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Sample records for control effective properties

  1. Using nonlinearity and spatiotemporal property modulation to control effective structural properties: dynamic rods

    DEFF Research Database (Denmark)

    Thomsen, Jon Juel; Blekhman, Iliya I.

    2007-01-01

    What are the effective properties of a generally nonlinear material or structure, whose local properties are modulated in both space and time? It has been suggested to use spatiotemporal modulation of structural properties to create materials and structures with adjustable effective properties......, and to call these dynamic materials or spatiotemporal composites. Also, according to theoretical predictions, structural nonlinearity enhances the possibilities of achieving specific effective properties. For example, with an elastic rod having cubical elastic nonlinearities, it seems possible to control......, and exemplified. Then simple approximate analytical expressions are derived for the effective wave speed and natural frequencies for one-dimensional wave propagation in a nonlinear elastic rod, where the spatiotemporal modulation is imposed as a high-frequency standing wave, supposed to be given. Finally the more...

  2. Effectiveness of SCADA Systems in Control of Green Sands Properties

    Directory of Open Access Journals (Sweden)

    Ignaszak Z.

    2016-03-01

    Full Text Available The paper undertakes an important topic of evaluation of effectiveness of SCADA (Supervisory Control and Data Acquisition systems, used for monitoring and control of selected processing parameters of classic green sands used in foundry. Main focus was put on process studies of properties of so-called 1st generation molding sands in the respect of their preparation process. Possible methods of control of this processing are presented, with consideration of application of fresh raw materials, return sand (regenerate and water. The studies conducted in one of European foundries were aimed at pointing out how much application of new, automated plant of sand processing incorporating the SCADA systems allows stabilizing results of measurement of selected sand parameters after its mixing. The studies concerned two comparative periods of time, before an implementation of the automated devices for green sands processing (ASMS - Automatic Sand Measurement System and MCM – Main Control Module and after the implementation. Results of measurement of selected sand properties after implementation of the ASMS were also evaluated and compared with testing studies conducted periodically in laboratory.

  3. Are Effective Properties Effective?

    International Nuclear Information System (INIS)

    Han, Ru; Ingber, Marc S.; Hsiao, S.-C.

    2008-01-01

    The effective moduli (effective Young's modulus, effective Poisson's ratio, effective shear modulus, and effective bulk modulus) of dispersed-phase-reinforced composite materials are determined at the mesoscopic level using three-dimensional parallel boundary element simulations. By comparing the mesoscopic BEM results and the macroscopic results based on effective properties, limitations in the effective property approach have been examined

  4. Effects of instant controlled pressure drop process on physical and sensory properties of puffed wheat snack.

    Science.gov (United States)

    Yağcı, Sibel

    2017-04-01

    In this study, research on the development of a puffed wheat snack using the instant controlled pressure drop (DIC) process was carried out. Snack products were produced by expanding moistened wheat under various DIC processing conditions in order to obtain adequate puffing, followed by drying in a hot air dryer. The effects of operational variables such as wheat initial moisture content (11-23% w/w, wet basis), processing pressure (3-5 × 10 2 kPa) and processing time (3-11 min) on the physical (density, color and textural characteristics) and sensory properties of the product were investigated. The physical properties of the wheat snack were most affected by changes in processing pressure, followed by processing time and wheat moisture content. Increasing processing pressure and time often improved expansion and textural properties but led to darkening of the raw wheat color. The most acceptable snack in terms of physical properties was obtained at the lowest wheat moisture content. Sensory analysis suggested that consumer acceptability was optimal for wheat snacks produced at higher processing pressure, medium processing time and lower moisture content. The most desirable conditions for puffed wheat snack production using the DIC process were determined as 11% (w/w) of wheat moisture content, 5 × 10 2 kPa of processing pressure and 7 min of processing time. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  5. Effect of solvent-controlled aggregation on the intrinsic emission properties of PAMAM dendrimers

    International Nuclear Information System (INIS)

