Science.gov

Sample records for moisture performance characteristics

  1. Moisture-dependent color characteristics of walnuts

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Characterizing the shell color of walnuts based on their moisture content (MC) at harvest can provide valuable information for performing walnut sorting before drying. The objective of this study was to investigate the relationship between the color characteristics of the shell of walnuts and their...

  2. [Performance characteristics of root zone moisture and water potential sensors for greenhouses in the conditions of extended space flight].

    PubMed

    Podolskiy, I G; Strugov, O M; Bingham, G E

    2014-01-01

    The investigation was performed using greenhouse Lada in the Russian segment of the International space station (ISS RS) as part of space experiment Plants-2 during ISS missions 5 through to 22. A set of 6 point moisture sensors embedded in the root zone (turface particles of 1-2 mm in diam.) and 4 tensiometers inside root modules (RM) were used to monitor moisture content and water potential in the root zone. The purpose was to verify functionality and to test performance of the sensors in the spacefight environment. It was shown that with the average RZ moisture content of 80% the measurement error of the sensors do not exceed ± 1.5%. Dynamic analysis of the tensiometers measurements attests that error in water potential measurements does not exceed ± 111 Pa.

  3. A Field Study Comparison of the Energy and Moisture Performance Characteristics of Ventilated Versus Sealed Crawl Spaces in the South

    SciTech Connect

    Bruce Davis; Cyrus Dastur; William E. Warren; Shawn Fitzpatrick; Christine Maurer; Rob Stevens; Terry Brennan; William Rose

    2005-06-22

    This study compared the performance of closed crawl spaces, which had sealed foundation wall vents, a sealed polyethylene film liner and various insulation and drying strategies, to traditional wall-vented crawl spaces with perimeter wall vents and polyethylene film covering 100% of the ground surface. The study was conducted at 12 owner-occupied, all electric, single-family detached houses with the same floor plan located on one cul-de-sac in the southeastern United States. Using the matched pairs approach, the houses were divided into three study groups of four houses each. Comparative data was recorded for each house to evaluate sub-metered heat pump energy consumption, relative humidity, wood moisture content, duct infiltration, house infiltration, temperature, radon, and bioaerosol levels. Findings indicated that in the humid conditions of the southeastern United States, a properly closed crawl space is a robust construction measure that produces a substantially drier crawl space and significantly reduces occupied space conditioning energy use on an annual basis.

  4. Moisture performance analysis of EPS frost insulation

    SciTech Connect

    Ojanen, T.; Kokko, E.

    1997-11-01

    A horizontal layer of expanded polystyrene foam (EPS) is widely used as a frost insulation of building foundations in the Nordic countries. The performance properties of the insulation depend strongly on the moisture level of the material. Experimental methods are needed to produce samples for testing the material properties in realistic moisture conditions. The objective was to analyze the moisture loads and the wetting mechanisms of horizontal EPS frost insulation. Typical wetting tests, water immersion and diffusive water vapor absorption tests, were studied and the results were compared with the data from site investigations. Usually these tests give higher moisture contents of EPS than what are detected in drained frost insulation applications. Also the effect of different parameters, like the immersion depth and temperature gradient were studied. Special attention was paid to study the effect of diffusion on the wetting process. Numerical simulation showed that under real working conditions the long period diffusive moisture absorption in EPS frost insulation remained lower than 1% Vol. Moisture performance was determined experimentally as a function of the distance between the insulation and the free water level in the ground. The main moisture loads and the principles for good moisture performance of frost insulation are presented.

  5. Continuous columns for determining moisture characteristic curves of soilless substrates

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sound water management is essential for effectively producing nursery crops. Understanding substrate water availability is a critical component to managing irrigation properly. The objective of this paper is to report a method for generating moisture characteristic curves of soilless substrate tha...

  6. Size and moisture distribution characteristics of walnuts and their components

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objective of this study was to determine the size characteristics and moisture content (MC) distributions of individual walnuts and their components, including hulls, shells and kernels under different harvest conditions. Measurements were carried out for three walnut varieties, Tulare, Howard a...

  7. Moisture sorption characteristics of freeze-dried human platelets*

    PubMed Central

    Xu, Meng-jie; Chen, Guang-ming; Fan, Ju-li; Liu, Jin-hui; Xu, Xian-guo; Zhang, Shao-zhi

    2011-01-01

    Freeze-drying is a promising method for a long-term storage of human platelets. The moisture sorption characteristics of freeze-dried human platelets (FDHPs) were studied in this paper. The moisture sorption isotherms of FDHPs and freeze-dried lyophilization buffer (FDLB) were measured at 4, 25, and 37 °C. The experimental data were fitted to Brunauer-Emmett-Teller (BET) and Guggenheim-Anderson-de Boer (GAB) equations. There were no significant statistical differences (P>0.05) between the sorption characteristics of FDHPs and FDLB at 4 and 25 °C, while FDHPs absorbed more water at 37 °C. The net isosteric heat of sorption was derived. The heat for FDHPs showed an abnormal negative value at low moisture contents when 25 and 37 °C data were used. Dynamic sorption experiments were carried out at 25 °C with environmental water activity controlled at 0.75, 0.85, and 0.90. The moisture diffusion coefficient was fitted to be 8.24×10−12 m2/s when experimental data at initial time were used. These results would be helpful in choosing prehydration and storage condition for FDHPs. PMID:21370506

  8. Effect of moisture sorption on the performance of crospovidone.

    PubMed

    Hiew, Tze Ning; Johan, Nur Atiqah Binte; Desai, Parind Mahendrakumar; Chua, Siang Meng; Loh, Zhi Hui; Heng, Paul Wan Sia

    2016-11-30

    Crospovidone is a commonly used tablet disintegrant. However, the synthetic disintegrant has been known to be hygroscopic and high moisture content in crospovidone used could exert deleterious effects on tablets formulated with it. The objective of this study was to elicit a better understanding between crospovidone-water interaction and its effect on disintegrant performance. Moisture sorption and desorption isotherms were obtained together with the enthalpy of immersion. Crospovidone samples stored at four relative humidities were used to formulate tablets and the resultant tablets were evaluated for their mechanical, dimensional and disintegratability attributes. Analyses of the moisture sorption isotherms indicated that externally adsorbed moisture accounted for the bulk of the total moisture content in crospovidone, with minimal amount of moisture absorbed intramolecularly. Enthalpy of immersion became less exothermic with crospovidone samples stored at increasing storage humidity. Correspondingly, improvement in disintegration time became less pronounced. This was postulated to be a consequence of premature wetting of the particle surfaces by externally adsorbed moisture. High humidity was also detrimental to tablet hardness and thickness. In conclusion, the impact of moisture sorption during storage by excipients such as crospovidone could be better understood by the appreciation of crospovidone-water interaction and its consequence on tablet quality.

  9. Moisture diffusion and permeability characteristics of hydroxypropylmethylcellulose and hard gelatin capsules.

    PubMed

    Barham, Ahmad S; Tewes, Frederic; Healy, Anne Marie

    2015-01-30

    The primary objective of this paper is to compare the sorption characteristics of hydroxypropylmethylcellulose (HPMC) and hard gelatin (HG) capsules and their ability to protect capsule contents. Moisture sorption and desorption isotherms for empty HPMC and HG capsules have been investigated using dynamic vapour sorption (DVS) at 25°C. All sorption studies were analysed using the Young-Nelson model equations which distinguishes three moisture sorption types: monolayer adsorption moisture, condensation and absorption. Water vapour diffusion coefficients (D), solubility (S) and permeability (P) parameters of the capsule shells were calculated. ANOVA was performed with the Tukey comparison test to analyse the effect of %RH and capsule type on S, P, and D parameters. The moisture uptake of HG capsules were higher than HPMC capsules at all %RH conditions studied. It was found that values of D and P across HPMC capsules were greater than for HG capsules at 0-40 %RH; whereas over the same %RH range S values were higher for HG than for HPMC capsules. S values decreased gradually as the %RH was increased up to 60% RH. To probe the effect of moisture ingress, spray dried lactose was loaded into capsules. Phase evolution was characterised by scanning electron microscopy (SEM), X-ray powder diffraction (XRD), and differential scanning calorimetry (DSC). The capsules under investigation are not capable of protecting spray dried lactose from induced solid state changes as a result of moisture uptake. For somewhat less moisture sensitive formulations, HPMC would appear to be a better choice than HG in terms of protection of moisture induced deterioration.

  10. The Temperature Dependence of Soil Moisture Characteristics of Agricultural Soils

    NASA Astrophysics Data System (ADS)

    Salehzadeh, Amir

    1990-01-01

    The temperature dependence of static and dynamic characteristics of four soils: glass beads, Plainfield sand, Plano silt loam, and Elkmound sandy loam were explored. Gain -factor model was employed for quantifying the temperature dependences. The study required novel methods and technologies which were developed and employed for the rapid, and transient measurement of soil-moisture characteristics of these soils. A pressurized 2 cm-high column of soil is sandwiched between two air blocking membranes interfacing outside pressurized water system. Water content (Theta ) is measured with a 2 Curie gamma-ray source combined with a fast detection system giving a statistical accuracy of +/-0.2%. Moisture potential ( Psi) down to -2000 cm was measured with a newly developed "stripper" tensionmeter. While a slowly varying soil-water pressure was imposed on the thin sample through the membranes, firmly held in contact with the soil, water content and moisture -potentials were being monitored in the sample. A plot of water content versus water pressure gave the static characteristics (Theta,Psi ) of soils. An array of tensiometers (between the membranes) allowed measurement of the potential profile; in conjunction with the time-varying water content this permitted measurement of dynamic characteristics, conductivity versus water content (K,Theta). For the (Theta, Psi) characteristics, the measurements indicated that, wholly for glass beads, and largely for sand, the surface tension of pure water governs the temperature response. The temperature dependence of Plano silt loam was largely independent of water content and was roughly five times the temperature dependence of the surface tension of pure water. For Elkmound sandy loam the dependence was complex and not easily explained. Two factors appear to limit further system improvement. (1) A sample thinner than 2 cm faces difficulties of fitting three tensionmeters into the thickness. This limit on the thickness, in turn

  11. Effects of feeding combinations of steam-flaked grain sorghum and steam-flaked, high-moisture, or dry-rolled corn on growth performance and carcass characteristics in feedlot cattle.

    PubMed

    Huck, G L; Kreikemeier, K K; Kuhl, G L; Eck, T P; Bolsen, K K

    1998-12-01

    The objective of these two feeding trials was to determine the associative effects of feeding steam-flaked grain sorghum (SFGS) in combination with steam-flaked (SFC), dry-rolled (DRC), or high-moisture (HMC) corn on growth performance and carcass characteristics in feedlot cattle. In Trial 1, 200 yearling heifers were blocked by weight, allotted to 25 pens, and fed one of five finishing diets (77% grain, 15% corn silage, and 8% supplement on a DM basis) for an average of 137 d. The grain combinations were 100:0, 75:25, 50:50, 25:75, and 0:100 SFC:SFGS, respectively. Treatment had no effect on DMI (P > .05), but ADG, gain efficiency, and final live and hot carcass weights decreased linearly (P < .05) as the proportion of SFGS increased in the diet. Carcass backfat, quality grade, and liver abscess score were not affected (P > .05) by treatment. In Trial 2, 306 yearling steers were blocked by weight, allotted to 30 pens, and fed diets that contained 74.5% grain, 10% corn silage, 7.5% soybean meal, 4% tallow, and 4% supplement (DM basis) for an average of 139 d. The grain and grain combinations were 100% DRC, HMC, SFC, or SFGS and a 67%:33% combination of SFGS: DRC or SFGS:HMC. For steers fed diets containing a single source of grain, those fed SFC gained 7% more live weight and had a 7% higher gain efficiency (P < .05) than those fed DRC or HMC. Growth performance of steers fed SFGS was intermediate. Feeding grain combinations (67% SFGS:33% HMC or DRC) resulted in a 5 to 6% positive associative effect (P < .05) for ADG and gain efficiency. Carcass characteristics were not affected (P > .05) by treatment. We concluded that there were significant benefits (positive associative effects) when SFGS was fed in combination with DRC or HMC, but the effects were smaller when SFGS was fed in combination with SFC.

  12. [Characteristics of soil moisture in artificial impermeable layers].

    PubMed

    Suo, Gai-Di; Xie, Yong-Sheng; Tian, Fei; Chuai, Jun-Feng; Jing, Min-Xiao

    2014-09-01

    For the problem of low water and fertilizer use efficiency caused by nitrate nitrogen lea- ching into deep soil layer and soil desiccation in dryland apple orchard, characteristics of soil moisture were investigated by means of hand tamping in order to find a new approach in improving the water and fertilizer use efficiency in the apple orchard. Two artificial impermeable layers of red clay and dark loessial soil were built in soil, with a thickness of 3 or 5 cm. Results showed that artificial impermeable layers with the two different thicknesses were effective in reducing or blocking water infiltration into soil and had higher seepage controlling efficiency. Seepage controlling efficiency for the red clay impermeable layer was better than that for the dark loessial soil impermeable layer. Among all the treatments, the red clay impermeable layer of 5 cm thickness had the highest bulk density, the lowest initial infiltration rate (0.033 mm · min(-1)) and stable infiltration rate (0.018 mm · min(-1)) among all treatments. After dry-wet alternation in summer and freezing-thawing cycle in winter, its physiochemical properties changed little. Increase in years did not affect stable infiltration rate of soil water. The red clay impermeable layer of 5 cm thickness could effectively increase soil moisture content in upper soil layer which was conducive to raise the water and nutrient use efficiency. The approach could be applied to the apple production of dryland orchard.

  13. NASA Soil Moisture Active Passive Mission Status and Science Performance

    NASA Technical Reports Server (NTRS)

    Yueh, Simon H.; Entekhabi, Dara; O'Neill, Peggy; Njoku, Eni; Entin, Jared K.

    2016-01-01

    The Soil Moisture Active Passive (SMAP) observatory was launched January 31, 2015, and its L-band radiometer and radar instruments became operational since mid-April 2015. The SMAP radiometer has been operating flawlessly, but the radar transmitter ceased operation on July 7. This paper provides a status summary of the calibration and validation of the SMAP instruments and the quality assessment of its soil moisture and freeze/thaw products. Since the loss of the radar in July, the SMAP project has been conducting two parallel activities to enhance the resolution of soil moisture products. One of them explores the Backus Gilbert optimum interpolation and de-convolution techniques based on the oversampling characteristics of the SMAP radiometer. The other investigates the disaggregation of the SMAP radiometer data using the European Space Agency's Sentinel-1 C-band synthetic radar data to obtain soil moisture products at about 1 to 3 kilometers resolution. In addition, SMAP's L-band data have found many new applications, including vegetation opacity, ocean surface salinity and hurricane ocean surface wind mapping. Highlights of these new applications will be provided.

  14. Effect of heat-moisture treatment on the structural, physicochemical, and rheological characteristics of arrowroot starch.

    PubMed

    Pepe, Larissa S; Moraes, Jaqueline; Albano, Kivia M; Telis, Vânia R N; Franco, Célia M L

    2016-04-01

    The effect of heat-moisture treatment on structural, physicochemical, and rheological characteristics of arrowroot starch was investigated. Heat-moisture treatment was performed with starch samples conditioned to 28% moisture at 100 ℃ for 2, 4, 8, and 16 h. Structural and physicochemical characterization of native and modified starches, as well as rheological assays with gels of native and 4 h modified starches subjected to acid and sterilization stresses were performed. Arrowroot starch had 23.1% of amylose and a CA-type crystalline pattern that changed over the treatment time to A-type. Modified starches had higher pasting temperature and lower peak viscosity while breakdown viscosity practically disappeared, independently of the treatment time. Gelatinization temperature and crystallinity increased, while enthalpy, swelling power, and solubility decreased with the treatment. Gels from modified starches, independently of the stress conditions, were found to have more stable apparent viscosities and higher G' and G″ than gels from native starch. Heat-moisture treatment caused a reorganization of starch chains that increased molecular interactions. This increase resulted in higher paste stability and strengthened gels that showed higher resistance to shearing and heat, even after acid or sterilization conditions. A treatment time of 4 h was enough to deeply changing the physicochemical properties of starch.

  15. Moisture Adsorption Isotherms and Thermodynamic Characteristics of Tannic Acid

    NASA Astrophysics Data System (ADS)

    Červenka, L.; Cacková, L.

    2016-09-01

    Moisture adsorption isotherms of tannic acid were determined at 5, 15, and 35°C with the use of the static gravimetric method in the range 0.113-0.980 aw (aw is the water activity). It was shown that tannic acid adsorbed more water at 5°C. The experimental data fitted well to the Guggenheim-Anderson-de Boer and Yanniotis-Blahovec equations, giving the corresponding parameters by nonlinear regression. The monolayer moisture content, number of monolayers, and the surface area of sorption were demonstrated to decrease with increasing temperature. Mesopores dominated below the monolayer moisture content followed by the formation of macropores. The variation of the differential enthalpy and entropy with the moisture content showed that water was strongly bound to the surface of tannic acid below the moisture content 5.0 g water/100 g dry basis. The adsorption process was found to be enthalpy-driven; however, it was not spontaneous at a low moisture content, as follows from the enthalpy-entropy compensation theory. The variation of the net integral enthalpy and entropy (at a constant spreading pressure) with the moisture content exhibited maximum and minimum values, respectively. This behavior indicated that water molecules were strongly bound to the tannic acid surface at the moisture content up to its monolayer values.

  16. Moisture and Structural Analysis for High Performance Hybrid Wall Assemblies

    SciTech Connect

    Grin, A.; Lstiburek, J.

    2012-09-01

    Based on past experience in the Building America program, BSC has found that combinations of materials and approaches—in other words, systems—usually provide optimum performance. Integration is necessary, as described in this research project. The hybrid walls analyzed utilize a combination of exterior insulation, diagonal metal strapping, and spray polyurethane foam and leave room for cavity-fill insulation. These systems can provide effective thermal, air, moisture, and water barrier systems in one assembly and provide structure.

  17. Soil moisture dynamics and their effect on bioretention performance in Northeast Ohio

    NASA Astrophysics Data System (ADS)

    Bush, S. A.; Jefferson, A.; Jarden, K.; Kinsman-Costello, L. E.; Grieser, J.

    2014-12-01

    Urban impervious surfaces lead to increases in stormwater runoff. Green infrastructure, like bioretention cells, is being used to mitigate negative impacts of runoff by disconnecting impervious surfaces from storm water systems and redirecting flow to decentralized treatment areas. While bioretention soil characteristics are carefully designed, little research is available on soil moisture dynamics within the cells and how these might relate to inter-storm variability in performance. Bioretentions have been installed along a residential street in Parma, Ohio to determine the impact of green infrastructure on the West Creek watershed, a 36 km2 subwatershed of the Cuyahoga River. Bioretentions were installed in two phases (Phase I in 2013 and Phase II in 2014); design and vegetation density vary slightly between the two phases. Our research focuses on characterizing soil moisture dynamics of multiple bioretentions and assessing their impact on stormwater runoff at the street scale. Soil moisture measurements were collected in transects for eight bioretentions over the course of one summer. Vegetation indices of canopy height, percent vegetative cover, species richness and NDVI were also measured. A flow meter in the storm drain at the end of the street measured storm sewer discharge. Precipitation was recorded from a meteorological station 2 km from the research site. Soil moisture increased in response to precipitation and decreased to relatively stable conditions within 3 days following a rain event. Phase II bioretentions exhibited greater soil moisture and less vegetation than Phase I bioretentions, though the relationship between soil moisture and vegetative cover is inconclusive for bioretentions constructed in the same phase. Data from five storms suggest that pre-event soil moisture does not control the runoff-to-rainfall ratio, which we use as a measure of bioretention performance. However, discharge data indicate that hydrograph characteristics, such as lag

  18. Moisture absorption and bakeout characteristics of rigid-flexible multilayer printed wiring boards

    SciTech Connect

    Lula, J.W.

    1991-01-01

    Moisture absorption and bakeout characteristics of Allied-Signal Inc., Kansas City Division (KCD) rigid-flexible printed wiring boards were determined. It was found that test specimens had absorbed 0.95 weight percent moisture when equilibrated to a 50 percent RH, 25{degree}C environment. Heating those equilibrated specimens in a 120{degree}C static air oven removed 92 percent of this absorbed moisture in 24 h. Heating the samples in a 80{degree}C static air oven removed only 64 percent of the absorbed moisture at the end of 24 h. A 120{degree}C vacuum bake removed moisture at essentially the same rate with parylene slowed the absorption rate by approximately 50 percent but did not appreciably affect the equilibrium moisture content or the drying rate.

  19. Magnetic method for measuring moisture content using diamagnetic characteristics of water

    NASA Astrophysics Data System (ADS)

    Keiji, Tsukada; Yasuaki, Matsunaga; Yuta, Nakamura; Ryota, Isshiki; Kayo, Fujimoto; Kenji, Sakai; Toshihiko, Kiwa

    2017-01-01

    Moisture content measurements of rice kernels and soil are important for agriculture. Therefore, in this study, a new measurement method using the diamagnetic characteristics of water was developed for measurements of the moisture content of rice kernels and soil. The magnetic characteristics of the samples were determined using a magnetometer developed by us based on a superconducting quantum interference device. Because of the diamagnetic characteristics of water, the susceptibility of rice kernels became more negative with increasing moisture content. In the case of soil, which is a mixture of diamagnetic and ferromagnetic materials, a second-harmonic detection method using AC with DC bias magnetic field was applied to reduce the influence of the ferromagnetic signal. The intensity of the second-harmonic signal of a soil was determined to be proportional to its moisture content.

  20. Humidification performance of heat and moisture exchangers for pediatric use.

    PubMed

    Chikata, Yusuke; Sumida, Chihiro; Oto, Jun; Imanaka, Hideaki; Nishimura, Masaji

    2012-01-01

    Background. While heat and moisture exchangers (HMEs) have been increasingly used for humidification during mechanical ventilation, the efficacy of pediatric HMEs has not yet been fully evaluated. Methods. We tested ten pediatric HMEs when mechanically ventilating a model lung at respiratory rates of 20 and 30 breaths/min and pressure control of 10, 15, and 20 cmH(2)O. The expiratory gas passed through a heated humidifier. We created two rates of leakage: 3.2 L/min (small) and 5.1 L/min (large) when pressure was 10 cmH(2)O. We measured absolute humidity (AH) at the Y-piece. Results. Without leakage, eight of ten HMEs maintained AH at more than 30 mg/L. With the small leak, AH decreased below 30 mg/L (26.6 to 29.5 mg/L), decreasing further (19.7 to 27.3 mg/L) with the large leak. Respiratory rate and pressure control level did not affect AH values. Conclusions. Pediatric HMEs provide adequate humidification performance when leakage is absent.

  1. Humidification Performance of Heat and Moisture Exchangers for Pediatric Use

    PubMed Central

    Chikata, Yusuke; Sumida, Chihiro; Oto, Jun; Imanaka, Hideaki; Nishimura, Masaji

    2012-01-01

    Background. While heat and moisture exchangers (HMEs) have been increasingly used for humidification during mechanical ventilation, the efficacy of pediatric HMEs has not yet been fully evaluated. Methods. We tested ten pediatric HMEs when mechanically ventilating a model lung at respiratory rates of 20 and 30 breaths/min and pressure control of 10, 15, and 20 cmH2O. The expiratory gas passed through a heated humidifier. We created two rates of leakage: 3.2 L/min (small) and 5.1 L/min (large) when pressure was 10 cmH2O. We measured absolute humidity (AH) at the Y-piece. Results. Without leakage, eight of ten HMEs maintained AH at more than 30 mg/L. With the small leak, AH decreased below 30 mg/L (26.6 to 29.5 mg/L), decreasing further (19.7 to 27.3 mg/L) with the large leak. Respiratory rate and pressure control level did not affect AH values. Conclusions. Pediatric HMEs provide adequate humidification performance when leakage is absent. PMID:22312483

  2. A comparison of soil moisture characteristics predicted by the Arya-Paris model with laboratory-measured data

    NASA Technical Reports Server (NTRS)

    Arya, L. M.; Richter, J. C.; Davidson, S. A. (Principal Investigator)

    1982-01-01

    Soil moisture characteristics predicted by the Arya-Paris model were compared with the laboratory measured data for 181 New Jersey soil horizons. For a number of soil horizons, the predicted and the measured moisture characteristic curves are almost coincident; for a large number of other horizons, despite some disparity, their shapes are strikingly similar. Uncertainties in the model input and laboratory measurement of the moisture characteristic are indicated, and recommendations for additional experimentation and testing are made.

  3. The Effect of Compaction on Moisture Characteristic Curves of Compactible Soils Measured in a UFAT

    NASA Astrophysics Data System (ADS)

    Baker, K. E.; Poloski, A. P.; Owen, A. T.; Lindenmeier, C. W.; Thompson, D. N.

    2001-12-01

    The objective of this study was to develop and test methods to allow the use of the Unsaturated Flow Apparatus (UFAT) for characterization of hydraulic properties of compactable soils often encountered in vadose zone environments. Use of the UFA in this application is limited by compaction of the soil under the applied centrifugal force. The UFA significantly reduces the time required to reach moisture equilibrium by applying driving forces thousands of times greater than natural driving forces for unsaturated flow through sample cores. However, the centrifugal force will also cause some soils to compress in the instrument, significantly changing the macropore volume distribution and thus the moisture characteristic curve. Moisture characteristic curves of undisturbed soil cores were measured both by traditional methods and in the UFA. Changes in pore volume distributions were estimated using X-ray micro-focus tomography (XMT) both before and after adjustment of the moisture content. Using a mathematical model, compaction of the pores at each UFA rotational speed can be accounted for and an original uncompacted macropore volume distribution can be estimated. This uncompacted macropore volume distribution can then be used to predict the moisture characteristic curve of the original soil, greatly shortening the time necessary to complete these measurements.

  4. Evaluation residual moisture in lithium-ion battery electrodes and its effect on electrode performance

    DOE PAGES

    Li, Jianlin; Daniel, Claus; Wood, III, David L.; ...

    2016-01-11

    Removing residual moisture in lithium-ion battery electrodes is essential for desired electrochemical performance. In this manuscript, the residual moisture in LiNi0.5Mn0.3Co0.2O2 cathodes produced by conventional solvent-based and aqueous processing is characterized and compared. The electrochemical performance has also been investigated for various residual moisture contents. As a result, it has been demonstrated that the residual moisture lowers the first cycle coulombic efficiency, but its effect on short term cycle life is insignificant.

  5. Evaluation residual moisture in lithium-ion battery electrodes and its effect on electrode performance

    SciTech Connect

    Li, Jianlin; Daniel, Claus; Wood, III, David L.; An, Seong Jin

    2016-01-11

    Removing residual moisture in lithium-ion battery electrodes is essential for desired electrochemical performance. In this manuscript, the residual moisture in LiNi0.5Mn0.3Co0.2O2 cathodes produced by conventional solvent-based and aqueous processing is characterized and compared. The electrochemical performance has also been investigated for various residual moisture contents. As a result, it has been demonstrated that the residual moisture lowers the first cycle coulombic efficiency, but its effect on short term cycle life is insignificant.

  6. High Energy Moisture Characteristics: Linking Between Soil Physical Processes and Structure Stability

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Water storage and flow in soils is usually complicated by the intricate nature of and changes in soil pore size distribution (PSD) due to modifications in soil structure following changes in agricultural management. The paper presents the Soil High Energy Moisture Characteristic (Soil-HEMC) method f...

  7. Moisture removal characteristics of thin layer rough rice under sequenced infrared radiation heating and cooling

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rice drying with infrared (IR) radiation has been investigated during recent years and showed promising potential with improved quality and energy efficiency. The objective of this study was to further investigate the moisture removal characteristics of thin layer rough rice heated by IR and cooled ...

  8. Moisture characteristics of water-repellent consolidants and their applicability to existing buildings

    NASA Astrophysics Data System (ADS)

    Iba, Chiemi; Fukui, Kazuma; Hokoi, Shuichi

    2016-07-01

    Water-repellent agents are considered an effective measure of preventing moisture damage in building materials. However, data on the moisture transfer characteristics of repellent materials are insufficient. This study focused on the transfer of liquid water in a porous building material and quantitatively evaluated the applicability of a water-repellent consolidant as a protection agent via water infiltration experiments and numerical analysis. The experimental results could be reproduced by treating the water-repellent consolidant as having two layers with different water conductivities.

  9. Use of a submersible pressure outflow cell for determination of moisture characteristic curves on rock core

    SciTech Connect

    Flint, L.E.; Flint, A.L.

    1993-06-01

    A simple device for developing moisture characteristic data curves, the submersible pressure outflow cell, was modified for application to rock core at matric potentials of 0 to -0.5 megapascals (MPa) and possibly to -1.0 Mpa. An automated system was developed to continuously and simultaneously collect data from many cells, obtain sorption and desorption characteristic curves to provide hysteretic information, and data from multi-step outflow experiments. The latter can be used to estimate unsaturated hydraulic conductivity. The system has resolved many of the problems inherent in standard measurement techniques. Model simulation of imbibition using the hysteretic data collected are in close agreement with laboratory measurements of imbibition, data collected are in close agreement with laboratory measurements of imbibition, suggesting the moisture characteristic data correctly describes the core properties.19 refs., 4 figs.

  10. Moisture content behaviour in extensive green roofs during dry periods: The influence of vegetation and substrate characteristics

    NASA Astrophysics Data System (ADS)

    Berretta, Christian; Poë, Simon; Stovin, Virginia

    2014-04-01

    Evapotranspiration (ET) is a key parameter that influences the stormwater retention capacity, and thus the hydrological performance, of green roofs. This paper investigates how the moisture content in extensive green roofs varies during dry periods due to evapotranspiration. The study is supported by 29 months continuous field monitoring of the moisture content within four green roof test beds. The beds incorporated three different substrates, with three being vegetated with sedum and one left unvegetated. Water content reflectometers were located at three different soil depths to measure the soil moisture profile and to record temporal changes in moisture content at a five-minute resolution. The moisture content vertical profiles varied consistently, with slightly elevated moisture content levels being recorded at the deepest substrate layer in the vegetated systems. Daily moisture loss rates were influenced by both temperature and moisture content, with reduced moisture loss/evapotranspiration when the soil moisture was restricted. The presence of vegetation resulted in higher daily moisture loss. Finally, it is demonstrated that the observed moisture content data can be accurately simulated using a hydrologic model based on water balance and two conventional Potential ET models (Hargreaves and FAO56 Penman-Monteith) combined with a soil moisture extraction function. Configuration-specific correction factors have been proposed to account for differences between green roof systems and standard reference crops.

  11. [Variation characteristics of soil moisture in apple orchards of Luochuan County, Shaanxi Province of Northwest China].

    PubMed

    Wang, Yan-Ping; Han, Ming-Yu; Zhang, Lin-Sen; Dang, Yong-Jian; Qu, Jun-Tao

    2012-03-01

    To have an overall understanding on the soil moisture characteristics in the apple orchards of Luochuan County can not only provide theoretical basis for selecting apple orchard sites, choosing the best root-stock combination, and improving the soil water management, but also has reference importance in increasing the productive efficiency of our apple orchards. In this study, a fixed-point continuous monitoring was conducted on the overall soil moisture environment and the variation characteristics of soil moisture in the County apple orchards differed in age class, stand type, and tree type (standard or dwarfed). For the apple orchards in the County, the rhizosphere (0-200 cm) soils of most apple trees were water-deficient, and the deficit in 0-60 cm soil layer was less than that in 60-200 cm layer. During growth season, the water storage in 0-60 cm soil layer had the same variation trend as the rainfall pattern. The relative soil moisture content in most orchards was less than 60% , and seasonal drought was quite severe. The coefficient of variation of soil moisture content decreased with soil depth. With the increasing age of the orchards, soil water storage decreased. At the same planting density, the orchards with dwarfed trees had more water storage in 0-5 m soil layer than the orchards with standard trees. However, when the orchards were planted with dwarfed trees at a higher density, the soil water storage in the orchards with dwarfed trees was lesser than that in the standard orchards. The mature orchards on highland had the highest soil moisture content, followed by the mature orchards on flat land, and on terraced land. Tree density had great effects on the soil moisture content. When the tree density was the same, planting dwarfed trees could decrease the water consumption, and increase the soil moisture content significantly. To decrease the planting density through the removal of trees would be an effective way to maintain the soil water balance of

  12. Detection of soil moisture and snow characteristics from Skylab. [Texas and Kansas

    NASA Technical Reports Server (NTRS)

    Eagleman, J. R. (Principal Investigator); Lin, W. C.; Hardy, N.; Sloan, R.; Parashar, S. K.; Perry, C.; League, L.; Engling, M.; Pogge, E. C.; Moore, R. K.

    1975-01-01

    The author has identified the following significant results. The most significant result is the good response of the passive radiometers, particularly the L-band radiometer, to changing soil moisture conditions near the surface of the earth. Radiometer response was very good for the five complete data sets consisting of three passes across Texas and two passes across Kansas. When data from the five different passes were combined, the correlation between the S194 radiometric temperature and soil moisture content remained high with a value of -0.96. The performance of the S193 passive radiometer was less consistent; however, one data set gave a very high correlation of -0.95. The scatterometer response to soil moisture at incidence angles near 30 deg was not as good as for the radiometers.

  13. [Soil moisture characteristics of apple-planting subarea in Weibei dry highland, Shaanxi Province].

    PubMed

    Liu, Xianzhao; Yi, Huapeng; Li, Shitai

    2004-11-01

    Based on the data of regional scale and located field measurement, this paper investigated the soil moisture characteristics of the apple-planting subarea in Weibei dry highland, Shanxi Province. The results showed that the soil moisture characteristics in this subarea were affected by precipitation and evapotranspiration. At regional scale, the apple-land evapotranspiration in east Weibei area was the largest, and that in tableland gully and in west Weibei area was the medium and the smallest, respectively. Soil water deficit phenomenon was observed in three type areas. In east Weibei area, the mean water deficit amount was about 390.9 mm, the maximum was 674.6 mm, and the minimum value was 186.3 mm. In tableland gully area, the average and maximum values were 264.4 and 441.2 mm, respectively, and sometimes water surplus occurred. As a whole, soil moisture in west Weibei area was deficit, but the phenomena of water surplus were more prevalent than those in tableland gully area, and the maximum value was 151.8 mm. Soil moisture storage amount existed spatial and temporal variations in 3 different areas. The value of 2 m profile in apple growth season in west Weibei area was the largest, and that in Weibei tableland gully area and in Weibei east area was the medium and the smallest, respectively. The characteristics of soil moisture storage depended mainly on precipitation and its spatial-temporal distribution, as well as its consumed amount by apple trees. Water consumption in east Weibei area was the largest, the second was in gully area, and that in west Weibei area was the smallest. During apple growth season, the water consumption in dry year was less than that in wet year. In dry year, except for available precipitation, a considerable part of water used by apple trees came from deep (exceeded 3 m) soil moisture storage, which resulted in a dried soil layer and would affected the sustainable development of fruit production.

  14. Building characteristics associated with moisture related problems in 8,918 Swedish dwellings.

    PubMed

    Hägerhed-Engman, Linda; Bornehag, Carl-Gustaf; Sundell, Jan

    2009-08-01

    Moisture problems in buildings have in a number of studies been shown to increase the risk for respiratory symptoms. The study Dampness in Buildings and Health (DBH) was initiated with the aim to identify health relevant exposures related to dampness in buildings. A questionnaire study about home environment with a focus on dampness problems and health was conducted in one county of Sweden (8,918 homes, response rate 79%). Building characteristics that were associated with one or more of the dampness indicators were for single-family houses, older houses, flat-roofed houses built in the 1960s and 1970s, houses with a concrete slab on the ground that were built before 1983. Moreover, tenancy and earlier renovation due to mould or moisture problems was strongly associated with dampness. A perception of dry air was associated with window-pane condensation, e.g. humid indoor air.

  15. Multi-scale characteristics of moisture transport during a rainstorm process in North China

    NASA Astrophysics Data System (ADS)

    Wang, Chengxin; Gao, Shouting; Liang, Li; Deng, Difei; Gong, Hainan

    2014-08-01

    A rainstorm process that occurred in North China from July 24-25, 2011 was accurately simulated using the Weather Research and Forecasting model, and the multi-scale characteristics of moisture transport were studied based on the simulated results. The results indicated that water vapor was carried to North China mainly by the southwest low-level jet and easterly flow, with the former playing a principal role. The enhancement and northward extension of the southwesterly wind were consistent with the increase of magnitude and northward propulsion of the moisture flux. The variation of the winds mirrored fluctuations in the amount of precipitation. In addition, the water vapor from low latitudes to North China was transported first near the boundary layer over 15°N-21°N and then primarily at 850 hPa over 21°N-30°N, 900 hPa over 30°N-39°N, and 800 hPa over the region north of 39°N. The net budget of water vapor in North China was always positive during the rainstorm process because the zonal deficit was much smaller than the meridional surplus. The contribution of the water vapor advection was larger than that of the water vapor convergence in the prior period of rainfall, and the subsequent moisture aggregation relied on the water vapor convergence. The rainband in North China presented frontal mesoscale characteristics, and the short-term aggregation of moisture was closely related to the genesis and development of the mesoscale convective system that was triggered mainly by the cold air intrusion near the boundary layer. The underlying cold air not only lifted the warm air to trigger the convection, but it also influenced the development of the low pressure system in the lower levels, which further intensified the convergence and benefited the rapid accumulation of moisture to the convective zone near the boundary layer. The moisture transport reached its maximum an hour before the rainstorm occurred.

  16. Footprint Characteristics of Cosmic-Ray Neutron Sensors for Soil Moisture Monitoring

    NASA Astrophysics Data System (ADS)

    Schrön, Martin; Köhli, Markus; Zreda, Marek; Dietrich, Peter; Zacharias, Steffen

    2015-04-01

    Cosmic-ray neutron sensing is a unique and an increasingly accepted method to monitor the effective soil water content at the field scale. The technology is famous for its low maintenance, non-invasiveness, continuous measurement, and most importantly, for its large footprint. Being more representative than point data and finer resolved than remote-sensing products, cosmic-ray neutron derived soil moisture products provide unrivaled advantage for mesoscale hydrologic and land surface models. The method takes advantage of neutrons induced by cosmic radiation which are extraordinarily sensitive to hydrogen and behave like a hot gas. Information about nearby water sources are quickly mixed in a domain of tens of hectares in air. Since experimental determination of the actual spatial extent is hardly possible, scientists have applied numerical models to address the footprint characteristics. We have revisited previous neutron transport simulations and present a modified conceptual design and refined physical assumptions. Our revised study reveals new insights into probing distance and water sensitivity of detected neutrons under various environmental conditions. These results sharpen the range of interpretation concerning the spatial extent of integral soil moisture products derived from cosmic-ray neutron counts. Our findings will have important impact on calibration strategies, on scales for data assimilation and on the interpolation of soil moisture data derived from mobile cosmic-ray neutron surveys.

  17. Footprint Characteristics of Cosmic-Ray Neutron Sensing for Soil Moisture Monitoring

    NASA Astrophysics Data System (ADS)

    Schrön, M.; Köhli, M.; Zreda, M. G.; Dietrich, P.; Zacharias, S.

    2014-12-01

    Cosmic-ray neutron sensing has become an increasingly accepted and unique method to monitor the effective soil water content at the field scale. The technology is famous for its low maintenance, non-invasiveness, continuous measurement, and most importantly, for its large footprint. Being more representative than point data and finer resolved than remote-sensing products, cosmic-ray neutron derived soil moisture products provide unrivaled advantage for mesoscale hydrologic and land surface models. The method takes advantage of neutrons induced by cosmic radiation which are extraordinarily sensitive to hydrogen and behave like a hot gas. Information about nearby water sources quickly mixes a domain of tens of hectares in air. Since experimental determination of the actual spatial extent is hardly possible, scientists have applied numerical models to address the footprint characteristics. We have revisited previous neutron transport simulations and present a modified conceptual design and refined physical assumptions. Our revised study reveals new insights to energy spectra, probing distance and water sensitivity of detected neutrons under various environmental conditions. These results sharpen the range of interpretation concerning the spatial extent of integral soil moisture products derived from cosmic-ray neutron counts. Our findings will have important impact calibration strategies, on scales for data assimilation and on the interpolation of soil moisture data derived from mobile cosmic-ray neutron surveys.

  18. Moisture and Structural Analysis for High Performance Hybrid Wall Assemblies

    SciTech Connect

    Grin, A.; Lstiburek, J.

    2012-09-01

    This report describes the work conducted by the Building Science Corporation (BSC) Building America Research Team's 'Energy Efficient Housing Research Partnerships' project. Based on past experience in the Building America program, they have found that combinations of materials and approaches---in other words, systems--usually provide optimum performance. No single manufacturer typically provides all of the components for an assembly, nor has the specific understanding of all the individual components necessary for optimum performance.

  19. Estimation of hectare-scale soil-moisture characteristics from aquifer-test data

    USGS Publications Warehouse

    Moench, A.F.

    2003-01-01

    Analysis of a 72-h, constant-rate aquifer test conducted in a coarse-grained and highly permeable, glacial outwash deposit on Cape Cod, Massachusetts revealed that drawdowns measured in 20 piezometers located at various depths below the water table and distances from the pumped well were significantly influenced by effects of drainage from the vadose zone. The influence was greatest in piezometers located close to the water table and diminished with increasing depth. The influence of the vadose zone was evident from a gap, in the intermediate-time zone, between measured drawdowns and drawdowns computed under the assumption that drainage from the vadose zone occurred instantaneously in response to a decline in the elevation of the water table. By means of an analytical model that was designed to account for time-varying drainage, simulated drawdowns could be closely fitted to measured drawdowns regardless of the piezometer locations. Because of the exceptional quality and quantity of the data and the relatively small aquifer heterogeneity, it was possible by inverse modeling to estimate all relevant aquifer parameters and a set of three empirical constants used in the upper-boundary condition to account for the dynamic drainage process. The empirical constants were used to define a one-dimensional (ID) drainage versus time curve that is assumed to be representative of the bulk material overlying the water table. The curve was inverted with a parameter estimation algorithm and a ID numerical model for variably saturated flow to obtain soil-moisture retention curves and unsaturated hydraulic conductivity relationships defined by the Brooks and Corey equations. Direct analysis of the aquifer-test data using a parameter estimation algorithm and a two-dimensional, axisymmetric numerical model for variably saturated flow yielded similar soil-moisture characteristics. Results suggest that hectare-scale soil-moisture characteristics are different from core-scale predictions

  20. Moisture absorption characteristics of the Orbiter thermal protection system and methods used to prevent water ingestion

    NASA Technical Reports Server (NTRS)

    Schomburg, C.; Dotts, R. L.; Tillian, D. J.

    1983-01-01

    The Space Shuttle Orbiter's silica tile Thermal Protection System (TPS) is beset by the moisture absorption problems inherently associated with low density, highly porous insulation systems. Attention is presently given to the comparative success of methods for the minimization and/or prevention of water ingestion by the TPS tiles, covering the development of water-repellent agents and their tile application techniques, flight test program results, and materials improvements. The use of external films for rewaterproofing of the TPS tiles after each mission have demonstrated marginal to unacceptable performance. By contrast, a tile interior waterproofing agent has shown promise.

  1. Baking Performance of Phosphorylated Cross-Linked Resistant Starch in Low-Moisture Bakery Goods

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Phosphorylated cross-linked resistant starch (RS) is a type 4 RS, which can be used for enhancing the benefits of dietary fiber. The baking performance of the RS was explored using wire-cut cookie baking and benchtop chemically-leavened cracker baking methods to produce low-moisture baked goods (coo...

  2. [Effects of soil moisture content and light intensity on the plant growth and leaf physiological characteristics of squash].

    PubMed

    Du, She-ni; Bai, Gang-shuan; Liang, Yin-li

    2011-04-01

    A pot experiment with artificial shading was conducted to study the effects of soil moisture content and light intensity on the plant growth and leaf physiological characteristics of squash variety "Jingyingyihao". Under all test soil moisture conditions, 30% shading promoted the growth of "Jingyingyihao", with the highest yield at 70% - 80% soil relative moisture contents. 70% shading inhibited plant growth severely, only flowering and not bearing fruits, no economic yield produced. In all treatments, there was a similar water consumption trend, i. e., both the daily and the total water consumption decreased with increasing shading and decreasing soil moisture content. Among all treatments, 30% shading and 70% - 80% soil relative moisture contents had the highest water use efficiency (2.36 kg mm(-1) hm(-2)) and water output rate (1.57 kg mm(-1) hm(-2)). The net photosynthetic rate, transpiration rate, stomatal conductance, and chlorophyll content of squash leaves decreased with increasing shading, whereas the intercellular CO2 concentration was in adverse. The leaf protective enzyme activity and proline content decreased with increasing shading, and the leaf MAD content decreased in the order of 70% shading, natural radiation, and 30% shading. Under the three light intensities, the change characteristics of squash leaf photosynthesis, protective enzyme activity, and proline and MAD contents differed with the increase of soil relative moisture content.

  3. The effects of surface wettability on the fog and dew moisture harvesting performance on tubular surfaces

    PubMed Central

    Seo, Donghyun; Lee, Junghun; Lee, Choongyeop; Nam, Youngsuk

    2016-01-01

    The efficient water harvesting from air-laden moisture has been a subject of great interest to address world-wide water shortage issues. Recently, it has been shown that tailoring surface wettability can enhance the moisture harvesting performance. However, depending on the harvesting condition, a different conclusion has often been reported and it remains unclear what type of surface wettability would be desirable for the efficient water harvesting under the given condition. Here we compare the water harvesting performance of the surfaces with various wettability under two different harvesting conditions–dewing and fogging, and show that the different harvesting efficiency of each surface under these two conditions can be understood by considering the relative importance of the water capturing and removal efficiency of the surface. At fogging, the moisture harvesting performance is determined by the water removal efficiency of the surface with the oil-infused surfaces exhibiting the best performance. Meanwhile, at dewing, both the water capturing and removal efficiency are crucial to the harvesting performance. And well-wetting surfaces with a lower barrier to nucleation of condensates exhibit a better harvesting performance due to the increasing importance of the water capture efficiency over the water removal efficiency at dewing. PMID:27063149

  4. The effects of surface wettability on the fog and dew moisture harvesting performance on tubular surfaces.

    PubMed

    Seo, Donghyun; Lee, Junghun; Lee, Choongyeop; Nam, Youngsuk

    2016-04-11

    The efficient water harvesting from air-laden moisture has been a subject of great interest to address world-wide water shortage issues. Recently, it has been shown that tailoring surface wettability can enhance the moisture harvesting performance. However, depending on the harvesting condition, a different conclusion has often been reported and it remains unclear what type of surface wettability would be desirable for the efficient water harvesting under the given condition. Here we compare the water harvesting performance of the surfaces with various wettability under two different harvesting conditions-dewing and fogging, and show that the different harvesting efficiency of each surface under these two conditions can be understood by considering the relative importance of the water capturing and removal efficiency of the surface. At fogging, the moisture harvesting performance is determined by the water removal efficiency of the surface with the oil-infused surfaces exhibiting the best performance. Meanwhile, at dewing, both the water capturing and removal efficiency are crucial to the harvesting performance. And well-wetting surfaces with a lower barrier to nucleation of condensates exhibit a better harvesting performance due to the increasing importance of the water capture efficiency over the water removal efficiency at dewing.

  5. The effects of surface wettability on the fog and dew moisture harvesting performance on tubular surfaces

    NASA Astrophysics Data System (ADS)

    Seo, Donghyun; Lee, Junghun; Lee, Choongyeop; Nam, Youngsuk

    2016-04-01

    The efficient water harvesting from air-laden moisture has been a subject of great interest to address world-wide water shortage issues. Recently, it has been shown that tailoring surface wettability can enhance the moisture harvesting performance. However, depending on the harvesting condition, a different conclusion has often been reported and it remains unclear what type of surface wettability would be desirable for the efficient water harvesting under the given condition. Here we compare the water harvesting performance of the surfaces with various wettability under two different harvesting conditions–dewing and fogging, and show that the different harvesting efficiency of each surface under these two conditions can be understood by considering the relative importance of the water capturing and removal efficiency of the surface. At fogging, the moisture harvesting performance is determined by the water removal efficiency of the surface with the oil-infused surfaces exhibiting the best performance. Meanwhile, at dewing, both the water capturing and removal efficiency are crucial to the harvesting performance. And well-wetting surfaces with a lower barrier to nucleation of condensates exhibit a better harvesting performance due to the increasing importance of the water capture efficiency over the water removal efficiency at dewing.

  6. Assessment of Soil Moisture and Fixatives Performance in Controlling Wind Erosion of Contaminated Soil at the Hanford Site

    SciTech Connect

    Lagos, L.E.; Gudavalli, R.K.

    2008-07-01

    During the remediation of burial grounds at the US Department of Energy's (DOE's) Hanford Site in Washington State, the dispersion of contaminated soil particles and dust is an issue that is faced by site workers on a daily basis. This contamination issue is even more of a concern when one takes into account the semi-arid characteristics of the region where the site is located. To mitigate this problem, workers at the site use a variety of engineered methods to minimize the dispersion of contaminated soil and dust particles. Once such methods is the use of water and/or suppression agents (fixatives) that stabilizes the soil prior to soil excavation, segregation, and removal activities. A primary contributor to the dispersion of contaminated soil and dust is wind soil erosion. The erosion process occurs when the wind speed exceeds a certain threshold value (threshold shear velocity), which depends on a number of factors including wind force loading, particle size, surface soil moisture, and the geometry of the soil. Thus under these circumstances the mobility of contaminated soil and generation and dispersion of particulate matter are significantly influenced by these parameters. Wind tunnel experiments were conducted at the Florida International University's Applied Research Center (FIU-ARC) to evaluate the effectiveness of three commercially available fixatives in controlling the mobility of soil particles on soil mounds when exposed to varying wind forces. The fixatives tested included: (1) a calcium chloride solution; (2) a petroleum hydrocarbon emulsion; and 3) a synthetic organic. As an initial step, approximately 500 lbs of uncontaminated soil was obtained from the Hanford Reservation in Washington State. Soil samples were placed in an open-loop, low speed wind tunnel and exposed to wind forces ranging from 10 to 30 miles per hour (mph). Wind erosion controlling capabilities of commercially available fixatives and soil moisture were tested at a laboratory

  7. Evaluating the Performance of a Soil Moisture Data Assimilation System for Agricultural Drought Monitoring

    NASA Astrophysics Data System (ADS)

    Han, E.; Crow, W. T.; Holmes, T. R.; Bolten, J. D.

    2013-12-01

    Despite considerable interest in the application of land surface data assimilation systems (LDAS) for agricultural drought applications, relatively little is known about the large-scale performance of such systems and, thus, the optimal methodological approach for implementing them. To address this need, we evaluates a soil moisture assimilation system for agricultural drought monitoring by benchmarking each component of the system (i.e., a satellite soil moisture retrieval algorithm, a soil water balance model and a sequential data assimilation filter) against a series of linear models which perform the same function (i.e., have the same basic inputs/output) as the full component. Lagged soil moisture/NDVI correlations obtained using individual LDAS components versus their linear analogs reveal the degree to which non-linearities and/or complexities contained within each component actually contribute to the performance of the LDAS system as a whole. Here, a particular system based on surface soil moisture retrievals from the Land Parameter Retrieval Model (LPRM), a two-layer Palmer soil water balance model and an Ensemble Kalman filter (EnKF) is benchmarked. Results suggest significant room for improvement in each component of the system. First, the non-linear LPRM retrieval algorithm does not appear to add much additional predictive information for future NDVI compared to the simple linear benchmark model comprised of initial AMSR-E observations (horizontally and vertically polarized brightness temperatures and surface temperature). Second, the Palmer model performed worse than the purely linear prognostic model (Antecedent Precipitation Index model) in predicting future vegetation condition. This result points out that the saturation threshold of soil layers in the modern LSMs for runoff generation hinders maximum utilization of meteorological input information for agricultural drought monitoring. As to the assimilation algorithm, better performance of the

  8. High-Performance Bio-Based Cyanate Esters with Low Moisture Uptake

    DTIC Science & Technology

    2012-04-01

    Uptake 5a. CONTRACT NUMBER In-House 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT NUMBER Andrew Guenthner , Matthew...release, distribution is unlimited. HIGH-PERFORMANCE BIO-BASED CYANATE ESTER RESINS WITH LOW MOISTURE UPTAKE Andrew J. Guenthner ,1 Matthew C. Davis,2...275. 2. Illicium, pimpinella, and foeniculum. Jodral, M. M., Ed.; CRC Press: Washington, DC, 2004. 3. Guenthner , A. J.; Lamison, K. R.; Vij, V

  9. Investigating the impact of limited irrigation practices on soil moisture variability and vineyard performance, Boise, Idaho

    NASA Astrophysics Data System (ADS)

    Duffin, J.; Wilkins, D. E.; Guenther, J.

    2012-12-01

    In semiarid regions, the changing climate may affect the timing and form of precipitation. This could result in increased water stress for agricultural production as available surface water for irrigation diminishes. To prepare for these changing conditions the possibility of limited-irrigation agriculture as an alternative to heavily-irrigated production is being investigated. This study specifically investigates the ability to grow productive wine grapes with different levels of limited irrigation in the Boise Front foothills at the West Foothills TIC Vineyard, located in a climate zone receiving less than 300 mm of annual precipitation over two growing seasons (2011-2012). The vineyard is divided into three test plots on a northwest facing-slope. Soil texture analyses show that soils are homogenous across all three plots. Traditional vineyard performance factors, such as planting densities, soil type, rootstock, and climate, are standardized and serve as constants in this study. Thus, the limiting factor for vine performance is the difference in irrigation on each plot. Water delivery through drip emitters varies in each of the three vineyard test plots from 2 gallons per week to 0.75 gallons per week. Soil moisture is monitored at depths of 0.25 meters and 0.50 meters in two pits in each of the test plots, collecting data in 2011 and 2012, and in a third pit added to each plot in 2012 at upper elevations. The paired upper elevation sensors record the natural soil moisture and the irrigated soil moisture in each irrigation scheme. Soil moisture for each plot, compared to the annual mortality and growth rates of the vines, will suggest a minimum irrigation level needed for limited irrigation farming and highlight other factors that may affect vine performance in this location.

  10. Characteristics of soil moisture in relation to microtopography in the Loess region of Northern Shaanxi, China.

    PubMed

    Bo, Yaojun; Zhu, Qingke; Zhao, Weijun

    2014-07-01

    Soil moisture is the primary factor limiting plant growth and vegetation rehabilitation in the loess region of northern Shaanxi, China. This 5-year (2008-2012) study investigated methods of selecting appropriate microsites for vegetation restoration based on efficient use of soil moisture; 5-year data were compared with 56 years of precipitation data using standardized precipitation index. In addition, the effects of microtopography on the spatiotemporal variations of soil moisture were analyzed at the Wuqi Ecological Station of Beijing Forestry University. Results showed that average annual precipitation during last 5 years fell by 12.4% during the growing season compared with 1957-2012 data and soil moisture content at depth of 0-160 cm under went dramatic changes and became relatively low in July and August. Soil moisture content varied in different microtopographical units as follows: gullies > gently-sloped terraces > collapsed soils > undisturbed slopes (control) > furrows > escarpments. The vertical distribution of soil moisture content in different microtopographical units showed dramatic changes at depth of 0-40 cm. Soil moisture content of gently-sloped terraces, gullies, collapsed areas, furrows, and undisturbed slopes was highest at depth of 80-160 cm with a level of instability at depth of 40-80 cm. For gently-sloped terraces and gullies, soil moisture content followed the order of 40-80 cm > 0-40 cm; for collapsed areas, furrows, and undisturbed slopes, soil moisture content follows the order of 0-40 cm > 40-80 cm. For escarpments, soil moisture content varied with depth in a different pattern: 0-40 cm > 80-160 cm > 40-80 cm. This study is of theoretical significance and will help guide the sustainable development of ecological restoration and vegetation rehabilitation in the Loess region.

  11. Synergistic proinflammatory interactions of microbial toxins and structural components characteristic to moisture-damaged buildings.

    PubMed

    Korkalainen, M; Täubel, M; Naarala, J; Kirjavainen, P; Koistinen, A; Hyvärinen, A; Komulainen, H; Viluksela, M

    2017-01-01

    Indoor exposure to microbes and their structural and metabolic compounds is notoriously complex. To study proinflammatory interactions between the multiple microbial agents, macrophages derived from human THP-1 monocytic cells were exposed to several concentrations of microbial toxins alone (emodin, enniatin B, physcion, sterigmatocystin, valinomycin) and in combination with microbial structural components (bacterial lipopolysaccharide [LPS] or fungal β-glucan). While the expression of proinflammatory cytokines TNFα and IL-1β to single toxins alone was modest, low-dose co-exposure with structural components increased the responses of emodin, enniatin B, and valinomycin synergistically, both at the mRNA and protein level, as measured by RT-qPCR and ELISA, respectively. Co-exposure of toxins and β-glucan resulted in consistent synergistically increased expression of several inflammation-related genes, while some of the responses with LPS were also inhibitory. Co-exposure of toxins with either β-glucan or LPS induced also mitochondrial damage and autophagocytosis. The results demonstrate that microbial toxins together with bacterial and fungal structural components characteristic to moisture-damaged buildings can have drastic synergistic proinflammatory interactions at low exposure levels.

  12. Effects of beet pulp supplementation on growth performance, fecal moisture, serum hormones and litter performance in lactating sows.

    PubMed

    Zhao, Pinyao; Zhang, Zhengfan; Kim, In Ho

    2015-06-01

    This study was conducted to evaluate effects of beet pulp supplementation on growth performance, fecal moisture, serum hormones and litter performance in lactating sows. Ninety primiparous sows (Landrace × Yorkshire) were randomly allotted to one of three dietary treatments in a 21-day trial starting 3 days before parturition. The three dietary treatments were supplemented with 0, 10 and 20% beet pulp, respectively. Backfat loss and fecal moisture content were increased (P < 0.05), where cortisol and norepinephrine levels were decreased (P < 0.05) in sows fed beet pulp supplementation diets compared with control diet, but there was no difference between 10% and 20% beet pulp supplementation treatments. No effect was observed on bodyweight, average daily intake, weaning to estrus interval, epinephrine level in sows and litter weight, litter size, survivability in piglets among dietary treatments. Taken together, beet pulp supplementation has no significant effect of growth performance of lactating sows and piglets with decreased cortisol and norepinephrine levels in lactating sows, but it can increase fecal moisture content which is beneficial for sow feces excretion.

  13. [Soil moisture characteristics at the boundary of forestland-grassland in hilly area of Loess Plateau].

    PubMed

    You, Wenzhong; Zeng, Dehui; Liu, Mingguo; Song, Xide

    2006-06-01

    In this paper, the spatial distribution pattern of soil moisture at the boundary of forestland-grassland in hilly area of Loess Plateau was studied in dry season of June and rainy season of August 2004. The results showed that the variance coefficient of soil moisture content was smaller, and the difference of moisture content between soil layers was less significant in forestland than in grassland in June while reversed in August. There was a weak or medium differentiation of moisture content in different soil layers at the boundary of forestland-grassland. The edge effect area at the boundary was from 2 m (0. 4 of tree height) outside forestland to 2 m inside forestland in June, and from 2 m outside forestland to 4 m (0. 8 of tree height) inside forestland in August. The forestland-grassland landscape could be divided into 3 parts, i.e., grassland area, forest edge area, and forestland area, and the vertical distribution of soil moisture in these three parts showed different traits. In June, soil moisture content increased with increasing soil depth, with a smaller increment in grassland than in forestland, but in August, it was reversed. The vertical distribution of soil moisture at forest edge area showed an in-between feature.

  14. Moisture performance of sealed attics in the mixed-humid climate

    SciTech Connect

    Boudreaux, Philip R.; Pallin, Simon B.; Jackson, Roderick K.

    2013-12-01

    Oak Ridge National Laboratory studied 8 homes in the mixed-humid climate, 4 with vented attics and 4 with sealed attics. ORNL wanted to understand the moisture performance of the sealed attic and how it affected the interior environment. We found that the attic and interior of sealed attic homes were more humid than the attic and interior observed in vented attic homes. This is due to the lack of ventilation in the sealed attic. Historically attics have been vented to dehumidify the attic and interior of the home. A sealed attic design greatly reduces the venting potential and thus this drying pathway and can cause elevated interior moisture over a vented attic home. Despite the elevated attic and interior moisture in the sealed attic homes, so far no mold or material degradation has been found. The roof sheathing moisture content has stayed below 20%, indicating low potential for material degradation. Also the relative humidity at the roof sheathing has stayed within the ASHRAE 160 design criteria except for a short time during the 2011/2012 winter. This was due to a combination of the sealed attic design (minimal venting to the outside) and the duct work not being operated in the attic which usually provides a dehumidification pathway. It was also found that when the humidity was controlled using the HVAC system, it resulted in 7% more cooling energy consumption. In the mixed-humid climate this reduces the cost effectiveness of the sealed attic design as a solution for bringing ducts into a semi-conditioned space. Because of this we are recommending the other alternatives be used to bringing ducts into the conditioned space in both new construction and retrofit work in the mixed-humid climate.

  15. F-5-L Boat Seaplane : performance characteristics

    NASA Technical Reports Server (NTRS)

    Diehl, W S

    1922-01-01

    Performance characteristics for the F-5-L Boat Seaplane are given. Characteristic curves for the RAF-6 airfoil and the F-5-L wings, parasite resistance and velocity data, engine and propeller characteristics, effective and maximum horsepower, and cruising performance are discussed.

  16. An investigation of chemically-induced improvement in saturation moisture characteristics of epoxies

    NASA Technical Reports Server (NTRS)

    Singh, J. J.; St.clair, T. L.; Stoakley, D. M.

    1984-01-01

    MY-720/DDS epoxy samples were treated with three selected chemical compounds to render the active H-sites inactive for moisture absorption. Treating the epoxy castings with acetyl chloride and dichlorodimethyl silane leads only to surface changes indicating that these molecules are too large to penetrate the epoxy castings. Boron trifluoride, on the other hand, does penetrate the epoxy chain as is indicated by the formation of green domains in the interior of the castings. However, the process of saturating the specimens with moisture appears to leach out the chemical additives--thereby nullifying their possible ameliorative effects.

  17. Characteristics and controls of variability in soil moisture and groundwater in a headwater catchment

    NASA Astrophysics Data System (ADS)

    McMillan, H. K.; Srinivasan, M. S.

    2015-04-01

    Hydrological processes, including runoff generation, depend on the distribution of water in a catchment, which varies in space and time. This paper presents experimental results from a headwater research catchment in New Zealand, where we made distributed measurements of streamflow, soil moisture and groundwater levels, sampling across a range of aspects, hillslope positions, distances from stream and depths. Our aim was to assess the controls, types and implications of spatial and temporal variability in soil moisture and groundwater tables. We found that temporal variability in soil moisture and water table is strongly controlled by the seasonal cycle in potential evapotranspiration, for both the mean and extremes of their distributions. Groundwater is a larger water storage component than soil moisture, and this general difference increases even more with increasing catchment wetness. The spatial standard deviation of both soil moisture and groundwater is larger in winter than in summer. It peaks during rainfall events due to partial saturation of the catchment, and also rises in spring as different locations dry out at different rates. The most important controls on spatial variability in storage are aspect and distance from the stream. South-facing and near-stream locations have higher water tables and showed soil moisture responses for more events. Typical hydrological models do not explicitly account for aspect, but our results suggest that it is an important factor in hillslope runoff generation. Co-measurement of soil moisture and water table level allowed us to identify relationships between the two. Locations where water tables peaked closer to the surface had consistently wetter soils and higher water tables. These wetter sites were the same across seasons. However, patterns of strong soil moisture responses to summer storms did not correspond to the wetter sites. Total catchment spatial variability is composed of multiple variability sources, and the

  18. Seasonal characteristics of the large-scale moisture flux transport over the Arabian Peninsula

    NASA Astrophysics Data System (ADS)

    Athar, H.; Ammar, K.

    2016-05-01

    The relationship between the lower tropospheric (1000 to 850 hPa) large-scale moisture flux transport and the precipitation over the Arabian Peninsula (AP), on a seasonal basis, using the NCEP-NCAR gridded dataset for the 53-year period (1958-2010), is investigated. The lower tropospheric moisture flux divergence occurs due to the Hadley cell-based descending air over the AP, as well as due to the presence of Somali jet in dry season (June to September) for the southern (≤22° N) AP domain, leading to significantly reduced precipitation in the AP. The AP thus acts more as a net transporter of moisture flux from adjacent Sea areas to nearby regions. The North Atlantic Oscillation (NAO) and the Artic Oscillation (AO) climatic indices are found to modulate significantly the net seasonal moisture flux into the AP region animating from the Mediterranean Sea, and the Arabian Sea, both for the northern (≥22° N) and southern AP domains.

  19. Storage characteristics of large round and square alfalfa bales: low-moisture wrapped bales

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Substantial dry matter (DM) and quality losses have been reported for partially dried alfalfa that has been rained on before moisture reduction to levels acceptable for dry hay storage. The objective of this research was to determine the feasibility of preserving alfalfa baled at less than 45% mois...

  20. A Literature Review of Sealed and Insulated Attics—Thermal, Moisture and Energy Performance

    SciTech Connect

    Less, Brennan; Walker, Iain; Levinson, Ronnen

    2016-08-01

    In this literature review and analysis, we focus on the thermal, moisture and energy performance of sealed and insulated attics in California climates. Thermal. Sealed and insulated attics are expected to maintain attic air temperatures that are similar to those in the house within +/- 10°F. Thermal stress on the assembly, namely high shingle and sheathing temperatures, are of minimal concern. In the past, many sealed and insulated attics were constructed with insufficient insulation levels (~R-20) and with too much air leakage to outside, leading to poor thermal performance. To ensure high performance, sealed and insulated attics in new California homes should be insulated at levels at least equivalent to the flat ceiling requirements in the code, and attic envelopes and ducts should be airtight. We expect that duct systems in well-constructed sealed and insulated attics should have less than 2% HVAC system leakage to outside. Moisture. Moisture risk in sealed and insulated California attics will increase with colder climate regions and more humid outside air in marine zones. Risk is considered low in the hot-dry, highly populated regions of the state, where most new home construction occurs. Indoor humidity levels should be controlled by following code requirements for continuous whole-house ventilation and local exhaust. Pending development of further guidance, we recommend that the air impermeable insulation requirements of the International Residential Code (2012) be used, as they vary with IECC climate region and roof finish. Energy. Sealed and insulated attics provide energy benefits only if HVAC equipment is located in the attic volume, and the benefits depend strongly on the insulation and airtightness of the attic and ducts. Existing homes with leaky, uninsulated ducts in the attic should have major savings. When compared with modern, airtight duct systems in a vented attic, sealed and insulated attics in California may still provide substantial benefit

  1. The performance assessment impacts of disposal of high-moisture, low-level radioactive waste at the Nevada Test Site

    SciTech Connect

    Crowe, B.M.; Hansen, W.; Hechnova, A.; Jacobson, R.; Voss, C.; Waters, R.; Sully, M.; Levitt, D.

    1999-03-01

    A panel of independent scientists was convened by the Department of Energy to assess the performance impacts of disposal of low-level radioactive waste from the Fernald Environmental Management Project. This waste stream was involved in a transportation incident in December 1997. A resulting outgrowth of investigations of the transportation incident was the recognition that the waste was transported and disposed in stress-fractured metal boxes and some of the waste contained excess moisture (high volumetric water contents). The panel was charged with determining whether disposal of this waste in the Area 5 radioactive waste management site on the Nevada Test Site has impacted the conclusions of the completed performance assessment. Three questions were developed by the panel to assess performance impacts: (1) the performance impacts of reduced container integrity, (2) the impact of reduced container integrity on subsidence of waste in the disposal pits and (3) the performance impacts of excess moisture. No performance or subsidence impacts were noted from disposal of the Fernald waste. The impacts of excess moisture were assessed through simulation modeling of the movement of moisture in the vadose zone assuming high water contents (wet waste) for different percentages of the waste inventory. No performance impacts were noted for either the base-case scenario (ambient conditions) or a scenario involving subsidence and flooding of the waste cells. The absence of performance impacts results form the extreme conservatism used in the Area 5-performance assessment and the robust nature of the disposal site.

  2. Performance characteristics of STIS detectors

    NASA Technical Reports Server (NTRS)

    Stern, Robert A.

