, that emotions are grounded in core affect--a person's fluctuating level of pleasant or unpleasant arousal. A neuroimaging study revealed that participants' subjective ratings of valence (i.e., pleasure/displeasure) and of arousal evoked by various fear, happiness, and sadness experiences correlated with neural activity in specific brain regions (orbitofrontal cortex and amygdala, respectively). We observed these correlations across diverse instances within each emotion category, as well as across instances from all three categories. Consistent with a psychological construction approach to emotion, the results suggest that neural circuitry realizes more basic processes across discrete emotions. The implicated brain regions regulate the body to deal with the world, producing the affective changes at the core of emotions and many other psychological phenomena.

  18. Does utility spent nuclear fuel storage affect local property values?

    SciTech Connect

    Metz, W.C.; Allison, T.; Clark, D.E.

    1997-05-01

    With federal policy apparently forcing more utilities to store their spent nuclear fuel at their reactor sites for the foreseeable future, the question arises whether residential sale prices will be affected because of the public perceptions of risk and negative imagery. This article discusses the question using the following topic areas: estimates of economic consequences; california plant case studies; real estate data used in the analyses; hedonic modeling; iterative hedonic modeling; 25-mile analyses; 15 mile analyses; news coverage analysis. 3 figs.

  19. Soil properties affecting wheat yields following drilling-fluid application.

    PubMed

    Bauder, T A; Barbarick, K A; Ippolito, J A; Shanahan, J F; Ayers, P D

    2005-01-01

    Oil and gas drilling operations use drilling fluids (mud) to lubricate the drill bit and stem, transport formation cuttings to the surface, and seal off porous geologic formations. Following completion of the well, waste drilling fluid is often applied to cropland. We studied potential changes in soil compaction as indicated by cone penetration resistance, pH, electrical conductivity (EC(e)), sodium adsorption ratio (SAR), extractable soil and total straw and grain trace metal and nutrient concentrations, and winter wheat (Triticum aestivum L. 'TAM 107') grain yield following water-based, bentonitic drilling-fluid application (0-94 Mg ha(-1)) to field test plots. Three methods of application (normal, splash-plate, and spreader-bar) were used to study compaction effects. We measured increasing SAR, EC(e), and pH with drilling-fluid rates, but not to levels detrimental to crop production. Field measurements revealed significantly higher compaction within areas affected by truck travel, but also not enough to affect crop yield. In three of four site years, neither drilling-fluid rate nor application method affected grain yield. Extractions representing plant availability and plant analyses results indicated that drilling fluid did not significantly increase most trace elements or nutrient concentrations. These results support land application of water-based bentonitic drilling fluids as an acceptable practice on well-drained soils using controlled rates. PMID:16091622

  20. Soil properties affecting wheat yields following drilling-fluid application.

    PubMed

    Bauder, T A; Barbarick, K A; Ippolito, J A; Shanahan, J F; Ayers, P D

    2005-01-01

    Oil and gas drilling operations use drilling fluids (mud) to lubricate the drill bit and stem, transport formation cuttings to the surface, and seal off porous geologic formations. Following completion of the well, waste drilling fluid is often applied to cropland. We studied potential changes in soil compaction as indicated by cone penetration resistance, pH, electrical conductivity (EC(e)), sodium adsorption ratio (SAR), extractable soil and total straw and grain trace metal and nutrient concentrations, and winter wheat (Triticum aestivum L. 'TAM 107') grain yield following water-based, bentonitic drilling-fluid application (0-94 Mg ha(-1)) to field test plots. Three methods of application (normal, splash-plate, and spreader-bar) were used to study compaction effects. We measured increasing SAR, EC(e), and pH with drilling-fluid rates, but not to levels detrimental to crop production. Field measurements revealed significantly higher compaction within areas affected by truck travel, but also not enough to affect crop yield. In three of four site years, neither drilling-fluid rate nor application method affected grain yield. Extractions representing plant availability and plant analyses results indicated that drilling fluid did not significantly increase most trace elements or nutrient concentrations. These results support land application of water-based bentonitic drilling fluids as an acceptable practice on well-drained soils using controlled rates.

  1. 12 CFR 617.7630 - Does this Federal requirement affect any state property laws?

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... BORROWER RIGHTS Right of First Refusal § 617.7630 Does this Federal requirement affect any state property laws? The rights provided under section 4.36 of the Act and this section do not affect any right of first refusal under the law of the state in which the property is located....

  2. Impact of physical maltreatment on the regulation of negative affect and aggression.

    PubMed

    Shackman, Jessica E; Pollak, Seth D

    2014-11-01

    Physically maltreated children are at risk for developing externalizing behavioral problems characterized by reactive aggression. The current experiment tested the relationships between individual differences in a neural index of social information processing, histories of child maltreatment, child negative affect, and aggressive behavior. Fifty boys (17 maltreated) performed an emotion recognition task while the P3b component of the event-related potential was recorded to index attention allocation to angry faces. Children then participated in a peer-directed aggression task. Negative affect was measured by recording facial electromyography, and aggression was indexed by the feedback that children provided to a putative peer. Physically maltreated children exhibited greater negative affect and more aggressive behavior, compared to nonmaltreated children, and this relationship was mediated by children's allocation of attention to angry faces. These data suggest that physical maltreatment leads to inappropriate regulation of both negative affect and aggression, which likely place maltreated children at increased risk for the development and maintenance of externalizing behavior disorders. PMID:24914736

  3. Impact of physical maltreatment on the regulation of negative affect and aggression.

    PubMed

    Shackman, Jessica E; Pollak, Seth D

    2014-11-01

    Physically maltreated children are at risk for developing externalizing behavioral problems characterized by reactive aggression. The current experiment tested the relationships between individual differences in a neural index of social information processing, histories of child maltreatment, child negative affect, and aggressive behavior. Fifty boys (17 maltreated) performed an emotion recognition task while the P3b component of the event-related potential was recorded to index attention allocation to angry faces. Children then participated in a peer-directed aggression task. Negative affect was measured by recording facial electromyography, and aggression was indexed by the feedback that children provided to a putative peer. Physically maltreated children exhibited greater negative affect and more aggressive behavior, compared to nonmaltreated children, and this relationship was mediated by children's allocation of attention to angry faces. These data suggest that physical maltreatment leads to inappropriate regulation of both negative affect and aggression, which likely place maltreated children at increased risk for the development and maintenance of externalizing behavior disorders.

  4. Impact of physical maltreatment on the regulation of negative affect and aggression

    PubMed Central

    SHACKMAN, JESSICA E.; POLLAK, SETH D.

    2015-01-01

    Physically maltreated children are at risk for developing externalizing behavioral problems characterized by reactive aggression. The current experiment tested the relationships between individual differences in a neural index of social information processing, histories of child maltreatment, child negative affect, and aggressive behavior. Fifty boys (17 maltreated) performed an emotion recognition task while the P3b component of the event-related potential was recorded to index attention allocation to angry faces. Children then participated in a peer-directed aggression task. Negative affect was measured by recording facial electromyography, and aggression was indexed by the feedback that children provided to a putative peer. Physically maltreated children exhibited greater negative affect and more aggressive behavior, compared to nonmaltreated children, and this relationship was mediated by children’s allocation of attention to angry faces. These data suggest that physical maltreatment leads to inappropriate regulation of both negative affect and aggression, which likely place maltreated children at increased risk for the development and maintenance of externalizing behavior disorders. PMID:24914736

  5. HYDRAULIC AND PHYSICAL PROPERTIES OF SALTSTONE GROUTS AND VAULT CONCRETES

    SciTech Connect

    Dixon, K; John Harbour, J; Mark Phifer, M

    2008-11-25

    The Saltstone Disposal Facility (SDF), located in the Z-Area of the Savannah River Site (SRS), is used for the disposal of low-level radioactive salt solution. The SDF currently contains two vaults: Vault 1 (6 cells) and Vault 4 (12 cells). Additional disposal cells are currently in the design phase. The individual cells of the saltstone facility are filled with saltstone. Saltstone is produced by mixing the low-level radioactive salt solution, with blast furnace slag, fly ash, and cement (dry premix) to form a dense, micro-porous, monolithic, low-level radioactive waste form. The saltstone is pumped into the disposal cells where it subsequently solidifies. Significant effort has been undertaken to accurately model the movement of water and contaminants through the facility. Key to this effort is an accurate understanding of the hydraulic and physical properties of the solidified saltstone. To date, limited testing has been conducted to characterize the saltstone. The primary focus of this task was to estimate the hydraulic and physical properties of three types of saltstone and two vault concretes. The saltstone formulations included saltstone premix batched with (1) Deliquification, Dissolution, and Adjustment (DDA) salt simulant (w/pm 0.60), (2) Actinide Removal Process (ARP)/Modular Caustic Side Solvent Extraction Unit (MCU) salt simulant (w/pm 0.60), and (3) Salt Waste Processing Facility (SWPF) salt simulant (w/pm 0.60). The vault concrete formulations tested included the Vault 1/4 concrete and two variations of the Vault 2 concrete (Mix 1 and Mix 2). Wet properties measured for the saltstone formulations included yield stress, plastic viscosity, wet unit weight, bleed water volume, gel time, set time, and heat of hydration. Hydraulic and physical properties measured on the cured saltstone and concrete samples included saturated hydraulic conductivity, moisture retention, compressive strength, porosity, particle density, and dry bulk density. These properties

  6. Polymer crystallization in thin films: morphology and physical properties

    NASA Astrophysics Data System (ADS)

    Kelly, Giovanni; Albert, Julie

    Polymer crystallization has been studied both computationally and experimentally for decades, elucidating many of the mysteries surrounding crystallization kinetics and thermodynamics. However, many unanswered questions remain pertaining to the relationships between crystallization phenomena and material properties needed for specific applications that range from drug delivery and tissue engineering to optical devices and mechanically robust membranes. One of the especially interesting facets of polymer crystallization is the behavior observed when these long chain molecules are spatially confined in thin and ultrathin films. Confined geometry leads to chain configurations, and therefore thermal, mechanical, and optical properties, sometimes far removed from reported bulk values. This project aims to study the phenomena exhibited by linear semi-crystalline polymers in thin films as well as the way in which blending with homopolymers, block copolymers, and novel polymer chain architectures affect morphology, biodegradation, optical, thermal, and mechanical properties.

  7. The number comb for a soil physical properties dynamic measurement

    NASA Astrophysics Data System (ADS)

    Olechko, K.; Patiño, P.; Tarquis, A. M.

    2012-04-01

    We propose the prime numbers distribution extracted from the soil digital multiscale images and some physical properties time series as the precise indicator of the spatial and temporal dynamics under soil management changes. With this new indicator the soil dynamics can be studied as a critical phenomenon where each phase transition is estimated and modeled by the graph partitioning induced phase transition. The critical point of prime numbers distribution was correlated with the beginning of Andosols, Vertisols and saline soils physical degradation under the unsustainable soil management in Michoacan, Guanajuato and Veracruz States of Mexico. The data banks corresponding to the long time periods (between 10 and 28 years) were statistically compared by RISK 5.0 software and our own algorithms. Our approach makes us able to distill free-form natural laws of soils physical properties dynamics directly from the experimental data. The Richter (1987) and Schmidt and Lipson (2009) original approaches were very useful to design the algorithms to identify Hamiltonians, Lagrangians and other laws of geometric and momentum conservation especially for erosion case.

  8. The Affect and Arousal Scales: Psychometric Properties of the Dutch Version and Multigroup Confirmatory Factor Analyses

    ERIC Educational Resources Information Center

    De Bolle, Marleen; De Fruyt, Filip; Decuyper, Mieke

    2010-01-01

    Psychometric properties of the Dutch version of the Affect and Arousal Scales (AFARS) were inspected in a combined clinical and population sample (N = 1,215). The validity of the tripartite structure and the relations between Negative Affect, Positive Affect, and Physiological Hyperarousal (PH) were investigated for boys and girls, younger (8-11…

  9. Physical Origins of Thermal Properties of Cement Paste

    NASA Astrophysics Data System (ADS)

    Abdolhosseini Qomi, Mohammad Javad; Ulm, Franz-Josef; Pellenq, Roland J.-M.

    2015-06-01

    Despite the ever-increasing interest in multiscale porous materials, the chemophysical origin of their thermal properties at the nanoscale and its connection to the macroscale properties still remain rather obscure. In this paper, we link the atomic- and macroscopic-level thermal properties by combining tools of statistical physics and mean-field homogenization theory. We begin with analyzing the vibrational density of states of several calcium-silicate materials in the cement paste. Unlike crystalline phases, we indicate that calcium silicate hydrates (CSH) exhibit extra vibrational states at low frequencies (<2 THz ) compared to the vibrational states predicted by the Debye model. This anomaly is commonly referred to as the boson peak in glass physics. In addition, the specific-heat capacity of CSH in both dry and saturated states scales linearly with the calcium-to-silicon ratio. We show that the nanoscale-confining environment of CSH decreases the apparent heat capacity of water by a factor of 4. Furthermore, full thermal conductivity tensors for all phases are calculated via the Green-Kubo formalism. We estimate the mean free path of phonons in calcium silicates to be on the order of interatomic bonds. This satisfies the scale separability condition and justifies the use of mean-field homogenization theories for upscaling purposes. Upscaling schemes yield a good estimate of the macroscopic specific-heat capacity and thermal conductivity of cement paste during the hydration process, independent of fitting parameters.

  10. Does severity of dermatochalasis in aging affect corneal biomechanical properties?

    PubMed Central

    Atalay, Kurşat; Gurez, Ceren; Kirgiz, Ahmet; Serefoglu Cabuk, Kubra

    2016-01-01

    Purpose The aim of this study was to investigate the possibility of a relationship between corneal biomechanical properties and different grades of dermatochalasis. Patients and methods Patients were assigned to four groups according to the severity of their dermatochalasis: normal (Group 1), mild (Group 2), moderate (Group 3), and severe (Group 4). An Ocular Response Analyzer device was used to measure corneal hysteresis (CH), corneal resistance factor (CRF), and corneal-compensated intraocular pressure (IOPcc). Results We found no significant differences in the mean values of the CH, CRF, and IOPcc of all groups (P=0.75, P=0.93, and P=0.11, respectively). However, CH and IOPcc were negatively correlated in Group 1, Group 2, and Group 3 patients (P=0.013, r=−0.49; P=0.015, r=−0.52; and P=0.011, r=−0.47, respectively), but this correlation was not apparent in the Group 4 patients (P=0.57, r=0.12). CRF and IOPcc were correlated, but only in Group 4 (P=0.001, r=0.66). Conclusion Severe dermatochalasis was associated with altered corneal biomechanical properties. Some of the important visual consequences of dermatochalasis and related diseases (such as floppy eyelid syndrome) can be understood by considering corneal biomechanical alterations. PMID:27274214

  11. Short communication: Factors affecting coagulation properties of Mediterranean buffalo milk.

    PubMed

    Cecchinato, A; Penasa, M; Gotet, C Cipolat; De Marchi, M; Bittante, G

    2012-04-01

    The aim of this study was to investigate sources of variation of milk coagulation properties (MCP) of buffalo cows. Individual milk samples were collected from 200 animals in 5 herds located in northern Italy from January to March 2010. Rennet coagulation time (RCT, min) and curd firmness after 30 min from rennet addition (a(30), mm) were measured using the Formagraph instrument (Foss Electric, Hillerød, Denmark). In addition to MCP, information on milk yield, fat, protein, and casein contents, pH, and somatic cell count (SCC) was available. Sources of variation of RCT and a(30) were investigated using a linear model that included fixed effects of herd, days in milk (DIM), parity, fat content, casein content (only for a(30)), and pH. The coefficient of determination was 51% for RCT and 48% for a(30). The most important sources of variation of MCP were the herd and pH effects, followed by DIM and fat content for RCT, and casein content for a(30). The relevance of acidity in explaining the variation of both RCT and a(30), and of casein content in explaining that of a(30), confirmed previous studies on dairy cows. Although future research is needed to investigate the effect of these sources of variation on cheese yield, findings from the present study suggest that casein content and acidity may be used as indicator traits to improve technological properties of buffalo milk. PMID:22459819

  12. QA/QC requirements for physical properties sampling and analysis

    SciTech Connect

    Innis, B.E.

    1993-07-21

    This report presents results of an assessment of the available information concerning US Environmental Protection Agency (EPA) quality assurance/quality control (QA/QC) requirements and guidance applicable to sampling, handling, and analyzing physical parameter samples at Comprehensive Environmental Restoration, Compensation, and Liability Act (CERCLA) investigation sites. Geotechnical testing laboratories measure the following physical properties of soil and sediment samples collected during CERCLA remedial investigations (RI) at the Hanford Site: moisture content, grain size by sieve, grain size by hydrometer, specific gravity, bulk density/porosity, saturated hydraulic conductivity, moisture retention, unsaturated hydraulic conductivity, and permeability of rocks by flowing air. Geotechnical testing laboratories also measure the following chemical parameters of soil and sediment samples collected during Hanford Site CERCLA RI: calcium carbonate and saturated column leach testing. Physical parameter data are used for (1) characterization of vadose and saturated zone geology and hydrogeology, (2) selection of monitoring well screen sizes, (3) to support modeling and analysis of the vadose and saturated zones, and (4) for engineering design. The objectives of this report are to determine the QA/QC levels accepted in the EPA Region 10 for the sampling, handling, and analysis of soil samples for physical parameters during CERCLA RI.

  13. Progress in physical properties of Chinese stock markets

    NASA Astrophysics Data System (ADS)

    Liang, Yuan; Yang, Guang; Huang, Ji-Ping

    2013-08-01

    In the past two decades, statistical physics was brought into the field of finance, applying new methods and concepts to financial time series and developing a new interdiscipline "econophysics". In this review, we introduce several commonly used methods for stock time series in econophysics including distribution functions, correlation functions, detrended fluctuation analysis method, detrended moving average method, and multifractal analysis. Then based on these methods, we review some statistical properties of Chinese stock markets including scaling behavior, long-term correlations, cross-correlations, leverage effects, antileverage effects, and multifractality. Last, based on an agent-based model, we develop a new option pricing model — financial market model that shows a good agreement with the prices using real Shanghai Index data. This review is helpful for people to understand and research statistical physics of financial markets.

  14. Rheological properties of ovalbumin hydrogels as affected by surfactants addition.

    PubMed

    Hassan, Natalia; Messina, Paula V; Dodero, Veronica I; Ruso, Juan M

    2011-04-01

    The gel properties of ovalbumin mixtures with three different surfactants (sodium perfluorooctanoate, sodium octanoate and sodium dodecanoate) have been studied by rheological techniques. The gel elasticities were determined as a function of surfactant concentration and surfactant type. The fractal dimension of the formed structures was evaluated from plots of storage modulus against surfactant concentration. The role of electrostatic, hydrophobic and disulfide SS interactions in these systems has been demonstrated to be the predominant. The viscosity of these structures tends to increase with surfactant concentration, except for the fluorinated one. Unfolded ovalbumin molecules tend to form fibrillar structures that tend to increase with surfactant concentration, except for the fluorinated one. This fact has been related to the particular nature of this molecule.

  15. Dietary levels of acrylamide affect rat cardiomyocyte properties.

    PubMed

    Walters, Brandan; Hariharan, Venkatesh; Huang, Hayden

    2014-09-01

    The toxic effects of acrylamide on cytoskeletal integrity and ion channel balance is well-established in many cell types, but there has been little examination regarding the effects of acrylamide on primary cardiomyocytes, despite the importance of such components in their function. Furthermore, acrylamide toxicity is generally examined using concentrations higher than those found in vivo under starch-rich diets. Accordingly, we sought to characterize the dose-dependent effects of acrylamide on various properties, including cell morphology, contraction patterns, and junctional connexin 43 staining, in primary cardiomyocytes. We show that several days exposure to 1-100 μM acrylamide resulted in altered morphology, irregular contraction patterns, and an increase in the amount of immunoreactive signal for connexin 43 at cell junctions. We conclude that dietary levels of acrylamide may alter cellular function with prolonged exposure, in primary cardiomyocytes.

  16. Protein composition affects variation in coagulation properties of buffalo milk.

    PubMed

    Bonfatti, V; Gervaso, M; Rostellato, R; Coletta, A; Carnier, P

    2013-07-01

    The aim of this study was to investigate the effects exerted by the content of casein and whey protein fractions on variation of pH, rennet-coagulation time (RCT), curd-firming time (K20), and curd firmness of Mediterranean buffalo individual milk. Measures of milk protein composition and assessment of genotypes at CSN1S1 and CSN3 were obtained by reversed-phase HPLC analysis of 621 individual milk samples. Increased content of αS1-casein (CN) was associated with delayed coagulation onset and increased K20, whereas average pH, RCT, and K20 decreased when β-CN content increased. Milk with low κ-CN content exhibited low pH and RCT relative to milk with high content of κ-CN. Increased content of glycosylated κ-CN was associated with unfavorable effects on RCT. Effects of milk protein composition on curd firmness were less important than those on pH, RCT, and K20. Likely, this occurred as a consequence of the very short RCT of buffalo milk, which guaranteed a complete strengthening of the curd even in the restricted 31 min time of analysis of coagulation properties and for samples initially showing soft curds. Effects of CSN1S1-CSN3 genotypes on coagulation properties were not to be entirely ascribed to existing variation in milk protein composition associated with polymorphisms at CSN1S1 and CSN3 genes. Although the role of detailed milk protein composition in variation of cheese yield needs to be further investigated, findings of this study suggest that modification of the relative content of specific CN fractions can relevantly influence the behavior of buffalo milk during processing.

  17. Neural heterogeneities and stimulus properties affect burst coding in vivo.

    PubMed

    Avila-Akerberg, O; Krahe, R; Chacron, M J

    2010-06-16

    Many neurons tend to fire clusters of action potentials called bursts followed by quiescence in response to sensory input. While the mechanisms that underlie burst firing are generally well understood in vitro, the functional role of these bursts in generating behavioral responses to sensory input in vivo are less clear. Pyramidal cells within the electrosensory lateral line lobe (ELL) of weakly electric fish offer an attractive model system for studying the coding properties of burst firing, because the anatomy and physiology of the electrosensory circuitry are well understood, and the burst mechanism of ELL pyramidal cells has been thoroughly characterized in vitro. We investigated the coding properties of bursts generated by these cells in vivo in response to mimics of behaviorally relevant sensory input. We found that heterogeneities within the pyramidal cell population had quantitative but not qualitative effects on burst coding for the low frequency components of broadband time varying input. Moreover, spatially localized stimuli mimicking, for example, prey tended to elicit more bursts than spatially global stimuli mimicking conspecific-related stimuli. We also found small but significant correlations between burst attributes such as the number of spikes per burst or the interspike interval during the burst and stimulus attributes such as stimulus amplitude or slope. These correlations were much weaker in magnitude than those observed in vitro. More surprisingly, our results show that correlations between burst and stimulus attributes actually decreased in magnitude when we used low frequency stimuli that are expected to promote burst firing. We propose that this discrepancy is attributable to differences between ELL pyramidal cell burst firing under in vivo and in vitro conditions.

  18. Protein composition affects variation in coagulation properties of buffalo milk.

    PubMed

    Bonfatti, V; Gervaso, M; Rostellato, R; Coletta, A; Carnier, P

    2013-07-01

    The aim of this study was to investigate the effects exerted by the content of casein and whey protein fractions on variation of pH, rennet-coagulation time (RCT), curd-firming time (K20), and curd firmness of Mediterranean buffalo individual milk. Measures of milk protein composition and assessment of genotypes at CSN1S1 and CSN3 were obtained by reversed-phase HPLC analysis of 621 individual milk samples. Increased content of αS1-casein (CN) was associated with delayed coagulation onset and increased K20, whereas average pH, RCT, and K20 decreased when β-CN content increased. Milk with low κ-CN content exhibited low pH and RCT relative to milk with high content of κ-CN. Increased content of glycosylated κ-CN was associated with unfavorable effects on RCT. Effects of milk protein composition on curd firmness were less important than those on pH, RCT, and K20. Likely, this occurred as a consequence of the very short RCT of buffalo milk, which guaranteed a complete strengthening of the curd even in the restricted 31 min time of analysis of coagulation properties and for samples initially showing soft curds. Effects of CSN1S1-CSN3 genotypes on coagulation properties were not to be entirely ascribed to existing variation in milk protein composition associated with polymorphisms at CSN1S1 and CSN3 genes. Although the role of detailed milk protein composition in variation of cheese yield needs to be further investigated, findings of this study suggest that modification of the relative content of specific CN fractions can relevantly influence the behavior of buffalo milk during processing. PMID:23684020

  19. MEASUREMENTS OF BLACK CARBON PARTICLES CHEMICAL, PHYSICAL, AND OPTICAL PROPERTIES

    SciTech Connect

    Onasch, T.B.; Sedlacek, A.; Cross, E. S.; Davidovits, P.; Worsnop, D. R.; Ahern, A.; Lack, D. A.; Cappa, C. D.; Trimborn, A.; Freedman, A.; Olfert, J. S.; Jayne, J. T.; Massoli, P.; Williams, L. R.; Mazzoleni, C.; Schwarz, J. P.; Thornhill, D. A.; Slowik, J. G.; Kok, G. L.; Brem, B. T.; Subramanian, R.; Spackman, J. R.; Freitag, S.; and Dubey, M. K.

    2009-12-14

    Accurate measurements of the chemical, physical, and optical properties of aerosol particles containing black carbon are necessary to improve current estimates of the radiative forcing in the atmosphere. A collaborative research effort between Aerodyne Research, Inc. and Boston College has focused on conducting field and laboratory experiments on carbonaceous particles and the development and characterization of new particulate instrumentation. This presentation will focus on the chemical, physical, and optical properties of black carbon particles measured in the laboratory in order to understand the effects of atmospheric processing on black carbon particles. Results from a three-week study during July 2008 of mass- and optical-based black carbon measurements will be presented. The project utilized the Boston College laboratory flame apparatus and aerosol conditioning and characterization equipment. A pre-mixed flat flame burner operating at controlled fuel-to-air ratios produced stable and reproducible concentrations of soot particles with known sizes, morphologies, and chemical compositions. In addition, other black carbon particle types, including fullerene soot, glassy carbon spheres, oxidized flame soot, Regal black, and Aquadag, were also atomized, size selected, and sampled. The study covered an experimental matrix that systematically selected particle mobility size (30 to 300 nm) and black carbon particle mass, particle number concentration, particle shape (dynamic shape factor and fractal dimension), and particle chemistry and density (changed via coatings). Particles were coated with a measured thickness (few nm to {approx}150 nm) of sulfuric acid or bis (2-ethylhexyl) sebacate and passed through a thermal denuder to remove the coatings. Highlights of the study to be presented include: (1) Characterization of the chemical and physical properties of various types of black carbon particles, (2) Mass specific absorption measurements as a function of fuel

  20. Affect and Subsequent Physical Activity: An Ambulatory Assessment Study Examining the Affect-Activity Association in a Real-Life Context

    PubMed Central

    Niermann, Christina Y. N.; Herrmann, Christian; von Haaren, Birte; van Kann, Dave; Woll, Alexander

    2016-01-01

    Traditionally, cognitive, motivational, and volitional determinants have been used to explain and predict health behaviors such as physical activity. Recently, the role of affect in influencing and regulating health behaviors received more attention. Affects as internal cues may automatically activate unconscious processes of behavior regulation. The aim of our study was to examine the association between affect and physical activity in daily life. In addition, we studied the influence of the habit of being physically active on this relationship. An ambulatory assessment study in 89 persons (33.7% male, 25 to 65 years, M = 45.2, SD = 8.1) was conducted. Affect was assessed in the afternoon on 5 weekdays using smartphones. Physical activity was measured continuously objectively using accelerometers and subjectively using smartphones in the evening. Habit strength was assessed at the beginning of the diary period. The outcomes were objectively and subjectively measured moderate-to-vigorous physical activity (MVPA) performed after work. Multilevel regression models were used to analyze the association between affect and after work MVPA. In addition, the cross-level interaction of habit strength and affect on after work MVPA was tested. Positive affect was positively related to objectively measured and self-reported after work MVPA: the greater the positive affect the more time persons subsequently spent on MVPA. An inverse relationship was found for negative affect: the greater the negative affect the less time persons spent on MVPA. The cross-level interaction effect was significant only for objectively measured MVPA. A strong habit seems to strengthen both the positive influence of positive affect and the negative influence of negative affect. The results of this study confirm previous results and indicate that affect plays an important role for the regulation of physical activity behavior in daily life. The results for positive affect were consistent. However, in

  1. Affect and Subsequent Physical Activity: An Ambulatory Assessment Study Examining the Affect-Activity Association in a Real-Life Context.

    PubMed

    Niermann, Christina Y N; Herrmann, Christian; von Haaren, Birte; van Kann, Dave; Woll, Alexander

    2016-01-01

    Traditionally, cognitive, motivational, and volitional determinants have been used to explain and predict health behaviors such as physical activity. Recently, the role of affect in influencing and regulating health behaviors received more attention. Affects as internal cues may automatically activate unconscious processes of behavior regulation. The aim of our study was to examine the association between affect and physical activity in daily life. In addition, we studied the influence of the habit of being physically active on this relationship. An ambulatory assessment study in 89 persons (33.7% male, 25 to 65 years, M = 45.2, SD = 8.1) was conducted. Affect was assessed in the afternoon on 5 weekdays using smartphones. Physical activity was measured continuously objectively using accelerometers and subjectively using smartphones in the evening. Habit strength was assessed at the beginning of the diary period. The outcomes were objectively and subjectively measured moderate-to-vigorous physical activity (MVPA) performed after work. Multilevel regression models were used to analyze the association between affect and after work MVPA. In addition, the cross-level interaction of habit strength and affect on after work MVPA was tested. Positive affect was positively related to objectively measured and self-reported after work MVPA: the greater the positive affect the more time persons subsequently spent on MVPA. An inverse relationship was found for negative affect: the greater the negative affect the less time persons spent on MVPA. The cross-level interaction effect was significant only for objectively measured MVPA. A strong habit seems to strengthen both the positive influence of positive affect and the negative influence of negative affect. The results of this study confirm previous results and indicate that affect plays an important role for the regulation of physical activity behavior in daily life. The results for positive affect were consistent. However, in

  2. The clouds of Venus. [physical and chemical properties

    NASA Technical Reports Server (NTRS)

    Young, A. T.

    1975-01-01

    The physical and chemical properties of the clouds of Venus are reviewed, with special emphasis on data that are related to cloud dynamics. None of the currently-popular interpretations of cloud phenomena on Venus is consistent with all the data. Either a considerable fraction of the observational evidence is faulty or has been misinterpreted, or the clouds of Venus are much more complex than the current simplistic models. Several lines of attack are suggested to resolve some of the contradictions. A sound understanding of the clouds appears to be several years in the future.

  3. Physical properties of coriander seeds at different moisture content

    NASA Astrophysics Data System (ADS)

    Balasubramanian, S.; Singh, K. K.; Kumar, R.

    2012-10-01

    Physical properties of coriander seeds were determined at moisture content of 3.5-17.7%, d.b. The major axis and 1 000 seeds mass were found to decrease nonlinearly with increase in seed moisture. The medium and minor axes, geometric mean diameter, sphericity, unit volume, surface area and angle of repose increased linearly. Bulk density decreased linearly, however the true density increased non-linearly. The coefficient of static friction increased nonlinearly for different surfaces with increase in moisture level and its maximum was found for plywood surface. The rupture force and energy absorbed decreased linearly with increasing moisture content.

  4. Effects of Surface Coating on Physical Properties of Silver Nanoparticles

    NASA Astrophysics Data System (ADS)

    Tariq, M.; Hasnain, S. M.

    2015-08-01

    Polymer-coated nanoparticles improve the stability of materials against aggregation and enhance the physical properties, thus making it possible to use different applications in vast fields of science. In this work, silver nanoparticles were synthesized by a chemical reduction method and were further coated with the polymers polyvinyl alcohol (PVA) and polystyrene (PS). The influence of the polymer coating on the optical and electrical properties of the silver nanoparticles were investigated and compared with that of as-prepared silver nanoparticles. The nature of the prepared silver nanoparticles in the face-centered cubic structure is confirmed by peaks in the x-ray diffraction pattern. The temperature dependence of resistivity of the silver nanoparticles exhibit semiconducting behavior in the temperature range 100-300 K.

  5. Physical properties of alternatives to the fully halogenated chlorofluorocarbons

    NASA Technical Reports Server (NTRS)

    Mclinden, Mark O.

    1990-01-01

    Presented here are recommended values and correlations of selected physical properties of several alternatives to the fully halogenated chlorocarbons. The quality of the data used in this compilation varies widely, ranging from well-documented, high accuracy measurements from published sources to completely undocumented values listed on anonymous data sheets. That some of the properties for some fluids are available only from the latter type of source is clearly not the desired state of affairs. While some would reject all such data, the compilation given here is presented in the spirit of laying out the present state of knowledge and making available a set of data in a timely manner, even though its quality is sometimes uncertain. The correlations presented here are certain to change quickly as additional information becomes available.

  6. Nanoionic devices: Interface nanoarchitechtonics for physical property tuning and enhancement

    NASA Astrophysics Data System (ADS)

    Tsuchiya, Takashi; Terabe, Kazuya; Yang, Rui; Aono, Masakazu

    2016-11-01

    Nanoionic devices have been developed to generate novel functions overcoming limitations of conventional materials synthesis and semiconductor technology. Various physical properties can be tuned and enhanced by local ion transport near the solid/solid interface. Two electronic carrier doping methods can be used to achieve extremely high-density electronic carriers: one is electrostatic carrier doping using an electric double layer (EDL); the other is electrochemical carrier doping using a redox reaction. Atomistic restructuring near the solid/solid interface driven by a DC voltage, namely, interface nanoarchitechtonics, has huge potential. For instance, the use of EDL enables high-density carrier doping in potential superconductors, which can hardly accept chemical doping, in order to achieve room-temperature superconductivity. Optical bandgap and photoluminescence can be controlled for various applications including smart windows and biosensors. In situ tuning of magnetic properties is promising for low-power-consumption spintronics. Synaptic plasticity in the human brain is achieved in neuromorphic devices.

  7. Physical properties of superconducting single crystal iron sulfide

    NASA Astrophysics Data System (ADS)

    Rodriguez, Efrain E.; Borg, Christopher K. H.; Zhou, Xiuquan; Paglione, Johnpierre; University of Maryland Collaboration

    Recently, the simple binary tetragonal iron sulfide, FeS, was found to be a superconductor with a Tc = 5 K. We have prepared single crystals of tetragonal iron sulfide through hydrothermal de-intercalation of KxFe2-yS2. The KxFe2-yS2 single crystal precursors were grown by slow cooling of stoichiometric melts of K, Fe and S. The silver, plate-like FeS single crystals were highly crystalline with a superconducting transition temperature (Tc) of 4 K. The high quality of the FeS crystals revealed highly anisotropic nature of the magnetic and electronic properties intrinsic to FeS. The physical properties and thermal stability of single crystal FeS will be discussed in detail.

  8. Thermo-Physical Properties of Intermediate Temperature Heat Pipe Fluids

    NASA Technical Reports Server (NTRS)

    Beach, Duane E. (Technical Monitor); Devarakonda, Angirasa; Anderson, William G.

    2005-01-01

    Heat pipes are among the most promising technologies for space radiator systems. The paper reports further evaluation of potential heat pipe fluids in the intermediate temperature range of 400 to 700 K in continuation of two recent reports. More thermo-physical property data are examined. Organic, inorganic, and elemental substances are considered. The evaluation of surface tension and other fluid properties are examined. Halides are evaluated as potential heat pipe fluids. Reliable data are not available for all fluids and further database development is necessary. Many of the fluids considered are promising candidates as heat pipe fluids. Water is promising as a heat pipe fluid up to 500 to 550 K. Life test data for thermo-chemical compatibility are almost non-existent.

  9. Physical properties and compression loading behaviour of corn seed

    NASA Astrophysics Data System (ADS)

    Babić, Lj.; Radojèin, M.; Pavkov, I.; Babić, M.; Turan, J.; Zoranović, M.; Stanišić, S.

    2013-03-01

    The aim of this study was to acquire data on the physical properties and compression loading behaviour of seed of six corn hybrid varieties. The mean values of length, width, thickness, geometric diameter, surface area, porosity, single kernel mass, sphericity, bulk and true density, 1 000 kernelmass and coefficient of friction were studied at single level of corn seed moisture content. The calculated secant modulus of elasticity during compressive loading for dent corn was 0.995 times that of the semi-flint type; there were no significant differences in the value of this mechanical property between semi-flint and dent corn varieties. The linear model showed a decreasing tendency of secant modulus of elasticity for all hybrids as the moisture content of seeds increased.

  10. Thermo-Physical Properties of Intermediate Temperature Heat Pipe Fluids

    NASA Technical Reports Server (NTRS)

    Devarakonda, Angirasa; Anderson, William G.

    2004-01-01

    Heat pipes are among the most promising technologies for space radiator systems. The paper reports further evaluation of potential heat pipe fluids in the intermediate temperature range of 400 to 700 K in continuation of two recent reports. More thermo-physical property data are examined. Organic, inorganic and elemental substances are considered. The evaluation of surface tension and other fluid properties are examined. Halides are evaluated as potential heat pipe fluids. Reliable data are not available for all fluids and further database development in necessary. Many of the fluids considered are promising candidates as heat pipe fluids. Water is promising as a heat pipe fluid up to 500-550 K. Life test data for thermo-chemical compatibility are almost non-existent.

  11. The effects of physical environments in medical wards on medication communication processes affecting patient safety.