    Jasmine, Maria J.; Kavitha, Manniledam; Prasad, Edamana

    2009-01-01

    Solvent-induced aggregation and its effect on the intrinsic emission properties of amine, hydroxy and carboxylate terminated, poly(amidoamine) (PAMAM) dendrimers have been investigated in glycerol, ethylene glycol, methanol, ethylene diamine and water. Altering the solvent medium induces remarkable changes in the intrinsic emission properties of the PAMAM dendrimers at identical concentration. Upon excitation at 370 nm, amine terminated PAMAM dendrimer exhibits an intense emission at 470 nm in glycerol, ethylene glycol as well as glycerol-water mixtures. Conversely, weak luminescence is observed for hydroxy and carboxylate terminated PAMAM dendrimers in the same solvent systems. When the solvent is changed to ethylene diamine, hydroxy terminated PAMAM exhibits intense blue emission at 425 nm. While the emission intensity is varied when the solvent milieu is changed, excited state lifetime values of PAMAM dendrimers remain independent of the solvent used. UV-visible absorption and dynamic light scattering (DLS) experiments confirm the formation of solvent-controlled dendrimer aggregates in the systems. Comparison of the fluorescence and DLS data reveals that the size distribution of the dendrimer aggregates in each solvent system is distinct, which control the intrinsic emission intensity from PAMAM dendrimers. The experimental results suggest that intrinsic emission intensity from PAMAM dendrimers can be regulated by proper selection of solvents at neutral conditions and room temperature

  6. Effect of Controlled Rolling and Cooling On Microstructure and Mechanical Properties of 30crmnti Wire Rod

    Science.gov (United States)

    Ruan, Shipeng; Dong, Qing; Zhang, Lei; Wang, Lijun

    2017-09-01

    The effect of controlled rolling and cooling on microstructure and mechanical properties of alloy structure steel 30CrMnTi wire rod with diameter 6.5mm was studied. The results show that the lower finish rolling temperature resulted in a decrease in tensile strength but an increase in elongation and reduction of area. When the finish rolling temperature decreases from 950°C to 850°C, the tensile strength value decreases from 750MPa to 660MPa, and the elongation increases from 21% to 30%, the reduction of area increases from 64% to 71%. The grain size also refines from 20μm to 9.9μm when the finish rolling temperature decreases from 950°C to 850°C. The decrease of tensile strength is due to the change of microstructure which evolved from more bainite to ferrite and pearlite.

  7. Effect of controlled atmosphere on the mig-mag arc weldment properties

    International Nuclear Information System (INIS)

    Kacar, Ramazan; Koekemli, Koray

    2005-01-01

    Due to their higher welding speed, automation and weld pool protection against to the atmosphere gases, gas metal arc welding (GMAW) process is widely used in industry. Due to the less stable arc associated with the use of consumable electrodes, GMAW process is not clean as good as gas tungsten arc welding process. Furthermore, the greater arc length in GMAW process also reduces the protective effect of the shielding gas. Due to electrochemical and thermochemical reactions between weld pool and arc atmosphere, it is quite important, especially weld metal toughness and joining of reactive materials to entirely create inert atmosphere for GMAW process. Therefore, a controlled atmosphere cabinet was developed for GMAW process. Low carbon steel combinations were welded with classical GMAW process in argon atmosphere as well as controlled atmosphere cabinet by using similar welding parameters. The mechanical and metallurgical properties of both weldments were evaluated. Result shows that toughness of the weld metal that was obtained in the controlled atmosphere cabinet much higher than that of classical GMAW process. The metallographic examination also clarified that there was not any gas porosity and inclusion in the weld metal compared with classical process

  8. Mechanisms for redox control and their effects upon modelled properties of Aespoe groundwaters

    International Nuclear Information System (INIS)

    Emren, A.T.