    1992-01-01

    We report quantum efficiency measurements of back-illuminated, ion-implanted, laser-annealed charge coupled devices (CCD's) in the wavelength range 13-10,000 A. The equivalent quantum efficiency (EQE = effective photons detected per incident photon) ranges from a minimum of 5 percent as 1216 A to a maximum of 87 percent at 135 A. Using a simple relationship for the charge collection efficiency of the CCD pixels as a function of depth, we present a semi-empirical model with few parameters which reproduces our measurements with a fair degree of accuracy. The advantage of this model is that is can be used to predict CCD QE performance for shallow backside implanted devices without detailed solution of a system of differential equations, as in conventional approaches, and yields a simple analytic form for the charge collection efficiency which is adequate for detector calibration purposes. Making detailed assumptions about the dopant profile, we also solve the carrier density and continuity equations in order to relate our semi-empirical model parameters to surface and bulk device properties. The latter procedure helps to better establish device processing parameters for a given level of CCD QE performance.

  3. [Effects of soil moisture and shading levels on photosynthetic characteristics of cotton leaves].

    PubMed

    Liu, X; Kang, S; Shao, M; Wang, L

    2000-06-01

    The effects of different soil moistures and shading levels on stomatal conductance(Gs), net photosynthetic rates(Pn), transpiration and leaf water potential(LWP) of cotton (variety Zhongmian No. 23) grown in pots from the seedling to flower bud stages in summer noon were evaluated. We designed three shading levels: no-shading(CK), 75% shading (DN), 40% shading(SN); and three soil moistures; 85%-100% (high water, HW), 65%-85% (medium water, MW) and 45%-65% (low water, LW) of field water-bolding capacity. The Gs of DN and SN increased by 16.69% and 28.01% compared with CK at HW, respectively, while the Pn of DN and SN declined by 45.74% and 20.54%, respectively. The Gs of DN and SN enhanced by 28.86% and 23.28% compareds with CK at MW, respectively, while the Pn of DN and SN decreased by 31.97% and 1.64%, respectively. The Gs of CK, DN and Sn did not exhibit significant differences at LW, while Pn of DN and SN reduced by 46.22% and 13.45%, respectively. Significant difference in Gs did not exist between DN and SN at the same soil moisture, but there was significant difference in Pa between them (except at LW). It was suggested that Gs declined with the increasing of leaf-to-air vapor pressure difference (VPD) and showed weak correlation with Pn by regression. The combined effects of soil moistures and shading levels on LWP and transpiration rate were not significant. There was no significant difference in LWP and transpiration rate among three shading treatments. Contrasted to treatment CK, intercellular CO2 concentration (Ci) in DN and SN at HW, MW and LW increased significantly, except no apparent change of Ci in SN at MW.

  4. Characteristics of moisture and salinity of soil in Taklimakan Desert, China.

    PubMed

    Wang, Zhimin; Li, Guomin; Li, Xue; Shan, Shuo; Zhang, Jiangyi; Li, Shengyu; Fan, Jinglong

    2012-01-01

    The Taklimakan desert is known as the largest dunefield in China and also as the world's second largest shifting sand desert. The Tarim Desert Highway, which is the first highway to cross the Taklimakan desert, was built for the purpose of oil and gas resources extraction in the Tarim area, as well as for the development of the southern area of the Xinjiang Uygur Autonomous Region. Shelterbelts have been planted along the highway to prevent shifting sand from burying the road. This paper analyzes the variations of moisture and salinity of the unirrigated desert soil under natural conditions in the center of Taklimakan Desert. A number of important findings indicating the moisture and salinity of the soil at capillary saturation zone were determined by the groundwater and related to the evaporation on the top. Salinity could be affected by vegetation, which was different from moisture in the soil. Meanwhile, clay layer played an important role in water preservation in the soil, which was also beneficial to the accumulation of salinity in soil. Compared with clay layer, vegetation was a decisive factor for the gathering of salinity. The findings were significant for reasonable adjustment of irrigation in the shelterbelts for the further development of the Tarim Desert Highway.

  5. Moisture effects on the prediction performance of a single kernel near-infrared deoxynivalenol calibration

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Effect of moisture content variation on the accuracy of single kernel deoxynivalenol (DON) prediction by near-infrared (NIR) spectroscopy was investigated. Sample moisture content (MC) considerably affected accuracy of the current NIR DON calibration by underestimating or over estimating DON at high...

  6. Performance of a Commercially Available Microwave-based Bale Moisture Content Meter

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Measuring the moisture content of cotton bales has been a topic of intense interest in the last few years. In 2006 the Farm Service Agency defined cotton bales with excessive moisture as those with mc greater than 7.5%, wet basis, at the gin. Therefore it is important for gins to assure themselves...

  7. [Characteristics of Stable Isotopes in Precipitation and Their Moisture Sources in Mengzi Region, Southern Yunnan].

    PubMed

    Li, Guang; Zhang, Xin-ping; Xu, You-peng; Song, Song; Wang, Yue-feng; Ji, Xiao-min; Xiang, Jie; Yang, Jie

    2016-04-15

    The δD and δ¹⁸O values in precpitation have disciplinary variations, and they have close connections with meteorological parameters and moisture sources. Based on the continuously collected precipitation samples in Mengzi from Jan. 2009 to Dec. 2011, the reanalysis data from the European Centre for Medium-Range Weather Forecasts (ECMWF) and the National Centre for Environmental Prediction/National Centre for Atmospheric Research (NCEP/NCAR), and the Hybrid Single-Particle Lagrangian Integrated Trajectory for 4.8 (HYSPLIT_4.8) model, we analyzed the variations of δD and δ¹⁸O in precipitation at synoptic scale in Mengzi, and the relations between δ¹⁸O in precipitation and air temperature, δ¹⁸O in precipitation and amount, δ¹⁸O in precipitation and wind speed, δ¹⁸O in precipitation and moisture sources. The results showed that the variations of δD and δ¹⁸O values in precipitation exhibited remarkable seasonal variability. The stable isotopic values in precipitation were higher during dry season than those during wet season. The relations between δ¹⁸O in precipitation and air temperature, δ¹⁸O in precipitation and amount indicated significant negative correlations. However, it exhibited significant positive correlation between precipitation δ¹⁸O and wind speed at different pressure levels (300 hPa, 500 hPa, 700 hPa, and 800 hPa), and this result indicated that the wind speed was an important influencing factor for the variations of precipitation δ¹⁸O. With the increasing rainfall levels, the intercept and slope of meteoric water line also increased, and this phenomenon suggested that there was a secondary evaporation effect under sub-cloud in stable isotopes of precipitation. The backward trajectory model showed that the main moisture sources during dry season came from the westerly and the inland. However, during wet season, the remote ocean vapor was the main moisture source in Mengzi, and the δ¹⁸O values in

  8. Drying characteristics and equilibrium moisture content of steam-treated Douglas fir (Pseudotsuga menziesii L.).

    PubMed

    Lam, Pak Sui; Sokhansanj, Shahab; Bi, Xiaotao T; Lim, C Jim; Larsson, Sylvia H

    2012-07-01

    Douglas fir (Pseudotsuga menziesii L.) particles were exposed to high pressure saturated steam (200 and 220 °C for 5 and 10 min) to improve the durability and hydrophobicity of pellets produced from them. Depending on treatment severity, the moisture content of the particles increased from 10% to 36% (wet basis). Douglas fir particles steam-treated at 220 °C for 10 min had the fastest drying rate of 0.014 min(-1). The equilibrium moisture content (EMC) of steam-treated samples decreased with increasing steam temperature and treatment time. The Giggnheim-Anderson-deBoer (GAB) equilibrium model gave a good fit with the equilibrium data with R(2) = 0.99. The adsorption rate of untreated pellets exposed to humid air (30 °C, 90% RH) for 72 h was 0.0152 min(-1) while that of steam-treated pellets ranged from 0.0125 to 0.0135 min(-1) without a clear trend with steam treatment severity. These findings are critical to develop durable and less hygroscopic pellets.

  9. An experimental investigation of the effect of moisture on the performance of an air-conditioning system

    SciTech Connect

    Goswami, D.Y.; Mathur, G.D.; Gupta, S.; Stoff, L.; Colacino, F.

    1996-12-31

    Tests were conducted at the University of Florida`s Solar Energy and Energy Conversion Laboratory (SEECL) to determine the effect of the moisture on the performance of a 3 ton residential heat pump system with R-22 as the working fluid. The performance of the heat pump system was tested in accordance with the ARI Standard 210/240 (ARI 1989) and ANSI/ASHRAE-37-1988 for testing unitary equipment. ASHRAE`s Air Enthalpy Method was used to determine the performance of heat pump system and ASHRAE`s condition A [Outside 95 F DBT/75 F WBT; Inside 80 F DBT/67 F WBT] was maintained for the tests. The experimental data reveals that moisture levels of approximately 700 ppm in the refrigerant can decrease the system performance by 10--15%. Approximately 50--60% of the moisture injected into the system remains in the refrigerant and the rest mixes with the compressor oil. Hence, it is possible that over a period of time the moisture in the compressor oil may breakdown at the prevailing temperatures and pressures to form acids which may result in catastrophic failure.

  10. WindSat Soil Moisture and Vegetation Validation and Performance Prediction for the NPOESS Microwave Imager/Sounder (MIS)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The National Polar-orbiting Operational Environmental Satellite System’s (NPOESS) Microwave Imager/Sounder (MIS) instrument is in development, with soil moisture sensing depth as one of the two Key Performance Parameters (KPPs). The other one is ocean surface wind speed precision. Based on the curre...

  11. High-performance and moisture-stable cellulose-starch nanocomposites based on bioinspired core-shell nanofibers.

    PubMed

    Prakobna, Kasinee; Galland, Sylvain; Berglund, Lars A

    2015-03-09

    Moisture stability and brittleness are challenges for plant fiber biocomposites intended for load-bearing applications, for instance those based on an amylopectin-rich (AP) starch matrix. Core-shell amylopectin-coated cellulose nanofibers and nanocomposites are prepared to investigate effects from the distribution of AP matrix. The core-shell nanocomposites are compared with nanocomposites with more irregular amylopectin (AP) distribution. Colloidal properties (DLS), AP adsorption, nanofiber dimensions (atomic force microscopy), and nanocomposite structure (transmission electron microscopy) are analyzed. Tensile tests are performed at different moisture contents. The core-shell nanofibers result in exceptionally moisture stable, ductile, and strong nanocomposites, much superior to reference CNF/AP nanocomposites with more irregular AP distribution. The reduction in AP properties is less pronounced as the AP forms a favorable interphase around individual CNF nanofibers.

  12. The influence of soil moisture on the planetary boundary layer characteristics and on cumulus convection over an isolated mountain

    NASA Astrophysics Data System (ADS)

    Zhou, Xin

    Many studies have examined how regional soil moisture anomalies impact warm-season precipitation. The focus of this study is on some specific processes relevant to this broader question of land-atmosphere feedback. This study investigates the environment where convection is triggered by mountains, i.e. in the southwestern USA during the monsoon season. Specifically, we examine the relationship between the surface energy balance, boundary-layer (BL) characteristics, thermally-forced orographic circulations, and orographic cumulus convection. Our approach is both observational and numerical. An intensive field campaign was conducted around the Santa Catalina Mountains in Arizona in July and August 2006, i.e. the Cumulus Photogrammetric, In Situ and Doppler Observations (CuPIDO) experiment. An unusual wet spell in late July 2006 allows clear separation of the two-month campaign in two parts, a dry soil period and a wet soil period. Surface flux stations positioned around the mountain range indicate that days in the wet soil period tend to have a higher surface latent heat flux, lower soil and air temperatures, a more stable and shallower BL, and weaker solenoidal forcing resulting in weaker anabatic flow, in comparison with days in the dry soil period. The wet soil period is characterized also by higher humidity and moist static energy in the BL, implying a lower cumulus cloud base and higher convective available potential energy. Therefore this period witnesses rather early growth of orographic cumulus convection, growing rapidly to the cumulonimbus stage, often before noon, and producing precipitation rather efficiently, with relatively little lightning. The wet soil period also witnessed some nocturnal MCSs producing widespread precipitation. Observational data alone do not allow discrimination between soil moisture and advected airmass characteristics in explaining these differences. Hence the Weather Research and Forecasting (WRF) model with Noah land surface

  13. Structural characteristics of slowly digestible starch and resistant starch isolated from heat-moisture treated waxy potato starch.

    PubMed

    Lee, Chang Joo; Moon, Tae Wha

    2015-07-10

    The objective of this study was to investigate the structural characteristics of slowly digestible starch (SDS) and resistant starch (RS) fractions isolated from heat-moisture treated waxy potato starch. The waxy potato starch with 25.7% moisture content was heated at 120°C for 5.3h. Scanning electron micrographs of the cross sections of RS and SDS+RS fractions revealed a growth ring structure. The branch chain-length distribution of debranched amylopectin from the RS fraction had a higher proportion of long chains (DP ≥ 37) than the SDS+RS fraction. The X-ray diffraction intensities of RS and SDS+RS fractions were increased compared to the control. The SDS+RS fraction showed a lower gelatinization enthalpy than the control while the RS fraction had a higher value than the SDS+RS fraction. In this study we showed the RS fraction is composed mainly of crystalline structure and the SDS fraction consists of weak crystallites and amorphous regions.

  14. L-Leucine as an excipient against moisture on in vitro aerosolization performances of highly hygroscopic spray-dried powders.

    PubMed

    Li, Liang; Sun, Siping; Parumasivam, Thaigarajan; Denman, John A; Gengenbach, Thomas; Tang, Patricia; Mao, Shirui; Chan, Hak-Kim

    2016-05-01

    L-Leucine (LL) has been widely used to enhance the dispersion performance of powders for inhalation. LL can also protect powders against moisture, but this effect is much less studied. The aim of this study was to investigate whether LL could prevent moisture-induced deterioration in in vitro aerosolization performances of highly hygroscopic spray-dried powders. Disodium cromoglycate (DSCG) was chosen as a model drug and different amounts of LL (2-40% w/w) were added to the formulation, with the aim to explore the relationship between powder dispersion, moisture protection and physicochemical properties of the powders. The powder formulations were prepared by spray drying of aqueous solutions containing known concentrations of DSCG and LL. The particle sizes were measured by laser diffraction. The physicochemical properties of fine particles were characterized by X-ray powder diffraction (XRD), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and dynamic vapor sorption (DVS). The surface morphology and chemistry of fine particles were analyzed by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and time-of-flight secondary ion mass spectrometry (ToF-SIMS). In vitro aerosolization performances were evaluated by a next generation impactor (NGI) after the powders were stored at 60% or 75% relative humidity (RH), and 25°C for 24h. Spray-dried (SD) DSCG powders were amorphous and absorbed 30-45% (w/w) water at 70-80% RH, resulting in deterioration in the aerosolization performance of the powders. LL did not decrease the water uptake of DSCG powders, but it could significantly reduce the effect of moisture on aerosolization performances. This is due to enrichment of crystalline LL on the surface of the composite particles. The effect was directly related to the percentage of LL coverage on the surface of particles. Formulations having 61-73% (molar percent) of LL on the particle surface (which correspond to 10-20% (w

  15. Thermic diode performance characteristics and design manual

    NASA Technical Reports Server (NTRS)

    Bernard, D. E.; Buckley, S.

    1979-01-01

    Thermic diode solar panels are a passive method of space and hot water heating using the thermosyphon principle. Simplified methods of sizing and performing economic analyses of solar heating systems had until now been limited to passive systems. A mathematical model of the thermic diode including its high level of stratification has been constructed allowing its performance characteristics to be studied. Further analysis resulted in a thermic diode design manual based on the f-chart method.

  16. Performance Characteristics of an Isothermal Freeze Valve

    SciTech Connect

    Hailey, A.E.

    2001-08-22

    This document discusses performance characteristics of an isothermal freeze valve. A freeze valve has been specified for draining the DWPF melter at the end of its lifetime. Two freeze valve designs have been evaluated on the Small Cylindrical Melter-2 (SCM-2). In order to size the DWPF freeze valve, the basic principles governing freeze valve behavior need to be identified and understood.

  17. Improved Methods for Estimating Microbial Activity and Moisture Characteristic Curves in Intact Unsaturated Soil Cores

    NASA Astrophysics Data System (ADS)

    Thompson, D. N.; Baker, K. E.

    2001-12-01

    Estimation of microbial activity in soils is a complex and often difficult process. In this work, we describe several new and innovative methods we have developed to measure microbial respiration in intact cores of unsaturated soils. The ultimate goal of this work is to predict the effect of microbial activity on contaminant mobility via CO2 generation in variably saturated vadose zone soils. This goal requires estimation of the effect of available water (i.e. in pores accessible to the microbes) on the microbial activity, and thus a homogeneous distribution of substrate throughout the soil water. Prior studies have added substrate solution drop wise to the soil, and then distributed the substrate throughout the soil by mixing. While this method distributes the substrate well, it alters the in situ pore volume distribution and has been shown to result in an anomalously high degree of microbial activity shortly after mixing. Traditional methods for uniformly distributing substrate in intact unsaturated soils require days to weeks to reach equilibrium. Since the substrate would be completely consumed in this time frame, an innovative approach is being used in this study to drain intact soil cores to the desired moisture contents in a matter of hours. This approach involves the use of the Unsaturated Flow Apparatus (UFAT). In the method, the samples are vacuum saturated under refrigeration to uniformly distribute a 14C-labeled substrate throughout the soil water, drained to various pressures in the UFA, and transferred to a sealed container and incubated. The labeled 14CO2 is then trapped and counted after incubation to determine microbial activity. Since the soil used in this study contains a high percentage of swelling clays, the cores tend to compact in the UFA, altering the macropore volume distribution. To address this alteration, we developed a correction function to correct the UFA-measured pore volume distribution at each rotational speed. Finally, the high

  18. Design and performance of a capicitor sensor and impedance analyzer for nondestructive moisture content detemination

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This paper describes a method to determine the moisture content of in-shell peanuts with a parallel-plate electrode system fitted inside a cylinder by using impedance measurements made on the system. Two parallel-plate electrodes were mounted inside a cylinder, made of acrylic material, and the spac...

  19. Overview of SMOS performance in terms of global soil moisture monitoring after six years in operation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Soil Moisture and Ocean Salinity satellite (SMOS) was launched in November 2009 and started delivering data in January 2010. The commissioning phase ended in May 2010. Subsequently, the satellite has been in operation for over 5 years while the retrieval algorithms from Level 1 to Level 2 underw...

  20. Evaluation of Soil Moisture, Storm Characteristics, and Their Influence on Storm Runoff and Water Yield at the Panola Mountain Research Watershed, Georgia, U.S.A.

    NASA Astrophysics Data System (ADS)

    Riley, J. W.; Aulenbach, B. T.

    2015-12-01

    Understanding the factors that control runoff processes is important for many aspects of water supply and ecosystem protection, especially during climatic extremes that result in flooding or droughts; potentially impacting human safety. Furthermore, having knowledge of the conditions during which runoff occurs contributes to the conceptual understanding of the hydrologic cycle and may improve parameterization of hydrologic models. We evaluated soil moisture, storm characteristics, and the subsequent runoff and water yield for 297 storms over an eight-year period at Panola Mountain Research Watershed to better understand runoff generation processes. Panola Mountain Research Watershed is a small (41-hectare), relatively undisturbed forested watershed near Atlanta, GA, U.S.A. Strong relations were observed between total precipitation for a given storm, deep (70 cm below surface) antecedent soil moisture content and the volume of runoff. However, the strength of the relations varied based on occurrence during the growing (April - September; 172 storms) or dormant (October - March; 125 storms) period. In general, soil moisture responded at a minimum of 15 cm depth for all but 18 events. In addition, we found storms that initiated a response of deep soil moisture (70 cm below surface) to be an important factor relating to storm runoff and water yield. Seventy percent of the dormant period storms generated a response at 70 cm depth compared to 58% of growing period storms. A stronger relation between soil moisture and water yield was noted during the dormant period and indicated that all storms that produced a water yield >12% occurred when deep pre-event soil moisture was >20%. Similar patterns were also present during the growing season with occasional intense thunderstorms also generating higher water yields even in the absence of high soil moisture. The importance of deep soil moisture likely reflects the overall status of watershed storage conditions.

  1. Performance Characteristics of a Preformed Elliptical Parachute

    NASA Technical Reports Server (NTRS)

    1963-01-01

    Performance Characteristics of a Preformed Elliptical Parachute at Altitudes between 200,000 and 100,000 Thousand Feet Obtained by In-Flight Photography. The performance characteristics of a pre-formed elliptical parachute at altitudes between 200,000 and 100,000 feet were obtained by means of in-flight photography. The tests demonstrate that this type of parachute will open at altitudes of about 200,000 feet if conditions such as twisting of the suspension lines or draping of the suspension lines over the canopy do not occur. Drag-coefficient values between 0.6 and 0.8 were found to be reasonable for this type of parachute system in the altitude range between 200,000 and 100,000 feet. [Entire movie available on DVD from CASI as Doc ID 20070030980. Contact help@sti.nasa.gov

  2. Interactions Between Structure and Processing that Control Moisture Uptake in High-Performance Polycyanurates (Briefing Charts)

    DTIC Science & Technology

    2015-03-24

    Edwards AFB, CA 4 California State University, Long Beach, CA 90840 2 Outline: Basic Studies of Moisture Uptake in Cyanate Ester Networks • Background...Though more stable than epoxy resins, cyanate esters can degrade on long-term exposure to hot water U.S. Navy photo by Mass Communication Specialist...Temperature Thermosetting Polymers: Cyanate Esters • Glass transition temperatures at full cure of 200 – 400°C • Uncured resins exist as low-melting solids

  3. Study on near infrared technology for the measurement of moisture

    NASA Astrophysics Data System (ADS)

    Guo, Yong-cai; Chen, Zhao

    2006-02-01

    This paper studies near infrared technology for measuring moisture content in solid substance. After analyzing and improving traditional moisture instruments and discussing their disadvantages, we present a measuring scheme and instrument structure design with high performance and stability. The novel instrument utilizing near infrared range analysis (NIRA) technology possesses characteristics of on-line working, high accuracy, distribution and non-contact measurement.

  4. High-R Walls for Remodeling. Wall Cavity Moisture Monitoring

    SciTech Connect

    Wiehagen, J.; Kochkin, V.

    2012-12-01

    The focus of the study is on the performance of wall systems, and in particular, the moisture characteristics inside the wall cavity and in the wood sheathing. Furthermore, while this research will initially address new home construction, the goal is to address potential moisture issues in wall cavities of existing homes when insulation and air sealing improvements are made.

  5. High-R Walls for Remodeling: Wall Cavity Moisture Monitoring

    SciTech Connect

    Wiehagen, J.; Kochkin, V.

    2012-12-01

    The focus of the study is on the performance of wall systems, and in particular, the moisture characteristics inside the wall cavity and in the wood sheathing. Furthermore, while this research will initially address new home construction, the goal is to address potential moisture issues in wall cavities of existing homes when insulation and air sealing improvements are made.

  6. Estimating the timing of long bone fractures: correlation between the postmortem interval, bone moisture content, and blunt force trauma fracture characteristics*.

    PubMed

    Wieberg, Danielle A M; Wescott, Daniel J

    2008-09-01

    There is very limited knowledge about how long perimortem fracture characteristics persist into the postmortem interval (PMI). Therefore, in this study, 60 porcine long bones were exposed to natural taphonomic conditions and fractured with a steel bone breaking apparatus every 28 days throughout a 141-day period. Differences between macroscopic blunt force trauma fracture characteristics (fracture angle, surface morphology, and outline) were examined to determine if they varied over time or in relationship to bone moisture content (ash weight) and overall assessment. There are significant relationships between (1) PMI and percent ash weight (%AW), fracture surface, and fracture angle and (2) %AW and fracture surface and fracture angle. Bone moisture content correlates significantly with fracture morphology and other characteristics commonly used by forensic anthropologists to determine the timing of traumatic injuries. However, fracture characteristics normally associated with perimortem trauma can persist long into the PMI.

  7. Performance Characteristics of Leaky Coaxial Cables.

    DTIC Science & Technology

    1980-04-01

    although it could result from very localized differences in ground moisture (puddle for- mation perhaps, caused by a local ground depression ). Table 3.5...1973 6NfATETI STATION PRSSURI I~p., 19910. PRISSION MAXIMAL! A LA STATION I.P.1 102.7 15 102.6 2530. 5 17 LEAST STATION PRESEISGI .. 0.71 .7 - AISSION

  8. Effects of whey protein concentrate, feed moisture and temperature on the physicochemical characteristics of a rice-based extruded flour.

    PubMed

    Teba, Carla da Silva; Silva, Erika Madeira Moreira da; Chávez, Davy William Hidalgo; Carvalho, Carlos Wanderlei Piler de; Ascheri, José Luis Ramírez

    2017-08-01

    The influence of whey protein concentrate (WPC), feed moisture and temperature on the physicochemical properties of rice-based extrudates has been investigated. WPC (0.64-7.36g/100g rice) was extruded under 5 moisture (16.64-23.36g/100g) and 5 temperature (106.36-173.64°C) established by a 3(2) central composite rotational design. Physicochemical properties [color, porosimetry, crystallinity, water solubility and absorption, pasting properties, reconstitution test, proximate composition, amino acids, minerals and electrophoresis] were determined. WPC and feed moisture increased redness, yellowness and decreased luminosity. Feed moisture and temperature increased density and total volume pore. WPC and moisture increased crystallinity, but only WPC increased solubility and decrease the retrogradation tendency. Increasing temperature increased the viscosity of the extrudates. The addition of WPC improved the nutritional composition of the extrudates, especially proteins. It is suggested that the extrusion process positively affected the retention of most of the polypeptides chains.

  9. Effect of debranching and heat-moisture treatments on structural characteristics and digestibility of sweet potato starch.

    PubMed

    Huang, Ting-Ting; Zhou, Da-Nian; Jin, Zheng-Yu; Xu, Xue-Ming; Chen, Han-Qing

    2015-11-15

    The effects of debranching treatment (DT) and debranching-heat-moisture treatment (D-HMT) on the structural characteristics and in vitro digestibility of sweet potato starch were investigated. The results indicated that DT and D-HMT decreased the percentage of starch fraction with degree of polymerization (DP) ⩽ 13, increased the percentages of the other fractions, and decreased the molecular weight of starch sample. The D-HMT starch showed a considerable SDS content of 31.60%. Compared with the DT starch sample, the T(o), T(p), T(c), T(c)-T(o) and ΔH of D-HMT starch samples for the second endothermal were increased significantly, crystalline pattern was altered from C(a) to A type, the surface became more smooth. The pasting temperatures of DT and D-HMT starch samples were higher while the peak viscosities, breakdown and setback values were lower than that of native starch. These results suggested that structural changes of sweet potato starch by D-HMT significantly affected the digestibility.

  10. Solid waste leach characteristics and contaminant-sediment interactions Volume 2: Contaminant transport under unsaturated moisture contents

    SciTech Connect

    Lindenmeier, C.W.; Serne, R.J.; Conca, J.L.

    1995-09-01

    The objectives of this report and subsequent volumes include describing progress on (1) development and optimization of experimental methods to quantify the release of contaminants from solid wastes and their subsequent interactions with unsaturated sediments and (2) the creation of empirical data that become input parameters to performance assessment (PA) analyses for future Hanford Site disposal units and baseline risk assessments for inactive and existing solid waste disposal units. For this report, efforts focused on developing methodologies to evaluate contaminant transport in Trench 8 (W-5 Burial Ground) sediments under unsaturated (vadose zone) conditions. To accomplish this task, a series of flow-through column tests were run using standard saturated column systems, Wierenga unsaturated column systems (both commercial and modified), and the Unsaturated Flow Apparatus (UFA). The reactants investigated were {sup 85}Sr, {sup 236}U, and {sup 238}U as reactive tracers, and tritium as a non-reactive tracer. Results indicate that for moderately unsaturated conditions (volumetric water contents >50 % of saturation), the Wierenga system performed reasonably well such that long water residence times (50-147 h) were achieved, and reasonably good steady-state flow conditions were maintained. The major drawbacks in using this system for reactive tracer work included (1) the inability to achieve reproducible and constant moisture content below 50% of saturation, (2) the four to six month time required to complete a single test, and (3) the propensity for mechanical failure resulting from laboratory power outages during the prolonged testing period.

  11. Effect of intra- and interspecific competition on the performance of native and invasive species of Impatiens under varying levels of shade and moisture.

    PubMed

    Skálová, Hana; Jarošík, Vojtěch; Dvořáčková, Śárka; Pyšek, Petr

    2013-01-01

    Many alien plants are thought to be invasive because of unique traits and greater phenotypic plasticity relative to resident species. However, many studies of invasive species are unable to quantify the importance of particular traits and phenotypic plasticity in conferring invasive behavior because traits used in comparative studies are often measured in a single environment and by using plants from a single population. To obtain a deeper insight into the role of environmental factors, local differences and competition in plant invasions, we compared species of Impatiens (Balsaminaceae) of different origin and invasion status that occur in central Europe: native I. noli-tangere and three alien species (highly invasive I. glandulifera, less invasive I. parviflora and potentially invasive I. capensis). In two experiments we harvested late-stage reproductive plants to estimate performance. The first experiment quantified how populations differed in performance under varying light and moisture levels in the absence of competition. The second experiment quantified performance across these environments in the presence of intra- and inter-specific competition. The highly invasive I. glandulifera was the strongest competitor, was the tallest and produced the greatest biomass. Small size and high plasticity were characteristic for I. parviflora. This species appeared to be the second strongest competitor, especially under low soil moisture. The performance of I. capensis was within the range of the other Impatiens species studied, but sometimes limited by alien competitors. Our results suggest that invasion success within the genus Impatiens depends on the ability to grow large under a range of environmental conditions, including competition. The invasive species also exhibited greater phenotypic plasticity across environmental conditions than the native species. Finally, the decreased performance of the native I. noli-tangere in competition with other species studied

  12. Performance of MODIS satellite and mesoscale model based land surface temperature for soil moisture deficit estimation using Neural Network

    NASA Astrophysics Data System (ADS)

    Srivastava, Prashant K.; Petropoulos, George P.; Gupta, Manika; Islam, Tanvir

    2015-04-01

    Soil Moisture Deficit (SMD) is a key variable in the water and energy exchanges that occur at the land-surface/atmosphere interface. Monitoring SMD is an alternate method of irrigation scheduling and represents the use of the suitable quantity of water at the proper time by combining measurements of soil moisture deficit. In past it is found that LST has a strong relation to SMD, which can be estimated by MODIS or numerical weather prediction model such as WRF (Weather Research and Forecasting model). By looking into the importance of SMD, this work focused on the application of Artificial Neural Network (ANN) for evaluating its capabilities towards SMD estimation using the LST data estimated from MODIS and WRF mesoscale model. The benchmark SMD estimated from Probability Distribution Model (PDM) over the Brue catchment, Southwest of England, U.K. is used for all the calibration and validation experiments. The performances between observed and simulated SMD are assessed in terms of the Nash-Sutcliffe Efficiency (NSE), the Root Mean Square Error (RMSE) and the percentage of bias (%Bias). The application of the ANN confirmed a high capability WRF and MODIS LST for prediction of SMD. Performance during the ANN calibration and validation showed a good agreement between benchmark and estimated SMD with MODIS LST information with significantly higher performance than WRF simulated LST. The work presented showed the first comprehensive application of LST from MODIS and WRF mesoscale model for hydrological SMD estimation, particularly for the maritime climate. More studies in this direction are recommended to hydro-meteorological community, so that useful information will be accumulated in the technical literature domain for different geographical locations and climatic conditions. Keyword: WRF, Land Surface Temperature, MODIS satellite, Soil Moisture Deficit, Neural Network

  13. Performance characteristics of pulse tube refrigerators

    NASA Astrophysics Data System (ADS)

    Huang, B. J.; Tzeng, T. M.

    In the present study experiments were carried out to investigate the performance characteristics of pulse tube refrigerators. It was found that the cool-down time tc during the transient or start-up period is dominated by the time constant of the pulse tube wall τpt and that the dynamics of a basic pulse tube (BPT) refrigerator approaches that of a first-order system. For steady state operation, the cold-end temperature TL was found to vary with τpt, and the cooling load QL increases monotonically with increasing τpt. This indicates that heat pumped by the gas from the cold to the hot end increases with decreasing hpt (i.e. less energy exchange between the gas and wall). The process of heat storage or release of the pulse tube wall is thus shown to have a negative effect on the performance of a BPT refrigerator. It was thus found experimentally that the gas compression/expansion process inside the pulse tube, which is similar to a Brayton cycle but lies between isothermal and adiabatic, can explain the performance of BPT refrigerators. The present experiment also shows that the performance of a pulse tube refrigerator at transient and steady states is mainly dominated by the time constant of the pulse tube wall τpt.

  14. Effect of impurities and moisture on lithium bisoxalatoborate (LiBOB) electrolyte performance in lithium-ion cells

    NASA Astrophysics Data System (ADS)

    Yang, L.; Furczon, M. M.; Xiao, A.; Lucht, B. L.; Zhang, Z.; Abraham, D. P.

    Electrolytes containing LiB(C 2O 4) 2 (LiBOB) salts are of increasing interest for lithium-ion cells for several reasons that include their ability to form a stable solid electrolyte interphase on graphite electrodes. However, cells containing these electrolytes often show inconsistent performance because of impurities in the LiBOB salt. In this work we compare cycling and impedance data from cells containing electrolytes with LiBOB that was obtained commercially and LiBOB purified by a rigorous recrystallization procedure. We relate the difference in performance to a lithium oxalate impurity that may be a residual from the salt manufacturing process. We also examine the reaction of LiBOB with water to determine the effect of salt storage in high-humidity environments. Although LiBOB electrolytes containing trace amounts (∼100 ppm) of moisture appear relatively stable, higher moisture contents (∼1 wt%) lead to observable salt decomposition resulting in the generation of B(C 2O 4)(OH) and LiB(C 2O 4)(OH) 2 compounds that do not dissolve in typical carbonate solutions and impair lithium-ion cell performance.

  15. Moisturizer Allergy

    PubMed Central

    Stechschulte, Sarah A.

    2008-01-01

    Background: Moisturizers are used by patients with dry skin conditions as well as those with healthy skin to enhance and preserve the smoothness of the skin and to interrupt the dry-skin cycle. Moisturizers are generally considered safe, although skin reactions, such as allergic contact dermatitis from topical preparations may occur. Cosmetic products including moisturizers are among the main culprits of allergic contact dermatitis. Methods: Utilizing a recently published database of all moisturizers available at Walgreens Pharmacies (Chicago, Illinois), which listed each product's allergens from the North American Contact Dermatitis Group (NACDG) screening panel, we evaluated the number of moisturizers containing each allergen. Results: Of the 276 moisturizers accounted for in the database, 68 percent contained fragrance making it the most common allergen found in these moisturizers. Parabens were discovered in 62 percent of moisturizers, followed by Vitamin E in 55 percent of products. Essential oils and biologic additives were found in 45 percent of products, followed by benzyl alcohol in 24 percent of moisturizers. Propylene glycol was found in 20 percent of moisturizers, followed by formaldehyde releasers in 20 percent of products. Iodopropynyl butylcarbamate was discovered in 16 percent of products, followed by lanolin in 10 percent of moisturizers. Methylisothiazolinone/methylchloroisothiazolinone was found in six percent of available products. Conclusions: Many ingredients of moisturizers have the potential to cause irritant and allergic contact dermatitis; therefore, it is necessary for clinicians to be aware of such potential allergens in order to manage and advise their patients accordingly. PMID:21212847

  16. Laser Microprobe Mass Spectrometry 1: Basic Principles and Performance Characteristics.

    ERIC Educational Resources Information Center

    Denoyer, Eric; And Others

    1982-01-01

    Describes the historical development, performance characteristics (sample requirements, analysis time, ionization characteristics, speciation capabilities, and figures of merit), and applications of laser microprobe mass spectrometry. (JN)

  17. Performance characteristics of pitching flexible foil propulsors

    NASA Astrophysics Data System (ADS)

    Brownell, Cody; Egan, Brendan; Murray, Mark

    2014-11-01

    Performance characteristics of flexible foil propulsors are studied experimentally. The project investigates the dependence of thrust and efficiency on foil elasticity, Strouhal number, and flow velocity. The experiments took place in a large recirculating water channel, using full span flexible propulsor models to approximate a 2D geometry. The propulsor pitched about a fixed axis at its quarter chord, with a six-axis load cell measuring the forces and torques on the shaft. Propulsive efficiency is found to peak at an optimum Strouhal number for each foil tested. Varying elasticity did not produce a similar local maximum over the sampled parameter space. The ensemble data will facilitate the engineering of fish-like propulsion systems for future application of this technology.

  18. Physicochemical characteristics and in vitro digestibility of potato and cassava starches under organic acid and heat-moisture treatments.

    PubMed

    Van Hung, Pham; Huong, Nguyen Thi Mai; Phi, Nguyen Thi Lan; Tien, Nguyen Ngoc Thanh

    2017-02-01

    A combination of acid (citric acid or lactic acid) and heat-moisture treatment was used to modify cassava and potato starches in this study. Changes in physicochemical properties and in vitro digestibility of the treated starches were investigated. The cassava starch contained 17.0% amylose and possessed A-type crystallinity, whereas the potato starch had 27.4% amylose and possessed B-type crystallinity. After acid and heat-moisture treatment, the crystalline structure of the cassava starch remained unchanged (A type), while the crystalline structure of the potato starch changed from B type to the C (B+A) type. The acid and heat-moisture treatment increased gelatinization temperature, peak and final viscosities of cassava starch but reduced peak and breakdown viscosities of the potato starch. After acid and heat-moisture treatment, rapid digestible starch contents of the treated cassava and potato starches were significantly reduced. However, resistant starch (RS) contents of the treated starches significantly increased as compared to the native starches. Citric acid was found to have high impact on formation of RS in starches. The RS contents of cassava and potato starches obtained under the citric acid and heat-moisture treatment were 40.2% and 39.0%, respectively, two times higher than those of the native starches.

  19. Effect of heat and moisture transport and storage properties of building stones on the hygrothermal performance of historical building envelopes

    NASA Astrophysics Data System (ADS)

    KoÅáková, Dana; Kočí, Václav; Žumár, Jaromír; Keppert, Martin; Holčapek, Ondřej; Vejmelková, Eva; Černý, Robert

    2016-12-01

    The heat and moisture transport and storage parameters of three different natural stones used on the Czech territory since medieval times are determined experimentally, together with the basic physical properties and mechanical parameters. The measured data are applied as input parameters in the computational modeling of hygrothermal performance of building envelopes made of the analyzed stones. Test reference year climatic data of three different locations within the Czech Republic are used as boundary conditions on the exterior side. Using the simulated hygric and thermal performance of particular stone walls, their applicability is assessed in a relation to the geographical and climatic conditions. The obtained results indicate that all three investigated stones are highly resistant to weather conditions, freeze/thaw cycles in particular.

  20. Characteristics of High-Performing School Districts

    ERIC Educational Resources Information Center

    Leithwood, Kenneth; Azah, Vera N.

    2017-01-01

    This mixed-methods study inquired about characteristics of districts which influence changes in student achievement and how those characteristics are developed. Staff in 49 Ontario districts were surveyed to estimate the status of nine district characteristics on changes in provincial tests of math and language achievement over five years. A…

  1. Slowly digestible starch from heat-moisture treated waxy potato starch: preparation, structural characteristics, and glucose response in mice

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Heat-moisture treatment (HMT) was optimized to increase the formation of slowly digestible starch (SDS) in waxy potato starch, and the structural and physiological properties of this starch were investigated. A maximum SDS content (41.8%) consistent with the expected value (40.1%) was obtained after...

  2. Real-time measurements of temperature, pressure and moisture profiles in High-Performance Concrete exposed to high temperatures during neutron radiography imaging

    SciTech Connect

    Toropovs, N.; Lo Monte, F.; Wyrzykowski, M.; Weber, B.; Sahmenko, G.; Vontobel, P.; Felicetti, R.; Lura, P.

    2015-02-15

    High-Performance Concrete (HPC) is particularly prone to explosive spalling when exposed to high temperature. Although the exact causes that lead to spalling are still being debated, moisture transport during heating plays an important role in all proposed mechanisms. In this study, slabs made of high-performance, low water-to-binder ratio mortars with addition of superabsorbent polymers (SAP) and polypropylene fibers (PP) were heated from one side on a temperature-controlled plate up to 550 °C. A combination of measurements was performed simultaneously on the same sample: moisture profiles via neutron radiography, temperature profiles with embedded thermocouples and pore pressure evolution with embedded pressure sensors. Spalling occurred in the sample with SAP, where sharp profiles of moisture and temperature were observed. No spalling occurred when PP-fibers were introduced in addition to SAP. The experimental procedure described here is essential for developing and verifying numerical models and studying measures against fire spalling risk in HPC.

  3. Key Characteristics of Middle School Performance

    ERIC Educational Resources Information Center

    Styron, Ronald A., Jr.; Nyman, Terri R.

    2008-01-01

    This research project examined student performance in middle schools with a grade configuration of six through eight. Schools were categorized into two groups: high-performing middle schools--middle schools making adequate yearly progress for two consecutive school years, and low-performing middle schools--middle schools not making adequate yearly…

  4. Laboratory Performance of Five Selected Soil Moisture Sensors Applying Factory and Own Calibration Equations for Two Soil Media of Different Bulk Density and Salinity Levels.

    PubMed

    Matula, Svatopluk; Báťková, Kamila; Legese, Wossenu Lemma

    2016-11-15

    Non-destructive soil water content determination is a fundamental component for many agricultural and environmental applications. The accuracy and costs of the sensors define the measurement scheme and the ability to fit the natural heterogeneous conditions. The aim of this study was to evaluate five commercially available and relatively cheap sensors usually grouped with impedance and FDR sensors. ThetaProbe ML2x (impedance) and ECH₂O EC-10, ECH₂O EC-20, ECH₂O EC-5, and ECH₂O TE (all FDR) were tested on silica sand and loess of defined characteristics under controlled laboratory conditions. The calibrations were carried out in nine consecutive soil water contents from dry to saturated conditions (pure water and saline water). The gravimetric method was used as a reference method for the statistical evaluation (ANOVA with significance level 0.05). Generally, the results showed that our own calibrations led to more accurate soil moisture estimates. Variance component analysis arranged the factors contributing to the total variation as follows: calibration (contributed 42%), sensor type (contributed 29%), material (contributed 18%), and dry bulk density (contributed 11%). All the tested sensors performed very well within the whole range of water content, especially the sensors ECH₂O EC-5 and ECH₂O TE, which also performed surprisingly well in saline conditions.

  5. Laboratory Performance of Five Selected Soil Moisture Sensors Applying Factory and Own Calibration Equations for Two Soil Media of Different Bulk Density and Salinity Levels

    PubMed Central

    Matula, Svatopluk; Báťková, Kamila; Legese, Wossenu Lemma

    2016-01-01

    Non-destructive soil water content determination is a fundamental component for many agricultural and environmental applications. The accuracy and costs of the sensors define the measurement scheme and the ability to fit the natural heterogeneous conditions. The aim of this study was to evaluate five commercially available and relatively cheap sensors usually grouped with impedance and FDR sensors. ThetaProbe ML2x (impedance) and ECH2O EC-10, ECH2O EC-20, ECH2O EC-5, and ECH2O TE (all FDR) were tested on silica sand and loess of defined characteristics under controlled laboratory conditions. The calibrations were carried out in nine consecutive soil water contents from dry to saturated conditions (pure water and saline water). The gravimetric method was used as a reference method for the statistical evaluation (ANOVA with significance level 0.05). Generally, the results showed that our own calibrations led to more accurate soil moisture estimates. Variance component analysis arranged the factors contributing to the total variation as follows: calibration (contributed 42%), sensor type (contributed 29%), material (contributed 18%), and dry bulk density (contributed 11%). All the tested sensors performed very well within the whole range of water content, especially the sensors ECH2O EC-5 and ECH2O TE, which also performed surprisingly well in saline conditions. PMID:27854263

  6. Determination of the analytical performance of a headspace capillary gas chromatographic technique and karl Fischer coulometric titration by system calibration using oil samples containing known amounts of moisture.

    PubMed

    Jalbert, J; Gilbert, R; Tétreault, P

    1999-08-01

    Over the past few years, concerns have been raised in the literature about the accuracy of the Karl Fischer (KF) method for assessing moisture in transformer mineral oils. To better understand this issue, the performance of a static headspace capillary gas chromatographic (HS-CGC) technique was compared to that of KF coulometric titration by analyzing moisture in samples containing known amounts of water and various samples obtained from the National Institute of Standards and Technology (NIST). Two modes of adding samples into the KF vessel were used:  direct injection and indirect injection via an azeotropic distillation of the moisture with toluene. Under the conditions used for direct injection, the oil matrix was totally dissolved in the anolyte, which allowed the moisture to be titrated in a single-phase solution rather than in a suspension. The results have shown that when HS-CGC and combined azeotropic distillation/KF titration are calibrated with moisture-in-oil standards, a linear relation is observed over 0-60 ppm H(2)O with a correlation coefficient better than 0.9994 (95% confidence), with the regression line crossing through zero. A similar relation can also be observed when calibration is achieved by direct KF addition of standards prepared with octanol-1, but in this case an intercept of 4-5 ppm is noted. The amount of moisture determined by curve interpolation in NIST reference materials by the three calibrated systems ranges from 13.0 to 14.8 ppm for RM 8506 and 42.5 to 46.4 ppm for RM 8507, and in any case, the results were as high as those reported in the literature with volumetric KF titration. However, titration of various dehydrated oil and solvent samples showed that direct KF titration is affected by a small bias when samples contain very little moisture. The source of error after correction for the large sample volume used for the determination (8 mL) is about 6 ppm for Voltesso naphthenic oil and 4 ppm for toluene, revealing a matrix

  7. [Effects of supplemental irrigation based on the measurement of moisture content in different soil layers on the water consumption characteristics and grain yield of winter wheat].

    PubMed

    Yi, Li-Pan; Yu, Zhen-Wen; Zhang, Yong-Li; Wang, Dong; Shi, Yu; Zhao, Jun-Ye

    2013-05-01

    In 2010-2011, a field experiment with high-yielding winter wheat cultivar Jimai 22 was conducted to study the effects of supplemental irrigation based on the measurement of moisture content in different soil layers on the water consumption characteristics and grain yield of winter wheat. Four soil layers (0-20 cm, W1; 0-40 cm, W2; 0-60 cm, W3; and 0-140 cm, W4) were designed to make the supplemental irrigation at wintering stage (target soil relative moisture content = 75%), jointing stage (target soil relative moisture content = 70%), and anthesis stage (target soil relative moisture content = 70%), taking no irrigation (W0) during the whole growth season as the control. At the wintering, jointing, and anthesis stages, the required irrigation amount followed the order of W3 > W2 > W1. Treatment W4 required smaller irrigation amount at wintering and jointing stages, but significantly higher one at anthesis stage than the other treatments. The proportion of the irrigation amount relative to the total water consumption over the entire growth season followed the sequence of W4, W3 > W2 > W1. By contrast, the proportion of soil water consumption relative to the total water consumption followed the trend of W1 > W2 > W3 > W4. With the increase of the test soil depths, the soil water utilization ratio decreased. The water consumption in 80-140 cm and 160-200 cm soil layers was significantly higher in W2 than in W3 and W4. The required total irrigation amount was in the order of W3 > W4 > W2 > W1, the grain yield was in the order of W2, W3, W4 > W1 > W0, and the water use efficiency followed the order of W2, W4 > W0, W1 > W3. To consider the irrigation amount, grain yield, and water use efficiency comprehensively, treatment W2 under our experimental condition could be the optimal treatment, i. e., the required amount of supplemental irrigation based on the measurement of the moisture content in 0-40 cm soil layer should be feasible for the local winter wheat production.

  8. The Factor Structure of Test Task Characteristics and Examinee Performance

    ERIC Educational Resources Information Center

    Carr, Nathan T.

    2006-01-01

    The present study focuses on the task characteristics of reading passages and key sentences in a test of second language reading. Using a new methodological approach to describe variation in test task characteristics and explore how differences in these characteristics might relate to examinee performance, it posed the two following research…

  9. Preclinical Curriculum Characteristics and Institutional Performance on NBME Part I.

    ERIC Educational Resources Information Center

    Jones, Robert F.; And Others

    1986-01-01

    The relationship between characteristics of the preclinical curriculum and institutional performance on the Part I examination of the National Board of Medical Examiners at U.S. medical schools was analyzed. Total scheduled hours per week was the single curriculum characteristic having a positive and significant relationship with performance.…

  10. A real time approach for revising generation unit performance characteristics

    SciTech Connect

    Viviani, G.L.; Lin, C.E.; Webb, M.G.

    1985-02-01

    This paper presents a unique method for representing the performance characteristics of generation units of electric utilities. The approach utilizes digitally sampled information in an on-line enviroment. The resulting accuracy is superior to conventional approaches, as the true time varying nature of performance characteristics is taken into account.

  11. Moisture sorption kinetics of switchgrass, big bluestem, and bromegrass biomass

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Moisture status in biomass is the most influential factor of biomass storage, and hydration kinetics control the dynamic moisture condition of the biomass, thus affecting biomass storage and processing operations and final utilization applications. Moisture hydration characteristics of switchgrass, ...

  12. Precision moisture generation and measurement.

    SciTech Connect

    Thornberg, Steven Michael; White, Michael I.; Irwin, Adriane Nadine

    2010-03-01

    In many industrial processes, gaseous moisture is undesirable as it can lead to metal corrosion, polymer degradation, and other materials aging processes. However, generating and measuring precise moisture concentrations is challenging due to the need to cover a broad concentration range (parts-per-billion to percent) and the affinity of moisture to a wide range surfaces and materials. This document will discuss the techniques employed by the Mass Spectrometry Laboratory of the Materials Reliability Department at Sandia National Laboratories to generate and measure known gaseous moisture concentrations. This document highlights the use of a chilled mirror and primary standard humidity generator for the characterization of aluminum oxide moisture sensors. The data presented shows an excellent correlation in frost point measured between the two instruments, and thus provides an accurate and reliable platform for characterizing moisture sensors and performing other moisture related experiments.

  13. Performance characteristics of a laser initiated microdetonator

    NASA Technical Reports Server (NTRS)

    Yang, L. C.

    1981-01-01

    The test results of 320 units of a laser initiated microdetonator are summarized. The commercially fabricated units used a lead styphnate/lead azide/HMX (1 mg/13.5 mg) explosive train design contained in a miniature aluminum can that was capped with a glass-metal seal window. The test parameters were the laser energy, temperature, laser pulse duration, laser wavelength and nuclear radiation (5,000,000 rad of 1 MeV gamma rays). The performance parameters were the laser energy for ignition and the actuation response time.

  14. Novel Estimation of Pilot Performance Characteristics

    NASA Technical Reports Server (NTRS)

    Bachelder, Edward N.; Aponso, Bimal

    2017-01-01

    Two mechanisms internal to the pilot that affect performance during a tracking task are: 1) Pilot equalization (i.e. lead/lag); and 2) Pilot gain (i.e. sensitivity to the error signal). For some applications McRuer's Crossover Model can be used to anticipate what equalization will be employed to control a vehicle's dynamics. McRuer also established approximate time delays associated with different types of equalization - the more cognitive processing that is required due to equalization difficulty, the larger the time delay. However, the Crossover Model does not predict what the pilot gain will be. A nonlinear pilot control technique, observed and coined by the authors as 'amplitude clipping', is shown to improve stability, performance, and reduce workload when employed with vehicle dynamics that require high lead compensation by the pilot. Combining linear and nonlinear methods a novel approach is used to measure the pilot control parameters when amplitude clipping is present, allowing precise measurement in real time of key pilot control parameters. Based on the results of an experiment which was designed to probe workload primary drivers, a method is developed that estimates pilot spare capacity from readily observable measures and is tested for generality using multi-axis flight data. This paper documents the initial steps to developing a novel, simple objective metric for assessing pilot workload and its variation over time across a wide variety of tasks. Additionally, it offers a tangible, easily implementable methodology for anticipating a pilot's operating parameters and workload, and an effective design tool. The model shows promise in being able to precisely predict the actual pilot settings and workload, and observed tolerance of pilot parameter variation over the course of operation. Finally, an approach is proposed for generating Cooper-Harper ratings based on the workload and parameter estimation methodology.

  15. Job Characteristics, Work Involvement, and Job Performance of Public Servants

    ERIC Educational Resources Information Center

    Johari, Johanim; Yahya, Khulida Kirana

    2016-01-01

    Purpose: The primary purpose of this study is to assess the predicting role of job characteristics on job performance. Dimensions in the job characteristics construct are skill variety, task identity, task significance, autonomy and feedback. Further, work involvement is tested as a mediator in the hypothesized link. Design/methodology/approach: A…

  16. Evaluation of soil moisture data products over Indian region and analysis of spatio-temporal characteristics with respect to monsoon rainfall

    NASA Astrophysics Data System (ADS)

    Sathyanadh, Anusha; Karipot, Anandakumar; Ranalkar, Manish; Prabhakaran, Thara

    2016-11-01

    Soil moisture (SM) is an essential climate variable of greater relevance in the monsoon scenario, hence validation and understanding of its spatio-temporal variability over the Indian region is of high significance. In the present study, five SM products are evaluated against in situ SM measurements conducted by India Meteorological Department and the selected data product is used for spatio-temporal characterization of SM in relation to monsoon rainfall. The data products evaluated are: European Space Agency's merged satellite SM, Modern-Era Retrospective analysis for Research and Applications (MERRA) Land SM, ECMWF's ERA interim SM, Climate Forecast System Reanalysis SM, and Global Land Data Assimilation System Noah Land Surface Model SM. Comparisons show that seasonal SM patterns in all products generally follow the characteristics of rainfall, even though there are certain differences in details. The statistical estimates indicate fairly good agreement between in situ and the five products, with some variations among them and over the homogeneous rainfall regions. On comparison, MERRA SM is found appropriate for further analyses on spatio-temporal characteristics, which are then carried out with the 20 year (1993-2012) SM data. Stability analyses revealed SM patterns indicative of relative SM variability as well as persistence. The spatial stability analysis depicts dry and wet patterns and their seasonal variations over different geographical locations in relation to all India spatial average. Large temporal variations are found over central, western and northern Indian regions caused by large intraseasonal variability in rainfall. In brief, intraseasonal and interannual soil moisture variations broadly follow the rainfall pattern, with long-term influences attributed to SM memory effects. The soil moisture persistence and dominant scales of variability are explored with autocorrelation and wavelet transform techniques. Seasonal persistence is large over

  17. Sensor Technology Performance Characteristics- Field and Laboratory Observations

    EPA Science Inventory

    Observed Intangible Performance Characteristics RH and temperature impacts may be significant for some devices Internal battery lifetimes range from 4 to 24 hoursSensor packaging can interfere with accurate measurements (reactivity)Wireless communication protocols are not foolpr...

  18. Design and Performance of an Impedance Analyzer for Nondestructive Moisture Content Determination of In-Shell Peanuts

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Moisture content (MC) in peanuts is measured at various stages of their processing and storage in the peanut industry. A method was developed earlier that would estimate the MC of a small sample of in-shell peanuts (peanut pods) held between two circular parallel-plates, from the values of capacita...

  19. Indoor climate and moisture durability performances of houses with unvented attic roof constructions in a mixed-humid climate.

    SciTech Connect

    Pallin, Simon B.; Boudreaux, Philip R.; Jackson, Roderick K.

    2014-10-01

    A sealed or unvented attic is an energy-efficient envelope component that can reduce the amount of energy a house consumes for space conditioning if the air handler and/or ducts are located in the attic. The attic is typically sealed by using spray foam on the underside of the roof deck and covering the soffit, ridge and gable vents to minimize air leakage from the attic to the outside. This approach can save up to 10% in space-conditioning energy when ducts are located in the attic (DOE 2013). Past research done by ORNL and Florida Solar Energy Center suggests that in more hot, humid climates, an unvented attic could potentially create a more humid, uncomfortable living environment than a vented attic (Colon 2011, Boudreaux, Pallin et al. 2013). Research showed that controlling the higher indoor humidity could reduce the energy savings from the sealed, unvented attic, which in turn would decrease the energy savings payback. Research also showed that the roof assembly (5.5 inches of open-cell foam, 1inch of closed-cell foam, OSB, felt paper, and asphalt shingles) stored moisture, thus acting as a moisture buffer. During the fall and winter, the roof assembly stored moisture and during the spring and summer it released moisture. This phenomenon is not seen in a vented attic, in which the air exchange rate to the outside is greater and, in the winter, helps to dehumidify the attic air. It was also seen that in a vented attic, the direction of water vapor diffusion is on average from the attic to the interior of the house. Air leakage from the attic to the interior also occurs during more of the year in a house with an unvented attic than in one with a vented attic. These discoveries show that the moisture dynamics in a house with an unvented attic are much different from those in a house with a vented attic. This study reports on a series of computer model investigations completed to determine the key variables impacting indoor comfort and the durability of roof

  20. The impact of the uncertainty in the initial soil moisture condition of irrigated areas on the spatiotemporal characteristics of convective activity in Central Greece

    NASA Astrophysics Data System (ADS)

    Kotsopoulos, Stylianos; Ioannis, Tegoulias; Ioannis, Pytharoulis; Stergios, Kartsios; Dimitrios, Bampzelis; Theodore, Karacostas

    2015-04-01

    The region of Thessaly is the second largest plain in Greece and has a vital role in the financial life of the country, because of its significant agricultural production. The intensive and extensive cultivation of irrigated crops, in combination with the population increase and the alteration of precipitation patterns due to climate change, often leading the region to experience severe drought conditions, especially during the warm period of the year. The aim of the DAPHNE project is to tackle the problem of drought in this area by means of Weather Modification.In the framework of the project DAPHNE, the numerical weather prediction model WRF-ARW 3.5.1 is used to provide operational forecasts and hindcasts for the region of Thessaly. The goal of this study is to investigate the impact of the uncertainty in the initial soil moisture condition of irrigated areas, on the spatiotemporal characteristics of convective activity in the region of interest. To this end, six cases under the six most frequent synoptic conditions, which are associated with convective activity in the region of interest, are utilized, considering six different soil moisture initialization scenarios. In the first scenario (Control Run), the model is initialized with the surface soil moisture of the ECMWF analysis data, that usually does not take into account the modification of soil moisture due to agricultural activity in the area of interest. In the other five scenarios (Experiment 1,2,3,4,5) the soil moisture in the upper soil layers of the study area are modified from -50% to 50% of field capacity (-50%FC, -25%FC, FC, 25%FC, 50%FC),for the irrigated cropland.Three model domains, covering Europe, the Mediterranean Sea and northern Africa (d01), the wider area of Greece (d02) and central Greece - Thessaly region (d03) are used at horizontal grid-spacings of 15km, 5km and 1km respectively. ECMWF operational analyses at 6-hourly intervals (0.25ox0.25o lat.-long.) are imported as initial and

  1. Relationships of physician characteristics to performance quality and improvement.

    PubMed Central

    Payne, B C; Lyons, T F; Neuhaus, E

    1984-01-01

    The quality of ambulatory medical care provided by 1,135 physicians in five separate practice settings in the Midwest was measured using predetermined process criteria. Specialists performed better in their own areas of specialized training than did family/general practitioners or specialists performing outside their specialty areas. Physicians with fewer years of practice performed somewhat better than physicians with more years since medical school graduation. Board certification was not consistently related to performance. Performances of the physicians improved following quality assurance interventions in these sites. Differences in the rates of change in performance quality were not consistently related to any of the physician characteristics studied. PMID:6746295

  2. [Effects of supplemental irrigation by measuring moisture content in different soil layers on water consumption characteristics, photosynthesis and grain yield of winter wheat].

    PubMed

    Man, Jian-guo; Yu, Zhen-wen; Shi, Yu; Zhang, Yong-li

    2015-08-01

    Field experiments were conducted during 2012-2014 winter wheat growing seasons. Six irrigation treatments were designed: rainfed, W0; a local irrigation practice that irrigated at jointing and anthesis with 60 mm each time, W1; four irrigation treatments were designed with target relative soil moisture of 65% field capacity (FC) at jointing and 70% FC at anthesis in 0-20 (W2) 0-40 (W3), 0-60 (W4) , and 0-140 cm (W5) soil layers, respectively, to study the effects of supplemental irrigation by measuring moisture content in different soil layers on water consumption characteristics and photosynthesis and grain yield of winter wheat. The irrigation amounts at jointing in W1 and W4 were the highest, followed by W3 treatment, W2 and W5 were the lowest. The irrigation amounts at anthesis and total irrigation amounts were ranked as W5 > Wl, W4 > W3 > W2, the total water consumption in W3 was higher than that in W2, but had no difference with that in W1, W4 and W5 treatments, W3 had the higher soil water consumption than W1, W4 and W5 treatments, and the soil water consumption in 40-140 cm soil layers from jointing to anthesis and in 60-140 cm soil layers from anthesis to maturity in W3 were significantly higher than the other treatments. The photosynthetic rate, transpiration rate and water use efficiency of flag leaf at middle stage of grain filling from the W3 treatment were the highest, followed by the W1 and W4 treatments, and W0 treatment was the lowest. In the two growing seasons, the grain yield and water use efficiency in the W3 were 9077-9260 kg · hm(-2) and 20.7-20.9 kg · hm(-2) · mm(-1), respectively, which were higher than those from the other treatments, and the irrigation water productivity in the W3 was the highest. As far as high-yield and high-water use efficiency were concerned in this experiment, the most appropriate soil layer for measuring moisture content was 0-40 cm.

  3. Influence of the feed moisture, rotor speed, and blades gap on the performances of a biomass pulverization technology.

    PubMed

    Luo, Siyi; Zhou, Yangmin; Yi, Chuijie; Luo, Yin; Fu, Jie

    2014-01-01

    Recently, a novel biomass pulverization technology was proposed by our group. In this paper, further detailed studies of this technology were carried out. The effects of feed moisture and crusher operational parameters (rotor speed and blades gap) on product particle size distribution and energy consumption were investigated. The results showed that higher rotor speed and smaller blades gap could improve the hit probability between blades and materials and enhance the impacting and grinding effects to generate finer products, however, resulting in the increase of energy consumption. Under dry conditions finer particles were much more easily achieved, and there was a tendency for the specific energy to increase with increasing feed moisture. Therefore, it is necessary for the raw biomass material to be dried before pulverization.

  4. Covariance of engineering management characteristics with engineering employee performance

    NASA Astrophysics Data System (ADS)

    Hesketh, Andrew Arthur

    1998-12-01

    As business in the 1990's grapples with the impact of continuous improvement and quality to meet market demands, there is an increased need to improve the leadership capabilities of our managers. Engineers have indicated desire for certain managerial characteristics in their leadership but there have been no studies completed that approached the problem of determining what managerial characteristics were best at improving employee performance. This study addressed the idea of identifying certain managerial characteristics that enhance employee performance. In the early 1990's, McDonnell Douglas Aerospace in St. Louis used a forced distribution system and allocated 35% of its employees into a "exceeds expectations" category and 60% into a "meets expectations" category. A twenty-question 5 point Likert scale survey on managerial capabilities was administered to a sample engineering population that also obtained their "expectations" category. A single factor ANOVA on the survey results determined a statistical difference between the "exceeds" and "meets" employees with four of the managerial capability questions. The "exceeds expectations" employee indicated that supervision did a better job of supporting subordinate development, clearly communicating performance expectations, and providing timely performance feedback when compared to the "meets expectations" employee. The "meets expectations" employee felt that their opinions, when different from their supervisor's, were more often ignored when compared to the "exceeds expectations" employee. These four questions relate to two specific managerial characteristics, "gaining (informal) authority and support" or "control" characteristic and "providing assistance and guidance" or "command" characteristic, that can be emphasized in managerial training programs.

  5. Effect of Moisture Content on Thermal Properties of Porous Building Materials

    NASA Astrophysics Data System (ADS)

    Kočí, Václav; Vejmelková, Eva; Čáchová, Monika; Koňáková, Dana; Keppert, Martin; Maděra, Jiří; Černý, Robert

    2017-02-01

    The thermal conductivity and specific heat capacity of characteristic types of porous building materials are determined in the whole range of moisture content from dry to fully water-saturated state. A transient pulse technique is used in the experiments, in order to avoid the influence of moisture transport on measured data. The investigated specimens include cement composites, ceramics, plasters, and thermal insulation boards. The effect of moisture-induced changes in thermal conductivity and specific heat capacity on the energy performance of selected building envelopes containing the studied materials is then analyzed using computational modeling of coupled heat and moisture transport. The results show an increased moisture content as a substantial negative factor affecting both thermal properties of materials and energy balance of envelopes, which underlines the necessity to use moisture-dependent thermal parameters of building materials in energy-related calculations.

  6. Soil Moisture State and Hydrologic Process

    NASA Astrophysics Data System (ADS)

    Western, A. W.; Grayson, R. B.; Blöschl, G.; Wilson, D.; Longobardi, A.; Villani, P.; Duncan, M.

    It has long been recognized that soil moisture has a key role in controlling evapo- transpiration during dryer periods, as well as runoff processes, particularly saturation excess runoff. The temporal and spatial variability of moisture can be an important influence on the temporal and spatial characteristics of these processes. More recently, the role of soil moisture in controlling lateral flow processes has re- ceived close attention, with switching between persistent dry and wet states leading to switches between controls on spatial patterns of soil moisture and consequent changes in runoff behaviour. In this paper we will review results on the spatial and temporal variability of soil moisture at the small catchment scale, concentrating in particular on dominant controls and temporal changes in dominant controls. We will discuss the climatic and catchment characteristics under which switching between dominant controls is likely. We will also present results relating spatial soil moisture behaviour to soil moisture state and relating rainfall-runoff response to moisture state: in particular we investi- gated the relationships between the basin soil moisture dynamic and the occurrence of very extreme flood events. The spatial probability density function of soil moisture is bounded by wilting point and porosity. This bounding combined with catchment processes leads to a strong link between spatial variance and spatial mean soil mois- ture, with an initial increase in variance followed by a decrease as mean soil moisture increases from wilting point to saturation. Changes in the spatial control of soil mois- ture and the relationship between soil moisture and terrain also occur as the spatial controls on the soil moisture pattern change in response to mean soil moisture. Strong links between the changes in the spatial characteristics of soil moisture will be demon- strated and the potential of measurements of soil moisture to provide information on catchment state

  7. [Change characteristics of soil moisture and nutrients in rain-fed winter wheat field under different fertilization modes in Southern Shanxi of China during summer fallow period].

    PubMed

    Li, Ting-Liang; Xie, Ying-He; Hong, Jian-Ping; Feng, Qian; Sun, Cheng-Hong; Wang, Zhi-Wei

    2013-06-01

    In 2009-2011, a field experiment was conducted in a rain-fed winter wheat field in Southern Shanxi of China to study the effects of different fertilization modes on the change characteristics of soil moisture and nitrate-N contents in 0-200 cm layer and of soil available phosphorus (Oslen-P) and potassium contents in 0-40 cm layer during summer fallow period (from June to September). Three fertilization modes were installed, i. e., conventional fertilization (CF), recommended fertilization (RF), and ridge film furrow planting (RFFP) combined with straw mulch. The results showed that the rainfall in summer fallow period could complement the consumed water in 0-200 cm soil layer in dryland wheat field throughout the growth season, and more than 94% of the water storage was in 0-140 cm soil layer, with the fallow efficiency ranged from 6% to 27%. The rainfall in summer fallow period caused the soil nitrate-N moving downward. 357-400 mm rainfall could make the soil nitrate-N leaching down to 100 cm soil layer, with the peak in 20-40 cm soil layer. Straw mulching or plastic film with straw mulch in summer fallow period could effectively increase the Oslen-P and available K contents in 0-40 cm soil layer, and the accumulative increment in three summer fallow periods was 16-45% and 36-49%, respectively. Among the three modes, the binary coverage mode of RFFP plus furrow straw mulching had the best effect in maintaining soil water and fertility. The accumulative water storage and mineral N in 0-200 cm soil layer in three summer fallow periods were up to 215 mm and 90 kg x hm(-2), and the accumulative Oslen-P and available K contents in plough layer were increased by 2.7 mg x kg(-1) and 83 mg x kg(-1), respectively, being significantly higher than those in treatments CF and RF. There were no significant differences in the change characteristics in the soil moisture and nutrients between treatments CF and RF.

  8. Effects of isoprene production on the photosynthetic performance of Poplars (Populus sp.) under thermal and moisture stress

    NASA Astrophysics Data System (ADS)

    Parra, E. A.; McFarland, E.; Minor, R. L.; Heard, M. M.; Barron-Gafford, G.