    PubMed

    Liu, Wei; Manias, Elizabeth; Gerdtz, Marie

    2014-03-01

    Physical environments of clinical settings play an important role in health communication processes. Effective medication management requires seamless communication among health professionals of different disciplines. This paper explores how physical environments affect communication processes for managing medications and patient safety in acute care hospital settings. Findings highlighted the impact of environmental interruptions on communication processes about medications. In response to frequent interruptions and limited space within working environments, nurses, doctors and pharmacists developed adaptive practices in the local clinical context. Communication difficulties were associated with the ward physical layout, the controlled drug key and the medication retrieving device. Health professionals should be provided with opportunities to discuss the effects of ward environments on medication communication processes and how this impacts medication safety. Hospital administrators and architects need to consider health professionals' views and experiences when designing hospital spaces. PMID:24486620

  12. The effects of physical environments in medical wards on medication communication processes affecting patient safety.

    PubMed

    Liu, Wei; Manias, Elizabeth; Gerdtz, Marie

    2014-03-01

    Physical environments of clinical settings play an important role in health communication processes. Effective medication management requires seamless communication among health professionals of different disciplines. This paper explores how physical environments affect communication processes for managing medications and patient safety in acute care hospital settings. Findings highlighted the impact of environmental interruptions on communication processes about medications. In response to frequent interruptions and limited space within working environments, nurses, doctors and pharmacists developed adaptive practices in the local clinical context. Communication difficulties were associated with the ward physical layout, the controlled drug key and the medication retrieving device. Health professionals should be provided with opportunities to discuss the effects of ward environments on medication communication processes and how this impacts medication safety. Hospital administrators and architects need to consider health professionals' views and experiences when designing hospital spaces.

  13. Physicochemical properties of foal meat as affected by cooking methods.

    PubMed

    Lorenzo, José M; Cittadini, Aurora; Munekata, Paulo E; Domínguez, Rubén

    2015-10-01

    The present study deals with the effect of four different cooking techniques (roasting, grilling, microwave baking and frying with olive oil) on physicochemical parameters (cooking loss, WHC, texture and colour) and lipid oxidation (by TBARS measurement) of foal meat. Thermal treatments induced water loss (P<0.001), being lower in foal steaks cooked in the grill (25.8%) and higher in foal samples cooked in the microwave (39.5%). As it was expected, all the cooking methods increased TBARS index, since high temperature during cooking seems to cause an increase of the lipid oxidation in foal steaks. Statistical analysis displayed that WHC was affected (P<0.001) by thermal treatment, since the smallest WHC values were observed in samples from microwave treatment. Thermal treatment also caused a significant (P<0.001) increase in the force needed to cut the foal steaks. Regarding colour parameter, cooking led to an increase of L*-value (lightness) and b*-value (yellowness), while a*-value (redness) markedly decreased in all samples.

  14. Physicochemical properties of foal meat as affected by cooking methods.

    PubMed

    Lorenzo, José M; Cittadini, Aurora; Munekata, Paulo E; Domínguez, Rubén

    2015-10-01

    The present study deals with the effect of four different cooking techniques (roasting, grilling, microwave baking and frying with olive oil) on physicochemical parameters (cooking loss, WHC, texture and colour) and lipid oxidation (by TBARS measurement) of foal meat. Thermal treatments induced water loss (P<0.001), being lower in foal steaks cooked in the grill (25.8%) and higher in foal samples cooked in the microwave (39.5%). As it was expected, all the cooking methods increased TBARS index, since high temperature during cooking seems to cause an increase of the lipid oxidation in foal steaks. Statistical analysis displayed that WHC was affected (P<0.001) by thermal treatment, since the smallest WHC values were observed in samples from microwave treatment. Thermal treatment also caused a significant (P<0.001) increase in the force needed to cut the foal steaks. Regarding colour parameter, cooking led to an increase of L*-value (lightness) and b*-value (yellowness), while a*-value (redness) markedly decreased in all samples. PMID:26042921

  15. Sodic soil properties and sunflower growth as affected by byproducts of flue gas desulfurization.

    PubMed

    Wang, Jinman; Bai, Zhongke; Yang, Peiling

    2012-01-01

    The main component of the byproducts of flue gas desulfurization (BFGD) is CaSO(4), which can be used to improve sodic soils. The effects of BFGD on sodic soil properties and sunflower growth were studied in a pot experiment. The experiment consisted of eight treatments, at four BFGD rates (0, 7.5, 15 and 22.5 t ha(-1)) and two leaching levels (750 and 1200 m(3) ha(-1)). The germination rate and yield of the sunflower increased, and the exchangeable sodium percentage (ESP), pH and total dissolved salts (TDS) in the soils decreased after the byproducts were applied. Excessive BFGD also affected sunflower germination and growth, and leaching improved reclamation efficiency. The physical and chemical properties of the reclaimed soils were best when the byproducts were applied at 7.5 t ha(-1) and water was supplied at 1200 m(3)·ha(-1). Under these conditions, the soil pH, ESP, and TDS decreased from 9.2, 63.5 and 0.65% to 7.8, 2.8 and 0.06%, and the germination rate and yield per sunflower reached 90% and 36.4 g, respectively. Salinity should be controlled by leaching when sodic soils are reclaimed with BFGD as sunflower growth is very sensitive to salinity during its seedling stage. PMID:23285042

  16. Sodic Soil Properties and Sunflower Growth as Affected by Byproducts of Flue Gas Desulfurization

    PubMed Central

    Wang, Jinman; Bai, Zhongke; Yang, Peiling

    2012-01-01

    The main component of the byproducts of flue gas desulfurization (BFGD) is CaSO4, which can be used to improve sodic soils. The effects of BFGD on sodic soil properties and sunflower growth were studied in a pot experiment. The experiment consisted of eight treatments, at four BFGD rates (0, 7.5, 15 and 22.5 t ha−1) and two leaching levels (750 and 1200 m3 ha−1). The germination rate and yield of the sunflower increased, and the exchangeable sodium percentage (ESP), pH and total dissolved salts (TDS) in the soils decreased after the byproducts were applied. Excessive BFGD also affected sunflower germination and growth, and leaching improved reclamation efficiency. The physical and chemical properties of the reclaimed soils were best when the byproducts were applied at 7.5 t ha−1 and water was supplied at 1200 m3·ha−1. Under these conditions, the soil pH, ESP, and TDS decreased from 9.2, 63.5 and 0.65% to 7.8, 2.8 and 0.06%, and the germination rate and yield per sunflower reached 90% and 36.4 g, respectively. Salinity should be controlled by leaching when sodic soils are reclaimed with BFGD as sunflower growth is very sensitive to salinity during its seedling stage. PMID:23285042

  17. Study of the physical properties of crystalline rocks in the southeast Voronezh anteclise

    NASA Technical Reports Server (NTRS)

    Dmitriyevskiy, V. S.; Afanasyev, N. S.; Frolov, S. M.

    1985-01-01

    The physical properties of rocks, in the crystalline mass of the Voronezh anteclise, were studied. The study of the physical properties of rocks is important for the improvement of geophysical methods for mapping crystalline rocks in the foundation and exploration of different geological objects which are associated with the crystalline foundation, covered by the sedimentary mantle. It is found that: (1) rocks in the crystalline foundation are very different in physical properties; (2) the physical properties are closely related to their substance composition and genesis; (3) petrographic properties give clues of rock afficiation to certain complexes; and (4) physical and magnetic properties should be examined by petrography, chemical and X-ray analysis.

  18. N-Methylmelamines: Synthesis, Characterization, and Physical Properties.

    PubMed

    List, Manuela; Puchinger, Helmut; Gabriel, Herbert; Monkowius, Uwe; Schwarzinger, Clemens

    2016-05-20

    N-Methylmelamines have recently gained importance as valuable compounds for manufacturing modified melamine formaldehyde resins and other polymer building blocks. A great advantage of these polymers is the reduction of the carcinogenic formaldehyde. Selecting the polymerization processes (e.g., substance polymerization, polymerization in solution) and controlling the polymerization reaction and properties of these novel materials requires knowledge of the properties of the individual melamine derivatives used as new building blocks. All possible permutations of N-methylmelamines were prepared, and reaction progress was monitored by GC/MS. 2,4,6-Tris(dimethylamino)-1,3,5-triazine was prepared to complete the series; this is, however, also a possible byproduct in various synthesis routes. The reaction conditions were optimized to obtain high yields of each derivative with the highest possible purity. The substances were characterized by NMR and IR spectroscopy, mass spectrometry, elemental analysis, and single-crystal X-ray diffraction. In addition, physical properties, such as solubility, melting points, and pKb values, were determined. The number of amino-, methylamino-, and dimethylamino groups has a significant effect on these properties. In summary, we found that by increasing the number of amino- and methylamino groups, solubility and pKb increase. With increasing number of amino groups, the compounds tend to form hydrogen bonds, and thus, the melting point shifts to higher temperature ranges where they start to decompose. PMID:27100712

  19. N-Methylmelamines: Synthesis, Characterization, and Physical Properties.

    PubMed

    List, Manuela; Puchinger, Helmut; Gabriel, Herbert; Monkowius, Uwe; Schwarzinger, Clemens

    2016-05-20

    N-Methylmelamines have recently gained importance as valuable compounds for manufacturing modified melamine formaldehyde resins and other polymer building blocks. A great advantage of these polymers is the reduction of the carcinogenic formaldehyde. Selecting the polymerization processes (e.g., substance polymerization, polymerization in solution) and controlling the polymerization reaction and properties of these novel materials requires knowledge of the properties of the individual melamine derivatives used as new building blocks. All possible permutations of N-methylmelamines were prepared, and reaction progress was monitored by GC/MS. 2,4,6-Tris(dimethylamino)-1,3,5-triazine was prepared to complete the series; this is, however, also a possible byproduct in various synthesis routes. The reaction conditions were optimized to obtain high yields of each derivative with the highest possible purity. The substances were characterized by NMR and IR spectroscopy, mass spectrometry, elemental analysis, and single-crystal X-ray diffraction. In addition, physical properties, such as solubility, melting points, and pKb values, were determined. The number of amino-, methylamino-, and dimethylamino groups has a significant effect on these properties. In summary, we found that by increasing the number of amino- and methylamino groups, solubility and pKb increase. With increasing number of amino groups, the compounds tend to form hydrogen bonds, and thus, the melting point shifts to higher temperature ranges where they start to decompose.

  20. Nuclear Envelopes Properties and Physical Interactions with Nucleoplasm

    NASA Astrophysics Data System (ADS)

    Discher, Dennis; Dahl, Kris; Wilson, Kathy

    2004-03-01

    Given the stresses imposed on a cell and its organelles and the nuclear envelope's important role as a barrier between cytoplasm and nucleoplasm, we sought to measure and model mechanical properties of isolated nuclear envelopes. Xenopus laevis oocyte (XO) nuclei are primarily used since they have been widely studied in many fields as model systems for nuclear structure and function. We manipulate the nuclear envelope by both osmotic swelling and micromanipulation to determine an effective elastic modulus. We show the envelope properties are independent of the effects of the nucleoplasm. Micropipette aspiration of XO nuclei gives an effective elastic modulus of the nuclear envelope of 250 mN/m with similar results obtained from isotropic swelling of XO nuclear envelopes. The results suggest that these nuclear envelopes have relatively homogeneous properties and are highly elastic, sustaining strains of 50-100Square-net simulations and comparisons to polymer network models suggests that XO nuclear envelope physical properties are dominated by the lamin network. If applicable to nuclei in other cells, a "pre-compressed" state envisioned here would allow for significant shear flexibility, especially important for motile cells whose nuclei need to rapidly deform.

  1. Greater effort boosts the affective taste properties of food

    PubMed Central

    Johnson, Alexander W.; Gallagher, Michela

    2011-01-01

    Actions can create preferences, increasing the value ascribed to commodities acquired at greater cost. This behavioural finding has been observed in a variety of species; however, the causal factors underlying the phenomenon are relatively unknown. We sought to develop a behavioural platform to examine the relationship between effort and reinforcer value in mice trained under demanding or lenient schedules of reinforcement to obtain food. In the initial experiment, expenditure of effort enhanced the value of the associated food via relatively lasting changes in its hedonic attributes, promoting an acquired preference for these reinforcers when tested outside of the training environment. Moreover, otherwise neutral cues associated with those reinforcers during training similarly acquired greater reinforcing value, as assessed under conditioned reinforcement. In a separate experiment, expenditure of effort was also capable of enhancing the value of less-preferred low-caloric reinforcers. Analysis of licking microstructure revealed the basis for this increased valuation was, in part, due to increased palatability of the associated reinforcer. This change in the hedonic taste properties of the food can not only serve as a basis for preference, but also guide decision-making and foraging behaviour by coordinating a potentially adaptive repertoire of incentive motivation, goal-directed action and consumption. PMID:21047860

  2. How Tissue Mechanical Properties Affect Enteric Neural Crest Cell Migration

    NASA Astrophysics Data System (ADS)

    Chevalier, N. R.; Gazguez, E.; Bidault, L.; Guilbert, T.; Vias, C.; Vian, E.; Watanabe, Y.; Muller, L.; Germain, S.; Bondurand, N.; Dufour, S.; Fleury, V.

    2016-02-01

    Neural crest cells (NCCs) are a population of multipotent cells that migrate extensively during vertebrate development. Alterations to neural crest ontogenesis cause several diseases, including cancers and congenital defects, such as Hirschprung disease, which results from incomplete colonization of the colon by enteric NCCs (ENCCs). We investigated the influence of the stiffness and structure of the environment on ENCC migration in vitro and during colonization of the gastrointestinal tract in chicken and mouse embryos. We showed using tensile stretching and atomic force microscopy (AFM) that the mesenchyme of the gut was initially soft but gradually stiffened during the period of ENCC colonization. Second-harmonic generation (SHG) microscopy revealed that this stiffening was associated with a gradual organization and enrichment of collagen fibers in the developing gut. Ex-vivo 2D cell migration assays showed that ENCCs migrated on substrates with very low levels of stiffness. In 3D collagen gels, the speed of the ENCC migratory front decreased with increasing gel stiffness, whereas no correlation was found between porosity and ENCC migration behavior. Metalloprotease inhibition experiments showed that ENCCs actively degraded collagen in order to progress. These results shed light on the role of the mechanical properties of tissues in ENCC migration during development.

  3. How Tissue Mechanical Properties Affect Enteric Neural Crest Cell Migration

    PubMed Central

    Chevalier, N.R.; Gazguez, E.; Bidault, L.; Guilbert, T.; Vias, C.; Vian, E.; Watanabe, Y.; Muller, L.; Germain, S.; Bondurand, N.; Dufour, S.; Fleury, V.

    2016-01-01

    Neural crest cells (NCCs) are a population of multipotent cells that migrate extensively during vertebrate development. Alterations to neural crest ontogenesis cause several diseases, including cancers and congenital defects, such as Hirschprung disease, which results from incomplete colonization of the colon by enteric NCCs (ENCCs). We investigated the influence of the stiffness and structure of the environment on ENCC migration in vitro and during colonization of the gastrointestinal tract in chicken and mouse embryos. We showed using tensile stretching and atomic force microscopy (AFM) that the mesenchyme of the gut was initially soft but gradually stiffened during the period of ENCC colonization. Second-harmonic generation (SHG) microscopy revealed that this stiffening was associated with a gradual organization and enrichment of collagen fibers in the developing gut. Ex-vivo 2D cell migration assays showed that ENCCs migrated on substrates with very low levels of stiffness. In 3D collagen gels, the speed of the ENCC migratory front decreased with increasing gel stiffness, whereas no correlation was found between porosity and ENCC migration behavior. Metalloprotease inhibition experiments showed that ENCCs actively degraded collagen in order to progress. These results shed light on the role of the mechanical properties of tissues in ENCC migration during development. PMID:26887292

  4. Factors Affecting Length of Stay in Adult Outpatient Physical Rehabilitation: A Scoping Review of the Literature

    PubMed Central

    Da Costa, Christina; Turgeon-Provost, Félix; Dagenais, Kristin; Roy-Mathie, Bianca; Aggban, Martina; Preuss, Richard

    2015-01-01

    ABSTRACT Purpose: To identify factors affecting length of stay (LOS) for adults participating in outpatient physical or occupational therapy programmes. Method: A scoping review of the literature was conducted using the Ovid MEDLINE, EMBASE, CINAHL, AMED, and Cochrane Library databases. Results: A total of 19 articles were retained from the search, and 2 additional articles were retrieved from grey literature (i.e., non-published sources). Personal factors affecting LOS are age and sex, both of which had inconsistent effects on LOS, and communication, language, physical, and cognitive difficulties, for which higher levels of function were generally associated with shorter LOS. Institutional factors affecting LOS were location, interdisciplinary communication, number of disciplines involved, and type of rehabilitation setting. Finally, two clinician-related factors—fewer treatment goals and a selection of evidence-informed treatment techniques—were associated with shorter LOS. Conclusions: Research on factors affecting adult outpatient rehabilitation LOS is limited and inconsistent. A preliminary list of LOS factors was produced, but this topic should be further explored with the collaboration of researchers and clinical institutions. PMID:27504032

  5. Physical Activity, Mind Wandering, Affect, and Sleep: An Ecological Momentary Assessment

    PubMed Central

    Mackenzie, Michael; Roberts, Sarah; Crato, Ines; Ehlers, Diane; McAuley, Edward

    2016-01-01

    Background A considerable portion of daily thought is spent in mind wandering. This behavior has been related to positive (eg, future planning, problem solving) and negative (eg, unhappiness, impaired cognitive performance) outcomes. Objective Based on previous research suggesting future-oriented (ie, prospective) mind wandering may support autobiographical planning and self-regulation, this study examined associations between hourly mind wandering and moderate-to-vigorous physical activity (MVPA), and the impact of affect and daily sleep on these relations. Methods College-aged adults (N=33) participated in a mobile phone-delivered ecological momentary assessment study for 1 week. Sixteen hourly prompts assessing mind wandering and affect were delivered daily via participants’ mobile phones. Perceived sleep quality and duration was assessed during the first prompt each day, and participants wore an ActiGraph accelerometer during waking hours throughout the study week. Results Study findings suggest present-moment mind wandering was positively associated with future MVPA (P=.03), and this relationship was moderated by affective state (P=.04). Moreover, excessive sleep the previous evening was related to less MVPA across the following day (P=.007). Further, mind wandering was positively related to activity only among those who did not oversleep (P=.007). Conclusions Together, these results have implications for multiple health behavior interventions targeting physical activity, affect, and sleep. Researchers may also build on this work by studying these relationships in the context of other important behaviors and psychosocial factors (eg, tobacco use, depression, loneliness). PMID:27580673

  6. Characterizing Fault Damage Zones in the Field and Laboratory; Scaling and Physical Properties

    NASA Astrophysics Data System (ADS)

    Faulkner, D. R.; Armitage, P. J.; Blake, O. O.; Mitchell, T. M.

    2011-12-01

    Fault damage zones are a key component of faults as they control the fluid flow, rupture and seismological properties of faults. Fracturing around faults occurs on a range of scales, from small scale (microfracturing) to larger scale (macrofracturing), with varying intensities ranging from background levels to pervasive pulverization of the country rock. Fracturing generally results in permeability increases in crystalline rocks. Fracturing in the damage zone during earthquake rupture leads to energy loss, and pre-existing fracture damage and associated modifications of elastic properties may control rupture properties such as directivity. Despite their importance, the full characterization of the spatial extent of damage zones and their associated physical properties is still at an early stage. Recent field measurements of the width of damage zones suggest that they scale positively with fault displacement, although this relationship is masked by other parameters such as depth of faulting, lithology, mode of faulting and tectonic environment. The well-established exponential decay of fracture damage with distance from the fault likely relates to elastic decay of stress. Determining the physical properties of natural fault damage zones has proved problematic, as fault-related fractures in the damage zones are commonly modified by healing and sealing, and the rocks are generally affected by exhumation. Another approach is to mimic the level of fracture damage on the small scale in laboratory experiments on initially intact rocks. Here, experiments have been completed under triaxial stresses. Variably fractured samples are produced by stress cycling, and the seismic velocity, crack surface area and permeability have been measured. These physical properties can be mapped onto natural fault damage zones by relating the fracture damage in laboratory samples with that in natural faults. The results give insights into the transport properties of faults and the energy

  7. Photo-physical properties of 2-(1-ethynylpyrene)-adenosine: influence of hydrogen bonding on excited state properties.

    PubMed

    Trojanowski, P; Plötner, J; Grünewald, C; Graupner, F F; Slavov, C; Reuss, A J; Braun, M; Engels, J W; Wachtveitl, J

    2014-07-21

    The photo-physical properties of 2-(1-ethynylpyrene)-adenosine (PyA), a fluorescent probe for RNA dynamics, were examined by solvation studies. The excited-state dynamics display the influence of the vicinity on the spectral features. Combining improved transient absorption and streak camera measurements along with a new analysis method provide a detailed molecular picture of the photophysics. After intramolecular vibrational energy redistribution (IVR), two distinct states are observed. Solvent class (protic/aprotic) and permittivity strongly affect the properties of these states and their population ratio. As a result their emission spectrum is altered, while the fluorescence quantum yield and the overall lifetime remain nearly unchanged. Consequently, the hitherto existing model of the photophysics is herein refined and extended. The findings can serve as basis for improving the information content of measurements with PyA as a label in RNA. PMID:24894337

  8. Physical-chemical property based sequence motifs and methods regarding same

    DOEpatents

    Braun, Werner; Mathura, Venkatarajan S.; Schein, Catherine H.

    2008-09-09

    A data analysis system, program, and/or method, e.g., a data mining/data exploration method, using physical-chemical property motifs. For example, a sequence database may be searched for identifying segments thereof having physical-chemical properties similar to the physical-chemical property motifs.

  9. Physical and mechanical properties of calf lumbosacral trabecular bone.

    PubMed

    Swartz, D E; Wittenberg, R H; Shea, M; White, A A; Hayes, W C

    1991-01-01

    The physical and mechanical properties of calf lumbar and sacral trabecular bone were determined and compared with those of human trabecular bone. The mean tissue density (1.66 +/- 0.12 g cm-3), equivalent mineral density (169 +/- 36 mg cm-3), apparent density (453 +/- 89 mg cm-3), ash density (194 +/- 59 mg cm-3), ash content (0.6 +/- 0.05%), compressive strength (7.1 +/- 3.0 MPa) and compressive modulus (173 +/- 97 MPa) of calf trabecular bone are similar to those of young human. There were moderate, positive linear correlations between apparent density and equivalent mineral density, ash density, and compressive strength; and between compressive strength and equivalent mineral density (R2 ranging from 0.35 to 0.48, p less than 0.001). Apparent density, ash density, and equivalent mineral density did not differ significantly in different regions. In contrast to humans, the compressive strength increased from posterior, near the facet, to the anterior vertebral body. These comparisons of physical and mechanical properties, as well as anatomical comparisons by others, indicate that the calf spine is a good model of the young non-osteoporotic human spine and thus useful for the testing of spinal instrumentation.

  10. [Physical and chemical properties of vanadium and its compounds].

    PubMed

    Tudares, C

    1998-04-01

    Vanadium is present in the earth crust mainly in the heavy oils, carbons and bituminous materials, where is associated with the heavy fractions. Many live beings have vanadium in their tissues. Their industrial applications are fundamentally based in the physical and chemical properties. From the environmental point of view the vanadium emissions to the atmosphere are produced in areas around siderurgical industries, oil refineries and cities that use fossil fuels for heating. The pollution process in these areas is associated partially with the presence of vanadium compounds, as is the case in the eastern coast of the lake of Maracaibo, Venezuela. Some clinical-epidemiological researches report a high incidence of congenital malformations at the Central Nervous System level, and this has been associated with the intense oil activities of the region. The high incidence of the Central Nervous System congenital malformations could be associated with the vanadium compounds present in the eastern coast of the lake of Maracaibo; here is the interest in the physical and chemical properties knowledge of vanadium and their compounds.

  11. Physical properties of ice cream containing milk protein concentrates.

    PubMed

    Alvarez, V B; Wolters, C L; Vodovotz, Y; Ji, T

    2005-03-01

    Two milk protein concentrates (MPC, 56 and 85%) were studied as substitutes for 20 and 50% of the protein content in ice cream mix. The basic mix formula had 12% fat, 11% nonfat milk solids, 15% sweetener, and 0.3% stabilizer/emulsifier blend. Protein levels remained constant, and total solids were compensated for in MPC mixes by the addition of polydextrose. Physical properties investigated included apparent viscosity, fat globule size, melting rate, shape retention, and freezing behavior using differential scanning calorimetry. Milk protein concentrate formulations had higher mix viscosity, larger amount of fat destabilization, narrower ice melting curves, and greater shape retention compared with the control. Milk protein concentrates did not offer significant modifications of ice cream physical properties on a constant protein basis when substituted for up to 50% of the protein supplied by nonfat dry milk. Milk protein concentrates may offer ice cream manufacturers an alternative source of milk solids non-fat, especially in mixes reduced in lactose or fat, where higher milk solids nonfat are needed to compensate other losses of total solids.

  12. Circulating tumor cell enrichment based on physical properties

    PubMed Central

    Harouaka, Ramdane A.; Nisic, Merisa; Zheng, Si-Yang

    2013-01-01

    The metastatic dissemination and spread of malignant circulating tumor cells (CTCs) accounts for over 90% of cancer related deaths. CTCs detach from a primary tumor, travel through the circulatory system, then invade and proliferate in distant organs. The detection of CTCs from blood has been established for prognostic monitoring and is predictive of patient outcome. Analysis of CTCs could enable the means for early detection and screening in cancer, as well as provide diagnostic access to tumor tissues in a minimally invasive way. The fundamental challenge with analyzing CTCs is the fact that they occur at extremely low concentrations in blood, on the order of one out of a billion cells. Various technologies have been proposed to isolate CTCs for enrichment. Here we focus on antigen-independent approaches that are not limited by specific capture antibodies. Intrinsic physical properties of CTCs including cell size, deformability, and electrical properties are reviewed, and technologies developed to exploit them for enrichment from blood are summarized. Physical enrichment technologies are of particular interest as they have the potential to increase yield, and enable the analysis of rare CTC phenotypes that may not be otherwise obtained. PMID:23832928

  13. Hanford Waste Physical and Rheological Properties: Data and Gaps - 12078

    SciTech Connect

    Kurath, D.E.; Wells, B.E.; Huckaby, J.L.; Mahoney, L.A.; Daniel, R.C.; Burns, C.A.; Tingey, J.M.; Cooley, S.K.

    2012-07-01

    The retrieval, transport, treatment and disposal operations associated with Hanford Tank Wastes involve the handling of a wide range of slurries. Knowledge of the physical and rheological properties of the waste is a key component to the success of the design and implementation of the waste processing facilities. Previous efforts to compile and analyze the physical and rheological properties were updated with new results including information on solids composition and density, particle size distributions, slurry rheology, and particle settling behavior. The primary source of additional data is from a recent series of tests sponsored by the Hanford Waste Treatment and Immobilization Plant (WTP). These tests involved an extensive suite of characterization and bench-scale process testing of 8 waste groups representing approximately 75% of the high-level waste mass expected to be processed through the WTP. Additional information on the morphology of the waste solids was also included. Based on the updated results, a gap analysis to identify gaps in characterization data, analytical methods and data interpretation was completed. (authors)

  14. Hanford Waste Physical and Rheological Properties: Data and Gaps

    SciTech Connect

    Kurath, Dean E.; Wells, Beric E.; Huckaby, James L.; Mahoney, Lenna A.; Daniel, Richard C.; Burns, Carolyn A.; Tingey, Joel M.; Cooley, Scott K.

    2012-03-01

    The retrieval, transport, treatment and disposal operations associated with Hanford Tank Wastes involve the handling of a wide range of slurries. Knowledge of the physical and rheological properties of the waste is a key component to the success of the design and implementation of the waste processing facilities. Previous efforts to compile and analyze the physical and rheological properties were updated with new results including information on solids composition and density, particle size distributions, slurry rheology, and particle settling behavior. The primary source of additional data is from a recent series of tests sponsored by the Hanford Waste Treatment and Immobilization Plant. These tests involved an extensive suite of characterization and bench-scale process testing of 8 waste groups representing approximately 75% of the high-level waste mass expected to be processed through the WTP. Additional information on the morphology of the waste solids was also included. Based on the updated results, a gap analysis to identify gaps in characterization data, analytical methods and data interpretation was completed.

  15. Physical properties of polymorphic yeast prion amyloid fibers.

    PubMed

    Castro, Carlos E; Dong, Jijun; Boyce, Mary C; Lindquist, Susan; Lang, Matthew J

    2011-07-20

    Amyloid fibers play important roles in many human diseases and natural biological processes and have immense potential as novel nanomaterials. We explore the physical properties of polymorphic amyloid fibers formed by yeast prion protein Sup35. Amyloid fibers that conferred distinct prion phenotypes ([PSI(+)]), strong (S) versus weak (W) nonsense suppression, displayed different physical properties. Both S[PSI(+)] and W[PSI(+)] fibers contained structural inhomogeneities, specifically local regions of static curvature in S[PSI(+)] fibers and kinks and self-cross-linking in W[PSI(+)] fibers. Force-extension experiments with optical tweezers revealed persistence lengths of 1.5 μm and 3.3 μm and axial stiffness of 5600 pN and 9100 pN for S[PSI(+)] and W[PSI(+)] fibers, respectively. Thermal fluctuation analysis confirmed the twofold difference in persistence length between S[PSI(+)] and W[PSI(+)] fibers and revealed a torsional stiffness of kinks and cross-links of ~100-200 pN·nm/rad. PMID:21767497

  16. Physical Properties of Saturn's Rings from Cassini Radio Occultations

    NASA Astrophysics Data System (ADS)

    Marouf, Essam A.; French, R.; Rappaport, N.; Wong, K.; McGhee, C.; Anabtawi, A.

    2008-09-01

    Twenty-four one-sided Cassini radio occultation observations have been successfully completed. Two types of observations provide information about physical ring properties. The first is differential extinction of three sinusoidal signals simultaneously transmitted through the rings (0.94, 3.6, and 13 cm-wavelength). The observations reveal remarkable variability among the three main rings, A, B, and C, and across local features within each ring. Assuming "classical” ring model and solid water ice composition, comparison of observed differential optical depth with theoretical predictions based on a power-law size distribution constrains the power law index and the minimum radius of abundant particle sizes. In particular, the smallest particle radius in most of Ring C, inner Ring B, and outer ring A appear to be limited to about 4 to 5 mm, and in regions B2 and B4 of Ring B, and in the inner region of Ring A to be greater than few tens of centimeters. The second observation type is the near-forward scattered signal. The measured spectrograms provide characterization of the collective diffraction pattern of the particles and particle clusters. In ring regions where gravitational wakes are likely absent, inversion of the spectral measurement yields the size distribution of particles of radius > about 1 m. The results are consistent with the Voyager results, showing sharp upper size cutoff in the few to several meters radius range. In regions of gravitational wakes, we constrain physical ring properties using comparisons of the observations with predictions of Monte-Carlo simulations of extinction and near-forward diffraction by randomly blocked diffraction screen ring models. The comparisons constrain particle cluster sizes, spatial density, orientation, and ring vertical thickness. The simulations also allow for investigation of physical ring models that account in a self-consistent manner for observed variation of optical depth and forward scattering with ring

  17. Quasar Spectral Energy Distributions As A Function Of Physical Property

    NASA Astrophysics Data System (ADS)

    Townsend, Shonda; Ganguly, R.; Stark, M. A.; Derseweh, J. A.; Richmond, J. M.

    2012-05-01

    Galaxy evolution models have shown that quasars are a crucial ingredient in the evolution of massive galaxies. Outflows play a key role in the story of quasars and their host galaxies, by helping regulate the accretion process, the star-formation rate and mass of the host galaxy (i.e., feedback). The prescription for modeling outflows as a contributor to feedback requires knowledge of the outflow velocity, geometry, and column density. In particular, we need to understand how these depend on physical parameters and how much is determined stochastically (and with what distribution). In turn, models of outflows have shown particular sensitivity to the shape of the spectral energy distribution (SED), depending on the UV luminosity to transfer momentum to the gas, the X-ray luminosity to regulate how efficiently that transfer can be, etc. To investigate how SED changes with physical properties, we follow up on Richards et al. (2006), who constructed SEDs with varying luminosity. Here, we construct SEDs as a function of redshift, and physical property (black hole mass, bolometric luminosity, Eddington ratio) for volume limited samples drawn from the Sloan Digital Sky Survey, with photometry supplemented from 2MASS, WISE, GALEX, ROSAT, and Chandra. To estimate black hole masses, we adopt the scaling relations from Greene & Ho (2005) based on the H-alpha emission line FWHM. This requires redshifts less than 0.4. To construct volume-limited subsamples, we begin by adopting g=19.8 as a nominal limiting magnitude over which we are guaranteed to detect z<0.4 quasars. At redshift 0.4, we are complete down to Mg=-21.8, which yields 3300 objects from Data Release 7. At z=0.1, we are complete down to Mg=-18.5. This material is based upon work supported by the National Aeronautics and Space Administration under Grant No. 09-ADP09-0016 issued through the Astrophysics Data Analysis Program.

  18. Physical and functional properties of arrowroot starch extrudates.

    PubMed

    Jyothi, A N; Sheriff, J T; Sajeev, M S

    2009-03-01

    Arrowroot starch, a commercially underexploited tuber starch but having potential digestive and medicinal properties, has been subjected to extrusion cooking using a single screw food extruder. Different levels of feed moisture (12%, 14%, and 16%) and extrusion temperatures (140, 150, 160, 170, 180, and 190 degrees C) were used for extrusion. The physical properties--bulk density, true density, porosity, and expansion ratio; functional properties such as water absorption index, water solubility index, oil absorption index, pasting, rheological, and textural properties; and in vitro enzyme digestibility of the extrudates were determined. The expansion ratio of the extrudates ranged from 3.22 to 6.09. The water absorption index (6.52 to 8.85 g gel/g dry sample), water solubility index (15.92% to 41.31%), and oil absorption index (0.50 to 1.70 g/g) were higher for the extrudates in comparison to native starch (1.81 g gel/g dry sample, 1.16% and 0.60 g/g, respectively). The rheological properties, storage modulus, and loss modulus of the gelatinized powdered extrudates were significantly lower (P < 0.05) and these behaved like solutions rather than a paste or a gel. Hardness and toughness were more for the samples extruded at higher feed moisture and lower extrusion temperature, whereas snap force and energy were higher at lower feed moisture and temperature. There was a significant decrease in the percentage digestibility of arrowroot starch (30.07% after 30 min of incubation with the enzyme) after extrusion (25.27% to 30.56%). Extrusion cooking of arrowroot starch resulted in products with very good expansion, color, and lower digestibility, which can be exploited for its potential use as a snack food. PMID:19323747

  19. Physical and functional properties of arrowroot starch extrudates.

    PubMed

    Jyothi, A N; Sheriff, J T; Sajeev, M S

    2009-03-01

    Arrowroot starch, a commercially underexploited tuber starch but having potential digestive and medicinal properties, has been subjected to extrusion cooking using a single screw food extruder. Different levels of feed moisture (12%, 14%, and 16%) and extrusion temperatures (140, 150, 160, 170, 180, and 190 degrees C) were used for extrusion. The physical properties--bulk density, true density, porosity, and expansion ratio; functional properties such as water absorption index, water solubility index, oil absorption index, pasting, rheological, and textural properties; and in vitro enzyme digestibility of the extrudates were determined. The expansion ratio of the extrudates ranged from 3.22 to 6.09. The water absorption index (6.52 to 8.85 g gel/g dry sample), water solubility index (15.92% to 41.31%), and oil absorption index (0.50 to 1.70 g/g) were higher for the extrudates in comparison to native starch (1.81 g gel/g dry sample, 1.16% and 0.60 g/g, respectively). The rheological properties, storage modulus, and loss modulus of the gelatinized powdered extrudates were significantly lower (P < 0.05) and these behaved like solutions rather than a paste or a gel. Hardness and toughness were more for the samples extruded at higher feed moisture and lower extrusion temperature, whereas snap force and energy were higher at lower feed moisture and temperature. There was a significant decrease in the percentage digestibility of arrowroot starch (30.07% after 30 min of incubation with the enzyme) after extrusion (25.27% to 30.56%). Extrusion cooking of arrowroot starch resulted in products with very good expansion, color, and lower digestibility, which can be exploited for its potential use as a snack food.

  20. Aerosols physical properties at Hada Al Sham, western Saudi Arabia

    NASA Astrophysics Data System (ADS)

    Lihavainen, H.; Alghamdi, M. A.; Hyvärinen, A.-P.; Hussein, T.; Aaltonen, V.; Abdelmaksoud, A. S.; Al-Jeelani, H.; Almazroui, M.; Almehmadi, F. M.; Al Zawad, F. M.; Hakala, J.; Khoder, M.; Neitola, K.; Petäjä, T.; Shabbaj, I. I.; Hämeri, K.

    2016-06-01

    This is the first time to clearly derive the comprehensive physical properties of aerosols at a rural background area in Saudi Arabia. Aerosol measurements station was established at a rural background area in the Western Saudi Arabia to study the aerosol properties. This study gives overview of the aerosol physical properties (PM10, PM2.5, black carbon and total number concentration) over the measurement period from November 2012 to February 2015. The average PM10 and PM2.5 concentrations were 95 ± 78 μg m-3 (mean ± STD, at ambient conditions) and 33 ± 68 μg m-3 (at ambient conditions), respectively. As expected PM10 concentration was dominated by coarse mode particles (PM10-PM2.5), most probably desert dust. Especially from February to June the coarse mode concentrations were high because of dust storm season. Aerosol mass concentrations had clear diurnal cycle. Lower values were observed around noon. This behavior is caused by wind direction and speed, during night time very calm easterly winds are dominating whereas during daytime the stronger westerly winds are dominating (sea breeze). During the day time the boundary layer is evolving, causing enhanced mixing and dilution leading to lower concentration. PM10 and PM2.5 concentrations were comparable to values measured at close by city of Jeddah. Black carbon concentration was about 2% and 6% of PM10 and PM2.5 mass, respectively. Total number concentration was dominated by frequent new particle formation and particle growth events. The typical diurnal cycle in particle total number concentration was clearly different from PM10 and PM2.5.