    1996-01-01

    In the literature, one finds several models for control of redox properties in groundwater. The proposals for redox controlling substances include iron oxides, chlorites, methane, pyrite and polysulphides. The CRACKER program, which has been successful in modelling of observed Aespoe groundwaters has been used to investigate the influence of several redox control models on the modelled properties of present and possible future Aespoe groundwaters. In the simulations, one or more of the possible redox reactions have been prevented from occurring. The groundwater has then been assumed to react with minerals distributed in the fracture walls. Due to the discreteness of mineral grains, a certain amount of fluctuations in groundwater properties is occurring. The process of sampling water for measurement has been simulated by letting about 900 waters from different locations mix. It has been found that some of the models have difficulties in explaining important groundwater properties, while other models perform quite well. With identical mineral sets, the properties of future groundwaters have been simulated. It is found that some changes in groundwater properties at elevated temperatures may be of importance for assessment of the safety of a future repository for spent nuclear fuel. The difference in behaviour is caused mostly by the fact that the solubility increases with temperature for some minerals, while it decreases for other minerals. (author)

  9. Using strong nonlinearity and high-frequency vibrations to control effective properties of discrete elastic waveguides

    DEFF Research Database (Denmark)

    Lazarov, Boyan Stefanov; Thomsen, Jon Juel; Snaeland, Sveinn Orri

    2008-01-01

    The aim of this article is to investigate how highfrequency (HF) excitation, combined with strong nonlinear elastic material behavior, influences the effective material or structural properties for low-frequency excitation and wave propagation. The HF effects are demonstrated on discrete linear s...

  10. Effect of weed control methods on some soil properties of a newly ...

    African Journals Online (AJOL)

    Weed control constitutes a high percentage of the total field maintenance cost of newly planted cocoa. Soil samples were collected from an experiment that was designed to evaluate some weed control methods during cocoa establishment. The objective of the experiment was to assess the effect of the weed control ...

  11. Division 1137 property control system

    Energy Technology Data Exchange (ETDEWEB)

    Pastor, D.J.

    1982-01-01

    An automated data processing property control system was developed by Mobile and Remote Range Division 1137. This report describes the operation of the system and examines ways of using it in operational planning and control.

  12. Effect of spaceflight hardware on the skeletal properties of ground control mice

    Science.gov (United States)

    Bateman, Ted; Lloyd, Shane; Dunlap, Alex; Ferguson, Virginia; Simske, Steven; Stodieck, Louis; Livingston, Eric

    Introduction: Spaceflight experiments using mouse or rat models require habitats that are specifically designed for the microgravity environment. During spaceflight, rodents are housed in a specially designed stainless steel meshed cage with gravity-independent food and water delivery systems and constant airflow to push floating urine and feces towards a waste filter. Differences in the housing environment alone, not even considering the spaceflight environment itself, may lead to physiological changes in the animals contained within. It is important to characterize these cage differences so that results from spaceflight experiments can be more reliably compared to studies from other laboratories. Methods: For this study, we examined the effect of NASA's Animal Enclosure Module (AEM) spaceflight hardware on the skeletal properties of 8-week-old female C57BL/6J mice. This 13-day experiment, conducted on the ground, modeled the flight experiment profile of the CBTM-01 payload on STS-108, with standard vivarium-housed mice being compared to AEM-housed mice (n = 12/group). Functional differences were compared via mechanical testing, micro-hardness indentation, microcomputed tomography, and mineral/matrix composition. Cellular changes were examined by serum chemistry, histology, quantitative histomorphometry, and RT-PCR. A Student's t-test was utilized, with the level of Type I error set at 95 Results: There was no change in elastic, maximum, or fracture force mechanical properties at the femur mid-diaphysis, however, structural stiffness was -17.5 Conclusions: Housing mice in the AEM spaceflight hardware had minimal effects on femur cortical bone properties. However, trabecular bone at the proximal tibia in AEM mice experi-enced large increases in microarchitecture and mineral composition. Increases in bone density were accompanied by reductions in bone-forming osteoblasts and bone-resorbing osteoclasts, representing a general decline in bone turnover at this site

  13. Petri neural network model for the effect of controlled thermomechanical process parameters on the mechanical properties of HSLA steels

    Energy Technology Data Exchange (ETDEWEB)

    Datta, S.

