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Sample records for sward structural characteristics

  1. Influence of sward characteristics on grazing behaviour and short ...

    African Journals Online (AJOL)

    The feasibility of intensifying grazing studies in the tropics, particularly in Nigeria, to examine the behaviour of ruminants in highly heterogeneous pastures has the potential to provide integrated (sward, animal, management) strategies for sustainable livestock production in Nigeria. Key Words: Sward characteristics; Grazing ...

  2. The relationship between sward structure, ingestive behavior and ...

    African Journals Online (AJOL)

    The relationship between sward structure, ingestive behaviour (bite size, biting rate and intake rate) and dietary crude protein (CP) content was studied on a Chloris gayana pasture at different growth stages using oesophageally-fistulated steers. As the pasture matured, leaf table height, plan height, disc height, stemminess ...

  3. Sward structure and nutritive value of Alexandergrass fertilized with nitrogen

    Directory of Open Access Journals (Sweden)

    Paulo R. Salvador

    2016-03-01

    Full Text Available This experiment evaluated forage production, sward structure, stocking rate, weight gain per area and nutritive value of forage as grazed by beef heifers on Alexandergrass (Urochloa plantaginea (Link Hitch pasture fertilized with nitrogen (N: 0; 100; 200 or 300 kg of N/ha. The experiment was a completely randomized design following a repeated measurement arrangement. The experimental animals were Angus heifers with initial age and weight of 15 months and 241.5±5 kg, respectively. The grazing method was continuous, with put-and-take stocking. N utilization, regardless of the level, increase by 25% the daily forage accumulation rate and the weight gain per area by 23%. The level of 97.2 kg N/ha leads to a higher leaf blade mass and increases by 20% the leaf:stem ratio. Alterations in sward structure changes the nutritive value of forage as grazed. The utilization of 112.7 kg of N/ha allows the highest stocking rate (2049.8 kg of BW/ha, equivalent to 7.5 heifers per hectare.

  4. Relationship of bite mass of cattle to sward structure of four temperate grasses in short-term foraging sessions

    Science.gov (United States)

    Bite mass is a fundamental element of ruminant ingestive behavior and is highly influenced by sward structure. We compared the sward structure of four grasses and related structure to the bite mass of cattle grazing the grasses. Reed canarygrass (RCG; Phalaris arundinacea L), quackgrass (QG; Elytri...

  5. Habitat use by indigenous grazing ungulates in relation to sward ...

    African Journals Online (AJOL)

    The objective of this study was to examine the relationships between the habitat requirements of different wild ungulate species, sward structure and veld condition. Veld condition score was correlated with sward height: habitats with high condition scores were dominated by tall grass species, whereas habitats with low ...

  6. Wildlife Habitat Quality (Sward Structure and Ground Cover Response of Mixed Native Warm-Season Grasses to Harvesting

    Directory of Open Access Journals (Sweden)

    Vitalis W. Temu

    2014-08-01

    Full Text Available Agricultural intensification in America has replaced native warm-season grasses (NWSG with introduced forages causing wildlife habitat loss and population declines for the northern bobwhite (Colinus virginianus and similar ground-nesting birds. Reintroducing NWSGs onto managed grasslands to reverse grassland bird population declines lacks information about appropriate multi-purpose management. Post-season nesting habitat quality of mixed NWSGs (indiangrass (IG, Sorghastrum nutans, big bluestem (BB, Andropogon gerardii and little bluestem (LB, Schizachyrium scoparium responding to previous-year(s harvest intervals (treatments, 30-, 40-, 60-, 90 or 120-d and duration (years in production, were assessed on late-spring-early-summer re-growths. Yearly phased harvestings were initiated in May on sets of randomized plots, ≥90-cm apart, in five replications (blocks to produce one-, two-, and three-year old stands by the third year. Sward heights and canopy closure were recorded a day before harvest, followed a week after by visual estimates of ground cover of plant species and litter. Harvesting increased post-season grass cover and reduced forbs following a high rainfall year. Harvested plot swards showed no treatment differences, but were shorter and intercepted more sunlight. Similarly, harvest duration increased grass cover with no year effect but reduced forbs following a high rainfall year. One- or two-year full-season harvesting of similar stands may not compromise subsequent bobwhite nesting-cover provided post-season harvesting starts after the breeding cycle is completed.

  7. Efeito da altura do capim-Tanzânia diferido nas características da pastagem no período do inverno Sward characteristics of deferred tanzania grass under different height levels, in the winter time

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    Marcos Weber do Canto

    2001-07-01

    Full Text Available O estudo foi desenvolvido no Município de Astorga, PR, na Fazenda Nossa Senhora de Aparecida, com o objetivo de avaliar as características da pastagem e o acúmulo de forragem em capim-Tanzânia (Panicum maximum Jacq., diferido e após pastejado no período de 23/07 a 18/09/1999, sob diferentes níveis de altura de pasto. O delineamento experimental usado foi o inteiramente casualizado, com duas repetições. Os tratamentos foram quatro alturas de pasto: T1=20, T2=40, T3=60 e T4=80 cm. Entretanto, para a análise estatística, utilizaram-se as alturas reais de pasto mantidas nas unidades experimentais, sendo: T1R1 = 26,3, T1R2 = 24,6, T2R1 = 47,9, T2R2 = 42,5, T3R1 = 55,8, T3R2 = 61,7, T4R1 = 69,2 e T4R2 = 71,4 cm. Pode-se concluir que a altura de pasto aumenta de forma linear as massas de forragem e de colmos verdes. O acúmulo de forragem não foi afetado pelas diferentes alturas de pasto.The study was carried out in the county of Astorga, PR, Brazil, in the Nossa Senhora de Aparecida farm. The objective was to study the sward characteristics and forage accumulation of tanzania grass, deferred and after grazed from 07/23 to 09/18/1999, under different sward height levels. The experimental design was a completely randommized, with two replications. The treatments were four levels of sward height: T1=20, T2=40, T3=60 and T4=80 cm. However, the true sward height levels were used for analysis statistics; T1R1=26,3, T1R2=24,6, T2R1=47,9, T2R2=42,5, T3R1=55,8, T3R2=61,7, T4R1=69,2 e T4R2=71,4 cm. Results indicate that: forage mass and green culm mass increased of the positive linear way with increased of sward height. There was no effect of sward height levels on the forage accumulation.

  8. Características fermentativas da silagem do capim Marandu manejado em diferentes alturas de dossel Marandu grass silage fermentative characteristic managed under different sward heights

    Directory of Open Access Journals (Sweden)

    Virgílio Jamir Gonçalves Mota

    2011-06-01

    Full Text Available Objetivou-se avaliar as características fermentativas da silagem de Brachiaria brizantha (Hochst ex. Rich Stapf cv. Marandu manejada em diferentes alturas de dossel. Utilizou-se o delineamento em blocos ao acaso, com quatro alturas de dossel (30; 45; 60 e 75cm em cinco blocos, totalizando 20 unidades experimentais. A gramínea foi ensilada em silos experimentais de PVC, com peso conhecido. A abertura dos silos foi realizada aos 56 dias após a ensilagem. Momentos antes da abertura, os silos foram pesados para avaliar as perdas por gases, e em seguida, abertos para retirada da silagem e quantificação das perdas por efluentes. Foram determinados os valores de pH, nitrogênio amoniacal, teores de ácidos orgânicos (lático, acético e butírico e matéria seca. Os dados coletados foram submetidos à análise de variância, e quando significativa, as médias de tratamentos foram submetidas ao estudo de regressão. A gramínea manejada a 30 e a 45cm de dossel resultou em silagens com melhores características fermentativas, com maior conteúdo de ácido lático, menores conteúdos de ácido butírico e nitrogênio amoniacal, e menores perdas durante a fermentação. A gramínea manejada a 60 e a 75cm apresentou processo fermentativo totalmente inadequado à conservação da forragem, portanto classificada como de péssima qualidade. Conclui-se que a altura de dossel de 30 e de 45cm do capim Marandu resultou em silagem com melhores características fermentativas, quando comparada com as silagens das demais alturas avaliadas, porém não atingiu um nível de qualidade desejada.The objective of this study was to evaluate the fermentation characteristics of Brachiaria brizantha Hochst ex. Rich Stapf cv. Marandu managed under different sward heights. We used a complete randomized block delimitation layout, with four sward heights (30; 45; 60 and 75cm in 5 blocks totaling 20 experimental units. The grass was packed and weighted in PVC silos. The silos

  9. Fusion of Ultrasonic and Spectral Sensor Data for Improving the Estimation of Biomass in Grasslands with Heterogeneous Sward Structure

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    Thomas Moeckel

    2017-01-01

    Full Text Available An accurate estimation of biomass is needed to understand the spatio-temporal changes of forage resources in pasture ecosystems and to support grazing management decisions. A timely evaluation of biomass is challenging, as it requires efficient means such as technical sensing methods to assess numerous data and create continuous maps. In order to calibrate ultrasonic and spectral sensors, a field experiment with heterogeneous pastures continuously stocked by cows at three grazing intensities was conducted. Sensor data fusion by combining ultrasonic sward height (USH with narrow band normalized difference spectral index (NDSI (R2CV = 0.52 or simulated WorldView2 (WV2 (R2CV = 0.48 satellite broad bands increased the prediction accuracy significantly, compared to the exclusive use of USH or spectral measurements. Some combinations were even better than the use of the full hyperspectral information (R2CV = 0.48. Spectral regions related to plant water content were found to be of particular importance (996–1225 nm. Fusion of ultrasonic and spectral sensors is a promising approach to assess biomass even in heterogeneous pastures. However, the suggested technique may have limited usefulness in the second half of the growing season, due to an increasing abundance of senesced material.

  10. Sward characteristics and performance of dairy cows in organic grass-legume pastures shaded by tropical trees.

    Science.gov (United States)

    Paciullo, D S C; Pires, M F A; Aroeira, L J M; Morenz, M J F; Maurício, R M; Gomide, C A M; Silveira, S R

    2014-08-01

    The silvopastoral system (SPS) has been suggested to ensure sustainability in animal production systems in tropical ecosystems. The objective of this study was to evaluate pasture characteristics, herbage intake, grazing activity and milk yield of Holstein×Zebu cows managed in two grazing systems (treatments): SPS dominated by a graminaceous forage (Brachiaria decumbens) intercropped with different leguminous herbaceous forages (Stylosanthes spp., Pueraria phaseoloides and Calopogonium mucunoides) and legume trees (Acacia mangium, Gliricidia sepium and Leucaena leucocephala), and open pasture (OP) of B. decumbens intercropped only with Stylosanthes spp. Pastures were managed according to the rules for organic cattle production. The study was carried out by following a switch back format with 12 cows, 6 for each treatment, over 3 experimental years. Herbage mass was similar (P>0.05) for both treatments, supporting an average stocking rate of 1.23 AU/ha. Daily dry matter intake did not vary (P>0.05) between treatments (average of 11.3±1.02 kg/cow per day, corresponding to 2.23±0.2% BW). Milk yield was higher (P0.05) in subsequent years. The highest (P0.05) milk yields. Low persistence of Stylosanthes guianensis was observed over the experimental period, indicating that the persistence of forage legumes under grazing could be improved using adapted cultivars that have higher annual seed production. The SPS and a diversified botanical composition of the pasture using legume species mixed with grasses are recommended for organic milk production.

  11. Sward canopy structure and performance of beef heifers under supplementation in Brachiaria brizantha cv. Marandu pastures maintained with three grazing intensities in a continuous stocking system

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    Daniel Rume Casagrande

    2011-10-01

    Full Text Available The objective of this study was to assess the sward canopy structure of Brachiaria brizantha cv. Marandu pastures maintained in three grazing intensities under continuous stocking system during the rainy season, along with the behavior and performance of grazing beef heifers supplemented with mineral salt or an energy/protein supplement. Three levels of forage allowance were assessed: 2.0, 2.5 and 3.0 kg of forage/kg of live weight, combined with two supplements (ad libitum mineral salt, and an energy/protein supplement at 0.3% of live weight/day, supplied daily. The experiment was designed as a randomized block study with two replications. The supplements did not influence the variables related to the canopy structure. Canopy height was greater at higher forage allowances during the late summer and early fall. Similarly, the stem mass was greater in pastures with higher forage allowances. Animals fed protein supplement spent less time grazing than animals supplemented with mineral salt. Stocking rate was higher in pastures with lower forage allowance levels, which increased the live weight gain per grazing area. Daily weight gain did not vary according to the forage allowance levels. The use of an energy/protein supplement did not affect the stocking rate; however, it increased individual live weight gain and live weight gain per grazing area compared with mineral salt supplementation. The use of energy/protein supplements is an efficient alternative to enhance animal performance and production under grazing systems during the rainy season

  12. Research Note: Precision and accuracy of sward height distributions ...

    African Journals Online (AJOL)

    African Journal of Range and Forage Science ... Research Note: Precision and accuracy of sward height distributions. CD Morris, PJK Zacharias ... The effect of sample size on the precision and accuracy of parameters of sward height distributions was examined by drawing sub-samples (n = 10) of increasing sample size ...

  13. Sward structure and herbage yield of rotationally stocked pastures of 'Marandu' palisadegrass [Brachiaria brizantha (A.Rich. Stapf] as affected by herbage allowance Estrutura do dossel e produção de forragem em pastagens de capim Marandu [Brachiaria brizantha (A.Rich. Stapf] sob lotação rotacionada em resposta à oferta de forragem

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    Gustavo José Braga

    2006-04-01

    Full Text Available In ruminant-forage systems herbage allowance (HAL has a major impact on grazing intensity and sward structure, affecting animals, plants, and ultimately, pasture yield. Data on HAL responses of tropical cultivated pastures are scarce and this information may be useful in optimizing pasture utilization. The objective of this study was to describe and contrast sward structure and herbage accumulation responses of 'Marandu' palisadegrass [Brachiaria brizantha (A.Rich. Stapf] pastures to HAL during two grazing seasons (warm-rainy season of 2003 and 2004. Treatments were four daily HAL levels, 5, 10, 15 and 20 kg herbage mass per 100 kg live weight (% in a rotational stocking system with 35 days of grazing cycle (28-day rest; 7-d grazing. Post-graze swards were shorter (~17 cm under 5% HAL. For the other HAL levels, postgraze sward height increased throughout the experiment (21 to 50 cm. Changes in sward light interception (LI were highly associated with height, but differed across HALs in 2004. Early in the 2003 season, HAL increases resulted in linear increase of the daily herbage accumulation rate (HAR; 47, 66, 78, and 98 kg DM ha-1 d-1 for 5, 10, 15 and 20%-HAL, respectively. For the subsequent grazing cycles of 2003 and all through 2004, HAR decreased with increasing HAL. This was associated with the excessive increase in sward height and mean forage mass, caused by lower grazing intensity. The use of lax (high HAL to maximize animal performance, especially 10, 15 and 20%-HAL, resulted in decreased pasture performance (lower herbage accumulation, HAC in palisadegrass pastures.A oferta de forragem (OF aos animais em pastejo causa forte impacto na intensidade de desfolhação e conseqüentemente na estrutura do dossel, influindo indiretamente no acúmulo de forragem. O objetivo deste estudo foi avaliar estrutura do dossel e acúmulo de forragem em pastagens de capim-Marandu em resposta à OF. Os tratamentos foram quatro OFs, 5, 10, 15 e 20 kg

  14. Impact of combined management on the newly established pasture sward

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    Pavlína Hakrová

    2012-01-01

    Full Text Available The effect of the combined grazing and cutting management on the phytocenological characteristics was examined at the submountain paddock in the South Bohemia. The botanical scans were sampled during the five-years study (2006–2010 starting after the sowing the pasture sward in the originally arable field and 0–2 years after the beginning of the grazing (paddock A and paddock B, respectively. The paddock A was grazed all year round, whereas the paddock B was grazed in spring and autumn and cut in summer for hay. At both paddocks, Lolium perenne, Trifolium repens and Taraxacum sect. Ruderalia dominated the community of total 43 and 47 species (paddock A and B, respectively. Among the sowing species, Lolium perenne, Festuca pratensis, Poa pratensis, Festuca rubra and Trifolium repens increased its cover on both paddocks, while Phleum pratense increased its cover only at paddock B. Lolium multiflorum decreased it cover at both paddocks. Most of arable field weeds disappeared (paddock A or decreased its cover (paddock B. The cover of herb layer was higher at paddock A than at paddock B, whereas the number of species (N, the diversity (H and the equitability (J was higher at paddock B than at paddock A. The cover of herb layer increased during the study at both the paddocks, while the number of species declined at paddock A and increased at paddock B.

  15. The seasonal growth patterns of a Tall Grassveld sward | NFG ...

    African Journals Online (AJOL)

    The growth patterns of a Tall Grassveld sward measured with an inclined point and by clipping and weighing were determined by moisture conditions except in winter when temperature was limiting. The inclined point as a method of determining yield which might replace clipping and weighing, holds promise but is unlikely ...

  16. Hydrologic properties of grazed perennial swards in semiarid ...

    African Journals Online (AJOL)

    Identification of plant resources that persist under grazing pressure, support desirable levels of production and at the same time protect the grazing environment is central to sustainable livestock production. This study assessed the infiltration capacity and soil loss associated with perennial swards subjected to different ...

  17. Effects of chicory/perennial ryegrass swards compared with perennial ryegrass swards on the performance and carcass quality of grazing beef steers.

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    Christina L Marley

    Full Text Available An experiment investigated whether the inclusion of chicory (Cichorium intybus in swards grazed by beef steers altered their performance, carcass characteristics or parasitism when compared to steers grazing perennial ryegrass (Lolium perenne. Triplicate 2-ha plots were established with a chicory/ryegrass mix or ryegrass control. Forty-eight Belgian Blue-cross steers were used in the first grazing season and a core group (n = 36 were retained for finishing in the second grazing season. The experiment comprised of a standardisation and measurement period. During standardisation, steers grazed a ryegrass/white clover pasture as one group. Animals were allocated to treatment on the basis of liveweight, body condition and faecal egg counts (FEC determined 7 days prior to the measurement period. The measurement period ran from 25 May until 28 September 2010 and 12 April until 11 October 2011 in the first and second grazing year. Steers were weighed every 14 days at pasture or 28 days during housing. In the first grazing year, faecal samples were collected for FEC and parasite cultures. At the end of the first grazing year, individual blood samples were taken to determine O. ostertagi antibody and plasma pepsinogen levels. During winter, animals were housed as one group and fed silage. In the second grazing year, steers were slaughtered when deemed to reach fat class 3. Data on steer performance showed no differences in daily live-weight gain which averaged 1.04 kg/day. The conformation, fat grade and killing out proportion of beef steers grazing chicory/ryegrass or ryegrass were not found to differ. No differences in FEC, O. ostertagi antibody or plasma pepsinogen levels of beef steers grazing either chicory/ryegrass or ryegrass were observed. Overall, there were no detrimental effects of including chicory in swards grazed by beef cattle on their performance, carcass characteristics or helminth parasitism, when compared with steers grazing ryegrass.

  18. Pasture characteristics of Italian ryegrass and milk production under different management strategies

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    Marcolino Frederico Miguel

    2012-06-01

    Full Text Available The objective of this work was to assess the effects of the sward structure of Italian ryegrass (Lolium multiflorum, during the first grazing cycle, on its morphological and bromatological characteristics throughout the growing season, and on the performance of dairy cows. The treatments consisted of two structures obtained as a function of canopy-light interception: high-light interception (HLI and low-light interception (LLI, with different pre-grazing heights in the first grazing cycle. Pasture was managed under rotational grazing with a herbage allowance not below 30 kg dry matter (DM per cow per day. Three grazing cycles, with a grazing interval of 30 days, were evaluated. Pre-grazing herbage mass was greater (2,240 vs. 1,656 kg ha-1 DM, but the proportion of leaf blades was smaller (0.35 vs. 0.43 for HLI swards. Neutral detergent fiber (NDF content and organic matter digestibility (OMD were similar between treatments in the first grazing cycle, but in the second and third ones NDF was greater, and OMD lower, for the HLI swards. Milk yields were greater for cows grazing LLI swards (19.4 vs. 21.1 kg per day. Initial grazing with 90% of light interception promotes greater nutritional value in the subsequent cycles.

  19. Productivity, utilization efficiency and sward targets for mixed pastures of marandugrass, forage peanut and tropical kudzu

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    Carlos Mauricio Soares de Andrade

    2012-03-01

    Full Text Available This study was carried out to evaluate the productivity and utilization efficiency of a mixed marandugrass (Brachiaria brizantha cv. Marandu, forage peanut (Arachis pintoi cv. Mandobi and tropical kudzu (Pueraria phaseoloides pasture, rotationally stocked at four daily forage allowance levels (6.6, 10.3, 14.3 and 17.9% of live weight, in order to define sward management targets for these mixtures. In each stocking cycle, dry matter (DM accumulation rates, defoliation intensity (%, grazing depth (% and grazed horizon (cm were evaluated. Sward targets were defined according to the sward condition that best conciliated the grass-legume balance and the equilibrium between forage production and utilization. Pastures submitted to higher forage allowance levels showed higher productivity, but were less efficiently utilized. It was not possible to establish sward management targets for marandugrass-tropical kudzu pastures. For marandugrass-forage peanut pastures the best sward state was set with forage allowance of 10.3% of live weight. Under rotational stocking, the following sward targets were suggested for these pastures in the Western Amazon: pre-grazing height of 30-35 cm (June to September or 45-50 cm (October to May and post-grazing sward height of 20-25 cm (June to September or 25-30 cm (October to May.

  20. Structural characteristics and forage mass of Tifton 85 pastures managed under three post-grazing residual leaf areas

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    Wilton Ladeira da Silva

    2013-04-01

    Full Text Available The experiment was carried out on Cynodon spp cv. Tifton 85 pastures grazed by sheep under rotational stocking, with the objective of evaluating the structural characteristics as well as the forage mass of the pastures subjected to three grazing intensities in successive cycles. Treatments were composed of three residual leaf area indices (rLAI; 2.4; 1.6 and 0.8, allocated in completely randomized blocks with seven replications, totaling 21 experimental units. Tiller population density, pasture height, leaf area index, forage morphological composition and pasture forage mass were evaluated. The rLAI modified the tiller population density, which increased linearly with decrease in the rLAI of the pastures. Dry masses of leaf blade, stem and dead material were inferior when the rLAI imposed were lower, which resulted in differentiated forage production among the treatments. Tifton 85 pastures grazed by sheep in rotational stocking under tropical conditions with different rLAI show a modified sward structure over successive grazing cycles, mainly by alteration in the height and LAI of the plants at pre-grazing and by light interception post-grazing, which change the tiller population density. The residual leaf area index of 1.6 is the most suitable for pasture management for being equivalent to the heights of entrance and exit of animals on and from paddocks of 33 and 19 cm, respectively, which avoid great accumulation of dead material and excessive stem elongation, in addition to ensuring tillering in the sward.

  1. Matgrass sward plant species benefit from soil organisms

    NARCIS (Netherlands)

    Brinkman, E.P.; Raaijmakers, C.E.; Bakx-Schotman, J.M.T.; Hannula, S.E.; Kemmers, R.H.; De Boer, W.; Van der Putten, W.H.

    2012-01-01

    Soilorganisms are important in the structuring of plant communities. However, little is known about how to apply this knowledge to vegetation management. Here, we examined if soilorganisms may promote plantspecies of characteristic habitats, and suppress plantspecies of disturbed habitats. We

  2. The relationship between sward structure, ingestive behavior and ...

    African Journals Online (AJOL)

    Animals adjusted biting rates to compensate for changes in bite size and thus maintained rates of intake. Bite size and dietary CP were negatively correlated. It was argued that, in the present study, leaf table height, stemminess, leaf density and leaf % were the main determinants of dietary CP and ingestive behaviour.

  3. Deformation Characteristics of Composite Structures

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    Theddeus T. AKANO

    2016-08-01

    Full Text Available The composites provide design flexibility because many of them can be moulded into complex shapes. The carbon fibre-reinforced epoxy composites exhibit excellent fatigue tolerance and high specific strength and stiffness which have led to numerous advanced applications ranging from the military and civil aircraft structures to the consumer products. However, the modelling of the beams undergoing the arbitrarily large displacements and rotations, but small strains, is a common problem in the application of these engineering composite systems. This paper presents a nonlinear finite element model which is able to estimate the deformations of the fibre-reinforced epoxy composite beams. The governing equations are based on the Euler-Bernoulli beam theory (EBBT with a von Kármán type of kinematic nonlinearity. The anisotropic elasticity is employed for the material model of the composite material. Moreover, the characterization of the mechanical properties of the composite material is achieved through a tensile test, while a simple laboratory experiment is used to validate the model. The results reveal that the composite fibre orientation, the type of applied load and boundary condition, affect the deformation characteristics of the composite structures. The nonlinearity is an important factor that should be taken into consideration in the analysis of the fibre-reinforced epoxy composites.

  4. A note on the effects of paddock size on the white clover content of swards grazed by sheep

    NARCIS (Netherlands)

    Wolf, de P.L.; Schulte, R.P.O.; Lantinga, E.A.

    2004-01-01

    The maintenance of a high white clover content in mixed swards under sheep grazing has been a challenge to date. This paper presents the results of an experiment in which the effect of the length of a grazing period on the botanical composition of a mixed sward was studied. Paddocks ranging in size

  5. Matgrass sward plant species benefit from soil organisms

    NARCIS (Netherlands)

    Brinkman, E.P.; Raaijmakers, C.E.; Bakx-Schotman, J.M.T.; Hannula, S.E.; Kemmers, R.H.; Boer, de W.; Putten, van der W.H.

    2012-01-01

    Soil organisms are important in the structuring of plant communities. However, little is known about how to apply this knowledge to vegetation management. Here, we examined if soil organisms may promote plant species of characteristic habitats, and suppress plant species of disturbed habitats. We

  6. Effect of owersowing on yields and botanical composition of pasture sward

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    Martin Müller

    2008-01-01

    Full Text Available There are several metods of permanent pasture renovation. Different technologies were investigated on a pasture sward. Three seeders (Einböck seeder with the tine harrow, no-till Sulky disc seeder and SPP 8 strip seeder and two fertilization regimes (with no fertilization and with mineral fertilization N90P30K60 kg.ha−1 were used to determine optimum methods of establishment and the use of oversowed pasture swards. In the first year, renovated plots had a higher DM production than control plots. The pasture oversowing had no effect on herbage production in the second production year. The fertilization had no effect in the first production year with a higher clover content in the sward. The share of clovers was higher in plots oversown with the Einböck and Sulky seeders but only in the second and third cuts of the first production year and in the third cut of the second production year. The highest content of clovers was observed in the second and third cuts. There was a positive correlation between the clover content in DM yield and herbage DM production. The oversowing did not show any effect on the grass content in the pasture sward.

  7. Tiller size/density compensation in grazed Tifton 85 bermudagrass swards

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    Sbrissia André Fischer

    2003-01-01

    Full Text Available The objective of this study was to evaluate the occurrence of the tiller size/density compensation mechanism in Tifton 85 bermudagrass swards grazed by sheep under continuous stocking. Treatments corresponded to four sward steady state conditions (5, 10, 15, and 20 cm of sward surface height, maintained by sheep grazing. The experimental design was a complete randomized block with four replicates. Pasture responses evaluated include: tiller population density, tiller mass, leaf mass and leaf area per tiller, and herbage mass. Tiller volume, leaf area index, tiller leaf/stem ratio, and tiller leaf area/volume ratio were calculated and simple regression analyses between tiller population density and tiller mass were performed. Measurements were made in December, 1998, and January, April, and July, 1999. The swards showed a tiller size/density compensation mechanism in which high tiller population densities were associated with small tillers and vice-versa, except in July, 1999. Regression analyses revealed that linear coefficients were steeper than the theoretical expectation of -3/2. Increments in herbage mass were attributable to increases in tiller mass in December and January. Leaf area/volume ratio values of Tifton 85 tillers were much lower than those commonly found for temperate grass species.

  8. Imaging spectroscopy for early detection of nitrogen deficiency in grass swards

    NARCIS (Netherlands)

    Schut, A.G.T.; Ketelaars, J.J.M.H.

    2003-01-01

    The potential of an experimental imaging spectroscopy system with high spatial (0.16–0.28 mm²) ) and spectral resolution (5–13 nm) was explored for early detection of nitrogen (N) stress. From June through October 2000, a greenhouse experiment was conducted with 15 Lolium perenne L. mini-swards and

  9. Early detection of drought stress in grass swards with imaging spectroscopy

    NARCIS (Netherlands)

    Schut, A.G.T.; Ketelaars, J.J.M.H.

    2003-01-01

    The potential of an experimental imaging spectroscopy system with high spatial (0.28-1.45 mm2) and spectral (5-13 nm) resolution was explored for early detection of drought stress in grass. A climate chamber experiment was conducted with nine Lolium perenne L. mini swards with drought stress

  10. Complementary effects of red clover inclusion in ryegrass-white clover swards for grazing and cutting

    DEFF Research Database (Denmark)

    Eriksen, Jørgen; Askegaard, Margrethe; Søegaard, Karen

    2014-01-01

    Increasing plant species diversity in grasslands may improve productivity and stability of yields. In a field experiment, we investigated the herbage dry-matter (DM) yield and crude protein content of two-species swards of perennial ryegrass–white clover (Lolium perenne L.–Trifolium repens L...

  11. Ingestive behavior of supplemented Nellore heifers grazing palisadegrass pastures managed with different sward heights.

    Science.gov (United States)

    Vieira, Bruno Ramalho; Azenha, Mariana Vieira; Casagrande, Daniel Rume; Costa, Diogo Fleury Azevedo; Ruggieri, Ana Cláudia; Berchielli, Telma Teresinha; Reis, Ricardo Andrade

    2017-04-01

    Three sward heights (15, 25 and 35 cm) and three supplement types (energy, energy-protein, and a mineral mix supplement) were evaluated in a 3 × 3 factorial arrangement distributed in a completely randomized design to study changes in forage search patterns in Nellore heifers in a continuous grazing system. Pasture data were collected using two replicates (paddocks) per treatment over four periods during the rainy season. The behavior assessments were made in the first and fourth grazing seasons. It was hypothesized that supplements and pasture management would modify ingestive behavior, considering that animals would require less time grazing if they had energy requirements met through higher digestibility of better managed paddocks, or use of supplements high in energy. Total and green forage masses along with green : dead material ratio were greater in treatments managed with higher sward heights. Sward managed with 35 cm height resulted in lower leaf : stem ratio compared with 15 cm sward height treatments. The animals on the 15 cm pastures spent more time grazing overall and during each meal, but there were no differences observed in meal numbers in comparison to 35 cm treatments. Heifers fed protein and/or energy supplements spent less time grazing in the early afternoon, but overall grazing time was the same for all animals. © 2016 Japanese Society of Animal Science.

  12. STRUCTURE OF BOXERS´ MORPHOLOGICAL CHARACTERISTICS

    OpenAIRE

    Benin Murić; Izet Kahrović

    2008-01-01

    We wanted to help solving the problems we meet every day, and through this research we did. Research was done on population of boxers 15-19 years old, who compete in Serbian Youth League. We keep being asked: “How big is the morphological characteristics influence on a boxer`s success? While selecting boys for boxing, on which morphological characteristics we need to pay our attention most?” Based on results we got in this research, boys must have a good relation of height and weight, and rel...

  13. STRUCTURE OF BOXERS´ MORPHOLOGICAL CHARACTERISTICS

    Directory of Open Access Journals (Sweden)

    Benin Murić

    2008-08-01

    Full Text Available We wanted to help solving the problems we meet every day, and through this research we did. Research was done on population of boxers 15-19 years old, who compete in Serbian Youth League. We keep being asked: “How big is the morphological characteristics influence on a boxer`s success? While selecting boys for boxing, on which morphological characteristics we need to pay our attention most?” Based on results we got in this research, boys must have a good relation of height and weight, and relatively long legs and arms.

  14. Some Structural Characteristics of Music Television Videos.

    Science.gov (United States)

    Fry, Donald L.; Fry, Virginia H.

    1987-01-01

    Indicates, by analyzing two types of montage structures, that music television is a hybrid form of television programing displaying visual characteristics of both television commercials and drama. Argues that this amalgam of different characteristics gives music television its distinctive look and power as a promotional tool for the record…

  15. Early detection of drought stress in grass swards with imaging spectroscopy

    OpenAIRE

    Schut, A.G.T.; Ketelaars, J.J.M.H.

    2003-01-01

    The potential of an experimental imaging spectroscopy system with high spatial (0.28-1.45 mm2) and spectral (5-13 nm) resolution was explored for early detection of drought stress in grass. A climate chamber experiment was conducted with nine Lolium perenne L. mini swards with drought stress treatments at two nitrogen levels. Images were recorded once every two days. Growth was monitored by changes in ground cover (GC), index of reflection intensity (IRI) and wavelength position of and gradie...

  16. Seasonal and interannual variations in feeding station behavior of cattle: effects of sward and meteorological conditions.

    Science.gov (United States)

    Hirata, M; Matsumoto, Y; Izumi, S; Soga, Y; Hirota, F; Tobisa, M

    2015-04-01

    A feeding station is the area of forage a grazing animal can reach without moving its forefeet. Grazing behavior can be divided into residence within feeding stations (with bites as benefits) and movement between feeding stations (with steps as costs). However, relatively little information has been reported on how grazing animals modify their feeding station behavior seasonally and interannually in response to varying environmental conditions. The feeding station behavior of beef cows (Japanese Black) stocked on a tropical grass pasture (bahiagrass dominant) was monitored for 4 years (2010 to 2013) in order to investigate the association of feeding station behavior with meteorological and sward conditions across the seasons and years. Mean air temperature during stocking often exceeded 30°C during summer months. A severe summer drought in 2013 decreased herbage mass and sward height of the pasture and increased nitrogen concentration of herbage from summer to autumn. A markedly high feeding station number per unit foraging time, low bite numbers per feeding station and a low bite rate were observed in summer 2013 compared with the other seasons and years. Bite number per feeding station was explained by a multiple regression equation, where sward height and dry matter digestibility of herbage had a positive effect, whereas air temperature during stocking had a negative effect (R 2=0.658, Pstation number per minute was negatively correlated with bite number per feeding station (r=-0.838, Pstation in response to the sward and meteorological conditions, and this largely determined the number of feeding stations the animals visited per minute. The results indicate potential value of bite number per feeding station as an indicator of daily intake in grazing animals, and an opportunity for livestock and pasture managers to control feeding station behavior of animals through managements (e.g. fertilizer application, manipulation of stocking intensity and stocking time

  17. Assessment of Hyperspectral Remote Sensing for Analyzing the Impact of Human Trampling on Alpine Swards

    Directory of Open Access Journals (Sweden)

    Marlena Kycko

    2017-02-01

    Full Text Available Tourist traffic has been observed to cause changes in vegetation cover, particularly in alpine areas. These changes can be monitored using remote-sensing methods. This paper presents an analysis of the condition of the dominant sward species surrounding the most frequented alpine tourist trails in the Tatra National Park, one of the most visited natural mountain parks in Poland and a UNESCO Man and the Biosphere Reserve. Hyperspectral measurements of interactions between the electromagnetic spectrum and the morphology and physiology of plants were presented. The spectral properties of plants and remote-sensing vegetation indices could be used at a later date for monitoring, for example from the air. The results identified the species' sensitivity and resistance to trampling and allowed an assessment of their physiological condition. Differences were observed in the conditions of trampled and control plants. The alpine swards in the Tatra National Park were assessed as being in good condition, with only small areas located close to the most popular trails showing damage. The proposed method for analyzing the condition of alpine swards could be a useful tool for the future management of protected areas.

  18. Dynamics of sward condition and botanical composition in mixed pastures of marandugrass, forage peanut and tropical kudzu

    Directory of Open Access Journals (Sweden)

    Carlos Mauricio Soares de Andrade

    2012-03-01

    Full Text Available This study was carried out to evaluate the dynamics of sward condition and botanical composition of a mixed pasture of marandugrass (Brachiaria brizantha cv. Marandu, forage peanut (Arachis pintoi cv. Mandobi and tropical kudzu (Pueraria phaseoloides, rotationally stocked at four daily forage allowance levels (6.6, 10.3, 14.3 and 17.9% of live weight. Sward condition was characterized in each stocking cycle by measuring pre- and post-grazing sward height, forage mass and percentage of bare ground. Botanical composition (grass, forage peanut, tropical kudzu and weeds was evaluated before each stocking period. Swards under smaller forage allowances presented lower height, forage mass and ground cover. This condition favored the growth of forage peanut, which constituted 21.1, 15.2, 8.4 and 3.8% of forage mass in the last quarter of the experimental period, from the lowest to the highest forage allowance, respectively. Tropical kudzu was sensitive to all forage allowance levels and its percentage in the botanical composition was strongly reduced along the experimental period, especially during the dry season (July to September. Forage peanut cv. Mandobi and marandugrass form a more balanced mixture when pre-grazing sward height is maintained shorter than 45 cm. Tropical kudzu is intolerant to intensive grazing management systems when associated to marandugrass.

  19. Structural characteristics and antihypertensive effects of angiotensin ...

    African Journals Online (AJOL)

    Structural characteristics and antihypertensive effects of angiotensin-iconverting enzyme inhibitory peptides in the renin-angiotensin and kallikrein kinin systems. ... Background: The commercially available synthetic angiotensin-I-converting enzyme (ACE) inhibitors are known to exert negative side effects which have driven ...

  20. The combined effect of fertiliser nitrogen and phosphorus on herbage yield and change in soil nutrients of a grass/clover and grass-only sward

    NARCIS (Netherlands)

    Schils, R.L.M.; Snijders, P.J.M.

    2004-01-01

    The combined effect of reduced nitrogen ( N ) and phosphorus ( P ) application on the production of grass- only and grass/ clover swards was studied in a five- year cutting experiment on a marine clay soil, established on newly sown swards. Furthermore, changes in soil N, P and carbon ( C ) were

  1. Tiller size/population density compensation in grazed Coastcross bermudagrass swards

    Directory of Open Access Journals (Sweden)

    Sbrissia André Fischer

    2001-01-01

    Full Text Available Several compensatory mechanisms in pastures do not allow optimisation of responses from the processes of herbage production and utilisation. Compensation due to tiller size/density relationships is one of these mechanisms. This experiment evaluated this process for Coastcross bermudagrass and compared the responses to those reported for temperate forages. Treatments were "steady state" sward surface heights of 5, 10, 15, and 20 cm that were maintained from August, 1998, through July, 1999 by sheep grazing. The experimental design was a randomised complete block, replicated four times. Pasture responses were evaluated on four separate dates (15/12/1998, 25/01/1999, 07/04/1999 and 04/07/1999 with respect to: tiller population density, tiller weight, leaf mass and leaf area per tiller and herbage mass (biomass. Tiller volume, leaf area index (LAI, tiller leaf:stem ratio and tiller leaf area:volume ratio (R were calculated. Simple regression analyses between tiller population density and tiller weight were also performed. Coastcross swards showed a tiller size/density compensation mechanism where high tiller population densities were associated with small tillers and vice-versa; except on the last evaluation. However, regression analysis revealed linear coefficients of -3.83 to -2.05, which are lower than the theoretical expectation of -3/2. The lower R values observed, when compared to those reported for perennial ryegrass, suggest that Coastcross swards optimised their LAI via clonal integration among tillers in contrast with tillers of cool-season grasses that respond more as individuals. However, this hypothesis has yet to be experimentally verified.

  2. Using post-grazing sward height to impose dietary restrictions of varying duration in early lactation: its effects on spring-calving dairy cow production.

    Science.gov (United States)

    Crosse, M; O'Donovan, M; Boland, T M; Delaby, L; Ganche, E; Kennedy, E

    2015-04-01

    The objective of this study was to investigate the immediate and carryover effects of imposing two post-grazing sward heights (PGSH) for varying duration during early lactation on sward characteristics and dairy cow production. The experiment was a randomised block design with a 2×2 factorial arrangement of treatments. A total of 80 spring-calving (mean calving date - 6 February) dairy cows were randomly assigned, pre-calving, to one of the two (n=40) PGSH treatments - S (2.7 cm) and M (3.5 cm) - from 13 February to 18 March, 2012 (P1). For the subsequent 5-week period (P2: 19 March to 22 April, 2012), half the animals from each P1 treatment remained on their treatment, whereas the other half of the animals switched to the opposing treatment. Following P2, all cows were managed similarly for the remainder of the lactation (P3: 23 April to 4 November, 2012) to measure the carryover effect. Milk production, BW and body condition score were measured weekly, and grass dry matter intake (GDMI) was measured on four occasions - approximately weeks 5, 10, 15 and 20 of lactation. Sward utilisation (above 2.7 cm; P1 and P2) was significantly improved by reducing the PGSH from 3.5 (0.83) to 2.7 cm (0.96). There was no effect of PGSH on cumulative annual grass dry matter (DM) production (15.3 t DM/ha). Grazing to 2.7 cm reduced GDMI by 1.7 and 0.8 kg DM/cow in P1 and P2, respectively, when compared with 3.5 cm (13.3 and 14.0 kg/cow per day, respectively). Cows grazing to 2.7 cm for both P1 and P2 (SS) tended to have reduced cumulative 10-week milk yield (-105 kg) and milk solids yield (-9 kg) when compared with cows grazing to 3.5 cm for both periods (MM; 1608 and 128 kg/cow, respectively). Treatments that alternated PGSH at the end of P1, SM and MS had intermediate results. There was no interaction between P1 and P2 treatments. There was also no carryover effect of early lactation grazing regime on milk and milk solids production in P3, given the reduction in early lactation

  3. Meta-analysis of the effect of white clover inclusion in perennial ryegrass swards on milk production.

    Science.gov (United States)

    Dineen, M; Delaby, L; Gilliland, T; McCarthy, B

    2018-02-01

    There is increased demand for dairy products worldwide, which is coupled with the realization that consumers want dairy products that are produced in a sustainable and environmentally benign manner. Forage legumes, and white clover (Trifolium repens L.; WC) in particular, have the potential to positively influence the sustainability of pasture-based ruminant production systems. Therefore, there is increased interest in the use of forage legumes because they offer opportunities for sustainable pasture-based production systems. A meta-analysis was undertaken to quantify the milk production response associated with the introduction of WC into perennial ryegrass swards and to investigate the optimal WC content of dairy pastures to increase milk production. Two separate databases were created. In the grass-WC database, papers were selected if they compared milk production of lactating dairy cows grazing perennial ryegrass-WC (GC) swards with that of cows grazing perennial ryegrass-only swards (GO). In the WC-only database, papers were selected if they contained milk production from lactating dairy cows grazing on GC swards with varying levels of WC content. Data from both databases were analyzed using mixed models (PROC MIXED) in SAS (SAS Institute, Cary, NC). Within the grass-WC database, where mean sward WC content was 31.6%, mean daily milk and milk solids yield per cow were increased by 1.4 and 0.12 kg, respectively, whereas milk and milk solids yield per hectare were unaffected when cows grazed GC compared with GO swards. Stocking rate and nitrogen fertilizer application were reduced by 0.25 cows/ha and 81 kg/ha, respectively, on GC swards compared with GO swards. These results highlight the potential of GC production systems to achieve similar levels of production to GO systems but with reduced fertilizer nitrogen inputs, which is beneficial from both an economic and environmental point of view. In the context of increased demand for dairy products, there may be

  4. Estimated metabolizable energy yields of perennial and annual grass swards compared with those of spring barley and oat

    Directory of Open Access Journals (Sweden)

    O. NIEMELÄINEN

    2008-12-01

    Full Text Available The dry matter yields of cultivar trials (from 1976 to 1998 at 15 sites in Finland of perennial grass sward (meadow fescue (Festuca pratensis cv. Boris, annual grass sward (Italian ryegrass (Lolium multiflorum, cv. Barmultra and Mitos, spring barley (Hordeum vulgare cv. Otra, Arra, Arve and oat (Avena sativa cv. Veli were used to estimate metabolisable energy yields (MEY by using the feeds metabolisable energy concentration values (MJ/kg DM from ruminant feed tables. Harvest index (HI of barley and oat was set to 50%, and straw yields and whole crop cereal silage (WCCS yields were generated from grain yields accordingly. The MEY in the third year of perennial grass (81.4 GJ/ha was significantly lower than that in the first (90.0 GJ/ha and second years (90.7 GJ/ha. However, on average, the one to three year old perennial grass-swards had significantly higher MEY than the annual grass swards (87.7 vs. 83.3 GJ/ha, respectively. The MEYs of perennial and annual grass swards were substantially higher than the MEY of barley grain (52.7 GJ/ha and oat grain (47. 8 GJ/ha. When the total herbage of cereals, i.e. straw and grain, was used in the calculations, at a ME value of 6.0 MJ/ kg dry matter (DM for straw, the MEY of barley rose to 75.8 GJ/ha and that of oat to 72.6 GJ/ha. Additionally, the MEY of barley was estimated in the WCCS production situation by converting total herbage to MEY by using ME value 9.9 MJ/kg DM. The MEY of barley in the WCCS calculations was 77.4 GJ/ha, which was significantly lower than the MEY of annual and perennial grass swards. The MEY of barley was a 60%, b 86%, and c 88% of the average MEY of one to three year old perennial grass sward when the MEY of barley was calculated according to a grain, b grain + straw, and c whole crop cereal silage. Perennial grass sward was the most productive of the studied crops in metabolisable energy production for ruminants.

  5. Characteristic imsets for learning Bayesian network structure

    Czech Academy of Sciences Publication Activity Database

    Hemmecke, R.; Lindner, S.; Studený, Milan

    2012-01-01

    Roč. 53, č. 9 (2012), s. 1336-1349 ISSN 0888-613X R&D Projects: GA MŠk(CZ) 1M0572; GA ČR GA201/08/0539 Institutional support: RVO:67985556 Keywords : learning Bayesian network structure * essential graph * standard imset * characteristic imset * LP relaxation of a polytope Subject RIV: BA - General Mathematics Impact factor: 1.729, year: 2012 http://library.utia.cas.cz/separaty/2012/MTR/studeny-0382596.pdf

  6. Características morfogênicas e estruturais do capim-marandu submetido a combinações de alturas e intervalos de corte Morphogenetic and structural characteristics of marandu palisadegrass subjected to combinations of cutting heights and cutting intervals

    Directory of Open Access Journals (Sweden)

    Gelson dos Santos Difante

    2011-05-01

    Full Text Available Desenvolveu-se este estudo com o objetivo de avaliar o acúmulo de forragem e as características morfogênicas e estruturais do capim-marandu submetido a combinações de alturas e intervalos de corte. O experimento foi realizado no período de agosto de 2003 a abril de 2004. Os tratamentos corresponderam a combinações entre duas alturas (15 e 30 cm e três intervalos de corte (tempo correspondente para o aparecimento de três, quatro e cinco folhas por perfilho e foram alocados às unidades experimentais em arranjo fatorial 2 × 3 e delineamento de blocos completos casualizados com três repetições. Foram avaliados o acúmulo total de forragem, o acúmulo de lâminas foliares, colmos e material morto, as variáveis morfogênicas e as estruturais, assim como a altura do dossel no pré-corte e a duração do período de rebrotação. O corte a 15 cm resultou em menor período de rebrotação, altura pré-corte, alongamento de colmo e tamanho final da folha e maior densidade populacional de perfilhos em comparação ao corte a 30 cm. O intervalo de corte correspondente ao aparecimento de cinco folhas por perfilho resultou em maiores alturas pré-corte, taxas de alongamento de folhas, tamanho final das folhas e acúmulo de colmos e em menor densidade populacional de perfilhos em comparação aos intervalos correspondentes a três e quatro folhas surgidas por perfilho. A maior eficiência de utilização dos pastos de capim-marandu foi alcançada com cortes a 15 cm. Pastos manejados com intervalo de corte correspondente a três folhas surgidas por perfilho, independentemente da altura de corte avaliada, acumulam elevada quantidade de folhas, componente altamente desejável para alimentação animal.The objective of this study was to evaluate forage accumulation and morphogenetic and structural characteristics of marandu palisadegrass subjected to combinations of cutting heights and cutting intervals. The experiment was carried out from August

  7. Dairy cow excreta patches change the boreal grass swards from sink to source of methane

    Directory of Open Access Journals (Sweden)

    Marja Elisa Maljanen

    2012-06-01

    Full Text Available We studied methane (CH4 flux rates from experimental excreta patches on a dairy pasture with a chamber technique during snow free seasons and with a gas gradient technique during winter from timothy-meadow fescue sward with mineral N fertilization (220 kg ha-1 and from grass-white clover mixture without fertilization. The dung and urine patches were applied in June or August two consecutive grazing seasons and the measurements were carried out for a year following each application. There were no significant differences in CH4 fluxes between plant species and emissions originated mainly from the fresh dung pats. The average annual CH4 fluxes from the control sites without excreta were -0.60±0.1 and with the excreta 0.47±0.3 kg CH4 ha-1. Thus, excreta originating from dairy cows can turn boreal swards from weak sinks to small sources of CH4. However, these emissions are only 0.2% of the total CH4 emissions from a dairy cow.

  8. Real Capital: Complementarity and Structural Characteristics

    Directory of Open Access Journals (Sweden)

    Miriasov Iurii О.

    2016-05-01

    Full Text Available Two opposite approaches to the concept of real capital are considered. The presupposition for studying capital within the neoclassical school, which can be characterized as “empirical realism”, is the homogeneity of capital. This allows to apply formal methods of studying and modeling industrial processes but excludes from consideration the properties and characteristics of capital as a real factor of production. The approach of the Austrian school corresponding to traditions of “critical realism” in the economy focuses on real properties of capital and its role in the process of public production. The aim of this study is to clarify the idea of real capital, its properties, structural characteristics and mechanisms of formation. According to this, the characteristic of two different approaches is given. It is shown that the heterogeneity of capital is the basis of complementarity of capital goods and their combinations in each particular case of their application. The same capital goods have different performance depending on the method of their combination as a result of the production plans of entrepreneurs. Emergent properties of capital are also the result of the combination. Differences in the use and combination of capital determine its overall structure, subsystems of which are natural objects at different levels included in the production, capital goods themselves and their various combinations, social capital. Each of these subsystems is relatively independent and forms a higher level subsystem.

  9. Animal production in Tanzania grass swards fertilized with nitrogen Produção animal em pastos de capim-tanzânia adubadas com nitrogênio

    Directory of Open Access Journals (Sweden)

    Marcos Weber do Canto

    2009-07-01

    Full Text Available Nitrogen (N at 100, 200, 300, and 400 kg ha-1 was applied to Tanzania grass swards to evaluate the animal response and relationships between sward characteristics and the performance of young Nellore bulls (Bos indicus under continuous stocking. A completely randomized experimental design was used with two replications between 11 November 2001 and 15 April 2002 when the sward heights were maintained at 60 cm by using different stocking rates. The average daily gain (ADG (0.73 kg d-1 was not affected by N doses while the number of animal days ha-1 increased linearly from 515 to 1267. On the other hand, the linear increase in the animal yield was 399, 653, 755, and 895 kg ha-1 for N at 100, 200, 300, and 400 kg ha-1, respectively, while the ratio between the liveweight gain (kg and N (kg ha-1 decreased. Correlation coefficients between ADG and herbage mass, green leaf mass, green herbage mass, proportion of green leaf and leaf:culm ratio were low and nonsignificant. Under the conditions in Northwestern Paraná, the application of N to swards of Tanzania grass is a management option for increasing beef cattle production.Doses de nitrogênio (N de 100, 200, 300 e 400 kg/ha foram aplicadas em pastos de capim-tanzânia, utilizados sob lotação contínua, visando avaliar a resposta animal e as relações entre características do pasto e o desempenho animal. As avaliações foram realizadas no período de 10 de novembro de 2001 a 15 de abril de 2002 utilizando-se tourinhos da raça Nelore (Bos indicus, em delineamento inteiramente ao acaso com duas repetições. A altura do pasto foi mantida em 60 cm por meio de ajustes da taxa de lotação. O ganho médio diário (GMD por animal dos tourinhos foi semelhante entre as doses de N, com média de 0,73 kg/animal.dia. O número de animais.dia/ha aumentou linearmente com as aplicações de N, de 515 a 1.267. A adubação nitrogenada aumentou de modo linear a produtividade (animal/ha. Nas doses de N de 100

  10. Effects of white clover cultivar and companion grass on winter survival of seedlings in autumn-sown swards

    NARCIS (Netherlands)

    Elgersma, A.; Schlepers, H.

    2003-01-01

    The aim was to study the effects of white clover cultivar and combinations with perennial ryegrass cultivars on seedling establishment in autumn-sown swards and on winter survival of seedlings. Large-leaved white clover cv. Alice and small-leaved white clover cv. Gwenda, and an erect and a prostrate

  11. Sward and milk production response to early turnout of dairy cows to pasture in Finland

    Directory of Open Access Journals (Sweden)

    P. VIRKAJÄRVI

    2008-12-01

    Full Text Available The timing of turnout is an important factor affecting the grazing management of dairy cows. However,its consequences are not well known in the short grazing season of northern Europe. Thus, the effect of the turnout date of dairy cows to pasture on sward regrowth, herbage mass production and milk production was studied in two experiments,1a grazing trial with 16 Holstein-Friesian dairy cows and 2a plot trial where the treatments simulated the grazing trial.The treatments were early turnout (1 Juneand normal turnout (6 June.Early turnout decreased the annual herbage mass (HM production in the plot trial (P =0.005,but due to a higher average organic matter (OMdigestibility (P 0.05. Although early turnout had no effect on milk yields it meant easier management of pastures.;

  12. Nitrogen fertilization of grass/clover swards under cutting or grazing by dairy cows

    DEFF Research Database (Denmark)

    Søegaard, Karen

    2009-01-01

    Intensively managed perennial ryegrass/white clover (Lolium perenne L. and Trifolium repens L.) swards receive relatively high levels of fertilizer N, and high N surpluses can subsequently be found. The N-fertilization effects on growth, yield, and herbage quality were therefore examined on three...... farms over a period of three years. Nitrogen was applied at four rates (0, 75, 150, and 225 kg N year-1) with cutting or grazing regime in Year 1 and Year 2, after establishment. A spring-only application of 150 kg N was compared with four applications during the season, which was the fertilization...... management in the rest of the experiment. N-response was greatly affected by management. Under cutting it was higher in Year 1 [16 kg dry matter (DM) kg-1 N] than in Year 2 (9 and 13 kg DM kg-1 N with and without residual effects of fertilization in Year 1). Under grazing with one or two rest periods...

  13. Influência de variáveis químicas e estruturais do dossel sobre a taxa de ingestão instantânea em bovinos manejados em pastagens tropicais Influence of structural characteristics and chemical composition of tropical grasses on the instantaneous forage intake rate

    Directory of Open Access Journals (Sweden)

    Fabíola Cristine de Almeida Rego

    2006-06-01

    - altura capim-marandu, PBL - PB lâminas de capim-marandu.Steer forage intake rate (IR was evaluated in pastures of Brachiaria brizantha, Panicum maximum cv. Tanzania, Arachis pintoi and a mixed of Brachiaria brizantha with Arachis pintoi. The objectives were to define sward structural characteristics and chemical composition nutrients of each pasture most determinant of forage intake rate by grazing steers. The steers grazed in pairs, passing through all grass species maintained at different sward heights in successive days. After three hours fast the animals were allowed to graze each experimental area for 60 minutes and had their grazing time and bite numbers registered. Forage intake was estimated by the double sampling technique. Sward structural characteristics used in the model for estimation of IR were: average sward height, morphological component proportion (%, morphological component mass (ton DM/ha and density of morphological components (kg DM/ha/cm. The chemical composition was expressed as crude protein (CP and neutral detergent fiber (NDF. Sward variables were selected using the stepwise statistical procedure. The IR equations defined from the studied characteristics were: Marandu grass: IR = 59,8980 + 0,7299 GL + 3,5777 DMA - 1,2459 NDFL + 0,2882 SH (GL - proportion of green leaves, FM - forage mass, NDFL - NDF of leaves, SH - average sward height. Tanzania grass: IR = 111,762 -4,1532 CPL + 0,3469 GL - 0,5207 NDFL (CP of leaves, GL - proportion of green leaves, NDFL - NDF of leaves. Peanut forage: IR = -196,589 + 12,1978 CPS + 8,3406 DMA + 1,1060 GS +17,3669 GLA (CPS - stem CP, DMA - dry matter availability, GLA - green leaves availability. Mixed pasture: IR= -7,25 + 1,15HA -0,22HI + 18,49AA -9,88GLA + 0,49HM + 1,00CPL (HA - Peanut forage height, HI - weed species height, AA - Arachis availability, GLA - green leaf availability of Marandu grass, HB - marandugrass sward height, CPL - CP of leaves of marandugrass.

  14. STRUCTURE AND CHARACTERISTICS OF PATENTED HIGH-CARBON WIRE

    Directory of Open Access Journals (Sweden)

    A. Ju. Borisenko

    2011-01-01

    Full Text Available The influence of bainite structure on mechanical characteristics of wire of steel 80 after patenting is studied. The quantity and structure state of bainite, providing high complex of mechanical characteristics of high-carbon wire, is determined.

  15. Database on wind characteristics - Structure and philosophy

    Energy Technology Data Exchange (ETDEWEB)

    Larsen, G.C.; Hansen, K.S.

    2001-11-01

    The main objective of IEA R and D Wind Annex XVII - Database on Wind Characteristics - is to provide wind energy planners and designers, as well as the international wind engineering community in general, with easy access to quality controlled measured wind field time series observed in a wide range of environments. The project partners are Sweden, Norway, U.S.A., The Netherlands, Japan and Denmark, with Denmark as the Operating Agent. The reporting of IEA R and D Annex XVII falls in three separate parts. Part one deals with the overall structure and philosophy behind the database, part two accounts in details for the available data in the established database bank and part three is the Users Manual describing the various ways to access and analyse the data. The present report constitutes the first part of the Annex XVII reporting, and it contains a detailed description of the database structure, the data quality control procedures, the selected indexing of the data and the hardware system. (au)

  16. STRUCTURE OF MORPHOLOGIC CHARACTERISTICS OF BODYBUILDERS

    Directory of Open Access Journals (Sweden)

    Vladimir Mutavdžić

    2007-05-01

    Full Text Available Today body-building as a spport is well known and accepted world-wide. When scientifi researches on this fi eld are in question, it is evident that they are very rare partly and probably due to its real interpretation as well as due to its insuffi cient affi rmation and popularization here. Reason for this is also the wrong interpretation of the sport’s essence among sports-people – the body-builders themselves and among the experts and scientists from this fi eld. Intrest in the research of morphological sphere of body-builders was inspired by the fact that exercising body-building is a very specifi c physical activity that, due to its nature, demands body-builders to have specifi c morphological characteristics that characterize and differ them from other sports-people. The goal of this research was determining the structure of the morhologicall sphere of a body-builder. It was performed on the sample of 30 selected sportsmen, bodybuilders, of chronological age between 17 and 19 ( 6 months, members of the Sports' Club Strength ''Leskovac'', the Weight Lifters' Club '' Dubočica'' and the Body-building Club '' Dubočica'' from Leskovac. All the examiees have been submitted to training processes during a period longer than a year. For the purpose of determining the structure of the morphological sphere the Factor Analysis has been applied. Based on the data from the matrix of the Factor Structure the isolated factors can be interpreted in the following manner: The fi rst isolated factor in the sphere of applied anthropometric variables can be defi ned as a dimension of the body-volume and the transversal dimensionality of the skeleton sine it’s best defi ned by the following variables: the chest-circumference (AOGKS, the upper-arm circumference (AONAD, the thigh circumference (AOBUT, the body-weight (AMAST and the shoulder-width (ASIRA. The second isolated factor in the sphere of applied anthropometric variables can be defi ned as the

  17. Evaluation of fecal contamination indicators (fecal coliforms, somatic phages, and helminth eggs) in ryegrass sward farming.

    Science.gov (United States)

    Cárdenas, Martha; Moreno, Gerardo; Campos, Claudia

    2009-02-15

    The effect of soil supplementation with biosolids at various ratios on fecal-origin microorganism activity was evaluated in a ryegrass sward farm. Fifteen plots with 3 different soil and biosolid mixture ratios were assessed. Soil and grass were sampled over a period of 4 months (days 0, 30, 45, 60, 75, and 120) for soil and on days 75 and 120 for grass, corresponding to first and second grass harvest periods. We analyzed fecal coliforms, somatic phages, helminth eggs, and environmental factors, such as rainfall, temperature, and moisture. The fecal coliforms decreased by 2 logarithmic units (LU) in all soils containing biosolids and by 1 LU in the soil alone and in biosolid control plots alone. The concentration of somatic phages decreased to 2 to 3 LU in the soil containing biosolids and to 1 to 2 LU in the control plots. In contrast, however, there was a noticeable increase in helminth eggs on days 75 ad 120, but not in the soil control alone. Maximum concentrations (10(2) CFU/g TS; colony forming units per gram total solids) of fecal coliforms were found on the grass and in other samples, but the concentrations of phages and helminth eggs were below detection limits. Environmental factors did not significantly influence the results, and grass production increased from 35 to 50 Ton/Ha (tons per hectare) with biosolid supplementation, as compared with controls (14 Ton/Ha).

  18. RESEARCH OF BRIDGE STRUCTURE VIBRATION CHARACTERISTICS

    Directory of Open Access Journals (Sweden)

    V.P. Babak

    2005-02-01

    Full Text Available  Bridge structure test results with using different types of dynamic force have been considered. It has been shown, that the developed technique of registering and processing vibration signals allows obtaining thin spectrum structure. The analysis of its change that is defined by the type of structure loading applied has been carried out. Key parameters of the vibration signals registered have been defined.

  19. Video Game Structural Characteristics: A New Psychological Taxonomy

    Science.gov (United States)

    King, Daniel; Delfabbro, Paul; Griffiths, Mark

    2010-01-01

    Excessive video game playing behaviour may be influenced by a variety of factors including the structural characteristics of video games. Structural characteristics refer to those features inherent within the video game itself that may facilitate initiation, development and maintenance of video game playing over time. Numerous structural…

  20. Strength characteristics for the structural assessment of existing concrete structures

    NARCIS (Netherlands)

    Vervuurt, A.; Courage, W.; Steenbergen, R.

    2013-01-01

    For the assessment of the in situ compressive strength in structures and precast concrete components EN 13791 applies. Among others, this standard may be adopted when doubt arises about the compressive strength in the structure. However, for assessing the structural safety of existing structures of

  1. CHARACTERISTIC STRUCTURE OF STAR-FORMING CLOUDS

    Energy Technology Data Exchange (ETDEWEB)

    Myers, Philip C., E-mail: pmyers@cfa.harvard.edu [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States)

    2015-06-20

    This paper presents a new method to diagnose the star-forming potential of a molecular cloud region from the probability density function of its column density (N-pdf). This method provides expressions for the column density and mass profiles of a symmetric filament having the same N-pdf as a filamentary region. The central concentration of this characteristic filament can distinguish regions and can quantify their fertility for star formation. Profiles are calculated for N-pdfs which are pure lognormal, pure power law, or a combination. In relation to models of singular polytropic cylinders, characteristic filaments can be unbound, bound, or collapsing depending on their central concentration. Such filamentary models of the dynamical state of N-pdf gas are more relevant to star-forming regions than are spherical collapse models. The star formation fertility of a bound or collapsing filament is quantified by its mean mass accretion rate when in radial free fall. For a given mass per length, the fertility increases with the filament mean column density and with its initial concentration. In selected regions the fertility of their characteristic filaments increases with the level of star formation.

  2. An overview of structural characteristics in problematic video game playing

    OpenAIRE

    Griffiths, MD; Nuyens, F

    2017-01-01

    Purpose of Review: There are many different factors involved in how and why people develop problems with video game playing. One such set of factors concerns the structural characteristics of video games (i.e., the structure, elements, and components of the video games themselves). Much of the research examining the structural characteristics of video games was initially based on research and theorizing from the gambling studies field. The present review briefly overviews the key papers in th...

  3. NSF tandem stack support structure deflection characteristics

    International Nuclear Information System (INIS)

    Cook, J.

    1979-12-01

    Results are reported of load tests carried out on the glass legs of the insulating stack of the 30 MV tandem Van de Graaff accelerator now under construction at Daresbury Laboratory. The tests to investigate the vulnerability of the legs when subjected to tensile stresses were designed to; establish the angle of rotation of the pads from which the stresses in the glass legs may be calculated, proof-test the structure and at the same time reveal any asymmetry in pad rotations or deflections, and to confirm the validity of the computer design analysis. (UK)

  4. An Overview of Structural Characteristics in Problematic Video Game Playing.

    Science.gov (United States)

    Griffiths, Mark D; Nuyens, Filip

    2017-01-01

    There are many different factors involved in how and why people develop problems with video game playing. One such set of factors concerns the structural characteristics of video games (i.e., the structure, elements, and components of the video games themselves). Much of the research examining the structural characteristics of video games was initially based on research and theorizing from the gambling studies field. The present review briefly overviews the key papers in the field to date. The paper examines a number of areas including (i) similarities in structural characteristics of gambling and video gaming, (ii) structural characteristics in video games, (iii) narrative and flow in video games, (iv) structural characteristic taxonomies for video games, and (v) video game structural characteristics and game design ethics. Many of the studies carried out to date are small-scale, and comprise self-selected convenience samples (typically using self-report surveys or non-ecologically valid laboratory experiments). Based on the small amount of empirical data, it appears that structural features that take a long time to achieve in-game are the ones most associated with problematic video game play (e.g., earning experience points, managing in-game resources, mastering the video game, getting 100% in-game). The study of video games from a structural characteristic perspective is of benefit to many different stakeholders including academic researchers, video game players, and video game designers, as well as those interested in prevention and policymaking by making the games more socially responsible. It is important that researchers understand and recognize the psycho-social effects and impacts that the structural characteristics of video games can have on players, both positive and negative.

  5. NACP MsTMIP Summary of Model Structure and Characteristics

    Data.gov (United States)

    National Aeronautics and Space Administration — ABSTRACT: This data set provides a summary of the model structure and characteristics of participating models in the North American Carbon Program (NACP) Multi-scale...

  6. NACP MsTMIP Summary of Model Structure and Characteristics

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set provides a summary of the model structure and characteristics of participating models in the North American Carbon Program (NACP) Multi-scale synthesis...

  7. Characteristics of matrix structures and their effects on project success

    OpenAIRE

    Schnetler, Rohann; Steyn, Herman; Van Staden, Paul J.

    2015-01-01

    This paper investigates the characteristics of matrix structures and their relationships with drivers of project success, such as communication, collaboration, and trust between project team members. Matrix characteristics that were expected to correlate positively with project success mostly did correlate with the success drivers. However, characteristics expected to impact negatively on project success did not show such significant correlations; some even correlated positively with success ...

  8. Limitations and corrections in measuring dynamic characteristics of structural systems

    International Nuclear Information System (INIS)

    Walter, P.L.

    1978-10-01

    The work deals with limitations encountered in measuring the dynamic characteristics of structural systems. Structural loading and response are measured by transducers possessing multiple resonant frequencies in their transfer function. In transient environments, the resultant signals from these transducers are shown to be analytically unpredictable in amplitude level and frequency content. Data recorded during nuclear effects simulation testing on structures are analyzed. Results of analysis can be generalized to any structure which encounters dynamic loading. Methods to improve the recorded data are described which can be implemented on a frequency selective basis during the measurement process. These improvements minimize data distortion attributable to the transfer characteristics of the measuring transducers

  9. Dynamic characteristics of cylindrical shells considering Fluid-structure interaction

    International Nuclear Information System (INIS)

    Jhung, Myung Jo; Kim, Wal Tae; Ryu, Yong Ho

    2009-01-01

    To assure the reliability of cylinders or shells with fluid-filled annulus, it is necessary to investigate the modal characteristics considering fluid-structure interaction effect. In this study, theoretical background and several finite element models are developed for cylindrical shells with fluid-filled annulus considering fluid-structure interaction. The effect of the inclusion of the fluid-filled annulus on the natural frequencies is investigated, which frequencies are used for typical dynamic analyses such as responses spectrum, power spectral density and unit load excitation. Their response characteristics are addressed with respect to the various representations of the fluid-structure interaction effect

  10. [Functional characteristics of flexible supporting structures for heart valve bioprosthesis].

    Science.gov (United States)

    Dobrova, N B; Agafonov, A V; Barbarash, L S; Zavalishin, N N; Neniukov, A K

    1984-01-01

    Hydraulic characteristics of heart valve bioprostheses mounted on supporting structures of various rigidity have been studied under physiologic conditions. An actual mobility of the supporting structures made of different polymers is determined. Static and dynamic components of the support displacements have been shown to develop as the bioprosthesis is under the load, the dynamic component being strongly dependent upon the rigidity of fastening the bioprosthesis on the axis. It is noted that considerable improvements in hydraulic characteristics of bioprostheses are achieved through the use of flexible supporting structures.

  11. Desempenho animal, produção de forragem e características estruturais dos capins marandu e xaraés submetidos a intensidades de pastejo Animal performance, forage yield and structural characteristics in the palisadegrass cvs. marandu and xaraés submitted to grazing intensities

    Directory of Open Access Journals (Sweden)

    Renata Santos Flores

    2008-08-01

    palisadegrass cvs. Marandu and Xaraés pastures submitted to three grazing intensities. The experiment was carried out at Embrapa Gado de Corte. The experimental period was from October 2005 to June 2006. The area was of 8 ha, divided in 12 paddocks of 0.67 ha. Two cultivars of palisadegrass, Marandu and Xaraés, and three grazing intensities, 15, 30, and 45 cm of sward height were evaluated. The experimental design was randomized block in a split plot arrangement and two replications. The main plot was constituted by cultivars and the subplot by the grazing intensities. The grazing was continuously stocking with variable stocking rate. Each paddock was grazed by three steers and regulating animals were utilized to adjust the sward heights. The sward heights were monitored twice per week. The grass was sampled each 28 days to estimate the herbage yield, herbage accumulation rate, pasture structural characteristics, and nutritive value. Animals were weighed each 28 days. The dry matter intake was estimated in the summer and the autumn, and the grazing behavior in the summer. Herbage accumulation and average daily gain decreased as the grazing intensities increased for both palisadegrass cvs. Xaraés and Marandu. The forage intake for the animals in xaraés grass pasture was limited by the variation in the sward structure. Based on the sward structural characteristics, forage intake and the productivity, these grasses require differentiated management. Marandu grass must be managed between 25 and 40 cm of height and xaraés grass at 40 cm.