  1. Planetary Defense and the High Temperture Physical Properties of Meteorites.

    NASA Astrophysics Data System (ADS)

    Ostrowski, D. R.; Sears, D. W. G.; Bryson, K.

    2015-12-01

    The Ames Meteorite Characterization Laboratory is examining the physical proprerties of a diverse selection of meteorites. Each meteorite will be processed by the full suite of observations and measurements: petrographic/microscopic studies, density, porosity, albedo, shock effects, thermal conductivity, heat capacity, emissivity, and acoustic velocity. Of these measurments, density and porosity are the most studied to date (Macke, 2010; Britt and Consolmagno, 2003). The thermal properties of meteorites are less well understood. Thermal conductivity, heat capacity, and thermal emissivity are important data for a number of applications but especially to understanding the behavior of a meteor as it passes through the atmosphere. Opeil et al. (2010) have shown that meteorites have a thermal conductivities lower than the pure minerals they are composed of by a factor of 3 to 10, with the values coming to a roughly constant number from 150 to 300 K. Calculated conductivity numbers from Yomogida and Matsui (1983) show the H chondrites have the higest conductivity in the range of 3.8 W/m*K at 200 K and then slowly decreases to 3.2 W/m*K at 400 K. Whereas they show the LL chondrites do not reach 1 W/m*K over the temperature range 100 to 400 K. While there have been several high temperature spectroscopic studies of meteorites, to date all experimental data for the physical properties of meteorites were obtained at temperatures below 400 K, since previous studies were made in attempts to understand the formation and evolution of asteroids. Our laboratory will focus on understanding the thermal properties of materials at temperatures above 300 K and, where possible, up to atmospheric entry temperatures. Work on pure minerals has shown that thermal conductivity decreases as temperatures exceed 300 K but it is unknown whether this holds true for meteorites. We will describe our laboratory and procedures, and present some preliminary data, at the meeting.

  2. Physical properties of ebony seed (Pithecellobium flexicaule) and functional properties of whole and defatted ebony seed meal.

    PubMed

    Hernández-Santos, Betsabé; Santiago-Adame, Rubén; Navarro-Cortéz, Ricardo O; Gómez-Aldapa, Carlos A; Castro-Rosas, Javier; Martínez-Sánchez, Cecilia E; Vivar-Vera, María A; Herman-Lara, Erasmo; Rodríguez-Miranda, Jesús

    2015-07-01

    A partial characterization was done of ebony (Pithecellobium flexicaule) seed physical properties, and how defatting affected some functional properties of ebony seed meal. Average seed dimensions were 13.02 mm length, 8.78 mm width and 9.65 mm thickness. Geometric diameter was 10.76 mm, volume was 530 mm(3), surface area was 364.33 mm(2), sphericity was 83.26 % and aspect ratio was 68.24 %. Thousand-seed weight was 0.70 Kg, of which 0.42 Kg (60 %) represented the kernel. Defatted ebony seed meal differed from whole meal in all measured parameters, particularly in its protein (44.72 g/100 g) and carbohydrates (44.12 g/100 g) proportions. The defatted meal had higher water absorption capacity (1.28 g/g sample), water solubility capacity (26.06 %), oil absorption capacity (2.04 g/g sample), emulsifying capacity (53.78 %) and gelling capacity (8 % w/v) than the whole meal. Ebony seed physical properties may prove useful in designing post-harvest processing equipment and in quality control. The high protein content of defatted ebony seed meal suggests its use as a natural alternative ingredient in numerous food industry applications.

  3. Do government brochures affect physical activity cognition? A pilot study of Canada's physical activity guide to healthy active living.

    PubMed

    Kliman, Aviva M; Rhodes, Ryan

    2008-08-01

    Health Canada has published national physical activity (PA) guidelines, which are included in their 26-page Physical Activity Guide to Healthy Active Living (CPAG). To date, the use of CPAG as a motivational instrument for PA promotion has not been evaluated. The purpose of this study was to determine whether reading CPAG 1) increased motivational antecedents to engage in regular PA, and 2) increased regular PA intention and behaviour over 1 month. Participants included 130 randomly sampled Canadian adults (18 years or older) who were randomly mailed pack ages consisting of either 1) a questionnaire and a copy of CPAG, or 2) a questionnaire. Questionnaire items pertained to participants' sociodemographics, previous PA behaviours (Godin Leisure-Time Questionnaire) and PA motivation (theory of planned behaviour). Participants were then sent a follow-up questionnaire pertaining to their PA behaviours throughout the previous month. Results revealed significant interactions between the guide condition and previous activity status on instrumental behavioural beliefs about strength activities and subjective norms about endurance activities (p < 0.05), but all other factors were not significantly different. It was concluded that among previously inactive people, receiving this guide may change some informational/motivational constructs, but key motivational antecedents (affective attitude, perceived behavioural control) and outcomes (intention, behaviour) seem unaffected. PMID:18825580

  4. Relationships between physical properties and sequence in silkworm silks

    NASA Astrophysics Data System (ADS)

    Malay, Ali D.; Sato, Ryota; Yazawa, Kenjiro; Watanabe, Hiroe; Ifuku, Nao; Masunaga, Hiroyasu; Hikima, Takaaki; Guan, Juan; Mandal, Biman B.; Damrongsakkul, Siriporn; Numata, Keiji

    2016-06-01

    Silk has attracted widespread attention due to its superlative material properties and promising applications. However, the determinants behind the variations in material properties among different types of silk are not well understood. We analysed the physical properties of silk samples from a variety of silkmoth cocoons, including domesticated Bombyx mori varieties and several species from Saturniidae. Tensile deformation tests, thermal analyses, and investigations on crystalline structure and orientation of the fibres were performed. The results showed that saturniid silks produce more highly-defined structural transitions compared to B. mori, as seen in the yielding and strain hardening events during tensile deformation and in the changes observed during thermal analyses. These observations were analysed in terms of the constituent fibroin sequences, which in B. mori are predicted to produce heterogeneous structures, whereas the strictly modular repeats of the saturniid sequences are hypothesized to produce structures that respond in a concerted manner. Within saturniid fibroins, thermal stability was found to correlate with the abundance of poly-alanine residues, whereas differences in fibre extensibility can be related to varying ratios of GGX motifs versus bulky hydrophobic residues in the amorphous phase.

  5. Structure and physical properties of Hydrogrossular mineral series

    NASA Astrophysics Data System (ADS)

    Adhikari, Puja

    The mineral hydrogrossular series (Ca3Al2(SiO 4)3-x(OH)4x; 0 ≤ x ≤ 3) are important water bearing minerals found in the upper and lower part of the Earth's mantle. They are vital to the planet's hydrosphere under different hydrothermal conditions. The composition and structure of this mineral series are important in geoscience and share many commonalities with cement and clay materials. Other than the end members of the series x = 0 (grossular) and x = 3 (katoite) which have a cubic garnet structure, the structure of the series is totally unknown. We used large-scale ab initio modeling to investigate the structures and properties for hydrogrossular series for x = 0, 0.5, 1, 1.5, 2, 2.5, 3. Results indicate that for x > 0 and x < 3, the structures are tetragonal. This shows that there is structural change related to the lowering of overall symmetry associated with the composition of SiO4 tetrahedra and AlO6 octahedra. Total Bond order also explains the reason behind the change in the compressibility of the series. The electronic structure, mechanical and optical properties of the hydrogrossular series are calculated and the results for grossular and katoite are in good agreement with the available experimental data. The x--dependence of these physical properties for the series supports the notion of the aforementioned structural transition from cubic to tetragonal.

  6. Relationships between physical properties and sequence in silkworm silks

    PubMed Central

    Malay, Ali D.; Sato, Ryota; Yazawa, Kenjiro; Watanabe, Hiroe; Ifuku, Nao; Masunaga, Hiroyasu; Hikima, Takaaki; Guan, Juan; Mandal, Biman B.; Damrongsakkul, Siriporn; Numata, Keiji

    2016-01-01

    Silk has attracted widespread attention due to its superlative material properties and promising applications. However, the determinants behind the variations in material properties among different types of silk are not well understood. We analysed the physical properties of silk samples from a variety of silkmoth cocoons, including domesticated Bombyx mori varieties and several species from Saturniidae. Tensile deformation tests, thermal analyses, and investigations on crystalline structure and orientation of the fibres were performed. The results showed that saturniid silks produce more highly-defined structural transitions compared to B. mori, as seen in the yielding and strain hardening events during tensile deformation and in the changes observed during thermal analyses. These observations were analysed in terms of the constituent fibroin sequences, which in B. mori are predicted to produce heterogeneous structures, whereas the strictly modular repeats of the saturniid sequences are hypothesized to produce structures that respond in a concerted manner. Within saturniid fibroins, thermal stability was found to correlate with the abundance of poly-alanine residues, whereas differences in fibre extensibility can be related to varying ratios of GGX motifs versus bulky hydrophobic residues in the amorphous phase. PMID:27279149

  7. Computational Studies of Physical Properties of Boron Carbide

    SciTech Connect

    Lizhi Ouyang

    2011-09-30

    The overall goal is to provide valuable insight in to the mechanisms and processes that could lead to better engineering the widely used boron carbide which could play an important role in current plight towards greener energy. Carbon distribution in boron carbide, which has been difficult to retrieve from experimental methods, is critical to our understanding of its structure-properties relation. For modeling disorders in boron carbide, we implemented a first principles method based on supercell approach within our G(P,T) package. The supercell approach was applied to boron carbide to determine its carbon distribution. Our results reveal that carbon prefers to occupy the end sites of the 3-atom chain in boron carbide and further carbon atoms will distribute mainly on the equatorial sites with a small percentage on the 3-atom chains and the apex sites. Supercell approach was also applied to study mechanical properties of boron carbide under uniaxial load. We found that uniaxial load can lead to amorphization. Other physical properties of boron carbide were calculated using the G(P,T) package.

  8. Relationships between physical properties and sequence in silkworm silks.

    PubMed

    Malay, Ali D; Sato, Ryota; Yazawa, Kenjiro; Watanabe, Hiroe; Ifuku, Nao; Masunaga, Hiroyasu; Hikima, Takaaki; Guan, Juan; Mandal, Biman B; Damrongsakkul, Siriporn; Numata, Keiji

    2016-01-01

    Silk has attracted widespread attention due to its superlative material properties and promising applications. However, the determinants behind the variations in material properties among different types of silk are not well understood. We analysed the physical properties of silk samples from a variety of silkmoth cocoons, including domesticated Bombyx mori varieties and several species from Saturniidae. Tensile deformation tests, thermal analyses, and investigations on crystalline structure and orientation of the fibres were performed. The results showed that saturniid silks produce more highly-defined structural transitions compared to B. mori, as seen in the yielding and strain hardening events during tensile deformation and in the changes observed during thermal analyses. These observations were analysed in terms of the constituent fibroin sequences, which in B. mori are predicted to produce heterogeneous structures, whereas the strictly modular repeats of the saturniid sequences are hypothesized to produce structures that respond in a concerted manner. Within saturniid fibroins, thermal stability was found to correlate with the abundance of poly-alanine residues, whereas differences in fibre extensibility can be related to varying ratios of GGX motifs versus bulky hydrophobic residues in the amorphous phase. PMID:27279149

  9. Gamma irradiation influence on physical properties of milk proteins

    NASA Astrophysics Data System (ADS)

    Cieśla, K.; Salmieri, S.; Lacroix, M.; Tien, C. Le

    2004-09-01

    Gamma irradiation was found to be an effective method for the improvement of both barrier and mechanical properties of the edible films and coatings based on calcium and sodium caseinates alone or combined with some globular proteins. Our current studies concern gamma irradiation influence on the physical properties of calcium caseinate-whey protein isolate-glycerol (1:1:1) solutions and gels, used for films preparation. Irradiation of solutions was carried out with Co-60 gamma rays applying 0 and 32 kGy dose. The increase in viscosity of solutions was found after irradiation connected to induced crosslinking. Lower viscosity values were detected, however, after heating of the solutions irradiated with a 32 kGy dose than after heating of the non-irradiated ones regarding differences in the structure of gels and resulting in different temperature-viscosity curves that were recorded for the irradiated and the non-irradiated samples during heating and cooling. Creation of less stiff but better ordered gels after irradiation arises probably from reorganisation of aperiodic helical phase and β-sheets, in particular from increase of β-strands, detected by FTIR. Films obtained from these gels are characterised by improved barrier properties and mechanical resistance and are more rigid than those prepared from the non-irradiated gels. The route of gel creation was investigated for the control and the irradiated samples during heating and the subsequent cooling.

  10. Phytoplankton behavior affects ocean mixed layer dynamics through biological-physical feedback mechanisms

    NASA Astrophysics Data System (ADS)

    Sonntag, S.; Hense, I.

    2011-08-01

    Biologically induced changes in physical oceanic properties through phytoplankton provide potential positive and negative feedback loops. In particular, surface floating cyanobacteria, which are expected to be favored from future environmental conditions and can form large surface mats, can increase light absorption and the surface albedo and decrease momentum input from the atmosphere by wind. In this work we study the effect of a changing phytoplankton community composition to one dominated by buoyant cyanobacteria on the physical oceanic properties. We use the water column model General Ocean Turbulence Model and set up an idealized biological model taking into account the phytoplankton species' characteristics as well as the effects of biology on physics. The model results show that an increase of buoyant cyanobacteria leads to substantial changes in the seasonal cycle of the mixed layer. The results furthermore indicate that the effects due to altered absorption and biologically induced reduction of the wind drag are larger than contrary effects due to changes in the surface albedo. Overall, our model results suggest that the development of cyanobacterial surface blooms and their feedbacks on light absorption and wind drag need to be taken into account in ocean models used for climate scenarios in order to capture changes in the dynamics of the upper ocean.

  11. Nurses' perceptions of how physical environment affects medication errors in acute care settings.

    PubMed

    Mahmood, Atiya; Chaudhury, Habib; Valente, Maria

    2011-11-01

    The work that nurses perform in hospital environments is physically and psychologically intense, with the potential for burnout and stress. This issue is compounded by crowded and poorly designed work spaces in nursing units that can contribute to medical mistakes, including medication errors. This article is based on a study that examined the nurses' perception of how the physical environment in hospitals affects medication errors. Literature suggests that reduction of staff stress can be achieved through physical environmental considerations, such as improved air quality, acoustics, and lighting. However, there is no empirical study specifically exploring the relationship between aspects of the physical environment and medication errors. In this study, a cross-sectional survey was conducted with nursing staff (N = 84) in four hospitals in the Pacific Northwest region of the United States. The survey included questions on nursing unit design, medication room configurations, perceived incidence of errors, and adverse events. Respondents noted several physical environmental factors that are potentially problematic in the nursing station area and can lead to medication, documentation, and other types of nursing errors. These factors include inadequate space in charting and documentation area, lengthy walking distances to patient rooms, insufficient patient surveillance opportunity/lack of visibility to all parts of the nursing unit, small size of the medication room, inappropriate organization of medical supplies, high noise levels in nursing unit, poor lighting, and lack of privacy in the nursing stations. As administrators in acute care facilities consider strategies for organizational and staff interventions to reduce medication errors, it is important to consider physical environmental factors to have a comprehensive understanding of the issue.

  12. PHYSICAL PROPERTIES AND CHEMICAL COMPOSITION OF BETA-GLUCANS FROM FLESHY FUNGI.

    PubMed

    WALLEN, L L; RHODES, R A; SHULKE, H R

    1965-03-01

    Physical properties and chemical structure of two related polysaccharides produced fermentatively by Plectania occidentalis NRRL 3137 and by Helotium sp. NRRL 3129 were studied. Both polymers were readily recovered as amorphous gels by precipitation from culture liquors with two parts of ethyl alcohol or methanol. Dried polymeric material was redissolved in water with agitation to give uniform aqueous solutions up to about 1.5% by weight. The polymers were similar in physical properties but possessed different chemical structures. The viscosity of aqueous solutions of each polymer varied from about 50 centipoises at 0.1% to approximately 2,200 centipoises at 1.4% concentrations by weight. Highly viscous solutions at concentrations of 1% or greater behaved like thixotropic gels. Mono-, di-, and trivalent salts, except borate, did not affect viscosity of either polymer. The viscosities were slightly increased by the addition of borate. Autoclaving did not alter the physical properties of neutral polymer solutions. The polymers were stable in acid or alkaline solutions at moderate temperatures but degraded under extremes of pH at 70 C or above. Each polymer had a specific rotation of +20 degrees in aqueous dimethylformamide (1:1). The results of acid hydrolysis and periodate oxidation, in conjunction with paper and gas chromatography, indicate that both polymers are branched glucans containing appreciable amounts of beta-1,3 linkages.

  13. Role of olive oil phenolics in physical properties and stability of mayonnaise-like emulsions.

    PubMed

    Giacintucci, Veronica; Di Mattia, Carla; Sacchetti, Giampiero; Neri, Lilia; Pittia, Paola

    2016-12-15

    The effect of olive oil phenolic content and pattern on the physical properties and stability of olive oil mayonnaise-like emulsions has been investigated. Mayonnaises were formulated with either naturally phenolic-rich extra virgin olive oils or purified olive oil artificially enriched with a phenolic-rich olive extract and pure oleuropein. Mayonnaises were characterized by droplet size distribution, microstructure, textural properties and flow behaviour. The addition of phenolic extracts significantly affected the dispersion degree of the corresponding mayonnaise-like emulsions, their microstructure and physical stability especially in the systems prepared with purified olive oil treated with pure oleuropein and the highest olive phenolic extract concentration. The viscosity and back-extrusion analyses evidenced that the systems characterized by a relatively high content of phenolics, either natural or by addition, presented lower yield stress and viscosity indices and were easier to deform and to break. This study confirms the main role of olive phenolic compounds, and in particular that of oleuropein, in the dispersion state, and physical properties of emulsions with main effects on their quality and stability.

  14. Effects of preparation steps on the physical parameters and electromechanical properties of IPMC actuators

    NASA Astrophysics Data System (ADS)

    Wang, Yanjie; Zhu, Zicai; Chen, Hualing; Luo, Bin; Chang, Longfei; Wang, Yongquan; Li, Dichen

    2014-12-01

    The electromechanical properties of ionic polymer-metal composites (IPMC) are affected by many factors, including resistivity of surface electrodes, bending stiffness and dielectric modulus, etc, which are closely related to physical and chemical preparation steps. This paper focuses on the effects of preparation steps on these physical parameters and electromechanical properties of IPMC actuators. The mechanisms of electrode formation in the preparation steps are also clarified and investigated. To obtain samples with different features, one or more of the crucial process steps, including pretreatment, impregnation-reduction and chemical plating, were selected to fabricate IPMC. The experimental observations revealed that the physical parameters of IPMC strongly depend on their electrode morphologies caused by different steps, which were reasonable from the standpoint of physics. IPMC with the characteristics of low surface resistance and low bending stiffness, and a large area of interface electrode exhibits a perfect performance. The improvements were considered to be attributed to the double-layer electrostatic effect, induced by the broad dispersion of penetrated electrode nanoparticles. An electrical component, consisting of an equivalent circuit of a parallel combination of the serial circuit of the resistance and the electric double-layer capacitance, is introduced to qualitatively explain the deformation behaviors of IPMC. This research helps to improve the preparation steps and promote the understanding of IPMC.

  15. Interacting Physical and Biological Processes Affecting Nutrient Transport Through Human Dominated Landscapes

    NASA Astrophysics Data System (ADS)

    Finlay, J. C.

    2015-12-01

    Human activities increasingly dominate biogeochemical cycles of limiting nutrients on Earth. Urban and agricultural landscapes represent the largest sources of excess nutrients that drive water quality degradation. The physical structure of both urban and agricultural watersheds has been extensively modified, and these changes have large impacts on water and nutrient transport. Despite strong physical controls over nutrient transport in human dominated landscapes, biological processes play important roles in determining the fates of both nitrogen and phosphorus. This talk uses examples from research in urban and agricultural watersheds in the Midwestern USA to illustrate interactions of physical and biological controls over nutrient cycles that have shifted nitrogen (N) and phosphorus (P) sources and cycling in unexpected ways in response to management changes. In urban watersheds, efforts to improve water quality have been hindered by legacy sources of phosphorus added to storm water through transport to drainage systems by vegetation. Similarly, reductions in field erosion in agricultural watersheds have not led to major reductions in phosphorus transport, because of continued release of biological sources of P. Where management of phosphorus has been most effective in reducing eutrophication of lakes, decreases in N removal processes have led to long term increases in N concentration and transport. Together, these examples show important roles for biological processes affecting nutrient movement in highly modified landscapes. Consideration of the downstream physical and biological responses of management changes are thus critical toward identification of actions that will most effectively reduce excess nutrients watersheds and coastal zones.

  16. A brief intervention affects parents' attitudes toward using less physical punishment.

    PubMed

    Chavis, Antwon; Hudnut-Beumler, Julia; Webb, Margaret W; Neely, Jill A; Bickman, Len; Dietrich, Mary S; Scholer, Seth J

    2013-12-01

    Consecutive English and Spanish speaking caregivers of 6-24 month old children were randomly assigned to either a control or intervention group. Parents in the intervention group were instructed to view at least 4 options to discipline a child in an interactive multimedia program. The control group participants received routine primary care with their resident physician. After the clinic visit, all parents were invited to participate in a research study; the participation rate was 98% (258/263). The key measure was the Attitudes Toward Spanking (ATS) scale. The ATS is correlated with parents' actual use of physical punishment. Parents with higher scores are more likely to use physical punishment to discipline their children. Parents in the intervention group had an ATS score that was significantly lower than the ATS score of parents in the control group (median=24.0, vs. median=30; p=0.043). Parents in the control group were 2 times more likely to report that they would spank a child who was misbehaving compared with parents in the intervention group (16.9% vs. 7.0%, p=0.015). In the short-term, a brief intervention, integrated into the primary care visit, can affect parents' attitudes toward using less physical punishment. It may be feasible to teach parents to not use physical punishment using a population-based approach. The findings have implications for how to improve primary care services and the prevention of violence.

  17. A brief intervention affects parents' attitudes toward using less physical punishment.

    PubMed

    Chavis, Antwon; Hudnut-Beumler, Julia; Webb, Margaret W; Neely, Jill A; Bickman, Len; Dietrich, Mary S; Scholer, Seth J

    2013-12-01

    Consecutive English and Spanish speaking caregivers of 6-24 month old children were randomly assigned to either a control or intervention group. Parents in the intervention group were instructed to view at least 4 options to discipline a child in an interactive multimedia program. The control group participants received routine primary care with their resident physician. After the clinic visit, all parents were invited to participate in a research study; the participation rate was 98% (258/263). The key measure was the Attitudes Toward Spanking (ATS) scale. The ATS is correlated with parents' actual use of physical punishment. Parents with higher scores are more likely to use physical punishment to discipline their children. Parents in the intervention group had an ATS score that was significantly lower than the ATS score of parents in the control group (median=24.0, vs. median=30; p=0.043). Parents in the control group were 2 times more likely to report that they would spank a child who was misbehaving compared with parents in the intervention group (16.9% vs. 7.0%, p=0.015). In the short-term, a brief intervention, integrated into the primary care visit, can affect parents' attitudes toward using less physical punishment. It may be feasible to teach parents to not use physical punishment using a population-based approach. The findings have implications for how to improve primary care services and the prevention of violence. PMID:23859768

  18. How contrast situations affect the assignment of causality in symmetric physical settings

    PubMed Central

    Beller, Sieghard; Bender, Andrea

    2015-01-01

    In determining the prime cause of a physical event, people often weight one of two entities in a symmetric physical relation as more important for bringing about the causal effect than the other. In a broad survey (Bender and Beller, 2011), we documented such weighting effects for different kinds of physical events and found that their direction and strength depended on a variety of factors. Here, we focus on one of those: adding a contrast situation that—while being formally irrelevant—foregrounds one of the factors and thus frames the task in a specific way. In two experiments, we generalize and validate our previous findings by using different stimulus material (in Experiment 1), by applying a different response format to elicit causal assignments, an analog rating scale instead of a forced-choice decision (in Experiment 2), and by eliciting explanations for the physical events in question (in both Experiments). The results generally confirm the contrast effects for both response formats; however, the effects were more pronounced with the force-choice format than with the rating format. People tended to refer to the given contrast in their explanations, which validates our manipulation. Finally, people’s causal assignments are reflected in the type of explanation given in that contrast and property explanations were associated with biased causal assignments, whereas relational explanations were associated with unbiased assignments. In the discussion, we pick up the normative questions of whether or not these contrast effects constitute a bias in causal reasoning. PMID:25620937

  19. How contrast situations affect the assignment of causality in symmetric physical settings.

    PubMed

    Beller, Sieghard; Bender, Andrea

    2014-01-01

    In determining the prime cause of a physical event, people often weight one of two entities in a symmetric physical relation as more important for bringing about the causal effect than the other. In a broad survey (Bender and Beller, 2011), we documented such weighting effects for different kinds of physical events and found that their direction and strength depended on a variety of factors. Here, we focus on one of those: adding a contrast situation that-while being formally irrelevant-foregrounds one of the factors and thus frames the task in a specific way. In two experiments, we generalize and validate our previous findings by using different stimulus material (in Experiment 1), by applying a different response format to elicit causal assignments, an analog rating scale instead of a forced-choice decision (in Experiment 2), and by eliciting explanations for the physical events in question (in both Experiments). The results generally confirm the contrast effects for both response formats; however, the effects were more pronounced with the force-choice format than with the rating format. People tended to refer to the given contrast in their explanations, which validates our manipulation. Finally, people's causal assignments are reflected in the type of explanation given in that contrast and property explanations were associated with biased causal assignments, whereas relational explanations were associated with unbiased assignments. In the discussion, we pick up the normative questions of whether or not these contrast effects constitute a bias in causal reasoning.

  20. Affective Properties of Mothers' Speech to Infants with Hearing Impairment and Cochlear Implants

    ERIC Educational Resources Information Center

    Kondaurova, Maria V.; Bergeson, Tonya R.; Xu, Huiping; Kitamura, Christine

    2015-01-01

    Purpose: The affective properties of infant-directed speech influence the attention of infants with normal hearing to speech sounds. This study explored the affective quality of maternal speech to infants with hearing impairment (HI) during the 1st year after cochlear implantation as compared to speech to infants with normal hearing. Method:…

  1. Psychometric Properties of the Affect Intensity and Reactivity Measure Adapted for Youth (AIR-Y)

    ERIC Educational Resources Information Center

    Jones, Rachel E.; Leen-Feldner, Ellen W.; Olatunji, Bunmi O.; Reardon, Laura E.; Hawks, Erin

    2009-01-01

    A valid and reliable instrument for measuring affect intensity does not exist for adolescents; such a measure may help to refine understanding of emotion among youths. The purpose of the current study was to evaluate the psychometric properties and clinical relevance of a measure of affect intensity adapted for youths. Two hundred five community…

  2. Physical properties of the WR stars in Westerlund 1

    NASA Astrophysics Data System (ADS)

    Rosslowe, C. K.; Crowther, P. A.; Clark, J. S.; Negueruela, I.

    The Westerlund 1 (Wd1) cluster hosts a rich and varied collection of massive stars. Its dynamical youth and the absence of ongoing star formation indicate a coeval population. As such, the simultaneous presence of both late-type supergiants and Wolf-Rayet stars has defied explanation in the context of single-star evolution. Observational evidence points to a high binary fraction, hence this stellar population offers a robust test for stellar models accounting for both single-star and binary evolution. We present an optical to near-IR (VLT & NTT) spectroscopic analysis of 22 WR stars in Wd 1, delivering physical properties for the WR stars. We discuss how these differ from the Galactic field population, and how they may be reconciled with the predictions of single and binary evolutionary models.

  3. Struvite-based fertilizer and its physical and chemical properties.

    PubMed

    Latifian, Maryam; Liu, Jing; Mattiasson, Bo

    2012-12-01

    This study describes a method to formulate struvite fine powder into pellets that are easy to spread on agricultural land. To evaluate the quality of produced pellets, some chemical and physical properties commonly measured for fertilizers were tested. The findings indicated that the salt index and heavy metal content ofstruvite pellets were significantly lower than those of commercial NPK fertilizers. In addition, the percentage of nutrient released from struvite pellets after 105 days was in the range of 9.6-23.2, 8.4-26.7 and 11.3-32.6% for nitrogen, phosphorous and magnesium, respectively, which is considerably lower than that of commercial NPK fertilizer. Among different formulations between struvite crystals and binders, starch and bentonite were the most efficient in agglomerating struvite powder, leading to an increase in the crush strength to over the recommended limit of >2.5 kgf for fertilizer hardness. PMID:23437670

  4. Some physical properties of ginkgo nuts and kernels

    NASA Astrophysics Data System (ADS)

    Ch'ng, P. E.; Abdullah, M. H. R. O.; Mathai, E. J.; Yunus, N. A.

    2013-12-01

    Some data of the physical properties of ginkgo nuts at a moisture content of 45.53% (±2.07) (wet basis) and of their kernels at 60.13% (± 2.00) (wet basis) are presented in this paper. It consists of the estimation of the mean length, width, thickness, the geometric mean diameter, sphericity, aspect ratio, unit mass, surface area, volume, true density, bulk density, and porosity measures. The coefficient of static friction for nuts and kernels was determined by using plywood, glass, rubber, and galvanized steel sheet. The data are essential in the field of food engineering especially dealing with design and development of machines, and equipment for processing and handling agriculture products.

  5. Physical properties of wild mango fruit and nut

    NASA Astrophysics Data System (ADS)

    Ehiem, J. C.; Simonyan, K. J.

    2012-02-01

    Physical properties of two wild mango varieties were studied at 81.9 and 24.5% moisture (w.b.) for the fruits and nuts, respectively. The shape and size of the fruit are the same while that of nuts differs at P = 0.05. The mass, density and bulk density of the fruits are statistically different at P = 0.05 but the volume is the same. The shape and size, volume and bulk density of the nuts are statistically the same at P = 0.05. The nuts of both varieties are also the same at P = 0.05 in terms of mass and density. The packing factor for both fruits and nut of the two varieties are the same at 0.95. The relevant data obtained for the two varieties would be useful for design and development of machines and equipment for processing and handling operations.

  6. Linking hydraulic properties of fire-affected soils to infiltration and water repellency

    USGS Publications Warehouse

    Moody, J.A.; Kinner, D.A.; Ubeda, X.

    2009-01-01

    Heat from wildfires can produce a two-layer system composed of extremely dry soil covered by a layer of ash, which when subjected to rainfall, may produce extreme floods. To understand the soil physics controlling runoff for these initial conditions, we used a small, portable disk infiltrometer to measure two hydraulic properties: (1) near-saturated hydraulic conductivity, Kf and (2) sorptivity, S(??i), as a function of initial soil moisture content, ??i, ranging from extremely dry conditions (??i < 0.02 cm3 cm-3) to near saturation. In the field and in the laboratory replicate measurements were made of ash, reference soils, soils unaffected by fire, and fire-affected soils. Each has a different degrees of water repellency that influences Kf and S(??i). Values of Kf ranged from 4.5 ?? 10-3 to 53 ?? 10-3 cm s-1 for ash; from 0.93 ?? 10-3 to 130 ?? 10-3 cm s-1 for reference soils; and from 0.86 ?? 10-3 to 3.0 ?? 10-3 cm s-1, for soil unaffected by fire, which had the lowest values of Kf. Measurements indicated that S(??i) could be represented by an empirical non-linear function of ??i with a sorptivity maximum of 0.18-0.20 cm s-0.5, between 0.03 and 0.08 cm3 cm-3. This functional form differs from the monotonically decreasing non-linear functions often used to represent S(??i) for rainfall-runoff modeling. The sorptivity maximum may represent the combined effects of gravity, capillarity, and adsorption in a transitional domain corresponding to extremely dry soil, and moreover, it may explain the observed non-linear behavior, and the critical soil-moisture threshold of water repellent soils. Laboratory measurements of Kf and S(??i) are the first for ash and fire-affected soil, but additional measurements are needed of these hydraulic properties for in situ fire-affected soils. They provide insight into water repellency behavior and infiltration under extremely dry conditions. Most importantly, they indicate how existing rainfall-runoff models can be modified to

  7. Aerosol physical properties and their impact on climate change processes

    NASA Astrophysics Data System (ADS)

    Strzalkowska, Agata; Zielinski, Tymon; Petelski, Tomasz; Makuch, Przemyslaw; Pakszys, Paulina; Markuszewski, Piotr; Piskozub, Jacek; Drozdowska, Violetta; Gutowska, Dorota; Rozwadowska, Anna

    2013-04-01

    Characterizing aerosols involves the specification of not only their spatial and temporal distributions but their multi-component composition, particle size distribution and physical properties as well. Due to their light attenuation and scattering properties, aerosols influence radiance measured by satellite for ocean color remote sensing. Studies of marine aerosol production and transport are important for many earth sciences such as cloud physics, atmospheric optics, environmental pollution studies, and interaction between ocean and atmosphere. It was one of the reasons for the growth in the number of research programs dealing with marine aerosols. Sea salt aerosols are among the most abundant components of the atmospheric aerosol, and thus it exerts a strong influence on radiation, cloud formation, meteorology and chemistry of the marine atmosphere. An accurate understanding and description of these mechanisms is crucial to modeling climate and climate change. This work provides information on combined aerosol studies made with lidars and sun photometers onboard the ship and in different coastal areas. We concentrate on aerosol optical thickness and its variations with aerosol advections into the study area. We pay special attention to the problem of proper data collection and analyses techniques. We showed that in order to detect the dynamics of potential aerosol composition changes it is necessary to use data from different stations where measurements are made using the same techniques. The combination of such information with air mass back-trajectories and data collected at stations located on the route of air masses provides comprehensive picture of aerosol variations in the study area both vertically and horizontally. Acknowledgements: The support for this study was provided by the project Satellite Monitoring of the Baltic Sea Environment - SatBałtyk founded by European Union through European Regional Development Fund contract No. POIG 01

  8. Chemical and physical properties of dry flue gas desulfurization products.

    PubMed

    Kost, David A; Bigham, Jerry M; Stehouwer, Richard C; Beeghly, Joel H; Fowler, Randy; Traina, Samuel J; Wolfe, William E; Dick, Warren A

    2005-01-01

    Beneficial and environmentally safe recycling of flue gas desulfurization (FGD) products requires detailed knowledge of their chemical and physical properties. We analyzed 59 dry FGD samples collected from 13 locations representing four major FGD scrubbing technologies. The chemistry of all samples was dominated by Ca, S, Al, Fe, and Si and strong preferential partitioning into the acid insoluble residue (i.e., coal ash residue) was observed for Al, Ba, Be, Cr, Fe, Li, K, Pb, Si, and V. Sulfur, Ca, and Mg occurred primarily in water- or acid-soluble forms associated with the sorbents or scrubber reaction products. Deionized water leachates (American Society for Testing and Materials [ASTM] method) and dilute acetic acid leachates (toxicity characteristic leaching procedure [TCLP] method) had mean pH values of >11.2 and high mean concentrations of S primarily as SO(2-)4 and Ca. Concentrations of Ag, As, Ba, Cd, Cr, Hg, Pb, and Se (except for ASTM Se in two samples) were below drinking water standards in both ASTM and TCLP leachates. Total toxicity equivalents (TEQ) of dioxins, for two FGD products used for mine reclamation, were 0.48 and 0.53 ng kg(-1). This was similar to the background level of the mine spoil (0.57 ng kg(-1)). The FGD materials were mostly uniform in particle size. Specific surface area (m2 g(-1)) was related to particle size and varied from 1.3 for bed ash to 9.5 for spray dryer material. Many of the chemical and physical properties of these FGD samples were associated with the quality of the coal rather than the combustion and SO2 scrubbing processes used.

  9. 30 CFR 250.205 - Are there special requirements if my well affects an adjacent property?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 2 2011-07-01 2011-07-01 false Are there special requirements if my well affects an adjacent property? 250.205 Section 250.205 Mineral Resources BUREAU OF OCEAN ENERGY MANAGEMENT... property, the Regional Supervisor may require special measures to protect the rights of the...

  10. Novel biodegradable composite wound dressings with controlled release of antibiotics: microstructure, mechanical and physical properties.

    PubMed

    Elsner, Jonathan J; Shefy-Peleg, Adaya; Zilberman, Meital

    2010-05-01

    Wound dressings aim to restore the milieu required for skin regeneration and protect the wound from environmental threats, including penetration of bacteria. The dressings should be easy to apply and remove and maintain a moist healing environment. In this study, novel biodegradable composite wound dressings based on a polyglyconate mesh and a porous PDLGA binding matrix were developed and studied. These novel dressings were prepared by dip-coating woven meshes in inverted emulsions, followed by freeze-drying. Their investigation focused on the microstructure, mechanical and physical properties, and the release profile of the antibiotic drug ceftazidime from the binding matrix. The mechanical properties of our wound-dressing structures were found to be superior, combining relatively high tensile strength and ductility, which changed only slightly during 3 weeks of incubation in an aqueous medium. The parameters of the inverted emulsion, the organic-aqueous phase ratio, and the type of surfactant used for stabilizing the emulsion were found to affect the microstructure of the binding matrix and the resulting properties, i.e., water absorbance, water vapor transmission rate, and drug-release profile from the binding matrix. Appropriate selection of these parameters can yield composite structures that have the desired physical properties and drug release behavior. Thus, these unique structures are potentially very useful as burn and ulcer dressings.

  11. The physical properties of the interstellar cloud around the heliosphere

    NASA Astrophysics Data System (ADS)

    Gry, C.