    1999-10-01

    The effect of composition and controlled thermomechanical process parameters on the mechanical properties of HSLA steels is modelled using the Widrow-Hoff's concept of training a neural net with feed-forward topology by applying Rumelhart's back propagation type algorithm for supervised learning, using a Petri like net structure. The data used are from laboratory experiments as well as from the published literature. The results from the neural network are found to be consistent and in good agreement with the experimented results. (author)

  14. The effect of process control agent on the structure and magnetic properties of nanocrystalline mechanically alloyed Fe–45% Ni powders

    Energy Technology Data Exchange (ETDEWEB)

    Gheisari, Kh., E-mail: khgheisari@scu.ac.ir [Department of Materials Science and Engineering, Faculty of Engineering, Shahid Chamran University, Ahvaz (Iran, Islamic Republic of); Javadpour, S. [Department of Materials Science and Engineering, School of Engineering, Shiraz University, Shiraz (Iran, Islamic Republic of)

    2013-10-15

    In this study, nanocrystalline Fe-45 wt% Ni alloy powders were prepared by mechanical alloying via high-energy ball milling. The effect of adding stearic acid as a process control agent (PCA) on the particle size, structure and magnetic properties of Fe-45 wt% Ni alloy powders have been studied by X-ray diffraction, scanning electron microscope and vibrating sample magnetometer measurements. The results show that the addition of 1 wt% PCA causes fine uniform spherical powder particles of the fcc γ-(Fe, Ni) phase to be formed after 48 h milling time. It is also found that crystallite size, lattice strain and content of γ-(Fe, Ni) phase are three of the most important variables that are significantly affected by PCA content and can influence the magnetic properties. - Highlights: • Different amount of stearic acid as a PCA was used during milling. • Particle size and crystallite size decrease with increasing PCA content. • The addition of 1 wt% PCA leads to a good combination of structure and magnetic properties.

  15. The effect of process control agent on the structure and magnetic properties of nanocrystalline mechanically alloyed Fe–45% Ni powders

    International Nuclear Information System (INIS)

    Gheisari, Kh.; Javadpour, S.

    2013-01-01

    In this study, nanocrystalline Fe-45 wt% Ni alloy powders were prepared by mechanical alloying via high-energy ball milling. The effect of adding stearic acid as a process control agent (PCA) on the particle size, structure and magnetic properties of Fe-45 wt% Ni alloy powders have been studied by X-ray diffraction, scanning electron microscope and vibrating sample magnetometer measurements. The results show that the addition of 1 wt% PCA causes fine uniform spherical powder particles of the fcc γ-(Fe, Ni) phase to be formed after 48 h milling time. It is also found that crystallite size, lattice strain and content of γ-(Fe, Ni) phase are three of the most important variables that are significantly affected by PCA content and can influence the magnetic properties. - Highlights: • Different amount of stearic acid as a PCA was used during milling. • Particle size and crystallite size decrease with increasing PCA content. • The addition of 1 wt% PCA leads to a good combination of structure and magnetic properties

  16. Length-controlled few-walled carbon nanotubes and their effect on the electrical property of flexible transparent conductive films

    Science.gov (United States)

    Lee, Byeong-Joo; Shin, Eui-Chul; Jeong, Goo-Hwan

    2012-06-01

    We investigated the effect of the length of carbon nanotubes (CNTs) on the electrical property of CNT-based flexible, transparent, and conductive films (TCFs). We grew vertically aligned CNTs with controlled lengths, dispersed them in ethanol by ultrasonication, and spray coated them onto polyethylene terephthalate (PET) sheets. We focused on the variation in the sheet resistance and transmittance of the above-mentioned films as a function of the CNT length, and we found that the optimum CNT length was 200 μm. We concluded that the CNT length should be carefully optimized because a shorter tube affords the advantage of efficient dispersion, while a longer tube helps in reducing the number of contact points between tubes along the electrical conduction path.

  17. Effects of secondary loudspeaker properties on broadband feedforward active duct noise control.

    Science.gov (United States)

    Chan, Yum-Ji; Huang, Lixi; Lam, James

    2013-07-01

    Dependence of the performance of feedforward active duct noise control on secondary loudspeaker parameters is investigated. Noise reduction performance can be improved if the force factor of the secondary loudspeaker is higher. For example, broadband noise reduction improvement up to 1.6 dB is predicted by increasing the force factor by 50%. In addition, a secondary loudspeaker with a larger force factor was found to have quicker convergence in the adaptive algorithm in experiment. In simulations, noise reduction is improved in using an adaptive algorithm by using a secondary loudspeaker with a heavier moving mass. It is predicted that an extra broadband noise reduction of more than 7 dB can be gained using an adaptive filter if the force factor, moving mass and coil inductance of a commercially available loudspeaker are doubled. Methods to increase the force factor beyond those of commercially available loudspeakers are proposed.