  12. Effect of sward height and distance between pasture and barn on cows' visits to an automatic milking system and other behaviour

    NARCIS (Netherlands)

    Ketelaar-de Lauwere, C.C.; Ipema, A.H.; Lokhorst, C.; Metz, J.H.M.; Noordhuizen, J.P.T.M.; Schouten, W.G.P.; Smits, A.C.

    2000-01-01

    Two experiments were conducted to study the effects of sward height (experiment I) and the distance between barn and pasture plot (experiment II) on cows’ visits to an automatic milking system (AMS) and other behaviour. The study was carried out in a situation in which grazing was combined with

  13. Rumen degradation characteristics of perennial ryegrass cultivars during the growing season

    NARCIS (Netherlands)

    Tas, B.M.; Taweel, H.Z.; Smit, H.J.; Elgersma, A.; Dijkstra, J.; Tamminga, S.

    2006-01-01

    The objective of this experiment was to evaluate the effects of sward characteristics and chemical composition of eight diploid perennial ryegrass cultivars during the growing season on degradation characteristics in the rumen of dairy cows. As part of an indoor-feeding experiment with dairy cows,

  14. Some Material Characteristics of Cold-Sprayed Structures

    Directory of Open Access Journals (Sweden)

    Victor K. Champagne

    2007-01-01

    Full Text Available The deposition and consolidation of metal powders by means of cold spray are methods whereby powder particles are accelerated to high velocity through entrainment in a gas undergoing expansion in a rocket nozzle and are subsequently impacted upon a surface. The impacted powder particles form a consolidated structure which can be several centimeters thick. The characteristics of this structure depend on the initial characteristics of the metal powder and upon impact velocity. The influence of impact velocity on strain hardening and porosity are examined. A materials model is proposed for these phenomena, and model calculation is compared with experiment for the cold spraying of aluminum.

  15. Characteristics of de novo structural changes in the human genome

    NARCIS (Netherlands)

    Kloosterman, Wigard P.; Francioli, Laurent C.; Hormozdiari, Fereydoun; Marschall, Tobias; Hehir-Kwa, Jayne Y.; Abdellaoui, Abdel; Lameijer, Eric-Wubbo; Moed, Matthijs H.; Koval, Vyacheslav; Renkens, Ivo; van Roosmalen, Markus J.; Arp, Pascal; Karssen, Lennart C.; Coe, Bradley P.; Handsaker, Robert E.; Suchiman, Eka D.; Cuppen, Edwin; Thung, Djie Tjwan; McVey, Mitch; Wendl, Michael C.; Uitterlinden, Andre; van Duijn, Cornelia M.; Swertz, Morris A.; Wijmenga, Cisca; van Ommen, GertJan B.; Slagboom, P. Eline; Boomsma, Dorret I.; Schoenhuth, Alexander; Eichler, Evan E.; de Bakker, Paul I. W.; Ye, Kai; Guryev, Victor

    Small insertions and deletions (indels) and large structural variations (SVs) are major contributors to human genetic diversity and disease. However, mutation rates and characteristics of de novo indels and SVs in the general population have remained largely unexplored. We report 332 validated de

  16. Structural analysis and functional characteristics of greenhouses in ...

    African Journals Online (AJOL)

    This study was carried out to determine the structural analysis and functional characteristics of the greenhouses in the Mediterranean region where 87% of the greenhouse production area in Turkey is concentrated. Information about types, material and construction properties, placement and arrangement of greenhouses in ...

  17. Design characteristics and case study of KALIMER reactor support structure

    International Nuclear Information System (INIS)

    Kim, J. B.; Lee, H. Y.; You, B.

    1999-01-01

    In this paper, six design alternatives to the preliminary design concept of the reactor support structure of which shape is support arm type were presented and the comparative study has been carried out considering design adequacy, simplicity, in-service-inspection, and interface requirements qualitatively. The structural analyses using ANSYS code have been performed with respect to three different design concepts selected from qualitative comparison study. It is concluded that the support ring attached to the reactor head(6th design alternative) is the most appropriate conceptual design shape considering both design characteristics and structural integrity

  18. Strain Concentration at Structural Discontinuities and Its Prediction Based on Characteristics of Compliance Change in Structures

    Science.gov (United States)

    Kasahara, Naoto

    Elevated temperature structural design codes pay attention to strain concentration at structural discontinuities due to creep and plasticity, since it causes an increase in creep-fatigue damage of materials. One of the difficulties in predicting strain concentration is its dependence on the magnitude of loading, the constitutive equations, and the duration of loading. In this study, the author investigated the fundamental mechanism of strain concentration and its main factors. The results revealed that strain concentration is caused by strain redistribution between elastic and inelastic regions, which can be quantified by the characteristics of structural compliance. The characteristics of structural compliance are controlled by elastic region in structures and are insensitive to constitutive equations. It means that inelastic analysis can be easily applied to obtain compliance characteristics. By utilizing this fact, a simplified inelastic analysis method was proposed based on the characteristics of compliance change for the prediction of strain concentration.

  19. Dynamic characteristics analysis of deployable space structures considering joint clearance

    Science.gov (United States)

    Li, Tuanjie; Guo, Jian; Cao, Yuyan

    2011-04-01

    The clearance in joints influences the dynamic stability and the performance of deployable space structures (DSS). A virtual experimental modal analysis (VEMA) method is proposed to deal with the effects of joint clearance and link flexibility on the dynamic characteristics of the DSS in this paper. The focus is on the finite element modeling of the clearance joint, VEMA and the modal parameters identification of the DSS. The finite element models (FEM) of the clearance joint and the deployable structure are established in ANSYS. The transient dynamic analysis is conducted to provide the time history data of excitation and response for the VEMA. The fast Fourier transform (FFT) technique is used to transform the data from time domain to frequency domain. The frequency response function is calculated to identify the modal parameters of the deployable structure. Experimental verification is provided to indicate the VEMA method is both a cost and time efficient approach to obtain the dynamic characteristics of the DSS. Finally, we analyze the effects of clearance size and gravity on the dynamic characteristics of the DSS. The analysis results indicate that the joint clearance and gravity strongly influence the dynamic characteristics of the DSS.

  20. Ingestive behavior of crossbred heifers in four seasons related to the structure of stargrass pasture

    Directory of Open Access Journals (Sweden)

    Ludmila Lacerda Campana

    2015-02-01

    Full Text Available The ingestive behavior of crossbred heifers grazing on stargrass pasture was managed at two levels of light interception and two levels of post-grazing residual height. The experiment was conducted at Pesagro (Seropédica, Rio de Janeiro State between April 2012 and January 2013. The grazing (GT, rumination (RT and idling (IT times were evaluated every 10 minutes throughout a 24-hour period. Forage samples were collected for the analysis of chemical composition and for leaf:stem ratio determination. Dry bulb, wet bulb and black globe temperatures were evaluated every hour along with the relative humidity, during grazing to characterize the environment and calculate the Black Globe Humidity Index (BGHI. The mean grazing time (6 hours was inversely related to sward height. The rumination time was associated with lignin content, in autumn and spring. The mean idle time (9 hours was related to the grazing time. Animals became tolerant to climatic variations, as GT, RT and IT showed no temporal variations. On the other hand, the sward structure and its chemical characteristics showed greater influence on the ingestive activities of cattle grazing on pasture.

  1. Best Entry Points for Structured Document Retrieval - Part I: Characteristics

    DEFF Research Database (Denmark)

    Reid, Jane; Lalmas, Mounia; Finesilver, Karen

    2006-01-01

    Structured document retrieval makes use of document components as the basis of the retrieval process, rather than complete documents. The inherent relationships between these components make it vital to support users' natural browsing behaviour in order to offer effective and efficient access...... to structured documents. This paper examines the concept of best entry points, which are document components from which the user can browse to obtain optimal access to relevant document components. In particular this paper investigates the basic characteristics of best entry points....

  2. Study of damping characteristics of fibre reinforced composite aerospace structure

    International Nuclear Information System (INIS)

    Khan, M.Z.; Saleh, S.; Munir, A.

    2006-01-01

    Composite materials are used in a variety of high demanding structural applications. Apart from their other preferable properties, they have high-energy dissipation characteristics, which is important aspect when we repeatedly wiggle the system back and forth. It is important to have thorough understanding of material damping behavior; in general materials damping tends to be complex nonlinear function of vibration amplitude, frequency of loading and material formulation. There are number of mathematical models available in literature to obtain hysteresis curves. One approach for identifying damping characteristics used mechanical hysteresis curves. In present work, a phenomenon was observed during testing of fibre reinforced composite beam of an aerospace structure, that for increase load in structure, the path of Force vs. Displacement curve is different than the path of unloading. A plot is generated which indicate the hysteresis loop representing the steady state dynamic behavior of material. The area enclosed by such curves is proportional to energy dissipation per cycle. However, the specific shape of the curve also has important implications for characterizing the specific functional form of the damping. Therefore, it is important to develop methods for accurately accounting for such effects. The current work explores the damping characteristics both theoretically and experimentally. (author)

  3. Association between brain structure and phenotypic characteristics in pedophilia.

    Science.gov (United States)

    Poeppl, Timm B; Nitschke, Joachim; Santtila, Pekka; Schecklmann, Martin; Langguth, Berthold; Greenlee, Mark W; Osterheider, Michael; Mokros, Andreas

    2013-05-01

    Studies applying structural neuroimaging to pedophiles are scarce and have shown conflicting results. Although first findings suggested reduced volume of the amygdala, pronounced gray matter decreases in frontal regions were observed in another group of pedophilic offenders. When compared to non-sexual offenders instead of community controls, pedophiles revealed deficiencies in white matter only. The present study sought to test the hypotheses of structurally compromised prefrontal and limbic networks and whether structural brain abnormalities are related to phenotypic characteristics in pedophiles. We compared gray matter volume of male pedophilic offenders and non-sexual offenders from high-security forensic hospitals using voxel-based morphometry in cross-sectional and correlational whole-brain analyses. The significance threshold was set to p pedophilia. The neuroanatomical abnormalities in pedophilia seem to be of a dimensional rather than a categorical nature, supporting the notion of a multifaceted disorder. Copyright © 2013 Elsevier Ltd. All rights reserved.

  4. [Age structure and growth characteristic of Castanopsis fargesii population].

    Science.gov (United States)

    Song, Kun; Da, Liang-jun; Yang, Tong-hui; Yang, Xu-feng

    2007-02-01

    In this paper, the age structure and growth characteristics of Castanopsis fargesii population in a shade-tolerant broadleaved evergreen forest were studied, aimed to understand more about the regeneration patterns and dynamics of this population. The results showed that the age structure of C. fargesii population was of sporadic type, with two death peaks of a 30-year gap. This population had a good plasticity in growth to light condition. Because there were no significant differences in light condition under the canopy in vertical, the saplings came into their first suppression period when they were 5-8 years old, with a height growth rate less than 0. 1 m x a(-1) lasting for 10 years. The beginning time of the first growth suppression period was by the end of the first death peak of the population, and the ending time of the first growth suppression period was at the beginning of the second death peak of the population, demonstrating that growth characteristic was the key factor affecting the age structure of C. fargesii.

  5. Abundance and guild structure of grasshoppers (Orthoptera ...

    African Journals Online (AJOL)

    This study was conducted to determine how savanna grass sward modifications caused by heavy grazing pressure influenced the abundance and guild structure of grasshoppers. Heavily grazed communal land was compared with a lightly grazed area and a mowed airstrip, in adjacent protected land, in the Mpumalanga ...

  6. Structural and morphological characteristics of composite: polyamide 6/ferrite nickel

    International Nuclear Information System (INIS)

    Fernandes, P.C.; Santos, P.T.A.; Silva, T.R.G.; Araujo, E.M.; Costa, A.C.F.M.

    2010-01-01

    This study aims to evaluate the structural and morphological characteristics of a composite polyamide 6 with 50% loading of nickel ferrite. The ferrite was obtained by combustion synthesis and calcined in muffle furnace at 700 deg C. The polymer matrix was previously dried in vacuum oven at 80 deg C / 48 h to eliminate moisture. The composites were characterized by XRD and SEM. XRD results show the incorporation of cargo in the matrix, and that increasing temperature led to a considerable increase in crystallinity. The particle size of the load in the matrix was changed by increasing temperature. (author)

  7. China’s Capital Market: its Structure and Characteristics

    Directory of Open Access Journals (Sweden)

    Ionela Bălțătescu

    2010-10-01

    Full Text Available The purpose of the present article is to briefly overview the main characteristics and structure of China’s capital market. The first part of the paper presents the main stock exchanges, futures exchanges and commodity exchanges of China, securities products available in China, China’s level of domestic market capitalization and other key financial information and statistics regarding China capital market. The second part of the paper contains a short review on the liberalization and reforms of China’s financial market, especially the programs QFII (Qualified Foreign Institutional Investor, QDII (Qualified Domestic Institutional Investor and mini-QFII.

  8. Towards Multifunctional Characteristics of Embedded Structures With Carbon Nanotube Yarns

    Science.gov (United States)

    Hernandez, Corey D.; Gates, Thomas S.; Kahng, Seun K.

    2006-01-01

    This paper presents recent results on research of achieving multifunctional structures utilizing Carbon Nanotube (CNT) yarns. The investigation centers on creating composite structures with CNT yarns to simultaneously achieve increases in mechanical strength and the ability to sense strain. The CNT yarns used in our experiments are of the single-ply and two-ply variety with the single-ply yarns having diameters on the order of 10-20 m. The yarns are embedded in silicon rubber and polyurethane test specimens. Mechanical tests show an increase in modulus of elasticity, with an additional weight increase of far less than one-percent. Sensing characteristics of the yarns are investigated on stainless steel test beams in an electrical bridge configuration, and are observed to have a strain sensitivity of 0.7mV/V/1000 micro-strain. Also reported are measurements of the average strain distribution along the direction of the CNT yarns on square silicon rubber membranes.

  9. Structural-semantic characteristic of phraseologisms in modern German language

    Directory of Open Access Journals (Sweden)

    Abramova Natalya Viktorovna

    2015-03-01

    Full Text Available The article is devoted to the structural and semantic characteristics of phraseology of the modern German language. It reveals the essence of the concept of “idioms”, discusses various classification of phraseological units in German. Many linguists offer a variety of phraseological units classification. It is studied in detailed the classification by B. Fleischer, where the following types of phraseological units are distinguished: nominative collocations, communication idioms, phrasal templates. V.V. Vinogradov classified phraseological units according to their degree of semantic fusion. He identified three major types of phraseological units: phraseological seam, phraseological unity and phraseological (non-free combination. M.D. Stepanova and I.I. Chernyshev worked out structural and semantic classification of phraseological units, consisting of three groups: phraseological units, phraseological combinations, phraseological expressions. A special group of phraseological combinations is of E. Agricola - stable phrases. H. Burger classifies idioms according to their function in the communication process: reference idioms, structural phraseological units, communication idioms. Each classification is provided with vivid examples that characterize the structure and semantics of phraseological units of modern German language.

  10. Characteristics and crystal structure of bacterial inosine-5'-monophosphate dehydrogenase

    International Nuclear Information System (INIS)

    Zhang, R.; Evans, G.; Rotella, F.J.; Westbrook, E.M.; Beno, D.; Huberman, E.; Joachimiak, A.; Collart, F.R.

    1999-01-01

    IMP dehydrogenase (IMPDH) is an essential enzyme that catalyzes the first step unique to GTP synthesis. To provide a basis for the evaluation of IMPDH inhibitors as antimicrobial agents, we have expressed and characterized IMPDH from the pathogenic bacterium Streptococcus pyogenes. Our results show that the biochemical and kinetic characteristics of S. pyogenes IMPDH are similar to other bacterial IMPDH enzymes. However, the lack of sensitivity to mycophenolic acid and the K m for NAD (1180 μM) exemplify some of the differences between the bacterial and mammalian IMPDH enzymes, making it an attractive target for antimicrobial agents. To evaluate the basis for these differences, we determined the crystal structure of the bacterial enzyme at 1.9 (angstrom) with substrate bound in the catalytic site. The structure was determined using selenomethionine-substituted protein and multiwavelength anomalous (MAD) analysis of data obtained with synchrotron radiation from the undulator beamline (19ID) of the Structural Biology Center at Argonne's Advanced Photon Source. S. pyogenes IMPDH is a tetramer with its four subunits related by a crystallographic 4-fold axis. The protein is composed of two domains: a TIM barrel domain that embodies the catalytic framework and a cystathione β-synthase (CBS) dimer domain of so far unknown function. Using information provided by sequence alignments and the crystal structure, we prepared several site-specific mutants to examine the role of various active site regions in catalysis. These variants implicate the active site flap as an essential catalytic element and indicate there are significant differences in the catalytic environment of bacterial and mammalian IMPDH enzymes. Comparison of the structure of bacterial IMPDH with the known partial structures from eukaryotic organisms will provide an explanation of their distinct properties and contribute to the design of specific bacterial IMPDH inhibitors

  11. Capacitance-voltage characteristics of quantum well structures

    CERN Document Server

    Moon, C R; Choe, B D

    1999-01-01

    The characteristics of the apparent carrier distribution (ACD) of quantum well (QW) structures are investigated using the self-consistent simulation and the capacitance-voltage (C-V) profiling techniques. The simulation results on the differential carrier distribution show that the change of position expectation value of two-dimensional electrons determines the full width at half maximum of 100 K ACD peaks when conduction band offset is DELTA E sub c = 160 meV and the QW width t sub w is greater than 120 A. The contribution of Debye averaging effects to the ACD peaks becomes important as t sub w and DELTA E sub c values decrease and the temperature is increased. The influence of Debye averaging effects on ACD peaks appears differently according to the location of each well in multiple QWs. These results indicate that the extraction of QW parameters from the C-V profile should be done with caution.

  12. FINITE VOLUME METHOD FOR DETERMINING THE NATURAL CHARACTERISTICS OF STRUCTURES

    Directory of Open Access Journals (Sweden)

    N. FALLAH

    2013-02-01

    Full Text Available In this paper a finite volume based formulation is developed to calculate the structural natural characteristics including the natural frequencies and the critical buckling loads of slender beam/beam-columns in which the shear effects are taken into account. For natural frequency calculations, both shear effects and rotational inertia effects are considered. In this finite volume based approach, the equilibrium equations of control volumes are expressed and used with the boundary conditions to obtain the eigenvalue equation in the standard format. Then, the natural characteristics of beam/beam-columns are obtained by solving the eigenvalue equations. The formulation is tested on a number of benchmark problems. Accordingly, the proposed formulation has been found to accurately predict the natural frequencies and the critical buckling loads of the test problems. Also, the formulation is tested for the very thin and thick beams. It is found that the formulation is also able to analyze the thin beams in which no shear locks is observed.

  13. Structural Characteristics of Rotate Vector Reducer Free Vibration

    Directory of Open Access Journals (Sweden)

    Chuan Chen

    2017-01-01

    Full Text Available For RV reducer widely used in robots, vibration significantly affects its performance. A lumped parameter model is developed to investigate free vibration characteristics without and with gyroscopic effects. The dynamic model considers key factors affecting vibration such as involute and cycloid gear mesh stiffness, crankshaft bending stiffness, and bearing stiffness. For both nongyroscopic and gyroscopic systems, free vibrations are examined and compared with each other. Results reveal the specific structure of vibration modes for both systems, which results from symmetry structure of RV reducer. According to vibration of the central components, vibration modes of two systems can be classified into three types, rotational, translational, and planetary component modes. Different from nongyroscopic system, the eigenvalues with gyroscopic effects are complex-valued and speed-dependent. The eigenvalue for a range of carrier speeds is obtained by numerical simulation. Divergence and flutter instability is observed at speeds adjacent to critical speeds. Furthermore, the work studies effects of key factors, which include crankshaft eccentricity and the number of pins, on eigenvalues. Finally, experiment is performed to verify the effectiveness of the dynamic model. The research of this paper is helpful for the analysis on free vibration and dynamic design of RV reducer.

  14. Canopy characteristics, animal behavior and forage intake by goats grazing on Tanzania-grass pasture with different heights - doi: 10.4025/actascianimsci.v34i4.14544

    Directory of Open Access Journals (Sweden)

    Maurílio Souza dos Santos

    2012-10-01

    Full Text Available This study evaluated the influence of Tanzania-grass sward height (30, 50, 70 and 90 cm on the morphological characteristics of the canopy, grazing behavior and forage intake by adult Anglo Nubian female goats. A completely randomized experimental design was employed, with two replicates in space and two replicates in time. Six animals were used to assess the grazing behavior, and four, the ingestion process. The rise in sward height increased the forage and leaf mass, the percentages of stem and dead material, and reduced the leaf stem-1 ratio. Above 50 cm there was an increase in grazing time and a decrease in leisure time. A positive linear correlation was detected between sward height and bite depth. The consumed forage mass, ingestion rate and daily intake were higher at 50 cm, indicating that the other heights reduced the intake process. The sward height was negatively correlated to the bite rate and positively to the bite time. The sward height of 50 cm presents the best combination of features, favoring the grazing and ingestive behavior of female adult goats.

  15. Macular structural characteristics in children with Down syndrome.

    Science.gov (United States)

    O'Brien, Scott; Wang, Jingyun; Smith, Heather A; Donaldson, Dana L; Haider, Kathryn M; Roberts, Gavin J; Sprunger, Derek T; Neely, Daniel E; Plager, David A

    2015-12-01

    This prospective study aimed to investigate macular structural characteristics in children with Down syndrome compared to those in healthy children. Two groups of children (aged 6-16 years) were enrolled: children with Down syndrome (Down syndrome group, N = 17) and age-matched healthy children who were full-term at birth (control group, N = 18). Eligible patients had visual acuity of 20/100 or better and gestational age at birth of ≥ 36 weeks. Fourier domain optical coherence tomography was used for imaging of the macular retinal structure, and retinal volume scans centered on the macula were obtained. Central subfield thickness (CST) and the thickness of the inner and outer retinal layer regions were analyzed using the instrument's segmentation software. The analysis of data is provided for the right eye only, since there was no significant difference between right and left eyes for either the Down syndrome or control groups. Children in the Down syndrome group generally had identifiable retinal structure. The CST for the full retina and inner and outer retinal layers were all significantly greater in the Down syndrome group than the control group (independent t test, all p syndrome had macular thickness outside the normal range. Visual acuity in the Down syndrome group was not directly correlated with increased CST (t = 1.288, r = 0.326, p = 0.202). On average, CST in the Down syndrome group was greater than that in the control group, suggesting abnormal macular development in children with Down syndrome.

  16. The response of sward-dwelling arthropod communities to reduced grassland management intensity in pastures

    Directory of Open Access Journals (Sweden)

    Helden Alvin J.

    2015-12-01

    Full Text Available We compared arthropod taxon richness, diversity and community structure of two replicated grassland husbandry experiments to investigate effects of reduced management intensity, as measured by nutrient input levels (390, 224 and 0 kg/ha per year N in one experiment, and 225 and 88 kg/ha per year N in another. Suction sampling was used to collect Araneae, Coleoptera, Hemiptera and Hymenoptera, with Araneae and Coleoptera also sampled with pitfall trapping. Univariate analyses found no significant differences in abundance and species density between treatments. However, with multivariate analysis, there were significant differences in arthropod community structure between treatments in both experiments.

  17. A review of the structural characteristics of alloy 800

    International Nuclear Information System (INIS)

    Orr, J.

    1978-01-01

    The published literature is reviewed and supplemented by current information from the author's laboratory, to show the influence of various compositional, heat treatment and thermomechanical factors on the structural characteristics of Alloy 800. The features discussed include carbon, aluminium, titanium and boron, solution treatment, ageing treatments with and without applied strain, and cold working. Examples of the aspects reviewed include the effect of heat treatment and service or testing temperature on the austenite grain size, and the relative importance of M 23 C 6 and TiC, the influence of carbon level on gamma prime, the effect of residual or steady stress combined with time at temperature on changes in carbide or gamma prime morphology, and on the appearance of sigma or other intermetallic phases. The questions posed by these features are discussed generally, in terms of their effect on the mechanical properties at ambient and elevated temperatures and on the time-dependent properties. The review also suggests areas where further research work is required on Alloy 800. (Auth.)

  18. Multiview hyperspectral topography of tissue structural and functional characteristics

    Science.gov (United States)

    Liu, Peng; Huang, Jiwei; Zhang, Shiwu; Xu, Ronald X.

    2016-01-01

    Accurate and in vivo characterization of structural, functional, and molecular characteristics of biological tissue will facilitate quantitative diagnosis, therapeutic guidance, and outcome assessment in many clinical applications, such as wound healing, cancer surgery, and organ transplantation. We introduced and tested a multiview hyperspectral imaging technique for noninvasive topographic imaging of cutaneous wound oxygenation. The technique integrated a multiview module and a hyperspectral module in a single portable unit. Four plane mirrors were cohered to form a multiview reflective mirror set with a rectangular cross section. The mirror set was placed between a hyperspectral camera and the target biological tissue. For a single image acquisition task, a hyperspectral data cube with five views was obtained. The five-view hyperspectral image consisted of a main objective image and four reflective images. Three-dimensional (3-D) topography of the scene was achieved by correlating the matching pixels between the objective image and the reflective images. 3-D mapping of tissue oxygenation was achieved using a hyperspectral oxygenation algorithm. The multiview hyperspectral imaging technique was validated in a wound model, a tissue-simulating blood phantom, and in vivo biological tissue. The experimental results demonstrated the technical feasibility of using multiview hyperspectral imaging for 3-D topography of tissue functional properties.

  19. Improving the Dynamic Characteristics of Body-in-White Structure Using Structural Optimization

    Directory of Open Access Journals (Sweden)

    Aizzat S. Yahaya Rashid

    2014-01-01

    Full Text Available The dynamic behavior of a body-in-white (BIW structure has significant influence on the noise, vibration, and harshness (NVH and crashworthiness of a car. Therefore, by improving the dynamic characteristics of BIW, problems and failures associated with resonance and fatigue can be prevented. The design objectives attempt to improve the existing torsion and bending modes by using structural optimization subjected to dynamic load without compromising other factors such as mass and stiffness of the structure. The natural frequency of the design was modified by identifying and reinforcing the structure at critical locations. These crucial points are first identified by topology optimization using mass and natural frequencies as the design variables. The individual components obtained from the analysis go through a size optimization step to find their target thickness of the structure. The thickness of affected regions of the components will be modified according to the analysis. The results of both optimization steps suggest several design modifications to achieve the target vibration specifications without compromising the stiffness of the structure. A method of combining both optimization approaches is proposed to improve the design modification process.

  20. Characteristics of wave structures derived from lidar measurements

    Science.gov (United States)

    Baumgarten, Kathrin; Gerding, Michael; Höffner, Josef; Lübken, Franz-Josef

    2016-04-01

    A daylight capable Rayleigh-Mie-Raman (RMR) lidar is in operation since summer 2010 at the mid-latitude station at Kühlungsborn (54° N, 12° E). The RMR lidar system is used for measuring wave structures at day and night to investigate short and long periodic atmospheric waves, like gravity waves (GW) and thermal tides (with diurnal, semidiurnal and terdiurnal components). About 6150 h of data have been acquired so far, with each sounding lasting for at least 6 h. For such long lasting data sets the general problem is the separation of the different wave contributions from the observed superposition of GW, tides or even longer periodic waves in the time series of temperature profiles. For extracting wave induced temperature deviations the most common method is to calculate these from the daily mean. Using this method the daylight capability allows the characterization of tides for a long lasting measurement. We will present the variability of tidal amplitudes on scales of days that are not represented in monthly averages. Because short periodic GW can at least partly hide behind those temperature deviations induced by tides, we use spectral filter methods for extracting GW induced temperature deviations. We will show a comparison of different methods with regard to gravity waves. GW activity and characteristics are derived in an altitude range between ~30 and ~70 km. The results demonstrate that the gravity wave potential energy density (GWPED) strongly depends on the used filter method. The contribution of different spectral ranges to the total GWPED will be presented.

  1. field occurrence and structural characteristics of basement rocks ...

    African Journals Online (AJOL)

    Global Journal

    NNW/NW- (65.68%). • E - W (8.28%). • NE - SW (26.04%). The brittle structures trend predominantly in the. NNW/NW direction while the ductile structures trend in the. NNE/NE direction. Table 3: Summary of strike azimuth frequency data of structures (foliations, joints/fractures and veins) in the study area. Structural Elements.

  2. Egg structural characteristics of Pygmy Cormorant (Microcarbo pygmaeus)

    OpenAIRE

    Faris A. Al-Obaidi; Shahrazad M. Al-Shadeedi

    2012-01-01

    This study was carried out to determine egg morphology characteristics and component of Pygmy Cormorant (Microcarbo pygmaeus) in Iraq. Freshly Pygmy Cormorant eggs without developed embryo were collected from Al- Tarmiya lakes north of Baghdad city to determined egg morphology characteristics including egg shape dimensions: weight, volume, specific gravity, shell, yolk, albumin weight as well as percentage of shell, yolk and albumin. Result...

  3. Simulation and experimental investigation of structural dynamic frequency characteristics control.

    Science.gov (United States)

    Zhang, Xingwu; Chen, Xuefeng; You, Shangqin; He, Zhengjia; Li, Bing

    2012-01-01

    In general, mechanical equipment such as cars, airplanes, and machine tools all operate with constant frequency characteristics. These constant working characteristics should be controlled if the dynamic performance of the equipment demands improvement or the dynamic characteristics is intended to change with different working conditions. Active control is a stable and beneficial method for this, but current active control methods mainly focus on vibration control for reducing the vibration amplitudes in the time domain or frequency domain. In this paper, a new method of dynamic frequency characteristics active control (DFCAC) is presented for a flat plate, which can not only accomplish vibration control but also arbitrarily change the dynamic characteristics of the equipment. The proposed DFCAC algorithm is based on a neural network including two parts of the identification implement and the controller. The effectiveness of the DFCAC method is verified by several simulation and experiments, which provide desirable results.

  4. Structural Characteristics of HPDSP Concrete on Beam Column Joints

    OpenAIRE

    Sushil Kumar Swar; Sanjay Kumar Sharma; Hari Krishan Sharma; Sushil Kumar

    2015-01-01

    The seriously damaged structures during earthquakes show the need and importance of design of reinforced concrete structures with high ductility. Reinforced concrete beam-column joints have an important function in all structures. Under seismic excitation, the beam column joint region is subjected to horizontal and vertical shear forces whose magnitude is many times higher than the adjacent beam and column. Strength and ductility of structures depends mainly on proper det...

  5. Stability of Electrical Characteristics of MOS Structures Based on Gallium Oxide

    Science.gov (United States)

    Kalygina, V. M.; Petrova, Yu. S.; Prudaev, I. A.; Tolbanov, O. P.

    2016-10-01

    We present the results of studying the capacitance-voltage and conductance-voltage characteristics of the GaxOy/ GaAs-based metal - oxide - semiconductor structures obtained by thermal evaporation. Influence of the annealing temperature on the characteristics of the structures is established. It is found that at long-term storage in the room atmosphere, the structures do not change their properties, which is manifested in the stability of electrical characteristics.

  6. Digital Learning Characteristics and Principles of Information Resources Knowledge Structuring

    Science.gov (United States)

    Belichenko, Margarita; Davidovitch, Nitza; Kravchenko, Yuri

    2017-01-01

    Analysis of principles knowledge representation in information systems led to the necessity of improving the structuring knowledge. It is caused by the development of software component and new possibilities of information technologies. The article combines methodological aspects of structuring knowledge and effective usage of information…

  7. Characteristics of surface wind structure of tropical cyclones over the ...

    Indian Academy of Sciences (India)

    the effective utilization of above-mentioned multi- platform-based satellite-derived wind product is very essential to minimize the error in intensity and structure monitoring and forecast. So, a study has been undertaken to analyze the mean character- istics of surface wind distribution and hence the structure of TC based on ...

  8. On the modal characteristics of damaging structures subjected to earthquakes

    Science.gov (United States)

    Carlo Ponzo, Felice; Ditommaso, Rocco; Auletta, Gianluca; Iacovino, Chiara; Mossucca, Antonello; Nigro, Antonella; Nigro, Domenico

    2015-04-01

    Structural Health Monitoring, especially for structures located in seismic prone areas, has assumed a meaning of great importance in last years, for the possibility to make a more objective and more rapid estimation of the damage occurred on buildings after a seismic event. In the last years many researchers are working to set-up new methodologies for Non-destructive Damage Evaluation based on the variation of the dynamic behaviour of structures under seismic loads. The NDE methods for damage detection and evaluation can be classified into four levels, according to the specific criteria provided by the Rytter. Each level of identification is correlated with specific information related to monitored structure. In fact, by increasing the level it is possible to obtain more information about the state of the health of the structures, to know if damage occurred on the structures, to quantify and localize the damage and to evaluate its impact on the monitored structure. Several authors discussed on the possibility to use the mode shape curvature to localize damage on structural elements, for example, by applying the curvature-based method to frequency response function instead of mode shape, and demonstrated the potential of this approach by considering real data. Damage detection approach based on dynamic monitoring of structural properties over time has received a considerable attention in recent scientific literature. In earthquake engineering field, the recourse to experimental research is necessary to understand the mechanical behaviour of the various structural and non-structural components. In this paper a new methodology to detect and localize a possible damage occurred on a framed structure after an earthquake is presented and discussed. The main outcomes retrieved from many numerical non linear dynamic models of reinforced concrete framed structures characterized by 3, 5 and 8 floors with different geometric configurations and designed for gravity loads only

  9. Thermo-mechanical Characteristics of Smart Skin Antenna Structures

    Science.gov (United States)

    Lee, Chang-Yull; Yoo, Kwang-Kyu; Kim, Ji-Hwan

    Analysis on the thermo-mechanical behaviors of smart skin antenna structures under air flow is performed. The model is a conformal load-bearing structure, reducing radar cross section and increasing stealth functions are very important. The skin is modeled as a multi-layer sandwich structure composed of carbon/epoxy, glass/epoxy and a dielectric polymer. Furthermore, a dielectric layer is embedded on the middle surface of the sandwich structure to act as antenna or radars. The formulation of the structural model is based on the first-order shear deformation plate theory. Lastly, Newton-Raphson iterative method applied for solving the nonlinear equations of the thermal postbuckling analysis and numerical results are calculated by finite element method.

  10. Evaluation of structural behavior, geological and hydrogeological characteristics

    International Nuclear Information System (INIS)

    Kim, Jhin Wung; Kim, Sun Hoon; Kim, Dae Hong; Choi, Kyu Sup

    1992-02-01

    In order to understand the behavior of an underground structure properly, this report includes the study on the structural behavior of rock masses surrounding underground openings considering the effect of excavation. Before analyzing the underground structure, the followings are studied: initial stress distribution before excavation, stress release and redistribution due to the sequential excavation, comparison of analysis methods, discussions on numerical simulation techniques for the sequential excavation and an numerical analysis modeling. The underground structure in then analyzed using the finite element and distinct element methods of analysis considering the effect of sequential excavation, Based on the results of the analysis, the followings are discussed: shape of the opening, distance between openings, method and sequence of excavation, and structural reinforcement. (Author)

  11. Synthesis of gold nanoparticles with different atomistic structural characteristics

    International Nuclear Information System (INIS)

    Esparza, R.; Rosas, G.; Lopez Fuentes, M.; Sanchez Ramirez, J.F.; Pal, U.; Ascencio, J.A.; Perez, R.

    2007-01-01

    A chemical reduction method was used to produce nanometric gold particles. Depending on the concentration of the main reactant compound different nanometric sizes and consequently different atomic structural configurations of the particles are obtained. Insights on the structural nature of the gold nanoparticles are obtained through a comparison between digitally-processed experimental high-resolution electron microscopy images and theoretically-simulated images obtained with a multislice approach of the dynamical theory of electron diffraction. Quantum molecular mechanical calculations, based on density functional theory, are carried out to explain the relationships between the stability of the gold nanoparticles, the atomic structural configurations and the size of nanoparticles

  12. A setup for measuring characteristics of microwave electric vacuum devices with open resonance structures

    DEFF Research Database (Denmark)

    Rybalko, Oleksandr; Ruban, A. I.; Vorob’ev, G. S.

    2015-01-01

    -tuning range, an additional periodic metal–dielectric structure is introduced into the open resonator. The experimental results of investigations of the energy, volt–ampere, and frequency characteristics of the modified diffraction-radiation generator prototype are compared to the characteristics...... of the generator without a metal–dielectric structure....

  13. The impact of firm and industry characteristics on small firms' capital structure

    NARCIS (Netherlands)

    Degryse, H.A.; de Goeij, P. C.; Kappert, P.

    2012-01-01

    We study the impact of firm and industry characteristics on small firms’ capital structure, employing a proprietary database containing financial statements of Dutch small and medium-sized enterprises (SMEs) from 2003 to 2005. The firm characteristics suggest that the capital structure decision is

  14. The Role of Structural Characteristics in Problematic Video Game Play: An Empirical Study

    Science.gov (United States)

    King, Daniel L.; Delfabbro, Paul H.; Griffiths, Mark D.

    2011-01-01

    The research literature suggests that the structural characteristics of video games may play a considerable role in the initiation, development and maintenance of problematic video game playing. The present study investigated the role of structural characteristics in video game playing behaviour within a sample of 421 video game players aged…

  15. Characterisation of the dynamic characteristics of a complex jointed structure

    Directory of Open Access Journals (Sweden)

    Sulaiman M. S. A.

    2017-01-01

    Full Text Available Every structure that assembled with the joints has a significant effect on the dynamic behaviour of the structure. Therefore, the overall dynamic behaviour of the jointed structure highly relies on these joints. Finite element method (FEM is commonly used to model an element connector for the jointed structure due to its because every jointed structure has its owns joint properties. The aims of this research are to identify the potential element connectors that are available in commercial finite element analysis package in order to represent the joints for spot welds and adhesive joints. The reliability of potential connector elements are quantified by comparing the predicted result calculated from commercial finite element analysis package with the experimental result that obtained from the LMS Scadas. The model of element connectors have been constructed based on three types of the case studies. The comparison reveals that the combination of Type 2 (ACM2 and Type 3 (CWELD have shown a better capability to represent the joints of the complex jointed structure.

  16. Structure and electrochemical characteristics of RENi3 alloy

    International Nuclear Information System (INIS)

    Zhang Xinbo; Yin Wenya; Chai Yujun; Zhao Minshou

    2005-01-01

    The RENi 3 (RE = La, Ce, Pr, Nd, Sm, Gd, Tb, Dy, Ho, Er, Y) series compounds have been prepared by arc melting constituent elements under Ar atmosphere. X-ray diffraction (XRD) analysis reveals that the as-prepared alloys have different lattice parameters and cell volumes, depending on different rare earth (RE) element. The electrochemical characteristics, including the electrochemical capacity, P-C isotherms, high rate chargeability (HRC) and high-rate dischargeability (HRD), of these alloys have been studied through the charge-discharge recycle testing at different temperatures, charge currents and discharge currents. The results show that YNi 3 has the largest cell volume, smallest density, and moreover, it shows more satisfactory electrochemical characteristics than other alloys, including discharge capacity, HRC, HRD and low temperature dischargeablity

  17. Structural characteristics of annual precipitation in Lake Urmia basin

    Science.gov (United States)

    Vaheddoost, Babak; Aksoy, Hafzullah

    2017-05-01

    Precipitation as the main process that brings evaporated water from the oceans to the land's surface is a critical role player in Lake Urmia basin (Iran). As a hyper-saline lake declared as UNESCO's biosphere reserve in Ramsar Convention, it is dealing with gradual atrophy. In this study, characteristics of annual precipitation in the Lake Urmia basin are investigated by means of several statistical measures and tests. Data in 53 meteorological stations widespread across the basin for a period of 31 years from 1981 to 2011 are considered for analysis. Fundamental statistical characteristics of the data like mean, maximum, minimum, standard deviation, coefficient of variation, coefficient of skewness, coefficient of kurtosis, auto-correlation and cross-correlation coefficients of the annual precipitation are calculated. Entropy in each station is also calculated with respect to the long-run mean precipitation of the basin. Results of the analysis are plotted in contour maps. Several tests for consistency, randomness, trend and best-fit probability distribution function are applied to investigate characteristics of the annual precipitation. Heterogeneity and dependence on local conditions are the main results revealed by this study while consistency and dependency of precipitation on North West and West of the basin are considered as the most effective among other regions. Due to the North-South oriented mountains, a relatively sharp decline in the precipitation from West to East can be compared to the gradual decline in precipitation from North to South due to smooth change in the terrain. It is also seen that such characteristics as probability distribution, consistency, randomness, trend, and uncertainty of annual precipitation in the Lake Urmia basin become more complex as crossing from West to East than crossing from North to South on the basin.

  18. Structural Characteristics of Rotate Vector Reducer Free Vibration

    OpenAIRE

    Chen, Chuan; Yang, Yuhu

    2017-01-01

    For RV reducer widely used in robots, vibration significantly affects its performance. A lumped parameter model is developed to investigate free vibration characteristics without and with gyroscopic effects. The dynamic model considers key factors affecting vibration such as involute and cycloid gear mesh stiffness, crankshaft bending stiffness, and bearing stiffness. For both nongyroscopic and gyroscopic systems, free vibrations are examined and compared with each other. Results reveal the s...

  19. Interrelation between structural and ion-diffusion dynamic characteristics of α-AgI

    International Nuclear Information System (INIS)

    Polyakov, V.I.

    1998-01-01

    Interrelation of structural and dynamic characteristics of α-AgI superionic conductor is discussed in the framework of the theory of reaction absolute rates. Temperature dependences of structural (iodine-silver root-mean-square distance) and dynamic (diffusion coefficient of silver ions, characteristic time) characteristics have been calculated using statistical sums relating to silver ion states involved in retarded-rotational motion. A good agreement between calculated and experimental data is shown

  20. Característica produtiva e estrutural de pastos mistos de aveia e azevém manejados em quatro alturas sob lotação contínua Structural and productive characteristic of oat and ryegrass mixed pastures managed in four intensities with variable stocking rate

    Directory of Open Access Journals (Sweden)

    Paulo César de Faccio Carvalho

    2010-09-01

    Full Text Available Monitoraram-se variáveis relacionadas à produção e à estrutura de pastos de aveia-preta (Avena strigosa, Schreb e azevém (Lolium multiflorum, Lam manejados em quatro alturas (10, 20, 30 e 40 cm, em pastejo contínuo com lotação variável (put and take. Utilizaram-se novilhos de corte mestiços de aproximadamente 10 meses de idade com peso médio inicial de 190 kg, em delineamento de blocos completos casualizados com três repetições. Investigou-se o tipo de distribuição das frequências de altura em seis datas, bem como o potencial de predição da massa seca de forragem por meio da altura do pasto. A massa de forragem aumentou de forma linear de acordo com a altura do pasto: cada 1 cm de aumento na altura acima de 10 cm correspondeu a um acréscimo de cerca de 107 kg de MS/ha na massa de forragem. Não houve efeito da altura do pasto na taxa de acúmulo (55,8 kg de MS/ha.dia nem na produção total de matéria seca (8.210 kg de MS/ha. A distribuição das frequências ajustou ao modelo normal em apenas uma das 96 séries analisadas. A distribuição tipo Gamma foi a que mais frequentemente se ajustou aos dados de altura do pasto, porém, uma vez iniciado o pastejo, a heterogeneidade no pasto foi tão alta que a distribuição das alturas não se ajustou a nenhum dos modelos estudados. É possível estimar a massa seca de forragem existente no pasto por meio de sua altura média, assim, sugere-se estabelecer alturas variáveis ao longo do ciclo de pastejo, com o intuito de se administrar a heterogeneidade causada pelo animal.It was monitored variables related to production and structure of oat (Avena strigosa Schreb and ryegrass (Lolium multiflorum Lam pastures managed at four sward heights (10, 20, 30, and 40 cm on continuous grazing with variable stocking (put and take. It was used crossbred beef steers at approximately 10 months of age and an average initial weight 190 kg in a complete random block design with three replicates

  1. Shielding and Radiation Characteristics of Cylindrical Layered Bianisotropic Structures

    Directory of Open Access Journals (Sweden)

    A. Toscano

    2005-12-01

    Full Text Available In this paper we propose an analytical study in the spectral domainof cylindrical layered structures filled with general bianisotropicmedia and fed by a 3D electric source. The integrated structure ischaracterized in terms of transmission matrices leading to anequivalent circuit representation of the whole multilayered structure.Within the framework of this two-port formalism, we present a newcontribution to the computation of the Green's function arising in theanalysis of multilayered conformal integrated antennas loaded withgeneral bianisotropic materials. We also propose an analytical study ofthe shielding effectiveness of general bianisotropic materials locatedin multilayered, cylindrical configuration. The expression of theshielded fields sustained both by plane wave and arbitrary sources isobtained in a closed analytical form. Numerical results are alsopresented showing effects of electromagnetic parameters on radiationpattern, matching properties and radar cross section of the integratedstructure.

  2. Photoelectric characteristics of inhomogeneous MOS silicon-based structures

    Science.gov (United States)

    Voitsekhovskii, Aleksander V.; Nesmelov, Sergey N.

    1999-09-01

    The abnormal photoelectric properties of Si-MIS structures, such as a significant photo-emf signal in the state of enhancement and a drop of the local photo-emf in inversion, were investigated with integrate and local photoelectric measurements. It has been established that the reason for the significant photo-emf signal in enhancement and the related features of the photoelectric properties of the structure is the photosensitivity in the region away from the electrode associated with a nonuniform distribution of electrically active defects. It has been demonstrated that the nonuniformity in surface potential may result in a drop of the local photo-emf in inversion. A conclusion has been made that the redistribution of nonequilibrium carriers along the boundary must be taken into account in constructing equivalent circuits of actual MIS structures.

  3. Structural Characteristics of Bimetallic Catalysts Supported on Nano-Ceria

    Directory of Open Access Journals (Sweden)

    J. F. Bozeman

    2011-01-01

    Full Text Available Cu-Pt bimetal catalysts supported on nanocrystalline CeO2 (nano-ceria are synthesized via the low-cost sol-gel approach followed by impregnation processing. The average particle size of the catalytic composites is 63 nm. Ceria nanopowders sequentially impregnated in copper solution and then in Pt solution transformed into Pt-skin-structured Cu-Pt/ceria nanocomposite, based on the surface elemental and bulk compositional analyses. The ceria supporter has a fluorite structure, but the structure of Cu and Pt catalytic contents, not detected by X-ray diffraction spectroscopy due to the low loading level, is yet conclusive. The bimetallic catalytic nanocomposites may potentially serve as sulfur-tolerant anode in solid oxide fuel cells.

  4. EMC characteristics of composite structure - Electric/electromagnetic shielding attenuation

    Science.gov (United States)

    Wegertseder, P.; Breitsameter, R.

    1989-09-01

    The paper reports electric/electromagnetic shielding-attenuation experiments performed on different test boxes built with the same materials and processes as those to be used for the construction of a helicopter. The measurements are performed in the frequency range of 14 to 18 GHz, and the effects of different composite materials, jointing and bonding of structure parts of the boxes, application and bonding of the mesh, the construction of access panels, and conductive seals on these panels are assessed. It is demonstrated that moderate electric/electromagnetic shielding-attenuation values can be achieved by composite structures made from carbon, and materials and procedures required for high shielding attenuation are discussed.

  5. Thermodynamic and structural characteristics of cement minerals at elevated temperature

    International Nuclear Information System (INIS)

    Bruton, C.J.; Meike, A.; Viani, B.E.; Martin, S.; Phillips, B.L.

    1994-05-01

    We have instituted an experimental and including program designed to elucidate the structural and thermodynamic response of cement minerals to elevated temperature. Components of the program involve: (a) synthesis of hydrated Ca-silicates; (b) structural analysis of cement phases induced by heating and dehydration/rehydration; (c) mechanistic and thermodynamic descriptions of the hydration/dehydration behavior of hydrated Ca-silicates as a function of temperature, pressure and relative humidity; (d) study of naturally occurring hydrated Ca-silicates; and (e) measurements of thermodynamic data for hydrated Ca-silicates

  6. Crystallographic characteristics and fine structures of semiconducting transition metal silicides

    Energy Technology Data Exchange (ETDEWEB)

    Shao, G., E-mail: G.Shao@bolton.ac.uk [Institute for Materials Research and Innovation, University of Bolton, Bolton BL3 5AB (United Kingdom); Gao, Y. [Faculty of Physics and Electronic Technology, Hubei University, Wuhan 430062 (China); Xia, X.H. [Institute for Materials Research and Innovation, University of Bolton, Bolton BL3 5AB (United Kingdom); Faculty of Physics and Electronic Technology, Hubei University, Wuhan 430062 (China); Milosavljevic, M. [VINCA Institute of Nuclear Sciences, P.O. Box 522, Belgrade 11001 (Serbia)

    2011-10-03

    Silicide-based photonic materials have attracted a great deal of research interest due to their compatibility with the well-developed silicon technology. Extensive efforts have been made for the synthesis and characterisation of these materials. This paper covers some aspects of the microstructural and crystallographic characteristics of ion beam synthesised silicides such as the semiconducting iron and ruthenium silicides, using transmission electron microscopy. A previously predicted new orientation relationship has been found to exist between the Si substrate and ion beam synthesised {beta}FeSi{sub 2} nanocrystals, which are free of 90{sup o} rotational order domain boundaries.

  7. Characteristic Properties of Equivalent Structures in Compositional Models

    Czech Academy of Sciences Publication Activity Database

    Kratochvíl, Václav

    2011-01-01

    Roč. 52, č. 5 (2011), s. 599-612 ISSN 0888-613X R&D Projects: GA MŠk 1M0572; GA ČR GA201/09/1891; GA ČR GEICC/08/E010 Grant - others:GA MŠk(CZ) 2C06019 Institutional research plan: CEZ:AV0Z10750506 Keywords : Equivalence problem * Compositional model * Persegram * Characteristic properties Subject RIV: BA - General Mathematics Impact factor: 1.948, year: 2011 http://library.utia.cas.cz/separaty/2011/MTR/kratochvil-0359927.pdf

  8. Structural and growth characteristics of two avian reoviruses.

    Science.gov (United States)

    Nick, H; Cursiefen, D; Becht, H

    1975-01-01

    Two virus strains which had been suspected to be the etiological agents of infectious bursitis (Gumboro disease) and of inclusion body hepatitis of chickens were characterized by their morphology, their peptide composition and the segmented genome of their double-stranded RNA to be typical reoviruses. Although the 2 avian strains did not clearly differ in their serological behaviour, the size of some of their RNA segments were not identical. Both strains replicated in tissue cultures prepared from the chorioallantoic membrane of embryonated eggs with growth characteristics of reoviruses.

  9. Characteristic time structure in slow resonant extracted beam

    International Nuclear Information System (INIS)

    Crebbin, K.C.

    1983-08-01

    The phase diagram for resonant extraction is normally shown as a sharp line, passing through the unstable fixed point, dividing the stable region from the unstable region. This line is a sharp boundary line in the limiting mathematical case where the particle passes through all points on the line. In the physical case, a specific particle occupies only a limited number of phase points along the line. As a result, the line becomes a band of finite width containing a number of regions of stability and instability. The width of this band and the time structure extracted from this band is related to the tune shift and shape of the perturbation used in the extraction system. This paper discusses the physical reasons for this effect and presents computer calculations showing the time structure for the NU equals two-thirds extraction system in the Bevalac. Photomultiplier pictures of beam structure taken before and after recent changes in the perturbation magnet show similar changes in time structure corresponding to changes in operating values of the NU shift used for extraction

  10. Structural characteristics of titanium coating on copper substrates

    Indian Academy of Sciences (India)

    the nuclear industry. 2. Experimental. Coatings of Ti were sputter deposited from a high purity. (99·99%) Ti target of 76 mm diameter on oxygen-free high .... fashion. A detailed TEM analysis presented in the latter sec- tion will further discuss on the morphology of the columnar structure. Figure 4(b) shows the energy ...

  11. Field occurrence and structural characteristics of basement rocks ...

    African Journals Online (AJOL)

    Bunu Area in part of Kabba-Lokoja-Igarra Schist Belt, southwestern Nigeria. ... structures in the NW-SE to N-S directions are filled by quartz veins, dolerites and pegmatite dykes and serve as conduits and pathway of the gold bearing ore fluids.

  12. Characteristics of Structural Breakdown in Plastic Concrete and ...

    African Journals Online (AJOL)

    The structural breakdown of plastic concrete when sheared in. a Couette-type rheometer is discussed with particular emphasis on the significant features of the resultant thixotropic break-down curve. A typical trace has four such significant features which characterise the mix. The significance of these features are analysed ...

  13. Characteristics of aluminum alloy microplastic deformation in different structural states

    Energy Technology Data Exchange (ETDEWEB)

    Seregin, G.V.; Efimenko, L.L.; Leonov, M.V. [Novosibirsk Pedagogical Inst. (Russian Federation)

    1995-07-01

    The solution to the problem of improving the mechanical properties (including cyclic strength) of structural materials is largely dependent on our knowledge of the laws governing the development of microplastic deformations in them. The effect of heat and mechanical treatment on the elastoplastic properties and fatigue resistance of the commercial aluminum alloys AK4-1 and D16 is analyzed.

  14. Structural characteristics of the nonallosteric human cytosolic malic enzyme.

    Science.gov (United States)

    Hsieh, Ju-Yi; Li, Shao-Yu; Chen, Meng-Chun; Yang, Pai-Chun; Chen, Hui-Yi; Chan, Nei-Li; Liu, Jyung-Hurng; Hung, Hui-Chih

    2014-10-01

    Human cytosolic NADP(+)-dependent malic enzyme (c-NADP-ME) is neither a cooperative nor an allosteric enzyme, whereas mitochondrial NAD(P)(+)-dependent malic enzyme (m-NAD(P)-ME) is allosterically activated by fumarate. This study examines the molecular basis for the different allosteric properties and quaternary structural stability of m-NAD(P)-ME and c-NADP-ME. Multiple residues corresponding to the fumarate-binding site were mutated in human c-NADP-ME to correspond to those found in human m-NAD(P)-ME. Additionally, the crystal structure of the apo (ligand-free) human c-NADP-ME conformation was determined. Kinetic studies indicated no significant difference between the wild-type and mutant enzymes in Km,NADP, Km,malate, and kcat. A chimeric enzyme, [51-105]_c-NADP-ME, was designed to include the putative fumarate-binding site of m-NAD(P)-ME at the dimer interface of c-NADP-ME; however, this chimera remained nonallosteric. In addition to fumarate activation, the quaternary structural stability of c-NADP-ME and m-NAD(P)-ME is quite different; c-NADP-ME is a stable tetramer, whereas m-NAD(P)-ME exists in equilibrium between a dimer and a tetramer. The quaternary structures for the S57K/N59E/E73K/S102D and S57K/N59E/E73K/S102D/H74K/D78P/D80E/D87G mutants of c-NADP-ME are tetrameric, whereas the K57S/E59N/K73E/D102S m-NAD(P)-ME quadruple mutant is primarily monomeric with some dimer formation. These results strongly suggest that the structural features near the fumarate-binding site and the dimer interface are highly related to the quaternary structural stability of c-NADP-ME and m-NAD(P)-ME. In this study, we attempt to delineate the structural features governing the fumarate-induced allosteric activation of malic enzyme. Copyright © 2014 Elsevier B.V. All rights reserved.

  15. Hydration characteristics and structure formation of cement pastes containing metakaolin

    Directory of Open Access Journals (Sweden)

    Dvorkin Leonid

    2018-01-01

    Full Text Available Metakaolin (MK is one of the most effective mineral admixtures for cement-based composites. The deposits of kaolin clays are wide-spread in the world. Metakaolin is comparable to silica fume as an active mineral admixture for cement-based composites. In this paper, the rheological and mechanical properties of cement paste containing metakaolin are investigated. The effect of MK is more evident at “tight” hydration conditions within mixtures with low water-cement ratio, provided by application of superplasticizers. The cement is replaced with 0 to 15% metakaolin, and superplasticizer content ranged from 0 to 1.5% by weight of cementitious materials (i.e. cement and metakaolin. An equation is derived to describe the relationship between the metakaolin and superplasticizer content and consistency of pastes. There is a linear dependence between metakalolin content and water demand. Second-degree polynomial describe the influence of superplasticizer content. The application of SP and MK may produce cement-water suspensions with water-retaining capacity at 50-70% higher than control suspensions. The investigation of initial structure forming of cement pastes with SP-MK composite admixture indicates the extension of coagulation structure forming phase comparing to the pastes without additives. Crystallization stage was characterized by more intensive strengthening of the paste with SP-MK admixture comparing to the paste without admixtures and paste with SP. Results on the porosity parameters for hardened cement paste indicate a decrease in the average diameter of pores and refinement of pore structure in the presence of metakaolin. A finer pore structure associated with an increase in strength. X-ray analysis data reveal a growing number of small-crystalline low-alkaline calcium hydrosilicates and reducing portlandite content, when MK dosage increases. Scanning electron microscopy (SEM data confirm, that hardened cement paste containing MK has

  16. Composites based on cellulose fiber nonwovens and a water soluble polymer 1. Structure and strength-deformation characteristics of cellulose fiber nonwovens and structural characteristics of the composites

    Science.gov (United States)

    Cerpakovska, D.; Kalnins, M.

    2012-03-01

    The results of a study on the strength-deformation characteristics (tensile elastic modulus, ultimate strength, elongation at break, and punching and tearing strengths) of two kinds of cellulose fiber nonwovens (CFNs) with dissimilar void content and different geometrical parameters of cellulose fibers are discussed. The structural characteristics of composites prepared by impregnation with poly(vinyl alcohol) water solutions are analyzed, too. Composites with volume fractions of polymer up to 0.4% and volume fractions of voids up to 0.3% were prepared. Filling of voids by the polymer occurred without significant changes in the structure of CFNs. The fraction of closed voids increased with polymer content.

  17. Studying structurally-mechanical characteristics suppositories with amlodipine

    Directory of Open Access Journals (Sweden)

    Fadi Al Zedan

    2013-02-01

    Full Text Available Rheological behaviour suppositories with amlodipine on lypofiles to a basis are studied and character of temperature effect on their structurally-mechanical properties is positioned. It is revealed that the temperature of carrying out of technological operations of homogenization and overflow suppositories 50-55ºС is optimum, providing necessary fluidity suppositories masses at hypodispersion in it reacting and aids.

  18. Structural and energetic characteristics of alkali metal hexachlorouranates (5)

    International Nuclear Information System (INIS)

    Kudryashov, V.L.; Suglobova, I.G.; Chirkst, D.Eh.

    1978-01-01

    Structure types and lattice parameters of alkali metal hexachlorouranates (5) have been determined by indicating the X-ray diffraction patterns of polycrystals. α-NaVCl 6 has a cubic structure of the Csub(s)PFsub(6) type; β-NaVCl 6 -trigonal lattice of the LiSbF 6 type; KVCl 6 and RbVCl 6 crystallize in the RbPaF 6 structure type; CsVCl 6 is isomorphous to CsPF 6 . Enthalpy values of hexachlorouranates (5) dissolution in 0.5% FeCl 3 solution and in 2% HCl have been measured and the standard enthalpy values of their formation have been calculated. The energies of crystal lattices and of the uranium-uranium-chlorine bonds have been calculated. When uranium coordination number is 6 the energy of the uranium-chlorine bond is 99.6+-0.5; when this number is 8 the energy equals 101.9+-0.5 kcal/mol

  19. Spatial variation in spoil and vegetative characteristics of pastures on reclaimed surface mined land

    International Nuclear Information System (INIS)

    Teutsch, C.D.; Collins, M.; Ditsch, D.C.

    1999-01-01

    Kentucky has large areas of reclaimed surface mined land that could provide grazing for livestock. Research is needed to determine optimal stocking densities and to evaluate the sustainability of such grazing systems for this region. A long-term grazing study was initiated in 1997 on 151 ha of reclaimed land near Chavies, KY to determine spatial and temporal variation with stocking densities of 0, 0.28, 0.42, or 0.83 beef cow-calf units/ha. Global Positioning System and GIS technologies were used to establish pasture boundaries, locate permanent sampling markers at a density of 1 per 0.4 ha, and interpolate maps of physical, spoil, and vegetable pasture characteristics. Herbage and spoil samples were collected around the permanent markers in May of 1997. Stepwise regression was used to determine factors affecting the vegetative characteristics of the sites. Biomass density ranged from 0 to 2500 kg/ha with a mean of 570 kg/ha. Factors affecting biomass included legume and weed proportions in the sward, grazing activity, soil potassium, elevation, and potential acidity, cumulatively accounting for 32% of the variation. Ground cover ranged from 10 to 100% with an average of 74%. Soil pH, potassium, and grass in the sward accounted for 14% of the variation in ground cover. Legumes made up 0 to 61% of the sward with a mean of 13% over the pasture area. Variables affecting the amount of legume in the sward included biomass density, slope, elevation, pH, and stocking density, together accounting for 21% of the variation. Spatial variation in the physical, spoil, and vegetative characteristics of the pastures was large. Overall, regression accounted for a limited amount of the variation in the vegetative characteristics of the site indicating that other important variables exist

  20. Evaluation of physical structure value in spring-harvested grass/clover silage and hay fed to heifers

    DEFF Research Database (Denmark)

    Schulze, A.K.S.; Nørgaard, P.; Byskov, M.V.

    2015-01-01

    The physical structure value of conserved grass/clover forages of spring harvest was evaluated by assessing effects of harvest time, conservation method, iNDF/NDF ratio and NDF intake (NDFI) per kg BW on chewing activity and fecal particle size in dairy heifers. A mixed sward consisting of ryegrass...

  1. Functional and structural characteristics of anticancer peptide Pep27 analogues

    Directory of Open Access Journals (Sweden)

    Seo Youn-Kyung

    2005-07-01

    Full Text Available Abstract Background A secreted peptide Pep27 initiates the cell death program in S. pneumoniae through signal transduction. This study was undertaken to evaluate the relation between the structure and cytotoxic activity of Pep27 and its analogues on cancer cells. Results Pep27anal2 characterized substituting (2R→W, (4E→W, (11S→W and (13Q→W in native Pep27, exhibited greater hydrophobicity and anticancer activity than Pep27 and other analogues. The IC50 values of Pep27anal2 were approximately 10 – 30 μM in a number of cell lines (AML-2, HL-60, Jurkat, MCF-7 and SNU-601. Confocal microscopy showed that Pep27anal2-FITC was localized in the plasma membrane, and then moving from the membrane to subcellular compartments with the initiation of membrane blebbing. Flow cytometric analysis using propidium iodide and Annexin V also revealed that Pep27anal2 induced apoptosis with minor membrane damage. Electron microscopy revealed that Pep27 induced apoptosis in Jurkat cells. The anticancer activity of Pep27anal2 was neither abrogated by pan-caspase inhibitor (Z-VAD-fmk nor related to cytochrome c release from mitochondria. The 3D solution structures of these two Pep27 peptides revealed that both form a random coil conformation in water; however, they adopted stable α-helical conformations in solutions. Conclusion The results indicate that Pep27anal2 can penetrate the plasma membrane, and then induce apoptosis in both caspase-and cytochrome c-independent manner. The hydrophobicity of Pep27anal2 appears to play an important role in membrane permeabilization and/or anticancer properties. The structure-functional relationships of these peptides are also discussed. It is proposed that Pep27anal2 is a potential candidate for anticancer therapeutic agents.

  2. Structural characteristics of pumpkin pectin extracted by microwave heating.

    Science.gov (United States)

    Yoo, Sang-Ho; Lee, Byeong-Hoo; Lee, Heungsook; Lee, Suyong; Bae, In Young; Lee, Hyeon Gyu; Fishman, Marshall L; Chau, Hoa K; Savary, Brett J; Hotchkiss, Arland T

    2012-11-01

    To improve extraction yield of pumpkin pectin, microwave heating was adopted in this study. Using hot acid extraction, pumpkin pectin yield decreased from 5.7% to 1.0% as pH increased from pH 1.0 to 2.0. At pH 2.5, no pectin was recovered from pumpkin flesh powder. After a pretreatment at pH 1.0 and 25 °C for 1 h, pumpkin powder was microwave-extracted at 120 °C for 3 min resulting in 10.5% of pectin yield. However, premicrowave treatment at 60 °C for 20 min did not improve extraction yield. When microwave heating at 80 °C for 10 min was applied after premicrowave treatment, final pectin yield increased to 11.3%. When pH was adjusted to 2.0, the yield dropped to 7.7% under the same extraction conditions. Molecular shape and properties as well as chemical composition of pumpkin pectin were significantly affected depending on extraction methods. Galacturonic acid content (51% to 58%) of pumpkin pectin was lower than that detected in commercial acid-extracted citrus pectin, while higher content of neutral sugars and acetyl esters existed in pumpkin pectin structure. Molecular weight (M(w) ) and intrinsic viscosity (η(w) ) determined for microwave-extracted pumpkin pectins were substantially lower than acid-extracted pectin, whereas polydispersity was greater. However, microwave-extracted pectin at pH 2.0 had more than 5 times greater M(w) than did the pectin extracted at pH 1.0. The η(w) of microwave-extracted pectin produced at pH 2.0 was almost twice that of other microwave-extracted pectins, which were comparable to that of acid-extracted pectin. These results indicate that extraction yield of pumpkin pectin would be improved by microwave extraction and different pectin structure and properties can be obtained compared to acid extraction. Pumpkin is a promising alternative source for pectin material. Pumpkin pectin has a unique chemical structure and physical properties, presumably providing different functional properties compared to conventional commercial

  3. Experimental research on the structural characteristics of high organic soft soil in different deposition ages

    Science.gov (United States)

    Liu, Fei; Lin, Guo-he

    2018-03-01

    High organic soft soil, which is distributed at Ji Lin province in China, has been studied by a lot of scholars. In the paper, structural characteristics with different deposition ages have been researched by experimental tests. Firstly, the characteristics of deposition age, degree of decompositon, high-pressure consolidation and microstructure have been measured by a series of tests. Secondly, structural strengths which were deposited in different ages, have been carried out to test the significant differences of stress-strain relations between remoulded and undisturbed high organic soft soil samples. Results showed that high organic soft soil which is deposited at different ages will influence its structural characteristics.

  4. Physiochemical Characteristics and Molecular Structures for Digestible Carbohydrates of Silages.

    Science.gov (United States)

    Refat, Basim; Prates, Luciana L; Khan, Nazir A; Lei, Yaogeng; Christensen, David A; McKinnon, John J; Yu, Peiqiang

    2017-10-18

    The main objectives of this study were (1) to assess the magnitude of differences among new barley silage varieties (BS) selected for varying rates of in vitro neutral detergent fiber (NDF) digestibility (ivNDFD; Cowboy BS with higher ivNDFD, Copeland BS with intermediate ivNDFD, and Xena BS with lower ivNDFD) with regard to their carbohydrate (CHO) molecular makeup, CHO chemical fractions, and rumen degradability in dairy cows in comparison with a new corn silage hybrid (Pioneer 7213R) and (2) to quantify the strength and pattern of association between the molecular structures and digestibility of carbohydrates. The carbohydrate-related molecular structure spectral data was measured using advanced vibrational molecular spectroscopy (FT/IR). In comparison to BS, corn silage showed a significantly (P carbohydrates were significantly (P carbohydrate content of the silages. In conclusion, the univariate approach with only one-factor consideration (ivNDFD) might not be a satisfactory method for evaluating and ranking BS quality. FT/IR molecular spectroscopy can be used to evaluate silage quality rapidly, particularly the digestible fiber content.

  5. Color characteristics and crystal structure of cadmium sulfide

    International Nuclear Information System (INIS)

    Kalinskaya, T.V.; Iofe, L.N.; Novoselova, N.A.; Vasil'ev, L.N.; Buziner, L.Yu.; Smykalova, I.V.; Morozova, I.L.

    1989-01-01

    The boundaries of effect of crystal lattice type and its defectiveness on CdS color characteristics are quantitatively determined. 26 CdS samples prepared by three methods of industrial value are studied. The linear interrelation of the color tone (T) and lightness (L) during CdS color alteration from red-organge (T=49, L=57) to lemon (T=99, L=91) is established. The saturation value in this case varies in the 64-94 range. Well crystallized α-CdS samples with the dimension of particles equalling the dimensions of the region of X-ray coherent scattering (0.1-0.3 μm) are characterized by maximum saturated yellow tone. The reduction of saturation to the minimum value during tone change from lemon to red-organge is conditioned by the presence of built-in syngony elements of α-CdS and β-CdS and a small size of coherent scattering range. (less than 0.1 μm)

  6. Research on the Structural Characteristics of Transmission Grid Based on Complex Network Theory

    Directory of Open Access Journals (Sweden)

    Jinli Zhao

    2014-01-01

    Full Text Available Reasonable and strong structure is an important foundation for the smart transmission grid. For vigorously promoting construction of the smart grid, it is of great significance to have a thorough understanding of the complex structural characteristics of the power grid. The structural characteristics of several actual large-scale power grids of China are studied in this paper based on the complex network theory. Firstly, the topology-based network model of power grid is recalled for analyzing the statistical characteristic parameters. The result demonstrated that although some statistical characteristic parameters could reflect the topological characteristics of power grid from different ways, they have certain limitation in representing the electrical characteristics of power grid. Subsequently, the network model based on the electrical distance is established considering the limitation of topology-based model, which reflects that current and voltage distribution in the power grid are subject to Ohm's Law and Kirchhoff's Law. Comparing with the topology-based model, the electrical distance-based model performs better in reflecting the natural electrical characteristic structure of power grid, especially intuitive and effective in analyzing clustering characteristics and agglomeration characteristics of power grid. These two models could complement each other.