    2015-12-01

    A new interpretation of interstellar absorption lines in the spectra of nearby stars indicates that the medium surrounding the Sun can be regarded as a single, coherent cloud if we relax the assumption that a cloud behaves like a rigid body. This outlook permits us to construct a comprehensive picture of the local interstellar cloud and reveals that it departs from homogeneity in a number of aspects and physical properties: - This local cloud undergoes a deformation related to a compression in the direction of motion and an expansion in perpendicular directions, much like a squashed balloon. - The metal abundances decrease steadily from the rear to the head of the cloud, and this phenomenon does not appear to be related to ionization effects. - The cloud average HI density, estimated toward a number of nearby stars around which an astrophere is detected in Lyman alpha, varies from 0.03 to 0.1 cm-3. The cloud outer boundary inferred from the average density and column densities is very irregular with an average distance to the Sun of 9 +/- 7 pc. - The electron density and the cloud temperature can be derived from the combination of the ionization equilibrium of MgI and the excitation of CII in a restricted number of sightlines where column density is such that MgI and CII* features are strong enough to be detectable without saturating MgII. We present a few additional targets from which we examine the physical conditions inside the cloud.

  12. Linking membrane physical properties and low temperature tolerance in arthropods.

    PubMed

    Waagner, Dorthe; Bouvrais, Hélène; Ipsen, John H; Holmstrup, Martin

    2013-12-01

    Maintenance of membrane fluidity is of crucial importance in ectotherms experiencing thermal changes. This maintenance has in ectotherms most often been indicated using indirect measures of biochemical changes of phospholipid membranes, which is then assumed to modulate the physico-chemical properties of the membrane. Here, we measure bending rigidity characterizing the membrane flexibility of re-constituted membrane vesicles to provide a more direct link between membrane physical characteristics and low temperature tolerance. Bending rigidity of lipid bilayers was measured in vitro using Giant Unilamellar Vesicles formed from phospholipid extracts of the springtail, Folsomia candida. The bending rigidity of these membranes decreased when exposed to 0.4 vol% ethanol (0.23 mM/L). Springtails exposed to ethanol for 24h significantly increased their cold shock tolerance. Thus, by chemically inducing decreased membrane rigidity, we have shown a direct link between the physico-chemical properties of the membranes and the capacity to tolerate low temperature in a chill-susceptible arthropod. PMID:24080490

  13. Mineral trioxide aggregate: a review of physical properties.

    PubMed

    Malhotra, Neeraj; Agarwal, Antara; Mala, Kundabala

    2013-02-01

    The purpose of this two-part series is to review the composition, properties, products, and clinical aspects of mineral trioxide aggregate (MTA) materials. Electronic search of scientific papers from January 1991 to May 2010 was accomplished using PubMed and MedLine search engines to include relevant scientific citations from the peer-reviewed journals published in English. MTA is a refined form of the parent compound, Portland cement (PC). It demonstrates a strong biocompatible nature owing to the high pH and its ability to form hydroxyapatite. MTA materials provide a better seal than traditional endodontic materials as observed in dye leakage, fluid filtration, protein leakage, and bacterial penetration leakage studies, and it has been recognized as a bioactive material. Currently a variety of MTA commercial products are available, including Proroot Gray MTA and White MTA both from DENTSPLY Tulsa Dental Specialties (www.DENTSPLY.com), and MTA Angelus (Angelus,www.angelus.ind.br). Although these materials are indicated for various dental uses/applications, long-term in-vivo clinical studies are still needed to claim the same. This first of this series highlights and discusses the composition, physical, and/or chemical properties of MTA. A subsequent article will offer an overview of the material aspect (commercial products) and clinical considerations for MTA materials.

  14. Linking membrane physical properties and low temperature tolerance in arthropods.

    PubMed

    Waagner, Dorthe; Bouvrais, Hélène; Ipsen, John H; Holmstrup, Martin

    2013-12-01

    Maintenance of membrane fluidity is of crucial importance in ectotherms experiencing thermal changes. This maintenance has in ectotherms most often been indicated using indirect measures of biochemical changes of phospholipid membranes, which is then assumed to modulate the physico-chemical properties of the membrane. Here, we measure bending rigidity characterizing the membrane flexibility of re-constituted membrane vesicles to provide a more direct link between membrane physical characteristics and low temperature tolerance. Bending rigidity of lipid bilayers was measured in vitro using Giant Unilamellar Vesicles formed from phospholipid extracts of the springtail, Folsomia candida. The bending rigidity of these membranes decreased when exposed to 0.4 vol% ethanol (0.23 mM/L). Springtails exposed to ethanol for 24h significantly increased their cold shock tolerance. Thus, by chemically inducing decreased membrane rigidity, we have shown a direct link between the physico-chemical properties of the membranes and the capacity to tolerate low temperature in a chill-susceptible arthropod.

  15. Physical Properties of Volcanic Deposits on Venus from Radar Polarimetry

    NASA Technical Reports Server (NTRS)

    Carter, Lynn M.; Campbell, Donald B.; Campbell, Bruce A.

    2005-01-01

    Studies of the morphology and radar properties of volcanic deposits can aid in understanding their differences and formation. On Venus, volcanoes range in size from large highland edifices, such as Theia Mons, to small shields and domes which are often found in groups of tens to hundreds. In plains regions, windstreaks are sometimes found near shield fields, suggesting that there may be fine grained deposits associated with the volcanoes. Previous studies of Bell Regio suggest the presence of fine-grained material in a low dielectric constant triangular shaped region on the flank of Tepev Mons, which may be crater ejecta or a pyroclastic deposit spread westward by wind. The eastern caldera on Tepev Mons shows a steep trend in backscattered power with incidence angle and has high RMS-slopes, implying a finegrained covering such as ash. Radar waves can easily penetrate smooth mantling layers such as ash and aeolian deposits. If a radar system can measure two orthogonal polarizations, it is possible to detect subsurface scattering and infer the presence of surficial deposits. The Magellan spacecraft could only measure one polarization and was therefore not able to fully characterize the polarization state of the radar echoes. We compare Arecibo dual-polarization data for Venus to Magellan images and emissivity data to investigate the physical properties of volcanic deposits.

  16. Physical Properties of Intermetallic FE2VA1

    SciTech Connect

    Ye Feng

    2002-05-30

    Fe{sub 2}VAl has recently been discovered to have a negative temperature coefficient of resistivity, moderately enhanced specific heat coefficient, and a large DOS at the Fermi level by photoemission. This triggered a round of heated research to understand the ground state of this material, both theoretically and experimentally. here they report a comprehensive characterization of Fe{sub 2}VAl. X-ray diffraction exhibited appreciable antisite disorder in all of our samples. FTIR spectroscopy measurements showed that the carrier density and scattering time had little sample-to-sample variation or temperature dependence for near-stoichiometric samples. FTIR and DC resistivity suggest that the transport properties of Fe{sub 2}VAl are influenced by both localized and delocalized carriers, with the former primarily responsible for the negative temperature coefficient of resistivity. Magnetization measurements reveal that near-stoichiometric samples have superparamagnetic clusters with at least two sizes of moments. X-ray photoemission from Fe core level showed localized magnetic moments on site-exchanged Fe. They conclude that in Fe{sub 2}VAl, antisite disorder causes significant modification to the semi-metallic band structure proposed by LDA calculations. With antisite disorder considered, they are now able to explain most of the physical properties of Fe{sub 2}VAl.

  17. Influence of the Soil Genesis on Physical and Mechanical Properties

    PubMed Central

    Marschalko, Marian; Yilmaz, Işık; Fojtová, Lucie; Kubečka, Karel; Bouchal, Tomáš; Bednárik, Martin

    2013-01-01

    The paper deals with the influence of soil genesis on the physical-mechanical properties. The presented case study was conducted in the region of the Ostrava Basin where there is a varied genetic composition of the Quaternary geological structure on the underlying Neogeneous sediments which are sediments of analogous granulometry but different genesis. In this study, 7827 soil samples of an eolian, fluvial, glacial, and deluvial origin and their laboratory analyses results were used. The study identified different values in certain cases, mostly in coarser-grained foundation soils, such as sandy loam S4 (MS) and clayey sand F4 (CS). The soils of the fluvial origin manifest different values than other genetic types. Next, based on regression analyses, dependence was proved neither on the deposition depth (depth of samples) nor from the point of view of the individual foundation soil classes or the genetic types. The contribution of the paper is to point at the influence of genesis on the foundation soil properties so that engineering geologists and geotechnicians pay more attention to the genesis during engineering-geological and geotechnical investigations. PMID:23844398

  18. Mineral trioxide aggregate: a review of physical properties.

    PubMed

    Malhotra, Neeraj; Agarwal, Antara; Mala, Kundabala

    2013-02-01

    The purpose of this two-part series is to review the composition, properties, products, and clinical aspects of mineral trioxide aggregate (MTA) materials. Electronic search of scientific papers from January 1991 to May 2010 was accomplished using PubMed and MedLine search engines to include relevant scientific citations from the peer-reviewed journals published in English. MTA is a refined form of the parent compound, Portland cement (PC). It demonstrates a strong biocompatible nature owing to the high pH and its ability to form hydroxyapatite. MTA materials provide a better seal than traditional endodontic materials as observed in dye leakage, fluid filtration, protein leakage, and bacterial penetration leakage studies, and it has been recognized as a bioactive material. Currently a variety of MTA commercial products are available, including Proroot Gray MTA and White MTA both from DENTSPLY Tulsa Dental Specialties (www.DENTSPLY.com), and MTA Angelus (Angelus,www.angelus.ind.br). Although these materials are indicated for various dental uses/applications, long-term in-vivo clinical studies are still needed to claim the same. This first of this series highlights and discusses the composition, physical, and/or chemical properties of MTA. A subsequent article will offer an overview of the material aspect (commercial products) and clinical considerations for MTA materials. PMID:23627406

  19. Influence of the soil genesis on physical and mechanical properties.

    PubMed

    Marschalko, Marian; Yilmaz, Işık; Fojtová, Lucie; Kubečka, Karel; Bouchal, Tomáš; Bednárik, Martin

    2013-01-01

    The paper deals with the influence of soil genesis on the physical-mechanical properties. The presented case study was conducted in the region of the Ostrava Basin where there is a varied genetic composition of the Quaternary geological structure on the underlying Neogeneous sediments which are sediments of analogous granulometry but different genesis. In this study, 7827 soil samples of an eolian, fluvial, glacial, and deluvial origin and their laboratory analyses results were used. The study identified different values in certain cases, mostly in coarser-grained foundation soils, such as sandy loam S4 (MS) and clayey sand F4 (CS). The soils of the fluvial origin manifest different values than other genetic types. Next, based on regression analyses, dependence was proved neither on the deposition depth (depth of samples) nor from the point of view of the individual foundation soil classes or the genetic types. The contribution of the paper is to point at the influence of genesis on the foundation soil properties so that engineering geologists and geotechnicians pay more attention to the genesis during engineering-geological and geotechnical investigations.

  20. Physical and mechanical properties of elastomers in orthodontic positioners.

    PubMed

    Warunek, S P; Sorensen, S E; Cunat, J J; Green, L J

    1989-05-01

    Elastomers for conventional Kesling-type tooth positioners are relatively inelastic and are primarily indicated as finishing devices. However, new materials, first described in the Japanese literature, with claims of a greater range of tooth movement warrant a comparison with conventional materials. Physical and mechanical property testing of positioner elastomers has not been reported in the orthodontic literature. This investigation compared properties of a high temperature vulcanizing (HTV) Japanese silicone (Orthocon) to three traditional polyurethane and vinyl-based polymers and five experimental silicone elastomers. Fourier transform infrared spectroscopy established the definitive chemical composition of the urethane and vinyl materials obtained from a commercial positioner laboratory. Tear strength, tensile strength, tensile stress at selected elongations, and ultimate elongation of all materials were evaluated at 37 degrees C in an aqueous environment. Hardness and water sorption values also were determined and an in vitro force measurement apparatus was fabricated to determine force levels exerted by positioner materials at low displacements. Orthocon was statistically different (Duncan's multiple range test, p less than 0.05) from the traditional commercial urethane and vinyl materials. Orthocon had lower tear strength than the traditional materials. It also demonstrated lower stress values below 100% elongation. The parameters of tensile stress at 50% elongation and ultimate elongation were statistically identical for Orthocon and one experimental silicone material.

  1. Hardrock Elastic Physical Properties: Birch's Seismic Parameter Revisited

    NASA Astrophysics Data System (ADS)

    Wu, M.; Milkereit, B.

    2014-12-01

    Identifying rock composition and properties is imperative in a variety of fields including geotechnical engineering, mining, and petroleum exploration, in order to accurately make any petrophysical calculations. Density is, in particular, an important parameter that allows us to differentiate between lithologies and estimate or calculate other petrophysical properties. It is well established that compressional and shear wave velocities of common crystalline rocks increase with increasing densities (i.e. the Birch and Nafe-Drake relationships). Conventional empirical relations do not take into account S-wave velocity. Physical properties of Fe-oxides and massive sulfides, however, differ significantly from the empirical velocity-density relationships. Currently, acquiring in-situ density data is challenging and problematic, and therefore, developing an approximation for density based on seismic wave velocity and elastic moduli would be beneficial. With the goal of finding other possible or better relationships between density and the elastic moduli, a database of density, P-wave velocity, S-wave velocity, bulk modulus, shear modulus, Young's modulus, and Poisson's ratio was compiled based on a multitude of lab samples. The database is comprised of isotropic, non-porous metamorphic rock. Multi-parameter cross plots of the various elastic parameters have been analyzed in order to find a suitable parameter combination that reduces high density outliers. As expected, the P-wave velocity to S-wave velocity ratios show no correlation with density. However, Birch's seismic parameter, along with the bulk modulus, shows promise in providing a link between observed compressional and shear wave velocities and rock densities, including massive sulfides and Fe-oxides.

  2. Statistics of physical properties of dark matter clusters

    SciTech Connect

    Shaw, Laurie; Weller, Jochen; Ostriker, Jeremiah P.; Bode, Paul; /Princeton U. Observ.

    2005-09-01

    We have identified over 2000 well resolved cluster halos, and also their associated bound subhalos, from the output of 1024{sup 3} particle cosmological N-body simulation (of box size 320h{sup -1}Mpc and softening length 3.2h{sup -1}kpc). We present an algorithm to identify those halos still in the process of relaxing into dynamical equilibrium, and a detailed analysis of the integral and internal physical properties for all the halos in our sample. The majority are prolate, and tend to rotate around their minor principle axis. We find there to be no correlation between the spin and virial mass of the clusters halos and that the higher mass halos are less dynamically relaxed and have a lower concentration. Additionally, the orbital angular momentum of the substructure is typically well aligned with the rotational angular momentum of the ''host'' halo. There is also evidence of the transfer of angular momentum from subhalos to their host. Overall, we find that measured halo properties are often significantly influenced by the fraction of mass contained within substructure. Dimensionless properties do depend weakly on the ratio of halo mass (M{sub h}) to our characteristic mass scale (M{sub *} = 8 x 10{sup 14}h{sup -1}M{sub {circle_dot}}). This lack of self-similarity is in the expected sense in that, for example, ''old halos'' with M{sub h}/M{sub *} << 1 have less substructure than ''young halos'' with M{sub h}/M{sub *} >> 1.

  3. Physical characterization of functionalized spider silk: electronic and sensing properties

    NASA Astrophysics Data System (ADS)

    Steven, Eden; Park, Jin Gyu; Paravastu, Anant; Branco Lopes, Elsa; Brooks, James S.; Englander, Ongi; Siegrist, Theo; Kaner, Papatya; Alamo, Rufina G.

    2011-10-01

    This work explores functional, fundamental and applied aspects of naturally harvested spider silk fibers. Natural silk is a protein polymer where different amino acids control the physical properties of fibroin bundles, producing, for example, combinations of β-sheet (crystalline) and amorphous (helical) structural regions. This complexity presents opportunities for functional modification to obtain new types of material properties. Electrical conductivity is the starting point of this investigation, where the insulating nature of neat silk under ambient conditions is described first. Modification of the conductivity by humidity, exposure to polar solvents, iodine doping, pyrolization and deposition of a thin metallic film are explored next. The conductivity increases exponentially with relative humidity and/or solvent, whereas only an incremental increase occurs after iodine doping. In contrast, iodine doping, optimal at 70 °C, has a strong effect on the morphology of silk bundles (increasing their size), on the process of pyrolization (suppressing mass loss rates) and on the resulting carbonized fiber structure (that becomes more robust against bending and strain). The effects of iodine doping and other functional parameters (vacuum and thin film coating) motivated an investigation with magic angle spinning nuclear magnetic resonance (MAS-NMR) to monitor doping-induced changes in the amino acid-protein backbone signature. MAS-NMR revealed a moderate effect of iodine on the helical and β-sheet structures, and a lesser effect of gold sputtering. The effects of iodine doping were further probed by Fourier transform infrared (FTIR) spectroscopy, revealing a partial transformation of β-sheet-to-amorphous constituency. A model is proposed, based on the findings from the MAS-NMR and FTIR, which involves iodine-induced changes in the silk fibroin bundle environment that can account for the altered physical properties. Finally, proof-of-concept applications of

  4. Self-assembly and physical properties of atomic aggregates

    NASA Astrophysics Data System (ADS)

    Berber, Savas

    In this Thesis, I present a study of nanoscaled atomic aggregates such as fullerenes, nanotubes, diamondoids, and related materials. Nanotubes and fullerenes, which could be formed of any layered material, show unusual physical properties due to their lower dimensionality and nanometer size. I have investigated the microscopic self-assembly mechanisms and the physical properties of these nanoscale atomic aggregates through computer simulations primarily by using molecular dynamics simulations combined with structure optimization and total energy calculations. First, I determined the stability, optimum geometry and electronic properties of nanometer-sized capped graphitic cones, called "nanohorns". My main result, simulated scanning tunneling microscopy images of the various structures at different bias voltages, indicate a net electron transfer towards the pentagon vertex sites. Next, I investigated the absorption of fullerenes in a nanotube during a hierarchical self-assembly of "nanopeapods". I found the absorption through a defect to be significantly more efficient than the end-on absorption. I also investigated the energetics and detailed fusion mechanism of fullerenes inside a carbon nanotube. I found that fullerenes are pulled in by a "capillary" force, which yields an effective GPa pressure. Fusion of fullerenes continues along the minimum energy path as a sequence of Stone-Wales transformations. I have further investigated the microscopic dislocation mechanism leading to structural transformations in nanostructures. In particular, I studied the relative stability and the conversion mechanism between multi-wall carbon nanotubes and graphitic scrolls. I postulated a zipper-like mechanism, which converts a scroll to the more stable multiwall nanotube. I also found this transformation to proceed very efficiently due to the unusually low associated activation barrier. A further study related to defects in nanoscale systems involves the response of defective

  5. Impact of Plying on the Physical Properties of Vortex and Other Spun Yarns

    NASA Astrophysics Data System (ADS)

    Dhamija, Sudershan; Chowdhury, Amal; Chattopadhyay, Rabisankar

    2016-04-01

    The physical properties of two ply yarns made from vortex, ring, compact, and rotor singles have been investigated by changing ply twist factor. The physical parameters like yarn diameter, plied yarn length, twist liveliness have been found to be significantly affected by the ply twist factor. Though plying increases the yarn diameter for all, the percentage increase in diameter with respect to single yarn is the minimum for vortex yarns. The ply twist factor at which the real contraction starts is also the lowest for vortex yarns. Amongst the plied yarns, those made from rotor yarns show minimum twist liveliness. A minimum ply twist threshold exists below which hockles (a hole like structure) in ply yarns are observed.

  6. The Fox and the Grapes—How Physical Constraints Affect Value Based Decision Making

    PubMed Central

    Strobel, Martin

    2015-01-01

    One fundamental question in decision making research is how humans compute the values that guide their decisions. Recent studies showed that people assign higher value to goods that are closer to them, even when physical proximity should be irrelevant for the decision from a normative perspective. This phenomenon, however, seems reasonable from an evolutionary perspective. Most foraging decisions of animals involve the trade-off between the value that can be obtained and the associated effort of obtaining. Anticipated effort for physically obtaining a good could therefore affect the subjective value of this good. In this experiment, we test this hypothesis by letting participants state their subjective value for snack food while the effort that would be incurred when reaching for it was manipulated. Even though reaching was not required in the experiment, we find that willingness to pay was significantly lower when subjects wore heavy wristbands on their arms. Thus, when reaching was more difficult, items were perceived as less valuable. Importantly, this was only the case when items were physically in front of the participants but not when items were presented as text on a computer screen. Our results suggest automatic interactions of motor and valuation processes which are unexplored to this date and may account for irrational decisions that occur when reward is particularly easy to reach. PMID:26061087

  7. When music tempo affects the temporal congruence between physical practice and motor imagery.

    PubMed

    Debarnot, Ursula; Guillot, Aymeric

    2014-06-01

    When people listen to music, they hear beat and a metrical structure in the rhythm; these perceived patterns enable coordination with the music. A clear correspondence between the tempo of actual movement (e.g., walking) and that of music has been demonstrated, but whether similar coordination occurs during motor imagery is unknown. Twenty participants walked naturally for 8m, either physically or mentally, while listening to slow and fast music, or not listening to anything at all (control condition). Executed and imagined walking times were recorded to assess the temporal congruence between physical practice (PP) and motor imagery (MI). Results showed a difference when comparing slow and fast time conditions, but each of these durations did not differ from soundless condition times, hence showing that body movement may not necessarily change in order to synchronize with music. However, the main finding revealed that the ability to achieve temporal congruence between PP and MI times was altered when listening to either slow or fast music. These data suggest that when physical movement is modulated with respect to the musical tempo, the MI efficacy of the corresponding movement may be affected by the rhythm of the music. Practical applications in sport are discussed as athletes frequently listen to music before competing while they mentally practice their movements to be performed.

  8. Physical properties of organic and biomaterials: Fundamentals and applications

    NASA Astrophysics Data System (ADS)

    Steven, Eden

    Silk materials are natural protein-based materials with an exceptional toughness. In addition to their toughness, silk materials also possess complex physical properties and functions resulting from a particular set of amino-acid arrangement that produces structures with crystalline beta-sheets connected by amorphous chains. Extensive studies have been performed to study their structure-function relationship leading to recent advancements in bio-integrated devices. Applications to fields other than textiles and biomedicine, however, have been scarce. In this dissertation, an investigation of the electronic properties, functionalization, and role of silk materials (spider silk and Bombyx mori cocoon silk) in the field of organic materials research is presented. The investigation is conducted from an experimental physics point of view where correlations with charge transport mechanisms in disordered, semiconducting, and insulating materials are made when appropriate. First, I present the electronic properties of spider silk fibers under ambient, humidified, iodized, polar solvent exposure, and pyrolized conditions. The conductivity is exponentially dependent on relative humidity changes and the solvent polarity. Iodine doping increases the conductivity only slightly but has pronounced effects on the pyrolization process, increasing the yield and flexibility of the pyrolized silk fibers. The iodized samples were further studied using magic angle spinning nuclear magnetic resonance (MAS-NMR) and Fourier transform infrared spectroscopy (FTIR) revealing non-homogenous iodine doping and I2 induced hydrogenation that are responsible for the minimal conductivity improvement and the pyrolization effects, respectively. Next, I present the investigation of silk fiber functionalization with gold and its role in electrical measurements. The gold functionalized silk fiber (Au-SS) is metallic down to cryogenic temperatures, has a certain amount of flexibility, and possesses

  9. Effect of Antiadherents on the Physical and Drug Release Properties of Acrylic Polymeric Films.

    PubMed

    Ammar, Hussein O; Ghorab, Mamdouh M; Felton, Linda A; Gad, Shadeed; Fouly, Aya A

    2016-06-01

    Antiadherents are used to decrease tackiness of a polymer coating during both processing and subsequent storage. Despite being a common excipient in coating formulae, antiadherents may affect mechanical properties of the coating film as well as drug release from film-coated tablets, but how could addition of antiadherents affect these properties and to what extent and is there a relation between the physical characteristics of the tablet coat and the drug release mechanisms? The aim of this study was to evaluate physical characteristics of films containing different amounts of the antiadherents talc, glyceryl monostearate, and PlasACRYL(TM) T20. Eudragit RL30D and Eudragit RS30D as sustained release polymers and Eudragit FS30D as a delayed release material were used. Polymer films were characterized by tensile testing, differential scanning calorimetry (DSC), microscopic examination, and water content as calculated from loss on drying. The effect of antiadherents on in vitro drug release for the model acetylsalicylic acid tablets coated with Eudragit FS30D was also determined. Increasing talc concentration was found to decrease the ability of the polymer films to resist mechanical stress. In contrast, glyceryl monostearate (GMS) and PlasACRYL produced more elastic films. Talc at concentrations higher than 25% caused negative effects, which make 25% concentration recommended to be used with acrylic polymers. All antiadherents delayed the drug release at all coating levels; hence, different tailoring of drug release may be achieved by adjusting antiadherent concentration with coating level. PMID:26314244

  10. Effect of Antiadherents on the Physical and Drug Release Properties of Acrylic Polymeric Films.

    PubMed

    Ammar, Hussein O; Ghorab, Mamdouh M; Felton, Linda A; Gad, Shadeed; Fouly, Aya A

    2016-06-01

    Antiadherents are used to decrease tackiness of a polymer coating during both processing and subsequent storage. Despite being a common excipient in coating formulae, antiadherents may affect mechanical properties of the coating film as well as drug release from film-coated tablets, but how could addition of antiadherents affect these properties and to what extent and is there a relation between the physical characteristics of the tablet coat and the drug release mechanisms? The aim of this study was to evaluate physical characteristics of films containing different amounts of the antiadherents talc, glyceryl monostearate, and PlasACRYL(TM) T20. Eudragit RL30D and Eudragit RS30D as sustained release polymers and Eudragit FS30D as a delayed release material were used. Polymer films were characterized by tensile testing, differential scanning calorimetry (DSC), microscopic examination, and water content as calculated from loss on drying. The effect of antiadherents on in vitro drug release for the model acetylsalicylic acid tablets coated with Eudragit FS30D was also determined. Increasing talc concentration was found to decrease the ability of the polymer films to resist mechanical stress. In contrast, glyceryl monostearate (GMS) and PlasACRYL produced more elastic films. Talc at concentrations higher than 25% caused negative effects, which make 25% concentration recommended to be used with acrylic polymers. All antiadherents delayed the drug release at all coating levels; hence, different tailoring of drug release may be achieved by adjusting antiadherent concentration with coating level.

  11. Effect of the moisture content on the physical properties of bitter gourd seed

    NASA Astrophysics Data System (ADS)

    Ünal, H.; Alpsoy, H. C.; Ayhan, A.

    2013-12-01

    Some physical and germination properties of bitter gourd seed were determined in a moisture content range of 9.3-32.1% d.b. For this moisture, the average length, width, and thickness of seed increased by 3.68, 4.07, and 4.56%, respectively. The geometric properties increased with increasing moisture content. The bulk density and rupture force decreased while thousand seed mass, true density, porosity, terminal velocity and static coefficient of friction increased with increasing moisture content. At all moisture contents, the maximum friction was offered by rubber, followed by plywood, aluminum, and galvanized iron surface. The seed germination duration, seedling emergence percentage, and germination index values gave the best results at the 19.9% moisture content, whereas fresh seedling mass was not affected by different moisture contents.

  12. Rheological and physical properties of gelatin suspensions containing cellulose nanofibers for potential coatings.

    PubMed

    Andrade, Ricardo D; Skurtys, Olivier; Osorio, Fernando; Zuluaga, Robin; Gañán, Piedad; Castro, Cristina

    2015-07-01

    Rheological and physical properties of edible coating formulations containing gelatin, cellulose nanofibers (CNFs), and glycerol are characterized. Measured properties are analyzed in order to optimize edible coating thickness. Results show that coating formulations density increases linearly with gelatin concentration in presence of CNFs. Surface tension decreases with either gelatin or CNF concentration increases. Power law model well described the rheological behavior of edible coating formulations since determination coefficient was high (R(2 )> 0.98) and standard error was low (SE < 0.0052). Formulations showed pseudoplastic (shear-thinning) flow behavior and no time-dependent features were observed. The flow behavior index was not significantly affected by any factor. Consistency coefficient increases with gelatin concentrations but it decreases with glycerol concentrations.

  13. Physical, chemical, and biological properties of soils in the city of Mariupol, Ukraine

    NASA Astrophysics Data System (ADS)

    Shekhovtseva, O. G.; Mal'tseva, I. A.

    2015-12-01

    Physicochemical and biological properties of urbanized soils in the city of Mariupol have been considered in comparison with the background soils. The parametrical characteristics (abundance and biomass) of soil algal groups, the content of humus, the reaction of soil solution, the content of heavy metals, and the particle size distributions of soils under different anthropogenic impacts have been assessed. The physicochemical properties of soils developing under urboecosystem conditions affect the number of structure-forming species, biomass, and proportions of soil algae. According to the particle size distribution, urban soils are classified among the medium and heavy loamy soils with the predominance of the clay and coarse silt fractions. The fractions of physical clay and clay are of highest importance for the existence of algae. The accumulation of heavy metals in the surface horizons of soils can stimulate or inhibit the development of algae depending on the metal concentration.

  14. 41 CFR 109-1.5110 - Physical inventories of personal property.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 41 Public Contracts and Property Management 3 2011-01-01 2011-01-01 false Physical inventories of personal property. 109-1.5110 Section 109-1.5110 Public Contracts and Property Management Federal Property Management Regulations System (Continued) DEPARTMENT OF ENERGY PROPERTY MANAGEMENT REGULATIONS GENERAL...

  15. 41 CFR 109-1.5110 - Physical inventories of personal property.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 41 Public Contracts and Property Management 3 2013-07-01 2013-07-01 false Physical inventories of personal property. 109-1.5110 Section 109-1.5110 Public Contracts and Property Management Federal Property Management Regulations System (Continued) DEPARTMENT OF ENERGY PROPERTY MANAGEMENT REGULATIONS GENERAL...

  16. 41 CFR 109-1.5110 - Physical inventories of personal property.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 41 Public Contracts and Property Management 3 2012-01-01 2012-01-01 false Physical inventories of personal property. 109-1.5110 Section 109-1.5110 Public Contracts and Property Management Federal Property Management Regulations System (Continued) DEPARTMENT OF ENERGY PROPERTY MANAGEMENT REGULATIONS GENERAL...

  17. Determination of elastoplastic mechanical properties of the weld and heat affected zone metals in tailor-welded blanks by nanoindentation test

    NASA Astrophysics Data System (ADS)

    Ma, Xiangdong; Guan, Yingping; Yang, Liu

    2015-09-01

    The elastoplastic mechanical properties of the weld and heat affected zone metals have comparatively major impact on the forming process of tailor-welded blanks. A few scholars investigated the elastoplastic mechanical properties of the weld and heat affected zone, but they only simply assumed that it was a uniform distribution elastoplastic material different from the base materials. Four types of tailor-welded blanks which consist of ST12 and 304 stainless steel plates are selected as the research objects, the elastoplastic mechanical properties of the tailor-welded blanks weld and heat affected zone metals are obtained based on the nanoindentation tests, and the Erichsen cupping tests are conducted by combining numerical simulation with physical experiment. The nanoindentation tests results demonstrate that the elastoplastic mechanical properties of the weld and heat affected zone metals are not only different from the base materials, but also varying between the weld metals and the heat affected zone metals. Comparing the Erichsen cupping test resulted from numerical with that from experimental method, it is found that the numerical value of Erichsen cupping test which consider the elastoplastic mechanical properties of the weld and heat affected zone metals have a good agreement with the experimental result, and the relative error is only 4.8%. The proposed research provides good solutions for the inhomogeneous elastoplastic mechanical properties of the tailor-welded blanks weld and heat affected zone metals, and improves the control performance of tailor-welded blanks forming accuracy.

  18. Effect of variable physical properties on the thermal behavior of thin metallic wires under a DC field

    NASA Astrophysics Data System (ADS)

    Dey, Avishek Kumar; Ghosh, Abhishek Kumar; Ahmed, S. Reaz

    2016-07-01

    The effect of variable physical properties on the electro-thermal response of a thin metallic wire is investigated under a uniform direct current field. A general governing differential equation is derived for steady-state heat conduction in conductive wires with surface convection and Joule heating, in which the associated material as well as physical properties of the thermal and electrical problems are modeled as a function of temperature. The resulting nonlinear boundary-value problem is then solved by converting into an equivalent initial-value problem through a trial-and-error based numerical scheme. The electro-thermal characteristics of the wire are realized to be affected significantly when the physical properties are expressed as appropriate functions of temperature.

  19. Physical properties of organic and biomaterials: Fundamentals and applications

    NASA Astrophysics Data System (ADS)

    Steven, Eden

    Silk materials are natural protein-based materials with an exceptional toughness. In addition to their toughness, silk materials also possess complex physical properties and functions resulting from a particular set of amino-acid arrangement that produces structures with crystalline beta-sheets connected by amorphous chains. Extensive studies have been performed to study their structure-function relationship leading to recent advancements in bio-integrated devices. Applications to fields other than textiles and biomedicine, however, have been scarce. In this dissertation, an investigation of the electronic properties, functionalization, and role of silk materials (spider silk and Bombyx mori cocoon silk) in the field of organic materials research is presented. The investigation is conducted from an experimental physics point of view where correlations with charge transport mechanisms in disordered, semiconducting, and insulating materials are made when appropriate. First, I present the electronic properties of spider silk fibers under ambient, humidified, iodized, polar solvent exposure, and pyrolized conditions. The conductivity is exponentially dependent on relative humidity changes and the solvent polarity. Iodine doping increases the conductivity only slightly but has pronounced effects on the pyrolization process, increasing the yield and flexibility of the pyrolized silk fibers. The iodized samples were further studied using magic angle spinning nuclear magnetic resonance (MAS-NMR) and Fourier transform infrared spectroscopy (FTIR) revealing non-homogenous iodine doping and I2 induced hydrogenation that are responsible for the minimal conductivity improvement and the pyrolization effects, respectively. Next, I present the investigation of silk fiber functionalization with gold and its role in electrical measurements. The gold functionalized silk fiber (Au-SS) is metallic down to cryogenic temperatures, has a certain amount of flexibility, and possesses

  20. Physical and Mechanical Properties of Composites and Light Alloys Reinforced with Detonation Nanodiamonds

    NASA Astrophysics Data System (ADS)

    Sakovich, G. V.; Vorozhtsov, S. A.; Vorozhtsov, A. B.; Potekaev, A. I.; Kulkov, S. N.

    2016-07-01

    The influence of introduction of particles of detonation-synthesized nanodiamonds into composites and aluminum-base light alloys on their physical and mechanical properties is analyzed. The data on microstructure and physical and mechanical properties of composites and cast aluminum alloys reinforced with diamond nanoparticles are presented. The introduction of nanoparticles is shown to result in a significant improvement of the material properties.

  1. 41 CFR 109-1.5110 - Physical inventories of personal property.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...-INTRODUCTION 1.51-Personal Property Management Standards and Practices § 109-1.5110 Physical inventories of... items indicates that this action is necessary for effective property accounting, utilization, or control... property records, and with applicable financial control accounts. (j) The results of physical...

  2. Crop response to localized organic amendment in soils with limiting physical properties

    NASA Astrophysics Data System (ADS)

    Lordan, Joan; Pascual, Miquel; Fonseca, Francisco; Villar, Josep Maria; Montilla, Victor; Papió, Josep; Rufat, Josep

    2013-04-01

    This 2-year study evaluated the use of rice husk as a localized organic amendment in a soil with limiting physical properties. The research was conducted in a commercial peach orchard planted in 2011 using a ridge planting system. Six soil and water management treatments were evaluated in 18 experimental units, which were set up in the field using a randomized complete block design. The treatments were compared both in terms of soil physical properties and crop response. Soil amendment with rice husk was the most effective technique. It improved soil conditions (soil infiltration and soil porosity), providing a better soil environment for root activity and thereby resulted in better crop performance. Concerning growth parameters, the amended treatment presented the highest overall values without negatively affecting crop water status. These techniques were suitable for mitigating the effects of soils with limiting physical conditions. Localized applications of amendments, as proposed in this work, imply an important reduction in application rates. It is important to consider an efficient use of by-products since there is a growing interest in industrial and agronomical exploitations.

  3. Soil cultivation in vineyards alters interactions between soil biota and soil physical and hydrological properties

    NASA Astrophysics Data System (ADS)

    Zaller, Johann G.; Buchholz, Jacob; Querner, Pascal; Winter, Silvia; Kratschmer, Sophie; Pachinger, Bärbel; Strauss, Peter; Bauer, Thomas; Stiper, Katrin; Potthoff, Martin; Guernion, Muriel; Scimia, Jennifer; Cluzeau, Daniel

    2016-04-01

    Several ecosystem services provided by viticultural landscapes result from interactions between soil organisms and soil parameters. However, to what extent different soil cultivation intensities in vineyards compromise soil organisms and their interactions between soil physical and hydrological properties is not well understood. In this study we examined (i) to what extent different soil management intensities affect the activity and diversity of soil biota (earthworms, Collembola, litter decomposition), and (ii) how soil physical and hydrological properties influence these interactions, or vice versa. Investigating 16 vineyards in Austria, earthworms were assessed by hand sorting, Collembola via pitfall trapping and soil coring, litter decomposition by using the tea bag method. Additionally, soil physical (water infiltration, aggregate stability, porosity, bulk density, soil texture) and chemical (pH, soil carbon content, cation exchange capacity, potassium, phosphorus) parameters were assessed. Results showed complex ecological interactions between soil biota and various soil characteristics altered by management intensity. These investigations are part of the transdisciplinary BiodivERsA project VineDivers and will ultimately lead into management recommendations for various stakeholders.