    2015-12-01

    Poplars are an important agro-forestry product used for both biofuel and paper production. Importantly, all poplars are not created equal - some have the potential to produce isoprene, a compound thought to aid plants under temperatures and water stress conditions. Isoprene production, then, would be an important feature in a plant's response to projected climatic changes of warmer temperatures and longer inter-storm periods of drought. Our project observed how drought conditions modulated photosynthetic rates in two lineages of Populus trees, those that produce isoprene and those that have had isoprene gene knocked out. We measured leaf-level photosynthesis and thermal sensitivity from the two lineages under high and low soil water conditions in a common garden experiment. We found that both lines had similar photosynthetic rates over the range of temperatures and water exposure levels measured. However, we wondered if some of the variation we found in our data was due to the time of day of the measurements. Subsequent measurements of photosynthetic rates in the morning and afternoon on the same leaves illustrated that poplars reached higher rates of photosynthesis in the morning, but ultimately decreased faster than observed in the afternoon measurements (indicative of an eased thermal sensitivity in the afternoon). Also, we used measures of soil moisture and leaf water potential to determine that the "drought" treatment we had induced didn't actually yield any differences in the moisture status among the trees. Ultimately, our experiment showed that isoprene did not aid in photosynthesis under heat stressed conditions and that the common garden setting was not able to currently induce a water stress condition in the plants. We have begun exploring the use of low-altitude remote sensing by an unmanned aerial vehicles outfitted with thermal and multi-spectral cameras to quantify patterns of transpirational water loss, NDVI, leaf browning due to moisture stress

  9. Certain Organizational Characteristics Affect ACO Preventive Care Quality Performance.

    PubMed

    Ticse, Caroline

    2016-06-01

    Key findings. (1) ACOs at provider workforce extremes--few primary care providers or many specialists--performed worse on measures of preventive care quality relative to those with more PCPs and fewer specialists. (2) Upfront investment in ACO formation is associated with higher performance in preventive care quality. (3) ACOs with a higher proportion of minority beneficiaries performed worse on disease prevention measures than did ACOs with a lower proportion of minority beneficiaries. (4) ACOs facing barriers to quality performance may benefit from organizational characteristics such as electronic health record capabilities and hospital inclusion in the ACO.

  10. Transactive memory system links work team characteristics and performance.

    PubMed

    Zhang, Zhi-Xue; Hempel, Paul S; Han, Yu-Lan; Tjosvold, Dean

    2007-11-01

    Teamwork and coordination of expertise among team members with different backgrounds are increasingly recognized as important for team effectiveness. Recently, researchers have examined how team members rely on transactive memory system (TMS; D. M. Wegner, 1987) to share their distributed knowledge and expertise. To establish the ecological validity and generality of TMS research findings, this study sampled 104 work teams from a variety of organizational settings in China and examined the relationships between team characteristics, TMS, and team performance. The results suggest that task interdependence, cooperative goal interdependence, and support for innovation are positively related to work teams' TMS and that TMS is related to team performance; moreover, structural equation analysis indicates that TMS mediates the team characteristics-performance links. Findings have implications both for team leaders to manage their work teams effectively and for team members to improve their team performance.

  11. Performance characteristics of proximity focused ultraviolet image converters

    NASA Technical Reports Server (NTRS)

    Williams, J. T.; Feibelman, W. A.

    1973-01-01

    Performance characteristics of Bendix type BX 8025-4522 proximity focused image tubes for ultraviolet to visible light conversion are presented. Quantum efficiency, resolution, background, geometric distortion, and environmental test results are discussed. The converters use magnesium fluoride input windows with Cs - Te photocathodes, and P-11 phosphors on fiber optic output windows.

  12. Do the Managerial Characteristics of Schools Influence Their Performance?

    ERIC Educational Resources Information Center

    Agasisti, Tommaso; Bonomi, Francesca; Sibiano, Piergiacomo

    2012-01-01

    Purpose: The purpose of this paper is to investigate the role of governance and managerial characteristics of schools. More specifically, the aim is to individuate the factors that are associated to higher schools' performances, as measured through student achievement. Design/methodology/approach: The research is conducted by means of a survey in…

  13. Performance and carcass characteristics of growing pigs fed crude glycerol

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Performance and carcass characteristics of growing pigs fed crude glycerol, a co-product of biodiesel production, were determined in a 138-d feeding trial conducted at the Iowa State University Swine Nutrition Research Farm, Ames, IA. Pigs were weaned at 21d of age and were fed a commercial starter-...

  14. Artemisia dominant species succession relating to the soil moisture decrease in abandoned land of the Loess Plateau (China): comparative study of drought-adaptive characteristics.

    PubMed

    Wang, Yong; Yu, Jing; Xia, Pengguo; He, Shaoxuan; Zhou, Ziyun; Han, Ruilian; Liang, Zongsuo

    2016-01-01

    Artemisia scoparia, Artemisia sacrorum and Artemisia giraldii were three dominant Artemisia species which successive grew in the secondary succession on abandoned land of the Loess Plateau. The succession accompanied the soil moisture steady decrease with field age after their abandonment. To elucidate the relationship between the Artemisia species succession and their drought-adaptation, three dominant species and a contrastive species Artemisia annua (mesophyte), were selected to compare their drought-resistant characteristics, including morphological and anatomical traits of leaf and root. Then physiological responses were investigated in mature plants after drought treatment. The results indicated that three dominant species leaf presented drought-adaptive structures, such as bushy trichomes, transitional or isolateral leaf cells, thick cuticles and epidermal cells. However, A. annua had no leaf traits involved in drought-adaptation. In addition, A. sacrorum and A. giraldii contained large root systems, while A. scoparia and A. annua utilized succulent roots. The physiological responses to drought suggested that A. giraldii had strong regulation in water using strategy, growth, as well as superoxide dismutase and catalase activity. A. sacrorum and A. giraldii could maintain high ascorbate peroxidase activity and malondialdehyde content, while A. scoparia and A. giraldii presented higher peroxidase activity, ascorbate and soluble sugar content. A. annua exhibited high proline and carotenoid contents under drought. The drought-resistant of the four Artemisia species presented the order of A. giraldii > A. sacrorum > A. scoparia > A. annua, which was consistent with their succession on abandoned land.

  15. Detecting Moisture In Buildings Using Infrared Thermography

    NASA Astrophysics Data System (ADS)

    Marshall, Stephen J.

    1981-01-01

    Visual examination is a reliable means of moisture detection in building walls after serious damaR'e has been done. Traditional spot measurement instruments are inexpedient devices for elusive moisture detection in heterogeneous materials. The infrared thermal imaging system was found t be a more versatile tool for in-situ moisture detection because of its unique characteristics. Several thermographic examples of moisture detection in. building walls are presented, which will aid the reader in the qualitative interpretation o1 therm.ograms 1or moisture problem.s.

  16. GNSSProbe, penetrating GNSS signals for measuring soil moisture

    NASA Astrophysics Data System (ADS)

    Martin, Francisco; Navarro, Victor; Reppucci, Antonio; Mollfulleda, Antonio; Balzter, Heiko; Nicolas-Perea, Virginia; Kissick, Lucy

    2016-04-01

    Soil moisture content (SMC) is an essential parameter from both a scientific and economical point of view. On one hand, it is key for the understanding of hydrological. Secondly, it is a most relevant parameter for agricultural activities and water management. Wide research has been done in this field using different sensors, spanning different parts of the measured electromagnetic spectrum, leading thus several methodologies to estimate soil moisture content. However complying with requirements in terms of accuracy and spatial resolution is still a major challenge. A novel approach based on the measurement of GNSS signals penetrating a soil volume is proposed here. This model relates soil moisture content to the measured soil transmissivity, and attenuation coefficient, which are a function of the soil characteristics (i.e soil moisture content, soit type, soil temperature, etc). A preliminary experiment has been performed to demonstrate the validity of this technique, where the signal received by a GNSS-R L1/E1 RHCP antenna buried at 5, 10, and 15 cm below the surface, was compared to the one received by a GNSS-R L1/E1 RHCP antenna with clear sky visibility. Preliminary results show agreement with theoretical results based on transmissivity and with previous campaigns performed where the soil moisture were collected at two different depths (5 and 15 cm). Details related to the GNSS soil moisture modeling, instrument preparation, measurement campaign, data processing and main results will be presented at the conference.

  17. Evaluation of D-1 tape and cassette characteristics: Moisture content of Sony and Ampex D-1 tapes when delivered

    NASA Astrophysics Data System (ADS)

    Ashton, Gary

    Commercial D-1 cassette tapes and their associated recorders were designed to operate in broadcast studios and record in accordance with the International Radio Consultative Committee (CCIR) 607 digital video standards. The D-1 recorder resulted in the Society of Motion Picture and Television Engineers (SMPTE) standards 224 to 228 and is the first digital video recorder to be standardized for the broadcast industry. The D-1 cassette and associated media are currently marketed for broadcast use. The recorder was redesigned for data applications and is in the early stages of being evaluated. The digital data formats used are specified in MIL-STD-2179 and the American National Standards Institute (ANSI) X3.175-190 standard. In early 1990, the National Media Laboratory (NML) was asked to study the effects of time, temperature, and relative humidity on commercial D-1 cassettes. The environmental range to be studied was the one selected for the Advanced Tactical Air Reconnaissance System (ATARS) program. Several discussions between NML personnel, ATARS representatives, recorder contractors, and other interested parties were held to decide upon the experimental plan to be implemented. Review meetings were held periodically during the course of the experiment. The experiments were designed to determine the dimensional stability of the media and cassette since this is one of the major limiting factors of helical recorders when the media or recorders are subjected to non-broadcasting environments. Measurements were also made to characterize each sample of cassettes to give preliminary information on which purchase specifications could be developed. The actual tests performed on the cassettes and media before and after aging fall into the general categories listed.

  18. General performance characteristics of an irreversible ferromagnetic Stirling refrigeration cycle

    NASA Astrophysics Data System (ADS)

    Lin, G.; Tegus, O.; Zhang, L.; Brück, E.

    2004-02-01

    A new magnetic-refrigeration-cycle model using ferromagnetic materials as a cyclic working substance is set up, in which finite-rate heat transfer, heat leak and regeneration time are taken into account. On the basis of the thermodynamic properties of a ferromagnetic material, the general performance characteristics of the ferromagnetic Stirling refrigeration cycle are investigated and the effects of some key irreversibilities on the performance of the cycle are revealed. By using the optimal-control theory, the optimal relation between the coefficient of performance and the cooling rate is derived and some important performance bounds, e.g., the maximum cooling rate, the maximum coefficient of performance, are determined. Moreover, the optimal operating regions for cooling rate, coefficient of performance and the optimal operating temperatures of a cyclic working substance in the two heat-transfer processes are obtained. Furthermore, the influences of magnetization and magnetic field on the performance characteristics of the cycle are discussed. The results obtained here have general significance and can be deduced to the related ones of the Stirling refrigeration cycle using paramagnetic salt as a cyclic working substance.

  19. Computational studies on small wind turbine performance characteristics

    NASA Astrophysics Data System (ADS)

    Karthikeyan, N.; Suthakar, T.

    2016-10-01

    To optimize the selection of suitable airfoils for small wind turbine applications, computational investigation on aerodynamic characteristics of low Re airfoils MID321a, MID321d, SG6040, SG6041, SG6042 and SG6043 are carried out for the Reynolds number range of (0.5- 2)×105. The BEM method is used to determine the power coefficient of the rotor from the airfoil characteristics; in addition, the blade parameters like chord and twist are also determined. The newly designed MID321a airfoil shows better aerodynamic performance and maximum power coefficient as compared with other investigated airfoils for wider operating ranges.

  20. Auditory virtual environment with dynamic room characteristics for music performances

    NASA Astrophysics Data System (ADS)

    Choi, Daniel Dhaham

    A room-adaptive system was designed to simulate an electro-acoustic space that changes room characteristics in real-time according to the content of sound. In this specific case, the focus of the sound components is on the different styles and genres of music. This system is composed of real-time music recognition algorithms that analyze the different elements of music, determine the desired room characteristics, and output the acoustical parameters via multi-channel room simulation mechanisms. The system modifies the acoustic properties of a space and enables it to "improvise" its acoustical parameters based on the sounds of the music performances.

  1. Performance Characteristics of Absorption Hybrid Cycle Introduced Compressor

    NASA Astrophysics Data System (ADS)

    Iyoki, Shigeki; Kotani, Yuji; Uemura, Tadashi

    In this paper, four kinds of absorption hybrid cycle which introduced the compressor in the absorption cycle were proposed. As basic cycle of absorption refrigerating machine, the following were chosen: two kinds of single-stage absorption refrigerating machine and two kinds of double effect absorption refrigerating machine. As a working medium-absorbent system, NH3-H2O system, C2H5NH2-H2O system and C2H5NH2-H2O-LiBr system were adopted. Using these three kinds of working medium-absorbent system, the performance characteristics of four kinds of absorption hybrid cycle were simulated. And the performance characteristics of these cycles were compared.

  2. Moisture adsorption in optical coatings

    NASA Technical Reports Server (NTRS)

    Macleod, H. Angus

    1988-01-01

    The thin film filter is a very large aperture component which is exceedingly useful because of its small size, flexibility and ease of mounting. Thin film components, however, do have defects of performance and especially of stability which can cause problems in systems, particularly where long-term measurements are being made. Of all of the problems, those associated with moisture absorption are the most serious. Moisture absorption occurs in the pore-shaped voids inherent in the columnar structure of the layers. Ion-assisted deposition is a promising technique for substantially reducing moisture adsorption effects in thin film structures.

  3. Performance characteristics of 1977 Ford 300 Cid engine. Final report

    SciTech Connect

    Boziuk, J.

    1980-02-01

    Experimental data were obtained in dynamometer tests of a 1977 Ford 300 CID engine to determine fuel consumption and emissions (hydrocarbons, carbon monoxide, and oxides of nitrogen) at steady-state engine operating modes. The objective of the test was to obtain engine performance data for estimating fuel consumption and emissions for varied engine service and duty and to provide basic engine characteristic data required for the TSC Vehicle Simulator (VEHSIM).

  4. Performance characteristics of 1977 Chrysler 318 Cid engine. Final report

    SciTech Connect

    Boziuk, J.

    1980-02-01

    Experimental data were obtained in dynamometer tests of a 1977 Chrysler 318 CID engine to determine fuel consumption and emissions (hydrocarbons, carbon monoxide, and oxides of nitrogen) at steady-state engine operating modes. The objective of the test was to obtain engine performance data for estimating fuel consumption and emissions for varied engine service and duty and to provide basic engine characteristic data required for the TSC Vehicle Simulator (VEHSIM).

  5. Estimating Sahelian and East African soil moisture using the Normalized Difference Vegetation Index

    NASA Astrophysics Data System (ADS)

    McNally, A.; Funk, C.; Husak, G. J.; Michaelsen, J.; Cappelaere, B.; Demarty, J.; Pellarin, T.; Young, T. P.; Caylor, K. K.; Riginos, C.; Veblen, K. E.

    2013-06-01

    Rainfall gauge networks in Sub-Saharan Africa are inadequate for assessing Sahelian agricultural drought, hence satellite-based estimates of precipitation and vegetation indices such as the Normalized Difference Vegetation Index (NDVI) provide the main source of information for early warning systems. While it is common practice to translate precipitation into estimates of soil moisture, it is difficult to quantitatively compare precipitation and soil moisture estimates with variations in NDVI. In the context of agricultural drought early warning, this study quantitatively compares rainfall, soil moisture and NDVI using a simple statistical model to translate NDVI values into estimates of soil moisture. The model was calibrated using in-situ soil moisture observations from southwest Niger, and then used to estimate root zone soil moisture across the African Sahel from 2001-2012. We then used these NDVI-soil moisture estimates (NSM) to quantify agricultural drought, and compared our results with a precipitation-based estimate of soil moisture (the Antecedent Precipitation Index, API), calibrated to the same in-situ soil moisture observations. We also used in-situ soil moisture observations in Mali and Kenya to assess performance in other water-limited locations in sub Saharan Africa. The separate estimates of soil moisture were highly correlated across the semi-arid, West and Central African Sahel, where annual rainfall exhibits a uni-modal regime. We also found that seasonal API and NDVI-soil moisture showed high rank correlation with a crop water balance model, capturing known agricultural drought years in Niger, indicating that this new estimate of soil moisture can contribute to operational drought monitoring. In-situ soil moisture observations from Kenya highlighted how the rainfall-driven API needs to be recalibrated in locations with multiple rainy seasons (e.g., Ethiopia, Kenya, and Somalia). Our soil moisture estimates from NDVI, on the other hand, performed

  6. Internal performance characteristics of short convergent-divergent exhaust nozzles designed by the method of characteristics

    NASA Technical Reports Server (NTRS)

    Krull, H George; Beale, William T

    1956-01-01

    Internal performance data on a short exhaust nozzle designed by the method of characteristics were obtained over a range of pressure ratios from 1.5 to 22. The peak thrust coefficient was not affected by a shortened divergent section, but it occurred at lower pressure ratios due to reduction in expansion ratio. This nozzle contour based on characteristics solution gave higher thrust coefficients than a conical convergent-divergent nozzle of equivalent length. Abrupt-inlet sections permitted a reduction in nozzle length without a thrust-coefficient reduction.

  7. Performance and Characteristics of Heat Pump Clothes Drier

    NASA Astrophysics Data System (ADS)

    Ambarita, H.; Nasution, D. M.; Gunawan, S.; Nasution, A. H.

    2017-03-01

    In this paper, a study of clothes drying using a heat pump drier has been carried out. The objective is to examine the performance and drying characteristics of the heat pump clothes dryer. The result of performances and drying characteristics were compared with waste heat drying system of split-type residential air conditioner (RAC). A drying chamber with volume 1 m3 integrated with heat pump component had been designed and fabricated. The heat pump operated by vapor compression cycle with power input of 800W and refrigerant R22 as a working fluid. The clothes dried made of pure cotton with initial weight varied from 3.00 kg, 5.25 kg, and 6.38 kg, respectively. The results shown that the drying time and drying rate of heat pump drier are faster than waste heat drying system. The average total performance of heat pump clothes drier is 6.56. On the other hand, SMER which is obtained 1.492 kg/kWh. These values are lower than the SMER of waste heat drying system which shown the average value of 2.492 kg/kWh. In the case of drying clothes, waste heat drying of RAC shows a better performance in comparison with heat pump drying system.

  8. Numerical and experimental studies on effects of moisture content on combustion characteristics of simulated municipal solid wastes in a fixed bed

    SciTech Connect

    Sun, Rui; Ismail, Tamer M.; Ren, Xiaohan; Abd El-Salam, M.

    2015-05-15

    Highlights: • The effects of moisture content on the burning process of MSW are investigated. • A two-dimensional mathematical model was built to simulate the combustion process. • Temperature distributions, process rates, gas species were measured and simulated. • The The conversion ratio of C/CO and N/NO in MSW are inverse to moisture content. - Abstract: In order to reveal the features of the combustion process in the porous bed of a waste incinerator, a two-dimensional unsteady state model and experimental study were employed to investigate the combustion process in a fixed bed of municipal solid waste (MSW) on the combustion process in a fixed bed reactor. Conservation equations of the waste bed were implemented to describe the incineration process. The gas phase turbulence was modeled using the k–ε turbulent model and the particle phase was modeled using the kinetic theory of granular flow. The rate of moisture evaporation, devolatilization rate, and char burnout was calculated according to the waste property characters. The simulation results were then compared with experimental data for different moisture content of MSW, which shows that the incineration process of waste in the fixed bed is reasonably simulated. The simulation results of solid temperature, gas species and process rate in the bed are accordant with experimental data. Due to the high moisture content of fuel, moisture evaporation consumes a vast amount of heat, and the evaporation takes up most of the combustion time (about 2/3 of the whole combustion process). The whole bed combustion process reduces greatly as MSW moisture content increases. The experimental and simulation results provide direction for design and optimization of the fixed bed of MSW.

  9. Using soil moisture forecasts for sub-seasonal summer temperature predictions in Europe

    NASA Astrophysics Data System (ADS)

    Orth, René; Seneviratne, Sonia I.

    2014-12-01

    Soil moisture exhibits outstanding memory characteristics and plays a key role within the climate system. Especially through its impacts on the evapotranspiration of soils and plants, it may influence the land energy balance and therefore surface temperature. These attributes make soil moisture an important variable in the context of weather and climate forecasting. In this study we investigate the value of (initial) soil moisture information for sub-seasonal temperature forecasts. For this purpose we employ a simple water balance model to infer soil moisture from streamflow observations in 400 catchments across Europe. Running this model with forecasted atmospheric forcing, we derive soil moisture forecasts, which we then translate into temperature forecasts using simple linear relationships. The resulting temperature forecasts show skill beyond climatology up to 2 weeks in most of the considered catchments. Even if forecasting skills are rather small at longer lead times with significant skill only in some catchments at lead times of 3 and 4 weeks, this soil moisture-based approach shows local improvements compared to the monthly European Centre for Medium Range Weather Forecasting (ECMWF) temperature forecasts at these lead times. For both products (soil moisture-only forecast and ECMWF forecast), we find comparable or better forecast performance in the case of extreme events, especially at long lead times. Even though a product based on soil moisture information alone is not of practical relevance, our results indicate that soil moisture (memory) is a potentially valuable contributor to temperature forecast skill. Investigating the underlying soil moisture of the ECMWF forecasts we find good agreement with the simple model forecasts, especially at longer lead times. Analyzing the drivers of the temperature forecast skills we find that they are mainly controlled by the strengths of (1) the soil moisture-temperature coupling and (2) the soil moisture memory. We

  10. Characteristics and Performance of Existing Load Disaggregation Technologies

    SciTech Connect

    Mayhorn, Ebony T.; Sullivan, Greg P.; Butner, Ryan S.; Hao, He; Baechler, Michael C.

    2015-04-10

    Non-intrusive load monitoring (NILM) or non-intrusive appliance load monitoring (NIALM) is an analytic approach to disaggregate building loads based on a single metering point. This advanced load monitoring and disaggregation technique has the potential to provide an alternative solution to high-priced traditional sub-metering and enable innovative approaches for energy conservation, energy efficiency, and demand response. However, since the inception of the concept in the 1980’s, evaluations of these technologies have focused on reporting performance accuracy without investigating sources of inaccuracies or fully understanding and articulating the meaning of the metrics used to quantify performance. As a result, the market for, as well as, advances in these technologies have been slowly maturing.To improve the market for these NILM technologies, there has to be confidence that the deployment will lead to benefits. In reality, every end-user and application that this technology may enable does not require the highest levels of performance accuracy to produce benefits. Also, there are other important characteristics that need to be considered, which may affect the appeal of NILM products to certain market targets (i.e. residential and commercial building consumers) and the suitability for particular applications. These characteristics include the following: 1) ease of use, the level of expertise/bandwidth required to properly use the product; 2) ease of installation, the level of expertise required to install along with hardware needs that impact product cost; and 3) ability to inform decisions and actions, whether the energy outputs received by end-users (e.g. third party applications, residential users, building operators, etc.) empower decisions and actions to be taken at time frames required for certain applications. Therefore, stakeholders, researchers, and other interested parties should be kept abreast of the evolving capabilities, uses, and characteristics

  11. Anthropometrics, Physical Performance, and Injury Characteristics of Youth American Football

    PubMed Central

    Caswell, Shane V.; Ausborn, Ashley; Diao, Guoqing; Johnson, David C.; Johnson, Timothy S.; Atkins, Rickie; Ambegaonkar, Jatin P.; Cortes, Nelson

    2016-01-01

    Background: Prior research has described the anthropometric and physical performance characteristics of professional, collegiate, and high school American football players. Yet, little research has described these factors in American youth football and their potential relationship with injury. Purpose: To characterize anthropometric and physical performance measures, describe the epidemiology of injury, and examine the association of physical performance measures with injury among children participating within age-based divisions of a large metropolitan American youth football league. Study Design: Case-control study; Level of evidence, 3. Methods: Demographic, anthropometric, and physical performance characteristics and injuries of 819 male children were collected over a 2-year period (2011-2012). Injury data were collected by the league athletic trainer (AT) and coaches. Descriptive analysis of demographic, anthropometric, and physical performance measures (40-yard sprint, pro-agility, push-ups, and vertical jump) were conducted. Incidence rates were computed for all reported injuries; rates were calculated as the number of injuries per 1000 athlete-exposures (AEs). Multinomial logistic regression was used to identify whether the categories of no injury, no-time-loss (NTL) injury, and time-loss (TL) injury were associated with physical performance measures. Results: Of the 819 original participants, 760 (92.8%) completed preseason anthropometric measures (mean ± SD: age, 11.8 ± 1.2 years; height, 157.4 ± 10.7 cm; weight, 48.7 ± 13.3 kg; experience, 2.0 ± 1.8 years); 640 (78.1%) players completed physical performance measures. The mean (±SD) 40-yard sprint and pro-agility measures of the players were 6.5 ± 0.6 and 5.7 ± 0.5 seconds, respectively; the number of push-ups and maximal vertical jump height were 16.5 ± 9.3 repetitions and 42.3 ± 8.4 cm, respectively. Players assigned to different teams within age divisions demonstrated no differences in

  12. Drought monitoring using downscaled soil moisture through machine learning approaches over North and South Korea

    NASA Astrophysics Data System (ADS)

    Park, S.; Im, J.; Rhee, J.; Park, S.

    2015-12-01

    Soil moisture is one of the most important key variables for drought monitoring. It reflects hydrological and agricultural processes because soil moisture is a function of precipitation and energy flux and crop yield is highly related to soil moisture. Many satellites including Advanced Microwave Scanning Radiometer on the Earth Observing System (AMSR-E), Soil Moisture and Ocean Salinity sensor (SMOS), and Soil Moisture Active Passive (SMAP) provide global scale soil moisture products through microwave sensors. However, as the spatial resolution of soil moisture products is typically tens of kilometers, it is difficult to monitor drought using soil moisture at local or regional scale. In this study, AMSR-E and AMSR2 soil moisture were downscaled up to 1 km spatial resolution using Moderate Resolution Imaging Spectroradiometer (MODIS) data—Evapotranspiration, Land Surface Temperature, Leaf Area Index, Normalized Difference Vegetation Index, Enhanced Vegetation Index and Albedo—through machine learning approaches over Korean peninsula. To monitor drought from 2003 to 2014, each pixel of the downscaled soil moisture was scaled from 0 to 1 (1 is the wettest and 0 is the driest). The soil moisture based drought maps were validated using Standardized Precipitation Index (SPI) and crop yield data. Spatial distribution of drought status was also compared with other drought indices such as Scaled Drought Condition Index (SDCI). Machine learning approaches were performed well (R=0.905) for downscaling. Downscaled soil moisture was validated using in situ Asia flux data. The Root Mean Square Errors (RMSE) improved from 0.172 (25 km AMSR2) to 0.065 (downscaled soil moisture). The correlation coefficients improved from 0.201 (25 km AMSR2) to 0.341 (downscaled soil moisture). The soil moisture based drought maps and SDCI showed similar spatial distribution that caught both extreme drought and no drought. Since the proposed drought monitoring approach based on the downscaled

  13. Soil Moisture Prediction in the Soil, Vegetation and Snow (SVS) Scheme

    NASA Astrophysics Data System (ADS)

    Alavi, Nasim; Bélair, Stéphane; Fortin, Vincent; Zhang, Shunli; Husain, Syed; Carrera, Marco; Abrahamowicz, Maria

    2016-04-01

    A new land surface scheme has been developed at Environment of Canada to provide surface fluxes of momentum, heat and moisture for the Global Environmental Multiscale (GEM) atmospheric model. In this study, the performance of the soil, vegetation and snow (SVS) scheme in estimating surface and root-zone soil moisture is evaluated against the ISBA (Interactions between Surface, Biosphere, and Atmosphere) scheme currently used operationally within GEM for numerical weather prediction. In addition, the sensitivity of SVS soil moisture results to soil texture and vegetation data sources (type and fractional coverage) has been explored. The performance of SVS and ISBA was assessed against a large set of in situ as well as brightness temperature data from the Soil Moisture and Ocean Salinity (SMOS) satellite over North America. The results indicate that SVS estimates the time evolution of soil moisture more accurately, and compared to ISBA results in higher correlations with observations and reduced errors. The sensitivity tests carried out during this study revealed that SVS soil moisture results are not affected significantly by the soil texture data from different sources. The vegetation data source, however, has a major impact on the soil moisture results predicted by SVS, and accurate specification of vegetation characteristics is crucial for accurate soil moisture prediction.

  14. The impact of green roof ageing on substrate characteristics and hydrological performance

    NASA Astrophysics Data System (ADS)

    De-Ville, Simon; Menon, Manoj; Jia, Xiaodong; Reed, George; Stovin, Virginia

    2017-04-01

    Green roofs contribute to stormwater management through the retention of rainfall and the detention of runoff. However, there is very limited knowledge concerning the evolution of green roof hydrological performance with system age. This study presents a non-invasive technique which allows for repeatable determination of key substrate characteristics over time, and evaluates the impact of observed substrate changes on hydrological performance. The physical properties of 12 green roof substrate cores have been evaluated using non-invasive X-ray microtomography (XMT) imaging. The cores comprised three replicates of two contrasting substrate types at two different ages: unused virgin samples; and 5-year-old samples from existing green roof test beds. Whilst significant structural differences (density, pore and particle sizes, tortuosity) between virgin and aged samples of a crushed brick substrate were observed, these differences did not significantly affect hydrological characteristics (maximum water holding capacity and saturated hydraulic conductivity). A contrasting substrate based upon a light expanded clay aggregate experienced increases in the number of fine particles and pores over time, which led to increases in maximum water holding capacity of 7%. In both substrates, the saturated hydraulic conductivity estimated from the XMT images was lower in aged compared with virgin samples. Comparisons between physically-derived and XMT-derived substrate hydrological properties showed that similar values and trends in the data were identified, confirming the suitability of the non-invasive XMT technique for monitoring changes in engineered substrates over time. The observed effects of ageing on hydrological performance were modelled as two distinct hydrological processes, retention and detention. Retention performance was determined via a moisture-flux model using physically-derived values of virgin and aged maximum water holding capacity. Increased water holding

  15. Performance characteristics of CdTe drift ring detector

    NASA Astrophysics Data System (ADS)

    Alruhaili, A.; Sellin, P. J.; Lohstroh, A.; Veeramani, P.; Kazemi, S.; Veale, M. C.; Sawhney, K. J. S.; Kachkanov, V.

    2014-03-01

    CdTe and CdZnTe material is an excellent candidate for the fabrication of high energy X-ray spectroscopic detectors due to their good quantum efficiency and room temperature operation. The main material limitation is associated with the poor charge transport properties of holes. The motivation of this work is to investigate the performance characteristics of a detector fabricated with a drift ring geometry that is insensitive to the transport of holes. The performance of a prototype Ohmic CdTe drift ring detector fabricated by Acrorad with 3 drift rings is reported; measurements include room temperature current voltage characteristics (IV) and spectroscopic performance. The data shows that the energy resolution of the detector is limited by leakage current which is a combination of bulk and surface leakage currents. The energy resolution was studied as a function of incident X-ray position with an X-ray microbeam at the Diamond Light Source. Different ring biasing schemes were investigated and the results show that by increasing the lateral field (i.e. the bias gradient across the rings) the active area, evaluated by the detected count rate, increased significantly.

  16. Performance Characteristic Mems-Based IMUs for UAVs Navigation

    NASA Astrophysics Data System (ADS)

    Mohamed, H. A.; Hansen, J. M.; Elhabiby, M. M.; El-Sheimy, N.; Sesay, A. B.

    2015-08-01

    Accurate 3D reconstruction has become essential for non-traditional mapping applications such as urban planning, mining industry, environmental monitoring, navigation, surveillance, pipeline inspection, infrastructure monitoring, landslide hazard analysis, indoor localization, and military simulation. The needs of these applications cannot be satisfied by traditional mapping, which is based on dedicated data acquisition systems designed for mapping purposes. Recent advances in hardware and software development have made it possible to conduct accurate 3D mapping without using costly and high-end data acquisition systems. Low-cost digital cameras, laser scanners, and navigation systems can provide accurate mapping if they are properly integrated at the hardware and software levels. Unmanned Aerial Vehicles (UAVs) are emerging as a mobile mapping platform that can provide additional economical and practical advantages. However, such economical and practical requirements need navigation systems that can provide uninterrupted navigation solution. Hence, testing the performance characteristics of Micro-Electro-Mechanical Systems (MEMS) or low cost navigation sensors for various UAV applications is important research. This work focuses on studying the performance characteristics under different manoeuvres using inertial measurements integrated with single point positioning, Real-Time-Kinematic (RTK), and additional navigational aiding sensors. Furthermore, the performance of the inertial sensors is tested during Global Positioning System (GPS) signal outage.

  17. Study of high SAR backscattering caused by an increase of soil moisture over a sparsely vegetated area: Implications for characteristics of backscattering

    USGS Publications Warehouse

    Lu, Zhiming; Meyer, D.J.

    2002-01-01

    We used interferometric methods on a pair of repeat-pass ERS-1 synthetic aperture radar (SAR) images to study soil moisture changes over sparsely vegetated targets. The intensity of the SAR image acquired at one time was higher than that of an image acquired at an earlier time. We used a correlation image computed from the SAR image pair to study the cause of the observed changes in SAR intensity. Because a reduction of correlation over areas with intensity changes was not observed, we interpreted the intensity changes as not being caused by changes in roughness/structure, but by a change in soil moisture owing to rainfall. An increase in soil moisture ranging from 5% to 20% is the most likely explanation for the increase of intensity. These analyses imply that both intensity and phase information should be used in SAR change detection applications.

  18. Breeder design for enhanced performance and safety characteristics

    SciTech Connect

    Fischer, G J; Atefi, B; Yang, J W; Galperin, A; Segev, M

    1980-01-01

    A fast breeder reactor design has been created which offers a considerably extended fuel cycle and excellent performance characteristics. An example of a core designed to operate on a ten-year fuel cycle is described in some detail. Use of metal fuel along with a moderator such as beryllium oxide dispersed throughout the core provides both design flexibility and safety advantages such as a strong Doppler feedback and limited sodium void reactivity gain. Local power variations are small for the entire cycle; control requirements are also modest, and fuel cycle costs are low.

  19. Internal performance characteristics of thrust-vectored axisymmetric ejector nozzles

    NASA Technical Reports Server (NTRS)

    Lamb, Milton

    1995-01-01

    A series of thrust-vectored axisymmetric ejector nozzles were designed and experimentally tested for internal performance and pumping characteristics at the Langley research center. This study indicated that discontinuities in the performance occurred at low primary nozzle pressure ratios and that these discontinuities were mitigated by decreasing expansion area ratio. The addition of secondary flow increased the performance of the nozzles. The mid-to-high range of secondary flow provided the most overall improvements, and the greatest improvements were seen for the largest ejector area ratio. Thrust vectoring the ejector nozzles caused a reduction in performance and discharge coefficient. With or without secondary flow, the vectored ejector nozzles produced thrust vector angles that were equivalent to or greater than the geometric turning angle. With or without secondary flow, spacing ratio (ejector passage symmetry) had little effect on performance (gross thrust ratio), discharge coefficient, or thrust vector angle. For the unvectored ejectors, a small amount of secondary flow was sufficient to reduce the pressure levels on the shroud to provide cooling, but for the vectored ejector nozzles, a larger amount of secondary air was required to reduce the pressure levels to provide cooling.

  20. Characteristics and Applications of a High Performance, Miniaturized, Infrasound Sensor

    NASA Astrophysics Data System (ADS)

    Rothman, J. L.; Marriott, D. A.

    2015-12-01

    Infrasound Sensors have been used for many years to monitor a large number of geophysical phenomena and manmade sources. Due to their large size and power consumption these sensors have typically been deployed in fixed arrays, portable arrays have required trucks to transport the sensors and support equipment. A high performance, miniaturized, infrasound microphone has been developed to enable mobile infrasound measurements that would otherwise be impractical. The new device is slightly larger than a hockey puck, weighs 200g, and consumes less than 150mW. The sensitivity is 0.4V/Pa and self noise at 1Hz is less than 0.63μPa²/Hz. The characteristics were verified using a calibrator tracable to the Los Alamos calibration chamber. Field tests have demonstrated the performance is comparable to a Chaparral model 25. Applications include man portable arrays, mobile installations, and UAV based measurements.

  1. Moisture Research - Optimizing Wall Assemblies

    SciTech Connect

    Arena, L.; Mantha, P.

    2013-05-01

    The Consortium for Advanced Residential Buildings (CARB) evaluated several different configurations of wall assemblies to determine the accuracy of moisture modeling and make recommendations to ensure durable, efficient assemblies. WUFI and THERM were used to model the hygrothermal and heat transfer characteristics of these walls.

  2. The performance characteristics of a piezoelectric ultrasonic dental scaler.

    PubMed

    Pecheva, E; Sammons, R L; Walmsley, A D

    2016-02-01

    The objective of this work was to investigate the performance characteristics of a piezoelectric ultrasonic dental scaler using scanning laser vibrometry. The vibration characteristics of three standard piezoelectric tips were assessed with scanning laser vibrometry under various conditions: unconstrained, under a stream of flowing water, in a water tank, as well as subjected to loads to simulate clinical conditions. Subsequently, the tips were used to disrupt an in-vitro biofilm model of dental plaque, developed using a non-pathogenic Gram-negative species of Serratia (NCIMB40259). The laser vibrometry data showed that the oscillation pattern of the ultrasonic tip depends primarily on its shape and design, as well as on the generator power. Thin tips and high power settings induce the highest vibrations. Water irrigation of the tip and loads influence the tip performance by diminishing its vibration, while water volume increases it. Serratia biofilm was disrupted by the cavitation bubbles occurring around the scaler tip. The most effective biofilm removal occurred with the thinner tip. Understanding how the ultrasonic tip oscillates when in use and how it removes dental plaque is essential for gaining more knowledge regarding the cleaning mechanisms of the ultrasonic system. Cavitation may be used to remove plaque and calculus without a mechanical contact between the dental tip and the teeth. Better knowledge would enable dental specialists to understand and improve their techniques during routine cleaning of teeth. It will also lead to improving tip design and to the production of more effective instruments for clinical use.

  3. The responses of the quantitative characteristics of a ramet population of the ephemeroid rhizomatous sedge Carex physodes to the moisture content of the soil in various locations on sand dunes.

    PubMed

    Abudureheman, Buhailiqiemu; Liu, Huiliang; Zhang, Daoyuan; Guan, Kaiyun; Zhang, Yongkuan

    2014-01-01

    In this study, the soil moisture content was measured, and the quantitative characteristics of this sedge species were compared. The phenotypic plasticity of each parameter and the linear regression relationships were analyzed. The results showed that the soil moisture content was significantly affected by location, soil depth, and sampling date. The aboveground biomass, underground biomass, biomass density, and population density at the peak were significantly higher than elsewhere on the dune. However, the morphological plasticity index of the quantitative characteristics was higher at the base and middle of the dune. When the soil moisture content decreased, the underground biomass and ramet biomass density increased. The aboveground and underground biomasses were strongly negatively correlated, but the ramet height and aboveground biomass were strongly positively correlated. These results indicated that the soil water content significantly affected the clonal growth of C. physodes. The responsiveness of C. physodes may be adaptive when the soil resource supply is low. The strong morphological plasticity of the species appears to be ecologically important for the maintenance and dominance of this species in the dune habitat.

  4. Material characteristics for an analytic hypervelocity impact performance model

    NASA Astrophysics Data System (ADS)

    Miller, Joshua; Ryan, Shannon

    2015-06-01

    A performance model has recently been developed to describe the evolution of a hypervelocity impact of a threat with a dual-wall, Whipple shield. The Whipple shield uses an initial sacrificial wall to initiate threat fragmentation and melt before the debris expands over a void and is subsequently arrested by the second wall in front of a critical component. As such, understanding the initial interaction of the threat particle and the sacrificial wall is crucial to modeling the overall shield performance. Among the key material parameters that must be defined for the threat particle and sacrificial wall are the equilibrium shock wave states and tensile response to vacuum exposure. This paper documents the work performed to obtain the necessary material characteristics and a description of the fragmentation of the threat needed for the performance model. The results from the use of these quantities within the model are compared here with hydrodynamic simulations and available experimental records that have sought to characterize these parameters.

  5. Effect of dietary corn dried distillers grains with solubles, canola meal, and chloride on electrolyte balance, growth performance, and litter moisture of growing turkeys.

    PubMed

    Farahat, M H; Hassanein, E I; Abdel-Razik, W M; Noll, S L

    2013-05-01

    A study determined if dietary corn dried distillers grains with solubles (DDGS), canola meal (CM), or chloride (Cl) could adversely affect the performance and litter moisture of turkeys. A total of 1,089 Nicholas toms were used in a study during 2 to 14 wk of age. The poults were randomized into 99 pens (11 poults/pen) with number reduced to 10/pen at 8 wk. The factorial arrangement consisted of 3 diet sets [corn-soy (CS), CS + 20% DDGS, CS + 20% DDGS + 10% canola meal] and 3 Cl levels (0.22, 0.32, 0.42%), making 9 treatments distributed in 11 replicate blocks. Diets were formulated to be isocaloric with similar levels of digestible amino acids for each of 4 feeding phases. The dietary electrolyte balance varied with diet set and age period and ranged from 351 to 181 mEq/kg of diet (Na(+) + K(+) - Cl(-)) or 184 to -29 mEq/kg (Na(+) + K(+)) - (Cl(-) + S(2-)). Individual BW and pen feed residues were measured at each phase. Samples of litter were collected at 11 and 14 wk for measuring moisture. During 2 to 14 wk, no differences were observed in BW and ADG attributable to diet (P < 0.05). Birds fed diets containing DDGS or with CM consumed 6.0% more ADFI (P > 0.05). No differences were found for Cl or diet × Cl interaction for BW, ADG, or ADFI. The feed conversion ratio (FCR) was higher (P > 0.05) for birds fed diets containing DDGS or CM. A diet × Cl interaction was found for FCR during 8 to 14 wk; increasing Cl over 0.22% significantly increased the FCR by 3.0% only in diets containing DDGS with CM. Litter moisture was increased in diets containing DDGS or with CM, and by increased Cl. Including S in dietary electrolyte balance resulted in a better albeit weak correlation with ADG during 2 to 5 wk (-0.51 vs. -0.36) and FCR during 11 to 14 wk (-0.36 vs. -0.21). Due to the detrimental effect on FCR, high Cl should be avoided with DDGS and CM in turkey grower diets.

  6. Effect of phytase supplementation to diets varying in chloride level on performance, litter moisture, foot pad score, and gait score of growing turkeys.

    PubMed

    Farahat, M H; Abdel-Razik, W M; Hassanein, E I; Noll, S L

    2013-07-01

    Phytase was examined as a means to improve turkey performance in diets with high Cl by modifying dietary electrolyte balance. Nicholas turkey toms (10 poults/pen; 10 replicates per pen) were fed corn-soy-distillers dried grains with solubles-canola meal-based diets (DDGS/CM) with varying Cl (0.2, 0.3, 0.4, or 0.5%) and phytase (0 or 500 phytase units/kg of diet), making 8 treatments (4 × 2 factorial). A ninth treatment was a corn-soy based diet (CS) with 0.3% Cl and without phytase (positive control). The diets were formulated to contain similar AMEn and digestible amino acid levels for each of 5 feeding periods (2 to 5, 5 to 8, 8 to 11, 11 to 14, and 14 to 17 wk of age) and fed in mash form. Turkey BW, ADG, ADFI, and feed conversion ratio (FCR) were determined for each pen along with litter moisture, foot pad, and gait scores. An ANOVA was conducted to determine the effects of Cl, phytase, and their interaction. Turkey BW, ADG, and ADFI decreased in a linear or curvilinear manner with increasing diet Cl (P < 05). At 17 wk of age, litter moisture and foot pad score showed a cubic trend with diet Cl (P < 0.05). Phytase improved FCR during 8 to 11 wk and increased litter moisture at 11 wk of age (P < 0.003). Phytase modified the FCR response to Cl during 2 to 5 and 14 to 17 wk of age at the 2 lowest levels of dietary Cl (P < 0.05). Turkeys fed CS had better BW and FCR through 17 wk of age compared with those receiving DDGS/CM at 0.3% Cl. Based on BW, minimum dietary electrolyte balance based on Na, K, and Cl was found to be 247, 217, 200, and 171 mEq/kg during 5 to 8, 8 to 11, 11 to 14, and 14 to 17 wk of age, respectively. The present findings emphasized the importance of considering Cl, phytase, and associated dietary electrolyte balance in turkey diets containing high levels of alternative byproducts.

  7. Predicting root zone soil moisture using surface data

    NASA Astrophysics Data System (ADS)

    Manfreda, S.; Brocca, L.; Moramarco, T.; Melone, F.; Sheffield, J.; Fiorentino, M.

    2012-04-01

    In recent years, much effort has been given to monitoring of soil moisture from satellite remote sensing. These tools represent an extraordinary source of information for hydrological applications, but they only provide information on near-surface soil moisture. In the present work, we developed a new formulation for the estimation of the soil moisture in the root zone based on the measured value of soil moisture at the surface. The method derives from a simplified form of the soil water balance equation and for this reason all parameters adopted are physically consistent. The formulation provides a closed form of the relationship between the root zone soil moisture and the surface soil moisture with a limited number of parameters, such as: the ratio between the depth of the surface layer and the deeper layer, the water loss coefficient, and the field capacity. The method has been tested using modeled soil moisture obtained from the North American Land Data Assimilation System (NLDAS). The NLDAS is a multi-institution partnership aimed at developing a retrospective data set, using available atmospheric and land surface meteorological observations to compute the land surface hydrological budget. The NLDAS database was extremely useful for the scope of the present research since it provides simulated data over an extended area with different climatic and physical condition and moreover it provides soil moisture data averaged over different depths. In particular, we used values in the top 10 cm and 100 cm layers. One year of simulation was used to test the ability of the developed method to describe soil moisture fluctuation in the 100cm layer over the entire NLDAS domain. The method was adopted by calibrating one of its three parameters and defining the remaining two based on physical characteristics of the site (using the potential evapotranspiration and ratio between the first and the second soil layer depth). In general, the method performed better than

  8. Morphological characteristics and performance variables of women soccer players.

    PubMed

    Can, Filiz; Yilmaz, Ilker; Erden, Zafer

    2004-08-01

    The purpose of this study was to describe certain morphological characteristics of women soccer players and to examine aspects of training and performance. Twenty-two anthropometric sites were used in measurements of somatotype and body composition; flexibility, agility, anaerobic power, leg muscle power, and dynamic pulmonary functions were used as performance variables. Measurements were made on 17 professional athletes and 17 age-matched sedentary women who acted as controls. The women soccer players showed less fat content and less lean body mass than did the sedentary women. The mean somatotype for the soccer players was 3.07-3.55-2.43 and for the nonathletes was 3.57-3.35-2.90. Anaerobic power, leg muscle power, and agility in the athletes were higher than in the nonathletes, whereas no differences were found in flexibility and pulmonary functions (p > 0.05). The women soccer players showed more significantly mesomorphic, less endomorphic, least ectomorphic components and higher performance level than did the sedentary women.

  9. Performance of AMSR_E soil moisture data assimilation in CLM4.5 model for monitoring hydrologic fluxes at global scale

    NASA Astrophysics Data System (ADS)

    Liu, Di; Mishra, Ashok K.

    2017-04-01

    In this study, we evaluated the performance of community land surface model (CLM4.5) to simulate the hydrologic fluxes, such as, soil moisture (SM), evapotranspiration (ET) and runoff with (without) remote sensing data assimilation. The Advanced Microwave Scanning Radiometer-Earth Observing System (AMSR_E) daily SM (both ascending and descending) are incorporated into the CLM4.5 model using data assimilation (DA) technique. The GLDAS data is used to validate the AMSR_E SM data and evaluate the performance of CLM4.5 simulations. The AMSR_E SM data are rescaled to meet the resolution of CLM4.5 model. By assimilating the AMSR_E SM data into the CLM4.5 model can improve the SM simulations, especially over the climate transition zones in Africa, East Australia, South South America, Southeast Asia, and East North America in summer season. The Local Ensemble Kalman Filter (LEnKF) technique improves the performance of CLM4.5 model compared to the directly substituted method. The improvement in ET and surface runoff simulations from CLM4.5 model assimilated with AMSR_E SM data shares similar spatial patterns with SM.

  10. Performance Characteristics of a Vertical Axis Hydrokinetic Turbine

    NASA Astrophysics Data System (ADS)

    Bailin, Benjamin; Flack, Karen; Lust, Ethan

    2016-11-01

    Performance characteristics are presented for a vertical axis hydrokinetic turbine designed for use in a riverine environment. The test turbine is a 1:6 scale model of a three-bladed device (9.5 m span, 6.5 m diameter) that has been proposed by the Department of Energy. Experiments are conducted in the large towing tank (116 m long, 7.9 m wide, 5 m deep) at the United States Naval Academy. The large scale facility allows for scale independent results. The turbine is towed beneath a moving carriage at a constant speed in combination with a shaft brake to achieve the desired tip speed ratio (TSR) range. The measured quantities of turbine thrust, torque and RPM result in power and thrust coefficients for a range of TSR. Results will be presented for cases with quiescent flow and flow with mild surface waves, representative of riverine environments.

  11. Distributed utility technology cost, performance, and environmental characteristics

    SciTech Connect

    Wan, Y; Adelman, S

    1995-06-01

    Distributed Utility (DU) is an emerging concept in which modular generation and storage technologies sited near customer loads in distribution systems and specifically targeted demand-side management programs are used to supplement conventional central station generation plants to meet customer energy service needs. Research has shown that implementation of the DU concept could provide substantial benefits to utilities. This report summarizes the cost, performance, and environmental and siting characteristics of existing and emerging modular generation and storage technologies that are applicable under the DU concept. It is intended to be a practical reference guide for utility planners and engineers seeking information on DU technology options. This work was funded by the Office of Utility Technologies of the US Department of Energy.

  12. Multispectral sensing of moisture stress

    NASA Technical Reports Server (NTRS)

    Olson, C. E., Jr.

    1970-01-01

    Laboratory reflectance data, and field tests with multispectral remote sensors provide support for this hypotheses that differences in moisture content and water deficits are closely related to foliar reflectance from woody plants. When these relationships are taken into account, automatic recognition techniques become more powerful than when they are ignored. Evidence is increasing that moisture relationships inside plant foliage are much more closely related to foliar reflectance characteristics than are external variables such as soil moisture, wind, and air temperature. Short term changes in water deficits seem to have little influence on foliar reflectance, however. This is in distinct contrast to significant short-term changes in foliar emittance from the same plants with changing wind, air temperature, incident radiation, or water deficit conditions.

  13. Estimating Soil Moisture from Satellite Microwave Observations

    NASA Technical Reports Server (NTRS)

    Owe, M.; VandeGriend, A. A.; deJeu, R.; deVries, J.; Seyhan, E.

    1998-01-01

    and used to derive the one-way canopy transmissivity. Using a simple radiative transfer model, this information was combined with horizontally polarized 6.6 GHz SMMR observations to derive a 9-year time series of soil moisture for all of Spain at a one quarter degree spatial scale. Both day and night SMMR observations were used independently, in order to check the consistency of the results. A first order Fourier Transform was performed on the mean monthly soil moisture values to identify major characteristics of time series such as trend, amplitude, and phase shift.

  14. Radio frequency plasma power dependence of the moisture permeation barrier characteristics of Al{sub 2}O{sub 3} films deposited by remote plasma atomic layer deposition

    SciTech Connect

    Jung, Hyunsoo; Choi, Hagyoung; Lee, Sanghun; Jeon, Heeyoung; Jeon, Hyeongtag

    2013-11-07

    In the present study, we investigated the gas and moisture permeation barrier properties of Al{sub 2}O{sub 3} films deposited on polyethersulfone films (PES) by capacitively coupled plasma (CCP) type Remote Plasma Atomic Layer Deposition (RPALD) at Radio Frequency (RF) plasma powers ranging from 100 W to 400 W in 100 W increments using Trimethylaluminum [TMA, Al(CH{sub 3}){sub 3}] as the Al source and O{sub 2} plasma as the reactant. To study the gas and moisture permeation barrier properties of 100-nm-thick Al{sub 2}O{sub 3} at various plasma powers, the Water Vapor Transmission Rate (WVTR) was measured using an electrical Ca degradation test. WVTR decreased as plasma power increased with WVTR values for 400 W and 100 W of 2.6 × 10{sup −4} gm{sup −2}day{sup −1} and 1.2 × 10{sup −3} gm{sup −2}day{sup −1}, respectively. The trends for life time, Al-O and O-H bond, density, and stoichiometry were similar to that of WVTR with improvement associated with increasing plasma power. Further, among plasma power ranging from 100 W to 400 W, the highest power of 400 W resulted in the best moisture permeation barrier properties. This result was attributed to differences in volume and amount of ion and radical fluxes, to join the ALD process, generated by O{sub 2} plasma as the plasma power changed during ALD process, which was determined using a plasma diagnosis technique called the Floating Harmonic Method (FHM). Plasma diagnosis by FHM revealed an increase in ion flux with increasing plasma power. With respect to the ALD process, our results indicated that higher plasma power generated increased ion and radical flux compared with lower plasma power. Thus, a higher plasma power provides the best gas and moisture permeation barrier properties.

  15. Transonic Performance Characteristics of Several Jet Noise Suppressors

    NASA Technical Reports Server (NTRS)

    Schmeer, James W.; Salters, Leland B., Jr.; Cassetti, Marlowe D.

    1960-01-01

    An investigation of the transonic performance characteristics of several noise-suppressor configurations has been conducted in the Langley 16-foot transonic tunnel. The models were tested statically and over a Mach number range from 0.70 to 1.05 at an angle of attack of 0 deg. The primary jet total-pressure ratio was varied from 1.0 (jet off) to about 4.5. The effect of secondary air flow on the performance of two of the configurations was investigated. A hydrogen peroxide turbojet-engine simulator was used to supply the hot-jet exhaust. An 8-lobe afterbody with centerbody, short shroud, and secondary air had the highest thrust-minus-drag coefficients of the six noise-suppressor configurations tested. The 12-tube and 12-lobe afterbodies had the lowest internal losses. The presence of an ejector shroud partially shields the external pressure distribution of the 8-lobe after-body from the influence of the primary jet. A ring-airfoil shroud increased the static thrust of the annular nozzle but generally decreased the thrust minus drag at transonic Mach numbers.

  16. Organizational Characteristics Associated With Fundraising Performance of Nonprofit Hospitals.

    PubMed

    Erwin, Cathleen Owens; Landry, Amy Yarbrough

    2015-01-01

    Fundraising has become increasingly important to nonprofit hospitals as access to capital has grown more difficult and reimbursement for services more complex. This study analyzes the variation in organizational characteristics and fundraising performance among nonprofit acute care hospitals in the United States to identify and measure critical factors related to one key fundraising performance indicator: public support. Results indicate that the presence of an endowment, along with its value, investments in fundraising, and the geographic location of the organization, account for approximately 46% of variance in public support among nonprofit hospitals. The use of a separate foundation for the fundraising operation is not necessarily associated with measures of fundraising success; however, a majority of hospitals do use a foundation, signaling a strategic choice that may be made for numerous reasons. The study results and limitations are discussed and recommendations are made for maximizing the effectiveness of the fundraising enterprise within nonprofit hospitals. Increasing awareness of challenges associated with fundraising success will enhance the strategic management of fundraising operations by hospital executives and board members.

  17. Physical and performance characteristics of successful high school football players.

    PubMed

    Williford, H N; Kirkpatrick, J; Scharff-Olson, M; Blessing, D L; Wang, N Z

    1994-01-01

    The purpose of this investigation was to determine the performance and physiologic characteristics of a "successful" American high school football team, and to compare the present values with values reported for other groups of high school, college, and professional players. For descriptive purposes, players were divided into two groups: backs (N = 8) and linemen (N = 10). Maximal aerobic power (VO2max) was determined from a maximal treadmill test, and body composition was evaluated by hydrostatic weighing. Maximal strength values were evaluated by one-repetition maximum bench press and squat test; the sit-and-reach test was used to measure flexibility. Speed and power were evaluated by a vertical jump and a 36.6-meter sprint. Results indicate that compared with other groups of college and professional players, as the level of competition increases so do height, weight, and fat-free weight of the players. Similar maximum oxygen consumption values were found for the present group when compared with other groups of these players. From the strength and power standpoint, football players at all levels are becoming stronger. Incorporation of strength training programs has greatly improved strength and performance profiles of football players at all levels of competition.

  18. Performance characteristics of an MHD (Magnetohydrodynamic) pilot plant electrostatic precipitator

    NASA Astrophysics Data System (ADS)

    Lindner, J. S.; Jang, P. R.; Okhuysen, W. P.; Holt, J. K.

    In magnetohydrodynamic (MHD) power generation, a seed material, normally K2CO3, is added to enhance the conductivity of the coal-fired gas stream. The plasma is passed through a magnetic field and electricity is produced by the Hall effect. Future large scale MHD facilities are expected to be more efficient than conventional coal-fired power plants not only because of the dc electricity produced but also from increased heat recovery owing to the large (3000 K) combustion temperatures employed. There is; however, a finite cost for the seed material and the resulting K2SO4 particles (SO2 emissions are minimized by combination with seed potassium) must be collected, converted back to K2CO3 or KCO2H, and recycled back to the combustor. The performance characteristics of the MHD electrostatic precipitator (ESP) are therefore, of interest. We describe Mie scattering and electric field measurements on an MHD pilot scale ESP located at the Coal Fire Flow Facility (CFFF) at the University of Tennessee Space Institute. Results are reported for the determination of near-real-time collection efficiencies, the variation of the ESP performance with seed percentage, and initial studies on the extent of particle re-entrainment.

  19. Understanding Moisture and Carbon Dioxide Involved Interfacial Reactions on Electrochemical Performance of Lithium-Air Batteries Catalyzed by Gold/Manganese-Dioxide.

    PubMed

    Wang, Guoqing; Huang, Liliang; Liu, Shuangyu; Xie, Jian; Zhang, Shichao; Zhu, Peiyi; Cao, Gaoshao; Zhao, Xinbing

    2015-11-04

    Lithium-air (Li-air) battery works essentially based on the interfacial reaction of 2Li + O2 ↔ Li2O2 on the catalyst/oxygen-gas/electrolyte triphase interface. Operation of Li-air batteries in ambient air still remains a great challenge despite the recent development, because some side reactions related to moisture (H2O) and carbon dioxide (CO2) will occur on the interface with the formation of some inert byproducts on the surface of the catalyst. In this work, we investigated the effect of H2O and CO2 on the electrochemical performance of Li-air batteries to evaluate the practical operation of the batteries in ambient air. The use of a highly efficient gold/δ-manganese-dioxide (Au/δ-MnO2) catalyst helps to understand the intrinsic mechanism of the effect. We found that H2O has a more detrimental influence than CO2 on the battery performance when operated in ambient air. The battery operated in simulated dry air can sustain a stable cycling up to 200 cycles at 400 mA g(-1) with a relatively low polarization, which is comparable with that operated in pure O2. This work provides a possible method to operate Li-air batteries in ambient air by using optimized catalytic electrodes with a protective layer, for example a hydrophobic membrane.

  20. A model of the 1.6 GHz scatterometer. [performance of airborne scatterometer used as microwave remote sensor of soil moisture

    NASA Technical Reports Server (NTRS)

    Wang, J. R.

    1977-01-01

    The performance was studied of the 1.6 GHz airborne scatterometer system which is used as one of several Johnson Space Center (JSC) microwave remote sensors to detect moisture content of soil. The system is analyzed with respect to its antenna pattern and coupling, the signal flow in the receiver data channels, and the errors in the signal outputs. The operational principle and the sensitivity of the system, as well as data handling are also described. The finite cross-polarized gains of all four 1.6 GHz scatterometer antennae are found to have profound influence on the cross-polarized backscattered signal returns. If these signals are not analyzed properly, large errors could result in the estimate of the cross-polarized coefficient. It is also found necessary to make corrections to the variations of the aircraft parameters during data reduction in order to minimize the error in the coefficient estimate. Finally, a few recommendations are made to improve the overall performance of the scatterometer system.

  1. Performance and flow characteristics of MHD seawater thruster

    SciTech Connect

    Doss, E.D.

    1990-01-01

    The main goal of the research is to investigate the effects of strong magnetic fields on the electrical and flow fields inside MHD thrusters. The results of this study is important in the assessment of the feasibility of MHD seawater propulsion for the Navy. To accomplish this goal a three-dimensional fluid flow computer model has been developed and applied to study the concept of MHD seawater propulsion. The effects of strong magnetic fields on the current and electric fields inside the MHD thruster and their interaction with the flow fields, particularly those in the boundary layers, have been investigated. The results of the three-dimensional computations indicate that the velocity profiles are flatter over the sidewalls of the thruster walls in comparison to the velocity profiles over the electrode walls. These nonuniformities in the flow fields give rise to nonuniform distribution of the skin friction along the walls of the thrusters, where higher values are predicted over the sidewalls relative to those over the electrode walls. Also, a parametric study has been performed using the three-dimensional MHD flow model to analyze the performance of continuous electrode seawater thrusters under different operating parameters. The effects of these parameters on the fluid flow characteristics, and on the thruster efficiency have been investigated. Those parameters include the magnetic field (10--20 T), thruster diameter, surface roughness, flow velocity, and the electric load factor. The results show also that the thruster performance improves with the strength of the magnetic field and thruster diameter, and the efficiency decreases with the flow velocity and surface roughness.

  2. SOIL moisture data intercomparison

    NASA Astrophysics Data System (ADS)

    Kerr, Yann; Rodriguez-Frenandez, Nemesio; Al-Yaari, Amen; Parens, Marie; Molero, Beatriz; Mahmoodi, Ali; Mialon, Arnaud; Richaume, Philippe; Bindlish, Rajat; Mecklenburg, Susanne; Wigneron, Jean-Pierre

    2016-04-01

    The Soil Moisture and Ocean Salinity satellite (SMOS) was launched in November 2009 and started delivering data in January 2010. Subsequently, the satellite has been in operation for over 6 years while the retrieval algorithms from Level 1 to Level 2 underwent significant evolutions as knowledge improved. Other approaches for retrieval at Level 2 over land were also investigated while Level 3 and 4 were initiated. In this présentation these improvements are assessed by inter-comparisons of the current Level 2 (V620) against the previous version (V551) and new products either using neural networks or Level 3. In addition a global evaluation of different SMOS soil moisture (SM) products is performed comparing products with those of model simulations and other satellites (AMSR E/ AMSR2 and ASCAT). Finally, all products were evaluated against in situ measurements of soil moisture (SM). The study demonstrated that the V620 shows a significant improvement (including those at level1 improving level2)) with respect to the earlier version V551. Results also show that neural network based approaches can yield excellent results over areas where other products are poor. Finally, global comparison indicates that SMOS behaves very well when compared to other sensors/approaches and gives consistent results over all surfaces from very dry (African Sahel, Arizona), to wet (tropical rain forests). RFI (Radio Frequency Interference) is still an issue even though detection has been greatly improved while RFI sources in several areas of the world are significantly reduced. When compared to other satellite products, the analysis shows that SMOS achieves its expected goals and is globally consistent over different eco climate regions from low to high latitudes and throughout the seasons.

  3. Performance Characteristics of Plane-Wall Two-Dimensional Diffusers

    NASA Technical Reports Server (NTRS)

    Reid, Elliott G

    1953-01-01

    Experiments have been made at Stanford University to determine the performance characteristics of plane-wall, two-dimensional diffusers which were so proportioned as to insure reasonable approximation of two-dimensional flow. All of the diffusers had identical entrance cross sections and discharged directly into a large plenum chamber; the test program included wide variations of divergence angle and length. During all tests a dynamic pressure of 60 pounds per square foOt was maintained at the diffuser entrance and the boundary layer there was thin and fully turbulent. The most interesting flow characteristics observed were the occasional appearance of steady, unseparated, asymmetric flow - which was correlated with the boundary-layer coalescence - and the rapid deterioration of flow steadiness - which occurred as soon as the divergence angle for maximum static pressure recovery was exceeded. Pressure efficiency was found to be controlled almost exclusively by divergence angle, whereas static pressure recovery was markedly influenced by area ratio (or length) as well as divergence angle. Volumetric efficiency. diminished as area ratio increased, and at a greater rate with small lengths than with large ones. Large values of the static-pressure-recovery coefficient were attained only with long diffusers of large area ratio; under these conditions pressure efficiency was high and. volumetric efficiency low. Auxiliary tests with asymmetric diffusers demonstrated that longitudinal pressure gradient, rather than wall divergence angle, controlled flow separation. Others showed that the addition of even a short exit duct of uniform section augmented pressure recovery. Finally, it was found that the installation of a thin, central, longitudinal partition suppressed flow separation in short diffusers and thereby improved pressure recovery

  4. Silver arsenate amorphous electrolyte batteries: conduction characteristics and electrochemical performance

    NASA Astrophysics Data System (ADS)

    Sathya Sainath Prasad, P.; Rambabu, B.

    Transport properties of silver ion conducting ternary amorphous solid electrolytes, XAgI[(1 - X)( yAg 2O zAs 2O 3)] and XAgI[(1 - X)( yAg 2O zAs 2O 5)] for 30⩽ X⩽70 mol% AgI and 0.20 ⩽( z/y) ⩽3.0 were characterized in a two step process to determine the highest ion conducting composition. Interesting results were obtained by the variation of Glass Former to Glass Modifier ratio ( z/y) and AgI content ( X). Some of the results were previously reported with z/y as a variable parameter for a constant concentration of X. The values of z/y were maintained at the best conducting compositions as derived from the previous work, and the present study reports the conduction characteristics with X as a variable parameter. The best conducting amorphous electrolytes in these two systems were used in the fabrication of solid-state batteries, and their electrochemical performance has been evaluated. A comparison of the solid-state cells with amorphous and polycrystalline electrolytes was undertaken with regard to the current discharge profiles and the cell capacities.

  5. Evaluation of Dewatering Performance and Fractal Characteristics of Alum Sludge

    PubMed Central

    Sun, Yongjun; Fan, Wei; Zheng, Huaili; Zhang, Yuxin; Li, Fengting; Chen, Wei

    2015-01-01

    The dewatering performance and fractal characteristics of alum sludge from a drinking-water treatment plant were investigated in this study. Variations in residual turbidity of supernatant, dry solid content (DS), specific resistance to filtration (SRF), floc size, fractal dimension, and zeta potential were analyzed. Sludge dewatering efficiency was evaluated by measuring both DS and SRF. Results showed that the optimum sludge dewatering efficiency was achieved at 16 mg∙L-1 flocculant dosage and pH 7. Under these conditions, the maximum DS was 54.6%, and the minimum SRF was 0.61 × 1010 m∙kg-1. Floc-size measurements demonstrated that high flocculant dosage significantly improved floc size. Correlation analysis further revealed a strong correlation between fractal dimension and floc size after flocculation. A strong correlation also existed between floc size and zeta potential, and flocculants with a higher cationic degree had a larger correlation coefficient between floc size and zeta potential. In the flocculation process, the main flocculation mechanisms involved adsorption bridging under an acidic condition, and a combination between charge neutralization and adsorption-bridging interaction under neutral and alkaline conditions. PMID:26121132

  6. Evaluation of Dewatering Performance and Fractal Characteristics of Alum Sludge.

    PubMed

    Sun, Yongjun; Fan, Wei; Zheng, Huaili; Zhang, Yuxin; Li, Fengting; Chen, Wei

    2015-01-01

    The dewatering performance and fractal characteristics of alum sludge from a drinking-water treatment plant were investigated in this study. Variations in residual turbidity of supernatant, dry solid content (DS), specific resistance to filtration (SRF), floc size, fractal dimension, and zeta potential were analyzed. Sludge dewatering efficiency was evaluated by measuring both DS and SRF. Results showed that the optimum sludge dewatering efficiency was achieved at 16 mg∙L(-1) flocculant dosage and pH 7. Under these conditions, the maximum DS was 54.6%, and the minimum SRF was 0.61 × 10(10) m∙kg(-1). Floc-size measurements demonstrated that high flocculant dosage significantly improved floc size. Correlation analysis further revealed a strong correlation between fractal dimension and floc size after flocculation. A strong correlation also existed between floc size and zeta potential, and flocculants with a higher cationic degree had a larger correlation coefficient between floc size and zeta potential. In the flocculation process, the main flocculation mechanisms involved adsorption bridging under an acidic condition, and a combination between charge neutralization and adsorption-bridging interaction under neutral and alkaline conditions.