  7. Photoelectric characteristics of lead phthalocyanine/titanium oxide structures

    CERN Document Server

    Ray, A K; Hodgson, S N B

    2003-01-01

    A study has been carried out into the conduction, charge transfer/electron injection and photovoltaic conversion properties of TiO sub 2 -lead phthalocyanine (PbPc) heterojunctions. The results indicate that although the heterojunction area, and hence overall conversion efficiency, was low for the planar device structures used in the investigation, electron injection and effective charge separation across the dye-TiO sub 2 interface was achieved, with open circuit voltages in the region of 0.3 V. The conversion efficiency was found to be a function of the thickness of the phthalocyanine layer, increasing by a factor of more than 30 times as the thickness of the dye layer was reduced from 500 to 100 nm. The results suggest that under appropriate deposition conditions, to ensure effective coating of the inorganic phase, such phthalocyanine dyes may offer potential for use in dye sensitized photovoltaic cells.

  8. Model characteristics of the structure physical training fighters qualifications

    Directory of Open Access Journals (Sweden)

    Pryimakov O.O.

    2013-06-01

    Full Text Available Studied the structure of the relationship of physical fitness level fighters with physical disabilities and special performance. It is studied 147 athletes Ukraine qualifications in Greco-Roman and freestyle wrestling, judo. Applied the methods of anthropometry kaliperometrii, teacher testing, testing of a special performance. It is shown that the qualification defines the relationship and the relationship of morphometric and speed-power performance, the level of special performance athletes. With the advanced training of fighters increased level of speed, force readiness, increase the size Spigot neck, hips, chest, shoulders, reduced the percentage of fat component, increases muscular component, the index increased muscle development. Morphometric parameters with the most skilled fighters and cross-linked Spigot size of the body of the speed and power - explosive power, strength and speed-strength endurance, speed.

  9. Characteristics and structure of turbulent 3D offset jets

    International Nuclear Information System (INIS)

    Agelin-Chaab, M.; Tachie, M.F.

    2011-01-01

    Highlights: → We investigated three-dimensional turbulent offset jets using particle image velocimetry. → We examined the effects of offset height and Reynolds number on the structure of 3D offset jets. → Effects of Reynolds number and offset height on the decay and growth rates exist close to the exit. → This study provides additional insight and comprehensive data for validating numerical models. - Abstract: Three-dimensional turbulent offset jets were investigated using a particle image velocimetry technique. The measurements were performed at three different exit Reynolds numbers and for four offset heights. The results in the early region of flow development clearly show significant effects of Reynolds number and offset height on the decay of maximum mean velocity and growth of the shear layer. On the contrary, the decay and spread rates were found to be nearly independent of offset height at larger downstream distances. The decay rates of 1.18 ± 0.03 as well as the spread rates of 0.055 ± 0.001 and 0.250 ± 0.005 obtained, respectively, in the wall-normal and lateral directions fall in the range of values reported in previous studies. The locations of the maximum mean velocities increased nearly linearly with streamwise distance in the self-similar region. Analysis from two-point velocity correlations revealed substantially larger structures in the outer layer and self-similar region than in the inner layer and developing region. It was also observed that the hairpin vortices in the inner regions of the wall jets are inclined at angles of 11.2 o ± 0.6 o , which are in good agreement with reported values in boundary layer studies.

  10. Biochemical, structural, and physiological characteristics of vacuolar H+-pyrophosphatase.

    Science.gov (United States)

    Segami, Shoji; Asaoka, Mariko; Kinoshita, Satoru; Fukuda, Mayu; Nakanishi, Yoichi; Maeshima, Masayoshi

    2018-03-09

    Proton-translocating inorganic pyrophosphatase (H+-PPase) actively translocates protons across membranes coupled with the hydrolysis of inorganic pyrophosphate (PPi). H+-PPase, which is composed of a single protein and uses a simple compound as a substrate, has been recognized as a new type of ion pump in addition to the P-, F-, and V-type ion translocating ATPases. H+- and Na+-PPases are distributed in various organisms including plants, parasitic protozoa, Archaebacteria, and bacteria, but are not present in animals or yeast. Vacuolar H+-PPase has dual functions in plant cells: hydrolysis of cytosolic PPi to maintain the levels of PPi and translocation of protons into vacuoles to maintain the acidity of the vacuolar lumen. Acidification performed with the vacuolar type H+-ATPase and H+-PPase is essential to maintain acidic conditions, which are necessary for vacuolar hydrolytic enzymes and for supplying energy to secondary active transporters. Recent studies using loss-of-function mutant lines of H+-PPase and complementation lines with soluble PPases have emphasized the physiological importance of the scavenging role of PPi. An overview of the main features of H+-PPases present in the vacuolar membrane is provided in terms of tissue distribution in plants, intracellular localization, structure-function relationship, biochemical potential as a proton pump, and functional stability.

  11. Role of limbic structures in individual characteristics of behavior.

    Science.gov (United States)

    Simonov, P V

    1981-01-01

    The dogs with more frequent hippocampal theta-rhythm develop transswitching of food and defensive instrumental conditioned reflexes more rapidly and easily. Bilateral destructions of frontal regions of the neocortex and hippocampus in rats increased their reactivity to the aversive stimuli (intensive light and sound) and simultaneously decreased their sensitivity to the signals of defensive excitation ill the other animal. Bilateral damages of lateral and ventromedial hypothalamus equally increased the reactivity of rats to sound, light and cry of the partner. Confrontation of these results with the data obtained previously and those available in literature leads to the conclusion that individual features in the relation of "information system" (frontal neocortex and hippocampus) to "motivation system" (amygdala and hypothalamus) lie at the root of the extra-intraversion parameter. The relationship of the "frontal neocortex – hypothalamus" and "hippocampus – amygdala" systems is reflected in the scale of neurotism (emotionality). The activity of the "hypothalamus-hippocampus" produces mobility or inertness. Various forms of disorders in the normal interaction of the four indicated brain structures apparently determine the main types of neurosis.

  12. Synchrotron radiation : characteristics and application in structural studies and phase transformations of materials

    International Nuclear Information System (INIS)

    Craievich, A.F.

    1984-01-01

    The main characteristics of the synchrotron radiation for studying atomic structure and phase transformations in materials are presented. Some specific applications in alloys, glass and solids are described. (E.G.) [pt

  13. Measurements of electrophysical characteristics of semiconductor structures with the use of microwave photonic crystals

    Energy Technology Data Exchange (ETDEWEB)

    Usanov, D. A., E-mail: UsanovDA@info.sgu.ru [Chernyshevsky National Research State University (Russian Federation); Nikitov, S. A. [Russian Academy of Sciences, Kotelnikov Institute of Radio Engineering and Electronics (Russian Federation); Skripal, A. V.; Ponomarev, D. V.; Latysheva, E. V. [Chernyshevsky National Research State University (Russian Federation)

    2016-12-15

    A method is proposed for the measurement of the electrophysical characteristics of semiconductor structures: the electrical conductivity of the n layer, which plays the role of substrate for a semiconductor structure, and the thickness and electrical conductivity of the strongly doped epitaxial n{sup +} layer. The method is based on the use of a one-dimensional microwave photonic crystal with a violation of periodicity containing the semiconductor structure under investigation. The characteristics of epitaxial gallium-arsenide structures consisting of an epitaxial layer and the semi-insulating substrate measured by this method are presented.

  14. The Influence of Redundant Structural System Characteristics on the Value of SHM Information

    DEFF Research Database (Denmark)

    Thöns, Sebastian

    2015-01-01

    This paper addresses the influence of deteriorating structural system characteristics on the value of structural health monitoring (SHM) before its implementation. The value of SHM is quantified as the difference between the life cycle benefits with and without SHM for a structural system subjected...... to fatigue deterioration. The results indicate that the value of SHM is strongly influenced by the component reliability, comparably moderately by the resistance correlation and conditional moderately by the deterioration correlation between the structural components....

  15. Structural and Financial Characteristics of U.S. Sugar Beet Farms. Agricultural Economic Report Number 584.

    Science.gov (United States)

    Clauson, Annette L.; Hoff, Frederic L.

    This report analyzes production and financial characteristics of sugar beet producers in seven regions. Section 1 examines the structural characteristics of U.S. sugar beet producers. Sugar beet production; land use, tenure, irrigation, and livestock enterprises are considered. Section 2 discusses production costs, including cost estimates,…

  16. Capacitance-voltage characteristics of GaAs ion-implanted structures

    Directory of Open Access Journals (Sweden)

    Privalov E. N.

    2008-08-01

    Full Text Available A noniterative numerical method is proposed to calculate the barrier capacitance of GaAs ion-implanted structures as a function of the Schottky barrier bias. The features of the low- and high-frequency capacitance-voltage characteristics of these structures which are due to the presence of deep traps are elucidated.

  17. The Likelihood of Parent-Adult Child Coresidence: Effects of Family Structure and Parental Characteristics.

    Science.gov (United States)

    Aquilino, William S.

    1990-01-01

    Estimated influence of child, parent, and family structural characteristics on likelihood of parents having coresident adult child, based on national sample of 4,893 parents. Results indicated most parents maintained own households and most parents and adult children who coresided lived in parents' home. Family structure was found to exert strong…

  18. Structural Modeling and Analysis on Dynamic Characteristics of Antenna Pedestal in Airborne SAR

    Directory of Open Access Journals (Sweden)

    He Li-ping

    2012-06-01

    Full Text Available Finite element modeling and structural dynamic characteristics of antenna pedestal in airborne SAR were studied in this paper. The Finite element model of antenna pedestal in airborne SAR was set up on the basis of structural dynamic theory, then, the key technologies of dynamic simulation were pointed out, and the modal analysis and transient analysis were carried out. Simulation results show that the dynamic characteristics of antenna pedestal in airborne SAR can meet the requirements of servo bandwidth and structural strength. The fast finite element modeling and simulation method proposed in this paper are of great significance to the weight reducing design of antenna pedestal in airborne SAR.

  19. INFLUENCE OF LEGRAD THRESHOLD STRUCTURE ON HYDROGEOLOGICAL CHARACTERISTICS IN KOPRIVNICA AREA

    Directory of Open Access Journals (Sweden)

    Željko Duić

    2007-12-01

    Full Text Available Koprivnička Podravina area in structural sense belongs to structural unit of Drava basin. Special role in research area has structure of Legrad which is formed along Ludbreg-Nagykanizsa fault, and together with Drava fault as dominant structure in formation of Drava basin, represent most important structure in area. This is specially important when observing hydraulic characteristics of main well field in Koprivnica area-Ivanščak and Lipovec. Both of them are formated in quternary deposits, but have very different hydraulic and spatial characteristics. Intensive movement along structures has also dominant influence on sedimantation conditions, and consequently to groundwater quality (the paper is published in Croatian.

  20. The study on the mechanical characteristics of concrete of nuclear reactor containment structure

    International Nuclear Information System (INIS)

    Jung, W. S.; Kwon, K. J.; Cho, M. S.; Song, Y. C.

    2000-01-01

    Reactor containment structure of nuclear power plant designed by prestressed concrete causes time-dependent prestress loss due to the mechanical characteristics of concrete. Prestress loss strongly affects to the safety factor of structure under the circumstances of designing, construction and inspection. Thus, this study is to investigate the mechanical characteristics of reactor containment concrete structure of Yonggwang No. 5 and 6. In this study, the compressive strength, modulus of elasticity, poisson's ratio and creep test followed by ASTM code are performed to investigate the mechanical characteristics of concrete made by V type cement. Additionally, since creep causes more time-dependent prestress loss than the other, the measurement value from the creep test is compared with the results from the creep prediction equations by KSCE, JSCE, Hansen, ACI and CEB-FIP model for the effective application. Hereafter, the results of this study may enable to assist the calculation effective stress considering time-dependent prestress loss of the prestressed concrete structures

  1. Nuclear power plant design characteristics. Structure of nuclear power plant design characteristics in the IAEA Power Reactor Information System (PRIS)

    International Nuclear Information System (INIS)

    2007-03-01

    One of the IAEA's priorities has been to maintain the Power Reactor Information System (PRIS) database as a viable and useful source of information on nuclear reactors worldwide. To satisfy the needs of PRIS users as much as possible, the PRIS database has included also a set of nuclear power plant (NPP) design characteristics. Accordingly, the PRIS Technical Meeting, organized in Vienna 4-7 October 2004, initiated a thorough revision of the design data area of the PRIS database to establish the actual status of the data and make improvements. The revision first concentrated on a detailed review of the design data completion and the composition of the design characteristics. Based on the results of the review, a modified set and structure of the unit design characteristics for the PRIS database has been developed. The main objective of the development has been to cover all significant plant systems adequately and provide an even more comprehensive overview of NPP unit designs stored in the PRIS database

  2. Seismic Dynamic Damage Characteristics of Vertical and Batter Pile-supported Wharf Structure Systems

    Directory of Open Access Journals (Sweden)

    Li Jiren

    2015-10-01

    Full Text Available Considering a typical steel pipe pile-supported wharf as the research object, finite element analytical models of batter and vertical pile structures were established under the same construction site, service, and geological conditions to investigate the seismic dynamic damage characteristics of vertical and batter pile-supported wharf structures. By the numerical simulation and the nonlinear time history response analysis of structure system and the moment–axial force relation curve, we analyzed the dynamic damage characteristics of the two different structures of batter and vertical piles under different seismic ground motions to provide reasonable basis and reference for designing and selecting a pile-supported wharf structure. Results showed that the axial force of batter piles was dominant in the batter pile structure and that batter piles could effectively bear and share seismic load. Under the seismic ground motion with peak ground acceleration (PGA of 350 Gal and in consideration of the factors of the design requirement of horizontal displacement, the seismic performance of the batter pile structure was better than that of the vertical pile structure. Under the seismic ground motion with a PGA of 1000 Gal, plastic failure occurred in two different structures. The contrastive analysis of the development of plastic damage and the absorption and dissipation for seismic energy indicated that the seismic performance of the vertical pile structure was better than that of the batter pile structure.

  3. Analysis of structures based on a characteristic-strain model of creep

    International Nuclear Information System (INIS)

    Bolton, J.

    2008-01-01

    A companion paper [Bolton J. In: A characteristic-strain model for creep, ECCC/I.Mech.E. conference on creep and fracture in high-temperature components, London, September 2005] describes a creep model based on a constant 'characteristic strain' at any temperature. The present paper discusses the application of such a model, first to simple structures and then to engineering components of general form under steady loading. A basis is proposed for identifying the stress within a structure, or within the critical part of a structure, which can be considered to govern both its overall and local deformations. The concept is similar to skeletal-point stress but is more readily applied to components of any shape. The implementation of the concept of 'structural stress' is discussed in the context of finite-element creep calculations. Consideration is given to the analysis of cracked structures, where very high strains at the crack tip must be accommodated

  4. Internet-based structural characteristics of sports betting and problem gambling severity: is there a relationship?

    OpenAIRE

    Lopez-Gonzalez, H; Estévez, A; Griffiths, MD

    2018-01-01

    With the adoption and popularization of internet-based platforms, sports betting has introduced new functionalities that transform the design of its products and therefore the way bettors interact with them. This study aims to explore the association between the use of new structural characteristics of online betting and gambling severity. Five characteristics are examined here: (i) live in-play betting; (ii) cash out feature use (as example of in-play betting in-built features); (iii) fantas...

  5. Vibration Characteristics of Gravity-Type Caisson Breakwater Structure with Water-Level Variation

    OpenAIRE

    Lee, So-Young; Huynh, Thanh-Canh; Kim, Jeong-Tae; Yoon, Han-Sam; Han, Sang-Hun

    2013-01-01

    Vibration characteristics of gravity-type caisson breakwater structures which have water-level variations are experimentally examined by using wave load excitations. To achieve the objective, the following approaches are implemented. Firstly, vibration analysis methods are selected to examine the dynamic characteristics of the lab-scale caisson. Secondly, vibration test on a lab-scale caisson which is installed in a two-dimensional wave flume is performed under several excitation sources and ...

  6. INVESTIGATION OF DYNAMIC CHARACTERISTICS OF ELEMENTS OF AUTOMATICS OF A SMART HOUSE IN PARAMETRICAL STRUCTURAL SCHEMES

    Directory of Open Access Journals (Sweden)

    Petrova Irina Yur’evna

    2018-01-01

    Full Text Available Subject: automation of calculation of dynamic characteristics of the device being designed in the system of conceptual design of sensor equipment, structurally-parametric models of dynamic processes and algorithms for the automated calculation of the qualitative characteristics of elements of the information-measuring and control systems (IMCS. The stage of conceptual design most fully determines the operational characteristics of technical systems. However, none of the information support systems of this stage provides an opportunity to evaluate the performance characteristics of the element being designed taking into account its dynamic characteristics. Research objectives: increasing the effectiveness of the evaluation of dynamic characteristics of sensitive elements of the information-measuring and control systems of a smart house. Materials and methods: when solving the problems posed, the mathematical apparatus of system modeling was used (in particular, the energy-information method of modeling processes of various physical nature that occur in the sensor equipment; the main provisions of the theory of automatic control, the theory of constructing computer-aided design systems, the theory of operational calculus; basics of conceptual design of elements of the information-measuring and control systems. Results: we compared the known automated systems for conceptual design of sensors, highlighted their advantages and disadvantages and we showed that none of these systems allows us to investigate dynamic characteristics of the element being designed in a simple and understandable for engineer form. The authors proposed using energy-information method of modeling for the synthesis of operation principles of sensors and analysis of their dynamic characteristics. We considered elementary dynamic chains and issues of synthesis of parametrical structural schemes that reflect the dynamics of the process with the use of mathematical apparatus of

  7. Characteristics of Wave Reflection for Vertical and Slit Caissons with Porous Structures

    Directory of Open Access Journals (Sweden)

    Tae-Hwa Jung

    2012-01-01

    Full Text Available Offshore structures are occasionally located at a relatively deep water region, the outside of breakwater. In this case, these structures may be damaged by the supposition of incident and reflected waves from a vertical breakwater. To prevent the damage, the reflected waves are controlled by installing porous structures at the face of the vertical breakwater. In this study, numerical experiments are carried out to identify the characteristics of wave reflection from the porous structures installing in front of a vertical or slit caisson.

  8. The effects of the structure characteristics on Magnetic Barkhausen noise in commercial steels

    Science.gov (United States)

    Deng, Yu; Li, Zhe; Chen, Juan; Qi, Xin

    2018-04-01

    This study has been done by separately measuring Magnetic Barkhausen noise (MBN) under different structure characteristics, namely the carbon content, hardness, roughness, and elastic modulus in commercial steels. The result of the experiments shows a strong dependence of MBN parameters (peak height, Root mean square (RMS), and average value) on structure characteristics. These effects, according to this study, can be explained by two kinds of source mechanisms of the MBN, domain wall nucleation and wall propagation. The discovery obtained in this paper can provide basic knowledge to understand the existing surface condition problem of Magnetic Barkhausen noise as a non-destructive evaluation technique and bring MBN into wider application.

  9. Core-Shell Structured Electro- and Magneto-Responsive Materials: Fabrication and Characteristics

    Directory of Open Access Journals (Sweden)

    Hyoung Jin Choi

    2014-11-01

    Full Text Available Core-shell structured electrorheological (ER and magnetorheological (MR particles have attracted increasing interest owing to their outstanding field-responsive properties, including morphology, chemical and dispersion stability, and rheological characteristics of shear stress and yield stress. This study covers recent progress in the preparation of core-shell structured materials as well as their critical characteristics and advantages. Broad emphasises from the synthetic strategy of various core-shell particles to their feature behaviours in the magnetic and electric fields have been elaborated.

  10. [Monitoring of Crack Propagation in Repaired Structures Based on Characteristics of FBG Sensors Reflecting Spectra].

    Science.gov (United States)

    Yuan, Shen-fang; Jin, Xin; Qiu, Lei; Huang, Hong-mei

    2015-03-01

    In order to improve the security of aircraft repaired structures, a method of crack propagation monitoring in repaired structures is put forward basing on characteristics of Fiber Bragg Grating (FBG) reflecting spectra in this article. With the cyclic loading effecting on repaired structure, cracks propagate, while non-uniform strain field appears nearby the tip of crack which leads to the FBG sensors' reflecting spectra deformations. The crack propagating can be monitored by extracting the characteristics of FBG sensors' reflecting spectral deformations. A finite element model (FEM) of the specimen is established. Meanwhile, the distributions of strains which are under the action of cracks of different angles and lengths are obtained. The characteristics, such as main peak wavelength shift, area of reflecting spectra, second and third peak value and so on, are extracted from the FBGs' reflecting spectral which are calculated by transfer matrix algorithm. An artificial neural network is built to act as the model between the characteristics of the reflecting spectral and the propagation of crack. As a result, the crack propagation of repaired structures is monitored accurately and the error of crack length is less than 0.5 mm, the error of crack angle is less than 5 degree. The accurately monitoring problem of crack propagation of repaired structures is solved by taking use of this method. It has important significance in aircrafts safety improvement and maintenance cost reducing.

  11. Study on structural plane characteristics of deep rock mass based on acoustic borehole TV

    International Nuclear Information System (INIS)

    Wang Xiyong; Su Rui; Chen Liang; Tian Xiao

    2014-01-01

    Deep rock mass structural plane characteristics are one of the basic data for evaluating the quality of rock mass. Based on acoustic borehole TV, the structural plane quantity, density, attitude, dominant set, structural plane aperture of deep rock mass in boreholes BS15 # and BS16 # located in Beishan granite rock mass of Gansu Province have been calculated and compared with the results of geological documentation of drill core. The results indicate that acoustic borehole TV has the effect in study on characteristics of structural plane. But as a kind of technique of geophysical logging, the acoustic borehole TV has certain defect, and need to combine with the analysis of the other geological materials in applications. (authors)

  12. The role of structural characteristics in problem video game playing: a review

    OpenAIRE

    King, DL; Delfabbro, PH; Griffiths, MD

    2010-01-01

    The structural characteristics of video games may play an important role in explaining why some people play video games to excess. This paper provides a review of the literature on structural features of video games and the psychological experience of playing video games. The dominant view of the appeal of video games is based on operant conditioning theory and the notion that video games satisfy various needs for social interaction and belonging. However, there is a lack of experimental and ...

  13. Subharmonic gap structure in the characteristics of YBa2Cu3O7-x microbridges

    International Nuclear Information System (INIS)

    Pogrebnyakov, A.V.; Levinsen, M.T.; Sheng, Y.Q.; Freltoft, T.

    1996-01-01

    The subharmonic gap structures corresponding to large, 2Δ 1 =48 meV, and small, 2Δ 2 =10.3 meV, components of the energy gap were observed in the first derivatives of the current-voltage characteristics of YBa 2 Cu 3 O 7-x epitaxial thin film microbridges. The appearance of the subharmonic gap structures is attributed to Andreev reflection. (orig.)

  14. Effects of lysine residues on structural characteristics and stability of tau proteins

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Myeongsang; Baek, Inchul; Choi, Hyunsung; Kim, Jae In; Na, Sungsoo, E-mail: nass@korea.ac.kr

    2015-10-23

    Pathological amyloid proteins have been implicated in neuro-degenerative diseases, specifically Alzheimer's, Parkinson's, Lewy-body diseases and prion related diseases. In prion related diseases, functional tau proteins can be transformed into pathological agents by environmental factors, including oxidative stress, inflammation, Aβ-mediated toxicity and covalent modification. These pathological agents are stable under physiological conditions and are not easily degraded. This un-degradable characteristic of tau proteins enables their utilization as functional materials to capturing the carbon dioxides. For the proper utilization of amyloid proteins as functional materials efficiently, a basic study regarding their structural characteristic is necessary. Here, we investigated the basic tau protein structure of wild-type (WT) and tau proteins with lysine residues mutation at glutamic residue (Q2K) on tau protein at atomistic scale. We also reported the size effect of both the WT and Q2K structures, which allowed us to identify the stability of those amyloid structures. - Highlights: • Lysine mutation effect alters the structure conformation and characteristic of tau. • Over the 15 layers both WT and Q2K models, both tau proteins undergo fractions. • Lysine mutation causes the increment of non-bonded energy and solvent accessible surface area. • Structural instability of Q2K model was proved by the number of hydrogen bonds analysis.

  15. Structural, electrical and luminescent characteristics of ultraviolet light emitting structures grown by hydride vapor phase epitaxy

    Directory of Open Access Journals (Sweden)

    A.Y. Polyakov

    2017-03-01

    Full Text Available Electrical and luminescent properties of near-UV light emitting diode structures (LEDs prepared by hydride vapor phase epitaxy (HVPE were studied. Variations in photoluminescence and electroluminescence efficiency observed for LEDs grown under nominally similar conditions could be attributed to the difference in the structural quality (dislocation density, density of dislocations agglomerates of the GaN active layers, to the difference in strain relaxation achieved by growth of AlGaN/AlGaN superlattice and to the presence of current leakage channels in current confining AlGaN layers of the double heterostructure.

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

    Science.gov (United States)

    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...

  17. The Effect of Heat on Structural Characteristics and Water Absorption Behavior of Agave Fibers

    Science.gov (United States)

    Saikia, Dip

    2008-04-01

    The structural characteristics and water absorptions behavior agave fibers were investigated over a range of temperature by using XRD, IR, TG and gravimetric methods. Three distinct thermal processes were observed during heating the fiber in the temperature range 310-760 K in air, oxygen and nitrogen invariably. The cellulose structures of the fibers were unaffected on heating up to 450 K. The samples showed thermal decomposition processes beyond 500 K. Fibers displayed a two-stage diffusion behavior. The structural parameters and kinetic of water absorption of the fibers at specific temperatures were analyzed.

  18. Nitrogen excretion of adult sheep fed silages made of a mixed sward or of pure unfertilised grass alone and in combination with barley.

    Science.gov (United States)

    Seip, Katharina; Breves, Gerhard; Isselstein, Johannes; Abel, Hansjörg

    2011-08-01

    Four adult rumen-fistulated wether sheep were fed silages combined with barley. The silages consisted of 48% grasses, 28% legumes and 24% other forbs (GCF) or of pure grass (G). The swards received no mineral fertiliser. The dry matter (DM) and fibre contents were lower in GCF than in G. Crude protein content of DM in GCF and G were 145 g/kg and 102 g/kg respectively. DM content as ash, lipids and non-fibrous carbohydrates were rather similar in both silages. About 40g DM were offered per kg BW0.75 and day either as silage alone or as a mixture of silage and barley (60:40). Faecal N excretion was greater with GCF than with G. The proportion of faecal bacterial and endogenous debris N reached 75 and 73% when GCF or G was fed, respectively. Undigested dietary N represented about 20%, and water soluble N accounted for 5-6% of faecal N. GCF caused more urinary N than G. Barley reduced urinary N excretion when supplemented to GCF. No dietary influence on urinary non-urea nitrogenous compounds was shown. GCF caused higher urinary urea N excretion than G and barley reduced this fraction when replacing part of GCF. Based on the urinary urea N proportions, it is concluded that N intake exceeded N requirement for any of the four diets fed. Dietary supplementation of ruminally fermentable carbohydrates can reduce urinary N excretion and this improves the efficiency of utilisation of N in N-unfertilised biodiverse grassland/ruminant farming systems.

  19. Structural characteristics of alkaline phosphatase from the moderately halophilic bacterium Halomonas sp. 593

    Energy Technology Data Exchange (ETDEWEB)

    Arai, Shigeki; Yonezawa, Yasushi [Japan Atomic Energy Agency, 2-4 Shirakata-shirane, Tokai, Ibaraki 319-1195 (Japan); Ishibashi, Matsujiro [Faculty of Agriculture, Kagoshima University, 1-21-24 Korimoto, Kagoshima 890-0065 (Japan); Matsumoto, Fumiko; Adachi, Motoyasu; Tamada, Taro [Japan Atomic Energy Agency, 2-4 Shirakata-shirane, Tokai, Ibaraki 319-1195 (Japan); Tokunaga, Hiroko [Faculty of Agriculture, Kagoshima University, 1-21-24 Korimoto, Kagoshima 890-0065 (Japan); Blaber, Michael [Florida State University, 1115 West Call Street, Tallahassee, FL 32306-4300 (United States); Tokunaga, Masao [Faculty of Agriculture, Kagoshima University, 1-21-24 Korimoto, Kagoshima 890-0065 (Japan); Kuroki, Ryota, E-mail: kuroki.ryota@jaea.go.jp [Japan Atomic Energy Agency, 2-4 Shirakata-shirane, Tokai, Ibaraki 319-1195 (Japan)

    2014-03-01

    In order to clarify the structural basis of the halophilic characteristics of an alkaline phosphatase derived from the moderate halophile Halomonas sp. 593 (HaAP), the tertiary structure of HaAP was determined to 2.1 Å resolution by X-ray crystallography. The structural properties of surface negative charge and core hydrophobicity were shown to be intermediate between those characteristic of halophiles and non-halophiles, and may explain the unique functional adaptation to a wide range of salt concentrations. Alkaline phosphatase (AP) from the moderate halophilic bacterium Halomonas sp. 593 (HaAP) catalyzes the hydrolysis of phosphomonoesters over a wide salt-concentration range (1–4 M NaCl). In order to clarify the structural basis of its halophilic characteristics and its wide-range adaptation to salt concentration, the tertiary structure of HaAP was determined by X-ray crystallography to 2.1 Å resolution. The unit cell of HaAP contained one dimer unit corresponding to the biological unit. The monomer structure of HaAP contains a domain comprised of an 11-stranded β-sheet core with 19 surrounding α-helices similar to those of APs from other species, and a unique ‘crown’ domain containing an extended ‘arm’ structure that participates in formation of a hydrophobic cluster at the entrance to the substrate-binding site. The HaAP structure also displays a unique distribution of negatively charged residues and hydrophobic residues in comparison to other known AP structures. AP from Vibrio sp. G15-21 (VAP; a slight halophile) has the highest similarity in sequence (70.0% identity) and structure (C{sup α} r.m.s.d. of 0.82 Å for the monomer) to HaAP. The surface of the HaAP dimer is substantially more acidic than that of the VAP dimer (144 exposed Asp/Glu residues versus 114, respectively), and thus may enable the solubility of HaAP under high-salt conditions. Conversely, the monomer unit of HaAP formed a substantially larger hydrophobic interior

  20. The Relationship Between Structural Game Characteristics and Gambling Behavior: A Population-Level Study.

    Science.gov (United States)

    Leino, Tony; Torsheim, Torbjørn; Blaszczynski, Alex; Griffiths, Mark; Mentzoni, Rune; Pallesen, Ståle; Molde, Helge

    2015-12-01

    The aim of this study was to examine the relationship between the structural characteristics and gambling behavior among video lottery terminal (VLT) gamblers. The study was ecological valid, because the data consisted of actual gambling behavior registered in the participants natural gambling environment without intrusion by researchers. Online behavioral tracking data from Multix, an eight game video lottery terminal, were supplied by Norsk-Tipping (the state owned gambling company in Norway). The sample comprised the entire population of Multix gamblers (N = 31,109) who had gambled in January 2010. The individual number of bets made across games was defined as the dependent variable, reward characteristics of a game (i.e., payback percentage, hit frequency, size of winnings and size of jackpot) and bet characteristics of a game (i.e., range of betting options and availability of advanced betting options) served as the independent variables. Control variables were age and gender. Two separate cross-classified multilevel random intercepts models were used to analyze the relationship between bets made, reward characteristics and bet characteristics, where the number of bets was nested within both individuals and within games. The results show that the number of bets is positively associated with payback percentage, hit frequency, being female and age, and negatively associated with size of wins and range of available betting options. In summary, the results show that the reward characteristics and betting options explained 27% and 15% of the variance in the number of bets made, respectively. It is concluded that structural game characteristics affect gambling behavior. Implications of responsible gambling are discussed.

  1. Damping characteristic identification of non-linear soil-structural system interaction by phase resonance

    International Nuclear Information System (INIS)

    Poterasu, V.F.

    1984-01-01

    It is presented a method and the phase resonance for damping characteristic identification of non-linear soil-structural interaction. The algorithm can be applied in case of any, not necessarily, damping characteristic of the system examined. For the identification, the system is harmonically excited and are considered the super-harmonic amplitudes for odd and even powers of the x. The response of shear beam system for different levels of base excitation and for different locations of the load is considered. (Author) [pt

  2. Structural characteristics of a graphite moderated critical assembly for a Zero Power reactor at IEA (Brazil)

    International Nuclear Information System (INIS)

    Almeida Ferreira, A.C. de; Hukai, R.Y.

    1975-01-01

    The structural characteristics of a graphite moderated core of a critical assembly to be installed in the Zero Power Reactor of IEA have been defined. These characteristics are the graphite block dimensions, the number and dimensions of the holes in the graphite, the pitch, the dimensions of the sticks of fuel and graphite to be inserted in the holes, and the mechanical reproducibility of the system. The composition of the fuel and moderator sticks were also defined. The main boundary conditions were the range of the relation C/U and C/TH used in commercial HTGR and the neutronics homogeneity

  3. Características morfológicas, estruturais e produtividade do capim-braquiária e do amendoim forrageiro submetidos ao sombreamento Morphological and structural characteristics and productivity of Brachiaria grass and forage peanut submitted to shading

    Directory of Open Access Journals (Sweden)

    Kátia Fernanda Gobbi

    2009-09-01

    Full Text Available As características morfológicas, estruturais e a produção de matéria seca (PMS do capim-braquiária (Brachiaria decumbens, cv. Basilisk e do amendoim forrageiro (Arachis pintoi, cv. Amarillo foram avaliadas em resposta a três níveis de sombreamento artificial (0, 50 e 70%. Utilizou-se o delineamento em blocos casualizados, com três repetições. Foram realizados três e dois cortes, respectivamente, para avaliação do capim-braquiária e do amendoim forrageiro. O amendoim forrageiro apresentou redução significativa na produção de matéria seca com o sombreamento apenas no segundo corte. A produção de matéria seca no capim-braquiária diminuiu linearmente nos dois primeiros cortes. O sombreamento crescente estimulou o aumento da altura média do dossel e do comprimento de pecíolos, colmos e lâminas foliares em todos os cortes das espécies avaliadas. O sombreamento promoveu diminuição linear da densidade populacional de perfilhos no dossel de braquiária em todos os cortes. O peso médio dos perfilhos, no entanto, só foi afetado no terceiro corte, quando aumentou de forma linear de acordo com os níveis de sombreamento. A relação folha:caule da gramínea e da leguminosa não foi afetada pelo sombreamento. A área foliar específica, a área foliar por folíolo e a área foliar por perfilho aumentaram significativamente com o aumento dos níveis de sombreamento. O índice de área foliar (IAF reduziu de forma linear no segundo corte com o sombreamento do amendoim forrageiro e do capim-braquiária. O amendoim forrageiro e o capim-braquiária são forrageiras com bom potencial para avaliação e uso em sistemas silvipastoris com transmissão luminosa em torno de 50% da radiação fotossinteticamente ativa.The morphological and structural characteristics and dry matter production of signalgrass (Brachiaria decumbens, cv. Basilisk and forage peanut (Arachis pintoi, cv. Amarillo were evaluated in response to different shading

  4. QUALITY ANALYSIS OF THE GATE DIELECTRIC OF THE MOS-STRUCTURES BY CAPACITY-VOLTAGE CHARACTERISTICS

    Directory of Open Access Journals (Sweden)

    V. B. Odzhaev

    2015-01-01

    Full Text Available There were investigated the capacity-voltage characteristics of the MOS transistors, fabricated by the similar process charts, with the identical applied technological materials, however at various time (appropriately further in the text series A and series B. It was shown, that the measurements of the capacityvoltage characteristics of the MOS structures make it possible to perform the quality diagnostics of the gate dielectric. The kind and shape of the measured characteristics are determined by the value of the additional positive charge in the dielectrics and density of the fast surface states on the Si-SiO2 interface, which correlate with the surface concentration of the technological impurities, adsorbed on the surface of the wafers in process of the devices fabrication, which makes it possible to make a conclusion about the quality of the applied materials and compliance of the manufacturing process. 

  5. Influence of synthesis route in structural, thermal and morphological characteristics of perovskite materials

    International Nuclear Information System (INIS)

    Fernandes, I.A.; Araujo, E.M. de; Santos, T.L.; Viana, K.M.S.; Borges, M.M.; Ruiz, J.A.C.

    2016-01-01

    Oxides with perovskite structure are interesting objects of study because of their optical, magnetic, electrical properties and its possible application, for example, as automotive catalyst. Various methods have been proposed to synthesise materials with this structure in order to achieve better structural and morphological characteristics and therefore improved properties. In this study, the mixed oxide of the perovskite type La 0.8 Ca 0.2 MnO 3 was synthesized by three different routes: the polymeric precursors, also known as the Pechini, method of gelatin modified rout and combustion method. Ceramic materials were evaluated thermally morphologically and structurally through thermal gravimetric analysis (TG), scanning electron microscopy (SEM) and diffraction X-ray (XRD). The catalytic tests has been released, the material synthesized by the Pechini method had the best performance in relation to conversion and stability, two important properties for catalysts. (author)

  6. Effect of biochar on soil structural characteristics: water retention and gas transport

    DEFF Research Database (Denmark)

    Sun, Zhencai; Møldrup, Per; Vendelboe, Anders Lindblad

    Biochar addition to agricultural soil has been reported to reduce climate gas emission, as well as improve soil fertility and crop productivity. Little, however, is known about biochar effects on soil structural characteristics. This study investigates if biochar-application changes soil structural...... characteristics, as indicated from water retention and gas transport measurements on intact soil samples. Soil was sampled from a field experiment on a sandy loam with four control plots (C) without biochar and four plots (B) with incorporated biochar at a rate of 20 tons per hectare (plot size, 6 x 8 m). The C......-gas diffusivity on intact 100cm3 soil samples (5 replicates in each plot). We found that biochar application significantly decreased soil bulk density, hereby creating higher porosity. At the same soil-water matric potential, all the soil-gas phase parameters (air-filled porosity, air permeability and gas...

  7. Structural characteristics of a novel antifreeze protein from the longhorn beetle Rhagium inquisitor

    DEFF Research Database (Denmark)

    Kristiansen, E; Ramløv, Hans; Højrup, Peter

    2011-01-01

    beetle Rhagium inquisitor is known to express AFPs in its body fluids. In this work we report on the primary structure and structural characteristics of a 12.8 kDa AFP from this beetle (RiAFP). It has a high capacity to evoke antifreeze activity as compared to other known insect AFPs......Antifreeze proteins (AFPs) are characterized by their capacity to inhibit the growth of ice and are produced by a variety of polar fish, terrestrial arthropods and other organisms inhabiting cold environments. This capacity reflects their role as stabilizers of supercooled body fluids. The longhorn...

  8. Features Of Household Lexics, Their Characteristics And Structural Analysis In The Modern English Language

    Directory of Open Access Journals (Sweden)

    Aygun Yusifova

    2014-04-01

    Full Text Available The present paper aims to analyze the most inherent features and characteristics of household lexis in English. Special emphasis has been placed on their names of the objects used in everyday life, kitchen utensils, animal and birds. Lexical units concerning ceremonies, habits and traditions are also among the scope of the paper. Moreover, the study deals with the structural features of the units under consideration. It is believed that the thematic-semantic characterization of every-day lexis can have both pedagogical and linguistic implications, especially when dealing with comparative structures.

  9. Characteristics of exciton photoluminescence kinetics in low-dimensional silicon structures

    CERN Document Server

    Sachenko, A V; Manojlov, E G; Svechnikov, S V

    2001-01-01

    The time-resolved visible photoluminescence of porous nanocrystalline silicon films obtained by laser ablation have been measured within the temperature range 90-300 K. A study has been made of the interrelationship between photoluminescence characteristics (intensity, emission spectra, relaxation times, their temperature dependencies and structural and dielectric properties (size and shapes of Si nanocrystals, oxide phase of nanocrystal coating, porosity). A photoluminescence model is proposed that describes photon absorption and emission occurring in quantum-size Si nanocrystals while coupled subsystems of electron-hole pairs and excitons take part in the recombination. Possible excitonic Auger recombination mechanism in low-dimensional silicon structures is considered

  10. Ground Motion Characteristics of the 2015 Gorkha Earthquake, Survey of Damage to Stone Masonry Structures and Structural Field Tests

    Directory of Open Access Journals (Sweden)

    Rishi Ram Parajuli

    2015-11-01

    Full Text Available On April 25, 2015, a M7.8 earthquake rattled central Nepal; ground motion recorded in Kantipath, Kathmandu, 76.86 km east of the epicenter suggested that the low frequency component was dominant. We consider data from eight aftershocks following the Gorkha earthquake and analyze ground motion characteristics; we found that most of the ground motion records are dominated by low frequencies for events with a moment magnitude greater than 6. The Gorkha earthquake devastated hundreds of thousands of structures. In the countryside, and especially in rural mountainous areas, most of the buildings that collapsed were stone masonry constructions. Detailed damage assessments of stone masonry buildings in Harmi Gorkha had done, with an epicentral distance of about 17 km. Structures were categorized as large, medium and small depending on their plinth area size and number of stories. Most of the structures in the area were damaged; interestingly, all ridge-line structures were heavily damaged. Moreover, Schmidt hammer tests were undertaken to determine the compressive strength of stone masonry, brick masonry with mud mortar for normal buildings and historical monuments. The compressive strengths of stone and brick masonry were found to be 12.38 and 18.75 MPa, respectively. Historical structures constructed with special bricks had a compressive strength of 29.50 MPa. Pullout tests were also conducted to determine the stone masonry-mud mortar bond strength. The cohesive strength of mud mortar and the coefficient of friction were determined.

  11. Structural and Interpersonal Characteristics of Family Meals: Associations with Adolescent BMI and Dietary Patterns

    OpenAIRE

    Berge, Jerica M.; Jin, Seok Won; Hannan, Peter; Neumark-Sztainer, Dianne

    2013-01-01

    The last decade of research has suggested that family meals play an important role in promoting healthful dietary intake in youth. However, little is known about the structural characteristics and interpersonal dynamics of family meals that may help to inform why family meals are protective for youth. The current mixed methods, cross-sectional study conducted in 2010–2011 includes adolescents and parents who participated in two linked population-based studies. Participants included 40 parents...

  12. Dynamic response characteristics in the vertical direction of building structural systems

    International Nuclear Information System (INIS)

    Watabe, Makoto; Kubo, Tetsuo; Yamanouchi, Hiroyuki; Ohkawa, Izuru

    1985-01-01

    In nuclear reactor buildings, important systems such as generators or steam pipes are placed or fixed on the floor slabs of the building. To evaluate their dynamic responses during earthquakes, it is essential to obtain dynamic characteristics in the vertical direction of the reactor building. This study is to reveal the vertical responses of a building structural system by vibration tests with a shaker, and to verify the analytical computer program code for vertical responses. (author)

  13. Heat transfer characteristics and limitations analysis of heat-pipe-cooled thermal protection structure

    International Nuclear Information System (INIS)

    Guangming, Xiao; Yanxia, Du; Yewei, Gui; Lei, Liu; Xiaofeng, Yang; Dong, Wei

    2014-01-01

    The theories of heat transfer, thermodynamics and fluid dynamics are employed to develop the coupled heat transfer analytical methods for the heat-pipe-cooled thermal protection structure (HPC TPS), and a three-dimensional numerical method considering the sonic limit of heat pipe is proposed. To verify the calculation correctness, computations are carried out for a typical heat pipe and the results agree well with experimental data. Then, the heat transfer characteristics and limitations of HPC TPS are mainly studied. The studies indicate that the use of heat pipe can reduce the temperature at high heat flux region of structure efficiently. However, there is a frozen startup period before the heat pipe reaching a steady operating state, and the sonic limit will be a restriction on the heat transfer capability. Thus, the effects of frozen startup must be considered for the design of HPC TPS. The simulation model and numerical method proposed in this paper can predict the heat transfer characteristics of HPC TPS quickly and exactly, and the results will provide important references for the design or performance evaluation of HPC TPS. - Highlights: • Numerical methods for the heat-pipe-cooled thermal protection structure are studied. • Three-dimensional simulation model considering sonic limit of heat pipe is proposed. • The frozen startup process of the embedded heat pipe can be predicted exactly. • Heat transfer characteristics of TPS and limitations of heat pipe are discussed

  14. A diagnosis model for early Tourette syndrome children based on brain structural network characteristics

    Science.gov (United States)

    Wen, Hongwei; Liu, Yue; Wang, Jieqiong; Zhang, Jishui; Peng, Yun; He, Huiguang

    2016-03-01

    Tourette syndrome (TS) is a childhood-onset neurobehavioral disorder characterized by the presence of multiple motor and vocal tics. Tic generation has been linked to disturbed networks of brain areas involved in planning, controlling and execution of action. The aim of our work is to select topological characteristics of structural network which were most efficient for estimating the classification models to identify early TS children. Here we employed the diffusion tensor imaging (DTI) and deterministic tractography to construct the structural networks of 44 TS children and 48 age and gender matched healthy children. We calculated four different connection matrices (fiber number, mean FA, averaged fiber length weighted and binary matrices) and then applied graph theoretical methods to extract the regional nodal characteristics of structural network. For each weighted or binary network, nodal degree, nodal efficiency and nodal betweenness were selected as features. Support Vector Machine Recursive Feature Extraction (SVM-RFE) algorithm was used to estimate the best feature subset for classification. The accuracy of 88.26% evaluated by a nested cross validation was achieved on combing best feature subset of each network characteristic. The identified discriminative brain nodes mostly located in the basal ganglia and frontal cortico-cortical networks involved in TS children which was associated with tic severity. Our study holds promise for early identification and predicting prognosis of TS children.

  15. Engineering characterization of ground motion. Task II. Effects of ground motion characteristics on structural response considering localized structural nonlinearities and soil-structure interaction effects. Volume 2

    International Nuclear Information System (INIS)

    Kennedy, R.P.; Kincaid, R.H.; Short, S.A.

    1985-03-01

    This report presents the results of part of a two-task study on the engineering characterization of earthquake ground motion for nuclear power plant design. Task I of the study, which is presented in NUREG/CR-3805, Vol. 1, developed a basis for selecting design response spectra taking into account the characteristics of free-field ground motion found to be significant in causing structural damage. Task II incorporates additional considerations of effects of spatial variations of ground motions and soil-structure interaction on foundation motions and structural response. The results of Task II are presented in four parts: (1) effects of ground motion characteristics on structural response of a typical PWR reactor building with localized nonlinearities and soil-structure interaction effects; (2) empirical data on spatial variations of earthquake ground motion; (3) soil-structure interaction effects on structural response; and (4) summary of conclusions and recommendations based on Tasks I and II studies. This report presents the results of the first part of Task II. The results of the other parts will be presented in NUREG/CR-3805, Vols. 3 to 5

  16. Chromium-modified a-C films with advanced structural, mechanical and corrosive-resistant characteristics

    Energy Technology Data Exchange (ETDEWEB)

    Ming, Miao Yi [International Chinese-Belarusian scientific laboratory on vacuum-plasma technology, Nanjing University of Science and Technology, Nanjing 210094 (China); Francisk Skorina Gomel State University, Gomel 246019 (Belarus); Jiang, Xiaohong, E-mail: jxh0668@sina.com [International Chinese-Belarusian scientific laboratory on vacuum-plasma technology, Nanjing University of Science and Technology, Nanjing 210094 (China); Francisk Skorina Gomel State University, Gomel 246019 (Belarus); Piliptsou, D.G., E-mail: pdg_@mail.ru [International Chinese-Belarusian scientific laboratory on vacuum-plasma technology, Nanjing University of Science and Technology, Nanjing 210094 (China); Francisk Skorina Gomel State University, Gomel 246019 (Belarus); Zhuang, Yuzhao; Rogachev, A.V.; Rudenkov, A.S. [International Chinese-Belarusian scientific laboratory on vacuum-plasma technology, Nanjing University of Science and Technology, Nanjing 210094 (China); Francisk Skorina Gomel State University, Gomel 246019 (Belarus); Balmakou, A. [Faculty of Material Science and Technology, Slovak University of Technology, Trnava 91724 (Slovakia)

    2016-08-30

    Highlights: • Influence of the chromium interlayer on the structure and mechanical properties of a-C:Cr films. • Residual stress and wear of a-C:Cr and Cr/a-C varies due to their phase and surface morphology. • Chromium-modified a-C films with advanced structural, mechanical and corrosive-resistant characteristics. - Abstract: To improve structural, mechanical and chemical properties of diamond-like carbon films, we developed amorphous carbon chromium-modified composite films fabricated by means of cathode magnetic filtered arc deposition. The properties were analyzed by Raman spectroscopy, X-ray photoelectron spectroscopy and atomic force microscopy for the purpose of the structure characterization, elemental analysis and topology examination. Moreover, we also assessed residual stress, the coefficient of friction, hardness, the elastic modulus and corrosion parameters through X-ray double-crystal surface profilometry, tribo-testing, nanoindenter-testing, as well as contact angle measurements and potentiodynamic polarization analysis. As a result of a comparative analysis, we revealed a substantial improvement in the characteristics of developed composite films in comparison with amorphous carbon films. For example, Cr-modification is resulted, in greater integrated performance, toughness and corrosion resistance; the residual stress was reduced substantially.

  17. In situ KPFM imaging of local photovoltaic characteristics of structured organic photovoltaic devices.

    Science.gov (United States)

    Watanabe, Satoshi; Fukuchi, Yasumasa; Fukasawa, Masako; Sassa, Takafumi; Kimoto, Atsushi; Tajima, Yusuke; Uchiyama, Masanobu; Yamashita, Takashi; Matsumoto, Mutsuyoshi; Aoyama, Tetsuya

    2014-02-12

    Here, we discuss the local photovoltaic characteristics of a structured bulk heterojunction, organic photovoltaic devices fabricated with a liquid carbazole, and a fullerene derivative based on analysis by scanning kelvin probe force microscopy (KPFM). Periodic photopolymerization induced by an interference pattern from two laser beams formed surface relief gratings (SRG) in the structured films. The surface potential distribution in the SRGs indicates the formation of donor and acceptor spatial distribution. Under illumination, the surface potential reversibly changed because of the generation of fullerene anions and hole transport from the films to substrates, which indicates that we successfully imaged the local photovoltaic characteristics of the structured photovoltaic devices. Using atomic force microscopy, we confirmed the formation of the SRG because of the material migration to the photopolymerized region of the films, which was induced by light exposure through photomasks. The structuring technique allows for the direct fabrication and the control of donor and acceptor spatial distribution in organic photonic and electronic devices with minimized material consumption. This in situ KPFM technique is indispensable to the fabrication of nanoscale electron donor and electron acceptor spatial distribution in the devices.

  18. Numerical study on air-structure coupling dynamic characteristics of the axial fan blade

    Science.gov (United States)

    Chen, Q. G.; Xie, B.; Li, F.; Gu, W. G.

    2013-12-01

    In order to understand the dynamic characteristics of the axial-flow fan blade due to the effect of rotating stress and the action of unsteady aerodynamic forces caused by the airflow, a numerical simulation method for air-structure coupling in an axial-flow fan with fixed rear guide blades was performed. The dynamic characteristics of an axial-flow fan rotating blade were studied by using the two-way air-structure coupling method. Based on the standard k-ε turbulence model, and using weak coupling method, the preceding six orders modal parameters of the rotating blade were obtained, and the distributions of stress and strain on the rotating blade were presented. The results show that the modal frequency from the first to the sixth order is 3Hz higher than the modal frequency without considering air-structure coupling interaction; the maximum stress and the maximum strain are all occurred in the vicinity of root area of the blade no matter the air-structure coupling is considered or not, thus, the blade root is the dangerous location subjected to fatigue break; the position of maximum deformation is at the blade tip, so the vibration of the blade tip is significant. This study can provide theoretical references for the further study on the strength analysis and mechanical optimal design.

  19. Pore structure characteristics after two years biochar application to a sandy loam field

    DEFF Research Database (Denmark)

    Sun, Zhencai; Arthur, Emmanuel; de Jonge, Lis Wollesen

    2015-01-01

    Soil pore structure comprises the size and shape of soil pores and has a major impact on water retention and gas movement. The porous nature of biochar suggests that its application to soil can potentially alter soil pore structure characteristics, and the purpose of this study was to evaluate...... the effects of birch wood biochar (20, 40, and 100 Mg ha−1) applied to a sandy loam on soil total porosity and pore structure indices. Bulk and intact soil samples were collected for physicochemical analyses and water retention and gas diffusivity measurements between pF 1.0 and pF 3.0. Biochar application...... reduced bulk density and increased total porosity especially for soil with 100 Mg ha−1 biochar (16% and 14% reduction in bulk density and total porosity, respectively). Biochar application of more than 20 Mg ha−1 enhanced water retention, and the trend increased with increasing biochar application rate...

  20. Evaluation of seismic characteristics and structural integrity for the cabinet of HANARO seismic monitoring analysis system

    Energy Technology Data Exchange (ETDEWEB)

    Ryu, Jeong Soo; Yoon, Doo Byung

    2003-06-01

    The HANARO SMAS(Seismic Monitoring Analysis System) is classified as Non-Nuclear Safety(NNS), seismic category I, and quality class T. It is required that this system can perform required functions, which are to preserve its structural integrity during and after an OBE or SSE. In this work, the structural integrity and seismic characteristics of the cabinet of the newly developed SMAS have been estimated. The most parts of the cabinet are identically designed with those of Yonggwhang and Gori Nuclear Power Plants(NPPs), unit 1 that successfully completed the required seismic qualification tests. The structure of the cabinet of the SMAS is manufactured by the manufacturer of the cabinet of Yonggwhang and Gori NPPs. To evaluate the seismic characteristics of the SMAS, the RRS(Required Response Spectra) of the newly developed cabinet are compared with those of Yonggwhang and Gori NPPs, unit 1. In addition, natural frequencies of the cabinet of HANARO, Yonggwhang, and Gori NPPs were measured for the comparison of the seismic characteristics of the installed cabinets. In case of HANARO, the bottom of the cabinet is welded to the base plate. The base plate is fixed to the concrete foundation by using anchor bolts. For the evaluation of the structural integrity of the welding parts and the anchor bolts, the maximum stresses and forces of the welding parts and the anchor bolts due to seismic loading are estimated. The analysis results show that maximum stresses and forces are less than the allowable limits. This new SMAS is operating at HANARO instrument room to acquire and analyze the signal of earthquake.

  1. Tectonic characteristics and structural styles of a continental rifted basin: Revelation from deep seismic reflection profiles

    Directory of Open Access Journals (Sweden)

    Yuan Li

    2016-09-01

    Full Text Available The Fushan Depression is a half-graben rifted sub-basin located in the southeast of the Beibuwan Basin, South China Sea. The Paleogene Liushagang sequence is the main hydrocarbon-bearing stratigraphic unit in the sub-basin. Using three-dimensional (3-D seismic data and logging data over the sub-basin, we analyzed structural styles and sedimentary characteristics of the Liushagang sequence. Five types of structural styles were defined: ancient horst, traditional slope, flexure slope-break, faulted slope-break and multiple-stage faults slope, and interpretations for positions, background and development formations of each structural style were discussed. Structural framework across the sub-basin reveals that the most remarkable tectonic setting is represented by the central transfer zone (CTZ which divides the sub-basin into two independent depressions, and two kinds of sequence architectures are summarized: (i the western multi-stage faults slope; (ii the eastern flexure slope break belt. Combined with regional stress field of the Fushan Depression, we got plane combinations of the faults, and finally built up plan distribution maps of structural system for main sequence. Also, we discussed the controlling factors mainly focused on subsidence history and background tectonic activities such as volcanic activity and earthquakes. The analysis of structural styles and tectonic evolution provides strong theoretical support for future prospecting in the Fushan sub-basin and other similar rifted basins of the Beibuwan Basin in South China Sea.

  2. Variation in mangrove forest structure and sediment characteristics in Bocas del Toro, Panama

    Science.gov (United States)

    Lovelock, C.E.; Feller, Ilka C.; McKee, K.L.; Thompson, R.

    2005-01-01

    Mangrove forest structure and sediment characteristics were examined in the extensive mangroves of Bocas del Toro, Republic of Panama. Forest structure was characterized to determine if spatial vegetation patterns were repeated over the Bocas del Toro landscape. Using a series of permanent plots and transects we found that the forests of Bocas del Toro were dominated by Rhizophora mangle with very few individuals of Avicennia germinans and Laguncularia racemosa. Despite this low species diversity, there was large variation in forest structure and in edaphic conditions (salinity, concentration of available phosphorus, Eh and sulphide concentration). Aboveground biomass varied 20-fold, from 6.8 Mg ha-1 in dwarf forests to 194.3 Mg ha-1 in the forests fringing the land. But variation in forest structure was predictable across the intertidal zone. There was a strong tree height gradient from seaward fringe (mean tree height 3.9 m), decreasing in stature in the interior dwarf forests (mean tree height 0.7 m), and increasing in stature in forests adjacent to the terrestrial forest (mean tree height 4.1 m). The predictable variation in forest structure emerges due to the complex interactions among edaphic and plant factors. Identifying predictable patterns in forest structure will aid in scaling up the ecosystem services provided by mangrove forests in coastal landscapes. Copyright 2005 College of Arts and Sciences.

  3. Influence of emulsifiers on the characteristics of polyurethane structures used as drug carrier.

    Science.gov (United States)

    Heghes, Alina; Soica, Codruta M; Ardelean, Simona; Ambrus, Rita; Muntean, Danina; Galuscan, Atena; Dragos, Dan; Ionescu, Daniela; Borcan, Florin

    2013-04-10

    Emulsifiers have a significant role in the emulsion polymerization by reducing the interfacial tension thus increasing the stability of colloidal dispersions of polymer nanostructures. This study evaluates the impact of four emulsifiers on the characteristics of polyurethane hollow structures used as drug delivery system. Polyurethane (PU) structures with high stability and sizes ranging from nano- to micro-scale were obtained by interfacial polyaddition combined with spontaneous emulsification. The pH of PU aqueous solutions (0.1% w/w) was slightly acidic, which is acceptable for products intended to be used on human skin. Agglomerated structures with irregular shapes were observed by scanning electron microscopy. The synthesized structures have melting points between 245-265°C and reveal promising results in different evaluations (TEWL, mexametry) on murine skin. In this study hollow PU structures of reduced noxiousness were synthesized, their size and stability being influenced by emulsifiers. Such structures could be used in the pharmaceutical field as future drug delivery systems.

  4. Volatile and Nonvolatile Characteristics of Asymmetric Dual-Gate Thyristor RAM with Vertical Structure.

    Science.gov (United States)

    Kim, Hyun-Min; Kwon, Dae Woong; Kim, Sihyun; Lee, Kitae; Lee, Junil; Park, Euyhwan; Lee, Ryoongbin; Kim, Hyungjin; Kim, Sangwan; Park, Byung-Gook

    2018-09-01

    In this paper, the volatile and nonvolatile characteristics of asymmetric dual-gate thyristor random access memory (TRAM) are investigated using the technology of a computer-aided design (TCAD) simulation. Owing to the use of two independent gates having different gate dielectric layers, volatile and nonvolatile memory functions can be realized in a single device. The first gate with a silicon oxide layer controls the one-transistor dynamic random access memory (1T-DRAM) characteristics of the device. From the simulation results, a rapid write speed (107) can be achieved. The second gate, whose dielectric material is composed of oxide/nitride/oxide (O/N/O) layers, is used to implement the nonvolatile property by trapping charges in the nitride layer. In addition, this offers an advantage when processing the 3D-stack memory application, as the device has a vertical channel structure with polycrystalline silicon.

  5. The adhesion characteristics of protective coating materials for the containment structure in nuclear power plants

    International Nuclear Information System (INIS)

    Lee, Sang-Kook; Shin, Jae-Chul

    2003-01-01

    Protective coating materials used in the containment structures should be durable for the designed 30 to 40 year lifetime of a nuclear power plant. At the present, these materials have not yet been developed. Therefore it is very important to keep the durability of the protective coating materials through persistent maintenance, and in order to achieve this, understanding the adhesion characteristics of the coating materials is of utmost importance. Therefore, this study attempts to find any methods for durability maintenance of these protective coating materials. To accomplish these aims, this study applied an experimental deterioration environment condition relevant to Loss of Coolant Accident (LOCA) and Main Steam Line Break (MSLB), categorized as of Design Basis Accident (DBA), onto steel liner plate specimens covered with protective coating materials. Adhesion tests were performed on these deteriorated coating materials to characterize the physical properties and through these tests, the quantitative adhesion characteristics according to the history of deterioration environment were found

  6. Impact Characteristic According to the Structure of Crash Box at the Vehicle

    Directory of Open Access Journals (Sweden)

    Min B.S.

    2017-06-01

    Full Text Available The crash box between a bumper and a car body in automobiles can reduce impacts for car bodies with a bumper at a low-speed collision by preventing the shocks. Also, this crash box is the part playing a very important role for the safety of vehicle and the reduction of repair cost, and many studies have been investigated for the performance. In this study, aluminum foam was inserted in an aluminum crash box to analyze the relationships of deformation, stress and internal energy. The compression characteristics are compared with six cases. In addition, the load due to displacement at experiment for a case is verified by modeling with finite elements and performing the structural analysis. As these study results for investigating characteristics of the crash box, it is thought that the effective designs of crash box to enhance the durability for collision are made possible.

  7. Analysis of structural dynamic characteristics of a high speed light special catamaran

    Science.gov (United States)

    Sun, Li-Ping; Nie, Wu; Zhang, Wei

    2006-03-01

    In this paper, structural dynamic characteristics of a high-speed light special catamaran-wave piercing catamaran are analyzed using the FEA software MSC-NASTRAN. The dynamic reduction method is introduced to eliminate the local vibration modes in order to obtain the whole ship’s mode shapes. In the post-processor, a lot of accessorial methods are adopted to eliminate the local vibrations, so that the whole ship’s mode shapes can be identified. The modal analysis indicates that the dynamic reduction method fits for mode shapes identifying. In the end, the test results of a catamaran named Frederick G. Greed are used for reference to validate the obtained results. The comparison process shows that the results are credible. A special mode shape, which is quite different with that of conventional monohull ship, is also pointed out. The obtained results provide a valuable reference for the coming computation of catamaran’s vibration characteristics.

  8. Elemental composition and structural characteristics of as-received TriTaniumTM orthodontic archwire

    Science.gov (United States)

    Ilievska, I.; Petrov, V.; Mihailov, V.; Karatodorov, S.; Andreeva, L.; Zaleski, A.; Mikli, V.; Gueorgieva, M.; Petrova, V.; Stoyanova-Ivanova, A.

    2018-03-01

    Orthodontic archwires are among the most important devices of fixed orthodontic therapy. Many types of archwires are made available on the market by various manufacturers with different elemental composition and structural characteristics. Knowing this information is important when choosing a suitable archwire for a particular stage of orthodontic treatment. The aim of our study is to characterize a new type orthodontic archwires (TriTaniumTM, American Orthodontics) before their placement in the oral cavity. To achieve the aim, we used modern methods for determining their elemental composition and structural characteristics: laser-induced plasma spectroscopy (LIBS), X-ray diffraction analysis (XRD), scanning electronic microscopy (SEM), energy dispersive X-ray spectroscopy (EDX) and differential scanning calorimetry (DSC). The results obtained from the qualitative elemental analysis by LIBS and the quantitative elemental analysis by EDX showed that Ni and Ti are the main elements in the archwire studied. The room-temperature XRD patterns showed peaks typical for a Ni-Ti alloy with an austenite-type structure. Monitoring the phase transitions by means of DSC measurements in the temperature range from –50 °C to +50 °C, we showed that in TriTaniumTM archwires, besides the austenite to martensite transition, there exists a rhombohedral intermediate phase (R phase). This study will be useful in assisting orthodontists in applying appropriate nickel-titanium orthodontic archwires in the clinical practice.

  9. Object-Based Dense Matching Method for Maintaining Structure Characteristics of Linear Buildings.

    Science.gov (United States)

    Su, Nan; Yan, Yiming; Qiu, Mingjie; Zhao, Chunhui; Wang, Liguo

    2018-03-29

    In this paper, we proposed a novel object-based dense matching method specially for the high-precision disparity map of building objects in urban areas, which can maintain accurate object structure characteristics. The proposed framework mainly includes three stages. Firstly, an improved edge line extraction method is proposed for the edge segments to fit closely to building outlines. Secondly, a fusion method is proposed for the outlines under the constraint of straight lines, which can maintain the building structural attribute with parallel or vertical edges, which is very useful for the dense matching method. Finally, we proposed an edge constraint and outline compensation (ECAOC) dense matching method to maintain building object structural characteristics in the disparity map. In the proposed method, the improved edge lines are used to optimize matching search scope and matching template window, and the high-precision building outlines are used to compensate the shape feature of building objects. Our method can greatly increase the matching accuracy of building objects in urban areas, especially at building edges. For the outline extraction experiments, our fusion method verifies the superiority and robustness on panchromatic images of different satellites and different resolutions. For the dense matching experiments, our ECOAC method shows great advantages for matching accuracy of building objects in urban areas compared with three other methods.

  10. Object-Based Dense Matching Method for Maintaining Structure Characteristics of Linear Buildings

    Directory of Open Access Journals (Sweden)

    Nan Su

    2018-03-01

    Full Text Available In this paper, we proposed a novel object-based dense matching method specially for the high-precision disparity map of building objects in urban areas, which can maintain accurate object structure characteristics. The proposed framework mainly includes three stages. Firstly, an improved edge line extraction method is proposed for the edge segments to fit closely to building outlines. Secondly, a fusion method is proposed for the outlines under the constraint of straight lines, which can maintain the building structural attribute with parallel or vertical edges, which is very useful for the dense matching method. Finally, we proposed an edge constraint and outline compensation (ECAOC dense matching method to maintain building object structural characteristics in the disparity map. In the proposed method, the improved edge lines are used to optimize matching search scope and matching template window, and the high-precision building outlines are used to compensate the shape feature of building objects. Our method can greatly increase the matching accuracy of building objects in urban areas, especially at building edges. For the outline extraction experiments, our fusion method verifies the superiority and robustness on panchromatic images of different satellites and different resolutions. For the dense matching experiments, our ECOAC method shows great advantages for matching accuracy of building objects in urban areas compared with three other methods.

  11. Geological structure of Osaka basin and characteristic distributions of structural damage caused by earthquake; Osaka bonchi kozo to shingai tokusei

    Energy Technology Data Exchange (ETDEWEB)

    Nakagawa, K.; Shiono, K.; Inoue, N.; Senda, S. [Osaka City University, Osaka (JP. Faculty of Science); Ryoki, K. [Osaka Polytechnic Collage, Osaka (Japan); Shichi, R. [Nagoya University, Nagoya (Japan). Faculty of Science

    1996-05-01

    The paper investigates relations between the damage caused by the Hyogo-ken Nanbu earthquake and the deep underground structures. A characteristic of the earthquake damage distribution is that the damage concentrated near faults. Most of the damages were seen on the side of faults` relatively falling rather than right above the faults and of their slightly slanting to the seaside. Distribution like this seems to be closely related to underground structures. Therefore, a distribution map of the depth of basement granite in Osaka sedimentary basin was drawn, referring to the data on basement rock depth obtained from the distribution map of gravity anomaly and the result of the survey using the air gun reflection method. Moreover, cubic underground structures were determined by 3-D gravity analysis. The result was concluded as follows: when observing the M7 zone of the low land, in particular, where the damage was great from an aspect of gravity anomaly, the basement rock below the zone declined near the cliff toward the sea, which indicates a great possibility of its being a fault. There is a high possibility that the zone suffered mostly from the damage caused by focusing by refraction and total reflection of seismic wave rays. 3 refs., 8 figs.

  12. The evolutionary characteristics and structural biology of Gallus toll-like receptor 21.

    Science.gov (United States)

    Wu, Hongping; Wang, Hai; Jiang, Wuqi; Lian, Zhengxing

    2017-12-27

    Toll-like receptors (TLRs) are an important part of the innate immune system, acting as a first line of defense against many invading pathogens. The ligand known to bind Gallus toll-like receptor 21 (gTLR21) is the unmethylated cytosine phosphate guanine dideoxy nucleotide motif; however, the evolutionary characteristics and structural biology of gTLR21 are poorly elaborated. Our results suggest that gTLR21 is phylogenetically and evolutionarily related to the TLR11 family and is perhaps a close ortholog of the Mus TLR13. Structural biology of homology modeling of the gTLR21 ectodomain structure suggests that it has no Z-loop like that seen in Mus TLR9. The cytosolic toll-IL-1 receptor region of gTLR21 contains a central 4-stranded parallel β-sheet (βA-βD) surrounded by 5 α-helices (αA-αE) on both sides, a highly conserved structure also seen in other TLRs. Molecular docking analysis reveals that the gTLR21 ectodomain has the potential to distinguish between different ligands. Homodimer analysis results also suggest that Phe842 and Pro844 of the BB loop and Cys876 of the αC helix in gTLR21 are conserved in other cytosolic toll-IL-1 receptor domains of other TLRs and may contribute to the docking of homodimers. Our study on the evolutionary characteristics and structural biology of gTLR21 reveals that the molecule may have a broader role to play in innate immune system; however, further experimental validation is required to confirm our findings. © 2017 The Authors Journal of Molecular Recognition Published by John Wiley & Sons Ltd.