  4. Organic farming and cover crops as an alternative to mineral fertilizers to improve soil physical properties

    NASA Astrophysics Data System (ADS)

    Sánchez de Cima, Diego; Luik, Anne; Reintam, Endla

    2015-10-01

    For testing how cover crops and different fertilization managements affect the soil physical properties in a plough based tillage system, a five-year crop rotation experiment (field pea, white potato, common barley undersown with red clover, red clover, and winter wheat) was set. The rotation was managed under four different farming systems: two conventional: with and without mineral fertilizers and two organic, both with winter cover crops (later ploughed and used as green manure) and one where cattle manure was added yearly. The measurements conducted were penetration resistance, soil water content, porosity, water permeability, and organic carbon. Yearly variations were linked to the number of tillage operations, and a cumulative effect of soil organic carbon in the soil as a result of the different fertilization amendments, organic or mineral. All the systems showed similar tendencies along the three years of study and differences were only found between the control and the other systems. Mineral fertilizers enhanced the overall physical soil conditions due to the higher yield in the system. In the organic systems, cover crops and cattle manure did not have a significant effect on soil physical properties in comparison with the conventional ones, which were kept bare during the winter period. The extra organic matter boosted the positive effect of crop rotation, but the higher number of tillage operations in both organic systems counteracted this effect to a greater or lesser extent.

  5. Does management intensity in inter rows effect soil physical properties in Austrian and Romanian vineyards?

    NASA Astrophysics Data System (ADS)

    Bauer, Thomas; Strauss, Peter; Stiper, Katrin; Klipa, Vladimir; Popescu, Daniela; Winter, Silvia; Zaller, Johann G.

    2016-04-01

    Successful viticulture is mainly influenced by soil and climate. The availability of water during the growing season highly influences wine quality and quantity. To protect soil from being eroded most of the winegrowers keep the inter row zones of the vineyards green. Greening also helps to provide water-stress to the grapes for harvesting high quality wines. However, these greening strategies concerning the intensity of inter row management differ from farm to farm and are mainly based on personal experience of the winegrowers. However to what extent different inter row management practices affect soil physical properties are not clearly understood yet. To measure possible effects of inter row management in vineyards on soil physical parameters we selected paired vineyards with different inter row management in Austria and Romania. In total more than 7000 soil analysis were conducted for saturated and unsaturated hydraulic conductivity, soil water retention, water stable aggregates, total organic carbon, cation exchange capacity, potassium, phosphorous, soil texture, bulk density and water infiltration. The comparison between high intensity management with at least one soil disturbance per year, medium intensity with one soil disturbance every second inter row per year and low intensity management with no soil disturbance since at least 5 years indicates that investigated soil physical properties did not improve for the upper soil layer (3-8cm). This is in contrast to general perceptions of improved soil physical properties due to low intensity of inter row management, i.e. permanent vegetated inter rows. This may be attributed to long term and high frequency mechanical stress by agricultural machinery in inter rows.

  6. MICROSTRUCTURAL FEATURES AFFECTING PROPERTIES AND AGING OF TRITIUM-EXPOSED AUSTENTIC STAINLESS STEEL

    SciTech Connect

    Subramanian, K; Michael Morgan, M

    2004-01-10

    banding and nitrogen concentration were also included as features of interest. The microstructural features of interest included (1) grain size, shape, and orientation; (2) dislocation structure and distribution, or recovered vs. un-recovered. The grain size and orientation affect the grain boundary fracture stress and the hydrogen solubility and diffusion paths. The dislocation structure and distribution play a role in hydrogen trapping as well as potentially affecting the hydrogen assisted fracture path. The initial mechanical and physical properties that are to be included in the investigation are yield stress, fracture toughness, work-hardening capacity, threshold hydrogen cracking stress intensity and stacking-fault energy.

  7. Evaluation of Physical Properties of Generic and Branded Travoprost Formulations

    PubMed Central

    Wadhwani, Meenakshi; Mishra, Sanjay K; Velpandian, Thirumurthy; Sihota, Ramanjit; Kotnala, Ankita; Bhartiya, Shibal; Dada, Tanuj

    2016-01-01

    ABSTRACT Purpose: Comparative evaluation of pharmaceutical characteristics of three marketed generic vs branded travoprost formulations. Materials and methods: Three generic travoprost formulations and one branded (Travatan without benzalkonium chloride) formulation (10 vials each), obtained from authorized agents from the respective companies and having the same batch number, were used. These formulations were coded and labels were removed. At a standardized room temperature of 25°C, the drop size, pH, relative viscosity, and total drops per vial were determined for Travatan (Alcon, Fort Worth, TX, USA) and all the generic formulations. Travoprost concentration in all four brands was estimated by using liquid chromatography-coupled tandem mass spectrometry LCMS. Results: Out of the four formulations, two drugs (TP 1 and TP 4) were found to follow the United States Pharmacopoeia (USP) limits for ophthalmic formulation regarding drug concentration, while the remaining two drugs failed due to the limits being either above 110% (TP 2) or below 90% (TP 3). Two of them (TP 1 and TP 2) had osmolality of 313 and 262 mOsm respectively, which did not comply with the osmolality limits within 300 mOsm (+ 10%). The pH of all the formulations ranged between 4.7 and 5.9, and the mean drop size was 30.23 ± 6.03 uL. The total amount of drug volume in the bottles varied from 2.58 ± 0.15 to 3.38 ± 0.06 mL/bottle. Conclusion: There are wide variations in the physical properties of generic formulations available in India. Although some generic drugs are compliant with the pharmacopeia standards, this study underscores the need for a better quality control in the production of generic travoprost formulations. How to cite this article: Wadhwani M, Mishra SK, Angmo D, Velpandian T, Sihota R, Kotnala A, Bhartiya S, Dada T. Evaluation of Physical Properties of Generic and Branded Travoprost Formulations. J Curr Glaucoma Pract. 2016;10(2):49-55. PMID:27536047

  8. Physical Properties of Niobium and Specifications for Fabrication of Superconducting Cavities

    SciTech Connect

    Antoine, C.; Foley, M.; Dhanaraj, N.; /Fermilab

    2011-07-01

    It is important to distinguish among the properties of niobium, the ones that are related to the cavity's SRF performances, the formability of the material, and the mechanical behavior of the formed cavity. In general, the properties that dictate each of the above mentioned characteristics have a detrimental effect on one another and in order to preserve the superconducting properties without subduing the mechanical behavior, a balance has to be established. Depending on the applications, some parameters become less important and an understanding of the physical origin of the requirements might help in this optimization. SRF applications require high purity niobium (high RRR), but pure niobium is very soft from fabrication viewpoint. Moreover conventional fabrication techniques tend to override the effects of any metallurgical process meant to strengthen it. As those treatments dramatically affect the forming of the material they should be avoided. These unfavorable mechanical properties have to be accounted for in the design of the cavities rather than in the material specification. The aim of this paper is to review the significance of the important mechanical properties used to characterize niobium and to present the optimal range of values. Most of the following information deals with the specification of sheets for cell forming unless otherwise noted.

  9. Synthesis and physical properties of highly sulfonated polyaniline. Technical report

    SciTech Connect

    Wei, X.L.; Bobeczko, C.; Epstein, A.J.

    1996-03-01

    Sulfonated polyaniline (EB-SPAN) is a self-doped conducting polymer. It has a high water solubility and a novel pH-dependent DC conductivity that is of interest for fundamental science and also for applications in such areas as rechargeable battery and pH control technologies. The authors report here the extensive characterization and details of synthesis of a new form of sulfonated polyaniline (LEB-SPAN) which shows novel or significantly improved chemical and physical properties. LEB-SPAN has a much high sulfur to nitrogen ratio (S/N) of N approx. 0.75, 50% larger than that previously reported for EB-SPAN, S/N approx. 0.50. This change in composition leads to significant alteration of the properties including an order of magnitude increase in the room temperature DC conductivity to approx. 1 S./cm, nearly double the solubility in water, and a completely different pH-dependence of the oxidation potential (E1/2). For LEB-SPAN the DC conductivity is unaffected by pH over the range 0 < or = pH < or = 14, strikingly different from the behavior of both parent polyaniline and EB-SPAN which become insulating for pH > or = 3 and pH > or = 7.5; respectively. Temperature-dependent DC conductivity and EPR measurements for LEB-SPAN reveal a lower activation energy for the conductivity and a higher density of states at the Fermi energy as compared with EB-SPAN. The dramatic differences in the pH-dependence of the DC conductivity, cyclic voltammetry (CV), FTIR, and UV-Vis results for LEB-SPAN and EB-SPAN are shown to be a consequence of the much higher S/N ratio in LEB-SPAN.

  10. Physical properties of low-dimensional sp 2 -based carbon nanostructures

    NASA Astrophysics Data System (ADS)

    Meunier, V.; Souza Filho, A. G.; Barros, E. B.; Dresselhaus, M. S.

    2016-04-01

    The last two decades have witnessed a tremendous growth in the development and understanding of sp 2 carbon-based nanostructures. The impact of this research has led to a number of fundamental discoveries that have played a central role in the understanding of many aspects of materials physics and their applications. Much of this progress has been enabled by the development of new techniques to prepare, modify, and assemble low-dimensional materials into devices. The field has also benefited greatly from much progress in theoretical and computational modeling, as well as from advances in characterization techniques developed to probe and manipulate single atomic layers, nanoribbons, and nanotubes. Some of the most fundamental physical properties of sp2 carbon-based nanostructures are reviewed and their role as model systems for solid-state physics in one and two dimensions is highlighted. The objective of this review is to provide a thorough account on current understanding of how the details of the atomic structure affect phonons, electrons, and transport in these nanomaterials. The review starts with a description of the behavior of single-layer and few-layer graphene and then expands into the analysis of nanoribbons and nanotubes in terms of their reduced dimensionality and curvature. How the properties can be modified and tailored for specific applications is then discussed. The review concludes with a historical perspective and considers some open questions concerning future directions in the physics of low-dimensional systems and their impact on continued advances in solid-state physics, and also looks beyond carbon nanosystems.

  11. The chemical evolution & physical properties of organic aerosol: A molecular structure based approach

    NASA Astrophysics Data System (ADS)

    Wei, Yiyi; Cao, Tingting; Thompson, Jonathan E.

    2012-12-01

    Global climate, atmospheric chemistry, and air quality are affected by tropospheric particulate matter. Recent measurements suggest organic compounds present in this haze comprise roughly half of total aerosol fine mass concentration globally. Unlike the well-constrained processes which result in formation of nitrate or sulfate aerosol, the oxidation of volatile organics in the atmosphere can lead to thousands of stable compounds in the aerosol phase. Development of a tractable framework to consider the chemical and physical evolution of the organic aerosol is crucial for modeling its effect on global climate. Here we show coupling a 3-dimensional coordinate system defined by the molecular descriptors of molecular weight, heteroatom mass, and double bond equivalents (D.B.E.) with high-resolution molecular mass spectrometry is a powerful approach for describing key properties of the organic aerosol. The scheme is conceptually simple, yet maintains sufficient complexity to be compatible with quantitative structure-property relationships (QSPRs) used to predict chemical and physical properties that govern aerosol behavior. From available data, both ambient organic aerosol and laboratory generated organic aerosol frequently occupy the region characterized by <10 D.B.E. <600 M.W. and <200 heteroatom mass. A QSPR analysis conducted illustrates spatial trends within the 3D space for volatility and Henry's law constants for 31,000 organic compounds considered.

  12. Physical and processing properties of milk, butter, and cheddar cheese from cows fed supplemental fish meal.

    PubMed

    Avramis, C A; Wang, H; McBride, B W; Wright, T C; Hill, A R

    2003-08-01

    Physical, chemical, sensory and processing properties of milk produced by feeding a rumen-undegradable fish meal protein supplement to Holstein cows were investigated. The supplement contained (as fed basis) 25% soft-white wheat, 60% herring meal, and 15% feather meal. The total fat level in the milk decreased to 2.43%. For both pasteurized and ultra-high temperature processed drinking milk, no difference was found between fish meal (FM) milk and control milk in terms of color, flavor and flavor stability; in particular, no oxidized flavor was observed. Cheddar cheese made from FM milk ripened faster after 3 mo of ripening and developed a more desirable texture and stronger Cheddar flavor. The yield efficiencies for FM and control cheese, 94.4 (+/- 2.44 SE) and 96.4 (+/- 2.26 SE), respectively, were not different. Relative to controls, average fat globule size was smaller in FM milk and churning time of FM cream was longer. FM butter had softer texture and better cold spreadability, and butter oils from FM enriched milk had lower dropping points compared to control butter oil (average 32.89 versus 34.06 degrees C). These differences in physical properties of butter fat were greater than expected considering that iodine values were not different. This study demonstrates the feasibility of producing high quality products from milk naturally supplemented with FM, but the results also show that dietary changes affect processing properties.

  13. Are Physical Properties Able to Differentiate Glacial and Interglacial Coral Identity?

    NASA Astrophysics Data System (ADS)

    Lado-Insua, T.; Moran, K.; Anderson, L.; Webster, J. M.; Morgan, S.; Fehr, A.; Lofi, J.; Lukies, V.; Loggia, D.; Iodp Expedition 325 Scientists

    2010-12-01

    The Integrated Ocean Drilling Program Expedition 325 to the Great Barrier Reef provides new information on past sea-level changes and better understanding of mechanisms driving glacial-interglacial cycles. Coral samples recovered during this expedition provide a deeper understanding of coral reef responses to environmental stresses. Inter- and intra-specific differences, growth rates, coral health, symbiotic algae and environmental conditions are all potential causes of differences in the density of coral skeletons and their distribution. Past changes in sea level and temperature can be related not only to isotope ratios but also to the presence of different communities of corals. Density changes in the coral composition can be detected using physical properties such as an increase in the calcium carbonate of a sample. De’ath et al. (2009) reported severe and sudden recent declines in calcification in Porites spp. corals in the Great Barrier Reef in the present that have not been observed over at least the last 400 years, and they attributed the decrease in calcification to changes in sea level, sea surface temperature (SST) and saturation of aragonite in the water column, all of which can limit the capacity of the corals to precipitate calcium carbonate. Variation in Sr/Ca can be related to SST, but different strains of symbiotic algae in the corals’ tissues can also be an important factor affecting skeletal Sr/Ca ratios. Such changes have never been tracked during previous glaciations, but the samples from Expedition 325 give the opportunity to explore their values during and since the last glacial maximum. Physical properties such as gamma ray density, electrical resistivity, and acoustic p-wave velocity can be related to characteristics of the marine sediments that, in turn, are indicative of the depositional environments. We performed a multivariate analysis that relates physical characteristics measured with a multi-sensor core logger (MSCL) and downhole

  14. Gender Differences in Introductory University Physics Performance: The Influence of High School Physics Preparation and Affective Factors

    ERIC Educational Resources Information Center

    Hazari, Zahra; Tai, Robert H.; Sadler, Philip M.

    2007-01-01

    The attrition of females studying physics after high school is a growing concern to the science education community. Most undergraduate science programs require introductory physics coursework. Thus, success in introductory physics is usually necessary for students to progress to higher levels of science study. Success also influences attitudes;…

  15. Including physical and biological soil crusts properties in gully prediction

    NASA Astrophysics Data System (ADS)

    Gay, A.; Cerdan, O.; Desprats, J. F.; Malam Issa, O.; Valentin, C.; Rajot, J. L.; Descroix, L.

    2012-04-01

    In Sahelian region, concentrated overland flow often leads to the formation of gullies. Although this phenomenon is widespread in those regions, research efforts are still needed to be able to model their spatial distribution and the role of the different parameters involved in this process. In this context, the objectives of this study are twofold. The first step is to investigate to what extent the role of Sahelian soil surface crusts (biological and/or physical) on soil surface infiltrability and detachment affect the formation and development of gullies. The second step is to integrate the results of these investigations in a simple geomorphological model to predict gully location at the watershed scale. The evaluation of the resulting model on two test catchments demonstrated that the integration of soil crusting is a key parameter to insure the quality and relevance of gully prediction. The model is able to distinguish between two types of gullies, those whose width range between 0.5m and 4m and those whose width exceeds 4m. The application of the model at the regional scale is however limited by the resolution of available regional digital elevation model (i.e. the 90m resolution SRTM DEM) which only permits the prediction of large gullies (width > 4m).

  16. Temporal Variability of Physical Properties on an Aquic Argiudoll under no Tillage

    NASA Astrophysics Data System (ADS)

    Castiglione, M. G.; Sasal, M. C.; Wilson, M. G.; Paz González, A.; Oszust, J. D.

    2012-04-01

    Practices for the implementation and development of crops affect soil properties and processes in space and time with consequences for the accumulation and movement of water, nutrients and pollutants, which affects plant growth. The aim of this study was to determine the temporal variability of soil physical properties and its link with the infiltration process, on an Aquic Argiudoll of the Argentine Pampas under no-till cultivation. Sampling was performed during six dates in the INTA EEA Paraná (Entre Ríos, Argentina), in the course of the succession of wheat/ soybean-corn. In each of those dates, rain simulations were performed under covered and uncovered soil. From these results it was determined the saturated hydraulic conductivity (Ks), the runoff coefficient (EC), the accumulated rainfall up to ponding (Tp), the accumulated rainfall to reach the steady state infiltration rate (TI) and the decline slope of the infiltration rate (Pd). Also we determine: the initial soil water content (HI), bulk density (Dap), volume occupied by pores larger than 50 µm (> 50), volume occupied by pores between 10 and 50 µm (10-50), soil physical quality index (S) and structural stability (CDMP). On three dates HI was approximately 11%, two were between 22 and 27% and in the remaining time HI was 36%. Despite these variations we don't observed significant changes in most soil physical properties associated with the structure and pore size. However, we could prove significant differences between dates in Ks and EC, both on bare and cover soil. At the same time, differences in these parameters between coverage degrees were significant only in two dates. The HI affected the variability of Ks results. Also Ks ratio between covered and uncovered soil improved with HI increment, except for HI equal to 36%. We found highly significant linkage between Ks, CE and Pd with HI. This study reveals the importance of the temporal dynamics of water movement in this Aquic Argiudoll, although

  17. Flow-specific physical properties of coconut flours

    NASA Astrophysics Data System (ADS)

    Manikantan, Musuvadi R.; Kingsly Ambrose, Rose P.; Alavi, Sajid

    2015-10-01

    Coconut milk residue and virgin coconut oil cake are important co-products of virgin coconut oil that are used in the animal feed industry. Flour from these products has a number of potential human health benefits and can be used in different food formulations. The objective of this study was to find out the flow-specific physical properties of coconut flours at three moisture levels. Coconut milk residue flour with 4.53 to 8.18% moisture content (w.b.) had bulk density and tapped density of 317.37 to 312.65 and 371.44 to 377.23 kg m-3, respectively; the corresponding values for virgin coconut oil cake flour with 3.85 to 7.98% moisture content (wet basis) were 611.22 to 608.68 and 663.55 to 672.93 kg m-3, respectively. The compressibility index and Hausner ratio increased with moisture. The angle of repose increased with moisture and ranged from 34.12 to 36.20 and 21.07 to 23.82° for coconut milk residue flour and virgin coconut oil cake flour, respectively. The coefficient of static and rolling friction increased with moisture for all test surfaces, with the plywood offering more resistance to flow than other test surfaces. The results of this study will be helpful in designing handling, flow, and processing systems for coconut milk residue and virgin coconut oil cake flours.

  18. Physical properties of orbital debris from spectroscopic observations

    NASA Astrophysics Data System (ADS)

    Jorgensen, K.; Africano, J.; Hamada, K.; Stansbery, E.; Sydney, P.; Kervin, P.

    2004-01-01

    Currently, certain physical properties, such as material type and albedo, of orbital debris are assumed when used to determine the size of the objects. A study to ascertain whether or not the assumed values are valid has begun using reflectance spectroscopy as a means of determining the material type of the object. What appears to some as a squiggly line is actually the reflectance of sunlight from the object. By comparing the location, depth, and width of the absorption features on the squiggly lines, the material type of the debris object is identified. Once the material type is known, the albedo of the object can be determined. This paper discusses the results from observations of large rocket bodies and satellites in both lower and geosynchronous Earth orbits (LEO and GEO, respectively) taken at the air force maui optical and supercomputing (AMOS) site located in Maui, Hawaii. Using the 1.6-m telescope and a spectral range of 0.3-0.9 μm, differences between rocket bodies of different types and launch dates, as well as satellites of different types and launch dates are determined. Variations seen in the squiggle lines are due to colors of paint, space weathering, and for the satellites, orientation and size of the solar panels. Future direction of the project will be discussed as well as plans for future observations.

  19. Physical and mechanical properties of modified bacterial cellulose composite films

    NASA Astrophysics Data System (ADS)

    Indrarti, Lucia; Indriyati, Syampurwadi, Anung; Pujiastuti, Sri

    2016-02-01

    To open wide range application opportunities of Bacterial Cellulose (BC) such as for agricultural purposes and edible film, BC slurries were blended with Glycerol (Gly), Sorbitol (Sor) and Carboxymethyl Cellulose (CMC). The physical and mechanical properties of BC composites were investigated to gain a better understanding of the relationship between BC and the additive types. Addition of glycerol, sorbitol and CMC influenced the water solubility of BC composite films. FTIR analysis showed the characteristic bands of cellulose. Addition of CMC, glycerol, and sorbitol slightly changed the FTIR spectrum of the composites. Tensile test showed that CMC not only acted as cross-linking agent where the tensile strength doubled up to 180 MPa, but also acted as plasticizer with the elongation at break increased more than 100% compared to that of BC film. On the other hand, glycerol and sorbitol acted as plasticizers that decreased the tensile strength and increased the elongation. Addition of CMC can improve film transparency, which is quite important in consumer acceptance of edible films in food industry.

  20. Influence of moisture content on physical properties of minor millets.

    PubMed

    Balasubramanian, S; Viswanathan, R

    2010-06-01

    Physical properties including 1000 kernel weight, bulk density, true density, porosity, angle of repose, coefficient of static friction, coefficient of internal friction and grain hardness were determined for foxtail millet, little millet, kodo millet, common millet, barnyard millet and finger millet in the moisture content range of 11.1 to 25% db. Thousand kernel weight increased from 2.3 to 6.1 g and angle of repose increased from 25.0 to 38.2°. Bulk density decreased from 868.1 to 477.1 kg/m(3) and true density from 1988.7 to 884.4 kg/m(3) for all minor millets when observed in the moisture range of 11.1 to 25%. Porosity decreased from 63.7 to 32.5%. Coefficient of static friction of minor millets against mild steel surface increased from 0.253 to 0.728 and coefficient of internal friction was in the range of 1.217 and 1.964 in the moisture range studied. Grain hardness decreased from 30.7 to 12.4 for all minor millets when moisture content was increased from 11.1 to 25% db. PMID:23572637

  1. Theoretical study of photo-physical properties of indolylmaleimide derivatives.

    PubMed

    Zheng, ZiLong; Zhao, Yi; Nakazono, Manabu; Nanbu, Shinkoh

    2012-03-01

    Photo-physical properties of bromo-indolylmaleimide (IM-Br), indole-succinimide (IS), and their anions were theoretically investigated compared with the previous theoretical result for indolylmaleimide (IM) [Phys. Chem. Chem. Phys., 2010, 12, 9783]. The energies for the electronic excited states as well as the ground states were computed for these molecules using the multi-reference perturbation calculations based on the second order Rayleigh-Schrödinger perturbation theory (CASPT2) at the cc-pVDZ basis set level. The electron-accepting or electron-donating effect caused by bromine-substitution was discussed in the intra-molecular charge transfer (ICT) mechanism. The order of natural orbitals of the bromine-substituted monovalent anion with a deprotonated indole NH group (I((-))M-Br) was found to be rearranged by the effect of electron-donation, which leads to pseudo-crossing of the potential energy cures of the S(1) and S(2) states. The large stokes shift observed for I((-))M-Br was due to pseudo-crossing. Meanwhile, IM and IM-Br show abnormal deprotonation, which is explained by the charge distribution on the indole and maleimide moieties. Finally, the monovalent anions I((-))M-Br and I((-))M by a deprotonation of the indole NH end and the neutral IS were proposed to be the most feasible candidates corresponding to the experimental spectra in solution. PMID:22293896

  2. Near-surface physics during convection affecting air-water gas transfer

    NASA Astrophysics Data System (ADS)

    Fredriksson, S. T.; Arneborg, L.; Nilsson, H.; Handler, R. A.

    2016-05-01

    The gas flux at the water surface is affected by physical processes including turbulence from wind shear, microscale wave breaking, large-scale breaking, and convection due to heat loss at the surface. The main route in the parameterizations of the gas flux has been to use the wind speed as a proxy for the gas flux velocity, indirectly taking into account the dependency of the wind shear and the wave processes. The interest in the contributions from convection processes has increased as the gas flux from inland waters (with typically lower wind and sheltered conditions) now is believed to play a substantial role in the air-water gas flux budget. The gas flux is enhanced by convection through the mixing of the mixed layer as well as by decreasing the diffusive boundary layer thickness. The direct numerical simulations performed in this study are shown to be a valuable tool to enhance the understanding of this flow configuration often present in nature.

  3. Quality and safety aspects of meat products as affected by various physical manipulations of packaging materials.

    PubMed

    Lee, Keun Taik

    2010-09-01

    This article explores the effects of physically manipulated packaging materials on the quality and safety of meat products. Recently, innovative measures for improving quality and extending the shelf-life of packaged meat products have been developed, utilizing technologies including barrier film, active packaging, nanotechnology, microperforation, irradiation, plasma and far-infrared ray (FIR) treatments. Despite these developments, each technology has peculiar drawbacks which will need to be addressed by meat scientists in the future. To develop successful meat packaging systems, key product characteristics affecting stability, environmental conditions during storage until consumption, and consumers' packaging expectations must all be taken into consideration. Furthermore, the safety issues related to packaging materials must also be taken into account when processing, packaging and storing meat products.

  4. Physical property characterization of a damage zone in granitic rock - Implications for geothermal reservoir properties

    NASA Astrophysics Data System (ADS)

    Wenning, Quinn; Madonna, Claudio; Amann, Florian; Gischig, Valentin; Burg, Jean-Pierre

    2016-04-01

    Geothermal energy offers a viable alternative to mitigate greenhouse gas emitting energy production. A tradeoff between less expensive drilling costs and increased permeability at shallow depths versus increased heat production at deeper depths stipulates the economic energy potential of a given reservoir. From a geological perspective, successful retrieval of geothermal energy from the subsurface requires sufficient knowledge of the structural and stratigraphic relationship of the target formations, which govern the thermal conditions, physical properties, and fluid flow properties of reservoir rocks. In Switzerland, deep basement rocks (~5 km) with fluid conducting damage zones and enhanced fractured systems stimulated by hydraulic shearing are seen as a potential geothermal reservoir system. Damage zones, both natural and induced, provide permeability enhancement that is especially important for creating fluid conductivity where the matrix permeability is low. This study concentrates on characterizing the elastic and transport properties entering into a natural damage zone penetrated by a borehole at the Grimsel underground research laboratory. The borehole drilled from a cavern at 480 m below ground surface penetrates approximately 20 m of mostly intact Grimsel granodiorite before entering the first phyllosilicate-rich shear zone (~0.2 m thick). The borehole intersects a second shear zone at approximately 23.8m. Between the two shear zones the Grimsel granodiorite is heavily fractured. The minimum principle stress magnitude from in-situ measurements decreases along the borehole into the first shear zone. Two mutually perpendicular core samples of Grimsel granodiorite were taken every 0.1 m from 19.5 to 20.1 m to characterize the physical properties and anisotropy changes as a gradient away from the damage zone. Measurements of ultrasonic compressional (Vp) and shear (Vs) velocities at 1 MHz frequency are conducted at room temperature and hydrostatic pressures

  5. Qualitative case study of physical therapist students' attitudes, motivations, and affective behaviors.

    PubMed

    Hayward, L M; Noonan, A C; Shain, D

    1999-01-01

    The purposes of this study were 1) to describe and document the attitudes, motivations, and affective behaviors of senior physical therapist students at a single university, and 2) to determine how data gathered from this work might assist with curriculum changes designed to promote professional behavior and self-directed learning. Student attitudes, behaviors, and motivations were identified using a qualitative case-study method. Phase one of the study examined clinical experiences using four focus groups, one conducted with six clinical instructors and three with 21 senior physical therapist students. Five follow-up interviews were conducted with students. During phase two, the same 21 students were queried about their classroom experiences using three focus groups and five follow-up interviews. Five major themes were identified: 1) mismatch of expectations between students and instructors, 2) preferred learning environment, 3) student-instructor relationship, 4) vocational expectations, and 5) stress. These themes parallel Chickering's theory of social development in college students. The authors encourage curriculum changes that directly address issues of professionalism, create an active learning environment, promote collaboration, and provide students with strategies for stress management. PMID:10507499

  6. Wavelet coherency analysis to relate saturated hydraulic properties to soil physical properties

    NASA Astrophysics Data System (ADS)

    Si, Bing Cheng; Zeleke, Takele B.

    2005-11-01

    A soil property may be related to another and the relationships may change depending on the scale and location. Understanding these scale- and location-dependent relationships is important for prediction of one soil property based on another. The objective of this study is to use wavelet coherency analysis to examine whether the relationship between hydraulic properties and soil physical properties are scale- and location-dependent. Undisturbed cores were collected along a transect from the sandy loam soil of a farm field in northern Saskatchewan, Canada. Saturated hydraulic conductivity (Ks), sand content, and organic carbon content (OC) were measured on these cores, and their relationships as a function of scale and location were analyzed using wavelets. Results indicated that the wavelet coherency between Ks and sand content is only significantly different from that of red noises at the scales around 48 m. The cross-wavelet spectrum and wavelet coherency are predominantly in phase, suggesting a positive correlation between Ks and sand. For Ks and OC, significant coherency exists at scales from 30 to 48 and around 80 m. At the scales of 30-48 and around 80 m the relationships are predominantly out of phase, suggesting negative correlation. Therefore relationships between Ks and sand or Ks and OC are not only scale-dependent but also location-dependent. Scale and location dependence have an important implication for understanding the scaling relationships between Ks and sand and OC and for the prediction of Ks from sand and OC.

  7. Coarse fragments affects soil properties in a mantled-karst landscape of the Ozark Highlands

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This paper investigates the effect of rock fragments on soil physical hydraulic properties within the mantled karst landscapes of the Savoy Experimental Watershed (SEW), a setting typical of much of the Ozark Plateaus. Water resources in these settings are highly susceptible to contamination. As a r...

  8. Physical and Mechanical Properties of Niobium for SRF Science and Technology

    SciTech Connect

    Ganapati Rao Myneni

    2006-10-31

    Optimized mechanical and physical properties of high purity niobium are crucial for obtaining high performance SRF particle beam accelerator structures consistently. This paper summarizes these important material properties for both high purity polycrystalline and single crystal niobium.

  9. PHYSICAL PROPERTIES OF FLUORINATED PROPANE AND BUTANE DERIVATIVES AS ALTERNATIVE REFRIGERANTS

    EPA Science Inventory

    Physical property measurements are presented for 24 fluorinated propane and butane derivatives and one fluorinated ether. These measurements include melting point, boiling point, vapor pressure below the boiling point, heat of vaporization at the boiling point, critical propertie...

  10. Summary of tank waste physical properties at the Hanford Site

    SciTech Connect

    Nguyen, Q.H.

    1994-04-01

    This report summarizes the physical parameters measured from Hanford Site tank wastes. Physical parameters were measured to determine the physical nature of the tank wastes to develop simulants and design in-tank equipment. The physical parameters were measured mostly from core samples obtained directly below tank risers. Tank waste physical parameters were collected through a database search, interviewing and selecting references from documents. This report shows the data measured from tank waste but does not describe how the analyses wee done. This report will be updated as additional data are measured or more documents are reviewed.

  11. Effect of solvents on physical properties and release characteristics of monolithic hydroxypropylmethylcellulose matrix granules and tablets.

    PubMed

    Cao, Qing-Ri; Choi, Yun-Woong; Cui, Jing-Hao; Lee, Beom-Jin

    2005-04-01

    Effect of solvents on physical characteristics and release characteristics of monolithic acetaminophen (APAP) hydroxypropylmethylcellulose (HPMC) matrix granules and tablets were examined. Various types and amounts of solvents were employed for granulation and cOAting. APAP and other excipients were mixed and were then wet-granulated in a high-speed mixer. The dried granules were then directly compressed and film-coated with low viscosity grade HPMC. As the amount of water increased, the size of granules also increased, showing more spherical and regular shape. However, manufacturing problems such as capping and lamination in tableting occurred when water was used alone as a granulating solvent. The physical properties of HPMC matrix granules were not affected by the batch size. The initial release rate as well as the amount of APAP dissolved had a tendency to decrease as the water level increased. Addition of nonaqueous solvent like ethanol to water resulted in good physical properties of granules. When compared to water/ethanol as a coating solvent, the release rate of film-coated HPMC matrix tablets was more sensitive to the conditions of coating and drying in methylene chloride/ethanol. Most of all, monolithic HPMC matrix tablet when granulated in ethanol/water showed dual release with about 50% drug release immediately within few minutes followed by extended release. It was evident that the type and amount of solvents (mainly water and ethanol) were very important for wet granulation and film-coating of monolithic HPMC matrix tablet, because the plastic deforming and fragmenting properties of material were changed by the different strengths of the different solvents. PMID:15918526

  12. HETDEX: The Physical Properties of Lyman-alpha Emitters

    NASA Astrophysics Data System (ADS)

    Gronwall, Caryl; Blanc, G.; Ciardullo, R.; Finkelstein, S.; Gawiser, E.; Gebhardt, K.; HETDEX Collaboration

    2012-01-01

    Beginning in Fall 2012, the Hobby-Eberly Telescope Dark Energy Experiment (HETDEX) will map out 300 square degrees via a blind integral-field spectroscopic survey which will detect 800,000 Lyman-alpha emitters (LAEs) at 1.9 < z < 3.5. The goal of HETDEX is to explore the expansion history of the universe via the LAE power spectrum, but these emission-line sources are also important probes of galaxy evolution. LAEs are observed "in the act" of formation with low mass, little dust, very young ages, and a two-dimensional clustering scale-length that implies that they are the progenitors of today's Milky Way type galaxies. The unprecedented size of the HETDEX survey will allow us to explore the 3-D clustering of these objects and to measure their halo masses as a function of redshift. We will also be able to explore the physical properties of LAEs over a wide range of environments, and study how their luminosity functions, equivalent width distributions, and star formation rates change with galaxy density and redshift. In preparation for HETDEX, we undertook a 3 year pilot survey to test the feasibility of the experiment and design an optimal observing strategy. These observations were performed with a proto-type HETDEX spectrograph (VIRUS-P) on the McDonald 2.7-m telescope, and covered Ly-alpha in the redshift range 1.9 < z < 3.8. This survey discovered 104 Ly-alpha emitting galaxies in 169 sq. arcmin of sky, and reached objects with Ly-alpha line luminosities as faint as 3 x 1042 ergs/s. We will present the Ly-alpha luminosity function, equivalent width distributions, and star formation rates measured for this sample and discuss the implications of the pilot survey results for HETDEX.

  13. Characterization of sheep lung lymph lipoproteins: chemical and physical properties

    SciTech Connect

    Forte, T.M.; Cross, C.E.; Gunther, R.A.; Kramer, G.C.

    1983-01-01

    The authors have determined the composition and distribution of plasma and lung lymph lipoproteins from unanesthetized ewes. Cholesterol, triglyceride, and phospholipid levels in lung lymph were 45%, 50%, and 50%, respectively, of those in plasma. Lipoproteins from both lymph and plasma were separated into two major fractions: d < 1.063 g/ml or LDL, and d 1.063-1.21 g/ml or HDL. HDL was the major lipoprotein species in the plasma and lymph. Gradients gel electrophoresis of HDL on 4-30% gels showed that, in lymph, HDL particles were shifted to larger sizes; in addition to a peak at 8.5 nm, which was similar to plasma HDL, there were two additional components of larger size, one at 9.2 nm and the other at 12 nm. Electron microscopy revealed that lymph HDL contained two new particles not seen in plasma: large, round particles, 13.6 nm diameter, and discoidal particles, 18.7 by 4.9 nm, long and short axis, respectively. Compositional analysis of lymph HDL revealed a relative enrichment in free cholesterol as well as an enrichment in apolipoprotein E. Lymph LDL on gradient gel electrophoresis was extremely heterogeneous. Several peaks were evident in the 23-30 nm size range (similar to plasma LDL), but a supplementary component at approximately 15-16 nm was also present. Whereas plasma LDL on electron microscopy contained only round particles 26 nm in diameter, lymph contained an additional, unusual particle which was close-packed, with square geometry, and was 15 nm in diameter. Changes in the physical and chemical properties of lung lymph lipoproteins suggest that these particles are metabolically modified.

  14. Physical properties of luminous dust-poor quasars

    SciTech Connect

    Jun, Hyunsung David; Im, Myungshin E-mail: mim@astro.snu.ac.kr

    2013-12-20

    We identify and characterize a population of luminous, dust-poor quasars at 0 < z < 5 that is photometrically similar to objects previously found at z > 6. This class of active galactic nuclei is known to show little IR emission from dusty structure, but it is poorly understood in terms of number evolution and dependence on physical quantities. To better understand the properties of these quasars, we compile a rest-frame UV to IR library of 41,000 optically selected type 1 quasars with L {sub bol} > 10{sup 45.7} erg s{sup –1}. After fitting the broadband spectral energy distributions (SEDs) with accretion disk and dust components, we find 0.6% of our sample to be hot dust-poor, with rest-frame 2.3 μm to 0.51 μm flux density ratios of –0.5 dex or less. The dust-poor SEDs are blue in the UV-optical and weak in the mid-IR, such that their accretion disks are less obscured and the hot dust emission traces that of warm dust down to the dust-poor regime. At a given bolometric luminosity, dust-poor quasars are lower in black hole mass and higher in Eddington ratio than general luminous quasars, suggesting that they are in a rapidly growing evolutionary state in which the dust-poor phase appears as a short or rare phenomenon. The dust-poor fraction increases with redshift, and possible implications for their evolution are discussed.