  7. Performance Characteristics of the Multi-Zone NAS Parallel Benchmarks

    NASA Technical Reports Server (NTRS)

    Jin, Haoqiang; VanderWijngaart, Rob F.

    2003-01-01

    We describe a new suite of computational benchmarks that models applications featuring multiple levels of parallelism. Such parallelism is often available in realistic flow computations on systems of grids, but had not previously been captured in bench-marks. The new suite, named NPB Multi-Zone, is extended from the NAS Parallel Benchmarks suite, and involves solving the application benchmarks LU, BT and SP on collections of loosely coupled discretization meshes. The solutions on the meshes are updated independently, but after each time step they exchange boundary value information. This strategy provides relatively easily exploitable coarse-grain parallelism between meshes. Three reference implementations are available: one serial, one hybrid using the Message Passing Interface (MPI) and OpenMP, and another hybrid using a shared memory multi-level programming model (SMP+OpenMP). We examine the effectiveness of hybrid parallelization paradigms in these implementations on three different parallel computers. We also use an empirical formula to investigate the performance characteristics of the multi-zone benchmarks.

  8. ELBARA II, an L-Band Radiometer System for Soil Moisture Research

    PubMed Central

    Schwank, Mike; Wiesmann, Andreas; Werner, Charles; Mätzler, Christian; Weber, Daniel; Murk, Axel; Völksch, Ingo; Wegmüller, Urs

    2010-01-01

    L-band (1–2 GHz) microwave radiometry is a remote sensing technique that can be used to monitor soil moisture, and is deployed in the Soil Moisture and Ocean Salinity (SMOS) Mission of the European Space Agency (ESA). Performing ground-based radiometer campaigns before launch, during the commissioning phase and during the operative SMOS mission is important for validating the satellite data and for the further improvement of the radiative transfer models used in the soil-moisture retrieval algorithms. To address these needs, three identical L-band radiometer systems were ordered by ESA. They rely on the proven architecture of the ETH L-Band radiometer for soil moisture research (ELBARA) with major improvements in the microwave electronics, the internal calibration sources, the data acquisition, the user interface, and the mechanics. The purpose of this paper is to describe the design of the instruments and the main characteristics that are relevant for the user. PMID:22315556

  9. ELBARA II, an L-band radiometer system for soil moisture research.

    PubMed

    Schwank, Mike; Wiesmann, Andreas; Werner, Charles; Mätzler, Christian; Weber, Daniel; Murk, Axel; Völksch, Ingo; Wegmüller, Urs

    2010-01-01

    L-band (1-2 GHz) microwave radiometry is a remote sensing technique that can be used to monitor soil moisture, and is deployed in the Soil Moisture and Ocean Salinity (SMOS) Mission of the European Space Agency (ESA). Performing ground-based radiometer campaigns before launch, during the commissioning phase and during the operative SMOS mission is important for validating the satellite data and for the further improvement of the radiative transfer models used in the soil-moisture retrieval algorithms. To address these needs, three identical L-band radiometer systems were ordered by ESA. They rely on the proven architecture of the ETH L-Band radiometer for soil moisture research (ELBARA) with major improvements in the microwave electronics, the internal calibration sources, the data acquisition, the user interface, and the mechanics. The purpose of this paper is to describe the design of the instruments and the main characteristics that are relevant for the user.

  10. Anthropometric Characteristics and Physical Performance of Colombian Elite Male Wrestlers

    PubMed Central

    Ramirez-Velez, Robinson; Argothyd, Rodrigo; Meneses-Echavez, Jose Francisco; Beatriz Sanchez-Puccini, Maria; Lopez-Alban, Carlos Alejandro; Cohen, Daniel Dylan

    2014-01-01

    Background: Wrestling was an important part of the ancient Olympic Games and is still one of the most popular events of the modern Olympic Games. Studies indicate that general physiologic profile of successful wrestlers is high anaerobic power and capacity, muscular strength, above average aerobic power, exceptional flexibility, fat free mass, and a mesomorphic somatotype. Objectives: The objective of the present study was to evaluate anthropometric characteristics and physical performance of elite male wrestlers. Patients and Methods: The Colombian Wrestling Team was evaluated while in preparation for the Olympic Games (n = 21; age, 27.9 ± 6.7 years). Athletes were tested on anthropometric and fitness parameters: body composition, somatotype distribution according to Heath-Carter, aerobic capacity, vertical jump, and anaerobic power. Results: The evaluations showed a mean body fat percentage of 13.6% ± 3.0% (95% CI, 12.2%-15%), muscle mass of 46.4% ± 2.2% (95% CI, 45.4%-47.4%), Ponderal index of 41.0 ± 1.8 (95% CI, 40.2-41.8), body adiposity index (BAI) 25.1 ± 3.6 (95% CI, 23.5-26.8), and somatotype distribution mesomorphic-ectomorph (5.3-1.6-3.8). Mean aerobic capacity was 45.9 ± 6.6 mL/kg/min (95% CI, 42.8-48.9), vertical jump was 36.4 ± 6.6 cm (95% CI, 11.8-16.6), and anaerobic power was 92.6 ± 19.5 kg/s (95% CI, 83.7-101.5). Conclusions: These results provided a profile of elite wrestlers that could be used as training targets for developing athletes. The results may also provide information for training and tactical planning. PMID:25741411

  11. Influence of Surface Roughness Spatial Variability and Temporal Dynamics on the Retrieval of Soil Moisture from SAR Observations

    PubMed Central

    Álvarez-Mozos, Jesús; Verhoest, Niko E.C.; Larrañaga, Arantzazu; Casalí, Javier; González-Audícana, María

    2009-01-01

    Radar-based surface soil moisture retrieval has been subject of intense research during the last decades. However, several difficulties hamper the operational estimation of soil moisture based on currently available spaceborne sensors. The main difficulty experienced so far results from the strong influence of other surface characteristics, mainly roughness, on the backscattering coefficient, which hinders the soil moisture inversion. This is especially true for single configuration observations where the solution to the surface backscattering problem is ill-posed. Over agricultural areas cultivated with winter cereal crops, roughness can be assumed to remain constant along the growing cycle allowing the use of simplified approaches that facilitate the estimation of the moisture content of soils. However, the field scale spatial variability and temporal variations of roughness can introduce errors in the estimation of soil moisture that are difficult to evaluate. The objective of this study is to assess the impact of roughness spatial variability and roughness temporal variations on the retrieval of soil moisture from radar observations. A series of laser profilometer measurements were performed over several fields in an experimental watershed from September 2004 to March 2005. The influence of the observed roughness variability and its temporal variations on the retrieval of soil moisture is studied using simulations performed with the Integral Equation Model, considering different sensor configurations. Results show that both field scale roughness spatial variability and its temporal variations are aspects that need to be taken into account, since they can introduce large errors on the retrieved soil moisture values. PMID:22389611

  12. Ex vivo water exchange performance and short-term clinical feasibility assessment of newly developed heat and moisture exchangers for pulmonary rehabilitation after total laryngectomy.

    PubMed

    van den Boer, Cindy; Muller, Sara H; Vincent, Andrew D; Züchner, Klaus; van den Brekel, Michiel W M; Hilgers, Frans J M

    2014-02-01

    Laryngectomized patients suffer from respiratory complaints due to insufficient warming and humidification of inspired air in the upper respiratory tract. Improvement of pulmonary humidification with significant reduction of pulmonary complaints is achieved by the application of a heat and moisture exchanger (HME) over the tracheostoma. The aim of this study was to determine whether the new Provox HMEs (XM-HME and XF-HME) have a better water exchange performance than their predecessors (R-HME and L-HME, respectively; Atos Medical, Hörby, Sweden). The other aim was to assess the short-term clinical feasibility of these HMEs. The XM-HME and XF-HME were weighed at the end of inspiration and at the end of expiration at different breathing volumes produced by a healthy volunteer. The associations between weight changes, breathing volume and absolute humidity were determined using both linear and non-linear mixed effects models. Study-specific questionnaires and tally sheets were used in the clinical feasibility study. The weight change of the XM-HME is 3.6 mg, this is significantly higher than that of the R-HME (2.0 mg). The weight change of the XF-HME (2.0 mg) was not significantly higher than that of the L-HME (1.8 mg). The absolute humidity values of both XM- and XF-HME were significantly higher than that of their predecessors. The clinical feasibility study did not reveal any practical problems over the course of 3 weeks. The XM-HME has a significantly better water exchange performance than its predecessor (R-HME). Both newly designed HMEs did succeed in the clinical feasibility study.

  13. Characteristics of Whipple Shield Performance in the Shatter Regime

    NASA Technical Reports Server (NTRS)

    Ryan, Shannon; Bjorkman, Michael; Christiansen, Eric L.

    2009-01-01

    those obtained in this study at normal incidence, suggesting that shielding performance in the shatter regime could be well described by considering more complex phase conditions than currently implemented in most BLEs. Furthermore, evidence of these phase effects were found in the oblique test results, providing the basis for an empirical description of these effects that can be applied in MMOD risk assessment software. In this paper, results of the impact experiments are presented, and characteristics of target damage are evaluated. A comparison of intermediate velocity impact failure mechanisms in current BLEs are discussed and compared to the findings of the experimental study. Risk assessment calculations have been made on a simplified structure using currently implemented penetration equations and predicted limits from the experimental program, and the variation in perceived mission risk is discussed. It was found that ballistic limit curves that explicitly incorporated phase change effects within the intermediate regime lead to a decrease in predicted MMOD risk for ISS-representative orbits. When considered for all Whipple-based shielding configurations onboard the ISS, intermediate phase change effects could lead to significant variations in predicted mission risk.

  14. Soil moisture modeling review

    NASA Technical Reports Server (NTRS)

    Hildreth, W. W.

    1978-01-01

    A determination of the state of the art in soil moisture transport modeling based on physical or physiological principles was made. It was found that soil moisture models based on physical principles have been under development for more than 10 years. However, these models were shown to represent infiltration and redistribution of soil moisture quite well. Evapotranspiration has not been as adequately incorporated into the models.

  15. Performance and Safety Characteristics of Lithium-molybdenum Disulfide Cells

    NASA Technical Reports Server (NTRS)

    Stiles, J. A.

    1984-01-01

    The lithium-molybdenum disulfide system offers attractive characteristics including high rate capability, successful operation up to 75 C, a very low self-discharge rate, a good cycle life and safety characteristics which compare favorably to those of other lithium cells. Moreover, the materials and manufacturing costs for the system is effectively controlled, so the cells should ultimately be competitive with currently marketed rechargeable cells.

  16. Moisture detection in composites by terahertz spectroscopy

    NASA Astrophysics Data System (ADS)

    Malinowski, Paweł; Pałka, Norbert; Opoka, Szymon; Wandowski, Tomasz; Ostachowicz, Wiesław

    2015-07-01

    The application of Glass Fibre Reinforced Polymers (GFRP) in many branches of industry has been increasing steadily. Many research works focus on damage identification for structures made out of such materials. However, not only delaminations, cracks or other damage can have a negative influence of GFRP parts performance. Previous research proved that fluid absorption influences the mechanical performance of composites. GFRP parts can be contaminated by moisture or release agent during manufacturing, while fuel, hydraulic fluid and moisture ingression into the composite can be the in-service treats. In the reported research authors focus on moisture detection. There are numerous sources of moisture such as post manufacturing NDT inspection with ultrasonics coupled by water or exposition to moisture during transportation and in service. An NDT tool used for the research is a terahertz (THz) spectrometer. The device uses an electromagnetic radiation in the terahertz range (0.1-3 THz) and allows for reflection and transmission measurements. The spectrometer is equipped with moving table that allows for XY scanning of large objects such as GFRP panels. In the conducted research refractive indices were experimentally extracted from the materials of interest (water and GFRP). Time signals as well as C-scans were analysed for samples with moisture contamination. In order to be sure that the observed effects are related to moisture contamination reference measurements were conducted. The obtained results showed that the THz NDT technique can detect moisture hidden under a GFRP with multiple layers.

  17. Moisturizers for Acne

    PubMed Central

    Chularojanamontri, Leena; Tuchinda, Papapit; Kulthanan, Kanokvalai

    2014-01-01

    Acne is a chronic inflammatory disease of the pilosebaceous unit that affects almost all teenagers. Different treatments offer different modes of action, but aim to target acne pathology. Topical therapies, such as benzoyl peroxide, retinoids, antibiotics with alcohol-based preparations, and salicylic acid, can cause skin irritation resulting in a lack of patient adherence. Some physicians recommend patients use moisturizers as adjunctive treatment of acne, especially when either topical benzoyl peroxide or a retinoid is prescribed. Furthermore, some evidence shows that moisturizers can contribute independently to improve signs and symptoms of acne. Moisturizers contain three main properties, which are occlusive, humectant, and emollient effects. Currently, many moisturizers claim to be suitable for acne treatment. This article aims to provide a review of the active ingredients and properties of those moisturizers. Fifty-two moisturizers for acne were included for analysis. Most of the products (92%) have anti-inflammatory properties apart from occlusive, humectant, and emollient effects. Anti-acne medications, including salicylic acid, benzoyl peroxide, and retinol, were found respectively in 35, 10, and 8 percent of the moisturizer products containing anti-inflammatory properties. More than half of the products contain dimethicone and/or glycerin for its moisturizer property. Aloe vera and witch hazel are botanical anti-inflammatories that were commonly found in this study. Scientific data regarding some ingredients are discussed to provide a guide for physicians in selecting moisturizers for acne patients. PMID:24847408

  18. Performance characteristics of a new helical-channel microchannel plate

    NASA Technical Reports Server (NTRS)

    Slater, David C.; Timothy, J. Gethyn; Graves, Peter W.; Loretz, Thomas J.; Roy, Raymond L.

    1988-01-01

    An advanced version of the 'helical-channel' microchannel plate (MCP) is presented. This MCP is composed of four channels per fiber with each channel having a diameter of 50 microns. The dynamic range, pulse-height distribution, and gain characteristics of this MCP are discussed. It is found that increasing the twist density of the channels makes it possible to increase the detection efficiency and further improve the suppression of ion-feedback providing a tighter saturated pulse-height distribution and improved high-voltage characteristics.

  19. On-irrigator pasture soil moisture sensor

    NASA Astrophysics Data System (ADS)

    Eng-Choon Tan, Adrian; Richards, Sean; Platt, Ian; Woodhead, Ian

    2017-02-01

    In this paper, we presented the development of a proximal soil moisture sensor that measured the soil moisture content of dairy pasture directly from the boom of an irrigator. The proposed sensor was capable of soil moisture measurements at an accuracy of  ±5% volumetric moisture content, and at meter scale ground area resolutions. The sensor adopted techniques from the ultra-wideband radar to enable measurements of ground reflection at resolutions that are smaller than the antenna beamwidth of the sensor. An experimental prototype was developed for field measurements. Extensive field measurements using the developed prototype were conducted on grass pasture at different ground conditions to validate the accuracy of the sensor in performing soil moisture measurements.

  20. A Literature Review on the Study of Moisture in Polymers

    SciTech Connect

    Trautschold, Olivia Carol

    2016-05-25

    This literature review covers the main chemical and physical interactions between moisture and the polymer matrix. Fickian versus Non-Fickian diffusion behaviors are discussed in approximating the characteristics of moisture sorption. Also, bound water and free water sorbed in polymers are distinguished. Methods to distinguish between bound and free water include differential scanning calorimetry, infrared spectroscopy, and time-domain nuclear magnetic resonance spectroscopy. The difference between moisture sorption and water sorption is considered, as well as the difficulties associated with preventing moisture sorption. Furthermore, specific examples of how moisture sorption influences polymers include natural fiber-polymer composites, starch-based biodegradable thermoplastics, and thermoset polyurethane and epoxies.

  1. Soil Moisture Measurements and their Applications at the Savannah River Site

    SciTech Connect

    Buckley, R.

    2000-09-26

    the Savannah River Site (SRS), located in the southeastern US, which provides 15-minute average soil moisture data. The measurement technique is first discussed, along with characteristics of the observation sites. Several applications of the monitoring are then examined. This includes the use of soil moisture as a decision-making tool in performing prescribed fires of the local forest vegetation. Since soil moisture measurements are also very important in the proper determination of surface fluxes in atmospheric models, a comparison of these point measurements with the National Center for Atmospheric Predictions (NCEP) model simulations over an extended period of time are examined. Finally, simple expressions describing the temporal variation of the soil moisture with precipitation events at the SRS are discussed.

  2. Rail gun performance and plasma characteristics due to wall ablation

    NASA Technical Reports Server (NTRS)

    Ray, P. K.

    1986-01-01

    The experiment of Bauer, et al. (1982) is analyzed by considering wall ablation and viscous drag in the plasma. Plasma characteristics are evaluated through a simple fluid-mechanical analysis considering only wall ablation. By equating the energy dissipated in the plasma with the radiation heat loss, the average properties of the plasma are determined as a function of time.

  3. Effects of College Programme Characteristics on Graduates' Performance

    ERIC Educational Resources Information Center

    García-Aracil, Adela

    2015-01-01

    Education programmes are designed to equip young populations with the qualifications required to assume responsible roles in specific professions and in society generally. In this paper, the focus of the analysis is on the significance of a number of higher education programme characteristics in allocating young higher education graduates across…

  4. Understanding Soil Moisture

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Understanding soil moisture is critical for landscape irrigation management. This landscaep irrigation seminar will compare volumetric and matric potential soil-moisture sensors, discuss the relationship between their readings and demonstrate how to use these data. Soil water sensors attempt to sens...

  5. Effects of altering alfalfa hay quality when feeding steam-flaked versus high-moisture corn grain on ruminal fermentation and lactational performance of dairy cows.

    PubMed

    Eun, J-S; Kelley, A W; Neal, K; Young, A J; Hall, J O

    2014-12-01

    This experiment was performed to test a hypothesis that nutritive benefits of feeding high-moisture corn (HMC) would be different when fed with different qualities of alfalfa hay (AH) due to associative effects on ruminal fermentation and nutrient utilization efficiency. Eight multiparous lactating Holstein cows were used; 4 were surgically fitted with ruminal cannulas. Days in milk averaged 184 ± 10.7 at the start of the experiment. The experiment was performed in a duplicate 4 × 4 Latin square design. Within each square, cows were randomly assigned to a sequence of 4 diets during each of the four 21-d periods (14 d of treatment adaptation and 7 d of data collection and sampling). A 2 × 2 factorial arrangement was used; fair-quality AH [FAH; 39.6% neutral detergent fiber (NDF) and 17.9% crude protein (CP)] or high-quality AH (HAH; 33.6% NDF and 21.9% CP) was combined with steam-flaked corn (SFC) or HMC to form 4 treatments: FAH with SFC, FAH with HMC, HAH with SFC, and HAH with HMC. The AH was fed at 32% dry matter (DM) content, whereas SFC or HMC was included at 17% DM content. Quality of AH did not affect DM intake, whereas feeding HMC decreased DM intake, regardless of quality of AH. Digestibility of DM was greater for cows fed HAH compared with those fed FAH (70.1 vs. 67.6%). Digestibility of NDF increased by feeding HMC (67.6 vs. 58.4%), but not by quality of AH. Under FAH, starch digestibility decreased by feeding HMC compared with SFC (85.7 vs. 95.0%), but it was similar under HAH, resulting in an interaction between quality of AH and type of corn grain (CG). Feeding different qualities of AH did not affect milk yield; however, feeding HMC decreased milk yield in FAH diet, causing an AH × CG interaction. Efficiency of milk yield/DM intake was improved due to feeding HMC, regardless of the quality of the AH. In addition, dietary N utilization for milk N tended to increase by feeding HMC, but it was not influenced by quality of AH. Yield of microbial

  6. SMOS validation of soil moisture and ocen salinity (SMOS) soil moisture over watershed networks in the U.S.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Estimation of soil moisture at large scale has been performed using several satellite-based passive microwave sensors and a variety of retrieval methods. The most recent source of soil moisture is the European Space Agency Soil Moisture and Ocean Salinity (SMOS) mission. A thorough validation must b...

  7. Combination moisture and hydrogen getter

    DOEpatents

    Harrah, L.A.; Mead, K.E.; Smith, H.M.

    1983-09-20

    A combination moisture and hydrogen getter comprises (a) a moisture getter comprising a readily oxidizable metal; and (b) a hydrogen getter comprising (1) a solid acetylenic compound and (2) a hydrogenation catalyst. A method of scavenging moisture from a closed container uses the combination moisture and hydrogen getter to irreversibly chemically reduce the moisture and chemically bind the resultant hydrogen.

  8. Combination moisture and hydrogen getter

    DOEpatents

    Harrah, Larry A.; Mead, Keith E.; Smith, Henry M.

    1983-01-01

    A combination moisture and hydrogen getter comprises (a) a moisture getter comprising a readily oxidizable metal; and (b) a hydrogen getter comprising (i) a solid acetylenic compound and (ii) a hydrogenation catalyst. A method of scavenging moisture from a closed container uses the combination moisture and hydrogen getter to irreversibly chemically reduce the moisture and chemically bind the resultant hydrogen.

  9. Combination moisture and hydrogen getter

    DOEpatents

    Not Available

    1982-04-29

    A combination moisture and hydrogen getter comprises (a) a moisture getter comprising a readily oxidizable metal; and (b) a hydrogen getter comprising (i) a solid acetylenic compound and (ii) a hydrogenation catalyst. A method of scavenging moisture from a closed container uses the combination moisture and hydrogen getter to irreversibly chemically reduce the moisture and chemically bind the reusltant hydrogen.

  10. Dynamic Characteristics of Human Motor Performance in Control Systems.

    DTIC Science & Technology

    1979-01-01

    including the neural control of respiration and vestibular organization. In addition, computer simulations of small neuronal networks have added an understanding of circuits involved in motor performance. (Author)

  11. Gust characteristics for WECS design and performance analysis

    SciTech Connect

    Doran, J.C.; Powell, D.C.

    1980-05-01

    This document provides a description of some gust characteristics which are useful in the study of wind turbine fatigue caused by a fluctuating wind environment. The particular gust form chosen can also be used in the analysis of the dynamic response of a turbine. The statistical behavior of such gust characteristics is not identical to that determined simply from the wind recorded by an anemometer. These modes of behavior may be related, however, by the application of appropriate digital filters to the anemometer data. This procedure has been carried out for a number of sample cases, and the variations of the resultant gust features are presented. A number of suggestions on specific applications and interpretations of the data are included.

  12. Performance characteristics of gravity-assisted, potassium heat pipes

    SciTech Connect

    Prenger, F.C.; Keddy, E.S.; Sena, J.T.

    1985-01-01

    Experiments with potassium-stainless steel gravity-assisted heat pipes were performed. Performance limitations due to entrainment or flooding of the liquid return flow are compared with analytical model predictions. The effect of heated pool height was investigated and problems with surface wetting are discussed. A comparison between entrainment limits for smooth-walled and textured-walled heat pipes was made and a minimum internal surface texturing depth is suggested.

  13. Performance characteristics of gravity-assisted potassium heat pipes

    SciTech Connect

    Prenger, F.C.; Keddy, E.S.; Sena, J.T.

    1986-08-01

    Experiments with potassium-stainless steel gravity-assisted heat pipes were performed. Performance limitations due to entrainment or flooding of the liquid return flow are compared with analytical model predictions. The effect of heated pool height was investigated, and problems with surface wetting are discussed. A comparison between entrainment limits for smoothand textured-walled heat pipes was made, and a minimum internal surface texturing depth is suggested.

  14. Performance Characteristics of Current-Generation Immulite 2000 TORCH Assays

    PubMed Central

    Centonze, A. R.; Tonolli, E.

    2013-01-01

    The performances of seven Immulite 2000 (Siemens Healthcare Diagnostics) TORCH (Toxoplasma gondii, other microorganisms, rubella virus, cytomegalovirus, and herpes simplex virus) assays were evaluated in comparison with the performances of the ETI-MAX 3000 (DiaSorin) TORCH assays. The two systems demonstrated good agreement, and given their sensitivity, specificity, and positive predictive value, they can be used with confidence for TORCH prenatal screening. PMID:23175287

  15. Characteristics of Whipple Shield Performance in the Shatter Regime

    NASA Technical Reports Server (NTRS)

    Ryan, S.; Bjorkman, M.; Christiansen, E. L.

    2010-01-01

    Ballistic limit equations define the failure of metallic Whipple shields in three parts: low velocity, shatter, and hypervelocity. Failure limits in the shatter regime are based on a linear interpolation between the onset of projectile fragmentation, and impulsive rupture of the shield rear wall. A series of hypervelocity impact tests have been performed on aluminum alloy Whipple shields to investigate failure mechanisms and performance limits in the shatter regime. Test results demonstrated a more rapid increase in performance than predicted by the latest iteration of the JSC Whipple shield BLE following the onset of projectile fragmentation. This increase in performance was found to level out between 4.0-5.0 km/s, with a subsequent decrease in performance for velocities up to 6.0 km/s. For a detached spall failure criterion, the failure limit was found to continually decrease up to a velocity of 7.0 km/s, substantially varying from the BLE, while for perforation-based failure an increase in performance was observed. An existing phenomenological ballistic limit curve was found to provide a more accurate reproduction of shield behavior that the BLE, however a number of underlying assumptions such as the occurrence of complete projectile fragmentation and the effect on performance of incipient projectile melt were found to be inaccurate. A cratering relationship based on the largest residual fragment size has been derived for application at velocities between 3.0-4.0 km/s, and was shown to accurately reproduce the trends of the experimental data. Further investigation is required to allow a full analytical description of shatter regime performance for metallic Whipple shields.

  16. A novel approach to validate satellite soil moisture retrievals using precipitation data

    NASA Astrophysics Data System (ADS)

    Karthikeyan, L.; Kumar, D. Nagesh

    2016-10-01

    A novel approach is proposed that attempts to validate passive microwave soil moisture retrievals using precipitation data (applied over India). It is based on the concept that the expectation of precipitation conditioned on soil moisture follows a sigmoidal convex-concave-shaped curve, the characteristic of which was recently shown to be represented by mutual information estimated between soil moisture and precipitation. On this basis, with an emphasis over distribution-free nonparametric computations, a new measure called Copula-Kernel Density Estimator based Mutual Information (CKDEMI) is introduced. The validation approach is generic in nature and utilizes CKDEMI in tandem with a couple of proposed bootstrap strategies, to check accuracy of any two soil moisture products (here Advanced Microwave Scanning Radiometer-EOS sensor's Vrije Universiteit Amsterdam-NASA (VUAN) and University of Montana (MONT) products) using precipitation (India Meteorological Department) data. The proposed technique yields a "best choice soil moisture product" map which contains locations where any one of the two/none of the two/both the products have produced accurate retrievals. The results indicated that in general, VUA-NASA product has performed well over University of Montana's product for India. The best choice soil moisture map is then integrated with land use land cover and elevation information using a novel probability density function-based procedure to gain insight on conditions under which each of the products has performed well. Finally, the impact of using a different precipitation (Asian Precipitation-Highly-Resolved Observational Data Integration Towards Evaluation of Water Resources) data set over the best choice soil moisture product map is also analyzed. The proposed methodology assists researchers and practitioners in selecting the appropriate soil moisture product for various assimilation strategies at both basin and continental scales.

  17. Vegetable oils: Precombustion characteristics and performance as diesel fuels

    SciTech Connect

    Bagby, M.O.

    1986-03-01

    Vegetable oils show technical promise as alternative fuels for diesel engines and have good potential as emergency fuels. Realistically, vegetable oils cause a number of problems when used in direct-injection diesel engines, generally attributable to inefficient combustion. At least partially responsible for poor combustion of neat vegetable oils are their high viscosity and non-volatility. To improve combustion several somewhat empirical approaches involving both chemical and physical modifications have been investigated by endurance tests in a variety of engines. Using the EMA 200 h engine screening test, several fuels show technical promise. These include methyl, ethyl, and butyl esters; high-oleic oils:diesel blend (1:3); diesel:soybean oil:butanol:cetane improver (33:33:33:1); and microemulsion fuels (diesel:soybean oil:190 proff ethanol:butanol, 50:25:5:20) and (soybean oil:methanol:2-octanol:cetane improver, 53:13:33:1). Using a pressure vessel, fuel injection system, and high speed motion picture camera, fuel injection characteristics of vegetable oils, e.g., soybean, sunflower, cottonseed, and peanut, have been observed in a quiescent nitrogen atmosphere at 480/sup 0/C and 4.1MPa. Their injection and atomization characteristics are markedly different from those of petroleum derived diesel fuels. Heating the vegetable oils to lower their viscosities increased spray penetration rate, reduced spray cone angles, and resulted in spray characteristics resembling those of diesel fuel. Significant chemical changes occurred following injection. Samples collected at about 400 microseconds after the injection event consisted of appreciable quantities of C/sub 4/-C/sub 16/ hydrocarbons, and free carboxyl groups were present.

  18. Performance characteristics of three-phase induction motors

    NASA Technical Reports Server (NTRS)

    Wood, M. E.

    1977-01-01

    An investigation into the characteristics of three phase, 400 Hz, induction motors of the general type used on aircraft and spacecraft is summarized. Results of laboratory tests are presented and compared with results from a computer program. Representative motors were both tested and simulated under nominal conditions as well as off nominal conditions of temperature, frequency, voltage magnitude, and voltage balance. Good correlation was achieved between simulated and laboratory results. The primary purpose of the program was to verify the simulation accuracy of the computer program, which in turn will be used as an analytical tool to support the shuttle orbiter.

  19. Soil Moisture Workshop

    NASA Technical Reports Server (NTRS)

    Heilman, J. L. (Editor); Moore, D. G. (Editor); Schmugge, T. J. (Editor); Friedman, D. B. (Editor)

    1978-01-01

    The Soil Moisture Workshop was held at the United States Department of Agriculture National Agricultural Library in Beltsville, Maryland on January 17-19, 1978. The objectives of the Workshop were to evaluate the state of the art of remote sensing of soil moisture; examine the needs of potential users; and make recommendations concerning the future of soil moisture research and development. To accomplish these objectives, small working groups were organized in advance of the Workshop to prepare position papers. These papers served as the basis for this report.

  20. Performance characteristics of omnidirectional antennas for spacecraft using NASA networks

    NASA Technical Reports Server (NTRS)

    Hilliard, Lawrence M.

    1987-01-01

    Described are the performance capabilities and critical elements of the shaped omni antenna developed for NASA for space users of NASA networks. The shaped omni is designed to be operated in tandem for virtually omnidirectional coverage and uniform gain free of spacecraft interference. These antennas are ideal for low gain data requirements and emergency backup, deployment, amd retrieval of higher gain RF systems. Other omnidirectional antennas that have flown in space are described in the final section. A performance summary for the shaped omni is in the Appendix. This document introduces organizations and projects to the shaped omni applications for NASA's space use. Coverage, gain, weight, power, and implementation and other performance information for satisfying a wide range of data requirements are included.

  1. 78 FR 15112 - Rulemaking Advisory Committee; Transport Airplane Performance and Handling Characteristics-New Task

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-08

    ... guidance material for airplane performance and handling characteristics in new transport category airplanes... associated guidance material for airworthiness certification of airplane designs. Recommendations may result... Federal Aviation Administration Aviation Rulemaking Advisory Committee; Transport Airplane Performance...

  2. FIELD AND LABORATORY PERFORMANCE CHARACTERISTICS OF A NEW SAMPLING PROTOCOL FOR RIVERINE MACROINVERTEBRATE ASSEMBLAGES

    EPA Science Inventory

    Measurement and estimation of performance characteristics (i.e., precision, bias, performance range, interferences and sensitivity) are often neglected in the development and use of new biological sampling methods. However, knowledge of this information is critical in enabling p...

  3. School and Teacher Characteristics in Relationship to the Academic Performance of Elementary Schools in South Carolina

    ERIC Educational Resources Information Center

    Ray, Rhonda D.

    2013-01-01

    This correlation research study examined school and teacher characteristics in relationship to the academic performance of students in elementary schools in South Carolina. The school characteristics examined in this study were school size, poverty, minority level, and student teacher ratio. The teacher characteristics examined in this study were…

  4. Performance characteristics of a three-axis superconducting rock magnetometer

    NASA Technical Reports Server (NTRS)

    Lienert, B. R.

    1977-01-01

    A series of measurements are carried out with the purpose of quantitatively determining the characteristics of a commercial 6.8 cm access superconducting rock magnetometer located in the magnetic properties laboratory at the Goddard Space Flight Center. The measurements show that although a considerable improvement in measurement speed and signal to noise ratios can be obtained using such an instrument, a number of precautions are necessary to obtain accuracies comparable with more conventional magnetometers. These include careful calibration of the sensor outputs, optimum positioning of the sample within the detection region and quantitatively establishing the degree of cross-coupling between the detector coils. In order to examine the uniformity of response for each detector, the responses are mapped as a function of position, using a small dipole.

  5. Fiber optic moisture sensor

    DOEpatents

    Kirkham, R.R.

    1984-08-03

    A method and apparatus for sensing moisture changes by utilizing optical fiber technology. One embodiment uses a reflective target at the end of an optical fiber. The reflectance of the target varies with its moisture content and can be detected by a remote unit at the opposite end of the fiber. A second embodiment utilizes changes in light loss along the fiber length. This can be attributed to changes in reflectance of cladding material as a function of its moisture content. It can also be affected by holes or inserts interposed in the cladding material and/or fiber. Changing light levels can also be coupled from one fiber to another in an assembly of fibers as a function of varying moisture content in their overlapping lengths of cladding material.

  6. Experimental investigation of the performance characteristics of hydrocyclones

    SciTech Connect

    Sharma, S.P.

    1984-09-01

    A mathematical model of hydrocyclone classifiers used to process drilling fluid is presented. Four basic non-dimensional parameters are defined to describe the performance of the hydrocyclones. The mathematical model is based on data acquired during a series of tests using 3'', 4'', 5'', and 7'' cones with interchangable parts. The analysis of the model indicates a non-Stokesian behavior in the classification process. According to the present findings, a Stokesian model tends to underdesign the hydrocyclones by at least 15-25%. Further, an optimum value of 4 X 10/sup 4/ for the inlet Reynolds number to the hydrocyclones has been found. A term called the ''Performance Parameter,'' introduced in the analysis, can assist a designer to search for an optimum design through a parametric study.

  7. Performance characteristics of aerodynamically optimum turbines for wind energy generators

    NASA Technical Reports Server (NTRS)

    Rohrbach, C.; Worobel, R.

    1975-01-01

    This paper presents a brief discussion of the aerodynamic methodology for wind energy generator turbines, an approach to the design of aerodynamically optimum wind turbines covering a broad range of design parameters, some insight on the effect on performance of nonoptimum blade shapes which may represent lower fabrication costs, the annual wind turbine energy for a family of optimum wind turbines, and areas of needed research. On the basis of the investigation, it is concluded that optimum wind turbines show high performance over a wide range of design velocity ratios; that structural requirements impose constraints on blade geometry; that variable pitch wind turbines provide excellent power regulation and that annual energy output is insensitive to design rpm and solidity of optimum wind turbines.

  8. The Effects of Ratee Characteristics on Rater Performance Appraisal Behavior.

    DTIC Science & Technology

    1983-11-01

    should spend more time observing Kate and less time working on the 9.,e , e{e,,,,. ; c e’. ’,..... : ;..: ..-.- . . . . . . ... % Page-17 Favero & Ilg...observing, the more accurate were the performance ratings. Page-23 Favero & Ilgen Henneman & Wexley (in press) found a similar relationship between...Page-27 Favero & Ilgen Footnotes 1. We wish to thank Patricia C . Smith for providing us with this scale. 2. Other manipulations and measures included

  9. A Study of Coaxial Rotor Performance and Flow Field Characteristics

    DTIC Science & Technology

    2016-01-22

    opposite directions with a vertical separation distance equivalent to the separation between the upper and lower rotor of the coaxial system were simulated...lower rotor separately . Ramasamy provided a convenient summary of coaxial rotor hover perfor- mance measurements prior to 2013, including those surveyed 1...actual blades. Fig. 3. Performance of HC1 (Ref. 13) in hover compared with momentum theory, BEMT and RotUNS steady cal- culations. Rotor separation

  10. Design for the Maintainer: Projecting Maintenance Performance from Design Characteristics.

    DTIC Science & Technology

    1981-07-01

    come from experimentally produced changes in the micro-elements. Several projects have employed time synthesis simulation with generally positive ...would produce, positions the video tape unit to the segment showing that outcome, and plays the taped segment showing a technician performing the test and... Psycological Services, Inc. Massachusetts Institute of Technolgy 404 East Lancaster Street Cembridge, MA 02139 Wayne, PA 19087 Dr. Harry Snyder 1 Dr. W. S

  11. Pitching Flexible Propulsors: Experimental Assessment of Performance Characteristics

    DTIC Science & Technology

    2014-05-09

    E. Motor The motor, shown in Fig. 16, manipulated the angular position of the propulsor using a proportional/integral/derivative ( PID ) controller...cogging torque. The motor also became easier to tune for higher frequency oscillations. The increased frequency corresponded to an increase in the...frequency to resonant frequency, may allow for proper tuning of flexible oscillation parameters for increased performance. Operating at or near a resonant

  12. Moisture Research - Optimizing Wall Assemblies

    SciTech Connect

    Arena, Lois; Mantha, Pallavi

    2013-05-01

    In this project, the Consortium for Advanced Residential Buildings (CARB) team evaluated several different configurations of wall assemblies to determine the accuracy of moisture modeling and make recommendations to ensure durable, efficient assemblies. WUFI and THERM were used to model the hygrothermal and heat transfer characteristics of these walls. Wall assemblies evaluated included code minimum walls using spray foam insulation and fiberglass batts, high R-value walls at least 12 in. thick (R-40 and R-60 assemblies), and brick walls with interior insulation.

  13. Moisture map by IR thermography

    NASA Astrophysics Data System (ADS)

    Grinzato, E.; Cadelano, G.; Bison, P.

    2010-10-01

    A new approach to moisture detection in buildings by an optical method is presented. Limits of classical and new methods are discussed. The state of the art about the use of IR thermography is illustrated as well. The new technique exploits characteristics of the materials and takes into account explicitly the heat and mass exchange between surface and environment. A set of experiments in controlled laboratory conditions on different materials is used to better understand the physical problem. The testing procedure and the data reduction are illustrated. A case study on a heritage building points up the features of this technique.

  14. Calculation of the Characteristic Performance Indicators in an Electrochemical Process

    NASA Astrophysics Data System (ADS)

    Sánchez-Sánchez, C. M.; Expósito, E.; Solla-Gullón, J.; García-García, V.; Montiel, V.; Aldaz, A.

    2003-05-01

    Electrochemical engineering, a relatively young discipline, has important interrelationships with chemical engineering and electrochemistry. The main objectives of electrochemical engineering are the characterization and optimization, both in design and operation mode, of the mechanisms and the processes related to the conversion of chemical and electrical energies. Among the examples of electrochemical synthesis implemented at an industry scale are the synthesis of chlor alkali, aluminium, adiponitrile (an intermediate compound in the manufacture of Nylon). It is feasible to review the systems of electric energy generation (batteries and fuel cells) and sewage treatment. The definition of figures of merit is focused on the electrochemical process and is related to its yield. This concept constitutes a very useful tool to optimize the cost and the economic balance of this process. In this paper, the most characteristic figures of merit in an electrochemical process are defined. They are applied using experimental data obtained in an organic electrosynthesis process: the reduction of L-cystine to L-cysteine in acid media.

  15. Performance characteristics of gang scheduling in multiprogrammed environments

    SciTech Connect

    Jette, M.A.

    1997-11-01

    Gang scheduling provides both space-slicing and time-slicing of computer resources for parallel programs. Each thread of execution from a parallel job is concurrently scheduled on an independent processor in order to achieve an optimal level of program performance. Time-slicing of parallel jobs provides for better overall system responsiveness and utilization than otherwise possible. Lawrence Livermore National Laboratory has deployed three generations of its gang scheduler on a variety of computing platforms. Results indicate the potential benefits of this technology to parallel processing are no less significant than time-sharing was in the 1960`s.

  16. First soil moisture values from SMOS over a Sahelian region.

    NASA Astrophysics Data System (ADS)

    Gruhier, Claire; Kerr, Yann; de Rosnay, Patricia; Pellarin, Thierry; Grippa, Manuela

    2010-05-01

    Soil moisture is a crucial variable which influences the land surface processes. Numerous studies shown microwaves at low frequency are particularly performed to access to soil moisture values. SMOS (Soil Moisture and Ocean Salinity), launched the November 2th 2009, is the first space mission dedicated to soil moisture observations. Before SMOS, several soil moisture products were provided, based on active or passive microwaves measurements. Gruhier et al. (2010) analyse five of them over a Sahelian area. The results show that the range of volumetric soil moisture values obtained over Sahel is drastically different depending on the remote sensing approach used to produce soil moisture estimates. Although microwave bands currently available are not optimal, some products are in very good agreement with ground data. The main goal of this study is to introduce the first soil moisture maps from SMOS over West Africa. A first analyse of values over a Sahelian region is investigated. The study area is located in Gourma region in Mali. This site has been instrumented in the context of the AMMA project (African Monsoon Multidisciplinary Analysis) and was specifically designed to address the validation of remotely sensed soil moisture. SMOS soil moisture values was analysed with ground knowledge and placed in the context of previous soil moisture products. The high sensitivity of the L-band used by SMOS should provide very accurate soil moisture values.

  17. Assimilation of Passive and Active Microwave Soil Moisture Retrievals

    NASA Technical Reports Server (NTRS)

    Draper, C. S.; Reichle, R. H.; DeLannoy, G. J. M.; Liu, Q.

    2012-01-01

    Root-zone soil moisture is an important control over the partition of land surface energy and moisture, and the assimilation of remotely sensed near-surface soil moisture has been shown to improve model profile soil moisture [1]. To date, efforts to assimilate remotely sensed near-surface soil moisture at large scales have focused on soil moisture derived from the passive microwave Advanced Microwave Scanning Radiometer (AMSR-E) and the active Advanced Scatterometer (ASCAT; together with its predecessor on the European Remote Sensing satellites (ERS. The assimilation of passive and active microwave soil moisture observations has not yet been directly compared, and so this study compares the impact of assimilating ASCAT and AMSR-E soil moisture data, both separately and together. Since the soil moisture retrieval skill from active and passive microwave data is thought to differ according to surface characteristics [2], the impact of each assimilation on the model soil moisture skill is assessed according to land cover type, by comparison to in situ soil moisture observations.

  18. Effects of essential oil on performance characteristics, survival, processing characteristics, and fillet proximate composition of channel catfish, Ictalurus punctatus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We examined the effects of matrix encapsulated essential oils (Digestarom® P.E.P. MGE) on performance, survival, processing characteristics, and fillet proximate composition of channel catfish. Fifteen one-acre ponds at the Delta-Western Research Center, Indianola, MS were stocked with approximatel...

  19. Spatial Variation of Soil Type and Soil Moisture in the Regional Atmospheric Modeling System

    SciTech Connect

    Buckley, R.

    2001-06-27

    Soil characteristics (texture and moisture) are typically assumed to be initially constant when performing simulations with the Regional Atmospheric Modeling System (RAMS). Soil texture is spatially homogeneous and time-independent, while soil moisture is often spatially homogeneous initially, but time-dependent. This report discusses the conversion of a global data set of Food and Agriculture Organization (FAO) soil types to RAMS soil texture and the subsequent modifications required in RAMS to ingest this information. Spatial variations in initial soil moisture obtained from the National Center for Environmental Predictions (NCEP) large-scale models are also introduced. Comparisons involving simulations over the southeastern United States for two different time periods, one during warmer, more humid summer conditions, and one during cooler, dryer winter conditions, reveals differences in surface conditions related to increases or decreases in near-surface atmospheric moisture con tent as a result of different soil properties. Three separate simulation types were considered. The base case assumed spatially homogeneous soil texture and initial soil moisture. The second case assumed variable soil texture and constant initial soil moisture, while the third case allowed for both variable soil texture and initial soil moisture. The simulation domain was further divided into four geographically distinct regions. It is concluded there is a more dramatic impact on thermodynamic variables (surface temperature and dewpoint) than on surface winds, and a more pronounced variability in results during the summer period. While no obvious trends in surface winds or dewpoint temperature were found relative to observations covering all regions and times, improvement in surface temperatures in most regions and time periods was generally seen with the incorporation of variable soil texture and initial soil moisture.

  20. Performance characteristics of a new pixelated portable gamma camera

    PubMed Central

    Siman, W.; Cheenu Kappadath, S.

    2012-01-01

    Purpose: To evaluate and characterize the performance of a new commercially available pixelated portable gamma camera Ergo (Digirad, Poway, CA). Methods: The authors evaluated a pixelated portable gamma camera system, Ergo, that consists of 11 520 elements of 3 × 3 mm2 CsI(Tl) crystals that are 6-mm thick and are coupled to silicon photodiodes. The detector element has a size of 3.31 × 3.24 mm2. The gamma camera performance was evaluated for both low-energy all-purpose (LEAP) and low-energy high-resolution (LEHR) collimators. The flood-field uniformity for 99mTc and 201Tl was assessed using fillable uniform flood phantoms. Energy spectra were acquired for 99mTc, 111In, 201Tl, and 67Ga to evaluate energy linearity and energy resolution. Spectral fits were performed to calculate the photopeak energies and resolutions. The pixel size and multiwindow spatial registration (MWSR) was evaluated by measuring mixed 99mTc and 201Tl point sources placed at known distances apart. The system’s sensitivity was measured according to the National Electrical Manufacturer’s Association (NEMA) NU1-2007 standards for both LEAP and LEHR collimators as a function of distance from the collimator surface (5, 10, 15, 20, 25, 30, and 40 cm). The system resolution without scatter was measured for both LEAP and LEHR using 99mTc-filled capillary tubes located at 0, 2, 4, 6, 10, and 12 cm away from the surface of the collimator. As a measure of the spatial resolution, the full width at half maximum (FWHM) at a given distance was calculated from the presampling line spread function (LSF), constructed from the line profiles of the capillary tubes at the same distance. As a comparison, the FWHM at 10 cm away from LEHR and LEAP collimators was also calculated from linear interpolation as described by NEMA NU-1 2007 and from fitting the profiles to a Gaussian-plus-constant model. Results: All isotope-collimator pairs demonstrated good flood-field uniformity with an integral

  1. De-noising of microwave satellite soil moisture time series

    NASA Astrophysics Data System (ADS)

    Su, Chun-Hsu; Ryu, Dongryeol; Western, Andrew; Wagner, Wolfgang

    2013-04-01

    The use of satellite soil moisture data for scientific and operational hydrologic, meteorological and climatological applications is advancing rapidly due to increasing capability and temporal coverage of current and future missions. However evaluation studies of various existing remotely-sensed soil moisture products from these space-borne microwave sensors, which include AMSR-E (Advanced Microwave Scanning Radiometer) on Aqua satellite, SMOS (Soil Moisture and Ocean Salinity) mission and ASCAT (Advanced Scatterometer) on MetOp-A satellite, found them to be significantly different from in-situ observations, showing large biases and different dynamic ranges and temporal patterns (e.g., Albergel et al., 2012; Su et al., 2012). Moreover they can have different error profiles in terms of bias, variance and correlations and their performance varies with land surface characteristics (Su et al., 2012). These severely impede the effort to use soil moisture retrievals from multiple sensors concurrently in land surface modelling, cross-validation and multi-satellite blending. The issue of systematic errors present in data sets should be addressed prior to renormalisation of the data for blending and data assimilation. Triple collocation estimation technique has successfully yielded realistic error estimates (Scipal et al., 2008), but this method relies on availability of large number of coincident data from multiple independent satellite data sets. In this work, we propose, i) a conceptual framework for distinguishing systematic periodic errors in the form of false spectral resonances from non-systematic errors (stochastic noise) in remotely-sensed soil moisture data in the frequency domain; and ii) the use of digital filters to reduce the variance- and correlation-related errors in satellite data. In this work, we focus on the VUA-NASA (Vrije Universiteit Amsterdam with NASA) AMSR-E, CATDS (Centre National d'Etudes Spatiales, CNES) SMOS and TUWIEN (Vienna University of

  2. Performance characteristics of commercial Y-STR multiplex systems.

    PubMed

    Mayntz-Press, Kathleen A; Ballantyne, Jack

    2007-09-01

    In this work, a number of performance checks were carried out to evaluate the efficacy of commercial Y-short tandem repeats (Y-STR) kits for casework applications. The study evaluated the sensitivity, specificity and stability of the Y-STR markers used and the ability to obtain a male profile from postcoital samples taken at various time points after intercourse. All systems performed well with 1-3 ng of male DNA as recommended by the manufacturers. All systems gave full profiles at 100 pg of input DNA, which is within the realm of low copy number DNA analysis. Moreover all, except Y-Plex12, gave full profiles with 30-50 pg of male DNA. No increased performance was obtained with any of the systems by increasing the cycle number beyond that recommended by the various manufacturers. When up to 1 microg of female DNA was used (in the absence of male DNA) no female DNA cross reactivity was observed with the Y-Plex 12 and Y-Filer systems. PowerPlex Y produced female DNA derived products near the DYS438 and within the DYS392 loci at a rare allele position with high input DNA levels (300 ng and 1 microg, respectively). Male/female DNA admixture experiments indicated the particularly high specificity of the Y-Filer and PowerPlex Y systems under conditions of several thousand fold female DNA excess. All systems were able to detect the minor alleles in male/male DNA admixtures at a 1:5 dilution with the PowerPlex Y and Y-Filer being able to detect some minor alleles at 1:20. Species testing indicated some limited, minor cross reactivity of the commercial systems with some domestic male mammals although it is easily recognizable and would not pose any problems in casework analysis. As expected a significant number of cross-reacting products were obtained with nonhuman primate species. All Y-STR multiplex systems tested were able to produce complete Y-STR profiles from bloodstains and semen stains exposed up to 6 weeks when the samples were protected against precipitation and

  3. Comparison of physical characteristics and performance among elite snowboarders.

    PubMed

    Platzer, Hans-Peter; Raschner, Christian; Patterson, Carson; Lembert, Sandra

    2009-08-01

    There are little scientific data regarding snowboarding and the physiological demands on snowboarders. The aim of this study was to assemble and evaluate a battery of tests for the snowboard disciplines parallel, snowboard cross (SBX), big air, and half-pipe (HP). Thirty-seven competitive snowboarders participated in the study and completed a test battery that comprised tests for aerobic capacity, balance, jumping, isokinetic core power, isokinetic leg power, isometric bench press, isometric bench pull, and a snowboard start simulator. The results showed that the battery of tests explained between 61 and 98% of variance when predicting snowboard performance. The test battery predicts better for women than for men and better for SBX, HP, and overall World Cup ranking than for the other disciplines. The results indicate that starting speed, leg power, core power, and aerobic capacity are important in different snowboarding events.

  4. RPC detector characteristics and performance for INO-ICAL experiment

    NASA Astrophysics Data System (ADS)

    Kumar, A.; Gaur, A.; Hasbuddin, Md.; Naimuddin, Md.

    2016-03-01

    The India-based Neutrino Observatory (INO) is an approved multi-institutional collaboration neutrino physics project, aimed at building an underground laboratory in the southern India. INO will utilize a large magnetized Iron Calorimeter (ICAL) detector to study the atmospheric neutrinos, and to explore the unresolved issues related to neutrinos. The Resistive Plate Chambers (RPCs), interleaved in between iron absorber layers, are going to be used as the active signal readouts for the ICAL experiment at INO. The research and development is carried out to find structural quality and electrical response for RPC electrode materials available within local domain. The assembled 2 mm gap RPCs are tested using cosmic muons for their detection performance. The study also incorporates preliminary results on detector timing and signal induced charge measurements.

  5. Performance characteristics of a cosmology package on leading HPCarchitectures

    SciTech Connect

    Carter, Jonathan; Borrill, Julian; Oliker, Leonid

    2004-01-01

    The Cosmic Microwave Background (CMB) is a snapshot of the Universe some 400,000 years after the Big Bang. The pattern of anisotropies in the CMB carries a wealth of information about the fundamental parameters of cosmology. Extracting this information is an extremely computationally expensive endeavor, requiring massively parallel computers and software packages capable of exploiting them. One such package is the Microwave Anisotropy Dataset Computational Analysis Package (MADCAP) which has been used to analyze data from a number of CMB experiments. In this work, we compare MADCAP performance on the vector-based Earth Simulator (ES) and Cray X1 architectures and two leading superscalar systems, the IBM Power3 and Power4. Our results highlight the complex interplay between the problem size, architectural paradigm, interconnect, and vendor-supplied numerical libraries, while isolating the I/O file system as the key bottleneck across all the platforms.

  6. Performance characteristics and statistics of a laser initiated microdetonator

    NASA Technical Reports Server (NTRS)

    Yang, L. C.

    1979-01-01

    The test results of 320 units of the laser initiated microdetonator are summarized. The commercially fabricated units used a lead styphnate/lead azide/HMX (1 mg/17.5 mg/13.5 mg) explosive train design contained in a miniature aluminum can and completed with a glass-metal seal window. The test parameters were the high and low laser energy, high and low temperature, laser pulse duration, laser wavelength and nuclear radiation (5 x 10 to the 6th rads of 1 MeV gamma ray). The performance parameters were the laser energy for ignition and the actuation response time. Included also is a description of the development of a flexible, continuously advanced train of explosive devices by using the units, miniature optics and fiber optics.

  7. Performance characteristics of a wave attenuation for pulsed chemical lasers

    NASA Astrophysics Data System (ADS)

    Buonadonna, V.; Weisbach, M. F.; Tong, K.-O.; McClure, J. D.

    1981-06-01

    Parametric performance measurements are reported for a pulsed chemical laser wave attenuator. The attenuator utilizes the combined effects of flow channel area expansion, caustic water spray, and flow-through damping screens to suppress and control the pressure disturbances produced by the chemical heat release of the F2 + D2 chain reaction. Experimental results that illustrate the effects of different area expansion geometries, water spray configurations, and damping screen arrangements are presented. Capability to tune the attenuator system to provide short pressure wave clearing times is emphasized. An attenuator configuration is reported which gives a wave clearing time of 2 msec with a corresponding entropy-wave density nonuniformity of 0.001 for a 18.5/6/76.5 F2/O2/diluent gas mixture at a pulse repetition frequency of 100 Hz.

  8. Performance Characteristics of the Verbal QuickDASH

    PubMed Central

    London, Daniel A.; Stepan, Jeffrey G.; Boyer, Martin I.; Calfee, Ryan P.

    2013-01-01

    Purpose To quantify the performance of the verbally administered Quick Disabilities of the Arm, Shoulder, and Hand (QuickDASH) by assessing its replication of self-administered scores, its test-retest reliability, and its rate of scorable completion compared to its self-administered, written administration. Methods 50 patients presenting for initial visits to a hand clinic were enrolled regardless of diagnosis. All patients completed a written and a verbal QuickDASH 1 day apart (25 patients written first, 25 patients verbal first). Intraclass correlation coefficients quantified the verbal questionnaire’s ability to reproduce written scores. Participants verbally completed the questionnaire a final time, 5 months later, to assess test-retest reliability. To quantify the usability of survey data, we compared percentages of scorable surveys between written and verbally administered QuickDASH questionnaires in this study and in prior studies within our division. Results The intraclass correlation coefficient between the 2 QuickDASH administration types for the entire sample was 0.91. Across all participants, there was a minimal change in mean score from a patient’s written QuickDASH to that patient’s first verbal QuickDASH score. Scoring consistency between QuickDASH administrations was similar for each administration sequence (phone followed by written vs. written followed by phone) and by diagnosis. Test-retest reliability between the 2 verbal administrations demonstrated good reliability and a minimal difference between scores. In this study, no written or verbal surveys were incomplete. Reviewing our practice, 17% of 258 written questionnaires produced unscorable data compared to 0% of 140 verbally administered surveys. Discussion Our results indicate that verbal administration of the QuickDASH replicates clinically relevant scores of the written QuickDASH, has good test-retest performance, and may minimize unusable data. These data allow researchers greater

  9. Small-scale soil moisture determination with GPR

    NASA Astrophysics Data System (ADS)

    Igel, Jan; Preetz, Holger

    2010-05-01

    The knowledge of topsoil moisture distribution is an important input for modelling water flow and evapotranspiration which are essential processes in hydrology, meteorology, and agriculture. All these processes involve non-linear effects and thus the small-scale variability of input parameters play an important role. Using smoothed interpolations instead can cause significant biases. Lateral soil moisture distribution can be sensed by different techniques at various scales whereby geophysical methods provide spatial information which closes the gap between point measurements by classical soil scientific methods and measurements on the field or regional scale by remote sensing. Ground-penetrating radar (GPR) can be used to explore soil moisture on the field scale as propagation of electromagnetic waves is correlated to soil water content. By determining the velocity of the ground wave, which is a guided wave travelling along the soil surface, we can sense soil water content. This method has been applied to determine topsoil moisture for several years. We present a new groundwave technique which determines the velocity in between two receiving antennas which enables a higher lateral resolution (approx. 10 cm) compared to classical groundwave technique (half meter and more). We present synthetic data from finite-differences (FD) calculations as well as data from a sandbox experiment carried out under controlled conditions to demonstrate the performance of this method. Further, we carried out field measurements on two sites on a sandy soil which is used as grassland. The measurements were carried out in late summer at dry soil conditions. Soil moisture on the first site shows an isotropic pattern with correlation lengths of approx. 35 cm. We think this natural pattern is governed by rout distribution within the soil and the water uptake of vegetation. On the second site, soil moisture distribution shows a regular stripe pattern. As the land has been used as

  10. Evaluation of litter type and dietary coarse ground corn inclusion on broiler live performance, gastrointestinal tract development, and litter characteristics.

    PubMed

    Xu, Y; Stark, C R; Ferket, P R; Williams, C M; Nusairat, B; Brake, J

    2015-03-01

    Two 49 d floor pen studies were conducted to evaluate the effects of litter type and dietary coarse ground corn (CC) inclusion on broiler live performance, gastrointestinal tract (GIT) development, and litter characteristics. Experiment 1 was a 2×2 factorial arrangement of 2 genders (male or female) and 2 CC levels (0 or 50%). From 15 to 35 d, the addition of CC decreased feed intake (P<0.01) and BW gain (P<0.05) of males but not females. The inclusion of CC decreased feed intake (P<0.01) and BW gain (P<0.01) from 0 to 49 d but improved adjusted feed conversion ratio (AdjFCR) from 35 to 49 d (P<0.05). Male broilers exhibited better live performance than females during the study as evidenced by greater feed intake (P<0.01) and BW gain (P<0.01), and improved FCR (P<0.01), but with increased mortality (P<0.05). The inclusion of CC increased relative gizzard weight (P<0.01) and decreased relative proventriculus weight (P<0.01) at 49 d. Experiment 2 was a 2×2 factorial arrangement of 2 CC levels (0 or 50%) and 2 litter types (ground old litter or new wood shavings litter). The inclusion of CC decreased feed intake throughout the experiment without affecting final BW when only males were used and improved FCR after 25 d (P<0.01). New litter improved FCR from 1 to 14 d (P<0.01). At 49 d, the birds fed the CC diet had reduced excreta nitrogen (P<0.05) and litter moisture (P<0.05). In conclusion, 50% CC inclusion initially produced negative effects on live performance that became positive as BW increased. The effects of CC became evident at an earlier age for males. New litter had only a marginal benefit on broiler live performance.

  11. Method of Estimating the Principal Characteristics of an Infantry Fighting Vehicle from Basic Performance Requirements

    DTIC Science & Technology

    2013-08-01

    Characteristics of an Infantry Fighting Vehicle from Basic Performance Requirements David R. Gillingham Prashant R. Patel, Project Leader INSTITUTE FOR DEFENSE...Paul M. Kodzwa, David A. Sparrow, and Jeremy A. Teichman for performing technical review of this document. Copyright Notice © 2013 Institute for...Paper P-5032 Method of Estimating the Principal Characteristics of an Infantry Fighting Vehicle from Basic Performance Requirements David R. Gillingham

  12. NEXT Long-Duration Test Neutralizer Performance and Erosion Characteristics

    NASA Technical Reports Server (NTRS)

    Herman, Daniel A.; Soulas, George C.; Patterson, Michael J.

    2009-01-01

    The NASA's Evolutionary Xenon Thruster (NEXT) program is developing the next-generation ion propulsion system with significant enhancements beyond the state-of-the-art to provide future NASA science missions with enhanced capabilities at a low total development cost. A Long-Duration Test (LDT) was initiated in June 2005, to verify the NEXT propellant throughput capability to a qualification-level of 450 kg, 1.5 times the anticipated throughput requirement of 300 kg per thruster based on mission analyses. As of September 2, 2009, the thruster has accumulated 24,400 hr of operation with extensive durations at the following input powers: 6.9, 4.7, 1.1, and 0.5 kW. The thruster has processed 434 kg of xenon, surpassing the NASA Solar Technology Application Readiness (NSTAR) program thruster propellant throughput demonstrated during the extended life testing of the Deep Space 1 flight spare ion thruster and approaching the NEXT development qualification throughput goal of 450 kg. The NEXT LDT has demonstrated a total impulse of 16.1 10(exp 6zzz0 N s; the highest total impulse ever demonstrated by an ion thruster. A reduction in neutralizer flow margin has been the only appreciable source of thruster performance degradation. The behavior of the neutralizer is not easily predicted due to both erosion and deposition observed in previous wear tests. Spot-to-plume mode transition flow data and in-situ erosion results for the LDT neutralizer are discussed. This loss of flow margin has been addressed through a combination of a design change in the prototype-model neutralizer to increase flow margin at low emission current and to update the NEXT throttle table to ensure adequate flow margin as a function of propellant throughput processed. The new throttle table will be used for future LDT operations. The performance of the NEXT LDT neutralizer is consistent with that observed for long-life hollow cathodes. The neutralizer life-limiting failure modes are progressing as expected

  13. Towards uniformly dispersed battery electrode composite materials: Characteristics and performance

    SciTech Connect

    Yo Han Kwon; Takeuchi, Esther S.; Huie, Matthew M.; Choi, Dalsu; Chang, Mincheol; Marschilok, Amy C.; Takeuchi, Kenneth J.; Reichmanis, Elsa

    2016-01-14

    Battery electrodes are complex mesoscale systems comprised of electroactive components, conductive additives, and binders. In this report, methods for processing electrodes with dispersion of the components are described. To investigate the degree of material dispersion, a spin-coating technique was adopted to provide a thin, uniform layer that enabled observation of the morphology. Distinct differences in the distribution profile of the electrode components arising from individual materials physical affinities were readily identified. Hansen solubility parameter (HSP) analysis revealed pertinent surface interactions associated with materials dispersivity. Further studies demonstrated that HSPs can provide an effective strategy to identify surface modification approaches for improved dispersions of battery electrode materials. Specifically, introduction of surfactantlike functionality such as oleic acid (OA) capping and P3HT-conjugated polymer wrapping on the surface of nanomaterials significantly enhanced material dispersity over the composite electrode. The approach to the surface treatment on the basis of HSP study can facilitate design of composite electrodes with uniformly dispersed morphology and may contribute to enhancing their electrical and electrochemical behaviors. The conductivity of the composites and their electrochemical performance was also characterized. In conclusion, the study illustrates the importance of considering electronic conductivity, electron transfer, and ion transport in the design of environments incorporating active nanomaterials.

  14. Towards uniformly dispersed battery electrode composite materials: Characteristics and performance

    DOE PAGES

    Yo Han Kwon; Takeuchi, Esther S.; Huie, Matthew M.; ...

    2016-01-14

    Battery electrodes are complex mesoscale systems comprised of electroactive components, conductive additives, and binders. In this report, methods for processing electrodes with dispersion of the components are described. To investigate the degree of material dispersion, a spin-coating technique was adopted to provide a thin, uniform layer that enabled observation of the morphology. Distinct differences in the distribution profile of the electrode components arising from individual materials physical affinities were readily identified. Hansen solubility parameter (HSP) analysis revealed pertinent surface interactions associated with materials dispersivity. Further studies demonstrated that HSPs can provide an effective strategy to identify surface modification approaches formore » improved dispersions of battery electrode materials. Specifically, introduction of surfactantlike functionality such as oleic acid (OA) capping and P3HT-conjugated polymer wrapping on the surface of nanomaterials significantly enhanced material dispersity over the composite electrode. The approach to the surface treatment on the basis of HSP study can facilitate design of composite electrodes with uniformly dispersed morphology and may contribute to enhancing their electrical and electrochemical behaviors. The conductivity of the composites and their electrochemical performance was also characterized. In conclusion, the study illustrates the importance of considering electronic conductivity, electron transfer, and ion transport in the design of environments incorporating active nanomaterials.« less

  15. Performance characteristics of valveless and cantilever-valve micropump

    NASA Astrophysics Data System (ADS)

    Shukur, A. F. M.; Sabani, N.; Taib, B. N.; Azidin, M. A. M.; Shahimin, M. M.

    2013-12-01

    This paper presents comparison between two classes of micropump which are valveless micropump and cantilever-valve micropump. These micropumps consist of basic components which are diaphragm, pumping chamber, actuation mechanism, inlet and outlet. Piezoelectric actuation is carried out by applying pressure on the micropump diaphragm to produce deflection. The micropumps studied in this paper had been designed with specific diaphragm thickness and diameter; while varying the materials, pressure applied and liquid types used. The outer dimension for both micropumps is 4mm × 4mm × 0.5mm with diameter and thickness of the diaphragm are 3.8mm and 20μm respectively. Valveless micropump was shown in this paper to have better performance in mechanical and fluid analysis in terms of maximum deflection and maximum flow rate at actuation pressure 30kPa vis-à-vis cantilever-valve micropump. Valveless micropump was shown in this study to have maximum diaphragm deflection of 183.06μm and maximum flow rate with 191.635μL/s at actuation pressure 30kPa using silicon dioxide as material.

  16. Runway drainage characteristics related to tire friction performance

    NASA Technical Reports Server (NTRS)

    Yager, Thomas J.

    1991-01-01

    The capability of a runway pavement to rapidly drain water buildup during periods of precipitation is crucial to minimize tire hydroplaning potential and maintain adequate aircraft ground operational safety. Test results from instrumented aircraft, ground friction measuring vehicles, and NASA Langley's Aircraft Landing Dynamics Facility (ALDF) track have been summarized to indicate the adverse effects of pavement wetness conditions on tire friction performance. Water drainage measurements under a range of rainfall rates have been evaluated for several different runway surface treatments including the transversely grooved and longitudinally grinded concrete surfaces at the Space Shuttle Landing Facility (SLF) runway at NASA Kennedy Space Center in Florida. The major parameters influencing drainage rates and extent of flooding/drying conditions are identified. Existing drainage test data are compared to a previously derived empirical relationship and the need for some modification is indicated. The scope of future NASA Langley research directed toward improving empirical relationships to properly define runway drainage capability and consequently, enhance aircraft ground operational safety, is given.

  17. Toward Uniformly Dispersed Battery Electrode Composite Materials: Characteristics and Performance.

    PubMed

    Kwon, Yo Han; Huie, Matthew M; Choi, Dalsu; Chang, Mincheol; Marschilok, Amy C; Takeuchi, Kenneth J; Takeuchi, Esther S; Reichmanis, Elsa

    2016-02-10

    Battery electrodes are complex mesoscale systems comprised of electroactive components, conductive additives, and binders. In this report, methods for processing electrodes with dispersion of the components are described. To investigate the degree of material dispersion, a spin-coating technique was adopted to provide a thin, uniform layer that enabled observation of the morphology. Distinct differences in the distribution profile of the electrode components arising from individual materials physical affinities were readily identified. Hansen solubility parameter (HSP) analysis revealed pertinent surface interactions associated with materials dispersivity. Further studies demonstrated that HSPs can provide an effective strategy to identify surface modification approaches for improved dispersions of battery electrode materials. Specifically, introduction of surfactantlike functionality such as oleic acid (OA) capping and P3HT-conjugated polymer wrapping on the surface of nanomaterials significantly enhanced material dispersity over the composite electrode. The approach to the surface treatment on the basis of HSP study can facilitate design of composite electrodes with uniformly dispersed morphology and may contribute to enhancing their electrical and electrochemical behaviors. The conductivity of the composites and their electrochemical performance was also characterized. The study illustrates the importance of considering electronic conductivity, electron transfer, and ion transport in the design of environments incorporating active nanomaterials.