  13. Impact of Interfacial Characteristics on Foam Structure: Study on Model Fluids and at Pilot Scale

    Directory of Open Access Journals (Sweden)

    Mezdour Samir

    2017-03-01

    Full Text Available Foams represent an important area of research because of their relevance to many industrial processes. In continuous foaming operations, foaming ability depends on the process parameters and the characteristics of the raw materials used for foamed products. The effects of fluid viscosity and equilibrium surface tension on foam structure have been studied extensively. Furthermore, as surface active agents diffuse to the interface, they can modify other interface properties through their adsorption, such as interfacial rheology and surface tension kinetics. In order to better understand how these two interfacial properties influence foam structuring, we formulated model foaming solutions with different interface viscoelasticity levels and adsorption rates, but all with the same equilibrium surface tension and viscosity. The solutions were made up of a surface active agent and glucose syrup, so as to maintain a Newtonian behaviour. Five surface active agents were used: Whey Protein Isolate (WPI, sodium caseinate, saponin, cetyl phosphate and Sodium Dodecyl Sulphate (SDS, at concentrations ranging from 0.1% to 1%. Their molecular characteristics, and their interaction with the glucose syrup, made it possible to obtain a range of interface viscoelasticities and surface tension kinetics for these model solutions. The solutions were whipped in a continuously-operating industrial foaming device in order to control process parameters such as shearing and overrun, and to ensure that the experiment was representative of industrial production. The structure of the foams thus obtained foams was then determined by characterising bubble size using image analysis. For all the model solutions, both the viscoelastic moduli and apparent diffusion coefficient were linked to foam structure. The results showed that both high interface viscoelasticity and rapid diffusion kinetics induced a foam structure containing small bubbles. Both effects, as well as the impact of

  14. Relationship between Molecular Structure Characteristics of Feed Proteins and Protein Digestibility and Solubility

    Directory of Open Access Journals (Sweden)

    Mingmei Bai

    2016-08-01

    Full Text Available The nutritional value of feed proteins and their utilization by livestock are related not only to the chemical composition but also to the structure of feed proteins, but few studies thus far have investigated the relationship between the structure of feed proteins and their solubility as well as digestibility in monogastric animals. To address this question we analyzed soybean meal, fish meal, corn distiller’s dried grains with solubles, corn gluten meal, and feather meal by Fourier transform infrared (FTIR spectroscopy to determine the protein molecular spectral band characteristics for amides I and II as well as α-helices and β-sheets and their ratios. Protein solubility and in vitro digestibility were measured with the Kjeldahl method using 0.2% KOH solution and the pepsin-pancreatin two-step enzymatic method, respectively. We found that all measured spectral band intensities (height and area of feed proteins were correlated with their the in vitro digestibility and solubility (p≤0.003; moreover, the relatively quantitative amounts of α-helices, random coils, and α-helix to β-sheet ratio in protein secondary structures were positively correlated with protein in vitro digestibility and solubility (p≤0.004. On the other hand, the percentage of β-sheet structures was negatively correlated with protein in vitro digestibility (p<0.001 and solubility (p = 0.002. These results demonstrate that the molecular structure characteristics of feed proteins are closely related to their in vitro digestibility at 28 h and solubility. Furthermore, the α-helix-to-β-sheet ratio can be used to predict the nutritional value of feed proteins.

  15. Erosional stability of rehabilitated uranium mine structures incorporating natural landform characteristics, northern tropical Australia

    International Nuclear Information System (INIS)

    East, T.J.; Uren, C.J.; Noller, B.N.; Cull, R.F.; Curley, P.M.; Unger, C.J.

    1994-01-01

    Australian Government guidelines specify that tailings containment structures at rehabilitated uranium mines in the Alligator Rivers Region of tropical northern Australia should have an engineered structural life of 1000 years. As part of the containment structure design process, erosion plots incorporating both regional geomorphological characteristics (concave hillslope profiles and a weathering-resistant rock cover of schist) and more conventional engineering design parameters (straight slopes and mine waste rock) were constructed at the Ranger Uranium Mine. The plots were monitored for storm runoff, and concentrations of solutes, suspended solids and selected ions over successive wet seasons. The concave slopes (the hillslope analogues) had lower peak discharges and lower concentrations of suspended solids than the straight slopes. However, solute concentrations in runoff from the schist covered (hillslope) slopes were higher than from the waste rock covered plots. Solute (mainly magnesium sulfate) concentrations for both rock types decreased by about an order of magnitude over the wet season. High sulfate concentrations are also likely to decrease substantially after several wet seasons, due to settlement of the waste rock and a reduction in rates of weathering. Development of a vegetation cover on the rehabilitated landforms will reduce the high suspended sediment concentrations. These initial results suggest that rehabilitated uranium mine structures which utilise selected features of stable natural landforms in their design may have greater erosional stability than more conventionally engineered structures. (orig.)

  16. Erosional stability of rehabilitated uranium mine structures incorporating natural landform characteristics, northern tropical Australia

    Energy Technology Data Exchange (ETDEWEB)

    East, T.J. [Bureau of Resource Sciences, Canberra (Australia); Uren, C.J. [Alligator Rivers Region Research Institute, Jabiru Northern Territory (Australia); Noller, B.N. [Alligator Rivers Region Research Institute, Jabiru Northern Territory (Australia); Cull, R.F. [Alligator Rivers Region Research Institute, Jabiru Northern Territory (Australia); Curley, P.M. [Ranger Uranium Mines, Jabiru Northern Territory (Australia); Unger, C.J. [Ranger Uranium Mines, Jabiru Northern Territory (Australia)

    1994-09-01

    Australian Government guidelines specify that tailings containment structures at rehabilitated uranium mines in the Alligator Rivers Region of tropical northern Australia should have an engineered structural life of 1000 years. As part of the containment structure design process, erosion plots incorporating both regional geomorphological characteristics (concave hillslope profiles and a weathering-resistant rock cover of schist) and more conventional engineering design parameters (straight slopes and mine waste rock) were constructed at the Ranger Uranium Mine. The plots were monitored for storm runoff, and concentrations of solutes, suspended solids and selected ions over successive wet seasons. The concave slopes (the hillslope analogues) had lower peak discharges and lower concentrations of suspended solids than the straight slopes. However, solute concentrations in runoff from the schist covered (hillslope) slopes were higher than from the waste rock covered plots. Solute (mainly magnesium sulfate) concentrations for both rock types decreased by about an order of magnitude over the wet season. High sulfate concentrations are also likely to decrease substantially after several wet seasons, due to settlement of the waste rock and a reduction in rates of weathering. Development of a vegetation cover on the rehabilitated landforms will reduce the high suspended sediment concentrations. These initial results suggest that rehabilitated uranium mine structures which utilise selected features of stable natural landforms in their design may have greater erosional stability than more conventionally engineered structures. (orig.)

  17. Structural effects on the electronic characteristics of intramolecularly intercalated alkali-rubrene complexes

    Energy Technology Data Exchange (ETDEWEB)

    Li, Tsung-Lung, E-mail: quantum@mail.ncyu.edu.tw [Department of Electrophysics, National Chia-Yi University, 300 Hsueh-Fu Road, Chiayi, 60004, Taiwan, ROC (China); Lu, Wen-Cai, E-mail: wencailu@jlu.edu.cn [Laboratory of Fiber Materials and Modern Textile, Growing Base for State Key Laboratory, College of Physics, Qingdao University, Qingdao, Shandong 266071 (China); State Key Laboratory of Theoretical and Computational Chemistry, Institute of Theoretical Chemistry, Jilin University, Changchun, Jilin 130021 (China)

    2016-11-01

    The geometric and electronic structures of neutral monolithium- and monosodium-rubrene (Li{sub 1} Rub and Na{sub 1} Rub) isomers are investigated and compared with monopotassium-rubrene (K{sub 1} Rub). Based on the alkali binding site, all isomers of these alkali-rubrene complexes can be subdivided into two types: intramolecularly intercalated and extramolecularly adsorbed. The minimum-energy Li{sub 1} Rub and Na{sub 1} Rub are intercalated structures, whereas the minimum-energy K{sub 1} Rub is adsorbed. The fact that the intercalated Li{sub 1} Rub and Na{sub 1} Rub structures are energetically favorable over the adsorbed ones can be explained by two energy rules. First, “double” proximity of the intercalating alkali element to a pair of phenyl side groups enormously reduces the total energy. Second, accommodation of a minuscule intercalant does not significantly deform the carbon frame and, thus, increases the energy only by a small amount. Additionally, the peculiar effects of intramolecular intercalation on the electronic structures of molecules are also studied in this simulation of monoalkali intercalation. In the monoalkali-intercalated rubrene complex, only one of the two pairs of phenyl groups of rubrene is intercalated, intentionally leaving another pair pristine, which facilitates the comparison of electronic structures between the intercalated and pristine pairs of phenyl side groups in a single molecule. The uniformity of chemical environments of the phenyl groups of the intercalated Li{sub 1} Rub/Na{sub 1} Rub is deteriorated by the incorporation of the intercalant, and leads to their spectral characteristics in contrast to K{sub 1} Rub. In particular, the introduction of the intercalant promotes the carbon 2p orbitals of the intercalated phenyl pair to take part in the electronic structures of the HOMO and LUMO peaks of Li{sub 1} Rub/Na{sub 1} Rub. The unpaired electron in the HOMO is delocalized over the backbone with higher probability of

  18. Structural effects on the electronic characteristics of intramolecularly intercalated alkali-rubrene complexes

    International Nuclear Information System (INIS)

    Li, Tsung-Lung; Lu, Wen-Cai

    2016-01-01

    The geometric and electronic structures of neutral monolithium- and monosodium-rubrene (Li 1 Rub and Na 1 Rub) isomers are investigated and compared with monopotassium-rubrene (K 1 Rub). Based on the alkali binding site, all isomers of these alkali-rubrene complexes can be subdivided into two types: intramolecularly intercalated and extramolecularly adsorbed. The minimum-energy Li 1 Rub and Na 1 Rub are intercalated structures, whereas the minimum-energy K 1 Rub is adsorbed. The fact that the intercalated Li 1 Rub and Na 1 Rub structures are energetically favorable over the adsorbed ones can be explained by two energy rules. First, “double” proximity of the intercalating alkali element to a pair of phenyl side groups enormously reduces the total energy. Second, accommodation of a minuscule intercalant does not significantly deform the carbon frame and, thus, increases the energy only by a small amount. Additionally, the peculiar effects of intramolecular intercalation on the electronic structures of molecules are also studied in this simulation of monoalkali intercalation. In the monoalkali-intercalated rubrene complex, only one of the two pairs of phenyl groups of rubrene is intercalated, intentionally leaving another pair pristine, which facilitates the comparison of electronic structures between the intercalated and pristine pairs of phenyl side groups in a single molecule. The uniformity of chemical environments of the phenyl groups of the intercalated Li 1 Rub/Na 1 Rub is deteriorated by the incorporation of the intercalant, and leads to their spectral characteristics in contrast to K 1 Rub. In particular, the introduction of the intercalant promotes the carbon 2p orbitals of the intercalated phenyl pair to take part in the electronic structures of the HOMO and LUMO peaks of Li 1 Rub/Na 1 Rub. The unpaired electron in the HOMO is delocalized over the backbone with higher probability of distributing over the central two fused rings than over the outer two

  19. Effect of pulse electron beam characteristics on internal friction and structural alterations in epoxy

    Energy Technology Data Exchange (ETDEWEB)

    Zaikin, Yu.A. [Al Farabi Kazakh National University, Almaty (Kazakhstan)]. E-mail: drzaykin@mail.ru; Ismailova, G.A. [Al Farabi Kazakh National University, Almaty (Kazakhstan); Al-Sheikhly, M. [University of Maryland, College Park (United States)

    2007-08-15

    Temperature dependence of internal friction is experimentally studied in epoxy irradiated by 2.5 MeV pulse electron beam to different doses. Time dependence of internal friction characteristics associated with radiation-induced processes of polymer scission and cross-linking is analyzed and discussed. Experimental data on kinetics of structural transformations in epoxy are interpreted on the base of analytical solutions of differential equations for free radical accumulation during and after irradiation subject to the pulse irradiation mode and an arbitrary effective order of radical recombination.

  20. High-frequency characteristics of glass/ceramic composite and alumina multilayer structures

    International Nuclear Information System (INIS)

    Niwa, K.; Suzuki, H.; Yokoyama, H.; Kamechara, N.; Tsubone, K.; Tanisawa, H.; Sugiki, H.

    1990-01-01

    This paper reports the transmission characteristics of glass/ceramic composite (borosilicate glass/alumina) and alumina multilayer structures examined. The triplate stripline formed in the glass/ceramic multilayer shows low conductor and dielectric loss. Alumina multilayer, however, has twice the transmission loss at 10 GHz, because the resistivity of W in the alumina multilayer is higher than the Cu in the glass/ceramic multilayer. Crosstalk between striplines in the glass/ceramics is less than -80 dB up to 11 GHz and 9 GHz for alumina

  1. Effect of pulse electron beam characteristics on internal friction and structural alterations in epoxy

    International Nuclear Information System (INIS)

    Zaikin, Yu.A.; Ismailova, G.A.; Al-Sheikhly, M.

    2007-01-01

    Temperature dependence of internal friction is experimentally studied in epoxy irradiated by 2.5 MeV pulse electron beam to different doses. Time dependence of internal friction characteristics associated with radiation-induced processes of polymer scission and cross-linking is analyzed and discussed. Experimental data on kinetics of structural transformations in epoxy are interpreted on the base of analytical solutions of differential equations for free radical accumulation during and after irradiation subject to the pulse irradiation mode and an arbitrary effective order of radical recombination

  2. Sistema de integração lavoura-pecuária: efeito do manejo da altura em pastagem de aveia preta e azevém anual sobre o rendimento da cultura da soja Crop-livestock integration system: effect of oat and italian ryegrass sward height management on soybean yield

    Directory of Open Access Journals (Sweden)

    Marília Lazzarotto Terra Lopes

    2009-08-01

    Full Text Available O objetivo deste trabalho foi avaliar os efeitos da altura de manejo em pastagem de aveia preta e azevém anual sobre o estabelecimento e o rendimento de grãos da cultura de soja. Os tratamentos utilizados foram quatro alturas de manejo do pasto: 10, 20, 30 e 40cm e um tratamento sem pastejo. Foram avaliados atributos referentes à pastagem (altura do pasto, oferta de forragem, massa de forragem, taxa de acúmulo, taxa de lotação animal e palhada residual e à cultura da soja (estande inicial de plantas e rendimento de grãos. As alturas reais do pasto ficaram próximas daquelas pretendidas, havendo um aumento linear da oferta de forragem e da massa de forragem quando foi observado aumento das alturas de manejo do pasto. A taxa de acúmulo não foi afetada pelos tratamentos. A taxa de lotação apresentou resposta linear decrescente com o aumento da altura do pasto. A massa de forragem remanescente aumentou na medida em que houve incremento na altura de manejo do pasto. Foi observada diferença entre os tratamentos para palhada residual e estande inicial de plantas de soja, porém essas diferenças não afetaram o rendimento de grãos da cultura. Os resultados sugerem que a presença dos animais não prejudica o cultivo subsequente, possibilitando aumento da renda do produtor pela oportunidade de utilização das áreas durante a entressafra da soja.This trial aimed to evaluate the effects of sward height management of pastures composed by black oat and Italian ryegrass upon soybean establishment and yield. The treatments were four sward management heights: 10, 20, 30 and 40cm; and no grazing control. Pasture (sward height, herbage allowance, herbage mass, stocking rate and post grazing herbage mass and soybean (initial stand of plants and yield attributes were evaluated. The observed sward heights were very similar to those previously intended. There was a linear increase in herbage allowance and herbage mass with increasing sward height

  3. Influence of structure and hydrophobic properties on the characteristics of carbon-air electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Shteinberg, G.V.; Dribinsky, A.V.; Kukushkina, I.A.; Musiliva, M.; Mrha, J.

    1982-07-01

    The electrochemical parameters of carbon-oxygen gas-diffusion electrodes can be controlled over a wide range by varying the structure of the active carbon catalyst and the ratio of lyophilic and lyophobic pores in the catalyst particles. Two typical representatives of active carbon catalysts with significantly different hydrophobic properties have been investigated by mercury-alkali intrusion porosimetry and tested both in model floating electrodes and as the hydrophilic component of the active layer of two-layer, gas-diffusion working electrodes. The optimal electrolyte content in the active layer ensuring the maximum electrical characteristics of working electrodes has been found to depend on the structure and hydrophobic properties of the carbon catalyst. The gas pores in the carbon catalyst have been shown to play an essential role in the oxygen mass transfer process in the active layer.

  4. The role of structural characteristics in video-game play motivation: a Q-methodology study.

    Science.gov (United States)

    Westwood, Dave; Griffiths, Mark D

    2010-10-01

    Until recently, there has been very little naturalistic study of what gaming experiences are like, and how gaming fits into people's lives. Using a recently developed structural characteristic taxonomy of video games, this study examined the psycho-structural elements of computer games that motivate gamers to play them. Using Q-Sort methodology, 40 gamers participated in an online Q-sort task. Results identified six distinct types of gamers based on the factors generated: (a) story-driven solo gamers; (b) social gamers; (c) solo limited gamers; (d) hardcore online gamers; (e) solo control/identity gamers; and (f ) casual gamers. These gaming types are discussed, and a brief evaluation of similar and unique elements of the different types of gamer is also offered. The current study shows Q-methodology to be a relevant and applicable method in the psychological research of gaming.

  5. Effects of electron beam irradiation (EBI) on structure characteristics and thermal properties of walnut protein flour.

    Science.gov (United States)

    Zhao, Yue; Sun, Na; Li, Yong; Cheng, Sheng; Jiang, Chengyao; Lin, Songyi

    2017-10-01

    The effects of electron beam irradiation (EBI) on structure characteristics and thermal properties of walnut protein flour (WPF) were evaluated. The WPF was irradiated by 0-15.0kGy of the EBI. Scanning electron microscopy and X-ray diffraction analysis revealed that the EBI irradiation could not change the amorphous structure of WPF but resulted in puncture pores and fragmentation on microcosmic surface of WPF. Besides, low-field nuclear magnetic resonance results showed the EBI irradiation had effects on increasing denaturation temperature of WPF to 70°C, and the particle size of WPF hydrolysates (WPFHs) irradiated by EBI at dose of 5.0kGy significantly (Pthermal stability of WPF and didn't affect the physical stability of the WPFHs. Therefore, these results provided a theoretical foundation that the EBI applies on improving the properties of protein in the future. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Structure and characteristics of chromium steel coatings alloyed with boron carbide

    Science.gov (United States)

    Eremin, E. N.; Losev, A. S.; Borodikhin, S. A.; Matalasova, A. E.; Ponomarev, I. A.; Ivlev, K. E.

    2018-01-01

    This study explores the problems arising from the increase of wear resistance on the coatings of details of a wide range of applications, obtained by surfacing the Fe - Cr system with flux-cored wires. It has shown that insignificant wear resistance of such steel under conditions of metal friction against another metal is due to their relatively low hardness and the absence of strengthening phases. It also shows the effect of boron carbide on the structure and the characteristics of chromium steel obtained by the surfacing process. It was established that the use of high-chromium flux-cored wires alloyed with boron carbide aids the production of a deposited metal of a composite type, with a dispersed hardening based on chromium carboboride. The deposited metal with such structure has a high wear resistance and the hardness of 55 … 58 HRC and can be used for surfacing cladding the hardening, corrosion-resistant coatings.

  7. Investment drought in the Russian economy: Structural characteristics and turnaround perspectives

    Directory of Open Access Journals (Sweden)

    Olga Berezinskaya

    2017-03-01

    Full Text Available The investment drought of 2013–2015 in Russia is the first prolonged period of no capital investment growth in the last 17 years. After stagnation in 2013–2014, fixed capital investments in real terms have systemically lagged behind industrial output growth and GDP. Lack of capital expenditures not only lowers demand and inhibits growth of construction, machinery, industrial production and the economy as a whole, but also preserves existing structural imbalances and technological gaps in the Russian economy. The duration of investment drought and its significant disincentivizing effect on current and expected growth of the Russian economy suggest the importance of analyzing structural characteristics of the investment process and triggers of capital investment.

  8. Structural, morphological, Raman, optical, magnetic, and antibacterial characteristics of CeO2 nanostructures

    Science.gov (United States)

    Abbas, Fazal; Iqbal, Javed; Jan, Tariq; Badshah, Noor; Mansoor, Qaisar; Ismail, Muhammad

    2016-01-01

    In this study, CeO2 nanostructures were synthesized by a soft chemical method. A hydrothermal treatment was observed to lead to an interesting morphological transformation of the nanoparticles into homogeneous microspheres composed of nanosheets with an average thickness of 40 nm. Structural analysis revealed the formation of a single-phase cubic fluorite structure of CeO2 for both samples. A Raman spectroscopic study confirmed the XRD results and furthermore indicated the presence of a large number of oxygen vacancies in the nanosheets. These oxygen vacancies led to room-temperature ferromagnetism (RTFM) of the CeO2 nanosheets with enhanced magnetic characteristics. Amazingly, the nanosheets exhibited substantially greater antibacterial activity than the nanoparticles. This greater antibacterial activity was attributed to greater exposure of high-surface-energy polar surfaces and to the presence of oxygen vacancies.

  9. Molecular Structural Characteristics of Polysaccharide Fractions from Canarium album (Lour.) Raeusch and Their Antioxidant Activities.

    Science.gov (United States)

    Zeng, Hongliang; Miao, Song; Zheng, Baodong; Lin, Shan; Jian, Yeye; Chen, Shen; Zhang, Yi

    2015-11-01

    The objective of this study was to investigate the multiple relations between the preliminary molecular structural characteristics and antioxidant activities of polysaccharides from Canarium album (Lour.) Raeusch (CPS). Three polysaccharide fractions, CPS1, CPS2, and CPS3, were isolated from CPS by column chromatography. CPS1 and CPS3 were mainly composed of neutral polysaccharides linked by α- and β-glycosidic linkages while CPS2 was pectin polysaccharides mainly linked by β-glycosidic linkages. According to the SEC-MALLS-RI system, the molecular weight of CPS1 was greater compared to CPS2 and CPS3, and the molecular weight and radius of CPS did not display positive correlation. The chain conformation analysis indicated CPS1 and CPS2 were typical highly branched polysaccharides while CPS3 existed as a globular shape in aqueous. Furthermore, the antioxidant activity of CPS2 was better than that of CPS3, while that of CPS1 was the weakest. The antioxidant activities of polysaccharide fractions were affected by their monosaccharide composition, glycosidic linkage, molecular weight, and chain conformation. This functional property was a result of a combination of multiple molecular structural factors. CPS2 was the major antioxidant component of CPS and it could be exploited as a valued antioxidant product. The molecular structural characteristics, antioxidant activities, and structure-function relationships of polysaccharide fractions from Canarium album were first investigated in this study. The results provided background and practical knowledge for the deep-processed products of C. album with high added value. CPS2 was the major antioxidant component of CPS, which could be exploited as a valued antioxidant ingredient in food and pharmaceutical industries. © 2015 Institute of Food Technologists®

  10. Spatio-temporal structure, path characteristics and perceptual grouping in immediate serial spatial recall

    Directory of Open Access Journals (Sweden)

    Carlo De Lillo

    2016-11-01

    Full Text Available Immediate serial spatial recall measures the ability to retain sequences of locations in short-term memory and is considered the spatial equivalent of digit span. It is tested by requiring participants to reproduce sequences of movements performed by an experimenter or displayed on a monitor. Different organizational factors dramatically affect serial spatial recall but they are often confounded or underspecified. Untangling them is crucial for the characterization of working-memory models and for establishing the contribution of structure and memory capacity to spatial span. We report five experiments assessing the relative role and independence of factors that have been reported in the literature. Experiment 1 disentangled the effects of spatial clustering and path-length by manipulating the distance of items displayed on a touchscreen monitor. Long-path sequences segregated by spatial clusters were compared with short-path sequences not segregated by clusters. Recall was more accurate for sequences segregated by clusters independently from path-length. Experiment 2 featured conditions where temporal pauses were introduced between or within cluster boundaries during the presentation of sequences with the same paths. Thus, the temporal structure of the sequences was either consistent or inconsistent with a hierarchical representation based on segmentation by spatial clusters but the effect of structure could not be confounded with effects of path-characteristics. Pauses at cluster boundaries yielded more accurate recall, as predicted by a hierarchical model. In Experiment 3, the systematic manipulation of sequence structure, path-length and presence of path-crossings of sequences showed that structure explained most of the variance, followed by the presence/absence of path-crossings, and path-length. Experiments 4 and 5 replicated the results of the previous experiments in immersive virtual reality navigation tasks where the viewpoint of the

  11. Nanoparticles of ZnO doped with Mn: structural and morphological characteristics

    Energy Technology Data Exchange (ETDEWEB)

    Bonifacio, Maria Aparecida Ribeiro; Lira, Helio de Lucena; Gama, Lucianna, E-mail: m_aparecidaribeiro@yahoo.com.br [Universidade Federal de Campina Grande (UFCG), PB (Brazil). Departamento de Engenharia de Materiais; Neiva, Laedna Souto [Universidade Federal do Cariri (UFCA), Juazeiro do Norte, CE (Brazil). Unidade Academica de Materiais; Kiminami, Ruth H. G. A. [Universidade Federal de Sao Carlos (USCar), SP (Brazil). Departamento de Engenharia de Materiais

    2017-07-15

    In this study, the effects of dopant concentrations on the structural and morphological characteristics of Zn{sub 1-x}Mn{sub x} O powders (x= 0.025, 0.05, 0.075, and 0.1 mole) synthesized by the Pechini method has been investigated. The powder was characterized by X-ray diffraction (XRD), Brunauer-Emmet-Teller (BET) specific surface, energy dispersive X-ray (EDX), scanning electron microscopy (SEM) and Spectroscopy with Fourier transform (FTIR). An XRD analysis of the powder showed the formation of ZnO phase with a typical single phase wurtzite structure. The EDX analysis revealed Mn incorporated in the ZnO structure. The particle size calculated by BET ranged from 24 to 63 nm, confirming the nanometric size of the powder particles. The SEM analysis revealed irregular shaped particle agglomerates and the presence of nanosheets. From FTIR it was confirmed the wurtzite structure in ZnO and ZnO nanoparticles doped with Mn. (author)

  12. Relationship between Molecular Structure Characteristics of Feed Proteins and Protein In vitro Digestibility and Solubility.

    Science.gov (United States)

    Bai, Mingmei; Qin, Guixin; Sun, Zewei; Long, Guohui

    2016-08-01

    The nutritional value of feed proteins and their utilization by livestock are related not only to the chemical composition but also to the structure of feed proteins, but few studies thus far have investigated the relationship between the structure of feed proteins and their solubility as well as digestibility in monogastric animals. To address this question we analyzed soybean meal, fish meal, corn distiller's dried grains with solubles, corn gluten meal, and feather meal by Fourier transform infrared (FTIR) spectroscopy to determine the protein molecular spectral band characteristics for amides I and II as well as α-helices and β-sheets and their ratios. Protein solubility and in vitro digestibility were measured with the Kjeldahl method using 0.2% KOH solution and the pepsin-pancreatin two-step enzymatic method, respectively. We found that all measured spectral band intensities (height and area) of feed proteins were correlated with their the in vitro digestibility and solubility (p≤0.003); moreover, the relatively quantitative amounts of α-helices, random coils, and α-helix to β-sheet ratio in protein secondary structures were positively correlated with protein in vitro digestibility and solubility (p≤0.004). On the other hand, the percentage of β-sheet structures was negatively correlated with protein in vitro digestibility (pproteins are closely related to their in vitro digestibility at 28 h and solubility. Furthermore, the α-helix-to-β-sheet ratio can be used to predict the nutritional value of feed proteins.

  13. Habitat and landscape characteristics underlying anuran community structure along an urban-rural gradient.

    Science.gov (United States)

    Pillsbury, Finn C; Miller, James R

    2008-07-01

    Urbanization has been cited as an important factor in worldwide amphibian declines, and although recent work has illustrated the important influence of broad-scale ecological patterns and processes on amphibian populations, little is known about the factors structuring amphibian communities in urban landscapes. We therefore examined amphibian community responses to wetland habitat availability and landscape characteristics along an urban-rural gradient in central Iowa, USA, a region experiencing rapid suburban growth. We conducted call surveys at 61 wetlands to estimate anuran calling activity, and quantified wetland habitat structure and landscape context. We used canonical correspondence analysis (CCA) to examine patterns in anuran community structure and identify the most important variables associated with those patterns. Urban density at the landscape scale had a significant negative influence on overall anuran abundance and diversity. While every species exhibited a decrease in abundance with increasing urban density, this pattern was especially pronounced for species requiring post-breeding upland habitats. Anurans most affected by urbanization were those associated with short hydroperiods, early breeding activity, and substantial upland habitat use. We suggest that broad-scale landscape fragmentation is an important factor underlying anuran community structure in this region, possibly due to limitations on the accessibility of otherwise suitable habitat in fragmented urban landscapes. This study underscores the importance of a regional approach to amphibian conservation in urban and urbanizing areas; in fragmented landscapes, a network of interconnected wetland and upland habitats may be more likely to support a successful, diverse anuran community than will isolated sites.

  14. Structural and dynamical characteristics of tropomyosin epitopes as the major allergens in shrimp.

    Science.gov (United States)

    Ozawa, Hideo; Umezawa, Koji; Takano, Mitsunori; Ishizaki, Shoichiro; Watabe, Shugo; Ochiai, Yoshihiro

    2018-03-25

    Ingestion of marine invertebrates often causes food allergy, where the major allergens have been reported to be derived from tropomyosin (TM). Intact or the digestive fragments of food allergens generally show resistance to digestion, which is usually attributable to the structural stability (or rigidity). The difference in the structural and dynamical characteristics between the epitope and the non-epitope regions in TM has not yet been well understood. In the present study, molecular dynamics simulation was performed at constant pHs for shrimp TM. By analyzing the main-chain dihedral angle fluctuations and local α-helix contents, we found that the epitope regions are more stable than the non-epitope counterparts, providing a possible physical reason for the resistance to digestion in the epitopes regions. The difference of the structural stability between the epitope and the non-epitope regions was largest at low pHs, even though pH dependence of the structural stability in itself was not significant in both regions. The lower content of the Ala cluster in the epitope region is considered to cause the higher stability of the epitope region. Copyright © 2018 Elsevier Inc. All rights reserved.

  15. Vibration Characteristics Analysis of Cylindrical Shell-Plate Coupled Structure Using an Improved Fourier Series Method

    Directory of Open Access Journals (Sweden)

    Yipeng Cao

    2018-01-01

    Full Text Available A simple yet accurate solution procedure based on the improved Fourier series method (IFSM is applied to the vibration characteristics analysis of a cylindrical shell-circular plate (S-P coupled structure subjected to various boundary conditions. By applying four types of coupling springs with arbitrary stiffness at the junction of the coupled structure, the mechanical coupling effects are completely considered. Each of the plate and shell displacement functions is expressed as the superposition of a two-dimensional Fourier series and several supplementary functions. The unknown series-expansion coefficients are treated as the generalized coordinates and determined using the familiar Rayleigh-Ritz procedure. Using the IFSM, a unified solution for the S-P coupled structure with symmetrical and asymmetrical boundary conditions can be derived directly without the need to change either the equations of motion or the expressions of the displacements. This solution can be verified by comparing the current results with those calculated by the finite-element method (FEM. The effects of several significant factors, including the restraint stiffness, the coupling stiffness, and the situation of coupling, are presented. The forced vibration behaviors of the S-P coupled structure are also illustrated.

  16. Structural characteristics of hospitals and nurse-reported care quality, work environment, burnout and leaving intentions.

    Science.gov (United States)

    Lindqvist, Rikard; Smeds Alenius, Lisa; Griffiths, Peter; Runesdotter, Sara; Tishelman, Carol

    2015-03-01

    To investigate whether hospital characteristics not readily susceptible to change (i.e. hospital size, university status, and geographic location) are associated with specific self-reported nurse outcomes. Research often focuses on factors within hospitals (e.g. work environment), which are susceptible to change, rather than on structural factors in their own right. However, numerous assumptions exist about the role of structural factors that may lead to a sense of pessimism and undermine efforts at constructive change. Data was derived from survey questions on assessments of work environment and satisfaction, intention to leave, quality of care and burnout (measured by the Maslach Burnout Inventory), from a population-based sample of 11 000 registered nurses in Sweden. Mixed model regressions were used for analysis. Registered nurses in small hospitals were slightly more likely to rank their working environment and quality of nursing care better than others. For example 23% of staff in small hospitals were very satisfied with the work environment compared with 20% in medium-sized hospitals and 21% in large hospitals. Registered nurses in urban areas, who intended to leave their job, were more likely to seek work in another hospital (38% vs. 32%). While some structural factors were related to nurse-reported outcomes in this large sample, the associations were small or of questionable importance. The influence of structural factors such as hospital size on nurse-reported outcomes is small and unlikely to negate efforts to improve work environment. © 2013 John Wiley & Sons Ltd.

  17. The relationship of seismic velocity structure and surface fracture characteristics of basalt outcrops to rippability estimates

    International Nuclear Information System (INIS)

    Kay, S.E.; Dougherty, M.E.; Pelton, J.R.

    1994-01-01

    Seismic velocity has been shown in previous engineering studies to be related to the fracture characteristics and rippability of rock outcrops. However, common methods of measuring seismic velocity in outcrops do not take into account the many possible travel paths for wave propagation and the fact that velocity zones may exist within an outcrop. Presented here are the results of using raytracing inversion of first-arrival travel-time data to map P-velocity structure in basalt outcrops, and also the investigation of the relationship of the mapped velocities to observed surface fractures and hand-sample P-velocities. It is shown that basalt outcrops commonly consist of an irregular near-surface low-velocity zone underlain by higher velocity material; that velocity gradients can exist in outcrops; that hand-sample velocity measurements are typically higher than outcrop-scale measurements; and that the characteristics of surface fractures are empirically related to near-surface P-velocity. All of these findings are relevant to the estimated rippability of rock in geotechnical engineering. The data for this study are derived from eleven sites on basalt outcrops of the Troodos Ophiolite in Cyprus. The basalt types include pillow basalts, massive flows, and a pillow breccia. A commonly available raytracing inversion program (RAYINVR) was used to produce a velocity profile of each outcrop. Different velocity zones were detailed by inverting observed travel times to produce a model of outcrop velocity structure which produces rippability profiles for each outcrop. 16 refs., 9 figs

  18. Effect of storage and drying temperature on the gelation behavior and structural characteristics of sericin.

    Science.gov (United States)

    Jo, Yoon Nam; Park, Byung-Dae; Um, In Chul

    2015-11-01

    Owing to unique properties, including the wound healing effect, sericin gel and films have attracted significant attention in the biomedical and cosmetic fields. The structural characteristics and properties of sericin gels and films are especially important owing to their effect on the performance of sericin in biomedical and cosmetic applications. In the present study, the effect of temperature on the gelation behavior, gel disruption, and sol-gel transition of sericin was examined using rheometry. In addition, the effect of the drying temperature on the structural characteristics of the sericin film was determined via Fourier transform infrared (FTIR) spectroscopy. The strength of the sericin gel increased and the gelation process was prolonged with decreasing storage temperatures. FTIR and differential scanning calorimetry (DSC) results also revealed that the crystallinity and the thermal decomposition temperature of the sericin film increased with decreasing drying temperature. The sericin gels were disrupted at a storage time of 40min when they were stored at temperatures higher than 50°C, and the corresponding gel strength decreased with increasing temperature. Furthermore, the thermo-reversible nature of gel-sol transition of sericin was confirmed by rheological and FTIR measurements. Copyright © 2015 Elsevier B.V. All rights reserved.

  19. Characteristics and crystal structure of bacterial inosine-5'-monophosphate dehydrogenase.

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, R.; Evans, G.; Rotella, F. J.; Westbrook, E. M.; Beno, D.; Huberman, E.; Joachimiak, A.; Collart, F. R.

    1999-01-01

    IMP dehydrogenase (IMPDH) is an essential enzyme that catalyzes the first step unique to GTP synthesis. To provide a basis for the evaluation of IMPDH inhibitors as antimicrobial agents, we have expressed and characterized IMPDH from the pathogenic bacterium Streptococcus pyogenes. Our results show that the biochemical and kinetic characteristics of S. pyogenes IMPDH are similar to other bacterial IMPDH enzymes. However, the lack of sensitivity to mycophenolic acid and the K{sub m} for NAD (1180 {mu}M) exemplify some of the differences between the bacterial and mammalian IMPDH enzymes, making it an attractive target for antimicrobial agents. To evaluate the basis for these differences, we determined the crystal structure of the bacterial enzyme at 1.9 {angstrom} with substrate bound in the catalytic site. The structure was determined using selenomethionine-substituted protein and multiwavelength anomalous (MAD) analysis of data obtained with synchrotron radiation from the undulator beamline (19ID) of the Structural Biology Center at Argonne's Advanced Photon Source. S. pyogenes IMPDH is a tetramer with its four subunits related by a crystallographic 4-fold axis. The protein is composed of two domains: a TIM barrel domain that embodies the catalytic framework and a cystathione {beta}-synthase (CBS) dimer domain of so far unknown function. Using information provided by sequence alignments and the crystal structure, we prepared several site-specific mutants to examine the role of various active site regions in catalysis. These variants implicate the active site flap as an essential catalytic element and indicate there are significant differences in the catalytic environment of bacterial and mammalian IMPDH enzymes. Comparison of the structure of bacterial IMPDH with the known partial structures from eukaryotic organisms will provide an explanation of their distinct properties and contribute to the design of specific bacterial IMPDH inhibitors.

  20. Structural characteristics of the pedicle and its role in screw stability.

    Science.gov (United States)

    Hirano, T; Hasegawa, K; Takahashi, H E; Uchiyama, S; Hara, T; Washio, T; Sugiura, T; Yokaichiya, M; Ikeda, M

    1997-11-01

    Cross-sectional regional bone mineral density of the pedicle was measured by peripheral quantitative computed tomography. Biomechanical tests were performed to clarify the role of the pedicle in screw stability. To identify the structural characteristics of the pedicle that supports pedicle screw stability and the differences in these characteristics between normal and osteoporotic vertebrae. The pedicle screw is an essential component of many systems used to align the spine. The contribution of the pedicle to screw stability, however, has not been fully investigated. Trabecular, subcortical, and cortical bone mineral density and the area of the pedicle were measured by peripheral quantitative computed tomography. Bone mineral density also was recalculated in four circumferential layers. These parameters were compared between normal and osteoporotic individuals. The relative contribution of the pedicle to screw stability was evaluated by caudocephalad and pull-out loading in a vertebra with or without its body. Inner trabecular, middle subcortical, and outer cortical bone mineral density and cortical bone area in the pedicle were significantly lower in osteoporotic vertebrae than those in normal vertebrae. In the pedicle, bone mineral density increased close to the outer layer. Bone mineral density not as thick even in the outer layer in osteoporotic subjects. Approximately 80% of the caudocephalad stiffness and 60% of the pullout strength of the pedicle screw depended on the pedicle rather than on the vertebral body. Screw stability depends on the structural characteristics of the pedicle. The pedicle was denser in the subcortical bone, in which the threads of the screw engage, than in trabecular bone. In osteoporosis, bone mineral density was not as dense even in the outer layer, and the cortex was thinner than normal. A larger screw would not enhance screw stability and may break the thin cortex in osteoporotic vertebrae.

  1. Development of Structure and Characteristics Calculation Method for Γ- shape Rope Vubration Insulator

    Science.gov (United States)

    Ponomarev, Yury K.

    2018-01-01

    The paper gives an overview of the design of rope vibration insulators with elastic elements of the center line in the form of two rectilinear and one curved section. In the Russian-language scientific literature this type of rope vibration insulators received a stable name "Γ-shaped vibration insulators” by analogy with the shape of the letter “gamma-Γ" of the Greek alphabet and a similar letter of the Cyrillic alphabet. Despite the wide using of vibration insulators designed on this shape, its mathematical calculation model has not yet been developed. In this connection, in this article, for the first time on the basis of the “Method of Forces” and the “Mohr Method”, an analytical technique has been developed for calculating the characteristics of a vibration insulator in the directions of three mutually perpendicular axes. In addition, the article proposes a new structure of a vibration insulator consisting of several tiers of elements of this type, based on a new patented technology for manufacturing quasi-continuous woven rings, proposed by the author of this article in co-authorship with several employees of the Samara National Research University. Simple formulas are obtained for calculating the load characteristics in three mutually perpendicular directions. This makes it possible to calculate the corresponding stiffness and natural frequencies of mechanical vibration protection systems. It is established that the stiffness of the vibration insulator in the direction of the Z axis is greater than the stiffness in the X and Y axis directions, however, if a vibration insulator with equal, or close to equal characteristics, along three axes has to be designed according to the technical specification, this can be done by selecting the parameters included in the equations given in article for load characteristics.

  2. How Does Amino Acid Ligand Modulate Au Core Structure and Characteristics in Peptide Coated Au Nanocluster?

    Science.gov (United States)

    Li, Nan; Li, Xu; Zhao, Hongkang; Zhao, Lina

    2018-03-01

    The atomic structures and the corresponding physicochemical properties of peptide coated Au nanoclusters determine their distinctive biological targeting applications. To learn the modulation of amino acid ligand on the atomic structure and electronic characteristics of coated Au core is the fundamental knowledge for peptide coated Au nanocluster design and construction. Based on our recent coated Au nanocluster configuration study (Nanoscale, 2016, 8, 11454), we built the typically simplified Au13(Cys-Au-Cys) system to more clearly learn the basic modulation information of amino acid ligand on Au core by the density functional theory (DFT) calculations. There are two isomers as ligand adjacent bonding (Iso1) and diagonal bonding (Iso2) to Au13 cores. The geometry optimizations indicate the adjacent bonding Iso1 is more stable than Iso2. More important, the Au13 core of Iso1 distorts much more significantly than that of Iso2 by Cys-Au-Cys bonding through the root-mean-square deviation (RMSD) analysis, which modulate their electronic characteristics in different ways. In addition, the frontier molecular orbital results of Au13(Cys-Au-Cys) isomers confirm that the Au cores mainly determine the blue shifts of Au13(Cys-Au-Cys) systems versus the original Au13 core in their UV-visible absorption spectrum studies. The configuration of Au13 core performs deformation under Cys-Au-Cys ligand modulation to reach new stability with distinct atomic structure and electronic properties, which could be the theory basis for peptide coated AuNCs design and construction.

  3. INVESTIGATION OF NANOMODIFICATION INFLUENCE ON STRUCTURE AND CHARACTERISTICS OF CAST FAST-CUTTING STEEL R6M5L

    Directory of Open Access Journals (Sweden)

    D. M. Kukuj

    2010-01-01

    Full Text Available The influence of wide range of elements-modifiers on the structure, character of destruction and physico-mechanical characteristics of high-speed steels and instrument made of them is studied.

  4. Relevance of community structures and neighbourhood characteristics for participation of older adults: a qualitative study.

    Science.gov (United States)

    Strobl, Ralf; Maier, Werner; Ludyga, Alicja; Mielck, Andreas; Grill, Eva

    2016-01-01

    Community and neighbourhood structures contribute not only to the health and well-being, but also to the participation of older adults. The degree of participation depends on both the living environment and the individual's personal characteristics, preferences and perception. However, there is still limited empirical evidence on how community and neighbourhood structures are linked to participation and health in the aged population. A qualitative exploratory approach was chosen with a series of problem-centred, semi-structured focus group discussions. Study participants were selected from within the city of Augsburg, Southern Germany, and from two municipalities in surrounding rural districts. The interviews took place in 2013. Structuring content analysis was used to identify key concepts. We conducted 11 focus group discussions with a total of 78 different study participants. The study participants (33 men and 45 women) had a mean age of 74 years (range 65-92 years). Only two study participants lived in an assisted living facility. Of all study participants, 77% lived in urban and 23% in rural areas. We extracted four metacodes ('Usual activities', 'Requirements for participation', 'Barriers to participation' and 'Facilitators for participation') and 15 subcodes. Health and poorly designed infrastructure were mentioned as important barriers to participation, and friendship and neighbourhood cohesion as important facilitators. This qualitative study revealed that poor design and accessibility of municipal infrastructure are major barriers to participation in old age in Germany. Community and neighbourhood structures can be part of the problem but also part of the solution when accessibility and social networks are taken into account.

  5. Thermoelectric characteristics of Pt-silicide/silicon multi-layer structured p-type silicon

    International Nuclear Information System (INIS)

    Choi, Wonchul; Jun, Dongseok; Kim, Soojung; Shin, Mincheol; Jang, Moongyu

    2015-01-01

    Electric and thermoelectric properties of silicide/silicon multi-layer structured devices were investigated with the variation of silicide/silicon heterojunction numbers from 3 to 12 layers. For the fabrication of silicide/silicon multi-layered structure, platinum and silicon layers are repeatedly sputtered on the (100) silicon bulk substrate and rapid thermal annealing is carried out for the silicidation. The manufactured devices show ohmic current–voltage (I–V) characteristics. The Seebeck coefficient of bulk Si is evaluated as 195.8 ± 15.3 μV/K at 300 K, whereas the 12 layered silicide/silicon multi-layer structured device is evaluated as 201.8 ± 9.1 μV/K. As the temperature increases to 400 K, the Seebeck coefficient increases to 237.2 ± 4.7 μV/K and 277.0 ± 1.1 μV/K for bulk and 12 layered devices, respectively. The increase of Seebeck coefficient in multi-layered structure is mainly attributed to the electron filtering effect due to the Schottky barrier at Pt-silicide/silicon interface. At 400 K, the thermal conductivity is reduced by about half of magnitude compared to bulk in multi-layered device which shows the efficient suppression of phonon propagation by using Pt-silicide/silicon hetero-junctions. - Highlights: • Silicide/silicon multi-layer structured is proposed for thermoelectric devices. • Electric and thermoelectric properties with the number of layer are investigated. • An increase of Seebeck coefficient is mainly attributed the Schottky barrier. • Phonon propagation is suppressed with the existence of Schottky barrier. • Thermal conductivity is reduced due to the suppression of phonon propagation

  6. Características produtivas e estruturais do milheto e sua relação com o ganho de peso de bezerras sob suplementação alimentar Productive and structural characteristics of Pearl millet and their relationship with body weight gain of beef heifers receiving supplement

    Directory of Open Access Journals (Sweden)

    Juliano Roman

    2008-02-01

    Full Text Available Foram avaliadas características produtivas e estruturais do milheto (Pennisetum americanum (L. Leeke sob pastejo em lotação contínua e sua relação com o desempenho de bezerras exclusivamente em pastejo (PAST ou sob suplementação com grão de milho (PAST + M ou polpa cítrica (PAST + P. Não houve diferença entre tratamentos para a massa e oferta de forragem, a massa e oferta de lâminas foliares, a taxa de acúmulo diário e a produção total de forragem. A taxa de acúmulo diário de forragem, a massa e a oferta de lâminas foliares diminuíram linearmente durante o período de pastejo. A participação dos componentes de milheto na estrutura do dossel foi similar entre tratamentos e variou no tempo. A suplementação energética promoveu aumento da taxa de lotação no período inicial de pastejo, quando houve alta participação de lâminas foliares no dossel, e do ganho de peso médio diário nos períodos subseqüentes, quando houve redução da participação de lâminas foliares. Em pastagem de milheto, a resposta à suplementação energética varia com a quantidade e a distribuição de lâminas foliares no dossel. O fornecimento de suplemento energético aos animais em pastejo não interfere nas características produtivas e estruturais do milheto.The productive and structural characteristics of Pearl millet (Pennisetum americanum (L. Leeke under continuous stocking rate and their relationship with beef heifers performance exclusively under grazing (PAST, supplemented with corn grain (PAST + C or citric pulp (PAST + P was evaluated. There was no difference among treatments for herbage mass, forage allowance, leaf lamina mass, leaf lamina allowance, daily accumulation rate of forage and herbage total production. Daily accumulation rate of forage, leaf lamina mass and leaf lamina allowance decreased linearly during the grazing period. The participation of Pearl millet components in the sward structure was similar among

  7. A Review of the Structural Characteristics of Family Meals with Children in the United States12

    Science.gov (United States)

    McCullough, Mary Beth; Robson, Shannon M; Stark, Lori J

    2016-01-01

    Family meals are associated with a range of positive outcomes among children and adolescents. There is inconsistency, however, in the way in which studies have defined and measured family meals. Therefore, a systematic review of the literature was conducted to determine how studies describe family meals with the use of structural characteristics. The current review focused on studies in the United States that included children ages 2–18 y. A total of 33 studies were identified that characterized family meals with the use of ≥1 of the following structural features: frequency or mean number of family meals per week, length of family meal, people present at meal, and where meals occurred. No study characterized family meals by using all 4 family meal features, whereas most studies (81%) characterized family meals by using frequency or mean number of meals per week. Findings not only provide an initial understanding of the structural features used to define family meals but also point to the importance of developing a more comprehensive, sensitive assessment that can accurately capture the complex and multidimensional nature of family meals. PMID:27422500

  8. The structural and electro-optical characteristics of AZO/Cr:Cu/AZO transparent conductive film

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Tien-Chai [Department of Electrical Engineering, Kun Shan University, No. 195, Kun-Da Road, Yung-Kang Dist., Tainan 71003, Taiwan, ROC (China); Huang, Wen-Chang, E-mail: wchuang@mail.ksu.edu.tw [Department of Electro-Optical Engineering, Kun Shan University, No. 195, Kun-Da Road, Yung-Kang Dist., Tainan 71003, Taiwan, ROC (China); Tsai, Fu-Chun [Department of Electro-Optical Engineering, Kun Shan University, No. 195, Kun-Da Road, Yung-Kang Dist., Tainan 71003, Taiwan, ROC (China)

    2015-08-31

    A novel triple-layered transparent conductive film, AZO/Cr:Cu/AZO (ACCA), was presented in the paper. The structural and electro-optical properties of the ACCA film were discussed. The thickness of the middle metal layer was constant and those of the AZO layers were varied. The ACCA film shows an obvious ZnO (002) c-axis preferential growth. No diffraction peaks related to Cr and Cu were observed through x-ray diffraction analysis. The middle Cr:Cu layer showed a thickness of 8.16 nm with a continuous and amorphous structure by the observation of a high-resolution transmission electron microscopy (HR-TEM). For the electro-optical characteristic, a best figure of merit (FOM) value of 3.54 × 10{sup −3} Ω{sup −1} with a corresponding transmittance of 85% was obtained at the thickness of 116 nm of ACCA film. The high FOM value of the film is due to the improvement of conductivity and small sacrifices of transparency. - Highlights: • A novel triple-layered transparent conductive film, AZO/Cr:Cu/AZO is developed. • Chromium is added to copper to reduce the oxidation–reduction reaction. • The film has a FOM of 3.54 × 10{sup −3} Ω{sup −1} with a corresponding transmittance of 85%. • The Cr:Cu layer shows a continuous and amorphous structure.

  9. A Review of the Structural Characteristics of Family Meals with Children in the United States.

    Science.gov (United States)

    McCullough, Mary Beth; Robson, Shannon M; Stark, Lori J

    2016-07-01

    Family meals are associated with a range of positive outcomes among children and adolescents. There is inconsistency, however, in the way in which studies have defined and measured family meals. Therefore, a systematic review of the literature was conducted to determine how studies describe family meals with the use of structural characteristics. The current review focused on studies in the United States that included children ages 2-18 y. A total of 33 studies were identified that characterized family meals with the use of ≥1 of the following structural features: frequency or mean number of family meals per week, length of family meal, people present at meal, and where meals occurred. No study characterized family meals by using all 4 family meal features, whereas most studies (81%) characterized family meals by using frequency or mean number of meals per week. Findings not only provide an initial understanding of the structural features used to define family meals but also point to the importance of developing a more comprehensive, sensitive assessment that can accurately capture the complex and multidimensional nature of family meals. © 2016 American Society for Nutrition.

  10. Low sat-structured fats enriched in α-linolenic acid: physicochemical properties and crystallization characteristics.

    Science.gov (United States)

    Stahl, Marcella Aparecida; Buscato, Monise Helen Masuchi; Grimaldi, Renato; Cardoso, Lisandro Pavie; Ribeiro, Ana Paula Badan

    2017-10-01

    This work sought to obtain and evaluate zero trans-fat reduced in saturated fatty acids, with higher content of unsaturated fatty acids. Palm oil (PO) was used as the reference of zero trans lipid base. Different amounts of linseed oil (LO) were added to PO, obtaining the following blends: 100:0; 80:20; 60:40; 40:60; 20:80 and 0:100 of PO:LO (w/w%), respectively. These blends were added to fully hydrogenated soybean oil (FHSO) as the crystallization modifying agent, and to sorbitan monostearate (SMS) as the structuring element, both at a proportion of 3% to build the structured fractions. The control and the structured blends were evaluated for fatty acid composition, solid fat content, consistency, crystallization kinetics, thermal behavior, microstructure and polymorphism. With the addition of LO to the PO, an increase of up to 80% was observed in the content of alpha-linolenic acid and a reduction of saturated fatty acids to 47% in the blends. FHSO and SMS offered thermal resistance to the blends, with relevant changes in the crystallization kinetics and microstructure, affecting macroscopic characteristics with the increase in consistence. It was possible to obtain a lipid formulation with features of plasticity and enhanced nutritional quality, compatible with several food applications.

  11. Field emission characteristics of nano-structured carbon films deposited on differently pretreated Mo films

    International Nuclear Information System (INIS)

    Wang Longyang; Wang Xiaoping; Wang Lijun; Zhang Lei

    2008-01-01

    Nano-structured carbon films (NCFs) were grown on Mo layers by microwave plasma chemical vapor deposition (MPCVD) system. The Mo layers were deposited on ceramic substrates by electron beam deposition method and were pretreated by different techniques, which include ultrasonically scratching and laser-grooving technology (10 line/mm). NCFs were characterized by a field emission type scanning electron microscope (FE-SEM), Raman spectra and field emission (FE) I-V measurements. Effects of process parameters on morphologies, structures and FE properties of NCFs were examined. The experimental results show that two kinds of NCFs deposited at the same parameters employed for the MPCVD process were respectively composed of carbon nano-balls and reticular carbon nano-tubes inlayed by carbon nano-balls with dissimilar disorder structures, both NCFs showed each merits and exhibited good field emission properties, especially shown in the uniformity of FE, the uniform field emission images with areas of 4 cm 2 were obtained. Growth mechanism influenced by different pretreated method was discussed and the possible FE mechanisms of the NCFs were also investigated. Finally, the process characteristics of laser-grooving technology were analyzed, and its potential applications were predicted.

  12. Improvement of Swirl Chamber Structure of Swirl-Chamber Diesel Engine Based on Flow Field Characteristics

    Directory of Open Access Journals (Sweden)

    Wenhua Yuan

    2014-10-01

    Full Text Available In order to improve combustion characteristic of swirl chamber diesel engine, a simulation model about a traditional cylindrical flat-bottom swirl chamber turbulent combustion diesel engine was established within the timeframe of the piston motion from the bottom dead centre (BDC to the top dead centre (TDC with the fluent dynamic mesh technique and flow field vector of gas in swirl chamber and cylinder; the pressure variation and temperature variation were obtained and a new type of swirl chamber structure was proposed. The results reveal that the piston will move from BDC; air in the cylinder is compressed into the swirl chamber by the piston to develop a swirl inside the chamber, with the ongoing of compression; the pressure and temperature are also rising gradually. Under this condition, the demand of diesel oil mixing and combusting will be better satisfied. Moreover, the new structure will no longer forma small fluid retention zone at the lower end outside the chamber and will be more beneficial to the mixing of fuel oil and air, which has presented a new idea and theoretical foundation for the design and optimization of swirl chamber structure and is thus of good significance of guiding in this regard.

  13. Effects of sucrose reduction on the structural characteristics of sponge cake

    Directory of Open Access Journals (Sweden)

    Rosane Souza Cavalcante

    Full Text Available ABSTRACTThe consumption of reduced-calorie cakes has been increasing, however this has presented challenges to be overcome concerning the formation of their structure when the sucrose is substituted by alternative sweeteners, gums or thickening agents. The present study evaluated the internal characteristics of cakes with a reduction in sucrose, and the effects of its substitution on starch gelatinisation. Starting with a pre-established formulation, the sucrose was gradually substituted by a 1.0% mixture of sucralose in a 1.5% xanthan gum solution. In the substituted cake mix, the apparent viscosity and its thermal properties were evaluated using differential scanning calorimetry (DSC. Specific volume (SV and cell count (CC were evaluated in the cakes. As the sucrose content decreased (52.17 to 10.00%, the specific volume (1.94 to 0.7 mL/g, cell count (36.2 to 4.0 cell/cm2 and the apparent viscosity of the batter (337.56 to 631.40 cP were also reduced. The results showed that substituting the sucrose contributed greatly to the formation of defects in the cake structure (holes. From the data obtained, and thermograms of standard cake batters and those with a reduction in sucrose, it can be concluded that sucralose reduced the temperature of starch gelatinisation, speeding the process and causing compaction of the cake structure during baking, favouring the formation of bubbles throughout the batter.

  14. The dynamic characteristics and influencing factors of debt structure of the public companies in China

    Directory of Open Access Journals (Sweden)

    Zhefan Piao

    2013-09-01

    Full Text Available Design/methodology/approach: Learned from Leary (2009, Konstantinos Voutsinas and Richard A.Werner (2011, this study designs a model of debt maturity structure with an unbalanced panel data set. It consists of 1352 Chinese listed companies with8124 observations during the period of 2003-2011. Hausman test hasbeen used, and the findings support the fixed effects model.Findings: Besidesthe factors that have been confirmed by previous researches, debt maturitystructure is also sensitive to other factors, such as economicexpectations, monetary policy, financial restrictions and changes in tax rates.Research limitations/implications: There are still many cases, which affect the debt maturitystructure, are worth of further exploring, for instance, the impactof lagged monetary policy, the determinants of short-term debt ratio and thecost of operating.Practical implications: From the macro point of view, research in this area enable thegovernment to introduce more suitable policies that direct and promote thedevelopment of the bond market, thus it spurs corporations to choose theproper finance structure. From the micro point of view, firms can learn fromthe research to choose the efficient method and term of financing as well asdebt structure.Originality/value: In some way, conclusions of this papercontribute to the study of dynamic characteristics and factors of debt maturitystructure in Chinese listed companies.

  15. Investigation of structural modification and thermal characteristics of lignin after heat treatment.

    Science.gov (United States)

    Kim, Jae-Young; Hwang, Hyewon; Oh, Shinyoung; Kim, Yong-Sik; Kim, Ung-Jin; Choi, Joon Weon

    2014-05-01

    Milled wood lignin was subjected to heat treatment between 150 and 300°C to understand the pattern of its structural modification and thermal properties. When the temperature was elevated with interval of 50°C, the color of the lignin became dark brown and the lignin released various forms of phenols from terminal phenolic groups in the lignin, leading to two physical phenomena: (1) gradual weight loss of the lignin, up to 19% based on dry weight and (2) increase in the carbon content and decrease in the oxygen content. Nitrobenzene oxidation and (13)C NMR analyses confirmed a cleavage of β-O-4 linkage (depolymerization) and reduction of methoxyl as well as phenolic hydroxyl group were also characteristic in the lignin structure during heat treatment. Simultaneously with lignin depolymerization, GPC analysis provided a possibility that condensation between lignin fragments could also occur during heat treatment. TGA/DTG/DSC data revealed that thermal stability of lignin obviously increased after heat treatment, implicating the structural rearrangement of lignin to reduction of β-O-4 linkage as well as accumulation of CC bonds. Copyright © 2014 Elsevier B.V. All rights reserved.

  16. Gravity anomaly and crustal structure characteristics in North-South Seismic Belt of China

    Science.gov (United States)

    Shen, Chongyang; Xuan, Songtbai; Yang, Guangliang; Wu, Guiju

    2017-04-01

    The North-South Seismic Belt (NSSB) is the binary system boundary what is formed by the western Indian plate subduction pushing and the eastern west Pacific asthenosphere rising, and it is one of the three major seismic belts (Tianshan, Taiwan and NSSB) and mainly located between E102°and E107°. And it is mainly composed of topographic gradient zones, faults, cenozoic basins and strong earthquake zones, which form two distinct parts of tectonic and physical features in the west and east. The research results of geophysical and deep tectonic setting in the NSSB show that it is not only a gravity anomaly gradient zone, it is but also a belt of crustal thickness increasing sharply westward of abrupt change. Seismic tomography results show that the anomaly zone is deeper than hundreds of kilometers in the NSSB, and the composition and structure of the crust are more complex. We deployed multiple Gravity and GNSS synchronous detection profiles in the NSSB, and these profiles crossed the mainly faults structure and got thousands of points data. In the research, source analysis, density structure inversion, residual gravity related imaging and normalized full gradient methods were used, and analyzed gravity field, density and their structure features in different positions, finally obtained the crustal density structure section characteristics and depth structure differences. The research results showed that the gravity Bouguer anomaly is similar to the existing large scale result. The Bouguer anomaly is rising significantly from west to east, its trend variation coincides well with the trend change of Moho depth, which is agreeing with the material flows to the peripheral situation of the Tibetan plateau. The obvious difference changes of the residual anomaly is relative to the boundary of structure or main tectonics, it's also connected with the stop degree of the eurasian plate when the material migrates around. The density structure of the gravity profiles mainly

  17. Congestion Characteristics of Interrupted Flow for Urban Roads with Heterogeneous Traffic Structure

    Directory of Open Access Journals (Sweden)

    Sharma Hemant Kumar

    2016-01-01

    Full Text Available Traffic congestion is a severe trepidation to transportation engineers for its unrestrained growth and consequential losses. This paper presents congestion models and speed-flow analysis for urban roads with interrupted flow comprising of heterogeneous structure of traffic. Models have been developed for heterogeneous traffic under constraints of roadway geometry, vehicle characteristics, driving behaviour and traffic controls. The growth of congestion with flow in unsaturated and oversaturated states of flow has been analysed and quantified. The congestion model developed in this paper shows that there exist different regions of congestion- flow behaviour that can be characterized by different rate of change of congestion and the severity of congestion becomes tremendous for oversaturated flows. Different levels of service have been proposed to define operating conditions using more realistic parameter ‘congestion’.

  18. Random blebbing motion: A simple model linking cell structural properties to migration characteristics

    Science.gov (United States)

    Woolley, Thomas E.; Gaffney, Eamonn A.; Goriely, Alain

    2017-07-01

    If the plasma membrane of a cell is able to delaminate locally from its actin cortex, a cellular bleb can be produced. Blebs are pressure-driven protrusions, which are noteworthy for their ability to produce cellular motion. Starting from a general continuum mechanics description, we restrict ourselves to considering cell and bleb shapes that maintain approximately spherical forms. From this assumption, we obtain a tractable algebraic system for bleb formation. By including cell-substrate adhesions, we can model blebbing cell motility. Further, by considering mechanically isolated blebbing events, which are randomly distributed over the cell, we can derive equations linking the macroscopic migration characteristics to the microscopic structural parameters of the cell. This multiscale modeling framework is then used to provide parameter estimates, which are in agreement with current experimental data. In summary, the construction of the mathematical model provides testable relationships between the bleb size and cell motility.

  19. Dynamic Characteristics of Vertically Coupled Structures and the Design of a Decoupled Micro Gyroscope

    Science.gov (United States)

    Choi, Bumkyoo; Lee, Seung-Yop; Kim, Taekhyun; Baek, Seog Soon

    2008-01-01

    In a vertical type, vibratory gyroscope, the coupled motion between reference (driving) and sensing vibrations causes the zero-point output, which is the unwanted sensing vibration without angular velocity. This structural coupling leads to an inherent discrepancy between the natural frequencies of the reference and the sensing oscillations, causing curve veering in frequency loci. The coupled motion deteriorates sensing performance and dynamic stability. In this paper, the dynamic characteristics associated with the coupling phenomenon are theoretically analyzed. The effects of reference frequency and coupling factor on the rotational direction and amplitude of elliptic oscillation are determined. Based on the analytical studies on the coupling effects, we propose and fabricate a vertically decoupled vibratory gyroscope with the frequency matching. PMID:27879903

  20. Non-Volatile Flash Memory Characteristics of Tetralayer Nickel-Germanide Nanocrystals Embedded Structure.

    Science.gov (United States)

    Panda, D; Panda, M

    2016-01-01

    Formation of tetralayer memory structure having nickel-germanide nanocrystals using a Ge/Ni multilayers is proposed. X-ray diffraction study shows the NiGe (002) phase formation after proper annealing. Cross sectional HRTEM clearly shows the sharpness and the size (~4-6 nm) of the stacked nanocrystals embedded in the oxide matrix. A large anti-clockwise hysteresis memory win- dow of 13.4 Volt at ± 15 Volt is observed for the optimized samples. This large memory window indicates for the MLC applications. Frequency independent C-V curve confirms about the charge storage in the nanocrystals. A good charge retention and endurance characteristics are exhibited upto 125 °C for the nonvolatile memory application.

  1. Structural and optical characteristics of SnS thin film prepared by SILAR

    Directory of Open Access Journals (Sweden)

    Mukherjee A.

    2015-12-01

    Full Text Available SnS thin films were grown on glass substrates by a simple route named successive ion layer adsorption and reaction (SILAR method. The films were prepared using tin chloride as tin (Sn source and ammonium sulfide as sulphur (S source. The structural, optical and morphological study was done using XRD, FESEM, FT-IR and UV-Vis spectrophotometer. XRD measurement confirmed the presence of orthorhombic phase. Particle size estimated from XRD was about 45 nm which fitted well with the FESEM measurement. The value of band gap was about 1.63 eV indicating that SnS can be used as an important material for thin film solar cells. The surface morphology showed a smooth, homogenous film over the substrate. Characteristic stretching vibration mode of SnS was observed in the absorption band of FT-IR spectrum. The electrical activation energy was about 0.306 eV.

  2. Dynamic Characteristics of Vertically Coupled Structures and the Design of a Decoupled Micro Gyroscope.

    Science.gov (United States)

    Choi, Bumkyoo; Lee, Seung-Yop; Kim, Taekhyun; Baek, Seog Soon

    2008-06-03

    In a vertical type, vibratory gyroscope, the coupled motion between reference (driving) and sensing vibrations causes the zero-point output, which is the unwanted sensing vibration without angular velocity. This structural coupling leads to an inherent discrepancy between the natural frequencies of the reference and the sensing oscillations, causing curve veering in frequency loci. The coupled motion deteriorates sensing performance and dynamic stability. In this paper, the dynamic characteristics associated with the coupling phenomenon are theoretically analyzed. The effects of reference frequency and coupling factor on the rotational direction and amplitude of elliptic oscillation are determined. Based on the analytical studies on the coupling effects, we propose and fabricate a vertically decoupled vibratory gyroscope with the frequency matching.

  3. Structural, morphological, and magnetic characteristics of Cu-implanted nonpolar GaN films

    International Nuclear Information System (INIS)

    Sun Lili; Yan Fawang; Zhang Huixiao; Wang Junxi; Zeng Yiping; Wang Guohong; Li Jinmin

    2009-01-01

    Diluted magnetic nonpolar GaN:Cu films have been fabricated by implanting Cu ions into unintentionally doped nonpolar a-plane(112-bar 0) GaN films and a subsequent thermal annealing process. The structural, morphological and magnetic characteristics of the samples have been investigated by means of high-resolution X-ray diffraction (HRXRD), atomic force microscopy (AFM), and superconducting quantum interference device (SQUID). The sample shows a clear ferromagnetism behavior at room temperature. It is significantly shown that with a Cu concentration as low as 0.75% the sample exhibits a saturation magnetization about 0.65 μ B /Cu atom. Moreover, the possible origin of the ferromagnetism for the sample was also discussed briefly.

  4. A case-control study of brain structure and behavioral characteristics in 47,XXX syndrome.

    Science.gov (United States)

    Lenroot, R K; Blumenthal, J D; Wallace, G L; Clasen, L S; Lee, N R; Giedd, J N

    2014-11-01

    Trisomy X, the presence of an extra X chromosome in females (47,XXX), is a relatively common but under-recognized chromosomal disorder associated with characteristic cognitive and behavioral features of varying severity. The objective of this study was to determine whether there were neuroanatomical differences in girls with Trisomy X that could relate to cognitive and behavioral differences characteristic of the disorder during childhood and adolescence. MRI scans were obtained on 35 girls with Trisomy X (mean age 11.4, SD 5.5) and 70 age- and sex-matched healthy controls. Cognitive and behavioral testing was also performed. Trisomy X girls underwent a semi-structured psychiatric interview. Regional brain volumes and cortical thickness were compared between the two groups. Total brain volume was significantly decreased in subjects with Trisomy X, as were all regional volumes with the exception of parietal gray matter. Differences in cortical thickness had a mixed pattern. The subjects with Trisomy X had thicker cortex in bilateral medial prefrontal cortex and right medial temporal lobe, but decreased cortical thickness in both lateral temporal lobes. The most common psychiatric disorders present in this sample of Trisomy X girls included anxiety disorders (40%), attention-deficit disorder (17%) and depressive disorders (11%). The most strongly affected brain regions are consistent with phenotypic characteristics such as language delay, poor executive function and heightened anxiety previously described in population-based studies of Trisomy X and also found in our sample. Published 2014. This article is a U.S. Government work and is in the public domain in the USA.

  5. Characteristics of electrophysical and photoelectric properties of MOS-structures on indium arsenide

    Science.gov (United States)

    Loskutova, Y. A.; Davydov, V. N.; Lezina, T. D.

    1985-10-01

    An experimental study is made of MOS-structures on InAs, for an exploration of their electrophysical and photoelectric characteristics. Specimens are prepared from n-InAs single crystals with a 111 orientation and a donor concentration of 1.6 10 to the 16th power cu cm. Their chemico-mechanically and mechanically polished surfaces are oxidized galvanostatically in a 20% solution of orthophosphoric acid on ethylene glycol with an anodizing current density of 1 A/sq. cm., until a 0.1 micrometers thick anodic oxide film characterized by a breakdown voltage of 40 to 50 V and a leakage current of 10 to the -10 power A/sq. cm builds up. A semitransparent nickel electrode is deposited by vacuum evaporation. The capacitance-voltage characteristics are measured by the frequency-divider method at 1 MHz, with no capacitance dispersion found over the 300 kHz to 10 MHz range. The photo-emf is measured with a light-activated diode at the 0.95 micrometers wavelength and a 70 Hz modulation frequency. The data obtained include voltage of the flat energy bands and hysteresis of the capacitance-voltage characteristic on both positive and negative halves of the voltage sweep (-14 V yields 0 yields +14 V) at a constant reverse bias (-5 V), spectrum of surface states and voltage dependence of the small-signal photo-emf over the -10-(-2) V range at various voltage sweep rates, also dependence of the photo-emf on the frequency of radiation intensity modulation at various field-electrode voltages and temperature dependence of the photo-emf under weak and strong inversion of the InAs surface.