  15. Physical properties of orbital debris from squiggly lines

    NASA Astrophysics Data System (ADS)

    Jorgensen, K.; Africano, J.; Hamada, K.; Stansbery, E.; Sydney, P.; Kervin, P.

    Currently, certain physical properties, such as material type and albedo, of orbital debris are assumed when used to determine the size of the objects. A study to ascertain whether or not the assumed values are valid has begun using reflectance spectroscopy as a means of determining the material type of the object. What appears to some as a squiggly line is actually the reflectance of sunlight from the object. By comparing the location, depth, and width of the absorption features on the squiggly lines, the material type of the debris object is identified. Once the material type is known, the albedo of the object can be determined. This paper discusses the results from observations of large rocket bodies and satellites in both lower and geosynchronous Earth orbits (LEO and GEO, respectively) taken at the Air Force Maui Optical Supercomputing (AMOS) site located in Maui, Hawaii. Using the 1.6- meter telescope and a spectral range of 0.3 to 0.9 microns, differences between rocket bodies of different types and launch dates, as well as satellites of different types and launch dates are determined. Variations seen in the squiggle lines are due to colors of paint, space weathering, and for the satellites, orientation and size of the solar panels. Initial findings from an additional observation run using the 3.67-meter telescope equipped with both a visible and near-infrared spectrometer (out to 2 microns) are also described. Future direction of the project will be discussed as well as plans for future observations.

  16. Physical properties of antimony-doped tin oxide thick films

    NASA Astrophysics Data System (ADS)

    Kaneko, H.; Miyake, K.

    1982-05-01

    The physical properties of Sb-doped SnO2 thick films, prepared by a repeating chemical spray deposition method, have been investigated. The films 1000-14 000-Å thick were deposited on fused quartz, borosilicate glass, and soda lime glass substrates at 600 °C using an aqueous solution of a mixture of SnCl4 and SbCl3. The films prepared by the method are homogeneous, and the electrical resistivity of the films on fused quartz and borosilicate glass substrates were found to be independent of the film thickness, and are 9.5×10-4 Ω cm, and 8.6×10-4 Ω cm, respectively. The resistivity of the films thicker than 4000 Å on soda lime glass substrates is almost constant, and is 1.8×10-3 Ω cm, although a large increase in the resistivity of the thinner films was observed. The optical band gap of the films on fused quartz and borosilicate glass substrates is also independent of the film thickness, and is almost the same: 3.75 eV. But the band gap of the films on soda lime glass substrates depends on the film thickness, and increases from 2.85 to 3.08 eV with increasing thickness from 2250 to 13 000 Å. The Hall mobility and carrier concentration of the films were also measured. The results of x-ray diffraction analysis and observations by SEM are described.

  17. Physical and chemical properties of San Francisco Bay, California, 1980

    USGS Publications Warehouse

    Ota, Allan Y.; Schemel, L.E.; Hager, S.W.

    1989-01-01

    The U.S. Geological Survey conducted hydrologic investigations in both the deep water channels and the shallow-water regions of the San Francisco Bay estuarine system during 1980. Cruises were conducted regularly, usually at two-week intervals. Physical and chemical properties presented in this report include temperature , salinity, suspended particulate matter, turbidity, extinction coefficient, partial pressure of CO2, partial pressure of oxygen , dissolved organic carbon, particulate organic carbon, discrete chlorophyll a, fluorescence of photosynthetic pigments, dissolved silica, dissolved phosphate, nitrate plus nitrite, nitrite, ammonium, dissolved inorganic nitrogen, dissolved nitrogen, dissolved phosphorus, total nitrogen, and total phosphorus. Analytical methods are described. The body of data contained in this report characterizes hydrologic conditions in San Francisco Bay during a year with an average rate of freshwater inflow to the estuary. Concentrations of dissolved silica (discrete-sample) ranged from 3.8 to 310 micro-M in the northern reach of the bay, whereas the range in the southern reach was limited to 63 to 150 micro-M. Concentrations of phosphate (discrete-sample) ranged from 1.3 to 4.4 micro-M in the northern reach, which was narrow in comparison with that of 2.2 to 19.0 micro-M in the southern reach. Concentrations of nitrate plus nitrite (discrete-sample) ranged from near zero to 53 micro-M in the northern reach, and from 2.3 to 64 micro-M in the southern reach. Concentrations of nitrite (discrete-sample) were low in both reaches, exhibiting a range from nearly zero to approximately 2.3 micro-M. Concentrations of ammonium (discrete-sample) ranged from near zero to 14.2 micro-M in the northern reach, and from near zero to 8.3 micro-M in the southern reach. (USGS)

  18. Layered Nature With Different Physical Properties Of Firn

    NASA Astrophysics Data System (ADS)

    Okuyama, J.; Fujita, S.; Takeya, S.; Koerner, R. M.; Hondoh, T.

    2003-12-01

    To better understand the formation mechanism of the layered structures in firn, we have introduced new methods to clarify the various physical properties relating to the firn-densification process; that is, the X-ray transmission method for detailed profile of density, the X-ray CT for the anisotropy of crystal shapes, the X-ray diffraction method for the crystallographic orientations of both 0002 and 11-20, and the open resonator method for the dielectric permittivity tensor at microwave frequency. These methods have been applied to the firn in both the Dome Fuji ice core from East Antarctica and the P96 ice core from Penny Ice Cap, Baffin Island, Canada. We have found by these measurements that (1) the crystal shapes elongated vertically near the surface turn into spherical ones with depth, (2) the layers with the preferential c axis orientations (fabrics) in vertical alternate with those in horizontal, (3) these preferential orientations gradually vary towards random ones with depth, but (4) there still exist the layered structures with different fabrics even at the close-off depth, and (5) the dielectric anisotropy, or the difference between the dielectric constants parallel and perpendicular to the core axis, decreases with depth. On the basis of these findings, we propose a grain-rotation mechanism during the firn-densification process, which well explains the finding (3). The finding (4) suggests that ice below the close-off depth is also composed of the layered structures with different fabrics. Since the difference in fabrics between layers increases by plastic deformation of grains below the close-off depth, the layered structures with different fabrics must be developed with depth.

  19. Effect of chain microstructure on physical properties of olefin copolymers

    NASA Astrophysics Data System (ADS)

    Poon, Benjamin Chunman

    The effect of chain microstructure on various physical properties was studied in polyethylene and polypropylene copolymers. Adhesion of Ziegler-Natta (ZNPE) and metallocene (mPE) catalyzed ethylene-octene copolymers to polypropylene (PP) were studied by measuring the delamination toughness G of coextruded microlayers using the T-peel test. It was found that the heterogeneous ZNPE exhibited poor adhesion to polypropylene. It was proposed that the low molecular weight, highly branched ZNPE fractions migrate to the interface to form an amorphous layer. The homogeneous mPE with the same short chain branch content showed very high G. Blending ZNPE with an mPE increased G. Atomic force microscopy revealed that blending mPE into ZNPE reduced or eliminated the amorphous interfacial layer. It was hypothesized that mPE increased miscibility of low molecular weight, highly branched fractions of ZNPE and prevented their segregation at the interface. The solid state structure and properties of homogeneous propylene-octene copolymers were examined. Based on the combined observations from melting behavior, dynamic mechanical response, morphology with primarily atomic force microscopy, X-ray diffraction, and tensile deformation, a classification scheme with 4 distinct categories is proposed. The homopolymer with 60 wt% crystallinity constitutes Type IV. It is characterized by large alpha-positive spherulite. Copolymers with up to 5 mol% octene, with at least 35 wt% crystallinity, are classified as Type III. They crystallize as alpha-positive spherulites that are smaller than the homopolymer. Both Type IV and Type III materials exhibit thermoplastic behavior. Copolymers classified as Type II have between 5 and 10 mol% octene with crystallinity in the range of 20--35%. Type II materials have smaller impinging spherulites than Type III copolymers and they are negative. The materials in this category have plastomeric behavior. Type I copolymers have more than 10 mol% octene and less

  20. Investigation of the MBL Cloud Macro- and Micro-physical Properties over Pacific and Atlantic Oceans

    NASA Astrophysics Data System (ADS)

    Xi, B.; Dong, X.

    2013-12-01

    Marine boundary layer (MBL) cloud is an important cloud type in global climate system, and its macro- and micro- physical properties relate with not only the radiation budgets but also affect the sea surface temperature. Two DOE ARM Mobile Facilities (AMF1 and AMF2) were recently deployed at both Atlantic and Pacific Oceans. One was at the Graciosa Island, Azores in context of the Clouds, Aerosol and Precipitation in the Marine Boundary Layer (CAP-MBL) field campaign and the AMF1 collected the most continuous, valuable and comprehensive data of MBL clouds from Jun. 2009 to Dec. 2010. The other filed campaign is the Marine ARM GPCI Investigation of Clouds (MAGIC) IOP, which will provide a great opportunity for us to do the analysis of MBL over Pacific Ocean. The ARM Mobile Facility (AMF2) has been deployed on the Horizon Line cargo ship Spirit traversing the route between Los Angeles, CA and Honolulu, HI for one full year (Oct. 2012 to Sept. 2013) with two additional 2-week intensive observational periods in January and July 2013, such as including additional instruments and more soundings (3-hr). The AMF2 has very similar data sets as the AMF1 over Azores but will not focus on one single point. The AMF2 observations, as well as retrievals for MBL clouds during MAGIC will allow us to compare the MBL cloud properties between North Atlantic and Pacific Oceans. In this study, we will compare the MBL clouds macro- and micro- physical properties over two Oceans. These macro- and micro- physical properties of MBL clouds are derived from AMF1 and AMF2 measurements. In details, the cloud heights are derived from radar/lidar pairs; the cloud temperatures are from linearly interpreted soundings; liquid water path (LWP) is retrieved from microwave radiometer; cloud condensation nuclei are derived from AOS measurements under super-saturation ratio at 0.2. The MBL cloud microphysical properties at daytime ( cloud effective radius, optical thickness, and number concentration

  1. Physical properties of cobia (Rachycentron canadum) surimi: effect of washing cycle at different salt concentrations.

    PubMed

    Hamzah, N; Sarbon, N M; Amin, A M

    2015-08-01

    This study aimed to determine the effects of 2-5 wash cycles and the addition of tetrasodium pyrophosphate (TSPP) (0 %, 0.05 Surimi% and 0.1 % w/w)-with or without the addition of 0.4 % calcium chloride (CaCl2)-on the physical properties such as texture, colour, expressible moisture and microstructure of Cobia (Rachycentron canadum) surimi gel. The highest breaking force (484.85 g) was obtained with the addition 0.1 % TSPP alone on the fifth wash. However, a combination of 0.1 and 0.4 % CaCl2 in surimi gels at wash cycle 5 resulted in the highest degree of whiteness (86.8 %), as well as total expressible moisture (2.785 %) and deformation (17.11 mm). The highest surimi gel strength (6,923 g.mm) was obtained after three wash cycles with the addition of 0.1 % TSPP +0.4 % CaCl2. The physical properties of Cobia fish surimi gels were affected by the number of wash cycles and treatments with TSPP and CaCl2.

  2. Physical property comparison of 11 soft denture lining materials as a function of accelerated aging.

    PubMed

    Dootz, E R; Koran, A; Craig, R G

    1993-01-01

    Soft denture-lining materials are an important treatment option for patients who have chronic soreness associated with dental prostheses. Three distinctly different types of materials are generally used. These are plasticized polymers or copolymers, silicones, or polyphosphazene fluoroelastomer. The acceptance of these materials by patients and dentists is variable. The objective of this study is to compare the tensile strength, percent elongation, hardness, tear strength, and tear energy of eight plasticized polymers or copolymers, two silicones, and one polyphosphazene fluoroelastomer. Tests were run at 24 hours after specimen preparation and repeated after 900 hours of accelerated aging in a Weather-Ometer device. The data indicated a wide range of physical properties for soft denture-lining materials and showed that accelerated aging dramatically affected the physical and mechanical properties of many of the elastomers. No soft denture liner proved to be superior to all others. The data obtained should provide clinicians with useful information for selecting soft denture lining materials for patients.

  3. Effects of biogenic silica on acoustic and physical properties of clay-rich marine sediments

    SciTech Connect

    Tribble, J.S.; Mackenzie, F.T.; Urmos, J.; O'Brien, D.K.; Manghnani, M.H. )

    1992-06-01

    The physical properties of marine sediments are influenced by compaction and diagenesis during burial. Changes in mineralogy, chemistry, density, porosity, and microfabric all affect a sediment's acoustic and electrical properties. Sediments from the Japan Trench illustrate the dependence of physical properties on biogenic silica content. Increased opal-A content is correlated with increased porosity and decreased grain density and compressional velocity. Variations with depth in opal-A concentration are therefore reflected in highly variable and, at times, inverse velocity-depth gradients. The diagenetic conversion of opal-A to opal-CT and finally to quartz was investigated at a site in the San Miguel Gap, California. Distinct changes in microfabric, particularly in the porosity distribution, accompany the diagenetic reactions and contribute to a sharp velocity discontinuity at the depth of the opal-A to opal-CT conversion. Evaluation of this reaction at several sites indicates a systematic dependence on temperature and age in clay-rich and moderately siliceous sediments. In ocean margin regions, sediments are buried rapidly, and opal-A may be converted to opal-CT in less than 10 m.y. Temperatures of conversion range from 30{degree} to 50{degree}C. Much longer times (>40 m.y.) are required to complete the conversion in open ocean deposits which are exposed to temperatures less than 15{degree}C. In the absence of silica diagenesis, velocity-depth gradients of most clay-rich and moderately siliceous sediments fall in the narrow range of 0.15 to 0.25 km/s/km which brackets the gradient (0.18 km/s/km) determined for a type pelagic clay section. Relationships such as these can be useful in unraveling the history of a sediment sequence, including the evolution with time of reservoir properties and seismic signatures.

  4. Determination of the Geotechnical Characteristics of Hornfelsic Rocks with a Particular Emphasis on the Correlation Between Physical and Mechanical Properties

    NASA Astrophysics Data System (ADS)

    Fereidooni, Davood

    2016-07-01

    Geotechnical characteristics and relationships between various physical and mechanical properties were assessed for eight types of hornfelsic rock collected from southern and southwestern parts of the city of Hamedan in western Iran. Rock samples were subjected to mineralogical, physical, index, and mechanical laboratory tests and found to contain quartz, feldspar, biotite, muscovite, garnet, sillimanite, kyanite, staurolite, graphite, and other fine-grained cryptocrystalline matrix materials. Samples had a porphyroblastic texture, and the mineral contents and physical properties influenced various rock characteristics. Some rock characteristics were affected by mineral content, while others were affected by porosity. Dry unit weight, primary and secondary wave velocities, and slake-durability index were noteworthy characteristics affected by mineral content, while porosity had the greatest influence on water absorption, Schmidt hardness, point load index, Brazilian tensile strength, and uniaxial compressive strength. Empirical equations describing the relationships between different rock parameters are proposed for determining the essential characteristics of rock, such as secondary wave velocity, slake-durability index, point load index, Brazilian tensile strength, and uniaxial compressive strength. On the basis of these properties, the studied rocks were classified as being strong or very strong.

  5. Socioeconomic Factors Affecting Minority Physics Taking in U.S. High Schools

    ERIC Educational Resources Information Center

    Physics Teacher, 2011

    2011-01-01

    In the September issue, we saw that a lower proportion of Hispanics and blacks take physics in U.S. high schools than do whites and Asians. Last month, we examined physics offerings and students by socioeconomic profile of the high school as reported by the principal. We saw that there were more physics classes and more physics students at…

  6. Change in physical properties of pine bark and switchgrass substrates over time

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Alternatives to pine bark for nursery crop substrates have been proposed, including the use of straw materials such as switchgrass. While straw substrates can be developed with suitable physical properties measured immediately after mixing, little is known about how the physical properties of straw...

  7. Mental Rolodexing: Senior Chemistry Majors' Understanding of Chemical and Physical Properties

    ERIC Educational Resources Information Center

    DeFever, Ryan S.; Bruce, Heather; Bhattacharyya, Gautam

    2015-01-01

    Using a constructivist framework, eight senior chemistry majors were interviewed twice to determine: (i) structural inferences they are able to make from chemical and physical properties; and (ii) their ability to apply their inferences and understandings of these chemical and physical properties to solve tasks on the reactivity of organic…

  8. Effects of Pressure-shift Freezing on the Structural and Physical Properties of Gelatin Hydrogel Matrices

    PubMed Central

    Kim, Byeongsoo; Gil, Hyung Bae; Min, Sang-Gi; Lee, Si-Kyung; Choi, Mi-Jung

    2014-01-01

    This study investigates the effects of the gelatin concentration (10-40%, w/v), freezing temperatures (from -20℃ to -50℃) and freezing methods on the structural and physical properties of gelatin matrices. To freeze gelatin, the pressure-shift freezing (PSF) is being applied at 0.1 (under atmospheric control), 50 and 100 MPa, respectively. The freezing point of gelatin solutions decrease with increasing gelatin concentrations, from -0.2℃ (10% gelatin) to -6.7℃ (40% gelatin), while the extent of supercooling did not show any specific trends. The rheological properties of the gelatin indicate that both the storage (G') and loss (G") moduli were steady in the strain amplitude range of 0.1-10%. To characterize gelatin matrices formed by the various freezing methods, the ice crystal sizes which were being determined by the scanning electron microscopy (SEM) are affected by the gelatin concentrations. The ice crystal sizes are affected by gelatin concentrations and freezing temperature, while the size distributions of ice crystals depend on the freezing methods. Smaller ice crystals are being formed with PSF rather than under the atmospheric control where the freezing temperature is above -40℃. Thus, the results of this study indicate that the PSF processing at a very low freezing temperature (-50℃) offers a potential advantage over commercial atmospheric freezing points for the formation of small ice crystals. PMID:26760743

  9. Physical-mechanical and antimicrobial properties of nanocomposite films with pediocin and ZnO nanoparticles.

    PubMed

    Espitia, Paula Judith Perez; Soares, Nilda de Fátima Ferreira; Teófilo, Reinaldo F; Coimbra, Jane Sélia dos Reis; Vitor, Débora M; Batista, Rejane Andrade; Ferreira, Sukarno Olavo; de Andrade, Nélio José; Medeiros, Eber Antonio Alves

    2013-04-15

    This work aimed to develop nanocomposite films of methyl cellulose (MC) incorporated with pediocin and zinc oxide nanoparticles (nanoZnO) using the central composite design and response surface methodology. This study evaluated film physical-mechanical properties, including crystallography by X-ray diffraction, mechanical resistance, swelling and color properties, microscopy characterization, thermal stability, as well as antimicrobial activity against Staphylococcus aureus and Listeria monocytogenes. NanoZnO and pediocin affected the crystallinity of MC. Load at break and tensile strength at break did not differ among films. NanoZnO and pediocin significantly affected the elongation at break. Pediocin produced yellowish films, but nano ZnO balanced this effect, resulting in a whitish coloration. Nano ZnO exhibited good intercalation in MC and the addition of pediocin in high concentrations resulted crater-like pits in the film surfaces. Swelling of films diminished significantly compared to control. Higher concentrations of Nano ZnO resulted in enhanced thermal stability. Nanocomposite films presented antimicrobial activity against tested microorganisms.

  10. Physical properties of rocks and aqueous fluids at conditions simulating near- and supercritical reservoirs

    NASA Astrophysics Data System (ADS)

    Kummerow, Juliane; Raab, Siegfried

    2016-04-01

    The growing interest in exploiting supercritical geothermal reservoirs calls for a thorough identification and understanding of physico-chemical processes occuring in geological settings with a high heat flow. In reservoir engineering, electrical sounding methods are common geophysical exploration and monitoring tools. However, a realistic interpretation of field measurements is based on the knowledge of both, the physical properties of the rock and those of the interacting fluid at defined temperature and pressure conditions. Thus, laboratory studies at simulated in-situ conditions provide a link between the field data and the material properties in the depth. The physico-chemical properties of fluids change dramatically above the critical point, which is for pure water 374.21 °C and 221.2 bar. In supercritical fluids mass transfer and diffusion-controlled chemical reactions are enhanced and cause mineral alterations. Also, ion mobility and ion concentration are affected by the change of physical state. All this cause changes in the electrical resistivity of supercritical fluids and may have considerable effects on the porosity and hydraulic properties of the rocks they are in contact with. While there are some datasets available for physical and chemical properties of water and single component salt solutions above their critical points, there exist nearly no data for electrical properties of mixed brines, representing the composition of natural geothermal fluids. Also, the impact of fluid-rock interactions on the electrical properties of multicomponent fluids in a supercritical region is scarcely investigated. For a better understanding of fluid-driven processes in a near- and supercritical geological environment, in the framework of the EU-funded FP7 program IMAGE we have measured (1) the electrical resistivity of geothermal fluids and (2) physical properties of fluid saturated rock samples at simulated in-situ conditions. The permeability and electrical

  11. Soil physical properties: Key factors for successful reclamation of disturbed landscapes

    NASA Astrophysics Data System (ADS)

    Krümmelbein, Julia; Raab, Thomas

    2013-04-01

    The practice of open cast mining, e.g. for lignite, results in major landscape disturbances and especially affects soils because relocation and subsequent mixing of naturally developed soil horizons leads to areas with extremely altered soil properties compared to the undisturbed conditions. Various reclamation measures are applied to recover the reconstructed landscape for different land use options. Major parts of the post mining landscapes are used for agriculture, agroforestry or silviculture, the remaining voids of the coal mines fill successively with groundwater after mine closure and are or will be used mainly for touristic and leisure purposes. Small proportions of the post mining areas are left for natural succession, or habitats for endangered flora and fauna are initiated. In reclamation research, many studies have focused on soil chemical and biological constraints of post mining substrates and investigated factors such as unsuitable pH, in many cases very low pH, (poor) nutrient contents and (poor) biological activity. But the initial and developing soil physical parameters and functions are also key factors for the success of reclamation practices. The soil water and gas balance influence strongly the suitability of a site for the intended future land use. The mechanical stability of the soil determines the rigidity of the pore system against deforming forces and thereby the persistence of soil functions, such as water and air permeability over time. The amendment of unfavourable (initial) soil physical properties is in most cases more complex and time-consuming than e.g. optimization of pH or fertilization with nutrients. Moreover, regarding the suitability of a site e.g. as a habitat for plants or microorganisms, poor physical pre-conditions can turn substrates with perfect nutrient contents and composition and pH into infertile locations of very low productivity. We show results of an on-going field study where the effects of different

  12. Physical, proximate, functional and pasting properties of flour produced from gamma irradiated cowpea (Vigna unguiculata, L. Walp)

    NASA Astrophysics Data System (ADS)

    Darfour, B.; Wilson, D. D.; Ofosu, D. O.; Ocloo, F. C. K.

    2012-04-01

    Cowpeas are leguminous seeds widely produced and consumed in most developing countries of sub Saharan Africa. The aim of this study was to determine the physical, proximate, functional and pasting properties of flour obtained from gamma irradiated cowpea. Four cowpea cultivars were irradiated with gamma radiation at dose levels of 0.25, 0.5, 0.75, 1.0 and 1.5 kGy with the unirradiated cultivars serving as controls. The samples were hammer milled, sieved and stored at 4 °C for analysis. Physical, proximate, functional, pasting properties were determined using appropriate methods. In general, the irradiation dose applied to cowpea for insect control did not significantly affect the physical and proximate properties of the flour. However, significant increase (p<0.05) was achieved in paste bulk density, water and oil absorption capacities, foam capacities and least gelation concentrations of flour in general, which may be attributed to the irradiation. The radiation reduced the swelling power and water solubility index significantly. The peak temperature, peak viscosity and setback viscosity of the pastes were significantly (p<0.05) reduced while breakdown viscosity was significantly (p<0.05) increased by the radiation. It was established that the doses used on cowpea affected both the functional and pasting properties of the flour.

  13. Effect of sucrose on physical properties of spray-dried whole milk powder.

    PubMed

    Ma, U V Lay; Ziegler, G R; Floros, J D

    2008-11-01

    Spray-dried whole milk powders were prepared from whole condensed milk with various sucrose concentrations (0%, 2.5%, 5%, 7.5%, and 10% w/w), and their glass transition temperature and some physical properties of importance in chocolate manufacture were evaluated. In milk powder samples, the glass transition temperature and free-fat content decreased in a nonlinear manner with sucrose addition. Moreover, increasing sucrose concentration reduced the formation of dents on the particle surface. Addition of sucrose in whole condensed milk increased linearly the apparent particle density and in a nonlinear manner the particle size of spray-dried milk powders. The particle size volume distribution of milk powders with the highest sucrose concentration differed from the log-normal distribution of the other samples due to the formation of large agglomerates. Neither vacuole volume, nor the amorphous state of milk powders was affected by sucrose addition. PMID:19021798

  14. Effect of sucrose on physical properties of spray-dried whole milk powder.

    PubMed

    Ma, U V Lay; Ziegler, G R; Floros, J D

    2008-11-01

    Spray-dried whole milk powders were prepared from whole condensed milk with various sucrose concentrations (0%, 2.5%, 5%, 7.5%, and 10% w/w), and their glass transition temperature and some physical properties of importance in chocolate manufacture were evaluated. In milk powder samples, the glass transition temperature and free-fat content decreased in a nonlinear manner with sucrose addition. Moreover, increasing sucrose concentration reduced the formation of dents on the particle surface. Addition of sucrose in whole condensed milk increased linearly the apparent particle density and in a nonlinear manner the particle size of spray-dried milk powders. The particle size volume distribution of milk powders with the highest sucrose concentration differed from the log-normal distribution of the other samples due to the formation of large agglomerates. Neither vacuole volume, nor the amorphous state of milk powders was affected by sucrose addition.

  15. Effect of acetic acid on physical properties of pregelatinized wheat and corn starch gels.

    PubMed

    Majzoobi, Mahsa; Kaveh, Zahra; Farahnaky, Asgar

    2016-04-01

    Pregelatinized starches are physically modified starches with ability to absorb water and increase viscosity at ambient temperature. The main purpose of this study was to determine how different concentrations of acetic acid (0, 500, 1000, 10,000 mg/kg) can affect functional properties of pregelatinized wheat and corn starches (PGWS and PGCS, respectively) produced by a twin drum drier. With increasing acetic acid following changes occurred for both samples; cold water solubility (at 25 °C) increased, water absorption and apparent cold water viscosity (at 25 °C) reduced, the smooth surface of the starch particles converted to an uneven surface as confirmed by scanning electron microscopy, cohesiveness, consistency and turbidity of the starch gels reduced while their syneresis increased. It was found that in presence of acetic acid, PGWS resulted in higher water absorption and apparent cold water viscosity and produced more cohesive and turbid gels with less syneresis compared to PGCS. PMID:26593546

  16. Effect of acetic acid on physical properties of pregelatinized wheat and corn starch gels.

    PubMed

    Majzoobi, Mahsa; Kaveh, Zahra; Farahnaky, Asgar

    2016-04-01

    Pregelatinized starches are physically modified starches with ability to absorb water and increase viscosity at ambient temperature. The main purpose of this study was to determine how different concentrations of acetic acid (0, 500, 1000, 10,000 mg/kg) can affect functional properties of pregelatinized wheat and corn starches (PGWS and PGCS, respectively) produced by a twin drum drier. With increasing acetic acid following changes occurred for both samples; cold water solubility (at 25 °C) increased, water absorption and apparent cold water viscosity (at 25 °C) reduced, the smooth surface of the starch particles converted to an uneven surface as confirmed by scanning electron microscopy, cohesiveness, consistency and turbidity of the starch gels reduced while their syneresis increased. It was found that in presence of acetic acid, PGWS resulted in higher water absorption and apparent cold water viscosity and produced more cohesive and turbid gels with less syneresis compared to PGCS.

  17. Influence of physical properties of carrier on the performance of dry powder inhalers.

    PubMed

    Peng, Tingting; Lin, Shiqi; Niu, Boyi; Wang, Xinyi; Huang, Ying; Zhang, Xuejuan; Li, Ge; Pan, Xin; Wu, Chuanbin

    2016-07-01

    Dry powder inhalers (DPIs) offer distinct advantages as a means of pulmonary drug delivery and have attracted much attention in the field of pharmaceutical science. DPIs commonly contain micronized drug particles which, because of their cohesiveness and strong propensity to aggregate, have poor aerosolization performance. Thus carriers with a larger particle size are added to address this problem. However, the performance of DPIs is profoundly influenced by the physical properties of the carrier, particularly their particle size, morphology/shape and surface roughness. Because these factors are interdependent, it is difficult to completely understand how they individually influence DPI performance. The purpose of this review is to summarize and illuminate how these factors affect drug-carrier interaction and influence the performance of DPIs. PMID:27471671

  18. Physical and orbital properties of β Pictoris b

    NASA Astrophysics Data System (ADS)

    Bonnefoy, M.; Marleau, G.-D.; Galicher, R.; Beust, H.; Lagrange, A.-M.; Baudino, J.-L.; Chauvin, G.; Borgniet, S.; Meunier, N.; Rameau, J.; Boccaletti, A.; Cumming, A.; Helling, C.; Homeier, D.; Allard, F.; Delorme, P.

    2014-07-01

    The intermediate-mass star β Pictoris is known to be surrounded by a structured edge-on debris disk within which a gas giant planet was discovered orbiting at 8-10 AU. The physical properties of β Pic b were previously inferred from broad- and narrow-band 0.9-4.8 μm photometry. We used commissioning data of the Gemini Planet Imager (GPI) to obtain new astrometry and a low-resolution (R ~ 35-39) J-band (1.12-1.35 μm) spectrum of the planet. We find that the planet has passed the quadrature. We constrain its semi-major axis to ≤10 AU (90% prob.) with a peak at 8.9+0.4-0.6 AU. The joint fit of the planet astrometry and the most recent radial velocity measurements of the star yields a planet dynamical mass lower than 20 MJup (≥96% prob.). The extracted spectrum of β Pic b is similar to those of young L1-1.5+1 dwarfs. We used the spectral type estimate to revise the planet luminosity to log (L/L⊙) = -3.90 ± 0.07. The 0.9-4.8 μm photometry and spectrum are reproduced for Teff = 1650 ± 150 K and a log g ≤ 4.7 dex by 12 grids of PHOENIX-based and LESIA atmospheric models. For the most recent system age estimate (21 ± 4 Myr), the bolometric luminosity and the constraints on the dynamical mass of β Pic b are only reproduced by warm- and hot-start tracks with initial entropies Si> 10.5 kB/baryon. These initial conditions may result from an inefficient accretion shock and/or a planetesimal density at formation higher than in the classical core-accretion model. Considering a younger age for the system or a conservative formation time for β Pic b does not change these conclusions. Appendices are available in electronic form at http://www.aanda.org

  19. Physical properties of the Saturn's rings with the opposition effect.

    NASA Astrophysics Data System (ADS)

    Deau, E.

    2012-04-01

    We use the Cassini/ISS images from the early prime mission to build lit phase curves data from 0.01 degrees to 155 degrees at a solar elevation of 23-20 degrees. All the main rings exhibit on their phase curves a prominent surge at small phase angles. We use various opposition effect models to explain the opposition surge of the rings, including the coherent backscattering, the shadow hiding and a combination of the two (Kawata & Irvine 1974 In: Exploration of the planetary system Book p441; Shkuratov et al. 1999, Icarus, 141, p132; Poulet et al. 2002 Icarus, 158, p224 ; Hapke et al. 2002 Icarus, 157, p523). Our results show that either the coherent backscattering alone or a combination of the shadow hiding and the coherent backscattering can explain the observations providing physical properties (albedo, filling factor, grain size) consistent with previous other studies. However, they disagree with the most recent work of Degiorgio et al. 2011 (EPSC-DPS Abstract #732). We think that their attempt to use the shadow hiding alone lead to unrealistic values of the filling factor of the ring particles layer. For example they found 10^-3 in one of the thickest regions of the C ring (a plateau at R=88439km with an optical depth tau=0.22). We totally disagree with their conclusions stating that these values are consistent for the C ring plateaux and did not found any references that are consistent with theirs, as they claimed. We believe that their unrealistic values originated from the assumptions of the models they used (Kawata & Irvine and Hapke), which are basically an uniform size distribution. Any model using an uniform size distribution force the medium to be very diluted to reproduce the opposition surge. Our modeling that uses a power law size distribution provides realistic values. All these results have been already published previously (http://adsabs.harvard.edu/abs/2007PhDT........25D) and are summarized in a forthcoming manuscript submitted to publication so

  20. Physical, chemical, and mineral properties of the Polonnaruwa stones

    NASA Astrophysics Data System (ADS)

    Wallis, Jamie; Wickramasinghe, N. C.; Wallis, Daryl H.; Miyake, Nori; Wallis, M. K.; Hoover, Richard B.; Samaranayake, Anil; Wickramarathne, Keerthi; Oldroyd, Anthony

    2013-09-01

    We report on the physical, chemical and mineral properties of a series of stone fragments recovered from the North Central Province of Sri Lanka following a witnessed fireball event on 29 December 2012. The stones exhibit highly porous poikilitic textures comprising of isotropic silica-rich/plagioclase-like hosts. Inclusions range in size and shape from mm-sized to smaller subangular grains frequently more fractured than the surrounding host and include ilmenite, olivine (fayalitic), quartz and accessory zircon. Bulk mineral compositions include accessory cristobalite, hercynite, anorthite, wuestite, albite, anorthoclase and the high pressure olivine polymorph wadsleyite, suggesting previous endurance of a shock pressure of ~20 GPa. Further evidence of shock is confirmed by the conversion of all plagioclase to maskelynite. Here the infrared absorption spectra in the region 580 cm-1 to 380 cm-1 due to the Si-O-Si or Si-O-Al absorption band shows a partial shift in the peak at 380 cm-1 towards 480 cm-1 indicating an intermediate position between crystalline and amorphous phase. Host matrix chemical compositions vary between samples, but all are rich in SiO2. Silica-rich melts display a heterogeneous K-enrichment comparable to that reported in a range of non-terrestrial material from rare iron meteorites to LL chondritic breccias and Lunar granites. Bulk chemical compositions of plagioclase-like samples are comparable to reported data e.g. Miller Ranger 05035 (Lunar), while Si-rich samples accord well with mafic and felsic glasses reported in NWA 1664 (Howardite) as well as data for fusion crust present in a variety of meteoritic samples. Triple oxygen isotope results show Δ17O = -0.335 with δ18O (‰ rel. SMOW) values of 17.816 +/- 0.100 and compare well with those of known CI chondrites and are within the range of CI-like (Meta-C) chondrites. Rare earth elemental abundances show a profound Europium anomaly of between 0.7 and 0.9 ppm while CI normalized REE

  1. Physical, Chemical and Mineral Properties of the Polonnaruwa Stones

    NASA Astrophysics Data System (ADS)

    Wallis, Jamie; Wickramasinghe, N. C.; Wallis, Daryl H.; Miyake, Nori; Wallis, M. K.; Hoover, Richard B.; Samaranayake, Anil; Wickramarathne, Keerthi; Oldroyd, Anthony

    We report on the physical, chemical and mineral properties of a series of stone fragments recovered from the North Central Province of Sri Lanka following a witnessed fireball event on 29 December 2012. The stones exhibit highly porous poikilitic textures comprising of isotropic silica-rich/plagioclase-like hosts. Inclusions range in size and shape from mm-sized to smaller subangular grains frequently more fractured than the surrounding host and include ilmenite, olivine (fayalitic), quartz and accessory zircon. Bulk mineral compositions include accessory cristobalite, hercynite, anorthite, wuestite, albite, anorthoclase and the high pressure olivine polymorph wadsleyite, suggesting previous endurance of a shock pressure of ~20GPa. Further evidence of shock is confirmed by theconversion of all plagioclase to maskelynite. Here the infrared absorption spectra in the region 580 cm-1 to 380 cm-1 due to the Si-O-Si or Si-O-Al absorption band shows a partial shift in the peak at 380 cm-1 towards 480 cm-1 indicating an intermediate position between crystalline and amorphous phase. Host matrix chemical compositions vary between samples, but all are rich in SiO2. Silica-rich melts display a heterogeneous K-enrichment comparable to that reported in a range of nonterrestrial material from rare iron meteorites to LL chondritic breccias and Lunar granites. Bulk chemical compositions of plagioclase-like samples are comparable to reported data e.g. Miller Ranger 05035 (Lunar), while Si-rich samples accord well with mafic and felsic glasses reported in NWA 1664 (Howardite)as well asdata for fusion crust present in a variety of meteoritic samples.Triple oxygen isotope results show Δ17O = .0.335 with δ18O (‰ rel. SMOW) values of 17.816 ± 0.100 and compare well with those of known CI chondrites and are within the range of CI-like (Meta-C) chondrites. Rare earth elemental abundances show a profound Europium anomaly of between 0.7 and 0.9 ppm while CI normalized REE patterns

  2. Geochemical and physical properties of wetland soils at the Savannah River site

    SciTech Connect

    Dixon, K.L; Rogers, V.A.; Conner, S.P.; Cummings, C.L.; Gladden, J.B.; Weber, J.M.