  18. Passive Microwave Remote Sensing of Soil Moisture

    NASA Technical Reports Server (NTRS)

    Njoku, Eni G.; Entekhabi, Dara

    1996-01-01

    Microwave remote sensing provides a unique capability for direct observation of soil moisture. Remote measurements from space afford the possibility of obtaining frequent, global sampling of soil moisture over a large fraction of the Earth's land surface. Microwave measurements have the benefit of being largely unaffected by cloud cover and variable surface solar illumination, but accurate soil moisture estimates are limited to regions that have either bare soil or low to moderate amounts of vegetation cover. A particular advantage of passive microwave sensors is that in the absence of significant vegetation cover soil moisture is the dominant effect on the received signal. The spatial resolutions of passive Microwave soil moisture sensors currently considered for space operation are in the range 10-20 km. The most useful frequency range for soil moisture sensing is 1-5 GHz. System design considerations include optimum choice of frequencies, polarizations, and scanning configurations, based on trade-offs between requirements for high vegetation penetration capability, freedom from electromagnetic interference, manageable antenna size and complexity, and the requirement that a sufficient number of information channels be available to correct for perturbing geophysical effects. This paper outlines the basic principles of the passive microwave technique for soil moisture sensing, and reviews briefly the status of current retrieval methods. Particularly promising are methods for optimally assimilating passive microwave data into hydrologic models. Further studies are needed to investigate the effects on microwave observations of within-footprint spatial heterogeneity of vegetation cover and subsurface soil characteristics, and to assess the limitations imposed by heterogeneity on the retrievability of large-scale soil moisture information from remote observations.

  19. Effect of moisture on the aging behavior of asphalt binder

    NASA Astrophysics Data System (ADS)

    Ma, Tao; Huang, Xiao-Ming; Mahmoud, Enad; Garibaldy, Emil

    2011-08-01

    The moisture aging effect and mechanism of asphalt binder during the in-service life of pavement were investigated by laboratory simulating tests. Pressure aging vessel (PAV) test simulating the long-term aging of binder during the in-service life of pavement was modified to capture the long-term moisture aging effect of binder. Penetration grade tests including penetration test, soften point test, and ductility test as well as Superpave™ performance grade tests including viscosity test, dynamic shear rheometer test, and bending beam rheometer test were conducted to fully evaluate the moisture aging effect of binder. Fourier transform infrared spectroscopy test and Gel-permeation chromatography test were applied to provide a fundamental understanding of the moisture aging mechanism of binder. The results indicate that moisture condition can accelerate the aging of asphalt binder and shorten the service life of asphalt binder. The modified PAV test with moisture condition can well characterize the moisture aging properties of asphalt binder.

  20. Multilayer moisture barrier

    DOEpatents

    Pankow, Joel W; Jorgensen, Gary J; Terwilliger, Kent M; Glick, Stephen H; Isomaki, Nora; Harkonen, Kari; Turkulainen, Tommy

    2015-04-21

    A moisture barrier, device or product having a moisture barrier or a method of fabricating a moisture barrier having at least a polymer layer, and interfacial layer, and a barrier layer. The polymer layer may be fabricated from any suitable polymer including, but not limited to, fluoropolymers such as polyethylene terephthalate (PET) or polyethylene naphthalate (PEN), or ethylene-tetrafluoroethylene (ETFE). The interfacial layer may be formed by atomic layer deposition (ALD). In embodiments featuring an ALD interfacial layer, the deposited interfacial substance may be, but is not limited to, Al.sub.2O.sub.3, AlSiO.sub.x, TiO.sub.2, and an Al.sub.2O.sub.3/TiO.sub.2 laminate. The barrier layer associated with the interfacial layer may be deposited by plasma enhanced chemical vapor deposition (PECVD). The barrier layer may be a SiO.sub.xN.sub.y film.

  1. Moisturizers: The Slippery Road

    PubMed Central

    Sethi, Anisha; Kaur, Tejinder; Malhotra, SK; Gambhir, ML

    2016-01-01

    Moisturizers are an important part of a dermatologist's armamentarium although little is written and well, a less is truly known about them. There is a cornucopia of projected skin products in the market whose real scientific role is not proven. These products although at times are regarded as mere cosmetics but have a well-known role in many skin disorders. Adequate knowledge about their mechanism of action, dosage, usage, and adverse effects is must for a dermatologist in this era. This article aims to bring forth the ever hidden facts of the much-hyped moisturizers. It is probably the first of its kind covering all aspects of moisturizers ranging from basic science to clinical usage, a subject that receives a short shrift in the current dermatological text. PMID:27293248

  2. Global atmospheric moisture variability

    NASA Technical Reports Server (NTRS)

    Robertson, Franklin R.; James, Bonnie F.; Chi, Kay; Huang, Huo-Jin

    1989-01-01

    Research efforts during FY-88 have focused on completion of several projects relating to analysis of FGGE data during SOP-1 and on expanded studies of global atmospheric moisture. In particular, a revised paper on the relationship between diabatic heating and baroclinicity in the South Pacific Convergence Zone (SPCZ) was submitted. A summary of completed studies on diagnostic convective parameterization was presented at the Satellite Meteorology and Oceanography Convergence last February. These investigations of diabatic heating in the SPCZ have demonstrated the requirement for a more quantitative description of atmospheric moisture. As a result, efforts were directed toward use of passive remote microwave measurements from the Nimbus-7 SMMR and the DOD's Special Sensor Microwave Imager (SSMI/I) as critical sources of moisture data. Activities this year are summarized.

  3. Botswana water and surface energy balance research program. Part 2: Large scale moisture and passive microwaves

    NASA Technical Reports Server (NTRS)

    Vandegriend, A. A.; Owe, M.; Chang, A. T. C.

    1992-01-01

    The Botswana water and surface energy balance research program was developed to study and evaluate the integrated use of multispectral satellite remote sensing for monitoring the hydrological status of the Earth's surface. The research program consisted of two major, mutually related components: a surface energy balance modeling component, built around an extensive field campaign; and a passive microwave research component which consisted of a retrospective study of large scale moisture conditions and Nimbus scanning multichannel microwave radiometer microwave signatures. The integrated approach of both components are explained in general and activities performed within the passive microwave research component are summarized. The microwave theory is discussed taking into account: soil dielectric constant, emissivity, soil roughness effects, vegetation effects, optical depth, single scattering albedo, and wavelength effects. The study site is described. The soil moisture data and its processing are considered. The relation between observed large scale soil moisture and normalized brightness temperatures is discussed. Vegetation characteristics and inverse modeling of soil emissivity is considered.

  4. Thermodynamics of the Madden-Julian Oscillation in a Regional Model with Constrained Moisture

    SciTech Connect

    Hagos, Samson M.; Leung, Lai-Yung R.; Dudhia, Jimy

    2011-09-01

    In order to identify the main thermodynamic processes that sustain the Madden Julian Oscillation, an eddy available potential energy budget analysis is performed on a WRF simulation with moisture constrained by observations. The model realistically simulates the two MJO episodes observed during the winter of 2007-2008. The analysis shows that instabilities and damping associated with variations in diabatic heating and energy transport work in concert to provide the MJO with its observed characteristics. The results are used to construct a simplified paradigm of MJO thermodynamics. Furthermore, the effect of moisture nudging on the simulation is analyzed to understand the limitations of the model cumulus parameterization. Without moisture nudging, the parameterization fails to provide adequate low-level (upper-level) moistening during the early (late) stage of the MJO active phase. The moistening plays a critical role in providing stratiform heating variability that is an important source of eddy available potential energy for the model MJO.

  5. Physical properties and moisture

    SciTech Connect

    Schobert, H.H.; Tye, C.; Neumann, R.M.

    1985-07-01

    Our principal accomplishments in the physical property studies of low-rank coals are the determination of their: (A) relative amounts of tightly and loosely bound moisture, (B) porosity and pore size distribution, (C) mechanical and thermal friabilities, and (D) surface areas. The occurrence of moisture in low-rank coals involves at least two fundamentally different mechanisms for binding the water to the coal matrix. The first type of moisture behaves as if it were ''free''; the vapor pressure versus temperature behavior is similar to that of pure water. The second type occurs at sites where it is bound more tightly, resulting in a lowering of the corresponding vapor pressure. A dielectric-relaxation-spectroscopic investigation of a North Dakota lignite and a subbituminous coal provides direct evidence for the existence of the two types of moisture. Lignite incorporates 80% of its moisture in a loosely-bound form which freezes to ice and the remaining 20% is present possibly chemically bound to inorganic moieties. The subbituminous coal contains only the latter type of bound moisture. Small angle scattering has proven to be a useful and convenient method of studying the pore structure of coal, and yields information related to pore size, pore size distribution, specific surface area and specific volume. Calculation of values for these parameters must be made in terms of some model; a pore model developed at the University of Missouri has proven to be quite useful. The objective in friability studies is to determine the shift in particle size distribution as a result of tumbling or heating. 6 figs., 2 tabs.

  6. Soil moisture variability of root zone profiles within SMEX02 remote sensing footprints

    NASA Astrophysics Data System (ADS)

    Choi, Minha; Jacobs, Jennifer M.

    2007-04-01

    Remote sensing of soil moisture effectively provides soil moisture at a large scale, but does not explain highly heterogeneous soil moisture characteristics within remote sensing footprints. In this study, field scale spatio-temporal variability of root zone soil moisture was analyzed. During the Soil Moisture Experiment 2002 (SMEX02), daily soil moisture profiles (i.e., 0-6, 5-11, 15-21, and 25-31 cm) were measured in two fields in Walnut Creek watershed, Ames, Iowa, USA. Theta probe measurements of the volumetric soil moisture profile data were used to analyze statistical moments and time stability and to validate soil moisture predicted by a simple physical model simulation. For all depths, the coefficient of variation of soil moisture is well explained by the mean soil moisture using an exponential relationship. The simple model simulated very similar variability patterns as those observed. As soil depth increases, soil moisture distributions shift from skewed to normal patterns. At the surface depth, the soil moisture during dry down is log-normally distributed, while the soil moisture is normally distributed after rainfall. At all depths below the surface, the normal distribution captures the soil moisture variability for all conditions. Time stability analyses show that spatial patterns of sampling points are preserved for all depths and that time stability of surface measurements is a good indicator of subsurface time stability. The most time stable sampling sites estimate the field average root zone soil moisture value within ±2.1% volumetric soil moisture.

  7. Examining the Relationship between Learning Organization Characteristics and Change Adaptation, Innovation, and Organizational Performance

    ERIC Educational Resources Information Center

    Kontoghiorghes, Constantine; Awbre, Susan M.; Feurig, Pamela L.

    2005-01-01

    The main purpose of this exploratory study was to examine the relationship between certain learning organization characteristics and change adaptation, innovation, and bottom-line organizational performance. The following learning organization characteristics were found to be the strongest predictors of rapid change adaptation, quick product or…

  8. Job Characteristics and College Performance and Attitudes: A Model of Work-School Conflict and Facilitation

    ERIC Educational Resources Information Center

    Butler, Adam B.

    2007-01-01

    The processes linking job characteristics to school performance and satisfaction in a sample of 253 full-time college students were examined from 2 role theory perspectives, 1 of which emphasized resource scarcity and the other resource expansion. Model tests using structural equation modeling showed that 2 resource-enriching job characteristics,…

  9. Scaling surface soil moisture in the Walnut Gulch Experimental Watershed

    NASA Astrophysics Data System (ADS)

    Cosh, M. H.; Jackson, T. J.; Moran, S.; Bindlish, R.; Mladenova, I.

    2006-05-01

    The estimation of surface soil moisture in semi-arid and arid regions is complicated by the inherent heterogeneous precipitation patterns and ephemeral surface water characteristics. Large-scale sampling is inefficient for long term monitoring of surface soil moisture, especially with the goal of calibration of a satellite soil moisture product such as that generated by the AMSR-E instrument for example. Statistical methods of accurately monitoring and scaling point and watershed estimates to satellite scale moisture values are explored. The location for this study is the Walnut Gulch Experimental Watershed in Tombstone, Arizona, which is also the location of the Soil Moisture Experiment in 2004 (SMEX04). The variability of radiometric temperature brightness data is also examined for its relationships to land surface parameters, climate variables, and insitu soil moisture measurements. Variability assessment is also evaluated for consistency and persistence over a three-year period.

  10. Research on a novel infrared moisture instrument

    NASA Astrophysics Data System (ADS)

    Gao, Chao; Ma, Hao-bing

    2006-02-01

    Based on the principle of Beer-Lambert Law and aiming at the limit of traditional infrared measuring method of the moisture which utilizes mechanical modulating technology, the current paper presents a new-style measuring means, the measurement circuit and an optical structure which are based on electrically modulated technology. This application overcomes the disadvantages of common method and the moisture can be inspected uninterruptedly, untouchedly, great-range and fast if the infrared detector is used in the industry process. Without the effects of mechanical vibration, the whole system has the characteristics of low power consumption, high stability, high selectivity, free maintenance and is pocket-sized.

  11. Spatiotemporal moisture dynamics in a prairie pasture

    NASA Astrophysics Data System (ADS)

    Peterson, Amber; Ireson, Andrew; Helgason, Warren

    2016-04-01

    For most practical applications, soil moisture estimates are needed at field scale, integrated over the root zone. We present here results from a field study in a pasture site in Saskatchewan, Canada. We combine observations of point scale soil moisture content from an array of neutron probes with continuous, field scale, shallow soil moisture content observations from the COSMOS instrument. The neutron probe data provide insights into the spatial variability of soil moisture processes, which is highly significant at this site. In particular, we find that the field comprises non-participating profiles, where infiltration, change in storage and drainage are minimal, and dynamic profiles, where these processes are highly dynamic. This strongly affects the relationship between the spatial mean vs standard deviation of moisture content, with important implications for upscaling of point scale observations to field scale. The COSMOS performs well, but only captures changes in water content to a depth of around 20 cm, meaning that upscaling with depth is required to produce a field scale, root zone integrated estimation of soil moisture content. We compare three upscaling approaches.

  12. A Roadmap for Humidity and Moisture Measurement

    NASA Astrophysics Data System (ADS)

    Bell, S.; Benyon, R.; Böse, N.; Heinonen, M.

    2008-10-01

    An initial roadmap for humidity and related measurements was developed in Spring 2006 as part of the EUROMET iMERA activity toward increasing impact from national investment in European metrology R&D. The conclusions address both humidity (for which standards and traceability methodologies exist, but need to be developed) and moisture content of materials (for which measurement traceability is more problematic and is not so well developed in general). The roadmap represents a shared vision of how humidity and moisture measurements and standards should develop over the next 15 years to meet future needs, open to revision as needs and technologies evolve. The roadmap identifies the main social and economic triggers that drive developments in humidity and moisture measurements and standards—notably, global warming and advanced manufacturing processes. Stemming from these triggers, key targets that require improved humidity and moisture measurements are identified. In view of global warming, one key target is the development of improved models of climate through improved measurements of atmospheric water vapor. A further target is the reduction of carbon emissions through humidity measurement to optimize industrial heat treatment and combustion processes, and through humidity and moisture measurements to achieve energy-efficient buildings. For high-performance manufacturing, one key target is improved precision control of manufacturing processes through better humidity and moisture measurements. Another key target is contaminant-free manufacture in industries such as microelectronics, through high-purity gases of known moisture content at the parts-per-trillion level. To enable these outcomes, the roadmap identifies the advances needed in measurement standards. These include the following: improved trace humidity standards; new humidity standards to cover high temperatures and pressures, steam, and non-air gases; and improved standards for moisture content of

  13. Psychosocial Characteristics of Optimum Performance in Isolated and Confined Environments (ICE)

    NASA Technical Reports Server (NTRS)

    Palinkas, Lawrence A.; Keeton, Kathryn E.; Shea, Camille; Leveton, Lauren B.

    2010-01-01

    The Behavioral Health and Performance (BHP) Element addresses human health risks in the NASA Human Research Program (HRP), including the Risk of Adverse Behavioral Conditions and the Risk of Psychiatric Disorders. BHP supports and conducts research to help characteristics and mitigate the Behavioral Medicine risk for exploration missions, and in some instances, current Flight Medical Operations. The Behavioral Health and Performance (BHP) Element identified research gaps within the Behavioral Medicine Risk, including Gap BMed6: What psychosocial characteristics predict success in an isolated, confined environment (ICE)? To address this gap, we conducted an extensive and exhaustive literature review to identify the following: 1) psychosocial characteristics that predict success in ICE environments; 2) characteristics that are most malleable; and 3) specific countermeasures that could enhance malleable characteristics.

  14. Development of tough, moisture resistant laminating resins

    NASA Technical Reports Server (NTRS)

    Brand, R. A.; Harrison, E. S.

    1982-01-01

    Tough, moisture resistant laminating resins for employment with graphite fibers were developed. The new laminating resins exhibited cost, handleability and processing characteristics equivalent to 394K (250 F) curing epoxies. The laminating resins were based on bisphenol A dicyanate and monofunctional cyanates with hydrophobic substituents. These resins sorb only small quantities of moisture at equilibrium (0.5% or less) with minimal glass transition temperature depression and represent an improvement over epoxies which sorb around 2% moisture at equilibrium. Toughening was accomplished by the precipitation of small diameter particles of butadiene nitrile rubber throughout the resin matrix. The rubber domains act as microcrack termini and energy dissipation sites, allowing increased stress accommodation prior to catastrophic failure. A unique blend of amine terminated butadiene nitrile elastomer (MW 2,000) and a high nitrile content butadiene nitrile rubber yielded the desired resin morphology.

  15. Soil moisture and biogeochemical factors influence the distribution of annual Bromus species

    USGS Publications Warehouse

    Belnap, Jayne; Stark, John Thomas; Rau, Benjamin; Allen, Edith B.; Phillips, Sue

    2016-01-01

    Abiotic factors have a strong influence on where annual Bromus species are found. At the large regional scale, temperature and precipitation extremes determine the boundaries of Bromusoccurrence. At the more local scale, soil characteristics and climate influence distribution, cover, and performance. In hot, dry, summer-rainfall-dominated deserts (Sonoran, Chihuahuan), little or noBromus is found, likely due to timing or amount of soil moisture relative to Bromus phenology. In hot, winter-rainfall-dominated deserts (parts of the Mojave Desert), Bromus rubens is widespread and correlated with high phosphorus availability. It also responds positively to additions of nitrogen alone or with phosphorus. On the Colorado Plateau, with higher soil moisture availability, factors limiting Bromus tectorum populations vary with life stage: phosphorus and water limit germination, potassium and the potassium/magnesium ratio affect winter performance, and water and potassium/magnesium affect spring performance. Controlling nutrients also change with elevation. In cooler deserts with winter precipitation (Great Basin, Columbia Plateau) and thus even greater soil moisture availability, B. tectorum populations are controlled by nitrogen, phosphorus, or potassium. Experimental nitrogen additions stimulate Bromus performance. The reason for different nutrients limiting in dissimilar climatic regions is not known, but it is likely that site conditions such as soil texture (as it affects water and nutrient availability), organic matter, and/or chemistry interact in a manner that regulates nutrient availability and limitations. Under future drier, hotter conditions,Bromus distribution is likely to change due to changes in the interaction between moisture and nutrient availability.

  16. Comparison of the moisturization efficacy of two vaginal moisturizers: Pectin versus polycarbophil technologies.

    PubMed

    Caswell, Michael; Kane, Michael

    2002-01-01

    This study was designed to compare the vaginal deposition and moisturization of two vaginal moisturizers, Summer's Eve (SE), based on pectin, and Replens (Rp), based on polycarbophil, in a double-blind crossover study design. Fifty-one female patients were each randomly assigned to one of two treatment groups. After a one-week washout period, the products were used for two weeks. After another one-week washout period, product assignments were switched. Colposcopy examinations were performed at the beginning and at the end of each product use. Of the forty-seven patients completing the study, 41 (87%) were found to have no vaginal residue after SE vaginal moisturizer, while only 25 (53%) were found to have no vaginal residue after using Rp vaginal moisturizer. No difference in relief of vaginal dryness or in product acceptance was found between the two products. This study shows that the use of SE vaginal moisturizer, based on pectin, resulted in significantly less vaginal residue compared to Rp vaginal moisturizer, based on polycarbophil, and in comparable relief of vaginal dryness. These results strongly suggest that bioadhesion is not important in vaginal moisturizers.

  17. Academic Performance, Characteristics and Expenditures in New York City Elementary and Middle Schools. Condition Report.

    ERIC Educational Resources Information Center

    Stiefel, Leanna; Schwartz, Amy Ellen; Iatarola, Patrice; Fruchter, Norm

    This study examines the academic performance of students in New York City's elementary and middle schools, investigating variations across grades and schools and documenting differences in student and teacher characteristics and the pattern and level of expenditure between low, middle, and high performing schools. The study reports averages of…

  18. Relationship of Student Characteristics and Performance in a Personalized System of Instruction Course.

    ERIC Educational Resources Information Center

    Roberts, Michael C.; And Others

    1978-01-01

    The author examined college student characteristics and their relation to performance in a psychology course which employed a personalized system of instruction (PSI). Findings indicated that dependable predictors, such as past performance and ability measures, were as applicable to PSI courses as to traditional ones. (Author/DB)

  19. Supervisors' Performance Ratings Correlated with Selected Personal Characteristics of Attendants in a Mental Retardation Developmental Center.

    ERIC Educational Resources Information Center

    Frederick, Joseph; And Others

    A research study investigated the relationship between personal characteristics and selected demographic data of 75 attendants in a mental retardation developmental center and the assessment by 24 administrators of the attendants' job performance. Instruments used included a 20-item Direct Care Performance Scale and the Demographic Data Scale,…

  20. Influence of Morphological Characteristics on Physical and Physiological Performances of Tunisian Elite Male Handball Players

    PubMed Central

    Moncef, Cherif; Said, Mohamed; Olfa, Najlaoui; Dagbaji, Gomri

    2012-01-01

    Purpose The purpose of this study was to describe the body structure and morphological characteristics of Tunisian elite handball players, and to determine the effect of these variables on functional and physical performance levels. Methods A sample of 42 male handball players (mean age 21.98±3.24 years; training duration 12 years) at international level was submitted to a test battery comprising morphological, physical and physiological assessments. Tests were yo-yo intermittent recovery test, squat jump test, countermovement jump test, vertical-jump test, and Repeated sprint Ability. Measures for assessment of anthropometric characteristics were age, size, weight, body mass index, body fat, fat mass and thin mass. Results Weight was negatively correlated to the squat jump and the countermovement jump performance. Age, weight, and body composition measures (fat and thin body mass) were additionally negatively related to the maximal oxygen uptake, and to the maximal velocity obtained in the Yo-Yo recovery test. No relationship was found between size, body mass index, body fat and the physical abilities considered. Concerning the effects of physical characteristics on the functional performances, we can note a positive relationship between squat jump, countermovement jump, and the yo-yo recovery test performance. No relationship was found between vertical jump, repeated sprint ability, and the physiological performances. Conclusions Study results point to the existence of strong correlation between morphological and physical characteristics with functional characteristics. In handball, it is possible to have a reliable estimate of anthropometric measurements, physical and physiological performances. PMID:22942992

  1. A Study of the Associations between Conditions of Performance and Characteristics of Performers and New York State Solo Performance Ratings

    ERIC Educational Resources Information Center

    vonWurmb, Elizabeth C.

    2013-01-01

    This dissertation undertakes an analysis of 1,044 performance evaluations from New York State School Music Association (NYSSMA) Spring Festival solo adjudication ratings of student performers from a large suburban school district. It relies on results of evaluations of observed performances, and takes these evaluations as assessments of what the…

  2. Moisture Control Handbook: New, low-rise, residential construction

    SciTech Connect

    Lstiburek, J.; Carmody, J.

    1991-10-01

    Moisture problems are prevalent all over North America, almost independent of climate. They are viewed as one of the single largest factors limiting the useful service life of a building. Elevated levels of moisture in buildings also can lead to serious health effects for occupants. Until recently, very little consensus on moisture control existed in the building community. The information available was typically incomplete, contradictory, usually limited to specific regions, and in many cases misleading. A need to develop a document which presented the issues relating to moisture from a building science or ``systems`` approach existed. This handbook attempts to fill that need and illustrates that energy-efficient, tight envelope design is clearly part of the solution to healthy buildings when interior relative humidity, temperature, and pressure are controlled simultaneously. The first three chapters of the handbook present the basic principles of moisture problems and solutions in buildings. Chapter 1 -- Mold, Mildew, and Condensation, examines surface moisture problems. Chapter 2 -- Moisture Movement, examines how building assemblies get wet from both the exterior and interior. Chapter 3 -- Wetting and Drying of Building Assemblies, introduces the concepts of acceptable performance, moisture balance, and the redistribution of moisture within building assemblies. Chapters 4 through 6 apply the concepts outlined in the previous chapters and present specific moisture control practices for three basic US climate zones. The advantages and disadvantages of several wall, foundation, and roof assemblies are discussed for each climate zone.

  3. Influence of low energy argon plasma treatment on the moisture barrier performance of hot wire-CVD grown SiNx multilayers

    NASA Astrophysics Data System (ADS)

    Majee, Subimal; Fátima Cerqueira, Maria; Tondelier, Denis; Geffroy, Bernard; Bonnassieux, Yvan; Alpuim, Pedro; Bourée, Jean Eric

    2014-01-01

    The reliability and stability are key issues for the commercial utilization of organic photovoltaic devices based on flexible polymer substrates. To increase the shelf-lifetime of these devices, transparent moisture barriers of silicon nitride (SiNx) films are deposited at low temperature by hot wire CVD (HW-CVD) process. Instead of the conventional route based on organic/inorganic hybrid structures, this work defines a new route consisting in depositing multilayer stacks of SiNx thin films, each single layer being treated by argon plasma. The plasma treatment allows creating smoother surface and surface atom rearrangement. We define a critical thickness of the single layer film and focus our attention on the effect of increasing the number of SiNx single-layers on the barrier properties. A water vapor transmission rate (WVTR) of 2 × 10-4 g/(m2·day) is reported for SiNx multilayer stack and a physical interpretation of the plasma treatment effect is given.

  4. A Redesigned DFA Moisture Meter

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The DFA moisture meter has been internationally recognized as the standard for determining moisture content of dried fruit in general and is AOAC Official Method 972.2 for measuring moisture in prunes and raisins since 1972. The device has remained virtually unchanged since its inception, with its o...

  5. Moisture Metrics Project

    SciTech Connect

    Schuchmann, Mark

    2011-08-31

    the goal of this project was to determine the optimum moisture levels for biomass processing for pellets commercially, by correlating data taken from numerous points in the process, and across several different feedstock materials produced and harvested using a variety of different management practices. This was to be done by correlating energy consumption and material through put rates with the moisture content of incoming biomass ( corn & wheat stubble, native grasses, weeds, & grass straws), and the quality of the final pellet product.This project disseminated the data through a public website, and answering questions form universities across Missouri that are engaged in biomass conversion technologies. Student interns from a local university were employed to help collect data, which enabled them to learn firsthand about biomass processing.

  6. Physical properties and moisture

    SciTech Connect

    Hauserman, W.B.

    1984-05-01

    This is an interim report of work done to identify and define numerically a group of coal properties relating the structural integrity and intrinsic moisture content of coals. It represents work for the first time approaching a possibility of correlating properties formerly considered as completely unrelated subject areas. The data are still preliminary but demonstrate productive experimental techniques for further insight into the physical and molecular structure of coals. The only firm conclusion to be drawn from the friability and dielectric data together is that both are simple, numerical techniques to characterize and compare coals with respect to their mechanical structure and mode of intrinsic moisture attachment. Each provides sets of several variables, whose full significance can only be established after expanding the data base to include more coals, with more replications for statistical validity. The accomplishment to date consists of demonstrating that such data are possible. 10 references, 16 figures.

  7. Characterization of non-Fickian moisture absorption in thermosetting polymers

    NASA Astrophysics Data System (ADS)

    Guloglu, Gorkem E.; Altan, M. Cengiz

    2015-05-01

    A recently developed moisture absorption model for thermosetting polymers that combines the non-Fickian, diffusion hindrance effects and three-dimensional anisotropy is introduced. The hindered diffusion model is shown to predict both short term Fickian and long term anomalous moisture absorption behavior often observed in thermosetting polymers and their composites. The salient characteristics of long term moisture uptake such as the equilibrium moisture content and the effect of non-Fickian phenomena are presented. Anomalous moisture concentration profiles predicted by the two-dimensional solution of hindered diffusion model are demonstrated for various cases, including the through-the-thickness moisture profile of a 40-ply, quartz/bismaleimide (BMI) composite laminate. The effects of diffusion hindrance and anisotropy on the two-dimensional, through-the-thickness concentration profiles are illustrated. The moisture absorption parameters for an EPON 862 epoxy laminate are recovered from the experimental moisture absorption data. The hindered diffusion model is shown to accurately predict the moisture uptake of EPON 862 over the complete absorption time period. The non-Fickian effects governed by the hindrance coefficient are identified for both EPON 862 and quartz/BMI composite laminate. It is shown that the quartz/BMI laminate displays significant non-Fickian behavior compared to EPON 862 epoxy resin.

  8. Socioeconomic characteristics of enrollees appear to influence performance scores for medicare part D contractors.

    PubMed

    Young, Gary J; Rickles, Nathaniel M; Chou, Chia-Hung; Raver, Eli

    2014-01-01

    More than 150 private companies contract with the federal government to provide Part D prescription drug benefits to Medicare beneficiaries, either through stand-alone drug plans or as part of Medicare Advantage plans. The Centers for Medicare and Medicaid Services (CMS) evaluates these companies on a set of performance measures, including plan enrollees' medication adherence. We used 2012 data from CMS and data from the US Census Bureau to investigate whether these performance ratings are influenced by the socioeconomic characteristics of enrollee populations. We found that some companies have a substantial advantage over others because of their enrollees' socioeconomic characteristics, with more than a third of the variation in adherence scores tied to these characteristics. CMS should seriously consider adjusting adherence scores to account for differences in the socioeconomic characteristics of enrollee populations.

  9. Evaluation of moisture sources for the Central European summer flood of May/June 2013 based on regional climate model simulations

    NASA Astrophysics Data System (ADS)

    Kelemen, Fanni Dora; Ludwig, Patrick; Reyers, Mark; Ulbrich, Sven; Pinto, Joaquim G.

    2016-04-01

    Heavy precipitation affected Central Europe in May/June 2013, triggering damaging floods both on the Danube and the Elbe rivers. A modelling approach with COSMO-CLM is used for a detailed analysis of the evolution of the event. Moisture flux, backward trajectories, evaporation and cyclone track analysis are evaluated for the relevant time period 30 May to 2 June 2013. The aim is to identify potential moisture sources and to quantify their contribution to the flood event in the Danube basin. Control simulations with undisturbed ERA-Interim boundary conditions and sensitivity experiments with modified evaporation characteristics are performed to estimate the role of moisture evaporated from different marine and land areas. The simulated cyclone tracks and upper level flow are compared against reanalysis. Simulated precipitation amounts are validated against E-OBS precipitation data. Two relevant cyclones are identified, which moved counterclockwise in a retrograde path from Southeastern Europe over Eastern Europe towards the northern slopes of the Alps. The control simulations represent the cyclone characteristics and tracks reasonably well. The evolution of the precipitation event in the simulations shows some minor differences to the Reanalysis in terms of its spatial and temporal characteristics. Our sensitivity experiment results provide evidence that the two main sources contributing to the event were the continental evapotranspiration (moisture recycling) and the North Atlantic Ocean. The Mediterranean Sea played only a minor role as a moisture source. This study confirms the importance of continental moisture recycling for heavy precipitation events over Central Europe during the summer half year.

  10. Use of temperature and humidity sensors to determine moisture content of oolong tea.

    PubMed

    Chen, Andrew; Chen, Hsuan-Yu; Chen, Chiachung

    2014-08-22

    The measurement of tea moisture content is important for processing and storing tea. The moisture content of tea affects the quality and durability of the product. Some electrical devices have been proposed to measure the moisture content of tea leaves but are not practical. Their performance is influenced by material density and packing. The official oven method is time-consuming. In this study, the moisture content of Oolong tea was measured by the equilibrium relative humidity technique. The equilibrium relative humidity, and temperature, of tea materials were measured by using temperature and relative humidity sensors. Sensors were calibrated, and calibration equations were established to improve accuracy. The moisture content was calculated by using an equilibrium moisture content model. The error of the moisture content determined with this method was within 0.5% w.b. at moisture <15% w.b. Uncertainty analysis revealed that the performance of the humidity sensor had a significant effect on the accuracy of moisture determination.

  11. EDITORIAL: Microwave Moisture Measurements

    NASA Astrophysics Data System (ADS)

    Kaatze, Udo; Kupfer, Klaus; Hübner, Christof

    2007-04-01

    Microwave moisture measurements refer to a methodology by which the water content of materials is non-invasively determined using electromagnetic fields of radio and microwave frequencies. Being the omnipresent liquid on our planet, water occurs as a component in most materials and often exercises a significant influence on their properties. Precise measurements of the water content are thus extremely useful in pure sciences, particularly in biochemistry and biophysics. They are likewise important in many agricultural, technical and industrial fields. Applications are broad and diverse, and include the quality assessment of foodstuffs, the determination of water content in paper, cardboard and textile production, the monitoring of moisture in sands, gravels, soils and constructions, as well as the measurement of water admixtures to coal and crude oil in reservoirs and in pipelines. Microwave moisture measurements and evaluations require insights in various disciplines, such as materials science, dielectrics, the physical chemistry of water, electrodynamics and microwave techniques. The cooperation of experts from the different fields of science is thus necessary for the efficient development of this complex discipline. In order to advance cooperation the Workshop on Electromagnetic Wave Interaction with Water and Moist Substances was held in 1993 in Atlanta. It initiated a series of international conferences, of which the last one was held in 2005 in Weimar. The meeting brought together 130 scientists and engineers from all over the world. This special issue presents a collection of some selected papers that were given at the event. The papers cover most topics of the conference, featuring dielectric properties of aqueous materials, electromagnetic wave interactions, measurement methods and sensors, and various applications. The special issue is dedicated to Dr Andrzej W Kraszewski, who died in July 2006 after a distinguished career of 48 years in the research of

  12. Performance characteristics of LOX-H2, tangential-entry, swirl-coaxial, rocket injectors

    NASA Technical Reports Server (NTRS)

    Howell, Doug; Petersen, Eric; Clark, Jim

    1993-01-01

    Development of a high performing swirl-coaxial injector requires an understanding of fundamental performance characteristics. This paper addresses the findings of studies on cold flow atomic characterizations which provided information on the influence of fluid properties and element operating conditions on the produced droplet sprays. These findings are applied to actual rocket conditions. The performance characteristics of swirl-coaxial injection elements under multi-element hot-fire conditions were obtained by analysis of combustion performance data from three separate test series. The injection elements are described and test results are analyzed using multi-variable linear regression. A direct comparison of test results indicated that reduced fuel injection velocity improved injection element performance through improved propellant mixing.

  13. Perceptual characteristics of nutritional supplements determine the expected effectiveness in boosting strength, endurance, and concentration performances.

    PubMed

    Szabo, Attila; Bérdi, Márk; Köteles, Ferenc; Bárdos, György

    2013-12-01

    The aim of this work was to examine the link between the physical-perceptual characteristics of nutritional supplements and their expected effectiveness in enhancing sport performance. Participants (n = 267) ranked nine images of fictive nutritional supplements, varying in shape, color, and route of administration (e.g., pill, powder, lotion, etc.), in ranked- order of expected effectiveness. They performed the task three times, (1) for strength, (2) endurance, and (3) for concentration. Results have revealed that the perceived effectiveness of the supplements was statistically significantly different for the three types of performances (p < .001). A significant interpersonal variability was observed in the ranking-order of the supplements. The findings reveal that perceptual characteristics of 'believed to be nutritional supplements', aimed at sport performance enhancement, influence their perceived effectiveness. Future inquiries in sport nutrition should examine the relationship between expected and experienced effectiveness of various nutritional supplements in enhancing sport performance.

  14. Effects of various dietary lipid additives on lamb performance, carcass characteristics, adipose tissue fatty acid composition, and wool characteristics.

    PubMed

    Meale, S J; Chaves, A V; He, M L; Guan, L L; McAllister, T A

    2015-06-01

    Tasco (Ascophyllum nodosum; TA) was compared to canola (CO), flax (FO), and safflower oils (SO) for effects on performance, carcass characteristics, and fatty acid profiles of adipose tissue in skirt muscle (SM), subcutaneous and perirenal adipose tissues, and wool production and quality characteristics of Canadian Arcott lambs. Fifty-six lambs were randomly assigned to dietary treatments (n = 14 per treatment). Diets consisted of a pelleted, barley-based finishing diet containing either TA, CO, FO, or SO (2% of dietary DM). Feed deliveries and orts were recorded daily. Lambs were weighed weekly and slaughtered once they reached ≥ 45 kg BW. Carcass characteristics, rumen pH, and liver weights were determined at slaughter. Wool yield was determined on mid-side patches of 100 cm2 shorn at d 0 and on the day before slaughter (d 105 or 140). Dye-bands were used to determine wool growth, micrometer and staple length. Adipose tissues and SM samples were taken at slaughter and analyzed for FA profiles. No effects were observed on intake, growth, or carcass characteristics. A greater (P = 0.02) staple strength of lambs fed CO was the only effect observed in wool. Flax oil increased total n-3 and decreased the n-6/n-3 ratio in tissue FA profiles (P < 0.001) in comparison to other diets. Tasco increased (P ≤ 0.001) SFA/PUFA in all tissues, whereas concentrations of CLA c-9, t-11 were greatest with SO in all tissues (P ≤ 0.02), compared to other diets. These results suggest Tasco supplementation did not improve the n-3/n-6 or SFA/PUFA ratios of lamb adipose tissues compared to other dietary lipid additives.

  15. Modifiable Anthropometric Characteristics Are Associated With Unilateral and Bilateral Carry Performance.

    PubMed

    Beck, Ben; Carstairs, Greg L; Billing, Daniel C; Caldwell, Joanne N; Middleton, Kane J

    2017-02-01

    Beck, B, Carstairs, GL, Billing, DC, Caldwell, JN, and Middleton, KJ. Modifiable anthropometric characteristics are associated with unilateral and bilateral carry performance. J Strength Cond Res 31(2): 489-494, 2017-A mismatch between physical ability and task requirements can increase the risk of on-the-job injury. Therefore, understanding key anthropometric characteristics associated with job performance is important in developing targeted training programs and selecting employees in physically demanding occupations. The aims of this study were to understand which anthropometric and demographic (age/sex) characteristics were associated with performance in a unilateral stretcher carry and bilateral jerry can and kettle bell carries. Sixty-seven enlisted Australian Army soldiers (46 men and 21 women) participated in this investigation. Body composition was quantified using dual-energy X-ray absorptiometry. Univariate and multivariable regression techniques were used to quantify correlations between anthropometric characteristics and carry performance. Median carry distance was 650 m (interquartile range [IQR] = 425-1,025 m) in the stretcher carry, 300 m (IQR = 215-445 m) in the jerry can carry, and 265 m (IQR = 200-400 m) in the kettle bell carry. Univariate analyses demonstrated that whole body, trunk, upper arm, forearm, and leg lean mass, as well as stature and body mass were associated with performance across the 3 carry tasks. Of these, leg lean mass was shown to be a key characteristic associated with carry performance. Subsequently, it is suggested that training programs focus on whole-body lean mass with specific emphasis on leg lean mass. Additionally, we demonstrated that age and sex were not significantly associated with carry performance when controlling for leg lean mass, indicating that modifiable factors can be targeted in training programs to improve job performance.

  16. Root-zone soil moisture estimation from assimilation of downscaled Soil Moisture and Ocean Salinity data

    NASA Astrophysics Data System (ADS)

    Dumedah, Gift; Walker, Jeffrey P.; Merlin, Olivier

    2015-10-01

    The crucial role of root-zone soil moisture is widely recognized in land-atmosphere interaction, with direct practical use in hydrology, agriculture and meteorology. But it is difficult to estimate the root-zone soil moisture accurately because of its space-time variability and its nonlinear relationship with surface soil moisture. Typically, direct satellite observations at the surface are extended to estimate the root-zone soil moisture through data assimilation. But the results suffer from low spatial resolution of the satellite observation. While advances have been made recently to downscale the satellite soil moisture from Soil Moisture and Ocean Salinity (SMOS) mission using methods such as the Disaggregation based on Physical And Theoretical scale Change (DisPATCh), the assimilation of such data into high spatial resolution land surface models has not been examined to estimate the root-zone soil moisture. Consequently, this study assimilates the 1-km DisPATCh surface soil moisture into the Joint UK Land Environment Simulator (JULES) to better estimate the root-zone soil moisture. The assimilation is demonstrated using the advanced Evolutionary Data Assimilation (EDA) procedure for the Yanco area in south eastern Australia. When evaluated using in-situ OzNet soil moisture, the open loop was found to be 95% as accurate as the updated output, with the updated estimate improving the DisPATCh data by 14%, all based on the root mean square error (RMSE). Evaluation of the root-zone soil moisture with in-situ OzNet data found the updated output to improve the open loop estimate by 34% for the 0-30 cm soil depth, 59% for the 30-60 cm soil depth, and 63% for the 60-90 cm soil depth, based on RMSE. The increased performance of the updated output over the open loop estimate is associated with (i) consistent estimation accuracy across the three soil depths for the updated output, and (ii) the deterioration of the open loop output for deeper soil depths. Thus, the

  17. Governance and performance: the performance of Dutch hospitals explained by governance characteristics.

    PubMed

    Blank, Jos L T; van Hulst, Bart Laurents

    2011-10-01

    This paper describes the efficiency of Dutch hospitals using the Data Envelopment Analysis (DEA) method with bootstrapping. In particular, the analysis focuses on accounting for cost inefficiency measures on the part of hospital corporate governance. We use bootstrap techniques, as introduced by Simar and Wilson (J. Econom. 136(1):31-64, 2007), in order to obtain more efficient estimates of the effects of governance on the efficiency. The results show that part of the cost efficiency can be explained with governance. In particular we find that a higher remuneration of the board as well as a higher remuneration of the supervisory board does not implicate better performance.

  18. Performance Characteristics of Lithium-Ion Prototype Batteries for Mars Surveyor Program 2001 Lander

    NASA Technical Reports Server (NTRS)

    Smart, M. C.; Ratnakumar, B. V.; Whitcanack, L.; Surampudi, S.; Byers, J.; Marsh, R. A.

    2000-01-01

    A viewgraph presentation outlines the scientific payload, expected launch date and tasks, and an image of the Mars Surveyor 2001 Lander components. The Lander's battery specifications are given. The program objectives for the Li-ion cells for the Lander are listed, and results performance evaluation and cycle life performance tests are outlined for different temperatures. Cell charge characteristics are described, and test data is presented for charge capacity at varying temperatures. Capacity retention and storage characteristics tests are described and results are shown.

  19. Development of FEC and ESC performance characteristics for IDR carriers greater than 10 Mb/s

    NASA Astrophysics Data System (ADS)

    Loureiro, Francisco; Koga, Keiichiro

    1988-12-01

    The requirement for restoration of high capacity fiber optic cables and the new tariffs approved for Intelsat digital services has created a requirement to develop performance characteristics for intermediate data rate (IDR) carriers greater than 10 Mb/s. This paper presents the trade-offs used in this development, and estimates the coding gains needed to meet these requirements. A number of forward error correction schemes are evaluated and a rate 3/4 convolutional code with soft decision Viterbi decoding is selected. Engineering service circuits performance characteristics for IDR carriers greater than 10 Mb/s are presented.

  20. A scheme for assessing the performance characteristics of small field-of-view gamma cameras.

    PubMed

    Bhatia, B S; Bugby, S L; Lees, J E; Perkins, A C

    2015-02-01

    Existing protocols for assessing the performance characteristics of large field-of-view (LFOV) gamma cameras can be inappropriate and require modification for use with small field-of-view (SFOV) gamma camera systems. This communication proposes a generic scheme suitable for evaluating the performance characteristics of SFOV gamma cameras, based on modifications to the standard procedures of NEMA NU1-2007. Key differences in methodology between tests for LFOV and SFOV gamma cameras are highlighted along with the rationale for these changes. It is envisaged that this scheme will provide more appropriate methods for equipment characterisation, ensuring quality and consistency for all SFOV cameras.

  1. Technology Solutions Case Study: Moisture Management of High-Walls

    SciTech Connect

    2013-12-01

    Moisture management of high-R walls is important to ensure optimal performance. This case study, developed by Building America team Building Science Corporation, focuses on how eight high-R walls handle the three main sources of moisture—construction moisture, air leakage condensation, and bulk water leaks.

  2. Using ARM observations to test soil moisture dynamics in climate models

    NASA Astrophysics Data System (ADS)

    Sun, S.; Cook, D. R.; Drewniak, B. A.; Stein, M.; Collis, S. M.; Moyer, E. J.

    2015-12-01

    Potential changes in soil moisture may have significant societal impacts, as soil moisture directly influences agriculture. Soil moisture is also a critical factor in climate simulations as it is the moisture source for evapotranspiration over land. Climate model projections generally show reduced soil moisture in future warmer climate conditions, and the scale of potential adverse impacts means that validation of those projections is a science priority. Our understanding of soil moisture dynamics is hampered by limited suitable observational data, but the Southern Great Plains (SGP) Atmospheric Radiation Measurement (ARM) site offers a unique resource for this purpose, with over a decade of simultaneous measurements of soil moisture profiles and measurements of moisture fluxes and aboveground variables. In this work we use stations across SGP to identify statistical relationships in drivers of soil moisture dynamics. We also compare observed soil moisture dynamics to those in the Community Land Model version 4 (CLM4), running CLM4 in an offline mode with observationally derived atmospheric forcing, to identify similarities and discrepancies in resulting soil moisture evolution in observations and model. Preliminary comparison of metrics such as soil moisture characteristic time, soil moisture infiltration rate, etc. suggests that the governing hydrological and/or biophysical processes in models need improvements. The spatial heterogeneity of the SGP measurement stations also provides insight into the role of sub-grid scale features and the role of spatial resolution in producing accurate representations of soil moisture in climate models.

  3. Malaysian and Singaporean students' affective characteristics and mathematics performance: evidence from PISA 2012.

    PubMed

    Thien, Lei Mee; Ong, Mei Yean

    2015-01-01

    This paper attempts to identify the extent to which the affective characteristics of Malaysian and Singaporean students' attainment compared to the OECD average in Programme for International Student Assessment (PISA) 2012, and examine the influence of students' affective characteristics, gender, and their socioeconomic status on mathematics performance at both student and school levels. Sample consisted of 5197 and 5546 15-year-old Malaysian and Singaporean students. Data were analysed using hierarchical linear modelling approach with HLM 7.0 software. Results showed that the Index of economic, social, and cultural status (ESCS), mathematics self-efficacy, and mathematics anxiety have significant effects on mathematics performance in Malaysia and Singapore at the student level. Proportion of boys at the school level has no significant effects on mathematics performance for both Malaysian and Singaporean students. ESCS mean at the school level has positive and significant effects on mathematics performance in Malaysia, but not in Singapore. Limitations, implications, and future studies were discussed.

  4. Soil Moisture Estimation Using Hyperspectral SWIR Imagery

    NASA Astrophysics Data System (ADS)

    Lewis, D.

    2007-12-01

    The U.S. Geological Survey (USGS) is engaged with the U.S. Department of Agriculture's (USDA) Agricultural Research Service (ARS) and the University of Georgia's National Environmentally Sound Production Agriculture Laboratory (NESPAL) both in Tifton, Georgia, USA, to develop transformations for medium and high resolution remotely sensed images to generate moisture indicators for soil. The Institute for Technology Development (ITD) is located at the Stennis Space Center in southern Mississippi and has developed hyperspectral sensor systems that, when mounted in aircraft, collect electromagnetic reflectance data of the terrain. The sensor suite consists of sensors for three different sections of the electromagnetic spectrum; the Ultra-Violet (UV), Visible/Near InfraRed (VNIR) and Short Wave InfraRed (SWIR). The USDA/ ARS' Southeast Watershed Research Laboratory has probes that measure and record soil moisture. Data taken from the ITD SWIR sensor and the USDA/ARS soil moisture meters were analyzed to study the informatics relationships between SWIR data and measured soil moisture. The geographic locations of 29 soil moisture meters provided by the USDA/ARS are in the vicinity of Tifton, Georgia. Using USGS Digital Ortho Quads (DOQ), flightlines were drawn over the 29 soil moisture meters. The SWIR sensor was installed into an aircraft. The coordinates for the flightlines were also loaded into the navigational system of the aircraft. This airborne platform was used to collect the data over these flightlines. In order to prepare the data set for analysis, standard preprocessing was performed. These standard processes included sensor calibration, spectral subsetting, and atmospheric calibration. All 60 bands of the SWIR data were collected for each line in the image data, 15 bands of which were stripped from the data set leaving 45 bands of information in the wavelength range of 906 to 1705 nanometers. All the image files were calibrated using the regression equations

  5. Moisture Management of High-R Walls (Fact Sheet)

    SciTech Connect

    None, None

    2013-12-01

    The following report explains the moisture-related concerns for High R-value wall assemblies and discusses past Building America research work that informs this study. Hygrothermal simulations were prepared for several common approaches to High R-value wall construction in six cities (Houston, Atlanta, Seattle, St. Louis, Chicago, and International Falls) representing a range of climate zones (2, 3, 4C, 4, 5A, and 7, respectively). The simulations are informed by experience gained from past research in this area and validated by field measurement and forensic experience. The modeling program was developed to assess the moisture durability of the wall assemblies based on three primary sources of moisture: construction moisture, air leakage condensation, and bulk water leakage. The peak annual moisture content of the wood based exterior sheathing was used to comparatively analyze the response to the moisture loads for each of the walls in each given city. Walls which experienced sheathing moisture contents between 20% and 28% were identified as risky, whereas those exceeding 28% were identified as very high risk. All of the wall assemblies perform well under idealized conditions. However, only the walls with exterior insulation, or cavity insulation which provides a hygrothermal function similar to exterior insulation, perform adequately when exposed to moisture loads. Walls with only cavity insulation are particularly susceptible to air leakage condensation. None of the walls performed well when a precipitation based bulk water leak was introduced to the backside of the sheathing, emphasizing the importance of proper flashing details.

  6. Moisture Management for High R-Value Walls

    SciTech Connect

    Lepage, R.; Schumacher, C.; Lukachko, A.

    2013-11-01

    The following report explains the moisture-related concerns for High R-value wall assemblies and discusses past Building America research work that informs this study. Hygrothermal simulations were prepared for several common approaches to High R-value wall construction in six cities (Houston, Atlanta, Seattle, St. Louis, Chicago, and International Falls) representing a range of climate zones (2, 3, 4C, 4, 5A, and 7, respectively). The simulations are informed by experience gained from past research in this area and validated by field measurement and forensic experience. The modeling program was developed to assess the moisture durability of the wall assemblies based on three primary sources of moisture: construction moisture, air leakage condensation, and bulk water leakage. The peak annual moisture content of the wood based exterior sheathing was used to comparatively analyze the response to the moisture loads for each of the walls in each given city. Walls which experienced sheathing moisture contents between 20% and 28% were identified as risky, whereas those exceeding 28% were identified as very high risk. All of the wall assemblies perform well under idealized conditions. However, only the walls with exterior insulation, or cavity insulation which provides a hygrothermal function similar to exterior insulation, perform adequately when exposed to moisture loads. Walls with only cavity insulation are particularly susceptible to air leakage condensation. None of the walls performed well when a precipitation based bulk water leak was introduced to the backside of the sheathing, emphasizing the importance of proper flashing details.

  7. The NASA Soil Moisture Active Passive (SMAP) Mission - Science and Data Product Development Status

    NASA Technical Reports Server (NTRS)

    Nloku, E.; Entekhabi, D.; O'Neill, P.

    2012-01-01

    The Soil Moisture Active Passive (SMAP) mission, planned for launch in late 2014, has the objective of frequent, global mapping of near-surface soil moisture and its freeze-thaw state. The SMAP measurement system utilizes an L-band radar and radiometer sharing a rotating 6-meter mesh reflector antenna. The instruments will operate on a spacecraft in a 685 km polar orbit with 6am/6pm nodal crossings, viewing the surface at a constant 40-degree incidence angle with a 1000-km swath width, providing 3-day global coverage. Data from the instruments will yield global maps of soil moisture and freeze/thaw state at 10 km and 3 km resolutions, respectively, every two to three days. The 10-km soil moisture product will be generated using a combined radar and radiometer retrieval algorithm. SMAP will also provide a radiometer-only soil moisture product at 40-km spatial resolution and a radar-only soil moisture product at 3-km resolution. The relative accuracies of these products will vary regionally and will depend on surface characteristics such as vegetation water content, vegetation type, surface roughness, and landscape heterogeneity. The SMAP soil moisture and freeze/thaw measurements will enable significantly improved estimates of the fluxes of water, energy and carbon between the land and atmosphere. Soil moisture and freeze/thaw controls of these fluxes are key factors in the performance of models used for weather and climate predictions and for quantifYing the global carbon balance. Soil moisture measurements are also of importance in modeling and predicting extreme events such as floods and droughts. The algorithms and data products for SMAP are being developed in the SMAP Science Data System (SDS) Testbed. In the Testbed algorithms are developed and evaluated using simulated SMAP observations as well as observational data from current airborne and spaceborne L-band sensors including data from the SMOS and Aquarius missions. We report here on the development status

  8. Fingertip moisture is optimally modulated during object manipulation.

    PubMed

    André, T; Lefèvre, P; Thonnard, J-L

    2010-01-01

    Coordination between the normal force exerted by fingers on a held object and the tangential constraints at the fingertips helps to successfully manipulate objects. It is well established that the minimal grip force required to prevent an object from slipping strongly depends on the frictional properties at the finger-object interface. Moreover, interindividual variation in the modulation of grip force suggests that the moisture level of the skin could influence grip force strategy. In the present study we asked subjects to perform a horizontal point-to-point task holding an object with a precision grip. The object was equipped with a moisture sensor. We found large inter- and intraindividual moisture level variations. There was a strong correlation between grip force exerted and moisture level at the fingertips. Indeed, the grip force was minimal when the fingertip moisture was optimal with respect to friction. Furthermore, fingertip moisture tended toward this optimal level at which grip force is minimal. In conclusion, we showed a modulation of the grip force with moisture level and hypothesized novel mechanisms of moisture regulation that tend to stabilize the moisture level toward the value that minimizes grip force.

  9. Effect of backgrounding system on feedlot performance and carcass characteristics of beef steers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objective of this study was to evaluate feedlot performance and carcass characteristics of steers that were backgrounded using 1 of 3 treatments: 1) corn residue grazing supplemented 6 days a week with 2.77 kg DM/hd of distillers (CRD), 2) oat-brassica forage grazing (OBF) or 3) drylotting on a ...

  10. Hindi Heritage Language Learners' Performance during OPIs: Characteristics and Pedagogical Implications

    ERIC Educational Resources Information Center

    Ilieva, Gabriela Nik.

    2012-01-01

    The present paper examines the oral performance of Hindi language learners during practice Oral Proficiency Interviews (OPI) conducted during workshops hosted by New York University and sponsored by STARTALK. The most salient characteristics of the heritage language learners' output are compared with the output of foreign language learners who are…

  11. Performance characteristics of a low-cost, field-deployable miniature CCD spectrometer

    PubMed Central

    Coles, Simon; Nimmo, Malcolm; Worsfold, Paul J.

    2000-01-01

    Miniature spectrometers incorporating array detectors are becoming a viable, low-cost option for field and process deployments. The performance characteristics of one such instrument are reported and compared with those of a conventional benchtop instrument. The parameters investigated were wavelength repeatability, photometric linearity, instrumental noise (photometric precision) and instrumental drift. PMID:18924863

  12. Test-Taker Characteristics and Integrated Speaking Test Performance: A Path-Analytic Study

    ERIC Educational Resources Information Center

    Huang, Heng-Tsung Danny; Hung, Shao-Ting Alan; Hong, He-Ting Vivian

    2016-01-01

    This study explored the relationships among language proficiency, two selected test-taker characteristics (i.e., topical knowledge and anxiety), and integrated speaking test performance. Data collection capitalized on three sets of instruments: three integrated tasks derived from TOEFL-iBT preparation materials, the state anxiety inventory created…

  13. Postweaning feed restriction effects on steer feedlot performance and carcass characteristics

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objective was to evaluate impacts of 2 levels of supplemental feed provided to cows during late gestation and 2 levels of feed provided to their sons during postweaning development on subsequent feedlot performance and carcass characteristics. Bull calves (n = 56 in 2010; n = 51 in 2011) were bo...

  14. Physical Performance Characteristics of Assisted Living Residents and Risk for Adverse Health Outcomes

    ERIC Educational Resources Information Center

    Giuliani, Carol A.; Gruber-Baldini, Ann L.; Park, Nan S.; Schrodt, Lori A.; Rokoske, Franzi; Sloane, Philip D.; Zimmerman, Sheryl

    2008-01-01

    Purpose: Researchers know little about the physical performance ability of residential care/assisted living (RC/AL) residents and its relationship to adverse outcomes such as fracture, nursing home placement, functional decline, and death. The purposes of this article are to (a) describe the functional characteristics of RC/AL residents, (b)…

  15. Epilepsy in the School Aged Child: Cognitive-Behavioral Characteristics and Effects on Academic Performance.

    ERIC Educational Resources Information Center

    Black, Kathryn C.; Hynd, George W.

    1995-01-01

    Children with epilepsy frequently display cognitive sequelae that are overlooked or misunderstood by educational personnel, yet may adversely impact academic performance. Reviews common cognitive-behavioral characteristics of children with epilepsy, typical effects of anticonvulsant medications, and various periictal phenomena and their relative…

  16. Current Performance Characteristics of NASA Langley Research Center's Cockpit Motion Base and Standardized Test Procedure for Future Performance Characterization

    NASA Technical Reports Server (NTRS)

    Cowen, Brandon; Stringer, Mary T.; Hutchinson, Brian K.; Davidson, Paul C.; Gupton, Lawrence E.

    2014-01-01

    This report documents the updated performance characteristics of NASA Langley Research Center's (LaRC) Cockpit Motion Base (CMB) after recent revisions that were made to its inner-loop, feedback control law. The modifications to the control law will be briefly described. The performance of the Cockpit Motion Facility (CMF) will be presented. A short graphical comparison to the previous control law can be found in the appendix of this report. The revised controller will be shown to yield reduced parasitic accelerations with respect to the previous controller. Metrics based on the AGARD Advisory Report No. 144 are used to assess the overall system performance due to its recent control algorithm modification. This report also documents the standardized simulator test procedure which can be used in the future to evaluate potential updates to the control law.

  17. Effects of dietary coarsely ground corn and 3 bedding floor types on broiler live performance, litter characteristics, gizzard and proventriculus weight, and nutrient digestibility.

    PubMed

    Xu, Y; Lin, Y M; Stark, C R; Ferket, P R; Williams, C M; Brake, J

    2017-03-02

    The effects of zero or 50% dietary coarsely ground corn (CC) in pelleted and screened grower and finisher diets on broilers reared on 3 bedding floor types (plastic net [NET], new pine wood shavings litter [NEW], or old pine wood shavings litter [OLD]) on broiler live performance, litter characteristics, gizzard and proventriculus weight, and apparent ileal digestibility (AID) were studied in a 2 × 3 factorial arrangement of treatments. Fine corn was produced with a hammermill (271 μm) and CC with a roller mill (1145 μm). Utilization of CC reduced milling cost by 9.47 cents per MT with similar nutrient content of screened pellets. The 50% CC treatment exhibited improved (P ≤ 0.05) feed intake at 42 d (2.5%) and 49 d (3.0%), and BW (5.4%) and FCR from 28 d (1.4%). Birds on NEW litter exhibited improved (P < 0.05) BW at 28 and 35 d and 42 d FCR as compared to NET and 49 d FCR compared to NET and OLD. The 50% CC treatment exhibited increased (P < 0.05) gizzard weight but decreased proventriculus weight at 49 d. NEW litter birds exhibited increased (P ≤ 0.05) gizzard weight at 28 d and 49 d and decreased proventriculus weight as compared to NET at 49 days. The 50% CC treatment exhibited decreased (P ≤ 0.05) litter moisture at 35 and 42 d, litter N at 35 and 49 d, and litter pH at 49 days. OLD litter birds exhibited greater (P < 0.05) litter N at 14, 35, and 49 d, as well as litter moisture, pH, and ammonia concentration at 49 days. The 50% CC group also exhibited improved AID of nitrogen (P < 0.05). Broilers fed pelleted and screened diets containing 50% CC exhibited improved live performance and reduced litter moisture while use of NEW litter resulted in a somewhat similar effect, which indicated that consumption of NEW litter also facilitated gastric development and function.

  18. An integrated GIS application system for soil moisture data assimilation

    NASA Astrophysics Data System (ADS)

    Wang, Di; Shen, Runping; Huang, Xiaolong; Shi, Chunxiang

    2014-11-01

    The gaps in knowledge and existing challenges in precisely describing the land surface process make it critical to represent the massive soil moisture data visually and mine the data for further research.This article introduces a comprehensive soil moisture assimilation data analysis system, which is instructed by tools of C#, IDL, ArcSDE, Visual Studio 2008 and SQL Server 2005. The system provides integrated service, management of efficient graphics visualization and analysis of land surface data assimilation. The system is not only able to improve the efficiency of data assimilation management, but also comprehensively integrate the data processing and analysis tools into GIS development environment. So analyzing the soil moisture assimilation data and accomplishing GIS spatial analysis can be realized in the same system. This system provides basic GIS map functions, massive data process and soil moisture products analysis etc. Besides,it takes full advantage of a spatial data engine called ArcSDE to effeciently manage, retrieve and store all kinds of data. In the system, characteristics of temporal and spatial pattern of soil moiture will be plotted. By analyzing the soil moisture impact factors, it is possible to acquire the correlation coefficients between soil moisture value and its every single impact factor. Daily and monthly comparative analysis of soil moisture products among observations, simulation results and assimilations can be made in this system to display the different trends of these products. Furthermore, soil moisture map production function is realized for business application.

  19. The Thermal Performance and Air Leakage Characteristics of Six Log Homes in Idaho.

    SciTech Connect

    Roos, Carolyn; Eklund, Ken; Baylon, David

    1993-08-01

    The thermal performance and air leakage characteristics of four electrically heated log houses located in Idaho are summarized. The air leakage and construction characteristics of two additional log homes are also examined. The energy consumption of the four homes was submetered at weekly reporting intervals for up to 16 months. Blower door tests and site audits were performed. In addition, conditions at two of these homes, including heat flux through the log walls, indoor and outdoor temperatures, solar flux and envelope tightness, were measured in detail over several days during winter conditions. The energy use and thermal performance of these two homes were then modeled using SUNCODE-PC, an hourly thermal simulation program employing a finite difference technique.

  20. A study on the performance and emission characteristics of esterified pinnai oil tested in VCR engine.

    PubMed

    Ashok Kumar, T; Chandramouli, R; Mohanraj, T

    2015-11-01

    Biodiesel is a clean renewable fuel derived from vegetable oils and animal fats. It is biodegradable, oxygenated, non toxic and free from sulfur and aromatics. The biodiesel prepared from pinnai oil undergoes acid esterification followed by alkaline transesterification process. The fatty acid methyl esters components were identified using gas chromatography and compared with the standard properties. The properties of biodiesel are comparable with diesel. The yield of the biodiesel production depends upon the process parameters such as reaction temperature, pH, time duration and amount of catalyst. The yield of biodiesel by transesterification process was 73% at 55°C. This fuel was tested in a variable compression ratio engine with blend ratios of B10 and B20. During the test runs the compression ratio of the engine was varied from 15:1 to 18:1 and the torque is adjusted from zero to maximum value of 22Nm. The performance characteristics such as the brake thermal efficiency, brake specific energy consumption and exhaust gas temperature of the engine are analyzed. The combustion characteristics of biodiesel like ignition delay, combustion duration and maximum gas temperature and the emission characteristics are also analyzed. The performance characteristics, combustion characteristics and engine emission are effective in the variable compression ratio engine with biodiesel and it is compared with diesel.

  1. Observed inter-camera variability of clinically relevant performance characteristics for Siemens Symbia gamma cameras.

    PubMed

    Kappadath, S Cheenu; Erwin, William D; Wendt, Richard E

    2006-11-28

    We conducted an evaluation of the intercamera (i.e., between cameras) variability in clinically relevant performance characteristics for Symbia gamma cameras (Siemens Medical Solutions, Malvern, PA) based on measurements made using nine separate systems. The significance of the observed intercamera variability was determined by comparing it to the intracamera (i.e., within a single camera) variability. Measurements of performance characteristics were based on the standards of the National Electrical Manufacturers Association and reports 6, 9, 22, and 52 from the American Association of Physicists in Medicine. All measurements were performed using 99mTc (except 57Co used for extrinsic resolution) and low-energy, high-resolution collimation. Of the nine cameras, four have crystals 3/8 in. thick and five have crystals 5/8 in. thick. We evaluated intrinsic energy resolution, intrinsic and extrinsic spatial resolution, intrinsic integral and differential flood uniformity over the useful field-of-view, count rate at 20% count loss, planar sensitivity, single-photon emission computed tomography (SPECT) resolution, and SPECT integral uniformity. The intracamera variability was estimated by repeated measurements of the performance characteristics on a single system. The significance of the observed intercamera variability was evaluated using the two-tailed F distribution. The planar sensitivity of the gamma cameras tested was found be variable at the 99.8% confidence level for both the 3/8-in. and 5/8-in. crystal systems. The integral uniformity and energy resolution were found to be variable only for the 5/8-in. crystal systems at the 98% and 90% confidence level, respectively. All other performance characteristics tested exhibited no significant variability between camera systems. The measured variability reported here could perhaps be used to define nominal performance values of Symbia gamma cameras for planar and SPECT imaging.

  2. Off-Design Performance Prediction of Gas Turbines without the use of Compressor or Turbine Characteristics

    NASA Astrophysics Data System (ADS)

    Suraweera, Janitha Kanishka

    A new method of predicting gas turbine off-design performance is presented. This method, referred to as the core control method, is based on the idea that performance across a gas turbine depends on a single parameter that controls the energy input to the said gas turbine. It is shown that only the design-point performance of a gas turbine is needed to predict its off-design performance, and that neither compressor nor turbine characteristics are required. A thermodynamic model is developed for predicting the off-design performance of a single-spool turbojet and a two-spool gas generator with a free power turbine. This model is further developed to simulate the effects of handling bleed schedules, performance limiters and performance deterioration. The core control method is then used to predict the off-design performance of a Rolls-Royce Viper Mark 521 as a proof-of-concept, after which, the new and deteriorated off-design performance of three Rolls-Royce RB211-24GT gas turbines is predicted. In addition to the discussions on the involved theories and the performance predictions, the process by which the deteriorated RB211-24GT performance data was analyzed, and the sources and propagation of measurement uncertainties are also discussed.

  3. EFFECTS OF MOISTURE IN THE 9975 SHIPPING PACKAGE FIBERBOARD ASSEMBLY

    SciTech Connect

    Daugherty, W.; Dunn, K.; Murphy, J.; Hackney, B.

    2010-02-11

    The fiberboard assembly used in 9975 shipping packages as an impact-absorption and insulation component has the capacity to absorb moisture, with an accompanying change to its properties. While package fabrication requirements generally maintain the fiberboard moisture content within manufacturing range, there is the potential during use or storage for atypical handling or storage practices which result in the absorption of additional moisture. In addition to performing a transportation function, the 9975 shipping packages are used as a facility storage system for special nuclear materials at the Savannah River Site. A small number of packages after extended storage have been found to contain elevated moisture levels. Typically, this condition is accompanied by an axial compaction of the bottom fiberboard layers, and the growth of mold. In addition to potential atypical practices, fiberboard can exchange moisture with the surrounding air, depending on the ambient humidity. Laboratory data have been generated to correlate the equilibrium moisture content of cane fiberboard with the humidity of the surrounding air. These data are compared to measurements taken within shipping packages. With a reasonable measurement of the fiberboard moisture content, an estimate of the fiberboard properties can be made. Over time, elevated moisture levels will negatively impact performance properties, and promote fiberboard mold growth and resultant degradation.

  4. Soil Moisture Project Evaluation Workshop

    NASA Technical Reports Server (NTRS)

    Gilbert, R. H. (Editor)

    1980-01-01

    Approaches planned or being developed for measuring and modeling soil moisture parameters are discussed. Topics cover analysis of spatial variability of soil moisture as a function of terrain; the value of soil moisture information in developing stream flow data; energy/scene interactions; applications of satellite data; verifying soil water budget models; soil water profile/soil temperature profile models; soil moisture sensitivity analysis; combinations of the thermal model and microwave; determing planetary roughness and field roughness; how crust or a soil layer effects microwave return; truck radar; and truck/aircraft radar comparison.