  18. Effect of Ce on performance and physicochemical properties of Pt-containing automotive emission control catalysts

    International Nuclear Information System (INIS)

    Nunan, J.G.; Silver, R.G.; Bradley, S.A.

    1992-01-01

    Present-day automotive emission control catalysts contain noble metals such as Pt, Pd and Rh all on an alumina support with a variety of promoters. Ce is one of the most important promoters. In this paper, the interaction between Pt and Ce is studied using TPR and STEM on a variety of catalysts. The degree of Pt/Ce interaction is increased by decreasing CeO 2 crystallite size, and to a lesser extent by increasing CeO 2 loading. Direct Pt/Ce interaction leads to a synergistic reduction of both Pt and surface Ce. This reduction qualitatively correlates with catalyst performance after activation in a reducing gas. It is proposed that this synergistic reduction of Pt and Ce is associated with observed improvements in catalyst performance using a non-oscillating exhaust gas

  19. Effect of Graphene and Fullerene Nanofillers on Controlling the Pore Size and Physicochemical Properties of Chitosan Nanocomposite Mesoporous Membranes

    Directory of Open Access Journals (Sweden)

    Irene S. Fahim

    2015-01-01

    Full Text Available Chitosan (CS nanocomposite mesoporous membranes were fabricated by mixing CS with graphene (G and fullerene (F nanofillers, and the diffusion properties through CS membranes were studied. In addition, in order to enhance the binding between the internal CS chains, physical cross-linking of CS by sodium tripolyphosphate (TPP was carried out. F and G with different weight percentages (0.1, 0.5, and 1 wt.% were added on physically cross-linked chitosan (CLCS and non-cross-linked chitosan (NCLCS membranes by wet mixing. Permeability and diffusion time of CLCS and NCLCS membranes at different temperatures were investigated. The results revealed that the pore size of all fabricated CS membranes is in the mesoporous range (i.e., 2–50 nm. Moreover, the addition of G and F nanofillers to CLCS and NCLCS solutions aided in controlling the CS membranes’ pore size and was found to enhance the barrier effect of the CS membranes either by blocking the internal pores or decreasing the pore size. These results illustrate the significant possibility of controlling the pore size of CS membranes by cross-linking and more importantly the careful selection of nanofillers and their percentage within the CS membranes. Controlling the pore size of CS membranes is a fundamental factor in packaging applications and membrane technology.

  20. An Effective Acid Combination for Enhanced Properties and Corrosion Control of Acidizing Sandstone Formation

    International Nuclear Information System (INIS)

    Shafiq, Mian Umer; Mahmud, Hisham Khaled Ben

    2016-01-01

    To fulfill the demand of the world energy, more technologies to enhance the recovery of oil production are being developed. Sandstone acidizing has been introduced and it acts as one of the important means to increase oil and gas production. Sandstone acidizing operation generally uses acids, which create or enlarge the flow channels of formation around the wellbore. In sandstone matrix acidizing, acids are injected into the formation at a pressure below the formation fracturing pressure, in which the injected acids react with mineral particles that may restrict the flow of hydrocarbons. Most common combination is Hydrofluoric Acid - Hydrochloric with concentration (3% HF - 12% HCl) known as mud acid. But there are some problems associated with the use of mud acid i.e., corrosion, precipitation. In this paper several new combinations of acids were experimentally screened to identify the most effective combination. The combinations used consist of fluoboric, phosphoric, formic and hydrofluoric acids. Cores were allowed to react with these combinations and results are compared with the mud acid. The parameters, which are analyzed, are Improved Permeability Ratio, strength and mineralogy. The analysis showed that the new acid combination has the potential to be used in sandstone acidizing. (paper)

  1. Soil biochemical properties and microbial resilience in agroforestry systems: effects on wheat growth under controlled drought and flooding conditions.