  6. Structure-function characteristics of the biomaterials based on milk-derived proteins.

    Science.gov (United States)

    Ghosh, Arun; Ali, M Azam; Selvanesan, Luxmanan; Dias, George J

    2010-05-01

    There is an impetus on development of implantable biomaterials with the characteristics of improved biodegradability, bio-absorbability and wound healing activities. The milk proteins have valuable nutritional and biological properties, which lead to the promotion of quality health. In this study, whey protein isolate or WPI (highly aggregated) and its component lactalbumin (less aggregated) were melt blended with polycaprolactone (PCL) and then compression moulded into thin sheets ( approximately 1mm thickness). The effects of structural morphologies of the proteins on the mechanical, morphological, in vitro enzymatic degradation, and cytotoxicity and cell proliferation characteristics of the biomaterials were examined. In general, the tensile strength and modulus of the biomaterials decreased with increasing protein content. Compared to WPI, lactalbumin showed a better compatibility with the PCL matrix as observed in the mechanical properties and scanning electron microscopic morphology. The biomaterials exhibited a good retention of the mechanical characteristics after digestion in a physiologically simulated fluid containing trypsin enzyme. However, lactalbumin containing biomaterials showed a better retention of the tensile properties compared to WPI containing biomaterials. The cell culture studies indicated that the biomaterials have no cytotoxic effects, moreover they enhanced the proliferation of L929 cells compared to the pure PCL. Finally, this study indicated that the PCL based biomaterials with a protein content of 20wt% may be applied in fabrication of implantable devices for soft tissue engineering, where it requires a reasonably low to moderate mechanical strength (e.g., approximately 10MPa tensile strength), and improved biodegradability, biocompatibility and tissue healing activities. 2010 Elsevier B.V. All rights reserved.

  7. Structural and Environmental Characteristics of Extratropical Cyclones that Cause Tornado Outbreaks in the Warm Sector

    Science.gov (United States)

    Tochimoto, Eigo; Niino, Hiroshi

    2016-04-01

    The differences in structural and environmental characteristics of extratropical cyclones (hereafter, ECs) that cause tornado outbreaks and those that do not were examined through composite analyses of the newly-released Japanese reanalysis data (JRA-55) and idealized numerical experiments. ECs that developed in the United States in April and May between 1995 and 2012 are categorized into two groups: ECs accompanied by 15 or more tornadoes (hereafter, outbreak cyclones (OCs)) and ECs accompanied by 5 or less tornadoes (non-outbreak cyclones (NOCs)). 55 OCs and 41 NOCs that are of similar strength as OCs are selected in this study. The composite analyses show significant differences in convective environmental parameters between OCs and NOCs. For OCs, convective available potential energy (CAPE) and storm relative environmental helicity (SREH) are larger and the areas in which these parameters have significant values are wider in the warm sector. The larger CAPE in OCs is due to larger amount of low-level water vapor, while the larger SREH in OCs due to stronger southerly wind at low levels. A piecewise potential vorticity (PV) diagnostics (Davis and Emanuel, 1991) indicates that low- to mid-level PV anomalies mainly contribute to the difference in the low-level winds between OCs and NOCs. On the other hand, the low-level winds associated with upper-level PV anomalies are not the major contributor to the difference. The results of the idealized numerical experiments for OCs and NOCs (hereafter, referred to as OC-CTL and NOC-CTL, respectively) using WRF ver. 3.4 show that the characteristics of the low-level wind fields and SREH distributions for the simulated ECs in OC-CTL and NOC-CTL are similar to those for OCs and NOCs, respectively. In OC-CTL, SREH and low-level winds in the east-southeast region of the EC center is larger than those in NOC-CTL, respectively. It is suggested that these differences are due to the structures of jetstream. The structure of

  8. Structure characteristics and combustibility of carbonaceous materials from blast furnace flue dust

    International Nuclear Information System (INIS)

    Zhao, Di; Zhang, Jianliang; Wang, Guangwei; Conejo, Alberto N.; Xu, Runsheng; Wang, Haiyang; Zhong, Jianbo

    2016-01-01

    Highlights: • The combustion properties of carbonaceous materials in dust were investigated. • The mico-structures of carbon materials in dusts were exemplified distinctly. • The carbon activity differences were depended on their diverse mico-structures. • Kinetic parameters were obtained in the method of nonlinear least-squares fitting. • VM and RPM model for carbonaceous materials in dust and their pyrolytic coke. - Abstract: The structure characteristics and combustibility of carbonaceous materials from gravitational dust and bag dust of hop pocket were investigated using laser particle size analyzer, scanning electron microscopy, X-ray Diffraction, polarization microscopy and thermogravimetric analysis. Simultaneously, coal char and pyrolyzed coke were used as comparison. The acid-washing process was performed to avoid the effects of inorganic matters and beneficiate carbonaceous materials in dust. Three representative gas-solid reactivity models, random pore model, volume model, and unreacted core model were applied to study kinetic parameters. Results showed that carbonaceous materials in dust were mainly originated from coke fines and those in bag dust of hop pocket presented a high reactivity, mainly attributed to its more disordered crystalline structure and higher porosity. It was concluded from kinetic analysis that volume model was the best model for simulating the combustion process. The activation energies of bag dust of hop pocket, gravitational dust and coke calculated by this model were 118.6 kJ/mol, 141.7 kJ/mol, 156.1 kJ/mol, respectively, indicating carbon in bag dust of hop pocket are easily reacted with oxygen and proving its high combustibility.

  9. Insights on Structural Characteristics and Ligand Binding Mechanisms of CDK2

    Directory of Open Access Journals (Sweden)

    Yan Li

    2015-04-01

    Full Text Available Cyclin-dependent kinase 2 (CDK2 is a crucial regulator of the eukaryotic cell cycle. However it is well established that monomeric CDK2 lacks regulatory activity, which needs to be aroused by its positive regulators, cyclins E and A, or be phosphorylated on the catalytic segment. Interestingly, these activation steps bring some dynamic changes on the 3D-structure of the kinase, especially the activation segment. Until now, in the monomeric CDK2 structure, three binding sites have been reported, including the adenosine triphosphate (ATP binding site (Site I and two non-competitive binding sites (Site II and III. In addition, when the kinase is subjected to the cyclin binding process, the resulting structural changes give rise to a variation of the ATP binding site, thus generating an allosteric binding site (Site IV. All the four sites are demonstrated as being targeted by corresponding inhibitors, as is illustrated by the allosteric binding one which is targeted by inhibitor ANS (fluorophore 8-anilino-1-naphthalene sulfonate. In the present work, the binding mechanisms and their fluctuations during the activation process attract our attention. Therefore, we carry out corresponding studies on the structural characterization of CDK2, which are expected to facilitate the understanding of the molecular mechanisms of kinase proteins. Besides, the binding mechanisms of CDK2 with its relevant inhibitors, as well as the changes of binding mechanisms following conformational variations of CDK2, are summarized and compared. The summary of the conformational characteristics and ligand binding mechanisms of CDK2 in the present work will improve our understanding of the molecular mechanisms regulating the bioactivities of CDK2.

  10. Effect of immerse an organic layer in isopropyl alcohol on characteristics of hybrid photovoltaic structures

    Science.gov (United States)

    Olivares Vargas, A. J.; Cosme, I.; Mansurova, S.; Kosarev, A.; Itzmoyotl, A.

    2017-08-01

    Organic materials have become very important in recent years due to their potential use for photovoltaic applications. Among the main advantages of organic semiconductors are their functional and mechanical flexibility, as well as fabrication simplicity. However, these materials usually afford moderate efficiency in organic photovoltaic devices. On the other hand, hydrogenated amorphous silicon (a-Si:H) is a widely known inorganic semiconductor that compared to their organic counterparts has excellent photogeneration and transport properties and it is suitable for large area fabrication of flexible devices. The idea of combining organic semiconductors and amorphous silicon films in hybrid photovoltaic devices is very attractive due to the possibility to complement the useful properties of both material systems. The photovoltaic devices that we study in this work consist of a p-i-n structure, which is also commonly used in inorganic solar cells. In such kind of structures, the light is mainly absorbed in the intrinsic silicon film and the p- and ntype films are used to create an electric field that separates electrons and holes to produce a photocurrent. In this work, we use an organic material (PEDOT:PSS) to replace the p-type inorganic film in amorphous silicon p-i-n structure. It is widely known, that PEDOT:PSS based organic film is highly transparent and its conductivity can be modified e.g. immerse in a solvent type. Here we present the results of experimental investigation of the effect of isopropanol (IPA) treatments in p-type (PEDOT:PSS) organic layer on characteristics of hybrid solar cell structure.

  11. Freezing lines of colloidal Yukawa spheres. II. Local structure and characteristic lengths

    Energy Technology Data Exchange (ETDEWEB)

    Gapinski, Jacek, E-mail: gapinski@amu.edu.pl; Patkowski, Adam [Molecular Biophysics Division, Faculty of Physics, A. Mickiewicz University, Umultowska 85, 61-614 Poznań (Poland); NanoBioMedical Center, A. Mickiewicz University, Umultowska 85, 61-614 Poznań (Poland); Nägele, Gerhard [Institute of Complex Systems (ICS-3), Forschungszentrum Jülich, D-52425 Jülich (Germany)

    2014-09-28

    Using the Rogers-Young (RY) integral equation scheme for the static pair correlation functions combined with the liquid-phase Hansen-Verlet freezing rule, we study the generic behavior of the radial distribution function and static structure factor of monodisperse charge-stabilized suspensions with Yukawa-type repulsive particle interactions at freezing. In a related article, labeled Paper I [J. Gapinski, G. Nägele, and A. Patkowski, J. Chem. Phys. 136, 024507 (2012)], this hybrid method was used to determine two-parameter freezing lines for experimentally controllable parameters, characteristic of suspensions of charged silica spheres in dimethylformamide. A universal scaling of the RY radial distribution function maximum is shown to apply to the liquid-bcc and liquid-fcc segments of the universal freezing line. A thorough analysis is made of the behavior of characteristic distances and wavenumbers, next-neighbor particle coordination numbers, osmotic compressibility factor, and the Ravaché-Mountain-Streett minimum-maximum radial distribution function ratio.

  12. Non-linear elastic behaviour of carbon fibres of different structural and mechanical characteristic

    Directory of Open Access Journals (Sweden)

    ISIDOR M. DJORDJEVIC

    2007-05-01

    Full Text Available Five types of polyacrylonitrile, PAN, based carbon fibres, differing in modulus, breaking strain and in crystallite orientation, have been studied. Non-Hookean behaviour was investigated by computing the tangent tensile and compression moduli as a function of strain, from the axial stress–strain response obtained in standard tensile, compression, as well as in modified flexural tests of unidirectional carbon/ epoxy composites. The dependences of the tensile modulus on tensile strain of the carbon fibres were extracted from data obtained in single-filament tensile tests. Analytical expressions for the tensile modulus–tensile strain and compression modulus–compression strain dependences in the performed test were deduced. The structural characterization of the carbon fibres was performed by X-ray diffraction on bundle of parallel fibres. The interlayer spacing d002 and the apparent lateral dimension of the crystallites Lc were deduced by processing the 002 diffraction profiles. The established modulus–strain dependences were correlated with the fibre characteristics (breaking strain and mean modulus values, as well as with the characteristic of the 002 diffraction profile and the d002 and Lc values.

  13. Analysis of early accountable care organizations defines patient, structural, cost, and quality-of-care characteristics.

    Science.gov (United States)

    Epstein, Arnold M; Jha, Ashish K; Orav, E John; Liebman, Daniel L; Audet, Anne-Marie J; Zezza, Mark A; Guterman, Stuart

    2014-01-01

    Accountable care organizations (ACOs) have attracted interest from many policy makers and clinical leaders because of their potential to improve the quality of care and reduce costs. Federal ACO programs for Medicare beneficiaries are now up and running, but little information is available about the baseline characteristics of early entrants. In this descriptive study we present data on the structural and market characteristics of these early ACOs and compare ACOs' patient populations, costs, and quality with those of their non-ACO counterparts at baseline. We found that ACO patients were more likely than non-ACO patients to be older than age eighty and had higher incomes. ACO patients were less likely than non-ACO patients to be black, covered by Medicaid, or disabled. The cost of care for ACO patients was slightly lower than that for non-ACO patients. Slightly fewer than half of the ACOs had a participating hospital. Hospitals that were in ACOs were more likely than non-ACO hospitals to be large, teaching, and not-for-profit, although there was little difference in their performance on quality metrics. Our findings can be useful in interpreting the early results from the federal ACO programs and in establishing a baseline to assess the programs' development.

  14. Energy Trapping Characteristics of Bismuth Layer Structured Compound CaBi4Ti4O15

    Science.gov (United States)

    Kimura, Masahiko; Sawada, Takuya; Ando, Akira; Sakabe, Yukio

    1999-09-01

    Piezoelectric characteristics of bismuth layer structured compound CaBi4Ti4O15 ceramics were studied in terms of the energy trapping phenomenon of the second harmonic thickness extensional (TE2) vibration mode. An electrode-buried-type resonator was prepared by the co-firing technique to generate the TE2 mode, and frequency-lowering-type energy trapping was realized. Favorable resonant characteristics were obtained for piezoelectric filter and oscillator applications with narrow frequency tolerances, which require a small electromechanical coupling coefficient and a high mechanical quality factor. The electromechanical coupling coefficient for the TE2 vibration mode of the resonator was 13.9% and the mechanical quality factor Qm was 2560. The temperature coefficient of the resonance frequency was adequate for the applications. The microstructure of CaBi4Ti4O15 ceramic was also investigated. Marked shape anisotropy of the grain was observed; however, preferential grain orientation was not recognized when the ceramic was prepared by the ordinary firing process.

  15. Structural and interpersonal characteristics of family meals: associations with adolescent body mass index and dietary patterns.

    Science.gov (United States)

    Berge, Jerica M; Jin, Seok Won; Hannan, Peter; Neumark-Sztainer, Dianne

    2013-06-01

    The last decade of research has suggested that family meals play an important role in promoting healthful dietary intake in youth. However, little is known about the structural characteristics and interpersonal dynamics of family meals that might help to inform why family meals are protective for youth. The current mixed methods, cross-sectional study conducted in 2010-2011 includes adolescents and parents who participated in two linked population-based studies. Participants included 40 parents (91.5% female) and adolescents (57.5% female) from the Minneapolis/St Paul, MN, area participating in EAT (Eating and Activity Among Teens) 2010 and F-EAT (Families and Eating and Activity Among Teens). The structural (eg, length of the meal, types of foods served) and interpersonal characteristics (eg, communication, emotion/affect management) of family meals were described, and associations between interpersonal dynamics at family meals and adolescent body mass index and dietary intake were examined via direct observational methods. Families were videorecorded during two mealtimes in their homes. Results indicated that family meals were approximately 20 minutes in length, included multiple family members, were typically served family style (70%), and occurred in the kitchen 62% of the time and 38% of the time in another room (eg, family room, office). In addition, significant associations were found between positive interpersonal dynamics (ie, communication, affect management, interpersonal involvement, overall family functioning) at family meals and lower adolescent body mass index and higher vegetable intake. These findings add to the growing body of literature on family meals by providing a better understanding of what is happening at family meals in order to inform obesity-prevention studies and recommendations for providers working with families of youth. Copyright © 2013 Academy of Nutrition and Dietetics. Published by Elsevier Inc. All rights reserved.

  16. Structural and Interpersonal Characteristics of Family Meals: Associations with Adolescent BMI and Dietary Patterns

    Science.gov (United States)

    Berge, Jerica M.; Jin, Seok Won; Hannan, Peter; Neumark-Sztainer, Dianne

    2013-01-01

    The last decade of research has suggested that family meals play an important role in promoting healthful dietary intake in youth. However, little is known about the structural characteristics and interpersonal dynamics of family meals that may help to inform why family meals are protective for youth. The current mixed methods, cross-sectional study conducted in 2010–2011 includes adolescents and parents who participated in two linked population-based studies. Participants included 40 parents (91.5% female) and adolescents (57.5% female) from the Minneapolis/St. Paul area participating in EAT 2010 and F-EAT. The structural (e.g. length of the meal, types of foods served) and interpersonal characteristics (e.g., communication, emotion/affect management) of family meals were described and associations between interpersonal dynamics at family meals and adolescent body mass index (BMI) and dietary intake were examined via direct observational methods. Families were video-recorded during two mealtimes in their homes. Results indicated that family meals were approximately 20 minutes in length, included multiple family members, were typically served family style (70%) and occurred in the kitchen 62% of the time and 38% of the time in another room (e.g., family room, office). Additionally, significant associations were found between positive interpersonal dynamics (i.e., communication, affect management, interpersonal involvement, overall family functioning) at family meals and lower adolescent BMI and higher vegetable intake. These findings add to the growing body of literature on family meals by providing a better understanding of what is happening at family meals in order to inform obesity prevention studies and recommendations for providers working with families of youth. PMID:23567247

  17. Curative procedures of oral health and structural characteristics of primary dental care

    Science.gov (United States)

    Baumgarten, Alexandre; Hugo, Fernando Neves; Bulgarelli, Alexandre Fávero; Hilgert, Juliana Balbinot

    2018-01-01

    ABSTRACT OBJECTIVE To evaluate if the provision of clinical dental care, by means of the main curative procedures recommended in Primary Health Care, is associated with team structural characteristics, considering the presence of a minimum set of equipment, instrument, and supplies in Brazil’s primary health care services. METHODS A cross-sectional exploratory study based on data collected from 18,114 primary healthcare services with dental health teams in Brazil, in 2014. The outcome was created from the confirmation of five clinical procedures performed by the dentist, accounting for the presence of minimum equipment, instrument, and supplies to carry them out. Covariables were related to structural characteristics. Poisson regression with robust variance was used to obtain crude and adjusted prevalence ratios, with 95% confidence intervals. RESULTS A total of 1,190 (6.5%) dental health teams did not present the minimum equipment to provide clinical dental care and only 2,498 (14.8%) had all the instrument and supplies needed and provided the five curative procedures assessed. There was a positive association between the outcome and the composition of dental health teams, higher workload, performing analysis of health condition, and monitoring of oral health indicators. Additionally, the dental health teams that planned and programmed oral health actions with the primary care team monthly provided the procedures more frequently. Dentists with better employment status, career plans, graduation in public health or those who underwent permanent education activities provided the procedures more frequently. CONCLUSIONS A relevant number of Primary Health Care services did not have the infrastructure to provide clinical dental care. However, better results were found in dental health teams with oral health technicians, with higher workload and that plan their activities, as well as in those that employed dentists with better working relationships, who had dentists

  18. Structural, Nursing, and Physician Characteristics and 30-Day Mortality for Patients Undergoing Cardiac Surgery in Pennsylvania.

    Science.gov (United States)

    Lane-Fall, Meghan B; Ramaswamy, Tara S; Brown, Sydney E S; He, Xu; Gutsche, Jacob T; Fleisher, Lee A; Neuman, Mark D

    2017-09-01

    Cardiac surgery ICU characteristics and clinician staffing patterns have not been well characterized. We sought to describe Pennsylvania cardiac ICUs and to determine whether ICU characteristics are associated with mortality in the 30 days after cardiac surgery. From 2012 to 2013, we conducted a survey of cardiac surgery ICUs in Pennsylvania to assess ICU structure, care practices, and clinician staffing patterns. ICU data were linked to an administrative database of cardiac surgery patient discharges. We used logistic regression to measure the association between ICU variables and death in 30 days. Cardiac surgery ICUs in Pennsylvania. Patients having coronary artery bypass grafting and/or cardiac valve repair or replacement from 2009 to 2011. None. Of the 57 cardiac surgical ICUs in Pennsylvania, 43 (75.4%) responded to the facility survey. Rounds included respiratory therapists in 26 of 43 (60.5%) and pharmacists in 23 of 43 (53.5%). Eleven of 41 (26.8%) reported that at least 2/3 of their nurses had a bachelor's degree in nursing. Advanced practice providers were present in most of the ICUs (37/43; 86.0%) but residents (8/42; 18.6%) and fellows (7/43; 16.3%) were not. Daytime intensivists were present in 21 of 43 (48.8%) responding ICUs; eight of 43 (18.6%) had nighttime intensivists. Among 29,449 patients, there was no relationship between mortality and nurse ICU experience, presence of any intensivist, or absence of residents after risk adjustment. To exclude patients who may have undergone transcatheter aortic valve replacement, we conducted a subgroup analysis of patients undergoing only coronary artery bypass grafting, and results were similar. Pennsylvania cardiac surgery ICUs have variable structures, care practices, and clinician staffing, although none of these are statistically significantly associated with mortality in the 30 days following surgery after adjustment.

  19. [Structure and characteristics of technical support that psychiatric social workers of prefectural governments provide for municipalities].

    Science.gov (United States)

    Okada, Takashi

    2017-01-01

    Objectives The support to municipalities by prefectural governments has become necessary in the fields of mental health and welfare. Therefore, psychiatric social workers (PSW) ordered from the prefectural governor has been providing technical support (TS) that promote community activities of the municipality and improve staff support for persons with mental disabilities. The purpose of this study was to identify empirical structure and characteristics of TS that PSW provide for municipality staff.Method Semi-structured interviews were conducted with seven certified PSW randomly selected from the membership list of the National Psychiatric Social Worker Organization. Inclusion criteria required participants to have more than 10 years of experience at the prefectural government and experience providing TS in the last five years. Interviews focused on two situations: a casework and a project related to mental health. Interview data were analyzed using a qualitative content method, setting a framework for the consultation process.Results The analysis included five categories and 15 subcategories [ ], which consisted of 37 concepts. In category with municipalities consisted of [complementary relationship] and [partnership]. The category included two subcategories, [analyze/judgment from the conditions spread in front of] and [analyze/judgment be the accumulated skills and knowledge in person]. In category support policy>, six policies were considered as important, including [problem solving and promoting action], [fostering person centered care perspective], [promoting the understanding of residents], [provide psychological support to the staff], [clarify responsibility as the municipal officials], and [coordinate to improve the environment]. Category support techniques> consisted of both [support indirectly] and [support cooperatively]. The last category, support> included three subcategories, [lead to the maintenance and improvement of the system], [have the

  20. Structural health monitoring using DOG multi-scale space: an approach for analyzing damage characteristics

    Science.gov (United States)

    Guo, Tian; Xu, Zili

    2018-03-01

    Measurement noise is inevitable in practice; thus, it is difficult to identify defects, cracks or damage in a structure while suppressing noise simultaneously. In this work, a novel method is introduced to detect multiple damage in noisy environments. Based on multi-scale space analysis for discrete signals, a method for extracting damage characteristics from the measured displacement mode shape is illustrated. Moreover, the proposed method incorporates a data fusion algorithm to further eliminate measurement noise-based interference. The effectiveness of the method is verified by numerical and experimental methods applied to different structural types. The results demonstrate that there are two advantages to the proposed method. First, damage features are extracted by the difference of the multi-scale representation; this step is taken such that the interference of noise amplification can be avoided. Second, a data fusion technique applied to the proposed method provides a global decision, which retains the damage features while maximally eliminating the uncertainty. Monte Carlo simulations are utilized to validate that the proposed method has a higher accuracy in damage detection.

  1. Ensiling characteristics, structural and nonstructural carbohydrate composition and enzymatic digestibility of Napier grass ensiled with additives.

    Science.gov (United States)

    Desta, Seare T; Yuan, XianJun; Li, Junfeng; Shao, Tao

    2016-12-01

    Ensiling characteristics, structural and nonstructural carbohydrate composition and enzymatic digestibility (ED) of Napier grass silage was examined. Napier grass ensiled with no additive control, 0.2% formic acid, 0.4% molasses, and 0.3% fibrolytic enzyme for, 7, 30, 60 and 90days. Additives increased lactic acid, soluble carbohydrate and decreased all of lignocellulosic contents except acid detergent lignin and pH than control. The highest value of nonstructural carbohydrate and large reduction in lignocellulosic contents was observed in formic acid and fibrolytic enzyme silage respectively. The content of glucose and fructose showed rapid drop in the first 7days of ensilage. Ensilage decreased lignocellulosic contents and increased ED compared to fresh material. The ED of formic acid and molasses silage was significantly higher than control and fibrolytic enzyme silages in all tested days. In summery the ensiling quality structural and nonstructural carbohydrate and ED value of mature Napier grass silage improved through additives. Copyright © 2016 Elsevier Ltd. All rights reserved.

  2. Heat transfer characteristics in closed-loop spray cooling of micro-structured surfaces

    International Nuclear Information System (INIS)

    Zhang Wei; Wang Zhaoliang; Xu Minghai

    2012-01-01

    With water as the working fluid, experiments on the heat transfer characteristics of spray cooling of micro-structured surfaces were performed in a closed loop system. Experimental data were analyzed in the view of the ratio between convective heat transfer and phase change heat transfer. The results indicate that heat transfer is obviously enhanced for micro-channel surfaces relative to the flat surface because of higher phase change heat transfer. For the geometries tested at lower surface temperature, the straight finned surface has the largest heat flux; while at higher surface temperature, the cubic pin finned surface has the largest heat flux. Heat fluxes of all the surfaces grow with increasing flow rates, except for the straight finned surface under lower surface temperature. The ratio of phase change to total heat transfer is bigger than 20% for the flat surface, and higher than 50% for micro-structured surface. Critical heat fluxes of 159.1 W/cm 2 , 120.2 W/cm 2 , and 109.8 W/cm 2 are attained respectively for cubic pin finned, straight finned and flat surfaces when the flow rate is 15.9 mL/min, and the corresponding evaporation efficiency are 96.0%, 72.5%, 67.1%. (authors)

  3. Effect of chemisorption structure on the interfacial bonding characteristics of graphene-polymer composites

    International Nuclear Information System (INIS)

    Lv Cheng; Xue Qingzhong; Xia Dan; Ma Ming

    2012-01-01

    The influence of the chemical functionalization of graphene on the interfacial bonding characteristics between graphene and polymer was investigated using molecular mechanics and molecular dynamics simulations. In this study, three chemical functionalization, (a) phenyl groups, (b) -C 6 H 13 and(c) -C 2 H 4 (C 2 H 5 ) 2 , which have the same number of carbon atoms, were chosen to investigate the influence of the structure of functionalized groups on the bonding energy and shear stress in the graphene-polyethylene (PE) composites. Our simulations indicated that, the interfacial bonding energy between the graphene modified by -C 6 H 13 groups and PE matrix has the strongest enhancement, but the shear force between the graphene modified by -C 2 H 4 (C 2 H 5 ) 2 groups and PE matrix is the strongest in the graphene-polymer composites. Therefore, the suitable structure of chemical groups to the graphene surface may be an effective way to significantly improve the load transfer between the graphene and polymer when graphene is used to produce nanocomposites.

  4. Current Transport Mechanisms and Capacitance Characteristic in the InN/InP Schottky Structures

    Directory of Open Access Journals (Sweden)

    K. AMEUR

    2014-05-01

    Full Text Available In this work, electrical characterization of the current-voltage and capacitance- voltage curves for the Metal/InN/InP Schottky structures are investigated. We have studied electrically thin InN films realized by the nitridation of InP (100 substrates using a Glow Discharge Source (GDS in ultra high vacuum. The I (V curves have exhibited anomalous two-step (kink forward bias behaviour; a suitable fit was only obtained by using a model of two discrete diodes in parallel. Thus, we have calculated, using I(V and C(V curves of Hg/InN/InP Schottky structures, the ideality factor n, the saturation current Is, the barrier height jB, the series resistance Rs, the doping concentration Nd and the diffusion voltage Vd. We have also presented the band diagram of this heterojunction which indicates the presence of a channel formed by holes at the interface InN/InP which explain by the presence of two-dimensional electron gas (2-DEG and this was noticed in the presentation of characteristics C(V.

  5. Family Ownership, Firm’s Financial Characteristics and Capital Structure: Evidence from Public Listed Companies in Malaysia

    Directory of Open Access Journals (Sweden)

    Punitharaja NADARAJA

    2011-06-01

    Full Text Available Capital structure is identified as one of focal facet in corporate finance branch of learning. It provides comprehension on how firms choose to finance their operations and expansion. The objective of this study is to explore the determinants of capital structure of Malaysian public listed companies. The period of 2001-2006 was selected in this study, which reflected the post Asian financial crisis period. Firm’s financial characteristics consist of size, growth, profitability, liquidity and ability to service debt. Family ownership which was identified as a unique feature in the Malaysian corporate sector was used to measure the effect of corporate governance in capital structure decision. Using panel data approach, this study infers that the role of ownership structure in the form of family ownership though is not significantly related to capital structure, its inclusion in the empirical equation changes the significance of other variables. Except for growth, all other financial characteristics have significant relationships with capital structure.

  6. The structural and dynamic characteristics of a water-polimer high-speed jet

    Directory of Open Access Journals (Sweden)

    Андрій Володимирович Погребняк

    2017-07-01

    Full Text Available The aim is to study the structural and dynamic characteristics of the water-polymer jet, what is of decisive importance for understanding the nature of the abnormally high cutting ability. A complex study of the structure and dynamics of a water-polymer high-speed jet has been carried out. Analysis of the photographs of jets of aqueous PEO solution indicates that adding polyethylene oxide (PEO into water results in a significant increase in the initial sections of the water-polymer jet, which characterizes the quality of its formation, and leads to compactness due to a reduction of its diameter. The obtained experimental data made it possible to propose a relationship for determining the dimensionless value of the initial sections of jets of aqueous PEO solutions of different concentration and molecular mass of PEO, taking into account the real parameters of the jet forming head. Investigation of changes in the energy capabilities of water-polymer jets, which were estimated by the force of the jet impact on the steel obstacle, made it possible to establish the features of their dynamics. The obtained experimental data explain the nature of the change in the cutting properties of the water-polymer jet as a function of the distance between the surface of the material that is being cut and the cut of the nozzle. If the distance from the nozzle to the surface of the material is less than the size of the initial sections of the water-polymer jet, an increase in the diameter of the nozzle outlet hole will lead to a reduction in the depth of the cut. If, however, the distance from the nozzle to the surface of the material approaches or exceeds the size of the main part of the water-polymer jet, then the depth of the cut will increase with increasing diameter of the nozzle at a constant pressure. The use of structural and dynamic characteristics of water-polymer jets is substantiated when establishing rational parameters of equipment for water

  7. Population-level preferences for primary care physicians' characteristics in Japan: a structural equation modeling.

    Science.gov (United States)

    Takahashi, Osamu; Ohde, Sachiko; Jacobs, Joshua L; Tokuda, Yasuharu; Yanai, Haruo; Okubo, Tomoya; Shimbo, Takuro; Fukuhara, Shunichi; Hinohara, Shigeaki; Fukui, Tsuguya

    2010-01-01

    Primary care has potential to play a role for improving the patient care in Japanese health care system; however, little information is available about how patients perceive the roles of primary care physicians (PCPs) within the Japanese health care system. We aimed to assess population-level preferences for PCPs and investigated the extent to which preferences vary in relation to different population groups in Japan. Data were extracted from a cross-sectional questionnaire survey in October 2003. An 18-item questionnaire was used to measure the preferences for PCPs. Exploratory factor analysis was performed to identify latent factors, while confirmatory factor analysis was used to evaluate the fit of the structure using structural equation modeling (SEM). Nationally representative sample of the adult Japanese general population was chosen by controlling for age, sex, and the size of cities. A total of 2,453 adults>or=18-years-old were analyzed. SEM provided a 4-factor structural model of the population-level preference for PCPs, such as clinical competence (path coefficient (pc)=0.72), gate-keeping (pc=0.64), communication with patients or specialists (pc=0.49) and high education (pc=0.25) and demonstrated the best goodness-of-fit. Those who were middle aged, have a high family income, and a high level of education, placed more importance on gate-keeping characteristics, and the rural residents emphasized communication rather than clinical competence. Our results indicate that the preferences for PCPs are divided into four main factors and underscore the variation among preferences according to different population groups, such as age, socioeconomic and educational status, and places of living. These variations should be considered to improve the primary care system in Japan.

  8. Effects of alloying element and metallurgical structure on semiconducting characteristics of oxide film of zirconium alloy

    International Nuclear Information System (INIS)

    Inagaki, Masahisa; Kanno, Masayosi; Maki, Hideo.

    1991-01-01

    Semiconducting characteristics of oxide films formed on pure Zr, Zr-Sn binary alloy and Zr-Sn-X (X: Fe, Ni or Cr) ternary alloys were evaluated by photo-electrochemical method, in order to make clear the effects of alloying elements on oxidation mechanism of Zr alloy in BWR environment. Oxide films of the alloys showed the characteristics of n-type semiconductor. Maximum photocurrent (I max) was generated by an illumination of monochromatic light with the energy of 5 ∼ 6 eV, i.e. the band gap energy of the Zr alloy oxide was 5 ∼ 6 eV. This value is lower by 2 ∼ 3 eV than the theoretical band gap energy (8 eV) of stoichiometric ZrO 2 . These facts suggest that the generation of I max was resulted from an excitation of electrons trapped with anion vacancies (oxygen vacancies) of non-stoichiometric ZrO 2-x . Therefore, the value of I max is considered to be proportional to the density of anion vacancy. High corrosion resistant alloys showed lower value of I max. The changes of I max, due to change of chemical composition of alloys and due to the change of metallurgical structure, was able to be explained by the valence theory of oxide semiconductor, i.e. the decrease of 1 max was considered to be resulted from the decrease of anion vacancies due to the substitution of divalent cations (Ni 2+ ) and trivalent cations (Fe 3+ , Cr 3+ ) at Zr 4+ cation sites. From these results, it was concluded that oxidation rate of Zr alloy depended on the density of oxygen vacancies in oxide film. (author)

  9. Characteristics of seizure frequency among Malaysian children diagnosed with structural-metabolic epilepsy

    Directory of Open Access Journals (Sweden)

    Muhannad RM Salih

    2012-01-01

    Full Text Available Introduction: Seizure-free patients or substantial reduction in seizure frequency are the most important outcome measures in the management of epilepsy. The study aimed to evaluate the patterns of seizure frequency and its relationship with demographics, clinical characteristics, and outcomes. Materials and Methods: A retrospective cohort study was conducted at the Pediatric Neurology Clinic, Hospital Pulau Pinang. Over a period of 6 months, the required data were extracted from the medical records using a pre-designed data collection form. Results: Seizure frequency showed no significant association with patient′s demographics and clinical characteristic. However, significant reduction in seizure frequency from the baseline to the last follow-up visit was only seen in certain subgroups of patients including Malays, females, patients <4 years of age, patients with global developmental delay/intellectual disability, and patients with focal seizure. There was no significant association between seizure frequency and rate of adverse events. Polytherapy visits were associated with higher seizure frequency than monotherapy visits (27.97 ± 56.66, 10.94 ± 30.96 attack per month, respectively (P < 0.001. There was a clear tendency to get antiepileptic drugs used at doses above the recommended range in polytherapy (8.4% rather than in monotherapy (1.4% visits (P < 0.001. A significant correlation was found between seizure frequency and number of visits per patient per year (r = 0.450, P < 0.001. Conclusion: Among children with structural-metabolic epilepsy, Malays, females, patients <4 years of age, patients with global developmental delay/intellectual disability and patients manifested with focal seizure are more responsive antiepileptic drug therapy than the other subgroups of patients.

  10. Two-Phase Gas-Liquid Flow Structure Characteristics under Periodic Cross Forces Action

    Directory of Open Access Journals (Sweden)

    V. V. Perevezentsev

    2015-01-01

    Full Text Available The article presents a study of two-phase gas-liquid flow under the action of periodic cross forces. The work objective is to obtain experimental data for further analysis and have structure characteristics of the two-phase flow movement. For research, to obtain data without disturbing effect on the flow were used optic PIV (Particle Image Visualization methods because of their noninvasiveness. The cross forces influence was provided by an experimental stand design to change the angular amplitudes and the periods of channel movement cycle with two-phase flow. In the range of volume gas rates was shown a water flow rate versus the inclination angle of immovable riser section and the characteristic angular amplitudes and periods of riser section inclination cycle under periodic cross forces. Data on distribution of average water velocity in twophase flow in abovementioned cases were also obtained. These data allowed us to draw a conclusion that a velocity distribution depends on the angular amplitude and on the period of the riser section roll cycle. This article belongs to publications, which study two-phase flows with no disturbing effect on them. Obtained data give an insight into understanding a pattern of twophase gas-liquid flow under the action of periodic cross forces and can be used to verify the mathematical models of the CFD thermo-hydraulic codes. In the future, the work development expects taking measurements with more frequent interval in the ranges of angular amplitudes and periods of the channel movement cycle and create a mathematical model to show the action of periodic cross forces on two-phase gas-liquid flow.

  11. Structure stability and water retention near saturation characteristics as affected by soil texture, and polyacrylamide concentration

    Science.gov (United States)

    Mamedov, Amrakh I.; Ekberli, Imanverdi A.; Ozturk, Hasan S.; Wagner, Larry E.; Norton, Darrell L.; Levy, Guy J.

    2017-04-01

    Studying the effects of soil properties and amendment application on soil structure stability is important for the development of effective soil management and conservation practices for sustaining semi-arid soil and water quality under climate change scenarios. Two sets of experiments were conducted to evaluate the effects of soil texture and soil amendment polyacrylamide (PAM) rate on soil structural stability expressed in terms of near saturation soil water retention and aggregate stability using the high energy (0-5 J kg-1) moisture characteristic (HEMC) method. Contribution of (i) soil type were assessed using 30 soil samples varying in texture from sandy to clay taken from long term cultivated lands, covering a range of crop and land management practices, and (ii) anionic PAM concentration (0, 10, 25, 50, 100 & 200 mg l-1) were tested on selected loam and clay soils. The water retention curves of slow and fast wetted soil samples were characterized by a modified van Genuchten (1980) model that provides (i) model parameters α and n, which represent the location of the inflection point and the steepness of the S-shaped water retention curves, and (ii) a composite soil structure index (SI =VDP/MS; VDP-volume of drainable pores, MS-modal suction). The studied treatments had, generally, considerable effects on the shape of the water retention curves (α and n). Soil type, PAM concentration and their interaction had significantly effects on the stability indices (SI, VDP and MS) and the model parameters (α and n). The SI and α increased, and ndecreased exponentially with the increase in soil clay content and PAM concentration, but the shape of curves were soil texture and management dependent, since predominant changes were observed in the various range of studied macropores (pore size > 60 μm). An exponential type of relationship existed between SI and α and n. Effect of PAM contribution and wetting condition was more pronounced in the loam soil at low PAM

  12. Effect of Anode Structure on the Plasma Jet Characteristics of Arcjet Thruster

    Directory of Open Access Journals (Sweden)

    Du Zhenzhi

    2015-01-01

    Full Text Available In order to study the effects of anode geometry on volt-ampere characteristics and plasma jet characteristics of the arcjet thruster, the arcjet thruster flow characteristics were simulated. Through numerical simulation, the velocity field and temperature field of thruster were calculated, and the volt-ampere characteristics were obtained at different anode geometry. The calculation results show that the influence of the anode throat diameter was the most obvious, compared to the influence of the anode throat length and compression angle on volt-ampere characteristics and plasma jet characteristic of the arcjet thruster.

  13. Structural and functional characteristics of avicennia germinans mangrove formation of Chengue bay (Colombian Caribbean)

    International Nuclear Information System (INIS)

    Rodriguez Ramirez, Alberto; Nivia Ruiz, Jaime; Garzon Ferreira, Jaime

    2004-01-01

    Within the framework of the CARICOMP (Caribbean coastal marine productivity) monitoring program, a study of the avicennia germinans mangrove formation of Chengue bay (Tayrona natural park, Colombia) was performed between June 1995 and July 1996, based on the evaluation of structural and functional characteristics at three monitoring plots (10 x 10 m). The structure of the studied formation is coincident with that of fringing forests of the Caribbean region in having small trees (dbh=11.3 cm, total height=6.3 m) and high densities (16.3 trunks/0.01 ha). During the monitored period there was a low mortality rate (0.7 trees/year) and there were significant increases of the circumferences at breast height (as well as of the variables derived from this measure) average tree growth rates expressed in height, dbh and basal area were 26.7 cm/year, 0.17 cm/year and 2.9 cm/year respectively. Litterfall was composed principally by leaves (66.1%) and represented a mean production rate of 43.1 g/m2/month (5.2 t/ha/year). there was a temporal pattern of litterfall production associated with the climatic seasons in the area: during rainy months the production of total litterfall, leaves and fruits was higher, while during the dry season there was a reduction of these components and an increase of flowers and wood/twigs. therefore, flowering and fruit production periods are fitted to an annual reproductive cycle. In general, the information gathered during this study is a new contribution to the knowledge of mangrove ecology in Chengue and showed that the monitored trees had the conditions to grow and develop during the evaluated period

  14. In situ hydroxyapatite nanofiber growth on calcium borate silicate ceramics in SBF and its structural characteristics

    Energy Technology Data Exchange (ETDEWEB)

    Pu, Yinfu; Huang, Yanlin; Qi, Shuyun [College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123 (China); Chen, Cuili [Department of Physics and Interdisciplinary Program of Biomedical, Mechanical & Electrical Engineering, Pukyong National University, Busan 608-737 (Korea, Republic of); Seo, Hyo Jin, E-mail: hjseo@pknu.ac.kr [Department of Physics and Interdisciplinary Program of Biomedical, Mechanical & Electrical Engineering, Pukyong National University, Busan 608-737 (Korea, Republic of)

    2015-10-01

    A novel calcium silicate borate Ca{sub 11}Si{sub 4}B{sub 2}O{sub 22} ceramic was firstly prepared by the conventional solid-state reaction. In vitro hydroxyapatite mineralization was investigated by soaking the ceramics in simulated body fluid (SBF) solutions at body temperature (37 °C) for various time periods. Scanning electron microscopy (SEM) and X-ray diffraction analysis (XRD) measurements were applied to investigate the samples before and after the immersion of ceramics in SBF solution. The elemental compositions of a hydroxyapatite layer on the ceramics during the mineralization were confirmed by X-ray energy-dispersive spectra (EDS). Meanwhile, the bending strength and elastic modulus of Ca{sub 11}Si{sub 4}B{sub 2}O{sub 22} ceramics were also measured, which indicate that the biomaterials based on Ca{sub 11}Si{sub 4}B{sub 2}O{sub 22} ceramics possess bioactivity and might be a potential candidate as biomaterials for hard tissue repair. The bioactive mineralization ability was evaluated on the base of its crystal structural characteristics, i.e., silanol (Si–OH) and B–OH groups can be easily induced on the surface of Ca{sub 11}Si{sub 4}B{sub 2}O{sub 22} ceramics soaked in SBF solutions. - Highlights: • Calcium silicate borate Ca{sub 11}Si{sub 4}B{sub 2}O{sub 22} ceramics were developed as a new biomaterial. • Ca{sub 11}Si{sub 4}B{sub 2}O{sub 22} shows a superior in vitro bioactivity by inducing bone-like apatite. • Ca{sub 11}Si{sub 4}B{sub 2}O{sub 22} has good mechanical properties as potential candidate biomaterials. • The structure with SiO{sub 4} and BO{sub 3} groups is favorable for hydroxyapatite formation.

  15. Technical and structural reading on ode Alraieah of Omar ibn Abi Rabieah and its emotional characteristic

    Directory of Open Access Journals (Sweden)

    2015-09-01

    Full Text Available Abstract: This article examines the famous Rbheah ode of Omar ibn Abi With The aim of finding The Structural form and some nice features. Knowing that this ods is the most famous and longest ode of Omar and there is in it the most characteristic of his poetry in the storied format which includes elements of the short story with its modern sense and depicts a happy life of The Umayyad period particularly those aspects that relate to women. And from this perspective has become the registered office of the poet's life and Reflection for his inner emotions. The formation of discussion like the following: Discussion Started With the introduction of what it should be noted Based on the announce new version.Then Addressed in this fifth issues and termination: 1.the main Thoughts and ideas in the Ode and its position and the way in which the poet has written ode.2.The Storied Level and dialog in theOde.3.The music in the ode and role of its weighs.4.The imaging level of the Ode in reflection for the Hejaz life. 5. Structural level of the Ode and its emotional aspects. in the end, The Paper achieved some conclusions, such as: the most remarkable is that Ibn Rbia is Sensory and womanish school leader that could link the Old dialogue Soul to Our contemporary world with poeticlyrics and dialogue Fiction.He is first real poet that granted to lyric poem the numerous technical features such as storytelling and dialogue and simplifying weights to singing.and this ode became famous for High precision in the selection of words.

  16. Dynamic characteristics of a cyclic-periodic structure with a piezoelectric network

    Directory of Open Access Journals (Sweden)

    Li Lin

    2015-10-01

    Full Text Available This paper deals with a cyclic-periodic structure with a piezoelectric network. In such a system, there is not only mechanical connection but also electrical connection between adjacent periodic sectors. The objective is to learn whether the presence of a piezoelectric network would change the dynamic characteristics of the system. The background of the research is about vibration reduction of a bladed disk in an aero-engine, and the system is simulated by a lumped parameter model. The dynamic equations of the system are derived, and then the analytical solution corresponding to the eigenvalue problem is given. The vibration responses to single traveling wave excitations (EO excitations and multiple traveling wave excitations (NEO excitations are studied. The results show that the presence of a piezoelectric network would change the natural frequencies of the system compared with those of the system with the piezoelectric shunt circuit. The forced response is sensitive to the connection type and the elements of the network. An energy analysis of the electro-mechanical coupling system has been performed to understand its dynamic behavior, and the following conclusion is obtained: a vibration reduction to excitations whose primary harmonic component is not zero can be achieved by a parallel piezoelectric network, while a reduction to other excitations should be based on a series piezoelectric network.

  17. Structural and biochemical characteristics of locomotory muscles of emperor penguins, Aptenodytes forsteri.

    Science.gov (United States)

    Ponganis, P J; Costello, M L; Starke, L N; Mathieu-Costello, O; Kooyman, G L

    1997-07-01

    Structural and biochemical characteristics of the primary muscles used for swimming (pectoralis, PEC and supracoracoideus, SC) were compared to those of leg muscles in emperor penguins (Aptenodytes forsteri). The mass of PEC-SC was four times that of the leg musculature, and mitochondrial volume density in PEC and SC (4%) was two-thirds that in sartorius (S) and gastrocnemius. The differences in muscle mass and mitochondrial density yielded a 2.2-fold greater total mitochondrial content in PEC-SC than leg muscles, which appears to account for the 1.8-fold greater whole-body highest oxygen consumption previously recorded in emperor penguins during swimming compared to walking. Calculation of maximal mitochondrial O2 consumption in PEC-SC and leg muscle yielded value of 5.8-6.9 ml O2 ml-1 min-1, which are similar to those in locomotory muscles of most mammals and birds. A distinct feature of emperor penguin muscle was its myoglobin content, with concentrations in PEC-SC (6.4 g 100 g-1 among the highest measured in any species. This resulted in a PEC-SC O2 store greater than that of the entire blood. In addition, ratios of myoglobin content to mitochondrial volume density and to citrate synthase activity were 4.4 and 2.5 times greater in PEC than in S, indicative of the significant role of myoglobin in the adaptation of muscle to cardiovascular adjustments during diving.

  18. Structural and physicochemical characteristics of starch from sugar cane and sweet sorghum stalks.

    Science.gov (United States)

    Alves, Fernanda Viginotti; Polesi, Luís Fernando; Aguiar, Cláudio Lima; Sarmento, Silene Bruder Silveira

    2014-10-13

    The starch present in sugar cane and sorghum juice has been considered a problem to the sugar industry. The objective of this work was to study the structural and physicochemical characteristics of the starch present in sugar cane and sweet sorghum. Sugar cane and sweet sorghum starches presented small granules (maximum 5.9 and 7.9 μm), A-type diffraction pattern, high degree of relative crystallinity (44.4 and 42.0%), and low amylose content (17.5 and 16.4%), respectively. Sugar cane starch presented more uniformity in granule shape and size, more homogeneity in amylose chain length, higher number of long lateral chains of amylopectin, and higher susceptibility to enzymatic digestion. Besides being in higher amount in the juice, sweet sorghum starch presented lower values for thermal properties of gelatinization, as well as higher swelling factor, which can cause more problems during processing. Additional studies are needed to evaluate the variety and maturity influence on these properties. Copyright © 2014 Elsevier Ltd. All rights reserved.

  19. High voltage electric field effects on structure and biological characteristics of barley seeds

    Energy Technology Data Exchange (ETDEWEB)

    Khazaei, J. [Tehran Univ., Tehran (Iran, Islamic Republic of). Dept. of Agrotechnology, Univ. College of Abouraihan; Aliabadi, E. [Tehran Univ., Tehran (Iran, Islamic Republic of). Dept. of Crop Production Horticulture, Univ. College of Aburaihan; Shayegani, A.A. [Tehran Univ., Tehran (Iran, Islamic Republic of). Univ. College of Engineering

    2010-07-01

    Electric biostimulation of seeds is a pre-sowing treatment in which an electric field is applied to seeds to increase germination of non standard seeds. This paper reported on a study that examined the effects of AC electric field and exposure time on the structure and biological characteristics of barley seeds. The objective was to determine the potential to accelerate seed germination, plant growth and root development by the electric field strength and exposure time. Makooei cultivar barley seeds were used in this study. The effect of electric field strength (at 2, 4, 9, and 14 kV/m) and exposure time (at 15, 45, 80, and 150 min) on seed germination was studied along with height of seedling, length or root, height of stem, length of leaves, earliness, dry weight and wet weight of seedling. The treated seeds were stored for a month in a refrigerator at 5 degrees C prior to the germination experiments. The initial germination percent of the seed was 81 per cent. The treatment of barley seeds in an AC electric field had a positive effect on all investigated parameters. The germination percent of the treated seed increased to 94.5 per cent . The seeds exposed for long periods of time (45 to 150 min) showed better germination than the seeds exposed to lower exposure times. Dry and wet weights of seedling increased 143.4 per cent and 45.7 per cent, respectively.

  20. Structure and nano-mechanical characteristics of surface oxide layers on a metallic glass.

    Science.gov (United States)

    Caron, A; Qin, C L; Gu, L; González, S; Shluger, A; Fecht, H-J; Louzguine-Luzgin, D V; Inoue, A

    2011-03-04

    Owing to their low elastic moduli, high specific strength and excellent processing characteristics in the undercooled liquid state, metallic glasses are promising materials for applications in micromechanical systems. With miniaturization of metallic mechanical components down to the micrometer scale, the importance of a native oxide layer on a glass surface is increasing. In this work we use TEM and XPS to characterize the structure and properties of the native oxide layer grown on Ni(62)Nb(38) metallic glass and their evolution after annealing in air. The thickness of the oxide layer almost doubled after annealing. In both cases the oxide layer is amorphous and consists predominantly of Nb oxide. We investigate the friction behavior at low loads and in ambient conditions (i.e. at T = 295 K and 60% air humidity) of both as-cast and annealed samples by friction force microscopy. After annealing the friction coefficient is found to have significantly increased. We attribute this effect to the increase of the mechanical stability of the oxide layer upon annealing.

  1. Resistive switching characteristics of Pt/TaOx/HfNx structure and its performance improvement

    Directory of Open Access Journals (Sweden)

    Qigang Zhou

    2013-03-01

    Full Text Available The refractory transition metal nitride (TMN film Hafnium nitride (HfNx was successfully prepared on silicon-based substrates as bottom electrodes for resistive random access memory (RRAM cells in Pt (top/metal oxide/ HfNx (bottom sandwich structure. The reproducible resistive switching (RS characteristics of the memory cells were studied systematically for RRAM applications. The advantages of adopting HfNx instead of Pt as bottom electrode material were demonstrated, including the improvement of the low resistive state value, the RS endurance and the uniformity of RS parameters. The composition and chemical bonding states of the prepared HfNx was analyzed by X-ray photoelectron spectroscopy (XPS technique. The nitrogen content in the HfNx and the Gibbs free energy of the corresponding metal oxide formation has great influences on the RS properties. The oxygen reservoir ability and diffusion barrier effect of the HfNx play a key role in the RS performance improvement of the RRAM devices.

  2. Toward underlying reasons for rice starches having low viscosity and high amylose: physiochemical and structural characteristics.

    Science.gov (United States)

    Zhang, Changquan; Zhu, Lijia; Shao, Ke; Gu, Minghong; Liu, Qiaoquan

    2013-05-01

    To understand the reasons for low starch viscosity in rice variety Q11 (Qing-lu-zhan 11), the physiochemical and structural characteristics of flours and starches were investigated and compared with another rice cultivar with similar high amylose but normal viscosity. Our results showed that residual α-amylase activity and proteins were not the major causes of low starch viscosity in Q11 rice. Homogeneous small granule size and lower swelling power of high-amylose Q11 rice starches was one reason for the low swelling volume and thus the low pasting property. Q11 starch paste contained some partially swollen granules, which could increase the fluidity and thus cause the low paste viscosity. The small gelatinization enthalpy might be due to the lower crystallinity in Q11 starches. Moreover, Q11 starches consisted of more amylose with short chains, but also amylopectin with fewer short chains (DP 11-21) and more long chains (DP 22-54), which might be other important factors contributing to the low viscosity of Q11 starches. These data can add to our understanding of the relationships between low viscosity and physiochemical properties, and will be helpful in elucidating the underlying mechanism of formation of low starch viscosity, as well as applications for low-viscosity rice starches. © 2012 Society of Chemical Industry.

  3. In situ hydroxyapatite nanofiber growth on calcium borate silicate ceramics in SBF and its structural characteristics.

    Science.gov (United States)

    Pu, Yinfu; Huang, Yanlin; Qi, Shuyun; Chen, Cuili; Seo, Hyo Jin

    2015-10-01

    A novel calcium silicate borate Ca11Si4B2O22 ceramic was firstly prepared by the conventional solid-state reaction. In vitro hydroxyapatite mineralization was investigated by soaking the ceramics in simulated body fluid (SBF) solutions at body temperature (37 °C) for various time periods. Scanning electron microscopy (SEM) and X-ray diffraction analysis (XRD) measurements were applied to investigate the samples before and after the immersion of ceramics in SBF solution. The elemental compositions of a hydroxyapatite layer on the ceramics during the mineralization were confirmed by X-ray energy-dispersive spectra (EDS). Meanwhile, the bending strength and elastic modulus of Ca11Si4B2O22 ceramics were also measured, which indicate that the biomaterials based on Ca11Si4B2O22 ceramics possess bioactivity and might be a potential candidate as biomaterials for hard tissue repair. The bioactive mineralization ability was evaluated on the base of its crystal structural characteristics, i.e., silanol (Si-OH) and B-OH groups can be easily induced on the surface of Ca11Si4B2O22 ceramics soaked in SBF solutions. Copyright © 2015 Elsevier B.V. All rights reserved.

  4. New discussion on the structure characteristics for uranium formation in Xuemisitan-Tuoli area

    International Nuclear Information System (INIS)

    Ye Fawang; Zhang Jielin; Fang Maolong; Zhang Chuan

    2012-01-01

    Based on the ETM, QuickBird middle and high resolution remote sensing images as the main information source, and combining other geo-scientific datum, such as geology, geophysical and geochemical isotopic, the structural characteristics of uranium mineralization in Xuemisitan-Tuoli area, Xinjiang Autonomous region, were studied in the paper. Main contents includes: enhancement of remote sensing images, geological interpretation of faults, analysis of fault activity time and period. and the relationship between the fault and uranium mineralization. Above researches show the uranium mineralization points of Taergen and Beijingqi existed in Tuoli area and the Baiyanghe uranium deposit in Xuemisitan area were discovered to located in the same NE-trending fault. The fault was of properties of rock-control, mineralization-control, and basin-control In the same time, Baiyanghe uranium deposit has key relationship with the NE part of NE-trending in terms of spatial distribution and formation time. According to above result, the intersection area between N3-Trending main fault and NW-Trending miner fault located in the south of Baiyanghe deposit were considered as the favorable region for uranium formation. (authors)

  5. Perspectives on the production, structural characteristics and potential applications of bioplastics derived from polyhydroxyalkanoates.

    Science.gov (United States)

    Albuquerque, Priscilla B S; Malafaia, Carolina B

    2018-02-01

    Since the last two decades, the use of synthetic materials has increased and become more frequent in this capitalist system. Polymers used as raw materials are usually disposed very rapidly and considered serious damages when they return to the environment. Because of this behaviour, there was an increasing in the global awareness by minimizing the waste generated, in addition to the scientific community concern for technological alternatives to solve this problem. Alternatively, biodegradable polymers are attracting special interest due to their inherent properties, which are similar to the ones of the conventional plastics. Bioplastics covers plastics made from renewable resources, including plastics that biodegrade under controlled conditions at the end of their use phase. Polyhydroxyalkanoates (PHAs) are polyesters composed of hydroxy acids, synthesized by a variety of microorganisms as intracellular carbon and energy storage. These environmentally friendly biopolymers have excellent potential in domestic, agricultural, industrial and medical field, however their production on a large scale is still limited. This review considered the most recent scientific publications on the production of bioplastics based on PHAs, their structural characteristics and the exploitation of different renewable sources of raw materials. In addition, there were also considered the main biotechnological applications of these biopolymers. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. Structural and functional characteristics of myocard in patients with different forms of atrial fibrillation

    Directory of Open Access Journals (Sweden)

    L. I. Vasilyeva

    2015-02-01

    Full Text Available Aim. To study structural and functional characteristics of myocard in patients with different forms of atrial fibrillation. Atrial fibrillation is the most prevalent arrhythmia in clinical practice. Atrial fibrillation is a progressive disease: the duration of paroxysms increases over time and paroxysmal atrial fibrillation transforms to persistent, the last one becomes refractory to pharmacological and electrical cardioversion in time and transforms to permanent. So assessment of myocardial remodeling in patients with persistent and permanent atrial fibrillation is very actual. Methods and results. According to the aim of the study 133 patients with persistent atrial fibrillation and 100 patients with permanent atrial fibrillation were included into the study. Echocardiographic parameters of left and right atria function were studied. Conclusion. It was found that patients with persistent and permanent atrial fibrillation are characterized with both left and right atrias remodeling. Remodeling of the atrias is less pronounced in patients with permanent atrial fibrillation in comparison with persistent atrial fibrillation patients and arrhythmia recurrence.

  7. White matter structure and clinical characteristics of stroke patients: A diffusion tensor MRI study.

    Science.gov (United States)

    Ueda, Ryo; Yamada, Naoki; Kakuda, Wataru; Abo, Masahiro; Senoo, Atsushi

    2016-03-15

    Fractional anisotropy has been used in many studies that examined post-stroke changes in white matter. This study was performed to clarify cerebral white matter changes after stroke using generalized fractional anisotropy (GFA). White matter structure was visualized using diffusion tensor imaging in 72 patients with post-stroke arm paralysis. Exercise-related brain regions were examined in cerebral white matter using GFA. The relationship between GFA and clinical characteristics was examined. Overall, the mean GFA of the lesioned hemisphere was significantly lower than that of the non-lesioned hemisphere (PBrodmann area 5 of the non-lesioned hemisphere. Age correlated negatively with GFA in Brodmann areas 5 and 7 of the lesioned hemisphere. Though these results may be due to a decrease in the frequency of use of the paralyzed limb over time, GFA overall was significantly and negatively affected by the subject's age. The GFA values of patients with paralysis of the dominant hand were significantly different from those of patients with paralysis of the nondominant hand in Brodmann areas 4 and 6 of the non-lesioned hemisphere and Brodmann area 4 of the lesioned hemisphere (P<0.05). The stroke size and location were not associated with GFA differences. Differences between the GFA of the lesioned and non-lesioned hemispheres varied depending on the affected brain region, age at onset of paralysis, and paralysis of the dominant or non-dominant hand. Copyright © 2016 Elsevier B.V. All rights reserved.

  8. Structural and photovoltaic characteristics of hierarchical ZnO nanostructures electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Saleem, Muhammad, E-mail: saleem.malikape@gmail.com [Department of Physics, COMSATS Institute of Information Technology, Lahore 54000 (Pakistan); Key Laboratory of Optoelectronic Technology and Systems of the Education Ministry of China, Chongqing University, Chongqing 400044 (China); Fang, L. [Key Laboratory of Optoelectronic Technology and Systems of the Education Ministry of China, Chongqing University, Chongqing 400044 (China); Shaukat, Saleem F.; Ahmad, M. Ashfaq [Department of Physics, COMSATS Institute of Information Technology, Lahore 54000 (Pakistan); Raza, Rizwan, E-mail: razahussaini786@gmail.com [Department of Physics, COMSATS Institute of Information Technology, Lahore 54000 (Pakistan); Akhtar, Majid Niaz; Jamil, Ayesha; Aslam, Samia [Department of Physics, COMSATS Institute of Information Technology, Lahore 54000 (Pakistan); Abbas, Ghazanfar [Department of Physics, COMSATS Institute of Information Technology, Islamabad 44000 (Pakistan)

    2015-04-15

    Highlights: • Hierarchically ZnO nanostructures electrodes were grown using hot plate magnetic stirring at different growth reaction temperature. • We have investigated the effect of working temperature of 160°, 170°, 180°, and 190° on the growth mechanism of nanospheres and on the power conversion efficiency of DSSCs. • ZnO nanospheres with perfect aggregation show superior power conversion efficiency of 1.24% which is about 83% higher than nanoparticles DSSC. • An obvious vogue is that the overall power conversion efficiency decreases as the degree of the spherical aggregation is gradually destroyed. - Abstract: Structural and photovoltaic characteristics of hierarchical ZnO nanostructures solar cell have been studied in relation to growth reaction temperature. It is found that the hierarchical ZnO nanostructures network to act not only as large surface area substrates but also as a transport medium for electrons injected from the dye molecules. The incident photon-to-current conversion efficiency is decreased by increasing the growth reaction temperature of ZnO electrodes. The best conversion efficiency of a 0.25 cm{sup 2} cell is measured to be 1.24% under 100 mW cm{sup −2} irradiation.

  9. Effects of solvent on the solution properties, structural characteristics and properties of silk sericin.

    Science.gov (United States)

    Jo, Yoon Nam; Um, In Chul

    2015-07-01

    Sericin films have attracted much attention from researchers in biomedical and cosmetic fields because of its unique properties, including good cytocompatibility and its promotion of wound healing. However, poor mechanical properties of sericin films have restricted its application in these fields. In this study, a new solvent, formic acid, was used to fabricate sericin solutions and films. The effects of formic acid on the structural characteristics and mechanical properties of the sericin solutions and films were examined and compared with water. The sericin/formic acid solution showed fewer aggregated sericin molecules, resulting in a lower turbidity than that of the sericin/water solution. In addition, the gelation of the sericin solution was retarded in formic acid compared to that of water. Sericin films cast from the formic acid solution exhibited a much higher crystallinity index than that produced from water. The tensile strength and elongation of the sericin films cast from the formic acid solution were more than double that of the sericin films cast from water. It is expected that the more stable sericin solution and high-crystallinity sericin films, which have significantly improved mechanical properties, produced by using formic acid as the solvent could be utilized in biomedical and cosmetic applications. Copyright © 2015 Elsevier B.V. All rights reserved.

  10. A research on the mechanical property, work efficiency and structural characteristics of heavyweight concrete

    International Nuclear Information System (INIS)

    Ishimura, Kikuo; Ooue, Minoru; Noda, Shizuo; Suzuki, Keiichi; Ishii, Takakazu; Nakazawa, Kouichi; Mitsugi, Shiro.

    1991-01-01

    Generally thickness is increased in walls and slabs to improve the shielding ability of normal concrete in the buildings in nuclear power plants. On the other hand, the decrease of thickness of members and the decrease of building size can be expected by the adoption of heavy weight concrete. But there are little principal members such as shear walls using heavy weight concrete. Therefore, the data related to the mechanical properties and the construction method are not sufficient. This study was carried out to examine the properties and the structural characteristics of heavy weight concrete, and to establish the construction method. The selection of aggregate, the properties of aggregate and the properties of heavy weight concrete are reported. Pumping test was carried out with two kinds of the mixing proportion, and its procedure and the results are shown. The heavy weight concrete was placed as wall specimens, and its procedure and the results are described. The static loading test on shear wall specimens was carried out, and its procedure and the results are reported. Magnetite and hematite ores adopted as the aggregate caused no problem. (K.I.)

  11. Nano-structural characteristics and optical properties of silver chiral nano-flower sculptured thin films

    International Nuclear Information System (INIS)

    Savaloni, Hadi; Haydari-Nasab, Fatemh; Malmir, Mariam

    2011-01-01

    Silver chiral nano-flowers with 3-, 4- and 5-fold symmetry were produced using oblique angle deposition method in conjunction with the rotation of sample holder with different speeds at different sectors of each revolution corresponding to symmetry order of the acquired nano-flower. Atomic force microscopy (AFM) and field emission scanning electron microscopy (FESEM), were employed to obtain morphology and nano-structure of the films. Optical characteristics of silver chiral nano-flower thin films were obtained using single beam spectrophotometer with both s- and p-polarization incident light at 30 o and 70 o incidence angles and at different azimuthal angles (φ). Optical spectra showed both TM (TDM (transverse dipole mode) and TQM (transverse quadruple mode)) and LM (longitudinal mode) Plasmon resonance peaks. For 3- and 4-fold symmetry chiral nano-flowers the s-polarization extinction spectra obtained at different azimuthal angles did not show significant change in the Plasmon peak position while 5-fold symmetry chiral nano-flower showed a completely different behavior, which may be the result of increased surface anisotropy, so when the φ angle is changed the s-polarization response from the surface can change more significantly than that for lower symmetries. In general, for 3-, 4- and 5-fold symmetry chiral nano-flowers a sharp peak at lower wavelengths ( o incidence angle.

  12. Synthesis of Manganese Tetroxide Nanoparticles Using Precipitation and Study of Its Structure and Optical Characteristics

    Directory of Open Access Journals (Sweden)

    Reza Shokoohi

    2016-12-01

    Full Text Available Considering extensive applications of manganese tetroxide nanoparticles in various industries due to its special properties, conducting studies on how to achieve more suitable ways to produce smaller nanoparticles is of great importance. In this study, nanoparticles of manganese tetroxide (Mn3O4 were synthesized by a co-precipitation method. In order to determine the characteristics of the structure, size, and specific surface of the resulting nanoparticles, techniques such as XRD, BET, BJH, FESEM, and FTIR were employed. Also, the nanoparticles were quantified with EDS and their colony size was examined using DLS experiments. The findings revealed a production of crystalline manganese tetroxide nanoparticles with a space group of 141/amd (S.G. (141 and a molecular weight of 228.81 with the international code of ICSD Card # 89 - 4837. The specific surface area was 32.147 m2/g with a pore volume of 0.1041 cm3/g. The XRD and EDX analyses verify the production of the Mn3O4 nanoparticles. The size of the nanostructures is approximately 19 nm. The method used in this study could produce the Mn3O4 nanoparticles in a much easier way without the need for surfactants. Compared to the nanoparticles produced in other studies, the size of the nanoparticles produced in the present study is remarkably smaller. Moreover, less amount of the metal salt was used.

  13. A zero density change phase change memory material: GeTe-O structural characteristics upon crystallisation.

    Science.gov (United States)

    Zhou, Xilin; Dong, Weiling; Zhang, Hao; Simpson, Robert E

    2015-06-11

    Oxygen-doped germanium telluride phase change materials are proposed for high temperature applications. Up to 8 at.% oxygen is readily incorporated into GeTe, causing an increased crystallisation temperature and activation energy. The rhombohedral structure of the GeTe crystal is preserved in the oxygen doped films. For higher oxygen concentrations the material is found to phase separate into GeO2 and TeO2, which inhibits the technologically useful abrupt change in properties. Increasing the oxygen content in GeTe-O reduces the difference in film thickness and mass density between the amorphous and crystalline states. For oxygen concentrations between 5 and 6 at.%, the amorphous material and the crystalline material have the same density. Above 6 at.% O doping, crystallisation exhibits an anomalous density change, where the volume of the crystalline state is larger than that of the amorphous. The high thermal stability and zero-density change characteristic of Oxygen-incorporated GeTe, is recommended for efficient and low stress phase change memory devices that may operate at elevated temperatures.

  14. Understanding characteristics in multivariate traffic flow time series from complex network structure

    Science.gov (United States)

    Yan, Ying; Zhang, Shen; Tang, Jinjun; Wang, Xiaofei

    2017-07-01

    Discovering dynamic characteristics in traffic flow is the significant step to design effective traffic managing and controlling strategy for relieving traffic congestion in urban cities. A new method based on complex network theory is proposed to study multivariate traffic flow time series. The data were collected from loop detectors on freeway during a year. In order to construct complex network from original traffic flow, a weighted Froenius norm is adopt to estimate similarity between multivariate time series, and Principal Component Analysis is implemented to determine the weights. We discuss how to select optimal critical threshold for networks at different hour in term of cumulative probability distribution of degree. Furthermore, two statistical properties of networks: normalized network structure entropy and cumulative probability of degree, are utilized to explore hourly variation in traffic flow. The results demonstrate these two statistical quantities express similar pattern to traffic flow parameters with morning and evening peak hours. Accordingly, we detect three traffic states: trough, peak and transitional hours, according to the correlation between two aforementioned properties. The classifying results of states can actually represent hourly fluctuation in traffic flow by analyzing annual average hourly values of traffic volume, occupancy and speed in corresponding hours.