  5. Summary of directional divergence characteristics of several high performance aircraft configurations

    NASA Technical Reports Server (NTRS)

    Greer, H. D.

    1972-01-01

    The present paper summarizes the high-angle-of-attack characteristics of a number of high-performance aircraft as determined from model force tests and free-flight model tests and correlates these characteristics with the dynamic directional-stability parameter. This correlation shows that the dynamic directional-stability parameter correlates fairly well with directional divergence. Data are also presented to show the effect of some airframe modifications on the directional divergence potential of the configuration. These results show that leading-edge slates seem to be the most effective airframe modification for reducing or eliminating the directional divergence potential of aircraft with moderately swept wings.

  6. Simulation Model for Prediction of Transient Performance Characteristics of Single-Phase Shaded Pole Motor

    NASA Astrophysics Data System (ADS)

    Sarac, Vasilija; Atanasova-Pacemska, Tatjana

    2016-07-01

    Paper proposes mathematical model of single phase shaded pole motor suitable for analysis of motor dynamic behavior. Derived mathematical model from d-q reference frame theory is applied at motor simulation model. Derived simulation model enables analysis of transient performance characteristics of motor currents, speed and electromagnetic torque under different operating regimes. Obtained results from the simulation are compared with data from analytical calculations based on method of symmetrical components and data from experiment for the purpose of verification of the simulation model. Simulation model is useful for studying the effect of parameters on motor starting and running characteristics at different types of loads.

  7. Performance characteristics according to the channel length and magnetic fields of cylindrical Hall thrusters

    NASA Astrophysics Data System (ADS)

    Lee, Jongsub; Seo, Mihui; Seon, Jongho; June Lee, Hae; Choe, Wonho

    2011-09-01

    Performance characteristics of low power cylindrical Hall thrusters are investigated in terms of the length of the discharge channel. Thrust, efficiency, discharge current, and propellant utilization are evaluated for different channel lengths of 19, 22, and 25 mm. It is found that the propellant utilization and ion energy distribution function are strongly associated with the channel length. Increase of thrust and efficiency are also found with increasing channel lengths. These characteristics of the thruster are interpreted with possible generation of multi-charged ions due to increased residing time within the extended space inside the channel.

  8. Distributed Soil Moisture Estimation in a Mountainous Semiarid Basin: Constraining Soil Parameter Uncertainty through Field Studies

    NASA Astrophysics Data System (ADS)

    Yatheendradas, S.; Vivoni, E.

    2007-12-01

    A common practice in distributed hydrological modeling is to assign soil hydraulic properties based on coarse textural datasets. For semiarid regions with poor soil information, the performance of a model can be severely constrained due to the high model sensitivity to near-surface soil characteristics. Neglecting the uncertainty in soil hydraulic properties, their spatial variation and their naturally-occurring horizonation can potentially affect the modeled hydrological response. In this study, we investigate such effects using the TIN-based Real-time Integrated Basin Simulator (tRIBS) applied to the mid-sized (100 km2) Sierra Los Locos watershed in northern Sonora, Mexico. The Sierra Los Locos basin is characterized by complex mountainous terrain leading to topographic organization of soil characteristics and ecosystem distributions. We focus on simulations during the 2004 North American Monsoon Experiment (NAME) when intensive soil moisture measurements and aircraft- based soil moisture retrievals are available in the basin. Our experiments focus on soil moisture comparisons at the point, topographic transect and basin scales using a range of different soil characterizations. We compare the distributed soil moisture estimates obtained using (1) a deterministic simulation based on soil texture from coarse soil maps, (2) a set of ensemble simulations that capture soil parameter uncertainty and their spatial distribution, and (3) a set of simulations that conditions the ensemble on recent soil profile measurements. Uncertainties considered in near-surface soil characterization provide insights into their influence on the modeled uncertainty, into the value of soil profile observations, and into effective use of on-going field observations for constraining the soil moisture response uncertainty.

  9. SELECTION OF ENDOCRINOLOGY SUBSPECIALTY TRAINEES: WHICH APPLICANT CHARACTERISTICS ARE ASSOCIATED WITH PERFORMANCE DURING FELLOWSHIP TRAINING?

    PubMed Central

    Natt, Neena; Chang, Alice Y.; Berbari, Elie F.; Kennel, Kurt A.; Kearns, Ann E.

    2016-01-01

    Objective To determine which residency characteristics are associated with performance during endocrinology fellowship training as measured by competency-based faculty evaluation scores and faculty global ratings of trainee performance. Method We performed a retrospective review of interview applications from endocrinology fellows who graduated from a single academic institution between 2006 and 2013. Performance measures included competency-based faculty evaluation scores and faculty global ratings. The association between applicant characteristics and measures of performance during fellowship was examined by linear regression. Results The presence of a laudatory comparative statement in the residency program director’s letter of recommendation (LoR) or experience as a chief resident was significantly associated with competency-based faculty evaluation scores (β = 0.22, P = 0.001; and β = 0.24, P = 0.009, respectively) and faculty global ratings (β = 0.85, P = 0.006; and β = 0.96, P = 0.015, respectively). Conclusion The presence of a laudatory comparative statement in the residency program director’s LoR or experience as a chief resident were significantly associated with overall performance during subspecialty fellowship training. Future studies are needed in other cohorts to determine the broader implications of these findings in the application and selection process. PMID:26437219

  10. SMOS soil moisture validation with U.S. in situ newworks

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Estimation of soil moisture at large scale has been performed using several satellite-based passive microwave sensors using a variety of retrieval methods. The most recent source of soil moisture is the European Space Agency Soil Moisture and Ocean Salinity (SMOS) mission. Since it is a new sensor u...

  11. Estimation of surface heat and moisture fluxes over a prairie grassland. IV - Impact of satellite remote sensing of slow canopy variables on performance of a hybrid biosphere model

    NASA Technical Reports Server (NTRS)

    Crosson, William L.; Smith, Eric A.; Cooper, Harry J.

    1993-01-01

    Numerical experiments are conducted using the Ex-BATS model of Crosson and Weng (1993), which is an adaptation the Dickinson (1983, 1984) and Dickinson et al. (1986) biosphere model BATS. The purpose of these experiments is the assessment of the Ex-BATS performance when using remotely sensed data for the estimation of three key canopy variables retrieved from NOAA-AVHRR measurements: the total surface albedo, the leaf area index (LAI), and the nondiurnally varying component of stomatal resistance, r(s). The results of the simulations, which cover the entire FIFE 1987 time period, show that the satellite retrievals of r(s) are only 20 to 30 percent less accurate than the idealized results of the control experiment. The performance of the model which used satellite retrieval of the surface albedo and LAI was essentially equivalent to the hypothetical version.

  12. A quantitative comparison of soil moisture inversion algorithms

    NASA Technical Reports Server (NTRS)

    Zyl, J. J. van; Kim, Y.

    2001-01-01

    This paper compares the performance of four bare surface radar soil moisture inversion algorithms in the presence of measurement errors. The particular errors considered include calibration errors, system thermal noise, local topography and vegetation cover.

  13. Soil moisture and the persistence of North American drought

    NASA Technical Reports Server (NTRS)

    Oglesby, Robert J.; Erickson, David J., III

    1989-01-01

    Numerical sensitivity experiments on the effects of soil moisture on North American summertime climate are performed using a 12-layer global atmospheric general circulation model. Consideration is given to the hypothesis that reduced soil moisture may induce and amplify warm, dry summers of midlatitude continental interiors. The simulations resemble the conditions of the summer of 1988, including an extensive drought over much of North America. It is found that a reduction in soil moisture leads to an increase in surface temperature, lower surface pressure, increased ridging aloft, and a northward shift of the jet stream. It is shown that low-level moisture advection from the Gulf of Mexico is important in the maintenance of persistent soil moisture deficits.

  14. Prediction of Dried Durian Moisture Content Using Artificial Neural Networks

    NASA Astrophysics Data System (ADS)

    Husna, Marati; Purqon, Acep

    2016-08-01

    Moisture content has a crucial issue in post-harvest processing since it plays main role to estimate a quality of dried product. However, estimating the moisture content is difficult since it shows mathematically nonlinear systems and complex physical processes. We investigate the prediction of moisture content of dried product by using Artificial Neural Networks (ANN). Our sample is a Bengkulu's local durian that is dried using a microwave oven. Our results show that ANN can predict the moisture content by performing with R2 value is 98.47%. Moreover, the RMSE values is 3.97% and MSE values is 0.16%. Our results indicate that ANN model have high capability for predicting moisture content and it is potentially applied in post-harvest product, especially in drying product quality control.

  15. Analyzing the revolution of anaerobic ammonium oxidation (anammox) performance and sludge characteristics under zinc inhibition.

    PubMed

    Zhang, Qian-Qian; Zhang, Zheng-Zhe; Guo, Qiong; Wang, Jiao-Jiao; Wang, Hui-Zhong; Jin, Ren-Cun

    2015-04-01

    In the present study, the short- and long-term effects of Zn(II) on the anaerobic ammonium oxidation (anammox) performance and sludge characteristics were evaluated. The anammox activity decreased with increasing Zn(II) concentration and pre-exposure time in short-term tests. The half maximal inhibitory concentration (IC50) of Zn(II) was found to be 25.0 mg L(-1). The 24 and 48-h pre-exposure time was a restricted factor impacting the anammox activity, and washing the inhibited sludge with buffer solution only worked under 0 and 24-h pre-exposure time. The anammox sludge could tolerate 5 mg L(-1) Zn(II) but was suppressed at 8 mg L(-1). The inhibited performance could be remitted, as the combination strategies were applied, and after the short term of recovery period, the inhibited sludge characteristics were remitted to the normal.

  16. Predicting performance expectations from affective impressions: linking affect control theory and status characteristics theory.

    PubMed

    Dippong, Joseph; Kalkhoff, Will

    2015-03-01

    Affect control theory (ACT) and status characteristics theory (SCT) offer separate and distinct explanations for how individuals interpret and process status- and power-relevant information about interaction partners. Existing research within affect control theory offers evidence that status and power are related to the affective impressions that individuals form of others along the dimensions of evaluation and potency, respectively. Alternately, status characteristics theory suggests that status and power influence interaction through the mediating cognitive construct of performance expectations. Although both theories have amassed an impressive amount of empirical support, research has yet to articulate theoretical and empirical connections between affective impressions and performance expectations. The purpose of our study is to address this gap. Elaborating a link between ACT and SCT in terms of their central concepts can serve as a stepping stone to improving the explanatory capacity of both theories, while providing a potential bridge by which they can be employed jointly.

  17. Output power characteristics and performance of TOPAZ II Thermionic Fuel Element No. 24

    SciTech Connect

    Luchau, D.W.; Bruns, D.R.; Izhvanov, O.; Androsov, V.

    1996-03-01

    A final report on the output power characteristics and capabilities of single cell TOPAZ II Thermionic Fuel Element (TFE) No. 24 is presented. Thermal power tests were conducted for over 3000 hours to investigate converter performance under normal and adverse operating conditions. Experiments conducted include low power testing, high power testing, air introduction to the interelectrode gap, collector temperature optimization, thermal modeling, and output power characteristic measurements. During testing, no unexpected degradation in converter performance was observed. The TFE has been removed from the test stand and returned to Scientific Industrial Association {open_quote}{open_quote}LUCH{close_quote}{close_quote} for materials analysis and report. This research was conducted at the Thermionic System Evaluation Test (TSET) Facility at the New Mexico Engineering Research Institute (NMERI) as a part of the Topaz International Program (TIP) by the Air Force Phillips Laboratory (PL). {copyright} {ital 1996 American Institute of Physics.}

  18. Reader characteristics linked to detection of pulmonary nodules on radiographs: ROC vs. JAFROC analyses of performance

    NASA Astrophysics Data System (ADS)

    Kohli, Akshay; Robinson, John W.; Ryan, John; McEntee, Mark F.; Brennan, Patrick C.

    2011-03-01

    The purpose of this study is to explore whether reader characteristics are linked to heightened levels of diagnostic performance in chest radiology using receiver operating characteristic (ROC) and jackknife free response ROC (JAFROC) methodologies. A set of 40 postero-anterior chest radiographs was developed, of which 20 were abnormal containing one or more simulated nodules, of varying subtlety. Images were independently reviewed by 12 boardcertified radiologists including six chest specialists. The observer performance was measured in terms of ROC and JAFROC scores. For the ROC analysis, readers were asked to rate their degree of suspicion for the presence of nodules by using a confidence rating scale (1-6). JAFROC analysis required the readers to locate and rate as many suspicious areas as they wished using the same scale and resultant data were used to generate Az and FOM scores for ROC and JAFROC analyses respectively. Using Pearson methods, scores of performance were correlated with 7 reader characteristics recorded using a questionnaire. JAFROC analysis showed that improved reader performance was significantly (p<=0.05) linked with chest specialty (p<0.03), hours per week reading chest radiographs (p<0.03) and chest readings per year (p<0.04). ROC analyses demonstrated only one significant relationship, hours per week reading chest radiographs (p<0.02).The results of this study have shown that radiologist's performance in the detection of pulmonary nodules on radiographs is significantly linked to chest specialty, hours reading per week and number of radiographs read per year. Also, JAFROC is a more powerful predictor of performance as compared to ROC.

  19. Talent in Female Gymnastics: a Survival Analysis Based upon Performance Characteristics.

    PubMed

    Pion, J; Lenoir, M; Vandorpe, B; Segers, V

    2015-11-01

    This study investigated the link between the anthropometric, physical and motor characteristics assessed during talent identification and dropout in young female gymnasts. 3 cohorts of female gymnasts (n=243; 6-9 years) completed a test battery for talent identification. Performance-levels were monitored over 5 years of competition. Kaplan-Meier and Cox Proportional Hazards analyses were conducted to determine the survival rate and the characteristics that influence dropout respectively. Kaplan-Meier analysis indicated that only 18% of the female gymnasts that passed the baseline talent identification test survived at the highest competition level 5 years later. The Cox Proportional Hazards Model indicated that gymnasts with a score in the best quartile for a specific characteristic significantly increased chances of survival by 45-129%. These characteristics being: basic motor skills (129%), shoulder strength (96%), leg strength (53%) and 3 gross motor coordination items (45-73%). These results suggest that tests batteries commonly used for talent identification in young female gymnasts may also provide valuable insights into future dropout. Therefore, multidimensional test batteries deserve a prominent place in the selection process. The individual test results should encourage trainers to invest in an early development of basic physical and motor characteristics to prevent attrition.

  20. Space-time soil moisture variability for two different land use types: analysis at the plot scale

    NASA Astrophysics Data System (ADS)

    Zuecco, Giulia; Borga, Marco; Penna, Daniele; Canone, Davide; Ferraris, Stefano

    2013-04-01

    Understanding space-time soil moisture variability at various scales is a key issue in hydrological research. At the plot scale soil moisture variability is expected to be explained by physical factors such as soil hydraulic properties, local topography and vegetation cover. This study aims to: i) characterize the spatial and temporal variability of soil moisture at the plot scale at two soil depths and for two different types of land use (meadow and vineyard); ii) investigate the role of vegetation cover on the seasonal variability of soil moisture; iii) assess the capability of a dynamic model to explain soil moisture variability and the control exerted by land use. The work is based on soil moisture data collected on a plot (about 200 m2) in Grugliasco (Po River basin, Northern Italy) by means of Time Domain Reflectometry (TDR) measurements. The plot is divided into two subplots: one covered by grapevine plants, the other covered homogeneously by grass. The soil is sandy, the slope is about 1%, and there is a buffer grass area about 20 m wide around the measurement field. The characteristics of the site allow to isolate the contribution of soil hydraulic properties and land use to space-time soil moisture variability. We used the data of 40 probes distributed in the two subplots, vertically inserted into the soil at 0-30 cm and 0-60 cm depths. Precipitation and temperature are recorded continuously on site. Statistics were computed based on soil moisture measurements collected continuously at daily time step over three years (2006-2008). Results show that soil moisture spatial patterns at the two sampling depths are highly correlated for both land uses. Higher values of mean soil moisture at 0-60 cm depth with respect to 0-30 cm for both types of land use likely reflect the evaporation processes affecting more the surface layer. Spatial mean soil moisture is always higher in the vineyard than in the meadow (especially at 0-30 cm depth), implying the influence of

  1. Moisturizers: Options for Softer Skin

    MedlinePlus

    ... or blot your skin until it's just barely dry, then apply moisturizer immediately to help trap water in the surface cells. A pply moisturizer to your hands and body as needed. Apply after bathing or showering, before exercising outdoors in cold weather, and every time you wash your hands. Although ...

  2. Performance and operating characteristics of the arc-driven Langley 6-inch shock tube

    NASA Technical Reports Server (NTRS)

    Nealy, J. E.

    1972-01-01

    Performance characteristics for the arc-driven Langley 6-inch shock tube were determined for driver energies from 0.62 to 5 MJ. Voltage, current and pressure histories of the arc driver were recorded, and driver efficiencies were determined from measured shock velocities. Time-resolved spectra for test gases of air, carbon monoxide, xenon, and a mixture of 80 percent helium and 20 percent hydrogen are presented.

  3. Description and performance characteristics for the neutron Coincidence Collar for the verification of reactor fuel assemblies

    SciTech Connect

    Menlove, H.O.

    1981-08-01

    An active neutron interrogation method has been developed for the measurement of /sup 235/U content in fresh fuel assemblies. The neutron Coincidence Collar uses neutron interrogation with an AmLi neutron source and coincidence counting the induced fission reaction neutrons from the /sup 235/U. This manual describes the system components, operation, and performance characteristics. Applications of the Coincidence Collar to PWR and BWR types of reactor fuel assemblies are described.

  4. Performance characteristics of an isolated coannular plug nozzle at transonic speeds

    NASA Technical Reports Server (NTRS)

    Mercer, C. E.; Burley, J. R., II

    1985-01-01

    The Langley 16-Foot Transonic Tunnel was used to evaluate the performance characteristics of a coannular plug nozzle at static conditions (Mach number of 0) and at Mach numbers from 0.65 to 1.20. Jet total pressure ratio was varied from 1.0 (jet off) to 10.0. Thirty-seven configurations generated by the combination of three geometric variables - plug angle, shroud boattail length (fixed exit radius), and shroud extension length - were tested.

  5. The Design and Performance Characteristics of a Cellular Logic 3-D Image Classification Processor.

    DTIC Science & Technology

    1981-04-01

    number) Pattern Recognition Cellular Automata " Cellular Logic Target Classificatio4 1Neighborhood Transformation Image Processing Laser Radar iASSTRACT...AND PERFORMANCE CHARACTERISTICS OF A CELLULAR LOGIC 3-D IMAGE CLASSIFICATION PROCESSOR 1 &/. , DISSERTATION AFIT/DS/EE/81-1 Lawrence A. Ankeney... CELLULAR LOGIC 3-D IMAGE - -- A&I PRCSRDTIC T B CLASSIFICATION PROCESSOR Unannounced 0 Justificatio b yD t i u i n Lawrence A. Ankeney, B.S., M.S

  6. Aerodynamic and propeller performance characteristics of a propfan-powered, semispan model

    NASA Technical Reports Server (NTRS)

    Levin, Alan D.; Smith, Ronald C.; Wood, Richard D.

    1985-01-01

    A semispan wing/body model with a powered propeller was tested to provide data on a total powerplant installation drag penalty of advanced propfan-powered aircraft. The test objectives were to determine the total power plant installation drag penalty on a representative propfan aircraft; to study the effect of configuration modifications on the installed powerplant drag; and to determine performance characteristics of an advanced design propeller which was mounted on a representative nacelle in the presence of a wing.

  7. Performance characteristics of 1977 American Motors 304 CID engine. Final report

    SciTech Connect

    Boziuk, J.

    1980-02-01

    Experimental data were obtained in dynamometer tests of a 1977 AM 304 CID engine to determine fuel consumption and emissions (hydrocarbons, carbon monoxide, and oxides of nitrogen) at steady-state engine operating modes. The objective of the test was to obtain engine performance data for estimating fuel consumption and emissions for varied engine service and duty and to provide basic engine characteristic data required for the TSC Vehicle Simulator (VEHSIM).

  8. Performance characteristics of 1977 General Motors 350 CID engine. Final report

    SciTech Connect

    Boziuk, J.

    1980-02-01

    Experimental data were obtained in dynamometer tests of a 1977 GM 350 CID engine to determine fuel consumption and emissions (hydrocarbons, carbon monoxide, and oxides of nitrogen) at steady-state engine operating modes. The objective of the test was to obtain engine performance data for estimating fuel consumption and emissions for varied engine service and duty and to provide basic engine characteristic data required for the TSC Vehicle Simulator (VEHSIM).

  9. Analysis of Joint Masonry Moisture Content Monitoring

    SciTech Connect

    Ueno, Kohta

    2015-10-01

    Adding insulation to the interior side of walls of masonry buildings in cold (and wet) climates may cause performance and durability problems. Some concerns, such as condensation and freeze-thaw, have known solutions, but wood members embedded in the masonry structure will be colder (and potentially wetter) after an interior insulation retrofit. Moisture content & relative humidity were monitored at joist ends in historic mass brick masonry walls retrofitted with interior insulation in a cold climate (Zone 5A); data were collected from 2012-2015. Eleven joist ends were monitored in all four orientations. One limitation of these results is that the renovation is still ongoing, with limited wintertime construction heating and no permanent occupancy to date. Measurements show that many joists ends remain at high moisture contents, especially at north- and east-facing orientations, with constant 100% RH conditions at the worst cases. These high moisture levels are not conducive for wood durability, but no evidence for actual structural damage has been observed. Insulated versus non-insulated joist pockets do not show large differences. South facing joists have safe (10-15%) moisture contents. Given the uncertainty pointed out by research, definitive guidance on the vulnerability of embedded wood members is difficult to formulate. In high-risk situations, or when a very conservative approach is warranted, the embedded wood member condition can be eliminated entirely, supporting the joist ends outside of the masonry pocket.

  10. Optimization of rotor blades for combined structural, performance, and aeroelastic characteristics

    NASA Technical Reports Server (NTRS)

    Peters, David A.; Cheng, Y. P.

    1989-01-01

    The strategies whereby helicopter rotor blades can be optimized for combined structural, inertial, dynamic, aeroelastic, and aerodynamic performance characteristics are outlined. There are three key ingredients in the successful execution of such an interdisciplinary optimization. The first is the definition of a satisfactory performance index that combines all aspects of the problem without too many constraints. The second element is the judicious choice of computationally efficient analysis tools for the various quantitative components in both the cost functional and constraints. The third element is an effective strategy for combining the various disciplines either in parallel or sequential optimizations.

  11. Cavitation performance and flow characteristic in a centrifugal pump with inlet guide vanes

    NASA Astrophysics Data System (ADS)

    Tan, L.; Zha, L.; Cao, S. L.; Wang, Y. C.; Gui, S. B.

    2015-01-01

    The influence of prewhirl regulation by inlet guide vanes (IGVs) on cavitation performance and flow characteristic in a centrifugal pump is investigated. At the impeller inlet, the streamlines are regulated by the IGVs, and the axial velocity distribution is also influenced by the IGVs. Due to the total pressure loss on the IGVs, the cavitation performance of the centrifugal pump degrades. The cavitation area in impeller with IGVs is larger than one without IGVs. The specify values of total pressure loss between the suction pipe inlet and impeller inlet for three cavitation conditions show that the IGVs will generate additional pressure loss, which is related to the IGVs angles and cavitation conditions.

  12. Demand characteristics of music affect performance on the Wonderlic Personnel Test Of Intelligence.

    PubMed

    Verpaelst, Celissa C; Standing, Lionel G

    2007-02-01

    This study examined whether demand characteristics concerning music can change subjects' performance on the Wonderlic Personnel Test of intelligence. Participants (N= 60) were randomly assigned and informed either that Mozart's music typically enhances cognitive performance or diminishes it. They then completed the Wonderlic Personnel Test while listening to a Mozart piano sonata. The subjects with a positive set answered significantly more items correctly on the test (14%) than those with a negative set (p = .03). This result may hold implications for the study of the 'Mozart effect'.

  13. Study of performance and propagation characteristics of wire and planar structures around human body.

    PubMed

    Aroul, A L Praveen; Bhatia, Dinesh

    2011-01-01

    Continued miniaturization of electronic devices and technological advancements in wireless communications has made wearable body-centric telemedicine systems viable. Antennas play a crucial role in characterizing the efficiency and reliability of these systems. The performance characteristics such as the radiation pattern, gain, efficiency of the antennas get adversely affected due to the presence of lossy human body tissues. In this paper we investigate the above mentioned performance parameters and radio frequency transmission properties of wire and planar structures operating at ISM frequency band of 2.40-2.50 GHz in the proximity of human body.

  14. What Performance Characteristics Determine Elite Versus Nonelite Athletes in the Same Sport?

    PubMed Central

    Lorenz, Daniel S.; Reiman, Michael P.; Lehecka, B.J.; Naylor, Andrew

    2013-01-01

    Context: There are significant data comparing elite and nonelite athletes in anaerobic field and court sports as well as endurance sports. This review delineates specific performance characteristics in the elite athlete and may help guide rehabilitation. Evidence Acquisition: A Medline search from April 1982 to April 2012 was undertaken for articles written in English. Additional references were accrued from reference lists of research articles. Results: In the anaerobic athlete, maximal power production was consistently correlated to elite performance. Elite performance in the endurance athlete is more ambiguous, however, and appears to be related to the dependent variable investigated in each individual study. Conclusion: In anaerobic field and court sport athletes, maximal power output is most predictive of elite performance. In the endurance athlete, however, it is not as clear. Elite endurance athletes consistently test higher than nonelite athletes in running economy, anaerobic threshold, and VO2max. PMID:24427430

  15. Experimental study on multiple-pulse performance characteristics of ammonium perchlorate/aluminum powder rocket motor

    NASA Astrophysics Data System (ADS)

    Li, Yue; Hu, Chunbo; Deng, Zhe; Li, Chao; Sun, Haijun; Cai, Yupeng

    2017-04-01

    The performance characteristics of ammonium perchlorate/aluminum powder rocket motor were investigated experimentally based on a powder rocket testing system. Three-pulse experiment with one hour interval and four-pulse experiment with 15 s interval were conducted with a bi-propellant powder feed system. The experiments demonstrate the feasibility of the powder rocket for the multiple-pulse operation and the synchronization of powder feed method. The multiple-pulse performance characteristics were analyzed accordingly. It shows that the motor initiates steadily with the mass flow rate of 2.5 g/s for oxidizer powder fluidization gas and 2.0 g/s for fuel powder fluidization gas. The relative standard deviation was adopted to describe the repeatability characteristics of the pulses. The relative standard deviation of ammonium perchlorate and aluminum pistons velocity is 0.072 and 0.007, and that of oxidizer-fuel mass feed ratio is 0.052. The motor performed well with good repeatability of combustor pressure, start-up response and combustion efficiency during the multiple-pulse tests. Low frequency combustion pressure oscillations,3.6-4.2 Hz with amplitudes up to 18.7% of mean combustor pressure, were encountered. The phenomenon appeared seriously at first pulse, then alleviated at the following pulses. Further analysis of test results showed that increasing chamber pressure could ameliorate the oscillation.

  16. Physical performance characteristics of high-level female soccer players 12-21 years of age.

    PubMed

    Vescovi, J D; Rupf, R; Brown, T D; Marques, M C

    2011-10-01

    Performance assessment has become an invaluable component of monitoring player development and within talent identification programs in soccer, yet limited performance data are available for female soccer players across a wide age range. The aim of this study was to describe the physical performance characteristics of female soccer players ranging in age from 12 to 21 years. High-level female soccer players (n=414) were evaluated on linear sprinting (36.6 m with 9.1 m splits), countermovement jump (CMJ), and two agility tests. Separate one-way ANOVAs were used to compare performance characteristics between (1) each year of chronological age and (2) three age groups: 12-13 years, n=78, 14-17 years, n=223, and 18-21 years, n=113. Mean linear sprint speed over 9.1 m was similar across all chronological ages, however sprint speed over the final 9.1 m, CMJ height and agility scores improved until approximately 15-16 years. Outcomes from the group data indicated better performance on all tests for the 14-17-year-old group compared with the 12-13-year-old group. Additionally, sprint speed on the second and fourth 9.1 m splits and 36.6 m sprint speed as well as performance on the Illinois agility test was better in the 18-21-year-old group compared with the 14-17-year-old group. The findings from this study indicate that marked improvements of high intensity short duration work occur up until 15-16 years. Smaller gains in performance were observed beyond 16 years of age as evidenced by better performance on 36.6 m sprint speed, several sprint splits and the Illinois agility test in the college aged players (i.e., 18-21-year-old group).

  17. Estimation of surface heat and moisture fluxes over a prairie grassland. 4. Impact of satellite remote sensing of slow canopy variables on performance of a hybrid biosphere model

    SciTech Connect

    Crosson, W.L. ); Smith, E.A.; Cooper, H.J. )

    1993-03-20

    The authors present the results of a series of numerical experiments using the Ex-BATS biosphere model, which is an adaptation of Dickinson's biosphere-atmosphere transfer scheme (BATS). These simulations are used to assess how the model performs when remotely sensed data are used to estimate three key canopy variables. These canopy variables, which effectively represent the slowly changing boundary conditions of a vegetated surface, consist of the total surface albedo, leaf area index, and the nondiurnally varying component of stomatal resistance, referred to as stressed stomatal resistance. The surface albedo is retrieved from NOAA-AVHRR (advanced very high resolution radiometer) channel 1 spectral reflectance information in conjunction with a directional reflectance model which accounts for the strong diurnal variations in surface reflectance. A 4-channel vegetation index also retrieved from AVHRR measurements is used to estimate the leaf area index. A similar index derived from high-resolution SPOT visible and near-infrared information has been used to describe the spatial variations in such indices which impact the retrieval of the leaf area index. Satellite retrieval of stomatal resistance is based on split-window skin temperatures from AVHRR channels 4 and 5 from the afternoon overpass ([approximately]1630 LT). It was found that although stomatal resistance has little correlation with the diurnal amplitude of skin temperature, it is closely related to the daily maximum of skin temperature. Numerical experiments have been conducted to examine model sensitivity to each of these canopy variables. The rms measurement-model flux differences in every numerical trial were within 6 W m[sup [minus]2] of the rms differences obtained for the simulations performed using measured albedo and leaf area index. Measured stomatal resistance values were obtained using an inversion form of the model. 35 refs., 16 figs., 1 tab.

  18. Improving Global Soil Moisture Retrievals from AMSR-E through Enhanced Radiative Transfer Modeling and Parameter Calibration

    NASA Astrophysics Data System (ADS)

    Wood, Eric; Pan, Ming

    2013-04-01

    Accurate retrieval of soil moisture from satellites is always a challenge. A soil moisture retrieval product has been produced at Princeton University for last a few years from various passive microwave sensors (e. g. Advanced Microwave Scanning Radiometer - Earth Observing System: AMSR-E; TRMM Microwave Imager: TMI) by inverting a single-channel single-polarization (10 GHz Horizontal polarization) forward model (Land Surface Microwave Emission Model: LSMEM). Various characteristics are noticed in this product, such as regions of zero or saturation soil moisture retrievals, indicating an under-performing forward model. Additionally, an analysis of the data set reveals a number of problems related to the vegetation optical depth (VOD) parameter and some soil parameters. To improve the VOD estimation, the previous monthly vegetation parameter (previously static from year to year) is replaced with a dynamic VOD estimation module developed at University of Montana, which derives VOD from multiple microwave channels available on AMSR-E or TRMM. To improve the soil parameters, the surface roughness and soil texture parameters are calibrated to match the forward model predicted brightness temperature against the satellite observations, using one year of surface soil moisture from the VIC LSM. The new improved retrieval system that now utilizes multiple microwave channels significantly reduces the forward model bias and produces much more reasonable soil moisture estimates. Areas of active rainfall, snow cover, thick vegetation, and RFI are screened out using the microwave observations from the same platform. The new retrievals are compared to the uncalibrated LSMEM retrievals and are also assessed using soil moisture data from the NRCS SCAN and NCDC soil moisture networks.

  19. Class modality, student characteristics, and performance in a community college introductory STEM course

    NASA Astrophysics Data System (ADS)

    Fogle, Thomas Ty

    Research on introductory STEM course performance has indicated that student characteristics (age, ethnicity and gender) and Grade Point Average (G.P.A.) can be predictive of student performance, and by implication, a correlation among these factors can help determine course design interventions to help certain types of students perform well in introductory STEM courses. The basis of this study was a community college Visual Basic programming course taught in both online and hybrid format. Beginning students in this course represented a diverse population residing in a large, mid-western, city and surrounding communities. Many of these students were defined as "at-Risk" or "non-traditional, which generally means any combination of socio-economic, cultural, family and employment factors that indicate a student is non-traditional. Research has shown these students struggle academically in technologically dense STEM courses, and may require student services and support to achieve their individual performance goals. The overall number in the study range was 392 distance students and 287 blended course students. The main question of this research was to determine to what extent student characteristics in a community college context, and previous success, as measured in overall G.P.A., were related to course performance in an introductory Visual Basic programming (STEM) course; and, whether or not a combination of these factors and course modality was predictive of success. The study employed a quantitative, quasi-experimental design to assess whether students' course performance was linked to course modality, student characteristics and overall G.P.A. The results indicated that the only predictor of student performance was overall G.P.A. Despite the research analyzed in Chapter 2, there was no statistically significant relationship to modality, age, ethnicity, or gender to performance in the course. Cognitive load is significant in a computer programming course and it

  20. Crunchiness Loss and Moisture Toughening in Puffed Cereals and Snacks.

    PubMed

    Peleg, Micha

    2015-09-01

    Upon moisture uptake, dry cellular cereals and snacks loose their brittleness and become soggy. This familiar phenomenon is manifested in smoothing their compressive force-displacement curves. These curves' degree of jaggedness, expressed by their apparent fractal dimension, can serve as an instrumental measure of the particles' crunchiness. The relationship between the apparent fractal dimension and moisture content or water activity has a characteristic sigmoid shape. The relationship between the sensorily perceived crunchiness and moisture also has a sigmoid shape whose inflection point lies at about the same location. The transition between the brittle and soggy states, however, appears sharper in the apparent fractal dimension compared with moisture plot. Less familiar is the observation that at moderate levels of moisture content, while the particles' crunchiness is being lost, their stiffness actually rises, a phenomenon that can be dubbed "moisture toughening." We show this phenomenon in commercial Peanut Butter Crunch® (sweet starch-based cereal), Cheese Balls (salty starch-based snack), and Pork Rind also known as "Chicharon" (salty deep-fried pork skin), 3 crunchy foods that have very different chemical composition. We also show that in the first 2 foods, moisture toughening was perceived sensorily as increased "hardness." We have concluded that the partial plasticization, which caused the brittleness loss, also inhibited failure propagation, which allowed the solid matrix to sustain higher stresses. This can explain other published reports of the phenomenon in different foods and model systems.

  1. Directional moisture transfer through a wild silkworm cocoon wall.

    PubMed

    Jin, Xing; Zhang, Jin; Gao, Weimin; Du, Shan; Li, Jingliang; Wang, Xungai

    2016-06-25

    A silkworm cocoon is a porous biological structure with multiple protective functions. In the current work, the authors have used both experimental and numerical methods to reveal the unique moisture transfer characteristics through a wild Antheraea pernyi silkworm cocoon wall, in comparison with the long-domesticated Bombyx mori silkworm cocoon walls. The water vapor transmission and water vapor permeability (WVP) properties show that the A. pernyi cocoons exhibit directional moisture transfer behavior, with easier moisture transfer from inside out than outside in [e.g., the average WVP is 0.057 g/(h m bar) from inside out and is 0.034 g/(h m bar) from outside in]. Numerical analysis shows that the cubic mineral crystals in the outer section of the A. pernyi cocoon wall create a rough surface that facilitates air turbulence and promotes disturbance amplitude of the flow field, leading to lengthened water vapor transfer path and increased tortuosity of the moist air. It also indicates the vortex of water vapor can be generated in the outer section of cocoon wall, which increases the diffusion distance of water vapor and enhances the turbulence kinetic energy and turbulence eddy dissipation, signifying higher moisture resistance in the outer section. The difference in moisture resistance of the multiple A. pernyi cocoon layers is largely responsible for the unique directional moisture transfer behavior of this wild silkworm cocoon. These findings may inspire a biomimicry approach to develop novel lightweight moisture management materials and structures.

  2. Design Characteristics Influence Performance of Clinical Prediction Rules in Validation: A Meta-Epidemiological Study

    PubMed Central

    Ban, Jong-Wook; Emparanza, José Ignacio; Urreta, Iratxe; Burls, Amanda

    2016-01-01

    Background Many new clinical prediction rules are derived and validated. But the design and reporting quality of clinical prediction research has been less than optimal. We aimed to assess whether design characteristics of validation studies were associated with the overestimation of clinical prediction rules’ performance. We also aimed to evaluate whether validation studies clearly reported important methodological characteristics. Methods Electronic databases were searched for systematic reviews of clinical prediction rule studies published between 2006 and 2010. Data were extracted from the eligible validation studies included in the systematic reviews. A meta-analytic meta-epidemiological approach was used to assess the influence of design characteristics on predictive performance. From each validation study, it was assessed whether 7 design and 7 reporting characteristics were properly described. Results A total of 287 validation studies of clinical prediction rule were collected from 15 systematic reviews (31 meta-analyses). Validation studies using case-control design produced a summary diagnostic odds ratio (DOR) 2.2 times (95% CI: 1.2–4.3) larger than validation studies using cohort design and unclear design. When differential verification was used, the summary DOR was overestimated by twofold (95% CI: 1.2 -3.1) compared to complete, partial and unclear verification. The summary RDOR of validation studies with inadequate sample size was 1.9 (95% CI: 1.2 -3.1) compared to studies with adequate sample size. Study site, reliability, and clinical prediction rule was adequately described in 10.1%, 9.4%, and 7.0% of validation studies respectively. Conclusion Validation studies with design shortcomings may overestimate the performance of clinical prediction rules. The quality of reporting among studies validating clinical prediction rules needs to be improved. PMID:26730980

  3. The Physical and Athletic Performance Characteristics of Division I Collegiate Female Soccer Players by Position.

    PubMed

    Lockie, Robert G; Moreno, Matthew R; Lazar, Adrina; Orjalo, Ashley J; Giuliano, Dominic V; Risso, Fabrice G; Davis, DeShaun L; Crelling, Jeff B; Lockwood, John R; Jalilvand, Farzad

    2016-07-07

    Playing positions in soccer can exhibit different movement demands during a match, contributing to variations in physical and performance characteristics. NCAA soccer features different substitution rules when compared to FIFA-sanctioned matches, which could influence each players' characteristics. Therefore, this study determined the athletic performance characteristics of Division I female soccer players. Twenty-six players (3 goalkeepers; 8 defenders; 10 midfielders; 5 forwards) from the same squad completed assessments of: lower-body power (vertical and standing broad jump); linear (0-5, 0-10, 0-30 meter [m] sprint intervals) and change-of-direction (pro-agility shuttle; Arrowhead change-of-direction speed test) speed; and soccer-specific fitness (Yo-Yo Intermittent Recovery Test [YYIRT] levels 1 and 2). Players were split into position groups, and a Kruskal-Wallis H test with post hoc pairwise analyses (p < 0.05) calculated significant between-group differences. There were no differences in age, height, or body mass between the positions. Midfielders had a faster 0-5 m time compared to the defenders (p = 0.017), and the goalkeepers (p = 0.030). The defenders (p = 0.011) and midfielders (p = 0.013) covered a greater YYIRT2 distance compared to the goalkeepers. There were no other significant between-position differences. Overall, Division I collegiate female players from the same squad demonstrated similar characteristics as measured by soccer-specific performance tests, which could allow for flexibility in position assignments. However, a relatively homogenous squad could also indicate commonality in training prescription, particularly regarding acceleration and high-intensity running. Strength and conditioning coaches may have to consider the specific movement demands of individual positions when training these capacities.

  4. Triple-head gamma camera PET: system overview and performance characteristics.

    PubMed

    Grosev, D; Loncarić, S; Vandenberghe, S; Dodig, D

    2002-08-01

    Positron emission tomography (PET) is currently performed using either a dedicated PET scanner or scintillation gamma camera equipped with electronic circuitry for coincidence detection of 511 keV annihilation quanta (gamma camera PET system). Although the resolution limits of these two instruments are comparable, the sensitivity and count rate performance of the gamma camera PET system are several times lower than that of the PET scanner. Most gamma camera PET systems are manufactured as dual-detector systems capable of performing dual-head coincidence imaging. One possible step towards the improvement of the sensitivity of the gamma camera PET system is to add another detector head. This work investigates the characteristics of one such triple-head gamma camera PET system capable of performing triple-head coincidence imaging. The following performance characteristics of the system were assessed: spatial resolution, sensitivity, count rate performance. The spatial resolution, expressed as the full width at half-maximum (FWHM), at 1 cm radius is 5.9 mm; at 10 cm radius, the transverse radial resolution is 5.3 mm, whilst the transverse tangential and axial resolutions are 8.9 mm and 13.3 mm, respectively. The sensitivity for a standard cylindrical phantom is 255 counts.s(-1).MBq*(-1)), using a 30% width photopeak energy window. An increase of 35% in the PET sensitivity is achievable by opening an additional 30% width energy window in the Compton region. The count rate in coincidence mode, at the upper limit of the systems optimal performance, is 45 kc.s(-1) (kc=kilocounts) using the photopeak energy window only, and increases to 60 kc.s(-1) using the photopeak + Compton windows. Sensitivity results are compared with published data for a similar dual-head detector system.

  5. Physical characteristics, physiological attributes, and on-field performances of soccer goalkeepers.

    PubMed

    Ziv, Gal; Lidor, Ronnie

    2011-12-01

    The soccer goalkeeper (GK) is required to perform strenuous actions during practice sessions and actual games. One of the objectives of those professionals who work with GKs is to obtain relevant information on physical characteristics and physiological attributes of GKs, and to use it effectively when planning training programs for them. This article has three purposes: (a) to review a series of studies (n = 23) on physical characteristics, physiological attributes, and on-field performances of soccer GKs; (b) to outline a number of methodological limitations and research concerns associated with these studies; and (c) to suggest several practical recommendations for soccer coaches who work with GKs. Four main findings emerged from our review: (a) professional adult GKs usually are over 180 cm tall and have a body mass of over 77 kg; (b) studies on agility and speed produced mixed results, with some showing similar values between GKs and field players and others showing reduced performance in GKs; (c) GKs usually have higher vertical jump values when compared with players playing the various field positions; (d) GKs cover approximately 5.5 km during a game, mostly by walking and jogging. Four methodological limitations and research concerns associated with the reviewed studies were discussed, among them the lack of a longitudinal approach and the lack of on-field performance studies. Three practical recommendations are made for coaches, one of which is that coaches should adopt a careful approach when selecting testing protocols and devices for the assessment of GKs' physiological attributes.

  6. Chemical composition and moisture-absorption/retention ability of polysaccharides extracted from five algae.

    PubMed

    Wang, Jing; Jin, Weihua; Hou, Yun; Niu, Xizhen; Zhang, Hong; Zhang, Quanbin

    2013-06-01

    In this study, we prepared seven polysaccharides extracted from five algae including one brown alga Saccharina japonica, one red alga Porphyra haitanensis and three green algae Codium fragile, Enteromorpha linza and Bryopsis plumose. The chemical composition and capability of moisture-absorption and moisture-retention were investigated in comparison with those of hyaluronic acid (HA). The low molecular weight polysaccharides extracted from brown seaweed exhibited the highest moisture-absorption and moisture-retention abilities of all of the polysaccharides studied and performed better than HA. The relationships between chemical composition (including sulfated groups, monosaccharide, and molecular weight) and the functions of polysaccharides were also studied. We found the sulfated group was a main active site for moisture-absorption and moisture-retention abilities. These abilities were also related to molecular weight; with the exception of the low molecular weight polysaccharide extracted from red seaweed, lower molecular weight improved moisture-absorption and moisture-retention abilities.

  7. A descriptive-comparative study of performance characteristics in futsal players of different levels.

    PubMed

    Naser, Naser; Ali, Ajmol

    2016-09-01

    Despite the increasing popularity of futsal, there is little information on performance characteristics of players. We aimed to determine the validity and reliability of a futsal shooting test and to evaluate and compare performance characteristics of three futsal playing levels. Twenty-four males (n = 8 elite, n = 8 semi-elite, n = 8 social) completed two trials to examine the reliability of the Massey Futsal Shooting Test (MFST) and to compare various fitness characteristics between groups. MFST time taken (P = 0.010), shot speed (P < 0.001) and points scored per shot (P < 0.001) were better for elite relative to social players. Test-retest reliability was acceptable for all groups, but it was most repeatable in elite players. Loughborough Soccer Passing Test performance was better in elite relative to social players (P = 0.004). There were no differences in countermovement-jump height between groups. Elite players ran faster over 5 m than both semi-elite (P = 0.043) and social (P = 0.002) and faster than the social players through 10 m (P = 0.028) and 20 m (P = 0.026). Distance covered in the Futsal Intermittent Endurance Test was higher in elite relative to semi-elite (P = 0.005) and social (P < 0.001) groups. The MFST is a valid and reliable protocol to assess futsal shooting-skill performance; elite players have superior shooting and passing skill and have greater sprinting and intermittent-running ability.

  8. Soil moisture from temperature measurements at the Earth's surface, update

    NASA Technical Reports Server (NTRS)

    Welker, J. E.

    1984-01-01

    Soil moisture budgets at the Earth's surface were investigated based on soil and atmospheric temperature variations. A number of data sets were plotted and statistically analyzed in order to accentuate the existence and the characteristics of mesoscale soil temperature extrema variations and their relations to other parameters. The correlations between diurnal temperature extrema for air and soil in drought and non-drought periods appear to follow different characteristic patterns, allowing an inference of soil moisture content from temperature data. The recovery of temperature extrema after a precipitation event also follows a characteristic power curve rise between two limiting values which is an indicator of evaporation rates. If these indicators are applied universally to regional temperature data, soil moisture content or drought conditions can be inferred directly from temperature measurements.

  9. Early Soil Moisture Field Experiments

    NASA Astrophysics Data System (ADS)

    Schmugge, T.

    2008-12-01

    Before the large scale field experiments described in the call for papers, there were a number of experiments devoted to a single parameter, e.g. soil moisture. In the early 1970's, before the launch of the first microwave radiometer by NASA, there were a number of aircraft experiments to determine utility of these sensors for land observations. For soil moisture, these experiments were conducted in southwestern United States over irrigated agricultural areas which could provide a wide range of moisture conditions on a given day. The radiometers covered the wavelength range from 0.8 to 21 cm. These experiments demonstrated that it is possible to observe soil moisture variations remotely using a microwave radiometer with a sensitivity of about 3 K / unit of soil moisture. The results also showed that the longer wavelengths were better, with a radiometer at the 21 cm wavelength giving the best results. These positive results led to the development of Push Broom Microwave Radiometer (PBMR) and the Electrically Scanned Thinned Array Radiometer (ESTAR) instruments at the 21-cm wavelength. They have been used extensively in the large-scale experiments such as HAPEX-MOBILHY, FIFE, Monsoon90, SMEX, etc. The multi-beam nature of these instruments makes it possible to obtain more extensive coverage and thus to map spatial variations of surface soil moisture. Examples of the early results along with the more recent soil moisture maps will be presented.

  10. Heat Shielding Characteristics and Thermostructural Performance of a Superalloy Honeycomb Sandwich Thermal Protection System (TPS)

    NASA Technical Reports Server (NTRS)

    Ko, William L.

    2004-01-01

    Heat-transfer, thermal bending, and mechanical buckling analyses have been performed on a superalloy "honeycomb" thermal protection system (TPS) for future hypersonic flight vehicles. The studies focus on the effect of honeycomb cell geometry on the TPS heat-shielding performance, honeycomb cell wall buckling characteristics, and the effect of boundary conditions on the TPS thermal bending behavior. The results of the study show that the heat-shielding performance of a TPS panel is very sensitive to change in honeycomb core depth, but insensitive to change in honeycomb cell cross-sectional shape. The thermal deformations and thermal stresses in the TPS panel are found to be very sensitive to the edge support conditions. Slight corrugation of the honeycomb cell walls can greatly increase their buckling strength.

  11. Parametric performance characteristics and treatment of temperature coefficients of silicon solar cells for space application

    NASA Technical Reports Server (NTRS)

    Patterson, R. E.; Yasui, R. K.

    1973-01-01

    The electrical performance characteristics of 2 and 10 ohms-cm N/P-type silicon solar cells were measured at simulated solar intensities of 5, 50, 100, 140, 250, 400, 550, 700, and 850 mW/sq cm. At each intensity, the temperature was varied in increments of 20 deg between extremes of +160 and -160 C. Short-circuit current, open-circuit voltage, and maximum power are presented in graphical format. Also described are three methods for predicting solar cell electrical performance as a function of temperature and intensity. Two of the methods are suitable for use at extreme temperature-intensity conditions. These methods were used sucessfully to predict the performance of the transducer on board the Mariner Mars 1971 spacecraft.

  12. Effect of cinnamon (Cinnamomum zeylanicum) essential oil supplementation on lamb growth performance and meat quality characteristics.

    PubMed

    Simitzis, P E; Bronis, M; Charismiadou, M A; Mountzouris, K C; Deligeorgis, S G

    2014-09-01

    A trial was conducted to examine the effect of cinnamon essential oil supplementation on lamb growth performance and meat quality. Sixteen male lambs were randomly assigned to two groups. The first group served as control and was given a basal diet, and the second group was given the same diet supplemented with cinnamon oil (1 ml/kg of concentrated feed) for 35 days. Incorporation of cinnamon oil did not affect growth performance (P>0.05). Meat pH, colour, water-holding capacity, shear force, intramuscular fat and lipid oxidation values of longissimus thoracis muscle were not significantly influenced by cinnamon oil supplementation (P>0.05). The post-inoculation counts of Salmonella enteritidis and Listeria monocytogenes on raw meat during refrigerated storage for 6 days did not differ (P>0.05) between the two groups. The results show that cinnamon oil supplementation may not have the potential to improve lamb growth performance and meat quality characteristics.

  13. Effect of Fuel Injection and Mixing Characteristics on Pulse-Combustor Performance at High-Pressure

    NASA Technical Reports Server (NTRS)

    Yungster, Shaye; Paxson, Daniel E.; Perkins, Hugh D.

    2014-01-01

    Recent calculations of pulse-combustors operating at high-pressure conditions produced pressure gains significantly lower than those observed experimentally and computationally at atmospheric conditions. The factors limiting the pressure-gain at high-pressure conditions are identified, and the effects of fuel injection and air mixing characteristics on performance are investigated. New pulse-combustor configurations were developed, and the results show that by suitable changes to the combustor geometry, fuel injection scheme and valve dynamics the performance of the pulse-combustor operating at high-pressure conditions can be increased to levels comparable to those observed at atmospheric conditions. In addition, the new configurations can significantly reduce the levels of NOx emissions. One particular configuration resulted in extremely low levels of NO, producing an emission index much less than one, although at a lower pressure-gain. Calculations at representative cruise conditions demonstrated that pulse-combustors can achieve a high level of performance at such conditions.

  14. Experimental study on the performance characteristics and emission analysis of a diesel engine using vegetable oils

    NASA Astrophysics Data System (ADS)

    Saha, Anup; Ehite, Ekramul Haque; Alam, M. M.

    2016-07-01

    In this research, Vegetable oils derived from Sesame Seed and Rice Bran were used and experimented upon. Using Kerosene as the solvent in varying proportions (30%, 50%, 70% by volume) with the vegetables oils, different blends of Sesame and Rice Bran Oils were produced. The important characteristic properties were found by experimentation and compared with those of Straight Run Diesel. Subsequently, Straight Run Diesel, vegetable oils and their blends were used to run a diesel engine one-by-one and the performance analysis was conducted, followed by an investigation of the exhaust emissions. From the comparative performance analysis, it was found that Rice Bran oil showed better performance as a fuel than Sesame with regards to power production and specific fuel consumption and also resulted in less Carbon Monoxide (CO) emission than Sesame oil blends.

  15. Performance, emissions, and physical characteristics of a rotating combustion aircraft engine

    NASA Technical Reports Server (NTRS)

    Berkowitz, M.; Hermes, W. L.; Mount, R. E.; Myers, D.

    1976-01-01

    The RC2-75, a liquid cooled two chamber rotary combustion engine (Wankel type), designed for aircraft use, was tested and representative baseline (212 KW, 285 BHP) performance and emissions characteristics established. The testing included running fuel/air mixture control curves and varied ignition timing to permit selection of desirable and practical settings for running wide open throttle curves, propeller load curves, variable manifold pressure curves covering cruise conditions, and EPA cycle operating points. Performance and emissions data were recorded for all of the points run. In addition to the test data, information required to characterize the engine and evaluate its performance in aircraft use is provided over a range from one half to twice its present power. The exhaust emissions results are compared to the 1980 EPA requirements. Standard day take-off brake specific fuel consumption is 356 g/KW-HR (.585 lb/BHP-HR) for the configuration tested.

  16. Determination of moisture in Cheddar cheese by near infrared reflectance spectroscopy.

    PubMed

    Wehling, R L; Pierce, M M

    1988-01-01

    Near infrared reflectance (NIR) spectroscopy was used to determine the moisture content of Cheddar cheese. Through multiple linear regression analysis, a 3-wavelength calibration was developed for use with a commercial filter monochromator instrument. For a validation set of 47 samples, the correlation coefficient squared (r2) between the NIR and oven moisture methods was 0.92, with a standard error of performance (SEP) of 0.38%. Sample temperature was found to significantly affect the spectral response; therefore, it was necessary to equilibrate all samples to a uniform temperature prior to NIR analysis. Aging may also affect the NIR characteristics of cheese, although it was possible to develop a successful calibration that encompassed a wide range of aging times.

  17. Muscle characteristics and plasma lactate and ammonia response after racing in Standardbred trotters: relation to performance.

    PubMed

    Ronéus, N; Essén-Gustavsson, B; Lindholm, A; Persson, S

    1999-03-01

    Blood samples from the jugular vein and muscle biopsies (gluteus medius) in 25 Standardbred trotters were obtained 5-10 min after racing. The biopsies were analysed for fibre type composition and enzymatic profile and blood samples for plasma lactate and ammonia concentrations. Muscle characteristics, plasma lactate and ammonia concentrations after racing were compared with each horse's individual performance index (IPI). The IPI is calculated annually from the individual horse's racing performance (% placing 1, 2 or 3, total annual earnings, average earning per start, and best racing record), respectively, converted to and expressed as a percentage deviation from the average record of the same sex and age group. The IPI values were 100-116. Plasma lactate concentrations were 15.0-42.7 mmol/l (mean 31.3 mmol/l) and ammonia concentrations 65-210 micromol/l (mean 141 micromol/l) after racing. Fibre type composition varied among horses (range 9-27% for Type I, 32-54% for Type IIA, and 27-46% for Type IIB). Fibre type composition, enzyme activities, plasma lactate and ammonia responses to racing were not correlated to IPI. Ten of the horses also performed a submaximal test on the track, consisting of 5 incremental 1000 m heats at approximate speeds of 9.1, 9.5, 10.0, 10.5, and 11.1 m/s. Immediately after each heat a blood sample was drawn from the jugular vein for plasma lactate analysis. Plasma lactate response to exercise differed between horses, but no correlation was seen with IPI. Muscle characteristics, plasma lactate and ammonia concentrations after racing and lactate response to a submaximal track test did not correlate with current race performance expressed as IPI in a group of horses with average or better performance capacity at the time of testing. Analysis of lactate and ammonia in blood after racing is not a valuable tool to predict an individual performance index.

  18. Understanding natural moisturizing mechanisms: implications for moisturizer technology.

    PubMed

    Chandar, Prem; Nole, Greg; Johnson, Anthony W

    2009-07-01

    Dry skin and moisturization are important topics because they impact the lives of many individuals. For most individuals, dry skin is not a notable concern and can be adequately managed with current moisturizing products. However, dry skin can affect the quality of life of some individuals because of the challenges of either harsh environmental conditions or impaired stratum corneum (SC) dry skin protection processes resulting from various common skin diseases. Dry skin protection processes of the SC, such as the development of natural moisturizing factor (NMF), are complex, carefully balanced, and easily perturbed. We discuss the importance of the filaggrin-NMF system and the composition of NMF in both healthy and dry skin, and also reveal new insights that suggest the properties required for a new generation of moisturizing technologies.

  19. Fiber optic moisture sensor with moisture-absorbing reflective target

    DOEpatents

    Kirkham, Randy R.

    1987-01-01

    A method and apparatus for sensing moisture changes by utilizing optical fiber technology. One embodiment uses a reflective target at the end of an optical fiber. The reflectance of the target varies with its moisture content and can be detected by a remote unit at the opposite end of the fiber. A second embodiment utilizes changes in light loss along the fiber length. This can be attributed to changes in reflectance of cladding material as a function of its moisture content. It can also be affected by holes or inserts interposed in the cladding material and/or fiber. Changing light levels can also be coupled from one fiber to another in an assembly of fibers as a function of varying moisture content in their overlapping lengths of cladding material.

  20. Shear bond strength comparison of moisture-insensitive primer and self-etching primer

    PubMed Central

    Goswami, Arunima; Mitali, Borah; Roy, BK

    2014-01-01

    Context: The detrimental effect of moisture on orthodontic bonding has long been known. Hydrophilic bonding materials have been introduced suggesting the possibility of obtaining successful orthodontic bonding to a moisture contaminated enamel surface. Aims: This study has been performed with an aim to compare the in vitro shear bond strength (SBS) and debonding characteristic of moisture-insensitive primer (MIP) (Transbond MIP) (3M Unitek, South Peck Road, Monrovia, California, USA) and self-etching primer (SEP) (Transbond Plus SEP) (3M Unitek, South Peck Road, Monrovia, California, USA) in combination with a color changing adhesive system (Transbond Plus Color Change) (3M Unitek, South Peck Road, Monrovia, California, USA) under both dry and contaminated condition. Settings and Design: Randomized controlled clinical study. Subjects and Methods: One hundred and twenty freshly extracted teeth for the purpose of orthodontic treatment were collected. Teeth were randomly assigned into four groups, each consisting of 30 specimen and stainless steel brackets were bonded using each primer-adhesive combination under different enamel conditions, that is, dry and enamel contaminated with natural saliva. SBS and adhesive remnant index were calculated for each group. Results: Analysis of variance of SBS for both MIP and SEP under dry and contaminated condition showed no statistical significance (P = 0.5). Chi-square test showed significant difference in debonding characteristics among the test groups (P < 0.001). All the groups showed typical debonding characteristics of separation either at the bracket-adhesive interface or within the adhesive itself. Conclusions: Moisture contamination did not affect the SBS and adhesive remaining on tooth for both MIP and SEP. PMID:25143933

  1. The gender gap reloaded: are school characteristics linked to labor market performance?

    PubMed

    Konstantopoulos, Spyros; Constant, Amelie

    2008-06-01

    This study examines the wage gender gap of young adults in the 1970s, 1980s, and 2000 in the US. Using quantile regression we estimate the gender gap across the entire wage distribution. We also study the importance of high school characteristics in predicting future labor market performance. We conduct analyses for three major racial/ethnic groups in the US: Whites, Blacks, and Hispanics, employing data from two rich longitudinal studies: NLS and NELS. Our results indicate that while some school characteristics are positive and significant predictors of future wages for Whites, they are less so for the two minority groups. We find significant wage gender disparities favoring men across all three surveys in the 1970s, 1980s, and 2000. The wage gender gap is more pronounced in higher paid jobs (90th quantile) for all groups, indicating the presence of a persistent and alarming "glass ceiling."

  2. Supersonic aerodynamic characteristics of a variable-geometry spacecraft designed for high hypersonic performance

    NASA Technical Reports Server (NTRS)

    Spencer, B., Jr.; Fournier, R. H.

    1973-01-01

    An investigation was made in the high Mach number test section of the Langley Unitary Plan wind tunnel on a variable-geometry high hypersonic performance spacecraft concept at Mach numbers from 2.30 to 4.63. The basic lifting body is designed for hypersonic lift-drag ratio near 3.0. The variable-geometry feature is a single-pivot two-position high wing which is deployed at subsonic speeds to improve vehicle landing characteristics. For the present investigation the wing was maintained in a stowed position, and the effects of horizontal stabilizer dihedral, elevon control effectiveness, and the addition of either a conventional single vertical tail or dorsal-fin-type vertical stabilizers on the longitudinal and lateral-directional stability and control characteristics were studied.

  3. Passive microwave soil moisture research

    NASA Technical Reports Server (NTRS)

    Schmugge, T. J.; Oneill, P. E.; Wang, J. R.

    1985-01-01

    The AgRISTARS Soil Moisture Project has made significant progress in the quantification of microwave sensor capabilities for soil moisture remote sensing. The 21-cm wavelength has been verified to be the best single channel for radiometric observations of soil moisture. It has also been found that other remote sensing approaches used in conjunction with L-band passive data are more successful than multiple wavelength microwave radiometry in this application. AgRISTARS studies have also improved current understanding of noise factors affecting the interpretability of microwave emission data. The absorption of soil emission by vegetation has been quantified, although this effect is less important than absorption effects for microwave radiometry.

  4. Passive microwave soil moisture research

    NASA Technical Reports Server (NTRS)

    Schmugge, T.; Oneill, P. E.; Wang, J. R.

    1986-01-01

    During the four years of the AgRISTARS Program, significant progress was made in quantifying the capabilities of microwave sensors for the remote sensing of soil moisture. In this paper, a discussion is provided of the results of numerous field and aircraft experiments, analysis of spacecraft data, and modeling activities which examined the various noise factors such as roughness and vegetation that affect the interpretability of microwave emission measurements. While determining that a 21-cm wavelength radiometer was the best single sensor for soil moisture research, these studies demonstrated that a multisensor approach will provide more accurate soil moisture information for a wider range of naturally occurring conditions.

  5. Optimization of the performance characteristics in an irreversible magnetic Ericsson refrigeration cycle

    NASA Astrophysics Data System (ADS)

    Xia, Z. R.; Ye, X. M.; Lin, G. X.; Brück, E.

    2006-05-01

    A general model of an irreversible Ericsson refrigeration cycle employing paramagnetic materials as the working substance is presented, in which multi-irreversibilities such as finite-rate heat transfer, regenerative loss, heat leak, efficiency of regenerator and internal irreversibility resulting from magnetic working substances are taken into account. On the basis of the general thermodynamic properties of paramagnetic materials and the optimal-control theory, the optimal mathematical expressions of cooling load, coefficient of performance and power input of the irreversible Ericsson refrigeration cycle using paramagnetic materials as the working substance are derived. By means of a numerical approach, the influence of the heat leak, the internal irreversibility, the efficiency of regenerator, the ratio of the magnetic fields on the cyclic performance characteristics of the refrigeration cycle are revealed and discussed in detail. Some important performance bounds, e.g. the maximum cooling load and the corresponding coefficient of performance, the maximum coefficient of performance and the corresponding cooling load, are determined and evaluated. Furthermore, several special cases may be deduced from the primary results in this paper. The conclusions obtained in the present paper are more general and useful than those existing in literature and can provide some new important information for the optimal design and performance improvement of magnetic refrigerators.

  6. Influence of soil texture, moisture, and surface cracks on the performance of a root-feeding flea beetle, Longitarsus bethae (Coleoptera: Chrysomelidae), a biological control agent for Lantana camara (Verbenaceae).

    PubMed

    Simelane, David O

    2007-06-01

    Laboratory studies were conducted to determine the influence of soil texture, moisture and surface cracks on adult preference and survival of the root-feeding flea beetle, Longitarsus bethae Savini and Escalona (Coleoptera: Chrysomelidae), a natural enemy of the weed, Lantana camara L. (Verbenaceae). Adult feeding, oviposition preference, and survival of the immature stages of L. bethae were examined at four soil textures (clayey, silty loam, sandy loam, and sandy soil), three soil moisture levels (low, moderate, and high), and two soil surface conditions (with or without surface cracks). Both soil texture and moisture had no influence on leaf feeding and colonization by adult L. bethae. Soil texture had a significant influence on oviposition, with adults preferring to lay on clayey and sandy soils to silty or sandy loam soils. However, survival to adulthood was significantly higher in clayey soils than in other soil textures. There was a tendency for females to deposit more eggs at greater depth in both clayey and sandy soils than in other soil textures. Although oviposition preference and depth of oviposition were not influenced by soil moisture, survival in moderately moist soils was significantly higher than in other moisture levels. Development of immature stages in high soil moisture levels was significantly slower than in other soil moisture levels. There were no variations in the body size of beetles that emerged from different soil textures and moisture levels. Females laid almost three times more eggs on cracked than on noncracked soils. It is predicted that clayey and moderately moist soils will favor the survival of L. bethae, and under these conditions, damage to the roots is likely to be high. This information will aid in the selection of suitable release sites where L. bethae would be most likely to become established.

  7. Generic anthropometric and performance characteristics among elite adolescent boys in nine different sports.

    PubMed

    Pion, Johan; Segers, Veerle; Fransen, Job; Debuyck, Gijs; Deprez, Dieter; Haerens, Leen; Vaeyens, Roel; Philippaerts, Renaat; Lenoir, Matthieu

    2015-01-01

    The aim of the present study was to evaluate the Flemish Sports Compass (FSC), a non-sport-specific generic testing battery. It was hypothesised that a set of 22 tests would have sufficient discriminant power to allocate athletes to their own sport based on a unique combination of test scores. First, discriminant analyses were applied to the 22 tests of anthropometry, physical fitness and motor coordination in 141 boys under age 18 (16.1 ± 0.8 years) and post age at peak height velocity (maturity offset = 2.674 ± 0.926) from Flemish Top Sport Academies for badminton, basketball, gymnastics, handball, judo, soccer, table tennis, triathlon and volleyball. Second, nine sequential discriminant analyses were used to assess the ability of a set of relevant performance characteristics classifying participants and non-participants for the respective sports. Discriminant analyses resulted in a 96.4% correct classification of all participants for the nine different sports. When focusing on relevant performance characteristics, 80.1% to 97.2% of the total test sample was classified correctly within their respective disciplines. The discriminating characteristics were briefly the following: flexibility in gymnastics, explosive lower-limb strength in badminton and volleyball, speed and agility in badminton, judo, soccer and volleyball, upper-body strength in badminton, basketball and gymnastics, cardiorespiratory endurance in triathletes, dribbling skills in handball, basketball and soccer and overhead-throwing skills in badminton and volleyball. The generic talent characteristics of the FSC enable the distinction of adolescent boys according to their particular sport. Implications for talent programmes are discussed.

  8. Terrestrial precipitation and soil moisture: A case study over southern Arizona and data development

    NASA Astrophysics Data System (ADS)

    Stillman, Susan

    Quantifying climatological precipitation and soil moisture as well as interannual variability and trends requires extensive observation. This work focuses on the analysis of available precipitation and soil moisture data and the development of new ways to estimate these quantities. Precipitation and soil moisture characteristics are highly dependent on the spatial and temporal scales. We begin at the point scale, examining hourly precipitation and soil moisture at individual gauges. First, we focus on the Walnut Gulch Experimental Watershed (WGEW), a 150 km2 area in southern Arizona. The watershed has been measuring rainfall since 1956 with a very high density network of approximately 0.6 gauges per km2. Additionally, there are 19 soil moisture probes at 5 cm depth with data starting in 2002. In order to extend the measurement period, we have developed a water balance model which estimates monsoon season (Jul-Sep) soil moisture using only precipitation for input, and calibrated so that the modeled soil moisture fits best with the soil moisture measured by each of the 19 probes from 2002-2012. This observationally constrained soil moisture is highly correlated with the collocated probes (R=0.88), and extends the measurement period from 10 to 56 years and the number of gauges from 19 to 88. Then, we focus on the spatiotemporal variability within the watershed and the ability to estimate area averaged quantities. Spatially averaged precipitation and observationally constrained soil moisture from the 88 gauges is then used to evaluate various gridded datasets. We find that gauge-based precipitation products perform best followed by reanalyses and then satellite-based products. Coupled Model Intercomparison Project Phase 5 (CMIP5) models perform the worst and overestimate cold season precipitation while offsetting the monsoon peak precipitation forward or backward by a month. Satellite-based soil moisture is the best followed by land data assimilation systems and

  9. Performance characteristics of the 12 GHz, 200 watt Transmitter Experiment Package for CTS. [Communication Technology Satellite

    NASA Technical Reports Server (NTRS)

    Miller, E. F.; Fiala, J. L.; Hansen, I. G.