    1996-05-01

    The Savannah River Site (SRS), located in Aiken, Allendale, and Barnwell Counties, South Carolina, is a nuclear production facility operated for the U.S. Department of Energy (DOE) by Westinghouse Savannah River Company (WSRC). To facilitate future human health and ecological risk assessments, treatability studies, remedial investigations, and feasibility studies for its wetland areas, SRS needs a database of background geochemical and physical properties of wetland soils. These data are needed for comparison to data collected from wetland soils that may have been affected by SRS operations. SRS contains 36,000 acres of wetlands and an additional 5,000 acres of bottom land soils subject to flooding. Recent studies of wetland soils near various waste units at SRS show that some wetlands have been impacted by releases of contaminants resulting from SRS operations (WSRC, 1992). Waste waters originating from the operations facilities typically have been discharged into seepage basins located in upland soils, direct discharge of waste water to wetland areas has been minimal. This suggests that impacted wetland areas have been affected indirectly as a result of transport mechanisms such as surface runoff, groundwater seeps, fluvial or sediment transport, and leaching. Looney et al. (1990) conducted a study to characterize the geochemical and physical properties of upland soils and shallow sediments on the SRS. A primary objective of the upland study was to collect the data needed to assess the qualitative and quantitative impacts of SRS operations on the environment. By comparing the upland soils data to data collected from waste units located in similar soils, SRS impacts could be assessed. The data were also intended to aid in selection of remediation alternatives. Because waste units at SRS have historically been located in upland areas, wetland soils were not sampled. (Abstract Truncated)

  3. Affective Properties of Mothers' Speech to Infants With Hearing Impairment and Cochlear Implants

    PubMed Central

    Bergeson, Tonya R.; Xu, Huiping; Kitamura, Christine

    2015-01-01

    Purpose The affective properties of infant-directed speech influence the attention of infants with normal hearing to speech sounds. This study explored the affective quality of maternal speech to infants with hearing impairment (HI) during the 1st year after cochlear implantation as compared to speech to infants with normal hearing. Method Mothers of infants with HI and mothers of infants with normal hearing matched by age (NH-AM) or hearing experience (NH-EM) were recorded playing with their infants during 3 sessions over a 12-month period. Speech samples of 25 s were low-pass filtered, leaving intonation but not speech information intact. Sixty adults rated the stimuli along 5 scales: positive/negative affect and intention to express affection, to encourage attention, to comfort/soothe, and to direct behavior. Results Low-pass filtered speech to HI and NH-EM groups was rated as more positive, affective, and comforting compared with the such speech to the NH-AM group. Speech to infants with HI and with NH-AM was rated as more directive than speech to the NH-EM group. Mothers decreased affective qualities in speech to all infants but increased directive qualities in speech to infants with NH-EM over time. Conclusions Mothers fine-tune communicative intent in speech to their infant's developmental stage. They adjust affective qualities to infants' hearing experience rather than to chronological age but adjust directive qualities of speech to the chronological age of their infants. PMID:25679195

  4. PHYSICAL PROPERTIES OF THE CIRCUMNUCLEAR STARBURST RING IN THE BARRED GALAXY NGC 1097

    SciTech Connect

    Hsieh, Pei-Ying; Matsushita, Satoki; Ho, Paul T. P.; Wu, Ya-Lin; Liu, Guilin; Oi, Nagisa

    2011-08-01

    We report high-resolution {sup 12}CO(J = 2-1), {sup 13}CO(J = 2-1), and {sup 12}CO(J = 3-2) imaging of the Seyfert 1/starburst ring galaxy NGC 1097 with the Submillimeter Array for the purpose of studying the physical and kinematic properties of the 1 kpc circumnuclear starburst ring. Individual star clusters as detected in the Hubble Space Telescope map of Pa{alpha} line emission have been used to determine the star formation rate (SFR), and are compared with the properties of the molecular gas. The molecular ring has been resolved into individual clumps at the giant molecular cloud association (GMA) scale of 200-300 pc in all three CO lines. The intersection between the dust lanes and the starburst ring, which is associated with the orbit-crowding region, is resolved into two physically/kinematically distinct features in the 1.''5 x 1.''0 (105 x 70 pc) {sup 12}CO(J = 2-1) map. The clumps associated with the dust lanes have broader line widths, higher surface gas densities, and lower SFRs, while the narrow line clumps associated with the starburst ring have opposite characteristics. A Toomre-Q value lower than unity at the radius of the ring suggests that the molecular ring is gravitationally unstable to fragmentation at GMA scale. The line widths and surface density of the gas mass of the clumps show an azimuthal variation related to the large-scale dynamics. The SFR, on the other hand, is not significantly affected by the dynamics, but has a correlation with the intensity ratio of {sup 12}CO (J = 3-2) and {sup 12}CO(J = 2-1), which traces the denser gas associated with star formation. Our resolved CO map, especially in the orbit-crowding region, observationally demonstrates for the first time that the physical/kinematic properties of GMAs are affected by the large-scale bar-potential dynamics in NGC 1097.

  5. Optical Properties of Materials in an Undergraduate Physics Curriculum

    NASA Astrophysics Data System (ADS)

    Blanco, Julio R.

    2006-03-01

    The need to introduce physics undergraduates to non-traditional subjects is ever increasing due to the job opportunities in interdisciplinary fields. The traditional upper-level curricula after the standard sequence in introductory calculus-based physics is challenging to many students. Adding more elective requirements is not in vogue with university administrators that must deal with a large influx of students with fewer resources. Experimental physics lends itself well to introduce students to interdisciplinary concepts. At California State University Northridge (CSUN), we have introduced modules in experimental physics to meet this need. All juniors and seniors are required to take two units of experimental physics per semester, a total of eight units. An experimental unit represents three contact hours per week. Each two units consist of two modules, each lasting seven and a half weeks, six hours per week. One of these modules exposes the students to thin film deposition by sputtering, imaging by scanning electron microscopy, and optical characterization using scanning ellipsometry. This early exposure to interdisciplinary applied physics motivates students and identifies difficulties with fundamental concepts.

  6. Education Majors' Expectations and Reported Experiences with Inquiry-Based Physics: Implications for Student Affect

    ERIC Educational Resources Information Center

    Gaffney, Jon D. H.

    2013-01-01

    To address a perennial need to provide K-8 teachers with a solid foundation in science, there are many physics content courses throughout the United States. One such course is Physics and Astronomy for Teachers (PAT), which relies heavily on active-learning strategies. Although PAT is successful in teaching physics content, students sometimes…

  7. Gender Differences in the High School and Affective Experiences of Introductory College Physics Students

    ERIC Educational Resources Information Center

    Hazari, Zahra; Sadler, Philip M.; Tai, Robert H.

    2008-01-01

    The disparity in persistence between males and females studying physics has been a topic of concern to physics educators for decades. Overall, while female students perform as well as or better than male students, they continue to lag considerably in terms of persistence. The most significant drop in females studying physics occurs between high…

  8. Education Affects Attitudes of Physical Therapy Providers toward People with Dementia

    ERIC Educational Resources Information Center

    Staples, William H.; Killian, Clyde B.

    2012-01-01

    A survey was sent to every skilled nursing home (N = 495) in Indiana regarding the demographics, education, and whether the severity of dementia impacts the attitudes of people in physical therapy practice. Physical therapists (PTs) and physical therapist assistants (PTAs) practicing in nursing homes spend considerable time (44.0%) working with…

  9. Physical processes affecting availability of dissolved silicate for diatom production in the Arabian Sea

    NASA Technical Reports Server (NTRS)

    Young, David K.; Kindle, John C.

    1994-01-01

    A passive tracer to represent dissolved silicate concentrations, with biologically realistic uptake kinetics, is successfully incorporated into a three-dimensional, eddy-resolving, ocean circulation model of the Indian Ocean. Hypotheses are tested to evaluate physical processes which potentially affect the availability of silicate for diatom production in the Arabian Sea. An alternative mechanism is offered to the idea that open ocean upwelling is primarily responsible for the high, vertical nutrient flux and consequent large-scale phytoplankton bloom in the northwestern Arabian Sea during the southwest monsoon. Model results show that dissolved silicate in surface waters available for uptake by diatoms is primarily influenced by the intensity of nearshore upwelling from soutwest monsoonal wind forcing and by the offshore advective transport of surface waters. The upwelling, which in the model occurs within 200 +/- 50 km of the coast, appears to be a result of a combination of coastal upwelling, Elkman pumping, and divergence of the coastal flow as it turns offshore. Localized intensifications of silicate concentrations appear to be hydrodynamically driven and geographically correlated to coastal topographic features. The absence of diatoms in sediments of the eastern Arabian Basin is consistent with modeled distributional patterns of dissolved silicate resulting from limited westward advection of upwelled coastal waters from the western continental margin of India and rapid uptake of available silicate by diatoms. Concentrations of modeled silicate become sufficiently low to become unavailable for diatom production in the eastern Arabian Sea, a region between 61 deg E and 70 deg E at 8 deg N on the south, with the east and west boundaries converging on the north at approximately 67 deg E, 20 deg N.

  10. Differential Effects of Acute and Regular Physical Exercise on Cognition and Affect

    PubMed Central

    Hopkins, Michael E.; Davis, F. Caroline; VanTieghem, Michelle R.; Whalen, Paul J.; Bucci, David J.

    2012-01-01

    The effects of regular exercise versus a single bout of exercise on cognition, anxiety, and mood were systematically examined in healthy, sedentary young adults who were genotyped to determine brain-derived neurotrophic factor (BDNF) allelic status (i.e., Val-Val or Val66Met polymorphism). Participants were evaluated on novel object recognition (NOR) memory and a battery of mental health surveys before and after engaging in either a) a four-week exercise program, with exercise on the final test day, b) a four-week exercise program, without exercise on the final test day, c) a single bout of exercise on the final test day, or d) remaining sedentary between test days. Exercise enhanced object recognition memory and produced a beneficial decrease in perceived stress, but only in participants who exercised for four weeks including the final day of testing. In contrast, a single bout of exercise did not affect recognition memory and resulted in increased perceived stress levels. An additional novel finding was that the improvements on the NOR task were observed exclusively in participants who were homozygous for the BDNF Val allele, indicating that altered activity-dependent release of BDNF in Met allele carriers may attenuate the cognitive benefits of exercise. Importantly, exercise-induced changes in cognition were not correlated with changes in mood/anxiety, suggesting that separate neural systems mediate these effects. These data in humans mirror recent data from our group in rodents. Taken together, these current findings provide new insights into the behavioral and neural mechanisms that mediate the effects of physical exercise on memory and mental health in humans. PMID:22554780

  11. Valence of physical stimuli, not housing conditions, affects behaviour and frontal cortical brain activity in sheep.

    PubMed

    Vögeli, Sabine; Lutz, Janika; Wolf, Martin; Wechsler, Beat; Gygax, Lorenz

    2014-07-01

    Modulation of short-term emotions by long-term mood is little understood but relevant to understand the affective system and of importance in respect to animal welfare: a negative mood might taint experiences, whilst a positive mood might alleviate single negative events. To induce different mood states in sheep housing conditions were varied. Fourteen ewes were group-housed in an unpredictable, stimulus-poor and 15 ewes in a predictable, stimulus-rich environment. Sheep were tested individually for mood in a behavioural cognitive bias paradigm. Also, their reactions to three physical stimuli thought to differ in their perceived valence were observed (negative: pricking, intermediate: slight pressure, positive: kneading). General behaviour, activity, ear movements and positions, and haemodynamic changes in the cortical brain were recorded during stimulations. Generalised mixed-effects models and model probabilities based on the BIC (Bayesian information criterion) were used. Only weak evidence for mood difference was found. Sheep from the unpredictable, stimulus-poor housing condition had a somewhat more negative cognitive bias, showed slightly more aversive behaviour, were slightly more active and moved their ears somewhat more. Sheep most clearly differentiated the negative from the intermediate and positive stimulus in that they exhibited more aversive behaviour, less nibbling, were more active, showed more ear movements, more forward ear postures, fewer backward ear postures, and a stronger decrease in deoxyhaemoglobin when subjected to the negative stimulus. In conclusion, sheep reacted towards stimuli according to their presumed valence but their mood was not strongly influenced by housing conditions. Therefore, behavioural reactions and cortical brain activity towards the stimuli were hardly modulated by housing conditions.

  12. Differential effects of acute and regular physical exercise on cognition and affect.

    PubMed

    Hopkins, M E; Davis, F C; Vantieghem, M R; Whalen, P J; Bucci, D J

    2012-07-26

    The effects of regular exercise versus a single bout of exercise on cognition, anxiety, and mood were systematically examined in healthy, sedentary young adults who were genotyped to determine brain-derived neurotrophic factor (BDNF) allelic status (i.e., Val-Val or Val66Met polymorphism). Participants were evaluated on novel object recognition (NOR) memory and a battery of mental health surveys before and after engaging in either (a) a 4-week exercise program, with exercise on the final test day, (b) a 4-week exercise program, without exercise on the final test day, (c) a single bout of exercise on the final test day, or (d) remaining sedentary between test days. Exercise enhanced object recognition memory and produced a beneficial decrease in perceived stress, but only in participants who exercised for 4 weeks including the final day of testing. In contrast, a single bout of exercise did not affect recognition memory and resulted in increased perceived stress levels. An additional novel finding was that the improvements on the NOR task were observed exclusively in participants who were homozygous for the BDNF Val allele, indicating that altered activity-dependent release of BDNF in Met allele carriers may attenuate the cognitive benefits of exercise. Importantly, exercise-induced changes in cognition were not correlated with changes in mood/anxiety, suggesting that separate neural systems mediate these effects. These data in humans mirror recent data from our group in rodents. Taken together, these current findings provide new insights into the behavioral and neural mechanisms that mediate the effects of physical exercise on memory and mental health in humans.

  13. 3-D geometry and physical property of the Mega-Splay Fault in Nankai trough

    NASA Astrophysics Data System (ADS)

    Masui, R.; Tsuji, T.; Yamada, Y.; Environmental Resource; System Engineering laboratory

    2011-12-01

    The Nankai trough is a subduction zone, where the Philippine Sea plate is being subducted beneath southwest Japan at a rate of ~4-6.5 cm/y at an azimuth of ~300°-315°. A lot of operations have been done in Nankai, such as three-dimensional seismic reflection surveys and Deep Sea Drilling Project (DSDP), Ocean Drilling Program (ODP), Integrated Ocean Drilling Program (IODP). They revealed that there is a large splay fault, referred to as 'Mega-Splay'. The Mega-Splay Fault has caused a series of catastrophic earthquakes and submarine landslides, which may have led to TSUNAMI. Since fault development history may have affected the geometry of the Mega-Splay Fault and physical property within the fault zone, they need to be examined in detail. In this research, we used 3-D pre-stack depth migration (PSDM), 3-D pre-stack time migration (PSTM) and P-wave velocity in C0004B well (Logging data), in order to interpret 3-D structure of Mega-Splay Fault. The analysis in this research is basically divided into two parts. One is structural interpretation of Splay Fault, based on the high amplitude reflection surface on seismic profiles. The other part is acoustic impedance inversion (AI inversion), in which we inverted seismic waveform into physical property (in this study, acoustic impedance), with the P-wave velocity data at C0004B near Mega-Splay Fault. The 3-D PSDM (or PSTM) clearly images details of Splay Fault, with good continuity of reflections along the fault. It is possible on each seismic profile to trace the high amplitude lines, where rock-properties significantly change. Since Mega-Splay Fault has 45-59m width along the wells, we interpreted the upper limit and the lower limit of the Mega-Splay Fault, based on the high amplitude surfaces along 3-D PSDM. Our interpretation shows that the width of Mega-Splay Fault has variation along the fault, and the plan geometry of the fault toe has a salient at the middle of the 3D box area, suggesting the fault could be

  14. Outdoor temperature, precipitation, and wind speed affect physical activity levels in children: a longitudinal cohort study

    PubMed Central

    Edwards, Nicholas M.; Myer, Gregory D.; Kalkwarf, Heidi J.; Woo, Jessica G.; Khoury, Philip R.; Hewett, Timothy E.; Daniels, Stephen R.

    2015-01-01

    Objective Evaluate effects of local weather conditions on physical activity in early childhood. Methods Longitudinal prospective cohort study of 372 children, 3 years old at enrollment, drawn from a major US metropolitan community. Accelerometer-measured (RT3) physical activity was collected every 4 months over 5 years and matched with daily weather measures: day length, heating/cooling degrees (degrees mean temperature < 65°F or ≥ 65°F, respectively), wind, and precipitation. Mixed regression analyses, adjusted for repeated measures, were used to test the relationship between weather and physical activity. Results Precipitation and wind speed were negatively associated with total physical activity and moderate-vigorous physical activity (P<0.0001). Heating and cooling degrees were negatively associated with total physical activity and moderate-vigorous physical activity and positively associated with inactivity (all P<0.0001), independent of age, sex, race, BMI, day length, wind, and precipitation. For every 10 additional heating degrees there was a five-minute daily reduction in moderate-vigorous physical activity. For every additional 10 cooling degrees there was a 17-minute reduction in moderate-vigorous physical activity. Conclusions Inclement weather (higher/lower temperature, greater wind speed, more rain/snow) is associated with less physical activity in young children. These deleterious effects should be considered when planning physical activity research, interventions, and policies. PMID:25423667

  15. Gender Differences in the High School and Affective Experiences of Introductory College Physics Students

    NASA Astrophysics Data System (ADS)

    Hazari, Zahra; Sadler, Philip M.; Tai, Robert H.

    2008-10-01

    The disparity in persistence between males and females studying physics has been a topic of concern to physics educators for decades. Overall, while female students perform as well as or better than male students, they continue to lag considerably in terms of persistence. The most significant drop in females studying physics occurs between high school and college.2 Since most female physicists report that they became attracted to physics and decided to study it further while in high school, according to the International Study of Women in Physics,3 it is problematic that high school is also the stage at which females begin to opt out at much higher rates than males. Although half of the students taking one year of physics in high school are female, females are less likely than males to take a second or Advanced Placement (AP) physics course.4 In addition, the percentage of females taking the first physics course in college usually falls between 30% and 40%. In other words, although you may see gender parity in a first high school physics course, this parity does not usually persist to the next level of physics course. In addition, even if there is parity in a high school physics course, it does not mean that males and females experience the course in the same way. It is this difference in experience that may help to explain the drop in persistence of females.

  16. Lunar physical properties from analysis of magnetometer data

    NASA Technical Reports Server (NTRS)

    Daily, W. D.

    1979-01-01

    The electromagnetic properties of the lunar interior are discussed with emphasis on (1) bulk, crustal, and local anomalous conductivity; (2) bulk magnetic permeability measurements, iron abundance estimates, and core size limits; (3) lunar ionosphere and atmosphere; and (4) crustal magnetic remanence: scale size measurements and constraints on remanence origin. Appendices treat the phase relationship between the energetic particle flux modulation and current disc penetrations in the Jovian magnetosphere (Pioneer 10 inbound) theories for the origin of lunar magnetism; electrical conductivity anomalies associated with circular lunar maria; electromagnetic properties of the Moon; Mare Serenitatis conductivity anomaly detected by Apollo 16 and Lunokhod 2 magnetometers; and lunar properties from magnetometer data: effects of data errors.

  17. Physical properties of materials derived from diamondoid molecules

    NASA Astrophysics Data System (ADS)

    Clay, W. A.; Dahl, J. E. P.; Carlson, R. M. K.; Melosh, N. A.; Shen, Z.-X.

    2015-01-01

    Diamondoids are small hydrocarbon molecules which have the same rigid cage structure as bulk diamond. They can be considered the smallest nanoparticles of diamond. They exhibit a mixture of properties inherited from bulk cubic diamond as well as a number of unique properties related to their size and structure. Diamondoids with different sizes and shapes can be separated and purified, enabling detailed studies of the effects of size and structure on the diamondoids' properties and also allowing the creation of chemically functionalized diamondoids which can be used to create new materials. Most notable among these new materials are self-assembled monolayers of diamondoid-thiols, which exhibit a number of unique electron emission properties.

  18. CRC handbook of physical properties of rocks. Volume III

    SciTech Connect

    Carmichael, R.S.

    1984-01-01

    This book presents topics on: Density of rocks and minerals, includes histograms of density ranges; elastic constants of minerals, elastic moduli, thermal properties; inelastic properties, strength and rheology for rocks and minerals, rock mechanics and friction, and stress-strain relations; radioactivity, decay constants and heat production of isotope systems in geology; seismic attenuation, in rocks, minerals, and the earth, with application to oil exploration and terrestrial studies; and index.

  19. Particle size distribution of rice flour affecting the starch enzymatic hydrolysis and hydration properties.

    PubMed

    de la Hera, Esther; Gomez, Manuel; Rosell, Cristina M

    2013-10-15

    Rice flour is becoming very attractive as raw material, but there is lack of information about the influence of particle size on its functional properties and starch digestibility. This study evaluates the degree of dependence of the rice flour functional properties, mainly derived from starch behavior, with the particle size distribution. Hydration properties of flours and gels and starch enzymatic hydrolysis of individual fractions were assessed. Particle size heterogeneity on rice flour significantly affected functional properties and starch features, at room temperature and also after gelatinization; and the extent of that effect was grain type dependent. Particle size heterogeneity on rice flour induces different pattern in starch enzymatic hydrolysis, with the long grain having slower hydrolysis as indicated the rate constant (k). No correlation between starch digestibility and hydration properties or the protein content was observed. It seems that in intact granules interactions with other grain components must be taken into account. Overall, particle size fractionation of rice flour might be advisable for selecting specific physico-chemical properties.

  20. Effect of irrigation and nutrient on physical properties of safflower seeds

    NASA Astrophysics Data System (ADS)

    Feyzollahzadeh, Maziar; ModaresMotlagh, Asaad; Nikbakht, Ali M.

    2014-03-01

    The effect of irrigation and nutrient treatments on physical properties of safflower seeds was investigated. Physical properties of safflower seeds were determined at a moisture content of 7% w.b. The parameters determined at different treatments were: size, geometric mean diameter, sphericity, surface area, mass, volume, bulk and true densities, porosity, and static and dynamic coefficient of friction. The results showed a better effect of the use of organic fertilizers in comparison with chemical ones. The results showed that nutrient and irrigation treatments had a significant effect on most of the physical properties of safflower seeds at p<0.01.

  1. Physical Properties of Various Materials Relevant to Granular Flow

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Because of the ubiquitous nature of granular materials, ranging from natural avalanches to industrial storage and processing operations, interest in quantifying and predicting the dynamics of granular flow continues to increase. The objective of this study was to investigate various physical proper...

  2. Physical and Cognitive-Affective Factors Associated with Fatigue in Individuals with Fibromyalgia: A Multiple Regression Analysis

    ERIC Educational Resources Information Center

    Muller, Veronica; Brooks, Jessica; Tu, Wei-Mo; Moser, Erin; Lo, Chu-Ling; Chan, Fong

    2015-01-01

    Purpose: The main objective of this study was to determine the extent to which physical and cognitive-affective factors are associated with fibromyalgia (FM) fatigue. Method: A quantitative descriptive design using correlation techniques and multiple regression analysis. The participants consisted of 302 members of the National Fibromyalgia &…

  3. Assessing Assessment: Examination of Pre-Service Physics Teachers' Attitudes towards Assessment and Factors Affecting Their Attitudes

    ERIC Educational Resources Information Center

    Ogan-Bekiroglu, Feral

    2009-01-01

    The purpose of this study was to determine pre-service physics teachers' attitudes towards assessment. It was also aimed to examine the factors affecting their attitudes. Two factors were considered. The first was difficulties that pre-service teachers experienced relating to assessment. The second factor was teachers' self-efficacy regarding…

  4. Manipulation of the Self-Determined Learning Environment on Student Motivation and Affect within Secondary Physical Education

    ERIC Educational Resources Information Center

    Perlman, Dana

    2013-01-01

    Secondary physical education (PE) has become a popular area of inquiry because students are not meeting overarching goals of PE programs, are less motivated, and demonstrate negative affect while in class. As such, teachers and researchers are starting to examine pedagogical approaches that support student motivation as a means to alleviate some…

  5. Children's Use of the Yahooligans! Web Search Engine: I. Cognitive, Physical, and Affective Behaviors on Fact-based Search Tasks.

    ERIC Educational Resources Information Center

    Bilal, Dania

    2000-01-01

    Reports on a research project that investigated seventh grade science students' cognitive, affective, and physical behaviors as they used the Yahooligans! search engine to find information on a specific search task. Describes measurement techniques that included software, interviews, and questionnaires, and discusses implications for user training…

  6. Antimicrobial and physical-mechanical properties of agar-based films incorporated with grapefruit seed extract.

    PubMed

    Kanmani, Paulraj; Rhim, Jong-Whan

    2014-02-15

    The use of synthetic petroleum based packaging films caused serious environmental problems due to their difficulty in recycling and poor biodegradability. Therefore, present study was aimed to develop natural biopolymer-based antimicrobial packaging films as an alternative for the synthetic packaging films. As a natural antimicrobial agent, grapefruit seed extract (GSE) has been incorporated into agar to prepare antimicrobial packaging film. The films with different concentrations of GSE were prepared by a solvent casting method and the resulting composite films were examined physically and mechanically. In addition, the films were characterized by FE-SEM, XRD, FT-IR and TGA. The incorporation of GSE caused increase in color, UV barrier, moisture content, water solubility and water vapor permeability, while decrease in surface hydrophobicity, tensile strength and elastic modulus of the films. As the concentration of GSE increased from 0.6 to 13.3 μg/mL, the physical and mechanical properties of the films were affected significantly. The addition of GSE changed film microstructure of the film, but did not influence the crystallinity of agar and thermal stability of the agar-based films. The agar/GSE films exhibited distinctive antimicrobial activity against three test food pathogens, such as Listeria monocytogenes, Bacillus cereus and Escherichia coli. These results suggest that agar/GSE films have potential to be used in an active food packaging systems for maintaining food safety and extending the shelf-life of the packaged food. PMID:24507339

  7. Hand-held calculator programs determine natural-gas physical properties

    SciTech Connect

    Ajitsaria, N.K.

    1983-06-01

    Although physical properties of natural gas are readily available in the literature, the determination of such properties using a hand-held calculator can be of great convenience to the engineer. Two typical examples of gas properties often required in gas transmission and reservoir engineering calculations are compressibility factor (z factor) and viscosity (..mu..). In this article, programs developed for determining these properties are described.

  8. Factors that affect the physical science career interest of female students: Testing five common hypotheses

    NASA Astrophysics Data System (ADS)

    Hazari, Zahra; Potvin, Geoff; Lock, Robynne M.; Lung, Florin; Sonnert, Gerhard; Sadler, Philip M.

    2013-12-01

    There are many hypotheses regarding factors that may encourage female students to pursue careers in the physical sciences. Using multivariate matching methods on national data drawn from the Persistence Research in Science and Engineering (PRiSE) project (n=7505), we test the following five commonly held beliefs regarding what factors might impact females’ physical science career interest: (i) having a single-sex physics class, (ii) having a female physics teacher, (iii) having female scientist guest speakers in physics class, (iv) discussing the work of female scientists in physics class, and (v) discussing the underrepresentation of women in physics class. The effect of these experiences on physical science career interest is compared for female students who are matched on several factors, including prior science interests, prior mathematics interests, grades in science, grades in mathematics, and years of enrollment in high school physics. No significant effects are found for single-sex classes, female teachers, female scientist guest speakers, and discussing the work of female scientists. However, discussions about women’s underrepresentation have a significant positive effect.

  9. Socioeconomic factors affecting minority physics taking in U.S. high schools

    NASA Astrophysics Data System (ADS)

    2011-11-01

    In the September issue, we saw that a lower proportion of Hispanics and blacks take physics in U.S. high schools than do whites and Asians. Last month, we examined physics offerings and students by socioeconomic profile of the high school as reported by the principal. We saw that there were more physics classes and more physics students at better-off high schools. These increased offerings allow the teachers who teach physics to focus more on physics. We combined race and ethnicity data from the National Center for Education Statistics with data from our principals to examine the percent of each race and ethnicity attending schools by our socioeconomic profile of the school. Less than one-third of white and Asian public high school students attend a school that our principals classify as "worse off." Less than one-fourth of black and Hispanic students attend a school that our principals classify as "better off." The difference is stark. When combined with the percent of physics classes and physics students at each type of school, we have some insight into explaining the variation in physics taking by race and ethnicity.

  10. Selection and Physical Properties of High-redshift Galaxies

    NASA Astrophysics Data System (ADS)

    Fang, G. W.

    2014-09-01

    Extremely Red Objects (EROs) and BzKs continue to attract considerable interest. It has been suggested that they may be the direct progenitors of present-day massive E/S0 galaxies, and can provide crucial constraints on the current galaxy formation and evolution models. Therefore, the key question is to measure the relative fraction of OGs (old galaxies) and DGs (young, and dusty starburst galaxies) in the sample of EROs. Many groups have been currently investigating the fractions of these two ERO populations using a variety of observational approaches, but the fraction of OGs and DGs from different surveys is different. In the meantime, a number of observations suggest that the epoch of z˜2 also plays an important role in galaxy formation and evolution for various reasons: the cosmic star formation rate density (SFRD) begins to drop at z˜2 from a flat plateau at higher redshifts; the morphological type mix of field galaxies changes remarkably at z˜2; the number density of QSOs has a peak at z˜2; and about 50% to 70% of the stellar mass assembly of galaxies took place in the redshift range 1physical properties of passive and star-forming galaxies at z˜2 in the AEGIS field, and (3) the mid-infrared spectroscopy and multi-wavelength study of ultraluminous infrared galaxies (ULIRGs) at z˜2 in the AEGIS field. Chapter 1 gives a brief review on the research progresses of EROs at z˜1, BzKs at z˜2, and ULIRGs at z˜2, respectively. In Chapter 2 we present a quantitative study of the classification of EROs in the UDF and COSMOS field. Our sample includes 5264 (COSMOS, K_{Vega} ≤19.2) and 24 EROs (UDF, K_{Vega}≤22.0) with (i-K)_{AB}≥2.45. Using the fitting method of spectral energy distribution (SED), [3.6]-[8.0] color, and the nonparametric measures of galaxy morphology, we classify EROs into two classes: DGs and OGs. We find

  11. Nature's amazing biopolymer: basic mechanical and hydrological properties of soil affected by plant exudates

    NASA Astrophysics Data System (ADS)

    Naveed, Muhammad; Roose, Tiina; Raffan, Annette; George, Timothy; Bengough, Glyn; Brown, Lawrie; Keyes, Sam; Daly, Keith; Hallett, Paul

    2016-04-01

    Plant exudates are known to have a very large impact on soil physical properties through changes in mechanical and hydrological processes driven by long-chain polysaccharides and surface active compounds. Whilst these impacts are well known, the basic physical properties of these exudates have only been reported in a small number of studies. We present data for exudates obtained from barley roots and chia seeds, incorporating treatments examining biological decomposition of the exudates. When these exudates were added to a sandy loam soil, contact angle and drop penetration time increased exponentially with increasing exudate concentration. These wetting properties were strongly correlated with both exudate density and zero-shear viscosity, but not with exudate surface tension. Water holding capacity and water repellency of exudate mixed soil tremendously increased with exudate concentration, however they were significantly reduced on decomposition when measured after 14 days of incubation at 16C. Mechanical stability greatly increased with increasing exudate amendment to soils, which was assessed using a rheological amplitude sweep test near saturation, at -50 cm matric potential (field capacity) using indentation test, and at air-dry condition using the Brazilian test. This reflects that exudates not only attenuate plant water stress but also impart mechanical stability to the rhizosphere. These data are highly relevant to the understanding and modelling of rhizosphere development, which is the next phase of our research.

  12. Hostility and social support explain physical activity beyond negative affect among young men, but not women, in college.

    PubMed

    Maier, Karl J; James, Ashley E

    2014-01-01

    We examined social support as a moderator of cynical hostility in relation to physical activity and body mass index among college students (n = 859; M = 18.71 years (SD = 1.22); 60% women, 84% White). After controlling for negative affect in hierarchical linear regression models, greater hostility was associated with lesser physical activity among those with low social support, as expected. Greater hostility was also associated with greater physical activity among those high in social support, ps < .05. Effects were observed for men only. Hostility and social support were unrelated to body mass index, ps > .05. Young men with a hostile disposition and low social support may be at risk for a sedentary lifestyle for reasons other than negative affect.

  13. Physical properties of Ce-TZP at cryogenic temperature

    NASA Astrophysics Data System (ADS)

    Han, Y. M.; Chen, Z.; Zhou, M.; Huang, R. J.; Huang, C. J.; Li, L. F.

    2014-01-01

    Electrical insulators, which are used to insulate cryogenic supply lines and conductor windings, are critical units in superconducting TOKAMAK magnets. Electrical insulators used in superconducting magnets fall into axial and radial insulators. These insulators can be made from glass ribbon epoxy densification and have been used in the Experiment Advanced Superconducting Tokamak (EAST). The properties of Ce-TZP can satisfy the requirement of electrical insulators. In this paper, thermal conductivity, mechanical properties and coefficient of thermal expansion of Ce-TZP have been investigated at cryogenic temperatures. Results indicate that the Ce-TZP shows better properties than epoxy and it demonstrates that the Ce-TZP can be used as insulation material in superconducting magnets.

  14. Affective dysfunction in a mouse model of Rett syndrome: Therapeutic effects of environmental stimulation and physical activity.

    PubMed

    Kondo, Mari A; Gray, Laura J; Pelka, Gregory J; Leang, Sook-Kwan; Christodoulou, John; Tam, Patrick P L; Hannan, Anthony J

    2016-02-01

    Rett syndrome (RTT) is a neurodevelopmental disorder associated with mutations in the X-linked gene encoding methyl-CpG-binding protein 2 (MeCP2) and consequent dysregulation of brain maturation. Patients suffer from a range of debilitating physical symptoms, however, behavioral and emotional symptoms also severely affect their quality of life. Here, we present previously unreported and clinically relevant affective dysfunction in the female heterozygous Mecp2(tm1Tam) mouse model of RTT (129sv and C57BL6 mixed background). The affective dysfunction and aberrant anxiety-related behavior of the Mecp2(+/-) mice were found to be reversible with environmental enrichment (EE) from 4 weeks of age. The effect of exercise alone (via wheel running) was also explored, providing the first evidence that increased voluntary physical activity in an animal model of RTT is beneficial for some phenotypes. Mecp2(+/-) mutants displayed elevated corticosterone despite decreased Crh expression, demonstrating hypothalamic-pituitary-adrenal axis dysregulation. EE of Mecp2(+/-) mice normalized basal serum corticosterone and hippocampal BDNF protein levels. The enrichment-induced rescue appears independent of the transcriptional regulation of the MeCP2 targets Bdnf exon 4 and Crh. These findings provide new insight into the neurodevelopmental role of MeCP2 and pathogenesis of RTT, in particular the affective dysfunction. The positive outcomes of environmental stimulation and physical exercise have implications for the development of therapies targeting the affective symptoms, as well as behavioral and cognitive dimensions, of this devastating neurodevelopmental disorder.

  15. Synthesis, characterization, and physical properties of 1D nanostructures

    NASA Astrophysics Data System (ADS)

    Marley, Peter Mchael

    framework is facilitated by the nanometer-sized dimensions of the materials, which leads to accommodation of strain without amorphization. The topotactic approach demonstrated here indicates not just novel intercalation chemistry accessible at nanoscale dimensions but also suggests a facile synthetic route to ternary vanadium oxide bronzes (MxV2O 5) exhibiting intriguing physical properties that range from electronic phase transitions to charge ordering and superconductivity.

  16. Physical-Chemical Factors Affecting the Low Quality of Natural Water in the Khibiny Massif

    NASA Astrophysics Data System (ADS)

    Mazukhina, Svetlana; Masloboev, Vladimir; Chudnenko, Konstantin; Maksimova, Viktoriia; Belkina, Natalia

    2014-05-01

    One peculiarity of the Khibiny Massif is its spatial location. Rising over 1000 m above the surrounding hilly land and thus obstructing the passage of air masses, it promotes condensation and accumulation of surface and underground water. Annual precipitation here amounts to 600-700 mm in the valleys and up to 1600 mm on mountainous plateaus. Using this water for drinking and household purposes is problematic due to excess Al and F concentrations and high pH values. Now it is known that in its profile, the Massif is represented by three hydrogeological subzones: the upper (aerated), medium and lower ones. The upper subzone spreads throughout the Massif and is affected by the local drainage network and climatic conditions. The medium subzone is permanently saturated with underground water flowing horizontally to sites of discharge at the level of local river valleys and lakes. The fissure-vein water in the lower subzone is confined to tectonic fractures and faults in the so far underexplored, deeper parts of the Massif. Being abundant, this water ascends under high pressure. At places, water has been observed spurting from as deep as 700 m, and even 960 m. In the latter case, the temperature of ascending water was higher than 18 centigrade (Hydrogeology of the USSR, V. 27, 1971). This work was undertaken to reveal the nature of the low quality of water in the Khibiny by using physical-chemical modeling (software package Selector, Chudnenko, 2010). Processes of surface and underground water formation in the Khibiny were examined within a physical-chemical model (PCM) of the "water-rock-atmosphere-hydrogen" system. In a multi-vessel model used, each vessel represented a geochemical level of the process interpreted as spatiotemporal data - ξ (Karpov, 1981). The flow reactor consisted of 4 tanks. In the first tank, water of the Kuniok River (1000 L) interacted with atmosphere and an organic substance. The resulting solution proceeded to tanks 2-4 containing with

  17. On physical properties of planetary surfaces studied by modeling radar scattering

    NASA Astrophysics Data System (ADS)

    Virkki, Anne; Muinonen, Karri

    2015-11-01

    After decades of post-discovery characterization and orbital refinement of near-Earth objects using planetary radars, extensive literature describing the radar scattering properties of various objects of the Solar System has become available. At the same time, there is a shortage of work on what the observed values imply about the physical properties of the planetary surfaces. Our goal is to fill part of this gap.We investigate, which physical properties of a planetary surface or small body affect the radar echo and how. All of the work will be carried out by modeling electromagnetic scattering with the primary focus in the backscattering direction. As all models are only simplifications of the real world, it is necessary to study, which models are the best analogies to observations. Moreover, the number of scattering scenarios is near infinite, but numerical resources are limited. Due to the limitations of specific codes, several different codes are used.The simulations reveal, in the backscattering direction, polarization enhancement at certain bands of sizes and refractive indices. By studying spherical inhomogeneous particles, we found that the electric permittivity defines the phase shift caused by the scatterer, and hence, the depolarizing capability of the scatterer. By using large, irregular particles as the scatterers, a systematic effect of the absorption on the radar observables can be seen, which leads to a semi-analytic, novel form of the radar scattering laws. By using small (wavelength-scale) irregular particles as internal or external diffuse medium inside or on the surface of a very large particle, radar scattering can be simulated very realistically. The results mainly support the current understanding of the effects of the surface geometry, the electric permittivity, and multiple scattering. We also explain how the electric permittivity can affect the radar albedo and circular-polarization ratio by phase shift and absorption. In addition, we show

  18. Physical properties and bioactive constituents of powdered mixtures and drinks prepared with cocoa and various sweeteners.