    Science.gov (United States)

    Rivest, David; Lorente, Miren; Olivier, Alain; Messier, Christian

    2013-10-01

    Agroforestry is increasingly viewed as an effective means of maintaining or even increasing crop and tree productivity under climate change while promoting other ecosystem functions and services. This study focused on soil biochemical properties and resilience following disturbance within agroforestry and conventional agricultural systems and aimed to determine whether soil differences in terms of these biochemical properties and resilience would subsequently affect crop productivity under extreme soil water conditions. Two research sites that had been established on agricultural land were selected for this study. The first site included an 18-year-old windbreak, while the second site consisted in an 8-year-old tree-based intercropping system. In each site, soil samples were used for the determination of soil nutrient availability, microbial dynamics and microbial resilience to different wetting-drying perturbations and for a greenhouse pot experiment with wheat. Drying and flooding were selected as water stress treatments and compared to a control. These treatments were initiated at the beginning of the wheat anthesis period and maintained over 10 days. Trees contributed to increase soil nutrient pools, as evidenced by the higher extractable-P (both sites), and the higher total N and mineralizable N (tree-based intercropping site) found in the agroforestry compared to the conventional agricultural system. Metabolic quotient (qCO2) was lower in the agroforestry than in the conventional agricultural system, suggesting higher microbial substrate use efficiency in agroforestry systems. Microbial resilience was higher in the agroforestry soils compared to soils from the conventional agricultural system (windbreak site only). At the windbreak site, wheat growing in soils from agroforestry system exhibited higher aboveground biomass and number of grains per spike than in conventional agricultural system soils in the three water stress treatments. At the tree

  2. Multiple Property Cross Direction Control of Paper Machines

    Directory of Open Access Journals (Sweden)

    Markku Ohenoja

    2011-07-01

    Full Text Available Cross direction (CD control in sheet-forming process forms a challenging problem with high dimensions. Accounting the interactions between different properties and actuators, the dimensionality increases further and also computational issues arise. We present a multiple property controller feasible to be used especially with imaging measurements that provide high sampling frequency and therefore enable short control interval. The simulation results state the benefits of multiple property CD control over single property control and single property control using full feedforward compensation. The controller presented may also be tuned in automated manner and the results demonstrate the effect of tuning on input saturation.

  3. Effect of cutoff radius, long range interaction and temperature controller on thermodynamic properties of fluids: Methanol as an example

    Science.gov (United States)

    Obeidat, Abdalla; Jaradat, Adnan; Hamdan, Bushra; Abu-Ghazleh, Hind

    2018-04-01

    The best spherical cutoff radius, long range interaction and temperature controller were determined using surface tension, density, and diffusion coefficients of van Leeuwen and Smit methanol. A quite good range of cutoff radii from 0.75 to 1.45 nm has been studied on Coulomb cut-off and particle mesh Ewald (PME) long range interaction to determine the best cutoff radius and best long range interaction as well for four sets of temperature: 200, 230, 270 and 300 K. To determine the best temperature controller, the cutoff radius of 1.25 nm was fixed using PME long range interaction on calculating the above properties at low temperature range: 200-300 K.

  4. Enhancement of charge transport properties of small molecule semiconductors by controlling fluorine substitution and effects on photovoltaic properties of organic solar cells and perovskite solar cells.

    Science.gov (United States)

    Yun, Jae Hoon; Park, Sungmin; Heo, Jin Hyuck; Lee, Hyo-Sang; Yoon, Seongwon; Kang, Jinback; Im, Sang Hyuk; Kim, Hyunjung; Lee, Wonmok; Kim, BongSoo; Ko, Min Jae; Chung, Dae Sung; Son, Hae Jung