    1975-01-01

    Measured performance characteristics from ground test of the Transmitter Experiment Package (TEP) for the Communications Technology Satellite are presented. The experiment package consists of a 200 W Output Stage Tube (OST) powered by a Power Processing System (PPS). Descriptions of both the PPS and OST are given. The PPS provides the necessary voltages with a measured dc/dc conversion efficiency of 89 per cent. The OST, a traveling wave tube with multiple collectors, has a saturated rf output power of 224 W and operates at an overall efficiency exceeding 40 per cent over an 85 MHz bandwidth at 12 GHz. OST performance given includes frequency response, saturation characteristics, group delay, AM to PM conversion, intermodulation distortion, and two channel gain suppression. Single and dual channel FM video performance is presented. It was determined that for 12 MHz peak to peak frequency deviation on each channel, dual channel FM television signals can be transmitted through the TEP at 60 W, each channel, with 40 MHz channel spacing (center to center).

  10. Deployment and Performance Characteristics of 5-Foot Diameter Attached Inflatable Decelerators

    NASA Technical Reports Server (NTRS)

    1970-01-01

    Deployment and Performance Characteristics of 5-Foot Diameter (1.5m) Attached Inflatable Decelerators from Mach Numbers 2.2-4.4. Deployment characteristics and steady-state performance data were obtained over the Mach number range from 2.2 to 4.4 and at angles of attack from 0 degrees to l0 degrees. All attached inflatable decelerator (AID) models deployed successfully and exhibited flutter-free performance after deployment. Shock loads commonly associated with inflation of parachutes during deployment were not experienced. Force and moment data and ram-air pressure data were obtained throughout the Mach number range and at angles of attack from 0 degrees to l0 degrees. The high drag coefficient of 1.14 was in good agreement with the value predicted by the theory used in the design and indicated other AID shapes may be designed on a rational basis with a high degree of confidence. [Entire movie available on DVD from CASI as Doc ID 20070031006. Contact help@sti.nasa.gov

  11. Soil moisture responses to vapour pressure deficit in polytunnel-grown tomato under soil moisture triggered irrigation control

    NASA Astrophysics Data System (ADS)

    Goodchild, Martin; Kühn, Karl; Jenkins, Dick

    2014-05-01

    The aim of this work has been to investigate soil-to-atmosphere water transport in potted tomato plants by measuring and processing high-resolution soil moisture data against the environmental driver of vapour pressure deficit (VPD). Whilst many researchers have successfully employed sap flow sensors to determine water uptake by roots and transport through the canopy, the installation of sap flow sensors is non-trivial. This work presents an alternative method that can be integrated with irrigation controllers and data loggers that employ soil moisture feedback which can allow water uptake to be evaluated against environmental drivers such as VPD between irrigation events. In order to investigate water uptake against VPD, soil moisture measurements were taken with a resolution of 2 decimal places - and soil moisture, air temperature and relative humidity measurements were logged every 2 minutes. Data processing of the soil moisture was performed in an Excel spread sheet where changes in water transport were derived from the rate of change of soil moisture using the Slope function over 5 soil moisture readings. Results are presented from a small scale experiment using a GP2-based irrigation controller and data logger. Soil moisture feedback is provided from a single SM300 soil moisture sensor in order to regulate the soil moisture level and to assess the water flow from potted tomato plants between irrigation events. Soil moisture levels were set to avoid drainage water losses. By determining the rate of change in soil moisture between irrigation events, over a 16 day period whilst the tomato plant was in flower, it has been possible to observe very good correlation between soil water uptake and VPD - illustrating the link between plant physiology and environmental conditions. Further data is presented for a second potted tomato plant where the soil moisture level is switched between the level that avoids drainage losses and a significantly lower level. This data

  12. A Continental Scale Assessment of SMOS Derived Soil Moisture over the United States

    NASA Astrophysics Data System (ADS)

    Sahoo, A. K.; Pan, M.; Wood, E. F.; Al Bitar, A.; Leroux, D.; Kerr, Y. H.

    2011-12-01

    There has been a range of spaceborne remote sensing sensors deployed during the last two decades to retrieve near surface (~ 0 - 2 cm) soil moisture. The retrieval techniques to derive satellite based soil moisture include either physically based algorithms (such as radiative transfer equations) or various indirect statistical algorithms. Soil Moisture and Ocean Salinity (SMOS) mission is the latest addition to those suits of spaceborne sensors which was launched in November 2009, and has been providing 1.4GHz (L-band) measurements since then. The advantage of using the L-band channel is its better surface emission characteristics, which allows expanded spatial coverage over denser vegetated surfaces and should improve the retrieved surface soil moisture estimates. The latter offers information that can be used to estimate deeper soil layer moisture conditions for many agricultural, hydrologic and climate applications. Prior to using the SMOS soil moisture (SM) retrievals for scientific applications, it is absolutely necessary to verify the quality of the data products. In this study, we assess the recently available SMOS 1.4 GHz based soil moisture retrievals for 2010 are assessed over the Continental United States (CONUS) region, along with soil moisture retrievals produced at Princeton University based on AMSR-E 10.7 GHz brightness temperatures using the Land Surface Microwave Emission Model (AMSR-E/LSMEM) and in-situ measurements from the Natural Resource Conservation Service's (NRCS) Soil Climate Analysis Network (SCAN). The assessment is carried out using a performance metric developed earlier by Crow and Zhan (2007), which calculates the ability of soil moisture estimates to correct errors in water balance predictions through a linear Kalman filter algorithm. Within the framework proposed by Crow and Zhan (2007), it is found that current SMOS retrievals, which are based mostly on default parameters in its retrieval algorithm, performs slightly worse than the

  13. Performance characteristics of mobile MOSFET dosimeter for kilovoltage X-rays used in image guided radiotherapy

    PubMed Central

    Kumar, A. Sathish; Singh, I. Rabi Raja; Sharma, S. D.; Ravindran, B. Paul

    2015-01-01

    The main objective of this study was to investigate the characteristics of metal oxide semiconductor field effect transistor (MOSFET) dosimeter for kilovoltage (kV) X-ray beams in order to perform the in vivo dosimetry during image guidance in radiotherapy. The performance characteristics of high sensitivity MOSFET dosimeters were investigated for 80, 90, 100, 110, 120, and 125 kV X-ray beams used for imaging in radiotherapy. This study was performed using Clinac 2100 C/D medical electron linear accelerator with on-board imaging and kV cone beam computed tomography system. The characteristics studied in this work include energy dependence, angular dependence, and linearity. The X-ray beam outputs were measured as per American Association of Physicists in Medicine (AAPM) TG 61 recommendations using PTW parallel plate (PP) ionization chamber, which was calibrated in terms of air kerma (Nk) by the National Standard Laboratory. The MOSFET dosimeters were calibrated against the PP ionization chamber for all the kV X-ray beams and the calibration coefficient was found to be 0.11 cGy/mV with a standard deviation of about ±1%. The response of MOSFET was found to be energy independent for the kV X-ray energies used in this study. The response of the MOSFET dosimeter was also found independent of angle of incidence for the gantry angles in the range of 0° to 360° in-air as well as at 3 cm depth in tissue equivalent phantom. PMID:26500397

  14. The seasonal variations in anthropometric and performance characteristics of elite inter county Gaelic football players.

    PubMed

    Kelly, Richard A; Collins, Kieran

    2017-02-13

    There is limited research assessing the anthropometric and performance variations in elite Gaelic football. The aim of the current study was to assess the anthropometric and performance characteristics of an elite inter-county squad within a season. Following ethical approval and informed consent 26 participants were assessed at the start of pre-season (November), following early in-season (January) and mid-season (March). Measurements included stature, body mass, sum of 8 skinfold sites (ΣSkf8), estimated body fat (bf%), squat jump (SJ) and countermovement jump (CMJ), 5-, 10- and 20- m sprint time, upper and lower body strength (1RM) and Yo-Yo intermittent recovery test 2 (Yo-Yo IR2). A multivariate analysis of variance (MANOVA) was used to determine seasonal and positional variations. Anthropometric variations were observed with an overall increase in participants' body mass and a concomitant decrease in ΣSkf8 and bf% (-21.5%, p = 0.002, η = 0.15; -1.43 %, p = 0.004, η = 0.13). Performance variations showed improvements in sprint time over 5- (p = 0.001, η = 0.19) and 10-m (p = 0.008, η = 0.11), SJ (p = 0.013, η = 0.1), CMJ (p = 0.013, η = 0.1) height and Yo-Yo IRT2 (p < 0.001, η = 0.34) noted from pre-season to mid-season. Significant anthropometric variations are observed between the pre-season and early in-season, meanwhile significant performance variations are observed between the pre-season and mid-season. Distinct positional variations are evident for both anthropometric and performance characteristics at all time points. Applied practitioners should consider these findings when implementing a seasonal training plan.

  15. Relationship between Musical Characteristics and Temporal Breathing Pattern in Piano Performance.

    PubMed

    Sakaguchi, Yutaka; Aiba, Eriko

    2016-01-01

    Although there is growing evidence that breathing is modulated by various motor and cognitive activities, the nature of breathing in musical performance has been little explored. The present study examined the temporal breath pattern in piano performance, aiming to elucidate how breath timing is related to musical organization/events and performance. In the experiments, the respiration of 15 professional and amateur pianists, playing 10 music excerpts in total (from four-octave C major scale, Hanon's exercise, J. S. Bach's Invention, Mozart's Sonatas, and Debussy's Clair de lune), was monitored by capnography. The relationship between breathing and musical characteristics was analyzed. Five major results were obtained. (1) Mean breath interval was shortened for excerpts in faster tempi. (2) Fluctuation of breath intervals was reduced for the pieces for finger exercise and those in faster tempi. Pianists showing large within-trial fluctuation also exhibited large inter-excerpt difference. (3) Inter-trial consistency of the breath patterns depended on the excerpts. Consistency was generally reduced for the excerpts that could be performed mechanically (i.e., pieces for finger exercise), but interestingly, one third of the participant showed consistent patterns for the simple scale, correlated with the ascending/descending sequences. (4) Pianists tended to exhale just after the music onsets, inhale at the rests, and inhibit inhale during the slur parts. There was correlation between breathing pattern and two-voice polyphonic structure for several participants. (5) Respiratory patterns were notably different among the pianists. Every pianist showed his or her own characteristic features commonly for various musical works. These findings suggest that breathing in piano performance depends not only on musical parameters and organization written in the score but also some pianist-dependent factors which might be ingrained to individual pianists.

  16. Relationship between Musical Characteristics and Temporal Breathing Pattern in Piano Performance

    PubMed Central

    Sakaguchi, Yutaka; Aiba, Eriko

    2016-01-01

    Although there is growing evidence that breathing is modulated by various motor and cognitive activities, the nature of breathing in musical performance has been little explored. The present study examined the temporal breath pattern in piano performance, aiming to elucidate how breath timing is related to musical organization/events and performance. In the experiments, the respiration of 15 professional and amateur pianists, playing 10 music excerpts in total (from four-octave C major scale, Hanon's exercise, J. S. Bach's Invention, Mozart's Sonatas, and Debussy's Clair de lune), was monitored by capnography. The relationship between breathing and musical characteristics was analyzed. Five major results were obtained. (1) Mean breath interval was shortened for excerpts in faster tempi. (2) Fluctuation of breath intervals was reduced for the pieces for finger exercise and those in faster tempi. Pianists showing large within-trial fluctuation also exhibited large inter-excerpt difference. (3) Inter-trial consistency of the breath patterns depended on the excerpts. Consistency was generally reduced for the excerpts that could be performed mechanically (i.e., pieces for finger exercise), but interestingly, one third of the participant showed consistent patterns for the simple scale, correlated with the ascending/descending sequences. (4) Pianists tended to exhale just after the music onsets, inhale at the rests, and inhibit inhale during the slur parts. There was correlation between breathing pattern and two-voice polyphonic structure for several participants. (5) Respiratory patterns were notably different among the pianists. Every pianist showed his or her own characteristic features commonly for various musical works. These findings suggest that breathing in piano performance depends not only on musical parameters and organization written in the score but also some pianist-dependent factors which might be ingrained to individual pianists. PMID:27516736

  17. Wearing knee wraps affects mechanical output and performance characteristics of back squat exercise.

    PubMed

    Lake, Jason P; Carden, Patrick J C; Shorter, Kath A

    2012-10-01

    The aim of this study was to investigate the effects of wearing knee wraps on mechanical output and performance characteristics of back squat exercise. Ten resistance trained men (back squat 1 repetition maximum [1RM]: 160.5 ± 18.4 kg) performed 6 single back squats with 80% 1RM, 3 wearing knee wraps, 3 without. Mechanical output was obtained from ground reaction force, performance characteristics from digitized motion footage obtained from a single high-speed digital camera. Wearing knee wraps led to a 39% reduction (0.09 compared with 0.11 m, p = 0.037) in horizontal barbell displacement that continued during the lifting phase. Lowering phase vertical impulse remained within 1% across conditions; however, the lowering phase was performed 45% faster (1.13 compared with 1.57 seconds). This demonstrated that vertical force applied to the center of mass during the lowering phase was considerably larger and was likely a consequence of the generation and storage of elastic energy within the knee wrap. Subsequent vertical impulse applied to the center of mass was 10% greater (192 compared with 169 N·s, p = 0.018). Mechanical work involved in vertically displacing the center of mass was performed 20% faster and was reflected by a 10% increase in peak power (2,121 compared with 1,841 W, p = 0.019). The elastic properties of knee wraps increased mechanical output but altered back squat technique in a way that is likely to alter the musculature targeted by the exercise and possibly compromise the integrity of the knee joint. Knee wraps should not be worn during the strength and condition process, and perceived weakness in the knee joint should be assessed and treated.

  18. Improving the performance of predicting users' subjective evaluation characteristics to reduce their fatigue in IEC.

    PubMed

    Wang, Shangfei; Takagi, Hideyuki

    2005-01-01

    Users' fatigue is the biggest technological hurdle facing Interactive Evolutionary Computation (IEC). This paper introduces the idea of "absolute scale" and "neighbour scale" to improve the performance of predicting users' subjective evaluation characteristics in IEC, and thus it will accelerate EC convergence and reduce users' fatigue. We experimentally evaluate the effect of the proposed method using two benchmark functions. The experimental results show that the convergence speed of IEC using the proposed predictor, which learns from absolute evaluation data, is much faster than the conventional one, which learns from relative data, especially in early generations. Also, IEC with predictors that use recent data are more effective than those which use all past data.

  19. Characteristics and performance of the ESTEC large space simulator cryogenic system

    NASA Technical Reports Server (NTRS)

    Amlinger, H.; Bosma, S. J.

    1986-01-01

    The final concept and performance characteristics of the Large Space Simulator (LSS) at ESTEC, The Netherlands are discussed. The LSS cryogenics system has proven its operational capabilities under simulated heat load conditions and provides sufficient margin for future elevated requirements. The acceptance test proved that nominal operating pressures can be lower than the design parameters, providing increased system safety and reliability. The ease of access for repair and the incorporated redundancy will limit system downtime. Finally, the system design resulted in a low consumption of LN sub 2, which is an important factor in keeping the operational costs at a low level.

  20. Evaluation of the Performance Characteristics of BVA Resonators under Static and Dynamic Conditions.

    DTIC Science & Technology

    1981-08-01

    AO-AI05 064 FREQUENCY AND TIME SYSTEMS INC BEVERLY MA F/S 9/1. EVALUATION OF THE PERFORMANCE CHARACTERISTICS OF BVA RESONATORS--ETC(UI AUG 81 D A...HARACTERISTICS OF BVA ESONATORS UNDER STATIC AND YNAMIC CONDITIONS ecuency and Time Systems, Inc. DTIC ELECTE DonaW A. Emmons C APIROVED FOR PUlIC RELEASE... Time Systems, Inc. (FTS) relatinq to a novel quartz frequency control element, the BVA resonator. The pur- pose of the study has been to evaluate the

  1. Physical characteristics and performance of Japanese top-level American football players.

    PubMed

    Yamashita, Daichi; Asakura, Masaki; Ito, Yoshihiko; Yamada, Shinzo; Yamada, Yosuke

    2016-11-05

    This study aimed to compare the physical characteristics and performance between top-level non-professional football players in Japan and National Football League (NFL) Combine invited players and between top- and middle-level players in Japan in order to determine the factors that enhance performance in international and national competitions. One hundred sixty-eight American football players (>20 years) in Japan participated in an anthropometric (height and weight) and physical (vertical jump, long jump, 40-yard dash, pro-agility shuttle, three-cone drill, and bench press repetition test) measurement program based on the NFL Combine program to compete in the selection of candidates for the Senior World Championship. All players were categorized into one of three position groups based on playing position: skill players, big skill players, and linemen. Japanese players were additionally categorized into selected and non-selected players for the second tryout. The NFL Combine candidates had significantly better performance than selected Japanese players on all variables except on performance related to quickness among the three position groups. Compared with non-selected players, selected Japanese skill players had better performance in the 40-yard dash and bench press test and big skill players had better performance in the vertical jump, broad jump, and 40-yard dash. Selected and non-selected Japanese linemen were not different in any measurements. These results showed the challenges in American football in Japan, which include not only improving physical performance of top-level players, but also increasing the number of football players with good physical performance.This is an open-access article distributed under the terms of the Creative Commons Attribution-Non Commercial-No Derivatives License 4.0 (CCBY-NC-ND) , where it is permissible to download and share the work provided it is properly cited. The work cannot be changed in any way or used commercially

  2. The Growth Performance, Carcass Characteristics, and Meat Quality of Egg-Type Male Growing Chicken and White-Mini Broiler in Comparison with Commercial Broiler (Ross 308)

    PubMed Central

    Kim, Hyun-Wook; Kim, Cheon-Jei; Kim, Eun-Jib; Kim, Hee-Sung

    2014-01-01

    The present study was conducted to compare the growth performance, carcass characteristics, and meat quality of the egg-type male growing chicken (EM), white-mini broiler (WB), and commercial broiler (Ross 308, CB). A total of 360 1-d-old chicks were reared together using a completely randomized design with 4 replicates for each group under the identical feeding and rearing conditions. The ADG and gain:feed were the highest in CB, intermediate in WB, and the lowest in EM (p<0.05), and the live and carcass weights of CB and EM were significantly higher than those of WB (p<0.05). The pH of breast meat from WB and CB was significantly higher (p<0.05) than that from EM with a similar body weight. The EM had the lowest moisture (p<0.05) and the highest protein content (p<0.05), whereas the fat and ash contents were not different among groups. The mystiric acid (C14:0), palmitoleic acid (C16:1 ω7), and oleic acid (C18:1 ω9) levels were significantly higher in breast meat from CB (p<0.05). The monounsaturated fatty acid (MUFA) content showed the highest (p<0.05) levels in CB. In contrast, the polyunsaturated fatty acid (PUFA) contents of breast meat, including linoleic acid (C18:2 ω6) and arachidonic acid (C20:4 ω6), were higher (p<0.05) in EM and WB than in CB. In conclusion, the EM and WB had less growth performances in comparison with CB, but they each had some unique features (taste, flavor, and physiological characteristics) when raised under the identical rearing and feeding conditions. PMID:26761496

  3. The Integration of SMOS Soil Moisture in a Consistent Soil Moisture Climate Record

    NASA Astrophysics Data System (ADS)

    de Jeu, Richard; Kerr, Yann; Wigneron, Jean Pierre; Rodriguez-Fernandez, Nemesio; Al-Yaari, Amen; van der Schalie, Robin; Dolman, Han; Drusch, Matthias; Mecklenburg, Susanne

    2015-04-01

    Recently, a study funded by the European Space Agency (ESA) was set up to provide guidelines for the development of a global soil moisture climate record with a special emphasis on the integration of SMOS. Three different data fusion approaches were designed and implemented on 10 year passive microwave data (2003-2013) from two different satellite sensors; the ESA Soil Moisture Ocean Salinity Mission (SMOS) and the NASA/JAXA Advanced Scanning Microwave Radiometer (AMSR-E). The AMSR-E data covered the period from January 2003 until Oct 2011 and SMOS data covered the period from June 2010 until the end of 2013. The fusion approaches included a neural network approach (Rodriguez-Fernandez et al., this conference session HS6.4), a regression approach (Wigneron et al., 2004), and an approach based on the baseline algorithm of ESAs current Climate Change Initiative soil moisture program, the Land Parameter Retrieval Model (Van der Schalie et al., this conference session HS6.4). With this presentation we will show the first results from this study including a description of the different approaches and the validation activities using both globally covered modeled datasets and ground observations from the international soil moisture network. The statistical validation analyses will give us information on the temporal and spatial performance of the three different approaches. Based on these results we will then discuss the next steps towards a seamless integration of SMOS in a consistent soil moisture climate record. References Wigneron J.-P., J.-C. Calvet, P. de Rosnay, Y. Kerr, P. Waldteufel, K. Saleh, M. J. Escorihuela, A. Kruszewski, 'Soil Moisture Retrievals from Bi-Angular L-band Passive Microwave Observations', IEEE Trans. Geosc. Remote Sens. Let., vol 1, no. 4, 277-281, 2004.

  4. Effects of atmospheric moisture on rock resistivity.

    NASA Technical Reports Server (NTRS)

    Alvarez, R.

    1973-01-01

    This study examines the changes in resistivity of rock samples as induced by atmospheric moisture. Experiments were performed on samples of hematitic sandstone, pyrite, and galena. The sandstone underwent a change in resistivity of four orders of magnitude when it was measured in a vacuum of 500 ntorr and in air of 37% relative humidity. Pyrite and galena showed no variations in resistivity when they were measured under the same conditions. These results, plus others obtained elsewhere, indicate that rocks of the resistive type are affected in their electrical properties by atmospheric moisture, whereas rocks of the conductive type are not. The experimental evidence obtained is difficult to reconcile with a model of aqueous electrolytic conduction on the sample surface. It is instead suggested that adsorbed water molecules alter the surface resistivity in a manner similar to that observed in semiconductors and insulators.

  5. Instruments for measuring the amount of moisture in the air

    NASA Technical Reports Server (NTRS)

    Johnson, D. L.

    1978-01-01

    A summarization and discussion of the many systems available for measuring moisture in the atmosphere is presented. Conventional methods used in the field of meteorology and methods used in the laboratory are discussed. Performance accuracies, and response of the instruments were reviewed as well as the advantages and disadvantages of each. Methods of measuring humidity aloft by instrumentation onboard aircraft and balloons are given, in addition to the methods used to measure moisture at the Earth's surface.

  6. Thermal performance of multilayer insulations. [gas evacuation characteristics of three selected multilayer insulation composites

    NASA Technical Reports Server (NTRS)

    Keller, C. W.; Cunnington, G. R.; Glassford, A. P.

    1974-01-01

    Experimental and analytical studies were conducted in order to extend previous knowledge of the thermal performance and gas evacuation characteristics of three selected multilayer insulation (MLI) composites. Flat plate calorimeter heat flux measurements were obtained for 20- and 80- shield specimens using three representative layer densities over boundary temperatures ranging from 39 K (70 R) to 389 K (700 R). Laboratory gas evacuation tests were performed on representative specimens of each MLI composite after initially purging them with helium, nitrogen, or argon gases. In these tests, the specimens were maintained at temperatures between 128 K (230 R) and 300 K (540 R). Based on the results of the laboratory-scale tests, a composite MLI system consisting of 112 unperforated, double-aluminized Mylar reflective shields and 113 water preconditioned silk net spacer pairs was fabricated and installed on a 1.22-m-(4-ft-) diameter calorimeter tank.

  7. Summary and analysis of performance and stability characteristics of the refan JT8D-109 engine

    NASA Technical Reports Server (NTRS)

    Sanberg, K. G.; Mogielnicki, R. M.; Davis, J. C.; Scaramella, V. M.

    1975-01-01

    The refan JT8D-109 performance and stability characteristics are reported as determined from sea level testing, altitude testing, and DC-9 flight testing. The test results are summarized as follows: (1) TSFC at SLS achieved design goal of 12.66 percent reduction. (2) TSFC at altitude average cruise power 0.5 percent higher than design goal, (3) TSFC at altitude maximum cruise power 1.7-3.7 percent higher than design goal, (4) ground starting consistent with JT8D-9 base engine, (5) successful flight starts without starter assist, (6) transient surge margin equivalent to JT8D-9, (7) stable engine operation with inlet distortion, and (8) stable engine operation during snap acceleration and deceleration. A flight idle setting is required for acceptable aborted-landing go-around acceleration time due to increase in low-rotor moment of inertia, and a performance improvement program should be conducted as part of any future certification program.

  8. Performance characteristics of the 12 GHz, 200 watt transmitter experiment package for CTS

    NASA Technical Reports Server (NTRS)

    Miller, E. F.; Fiala, J. L.; Hansen, I. G.

    1975-01-01

    The experiment package consists of a 200 W output stage tube (OST) powered by a power processing system (PPS). Descriptions of both the PPS and OST are given. The PPS provides the necessary voltages with a measured dc/dc conversion efficiency of 89 percent. The OST, a traveling wave tube with multiple collectors, has a saturated rf output power of 224 W and operates at an overall efficiency exceeding 40 percent over an 85 MHz bandwidth at 12 GHz. OST performance given includes frequency response, saturation characteristics, group delay, AM to PM conversion, inter-modulation distortion, and two channel gain suppression. Single and dual channel FM video performance is presented. It was determined that for 12 MHz peak to peak frequency deviation on each channel, dual channel FM television signals can be transmitted through the TEP at 60 W, each channel, with 40 MHz channel spacing (center to center).

  9. Predicting performance on the Columbia Card Task: effects of personality characteristics, mood, and executive functions.

    PubMed

    Buelow, Melissa T

    2015-04-01

    Behavioral measures of risky decision making are frequently used by researchers and clinicians; however, most of these measures are strongly associated with personality characteristics and state mood. The present study sought to examine personality, mood, and executive function predictors of performance on a newer measure of decision making, the Columbia Card Task (CCT). Participants were 489 undergraduate students who completed either the hot or cold version of the CCT as well as measures of state mood, impulsive sensation seeking, behavioral inhibition and activation systems, and executive functions (Wisconsin Card Sort Task; Digit Span). Results indicated that performance on the CCT-cold was predicted by Wisconsin Card Sort Task errors, and Digit Span predicted the CCT-hot. In addition, significant correlations were found between the CCT information use variables and the predictor variables. Implications for the utility of the CCT as a clinical instrument and its relationship with other measures of decision making are discussed.

  10. Aerodynamic Characteristics and Glide-Back Performance of Langley Glide-Back Booster

    NASA Technical Reports Server (NTRS)

    Pamadi, Bandu N.; Covell, Peter F.; Tartabini, Paul V.; Murphy, Kelly J.

    2004-01-01

    NASA-Langley Research Center is conducting system level studies on an-house concept of a small launch vehicle to address NASA's needs for rapid deployment of small payloads to Low Earth Orbit. The vehicle concept is a three-stage system with a reusable first stage and expendable upper stages. The reusable first stage booster, which glides back to launch site after staging around Mach 3 is named the Langley Glide-Back Booster (LGBB). This paper discusses the aerodynamic characteristics of the LGBB from subsonic to supersonic speeds, development of the aerodynamic database and application of this database to evaluate the glide back performance of the LGBB. The aerodynamic database was assembled using a combination of wind tunnel test data and engineering level analysis. The glide back performance of the LGBB was evaluated using a trajectory optimization code and subject to constraints on angle of attack, dynamic pressure and normal acceleration.

  11. Soil moisture estimation with limited soil characterization for decision making

    NASA Astrophysics Data System (ADS)

    Chanzy, A.; Richard, G.; Boizard, H.; Défossez, P.

    2009-04-01

    Ross model [Ross, 2003, Crevoisier et al, 2009]. To meet the decision support context, we evaluated the model ability of evaluating the soil moisture level in comparison to a moisture threshold that splits soil conditions into desirable and undesirable cases. This threshold depends on soil properties, the farming operation and equipment characteristics. We evaluate the rate of making good decisions using either the TEC model with and without soil moisture measurements or an empirical algorithm that simulate the decision processes followed by farmers, currently. This later is a reference case that allows appreciating the adding value of using soil water transfer models. We found a significant improvement with a rate of success, which increases from 65% with the reference case to 90% when using the model with soil moisture assimilation. Chanzy, A., Mumen M., Richard, G.. (2008), Accuracy of top soil moisture simulation using a mechanistic model with limited soil characterization, Water Resources Research, 44(3), W03432. Crevoisier, D., Chanzy, A., Voltz M. (2009), Evaluation of the Ross Fast Solution of Richards' Equation in Unfavourable Conditions for Standard Finite Element Methods, Advances in Water Ressources, In revision. Ross, P. J. (2003). Modeling soil water and solute transport - Fast, simplified numerical solutions. Agronomy Journal 95:1352-1361.

  12. Chocolate swelling during storage caused by fat or moisture migration.

    PubMed

    Svanberg, L; Lorén, N; Ahrné, L

    2012-11-01

    Quantification of swelling in dark chocolate subjected to fat or moisture migration was conducted using a new method based on confocal chromatic displacement sensor. The nondestructive method allowed for the height profile of dark chocolate samples to be scanned with a sensitivity of ± 2.8 μm. By performing multiple scans on each sample prior to and after being subjected to fat or moisture migration, the induced swelling could be quantified. Applying the new method on confectionery systems revealed that fat and moisture migration generate different swelling behavior/kinetics in dark chocolate during storage. Moisture migration resulted in a rapid swelling once a water activity of 0.8 was reached in the chocolate, probably by interaction and absorption of moisture by the particulate solids. Fat migration also affected the swelling behavior in chocolate, possibly by inducing phase transitions in the continuous cocoa butter phase. Migrating fat also proved to induce a more pronounced swelling than the same amount of absorbed moisture which further consolidated that the observed swelling caused by fat or moisture migration is a result of significant different mechanisms.

  13. A density-independent method for high moisture content measurement using a microstrip transmission line.

    PubMed

    Zhang, Yangjun; Okamura, Seichi

    2006-01-01

    This paper describes a method to measure high moisture content in materials from 190% to 350% on a dry weight basis. The method uses a microstrip transmission line, on which the material under test is overlaid. A parameter calculated from the attenuation and phase shift of the microwave signal is proposed to measure the moisture content. The experiments were performed on samples of sawdust, and the results show that the method is able to determine high moisture content independent of density. The standard error of calibration for the moisture content determination was 12.4% in the moisture content range from 190% to 350%.

  14. Analysis of Joist Masonry Moisture Content Monitoring

    SciTech Connect

    Ueno, Kohta

    2015-10-08

    There are many existing buildings with load-bearing mass masonry walls, whose energy performance could be improved with the retrofit of insulation. However, adding insulation to the interior side of walls of such masonry buildings in cold (and wet) climates may cause performance and durability problems. Some concerns, such as condensation and freeze-thaw have known solutions. But wood members embedded in the masonry structure will be colder (and potentially wetter) after an interior insulation retrofit. Moisture content & relative humidity were monitored at joist ends in historic mass brick masonry walls retrofitted with interior insulation in a cold climate (Zone 5A); data were collected from 2012-2015. Eleven joist ends were monitored in all four orientations. One limitation of these results is that the renovation is still ongoing, with limited wintertime construction heating and no permanent occupancy to date. Measurements show that many joists ends remain at high moisture contents, especially at north- and east-facing orientations, with constant 100% RH conditions at the worst cases. These high moisture levels are not conducive for wood durability, but no evidence for actual structural damage has been observed. Insulated vs. non-insulated joist pockets do not show large differences. South facing joists have safe (10-15%) moisture contents. Given the uncertainty pointed out by research, definitive guidance on the vulnerability of embedded wood members is difficult to formulate. In high-risk situations, or when a very conservative approach is warranted, the embedded wood member condition can be eliminated entirely, supporting the joist ends outside of the masonry pocket.

  15. Influence of steam-flaked corn moisture level and density on the site and extent of digestibility and feeding value for finishing cattle.

    PubMed

    Sindt, J J; Drouillard, J S; Titgemeyer, E C; Montgomery, S P; Loe, E R; Depenbusch, B E; Walz, P H

    2006-02-01

    Performance and digestibility experiments were conducted to determine the influence of moisture and flake density (FD) on the feeding value of steam-flaked corn (SFC). Dietary treatments consisted of finishing diets that contained 78% (DM basis) SFC that was tempered using 0, 6, or 12% moisture and processed to either 360 (SF28) or 310 (SF24) g/L. A 3 x 2 factorial arrangement of treatments was used. In Exp. 1, 78 steers were individually fed the respective treatments for 106 d. Moisture added during tempering tended (linear; P < 0.10) to increase starch availability but linearly decreased (P < 0.01) particle size. Decreasing flake density increased (P < 0.001) starch availability and also decreased (P < 0.001) particle size. Starch availability (P < 0.001), moisture (P < 0.001), and particle size (P = 0.05) were all greater for SFC that was collected the day of processing compared with SFC that had been processed the previous day. Steers fed diets containing SF24 consumed less DM as the moisture level increased, whereas steers fed diets containing SF28 had increased DMI as moisture level increased (moisture x FD interaction; P < 0.01). Nonetheless, ADG, G:F, and most carcass characteristics did not differ among treatments. In Exp. 2, 6 multicannulated Jersey steers were used in a 6 x 6 Latin square using the same treatments as in Exp. 1. Increasing moisture intake linearly decreased (P < 0.05) starch intakes. Organic matter and N intakes followed similar trends but were not different. Decreasing FD tended to increase (P < 0.10) microbial N flow to the duodenum and increased microbial efficiency (P < 0.05). Ruminal starch digestibility was 90.5%, and total tract starch digestibility was 99.5% without adding moisture or processing beyond SF28. Moisture additions to corn before steam flaking resulted in few differences in performance or digestibility, despite increases in starch availability that occurred as moisture increased. Processing corn more extensively than

  16. Effects of the Programmed Nutrition Beef Program on feedlot performance and carcass characteristics.

    PubMed

    Phelps, K J; Drouillard, J S; Jennings, J S; Depenbusch, B E; Van Bibber-Krueger, C L; Miller, K A; Vaughn, M A; Burnett, D D; Gonzalez, J M

    2015-03-01

    The objective of this study was to examine the effects of alternative finishing strategies on feedlot performance and carcass characteristics. Beef steers (64 pens; 8 steers/pen) were allocated to a randomized complete block design with a 2 × 2 factorial treatment arrangement. Factor 1 consisted of diet, with cattle fed a conventional (CON) diet or a diet consisting of Programmed Nutrition Beef Program (PN) supplements. The PN treatment included Programmed Nutrition Beef Receiver fed from d 1 through 20 of feeding and Programmed Nutrition Beef Finisher fed from d 21 to harvest. Factor 2 evaluated the presence (EGP+) or absence (EGP-) of exogenous growth promotants (ExGP) in the production system. Steers in the EGP+ treatments were initially implanted with Component E-S, reimplanted with Component TE-IS, and fed 400 mg·animal·dof ractopamine hydrochloride for the final 28 d before harvest. Steers were harvested on d 175, and strip loins were removed from 2 carcasses selected at random from each pen for transport to Kansas State University. One 1.27-cm-thick steak was removed from the anterior face for proximate and long-chain fatty acid analysis. There were no diet × ExGP interactions ( > 0.10) for feedlot performance except for DMI ( = 0.02). Steers in the PN/EGP+ treatment consumed more feed than all other treatments ( < 0.05). Both diet and ExGP affected DMI ( < 0.05), with PN and EGP+ steers consuming more feed than their contemporaries. Gain:feed and ADG were unaffected ( > 0.10) by diet, but ExGP improved these measures ( < 0.01). There were no diet × ExGP interactions for carcass characteristics except KPH fat and percentages of yield grade 3 and 4 carcasses ( < 0.05). Diet affected total incidence of liver abscesses because PN steers had a greater ( = 0.05) incidence of liver abscesses than steers in the CON treatment. Diet did not affect the other carcass characteristics ( > 0.10). Use of ExGP increased ( < 0.05) HCW, LM area, and 12th-rib fat but did

  17. Standardization based on human factors for 3D display: performance characteristics and measurement methods

    NASA Astrophysics Data System (ADS)

    Uehara, Shin-ichi; Ujike, Hiroyasu; Hamagishi, Goro; Taira, Kazuki; Koike, Takafumi; Kato, Chiaki; Nomura, Toshio; Horikoshi, Tsutomu; Mashitani, Ken; Yuuki, Akimasa; Izumi, Kuniaki; Hisatake, Yuzo; Watanabe, Naoko; Umezu, Naoaki; Nakano, Yoshihiko

    2010-02-01

    We are engaged in international standardization activities for 3D displays. We consider that for a sound development of 3D displays' market, the standards should be based on not only mechanism of 3D displays, but also human factors for stereopsis. However, we think that there is no common understanding on what the 3D display should be and that the situation makes developing the standards difficult. In this paper, to understand the mechanism and human factors, we focus on a double image, which occurs in some conditions on an autostereoscopic display. Although the double image is generally considered as an unwanted effect, we consider that whether the double image is unwanted or not depends on the situation and that there are some allowable double images. We tried to classify the double images into the unwanted and the allowable in terms of the display mechanism and visual ergonomics for stereopsis. The issues associated with the double image are closely related to performance characteristics for the autostereoscopic display. We also propose performance characteristics, measurement and analysis methods to represent interocular crosstalk and motion parallax.

  18. Effects of Elevated Crude Glycerin Concentrations on Feedlot Performance and Carcass Characteristics in Finishing Steers

    PubMed Central

    Chanjula, P.; Raungprim, T.; Yimmongkol, S.; Poonko, S.; Majarune, S.; Maitreejet, W.

    2016-01-01

    Twenty crossbred steers (400±40.1 kg of initial body weight) were used to assess the effects of a dietary supplementation with crude glycerin (CG) as a substitute for corn grain on performance, carcass traits, and meat quality. Four isocaloric and isonitrogenous diets were offered to the experimental animals (5 steers per treatment) for 121 days using randomized complete block design. The steers individually received dietary treatments containing 0%, 7%, 14%, and 21% of CG (88.91% pure) on a dry matter (DM) basis. The diets were offered ad libitum as total mixed rations twice daily. Weight gain and carcass traits were determined. At the end of the experimental period, the harvest data and carcass characteristics of the steers were recorded, and meat quality was determined. No significant effect of CG inclusion was observed in any of the growth performance and carcass characteristics traits studied. Also, there were no apparent effects of diets (p>0.05) on meat quality (pH, water holding capacity, drip losses, and cooking losses). The study concluded that CG could be used as a substitute for corn grain up to the level of approximately 21% of DM in the diets of finishing steers. PMID:26732331

  19. Altitude Performance and Operational Characteristics of an XT38-A-2 Turboprop Engine

    NASA Technical Reports Server (NTRS)

    Essig, R H; Schulze, F W

    1954-01-01

    The overall engine performance and the starting and windmilling characteristics of an XT38-A-2 turboprop engine have been investigated in the NACA Lewis altitude wind tunnel. The simulated flight conditions ranged from altitudes of 5000 to 45,000 feet at a flight Mach number of 0.30 and from Mach numbers of 0.301 to 0.557 at an altitude of 35,000 feet. The engine, equipped with a standard-area exhaust nozzle, was operated with independent control of fuel flow and propeller pitch; operation was thereby allowed over a wide range of engine conditions. Windmilling characteristics were obtained at altitudes of 15,000 feet and 35,000 feet. Analysis of the performance maps obtained at each flight condition revealed that both altitude and flight Mach number had a major effect on corrected engine variables. The large reductions in corrected shaft horsepower occurring when the altitude was increased were the result of decreases in compressor and turbine efficiencies. Windmilling engine starts were made at altitudes as high as 35,000 feet at an engine speed of 2000 rpm.

  20. Performance characteristics of countercurrent separation in analysis of natural products of agricultural significance.

    PubMed

    Friesen, J Brent; Pauli, Guido F

    2008-01-09

    A standard test mix consisting of 21 commercially available natural products of agricultural significance, termed the GUESSmix, was employed to measure the countercurrent chromatography performance characteristics of a very popular quaternary solvent system family made up of hexane-ethyl acetate-methanol-water (HEMWat). The polarity range of the GUESSmix combined with the elution-extrusion countercurrent chromatography (EECCC) technique and the newly developed reciprocal symmetry (ReS) and reciprocal shifted symmetry (ReSS) plots allow liquid-liquid distribution ratios ( K D) to be plotted for every compound eluted on a scale of zero to infinity. It was demonstrated that 16 of the 21 GUESSmix compounds are found in the optimal range of resolution (0.25 < K(D) < 16) of at least one HEMWat solvent system. The HEMWat solvent systems represented by the ratios 4:6:5:5, 4:6:4:6, and 3:7:4:6 possess the most densely populated optimal ranges of resolution for this standard mix. ReS plots have been shown to reveal the symmetrical reversibility of the EECCC method in reference to K(D) = 1. This study lays the groundwork for evaluation and comparison of solvent system families proposed in the literature, as well as the creation of new solvent system families with desired performance characteristics.

  1. Performance Characteristics of Hybrid Cycle Combined Absorption Heat Transformer and Absorption Refrigerating Machine

    NASA Astrophysics Data System (ADS)

    Iyoki, Shigeki; Otsuka, Shin-Ichi; Uemura, Tadashi

    In this paper, four kinds of hybrid cycles which combined the single-stage absorption refrigerating machine and four kinds of absorption heat transformers were proposed. It is possible that each of these hybrid cycles gets high temperature and low temperature from one cycle, simultaneously. As basic cycle of absorption heat transformer, the following were chosen: two kinds of single-stage absorption heat transformer and two kinds of two-stage absorption heat transformer. As a working medium-absorbent system, H2O-LiBr system, H2O-LiBr-LiNO3 system, H2O-LiBr-LiNO3-LiCl system, H2O-LiBr-C2H6O2 system and H2O-LiNO3-LiCl system were adopted. Using these five kinds of working medium-absorbent system, the performance characteristics of four kinds of hybrid cycle were simulated. And the performance characteristics of these cycles were compared.

  2. The association of layperson characteristics with the quality of simulated cardiopulmonary resuscitation performance

    PubMed Central

    Leary, Marion; Buckler, David G.; Ikeda, Daniel J.; Saraiva, Daiane A.; Berg, Robert A.; Nadkarni, Vinay M.; Blewer, Audrey L.; Abella, Benjamin S.

    2017-01-01

    BACKGROUND: Few studies have examined the association of layperson characteristics with cardiopulmonary resuscitation (CPR) provision. Previous studies suggested provider characteristics, including age and gender, were associated with CPR quality, particularly chest compression (CC) depth. We sought to determine the association of subject characteristics, including age and gender with layperson CPR quality during an unannounced simulated CPR event. We hypothesized shallower CC depth in females, and older-aged subjects. METHODS: As part of a larger multicenter randomized controlled trial of CPR training for cardiac patients’ caregivers, CPR skills were assessed 6 months after training. We analyzed associations between subject characteristics and CC rate, CC depth and no-flow time. Each variable was analyzed independently; significant predictors determined via univariate analysis were assessed in a multivariate regression model. RESULTS: A total of 521 laypersons completed a 6-month CPR skills assessment and were included in the analysis. Mean age was 51.8±13.7 years, 75% were female, 57% were Caucasian. Overall, mean CC rate was 88.5±25.0 per minute, CC depth was 50.9±2.0 mm, and mean no-flow time was 15.9±2.7 sec/min. CC depth decreased significantly in subjects >62 years (P<0.001). Male subjects performed deeper CCs than female subjects (47.5±1.7 vs. 41.9±0.6, P<0.001). CONCLUSION: We found that layperson age >62 years and female gender are associated with shallower CC depth. PMID:28123614

  3. Effects of crude glycerin on performance and carcass characteristics of finishing wether lambs.

    PubMed

    Gunn, P J; Neary, M K; Lemenager, R P; Lake, S L

    2010-05-01

    The objective of this study was to evaluate the effects of crude glycerin on performance and carcass characteristics in finishing wether lambs. Thirty black-faced, Suffolk-cross wether lambs (44.1 +/- 5.6 kg initial BW) were stratified and blocked by BW to 1 of 5 individually fed, isocaloric, isonitrogenous dietary treatments containing 0, 5, 10, 15, or 20% crude glycerin (88% pure) on a DM basis. Diets were fed once daily for ad libitum consumption and contained 15% chopped hay, approximately 25% dried distillers grains with solubles, and the specified treatment combination of cracked corn replaced with increasing amounts of crude glycerin. Wethers were weighed on 14-d intervals and were selected for slaughter when they reached an approximate 12th-rib fat depth of 0.51 cm (28 to 84 d on trial). Carcass characteristics were collected after a 48-h chill. Dry matter intake (linear, P = 0.004) and ADG (quadratic, P = 0.05) increased with increasing concentrations of glycerin in the diet during the first 14 d of the feeding period. Similarly, G:F tended to increase quadratically (P = 0.06) with increasing concentrations of crude glycerin in the diet during the first 14 d. However, there were no differences among treatments for final BW, days on feed, or cumulative DMI, cumulative ADG, and cumulative G:F (P >or= 0.11). Body wall thickness, dressing percent, HCW, LM area, flank streaking, leg score, conformation score, quality grade, yield grade, and percent boneless, closely trimmed retail cuts did not differ (P >or= 0.21). Adding up to 15% crude glycerin to finishing wether diets improved feedlot performance, particularly during the first 14 d, without any concomitant effect on carcass characteristics.

  4. Moisture Management in an Active Sportswear: Techniques and Evaluation—A Review Article

    NASA Astrophysics Data System (ADS)

    Senthilkumar, Mani; Sampath, M. B.; Ramachandran, T.

    2013-07-01

    Moisture management property is an important aspect of any fabric meant for active sportswear, which decides the comfort level of that fabric. Every human being sweats during different kinds of activities. An important feature of any fabric is how it transports this water out of the body, so as to make the wearer feel comfortable. This paper reports the concept of moisture management, various production techniques and evaluation of the moisture management characteristics on fabrics for active sportswear.

  5. Impact performance characteristics and modeling failure mechanisms of pultruded glass-graphite/epoxy hybrid composite beams

    NASA Astrophysics Data System (ADS)

    Kowsika, Murthy V. S. L. N.

    In this study, investigation was performed to comprehend the influence of hybridization on the impact performance in terms of the energy absorption characteristics and delamination fracture toughness of pultruded uni-directional composite materials. In order to evaluate the improvements/changes in the impact performance as a result of hybridization, apart from considering mono-fiber reinforced all-graphite and all-glass composites, several types of sandwich hybrid composites comprising of both graphite as well as glass fibers were included in the investigation. By keeping a constant overall fiber content, the lay-up sequence and the volume fraction of each type of fiber are altered in these pultruded composites to determine the trend in the mechanical behavior as a result of hybridization. The response of pultruded all-graphite, all-glass and glass-graphite hybrid composites is evaluated under two different incident impact energy conditions. A high incident energy (HIE) and a low incident energy (LIE) of impact are chosen to cause either complete fracture or induce delamination, respectively, for assessing the energy absorption characteristics (crashworthiness) and delamination fracture toughness of these composites. Finite element modeling is performed under static as well as dynamic loading conditions to simulate the stress distribution and to predict the energy absorption behavior of composites. Progressive damage due to sequential ply failure was modeled by utilizing the failure strain data obtained from static and HTE impact tests for analyzing the post-initial ply failure characteristics of pultruded composites. Finite element modeling was also performed to simulate delamination crack propagation at various levels through the thickness. The strain energy release rate computed using the virtual crack closure technique was monitored to determine the likelihood of delamination crack propagation with increment in crack growth for the pultruded composites under

  6. Combustion Characteristics and Propulsive Performance of Boron/Ammonium Perchlorate Mixtures in Microtubes

    NASA Astrophysics Data System (ADS)

    Liang, Daolun; Liu, Jianzhong; Zhou, Junhu; Wang, Yang; Yang, Yuxin

    2016-07-01

    A microthruster is used for the operation tracking and posture control of microsatellites. In this work, the combustion characteristics and propulsive performance of a boron/ammonium perchlorate (B/AP) propellant mixture for a microthruster were investigated. Amorphous B and AP were used in different mass ratios to prepare the propellant samples. A laser-ignition solid micropropulsion test system was set up, and a differential scanning calorimeter was used. The solid combustion products of the samples with good performance were collected. Microstructural and component analyses of the combustion products were performed. Various performance parameters, including the combustion temperature, combustion velocity, spectral intensity, ignition delay time, thrust, specific impulse, density specific impulse, and heat flow, changed with the fuel-oxidant ratio. The optimal fuel-oxidant mass ratio of the propellant samples was 40%, with a density specific impulse of 0.474 kg/m2•s and a maximum heat flow of 4.4913 mW/mg. Analysis of the combustion products revealed that the clearance between particles significantly diminished after combustion. During combustion, the AP completely decomposed, and a large amount of H3BO3, B2O3, and HBO2 was generated.

  7. Analysis of performance of prepubertal swimmers assessed from anthropometric and bio-energetic characteristics.

    PubMed

    Duché, P; Falgairette, G; Bedu, M; Lac, G; Robert, A; Coudert, J

    1993-01-01

    The relationship between anthropometric and bio-energetic data and timed performance over 50 to 400 m was studied in 25 young male swimmers [11.3 (SD 1) years]. Anthropometric measurements included height, body mass, body fat mass, body area, thoracic section area (Ats) thoracic circumferences, lengths of upper limb, bi-acromial and bi-iliac diameters. Maximal oxygen consumption (VO2max; direct method), maximal anaerobic power (W(an),max; force-velocity test) and mean power in 30 s sprint (W30 s; Wingate test) were also measured. Each of these bio-energetic variables was expressed in absolute terms, relating to body mass, body area and Ats. The stepwise regression method was used to determine contribution of the variables (anthropometric and/or bio-energetic) of the time achieved over the distance. The W30 s/Ats accounted for 46% of the time over 50 m (negative correlation). The VO2max/Ats and height were negatively correlated with the times of performances over 100 m, 200 m and 400 m, these two variables accounted for 71% to 77% of the performance. These results would indicate that even in young boys, anthropometric and bio-energetic characteristics are both important in swimming performance, particularly the bio-energetic variables expressed per Ats.

  8. Steady-state performance characteristics of latent heat TES/heat pump systems

    NASA Astrophysics Data System (ADS)

    Sigmon, T. W.

    1982-03-01

    Two projects are currently being completed that wholly or in part address various technical issues involved in the implementation of heat pump systems combined with thermal energy storage (TES). The first of these involves the determination of steady state performance characteristics for six generic TES/heat pump configurations and the comparison of the operational performance of these systems with other space heating and cooling TES technologies. Of these latter systems four are commercial or near commerical air conditioner or heat pump coupled TES systems. Steady state performance has been established for all systems. Operational performance and system life cycle cost has been determined for the six generic designs for a limited set of application conditions. The intent of the second project is to establish a reliable method of estimating seasonal energy use by TES/heat pump systems, to utilize this methodology to evaluate a large number of possible system designs, identify a small number of systems that merit more detailed analysis, and, to the extent possible, conduct these detailed studies.

  9. Advanced EMU electrochemically regenerable CO2 and moisture absorber module breadboard

    NASA Technical Reports Server (NTRS)

    Lee, M. C.; Sudar, M.; Chang, B. J.

    1988-01-01

    The applicability of the Electrochemically Regenerable Carbon Dioxide and Moisture Absorption Technology to the advanced extravehicular mobility unit was demonstrated by designing, fabricating, and testing a breadboard Absorber Module and an Electrochemical Regenerator. Test results indicated that the absorber module meets or exceeds the carbon dioxide removal requirements specified for the design and can meet the moisture removal requirement when proper cooling is provided. CO2 concentration in the vent gas stream was reduced from 0.52 to 0.027 kPa (3.9 to 0.20 mm Hg) for the full five hour test period. Vent gas dew point was reduced from inlet values of 294 K (69 F) to 278 K (41 F) at the outlet. The regeneration of expended absorbent was achieved by the electrochemical method employed in the testing. An absorbent bed using microporous hydrophobic membrane sheets with circulating absorbent is shown to be the best approach to the design of an Absorber Module based on sizing and performance. Absorber Module safety design, comparison of various absorbents and their characteristics, moisture absorption and cooling study and subsystem design and operation time-lining study were also performed.

  10. Detection of moisture and moisture related phenomena from Skylab. [Texas

    NASA Technical Reports Server (NTRS)

    Eagleman, J. R.; Pogge, E. C.; Moore, R. K. (Principal Investigator); Hardy, N.; Lin, W.; League, L.

    1973-01-01

    The author has identified the following significant results. This is a preliminary report on the ability to detect soil moisture variation from the two different sensors on board Skylab. Initial investigations of S190A and Sl94 Skylab data and ground truth has indicated the following significant results. (1) There was a decrease in Sl94 antenna temperature from NW to SE across the Texas test site. (2) Soil moisture increases were measured from NW to SE across the test site. (3) There was a general increase in precipitation distribution and radar echoes from NW to SE across the site for the few days prior to measurements. This was consistent with the soil moisture measurements and gives more complete coverage of the site. (4) There are distinct variations in soil textures over the test site. This affects the moisture holding capacity of soils and must be considered. (5) Strong correlation coefficients were obtained between S194 antenna temperature and soil moisutre content. As the antenna temperature decreases soil moisture increases. (6) The Sl94 antenna temperature correlated best with soil mositure content in the upper two inches of the soil. A correlation coefficient of .988 was obtained. (7) Sl90A photographs in the red-infrared region were shown to be useful for identification of Abilene clay loam and for determining the distribution of this soil type.

  11. Large scale measurements of soil moisture for validation of remotely sensed data: Georgia soil moisture experiment of 2003

    NASA Astrophysics Data System (ADS)

    Bosch, D. D.; Lakshmi, V.; Jackson, T. J.; Choi, M.; Jacobs, J. M.

    2006-05-01

    A series of soil moisture experiments were conducted in 2003 (SMEX03) to develop enhanced datasets necessary to improve spatiotemporal characterization of soil moisture and to enhance satellite-based retrievals. One component of this research was conducted in South Central Georgia of the US, from June 17th to July 21st (SMEX03 GA). This study analyzes measurements of soil moisture and temperature collected during SMEX03 GA. A network of in situ soil moisture measurement devices, established to provide validation data for the satellite collections and for long-term estimation of soil moisture conditions throughout the region, provided continuous measurements at 19 sites. Additional soil moisture and temperature validation data were collected daily from 49 field sites. These sites represented a diversity of land covers including forest, cotton, peanut, and pasture. Precipitation that occurred prior to June 22nd and from June 29th through July 2nd produced drying conditions from June 23rd to June 28th and gradual wetting from June 29th through July 2nd. Soil moisture in the top 0-1 cm of the soil was found to be more responsive to precipitation and to have greater variability than soil moisture at the 0-3 or 3-6 cm layers. Within different land covers, soil moisture followed the same trends, but varied with land use. Pasture sites were consistently the wettest while row-crop sites were normally the driest. Good agreement was observed between soil moisture measurements collected with the in situ network and the 49 SMEX sites. For the study period, soil moisture across the entire 50 km by 75 km region and five of the six 25 km by 25 km EASE-Grids demonstrated time stable characteristics. Time stability analysis and statistical tests demonstrated the in situ stations had a small dry bias as compared to the SMEX03 GA measurements. These results indicate that the in situ network will be a good resource for long-term calibration of remotely sensed soil moisture and provide

  12. Relationship between performance at different exercise intensities and skeletal muscle characteristics.

    PubMed

    Iaia, F Marcello; Perez-Gomez, Jorge; Thomassen, Martin; Nordsborg, Nikolai B; Hellsten, Ylva; Bangsbo, Jens

    2011-06-01

    The hypothesis investigated whether exercise performance over a broad range of intensities is determined by specific skeletal muscle characteristics. Seven subjects performed 8-10 exhaustive cycle trials at different workloads, ranging from 150 to 700 W (150 min to 20 s). No relationships between the performance times at high and low workloads were observed. A relationship (P < 0.05) was noticed between the percentage of fast-twitch x fibers and the exercise time at 579 ± 21 W (∼30 s; r(2) = 0.88). Capillary-to-fiber-ratio (r(2): 0.58-0.85) was related (P < 0.05) to exercise time at work intensities ranging from 395 to 270 W (2.5-21 min). Capillary density was correlated (r(2) = 0.68; P < 0.05) with the net rate of plasma K(+) accumulation during an ∼3-min bout and was estimated to explain 50-80% (P < 0.05) of the total variance observed in exercise performances lasting ∼30 s to 3 min. The Na(+)-K(+) pump β(1)-subunit expression was found to account for 13-34% (P < 0.05) during exhaustive exercise of ∼1-4 min. In conclusion, exercise performance at different intensities is related to specific physiological variables. A large distribution of fast-twitch x fibers may play a role during very intense efforts, i.e., ∼30 s. Muscle capillaries and the Na(+)-K(+) pump β(1)-subunit seem to be important determinants for performance during exhaustive high-intensity exercises lasting between 30 s and 4 min.

  13. 7 CFR 52.3185 - Moisture limits.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 2 2012-01-01 2012-01-01 false Moisture limits. 52.3185 Section 52.3185 Agriculture... United States Standards for Grades of Dried Prunes Moisture, Uniformity of Size, Defects § 52.3185 Moisture limits. Dried prunes shall not exceed the moisture limits for the applicable grades and kind...

  14. 7 CFR 52.3185 - Moisture limits.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 2 2011-01-01 2011-01-01 false Moisture limits. 52.3185 Section 52.3185 Agriculture... United States Standards for Grades of Dried Prunes Moisture, Uniformity of Size, Defects § 52.3185 Moisture limits. Dried prunes shall not exceed the moisture limits for the applicable grades and kind...

  15. 7 CFR 52.3185 - Moisture limits.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 2 2014-01-01 2014-01-01 false Moisture limits. 52.3185 Section 52.3185 Agriculture... CERTAIN OTHER PROCESSED FOOD PRODUCTS 1 United States Standards for Grades of Dried Prunes Moisture, Uniformity of Size, Defects § 52.3185 Moisture limits. Dried prunes shall not exceed the moisture limits...

  16. 7 CFR 52.3185 - Moisture limits.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 2 2013-01-01 2013-01-01 false Moisture limits. 52.3185 Section 52.3185 Agriculture... CERTAIN OTHER PROCESSED FOOD PRODUCTS 1 United States Standards for Grades of Dried Prunes Moisture, Uniformity of Size, Defects § 52.3185 Moisture limits. Dried prunes shall not exceed the moisture limits...

  17. Performance characteristics of single effect lithium bromide/ water absorption chiller for small data centers

    NASA Astrophysics Data System (ADS)

    Mysore, Abhishek Arun Babu

    A medium data center consists of servers performing operations such as file sharing, collaboration and email. There are a large number of small and medium data centers across the world which consume more energy and are less efficient when compared to large data center facilities of companies such as GOOGLE, APPLE and FACEBOOK. Such companies are making their data center facilities more environmental friendly by employing renewable energy solutions such as wind and solar to power the data center or in data center cooling. This not only reduces the carbon footprint significantly but also decreases the costs incurred over a period of time. Cooling of data center play a vital role in proper functioning of the servers. It is found that cooling consumes about 50% of the total power consumed by the data center. Traditional method of cooling includes the use of mechanical compression chillers which consume lot of power and is not desirable. In order to eliminate the use of mechanical compressor chillers renewable energy resources such as solar and wind should be employed. One such technology is solar thermal cooling by means of absorption chiller which is powered by solar energy. The absorption chiller unit can be coupled with either flat plate or evacuated tube collectors in order to achieve the required inlet temperature for the generator of the absorption chiller unit. In this study a modular data center is considered having a cooling load requirement of 23kw. The performance characteristics of a single stage Lithium Bromide/ water refrigeration is presented in this study considering the cooling load of 23kw. Performance characteristics of each of the 4 heat exchangers within the unit is discussed which helps in customizing the unit according to the users' specific needs. This analysis helps in studying the importance of different properties such as the effect of inlet temperatures of hot water for generator, inlet temperatures of cooling water for absorber and

  18. Development of a deterministic downscaling algorithm for remote sensing soil moisture footprint using soil and vegetation classifications

    NASA Astrophysics Data System (ADS)

    Shin, Yongchul; Mohanty, Binayak P.

    2013-10-01

    Soil moisture (SM) at the local scale is required to account for small-scale spatial heterogeneity of land surface because many hydrological processes manifest at scales ranging from cm to km. Although remote sensing (RS) platforms provide large-scale soil moisture dynamics, scale discrepancy between observation scale (e.g., approximately several kilometers) and modeling scale (e.g., few hundred meters) leads to uncertainties in the performance of land surface hydrologic models. To overcome this drawback, we developed a new deterministic downscaling algorithm (DDA) for estimating fine-scale soil moisture with pixel-based RS soil moisture and evapotranspiration (ET) products using a genetic algorithm. This approach was evaluated under various synthetic and field experiments (Little Washita-LW 13 and 21, Oklahoma) conditions including homogeneous and heterogeneous land surface conditions composed of different soil textures and vegetations. Our algorithm is based on determining effective soil hydraulic properties for different subpixels within a RS pixel and estimating the long-term soil moisture dynamics of individual subpixels using the hydrological model with the extracted soil hydraulic parameters. The soil moisture dynamics of subpixels from synthetic experiments matched well with the observations under heterogeneous land surface condition, although uncertainties (Mean Bias Error, MBE: -0.073 to -0.049) exist. Field experiments have typically more variations due to weather conditions, measurement errors, unknown bottom boundary conditions, and scale discrepancy between remote sensing pixel and model grid resolution. However, the soil moisture estimates of individual subpixels (from the airborne Electronically Scanned Thinned Array Radiometer (ESTAR) footprints of 800 m × 800 m) downscaled by this approach matched well (R: 0.724 to -0.914, MBE: -0.203 to -0.169 for the LW 13; R: 0.343-0.865, MBE: -0.165 to -0.122 for the LW 21) with the in situ local scale soil

  19. HYGROSCOPIC MOISTURE SORPTION KINETICS MODELING OF CORN STOVER AND ITS FRACTIONS

    SciTech Connect

    Igathinathane, C.; Pordesimo, L. O.; Womac, A.R.; Sokhansanj, Shahabaddine

    2009-01-01

    Corn stover, a major crop-based lignocellulosic biomass feedstock, is required to be at an optimum moisture content for efficient bioconversion processes. Environmental conditions surrounding corn stover, as in storage facilities, affect its moisture due to hygroscopic sorption or desorption. The measurement and modeling of sorption characteristics of corn stover and its leaf, husk, and stalk fractions are useful from utilization and storage standpoints, hence investigated in this article. A benchtop low-temperature humidity chamber provided the test environments of 20 C, 30 C, and 40 C at a constant 95% relative humidity. Measured sorption characteristics with three replications for each fraction were obtained from instantaneous sample masses and initial moisture contents. Observed sorption characteristics were fitted using exponential, Page, and Peleg models. Corn stover fractions displayed a rapid initial moisture uptake followed by a slower sorption rates and eventually becoming almost asymptotic after 25 h. Sorption characteristics of all corn stover fractions were significantly different (P < 0.0001) but not the effect of temperature (P > 0.05) on these fractions. The initial 30 min of sorption was found to be critical due to peak rates of sorption from storage, handling, and processing standpoints. The Page and Peleg models had comparable performance fitting the sorption curves (R2 = 0.995), however the exponential model (R2 = 0.91) was not found suitable because of patterned residuals. The Arrhenius type relationship (P < 0.05; R2 = 0.80) explained the temperature variation of the fitted sorption model parameters. The Peleg model fitted constants, among the sorption models studied, had the best fit (R2 = 0.93) with the Arrhenius relationship. A developed method of mass proportion, involving individual corn stover fraction dry matter ratios, predicted the whole corn stover sorption characteristics from that of its individual fractions. Sorption

  20. Vinasse added to the concentrate for fattening lambs: intake, animal performance, and carcass and meat characteristics.

    PubMed

    López-Campos, Ó; Bodas, R; Prieto, N; Frutos, P; Andrés, S; Giráldez, F J

    2011-04-01

    Twenty-four Merino lambs (mean BW 15.4 ± 0.13 kg, 6 to 7 wk old) were used to study the effects of the addition of 0 (control), 100 (V10), and 200 (V20) g of vinasse per kilgram of concentrate on intake, animal performance, biochemical blood profile, and carcass and meat characteristics. Lambs were assigned to 1 of 3 experimental diets and fed barley straw and the corresponding concentrate ad libitum. When the animals reached 25 kg of BW, a sample of blood was taken and the lambs were slaughtered. Feed intake, growth rate, biochemical blood profile, and carcass and meat characteristics were assessed. Lambs that received the concentrates with vinasse showed a reduced concentrate intake (linear contrast, P = 0.029) and ADG (linear contrast, P = 0.004) and an increased length of fattening period (linear contrast, P = 0.002) as well as feed:gain ratio (linear contrast P = 0.011). Vinasse enhanced ruminal pH (orthogonal contrast control vs. V10 + V20; P = 0.007). Plasma glucose concentrations declined in lambs fed vinasse (linear contrast, P = 0.003), whereas plasma urea concentration increased in animals fed vinasse (linear contrast, P = 0.036). The plasma concentrations of creatinine, triglycerides, and lactate and the enzyme profile studied (alkaline phosphate, alanine transaminase, glutamate oxal-acetate transaminase, γ-glutamyl transpeptidase, and lactate dehydrogenase) were not modified in response to vinasse inclusion. Lambs in the vinasse groups had less Na(+) and nitrate and greater K(+) and nitrite plasma concentrations (linear contrasts, P < 0.05). None of the carcass characteristics studied was affected by vinasse (P > 0.10). Meat chemical composition and characteristics were unaffected (P > 0.10), but shear force was greater for lambs that received vinasse (orthogonal contrast, control vs. V10 + V20, P = 0.007). The addition of 100 or 200 g vinasse/kg of concentrate for fattening lambs reduced feed intake and growth rate and increased the feed:gain ratio

  1. Quantifying surface moisture influences on aeolian transport (Invited)

    NASA Astrophysics Data System (ADS)

    Nield, J. M.; Wiggs, G. F.

    2010-12-01

    Surface moisture plays an important role in determining sediment availability and aeolian transport in beach systems but is heterogeneous both spatially and temporally. The development of rippled aeolian sand strips and protodunes are particularly influenced by surface moisture and are inherently transient and therefore difficult to quantify using traditional point based sampling methods. Furthermore, these structures are influenced by saltation cloud formation and mutual feedback associated with surface characteristics and transport dynamics. Here we utilise terrestrial laser scanning (ground-based LiDAR) to accurately decipher beach surface moisture during transport events, elucidating the switch between erosivity and erodibility as the surface dries and saltation intensity increases. This technology is particularly useful at identifying surface moisture within 0-10%, precisely the range over which the aeolian transport threshold is found. The resolution of the instrument allows millimeter accuracy of surface topography, percent accuracy of surface moisture with short (minutes) data collection periods, enabling the examination of multiple relationships at unprecedented detail. Surface roughness and saltation cloud height increase over moist areas, particularly as saltation intensity increases, whilst deposition on the wet/dry boundary is a function of feedback between the surface properties and aerodynamic attributes which ultimately contributes towards protodune formation. These observed feedback mechanisms are incorporated into a cellular automaton-based algorithm to examine sand strip development and surface moisture interaction. Simulations suggest the development of differing mobility between small-scale ripples and larger sand strip is a function of the response of the surface moisture to sediment deposition and erosion. Our findings highlight the inherent complexity of surface moisture and sediment transport interactions, and the need to incorporate their

  2. Measurement of Moisture Content in Sand, Slag, and Crucible Materials

    SciTech Connect

    Gray, J.H.

    1999-09-20

    The deinventory process at Rocky Flats (RFETS) has included moisture content measurements of sand, slag, and crucible (SSC) materials by performing weight loss measurements at 210 degrees - 220 degrees Celsius on representative samples prior to packaging for shipment. Shipping requirements include knowledge of the moisture content. Work at the Savannah River Technology Center (SRTC) showed that the measurement at 210 degrees - 220 degrees Celsius did not account for all of the moisture. The objective of the work in this report was to determine if the measurement at 210 degrees - 220 degrees Celsius at RFETS could be used to set upper bounds on moisture content and therefore, eliminate the need for RFETS to unpack, reanalyze and repack the material.

  3. Remotely sensed soil moisture input to a hydrologic model

    NASA Technical Reports Server (NTRS)

    Engman, E. T.; Kustas, W. P.; Wang, J. R.