    PubMed

    Belscak-Cvitanović, Ana; Benković, Maja; Komes, Drazenka; Bauman, Ingrid; Horzić, Dunja; Dujmić, Filip; Matijasec, Matea

    2010-06-23

    In the present study the physical properties of powdered cocoa drink mixtures prepared from two cocoa powders with various fat contents and different sweeteners, as well as the bioactive content and sensory properties of cocoa drinks prepared from them, were investigated. Particle size and bulk density of the used sugars and sweeteners, as well as the formulated mixtures, were determined and their influence on cohesion index was evaluated. To compare the content of polyphenols in the formulated cocoa drink mixtures, UV-vis spectrophotometric methods were applied. Antioxidant capacity of cocoa drinks was evaluated by using the 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azinobis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS), and ferric reducing/antioxidant power (FRAP) assays. The analyzed cocoa drinks prepared from cocoa powder and different sugars or sweeteners delivered a substantial content of cocoa antioxidants, whereas the content and the type of sugar or sweetener did not affect the polyphenolic constituents of the prepared cocoa mixtures. Cocoa powder mixtures prepared with the cocoa powder containing higher fat content (16-18%) generally provided lower total polyphenol, total flavonoid, flavan-3-ol, and proanthocyanidin contents, compared to the mixtures prepared with cocoa containing lower fat content (10-12%). Total phenol content of cocoa drinks prepared from experimental mixtures ranged from 320.45 to 480.45 mg of GAE/L, whereas the ranking of the antioxidant capacities varied depending on the used assay, and the fat content of cocoa powder did not affect the antioxidant capacity of cocoa mixtures. As determined, the addition of sugar to cocoa powder increases the solubility and dispersibility of the mixtures; on the basis of their cohesion index all mixtures can be classified as very cohesive or hardened/extremely cohesive. Results of the sensory evaluation, using the 9-point hedonic scale, showed that there was a preference for the cocoa drinks made

  19. Physicochemical properties of physical chitin hydrogels: modeling and relation with the mechanical properties.

    PubMed

    Vachoud, L; Domard, A

    2001-01-01

    In this work, we were interested in the modeling of syneresis of physical chitin hydrogels by a mathematic law allowing us to predict the variation of the weight of the gel as a function of time. The variation of the weight of the gel during syneresis can be described by W(t)()/W(0) = (t(1/2) + (W(infinity)/W(0))t)/(t(1/2)) + t) where W(0), W(infinity), and W(t)() are the weights of the gel at the beginning of syneresis, for infinite time and for a time t, respectively. t(1/2) corresponds to the half-time of syneresis. W(infinity)/W(0) and t(1/2) were studied in relation with several parameters such as the ionic strength, pH, degree of acetylation of chitin and the initial concentration of polymer. The mechanical properties of chitin hydrogels maintained during syneresis in media of different pH's and ionic strengths were also investigated.

  20. Investigation of Demographic Properties and Motivation Factors of Physics Teachers

    ERIC Educational Resources Information Center

    Guzel, Hatice

    2011-01-01

    Scientific and technological developments resulted in an increase in the requirement of education in the society. In addition to this, the expectations from teachers differed and the need for more qualified teachers also increased. One of the factors affecting the quality of teachers is their motivation. In this research, it was aimed to reveal…

  1. Physical mechanisms affecting hot carrier-induced degradation in gallium nitride HEMTs

    NASA Astrophysics Data System (ADS)

    Mukherjee, Shubhajit

    Gallium Nitride or GaN-based high electron mobility transistors (HEMTs) is currently the most promising device technology in several key military and civilian applications due to excellent high-power as well as high-frequency performance. Even though the performance figures are outstanding, GaN-based HEMTs are not as mature as some competing technologies, which means that establishing the reliability of the technology is important to enable use in critical applications. The objective of this research is to understand the physical mechanisms affecting the reliability of GaN HEMTs at moderate drain biases (typically VDS < 30 V in the devices considered here). The degradation in device performance is believed to be due to the formation or modification of charged defects near the interface by hydrogen depassivation processes (due to electron-activated hydrogen removal) from energetic carriers. A rate-equation describing the defect generation process is formulated based on this assumption. A combination of ensemble Monte-Carlo (EMC) simulation statistics, ab-initio density functional theory (DFT) calculations, and accelerated stress experiments is used to relate the candidate defects to the overall degradation behavior (VT and gm). The focus of this work is on the 'semi-ON' mode of transistor operation in which the degradation is usually observed to be at its highest. This semi-ON state is reasonably close to the biasing region of class-AB high power amplifiers, which are popular because of the combination of high efficiency and low distortion that is associated with this configuration. The carrier-energy distributions are obtained using an EMC simulator that was developed specifically for III-V HFETs. The rate equation is used to model the degradation at different operating conditions as well as longer stress times from the result of one short duration stress test, by utilizing the carrier-energy distribution obtained from EMC simulations for one baseline condition

  2. Collagen oligomers modulate physical and biological properties of three-dimensional self-assembled matrices.

    PubMed

    Bailey, J L; Critser, P J; Whittington, C; Kuske, J L; Yoder, M C; Voytik-Harbin, S L

    2011-02-01

    Elucidation of mechanisms underlying collagen fibril assembly and matrix-induced guidance of cell fate will contribute to the design and expanded use of this biopolymer for research and clinical applications. Here, we define how Type I collagen oligomers affect in-vitro polymerization kinetics as well as fibril microstructure and mechanical properties of formed matrices. Monomers and oligomers were fractionated from acid-solubilized pig skin collagen and used to generate formulations varying in monomer/oligomer content or average polymer molecular weight (AMW). Polymerization half-times decreased with increasing collagen AMW and closely paralleled lag times, indicating that oligomers effectively served as nucleation sites. Furthermore, increasing AMW yielded matrices with increased interfibril branching and had no correlative effect on fibril density or diameter. These microstructure changes increased the stiffness of matrices as evidenced by increases in both shear storage and compressive moduli. Finally, the biological relevance of modulating collagen AMW was evidenced by the ability of cultured endothelial colony forming cells to sense associated changes in matrix physical properties and alter vacuole and capillary-like network formation. This work documents the importance of oligomers as another physiologically-relevant design parameter for development and standardization of polymerizable collagen formulations to be used for cell culture, regenerative medicine, and engineered tissue applications. PMID:20740490

  3. Effect of Orimulsion{reg_sign} physical properties and chemical composition on its behavior in water

    SciTech Connect

    Ojeda, M. de; Chirinos, M.L.

    1995-12-31

    Orimulsion{reg_sign} is the trade name given to a bitumen in water, 70:30, emulsion stabilized by a nonionic surfactant and used in industrial burners and power plants as a fuel. This paper summarizes the physical properties and chemical composition of Orimulsion{reg_sign} and their effect on the self dispersing properties of the product and its behavior in water. Also, the solubility and evaporation of the light hydrocarbon fraction from the bitumen, and the toxicity and biodegradation of the fuel are discussed. Salinity of the water affects the HLB of the surfactant and the stability of the bitumen droplets making them susceptible to coalesce. BTEX content of the bitumen was determined to be relatively low, an advantage in terms of its contribution to toxicity, when compared to other similar fuels (i.e., Fuel Oil No. 6). Because of the nature of the hydrocarbons components in the bitumen, biodegradation is estimated to be around 10% of the total bitumen fraction of the formulation. Detailed chemical characterization of each one of the constituents of the Orimulsion{reg_sign} formulation will be presented.

  4. Effects of sintering atmosphere on the physical and mechanical properties of modified BOF slag glass

    NASA Astrophysics Data System (ADS)

    Dai, Wen-bin; Li, Yu; Cang, Da-qiang; Zhou, Yuan-yuan; Fan, Yong

    2014-05-01

    This study proposes an efficient way to utilize all the chemical components of the basic oxygen furnace (BOF) slag to prepare high value-added glass-ceramics. A molten modified BOF slag was converted from the melting BOF slag by reducing it and separating out iron component in it, and the modified BOF slag was then quenched in water to form glasses with different basicities. The glasses were subsequently sintered in the temperature range of 600-1000°C in air or nitrogen atmosphere for 1 h. The effects of different atmospheres on the physical and mechanical properties of sintered samples were studied by using differential scanning calorimetry (DSC), X-ray diffraction (XRD) and scanning electron microscopy (SEM) and by conducting experiment on evaluating the sintering shrinkage, water absorption and bulk density. It is found that the kinetics of the sintering process is significantly affected by sintering atmosphere. In particular, compared with sintering in air atmosphere, sintering in N2 atmosphere promotes the synergistic growth of pyroxene and melilite crystalline phases, which can contribute to better mechanical properties and denser microstructure.

  5. Barriers Affecting Physical Activity in Rural Communities: Perceptions of Parents and Children

    ERIC Educational Resources Information Center

    McWhinney, Sharon; McDonald, Andrea; Dawkins-Moultin, Lenna; Outley, Corliss; McKyer, E. Lisako; Thomas, Audrene

    2011-01-01

    A comprehensive understanding of the barriers inhibiting physical activity among children is critical in the fight against childhood obesity. This qualitative interview study examined parents' and children's perceptions of the barriers to physical activity in rural communities of low socioeconomic status. Parents and children concurred that the…

  6. Using Conceptual Metaphor and Functional Grammar to Explore How Language Used in Physics Affects Student Learning

    ERIC Educational Resources Information Center

    Brookes, David T.; Etkina, Eugenia

    2007-01-01

    This paper introduces a theory about the role of language in learning physics. The theory is developed in the context of physics students and physicists talking and writing about the subject of quantum mechanics. We found that physicists' language encodes different varieties of analogical models through the use of grammar and conceptual metaphor.…

  7. Role Playing in Physical Education to Teach in the Affective Domain

    ERIC Educational Resources Information Center

    Samalot-Rivera, Amaury

    2014-01-01

    Using role playing during physical education provides limitless opportunities for intervention and for the demonstration of personal and social qualities. The purpose of this article is to provide easy steps for implementing role playing as a strategy to teach social skills to students in the physical education setting.

  8. How Student Characteristics Affect Girls' and Boys' Verbal Engagement in Physics Instruction

    ERIC Educational Resources Information Center

    Jurik, Verena; Groschner, Alexander; Seidel, Tina

    2013-01-01

    This study investigated how student characteristics predict the nature of girls' and boys' verbal interactions with their teachers in physics classes. The sample included (N = 1378) students from 81 randomly selected high-school physics classrooms in Germany and the German-speaking part of Switzerland. At the beginning of the school year, the…

  9. Stress in Context: Morpho-Syntactic Properties Affect Lexical Stress Assignment in Reading Aloud.

    PubMed

    Spinelli, Giacomo; Sulpizio, Simone; Primativo, Silvia; Burani, Cristina

    2016-01-01

    Recent findings from English and Russian have shown that grammatical category plays a key role in stress assignment. In these languages, some grammatical categories have a typical stress pattern and this information is used by readers. However, whether readers are sensitive to smaller distributional differences and other morpho-syntactic properties (e.g., gender, number, person) remains unclear. We addressed this issue in word and non-word reading in Italian, a language in which: (1) nouns and verbs differ in the proportion of words with a dominant stress pattern; (2) information specified by words sharing morpho-syntactic properties may contrast with other sources of information, such as stress neighborhood. Both aspects were addressed in two experiments in which context words were used to induce the desired morpho-syntactic properties. Experiment 1 showed that the relatively different proportions of stress patterns between grammatical categories do not affect stress processing in word reading. In contrast, Experiment 2 showed that information specified by words sharing morpho-syntactic properties outweighs stress neighborhood in non-word reading. Thus, while general information specified by grammatical categories may not be used by Italian readers, stress neighbors with morpho-syntactic properties congruent with those of the target stimulus have a primary role in stress assignment. These results underscore the importance of expanding investigations of stress assignment beyond single words, as current models of single-word reading seem unable to account for our results. PMID:27445910

  10. Stress in Context: Morpho-Syntactic Properties Affect Lexical Stress Assignment in Reading Aloud

    PubMed Central

    Spinelli, Giacomo; Sulpizio, Simone; Primativo, Silvia; Burani, Cristina

    2016-01-01

    Recent findings from English and Russian have shown that grammatical category plays a key role in stress assignment. In these languages, some grammatical categories have a typical stress pattern and this information is used by readers. However, whether readers are sensitive to smaller distributional differences and other morpho-syntactic properties (e.g., gender, number, person) remains unclear. We addressed this issue in word and non-word reading in Italian, a language in which: (1) nouns and verbs differ in the proportion of words with a dominant stress pattern; (2) information specified by words sharing morpho-syntactic properties may contrast with other sources of information, such as stress neighborhood. Both aspects were addressed in two experiments in which context words were used to induce the desired morpho-syntactic properties. Experiment 1 showed that the relatively different proportions of stress patterns between grammatical categories do not affect stress processing in word reading. In contrast, Experiment 2 showed that information specified by words sharing morpho-syntactic properties outweighs stress neighborhood in non-word reading. Thus, while general information specified by grammatical categories may not be used by Italian readers, stress neighbors with morpho-syntactic properties congruent with those of the target stimulus have a primary role in stress assignment. These results underscore the importance of expanding investigations of stress assignment beyond single words, as current models of single-word reading seem unable to account for our results. PMID:27445910

  11. Physical stigma and academic performance as factors affecting children's first impressions of handicapped peers.

    PubMed

    Siperstein, G N; Gottlieb, J

    1977-03-01

    The effects of four variables on attitudes toward children were studied: the sex and social status of the rater and the physical appearance and academic competence of the target child being rated. The results indicated that competent and physically nonstigmatized children were rated more favorably than incompetent and physically stigmatized children. The data also revealed that girls had a significantly more positive stereotype than did boys of a competent male target child but that boys were more willing to be in physical proximity to the male target child as measured by a social-distance scale. Finally, the results indicated that popular children rated the attractive and competent target child less favorably than children who were not so popular. However, the popular children rated the attractive and incompetent target child more favorably than the less popular children did. The findings were discussed in terms of the salience of physical labels (i.e., stigma) on attitudes toward children.

  12. Physical property measurements of doped cesium iodide crystals

    NASA Technical Reports Server (NTRS)

    Synder, R. S.; Clotfelter, W. N.

    1974-01-01

    Mechanical and thermal property values are reported for crystalline cesium iodide doped with sodium and thallium. Young's modulus, bulk modulus, shear modulus, and Poisson's ratio were obtained from ultrasonic measurements. Young's modulus and the samples' elastic and plastic behavior were also measured under tension and compression. Thermal expansion and thermal conductivity were the temperature dependent measurements that were made.

  13. Synthesis and physical properties of new estolide esters

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Vegetable oil-based oils usually fail to meet the rigorous demands of industrial lubricants by not having acceptable low temperature properties, pour point (PP) and/or cloud point (CP). The oleic estolide was esterified with a series of 16 different alcohols that were either branched or straight-cha...

  14. Physical properties of epoxy resin/titanium dioxide nanocomposites

    SciTech Connect

    Polyzos, Georgios; Tuncer, Enis; Sauers, Isidor; More, Karren Leslie

    2011-01-01

    A polymeric nanocomposite system (nanodielectric) was fabricated, and its mechanical properties were determined. The fabricated nanocomposite was composed of low concentrations of monodispersed titanium dioxide (TiO{sub 2}) nanoparticles and an epoxy resin specially designed for cryogenic applications. The monodispersed TiO{sub 2} nanoparticles were synthesized in an aqueous solution of titanium chloride and polyethylene glycol and subsequently dispersed in a commercial-grade epoxy resin (Araldite{reg_sign} 5808). Nanocomposite thin sheets were prepared at several weight fractions of TiO{sub 2}. The morphology of the composites, determined by transmission electron microscopy, showed that the nanoparticles aggregated to form particle clusters. The influence of thermal processing and the effect of filler dispersion on the structure-property relationships were identified by differential scanning calorimetry and dynamic mechanical analysis at a broad range of temperatures. The effect of the aggregates on the electrical insulation properties was determined by dielectric breakdown measurements. The optical properties of the nanocomposites and their potential use as filters in the ultraviolet-visible (UV-vis) range were determined by UV-vis spectroscopy.

  15. 40 CFR 716.50 - Reporting physical and chemical properties.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... they investigated one or more of the following properties: (a) Water solubility. (b) Adsorption/desorption on particulate surfaces, e.g., soil. (c) Vapor pressure. (d) Octanol/water partition coefficient. (e) Density/relative density (specific gravity). (f) Particle size distribution for insoluble...

  16. 40 CFR 716.50 - Reporting physical and chemical properties.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... they investigated one or more of the following properties: (a) Water solubility. (b) Adsorption/desorption on particulate surfaces, e.g., soil. (c) Vapor pressure. (d) Octanol/water partition coefficient. (e) Density/relative density (specific gravity). (f) Particle size distribution for insoluble...

  17. 40 CFR 716.50 - Reporting physical and chemical properties.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... they investigated one or more of the following properties: (a) Water solubility. (b) Adsorption/desorption on particulate surfaces, e.g., soil. (c) Vapor pressure. (d) Octanol/water partition coefficient. (e) Density/relative density (specific gravity). (f) Particle size distribution for insoluble...

  18. 40 CFR 716.50 - Reporting physical and chemical properties.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... they investigated one or more of the following properties: (a) Water solubility. (b) Adsorption/desorption on particulate surfaces, e.g., soil. (c) Vapor pressure. (d) Octanol/water partition coefficient. (e) Density/relative density (specific gravity). (f) Particle size distribution for insoluble...

  19. PHYSICAL PROPERTIES OF EXTRUDED AND INJECTION MOLDED CORN GLUTEN MEAL

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study was performed to investigate the compounding of corn gluten meal (CGM) and decanoic acid and to evaluate their mechanical properties. The mixture of CGM and 30% decanoic acid was compounded in a twin screw extruder, followed by injection molding. Scanning electron microscopy (SEM), tens...

  20. Program Gives Data On Physical Properties Of Hydrogen

    NASA Technical Reports Server (NTRS)

    Roder, H. M.; Mccarty, R. D.; Hall, W. J.

    1994-01-01

    TAB II computer program provides values of thermodynamic and transport properties of hydrogen in useful format. Also, provides values for equilibrium hydrogen and para-hydrogen. Program fast, moderately accurate, and operates over wide ranges of input variables. Written in FORTRAN 77.

  1. Synthesis and physical properties of isostearic acids and their esters

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Saturated branched-chain fatty acids (sbc-FAs) are found as minor constituents in several natural fats and oils. Sbc-FAs are of interest since they have lower melting points than their linear counterparts and exhibit good oxidative stability; properties that make them ideally suited in a number of ...

  2. ESTIMATION OF PHYSICAL PROPERTIES AND CHEMICAL REACTIVITY PARAMETERS OF ORGANIC COMPOUNDS

    EPA Science Inventory

    The computer program SPARC (Sparc Performs Automated Reasoning in Chemistry)has been under development for several years to estimate physical properties and chemical reactivity parameters of organic compounds strictly from molecular structure. SPARC uses computational algorithms ...

  3. PREDICTION OF CHEMICAL REACTIVITY PARAMETERS AND PHYSICAL PROPERTIES OF ORGANIC COMPOUNDS FROM MOLECULAR STRUCTURE USING SPARC

    EPA Science Inventory

    The computer program SPARC (SPARC Performs Automated Reasoning in Chemistry) has been under development for several years to estimate physical properties and chemical reactivity parameters of organic compounds strictly from molecular structure. SPARC uses computational algorithms...

  4. Evaluation of correlation between physical properties and ultrasonic pulse velocity of fired clay samples.

    PubMed

    Özkan, İlker; Yayla, Zeliha

    2016-03-01

    The aim of this study is to establish a correlation between physical properties and ultrasonic pulse velocity of clay samples fired at elevated temperatures. Brick-making clay and pottery clay were studied for this purpose. The physical properties of clay samples were assessed after firing pressed clay samples separately at temperatures of 850, 900, 950, 1000, 1050 and 1100 °C. A commercial ultrasonic testing instrument (Proceq Pundit Lab) was used to evaluate the ultrasonic pulse velocity measurements for each fired clay sample as a function of temperature. It was observed that there became a relationship between physical properties and ultrasonic pulse velocities of the samples. The results showed that in consequence of increasing densification of the samples, the differences between the ultrasonic pulse velocities were higher with increasing temperature. These findings may facilitate the use of ultrasonic pulse velocity for the estimation of physical properties of fired clay samples.

  5. VizieR Online Data Catalog: Physical properties of VVDS galaxies (Lamareille+, 2009)

    NASA Astrophysics Data System (ADS)

    Lamareille, F.; Brinchmann, J.; Contini, T.; Walcher, C. J.; Charlot, S.; Perez-Montero, E.; Zamorani, G.; Pozzetti, L.; Bolzonella, M.; Garilli, B.; Paltani, S.; Bongiorno, A.; Le Fevre, O.; Bottini, D.; Le Brun, V.; Maccagni, D.; Scaramella, R.; Scodeggio, M.; Tresse, L.; Vettolani, G.; Zanichelli, A.; Adami, C.; Arnouts, S.; Bardelli, S.; Cappi, A.; Ciliegi, P.; Foucaud, S.; Franzetti, P.; Gavignaud, I.; Guzzo, L.; Ilbert, O.; Iovino, A.; McCracken, H. J.; Marano, B.; Marinoni, C.; Mazure, A.; Meneux, B.; Merighi, R.; Pello, R.; Pollo, A.; Radovich, M.; Vergani, D.; Zucca, E.; Romano, A.; Grado, A.; Limatola, L.

    2009-01-01

    This catalog gives emission-line measurements and spectral indices for galaxies observed in the VIMOS/VLT Deep Survery (VVDS), together with derived physical properties such as stellar masses and metallicities. (3 data files).

  6. Preparation and Physical Properties of One-Dimensional Structures: Bap(Fe2S4)q.

    ERIC Educational Resources Information Center

    Swinnea, J. S.; Steinfink, H.

    1980-01-01

    Reviews the structure, preparation, and physical properties of a series of compounds characterized by structures formed from sublattices which have incommensurate repeat distances in one or two directions. (Author/CS)

  7. Viscoelastic, physical, and bio-degradable properties of dermal scaffolds and related cell behaviour.

    PubMed

    Sharma, Vaibhav; Patel, Nimesha; Kohli, Nupur; Ravindran, Nivedita; Hook, Lilian; Mason, Chris; García-Gareta, Elena

    2016-01-01

    Dermal scaffolds promote healing of debilitating skin injuries caused by burns and chronic skin conditions. Currently available products present disadvantages and therefore, there is still a clinical need for developing new dermal substitutes. This study aimed at comparing the viscoelastic, physical and bio-degradable properties of two dermal scaffolds, the collagen-based and clinically well established Integra(®) and a novel fibrin-based dermal scaffold developed at our laboratory called Smart Matrix(®), to further evaluate our previous published findings that suggested a higher influx of cells, reduced wound contraction and less scarring for Smart Matrix(®) when used in vivo. Rheological results showed that Integra(®) (G'  =  313.74 kPa) is mechanically stronger than Smart Matrix(®) (G'  =  8.26 kPa), due to the presence of the silicone backing layer in Integra(®). Micro-pores were observed on both dermal scaffolds, although nano-pores as well as densely packed nano-fibres were only observed for Smart Matrix(®). Average surface roughness was higher for Smart Matrix(®) (Sa  =  114.776 nm) than for Integra(®) (Sa  =  75.565 nm). Both scaffolds possess a highly porous structure (80-90%) and display a range of pore micro-sizes that represent the actual in vivo scenario. In vitro proteolytic bio-degradation suggested that Smart Matrix(®) would degrade faster upon implantation in vivo than Integra(®). For both scaffolds, the enzymatic digestion occurs via bulk degradation. These observed differences could affect cell behaviour on both scaffolds. Our results suggest that fine-tuning of scaffolds' viscoelastic, physical and bio-degradable properties can maximise cell behaviour in terms of attachment, proliferation and infiltration, which are essential for tissue repair. PMID:27586397

  8. Statistical evaluation of physical properties in Area 12, Nevada Test Site, using the USGS/DNA Storage and Retrieval System

    SciTech Connect

    Brethauer, G.E.; Magner, J.E.; Miller, D.R.

    1980-05-01

    The US Geological Survey/Defense Nuclear Agency Physical-Properties Storage and Retrieval System was used to generate tables displaying the basic statistics of physical-properties data sets sorted according to geologic identification and tunnel complex in Rainier and Aqueduct Mesas. An approximate procedure to statistically evaluate the significance of geologic identifier versus physical-property average value was developed. Results of this procedure indicate that no conclusive consistent relation exists between geologic identifier and physical-properties average value.

  9. Toxicity and physical properties of atrazine and its degradation products: A literature survey

    SciTech Connect

    Pugh, K.C.

    1994-10-01

    The Tennessee Valley Authority`s Environmental Research Center has been developing a means of detoxifying atrazine waste waters using TiO{sub 2} photocatalysis. The toxicity and physical properties of atrazine and its degradation products will probably be required information in obtaining permits from the United States Environmental Protection Agency for the demonstration of any photocatalytic treatment of atrazine waste waters. The following report is a literature survey of the toxicological and physical properties of atrazine and its degradation products.

  10. Pore-scale Analysis on Physics Property Changes of CO2 Bleached Sandstone, Entrada Fromation, Utah

    NASA Astrophysics Data System (ADS)

    Han, J.; Keehm, Y.

    2012-12-01

    Since carbon dioxide injected into geological formations can cause a variety of physical and chemical reaction with minerals, it is important to evaluate the characteristics and aspects of these effects in CO2 geological sequestration. For the analog of the phenomena, we conducted pore-scale analysis on porosity and permeability changes and their characteristics for CO2-bleached Entrada formation, Utah due to natural leakage of CO2. From thin section analysis, we observed mineralogical and pore-shape changes: precipitation of carbonate minerals. Then, we estimated porosity and permeability from thin section, using a computational rock physics technique. The estimated porosity of unbleached sample is approximately 13% and that of bleached sample is around 10%, which implies the precipitation of carbonate minerals. The estimated permeability showed a little differences between two samples. This observations seems to imply that the precipitation would occur where permeability is not significantly affected: grain contacts. For more systematic analysis, we obtained 3D pore microstructures by X-ray microtomography technique. The preliminary analysis using the 3D pore microstructures showed similar results to what we found in the thin-section analysis. And a set of simulations for porosity and permeability are now being conducted. The final result will help understand how injected CO2 changes pore structures and physical properties such as porosity and permeability, and will also help accurate monitoring of geological storage sites. Acknowledgement: This work was supported by the Energy Resources R&D program of the Korea Institute of Energy Technology Evaluation and Planning (KETEP) grant funded by the Korea government Ministry of Knowledge Economy (No. 2010201020001A).

  11. Individual factors affecting preferences for feedback message tactics in the contexts of physical activity.

    PubMed

    Hirvonen, Noora; Enwald, Heidi; Bath, Peter A; Pyky, Riitta; Korpelainen, Raija; Huotari, Maija-Leena

    2015-01-01

    Tailored feedback on personal physical activity behavior has been used to inform individuals and promote physical activity among different populations. This study aimed to increase the understanding of factors associated with young men's preferences for feedback message tactics in the context of physical activity and exercise. How preferences vary was analyzed in terms of the self-reported physical activity, stage of exercise behavior change, exercise self-efficacy, objectively measured physical health status, and sociodemographic characteristics of young Finnish men. Population-based survey data, including physiological measurements (n = 525), were collected at the Finnish Defence Forces' call-ups in the city of Oulu, Finland, in September 2011. The results indicate that the stage of exercise behavior change, exercise self-efficacy, physical health status, and educational level are associated with a preference for normative and ipsative comparison. Multivariate logistic regression models show that an advanced stage of exercise behavior change and education in the academic track of an upper secondary school are independent predictors of preferring ipsative and normative physical activity feedback among young men. The study provides new insights into how the stage of behavior change influences health information behavior and is in line with studies emphasizing social factors--including education--as being important in shaping health-related behavior. These factors could form the basis for tailoring information when designing health promotion. PMID:25491473

  12. Individual factors affecting preferences for feedback message tactics in the contexts of physical activity.

    PubMed

    Hirvonen, Noora; Enwald, Heidi; Bath, Peter A; Pyky, Riitta; Korpelainen, Raija; Huotari, Maija-Leena

    2015-01-01

    Tailored feedback on personal physical activity behavior has been used to inform individuals and promote physical activity among different populations. This study aimed to increase the understanding of factors associated with young men's preferences for feedback message tactics in the context of physical activity and exercise. How preferences vary was analyzed in terms of the self-reported physical activity, stage of exercise behavior change, exercise self-efficacy, objectively measured physical health status, and sociodemographic characteristics of young Finnish men. Population-based survey data, including physiological measurements (n = 525), were collected at the Finnish Defence Forces' call-ups in the city of Oulu, Finland, in September 2011. The results indicate that the stage of exercise behavior change, exercise self-efficacy, physical health status, and educational level are associated with a preference for normative and ipsative comparison. Multivariate logistic regression models show that an advanced stage of exercise behavior change and education in the academic track of an upper secondary school are independent predictors of preferring ipsative and normative physical activity feedback among young men. The study provides new insights into how the stage of behavior change influences health information behavior and is in line with studies emphasizing social factors--including education--as being important in shaping health-related behavior. These factors could form the basis for tailoring information when designing health promotion.

  13. [Evaluating method of the characteristic physical properties of the wetting mass using texture analyser].

    PubMed

    Gao, Ya; Hong, Yan-long; Xian, Jie-chen; Zhang, Ning; Feng, Yi; Yang, Xiu-juan

    2012-08-01

    To build the evaluating method of the characteristic physical properties of the wetting mass, this study reported the preparation of wetting mass by adding water into microcrystalline cellulose, and using texture analyser texture profile analysis to test its physical properties, including hardness, adhesiveness, springness, cohesiveness, chewiness, resilience and so on, then finding out the better method and parameters. The method was evaluated and used to test wetting mass, which was made of microcrystalline cellulose of different types and polyvinylpyrrolidone. When running texture profile analysis whose trigger force was 1500 g, the relative standard deviation was under 10%, and the trend of every characteristic physical property tallied with the theory result by water ratio increase. Testing result of the same excipient with the same water ratio had a higher precision, while characteristic physical properties of wetting mass who was made of the same excipient with different water ratios and different excipients had a great difference. Using texture analyser to test physical properties of wetting mass could get a result which tallied with the theory by water ratio increase, and had a well precision, accuracy and sensitivity, and thus it could also evaluate the characteristic physical properties of wetting mass relatively well. PMID:23162903

  14. Structural and physical properties of BiVO3

    NASA Astrophysics Data System (ADS)

    Singh, M. P.; Razavi, F. S.

    2014-03-01

    We report the phase stabilization and properties of BiVO3 (BVO) thin films, grown on (001) SrTiO3 and LaAlO3, using the pulsed laser deposition technique. Bi and V are in 3+ oxidation states as measured by using x-ray photoelectrons spectroscopy. BVO exhibits a Curie-Weiss paramagnetic behaviour and about -26 K Weiss temperature. This demonstrates the presence of a strong correlation effect due to the spin fluctuation. Additionally, these films exhibit a semiconducting behaviour owing to the thermally activated conduction process. A plausible explanation of the observed properties is presented by comparing with the closely related LaVO3 and other orthovanadates.

  15. Active doublet method for measuring small changes in physical properties

    DOEpatents

    Roberts, Peter M.; Fehler, Michael C.; Johnson, Paul A.; Phillips, W. Scott

    1994-01-01

    Small changes in material properties of a work piece are detected by measuring small changes in elastic wave velocity and attenuation within a work piece. Active, repeatable source generate coda wave responses from a work piece, where the coda wave responses are temporally displaced. By analyzing progressive relative phase and amplitude changes between the coda wave responses as a function of elapsed time, accurate determinations of velocity and attenuation changes are made. Thus, a small change in velocity occurring within a sample region during the time periods between excitation origin times (herein called "doublets") will produce a relative delay that changes with elapsed time over some portion of the scattered waves. This trend of changing delay is easier to detect than an isolated delay based on a single arrival and provides a direct measure of elastic wave velocity changes arising from changed material properties of the work piece.

  16. Physical properties of kraft black liquor. Final report. Phase I

    SciTech Connect

    Fricke, A.L.

    1983-12-01

    Methods were selected, equipment installed, and procedures developed for determining rheological properties; for determining thermal properties (stability, density, thermal expansion, and heat capacity); for purification and characterization of lignin (glass transition, stability, weight average molecular weight, and number average molecular weight); and for performing chemical analyses (negative inorganic ions, positive inorganic ions, acid organic salts, lignin, and total solids). A strategy for pulping to supply test liquors was developed, and a statistically designed pulping experiment was specified for a Southern softwood species. Arrangements were made for performing initial pulping work in an industrial pilot plant, and a preliminary set of pulping experiments were conducted. Liquors from the preliminary pulping experiments were used to test procedures and to determine reproducibility of the experiment. Literature was also surveyed and preliminary selection of designs for a pilot digester, and for equipment to determine surface tension were made.

  17. Structural and physical properties of BiVO{sub 3}

    SciTech Connect

    Singh, M. P. Razavi, F. S.

    2014-03-31

    We report the phase stabilization and properties of BiVO{sub 3} (BVO) thin films, grown on (001) SrTiO{sub 3} and LaAlO{sub 3}, using the pulsed laser deposition technique. Bi and V are in 3+ oxidation states as measured by using x-ray photoelectrons spectroscopy. BVO exhibits a Curie-Weiss paramagnetic behaviour and about −26 K Weiss temperature. This demonstrates the presence of a strong correlation effect due to the spin fluctuation. Additionally, these films exhibit a semiconducting behaviour owing to the thermally activated conduction process. A plausible explanation of the observed properties is presented by comparing with the closely related LaVO{sub 3} and other orthovanadates.

  18. Determination of physical properties of fibrous thermal insulation

    NASA Astrophysics Data System (ADS)

    Tilioua, A.; Libessart, L.; Joulin, A.; Lassue, S.; Monod, B.; Jeandel, G.

    2012-10-01

    The objective of this study is to characterize both experimentally and theoretically, conductive and radiative heat transfer within polyester batting. This material is derived from recycled bottles (PET) with fibres of constant diameters. Two other mineral and plant fibrous insulation materials, (glass wool and hemp wool) are also characterized for comparative purposes. To determine the overall thermophysical properties of the tested materials, heat flux measurement are carried out using a device developed in house. The radiative properties of the material are determined by an inverse method based on measurements of transmittance and reflectance using a FTIR spectrometer and by solving the equation of radiative heat transfer. These measures are compared to results of numerical simulations.

  19. Physical and Hydraulic Properties of Rock Specimens from Grimsel Test Site, Switzerland

    NASA Astrophysics Data System (ADS)

    Zhang, M.; Takeda, M.

    2007-12-01

    The Grimsel Test Site (GTS) is located at an altitude of 1730 meters in the granite rock of Aar Massif in central Switzerland. It lies at a depth of around 450 meters beneath the surface and was established over 20 years ago by the National Cooperative for the Disposal of Radioactive Waste (Nagra) as a center for underground Research and Development (R&D) supporting a wide range of related research projects. Among many of them, an international cooperative project defined as the Long Term Diffusion (LTD) has been performing to obtain quantitative information on matrix diffusion in rock strata under in-situ conditions. A set of laboratory experiments is also planed to determine the physical, hydraulic and diffusive transport properties of rock specimens taken from the same test site. In this poster, we present the preliminary results of both physical and hydraulic properties of the rock specimens being tested, including the bulk density, porosity, specific surface area and pore distribution, microstructure, P and S wave velocities, electrical resistivity, air and water permeabilities. The results obtained in this study indicate that: 1) The porosity and wave velocities of Grimsel granite are relatively low compared to the average values of igneous rocks indicating that micro-cracks can potentially exist within grain minerals. 2) The air and water permeabilities obtained from the air and water permeability tests are consistent that illustrates the accuracy of both experiments. 3) Permeability is not a simple function of effective confining pressure. It is very sensitive to confining pressure especially at low pressure levels. Besides, the permeability is hysteretic depending on confining pressure, pore pressure and stress history. 4) Similar to the hydraulic properties, diffusive transport properties of rock specimens can also be significantly affected by the confining pressure conditions. Laboratory diffusion tests considering the effects of stress conditions are

  20. Physical properties of preserved core from the Geysers scientific corehole

    SciTech Connect

    Roberts, J.J.; Bonner, B.P.; Duba, A.G.; Schneberk, D.L.

    1996-01-24

    X-ray attenuation, electrical conductivity, and ultrasonic velocity are reported for a segment of preserved core from SB-15D, 918 ft. X-ray tomography and ultrasonic measurements change as the core dries, providing information regarding handling and disturbance of the core. Electrical conductivity measurements at reservoir conditions indicate that pore fluid properties and pore microstructure control bulk conductivity. These data are useful for calibration and interpretation of field geophysical measurements.