  15. Morphogenetic and structural characteristics of guinea grass tillers at different ages under intermittent stocking

    Directory of Open Access Journals (Sweden)

    Rodrigo Amorim Barbosa

    2012-07-01

    Full Text Available The objective of this research was to assess morphogenetic and structural characteristics of tillers of guinea grass cv. Tanzania at different ages. The pastures of guinea grass were managed in six pasture conditions related to the combination of three frequencies (90, 95, and 99% light interception and two post-grazing heights (25 and 50 cm. In these six pastures conditions, three tiller ages were evaluated (young, mature, and old. The design was of completely randomized block with three replications. Young tillers exhibited higher leaf appearance rate and leaf elongation rate and, consequently, higher final leaf length and number of live leaves than mature and old tillers, regardless of the pasture condition. On pastures managed with 90 or 95% light interception associated with a post-grazing height of 25 cm, old tillers presented longer leaf lifespan than young and mature ones. There is a progressive reduction in the vigor of growth of pastures of guinea grass cv. Tanzania with advancing tiller age.

  16. The Social and Consumer Standards and Guarantees in Ukraine: the Current Structural and Dynamic Characteristics

    Directory of Open Access Journals (Sweden)

    Kolesov Oleksandr S.

    2017-04-01

    Full Text Available The article attempts to generalize the theoretical approaches to the social guarantees and standards as economic categories. The classification of social guarantees is provided. The dynamic parameters for development of the social and consumer standards adopted in Ukraine were considered. An evaluation of the real poverty level under the system of criteria was carried out. The inconsistency of methods for the poverty evaluation adopted by the Ministry of Social Policy of Ukraine and contradiction of its individual indicators has been indicated. The structural characteristics of the population’s income have been determined. The relevance of the existing social guarantees to their real value in today’s economic conditions have been analyzed. Tendencies of falling of the welfare level of population, resulting in a decline in the consumer demand and a narrowing of the domestic market for goods and services, have been identified. The need to take measures to stimulate small businesses, to overcome corruption, and to deregulate the economy has been indicated.

  17. Simulation and Measurement of Neuroelectrodes' Characteristics with Integrated High Aspect Ratio Nano Structures

    Directory of Open Access Journals (Sweden)

    Christoph Nick

    2015-07-01

    Full Text Available Improving the interface between electrodes and neurons has been the focus of research for the last decade. Neuroelectrodes should show small geometrical surface area and low impedance for measuring and high charge injection capacities for stimulation. Increasing the electrochemically active surface area by using nanoporous electrode material or by integrating nanostructures onto planar electrodes is a common approach to improve this interface. In this paper a simulation approach for neuro electrodes' characteristics with integrated high aspect ratio nano structures based on a point-contact-model is presented. The results are compared with experimental findings conducted with real nanostructured microelectrodes. In particular, effects of carbon nanotubes and gold nanowires integrated onto microelectrodes are described. Simulated and measured impedance properties are presented and its effects onto the transfer function between the neural membrane potential and the amplifier output signal are studied based on the point-contact-model. Simulations show, in good agreement with experimental results, that electrode impedances can be dramatically reduced by the integration of high aspect ratio nanostructures such as gold nanowires and carbon nanotubes. This lowers thermal noise and improves the signal-to-noise ratio for measuring electrodes. It also may increase the adhesion of cells to the substrate and thus increase measurable signal amplitudes.

  18. Quantitative analysis of characteristics of structure of metal on ''Kvantimet-720''

    International Nuclear Information System (INIS)

    Voronin, Yu.V.; Doronicheva, V.P.; Zueva, I.B.; Charchyan, G.Z.

    1977-01-01

    A method is presented for determining the volume characteristics of the grain structure of a metal with the aid of the automatic ''Kvantimet-720'' apparatus. The sizes of grains of a metallic section are measured in the apparatus with the aid of random secants (chords). The scanning of a single image field is equivalent to the analysis of 720 parallel secants. The subject of the investigation are specimens of molybdenum after deformation and annealing, prepared as metallographic sections and etched chemically to bring forth the grain boundaries. The employed conditions are based on the principle of a ''largest'' chord, i.e., in each field of the image the ''Kvantimet-720'' takes accont of chords of dimensions larger than a dimension specified on each of the 8 channels of modulus of the size distributior. The obtained histograms of the distribution of true dimensions of grains indicate that the asymmetry of the distribution of grains after the deformation and the low-temperature annealings is due to a pronounced difference in the size of grains, said difference falling off in the course of recrystallization

  19. Caesalpinia echinata Lam. - BRAZILWOOD: THERMAL BEHAVIOR, STRUCTURAL CHARACTERISTICS, AND RESISTANCE TO BIODETERIORATION IN STATIC SYSTEMS

    Directory of Open Access Journals (Sweden)

    Ana Paula Pinto Pinheiro

    Full Text Available ABSTRACT Wood is the best-known biological material used as a raw material since the dawn of mankind until present days. As a natural and renewable composite, its lifetime is limited by the degradation of its basic elements. This degradation can be caused by chemical reactions or by biological agents capable of accelerating the process of deterioration. In this work, the wear, thermal, and micro-structural characteristics, as also the bio-degradation behavior in static systems, of the wood species Brazilwood (Caesalpinia echinata were studied under laboratory conditions in order to use these woods in design. The results show that Brazilwood has a good visual performance after abrasion test, since it has not shown any representative roughness increase. In addition, Brazilwood has high level of crystallinity of, approximately, 68% and was almost insensitive to fungi attack, forming only 5.3 x 103 CFU/mL. Besides, its texture did not change due to exposure to water or sweat.

  20. Novel Biocompatible Thermoresponsive Poly(N-vinyl Caprolactam)/Clay Nanocomposite Hydrogels with Macroporous Structure and Improved Mechanical Characteristics.

    Science.gov (United States)

    Shi, Kun; Liu, Zhuang; Yang, Chao; Li, Xiao-Ying; Sun, Yi-Min; Deng, Yi; Wang, Wei; Ju, Xiao-Jie; Xie, Rui; Chu, Liang-Yin

    2017-07-05

    Poly(N-vinyl caprolactam) (PVCL) hydrogels usually suffer from the imporous structure and poor mechanical characteristics as well as the toxicity of cross-linkers, although PVCL itself is biocompatible. In this paper, novel biocompatible thermoresponsive poly(N-vinyl caprolactam)/clay nanocomposite (PVCL-Clay) hydrogels with macroporous structure and improved mechanical characteristics are developed for the first time. The macroporosity in the hydrogel is introduced by using Pickering emulsions as templates, which contain N-vinyl caprolactam (VCL) monomer as dispersed phase and clay sheets as stabilizers at the interface. After polymerization, macropores are formed inside the hydrogels with the residual unreacted VCL droplets as templates. The three-dimensional PVCL polymer networks are cross-linked by the clay nanosheets. Due to the nanocomposite structure, the hydrogel exhibits better mechanical characteristics in comparison to the conventional PVCL hydrogels cross-linked by N,N'-methylene diacrylamide (BIS). The prepared PVCL-Clay hydrogel possesses remarkable temperature-responsive characteristics with a volume phase transition temperature (VPTT) around 35 °C, and provides a feasible platform for cell culture. With macroporous structure and good mechanical characteristics as well as flexible assembly performance, the proposed biocompatible thermoresponsive PVCL-Clay nanocomposite hydrogels are ideal material candidates for biomedical, analytical, and other applications such as entrapment of enzymes, cell culture, tissue engineering, and affinity and displacement chromatography.

  1. Characteristics of behind armor blunt trauma produced by bullets with different structural materials: an experimental study

    Directory of Open Access Journals (Sweden)

    Ling-qing WANG

    2013-07-01

    The biomechanical response and injury characteristics are different of rifle bullets with different structural materials shooting at protected precordium in Landrace. Research of the effect of bullet structural materials on BABT may make a significant contribution to the treatment in battlefield and design of weapon and armor.

  2. Household structure, maternal characteristics and childhood mortality in rural sub-Saharan Africa.

    Science.gov (United States)

    Akinyemi, Joshua O; Chisumpa, Vesper H; Odimegwu, Clifford O

    2016-01-01

    The household dynamics of childhood mortality in rural areas of sub-Saharan Africa is less researched despite the fact that mortality rates are almost two times that of urban settings. This study aimed to investigate the influence of household structure on childhood mortality while controlling for household and maternal characteristics in rural sub-Saharan Africa. Eight countries with recent demographic and health survey data not earlier than the year 2010 were selected, two from each sub-region of sub-Saharan Africa. The outcome variables were risk of infant and child death while the main independent variables included sex of household head and household structure. Descriptive statistics were generated for all variables. Mortality rates disaggregated by sex of household head and household structure were estimated using the Kaplan-Meier method. Cox proportional hazard regression models were fitted to investigate the relationship between the outcome and explanatory variables in each country. The percentage of children living in female-headed households (FHHs) ranged from 5.2% in Burkina Faso to 49.1% in Namibia while those living in extended family households ranged from 27.4% in Rwanda to 59.9% in Namibia. Multivariate hazard regression showed that, in the majority of the countries, there was no significant relationship between living in FHHs and childhood mortality, but the direction and magnitude of effect varied across countries. A significant negative effect of FHHs on infant mortality was observed in Burkina Faso (HR=1.64, 95% confidence interval (CI): 1.09-2.48) and Zambia (HR=1.49, 95%CI: 1.02-2.17). Likewise, children in extended family households had a higher risk of child mortality in Burkina Faso (HR=1.33, 95%CI: 1.04-1.69) and Zambia (HR=1.59, 95%CI: 1.02-2.49). There was not much difference in the effect of FHHs between infancy (0-11 months) and childhood (12-59 months) in the other countries. The pooled adjusted hazard ratio (HR) showed that the risk

  3. Structure and physical characteristics of pumice from the climactic eruption of Mount Mazama (Crater Lake), Oregon

    Science.gov (United States)

    Klug, C.; Cashman, K.; Bacon, C.

    2002-01-01

    The vesicularity, permeability, and structure of pumice clasts provide insight into conditions of vesiculation and fragmentation during Plinian fall and pyroclastic flow-producing phases of the ???7,700 cal. year B.P. climactic eruption of Mount Mazama (Crater Lake), Oregon. We show that bulk properties (vesicularity and permeability) can be correlated with internal textures and that the clast structure can be related to inferred changes in eruption conditions. The vesicularity of all pumice clasts is 75-88%, with >90% interconnected pore volume. However, pumice clasts from the Plinian fall deposits exhibit a wider vesicularity range and higher volume percentage of interconnected vesicles than do clasts from pyroclastic-flow deposits. Pumice permeabilities also differ between the two clast types, with pumice from the fall deposit having higher minimum permeabilities (???5??10-13 m2) and a narrower permeability range (5-50??10-13 m2) than clasts from pyroclastic-flow deposits (0.2-330??10-13 m2). The observed permeability can be modeled to estimate average vesicle aperture radii of 1-5 ??m for the fall deposit clasts and 0.25-1 ??m for clasts from the pyroclastic flows. High vesicle number densities (???109 cm-3) in all clasts suggest that bubble nucleation occured rapidly and at high supersaturations. Post-nucleation modifications to bubble populations include both bubble growth and coalescence. A single stage of bubble nucleation and growth can account for 35-60% of the vesicle population in clasts from the fall deposits, and 65-80% in pumice from pyroclastic flows. Large vesicles form a separate population which defines a power law distribution with fractal dimension D=3.3 (range 3.0-3.5). The large D.value, coupled with textural evidence, suggests that the large vesicles formed primarily by coalescence. When viewed together, the bulk properties (vesicularity, permeability) and textural characteristics of all clasts indicate rapid bubble nucleation followed by

  4. The adsorption characteristics and porous structure of bentonite adsorbents as determined from the adsorption isotherms of benzene vapor

    Directory of Open Access Journals (Sweden)

    LEPA STOJANOVSKA

    2004-02-01

    Full Text Available The adsorption of benzene vapor on natural and acid activated bentonites was treated by the theory of volume filling of micropores. The micropore volume and characteristic values of the free energy of adsorption were determined from the adsorption isotherms. The Dubinin–Radushkevish–Stoeckli and Dubinin–Astakhov equations were used for this purpose. The results showed that natural bentonite has a more homogeneous micropore structure than the acid activated ones. The characteristic values of the free energy of adsorption for the natural bentonite were higher than those of the acid activated bentonite. This is due to differences in its structure and the pore size.

  5. Categorization of nano-structured titanium dioxide according to physicochemical characteristics and pulmonary toxicity

    Directory of Open Access Journals (Sweden)

    Naoki Hashizume

    Full Text Available A potentially useful means of predicting the pulmonary risk posed by new forms of nano-structured titanium dioxide (nano-TiO2 is to use the associations between the physicochemical properties and pulmonary toxicity of characterized forms of TiO2. In the present study, we conducted intratracheal administration studies in rats to clarify the associations between the physicochemical characteristics of seven characterized forms of TiO2 and their acute or subacute pulmonary inflammatory toxicity. Examination of the associations between the physicochemical characteristics of the TiO2 and the pulmonary inflammatory responses they induced revealed (1 that differences in the crystallinity or shape of the TiO2 particles were not associated with the acute pulmonary inflammatory response; (2 that particle size was associated with the acute pulmonary inflammatory response; and (3 that TiO2 particles coated with Al(OH3 induced a greater pulmonary inflammatory response than did non-coated particles. We separated the seven TiO2 into two groups: a group containing the six TiO2 with no surface coating and a group containing the one TiO2 with a surface coating. Intratracheal administration to rats of TiO2 from the first group (i.e., non-coated TiO2 induced only acute pulmonary inflammatory responses, and within this group, the acute pulmonary inflammatory response was equivalent when the particle size was the same, regardless of crystallinity or shape. In contrast, intratracheal administration to rats of the TiO2 from the second group (i.e., the coated TiO2 induced a more severe, subacute pulmonary inflammatory response compared with that produced by the non-coated TiO2. Since alteration of the pulmonary inflammatory response by surface treatment may depend on the coating material used, the pulmonary toxicities of coated TiO2 need to be further evaluated. Overall, the present results demonstrate that physicochemical properties may be useful for predicting the

  6. Emission Characteristics of Organic Light-Emitting Diodes and Organic Thin-Films with Planar and Corrugated Structures

    Directory of Open Access Journals (Sweden)

    Mao-Kuo Wei

    2010-04-01

    Full Text Available In this paper, we review the emission characteristics from organic light-emitting diodes (OLEDs and organic molecular thin films with planar and corrugated structures. In a planar thin film structure, light emission from OLEDs was strongly influenced by the interference effect. With suitable design of microcavity structure and layer thicknesses adjustment, optical characteristics can be engineered to achieve high optical intensity, suitable emission wavelength, and broad viewing angles. To increase the extraction efficiency from OLEDs and organic thin-films, corrugated structure with micro- and nano-scale were applied. Microstructures can effectively redirects the waveguiding light in the substrate outside the device. For nanostructures, it is also possible to couple out the organic and plasmonic modes, not only the substrate mode.

  7. Germination characteristics of Rhinanthus minor influence field emergence, competitiveness and potential use in restoration projects.

    Science.gov (United States)

    Marin, M; Laverack, G; Matthews, S; Powell, A A

    2018-02-10

    The facultative root hemi-parasite Rhinanthus minor is often used in grassland habitat restoration projects to regulate ecosystem structure and function. Its impact on community productivity and diversity as a function of resource supply, sward composition and management has been widely investigated. However, there is a lack of information about the possible influence of seed quality on the efficacy of the hemi-parasite. Ten seed lots from commercial sources were sown in the field and their germination characteristics were investigated in the laboratory. Seeds from four lots were also germinated and sown in pots alongside plants of two host species, Lotus corniculatus and Holcus lanatus. Plant establishment, height and flowering density were evaluated for the hemi-parasite, while plant biomass was measured for both R. minor and its host. Two aspects of seed quality influenced the field emergence of seed lots of R. minor, the radicle emergence (%) and the length of the lag period from the beginning of imbibition to germination (mean germination time), which indicates seed vigour. A longer lag period (lower vigour) was associated with higher levels of seedling mortality and lower plant vigour, in terms of plant height and biomass accumulation and was also reflected in the parasitic impact of the seed lots. Seed quality, specifically germination and vigour, can influence the establishment, survival, subsequent plant productivity and parasitic impact of R. minor in vegetation restoration projects. Seed quality is discussed as a key factor to consider when predicting the impact of the hemi-parasite on community productivity and diversity. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  8. Classes de perfilhos na composição do índice de área foliar em pastos de capim-elefante Tiller classes on leaf area index composition in elephant grass swards

    Directory of Open Access Journals (Sweden)

    Carlos Augusto Brandão de Carvalho

    2007-04-01

    Full Text Available O trabalho foi conduzido de outubro de 2002 a abril de 2003, em Coronel Pacheco, MG, com o objetivo de avaliar os efeitos da altura do resíduo pós-pastejo (50 e 100 cm sobre a radiação fotossinteticamente ativa (RFA interceptada pelo dossel e o coeficiente de extinção luminosa; a contribuição relativa de classes de perfilhos (basais e aéreos sobre o índice de área foliar (IAF e o acúmulo de forragem (AF, em pastos de capim-elefante (Pennisetum purpureum Schum. cv. Napier manejados com intervalos de 30 dias entre pastejos. Foi usado o delineamento blocos completos ao acaso e um arranjo de parcelas subdivididas com quatro repetições, com alturas de resíduo alocadas nas parcelas e as classes de perfilhos nas subparcelas. O IAF, a interceptação da RFA e o coeficiente de extinção luminosa foram influenciados pela altura do resíduo pós-pastejo. As interceptações da RFA foram maiores no verão do que na primavera, em pastos manejados com resíduo de 100 cm. As variações do IAF e da interceptação da RFA não estiveram associados, durante todos os ciclos de pastejo. O IAF e o AF apresentaram variações sazonais, relacionadas à participação de perfilhos basais e aéreos, na população de perfilhos do pasto.The work was carried out at Coronel Pacheco, MG, Brazil, from October 2002 to April 2003 with the objective of evaluating the effects of two post-grazing residues (50 and 100 cm on the interception of photosynthetically active radiation (PAR and light extinction coefficient; relative contribution of tiller classes (basal and aerial to leaf area index (LAI and herbage accumulation of elephant grass swards (Pennisetum purpureum Schum. cv. Napier subjected to grazing intervals of 30 days. The experimental design was a complete randomized block, and treatments were allocated to experimental units using a split plot arrangement, with four replicates. Post-grazing residues were allocated to plots and tiller classes to sub plots

  9. Dinâmica do acúmulo de matéria seca em pastagens de Tifton 85 sob pastejo Dry matter accumulation dynamics in grazed Tifton 85 bermudagrass swards

    Directory of Open Access Journals (Sweden)

    Luiz Felipe de Moura Pinto

    2001-09-01

    Full Text Available O acúmulo de forragem é o resultado líquido de dois processos concomitantes e antagônicos: o crescimento e a senescência e morte de tecidos. O presente trabalho teve por objetivo avaliar o processo de produção de forragem através do estudo de seus componentes; crescimento e senescência. Os tratamentos corresponderam a quatro condições de pasto caracterizadas pelas alturas de 5, 10, 15 e 20 cm, mantidas constante através do pastejo por ovinos em regime de lotação contínua e taxa de lotação variável. O delineamento experimental utilizado foi o de blocos completos casualizados, com quatro repetições. Foram avaliadas as seguintes respostas: alongamento de hastes, alongamento de folhas, senescência, filocrono e o número de folhas por perfilho. Os resultados revelaram um padrão estacional de produção de forragem, com as maiores taxas de crescimento e senescência sendo observadas nas alturas de pasto mais altas (15 e 20 cm. O filocrono variou com a época do ano e com a altura de pasto, revelando uma alta associação com variações em temperatura do ar, disponibilidade de água no solo e índice de área foliar do pasto. As alturas de 15 e 20 cm resultaram na maior produção de matéria seca. Os mesmos princípios e relações originalmente descritos para plantas forrageiras de clima temperado são válidos para plantas tropicais dentro do contexto das limitações fisiológicas e de ambiente inerentes para cada condição.Herbage dry matter accumulation from forage plants results from the balance between growth and senescence. Agronomic practices may influence both processes in different ways and, therefore, alter the quantitative and qualitative patterns of dry matter production. This study aimed at evaluating the process of dry matter accumulation through measurements of growth and senescence. Experimental treatments corresponded to four sward state conditions (5, 10, 15 and 20 cm of sward surface height - SSH generated

  10. Supercooling and cold energy storage characteristics of nano-media in ball-packed porous structures

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    Zhao Qunzhi

    2015-04-01

    Full Text Available The presented experiments aimed to study the supercooling and cold-energy storage characteristics of nanofluids and water-based nano-media in ball-packed porous structures (BPS. Titanium dioxide nanoparticles (TiO2 NPs measuring 20nm and 80nm were used as additives and sodium dodecyl benzene sulphonate (SDBS was used as anionic surfactant. The experiments used different concentrations of nanofluid, distilled with BPS of different spherical diameter and different concentrations of nano-media, and were conducted 20 times. Experimental results of supercooling were analysed by statistical methods. Results show that the average and peak supercooling degrees of nanofluids and nano-media in BPS are lower than those of distilled water. For the distilled water in BPS, the supercooling degree decreases on the whole with the decrease of the ball diameter. With the same spherical diameter (8mm of BPS, the supercooling degree of TiO2 NPs measuring 20nm is lower than the supercooling degree of distilled water in BPS. Step-cooling experiments of different concentrations of nanofluids and nano-media in BPS were also conducted. Results showed that phase transition time is reduced because of the presence of TiO2 NPs. The BPS substrate and the NPs enhance the heat transfer. Distilled water with a porous solid base and nanoparticles means the amount of cold-energy storage increases and the supercooling degree and the total time are greatly reduced. The phase transition time of distilled water is about 3.5 times that of nano-media in BPS.

  11. Structure dependent resistivity and dielectric characteristics of tantalum oxynitride thin films produced by magnetron sputtering

    Energy Technology Data Exchange (ETDEWEB)

    Cristea, D., E-mail: daniel.cristea@unitbv.ro [Department of Materials Science, Transilvania University, 500036 Brasov (Romania); Crisan, A. [Department of Materials Science, Transilvania University, 500036 Brasov (Romania); Cretu, N. [Electrical Engineering and Applied Physics Department, Transilvania University, 500036 Brasov (Romania); Borges, J. [Centro de Física, Universidade do Minho, Campus de Gualtar, 4710 - 057 Braga (Portugal); Instituto Pedro Nunes, Laboratório de Ensaios, Desgaste e Materiais, Rua Pedro Nunes, 3030-199 Coimbra (Portugal); SEG-CEMUC, Mechanical Engineering Department, University of Coimbra, 3030-788 Coimbra (Portugal); Lopes, C.; Cunha, L. [Centro de Física, Universidade do Minho, Campus de Gualtar, 4710 - 057 Braga (Portugal); Ion, V.; Dinescu, M. [National Institute for Lasers, Plasma and Radiation Physics, Lasers Department, “Photonic Processing of Advanced Materials” Group, PO Box MG-16, RO 77125 Magurele-Bucharest (Romania); Barradas, N.P. [Centro de Ciências e Tecnologias Nucleares, Instituto Superior Técnico, Universidade de Lisboa, E.N. 10 ao km 139,7, 2695-066 Bobadela LRS (Portugal); Alves, E. [Instituto de Plasmas e Fusão Nuclear, Instituto Superior Técnico, Universidade de Lisboa, E.N. 10 ao km 139,7, 2695-066 Bobadela LRS (Portugal); Apreutesei, M. [MATEIS Laboratory-INSA de Lyon, 21 Avenue Jean Capelle, 69621 Villeurbanne cedex (France); Université de Lyon, Institut des Nanotechnologies de Lyon INL-UMR5270, CNRS, Ecole Centrale de Lyon, Ecully F-69134 (France); Munteanu, D. [Department of Materials Science, Transilvania University, 500036 Brasov (Romania)

    2015-11-01

    Highlights: • Tantalum oxynitride thin films have been deposited by magnetron sputtering, in various configurations. • The rising of the reactive gases mixture flow has the consequence of a gradual increase in the non-metallic content in the films, which results in a 10 orders of magnitude resistivity domain. • The higher resistivity films exhibit dielectric constants up to 41 and quality factors up to 70. - Abstract: The main purpose of this work is to present and to interpret the change of electrical properties of Ta{sub x}N{sub y}O{sub z} thin films, produced by DC reactive magnetron sputtering. Some parameters were varied during deposition: the flow of the reactive gases mixture (N{sub 2} and O{sub 2}, with a constant concentration ratio of 17:3); the substrate voltage bias (grounded, −50 V or −100 V) and the substrate (glass, (1 0 0) Si or high speed steel). The obtained films exhibit significant differences. The variation of the deposition parameters induces variations of the composition, microstructure and morphology. These differences cause variation of the electrical resistivity essentially correlated with the composition and structural changes. The gradual decrease of the Ta concentration in the films induces amorphization and causes a raise of the resistivity. The dielectric characteristics of some of the high resistance Ta{sub x}N{sub y}O{sub z} films were obtained in the samples with a capacitor-like design (deposited onto high speed steel, with gold pads deposited on the dielectric Ta{sub x}N{sub y}O{sub z} films). Some of these films exhibited dielectric constant values higher than those reported for other tantalum based dielectric films.

  12. Structural Characteristics & Dielectric Properties of Tantalum Oxide Doped Barium Titanate Based Materials

    Directory of Open Access Journals (Sweden)

    Rubayyat Mahbub

    2012-11-01

    Full Text Available In this research, the causal relationship between the dielectric properties and the structural characteristics of 0.5 & 1.0 mol% Ta2O5 doped BaTiO3 based ceramic materials were investigated under different sintering conditions. Dielectric properties and microstructure of BaTio3 ceramics were significantly influenced by the addition of a small amount of Ta2O5. Dielectric properties were investigated by measuring the dielectric constant (k as a function of temperature and frequency. Percent theoretical density (%TD above 90% was achieved for 0.5 and 1.0 mol% Ta2O5 doped BaTiO3. It was observed that the grain size decreased markedly above a doping concentration of 0·5 mol% Ta2O5. Although fine grain size down to 200-300nm was attained, grain sizes in the range of 1-1.8µm showed the most alluring properties. The fine-grain quality and high density of the Ta2O5 doped BaTiO3 ceramic resulted in tenfold increase of dielectric constant. Stable value of dielectric constant as high as 13000-14000 was found in the temperature range of  55 to 80°C, for 1.0 mol% Ta2O5 doped samples with corresponding shift of Curie point to ~82°C. Experiments divulged that incorporation of a proper content of Ta2O5 in BaTiO3 could control the grain growth, shift the Curie temperature and hence significantly improve the dielectric property of the BaTiO3 ceramics.

  13. STRUCTURAL CHARACTERISTICS & DIELECTRIC PROPERTIES OF TANTALUM OXIDE DOPED BARIUM TITANATE BASED MATERIALS

    Directory of Open Access Journals (Sweden)

    Md. Fakhrul Islam

    2013-01-01

    Full Text Available In this research, the causal relationship between the dielectric properties and the structural characteristics of 0.5 & 1.0 mole % Ta2O5 doped BaTiO3 based ceramic materials were investigated under different sintering conditions. Dielectric properties and microstructure of BaTio3 ceramics were significantly influenced by the addition of a small amount of Ta2O5. Dielectric properties were investigated by measuring the dielectric constant (k as a function of temperature and frequency. Percent theoretical density (%TD above 90 % was achieved for 0.5 and 1.0 mole %Ta2O5 doped BaTiO3. It was observed that the grain size decreased markedly above a doping concentration of 0.5 mole % Ta2O5. Although fine grain size down to 200 - 300 nm was attained, grain sizes in the range of 1-1.8µm showed the most alluring properties. The fine-grain quality and high density of the Ta2O5 doped BaTiO3 ceramic resulted in tenfold increase of dielectric constant. Stable value of dielectric constant as high as 13000 - 14000 was found in the temperature range of 55 to 80 °C, for 1.0 mole % Ta2O5 doped samples with corresponding shift of Curie point to ~82 °C. Experiments divulged that incorporation of a proper content of Ta2O5 in BaTiO3 could control the grain growth, shift the Curie temperature and hence significantly improve the dielectric property of the BaTiO3 ceramics.

  14. Nano-structural characteristics and optical properties of silver chiral nano-flower sculptured thin films

    Energy Technology Data Exchange (ETDEWEB)

    Savaloni, Hadi, E-mail: savaloni@khayam.ut.ac.ir [Department of Physics, University of Tehran, North-Kargar Street, Tehran (Iran, Islamic Republic of); Haydari-Nasab, Fatemh; Malmir, Mariam [Department of Physics, University of Tehran, North-Kargar Street, Tehran (Iran, Islamic Republic of)

    2011-08-15

    Silver chiral nano-flowers with 3-, 4- and 5-fold symmetry were produced using oblique angle deposition method in conjunction with the rotation of sample holder with different speeds at different sectors of each revolution corresponding to symmetry order of the acquired nano-flower. Atomic force microscopy (AFM) and field emission scanning electron microscopy (FESEM), were employed to obtain morphology and nano-structure of the films. Optical characteristics of silver chiral nano-flower thin films were obtained using single beam spectrophotometer with both s- and p-polarization incident light at 30{sup o} and 70{sup o} incidence angles and at different azimuthal angles ({phi}). Optical spectra showed both TM (TDM (transverse dipole mode) and TQM (transverse quadruple mode)) and LM (longitudinal mode) Plasmon resonance peaks. For 3- and 4-fold symmetry chiral nano-flowers the s-polarization extinction spectra obtained at different azimuthal angles did not show significant change in the Plasmon peak position while 5-fold symmetry chiral nano-flower showed a completely different behavior, which may be the result of increased surface anisotropy, so when the {phi} angle is changed the s-polarization response from the surface can change more significantly than that for lower symmetries. In general, for 3-, 4- and 5-fold symmetry chiral nano-flowers a sharp peak at lower wavelengths (<450 nm) is observed in the s-polarization spectra, while in addition to this peak a broad peak at longer wavelengths (i.e., LM) observed in the p-polarization spectra, which is more dominant for 70{sup o} incidence angle.

  15. Agronomic, morphogenic and structural characteristics of Marandu grass in silvopastoral systems composed of babassu palm and grass monoculture

    Directory of Open Access Journals (Sweden)

    Rosane Cláudia Rodrigues

    2016-09-01

    Full Text Available This study evaluated the agronomic, morphogenic and structural characteristics of palisadegrass (Urochloa brizantha in silvopastoral systems (SSP’s composed of babassu palms (Attalea speciosa and grass monoculture in the Pre-Amazon region of the state of Maranhão, Brazil. The study followed a completely randomized design, with the arrangement in split plots with six replicates for the evaluation of agronomic characteristics and 30 repetitions for the morphogenic and structural characteristics. The plots were divided into pasture environments with different palm densities (monoculture, 80, 131, 160 palms.ha-¹, and the subplots were divided into the different seasons (rainy and dry. Total forage production was affected (P 0.05 by pastoral system during the rainy season, but in the dry period, higher responses were obtained in SSPs. Overall, SSPs with 80 palms.ha-¹ favored the agronomic characteristics of pastures. Morphogenic and structural characteristics were favored by increasing palm densities. Leaf senescence and duration were not affected by the system.

  16. Research on the Band Gap Characteristics of Two-Dimensional Phononic Crystals Microcavity with Local Resonant Structure

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    Mao Liu

    2015-01-01

    Full Text Available A new two-dimensional locally resonant phononic crystal with microcavity structure is proposed. The acoustic wave band gap characteristics of this new structure are studied using finite element method. At the same time, the corresponding displacement eigenmodes of the band edges of the lowest band gap and the transmission spectrum are calculated. The results proved that phononic crystals with microcavity structure exhibited complete band gaps in low-frequency range. The eigenfrequency of the lower edge of the first gap is lower than no microcavity structure. However, for no microcavity structure type of quadrilateral phononic crystal plate, the second band gap disappeared and the frequency range of the first band gap is relatively narrow. The main reason for appearing low-frequency band gaps is that the proposed phononic crystal introduced the local resonant microcavity structure. This study provides a good support for engineering application such as low-frequency vibration attenuation and noise control.

  17. Uso do método do disco e da altura da planta para estimar a massa de forragem em relvado de Cynodon spp. Rising plate meter and plant height to estimate the herbage mass in Cynodon ssp. Swards

    Directory of Open Access Journals (Sweden)

    Domingos Sávio Campos Paciullo

    2004-04-01

    Full Text Available A altura das plantas (AP e a altura comprimida da vegetação por disco (AD foram usadas para estimativas da massa de forragem antes e depois do pastejo em uma pastagem mista de capim-coastcross-1 (Cynodon dactylon (L. Pears e capim-estrela (Cynodon nlenfuensis var. nlenfuensis, manejada rotativamente. Foram estabelecidas equações de regressão entre a altura das plantas ou a altura comprimida da vegetação por disco de raio conhecido e o peso seco de forragem. Para a massa de forragem antes do pastejo, os coeficientes de determinação variaram de 0,70 a 0,87 com a AD e de 0,58 a 0,70 com a AP. Para a massa de forragem após o pastejo, observaram-se piores ajustes das equações, tendo em vista os baixos coeficientes de determinação (0,13 a 0,46. A AD apresentou melhores resultados para estimar a massa de forragem antes do pastejo. As técnicas apresentaram baixa confiabilidade para estimativas da massa de forragem após o pastejo.The techniques of plant height (PH and rising plate meter (RPM were used to estimate the herbage mass before and after grazing in Cynodon dactylon (L. Pears and Cynodon nlemfuensis var. nlenfuensis mixture pasture, under rotational system. Regression equations between sward surface heigth or compressed sward heigth by disk and the herbage dry weight were established. To herbage mass before grazing, the coefficients of determination (r² ranged from 0.70 to 0.87 for RPM and from 0.58 to 0.70 for PH. The residual herbage mass was poorly associated with heights of plant or disk (r² values varying from 0.13 to 0.46. The RPM showed better results to estimate the herbage mass before grazing than PH. The techniques could not be recomended to estimated herbage mass after grazing.

  18. Effects of structural and dynamic family characteristics on the development of depressive and aggressive problems during adolescence. The TRAILS study

    NARCIS (Netherlands)

    Sijtsema, J. J.; Oldehinkel, A. J.; Veenstra, René; Verhulst, F. C.; Ormel, J.

    Both structural (i.e., SES, familial psychopathology, family composition) and dynamic (i.e., parental warmth and rejection) family characteristics have been associated with aggressive and depressive problem development. However, it is unclear to what extent (changes in) dynamic family

  19. Effects of structural and dynamic family characteristics on the development of depressive and aggressive problems during adolescence. The TRAILS study

    NARCIS (Netherlands)

    Sijtsema, J.J.; Oldehinkel, A.J.; Veenstra, R.; Verhulst, F.C.; Ormel, J.

    2014-01-01

    Both structural (i.e., SES, familial psychopathology, family composition) and dynamic (i.e., parental warmth and rejection) family characteristics have been associated with aggressive and depressive problem development. However, it is unclear to what extent (changes in) dynamic family

  20. INFLUENCE OF MODIFICATION ON THE STRUCTURE AND CHARACTERISTICS OF THE STAINLESS STEEL 12X18H10TL

    Directory of Open Access Journals (Sweden)

    I. V. Zemskov

    2004-01-01

    Full Text Available There are given the results of investigation of influence of modification by ferrocerium, FS30RZM30B, FSMG, modifier MN, developed in BNTU, ferromolybdenum on the structure and characteristics of the steel 12X18H10TL.

  1. THE INFLUENCE OF FIRMS STRUCTURAL CHARACTERISTICS ON THE DEGREE OF AGGLOMERATION ECONOMIES ENJOYED AMONGST FIRMS IN THE LAGOS REGION, NIGERIA

    Directory of Open Access Journals (Sweden)

    FAGBOHUNKA Adejompo

    2015-12-01

    Full Text Available Agglomeration economies is a potent tool in socio-economic revamping, rejuvenation and sustenance of regions, this is as a result of the impulse it transmitted through the multiplier effect it is capable of generated. Therefore, this paper underscores the influence of firms structural characteristics on the degree of agglomeration economies enjoyed amongst firms, using the Lagos region as a case study. The first stage in the collection of primary data involves the reconnaissance survey, thereafter one hundred and three questionnaire were administered in twelve industrial estates; one questionnaire in each of the firm. The paper reveals the following structural characteristics as germane to industrial enterprise; age of firms, areal plant size (m², capacity utilization (in percentage, and Labour size and firms investment. The paper has also found out those agglomeration economies enjoyed ranges from transportation, labour, power supply, to joint water supply. The Roy’s Largest Root test employed to test for the significance of the canonical correlations at 0.05 significant levels shows the calculated F-value 3.5247 and the tabulated F-value 2.90. This suggests that the degree of agglomeration economies enjoyed by firms is significantly explained by the size and structural characteristics of the firms. The paper therefore recommends more and active government participation in the industrial scene, given the necessary support for the expansion of firm’s structural characteristics which will lead to increase agglomeration economies enjoyed by these firms.

  2. The structure and amphipathy characteristics of modified γ-zeins by SDS or alkali in conjunction with heating treatment.

    Science.gov (United States)

    Dong, Shi-Rong; Xu, Hong-Hua; Tan, Jun-Yan; Xie, Ming-Ming; Yu, Guo-Ping

    2017-10-15

    γ-Zein was modified by SDS or alkali combined with heating treatments in water and in 70% ethanol to change its amphipathic properties and explore the relationship between amphipathic characteristic and structure. γ-Zein water-dispersibility was dramatically increased via alkali or SDS combined with heating treatments, but their ethanol-dispersibilities were significantly different during ethanol evaporation. High both water-dispersibility and ethanol-dispersibility were found from alkali modified γ-zein while high water-dispersibility but low ethanol-dispersibility were obtained from SDS modified γ-zein, indicating that alkali modified γ-zein had better amphipathic characteristic compared with SDS modified γ-zein. Alkali modified γ-zein with higher amphipathic characteristic possessed higher structural inversion ability since it was easy to recover its native state as solvent changing from water to ethanol, contrary to SDS modified γ-zeins whose amphipathic characteristic was not improved. Moreover, the higher structural inversion ability of alkali modified γ-zein depended on the recovery capability of α-helix structure as solvent altering. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Erosion rates as a potential bottom-up control of forest structural characteristics in the Sierra Nevada Mountains.

    Science.gov (United States)

    Milodowski, David T; Mudd, Simon M; Mitchard, Edward T A

    2015-01-01

    The physical characteristics of landscapes place fundamental constraints on vegetation growth and ecosystem function. In actively eroding landscapes, many of these characteristics are controlled by long-term erosion rates: increased erosion rates generate steeper topography and reduce the depth and extent of weathering, limiting moisture storage capacity and impacting nutrient availability. Despite the potentially important bottom-up control that erosion rates place on substrate characteristics, the relationship between the two is largely unexplored. We investigate spatial variations in aboveground biomass (AGB) across a structurally diverse mixed coniferous/deciduous forest with an order of magnitude erosion-rate gradient in the Northern Californian Sierra Nevada, USA, using high resolution LiDAR data and field plots. Mean basin slope, a proxy for erosion rate, accounts for 32% of variance in AGB within our field area (P erosion rate as a potentially important, but hitherto unappreciated, control on AGB and forest structure.

  4. Características estruturais e acúmulo de forragem em capim-tanzânia sob pastejo rotativo Structural characteristics and herbage accumulation of Tanzania guineagrass subjected to rotational stocking

    Directory of Open Access Journals (Sweden)

    Anderson de Moura Zanine

    2011-11-01

    characteristics and herbage accumulation of tanzania guineagrass (Panicum maximum cv. Tanzania under rotational grazing and subjected to combinations of two grazing frequencies (time for the canopy to intercept 90 or 95% of the incident light and two post-grazing heights (30 or 50 cm. Treatments were assigned to experimental units according to a 2 × 2 factorial arrangement in a completely randomized design, with three replications. Sward heights at pre-grazing were consistent during the experimental period and were of around 65 and 75 cm, for 90% and 95% of light interception (LI, respectively. Pastures managed with post-grazing height of 50 cm and 90% of LI had higher number of grazing cycles when compared with those submitted to post-grazing height of 30 cm and 95% of LI. Herbage mass production was higher in summer, intermediate in late spring and lowest in fall and winter and early spring. Herbage mass and lamina leaves production were higher in pastures managed with post-grazing height of 30 cm when compared with post-grazing height of 50 cm. Nevertheless, the effects of frequency on herbage mass production were associated with the post-grazing height used. The LI levels (90 or 95% did not affect leaf lamina production. The combinations of frequency and severity of grazing resulted in little variation in the morphological composition of forage, except in the autumn, when there was a higher percentage of dead material in pastures managed with post-grazing height of 50 cm when compared with those with post-grazing height of 30 cm. The rotational grazing of tanzania guineagrass should be initiated when canopy intercepts 95% of incident light until a post-grazing height of 30 cm. When necessary and in order to generate flexibility in grazing management, the tanzania guineagrass can be grazed with 90% of light interception.

  5. Evolution processes of the corrosion behavior and structural characteristics of plasma electrolytic oxidation coatings on AZ31 magnesium alloy

    Science.gov (United States)

    Chen, Dong; Wang, Ruiqiang; Huang, Zhiquan; Wu, Yekang; Zhang, Yi; Wu, Guorui; Li, Dalong; Guo, Changhong; Jiang, Guirong; Yu, Shengxue; Shen, Dejiu; Nash, Philip

    2018-03-01

    Evolution processes of the corrosion behavior and structural characteristics of the plasma electrolytic oxidation (PEO) coated AZ31 magnesium alloy were investigated by using scanning electron microscope (SEM) equipped with energy dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), potentio-dynamic polarization curves and electrochemical impedance spectroscopy (EIS) measurements. Detached coating samples were fabricated by an electrochemical method and more details of the internal micro-structure of coatings were clearly observed on the fractured cross-section morphologies of the samples compared to general polished cross-section morphologies. Evolution mechanisms of the coating corrosion behavior in relation to the evolution of micro-structural characteristics were discussed in detail.

  6. Understanding effects of chemical structure on azo dye decolorization characteristics by Aeromonas hydrophila

    Energy Technology Data Exchange (ETDEWEB)

    Hsueh, Chung-Chuan [Department of Chemical and Materials Engineering, National I-Lan University, I-Lan 260, Taiwan (China); Chen, Bor-Yann, E-mail: bychen@niu.edu.tw [Department of Chemical and Materials Engineering, National I-Lan University, I-Lan 260, Taiwan (China); Yen, Chia-Yi [Department of Chemical and Materials Engineering, National I-Lan University, I-Lan 260, Taiwan (China)

    2009-08-15

    This novel comparative study tended to disclose how the molecular structures present in seven azo dyes including two types of azo dyes (i.e., naphthol type azo dyes - Reactive Black 5 (RB 5), Reactive Blue 171 (RB 171), Reactive Green 19 (RG19), Reactive Red 198 (RR198), Reactive Red 141 (RR141) and non-naphthol type azo dyes - Direct Yellow 86 (DY86), Reactive Yellow 84 (RY84)) affected color removal capability of Aeromonas hydrophila. Generally speaking, the decolorization rate of naphthol type azo dye with hydroxyl group at ortho to azo bond was faster than that of non-naphthol type azo dye without hydroxyl group, except of RG19. The azo dyes with electron-withdrawing groups (e.g., sulfo group in RR198, RB5 and RR141) would be easier to be decolorized than the azo dyes with the electron-releasing groups (e.g., -NH-triazine in RB171 and RG19). In addition, the azo dyes containing more electron-withdrawing groups (e.g., RR198, RB5 and RR141) showed significantly faster rate of decolorization. The azo dyes with electron-withdrawing groups (e.g., sulfo group) at para and ortho to azo bond (e.g., RR198, RB5 and RR141) could be more preferred for color removal than those at meta (e.g., DY86 and RY84). The former azo dyes with para and ortho sulfo group provided more effective resonance effects to withdraw electrons from azo bond, causing azo dyes to be highly electrophilic for faster rates of reductive biodecolorization. However, since the ortho substituent caused steric hindrance near azo linkage(s), azo dyes with para substituent could be more favorable (e.g., SO{sub 2}(CH{sub 2}){sub 2}SO{sub 4}{sup -} in RR198 and RB5) than those with ortho substituent (e.g., sulfo group at RR141) for decolorization. Thus, the ranking of the position for the electron-withdrawing substituent in azo dyes to escalate decolorization was para > ortho > meta. This study suggested that both the positions of substituents on the aromatic ring and the electronic characteristics of

  7. Sodar study of the characteristics of presumable big toroid structures above an overheated surface

    International Nuclear Information System (INIS)

    Valery, K

    2008-01-01

    A set of sodars allowed to investigate the spatial variability of meso-scale organized structures under conditions of strong convection and weak wind. The distribution of velocity within the structures and the structure typical sizes have been determined as a result of processing of experimental data

  8. Effect of estrogen on tendon collagen synthesis, tendon structural characteristics, and biomechanical properties in postmenopausal women

    DEFF Research Database (Denmark)

    Hansen, Mette; Kongsgaard, Mads; Holm, Lars

    2009-01-01

    and fibril characteristics were determined by MRI and transmission electron microscopy, whereas tendon biomechanical properties were measured during isometric maximal voluntary contraction by ultrasound recording. Tendon FSR was markedly higher in ERT users (P

  9. Application of Structural Equation Modelling to Assess the Impact of Entrepreneurial Characteristics on Students' Entrepreneurial Intentions

    NARCIS (Netherlands)

    Karimi, S.; Biemans, H.J.A.; Lans, T.; Arasti, Z.; Chizari, M.; Mulder, M.

    2011-01-01

    Entrepreneurship is considered to be an important driver for economic growth. Entrepreneurial intention is, based on the literature, suggested to be a predictor of future entrepreneurial behaviour. Entrepreneurial intention is influenced by several factors including entrepreneurial characteristics.

  10. Distribuição horizontal e taxas de crescimento, senescência e desfolhação de azevém perene e festuca, puros e em associação Horizontal distribution and growth, senescence and defoliation fluxes of perennial ryegrass and tall fescue pure and mixed swards

    Directory of Open Access Journals (Sweden)

    Andréa Machado Groff

    2002-09-01

    Full Text Available O experimento foi realizado no INRA (Institut National de la Recherche Agronomique em Theix, França. Duas gramíneas (azevém perene e festucaforam semeadas em caixas (0,13 m² usando-se três distribuições horizontais do pasto (pura, linhas alternadas e faixas alternadas e três intervalos de desfolhações (3,5, 7 e 14 dias, com quatro repetições por tratamento. Quatro meses após a semeadura, a cada data de desfolhação, as caixas foram oferecidas, individualmente, a quatro ovelhas secas e retiradas após a realização de 340 bocados.m-2. Para cada gramínea estudaram-se a densidade populacional e a massa de perfilhos, a altura e a produção de matéria seca, a profundidade e a massa do bocado e as taxas de crescimento, senescência e desfolhação. A maior altura do pasto, gerada por desfolhações menos freqüentes, promoveu a realização de bocados mais profundos e de maior massa. Por outro lado, em desfolhações mais freqüentes a altura do pasto foi mantida mais baixa, e a profundidade e massa do bocado foram menores. A distribuição horizontal das plantas promoveu respostas diferenciadas em relação as taxas de crescimento, senescência e desfolhação. Quando em linhas alternadas a festuca teve a taxa de crescimento limitada, provavelmente desfavorecida pela competição.The experiment was carried in INRA (Institut National de la Recherche Agronomique at Theix, France. Two grasses (perennial ryegrass and tall fescue were grown in sward boxes (0,13 m², using three different sward horizontal distribution (pure, alternate rows and alternate strips and three defoliation intervals (3,5, 7 and 14 days between two successive defoliation with four replications. Four months after sowing, at defoliation date, sward boxes were offered to four individual dry ewes and removed after 340 bites.m-2 had been taken. For each grass species, the population density and the tiller mass, sward height, herbage production, bite depth and bite mass

  11. Population Genetic Structure of Glycyrrhiza inflata B. (Fabaceae) Is Shaped by Habitat Fragmentation, Water Resources and Biological Characteristics.

    Science.gov (United States)

    Yang, Lulu; Chen, Jianjun; Hu, Weiming; Yang, Tianshun; Zhang, Yanjun; Yukiyoshi, Tamura; Zhou, Yanyang; Wang, Ying

    2016-01-01

    Habitat fragmentation, water resources and biological characteristics are important factors that shape the genetic structure and geographical distribution of desert plants. Analysis of the relationships between these factors and population genetic variation should help to determine the evolutionary potential and conservation strategies for genetic resources for desert plant populations. As a traditional Chinese herb, Glycyrrhiza inflata B. (Fabaceae) is restricted to the fragmented desert habitat in China and has undergone a dramatic decline due to long-term over-excavation. Determining the genetic structure of the G. inflata population and identifying a core collection could help with the development of strategies to conserve this species. We investigated the genetic variation of 25 G. inflata populations based on microsatellite markers. A high level of population genetic divergence (FST = 0.257), population bottlenecks, reduced gene flow and moderate genetic variation (HE = 0.383) were detected. The genetic distances between the populations significantly correlated with the geographical distances, and this suggests that habitat fragmentation has driven a special genetic structure of G. inflata in China through isolation by distance. STRUCTURE analysis showed that G. inflata populations were structured into three clusters and that the populations belonged to multiple water systems, which suggests that water resources were related to the genetic structure of G. inflata. In addition, the biological characteristics of the perennial species G. inflata, such as its long-lived seeds, asexual reproduction, and oasis ecology, may be related to its resistance to habitat fragmentation. A core collection of G. inflata, that included 57 accessions was further identified, which captured the main allelic diversity of G. inflata. Recent habitat fragmentation has accelerated genetic divergence. The population genetic structure of G. inflata has been shaped by habitat

  12. Differentially categorized structural brain hubs are involved in different microstructural, functional, and cognitive characteristics and contribute to individual identification.

    Science.gov (United States)

    Wang, Xindi; Lin, Qixiang; Xia, Mingrui; He, Yong

    2018-04-01

    Very little is known regarding whether structural hubs of human brain networks that enable efficient information communication may be classified into different categories. Using three multimodal neuroimaging data sets, we construct individual structural brain networks and further identify hub regions based on eight widely used graph-nodal metrics, followed by comprehensive characteristics and reproducibility analyses. We show the three categories of structural hubs in the brain network, namely, aggregated, distributed, and connector hubs. Spatially, these distinct categories of hubs are primarily located in the default-mode system and additionally in the visual and limbic systems for aggregated hubs, in the frontoparietal system for distributed hubs, and in the sensorimotor and ventral attention systems for connector hubs. These categorized hubs exhibit various distinct characteristics to support their differentiated roles, involving microstructural organization, wiring costs, topological vulnerability, functional modular integration, and cognitive flexibility; moreover, these characteristics are better in the hubs than nonhubs. Finally, all three categories of hubs display high across-session spatial similarities and act as structural fingerprints with high predictive rates (100%, 100%, and 84.2%) for individual identification. Collectively, we highlight three categories of brain hubs with differential microstructural, functional and, cognitive associations, which shed light on topological mechanisms of the human connectome. © 2018 Wiley Periodicals, Inc.

  13. Structural Model for the Effects of Environmental Elements on the Psychological Characteristics and Performance of the Employees of Manufacturing Systems

    Directory of Open Access Journals (Sweden)

    Arturo Realyvásquez

    2016-01-01

    Full Text Available 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.

  14. Structural Model for the Effects of Environmental Elements on the Psychological Characteristics and Performance of the Employees of Manufacturing Systems.

    Science.gov (United States)

    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.

  15. Characteristics of structural loess strength and preliminary framework for joint strength formula

    OpenAIRE

    Rong-jian Li; Jun-ding Liu; Rui Yan; Wen Zheng; Sheng-jun Shao

    2014-01-01

    The strength of structural loess consists of the shear strength and tensile strength. In this study, the stress path, the failure envelope of principal stress (Kf line), and the strength failure envelope of structurally intact loess and remolded loess were analyzed through three kinds of tests: the tensile strength test, the uniaxial compressive strength test, and the conventional triaxial shear strength test. Then, in order to describe the tensile strength and shear strength of structural lo...

  16. Improving stability and strength characteristics of framed structures with nonlinear behavior

    Science.gov (United States)

    Pezeshk, Shahram

    1990-01-01

    In this paper an optimal design procedure is introduced to improve the overall performance of nonlinear framed structures. The design methodology presented here is a multiple-objective optimization procedure whose objective functions involve the buckling eigenvalues and eigenvectors of the structure. A constant volume with bounds on the design variables is used in conjunction with an optimality criterion approach. The method provides a general tool for solving complex design problems and generally leads to structures with better limit strength and stability. Many algorithms have been developed to improve the limit strength of structures. In most applications geometrically linear analysis is employed with the consequence that overall strength of the design is overestimated. Directly optimizing the limit load of the structure would require a full nonlinear analysis at each iteration which would be prohibitively expensive. The objective of this paper is to develop an algorithm that can improve the limit-load of geometrically nonlinear framed structures while avoiding the nonlinear analysis. One of the novelties of the new design methodology is its ability to efficiently model and design structures under multiple loading conditions. These loading conditions can be different factored loads or any kind of loads that can be applied to the structure simultaneously or independently. Attention is focused on optimal design of space framed structures. Three-dimensional design problems are more complicated to carry out, but they yield insight into real behavior of the structure and can help avoiding some of the problems that might appear in planar design procedure such as the need for out-of-plane buckling constraint. Although researchers in the field of structural engineering generally agree that optimum design of three-dimension building frames especially in the seismic regions would be beneficial, methods have been slow to emerge. Most of the research in this area has dealt

  17. Structural and optical characteristics of GaN/ZnO coaxial nanotube heterostructure arrays for light-emitting device applications

    International Nuclear Information System (INIS)

    Hong, Young Joon; Jeon, Jong-Myeong; Kim, Miyoung; Jeon, Seong-Ran; Ho Park, Kyung; Yi, Gyu-Chul

    2009-01-01

    We report on the structural and optical characteristics of position-controlled GaN/ZnO coaxial nanotube heterostructure and GaN/In x Ga 1-x N coaxial nanotube quantum structure arrays for light-emitting diode (LED) applications. The GaN/ZnO nanotube heterostructures were fabricated by growing a GaN layer on the entire surface of position-controlled ZnO nanotube arrays using low-pressure metal-organic vapour-phase epitaxy. As determined by transmission-electron microscopy (TEM), an abrupt and coherent interface between the core ZnO and the GaN overlayer was observed. The optical characteristics of heteroepitaxial GaN/ZnO nanotube heterostructures were also investigated using cathodoluminescence (CL) spectroscopy. This position-controlled growth of high-quality single crystalline GaN/ZnO coaxial nanotube heterostructures allowed the fabrication of artificial arrays of high-quality GaN-based coaxial quantum structures by the heteroepitaxial growth of GaN/In x Ga 1-x N multiple quantum wells along the circumference of the GaN/ZnO nanotubes. The optical and structural characteristics of the position-controlled GaN/In x Ga 1-x N coaxial nanotube quantum structures were investigated by using CL spectroscopy and TEM analysis, respectively. The green LED microarrays were successfully fabricated by the controlled heteroepitaxial coaxial coatings of GaN/In x Ga 1-x N coaxial nanotube quantum structures and the outermost Mg-doped p-type GaN layer onto the GaN/ZnO coaxial nanotube heterostructures, presumably implying that the position-controlled growth of high-quality GaN/ZnO coaxial nanotube heterostructure arrays provides a general and rational route of integrating vertical nanodevices for nanoscale electronics and optoelectronics.

  18. Analysis of bandgap characteristics of two-dimensional periodic structures by using the source-model technique.

    Science.gov (United States)

    Ludwig, Alon; Leviatan, Yehuda

    2003-08-01

    We introduce a solution based on the source-model technique for periodic structures for the problem of electromagnetic scattering by a two-dimensional photonic bandgap crystal slab illuminated by a transverse-magnetic plane wave. The proposed technique takes advantage of the periodicity of the slab by solving the problem within the unit cell of the periodic structure. The results imply the existence of a frequency bandgap and provide a valuable insight into the relationship between the dimensions of a finite periodic structure and its frequency bandgap characteristics. A comparison shows a discrepancy between the frequency bandgap obtained for a very thick slab and the bandgap obtained by solving the corresponding two-dimensionally infinite periodic structure. The final part of the paper is devoted to explaining in detail this apparent discrepancy.

  19. Socio-demographic characteristics affecting sport tourism choices: A structural model

    Directory of Open Access Journals (Sweden)

    Nataša Slak Valek

    2014-03-01

    Full Text Available Background: Effective tourism management in the field of sports tourism requires an understanding of differences in socioeconomic characteristics both within and between different market segments. Objective: In the broad tourism market demographic characteristics have been extensively analyzed for differences in destination choices, however little is known about demographic factors affecting sport tourists' decisions. Methods: A sample of Slovenian sports tourists was analyzed using data from a comprehensive survey of local and outbound tourist activity conducted by the Statistical Office of the Republic of Slovenia in 2008. After data weighting the information for 353,783 sports related trips were available for analysis. The research model adopted suggests that four socio-demographic characteristics (gender, age, level of education and income significantly affect a tourist's choice of sports related travel either locally within Slovenia or to a foreign country. Furthermore the destination (local or foreign has an influence on the choice of the type of accommodation selected and the tourist's total expenditure for the trip. For testing the first part of our model (the socio-demographic characteristics effects a linear regression was used, and for the final part of the model (the selection of accommodation type and travel expenditure t-test were applied. Results: The result shows the standardized β regression coefficients are all statistically significant at the .001 level for the tested socio-demographic characteristics and also the overall regression model was statistically significant at .001 level. Conclusions: With these results the study confirmed that all the selected socio-demographic characteristics have a significant influence on the sport-active tourist when choosing between a domestic and foreign tourism destination which in turn affect the type of accommodation chosen and the level of expenditure while travelling.

  20. Concurrent improvement in optical and electrical characteristics by using inverted pyramidal array structures toward efficient Si heterojunction solar cells

    KAUST Repository

    Wang, Hsin Ping

    2016-03-02

    The Si heterojunction (SHJ) solar cell is presently the most popular design in the crystalline Si (c-Si) photovoltaics due to the high open-circuit voltages (V). Photon management by surface structuring techniques to control the light entering the devices is critical for boosting cell efficiency although it usually comes with the V loss caused by severe surface recombination. For the first time, the periodic inverted pyramid (IP) structure fabricated by photolithography and anisotropic etching processes was employed for SHJ solar cells, demonstrating concurrent improvement in optical and electrical characteristics (i.e., short-circuit current density (J) and V). Periodic IP structures show superior light-harvesting properties as most of the incident rays bounce three times on the walls of the IPs but only twice between conventional random upright pyramids (UPs). The high minority carrier lifetime of the IP structures after a-Si:H passivation results in an enhanced V by 28 mV, showing improved carrier collection efficiency due to the superior passivation of the IP structure over the random UP structures. The superior antireflective (AR) ability and passivation results demonstrate that the IP structure has the potential to replace conventional UP structures to further boost the efficiency in solar cell applications.

  1. Influence of the external heating type in the morphological and structural characteristics of alumina powder prepared by combustion reaction

    International Nuclear Information System (INIS)

    Cordeiro, V.V.; Freitas, N.L.; Viana, K.M.S.; Dias, G.; Costa, A.C.F.M.; Lira, H.L.

    2009-01-01

    The aim of this work is to evaluate the influence of the external heating in the morphological and structural characteristics of the alumina powder prepared by combustion reaction. It was evaluated different types of external heating: muffle oven, microwave oven and ceramic plate with electrical spiral resistance. The powders were prepared according to the propellants and explosives theory, using urea in the stoichiometric proportion (Φe = 1). During the synthesis parameters such as flame combustion time and temperature were measured. The structural and morphological characteristics of the powders were evaluate by XRD, particle size distribution, SEM and nitrogen adsorption (BET). The results showed the production of a-alumina as unique phase and formed by agglomerates with irregular plate shape of thin particles for all studied conditions. The powders prepared by electrical oven presented small particle size, with narrow agglomerates size distribution. (author)

  2. A Comparative Study of Dispersion Characteristics Determination of a Trapezoidally Corrugated Slow Wave Structure Using Different Techniques

    International Nuclear Information System (INIS)

    Saber, Md. Ghulam; Sagor, Rakibul Hasan; Amin, Md. Ruhul

    2016-01-01

    The linear dispersion relation of a trapezoidally corrugated slow wave structure (TCSWS) is analyzed and presented. The size parameters of the TCSWS are chosen in such a way that they operate in the x-band frequency range. The dispersion relation is solved by utilizing the Rayleigh–Fourier method by expressing the radial function in terms of the Fourier series. A highly accurate synthetic technique is also applied to determine the complete dispersion characteristics from experimentally measured resonances (cold test). Periodic structures resonate at specific frequencies when the terminals are shorted appropriately. The dispersion characteristics obtained from numerical calculation, synthetic technique and cold test are compared, and an excellent agreement is achieved. (paper)

  3. Magnetic Properties and Structural Characteristics of BaFe12O19 Hexaferrites Synthesized by the Zol-Gel Combustion

    Science.gov (United States)

    Zhuravlev, V. A.; Itin, V. I.; Minin, R. V.; Lopushnyak, Yu. M.; Velikanov, D. A.

    2018-03-01

    The phase structure, structural parameters, and basic magnetic characteristics of BaFe12O19 hexaferrites prepared by the zol-gel combustion method with subsequent annealing at a temperature of 850°C for 6 h are investigated. The influence of the organic fuel type on the properties of synthesized materials is analyzed. Values of the saturation magnetization and the anisotropy field are determined. It is established that they depend on the organic fuel type. It is shown that powders synthesized with citric acid used as a fuel have the largest particle sizes and the highest saturation magnetization.

  4. Calculation analysis of the radiation characteristics of the Ch NPP Unit 1 reactor structures after the final shutdown

    International Nuclear Information System (INIS)

    Burlakov, E.V.; Bylkin, B.K.; Garin, E.V.; Davydova, G.B.; Zverkov, Yu.A.; Krayushkin, A.V.; Neretin, Yu.A.; Nosovskij, A.V.; Sejda, V.A.; Skripov, A.E.; Tushev, D.V.

    2000-01-01

    The article deals with the ways of assessing RBMK structures radiation parameters, which can in future serve as a basis for work on the tasks related to planning and actual decommissioning of Power Units with RBMK reactors. It gives the main results of the calculation analysis of the radiation characteristics of the elements of the Ch NPP Unit 1 reactor structures at the final Unit shutdown stage. The article also gives a forecast of their changes as the time passes, up to 150 years of the reactor cooling. The article describes the methodology and the results of the analysis carried out. 8 refs., 3 tab., 4 figs

  5. Multi-scale structures and pasting characteristics of starch in whole-wheat flour treated by superfine grinding.

    Science.gov (United States)

    Niu, Meng; Zhang, Binjia; Jia, Caihua; Zhao, Siming

    2017-11-01

    The multi-scale structures and pasting properties of starch in WWF were investigated after superfine grinding. Five particle size distributions of WWF and their corresponding starch were obtained. The grinding process reduced the particle size of WWF and starch. However, a slight increase of fragments from starch granules was observed with enhanced grinding strength because of the small decrease in starch particle size and the existence of other WWF components that undertook some of shearing force and friction during grinding. A prominent reduction in starch crystallinity was resulted due to the destruction of crystalline structure by grinding. Small-angle X-ray scattering analyses indicated the disordering in starch semi-crystalline lamellae with thinner lamellae thickness. Additionally, the 13 C Nuclear Magnetic Resonance spectra demonstrated the alterations in starch chain conformation by varying peak areas of starch carbons (C1 and C4). Along with these structural changes, Starch pasting characteristics showed substantial variations, indicating decreased viscosities and higher pasting stability. The results suggest that the grinding treatments influenced the structures and pasting properties of starch even at a non-separated state, the changes in starch structures were related to the variations in starch gelatinization characteristics. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. Structure and Filling Characteristics of Paleokarst Reservoirs in the Northern Tarim Basin, Revealed by Outcrop, Core and Borehole Images

    Science.gov (United States)

    Tian, Fei; Lu, Xinbian; Zheng, Songqing; Zhang, Hongfang; Rong, Yuanshuai; Yang, Debin; Liu, Naigui

    2017-06-01

    The Ordovician paleokarst reservoirs in the Tahe oilfield, with burial depths of over 5300 m, experienced multiple phases of geologic processes and exhibit strong heterogeneity. Core testing can be used to analyse the characteristics of typical points at the centimetre scale, and seismic datasets can reveal the macroscopic outlines of reservoirs at the >10-m scale. However, neither method can identify caves, cave fills and fractures at the meter scale. Guided by outcrop investigations and calibrations based on core sample observations, this paper describes the interpretation of high longitudinal resolution borehole images, the identification of the characteristics of caves, cave fills (sedimentary, breccia and chemical fills) and fractures in single wells, and the identification of structures and fill characteristics at the meter scale in the strongly heterogeneous paleokarst reservoirs. The paleogeomorphology, a major controlling factor in the distribution of paleokarst reservoirs, was also analysed. The results show that one well can penetrate multiple cave layers of various sizes and that the caves are filled with multiple types of fill. The paleogeomorphology can be divided into highlands, slopes and depressions, which controlled the structure and fill characteristics of the paleokarst reservoirs. The results of this study can provide fundamental meter-scale datasets for interpreting detailed geologic features of deeply buried paleocaves, can be used to connect core- and seismic-scale interpretations, and can provide support for the recognition and development of these strongly heterogeneous reservoirs.

  7. Structure and Filling Characteristics of Paleokarst Reservoirs in the Northern Tarim Basin, Revealed by Outcrop, Core and Borehole Images

    Directory of Open Access Journals (Sweden)

    Tian Fei

    2017-06-01

    Full Text Available The Ordovician paleokarst reservoirs in the Tahe oilfield, with burial depths of over 5300 m, experienced multiple phases of geologic processes and exhibit strong heterogeneity. Core testing can be used to analyse the characteristics of typical points at the centimetre scale, and seismic datasets can reveal the macroscopic outlines of reservoirs at the >10-m scale. However, neither method can identify caves, cave fills and fractures at the meter scale. Guided by outcrop investigations and calibrations based on core sample observations, this paper describes the interpretation of high longitudinal resolution borehole images, the identification of the characteristics of caves, cave fills (sedimentary, breccia and chemical fills and fractures in single wells, and the identification of structures and fill characteristics at the meter scale in the strongly heterogeneous paleokarst reservoirs. The paleogeomorphology, a major controlling factor in the distribution of paleokarst reservoirs, was also analysed. The results show that one well can penetrate multiple cave layers of various sizes and that the caves are filled with multiple types of fill. The paleogeomorphology can be divided into highlands, slopes and depressions, which controlled the structure and fill characteristics of the paleokarst reservoirs. The results of this study can provide fundamental meter-scale datasets for interpreting detailed geologic features of deeply buried paleocaves, can be used to connect core- and seismic-scale interpretations, and can provide support for the recognition and development of these strongly heterogeneous reservoirs.

  8. Geochemically structural characteristics of municipal solid waste incineration fly ash particles and mineralogical surface conversions by chelate treatment.

    Science.gov (United States)

    Kitamura, Hiroki; Sawada, Takaya; Shimaoka, Takayuki; Takahashi, Fumitake

    2016-01-01

    Leaching behaviors of heavy metals contained in municipal solid waste incineration (MSWI) fly ash have been studied well. However, micro-characteristics of MSWI fly ash particles are still uncertain and might be non-negligible to describe their leaching behaviors. Therefore, this study investigated micro-characteristics of MSWI fly ash particles, especially their structural properties and impacts of chelate treatment on surface characteristics. According to SEM observations, raw fly ash particles could be categorized into four types based on their shapes. Because chelate treatment changed the surface of fly ash particles dramatically owing to secondary mineral formations like ettringite, two more types could be categorized for chelate-treated fly ash particles. Acid extraction experiments suggest that fly ash particles, tested in this study, consist of Si-base insoluble core structure, Al/Ca/Si-base semi-soluble matrices inside the body, and KCl/NaCl-base soluble aggregates on the surface. Scanning electron microscope (SEM) observations of the same fly ash particles during twice moistening treatments showed that KCl/NaCl moved under wet condition and concentrated at different places on the particle surface. However, element mobility depended on secondary mineral formations. When insoluble mineral like gypsum was generated and covered the particle surface, it inhibited element transfer under wet condition. Surface characteristics including secondary mineral formation of MSWI fly ash particles are likely non-negligible to describe trace element leaching behaviors.

  9. The basic characteristics of hybrid aircraft. [structural design criteria and weight analysis of airships for materials handling

    Science.gov (United States)

    Nichols, J. B.

    1975-01-01

    The transportation of very heavy or very bulky loads by airships, and the ability to carry out extended duration flights at low speeds and low costs was studied. Structural design and weight factors for airship construction are examined. The densities of various light gases to be used in airships are given, along with their lifting capacities. The aerodynamic characteristics of various airship configurations was studied. Propulsion system requirements for airships are briefly considered.

  10. Characteristics of the structure in the Galactic polarized radio background at 350 MHz

    NARCIS (Netherlands)

    Haverkorn, M; Katgert, P; de Bruyn, AG

    Angular power spectra and structure functions of the Stokes parameters Q and U and polarized intensity P are derived from three sets of radio polarimetric observations. Two of the observed fields have been studied at multiple frequencies, allowing determination of power spectra and structure

  11. Improvement in breakdown characteristics with multiguard structures in microstrip silicon detectors for CMS

    CERN Document Server

    Bacchetta, N; Candelori, A; Da Rold, M; Descovich, M; Kaminski, A; Messineo, A; Rizzo, F; Verzellesi, G

    2001-01-01

    To obtain full charge collection the CMS silicon detectors should be able to operate at high bias voltage. We observed that multiguard structures enhance the breakdown performance of the devices on several tens of baby detectors designed for CMS. The beneficial effects of the multiguard structures still remains after the strong neutron irradiation performed to simulate the operation at the LHC. (3 refs).