    1989-01-01

    The possibility of using detailed spatial soil moisture maps as input to a runoff model was investigated. The water balance of a small drainage basin was simulated using a simple storage model. Aircraft microwave measurements of soil moisture were used to construct two-dimensional maps of the spatial distribution of the soil moisture. Data from overflights on different dates provided the temporal changes resulting from soil drainage and evapotranspiration. The study site and data collection are described, and the soil measurement data are given. The model selection is discussed, and the simulation results are summarized. It is concluded that a time series of soil moisture is a valuable new type of data for verifying model performance and for updating and correcting simulated streamflow.

  4. Soil moisture and strength index for earthwork construction quality control

    NASA Astrophysics Data System (ADS)

    Sawangsuriya, A.; Wachiraporn, S.; Sramoon, W.

    2015-09-01

    This paper presents the implementation of soil moisture and strength index measurements for earthwork construction quality control as well as a link between the in situ testing and structural property of earthen materials. Use of the convenient Dynamic Cone Penetrometer (DCP) in conjunction with conventional moisture-density measurements enhances quality control by achieving acceptable level of compaction, more uniform structural properties, and aids developing a controlled design parameter during the earthwork construction. Soil strength in term of DCP index normalized by the deviation of compaction moisture content from the optimum moisture content is proposed as performance criteria for a variety of engineered earth fills and special engineering assessment, prevention, and mitigation of geohazards e.g. earthen flood defense embankments.

  5. Heat transfer and thermal performance characteristics of heat exchanger tube fitted with perforated twisted-tapes

    NASA Astrophysics Data System (ADS)

    Thianpong, Chinaruk; Eiamsa-ard, Petpices; Eiamsa-ard, Smith

    2012-06-01

    Twisted tape insert was applied as a swirling flow generator for the passive heat transfer enhancement in the present work. The influences of the perforated twisted tapes (PTs) on the heat transfer, pressure loss and thermal performance characteristics were investigated experimentally. The experiments were performed under uniform wall heat flux condition by using PTs with y/W = 3, 4 and 5, d/W = 0.11, 0.14 and 0.17 and s/W = 0.4, 0.6 and 0.8 where y is a twist length, d is a perforation hole diameter, s is a spacing between holes (pitch) and W is a tape width. The experimental results reveal that Nusselt number increased with decreasing s/W and y/W and increasing d/W. For the present range, the maximum heat transfer was obtained by utilizing the tape with s/W = 0.4, d/W = 0.17 and y/W = 3, which is higher than those obtained from the plain tube with and without typical twisted tape by around 27.4 and 86.7%, respectively. In addition, the empirical correlations for Nusselt number, friction factor and thermal performance are also proposed in the present paper.

  6. Heat transfer and performance characteristics of axial cooling fans with downstream guide vanes

    NASA Astrophysics Data System (ADS)

    Terzis, Alexandros; Stylianou, Ioannis; Kalfas, Anestis I.; Ott, Peter

    2012-04-01

    This study examines experimentally the effect of stators on the performance and heat transfer characteristics of small axial cooling fans. A single fan impeller, followed by nine stator blades in the case of a complete stage, was used for all the experimental configurations. Performance measurements were carried out in a constant speed stage performance test rig while the transient liquid crystal technique was used for the heat transfer measurements. Full surface heat transfer coefficient distributions were obtained by recording the temperature history of liquid crystals on a target plate. The experimental data indicated that the results are highly affected by the flow conditions at the fan outlet. Stators can be beneficial in terms of pressure drop and efficiency, and thus more economical operation, as well as, in the local heat transfer distribution at the wake of the stator blades if the fan is installed very close to the cooling object. However, as the separation distance increases, enhanced heat transfer rate in the order of 25% is observed in the case of the fan impeller.

  7. Performance characteristics of lithium primary cells after controlled storage. [on-orbit for energy power supply

    NASA Technical Reports Server (NTRS)

    Deligiannis, F.; Shen, D. H.; Halpert, G.; Ang, V.; Donley, S.

    1991-01-01

    A program was initiated to investigate the effects of storage on the performance of lithium primary cells. Two types of liquid cathode cells were chosen to investigate these effects. The cell types included Li-SOCl2/BCX cells, Li-SO2 cells from two different manufacturers, and a small sample size of 8-year-old Li-SO2 cells. The following measurements are performed at each test interval: open circuit voltage, resistance and weight, microcalorimetry, ac impedance, capacity, and voltage delay. The authors examine the performance characteristics of these cells after one year of controlled storage at two temperatures (10 and 30 C). The Li-SO2 cells experienced little to no voltage and capacity degradation after one year storage. The Li-SOCl2/BCX cells exhibited significant voltage and capacity degradation after 30 C storage. Predischarging shortly prior to use appears to be an effective method of reducing the initial voltage drop. Studies are in progress to correlate ac impedance and microcalorimetry measurements with capacity losses and voltage delay.

  8. Morphological characteristics of adult male handball players considering five levels of performance and playing position.

    PubMed

    Massuça, Luís; Fragoso, Isabel

    2015-03-01

    This study aims 1--to describe and compare the anthropometric characteristics of male handball players from different levels of performance, and 2--to identify the morphological variables that allow differentiation of the level of performance for each individual playing position. A total of 212 male handball players (age, 23.6 ± 5.2 years) were included in this study, and divided into five levels of performance for comparison. The playing position of each player was recorded. All participants were tested during the 2008-2009 Portuguese handball season. Twenty-eight anthropometric measures were taken by a group of anthropometrics accredited by International Society of the Advance of Kinanthropometry. Body composition, fat mass and muscle mass were calculated from the equations proposed by Faulkner26, Yuhase28, Durnin and Womersley25, Jackson and Pollock29, Matiegka33, Heymsfield, McManus, Smith, Stevens and Nixon34, Martin, Spenst, Drinkwater and Clarys21, Doupe, Martin, Searle, Kriellaars and Giesbrecht35 and Lee, Wang, Heo, Ross, Janssen and Heymsfield36. The research findings showed that the morphological optimization is important to have success in handball.

  9. Performance characteristic of a Stirling refrigeration cycle in micro/nano scale

    NASA Astrophysics Data System (ADS)

    Nie, Wenjie; He, Jizhou; Du, Jianqiang

    2009-02-01

    The aim of the paper is to present the performance characteristics of a Stirling refrigeration cycle in micro/nano scale, in which the working substance of cycle is an ideal Maxwellian gas. Due to the quantum boundary effect on the gas particles confined in the finite domain, the cycle no longer possesses the condition of perfect regeneration. The inherent regenerative losses, the refrigeration heat and coefficient of performance (COP) of the cycle are derived. It is found that, for the micro/nano scaled Stirling refrigeration cycle devices, the refrigeration heat and COP of cycle all depend on the surface area of the system (boundary of cycle) besides the temperature of the heat reservoirs, the volume of system and other parameters, while for the macro scaled refrigeration cycle devices, the refrigeration heat and COP of cycle are independent of the surface area of the system. Variations of the refrigeration heat ratio rR and the COP ratio rε with the temperature ratio τ and volume ratio rV for the different surface area ratio rA are examined, which reveals the influence of the boundary of cycle on the performance of a micro/nano scaled Stirling refrigeration cycle. The results are useful for designing of a micro/nano scaled Stirling cycle device and may conduce to confirming experimentally the quantum boundary effect in the micro/nano scaled devices.

  10. Low level moisture from VAS

    NASA Technical Reports Server (NTRS)

    Hayden, C. M.

    1980-01-01

    Previous research and current opinion are too pessimistic concerning the capability of defining moisture fields from satellite measurements. The TIROS-N sounder is a close analogue to what will fly on GEOS-D and can be used to investigate the probable capability of VAS. Basically, there are three frequencies applied to sensing moisture in the troposphere. The ability of these three measurements to define the moisture pattern is assessed. It is certainly true that one cannot achieve the detail available with a radiosonde hygristor. Sharp discontinuities cannot be sensed by a passive sounder, especially since the measurement tends to "saturate" with the first moisture layer encountered. However, the satellite measurements demonstrate a high degree of skill in defining the horizontal gradient. Moisture "tongues" and "dry lines" are readily delineated with some, perhaps two layers, of vertical definition. These attributes allow both the calculation of important advective quantities as well as (in concert with the temperature sounding) a gross definition of the vertical stability. The skill is demonstrably commensurate with subsynoptic forecast models and perhaps even to regional scale models.

  11. Ingested hyaluronan moisturizes dry skin

    PubMed Central

    2014-01-01

    Hyaluronan (HA) is present in many tissues of the body and is essential to maintain moistness in the skin tissues, which contain approximately half the body’s HA mass. Due to its viscosity and moisturizing effect, HA is widely distributed as a medicine, cosmetic, food, and, recently marketed in Japan as a popular dietary supplement to promote skin moisture. In a randomized, double-blind, placebo-controlled clinical study it was found that ingested HA increased skin moisture and improved treatment outcomes for patients with dry skin. HA is also reported to be absorbed by the body distributed, in part, to the skin. Ingested HA contributes to the increased synthesis of HA and promotes cell proliferation in fibroblasts. These effects show that ingestion of HA moisturizes the skin and is expected to improve the quality of life for people who suffer from dry skin. This review examines the moisturizing effects of dry skin by ingested HA and summarizes the series of mechanisms from absorption to pharmacological action. PMID:25014997

  12. Skin moisturization mechanisms: new data.

    PubMed

    Bonté, F

    2011-05-01

    The main function of the skin is to protect the body against exogenous substances and excessive water loss. The skin barrier is located in the outermost layer of the skin, called the stratum corneum, which is composed of corneocytes, originating from the keratinocytes differentiation process, embedded in organized complex lipid domains. Moisturizing of the skin is recognized as the first anti-aging skin care. Skin moisturization is essential for its appearance, protection, complexion, softness and the reinforcement of its barrier properties against deleterious and exogenous environmental factors. The intrinsic water binding capacity of skin is not only due to the complex natural moisturizing factor present in corneocytes, but also to hyaluronic acid and a regulated water transport within the skin. Recent data shows that the water movements between the cells at the different levels of the epidermis are due to dedicated water and glycerol transport proteins named aquaporins. Their role in the skin moisturization is completed by corneodesmosomes and tight junctions. Water and pH are now shown to be of prime importance in the regulation of the epidermal enzymes linked to corneocytes desquamation and lipid synthesis. Furthermore, the level of moisturization of the skin is important in its protection against repeated exposure to various irritant agents or phenomena such as very frequent washing with strong tensioactive materials.

  13. Remote sensing of soil moisture

    NASA Technical Reports Server (NTRS)

    Schmugge, T.

    1976-01-01

    The surface emissivity and reflectivity of soil are strong functions of its moisture content. Changes in emissivity, observed by passive microwave techniques (radiometry), and changes in reflectivity, observed by active microwave techniques (radar), can provide information on the moisture content of the 0 to 5 cm surface layer. In addition, the thermal inertia of the surface layer, which can be remotely sensed by observing the diurnal range of surface temperature, is an indicator of soil moisture content. The thermal infrared approach to remote sensing of soil moisture has little utility in the presence of cloud cover, but provides soil moisture data at high spatial resolutions and thermal data which are a potentially useful indicator of crop status. Microwave techniques can penetrate cloud covers. The passive technique has been demonstrated by both aircraft and spacecraft instruments, but spatial resolution is limited by the size of the antenna which can be flown. Active microwave systems offer the possibility of better spatial resolution, but have yet to be demonstrated from aircraft or spacecraft platforms.

  14. Tool Use and Performance: Relationships between Tool- and Learner-Related Characteristics in a Computer-Based Learning Environment

    ERIC Educational Resources Information Center

    Juarez-Collazo, Norma A.; Elen, Jan; Clarebout, Geraldine

    2013-01-01

    It is still unclear on what and how tool and learner characteristics influence tool use and consequently performance in computer-based learning environments (CBLEs). This study examines the relationships between tool-related characteristics (tool presentation: non-/embedded tool and instructional cues: non-/explained tool functionality) and…

  15. An Online Premium? Characteristics and Performance of Online versus Face-to-Face Students in Principles of Microeconomics

    ERIC Educational Resources Information Center

    Dendir, Seife

    2016-01-01

    The author uses data from two Principles of Microeconomics courses to examine differences in characteristics and performance of online versus face-to-face students. The analysis indicates that even in a traditional institution, the two delivery modes may be serving students with distinctly different backgrounds and characteristics. In terms of…

  16. Heat Transfer Characteristics and Performance of a Spirally Coiled Heat Exchanger under Sensible Cooling Conditions

    NASA Astrophysics Data System (ADS)

    Wongwises, Somchai; Naphon, Paisarn

    In the present study, new experimental data on the heat transfer characteristics and the performance of a spirally coiled heat exchanger under sensible cooling conditions is presented. The spiral-coil heat exchanger consists of a steel shell and a spirally coiled tube unit. The spiral-coil unit consists of six layers of concentric spirally coiled tubes. Each tube is fabricated by bending a 9.27mm diameter straight copper tube into a spiral-coil of five turns. The innermost and outermost diameters of each spiral-coil are 67.7 and 227.6mm, respectively. Air and water are used as working fluids in shell side and tube side, respectively. A mathematical model based on the conservation of energy is developed to determine the heat transfer characteristics. There is a reasonable agreement between the results obtained from the experiment and those obtained from the model and a good agreement for the high air mass flow rate region. The results obtained from the parametric study are also discussed.

  17. Numerical investigation of the variable nozzle effect on the mixed flow turbine performance characteristics

    NASA Astrophysics Data System (ADS)

    Meziri, B.; Hamel, M.; Hireche, O.; Hamidou, K.

    2016-09-01

    There are various matching ways between turbocharger and engine, the variable nozzle turbine is the most significant method. The turbine design must be economic with high efficiency and large capacity over a wide range of operational conditions. These design intents are used in order to decrease thermal load and improve thermal efficiency of the engine. This paper presents an original design method of a variable nozzle vane for mixed flow turbines developed from previous experimental and numerical studies. The new device is evaluated with a numerical simulation over a wide range of rotational speeds, pressure ratios, and different vane angles. The compressible turbulent steady flow is solved using the ANSYS CFX software. The numerical results agree well with experimental data in the nozzleless configuration. In the variable nozzle case, the results show that the turbine performance characteristics are well accepted in different open positions and improved significantly in low speed regime and at low pressure ratio.

  18. High performance and transparent multilayer MoS2 transistors: Tuning Schottky barrier characteristics

    NASA Astrophysics Data System (ADS)

    Hong, Young Ki; Yoo, Geonwook; Kwon, Junyeon; Hong, Seongin; Song, Won Geun; Liu, Na; Omkaram, Inturu; Yoo, Byungwook; Ju, Sanghyun; Kim, Sunkook; Oh, Min Suk

    2016-05-01

    Various strategies and mechanisms have been suggested for investigating a Schottky contact behavior in molybdenum disulfide (MoS2) thin-film transistor (TFT), which are still in much debate and controversy. As one of promising breakthrough for transparent electronics with a high device performance, we have realized MoS2 TFTs with source/drain electrodes consisting of transparent bi-layers of a conducting oxide over a thin film of low work function metal. Intercalation of a low work function metal layer, such as aluminum, between MoS2 and transparent source/drain electrodes makes it possible to optimize the Schottky contact characteristics, resulting in about 24-fold and 3 orders of magnitude enhancement of the field-effect mobility and on-off current ratio, respectively, as well as transmittance of 87.4 % in the visible wavelength range.

  19. RUSAP: A computer program for the calculation of Roll-Up Solar Array Performance characteristics

    NASA Technical Reports Server (NTRS)

    Ross, R. G., Jr.; Coyner, J. V., Jr.

    1973-01-01

    RUSAP is a FORTRAN 4 computer program designed to determine the performance characteristics (power-to-weight ratio, blanket tension, structural member section dimensions, and resonant frequencies) of large-area, roll-up solar arrays of the single-boom, tensioned-substrate design. The program includes the determination of the size and weight of the base structure supporting the boom and blanket and the determination of the blanket tension and deployable boom stiffness needed to achieve the minimum-weight design for a specified frequency for the first mode of vibration. A complete listing of the program, a description of the theoretical background, and all information necessary to use the program are provided.

  20. Performance characteristics and some applications of the nitrogen oxide gas sensor

    SciTech Connect

    Hassan, S.S.M.; Tadros, F.S.

    1985-01-01

    The performance characteristics of nitrogen oxide gas sensor with regard to the origin of response, limit of detection, response time, influence of the membrane type, and selectivity have been systematically examined. Optimum conditions for direct potentiometric determination of as low as 0.1 ..mu..mol mL/sup -1/ nitrite are described and results with an average recovery of 98.2% (standard deviation +/- 0.3%) are obtained. The sensor is also used to monitor direct titration of micromole per liter quantities of primary aryl amines, hydrazines, and azide with sodium nitrite or sodium cobaltinitrite. Results with an average recovery of 98.3% (standard deviation +/- 1.3%) are obtainable without any significant interference from 1000-fold molar excess of amides, imides, anilides, tertiary amines, and quaternary ammonium salts. 24 references, 2 figures, 4 tables.

  1. System characteristics and performance evaluation of a trailer-scale downdraft gasifier with different feedstock.

    PubMed

    Balu, Elango; Chung, J N

    2012-03-01

    The main objective of this study is to investigate the thermal profiles of a trailer-scale gasifier in different zones during the course of gasification and also to elaborate on the design, characteristics and performance of the gasification system using different biomass feedstock. The purpose is to emphasize on the effectiveness of distributed power generation systems and demonstrate the feasibility of such gasification systems in real world scenarios, where the lingo-cellulosic biomass resources are widely available and distributed across the board. Experimental data on the thermal profiles with respect to five different zones in the gasifier and a comprehensive thermal-chemical equilibrium model to predict the syngas composition are presented in detail. Four different feedstock-pine wood, horse manure, red oak, and cardboard were evaluated. The effects of C, H, O content variations in the feedstock on the thermal profiles, and the efficiency and viability of the trailer-scale gasifier are also discussed.

  2. An extraction/enzymatic procedure for serum cholesterol measurement: evaluation of performance characteristics.

    PubMed

    Franzini, C; Luraschi, P

    1990-12-01

    The performance characteristics of an extraction/enzymatic procedure for serum cholesterol measurement were evaluated. The procedure is substantially derived from the accepted reference method as standardized by the Centers for Disease Control, substituting the enzymatic reaction for the Liebermann-Burchard reaction. Imprecision (CV) was consistently less than 1.5%, and accuracy was comparable to that of the definitive isotope dilution mass spectrometry method and the accepted reference method. Direct comparison of the enzymatic with the Liebermann-Burchard reaction, using a set of 50 human sera, revealed about -0.05 mmol/l constant bias of the former versus the latter, this being possibly due to higher specificity of the enzymatic reaction. As compared with the accepted reference method, the method described is characterized by higher practicability, the reagent being easier to prepare and to handle, and generating a more stable, chemically defined end-product.

  3. Relationships between muscle fibre characteristics and physical performance capacity in trained athletic boys.

    PubMed

    Mero, A; Jaakkola, L; Komi, P V

    1991-01-01

    The relationships between muscle fibre characteristics and the physical performance capacity of trained athletic boys (aged 11-13 years) were studied over 2 days. The subjects were divided into two groups according to muscle fibre distribution. The 'fast' group (FG) comprised 10 subjects (sprinters, weightlifters, tennis players) with more than 50% fast-twitch fibres (type II), and the 'slow' group (SG) comprised 8 subjects (endurance runners, tennis players, one weightlifter) with more than 50% slow-twitch fibres (type I) in their vastus lateralis muscle. The 'fast' group had 59.2 +/- 6.3% and the 'slow' group had 39.4 +/- 9.8% type II fibres. Other clear differences (P less than 0.05-0.01) between the groups were observed as regards reaction time, rate of force development and rise of the body's centre of gravity in the squatting jump. For these variables, the 'fast' group was superior to the 'slow' group. Muscle fibre distribution (% type II) correlated (P less than 0.05-0.01) negatively with reaction time. Muscle fibre area (% type II) correlated negatively with reaction time (P less than 0.05-0.001) and positively with chronological age (P less than 0.05) height (P less than 0.05), mass (P less than 0.001), serum testosterone (P less than 0.05), force production (P less than 0.05-0.01) and blood lactate (P less than 0.05) in the 60-s maximal anaerobic test. There were no significant correlations between muscle fibre characteristics and maximal oxygen uptake. The present study assumes that heredity partly affects the selection of sporting event. Growth, development and training are associated with muscle fibre area, which affects the physical performance capacity of the neuromuscular system in trained young boys.

  4. Animal performance and meat characteristics in steers reared in intensive conditions fed with different vegetable oils.

    PubMed

    Castro, T; Cabezas, A; De la Fuente, J; Isabel, B; Manso, T; Jimeno, V

    2016-03-01

    Enhancing the quality of beef meat is an important goal in terms of improving both the nutritional value for the consumer and the commercial value for producers. The aim of this work was to study the effects of different vegetable oil supplements on growth performance, carcass quality and meat quality in beef steers reared under intensive conditions. A total of 240 Blonde D' Aquitaine steers (average BW=293.7±38.88 kg) were grouped into 24 batches (10 steers/batch) and were randomly assigned to one of the three dietary treatments (eight batches per treatment), each supplemented with either 4% hydrogenated palm oil (PALM) or fatty acids (FAs) from olive oil (OLI) or soybean oil (SOY). No differences in growth performance or carcass quality were observed. For the meat quality analysis, a steer was randomly selected from each batch and the 6th rib on the left half of the carcass was dissected. PALM meat had the highest percentage of 16:0 (P<0.05) and the lowest n-6/n-3 polyunsaturated fatty acids (PUFA) ratio (P<0.05), OLI had the highest content of t11-18:1 (P<0.01) and c9,t11-18:2 (P<0.05) and SOY showed the lowest value of monounsaturated fatty acids (MUFA) (P<0.001), the highest percentage of PUFA (P<0.01) and a lower index of atherogenicity (P=0.07) than PALM. No significant differences in the sensory characteristics of the meat were noted. However, the results of the principal component analysis of meat characteristics enabled meat from those steers that consumed fatty acids from olive oil to be differentiated from that of steers that consumed soybean oil.

  5. Effects of Morphological Characteristics of Muscle Fibers on Porcine Growth Performance and Pork Quality

    PubMed Central

    Kim, Jun-Mo; Ryu, Youn Chul

    2016-01-01

    The aim of this study was to investigate the effects of morphological characteristics of porcine muscle fibers on growth performance, muscle fiber characteristics, and pork quality taken from the longissimus dorsi muscle. A total of 239 crossbred pigs (164 castrated males and 75 females) were used in this study. Experimental pigs were categorized by the total number of muscle fiber (TNF: High and Low) and cross sectional area of muscle fiber (CSAF: Large, Middle, and Small). Their combinations were classified into six groups (High-Large, HL; High-Middle, HM; High-Small, HS; Low-Large, LL; Low-Middle, LM; Low-Small, LS). The TNF and CSAF were significantly (p<0.05) correlated with growth rate and carcass productivity, while the only of the type I number had no meaningful relationships excluding the correlation with loin area (p<0.001). The proportion of type I area was positively correlated with pH45 min while the proportion of type IIB area was negatively correlated with pH45 min and pH24 h (p<0.05). Drip loss and protein denaturation had strong relationships with the proportion of type IIB number or area. The HL group exhibited the greatest growth performance. In addition, the HL group had significantly greater values in protein solubility than the other groups. In conclusion, this study suggest that high TNF combined to large CSAF improve the ultimate lean meat productivity and assure normal meat quality simultaneously with increased both proportion of number and area of type I, type IIA muscle fibers and lowered proportion of number and area of type IIB. PMID:27857533

  6. Moisture level has greatest impact on boiler design

    SciTech Connect

    Schwieger, B.

    1980-02-01

    An analysis of the principal characteristics of wood are suggested before work should begin on designing a wood-fired system. These characteristis should include moisture content, ash content, volatile matter, fixed carbon content and particle size as they influence the total energy content of the wood.

  7. Wet distillers grains plus solubles concentration in steam-flaked-corn-based diets: Effects on feedlot cattle performance, carcass characteristics, nutrient digestibility, and ruminal fermentation characteristics

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Two experiments were conducted to determine the effects of wet distiller's grains plus solubles (WDG; < 15% sorghum grain) concentration in steam-flaked corn- (SFC) based diets on feedlot performance, carcass characteristics, ruminal fermentation, and diet digestibility of feeedlt ocattle. In Experi...

  8. Effects of sorghum wet distillers grains plus solubles in steam-flaked corn-based finishing diets on steer performance, carcass characteristics, and digestibility characteristics

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Two studies were conducted to evaluate the effects of sorghum wet distillers grains (SWDGS) in finishing diets on steer performance, carcass characteristics, and nutrient digestibility. In Exp. 1, 240 steers (initial BW = 379 +/-1 kg) were fed steam-flaked corn (SFC)-based diets with or without 25%...

  9. THERMALLY SHIELDED MOISTURE REMOVAL DEVICE

    DOEpatents

    Miller, O.E.

    1958-08-26

    An apparatus is presented for removing moisture from the air within tanks by condensation upon a cartridge containing liquid air. An insulating shell made in two halves covers the cartridge within the evacuated system. The shell halves are hinged together and are operated by a system of levers from outside the tank with the motion translated through a sylphon bellows to cover and uncover the cartridge. When the condensation of moisture is in process, the insulative shell is moved away from the liquid air cartridge, and during that part of the process when there is no freezing out of moisture, the shell halves are closed on the cell so thnt the accumulated frost is not evaporated. This insulating shell greatly reduces the consumption of liquid air in this condensation process.

  10. Growth performance and carcass characteristics of Improvac-treated male pigs compared with barrows.

    PubMed

    Albrecht, Anna; Grosse Beilage, Elisabeth; Henning, Martina; Bekendorf, Torsten; Krieter, Joachim

    2012-01-01

    The present study assessed the effects of using Improvac (Pfizer Animal Health, Germany) on growth performance and meat characteristics in cross-bred male pigs. In addition average daily weight gain of immunised and surgically castrated males was estimated in order to demonstrate differences in growing patterns in these two treatment groups. The study was carried out in two identical batches. Pigs within batches (n = 446) were allocated to two different treatment groups: immunisation (IM) versus surgical castration (CM). Within treatment groups pigs were randomly assigned to two different diets (low- and high-lysine diet) in order to examine interactions of growth performance and castration technique. Vaccination was performed on the day of entry to the fattening unit and four to six weeks prior to slaughter. At the second vaccination IM-pigs showed significantly lower body weights than the control group (p < 0.05) in both batches. Throughout the whole fattening period CM-pigs tended to have a higher feed intake than IM-pigs while IM-pigs had a significantly lower (better) feed conversion ratio than CM-pigs (p < 0.05).The different lysine content of the diets had no coherent effect on any of the growth performance parameters analysed. Immunised pigs of both feeding groups and in both batches showed a tendency towards a lower carcass weight, back fat values and dressing percentages than surgically castrated pigs.The castration technique had no significant effect on meat quality parameters such as drip loss, shear force or cooking loss while intramuscular fat content (IMF) in immunised pigs fed high-lysine diets (IM(high)) tended to be higher than IMF in immunised pigs fed low-lysine diets (IM(low)). This effect was not seen in surgical castrates in either batch. Immunisation against GnRH offers a good approach to produce taint-free pork while ensuring boar-like growth for a large part of the fattening period.

  11. Ten minutes of dynamic stretching is sufficient to potentiate vertical jump performance characteristics.

    PubMed

    Turki, Olfa; Chaouachi, Anis; Drinkwater, Eric J; Chtara, Moktar; Chamari, Karim; Amri, Mohamed; Behm, David G

    2011-09-01

    The current literature recommends dynamic rather than static stretching for the athletic warm-up. Dynamic stretching and various conditioning stimuli are used to induce potentiation in subsequent athletic performance. However, it is unknown as to which type of activity in conjunction with dynamic stretching within a warm-up provides the optimal potentiation of vertical jump performance. It was the objective of the study to examine the possible potentiating effect of various types of conditioning stimuli with dynamic stretching. Twenty athletes participated in 6 protocols. All the experimental protocols included 10 minutes of dynamic stretching. After the dynamic stretching, the subjects performed a (a) concentric (DS/CON): 3 sets of 3 repetition maximum deadlift exercise; (b) isometric (DS/ISOM): 3 sets of 3-second maximum voluntary contraction back squats; (c) plyometric (DS/PLYO): 3 sets of 3 tuck jumps; (d) eccentric (DS/ECC): 3 modified drop jumps; (e) dynamic stretching only (DS), and (f) control protocol (CON). Before the intervention and at recovery periods of 15 seconds, 4, 8, 12, 16, and 20 minutes, the participants performed 1-2 maximal countermovement jumps. The DS and DS/CON protocols generally had a 95-99% likelihood of exceeding the smallest worthwhile change for vertical jump height, peak power, velocity and force. However, the addition of the deadlift to the DS did not augment the potentiating effect. Time-to-peak potentiation was variable between individuals but was most consistent between 3 and 5 minutes. Thus, the volume and the intensity associated with 10 minutes of dynamic stretching were sufficient to provide the potentiation of vertical jump characteristics. Additional conditioning activities may promote fatigue processes, which do not permit further potentiation.

  12. HIIT enhances endurance performance and aerobic characteristics more than high-volume training in trained rowers.

    PubMed

    Ní Chéilleachair, Niamh J; Harrison, Andrew J; Warrington, Giles D

    2016-07-20

    This study compared the effects of long slow distance training (LSD) with high-intensity interval training (HIIT) in rowers. Nineteen well-trained rowers performed three tests before and after an 8-week training intervention: (1) 2000 m time trial; (2) seven-stage incremental step test to determine maximum oxygen uptake ([Formula: see text]O2max), power output at [Formula: see text]O2max (W[Formula: see text]O2max), peak power output (PPO), rowing economy and blood lactate indices and (3) seven-stroke power-output test to determine maximal power output (Wmax) and force (Fmax). After baseline testing, participants were randomly assigned either to a HIIT or LSD group. The LSD comprised 10 weekly aerobic sessions. The HIIT also comprised 10 weekly sessions: 8 aerobic and 2 HIIT. The HIIT sessions comprised 6-8 × 2.5 min intervals at 100% PPO with recovery time based on heart rate (HR) returning to 70% HRmax. Results demonstrated that the HIIT produced greater improvement in 2000 m time trial performance than the LSD (effect size (ES) = 0.25). Moreover, the HIIT produced greater improvements in [Formula: see text]O2max (ES = 0.95, P = 0.035) and power output at lactate threshold (WLT) (ES = 1.15, P = 0.008). Eight weeks of HIIT performed at 100% PPO is more effective than LSD in improving performance and aerobic characteristics in well-trained rowers.

  13. Effect of membrane characteristics on the performance of membrane bioreactors for oily wastewater treatment.

    PubMed

    Mafirad, S; Mehrnia, M R; Sarrafzadeh, M H

    2011-01-01

    Influence of membrane material and pore size on the performance of a submerged membrane bioreactor (sMBR) for oily wastewater treatment was investigated. The sMBR had a working volume of about 19 L with flat sheet modules at the same hydrodynamic conditions. Five types of micro- and ultra-polymeric membranes containing cellulose acetate (CA), cellulose nitrate (CN), polyamide (PA), polyvinylidene difluoride (PVDF) and polyethersulfone (PES) were used and their filtration performance in terms of permeability, permeate quality and fouling intensity were evaluated. Characterization of the membranes was done by performing some analysis such as pore size distribution; contact angle and scanning electronic microscopy (SEM) microphotograph on all membranes. The quality of permeates from each membrane was identified by measuring chemical oxygen demand (COD). The results showed more irreversible fouling intensity for membranes with larger pore size which can be due to more permeation of bioparticles and colloids inside the pores. Membrane characteristics have a major role in the preliminary time of the filtration before cake layer formation so that the PA with the highest hydrophilicity had the lowest permeability decline by fouling in this period. Also, the PVDF and PES membranes had better performance according to better permeate quality in the preliminary time of the filtration related to smaller pore size and also their better fouling resistance and chemical stability properties. However, all membranes resulted in the same permeability and permeate quality after cake layer formation. An overall efficiency of about 95% in COD removal was obtained for oily wastewater treatment by the membranes used in this study.

  14. Structural Model for the Effects of Environmental Elements on the Psychological Characteristics and Performance of the Employees of Manufacturing Systems

    PubMed Central

    Realyvásquez, Arturo; Maldonado-Macías, Aidé Aracely; García-Alcaraz, Jorge; Cortés-Robles, Guillermo; Blanco-Fernández, Julio

    2016-01-01

    This paper analyzes the effects of environmental elements on the psychological characteristics and performance of employees in manufacturing systems using structural equation modeling. Increasing the comprehension of these effects may help optimize manufacturing systems regarding their employees’ psychological characteristics and performance from a macroergonomic perspective. As the method, a new macroergonomic compatibility questionnaire (MCQ) was developed and statistically validated, and 158 respondents at four manufacture companies were considered. Noise, lighting and temperature, humidity and air quality (THAQ) were used as independent variables and psychological characteristics and employees’ performance as dependent variables. To propose and test the hypothetical causal model of significant relationships among the variables, a data analysis was deployed. Results found that the macroergonomic compatibility of environmental elements presents significant direct effects on employees’ psychological characteristics and either direct or indirect effects on the employees’ performance. THAQ had the highest direct and total effects on psychological characteristics. Regarding the direct and total effects on employees’ performance, the psychological characteristics presented the highest effects, followed by THAQ conditions. These results may help measure and optimize manufacturing systems’ performance by enhancing their macroergonomic compatibility and quality of life at work of the employees. PMID:26742054

  15. Structural Model for the Effects of Environmental Elements on the Psychological Characteristics and Performance of the Employees of Manufacturing Systems.

    PubMed

    Realyvásquez, Arturo; Maldonado-Macías, Aidé Aracely; García-Alcaraz, Jorge; Cortés-Robles, Guillermo; Blanco-Fernández, Julio

    2016-01-05

    This paper analyzes the effects of environmental elements on the psychological characteristics and performance of employees in manufacturing systems using structural equation modeling. Increasing the comprehension of these effects may help optimize manufacturing systems regarding their employees' psychological characteristics and performance from a macroergonomic perspective. As the method, a new macroergonomic compatibility questionnaire (MCQ) was developed and statistically validated, and 158 respondents at four manufacture companies were considered. Noise, lighting and temperature, humidity and air quality (THAQ) were used as independent variables and psychological characteristics and employees' performance as dependent variables. To propose and test the hypothetical causal model of significant relationships among the variables, a data analysis was deployed. Results found that the macroergonomic compatibility of environmental elements presents significant direct effects on employees' psychological characteristics and either direct or indirect effects on the employees' performance. THAQ had the highest direct and total effects on psychological characteristics. Regarding the direct and total effects on employees' performance, the psychological characteristics presented the highest effects, followed by THAQ conditions. These results may help measure and optimize manufacturing systems' performance by enhancing their macroergonomic compatibility and quality of life at work of the employees.

  16. The Snellen human calorimeter revisited, re-engineered and upgraded: design and performance characteristics.

    PubMed

    Reardon, Francis D; Leppik, Kalle E; Wegmann, René; Webb, Paul; Ducharme, Michel B; Kenny, Glen P

    2006-08-01

    The measurement of whole body heat loss in humans and the performance characteristics of a modified Snellen whole body air calorimeter are described. Modifications included the location of the calorimeter in a pressurized room, control of operating temperature over a range of - 15 to + 35 degrees C, control of ambient relative humidity over a range of 20-65%, incorporation of an air mass flow measuring system to provide real time measurement of air mass flow through the calorimeter, incorporation of a constant load 'eddy current' resistance ergometer and an open circuit, expired gas analysis calorimetry system. The performance of the calorimeter is a function of the sensitivity, precision, accuracy and response time characteristics of the fundamental measurement systems including: air mass flow; thermometry and hygrometry. Calibration experiments included a calibration of the air mass flow sensor, the response of the thermometric measurement system for dry heat loss and the response of the hygrometric measurement system for evaporative heat loss. The air mass flow system was evaluated using standard differential temperature procedures to demonstrate linearity and sensitivity of the device. A novel procedure based on differential hygrometry was developed to ascertain the absolute calibration of air mass flow by resolving the unique system coefficient K. The results of the hygrometric calibration demonstrate the air mass flow response of the system is linear over the range of air mass flows from 6 to 15 kg min(-1). R(2) was 0.995. The average half response time (tR50) was 14.5 +/- 2.1 s. Similarly the results of the thermometric calibration demonstrate that the response of the apparatus is linear over the range of power input measured (coefficient of linearity R(2)=0.9997) with a precision of 0.72 W and an accuracy to within 0.36 W. The average (tR50) over all conditions was 6.0 +/- 1.9 min. In summary, modifications brought to the Snellen calorimeter have

  17. Size reduction of high- and low-moisture corn stalks by linear knife grid system

    SciTech Connect

    Womac, A.R.; Igathinathane, C.; Sokhansanj, Shahabaddine; Narayan, S.

    2009-04-01

    High- and low-moisture corn stalks were tested using a linear knife grid size reduction device developed for first-stage size reduction. The device was used in conjunction with a universal test machine that quantified shearing stress and energy characteristics for forcing a bed of corn stalks through a grid of sharp knives. No published engineering performance data for corn stover with similar devices are available to optimize performance; however, commercial knife grid systems exist for forage size reduction. From the force displacement data, mean and maximum ultimate shear stresses, cumulative and peak mass-based cutting energies for corn stalks, and mean new surface area-based cutting energies were determined from 4 5 refill runs at two moisture contents (78.8% and 11.3% wet basis), three knife grid spacings (25.4, 50.8, and 101.6 mm), and three bed depths (50.8, 101.6, and 152.4 mm). In general, the results indicated that peak failure load, ultimate shear stress, and cutting energy values varied directly with bed depth and inversely with knife grid spacing. Mean separation analysis established that high- and low-moisture conditions and bed depths 101.6 mm did not differ significantly (P < 0.05) for ultimate stress and cutting energy values, but knife grid spacing were significantly different. Linear knife grid cutting energy requirements for both moisture conditions of corn stalks were much smaller than reported cutting energy requirements. Ultimate shear stress and cutting energy results of this research should aid the engineering design of commercial scale linear knife gird size reduction equipment for various biomass feedstocks.

  18. Analysis of Performance of Jet Engine from Characteristics of Components II : Interaction of Components as Determined from Engine Operation

    NASA Technical Reports Server (NTRS)

    Goldstein, Arthur W; Alpert, Sumner; Beede, William; Kovach, Karl

    1949-01-01

    In order to understand the operation and the interaction of jet-engine components during engine operation and to determine how component characteristics may be used to compute engine performance, a method to analyze and to estimate performance of such engines was devised and applied to the study of the characteristics of a research turbojet engine built for this investigation. An attempt was made to correlate turbine performance obtained from engine experiments with that obtained by the simpler procedure of separately calibrating the turbine with cold air as a driving fluid in order to investigate the applicability of component calibration. The system of analysis was also applied to prediction of the engine and component performance with assumed modifications of the burner and bearing characteristics, to prediction of component and engine operation during engine acceleration, and to estimates of the performance of the engine and the components when the exhaust gas was used to drive a power turbine.

  19. Performance characteristics of a turbo expander substituted for expansion valve on air-conditioner

    SciTech Connect

    Cho, Soo-Yong; Cho, Chong-Hyun; Kim, Chaesil

    2008-09-15

    An experimental study is conducted on a small turbo expander which could be applied to the expansion process in place of expansion valves in refrigerator or air-conditioner to improve the cycle efficiency by recovering energy from the throttling process. The operating gas is HFC134a and the maximum cooling capacity of experiment apparatus is 32.7 kW. Four different turbo expanders are tested to find the performance characteristics of the turbo expander when they operate at a low partial admission rate. The partial admission rate is 1.70% or 2.37, and expanders are operated in the supersonic flow. In the experiment, pressure and temperature are measured at 10 different locations in the experimental apparatus. In addition to these measurements, output power at the turbo expander is measured through a generator installed on a rotor shaft with the rotational speed. Performance data of the turbo expander are obtained at many part load operations by adjusting the output power of the generator. A maximum of 15.8% total-to-static efficiency is obtained when the pressure ratio and the partial admission ratio are 2.37 and 1.70%, respectively. Experimental results show that the optimal velocity ratio decreases when the pressure ratio is decreased, and peak efficiencies, which are obtained at locally maximized efficiency depending on the operating condition, vary linearly against the subcooling temperature or the pressure ratio. (author)

  20. Drag Reduction and Performance Improvement of Hydraulic Torque Converters with Multiple Biological Characteristics.

    PubMed

    Chunbao, Liu; Li, Li; Yulong, Lei; Changsuo, Liu; Yubo, Zhang

    2016-01-01

    Fish-like, dolphin-like, and bionic nonsmooth surfaces were employed in a hydraulic torque converter to achieve drag reduction and performance improvement, which were aimed at reducing profile loss, impacting loss and friction loss, respectively. YJSW335, a twin turbine torque converter, was bionically designed delicately. The biological characteristics consisted of fish-like blades in all four wheels, dolphin-like structure in the first turbine and the stator, and nonsmooth surfaces in the pump. The prediction performance of bionic YJSW335, obtained by computational fluid dynamics simulation, was improved compared with that of the original model, and then it could be proved that drag reduction had been achieved. The mechanism accounting for drag reduction of three factors was also investigated. After bionic design, the torque ratio and the highest efficiencies of YJSW335 were both advanced, which were very difficult to achieve through traditional design method. Moreover, the highest efficiency of the low speed area and high speed area is 85.65% and 86.32%, respectively. By economic matching analysis of the original and bionic powertrains, the latter can significantly reduce the fuel consumption and improve the operating economy of the loader.

  1. Performance characteristics of gas analysis systems: what we know and what we need to know.

    PubMed

    Atkinson, G; Davison, R C R; Nevill, A M

    2005-02-01

    It is important that sources of variation in gas analysis measurements are identified and described in an accurate and informative manner. In this paper, we discussed the potential sources of error, which should be considered in any measurement study on gas analysis systems. We then covered how errors in various terms associated with gas laws propagate to outcome measurements of gas exchange to help quantify the relative importance of sources of error. Finally, we performed a literature survey to explore the statistical methods researchers have employed to arrive at conclusions on the performance characteristics of gas analysis methods. We found examples of excellent practice in the literature, but there were also gaps in the knowledge of error in gas analysis systems. Consequently, we supplied guidelines for future method comparison studies. These guidelines included (i) a sample size of at least 40 participants and the citation of confidence intervals, (ii) a description of the relationships between systematic and random errors and the size of measured value, (iii) the parallel examination of test-retest error within a method comparison study, and (iv) an a priori-made judgement on how much systematic and random error between methods is acceptable for practical applications. We stressed that this judgement should be based on expert-agreed position statements about acceptable error, which unfortunately have yet to be formulated for gas analysis systems.

  2. Statistical Performance Evaluation of Spatiotemporal Characteristics of Groundwater Flow and Contaminant Mass Transport

    NASA Astrophysics Data System (ADS)

    Matiatos, Ioannis; Papadopoulou, Maria P.; Varouchakis, Emmanouil A.

    2016-04-01

    As groundwater remains one of the most critical natural resources worldwide, numerical models of groundwater flow and contaminant mass transport provide a reliable tool for the efficient protection, planning and sustainable management of groundwater resources. This work focuses on the evaluation of the performance of different numerical models which have been developed to simulate spatiotemporal groundwater flow and contaminant mass transport in a coastal aquifer system. The evaluation of the models' performance has been based on 9 different statistical measures and indices of goodness of fit. Overall, the simulation of groundwater level and contaminant mass concentration delivered very good calibration and validation results in all cases, quite close to the desired values. Maps of aquifer water level and contaminant mass concentrations are provided for all cases in order the differences to be discussed and assessed. The selection of the appropriate model(s) is case oriented and it should be based on the problem's characteristics in order the spatiotemporal variability of the components under study to be optimally estimated.

  3. A preliminary study of the performance and characteristics of a supersonic executive aircraft

    NASA Technical Reports Server (NTRS)

    Mascitti, V. R.

    1977-01-01

    The impact of advanced supersonic technologies on the performance and characteristics of a supersonic executive aircraft was studied in four configurations with different engine locations and wing/body blending and an advanced nonafterburning turbojet or variable cycle engine. An M 2.2 design Douglas scaled arrow-wing was used with Learjet 35 accommodations. All four configurations with turbojet engines meet the performance goals of 5926 km (3200 n.mi.) range, 1981 meters (6500 feet) takeoff field length, and 77 meters per second (150 knots) approach speed. The noise levels of of turbojet configurations studied are excessive. However, a turbojet with mechanical suppressor was not studied. The variable cycle engine configuration is deficient in range by 555 km (300 n.mi) but nearly meets subsonic noise rules (FAR 36 1977 edition), if coannular noise relief is assumed. All configurations are in the 33566 to 36287 kg (74,000 to 80,000 lbm) takeoff gross weight class when incorporating current titanium manufacturing technology.

  4. Development and performance characteristics of bipolar lithium/iron disulfide battery

    NASA Astrophysics Data System (ADS)

    Vissers, D. R.; Kaun, T. D.; Prakash, J.; Turner, R. L.; Hash, M. C.; Henriksen, G. L.

    1995-01-01

    The purpose is to review the projected performance and safety characteristics of the bipolar lithium/iron disulfide battery as it relates to a propulsion device for electric vehicles (EV's). Lithium/iron disulfide cells with a molten-salt electrolyte are well suited to the development of a bipolar battery. Long strings of series-connected cells are practical since these cells always fail in a short-circuit condition, and a technique has been developed to equalize the cells whose capacity may have gotten out of balance after many cycles. To maintain the electrolyte molten, the battery is normally operated at 425 C. The Li/FeS2 cell exhibits the high performance and long life needed for the electric vehicle application. The cell uses a molten-salt electrolyte whose composition is 34 mol% LiCl, 32.5 mol% LiBr, and 33.5. mol% KBr (m.p. 322 C), and a densely loaded FeS2 electrode that is only operated on the upper voltage plateau (UP). The Li-Al alloy is used as the negative electrode in the cell. The alloy is normally operated in the alpha + beta region of the phase diagram and covers a compositional range of 9 to 47 atom % lithium. This two-phase alloy is within 300 mV of the pure lithium metal potential, but remains solid at cell operating temperatures (400-450 C).

  5. Drag Reduction and Performance Improvement of Hydraulic Torque Converters with Multiple Biological Characteristics

    PubMed Central

    Chunbao, Liu; Changsuo, Liu; Yubo, Zhang

    2016-01-01

    Fish-like, dolphin-like, and bionic nonsmooth surfaces were employed in a hydraulic torque converter to achieve drag reduction and performance improvement, which were aimed at reducing profile loss, impacting loss and friction loss, respectively. YJSW335, a twin turbine torque converter, was bionically designed delicately. The biological characteristics consisted of fish-like blades in all four wheels, dolphin-like structure in the first turbine and the stator, and nonsmooth surfaces in the pump. The prediction performance of bionic YJSW335, obtained by computational fluid dynamics simulation, was improved compared with that of the original model, and then it could be proved that drag reduction had been achieved. The mechanism accounting for drag reduction of three factors was also investigated. After bionic design, the torque ratio and the highest efficiencies of YJSW335 were both advanced, which were very difficult to achieve through traditional design method. Moreover, the highest efficiency of the low speed area and high speed area is 85.65% and 86.32%, respectively. By economic matching analysis of the original and bionic powertrains, the latter can significantly reduce the fuel consumption and improve the operating economy of the loader. PMID:27752220

  6. Investigation of Performance Analysis and Emission Characteristics of Waste Plastic Fuel

    NASA Astrophysics Data System (ADS)

    Ruban, M.; Ramasubramanian, S.; Pugazhenthi, R.; Sivaganesan

    2017-03-01

    Today the world is confronted with the twin crisis of fossil fuel depletion and stringent emission norms, because of the environmental awareness. The disposal and degradation of waste plastic is a major issue and scarcities of fuel were major focus area of the researchers. In this virtue the waste plastic fuel extraction makes more attention to the researchers. In this research work focused to find the performance of the waste plastic fuel and compared to diesel. The waste plastic fuel extract from thermal cracking method this process the polymer chains were breakdown into useful lower molecular weight compounds and it becomes plastic pyrolysis it can be utilized as a fuel. The properties of the waste plastic fuel is obtained by various testing process and which is analyze and compare with the fossil fuel diesel. It is found that almost it has similar properties to the diesel and almost all properties of the pyrolysis is closer to that of diesel. The characteristics of the pyrolysis were tested in the engine test bed. The pyrolysis / waste plastic fuel can be directly used in diesel engines over the entire load spectrum smoothly without any major modification. The performance of the waste plastic fuel / pyrolysis is evidenced that it is one of the best alternative fuel as well as the waste plastic can be converted into a useful fuel

  7. Comparison of Thermal Performance Characteristics of Ammonia and Propylene Loop Heat Pipes

    NASA Technical Reports Server (NTRS)

    Kaya, Tarik; Baker, Charles; Ku, Jentung

    2000-01-01

    In this paper, experimental work performed on a breadboard Loop Heat Pipe (LHP) is presented. The test article was built by DCI for the Geoscience Laser Altimeter System (GLAS) instrument on the ICESat spacecraft. The thermal system requirements of GLAS have shown that ammonia cannot be used as the working fluid in this LHP because GLAS radiators could cool to well below the freezing point of ammonia. As a result, propylene was proposed as an alternative LHP working fluid since it has a lower freezing point than ammonia. Both working fluids were tested in the same LHP following a similar test plan in ambient conditions. The thermal performance characteristics of ammonia and propylene LHP's were then compared. In general, the propylene LHP required slightly less startup superheat 5nd less control heater power than the ammonia LHP, The thermal conductance values for the propylene LHP were also lower than the ammonia LHP. Later, the propylene LHP was tested in a thermal vacuum chamber. These tests demonstrated that propylene could meet the GLAS thermal design requirements. Design guidelines were proposed for the next flight-like Development Model (DM) LHP for thermal control of the GLAS instrument.

  8. Characteristic correlation study of UV disinfection performance for ballast water treatment

    NASA Astrophysics Data System (ADS)

    Ba, Te; Li, Hongying; Osman, Hafiiz; Kang, Chang-Wei

    2016-11-01

    Characteristic correlation between ultraviolet disinfection performance and operating parameters, including ultraviolet transmittance (UVT), lamp power and water flow rate, was studied by numerical and experimental methods. A three-stage model was developed to simulate the fluid flow, UV radiation and the trajectories of microorganisms. Navier-Stokes equation with k-epsilon turbulence was solved to model the fluid flow, while discrete ordinates (DO) radiation model and discrete phase model (DPM) were used to introduce UV radiation and microorganisms trajectories into the model, respectively. The UV dose statistical distribution for the microorganisms was found to move to higher value with the increase of UVT and lamp power, but moves to lower value when the water flow rate increases. Further investigation shows that the fluence rate increases exponentially with UVT but linearly with the lamp power. The average and minimum resident time decreases linearly with the water flow rate while the maximum resident time decrease rapidly in a certain range. The current study can be used as a digital design and performance evaluation tool of the UV reactor for ballast water treatment.

  9. Influence of guide vane setting in pump mode on performance characteristics of a pump-turbine

    NASA Astrophysics Data System (ADS)

    Li, Deyou; Wang, Hongjie; Nielsen, Torbjørn K.; Gong, Ruzhi; Wei, Xianzhu; Qin, Daqing

    2016-11-01

    Performance characteristics in pump mode of pump-turbines are vital for the safe and effective operation of pumped storage power plants. They are resultant of Euler head (power input) and hydraulic losses (power dissipation). In this paper, 3-D steady simulations were performed under 13mm, 19mm and 25mm guide vane openings (GVOs). Three groups of operating points under the three GVOs were chosen based on experimental validation to investigate the influence of guide vane setting on flow patterns upstream and downstream. Analysed results show that, the guide vane setting will obviously change the flow pattern downstream, which in turn influences the flow upstream. It shows a strong effect on hydraulic losses in guide and stay vanes. In addition, at the large part load conditions, the change of GVO will increase the relative flow angle at the runner outlet. As a consequence, it decreases the Euler head. However, at other operating conditions, it only has a little influence on Euler head. Flow patterns in pump mode are very dependent on the GVO and discharge.

  10. Communication and laboratory performance in parapsychology experiments: demand characteristics and the social organization of interaction.

    PubMed

    Wooffitt, Robin

    2007-09-01

    This paper reports findings from a conversation analytic study of experimenter-participant interaction in parapsychology experiments. It shows how properties of communication through which the routine business of the experiment is conducted may have an impact on the research participant's subsequent performance. In this, the study explores social psychological features of the psychology laboratory. In particular, it examines aspects of Orne's (1962) account of what he called the demand characteristics of the psychological experiment. The data come from a corpus of audio recordings of experimenter-participant interaction during experiments on extra-sensory perception. These kinds of experiments, and the phenomena they purport to study, are undoubtedly controversial; however, the paper argues that there are grounds for social psychologists to consider parapsychology experiments as a class (albeit distinctive) of psychology experiments, and, therefore, as sites in which general social psychological and communicative phenomena can be studied. The empirical sections of the paper examine interaction during part of the experimental procedure when the experimenter verbally reviews a record of the participant's imagery reported during an earlier part of the experiment. The analysis shows that the way in which the experimenter acknowledges the research participants' utterances may be significant for the trajectory of the experiment and explores how the participants' subsequent performance in the experiment may be influenced by interactionally generated contingencies.

  11. Associations between Otolaryngology Applicant Characteristics and Future Performance in Residency or Practice: A Systematic Review.

    PubMed

    Bowe, Sarah N; Laury, Adrienne M; Gray, Stacey T

    2017-03-01

    Objective This systematic review aims to evaluate which applicant characteristics available to an otolaryngology selection committee are associated with future performance in residency or practice. Data Sources PubMed, Scopus, ERIC, Health Business, Psychology and Behavioral Sciences Collection, and SocINDEX. Review Methods Study eligibility was performed by 2 independent investigators in accordance with the PRISMA protocol (Preferred Reporting Items for Systematic Reviews and Meta-analyses). Data obtained from each article included research questions, study design, predictors, outcomes, statistical analysis, and results/findings. Study bias was assessed with the Quality in Prognosis Studies tool. Results The initial search identified 439 abstracts. Six articles fulfilled all inclusion and exclusion criteria. All studies were retrospective cohort studies (level 4). Overall, the studies yielded relatively few criteria that correlated with residency success, with generally conflicting results. Most studies were found to have a high risk of bias. Conclusion Previous resident selection research has lacked a theoretical background, thus predisposing this work to inconsistent results and high risk of bias. The included studies provide historical insight into the predictors and criteria (eg, outcomes) previously deemed pertinent by the otolaryngology field. Additional research is needed, possibly integrating aspects of personnel selection, to engage in an evidence-based approach to identify highly qualified candidates who will succeed as future otolaryngologists.

  12. Effect of nano-scale characteristics of graphene on electrochemical performance of activated carbon supercapacitor electrodes

    NASA Astrophysics Data System (ADS)

    Jasni, M. R. M.; Deraman, M.; Suleman, M.; Hamdan, E.; Sazali, N. E. S.; Nor, N. S. M.; Shamsudin, S. A.

    2016-02-01

    Graphene with its typical nano-scale characteristic properties has been widely used as an additive in activated carbon electrodes in order to enhance the performance of the electrodes for their use in high performance supercapacitors. Activated carbon monoliths (ACMs) electrodes have been prepared by carbonization and activation of green monoliths (GMs) of pre-carbonized fibers of oil palm empty fruit bunches or self-adhesive carbon grains (SACGs) and SACGs added with 6 wt% of KOH-treated multi-layer graphene. ACMs electrodes have been assembled in symmetrical supercapacitor cells that employed aqueous KOH electrolyte (6 M). The cells have been tested with cyclic voltammetry, electrochemical impedance spectroscopy and galvanostatic charge discharge methods to investigate the effect of graphene addition on the specific capacitance (Csp), specific energy (E), specific power (P), equivalent series resistance (ESR) and response time (τo) of the supercapacitor cells. The results show that the addition of graphene in the GMs change the values of Csp, Emax, Pmax, ESR and τo from (61-96) F/g, 2 Wh/kg, 104 W/kg, 2.6 Ω and 38 s, to the respective values of (110-124) F/g, 3 Wh/kg, 156 W/kg, 3.4 Ω and 63 s. This study demonstrates that the graphene addition in the GMs has a significant effect on the electrochemical behavior of the electrodes.

  13. Effects of pre-germinated fenugreek seeds inclusion in low-fiber diets on post-weaned rabbits' health status, growth performances, carcass characteristics, and meat chemical composition.

    PubMed

    Mabrouki, Sabah; Chalghoumi, Raja; Abdouli, Hedi

    2017-03-01

    Newly weaned rabbits frequently suffer from digestive disorders particularly when fed low-fiber diets. Fenugreek seeds are rich in dietary fiber and would be suited to moderate such disorders. This study investigated the effect of pre-germinated fenugreek seeds (PGFS) on rabbits' health, digestibility, growth performance, and carcass parameters. Fourteen weaned rabbits were fed one of the following diets: (1) low fiber as negative control (NC), (2) low fiber containing 5% PGFS (F5), (3) low fiber containing 10% PGFS (F10), and (4) adequate fiber as positive control (PC). Each rabbit was reared in an individual cage for 7 weeks. Morbidity and sanitary risk indexes were not different (P > 0.05) between the four diets. Only 20% of the rabbits had a detectable caecal Escherichia Coli (E. coli) count (<10(5) cfu/g), and all rabbits did not show Eimeria oocysts in their feces. Compared to NC, PC gave a lower (P < 0.05) weight gain and a higher (P < 0.05) feed conversion ratio (FCR). It was associated with a lighter (P < 0.05) chilled carcass weight, and its meat had slightly more moisture and ether extract with less protein. Inclusion of PGFS decreased (P < 0.05) feed intake at the 10% level and, consequently, tended to improve FCR, while no effect was detected on carcass characteristics and meat composition. This study suggested that (1) the low-fiber diet was adequate for both health and growth aspects of post-weaned rabbits, and (2) the inclusion of PGFS was without consequence on rabbits' health status and growth performance.

  14. [Effects of soil thickness on spatiotemporal pattern of soil moisture in catchment level].

    PubMed

    Chen, Jia; Shi, Zhi-Hua; Li, Lu; Luo, Xuan

    2009-07-01

    Based on the fixed-spot observation, this paper analyzed the effects of soil thicknesses on the spatiotemporal pattern of soil moisture in the Wulongchi catchment of Danjiangkou, China. The soil moisture content increased soon after precipitation events, followed by a decline as the soil dried down, whilst its spatial heterogeneity exhibited an opposite pattern. The profile-averaged soil moisture content differed significantly with soil thickness. The soil with a thickness of 20 cm had lower profile-averaged moisture content whose variation trend was similar to that of precipitation and varied obviously among seasons; medium thickness (20-40 cm) soil had medium level of profile-averaged moisture content whose seasonal variation was moderately and affected by the characteristics of precipitation; while the soil with a thicknesses of > 40 cm had higher profile-averaged moisture content whose seasonal variation was relatively small. The profile distribution pattern of soil moisture was determined by the integrated effects of precipitation, evapotranspiration, and leakage, exhibiting increasing-type at semi-humid stage, waving-type at humid stage, and both of the two types at arid stage. There was a significant positive correlation between profile-averaged soil moisture content and soil thickness, and the correlation coefficient was 0.630-0.855. The moisture content in 0-15 cm soil layer had less correlation with soil thickness, but the moisture content in 20-55 cm soil layer was significantly correlated with soil thickness.

  15. Time series modeling of soil moisture dynamics on a steep mountainous hillside

    NASA Astrophysics Data System (ADS)

    Kim, Sanghyun

    2016-05-01

    The response of soil moisture to rainfall events along hillslope transects is an important hydrologic process and a critical component of interactions between soil vegetation and the atmosphere. In this context, the research described in this article addresses the spatial distribution of soil moisture as a function of topography. In order to characterize the temporal variation in soil moisture on a steep mountainous hillside, a transfer function, including a model for noise, was introduced. Soil moisture time series with similar rainfall amounts, but different wetness gradients were measured in the spring and fall. Water flux near the soil moisture sensors was modeled and mathematical expressions were developed to provide a basis for input-output modeling of rainfall and soil moisture using hydrological processes such as infiltration, exfiltration and downslope lateral flow. The characteristics of soil moisture response can be expressed in terms of model structure. A seasonal comparison of models reveals differences in soil moisture response to rainfall, possibly associated with eco-hydrological process and evapotranspiration. Modeling results along the hillslope indicate that the spatial structure of the soil moisture response patterns mainly appears in deeper layers. Similarities between topographic attributes and stochastic model structures are spatially organized. The impact of temporal and spatial discretization scales on parameter expression is addressed in the context of modeling results that link rainfall events and soil moisture.

  16. Anthropometric Characteristics and Performance Capabilities of Highly Trained Motocross Athletes Compared With Physically Active Men.

    PubMed

    Bach, Christopher W; Brown, Ann F; Kinsey, Amber W; Ormsbee, Michael J

    2015-12-01

    Motocross (MX) is a physically demanding sport with little research concerning the physiological characteristics of these athletes. The purpose of this study was to assess the anthropometric characteristics and performance capabilities of highly trained MX athletes (n = 20; 19 ± 1.6 years) compared with age-matched physically active (PA) men (n = 22; 22 ± 2.9 years). Testing was performed on 2 occasions. The initial visit consisted of a personality assessment in addition to the following (in order): anthropometrics, body composition, anaerobic power/fatigue, isokinetic/isometric strength and fatigue, and flexibility. The second visit consisted of peak oxygen uptake (V[Combining Dot Above]O2peak), handgrip strength, maximum push-ups in 1 minute, extended arm hang time to exhaustion (TTE), and 90° weighted wall-sit tests. All anthropometric and performance data were analyzed using independent samples t-tests to compare group means. Significance was set at p ≤ 0.05. Data are reported as mean ± SD. There were no significant differences between groups in anthropometric or body composition measurements except android fat (MX: 11.7 ± 1.9% vs. PA: 16.4 ± 8.4%, p = 0.04) and biceps circumference (MX: 30.1 ± 2.0 vs. PA: 33.1 ± 3.2 cm, p = 0.001). MX had significantly higher absolute and relative mean anaerobic power (747.3 ± 63.7 vs. 679.7 ± 93.5 W, p = 0.009 and 10.0 ± 0.6 vs. 9.2 ± 1.3 W·kg, p = 0.002, respectively), relative anaerobic peak power (12.7 ± 0.8 vs. 11.9 ± 1.4 W·kg, p = 0.029), TTE (550.1 ± 70.6 vs. 470.1 ± 93.2 seconds, p = 0.004), and extended arm hang duration (113.3 ± 44.9 vs. 73.4 ± 25.3 seconds, p = 0.001). These results suggest highly trained MX athletes possess certain physiological adaptations that likely result from sport-specific demands compared with PA.

  17. Performance and slipstream characteristics of small-scale propellers at low Reynolds numbers

    NASA Astrophysics Data System (ADS)

    Deters, Robert W.

    The low Reynolds number effects of small-scale propellers were investigated. At the Reynolds numbers of interest (below 100,000), a decrease in lift and an increase in drag is common making it difficult to predict propeller performance characteristics. A propeller testing apparatus was built to test small scale propellers in static conditions and in an advancing flow. Twenty-seven off-the-shelf propellers, with diameters ranging from 2.25 in to 9 in, were tested in order to determine the general effects of low Reynolds numbers on small propellers. From these tests, increasing the Reynolds number for a propeller increases its efficiency by either increasing the thrust produced or decreasing the power. By doubling the Reynolds number of a propeller, it is not uncommon to increase the efficiency by more the 10%. Using off-the-shelf propellers limits the geometry available and finding propellers of the same geometry but of different scale is very difficult. To solve this problem, four propellers were design and built using a 3D printer. Two of the propellers were simple rectangular twisted blades of different chords. Another propeller was modeled after a full-scale propeller. The fourth propeller was created using inverse design to minimize power loss. Each propeller was built in a 5-in and 9-in diameter version in order to test a larger range of Reynolds numbers. A separate propeller blade and hub system was created to allow each propeller to be tested with different pitch angles and to test each propeller in a 2-, 3-, and 4-blade version. From the performance results of the 3D printed propellers, it was shown that propellers of different scale, but tested at the same Reynolds number, had about the same performance results. Finally, the slipstreams of different propellers were measured using a 7-hole probe. Propeller slipstreams can have a large effect on the aerodynamics of lifting surfaces downstream of the propeller. Small UAVs and MAVs flying in close proximity

  18. Dynamic characteristics and performance evaluation for the part strut failure of the vibration isolation platform on satellites

    NASA Astrophysics Data System (ADS)

    Zhang, Yao; Sheng, Chao; Guo, Zixi; Wang, Youyi; Li, Wenbo

    2017-04-01

    The dynamic characteristics and performance evaluation for the part strut failure of the vibration isolation platform are presented in this paper. The first step provides and mathematically describes two types of strut failure: fractured and stuck. Secondly, the dynamic model of the vibration isolation platform, which considers the part strut failure, is established using the Newton-Euler method and a constraint equation to evaluate its dynamic characteristics and performance. Then, with reasonable assumptions, the dynamic model of the satellite, which has a vibration isolation platform and vibration sources (such as control moment gyros) of three working situations (without and with two types of strut failure), is simplified to analyse the frequency domain characteristic and coupling characteristic with the attitude control system. Finally, a numerical simulation is used to study the effect of the vibration isolation platform with part strut failure on the attitude control and stabilization, and the attitude control performance is evaluated.

  19. Assessment of SMOS Soil Moisture Retrieval Parameters Using Tau-Omega Algorithms for Soil Moisture Deficit Estimation

    NASA Technical Reports Server (NTRS)

    Srivastava, Prashant K.; Han, Dawei; Rico-Ramirez, Miguel A.; O'Neill, Peggy; Islam, Tanvir; Gupta, Manika

    2014-01-01

    Soil Moisture and Ocean Salinity (SMOS) is the latest mission which provides flow of coarse resolution soil moisture data for land applications. However, the efficient retrieval of soil moisture for hydrological applications depends on optimally choosing the soil and vegetation parameters. The first stage of this work involves the evaluation of SMOS Level 2 products and then several approaches for soil moisture retrieval from SMOS brightness temperature are performed to estimate Soil Moisture Deficit (SMD). The most widely applied algorithm i.e. Single channel algorithm (SCA), based on tau-omega is used in this study for the soil moisture retrieval. In tau-omega, the soil moisture is retrieved using the Horizontal (H) polarisation following Hallikainen dielectric model, roughness parameters, Fresnel's equation and estimated Vegetation Optical Depth (tau). The roughness parameters are empirically calibrated using the numerical optimization techniques. Further to explore the improvement in retrieval models, modifications have been incorporated in the algorithms with respect to the sources of the parameters, which include effective temperatures derived from the European Center for Medium-Range Weather Forecasts (ECMWF) downscaled using the Weather Research and Forecasting (WRF)-NOAH Land Surface Model and Moderate Resolution Imaging Spectroradiometer (MODIS) land surface temperature (LST) while the s is derived from MODIS Leaf Area Index (LAI). All the evaluations are performed against SMD, which is estimated using the Probability Distributed Model following a careful calibration and validation integrated with sensitivity and uncertainty analysis. The performance obtained after all those changes indicate that SCA-H using WRF-NOAH LSM downscaled ECMWF LST produces an improved performance for SMD estimation at a catchment scale.

  20. Testing a Regenerative Carbon Dioxide and Moisture Removal Technology

    NASA Astrophysics Data System (ADS)

    Barta, Daniel J.; Button, Amy; Sweterlitsch, Jeffrey; Curley, Suzanne

    The National Aeronautics and Space Administration supported the development of a new vacuum-desorbed regenerative carbon dioxide and humidity control technology for use in short duration human spacecraft. The technology was baselined for use in the Orion Crew Exploration Vehicle's Environmental Control and Life Support System (ECLSS). Termed the Carbon Diox-ide And Moisture Removal Amine Swing-bed (CAMRAS), the unit was developed by Hamilton Sundstrand and has undergone extensive testing at Johnson Space Center. The tests were per-formed to evaluate performance characteristics under range of operating conditions and human loads expected in future spacecraft applications, as part of maturation to increase its readiness for flight. Early tests, conducted at nominal atmospheric pressure, used human metabolic sim-ulators to generate loads, with later tests making us of human test subjects. During these tests many different test cases were performed, involving from 1 to 6 test subjects, with different activity profiles (sleep, nominal and exercise). These tests were conducted within the airlock portion of a human rated test chamber sized to simulate the Orion cabin free air volume. More recently, a test was completed that integrated the CAMRAS with a simulated suit loop using prototype umbilicals and was conducted at reduced atmospheric pressure and elevated oxygen levels. This paper will describe the facilities and procedures used to conduct these and future tests, and provide a summary of findings.