  12. Soil structure and characteristics of organic matter in two orchards differing in eartworm activity

    NARCIS (Netherlands)

    Jongmans, A.G.; Pulleman, M.M.; Balabane, M.; Oort, van F.; Marinissen, J.C.Y.

    2003-01-01

    By consuming plant remains and soil, earthworms incorporate organic matter (OM) into the soil and form biogenic soil structures, which can affect OM dynamics. We carried out a (micro)morphological study of soil structure development and OM distribution in two orchards (45 year) in a Dutch calcareous

  13. Pore structure, mechanical properties and polymer characteristics of porous materials impregnated with methylmethacrylate

    International Nuclear Information System (INIS)

    Hastrup, K.

    1976-05-01

    The pore structure of porous materials plays a decisive role with regard to many properties of the materials. One therefore expects property improvement due to impregnation to be mostly brought about as a result of pore structure modification. This supposition formed the basis for the project here presented, which had the main aim of investigating polymer impregnation in relation to pore structure. Objectives were: 1) to examine the pore structure of hardened cement paste, beech wood and porous glass before and after gas-phase impregnation with methyl-methacrylate monomer and in situ polymerization, 2) to investigate the influence of the pore structure on the molecular weight of the polymer, 3) to investigate the influence of the degree of pore filling on the elastic modulus, damping coefficient and bending strength. (author)

  14. Indoor transformer stations and ELF magnetic field exposure: use of transformer structural characteristics to improve exposure assessment.

    Science.gov (United States)

    Okokon, Enembe Oku; Roivainen, Päivi; Kheifets, Leeka; Mezei, Gabor; Juutilainen, Jukka

    2014-01-01

    Previous studies have shown that populations of multiapartment buildings with indoor transformer stations may serve as a basis for improved epidemiological studies on the relationship between childhood leukaemia and extremely-low-frequency (ELF) magnetic fields (MFs). This study investigated whether classification based on structural characteristics of the transformer stations would improve ELF MF exposure assessment. The data included MF measurements in apartments directly above transformer stations ("exposed" apartments) in 30 buildings in Finland, and reference apartments in the same buildings. Transformer structural characteristics (type and location of low-voltage conductors) were used to classify exposed apartments into high-exposure (HE) and intermediate-exposure (IE) categories. An exposure gradient was observed: both the time-average MF and time above a threshold (0.4 μT) were highest in the HE apartments and lowest in the reference apartments, showing a statistically significant trend. The differences between HE and IE apartments, however, were not statistically significant. A simulation exercise showed that the three-category classification did not perform better than a two-category classification (exposed and reference apartments) in detecting the existence of an increased risk. However, data on the structural characteristics of transformers is potentially useful for evaluating exposure-response relationship.

  15. Simulation of flow structure in the suction pipe of a hydroturbine by integral characteristics

    DEFF Research Database (Denmark)

    Kuibin, P.A.; Okulov, Valery; Pylev, I.M.

    2006-01-01

    Within the framework of a model of a twisted flow of an inviscid incompressible liquid, we solve the problem of determining the frequency and amplitude of oscillations caused by the precession of a helical vortex core in the suction tube of a hydroturbine from the specified integral characteristics...

  16. Features of Household Lexics, Their Characteristics and Structural Analysis in the Modern English Language

    Science.gov (United States)

    Yusifova, Aygun

    2014-01-01

    The present paper aims to analyze the most inherent features and characteristics of household lexis in English. Special emphasis has been placed on their names of the objects used in everyday life, kitchen utensils, animal and birds. Lexical units concerning ceremonies, habits and traditions are also among the scope of the paper. Moreover, the…

  17. Bearing alloys with hexagonal crystal structures provide improved friction and wear characteristics

    Science.gov (United States)

    Buckley, D. H.; Johnson, R. L.

    1966-01-01

    Bearings of titanium, cobalt, and other hexagonal crystal alloys are used in vacuum and high temperature environments. These temperature-stabilized alloys have reduced friction and wear characteristics and therefore have potential use in aircraft seals, hydraulic equipment, and artificial human joints.

  18. Development, characteristics and comparative structural analysis of tensegrity type cable domes

    Directory of Open Access Journals (Sweden)

    Nenadović Aleksandra

    2010-01-01

    Full Text Available Tensegrity type cable domes are three-dimensional structural configurations, prestressed inside the perimeter compression ring, in which the continuous tension throughout the roof structure is made by continuous tension cables and discontinuous compression struts. These kinds of structures can be formed like spatially triangulated networks or like networks nontriangulated in space. This paper examines some effects of network geometry on the behaviour and structural efficiency of tensegrity type cable domes. In this paper the roof cover is considered non-interactive with the supporting structure, unlike rigidly clad tensegrity type cable domes. Since the main bearing elements of tensegrity type cable domes are prestressed cables, they show non-linear load deformation and rely upon geometric stiffness. A geometrically non-linear analysis of non-triangulated and triangulated structures for different load conditions was conducted employing a computer program based on the perturbation theory. The incrementally-iterative procedure, with an approximation of the stiffness matrix by combining the elastic and geometric stiffness matrix, allows detection of structural instabilities.

  19. Recessed insulator and barrier AlGaN/GaN HEMT: A novel structure for improving DC and RF characteristics

    Science.gov (United States)

    Razavi, S. M.; Zahiri, S. H.; Hosseini, S. E.

    2017-04-01

    In this study, a gallium nitride (GaN) high electron mobility transistor (HEMT) with recessed insulator and barrier is reported. In the proposed structure, insulator is recessed into the barrier at the drain side and barrier is recessed into the buffer layer at the source side. We study important device characteristics such as electric field, breakdown voltage, drain current, maximum output power density, gate-drain capacitance, short channel effects and DC transconductance using two-dimensional and two-carrier device simulator. Recessed insulator in the drain side of the proposed structure reduces maximum electric field in the channel and therefore increases the breakdown voltage and maximum output power density compared to the conventional counterpart. Also, gate-drain capacitance value in the proposed structure is less than that of the conventional structure. Overall, the proposed structure reduces short channel effects. Because of the recessed regions at both the source and the drain sides, the average barrier thickness of the proposed structure is not changed. Thus, the drain current of the proposed structure is almost equivalent to that of the conventional transistor. In this work, length ( L r) and thickness ( T r) of the recessed region of the barrier at the source side are the same as those of the insulator at the drain side.

  20. Dependence of Internal Crystal Structures of InAs Nanowires on Electrical Characteristics of Field Effect Transistors

    Science.gov (United States)

    Han, Sangmoon; Choi, Ilgyu; Lee, Kwanjae; Lee, Cheul-Ro; Lee, Seoung-Ki; Hwang, Jeongwoo; Chung, Dong Chul; Kim, Jin Soo

    2018-02-01

    We report on the dependence of internal crystal structures on the electrical properties of a catalyst-free and undoped InAs nanowire (NW) formed on a Si(111) substrate by metal-organic chemical vapor deposition. Cross-sectional transmission electron microscopy images, obtained from four different positions of a single InAs NW, indicated that the wurtzite (WZ) structure with stacking faults was observed mostly in the bottom region of the NW. Vertically along the InAs NW, the amount of stacking faults decreased and a zinc-blende (ZB) structure was observed. At the top of the NW, the ZB structure was prominently observed. The resistance and resistivity of the top region of the undoped InAs NW with the ZB structure were measured to be 121.5 kΩ and 0.19 Ω cm, respectively, which are smaller than those of the bottom region with the WZ structure, i.e., 251.8 kΩ and 0.39 Ω cm, respectively. The reduction in the resistance of the top region of the NW is attributed to the improvement in the crystal quality and the change in the ZB crystal structure. For a field effect transistor with an undoped InAs NW channel, the drain current versus drain-source voltage characteristic curves under various negative gate-source voltages were successfully observed at room temperature.

  1. 13C-NMR Study on Structure Evolution Characteristics of High-Organic-Sulfur Coals from Typical Chinese Areas

    Directory of Open Access Journals (Sweden)

    Qiang Wei

    2018-02-01

    Full Text Available The structure evolution characteristics of high-organic-sulfur (HOS coals with a wide range of ranks from typical Chinese areas were investigated using 13C-CP/MAS NMR. The results indicate that the structure parameters that are relevant to coal rank include CH3 carbon (fal*, quaternary carbon, CH/CH2 carbon + quaternary carbon (falH, aliphatic carbon (falC, protonated aromatic carbon (faH, protonated aromatic carbon + aromatic bridgehead carbon (faH+B, aromaticity (faCP, and aromatic carbon (farC. The coal structure changed dramatically in the first two coalification jumps, especially the first one. A large number of aromatic structures condensed, and aliphatic structures rapidly developed at the initial stage of bituminous coal accompanied by remarkable decarboxylation. Compared to ordinary coals, the structure evolution characteristics of HOS coals manifest in three ways: First, the aromatic CH3 carbon, alkylated aromatic carbon (faS, aromatic bridgehead carbon (faB, and phenolic ether (faP are barely relevant to rank, and abundant organic sulfur has an impact on the normal evolution process of coal. Second, the average aromatic cluster sizes of some super-high-organic-sulfur (SHOS coals are not large, and the extensive development of cross bonds and/or bridged bonds form closer connections among the aromatic fringes. Moreover, sulfur-containing functional groups are probably significant components in these linkages. Third, a considerable portion of “oxygen-containing functional groups” in SHOS coals determined by 13C-NMR are actually sulfur-containing groups, which results in the anomaly that the oxygen-containing structures increase with coal rank.

  2. V-amylose structural characteristics, methods of preparation, significance, and potential applications

    CSIR Research Space (South Africa)

    Obiro, WC

    2012-02-01

    Full Text Available , and postprandial hyperglycaemia in diabetics. Various aspects of V-amylose structure, methods of preparation, factors that affect its formation, and the significance and potential applications of the V-amylose complexes are reviewed....

  3. Calculation of electrodynamical characteristics and choice of accelerating structure for storage ring

    International Nuclear Information System (INIS)

    Karnaukhov, I.M.; Popkov, Yu.P.; Telegin, Yu.N.; Trushkin, N.A.; Dajkovskij, A.G.; Zakamskaya, L.T.; Ryabov, A.D.

    1989-01-01

    Comparative analysis of several types of accelerating structures at standing E 010 wave is conducted on the basis of numerical calculations performed with the use of the PRUD-0 and PRUD programs. Dispersion dependences of electromagnetic field distribution, quality and coupling impedance are calculated both for axially symmetric and axially asymmetric modes of oscillations in structures with 699.3 MHz operating frequency. It is shown that structure with a cell the form of which is optimized with respect to shunt resistance on the main mode possesses the numerical spurious impedance in higher modes. This is the main factor when choosing accelerating structure for storage ring with multi-bunch operation conditions. 12 refs.; 3 figs.; 3 tabs

  4. Youth labour market integration across Europe: The impact of cyclical, structural, and institutional characteristics

    NARCIS (Netherlands)

    Lange, M. de; Gesthuizen, M.J.W.; Wolbers, M.H.J.

    2014-01-01

    Young people in Europe face great difficulties nowadays when entering the labour market. Unemployment and temporary employment are high among youth, although considerable differences exist between European countries. In this article, we study to what extent cyclical, structural, and institutional

  5. Structural characteristics of carbon nanofibers for on-chip interconnect applications

    International Nuclear Information System (INIS)

    Ominami, Yusuke; Ngo, Quoc; Austin, Alexander J.; Yoong, Hans; Yang, Cary Y.; Cassell, Alan M.; Cruden, Brett A.; Li Jun; Meyyappan, M.

    2005-01-01

    In this letter, we compare the structures of plasma-enhanced chemical vapor deposition of Ni-catalyzed and Pd-catalyzed carbon nanofibers (CNFs) synthesized for on-chip interconnect applications with scanning transmission electron microscopy (STEM). The Ni-catalyzed CNF has a conventional fiberlike structure and many graphitic layers that are almost parallel to the substrate at the CNF base. In contrast, the Pd-catalyzed CNF has a multiwall nanotubelike structure on the sidewall spanning the entire CNF. The microstructure observed in the Pd-catalyzed fibers at the CNF-metal interface has the potential to lower contact resistance significantly, as our electrical measurements using current-sensing atomic force microscopy indicate. A structural model is presented based on STEM image analysis

  6. Cost Characteristics of Telecom Networks and their Implications for Market Structures

    DEFF Research Database (Denmark)

    Falch, Morten

    1997-01-01

    The paper analyses the cost structure of telecom operators and test the hypotheses of economies of scale and economies of density. The impact of new technologies and the regulatory implications are analysed.......The paper analyses the cost structure of telecom operators and test the hypotheses of economies of scale and economies of density. The impact of new technologies and the regulatory implications are analysed....

  7. Relationship between Molecular Structure Characteristics of Feed Proteins and Protein In vitro Digestibility and Solubility

    OpenAIRE

    Bai, Mingmei; Qin, Guixin; Sun, Zewei; Long, Guohui

    2015-01-01

    The nutritional value of feed proteins and their utilization by livestock are related not only to the chemical composition but also to the structure of feed proteins, but few studies thus far have investigated the relationship between the structure of feed proteins and their solubility as well as digestibility in monogastric animals. To address this question we analyzed soybean meal, fish meal, corn distiller’s dried grains with solubles, corn gluten meal, and feather meal by Fourier transfor...

  8. Earthquake response characteristics of large structure 'JOYO' deeply embedded in quaternary ground, (3)

    International Nuclear Information System (INIS)

    Yajima, Hiroshi; Sawada, Yoshihiro; Hanada, Kazutake; Sawada, Makoto.

    1987-01-01

    In order to examine aseismicity of embedded structure and to clarify embedment effect, earthquake observations of the large structure 'JOYO' are carried out which is deeply embedded in quaternary ground, and the results are summarized as follows. (1) Amplification factors of horizontal component in ground surface is about 3 to 4 times against the bedrock. Contrastively on the structure, any amplification is not observed at the underground portion, however, little amplification exists at the ground portion of structure. (2) Transfer function of structure has several predominant peaks at frequencies of 4.3 Hz and 8.0 Hz which are well coincided with values obtained from force excitation tests. It is shown that transfer function between basement and ground surface is similar to that between ground of same level to basement and ground surface, suggesting the behavior of basement to be able to estimate by these under ground earthquake motion. (3) According to earthquake motion analysis using S-R models, without regard to consider or not the side ground stiffness, the calculated response values do not so much differ in each model and mostly correspond with observation data, provided that the underground earthquake motion at same level to basement is used as a input wave. Consequently, the behavior of these deeply embedded structure is subject to setting method of input wave rather than modeling method, and it is very useful in design that the most simple model without side ground stiffness can roughly represent the embedment effect. (author)

  9. Turbulence characteristics inside ionospheric small-scale expanding structures observed with SuperDARN HF radars

    Directory of Open Access Journals (Sweden)

    R. André

    2003-08-01

    Full Text Available Unusual structures characterized by a very high-velocity divergence have been observed in the high-latitude F-region with SuperDARN radars (André et al., 2000. These structures have been interpreted as due to local demagnetization of the plasma in the ionospheric F-region, during very specific geophysical conditions. In this study, the collective wave scattering theory is used to characterize the decameter-scale turbulence (l approx 15 m inside the structures. The distribution function of the diffusion coefficient is modified when the structures are generated, suggesting that two regimes of turbulence coexist. A temporal analysis decorrelates the two regimes and gives access to the dynamics associated with the structures. It is shown that a high turbulent regime precedes the plasma demagnetization and should be related to an energy deposition. Then a second regime appears when the plasma is demagnetized and disappears simultaneously with the structures. This study is the first application of the collective wave scattering theory to a specific geophysical event.Key words. Ionosphere (auroral ionosphere; ionospheric irregularities – Space plasma physics (turbulence

  10. Effect of structural heterogeneity water-coal fuel conditions and characteristics of ignition

    Directory of Open Access Journals (Sweden)

    Syrodoy S.V.

    2015-01-01

    Full Text Available The problem of the particle ignition of coal-water fuel (CWF with a joint course of the main processes of a thermal (thermal conductivity, evaporation, filtration heat and mass transfer, thermal decomposition of the organic part has been solved. According to the results of numerical simulation ways of describing the extent of the influence of the thermophysical properties on the characteristics and conditions of ignition WCF have been set.

  11. Creep and Fracture Characteristics of Materials and Structures at Elevated Temperatures.

    Science.gov (United States)

    1986-02-14

    44 Rissbruchkriterium bei iberlagerter Zug-, Druck - und Schubbeanspruchung. Schweissen Schneiden 29, 135-139 (1977) 58 0. Radaj and M. Heib, Energy...plane strain characteristics but is in transition between plane strain and plane stress. Figure 3d is a plot of the surface yield zone for a specimen with...expected. In all cases, the / .296 midplane yield zones are smaller than the surface zones. Fig. 3d . Surface yield zones for specimen with 2T - 3,175 Mm

  12. Investigation of structural properties, electrical and dielectrical characteristics of Al/Dy2O3/porous Si heterostructure

    Science.gov (United States)

    Cherif, A.; Jomni, S.; Belgacem, W.; Hannachi, R.; Mliki, N.; Beji, L.

    2014-04-01

    This paper describes the structural properties, electrical and dielectric characteristics for the first time of the high-k Dy2O3 oxide film deposited on the porous Si substrate by electron beam deposition under ultra vacuum. Structural and morphological characterizations are investigated by a scanning electron microscopy (SEM), atomic force microscopy (AFM), transmission electron microscopy (TEM) and X-ray diffraction measurements (XRD). The electrical and dielectric characteristics of the Al/Dy2O3/porous Si heterostructure are studied through current- voltage I (V), capacitance-voltage C (V), conductance- and capacitance-frequency dependencies (G (f) and C (f)). Therefore, the dominant conduction mechanisms for the Al/Dy2O3/porous Si heterostructure are extracted from the determining of Schottky coefficient (βSC) and Poole-Frenkel coefficient (βPF). The experimental values of βSC and βPF coefficients are calculated from I (V) characteristics and compared with theoretical values, thus, the appropriate model has been proposed. The C (V) characteristics at different frequencies revealed a large frequency-dispersion, indicative of a significant density of interface states. Furthermore, the G (f) characteristics were well fitted by the modified law GAC(f)=A1f+A2f and the results showed frequency dependent and evidence of two different behaviors in ac conductance i.e. the low-frequency conductivity is due to long-range ordering (frequency-independent) and high frequency conduction due to the localized orientation hopping mechanism. The Nyquist diagrams are used to identify the equivalent circuit, so, the Al/Dy2O3/porous Si heterostructure is accurately modeled at frequency ranges from 10 Hz to 1000 kHz, as a two parallel elements (RC) network placed in series.

  13. Analysis of vibration characteristics of opening device for deepwater robot cabin door and study of its structural optimization design

    Science.gov (United States)

    Zeng, Baoping; Liu, Jipeng; Zhang, Yu; Gong, Yajun; Hu, Sanbao

    2017-12-01

    Deepwater robots are important devices for human to explore the sea, which is being under development towards intellectualization, multitasking, long-endurance and large depth along with the development of science and technology. As far as a deep-water robot is concerned, its mechanical systems is an important subsystem because not only it influences the instrument measuring precision and shorten the service life of cabin devices but also its overlarge vibration and noise lead to disadvantageous effects to marine life within the operational area. Therefore, vibration characteristics shall be key factor for the deep-water robot system design. The sample collection and recycling system of some certain deepwater robot in a mechanism for opening the underwater cabin door for external operation and recycling test equipment is focused in this study. For improving vibration characteristics of locations of the cabin door during opening processes, a vibration model was established to the opening system; and the structural optimization design was carried out to its important structures by utilizing the multi-objective shape optimization and topology optimization method based on analysis of the system vibration. Analysis of characteristics of exciting forces causing vibration was first carried out, which include characteristics of dynamic loads within the hinge clearances and due to friction effects and the fluid dynamic exciting forces during processes of opening the cabin door. Moreover, vibration acceleration responses for a few important locations of the devices for opening the cabin cover were deduced by utilizing the modal synthesis method so that its rigidity and modal frequency may be one primary factor influencing the system vibration performances based on analysis of weighted acceleration responses. Thus, optimization design was carried out to the cabin cover by utilizing the multi-objective topology optimization method to perform reduction of weighted accelerations

  14. Phases and structural characteristics of high Tc superconducting oxide in (Bi, Pb)-Sr-Ca-Cu-O system

    International Nuclear Information System (INIS)

    Chen, Zuyano; Li, Zhengrong; Qian, Yitai; Zhou, Quien; Cheng, Tingzhu

    1989-01-01

    The various phases, which are responsible for variant maximum d-value including 18.5 angstrom, 15.4 angstrom, 12.2 angstrom, 6.2 angstrom, 3.2 angstrom and possible 9.1 angstrom respectively, observed in high Tc superconducting complex oxide of (Bi,Pb)-Sr-Ca-Cu-O system are reported in this paper according to the result of X-ray diffraction on platelike crystals or crystallites synthesized under different preparation conditions. The phase of tetragonal system with c=3.21 angstrom, a=3.86 angstrom is possible parent structural unit and it is of great significance to the structure constitution of various phases with large lattice parameter c and structural characteristics of superconducting oxide. In view of the above a model of two-dimension stack-up which causes a stack in variant styles along c-axis and constitute various phases with different lattice parameter c is proposed and discussed

  15. Characteristics of 2-D convective structures in Catalonia (NE Spain: an analysis using radar data and GIS

    Directory of Open Access Journals (Sweden)

    M. Barnolas

    2010-01-01

    Full Text Available Flood simulation studies use spatial-temporal rainfall data input into distributed hydrological models. A correct description of rainfall in space and in time contributes to improvements on hydrological modelling and design. This work is focused on the analysis of 2-D convective structures (rain cells, whose contribution is especially significant in most flood events. The objective of this paper is to provide statistical descriptors and distribution functions for convective structure characteristics of precipitation systems producing floods in Catalonia (NE Spain. To achieve this purpose heavy rainfall events recorded between 1996 and 2000 have been analysed. By means of weather radar, and applying 2-D radar algorithms a distinction between convective and stratiform precipitation is made. These data are introduced and analyzed with a GIS. In a first step different groups of connected pixels with convective precipitation are identified. Only convective structures with an area greater than 32 km2 are selected. Then, geometric characteristics (area, perimeter, orientation and dimensions of the ellipse, and rainfall statistics (maximum, mean, minimum, range, standard deviation, and sum of these structures are obtained and stored in a database. Finally, descriptive statistics for selected characteristics are calculated and statistical distributions are fitted to the observed frequency distributions. Statistical analyses reveal that the Generalized Pareto distribution for the area and the Generalized Extreme Value distribution for the perimeter, dimensions, orientation and mean areal precipitation are the statistical distributions that best fit the observed ones of these parameters. The statistical descriptors and the probability distribution functions obtained are of direct use as an input in spatial rainfall generators.

  16. Study on design method and vibration reduction characteristic of floating raft with periodic structure

    Science.gov (United States)

    Fang, Yuanyuan; Zuo, Yanyan; Xia, Zhaowang

    2018-03-01

    The noise level is getting higher with the development of high-power marine power plant. Mechanical noise is one of the most obvious noise sources which not only affect equipment reliability, riding comfort and working environment, but also enlarge underwater noise. The periodic truss type device which is commonly applied in fields of aerospace and architectural is introduced to floating raft construction in ship. Four different raft frame structure are designed in the paper. The vibration transmissibility is taken as an evaluation index to measure vibration isolation effect. A design scheme with the best vibration isolation effect is found by numerical method. Plate type and the optimized periodic truss type raft frame structure are processed to experimental verify vibration isolation effect of the structure of the periodic raft. The experimental results demonstrate that the same quality of the periodic truss floating raft has better isolation effect than that of the plate type floating raft.

  17. Dispersion characteristics of spin-electromagnetic waves in planar multiferroic structures

    Energy Technology Data Exchange (ETDEWEB)

    Nikitin, Andrey A.; Ustinov, Alexey B. [Department of Physical Electronics and Technology, St. Petersburg Electrotechnical University, St. Petersburg 197376 (Russian Federation); Department of Mathematics and Physics, Lappeenranta University of Technology, Lappeenranta 53850 (Finland); Vitko, Vitaliy V.; Semenov, Alexander A.; Mironenko, Igor G. [Department of Physical Electronics and Technology, St. Petersburg Electrotechnical University, St. Petersburg 197376 (Russian Federation); Belyavskiy, Pavel Yu.; Kalinikos, Boris A. [Department of Physical Electronics and Technology, St. Petersburg Electrotechnical University, St. Petersburg 197376 (Russian Federation); International Laboratory “MultiferrLab,” ITMO University, St. Petersburg 197101 (Russian Federation); Stashkevich, Andrey A. [International Laboratory “MultiferrLab,” ITMO University, St. Petersburg 197101 (Russian Federation); LSPM (CNRS-UPR 3407), Université Paris 13, Sorbonne Paris Cité, 93430 Villetaneuse (France); Lähderanta, E. [Department of Mathematics and Physics, Lappeenranta University of Technology, Lappeenranta 53850 (Finland)

    2015-11-14

    A method of approximate boundary conditions is used to derive dispersion relations for spin-electromagnetic waves (SEWs) propagating in thin ferrite films and in multiferroic layered structures. A high accuracy of this method is proven. It was shown that the spin-electromagnetic wave propagating in the structure composed of a thin ferrite film, a thin ferroelectric film, and a slot transmission line is formed as a result of hybridization of the surface spin wave in the ferrite film and the electromagnetic wave in the slot-line. The structure demonstrates dual electric and magnetic field tunability of the SEW spectrum. The electric field tunability is provided by the thin ferroelectric film. Its efficiency increases with an increase in the thicknesses of the ferrite and ferroelectric films and with a decrease in the slot-line gap width. The theory is confirmed by experimental data.

  18. Probing Structural and Catalytic Characteristics of Galactose Oxidase Confined in Nanoscale Chemical Environments

    DEFF Research Database (Denmark)

    Ikemoto, Hideki; Mossin, Susanne; Ulstrup, Jens

    2014-01-01

    Galactose oxidase (GAOX) is a special metalloenzyme in terms of its active site structure and catalytic mechanisms. This work reports a study where the enzyme confined in a nanoscale chemical environment provided by mesoporous silicas (MPS) is probed. Two types of MPS, i.e. SBA-15 and MCF, were...... synthesized and used to accommodate GAOX. SBA-15-ROD is rod-shaped particles with periodically ordered nanopores (9.5 nm), while MCF has a mesocellular foam-like structure with randomly distributed pores (23 nm) interconnected by smaller windows (8.8 nm). GAOX is non-covalently confined in SBA-15- ROD, while...... it is covalently immobilized in MCF. Relatively high loadings in the range of 50–60 mg g1 are achieved. Electron spin resonance (ESR) spectroscopy is used to probe the active site structures of the enzyme. The similar ESR spectra observed for GAOX in the free and immobilized states support that the electronic...

  19. Related electrical, superconducting and structural characteristics of low temperature indium films

    International Nuclear Information System (INIS)

    Belevtsev, B.I.; Pilipenko, V.V.; Yatsuk, L.Ya.

    1981-01-01

    Reported are results of a complex study of electrical, superconducting and structural properties of indium films vacuum evaporated onto a liquid helium-cooled substrate. Structural electron diffraction investigations gave a better insight into the general features of the annealing during the warming-up of cold-deposited films. It is found that the annealing of indium films to about 80 to 100 K entails an irreversible growth of interplanar separations due to decreasing inhomogeneous microstresses. As the films are warmed from 100 to 300 K, the principal annealing processes are determined by crystallite growth and development of dominating orientation. The changes in the residual resistance and in Tsub(c) with warming the cold-deported films are explained on the base of structural data obtained. In particular, a direct relationship is revealed between the crystallite size and Tsub(c) [ru

  20. The influences of soil and nearby structures on dispersion characteristics of wave propagating along buried plastic pipes

    Science.gov (United States)

    Liu, Shuyong; Jiang, J.; Parr, Nicola

    2016-09-01

    Water loss in distribution systems is a global problem for the water industry and governments. According to the international water supply association (IWSA), as a result of leaks from distribution pipes, 20% to 30% of water is lost while in transit from treatment plants to consumers. Although governments have tried to push the water industry to reduce the water leaks, a lot of experts have pointed out that a wide use of plastic pipes instead of metal pipes in recent years has caused difficulties in the detection of leaks using current acoustic technology. Leaks from plastic pipes are much quieter than traditional metal pipes and comparing to metal pipes the plastic pipes have very different coupling characteristics with soil, water and surrounding structures, such as other pipes, road surface and building foundations. The dispersion characteristics of wave propagating along buried plastic pipes are investigated in this paper using finite element and boundary element based models. Both empty and water- filled pipes were considered. Influences from nearby pipes and building foundations were carefully studied. The results showed that soil condition and nearby structures have significant influences on the dispersion characteristics of wave propagating along buried plastic pipes.

  1. Structural characteristics of active and inactive glutamate dehydrogenases from the hyperthermophile Pyrobaculum islandicum.

    Science.gov (United States)

    Ohshima, Toshihisa

    2012-01-01

    The enzymes from hyperthermophiles are generally extremely thermostable and lose little or no activity during long periods under a variety conditions. This high stability is very attractive, in that it gives the enzymes potential for use in numerous bioprocesses. My research group has investigated this high stability from the viewpoint of the relationship between function and structure. In this review, I describe the molecular mechanism underlying the extreme stability of unboiled NAD-dependent glutamate dehydrogenase from the hyperthermophile Pyrobaculum islandicum. I also describe the activation of the inactive recombinant enzyme produced in mesophilic Escherichia coli from the viewpoint of the relationship between structure and activity.

  2. A study on the fatigue strength characteristics of ship structural steel with gusset welds

    Directory of Open Access Journals (Sweden)

    Sung-Jo Park

    2012-06-01

    Full Text Available This study aims to assess fatigue property by the static overload and average load in the fillet welded joints which is on the ship structural steel having gusset welds. To this end, a small specimen was made, to which the same welding condition for the actual ship structure was applied, to perform fatigue tests. In this study, a method to simply assess changes in welding residual stress according to different static overload was suggested. By measuring actual strain at the weld toe, the weld stress concentration factor and property which is determined by recrystallization in the process of welding were estimated to investigate the relation between overload and fatigue strength.

  3. Fast argon ion irradiation effect on the characteristics of silicon planar structures

    CERN Document Server

    Karatetskii, S S; Sokolov, V I

    2002-01-01

    The effect of irradiating by the argon ions with the energy of 40 MeV on the planar structures parameters is studied with the purpose of determining the possibilities of their controlled change. It is shown, that the planar structures irradiation by the argon ions with the energy of 40 MeV leads to decrease in the capacitance of the MOS-condensers and narrows the area of the photosensitivity of the p - n-transitions. The observed effects are explained by the specificity of violations, created by fast ions in the crystal

  4. Structural characteristics of marine sedimentary humic acids by CP/MAS sup(13)C NMR spectroscopy

    Digital Repository Service at National Institute of Oceanography (India)

    Sardessai, S.; Wahidullah, S.

    acides humiques de la mer d’Arabie ; les acides humiques des stdiments estuariens et &tiers de la baie du Bengale sont dominks par les hyd.rates de carbone et les structures aro- matiques, ainsi que, dans une moindre mesure, par les structures... ont CtC Ctudiks dans diffkrents environnements de d6pp8ts par RMN du 13C (&at solide) et les rksultats ont Ctt cornparks avec les analyses chimiques traditionnelles en milieu liquide. Les donnkes obte- nues sont en accord avec la littkrature...

  5. Characteristics of sandwich-type structural elements built of advanced composite materials from three dimensional fabrics

    Directory of Open Access Journals (Sweden)

    Castejón, L.

    1997-12-01

    Full Text Available Sandwich-type structures have proved to be alternatives of great success for several fields of application, and specially in the building sector. This is due to their outstanding properties of .specific rigidity and strength against bending loads and other range of advantages like fatigue and impact resistance, attainment of flat and smooth surfaces, high electric and thermal insulation, design versatility and some others. However, traditional sandwich structures present problems like their tendency towards delamination, stress concentrations in bores or screwed Joints, and pre resistance. These problems are alleviated thanks to the use of new sandwich structures built using three dimensional structures of advanced composite materials, maintaining the present advantages for more traditional sandwich structures. At this rate, these new structures can be applied in several areas where conventional sandwich structures used to be like walls, partitions, floor and ceiling structures, domes, vaults and dwellings, but with greater success.

    Las estructuras tipo sándwich han demostrado ser alternativas de gran éxito para diversos campos de aplicación y, en concreto, en el sector de la construcción, listo es gracias a sus excelentes propiedades de rigidez y resistencia específica frente a cargas de flexión y otra larga lista de ventajas, a la que pertenecen, por ejemplo, su buena resistencia a fatiga, resistencia al impacto, obtención de superficies lisas y suaves, elevado aislamiento térmico y eléctrico, versatilidad de diseño y otras. Sin embargo, las estructuras sándwich, tradicionales presentan una problemática consistente en su tendencia a la delaminación, concentraciones de tensiones ¿aparecidas ante la existencia de agujeros o uniones atornilladas y resistencia al fuego. Estos problemas son pifiados gracias a la aplicación de estructuras novedosas tipo sándwich, construidas a partir de tejidos tridimensionales de materiales

  6. Overview of the Characteristics of Micro- and Nano-Structured Surface Plasmon Resonance Sensors

    Directory of Open Access Journals (Sweden)

    Byoungho Lee

    2011-01-01

    Full Text Available The performance of bio-chemical sensing devices has been greatly improved by the development of surface plasmon resonance (SPR based sensors. Advancements in micro- and nano-fabrication technologies have led to a variety of structures in SPR sensing systems being proposed. In this review, SPR sensors (from typical Kretschmann prism configurations to fiber sensor schemes with micro- or nano-structures for local light field enhancement, extraordinary optical transmission, interference of surface plasmon waves, plasmonic cavities, etc. are discussed. We summarize and compare their performances and present guidelines for the design of SPR sensors.

  7. Microconcrete - a reasonably priced method for examining the supporting characteristics of reinforced concrete structures

    International Nuclear Information System (INIS)

    Sautner, M.

    1982-01-01

    Micro-concrete technology was developed during the last few years so that investigations on small micro-concrete models with a length scale of about 1:15 can be carried out similar to large scale experiments on reinforced concrete. In this way, large scale experiments can be supplemented at a reasonable price, cheap data can be obtained for the further development of computer algorithms, the support characteristics studied and the basic dimensions can be worked out. This is important these days, so that on the one hand better use can be made of the material and on the other hand research resources can be saved. (orig.) [de

  8. Grazing management strategies for massaigrass-forage peanut pastures: 1. dynamics of sward condition and botanical composition Estratégias de manejo do pastejo para pastos consorciados de capim-massai e amendoim forrageiro: 1. dinâmica da condição do pasto e da composição botânica

    Directory of Open Access Journals (Sweden)

    Carlos Mauricio Soares de Andrade

    2006-04-01

    Full Text Available This study was carried out from October 2002 to December 2003 to evaluate the dynamics of sward condition and botanical composition of a mixed massaigrass (Panicum maximum x P. infestum, cv. Massai and forage peanut (Arachis pintoi Ac 01 pasture, intermittently stocked at three daily herbage allowance levels (9.0, 14.5 and 18.4% live weight. Sward condition was characterized in each grazing cycle in terms of the pre and post-grazing sward height, forage mass and percentage of bare ground. Botanical composition (grass, legume and weeds was evaluated before each grazing period. Sward height and forage mass increased linearly with increasing herbage allowance (HA levels, and higher values were observed during the rainy season. Percentage of bare ground increased primarily at the lowest HA level. Percentage of forage peanut increased throughout the experimental period, primarily in the barest and shortest swards, under the lowest HA level. In the last quarter of 2003 the legume constituted 23.5, 10.6 and 6.4% of the pasture forage mass, respectively, from the lowest to the highest HA level. These results suggest that forage peanut can be successfully associated with massaigrass, as long as the pre-grazing sward height is maintained shorter than 65-70 cm, which will prevent excessive shading to the legume.Este estudo foi realizado com o objetivo de avaliar a dinâmica e a composição botânica de uma pastagem consorciada de capim-massai (Panicum maximum x P. infestum, cv. Massai e amendoim forrageiro (Arachis pintoi Ac 01, manejada sob lotação rotacionada em três níveis de oferta diária de forragem (9,0; 14,5 e 18,4% do peso vivo. A condição da pastagem foi caracterizada em cada ciclo de pastejo, em termos de altura, massa de forragem e porcentagem de solo descoberto (pré e pós-pastejo. A composição botânica da pastagem (gramínea, leguminosa e invasoras foi monitorada antes de cada período de ocupação. Houve aumento linear da altura

  9. Clinical characteristics of pain originating from intra-articular structures of the knee joint in patients with medial knee osteoarthritis.

    Science.gov (United States)

    Ikeuchi, Masahiko; Izumi, Masashi; Aso, Koji; Sugimura, Natsuki; Tani, Toshikazu

    2013-01-01

    Although disease progression of osteoarthritis has been well documented, pain pathophysiology is largely unknown. This study was designed with two purposes: 1) to characterize patients with knee pain predominantly originating from intra-articular structures and 2) to describe the location and pattern of their pain. 103 patients with medial knee osteoarthritis underwent an intra-articular injection of local anesthetics (joint block). At least 70% pain relief was defined as positive for the joint block, while less than 50% as negative. Pain characteristics in patients positive for joint block were evaluated in detail using a knee pain map. Sixty three knees (61%) were positive and 33 knees (32%) were negative. Patients negative for the joint block were significantly higher age, suffered for longer time, and complained more diffuse pain. Although pain at anterior medial area during walk was the most common finding, pain characteristics differed among different knee areas. The characteristics of joint pain are widely variable even in patients with similar radiological features. Extra-articular sources are not negligible especially in older patients with a long history of diffuse pain. Differences in pain characteristics among knee areas should be taken into account when examining the pain source.

  10. Modifications of structural, chemical, and electrical characteristics of Er2O3/Si interface under Co-60 gamma irradiation

    Science.gov (United States)

    Kaya, Senol; Yilmaz, Ercan

    2018-03-01

    This paper reports the influences of gamma radiation on the structural, electrical, and chemical characteristics of erbium oxide (Er2O3) thin films and the possible mechanisms underlying these irradiation-induced effects. The crystallographic and morphological modifications under gamma irradiation were characterized by X-ray diffraction (XRD) and atomic force microscopy (AFM), respectively, while radiation influences on electrochemical characteristics were analyzed by X-ray photoelectron spectroscopy (XPS). Furthermore, changes in electrical characteristics were analyzed on the basis of capacitance-voltage (C-V) and conductance-voltage (G/ω-V) measurements. The XRD results demonstrated that small atomic displacement was observed and that the grain size of the nanostructure slightly increased. Improvements in surface roughness were observed in AFM measurements. The observed variations in the XRD and AFM measurements can be attributed to the radiation-induced local heating and microscopic atomic mobility. In addition, the XPS analysis obviously demonstrated that the oxygen vacancies increased with irradiation dose because of the breaking of Er2O3 and ErxOy bonds. Significant influences of the generated oxygen vacancies on the electrical measurements were observed, and the radiation-induced hole traps, which caused large flat band shifts, can be attributed to the generated oxygen vacancies. The results show that radiation does not degrade the physical characteristics significantly, but the generation of oxygen vacancies considerably increases the electrical sensitivity of the Er2O3 dielectric.

  11. Effect of test structure on electromigration characteristics in three-dimensional through silicon via stacked devices

    Science.gov (United States)

    Oba, Yoshiyuki; De Messemaeker, Joke; Tyrovouzi, Anna Maria; Miyamori, Yuichi; De Vos, Joeri; Wang, Teng; Beyer, Gerald; Beyne, Eric; De Wolf, Ingrid; Croes, Kristof

    2015-05-01

    Electromigration failure locations in three-dimensional (3D) interconnect structures with high-aspect-ratio through silicon vias, (TSVs, Φ5 × 50 µm2) connected to 40-µm-pitch CuSn solder joints have been identified using test structures which were designed to avoid failures in the back-end-of-line (BEOL). The resistance of the structures with the TSV and bump connections showed a continuous increase until failure. For the structures without a bump connection, where only TSV and re-distributed line (RDL) were the electrically connected, the resistance remained constant prior to the final failure. From cross-sectional analyses after the test, the failure locations were identified at the TSV bottom or at the bump bottom. The location of void formation was changed by applied current direction. The flux divergence generated by the barrier metal and the reservoir effect plays a crucial role in the void formation, and each failure mode is considered to have a different impact on the reliability performance.

  12. Structural features of condensed tannins affect in vitro ruminal methane production and fermentation characteristics

    NARCIS (Netherlands)

    HUYEN, N. T.; FRYGANAS, C.; UITTENBOGAARD, G.; MUELLER-HARVEY, I.; VERSTEGEN, M. W. A.; HENDRIKS, W. H.; PELLIKAAN, W. F.

    2016-01-01

    An in vitro study was conducted to investigate the effects of condensed tannin (CT) structural properties, i.e. average polymer size (or mean degree of polymerization), percentage of cis flavan-3-ols and percentage of prodelphinidins in CT extracts on methane (CH 4 ) production and fermentation

  13. Structural features of condensed tannins affect in vitro ruminal methane production and fermentation characteristics

    NARCIS (Netherlands)

    Huyen, N.T.; Fryganas, C.; Uittenbogaard, G.; Mueller-Harvey, I.; Verstegen, M.W.A.; Hendriks, W.H.; Pellikaan, W.F.

    2016-01-01

    An in vitro study was conducted to investigate the effects of condensed tannin (CT) structural properties, i.e. average polymer size (or mean degree of polymerization), percentage of cis flavan-3-ols and percentage of prodelphinidins in CT extracts on methane (CH4) production and

  14. Structural and optical characteristics of Ce, Nd, Gd, and Dy-doped ...

    Indian Academy of Sciences (India)

    Ashwini S Varpe

    2017-06-19

    Jun 19, 2017 ... Our optimized parameters are as follows: the nozzle to substrate distance = 16 cm, flow rate = 7 ml/min, and spray time = 20min. The glass substrate temperature is maintained at 400. ◦. C. The RE doping level is varied by changing the concentration of the. RE element by 0.5, 1, 3, and 5 mol%. The structural.

  15. Characteristics of cassava starch fermentation wastewater based on structural degradation of starch granules

    Directory of Open Access Journals (Sweden)

    Juliane Mascarenhas Pereira

    2016-01-01

    Full Text Available ABSTRACT: Sour cassava starch is a naturally modified starch produced by fermentation and sun drying, achieving the property of expansion upon baking. Sour cassava starch' bakery products can be prepared without the addition of yeast and it is gluten free. The fermentation process associated with this product has been well studied, but the wastewater, with high acidity and richness in other organic compounds derived from starch degradation, requires further investigation. In this study, the structure of solids present in this residue was studied, seeking to future applications for new materials. The solids of the wastewater were spray dried with maltodextrin (MD with dextrose equivalent (DE of 5 and 15 and the structure of the powder was evaluated by scanning electron microscopy. A regular structure with a network arrangement was observed for the dried material with MD of 5 DE, in contrast to the original and fermented starches structure, which suggests a regular organization of this new material, to be studied in future applications.

  16. An Application of Structural Equation Modeling for Developing Good Teaching Characteristics Ontology

    Science.gov (United States)

    Phiakoksong, Somjin; Niwattanakul, Suphakit; Angskun, Thara

    2013-01-01

    Ontology is a knowledge representation technique which aims to make knowledge explicit by defining the core concepts and their relationships. The Structural Equation Modeling (SEM) is a statistical technique which aims to explore the core factors from empirical data and estimates the relationship between these factors. This article presents an…

  17. Effects of structural modifications on some physical characteristics of exopolysaccharides from Lactococcus lactis

    NARCIS (Netherlands)

    Tuinier, R.; Casteren, van W.H.M.; Looijesteijn, P.J.; Schols, H.A.; Voragen, A.G.J.; Zoon, P.

    2001-01-01

    The relationship between the primary structure and the chain stiffness of exopolysaccharides (EPSs) and modified EPSs produced by two strains of Lactococcus lactis subsp. cremoris was investigated. The molar mass and radius of gyration of these exopolysaccharides were analyzed by multiangle static

  18. [Isolation and partial structural characteristics of major toxic components of Latrodectus pallidus venom].

    Science.gov (United States)

    Charakha, A R; Shevchenko, L V; Molodkin, A K; Pluzhnikov, K A; Volkova, T M; Grishin, E V

    1997-03-01

    Toxic components of the Latrodectus pallidus spider venom were isolated and characterized. The venom was shown to contain a toxin specific for mammals and at least one insectospecific toxin. Partial amino acid sequences of both toxins were determined, and their high structural homology with previously studied alpha-latrotoxin and alpha-latroinsectotoxin from L. mactans tredecimguttatus was found.

  19. The impact of structural and functional characteristics of social relations as determinants of functional decline

    DEFF Research Database (Denmark)

    Avlund, Kirsten; Lund, Rikke; Holstein, Bjørn E

    2004-01-01

    pattern (n = 565); and third, mortality (n = 651). Social relations were measured at baseline by several items focusing on the structure and function of the social network. RESULTS: In men, no weekly telephone contact was related to functional decline and mortality. Among women, less than weekly telephone...

  20. Meetings all over the world: structural and psychological characteristics of meetings in different countries

    NARCIS (Netherlands)

    van Eerde, W.; Buengeler, C.; Allen, J.A.; Lehmann-Willenbrock, N.; Rogelberg, S.G.

    2015-01-01

    Previous research on work meetings has mainly been conducted in the Anglo-Saxon context. In this chapter, we add an international perspective that addresses this question: Does the national context of the meeting influence how it is structured and perceived? We provide a descriptive-comparative

  1. Structural and water-holding characteristics of untreated and ensiled chicory root pulp

    NARCIS (Netherlands)

    Ramasamy, U.; Gruppen, H.; Schols, H.A.

    2013-01-01

    Cell wall polysaccharides (CWPs) from chicory root pulp (CRP) and the effect of ensiling on CWP structure to reduce the water-holding capacity (WHC) were studied. Sequential extractions of CRP showed that hot water extraction solubilized arabinan-rich pectin and inulin, each representing 6% of all

  2. Lagrangian coherent structures and turbulence characteristics downstream of prosthetic aortic valves

    Science.gov (United States)

    de Tullio, Marco D.

    2015-11-01

    The flowfield through prosthetic heart valves is investigated by means of direct numerical simulations, considering the fully coupled fluid-structure interaction problem. Two different aortic valve models are modeled: a bileaflet mechanical and a biological one. In order to reveal fluid flow structures and to better understand the transport mechanics, Lagrangian coherent structures (LCS) are used. LCS are distinguished material surfaces that can be identified as boundaries to regions with dynamically distinct behavior, and are revealed as hypersurfaces that locally maximize the finite-time Lyapunov exponent (FTLE) fields. Post-processing the flow simulation data, first FTLE fields are calculated integrating dense meshes of Lagrangian particles backward in time, and then attracting LCS are extracted. A three-jet configuration is distinctive of bi-leaflet mechanical valves, with higher turbulent shear stresses immediately distal to the valve leaflets, while a jet-like flow emerges from the central orifice of bio-prosthetic valves, with high turbulent shear stresses occurring at the edge of the jet. Details of the numerical methodology along with a thorough analysis of the different flow structures developing during the cardiac cycle for the two configurations will be provided.

  3. The functional and structural characteristics of the emotion network in alexithymia

    Directory of Open Access Journals (Sweden)

    Han D

    2018-04-01

    Full Text Available Dai Han,1–3 Mei Li,4 Minjun Mei,4 Xiaofei Sun4 1Institutes of Psychological Sciences, Hangzhou Normal University, Hangzhou, Zhejiang, China; 2Children and Adolescents Mental Health Joint Clinic, The Affiliated Hospital of Hangzhou Normal University, Hangzhou, Zhejiang, China; 3Zhejiang Key Laboratory for Research in Assessment of Cognitive Impairments, Hangzhou, Zhejiang, China; 4Mental Health Education and Counseling Center, Hangzhou Normal University, Hangzhou, Zhejiang, China Background: Alexithymia is a multifaceted personality trait characterized by emotional dysfunction.Methods: In this study, the functional and structural features of the emotion network in alexithymia were investigated using resting-state functional MRI (rsfMRI, voxel-based morphometry (VBM, functional connectivity (FC analysis, and diffusion tensor imaging (DTI. Alexithymic and non-alexithymic students were recruited from the local university. The intrinsic neural activity and gray matter density of the brain regions in the emotion network were measured using rsfMRI and VBM; the FC and structural connectivity of the brain regions in the emotion network were measured using FC analysis and DTI.Results: The altered intrinsic neural activity in V1, rostral dorsal anterior cingulate cortex, and left amygdala, and the weak FC between V1 and left superior temporal gyrus and V1 and left paracentral lobule in alexithymia subjects were identified. However, no alteration of the structure and structural connectivity of the emotion network was identified.Conclusion: The results indicated that the development of alexithymia might have been caused only by slight alteration of the neural activity. Furthermore, the results suggest that noninvasive treatment technologies for improving the brain activity are suitable for alexithymic individuals. Keywords: emotion network, rsfMRI, VBM, functional connectivity, structural connectivity

  4. Polarizing properties and structural characteristics of the cuticle of the scarab Beetle Chrysina gloriosa

    International Nuclear Information System (INIS)

    Fernández del Río, Lía; Arwin, Hans; Järrendahl, Kenneth

    2014-01-01

    The scarab beetle Chrysina gloriosa is green with gold-colored stripes along its elytras. The properties of light reflected on these areas are investigated using Mueller-matrix spectroscopic ellipsometry. Both areas reflect light with high degree of left-handed polarization but this effect occurs for specular reflection for the gold-colored areas and for off-specular angles for the green areas. The colors and polarization phenomena originate from reflection of light in the cuticle and a structural analysis is presented to facilitate understanding of the different behaviors of these two areas. Scanning electron microscopy (SEM) images of the cross section of beetle cuticles show a multilayered structure. On the gold-colored areas the layers are parallel to the surface whereas on the green-colored areas they form cusp-like structures. Optical microscopy images show a rather flat surface in the gold-colored areas compared to the green-colored areas which display a net of polygonal cells with star-shaped cavities in the center. Each of the polygons corresponds to one of the cusps observed in the SEM images. Atomic force microscopy images of the star-shaped cavities are also provided. The roughness of the surface and the cusp-like structure of the green-colored areas are considered to cause scattering on this area. - Highlights: • Chrysina gloriosa reflects light with high degree of left-handed polarization. • Gold-colored areas are good specular reflectors whereas green-colored areas scatter light. • The cusp-like structure in the green areas is responsible for the scattering

  5. Changing circulation structure and precipitation characteristics in Asian monsoon regions: greenhouse warming vs. aerosol effects

    Science.gov (United States)

    Lau, William K. M.; Kim, Kyu-Myong; Ruby Leung, L.

    2017-12-01

    Using model outputs from CMIP5 historical integrations, we have investigated the relative roles of anthropogenic emissions of greenhouse gases (GHG) and aerosols in changing the characteristics of the large-scale circulation and rainfall in Asian summer monsoon (ASM) regions. Under GHG warming, a strong positive trend in low-level moist static energy (MSE) is found over ASM regions, associated with increasing large-scale land-sea thermal contrast from 1870s to present. During the same period, a mid-tropospheric convective barrier (MCB) due to widespread reduction in relative humidity in the mid- and lower troposphere is strengthening over the ASM regions, in conjunction with expanding areas of anomalous subsidence associated with the Deep Tropical Squeeze (Lau and Kim in Proc Natl Acad Sci 12:3630-3635, 2015). The opposing effects of MSE and MCB lead to enhanced total ASM rainfall, but only a partial strengthening of the southern portion of the monsoon meridional circulation, coupled to anomalous multi-cellular overturning motions over ASM land. Including anthropogenic aerosol emissions strongly masks MSE but enhances MCB via increased stability in the lower troposphere, resulting in an overall weakened ASM circulation with suppressed rainfall. Analyses of rainfall characteristics indicate that under GHG, overall precipitation efficiency over the ASM region is reduced, manifesting in less moderate but more extreme heavy rain events. Under combined effects of GHG and aerosols, precipitation efficiency is unchanged, with more moderate, but less extreme rainfall.

  6. Barrier lowering effect and dark current characteristics in asymmetric GaAs/AlGaAs multi quantum well structure

    Energy Technology Data Exchange (ETDEWEB)

    Altin, E. [Inonu University, Scientific and Technological Research Center, Malatya (Turkey); Anadolu University, Department of Physics, Eskisehir (Turkey); Hostut, M. [Akdeniz University, Department of Secondary Education of Science and Maths., Division of Physics Education, Antalya (Turkey); Ergun, Y. [Anadolu University, Department of Physics, Eskisehir (Turkey)

    2011-12-15

    In this study, we investigate dark current voltage characteristics of GaAs/AlGaAs staircase-like asymmetric multiquantum well structure at various temperatures experimentally. The activation energy is calculated by using Arrhenius plots at different voltages. It is found that the activation energy decreased with increasing electric field. This result is evaluated using a barrier lowering effect which is a combination of geometrical and Poole-Frenkel effects. Measured dark current density-voltage (J-V) characteristics compared with the Levine model, 3D carrier drift model and the emission capture model. The best agreement with the experimental results of dark current densities is obtained by the Levine model. (orig.)

  7. Structural Characteristics and Magnetic Properties of Al2O3 Matrix-Based Co-Cermet Nanogranular Films

    Directory of Open Access Journals (Sweden)

    Giap Van Cuong

    2015-01-01

    Full Text Available Magnetic micro- and nanogranular materials prepared by different methods have been used widely in studies of magnetooptical response. However, among them there seems to be nothing about magnetic nanogranular thin films prepared by a rf cosputtering technique for both metals and insulators till now. This paper presented and discussed preparation, structural characteristics, and magnetic properties of alumina (Al2O3 matrix-based granular Co-cermet thin films deposited by means of the cosputtering technique for both Co and Al2O3. By varying the ferromagnetic (Co atomic fraction, x, from 0.04 to 0.63, several dominant features of deposition for these thin films were shown. Structural characteristics by X-ray diffraction confirmed a cermet-type structure for these films. Furthermore, magnetic behaviours presented a transition from paramagnetic- to superparamagnetic- and then to ferromagnetic-like properties, indicating agglomeration and growth following Co components of Co clusters or nanoparticles. These results show a typical granular Co-cermet feature for the Co-Al2O3 thin films prepared, in which Co magnetic nanogranules are dispersed in a ceramic matrix. Such nanomaterials can be applied suitably for our investigations in future on the magnetooptical responses of spinplasmonics.

  8. Comparison among structural characteristics of Ce1-xCuxO2 nanocatalysts obtained by two methods of distinct synthesis

    International Nuclear Information System (INIS)

    Neiva, L.S.; Bispo, A.; Santos, P.T.A.; Costa, A.C.F.M.; Gama, L.; Mascarenhas, A.J.S.

    2009-01-01

    The objective this work is to synthesize nano catalysts Ce 1-x Cu x O 2 type by the synthesis methods of the combustion reaction and Pechini. The value of the concentration (x) of the element dope (Cu) varies between 0,1 and 0,5 mols. It intends evaluate that form the synthesis method influences in the physical structural characteristics of this material. nano catalysts were characterized by ray- X diffraction. The results showed nano catalysts formation with a formed structure for the most part by the phase CeO 2 , as it was expected, since this is the hostess matrix of the element dope (Cu). Nano catalysts obtained by the method Pechini presents crystallinity larger deg, according with patterns of ray-X. Thus, it was concluded that synthesis employee method the kind in the methodology, as well as the value of the concentration of the element dope has influence on the final structural characteristics of the developed material. (author)

  9. Nurse characteristics, leadership, safety climate, emotional labour and intention to stay for nurses: a structural equation modelling approach.

    Science.gov (United States)

    Liang, Hui-Yu; Tang, Fu-In; Wang, Tze-Fang; Lin, Kai-Ching; Yu, Shu

    2016-12-01

    The aim of this study was to propose a theoretical model and apply it to examine the structural relationships among nurse characteristics, leadership characteristics, safety climate, emotional labour and intention to stay for hospital nurses. Global nursing shortages negatively affect the quality of care. The shortages can be reduced by retaining nurses. Few studies have independently examined the relationships among leadership, safety climate, emotional labour and nurses' intention to stay; more comprehensive theoretical foundations for examining nurses' intention to stay and its related factors are lacking. Cross-sectional. A purposive sample of 414 full-time nurses was recruited from two regional hospitals in Taiwan. A structured questionnaire was used to collect data from November 2013-June 2014. Structural equation modelling was employed to test the theoretical models of the relationships among the constructs. Our data supported the theoretical model. Intention to stay was positively correlated with age and the safety climate, whereas working hours per week and emotional labour were negatively correlated. The nursing position and transformational leadership indirectly affected intention to stay; this effect was mediated separately by emotional labour and the safety climate. Our data supported the model fit. Our findings provide practical implications for healthcare organizations and administrators to increase nurses' intent to stay. Strategies including a safer climate, appropriate working hours and lower emotional labour can directly increase nurses' intent to stay. Transformational leadership did not directly influence nurses' intention to stay; however, it reduced emotional labour, thereby increasing intention to stay. © 2016 John Wiley & Sons Ltd.

  10. A comparative study of thermal characteristics of GaN-based VCSELs with three different typical structures

    Science.gov (United States)

    Mei, Yang; Xu, Rong-Bin; Xu, Huan; Ying, Lei-Ying; Zheng, Zhi-Wei; Zhang, Bao-Ping; Li, Mo; Zhang, Jian

    2018-01-01

    Thermal characteristics of GaN-based vertical cavity surface emitting lasers (VCSELs) with three typical structures were investigated both theoretically and experimentally. The simulation results based on a steady state quasi three-dimensional cylindrical model show that the thermal resistance (R th) is affected by cavity length, mesa size, as well as the bottom distributed Bragg reflector (DBR) size, and the detail further depends on different structures. Among different devices, GaN VCSEL with a hybrid cavity formed by one nitride bottom DBR and another dielectric top DBR is featured with lower R th, which is meanwhile affected strongly by the materials of the epitaxial bottom DBR. The main issues affecting the thermal dissipation in VCSELs with double dielectric DBRs are the bottom dielectric DBR and the dielectric current-confinement layer. To validate the simulation results, GaN-based VCSEL bonded on a copper plate was fabricated. R th of this device was measured and the results agreed well with the simulation. This work provides a better understanding of the thermal characteristics of GaN-based VCSELs and is useful in optimizing the structure design and improving the device performance.

  11. Physical and electrical characteristics of metal/Dy{sub 2}O{sub 3}/p-GaAs structure

    Energy Technology Data Exchange (ETDEWEB)

    Saghrouni, H., E-mail: hayet_sagrouni@yahoo.fr [Université de Sousse, Laboratoire Energie-Matériaux, Ecole Supérieure des Sciences et de la Technologie, Rue Lamine Abessi, 4011 Hammam Sousse (Tunisia); Université de Sousse, Laboratoire Energie-Matériaux, Groupe de Recherche Nano-Matériaux pour les Télécommunications, Institut Supérieur d’informatique et des Techniques de Communications, Gp1 4011 Hammam Sousse (Tunisia); Jomni, S.; Belgacem, W. [Laboratoire de matériaux, organisation et proprieties, Faculté des Sciences de Tunis, Université de Tunis El Manar (Tunisia); Hamdaoui, N. [Université de Sousse, Laboratoire Energie-Matériaux, Ecole Supérieure des Sciences et de la Technologie, Rue Lamine Abessi, 4011 Hammam Sousse (Tunisia); Beji, L. [Université de Sousse, Laboratoire Energie-Matériaux, Ecole Supérieure des Sciences et de la Technologie, Rue Lamine Abessi, 4011 Hammam Sousse (Tunisia); Université de Sousse, Laboratoire Energie-Matériaux, Groupe de Recherche Nano-Matériaux pour les Télécommunications, Institut Supérieur d’informatique et des Techniques de Communications, Gp1 4011 Hammam Sousse (Tunisia)

    2014-07-01

    This paper describes the effect of post-deposition annealing on the physical and electrical characteristics of high-k Dy{sub 2}O{sub 3} dielectric films deposited at 250 °C on p-GaAs substrate by electron beam deposition under ultra vacuum. The morphological and structural features of Dy{sub 2}O{sub 3} layer before and after postdeposition annealing were studied by atomic force microscopy (AFM) and X-ray diffraction (XRD). The surface topography analysis reveals that the Dy{sub 2}O{sub 3} film is granular, and contains numerous contacts between columnar grains. While investigating the electrical properties Dy{sub 2}O{sub 3} oxide, the current–voltage characteristics I(V) suggest a Poole–Frenkel (PF) type mechanism of carrier transport for as-deposited and annealed layers. A deviation from the PF leakage current course was found and attributed to the current carrier trapping. The ac impedance properties of the structures have been studied in a wide frequency range at different bias voltage. The Dy{sub 2}O{sub 3} annealed exhibited excellent electrical properties such as small density of interface state and low leakage current. This phenomenon is attributed to a rather crystallized Dy{sub 2}O{sub 3} structure and the reduction of the defects at the oxide/GaAs interface.

  12. Photocapacitance characteristics of (In,Ga)N/GaN MQW structures

    International Nuclear Information System (INIS)

    Rivera, C.; Pau, J.L.; Munoz, E.; Ive, T.; Brandt, O.

    2006-01-01

    Photocapacitance techniques have been used to study the electronic properties of (In,Ga)N/GaN quantum wells (QWs). Negative differential capacitance (NDC) features were observed at room temperature for the first time in capacitance-voltage (C-V) experiments under optical excitation. A detailed analysis of the results seems to indicate that charge accumulation in quantum dot-like structures embedded in the QWs could be responsible of such behaviour. Polarization field effects present in these structures are detected through C-V hysteresis, allowing to estimate built-in electric fields as high as 1.9 MV/cm in 14% In QWs. (copyright 2006 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  13. Supramolecular Structure and Mechanical Characteristics of Ultrahigh-Molecular-Weight Polyethylene-Inorganic Nanoparticle Nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Okhlopkova, T. A.; Borisova, R. V.; Nikiforov, L. A.; Spiridonov, A. M.; Okhlopkova, A. A.; Cho, Jin-Ho [North-Eastern Federal University, Yakutsk (Russian Federation); Jeong, Dae-Yong [Inha University, Incheon (Korea, Republic of)

    2016-04-15

    We investigated the mechanical properties and structure of polymeric nanocomposites (PNCs) with anultrahigh-molecular-weight polyethylene (UHMWPE) matrix and aluminum and silicon oxide and nitride nanoparticle (NP) fillers. Mixing with a paddle mixer or by joint mechanical activation in a planetary mill was used for the PNC preparation. Joint mechanical activation afforded PNCs with better mechanical properties than paddle mixing. Scanning electron microscopy suggested that the poorer mechanical properties can be attributed to the disordered regions and imperfect spherulites in the PNC supramolecular structure arising from paddle mixing. The better mechanical properties observed with joint mechanical activation may derive from the uniform NP distribution in the polymer matrix and absence of disordered regions.

  14. Sulfonated polyaniline: influence of sulfonation routes on its thermal and structural characteristics

    Directory of Open Access Journals (Sweden)

    Luis Claudio Mendes

    2011-12-01

    Full Text Available In order to study the influence of different sulfonation routes on its thermal and structural properties sulfonated polyaniline (SPAni was prepared. FT-IR revealed that the formation of PAni salt or ring sulfonation depends on the route. UV-visible spectra pointed out that the level of the PAni protonation was dependent on the sulfonation route. A new approach was given for TG/DTG and DSC results correlating different energy levels with the distinguished sulfonation routes. The TG/DTG degradation steps and the amount of the released material corroborated the structural differences of the polyanilines. For each DSC first regime of heating, a broad and intense peak (from -30 to 250 ºC with different level of energy was noticed. That peak could be ascribed to the multiple relaxations and breaking of the PAni intra and inter hydrogen bonds after sulfonation.

  15. Working principle and structure characteristics analysis of the reactivity control drive mechanism

    International Nuclear Information System (INIS)

    Zhao Tianyu; Huang Zhiyong; Chen Feng; He Xuedong

    2010-01-01

    The startup, power regulation and safety shutdown of the nuclear reactor are operated by the reactivity control devices. Reactivity control drive mechanism is a key mechanical transmission component, which directly control the location of the neutron absorber in the core. Its working condition is complex, and its service life should be long., which requires high reliability. PWR as well as newly developed different type of reactors have different control devices drive mechanism. This paper mainly do analysis and comparison about the working environment, mechanical transmission principle, structure, performance, service life and other aspects of PWR, HTR control devices drive mechanism. In addition, this paper is also based on the working principles of reactive control devices drive mechanism, also consider the trends of its design and test verification by the international countries, and discussed the method and feasibility of improving and perfecting the structure and function of drive mechanism. (authors)

  16. Structural, electronic, and magnetic characteristics of Np.sub.2./sub.Co.sub.17./sub..

    Czech Academy of Sciences Publication Activity Database

    Halevy, I.; Hen, A.; Orion, I.; Colineau, E.; Eloirdi, R.; Griveau, J.C.; Gaczyński, E.; Wilhelm, F.; Rogalev, A.; Sanchez, J.-P.; Winterrose, M.L.; Magnani, N.; Shick, Alexander; Caciuffo, R.

    2012-01-01

    Roč. 85, č. 1 (2012), "01443-1"-"01443-8" ISSN 1098-0121 R&D Projects: GA ČR(CZ) GAP204/10/0330; GA AV ČR IAA100100912 Institutional research plan: CEZ:AV0Z10100520 Keywords : magnetic materials * XMCD * electronic structure Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 3.767, year: 2012 http://link.aps.org/doi/10.1103/PhysRevB.85.014434

  17. Structural Characteristics and Swelling Mechanism of Two Commercial Nitrile-Butadiene Elastomers in Various Fluids

    Science.gov (United States)

    2012-01-06

    reported here. The fluids used in these investigations included toluene, o- xylene , p- xylene , mesitylene, HISOL- 15, n-hexane, ethanol, tert-butyl...were monitored as a function of time. Structural characterization of the elastomer was done using x-ray diffraction and FTIR spectroscopy. Time...fluids are reported here. The fluids used in these investigations included toluene, o- xylene , p- xylene , mesitylene, HISOL-15, n-hexane, ethanol, tert

  18. Effects of anisotropy on structural and optical characteristics of LYSO:Ce crystal

    Czech Academy of Sciences Publication Activity Database

    Ding, D.; Yang, J.; Ren, G.; Nikl, Martin; Wang, S.; Wu, Y.; Mao, Z.

    2014-01-01

    Roč. 251, č. 6 (2014), s. 1202-1211 ISSN 0370-1972 R&D Projects: GA MŠk LH12185 Institutional support: RVO:68378271 Keywords : anisotropic properties * LYSO:Ce * optical properties * scintillation crystals * structural properties Subject RIV: BM - Solid Matter Physics ; Magnetism OBOR OECD: Condensed matter physics (including formerly solid state physics, supercond.) Impact factor: 1.489, year: 2014

  19. Structural and Optical Characteristics of Metamorphic Bulk InAsSb

    Science.gov (United States)

    2014-01-01

    heterostructure detectors with bulk InAsSb absorbers and AlSb -based barriers. These structures can outperform InSb homojunction photodetectors operating...Wu B.-R., Liao C., and Cheng K. Y., “High quality InAsSb grown on InP substrates using AlSb /AlAsSb buffer layers”, Appl. Phys. Lett., 92, 062111

  20. Sulfonated polyaniline: influence of sulfonation routes on its thermal and structural characteristics

    OpenAIRE

    Mendes,Luis Claudio; Falco,Ana Paula Santiago; Pinho,Magali Silveira; Marques,Priscila Oliveira

    2011-01-01

    In order to study the influence of different sulfonation routes on its thermal and structural properties sulfonated polyaniline (SPAni) was prepared. FT-IR revealed that the formation of PAni salt or ring sulfonation depends on the route. UV-visible spectra pointed out that the level of the PAni protonation was dependent on the sulfonation route. A new approach was given for TG/DTG and DSC results correlating different energy levels with the distinguished sulfonation routes. The TG/DTG degrad...

  1. Rainfall-induced landslide vulnerability Assessment in urban area reflecting Urban structure and building characteristics

    Science.gov (United States)

    Park, C.; Cho, M.; Lee, D.

    2017-12-01

    Landslide vulnerability assessment methodology of urban area is proposed with urban structure and building charateristics which can consider total damage cost of climate impacts. We used probabilistic analysis method for modeling rainfall-induced shallow landslide susceptibility by slope stability analysis and Monte Carlo simulations. And We combined debris flows with considering spatial movements under topographical condition and built environmental condition. Urban vulnerability of landslide is assessed by two categories: physical demages and urban structure aspect. Physical vulnerability is related to buildings, road, other ubran infra. Urban structure vulnerability is considered a function of the socio-economic factors, trigger factor of secondary damage, and preparedness level of the local government. An index-based model is developed to evaluate the life and indirect damage under landslide as well as the resilience ability against disasters. The analysis was performed in a geographic information system (GIS) environment because GIS can deal efficiently with a large volume of spatial data. The results of the landslide susceptibility assessment were compared with the landslide inventory, and the proposed approach demonstrated good predictive performance. The general trend found in this study indicates that the higher population density areas under a weaker fiscal condition that are located at the downstream of mountainous areas are more vulnerable than the areas in opposite conditions.

  2. Structural characteristic of the Eastern Plains soils of Colombia, submitted to several handling systems

    International Nuclear Information System (INIS)

    Amezquita, E; Saenz J I; Thomas, R J; Vera, R R; Hoyos, P; Molina, D L; Chavez, L F

    1997-01-01

    Soil productivity and sustainability depends on the building and/or conservation of an adequate and dynamic equilibrium between physical, chemical and biological properties and processes in the volume of soil explored by roots, so that there is no constraints in the availability of water and nutrients to plants. Soil structure is one of the soil properties that are more vulnerable to the intensity of use in tropical soils. Aggregate size distribution, aggregate stability and pore size distribution are some of the attributes that are usually used to describe structural changes and can act as indicators of structural sustainability. This paper presents and discusses the behavior of these attributes under different soil management treatments (native savanna, Brachiaria alone; Brachiaria + legume and monocrop) in the Colombian Eastern plains soil classified as Typic haplustox Kaolinitic iso-hyperthermic. These results showed highly statistical significant differences between treatments in the parameters studied and allow concluding that aggregate size distribution and stability could be indicators of susceptibility to degradation

  3. Comparative characteristics structure physically prepared fighters high qualification light, medium and heavy weight category

    Directory of Open Access Journals (Sweden)

    O.O. Pryimakov

    2014-09-01

    Full Text Available Purpose : study of the structure of physical preparedness (PP highly skilled fighters of different weight categories. Material : 147 athletes surveyed in separate weight classes. Recorded 26 indicators PP. Results : It was found that the mass of fighters is an important determinant of the level of development, value and structure of the phase relationship indicators. Informative indices PP interrelated with weight category fighters are: Runtime 45 shots in a specialized test, the number of pull-ups in the maximum rate of 10 seconds and the maximum number is not limited to a run-time while climbing a rope to a height of 4 m, height of jumps up to space. With the increase in the weight category of fighters dropping speed, relative strength, speed and power endurance, reduced muscle explosive quality, the level of special performance. Same relationship PP indicators reflecting its structure changed insignificantly. Conclusions : The developed regression models should be used for modeling and prediction of individual athletes sides PP light, medium and heavy weight categories, construction of group regulatory assessment scales.

  4. Microbial community structure characteristics associated membrane fouling in A/O-MBR system.

    Science.gov (United States)

    Gao, Da-Wen; Wen, Zhi-Dan; Li, Bao; Liang, Hong

    2014-02-01

    The study demonstrated the potential relationship between microbial community structure and membrane fouling in an anoxic-oxic membrane bioreactor (A/O-MBR). The results showed that the microbial community structure in biocake was different with aerobic mixture, and the dominant populations were out of sync during the fouling process. Based on microbial community structure and metabolites analysis, the results showed that the succession of microbial community might be the leading factor to the variation of metabolites, and it might be the primary cause of membrane fouling. The rise of Shannon diversity index (H) of the microbial community in A/O-MBR went with the gradually serious membrane fouling. Pareto-Lorenz curve was used to describe the evenness of microbial distribution in A/O-MBR, and the result indicated when community evenness was low, the membrane fouling took place smoothly or slightly, otherwise, high evenness of microbial community would lead to more seriously membrane fouling. Copyright © 2013 Elsevier Ltd. All rights reserved.

  5. Structural characteristics and corrosion behavior of biodegradable Mg-Zn, Mg-Zn-Gd alloys.

    Science.gov (United States)

    Kubásek, J; Vojtěch, D

    2013-07-01

    In this research, binary Mg-Zn (up to 3 wt% Zn) and ternary Mg-Zn-Gd (up to 3 wt% Gd, 3 wt% Zn) alloys were prepared by induction melting in an argon atmosphere. The structures of these alloys were characterized using light and scanning electron microscopy, energy dispersive spectrometry, X-ray diffraction and X-ray fluorescence. In addition, Brinell hardness measurements were taken to supplement these studies. Corrosion behavior was evaluated by immersion tests and potentiodynamic measurements in a physiological solution (9 g/l NaCl). Depending on the composition, structures of the as-cast alloys contained α-Mg dendrites, MgZn, Mg5Gd and Mg3Gd2Zn3 phases. Compared to pure Mg, zinc improved the corrosion resistance of binary Mg-Zn. Gadolinium also improved the corrosion resistance in the case of Mg-1Zn-3Gd alloy. The highest corrosion rate was observed for Mg-3Zn-3Gd alloy. Our results improve the understanding of the relationships between the structure and corrosion behavior of our studied alloy systems.

  6. BONE ALLOGRAFTING IN REVISION KNEE ARTHROPLASTY: HISTOLOGICAL CHARACTERISTICS OF STRUCTURAL ALLOGRAFTS 54 MONTHS FOLLOW UP

    Directory of Open Access Journals (Sweden)

    T. A. Kuliaba

    2016-01-01

    Full Text Available Compensation of large bone defects by AORI third type classification is the most difficult problem the audit knee arthroplasty. In this situation, the surgeon have to choose between three possibilities: to use metal cones/sleeves, and, in cases with severely damaged metaepiphysis, to use structural allografts or oncological megaimplants. No doubt, it is interesting to follow the processes that are taking place with massive structural allografts implanted into the human body long time ago. This article presents the case study of the rheumatoid arthritis patient’s treatment with a severe lesion of the knee joint, subjected to repeated revision surgeries, last two of which are made with the use of massive structural allograft of femur. Morphological study of a massive distal femur allograft in 54 months after surgery showed that superficial ingrowth of connective tissue and blood vessels happens on the allograft’s border with its partial restructuring of the bone tissue at the border with the recipient bone. However, the most of allograft remains unchanged even after 54 months after surgery.

  7. Structural, physical and electrochemical characteristics of a vanadium oxysulfide, a cathode material for lithium batteries

    Science.gov (United States)

    Ouvrard, G.; Tchangbédji, G.; Deniard, P.; Prouzet, E.

    A vanadium oxysulfide is obtained by a reaction between water solutions of a vanadyl salt and sodium sulfide at room temperature. After drying under mild conditions, the formulation of this phase is V 2O 3S·3H 2O. Thermogravimetric analyses show that it is not possible to remove completely water without losing sulfur. This is in agreement with proton nuclear magnetic resonance experiments which prove that water molecules are tightly bonded to vanadium. Magnetic susceptibility and X-ray absorption spectroscopy measurements allow to define the oxidation states of vanadium and sulfur, (IV) and (-II) respectively. From extended X-ray absorption fine structure spectroscopy at the vanadium K edge and infrared spectroscopy, the local structure around vanadium can be defined as a distorted octahedron, with a vanadyl bond and an opposite sulfur atom. Magnetic susceptibility and X-ray absorption spectroscopy measurements on chemically lithiated compounds show a complex charge transfer from lithium to the host structure upon lithium intercalation. If it appears that vanadium atoms are reduced, a possible role of sulfur atoms in the redox process has to be considered. Cycling tests of lithium batteries whose positive consists of oxysulfide are promising with 70 cycles under a regime of {C}/{8}, without noticeable loss in capacity of 120 Ah/kg.

  8. THE MODEL CHARACTERISTICS OF JUMP ACTIONS STRUCTURE OF HIGH PERFORMANCE FEMALE VOLLEYBALL PLAYERS

    Directory of Open Access Journals (Sweden)

    Stech M.

    2012-12-01

    Full Text Available The purpose of this study was to develop generalized and individual models of the jump actions of skilled female volleyball players. The main prerequisite for the development of the jump actions models were the results of our earlier studies of factor structure of jump actions of 10 sportswomen of the Polish volleyball team "Gedania" (Premier League in the preparatory and competitive periods of the annual cycle of preparation. The athletes age was 22.0 +- 2.9 years, the sports experience - 8.1 +- 3.1 years, body height - 181.9 +- 8.4 years and body weight - 72.8 +- 10.8 kg. Mathematical and statistical processing of the data (the definition of M ± SD and significant differences between the samples was performed using a standard computer program "STATISTICA 7,0". Based on the analysis of the factor structure of 20 jump actions of skilled women volleyball players determined to within 5 of the most informative indexes and their tentative values recommended for the formation of a generalized model of this structure. Comparison of individual models of jump actions of skilled women volleyball players with their generalized models in different periods of preparation can be used for the rational choice of means and methods for the increasing of the training process efficiency.

  9. A new structure design and the basic radiation characteristics test of the intense current tube

    Science.gov (United States)

    Li, Zhiyuan; Ai, Xianyun; Fu, Li; Cui, Hui

    2018-02-01

    As a kind of special G-M counter, the intense current tube (ICT) is characterized by small ratio of cathode to anode radius, high working current or count rate, and can be used as the detection units of ultra-high range radiation instruments. In this paper, a new design of ICT structure is introduced, not only does it have a minimum ratio of cathode to anode but it also has a cathode which directly sticks out from the sensitive gas. Using COMSOL Multiphysics, we simulated the electric field between the anode and cathode and finalized the optimal structure. The results of processes and experiments show that the structure has better properties, with plateau slope reaching up to 7.4% within 100V, and it also has a wider range of dose rate. The linear data between the bottom limit of 0.2mGy/h and the upper limit of 1Gy/h is quite accurate but it becomes less reliable beyond 1Gy/h. By using Paralyzable model, we deduce that the dead time of the said ICT is less than 13.4 µs, and we will further optimize the readout circuit in order to reduce the resolution time of the circuit in the near future.

  10. Thermal stability and structural characteristics of PTHF–Mmt organophile nanocomposite

    Directory of Open Access Journals (Sweden)

    Youcef Hattab

    2015-05-01

    The objective of this study is to use organophilized montmorillonites in the presence of monomer tetrahydrofuran to obtain polytétrahydrofuran montmorillonites (PTHF–Mmt of composites by polymerization in situ. The organophilisation of the Mmt is formed by active cationic surface. The obtained results show an increase in the distance inside the reticular in the diffractograms of X-rays (DRX and the appearance of absorption bands of the characteristics of polytétrahydrofuran on the spectra of infrared spectroscopy (IR, which indicate pre-polymerization of tetrahydrofuran in the galleries of clay and, therefore, the obtaining of a nanocomposite. We have also studied the thermal stability of the samples by differential analysis calorimetric (DSC analysis, and we can conclude that the nanocomposites are stabilized thermally by the presence of clay in the matrix.

  11. Characteristics of cell-structure hadron calorimeter on the base of plastic scintillator mouldings

    International Nuclear Information System (INIS)

    Bityukov, S.I.; Semenov, V.K.; Yablokov, A.P.

    1987-01-01

    Design features are considered and the results of measurements of the characteristics of a full-scale hadron calorimeter with 1 m 2 aperture, about 8 t in weight and the 10x10 cm cell are presented. The polysterene scintillator made by the moulding method has been used in the calorimeter. The calorimeter is aimed at measuring neutron energy in experiments with hyperon beams. The calorimeter possesses a good spatial (14 mm at 37.5 GeV energy) and energy (0.7/√E) resolution and permits to detect both charged and neutral hadrons in the wide energy range. The calorimeter is easily producible and reliable in operation. The calorimetr design permits to assemble detectors of a large aperture by joining of some modules with 1x1 m cross section

  12. Structural similarity causes different category-effects depending on task characteristics

    DEFF Research Database (Denmark)

    Gerlach, Christian

    2001-01-01

    are more globally visually similar than artefacts, but that this difference between categories affects performance in different ways depending on task characteristics. Thus, the greater overlap between natural objects may be a disadvantage when the demand on perceptual differentiation is high (as......It has been suggested that category-specific impairments for natural objects may reflect that natural objects are more globally visually similar than artefacts and therefore more difficult to recognize following brain damage [Aphasiology 13 (1992) 169]. This account has been challenged...... by the finding that the 'normal' disadvantage claimed for natural objects may be reversed when items from the categories of natural objects and artefacts are matched for visual complexity, familiarity and name frequency [Neuropsychologia 37 (1999) 1263]. In the experiments reported here it was investigated...

  13. Hybrid nanocomposite based on cellulose and tin oxide: growth, structure, tensile and electrical characteristics

    International Nuclear Information System (INIS)

    Mahadeva, Suresha K; Kim, Jaehwan

    2011-01-01

    A highly flexible nanocomposite was developed by coating a regenerated cellulose film with a thin layer of tin oxide (SnO 2 ) by liquid-phase deposition. Tin oxide was crystallized in solution and formed nanocrystal coatings on regenerated cellulose. The nanocrystalline layers did not exfoliate from cellulose. Transmission electron microscopy and energy dispersive x-ray spectroscopy suggest that SnO 2 was not only deposited over the cellulose surface, but also nucleated and grew inside the cellulose film. Current-voltage characteristics of the nanocomposite revealed that its electrical resistivity decreases with deposition time, with the lowest value obtained for 24 h of deposition. The cellulose-SnO 2 hybrid nanocomposite can be used for biodegradable and disposable chemical, humidity and biosensors.

  14. Effects of improved microchannel structures on the separation characteristics of microchip capillary electrophoresis

    CERN Document Server

    Utsumi, Y; Ozaki, M; Terabe, S

    2003-01-01

    We fabricated the electrophoresis microchips using the UV polymerization technique. We employed plastic substrates that were suitable for rapid prototyping instead of glass and quartz. A thick UV negative photo resist was used to form molds and poly-dimethylsilozane (PDMS) was polymerized by a thermal curing process on the mold to obtain replica microchips. Electroosmotic flow (EOF) was measured to evaluate the surface. Rhodamine B and sulforhodamine B are successfully separated using the microchip. Characteristic differences between UV-fabricated and SR-fabricated microchips were evaluated by EOF measurement. It was observed that accurately defined microchannels fabricated by synchrotron radiation (SR) lithography show constant peak heights and FWHMs. Thus the advantage of the application of SR lithography to the mold fabrication is also demonstrated. (author)

  15. Structural Modeling and Characteristics Analysis of Flow Interaction Networks in the Internet

    International Nuclear Information System (INIS)

    Wu Xiao-Yu; Gu Ren-Tao; Pan Zhuo-Ya; Jin Wei-Qi; Ji Yue-Feng

    2015-01-01

    Applying network duality and elastic mechanics, we investigate the interactions among Internet flows by constructing a weighted undirected network, where the vertices and the edges represent the flows and the mutual dependence between flows, respectively. Based on the obtained flow interaction network, we find the existence of ‘super flow’ in the Internet, indicating that some flows have a great impact on a huge number of other flows; moreover, one flow can spread its influence to another through a limited quantity of flows (less than 5 in the experimental simulations), which shows strong small-world characteristics like the social network. To reflect the flow interactions in the physical network congestion evaluation, the ‘congestion coefficient’ is proposed as a new metric which shows a finer observation on congestion than the conventional one. (paper)

  16. Structural characteristics and collapse mechanism of the late Cretaceous Geumseongsan Caldera, SE Korea

    Science.gov (United States)

    Lee, S.; Cheon, Y.; Lee, Y.; Son, M.

    2017-12-01

    The Geumseongsan caldera provides an opportunity to understand the structural evolution of volcanic collapse and the role of paleostress. We focus on structural elements of the exhumed caldera floor to interpret the collapse mechanism. The caldera shows an NNW-trending elliptical shape (8×12 km). Basaltic and rhyolitic rocks are situated in the central high of the caldera, while pre-volcanic sedimentary rocks in the perimetric lowland of the volcanic rocks. Stratal attitudes change sharply from the outside to the inside of caldera bounded with a sub-vertical ring fault. The outside strata show a homocline toward SE about 15°, whereas the inside is divided into four structural domains (NE-, NW-, SE-, and SW-domains) based on the changing attitudes. The strata in NW- and SE-domains dip toward SE and NW, respectively, making an overall synclinal fold. While NE- and SW-domains comprise re-oriented, folded strata, which generally have NE- and SW-trending axes plunging toward the center. In addition, extensional and contractional structures occur distinctively in NW- and SE-domains and in NE- and SW-domains, respectively, indicating an axisymmetric deformation around NE-SW axis. The results indicate that higher horizontal mass movement toward the center occurred in NW- and SE-domains than in NE- and SW-domains while vertical mass movement was more active in the latter. This axisymmetric deformation could be produced by regional stress during the volcanic activity, which affected the collapse pattern of caldera floor. The regional stress field during the late Cretaceous is known as NW-SE horizontal maximum and NE-SW horizontal minimum stresses due to the oblique subduction of proto-Pacific Plate underneath Eurasian Plate. NNW-trending elliptical shape of the caldera is interpreted to have formed under the influence of this stresses, like a tension gash. The NW-SE maximum stress possibly acted to resist vertical displacement along the marginal fault of NW- and SE

  17. Effects of structural and dynamic family characteristics on the development of depressive and aggressive problems during adolescence. The TRAILS study.

    Science.gov (United States)

    Sijtsema, J J; Oldehinkel, A J; Veenstra, R; Verhulst, F C; Ormel, J

    2014-06-01

    Both structural (i.e., SES, familial psychopathology, family composition) and dynamic (i.e., parental warmth and rejection) family characteristics have been associated with aggressive and depressive problem development. However, it is unclear to what extent (changes in) dynamic family characteristics have an independent effect on problem development while accounting for stable family characteristics and comorbid problem development. This issue was addressed by studying problem development in a large community sample (N = 2,230; age 10-20) of adolescents using Linear Mixed models. Paternal and maternal warmth and rejection were assessed via the Egna Minnen Beträffande Uppfostran for Children (EMBU-C). Aggressive and depressive problems were assessed via subscales of the Youth/Adult Self-Report. Results showed that dynamic family characteristics independently affected the development of aggressive problems. Moreover, maternal rejection in preadolescence and increases in paternal rejection were associated with aggressive problems, whereas decreases in maternal rejection were associated with decreases in depressive problems over time. Paternal and maternal warmth in preadolescence was associated with fewer depressive problems during adolescence. Moreover, increases in paternal warmth were associated with fewer depressive problems over time. Aggressive problems were a stable predictor of depressive problems over time. Finally, those who increased in depressive problems became more aggressive during adolescence, whereas those who decreased in depressive problems became also less aggressive. Besides the effect of comorbid problems, problem development is to a large extent due to dynamic family characteristics, and in particular to changes in parental rejection, which leaves much room for parenting-based interventions.

  18. Calculation of the Schottky barrier and current–voltage characteristics of metal–alloy structures based on silicon carbide

    Energy Technology Data Exchange (ETDEWEB)

    Altuhov, V. I., E-mail: altukhovv@mail.ru; Kasyanenko, I. S.; Sankin, A. V. [North Caucasian Federal University, Institute of Service, Tourism and Design (Branch) (Russian Federation); Bilalov, B. A. [Dagestan State Technical University (Russian Federation); Sigov, A. S. [Moscow State Technical University of Radio Engineering, Electronics, and Automation (Russian Federation)

    2016-09-15

    A simple but nonlinear model of the defect density at a metal–semiconductor interface, when a Schottky barrier is formed by surface defects states localized at the interface, is developed. It is shown that taking the nonlinear dependence of the Fermi level on the defect density into account leads to a Schottky barrier increase by 15–25%. The calculated barrier heights are used to analyze the current–voltage characteristics of n-M/p-(SiC){sub 1–x}(AlN){sub x} structures. The results of calculations are compared to experimental data.

  19. Engineering characterization of ground motion. Task I. Effects of characteristics of free-field motion on structural response

    International Nuclear Information System (INIS)

    Kennedy, R.P.; Short, S.A.; Merz, K.L.; Tokarz, F.J.; Idriss, I.M.; Power, M.S.; Sadigh, K.

    1984-05-01

    This report presents the results of the first task of a two-task study on the engineering characterization of earthquake ground motion for nuclear power plant design. The overall objective of this study is to develop recommendations for methods for selecting design response spectra or acceleration time histories to be used to characterize motion at the foundation level of nuclear power plants. Task I of the study develops a basis for selecting design response spectra, taking into account the characteristics of free-field ground motion found to be significant in causing structural damage

  20. Engineering characterization of ground motion. Task I. Effects of characteristics of free-field motion on structural response

    Energy Technology Data Exchange (ETDEWEB)

    Kennedy, R.P.; Short, S.A.; Merz, K.L.; Tokarz, F.J.; Idriss, I.M.; Power, M.S.; Sadigh, K.

    1984-05-01

    This report presents the results of the first task of a two-task study on the engineering characterization of earthquake ground motion for nuclear power plant design. The overall objective of this study is to develop recommendations for methods for selecting design response spectra or acceleration time histories to be used to characterize motion at the foundation level of nuclear power plants. Task I of the study develops a basis for selecting design response spectra, taking into account the characteristics of free-field ground motion found to be significant in causing structural damage.

  1. Comparison of computer simulated and observed force deformation characteristics of anti-seismic devices and isolated structures

    International Nuclear Information System (INIS)

    Bhoje, S.B.; Chellapandi, P.; Chetal, S.; Muralikrishna, R.; Salvaraj, T.

    2002-01-01

    The paper discusses the finite element analysis of the force deformation characteristics of high damping rubber bearings, lead rubber bearings and natural rubber bearings. The dynamic response of structures isolated using bearings is also presented. The general purpose finite element program ABAQUS has been used for the numerical predictions under monotonic loads. For computing the dynamic response, a simplified model of the rubber bearing in the form of elasto-plastic system is used. This equivalent model is implemented using the computer code CASTEM-2000 and the dynamic response is obtained. The numerical results are found to match well with the experimental results. (author)

  2. Structural characteristics of internally mixed carbonaceous aggregates from Barcelona (Spain) during DAURE winter campaign

    Science.gov (United States)

    Coz, Esther; Casuccio, Gary S.; Robinson, Allen L.; Moreno, Teresa; Mohr, Claudia; Prevot, Andre S. H.; Artíñano, Begoña.

    2010-05-01

    Particle structure, understood as the characterization of size, morphology, texture and the spatial distribution of the different compounds at an individual particle level, influences carbonaceous aggregates behavior in the atmosphere and the respiratory system. Additionally, the absorption and scattering of light is modified by the particle structure and also influences water absorption and water vapor nucleation and, hence cloud formation, residence time in the atmosphere and removal processes. Two factors seem determinant in these processes: quantity of scattering material adsorbed onto the light absorbing core during the residence in the atmosphere and subsequent aging, and the spatial distribution of this condensed matter (commonly discussed as internally/externally mixtures). Morning, noon, afternoon, and evening samples were collected for electron microscopy analyses during 3 consecutive days during an atmospheric episode of thermal inversion in February 2009 in an urban background area within the city of Barcelona. The main goal of this study was to quantify the variations in morphology and state of mixture of carbonaceous soot-like aggregate structures observed during different times of the day. The study was part of the winter campaign: "Determination of the sources of atmospheric Aerosols in Urban and Rural Environments in the western Mediterranean" (DAURE, February/March 2009). The analysis of the aggregate structure was conducted by digital image analysis of several thousand particles to determine variations on size, shape and texture by means of several different mathematical descriptors such as aspect ratio/elongation, compactness and roughness through fractal dimension analysis, textural energy and entropy. Results indicate that carbon aggregates were mostly within 200-400 nm of geometric size, with slightly smaller sizes during time intervals associated to traffic peaks compared to the daily average. The morphological parameters obtained for these

  3. Investigation of Hydraulic Binding Characteristics of Lime Based Mortars Used in Historical Masonry Structures

    Science.gov (United States)

    Binal, Adil

    2017-10-01

    In the historic masonry structures, hard and large rock fragments were used as the construction materials. The hydraulic binder material prepared to keep this used material in its entirety is a different material than the cement used today. Khorasan mortar made by using aggregate and lime exhibits a more flexible structure than the concrete. This feature allows the historic building to be more durable. There is also a significant industrial value because of the use of Khorasan mortar in the restoration of historic masonry structures. Therefore, the calculation of the ideal mixture of Khorasan mortar and the determination of its mechanical and physical properties are of great importance regarding preserving historic buildings. In this study, the mixtures of different lime and brick fractions were prepared. It was determined that Khorasan mortar shows the highest compressive strength in mixtures with water/lime ratio of 0.55 and lime/aggregate ratio of 0.66. By keeping the mixing ratio constant, it was observed that the strengths of the samples kept in the humidity chamber for different curing times increased day by day. The early strength values of samples with the high lime/aggregate ratio (l/a: 0.83) were higher than those with the low lime/aggregate ratio (l/a: 0.5). For the samples with low lime/aggregate ratio, there was an increase in the strength values depending on the curing period. As the cure duration increases, a chemical reaction takes place between the lime and the brick fracture, and as a result of this reaction, the strength values are increased.

  4. Structural and functional characteristics of cGMP-dependent methionine oxidation in Arabidopsis thaliana proteins

    KAUST Repository

    Marondedze, Claudius

    2013-01-05

    Background: Increasing structural and biochemical evidence suggests that post-translational methionine oxidation of proteins is not just a result of cellular damage but may provide the cell with information on the cellular oxidative status. In addition, oxidation of methionine residues in key regulatory proteins, such as calmodulin, does influence cellular homeostasis. Previous findings also indicate that oxidation of methionine residues in signaling molecules may have a role in stress responses since these specific structural modifications can in turn change biological activities of proteins. Findings. Here we use tandem mass spectrometry-based proteomics to show that treatment of Arabidopsis thaliana cells with a non-oxidative signaling molecule, the cell-permeant second messenger analogue, 8-bromo-3,5-cyclic guanosine monophosphate (8-Br-cGMP), results in a time-dependent increase in the content of oxidised methionine residues. Interestingly, the group of proteins affected by cGMP-dependent methionine oxidation is functionally enriched for stress response proteins. Furthermore, we also noted distinct signatures in the frequency of amino acids flanking oxidised and un-oxidised methionine residues on both the C- and N-terminus. Conclusions: Given both a structural and functional bias in methionine oxidation events in response to a signaling molecule, we propose that these are indicative of a specific role of such post-translational modifications in the direct or indirect regulation of cellular responses. The mechanisms that determine the specificity of the modifications remain to be elucidated. 2013 Marondedze et al.; licensee BioMed Central Ltd.

  5. Friction characteristics of submicrometre-structured surfaces fabricated by particle-assisted near-field enhancement with femtosecond laser

    International Nuclear Information System (INIS)

    Sakai, Tetsuo; Nedyalkov, Nikolay; Obara, Minoru

    2007-01-01

    We present friction characteristics of sliding textured silicon surfaces at the submicrometre scale. A two-dimensional submicrometre dimple array on the Si surface is fabricated by femtosecond laser processing. Direct femtosecond laser nano-structuring of the Si (1 0 0) substrate by polystyrene particle-assisted near-field enhancement is used. In the investigated hole diameter domain from 229 to 548 nm, an increase in the friction coefficient with the decrease in the hole size is found experimentally. The fabricated submicrometre dimples act evidently as lubricant reservoirs to supply lubricants and traps to capture wear debris. The fluctuation of the friction coefficient is also increased by reducing the dimple size. The lowest friction coefficient of 1.41 x 10 -2 is achieved with the dimple array having a diameter of about 550 nm. This value is 2.6 times lower than that of non-structured substrates

  6. Structural characteristics of the Semanggol formation on the east-west highway route 67 Baling Area, Kedah, Malaysia

    International Nuclear Information System (INIS)

    Yuniarti Ulfa; Mohd Hafiz Hafizzy NS; Muhammad Farhan MF

    2012-01-01

    The amounts of structural data available from the East-West Highway Route 67 of Baling Area have been used to unravel the structural characteristics of the Semanggol Formation, which comprises black mudstone, sandstone, tuffaceous sandstone, tuff, paraconglomerate, siliceous shale and chert. The area was cut by two sets of faults trending NW-SE and NE-SW. The main fault in this area is known as Bok Bak fault that is trending NW-SE and have moderately to steeply dips (40°- 88°) as compared to the conjugate faults. Two sets of folds trending NE-SW and NW-SE were also identified in this area, where most of them are symmetrical fold with gentle to open fold varies from non-plunging to nearly moderately plunging folds. Most of the faults have parallel orientation to the fold axis, indicated this pattern probably originated at the same period of deformation due to warping and uplifting. (author)

  7. Impact of synthesis parameters on structural and magnetic characteristics of Co-based nanoparticles

    International Nuclear Information System (INIS)

    Mourdikoudis, S.; Simeonidis, K.; Tsiaoussis, I.; Dendrinou-Samara, C.; Angelakeris, M.; Kalogirou, O.

    2009-01-01

    Two different Co-based nanostructures were produced via thermolytic decomposition or reduction of proper cobalt precursors in organic solvents under vigorous stirring. The effect of synthesis parameters on the shape, size, and composition of the particles was examined. We present the differences in the structural and magnetic properties among the as-prepared sub-micron Co 'polypod-like' particles, which display a remarkable value for saturation magnetization (182 emu/g), and the hollow CoO nanoparticles, which exhibit weak ferromagnetic features.

  8. Structural characteristics and elevated temperature mechanical properties of AJ62 Mg alloy

    International Nuclear Information System (INIS)

    Kubásek, J.; Vojtěch, D.; Martínek, M.

    2013-01-01

    Structure and mechanical properties of the novel casting AJ62 (Mg–6Al–2Sr) alloy developed for elevated temperature applications were studied. The AJ62 alloy was compared to commercial casting AZ91 (Mg–9Al–1Zn) and WE43 (Mg–4Y–3RE) alloys. The structure was examined by scanning electron microscopy, x-ray diffraction and energy dispersive spectrometry. Mechanical properties were characterized by Viskers hardness measurements in the as-cast state and after a long-term heat treatment at 250 °C/150 hours. Compressive mechanical tests were also carried out both at room and elevated temperatures. Compressive creep tests were conducted at a temperature of 250 °C and compressive stresses of 60, 100 and 140 MPa. The structure of the AJ62 alloy consisted of primary α-Mg dendrites and interdendritic nework of the Al 4 Sr and massive Al 3 Mg 13 Sr phases. By increasing the cooling rate during solidification from 10 and 120 K/s the average dendrite arm thickness decreased from 18 to 5 μm and the total volume fraction of the interdendritic phases from 20% to 30%. Both factors slightly increased hardness and compressive strength. The room temperature compressive strength and hardness of the alloy solidified at 30 K/s were 298 MPa and 50 HV 5, i.e. similar to those of the as-cast WE43 alloy and lower than those of the AZ91 alloy. At 250 °C the compressive strength of the AJ62 alloy decreased by 50 MPa, whereas those of the AZ91 and WE43 alloys by 100 and 20 MPa, respectively. The creep rate of the AJ62 alloy was higher than that of the WE43 alloy, but significantly lower in comparison with the AZ91 alloy. Different thermal stabilities of the alloys were discussed and related to structural changes during elevated temperature expositions. - Highlights: • Small effect of cooling rate on the compressive strength and hardness of AJ 62 • A bit lower compressive strength of AJ 62 compared to AZ91 at room temperature • Higher resistance of the AJ 62 alloy to the

  9. Influence of Biofield Treatment on Physical and Structural Characteristics of Barium Oxide and Zinc Sulfide

    OpenAIRE

    Branton, Alice; Trivedi, Mahendra Kumar; Trivedi, Dahryn; Nayak, Gopal

    2015-01-01

    Barium oxide (BaO) and zinc sulfide (ZnS) are well known for their applications in electrical, optical and chemical industries. The present study was aimed to evaluate the impact of biofield treatment on the structural and physical properties of BaO and ZnS powder. The study was carried out in two groups, one was set to control, and another group was subjected to Mr. Trivedi’s biofield treatment. Control and treated samples of BaO and ZnS were analyzed using X-ray diffraction (XRD), Fourier t...

  10. Influence of Biofield Treatment on Physical and Structural Characteristics of Barium Oxide and Zinc Sulfide

    OpenAIRE

    Mahendra Kumar Trivedi, Alice Branton

    2015-01-01

    Barium oxide (BaO) and zinc sulfide (ZnS) are well known for their applications in electrical, optical and chemical industries. The present study was aimed to evaluate the impact of biofield treatment on the structural and physical properties of BaO and ZnS powder. The study was carried out in two groups, one was set to control, and another group was subjected to Mr. Trivedi's biofield treatment. Control and treated samples of BaO and ZnS were analyzed using X-ray diffraction (XRD), Fourier t...

  11. Predicting road system speeds using spatial structure variables and network characteristics

    Science.gov (United States)

    Hackney, Jeremy K.; Bernard, Michael; Bindra, Sumit; Axhausen, Kay W.

    2007-12-01

    Spatial regression is applied to GPS floating car measurements to build a predictive model of road system speed as a function of link type, time period, and spatial structure. The models correct for correlated spatial errors and autocorrelation of speeds. Correlation neighborhoods are based on either Euclidean or network distance. Econometric and statistical methods are used to choose the best model form and statistical neighborhood. Models of different types have different coefficient estimates and fit quality, which might affect inferences. Speed predictions are validated against a holdout sample to illustrate the usefulness of spatial regression in road system speed monitoring.

  12. Speed characteristics of structure motion of the system "athletes-weight" in weightlifters of various gender

    Directory of Open Access Journals (Sweden)

    Oleshko V.G.

    2010-01-01

    Full Text Available Speed descriptions of structure of motion of barbell are certain during implementation of competition exercises weightlifters of high qualification of different floor. In researches these implementations of exercises are used 235 strongest weightlifters of the world. It is selected three most informing parameter of motion of barbell. Research receptions are a videocomputer analysis, mathematical statistics. Dependence of these parameters is set on sizes and mass of body of sportsman and floor. All sportsmen with the increase of gravimetric category have gradual growth of rate of climb of motion of barbell only in a jerk in the phase of previous acceleration.

  13. Analysis of the Governance Structures in Japan's Biosphere Reserves: Perspectives from Bottom-Up and Multilevel Characteristics

    Science.gov (United States)

    Tanaka, Toshinori; Wakamatsu, Nobuhiko

    2018-01-01

    This paper analyzes the governance structures of Biosphere Reserves (BRs) in Japan by focusing on six criteria that elucidate the main characteristics therein: general information (nomination process, year of designation, size, and population), legal frameworks, stakeholder identification, and decision-making processes (number of municipalities and role of consociation), administrative institutions (human resources, budgetary situation, and expense distribution), executed BR implementation activities, and participatory/collaborative frameworks. This research consists of a literature review, a questionnaire administered to the secretariats of seven existing BRs and follow-up interviews. Three main characteristics of BRs were identified. First, a responsible local government(s) is nominated to manage the BR rather than the central government. Consequently, BR implementation in Japan is led by those municipalities that have strong motivations for regional development using the BR concept. Second, two types of BR governance structures exist in Japan: the single municipality type and the multi-municipality type. All BRs have so called Kyougikai, a consociation for decision-making, consultation and/or collaboration among stakeholders. In the single municipality structure, the consociation includes diverse actors from private and community sectors, while in the multi-municipality structure, consociations are based in more diplomatic settings and only include members of the public sector. Third, gaps between pre/post-Seville BR implementation sites were identified. The motivations for the formation of pre-Seville BRs, which were designated in 1980 in a top-down fashion prior to an awareness of BRs, varied greatly from those BRs nominated by municipalities after 2010. The authors identified fewer administrative resources and activities associated with the pre-Seville sites.

  14. Study of Structure and Electro-Optical Characteristics of Indium Tin Oxide Thin Films

    Directory of Open Access Journals (Sweden)

    N. M. Khusayfan

    2013-01-01

    Full Text Available ITO thin films were prepared by electron beam evaporation of ceramic ITO target. The films were subsequently annealed in air atmosphere at the temperatures 300°C and 600°C in order to improve their optical and electrical properties. The crystal structure and morphology of the films are investigated by X-ray diffraction and scanning electron microscope techniques, respectively. The films exhibited cubic structure with predominant orientation of growth along (222 direction, and the crystallite size increases by rising annealing temperature. Transparency of the films, over the visible light region, is increased by annealing temperature. The resulting increase in the carrier concentration and in the carrier mobility decreases the resistivity of the films due to annealing. The absorption coefficient of the films is calculated and analyzed. The direct allowed optical band gap for as-deposited films is determined as 3.81 eV; this value is increased to 3.88 and 4.0 eV as a result of annealing at 300°C and 600°C, respectively. The electrical sheet resistance is significantly decreased by increasing annealing temperature, whereas figure of merit is increased.

  15. Structure characteristics for intestinal uptake of flavonoids in Caco-2 cells.

    Science.gov (United States)

    Fang, Yajing; Liang, Fuqiang; Liu, Kunyuan; Qaiser, Shakeel; Pan, Siyi; Xu, Xiaoyun

    2018-03-01

    Flavonoids are a large group of polyphenols and widely distributed in plant foods. Flavonoids exhibit various biological activities, such as anti-cancer, antioxidant and anti-inflammatory while poor oral bioavailability has been considered as a major hurdle in their use as functional foods. Cellular uptake and efflux of flavonoid implicates their bioavailability. To investigate the cellular uptake and efflux of flavonoids, 27 flavonoids were measured for their cellular uptake in Caco-2 cells with (CUV) and without (CU) the inhibitor of P-glycoprotein (P-gp) verapamil. Then, a quantitative structure-absorption relationship (QSAR) model containing 21 compounds as training set was obtained from their corresponding CU. The model showed good robustness and predictivity with a high cross-validation coefficient (Q 2 ) value of 0.809 and Log of the octanol/water partition coefficient (SlogP) and atomic charge on carbon 5 (Q C5 ) were related to flavonoid uptake. The CUV of some flavonoids were significantly (ppumped out by P-gp. The structure-affinity relationship of flavonoids as substrates of P-gp was determined with the presence of 4'-OCH 3 , 3'-OCH 3 and the absence of 3'-OH, 3-OH and 4'-OH favorable for the affinity of flavonoids. These results provide valuable information for screening flavonoids with good absorption and low affinity with transporters. Copyright © 2017. Published by Elsevier Ltd.

  16. Investigation of structure and characteristics of soil for foundation design of gamma irradiators capacity 2 MCi

    International Nuclear Information System (INIS)

    Kukuh Prayogo; Hasriyasti Saptowati

    2016-01-01

    Soil investigation conducted before the work of irradiator building structural foundation design is initiated. Intake of sample was set at some point drill at Irradiator facility site to the disturbed soil layer or not disturbed. From the results of this soil investigation will be selected as alternative / types, the depth and dimensions of the foundation of the most economical but still safe. Soil investigation method used was Deep Boring, undisturbed and disturbed sampling, SPT ( Standard Penetration Test ), CPT ( Cone Penetration Test / Sondir ). Testing conducted in the field and in the laboratory of soil mechanics to determine the mechanical properties, soil layer thickness and other physical properties for calculation of the bearing capacity of the foundation. The results of the soil investigation at the three-point drill showed the average depth of the bedrock -19.33 m and adhesion 3163.88 kg / cm’. Test boring at point BH1 found the depth of the bedrock -19.33 m and adhesion 3163.88 kg / cm’. Test boring at point BH1 found the bedrock at a depth of 32 m with a maximum SPT value 16. from the data can be determined the appropriate type of foundation is bored pile. The foundation is the upper structure support which can lead to a reduction / settlement if its bearing capacity is not able to withstand the load on it. (author)

  17. The packing saturation rule and the packing centre rule: structural characteristics in lanthanide coordination compounds

    International Nuclear Information System (INIS)

    Feng Xi-Zhang; Guo Ao-Ling; Xu Ying-Ting; Li Xing-Fu; Sun Peng-Nian

    1987-01-01

    The concepts of the Cone Packing Model, namely the Solid Angle Factor (SAF), Fan Angle (FA), Coordination Vector (r-bar), Gap and Hole have been introduced to describe steric packing around the metal centre. In a treatment of more than 160 structures of lanthanide coordination compounds, it was found that the sums of the ligand SAFs (SAS) are mainly in the region SAS=0.78, σ=0.05. This result provides concrete evidence that ''coordination saturation'' in the lanthanide compounds is actually saturation in the coordination space. The Packing Centre Rule has shown for the first time that the vector sum of the ligand SAFs, i.e. ΣSAF.r-bar, of each structure closely approaches zero with an average ΣSAF.r-bar of 0.02 and a standard deviation of 0.015. The Packing Centre Rule indicates that there is a clear tendency for the ligands to distribute themselves so that the non-bonding repulsions are at a minimum. (author)

  18. Effect of pullulanase debranching and storage temperatures on structural characteristics and digestibility of sweet potato starch

    Directory of Open Access Journals (Sweden)

    Ayenampudi Surendra Babu

    2018-04-01

    Full Text Available The effect of autoclaving (120 °C/30 min, debranching (2% pullulanase/1 h and storage at 4 °C (DS4 or 32 °C (DS32 or 60 °C (DS60 for 24 h on starch fractions, functional, pasting, thermal and structural properties of sweet potato starch was investigated. Results showed that DS4 sample displayed the lower functional properties than other modified starches. Debranching showed a significant increase in the apparent amylose content of native starch from 18.56% to 25%. A higher yield of RS (28.76% was observed in debranched starch stored at 4 °C (DS4 due to the higher degree of retrogradation. All debranched starches showed a substantial decrease in pasting profile and higher gelatinization temperatures than in native starch. B + V X-ray diffraction pattern was observed in debranched starches with increased crystallinity value. The scanning electron micrographs of debranched starches showed rough plate-like surfaces with irregularly shaped structures were observed due to debranching and retrogradation during storage. The study concludes that a combination of autoclaving, debranching and subsequent storage at 4 °C is best technique to produce a higher amount of resistant starch in the sweet potato starch. Keywords: Pullulanase, Functional properties, Resistant starch, RVA, XRD, SEM

  19. Biodiversity measure and structural characteristics from aerial observations at Mt. Kilimanjaro, Tanzania

    Science.gov (United States)

    Otte, Insa; Ziegler, Alice; Röder, Juliane; Renner, Marion; Schellenberger Costa, David; Brandl, Roland; Fischer, Markus; Hemp, Andreas; Huth, Andreas; Kleyer, Michael; Nauss, Thomas

    2017-04-01

    Methods for monitoring and mapping both, species diversity as well as ecosystem functions/processes are essentially for ecosystem assessments and conservational efforts. Remote sensing offers a unique potential in providing such spatially explicit information. Spectral complexity can be related to species diversity at different scales. Based on hyperspectral and LiDAR aerial observations, more than 30 research plots of different habitat types which are located at the southern slopes of Mt. Kilimanjaro will be characterized in detail concerning their species diversity in terms of spectral variability and their structural composition. This information will be used to assess the degree of representativeness of the research plots for the respective land-cover. We presume that the concept of "spectral species" results in biodiversity measures comparable to in-situ observed information and is therefore suitable for substituting time-consuming field work to a certain degree. Furthermore, we postulate that ecologically important plant species can be grouped into functional guilds that show a distinct spectral and structural pattern which enables their remote sensing based prediction from aerial datasets.

  20. Preparation and characteristics of core-shell structure cobalt/silica nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Fu Wuyou [National Laboratory of Superhard Materials, Jilin University, Changchun 130012 (China); Yang Haibin [National Laboratory of Superhard Materials, Jilin University, Changchun 130012 (China) and Henan Polytechnic University, Hennan Jiaozuo 454000 (China)]. E-mail: yanghb@jlu.edu.cn; Hari-Bala [College of Chemistry, Jilin University, Changchun 130023 (China); Liu Shikai [Henan Polytechnic University, Hennan Jiaozuo 454000 (China); Li, Minghui [National Laboratory of Superhard Materials, Jilin University, Changchun 130012 (China); Zou Guangtian [National Laboratory of Superhard Materials, Jilin University, Changchun 130012 (China)

    2006-12-10

    The silica nanolayer with different thickness was coated on the spherical cobalt nanoparticles (an average diameter of 67 nm) to form core-shell structure by the controlled hydrolysis and condensation of tetraethyl orthosilicate (TEOS). This coating process was based on the use of silane coupling agent 3-mercaptopropyltrimethoxysilane (HS-(CH{sub 2}){sub 3}Si(OCH{sub 3}){sub 3}, MPTS) as a primer to render the cobalt surface vitreophilic, thus rendering cobalt surface compatible with silica. The control over the silica coating layer thickness can be achieved by varying the reaction time. The cobalt nanoparticles and the cobalt coated with silica shell were confirmed by transmission electron microscopy (TEM). X-ray photoelectron spectroscopy (XPS) was used to gain insight into the way in which the MPTS is bound to the surface of the cobalt nanoparticles. Result of the thermogravimetric analysis (TGA) and differential thermal analysis (DTA) indicate that the thermal stability of cobalt/silica is better than that of pure cobalt nanoparticles. Magnetic properties of these powders have been evaluated. These cobalt/silica core-shell nanoparticles can be utilized as precursors for making property-tunable magnetic nanoparticles, thin films, and multilayered core-shell structure nanocomposites.

  1. Effects of Support Structure Changes on Flow-induced Vibration Characteristics of Steam Generator Tubes

    International Nuclear Information System (INIS)

    Ryu, Ki Wahn; Park, Chi Yong; Rhee, Hui Nam

    2010-01-01

    Fluid-elastic instability and turbulence-induced vibration of steam generator U-tubes of a nuclear power plant are studied numerically to investigate the effect of design changes of support structures in the upper region of the tubes. Two steam generator models, Model A and Model B, are considered in this study. The main design features of both models are identical except for the conditions of vertical and horizontal support bars. The location and number of vertical and horizontal support bars at the middle of the U-bend region in Model A differs from that of Model B. The stability ratio and the amplitude of turbulence-induced vibration are calculated by a computer program based on the ASME code. The mode shape with a large modal displacement at the upper region of the U-tube is the key parameter related to the fretting wear between the tube and its support structures, such as vertical, horizontal, and diagonal support bars. Therefore, the location and the number of vertical and horizontal support bars have a great influence on the fretting wear mechanism. The variation in the stability ratios for each vibrational mode is compared with respect to Model A and Model B. Even though both models satisfy the design criteria, Model A shows substantial improvements over Model B, particularly in terms of having greater amplitude margins in the turbulence-excited vibration (especially at the inner region of the tube bundle) and better stability ratios for the fluid-elastic instability

  2. Bioinformatics analysis of the structural and evolutionary characteristics for toll-like receptor 15

    Directory of Open Access Journals (Sweden)

    Jinlan Wang

    2016-05-01

    Full Text Available Toll-like receptors (TLRs play important role in the innate immune system. TLR15 is reported to have a unique role in defense against pathogens, but its structural and evolution characterizations are still poorly understood. In this study, we identified 57 completed TLR15 genes from avian and reptilian genomes. TLR15 clustered into an individual clade and was closely related to family 1 on the phylogenetic tree. Unlike the TLRs in family 1 with the broken asparagine ladders in the middle, TLR15 ectodomain had an intact asparagine ladder that is critical to maintain the overall shape of ectodomain. The conservation analysis found that TLR15 ectodomain had a highly evolutionarily conserved region on the convex surface of LRR11 module, which is probably involved in TLR15 activation process. Furthermore, the protein–protein docking analysis indicated that TLR15 TIR domains have the potential to form homodimers, the predicted interaction interface of TIR dimer was formed mainly by residues from the BB-loops and αC-helixes. Although TLR15 mainly underwent purifying selection, we detected 27 sites under positive selection for TLR15, 24 of which are located on its ectodomain. Our observations suggest the structural features of TLR15 which may be relevant to its function, but which requires further experimental validation.

  3. Engine structure modifications effect on the flow behavior, combustion, and performance characteristics of DI diesel engine

    International Nuclear Information System (INIS)

    Taghavifar, Hadi; Khalilarya, Shahram; Jafarmadar, Samad

    2014-01-01

    Highlights: • Engine geometrical configuration was modified based on bowl radius and displacement. • The best engine performance indices associated with D3 and R1 structures. • Increasing the bowl radius and outward bowl displacement increases ignition delay. • The best configuration for uniform air/fuel mixture, TKE, and temperature is found. - Abstract: The simulation was carried out based on 1.8 L Ford diesel engine and the geometrical modification in structure of piston were considered in terms of bowl movement and the bowl size in four equal increments. Two major conflicting parameters in combustion and engine efficiency were taken into account and visualized in contour plots as the bowl geometry was varied: (1) the air/fuel mixing process demonstrated by Homogeneity Factor and equivalence ratio, (2) combustion initiation and work delivery by heat release rate, pressure curves, and indicated thermal efficiency. A new version of Coherent Flame Model’s sub-model (ECFM-3Z) was adopted during the calculations to shed light into the combustion chemistry and reaction rate in detail. It was found that the bowl displacement toward the cylinder wall, increases the mixture uniformity (higher HF) thus higher pressure and heat release rate peak were obtained with the penalty of combustion delay which substantially reduces the effective in-cylinder pressure. Furthermore, it was demonstrated that smaller bowl size induces better squish and vortex formation in the chamber, although lesser spray penetration and flame quenching owing to the spray-wall impingement reduces ignition delay

  4. Structural characteristics of the redox-sensing coiled coil in the voltage-gated H+ channel.

    Science.gov (United States)

    Fujiwara, Yuichiro; Takeshita, Kohei; Nakagawa, Atsushi; Okamura, Yasushi

    2013-06-21

    Oxidation is an important biochemical defense mechanism, but it also elicits toxicity; therefore, oxidation must be under strict control. In phagocytotic events in neutrophils, the voltage-gated H(+) (Hv) channel is a key regulator of the production of reactive oxygen species against invading bacteria. The cytoplasmic domain of the Hv channel forms a dimeric coiled coil underpinning a dimerized functional unit. Importantly, in the alignment of the coiled-coil core, a conserved cysteine residue forms a potential intersubunit disulfide bond. In this study, we solved the crystal structures of the coiled-coil domain in reduced, oxidized, and mutated (Cys → Ser) states. The crystal structures indicate that a pair of Cys residues forms an intersubunit disulfide bond dependent on the redox conditions. CD spectroscopy revealed that the disulfide bond increases the thermal stability of the coiled-coil protein. We also reveal that two thiol modifier molecules are able to bind to Cys in a redox-dependent manner without disruption of the dimeric coiled-coil assembly. Thus, the biochemical properties of the cytoplasmic coiled-coil domain in the Hv channel depend on the redox condition, which may play a role in redox sensing in the phagosome.

  5. Structural characteristics of the online social networks of maltreated youth and offline sexual risk behavior.

    Science.gov (United States)

    Negriff, Sonya; Valente, Thomas W

    2018-02-07

    Maltreated youth are at risk for exposure to online sexual content and high-risk sexual behavior, yet characteristics of their online social networks have not been examined as a potential source of vulnerability. The aims of the current study were: 1) to test indicators of size (number of friends) and fragmentation (number of connections between friends) of maltreated young adults' online networks as predictors of intentional and unintentional exposure to sexual content and offline high-risk sexual behavior and 2) to test maltreatment as a moderator of these associations. Participants were selected from a longitudinal study on the effects of child maltreatment (n = 152; Mean age 21.84 years). Data downloaded from Facebook were used to calculate network variables of size (number of friends), density (connections between friends), average degree (average number of connections for each friend), and percent isolates (those not connected to others in the network). Self-reports of intentional and unintentional exposure to online sexual content and offline high-risk sexual behavior were the outcome variables. Multiple-group path modeling showed that only for the maltreated group having a higher percent of isolates in the network predicted intentional exposure to online sexual content and offline high-risk sexual behavior. An implication of this finding is that the composition of the Facebook network may be used as a risk indicator for individuals with child-welfare documented maltreatment experiences. Copyright © 2018. Published by Elsevier Ltd.

  6. Neutron irradiation effects on silicon detectors structure, electrical and mechanical characteristics

    International Nuclear Information System (INIS)

    Rabinovich, E.; Golan, G.; Axelevich, A.; Inberg, A.; Oksman, M.; Rosenwaks, I.; Lubarsky, G.; Seidman, A.; Croitoru, N.; Rancoita, P.G.; Rattaggi, M.

    1999-01-01

    Neutron irradiation effects on (p-n) and Schottky-junction silicon detectors were studied. It was shown that neutron interactions with monocrystalline silicon create specific types of microstructure defects with morphology differing according to the level of neutron fluences (Φ). The isolated dislocation loops, formed by interstitial atoms were observed in microstructure images for 10 10 ≤ Φ ≤ 10 12 n/cm 2 . A strong change in the dislocation loops density and a cluster formation was observed for Φ ≥ 10 13 n/cm 2 . A drastic silicon damage was found for fluences over 10 14 n/cm 2 . These fluences created zones enriched with all types of dislocations, covering more than 50 % of the total surface area. A mechanical fragility appeared in that fluence range in a form of microcracks. 10 14 n/cm 2 appears to be a critical value of neutron irradiation because of the radiation damage described above and because the characteristics I f -V f of silicon detectors can be differentiated from those obtained at low fluences. (A.C.)

  7. Structure Characteristics of the International Stock Market Complex Network in the Perspective of Whole and Part

    Directory of Open Access Journals (Sweden)

    Guangxi Cao

    2017-01-01

    Full Text Available International stock market forms an abstract complex network through the fluctuation correlation of stock price index. Past studies of complex network almost focus on single country’s stock market. Here we investigate the whole and partial characteristics of international stock market network (ISMN (hereinafter referred to as ISMN. For the analysis on the whole network, we firstly determine the reasonable threshold as the basic of the following study. Robustness is applied to analyze the stability of the network and the result shows that ISMN has robustness against random attack but intentional attack breaks the connection integrity of ISMN rapidly. In the partial network, the sliding window method is used to analyze the dynamic evolution of the relationship between the Chinese (Shanghai stock market and the international stock market. The connection between the Chinese stock market and foreign stock markets becomes increasingly closer, and the links between them show a significant enhancement especially after China joined the WTO. In general, we suggest that transnational investors pay more attention to some significant event of the stock market with large degree for better risk-circumvention.

  8. A modeling study of dynamic characteristic analysis of isolated structure for seismic exciting tests

    International Nuclear Information System (INIS)

    Lee, Jae Han; Koo, G. H.; Yoo, Bong

    1998-04-01

    The fundamental frequency of the isolated superstructure for seismic exciting tests was calculated by 16 Hz with a initial modal analysis model. but the actual modal test resulted in 5 Hz. This large difference was resulted from some uncertainties in analysis modeling of several connection parts between column and upper beam, cross bars of each face of the isolated superstructure. When the stiffness of cross-bars are larger than certain level in all the analyses, the joint stiffness between main slab and columns does not effect to the fundamental frequency. So the fundamental frequency of the isolated superstructure was governed by the cross-bar's stiffness. In actual tests the first and second frequencies show a little difference regardless of the cross section characteristics (inertia moments) of four columns because the joint stiffness between column and main slab is less than 10 8 1b f in/radian. The mounting device of each column to main slab, and the bolting device of each column to upper beam are fabricated with lower stiffness compared to design value. The bolting of cross-bars and the fitness of bolt-hole to bolt were loosed during the modal tests. In the future the tight connecting and the precise assembling of isolated superstructure are required to reduce the difference of the fundamental frequencies obtained from the modal analysis and actual test. (author). 4 refs

  9. Effect of Silver Nanoparticle Addition on the Structure And Characteristics of Radio-Photoluminescence Glass Dosimeter

    International Nuclear Information System (INIS)

    Irman Abdul Rahman; Muhammad Taqiyuddin Mawardi Ayob; Hur Munawar Kabir Mohd; Ainee Fatimah Ahmad; Shamellia Sharin; Faizal Mohamed; Muhammad Taqiyuddin Mawardi Ayob; Sidek Ab Aziz; Irman Abdul Rahman; Faizal Mohamed; Shahidan Radiman

    2016-01-01

    A series of silver-activated phosphate glass was prepared by melt quenching method. The effect of silver nanoparticle addition on the phosphate glass microstructure, composition and chemical characteristics was investigated using x-ray diffraction, fourier transform infrared and photoluminescence spectroscopy. Other physical property such as density was also evaluated. The density increased when the amount of silver ions were increased, due to the enhanced formation of non-bridging oxygen. In this study, we discuss the emission mechanism of two radio-photoluminescence peaks at 460 nm and 620 nm, where the electrons and holes produced by γ-irradiation a re-trapped by Ag + ions to produce Ag 0 and Ag 2+ ions respectively, when the Ag + -doped phosphate glass is exposed to γ-ray. We proposed that an emission mechanism of 460 and 620 nm radio-photoluminescence peaks with these Ag 2+ and Ag 0 ions. Furthermore, a correlation between the investigated properties and glass composition is discussed. (author)

  10. Structural Characteristics and Corrosion Behavior of Bio-Degradable Zn-Li Alloys in Stent Application

    Science.gov (United States)

    Zhao, Shan

    Zinc has begun to be studied as a bio-degradable material in recent years due to its excellent corrosion rate and optimal biocompatibility. Unfortunately, pure Zn's intrinsic ultimate tensile strength (UTS; below 120 MPa) is lower than the benchmark (about 300 MPa) for cardiovascular stent materials, raising concerns about sufficient strength to support the blood vessel. Thus, modifying pure Zn to improve its mechanical properties is an important research topic. In this dissertation project, a new Zn-Li alloy has been developed to retain the outstanding corrosion behavior from Zn while improving the mechanical characteristics and uniform biodegradation once it is implanted into the artery of Sprague-Dawley rats. The completed work includes: Manufactured Zn-Li alloy ingots and sheets via induction vacuum casting, melt spinning, hot rolling deformation, and wire electro discharge machining (wire EDM) technique; processed alloy samples using cross sectioning, mounting, etching and polishing technique; • Characterized alloy ingots, sheets and wires using hardness and tensile test, XRD, BEI imaging, SEM, ESEM, FTIR, ICP-OES and electrochemical test; then selected the optimum composition for in vitro and in vivo experiments; • Mimicked the degradation behavior of the Zn-Li alloy in vitro using simulated body fluid (SBF) and explored the relations between corrosion rate, corrosion products and surface morphology with changing compositions; • Explanted the Zn-Li alloy wire in abdominal aorta of rat over 12 months and studied its degradation mechanism, rate of bioabsorption, cytotoxicity and corrosion product migration from histological analysis.

  11. NMR Pore Structure and Dynamic Characteristics of Sandstone Caused by Ambient Freeze-Thaw Action

    Directory of Open Access Journals (Sweden)

    Bo Ke

    2017-01-01

    Full Text Available For a deeper understanding of the freeze-thaw weathering effects on the microstructure evolution and deterioration of dynamic mechanical properties of rock, the present paper conducted the nuclear magnetic resonance (NMR tests and impact loading experiments on sandstone under different freeze-thaw cycles. The results of NMR test show that, with the increase of freeze-thaw cycles, the pores expand and pores size tends to be uniform. The experimental results show that the stress-strain curves all go through four stages, namely, densification, elasticity, yielding, and failure. The densification curve is shorter, and the slope of elasticity curve decreases as the freeze-thaw cycles increase. With increasing freeze-thaw cycles, the dynamic peak stress decreases and energy absorption of sandstone increases. The dynamic failure form is an axial splitting failure, and the fragments increase and the size diminishes with increasing freeze-thaw cycles. The higher the porosity is, the more severe the degradation of dynamic characteristics is. An increase model for the relationships between the porosity or energy absorption and freeze-thaw cycles number was built to reveal the increasing trend with the freeze-thaw cycles increase; meanwhile, a decay model was built to predict the dynamic compressive strength degradation of rock after repeated freeze-thaw cycles.

  12. Structural Characteristics of Migrant Farmworkers Reporting a Relationship with a Primary Care Physician.

    Science.gov (United States)

    McCoy, H Virginia; Williams, Mark L; Atkinson, John S; Rubens, Muni

    2016-06-01

    Migrant farmworkers are disproportionately affected by many adverse health conditions, but access healthcare sparingly. This study of migrant farmworkers examined the distribution and general characteristics associated with having access to healthcare. Access to healthcare was measured by asking whether the participants (N = 413) had a primary care physician. Majority of participants did not have a primary care physician. Female migrant workers (AOR = 2.823 CI: 1.575-4.103) with insurance (AOR = 6.183 CI: 4.956-11.937) who lived at study site for more than 5 years (AOR = 2.728 CI: 1.936-7.837) and born in the United States (AOR = 2.648 CI: 1.373-3.338) had greater odds to have a primary care physician than recent male migrants without insurance who were born outside United States. There is a need to focus on Community Health Centers and Migrant Health Centers in tailoring their services and to widen the implementation and improve funding of Accountable Care Organizations to improve access to care of migrant farmworkers.

  13. Enrichment of probiotic ice cream with different dietary fibers: Structural characteristics and culture viability.

    Science.gov (United States)

    Akalın, A S; Kesenkas, H; Dinkci, N; Unal, G; Ozer, E; Kınık, O

    2018-01-01

    This study evaluated the effect of 5 dietary fibers (apple, orange, oat, bamboo, and wheat) on the physicochemical, rheological, and textural characteristics; sensory properties; and culture viability of probiotic ice cream stored at -18°C for 180 d. The presence of orange and apple fibers increased the titratable acidity, decreased the lightness (color) value of the ice creams, and enhanced the red and yellow coloration. Compared with the control sample, the consistency indices and apparent viscosities of the experimental samples increased with the addition of all dietary fibers except oat fiber. The highest viscosity was obtained in the sample fortified with apple fiber, whereas the ice cream containing orange fiber showed the highest hardness after d 60 of storage. The addition of orange and apple fibers significantly increased melting resistance; however, panelists did not generally like these samples in terms of taste-flavor. All ice creams had viable counts of Lactobacillus acidophilus of ≥7 log cfu/g during storage except the samples with orange and bamboo fiber. Bifidobacterium lactis counts were also found to be >6 log cfu/g in those samples until d 150 of storage. Copyright © 2018 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  14. Evaluation of seismic acceleration responses of base-isolated and nonisolated structures varying with mechanical characteristics of foundations

    Energy Technology Data Exchange (ETDEWEB)

    You, Bong; Lee, Jae Han; Ku, Kyung Hoi [Korea Atomic Energy Research Institute, Daeduk (Korea, Republic of)

    1996-05-01

    The evaluation of acceleration responses of isolated and nonisolated structures according to mechanical features of soils is important. The kinds of soils taken in analyses are soft, medium and hard rocks, and a fixed base condition is also taken for the comparison. The horizontal isolation frequency used is 0.5 Hz. The time history analyses of reference power plant using 1940 El Centro horizontal (NS) and vertical earthquakes are performed to investigate the seismic responses varying with soil characteristics for isolated and nonisolated structures. The horizontal acceleration responses of the horizontal isolated-structures show almost similar values irrespective of the various kinds of soils and are largely decreased in the frequency ranges above 2 hz. The vertical natural frequency, 21Hz of high damping rubber bearing does not affect the vertical acceleration responses in case of soft rock, but largely affects in hard rock condition. For nonisolated structures, the acceleration responses are decreased in both horizontal and vertical directions by taking into account the soils in the analysis model. The extent of reduction of acceleration responses is larger in vertical direction than in horizontal one, as the stiffness of rock becomes softer. 8 tabs., 21 figs., 8 refs. (Author) .new.

  15. Structure of protein emulsion in food impacts intestinal microbiota, caecal luminal content composition and distal intestine characteristics in rats.

    Science.gov (United States)

    Beaumont, Martin; Jaoui, Daphné; Douard, Véronique; Mat, Damien; Koeth, Fanny; Goustard, Bénédicte; Mayeur, Camille; Mondot, Stanislas; Hovaghimian, Anais; Le Feunteun, Steven; Chaumontet, Catherine; Davila, Anne-Marie; Tomé, Daniel; Souchon, Isabelle; Michon, Camille; Fromentin, Gilles; Blachier, François; Leclerc, Marion

    2017-10-01

    Few studies have evaluated in vivo the impact of food structure on digestion, absorption of nutrients and on microbiota composition and metabolism. In this study we evaluated in rat the impact of two structures of protein emulsion in food on gut microbiota, luminal content composition, and intestinal characteristics. Rats received for 3 weeks two diets of identical composition but based on lipid-protein matrices of liquid fine (LFE) or gelled coarse (GCE) emulsion. LFE diet led to higher abundance, when compared to the GCE, of Lactobacillaceae (Lactobacillus reuteri) in the ileum, higher β-diversity of the caecum mucus-associated bacteria. In contrast, the LFE diet led to a decrease in Akkermansia municiphila in the caecum. This coincided with heavier caecum content and higher amount of isovalerate in the LFE group. LFE diet induced an increased expression of (i) amino acid transporters in the ileum (ii) glucagon in the caecum, together with an elevated level of GLP-1 in portal plasma. However, these intestinal effects were not associated with modification of food intake or body weight gain. Overall, the structure of protein emulsion in food affects the expression of amino acid transporters and gut peptides concomitantly with modification of the gut microbiota composition and activity. Our data suggest that these effects of the emulsion structure are the result of a modification of protein digestion properties. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Fabrication of high aspect ratio nanopillars and micro/nano combined structures with hydrophobic surface characteristics by injection molding

    Science.gov (United States)

    Zhou, Mingyong; Xiong, Xiang; Jiang, Bingyan; Weng, Can

    2018-01-01

    Polymer products with micro/nano-structures have excellent mechanical and optical properties, chemical resistance, and other advantages. Injection molding is one of the most potential techniques to fabricate polymer products with micro/nano-structures artificially in large numbers. In this study, a surface approach to fabricate high aspect ratio nanopillars and micro/nano combined structures was presented. Mold insert with micropillar arrays and nanopillars on its surface was prepared by combing anodic aluminum oxide (AAO) template and etched plate. Anti-sticking modification was done on the template to realize a better demolding quality. The influences of mold temperature and polymer material on the final replication quality were investigated. The results showed that the final replication quality of high aspect ratio nanopillars was greatly improved as compared with the unprocessed template. Polymer with low elongation at break was not suitable to fabricate structures with high aspect ratio via injection molding. For polypropylene surface, the experimental results of static contact angles were almost consistent with Cassie-Baxter equation. When the mold temperature reached 178 °C, hair-like polycarbonate nanopillars were observed, resulting in an excellent hydrophobic characteristic.

  17. The Stiffness and Damping Characteristics of a Dual-Chamber Air Spring Device Applied to Motion Suppression of Marine Structures

    Directory of Open Access Journals (Sweden)

    Xiaohui Zeng

    2016-03-01

    Full Text Available Dual-chamber air springs are used as a key component for vibration isolation in some industrial applications. The working principle of the dual-chamber air spring device as applied to motion suppression of marine structures is similar to that of the traditional air spring, but they differ in their specific characteristics. The stiffness and damping of the dual-chamber air spring device determine the extent of motion suppression. In this article, we investigate the stiffness and damping characteristics of a dual-chamber air spring device applied to marine structure motion suppression using orthogonal analysis and an experimental method. We measure the effects of volume ratio, orifice ratio, excitation amplitude, and frequency on the stiffness and damping of the dual-chamber vibration absorber. Based on the experimental results, a higher-order non-linear regression method is obtained. We achieve a rapid calculation model for dual-chamber air spring stiffness and damping, which can provide guidance to project design.

  18. Coal Liquefaction characteristics and chemical structure of product oil; Sekitan ekika hanno tokusei to seiseibutsu no kagaku kozo

    Energy Technology Data Exchange (ETDEWEB)

    Endo, H.; Sato, M.; Chiba, T.; Hattori, H. [Hokkaido University, Sapporo (Japan). Center for Advanced Research of Energy Technology; Sasaki, M. [Hokkaido National Industrial Research Institute, Sapporo (Japan)

    1996-10-28

    Through the hydrogenolysis of Wandoan coal and Tanito Harum coal which are used for the NEDOL process, differences of liquefaction characteristics between them were found. The purpose of this study is to grasp these differences as differences of chemical structures of oil fractions. The compound type analysis was conducted for oil fractions obtained at varied reaction temperature for varied reaction time. Coal liquefaction characteristics of these coals were discussed by relating oil yields and chemical structures. For Tanito Harum coal, yields of gas and oil were considered to be lower than those for Wandoan coal, which reflected that the contents of partially hydrogenated hydroaromatics in oil fraction from the former were lower than those from the latter, and that the remarkable change of composition did not occur with the progress of the reaction. For both the coals, the remarkable changes in the average molecular weight of oil fraction were not observed with the progress of the reaction. While, the content of methane gradually increased with the progress of the reaction, which suggested that oil was gradually dealkylated. 5 figs.

  19. Structural characteristics and biological activity of Fucoidans from the brown algae Alaria sp. and Saccharina japonica of different reproductive status.

    Science.gov (United States)

    Vishchuk, Olesya S; Tarbeeva, Dariya V; Ermakova, Svetlana P; Zvyagintseva, Tatyana N

    2012-04-01

    Structural characteristics and the antitumor activity of fucoidans isolated from vegetative and reproductive tissue of the brown algae Alaria sp. and Saccharina japonica were studied. The reproductive status of the brown algae affected the yield of fucoidans and their structural characteristics. The fucoidan yield was 5.7% (w/w on the basis of the dried algae weight) for fertile and 3.8% for sterile Alaria sp. and 1.42 and 0.71% for fertile and sterile S. japonica, respectively. The fucoidans from fertile Alaria sp. and S. japonica had a slightly higher degree of sulfation and a somewhat more homogeneous monosaccharide composition, with predominate amounts of fucose and galactose, than those isolated from sterile algae tissue. The fucoidans from both the sterile and fertile brown algae tissue tested possessed selective cytotoxicity towards human breast cancer (T-47D) and melanoma (RPMI-7951) cell lines, but not to normal mouse epidermal cells (JB6 Cl41), and effectively inhibited the proliferation and colony formation of the breast cancer and melanoma cell lines. The fucoidans from reproductive tissue of brown algae possessed higher antitumor activity than those from vegetative plants. Copyright © 2012 Verlag Helvetica Chimica Acta AG, Zürich.

  20. Kinetics deformation of current-voltage characteristics of the varistor oxide structures due to overcharging of the localized states

    Directory of Open Access Journals (Sweden)

    Tonkoshkur A. S.

    2014-12-01

    Full Text Available Prolonged exposure of zinc oxide varistors to the electrical load leads to current-voltage characteristics (CVC deformation, which is associated with a change in the height and width of the intergranular barriers, which are main structural element of the varistors. Polarization phenomena in zinc oxide ceramics are studied in a number of works, but those are mainly limited to the study of the physics of the CVC deformation process and to determining the parameters of localized electronic states involved in this process. This paper presents the results on the simulation of the deformation of pulse CVC of a separate intergranular potential barrier at transient polarization/depolarization, associated with recharging of surface electronic states (SES, which cause this barrier. It is found that at high density of SES their degree of electron filling is small and the effect of DC voltage leads to a shift of pulse current-voltage characteristics into the region of small currents. Conversely, the low density SES are almost completely filled with electrons, and after crystallite polarization CVC is shifted to high currents. Experimental studies have confirmed the possibility of applying the discovered laws to ceramic varistor structures. The proposed model allows interpreting the «anomalous» effects (such as increase in the classification voltage and reduction of active losses power observed during the varistors accelerated aging test.