    2016-11-01

    We prepared a series of small molecules based on 7,7'-(4,4-bis(2-ethylhexyl)-4 H -silolo[3,2- b :4,5- b ']dithiophene-2,6-diyl)bis(4-(5'-hexyl-[2,2'-bithiophene]-5-yl)benzo[ c ][1,2,5]thiadiazole) with different fluorine substitution patterns ( 0F-4F ). Depending on symmetricity and numbers of fluorine atoms incorporated in the benzo[ c ][1,2,5]thiadiazole unit, they show very different optical and morphological properties in a film. 2F and 4F , which featured symmetric and even-numbered fluorine substitution patterns, display improved molecular packing structures and higher crystalline properties in a film compared with 1F and 3F and thus, 2F achieved the highest OTFT mobility, which is followed by 4F . In the bulk heterojunction solar cell fabricated with PC 71 BM, 2F achieves the highest photovoltaic performance with an 8.14% efficiency and 0F shows the lowest efficiency of 1.28%. Moreover, the planar-type perovskite solar cell (PSC) prepared with 2F as a dopant-free hole transport material shows a high power conversion efficiency of 14.5% due to its high charge transporting properties, which were significantly improved compared with the corresponding PSC device obtained from 0F (8.5%). From the studies, it is demonstrated that low variation in the local dipole moment and the narrow distribution of 2F conformers make intermolecular interactions favorable, which may effectively drive crystal formations in the solid state and thus, higher charge transport properties compared with 1F and 3F .

  5. Effect of Controlled Cooling on Microstructure and Tensile Properties of Low C Nb-Ti-Containing HSLA Steel for Construction

    Directory of Open Access Journals (Sweden)

    Yi Fan

    2017-01-01

    Full Text Available The thermo-mechanical control processing (TMCP of low carbon (C Nb-Ti-containing HSLA steel with different cooling rates from 5 to 20 °C/s was simulated using a Gleeble 3500 system. The samples’ microstructure was characterized and the tensile properties measured. The results show that a microstructure mainly consisting of quasi-polygonal ferrite (QPF, granular bainitic ferrite (GBF, and martensite/austenite (M/A constituent formed in each sample. Furthermore, the accelerated cooling led to a significant grain refinement of the QPF and GBF, and an increase in the density of dislocations, as well as suppressed the precipitation of nanoscale particles; however, the overall yield strength (YS still increased obviously. The accelerated cooling also brought about a decrease in amount of M/A constituent acting as a mixed hard phase, which weakened the overall strain-hardening capacity of the QPF + GBF + M/A multiphase steel and simultaneously elevated yield-to-tensile strength ratio (YR. In addition, the mechanisms in dominating the influence of controlled cooling on the final microstructure and tensile properties were discussed.

  6. Specific properties of the SI and SII somatosensory areas and their effects on motor control: a system neurophysiological study.

    Science.gov (United States)

    Friedrich, Julia; Mückschel, Moritz; Beste, Christian

    2018-03-01

    Sensorimotor integration is essential for successful motor control and the somatosensory modality has been shown to have strong effects on the execution of motor plans. The primary (SI) and the secondary somatosensory (SII) cortices are known to differ in their neuroanatomical connections to prefrontal areas, as well as in their involvement to encode cognitive aspects of tactile processing. Here, we ask whether the area-specific processing architecture or the structural neuroanatomical connections with prefrontal areas determine the efficacy of sensorimotor integration processes for motor control. In a system neurophysiological study including EEG signal decomposition (i.e., residue iteration decomposition, RIDE) and source localization, we investigated this question using vibrotactile stimuli optimized for SI or SII processing. The behavioral data show that when being triggered via the SI area, inhibitory control of motor processes is stronger as when being triggered via the SII area. On a neurophysiological level, these effects were reflected in the C-cluster as a result of a temporal decomposition of EEG data, indicating that the sensory processes affecting motor inhibition modulate the response selection level. These modulations were associated with a stronger activation of the right inferior frontal gyrus extending to the right middle frontal gyrus as parts of a network known to be involved in inhibitory motor control when response inhibition is triggered over SI. In addition, areas important for sensorimotor integration like the postcentral gyrus and superior parietal cortex showed activation differences. The data suggest that connection patterns are more important for sensorimotor integration and control than the more restricted area-specific processing architecture.

  7. Studies on thermal properties and thermal control effectiveness of a new shape-stabilized phase change material with high thermal conductivity

    International Nuclear Information System (INIS)

    Cheng Wenlong; Liu Na; Wu Wanfan

    2012-01-01

    In order to overcome the difficulty of conventional phase change materials (PCMs) in packaging, the shape-stabilized PCMs are proposed to be used in the electronic device thermal control. However, the conventional shape-stabilized PCMs have the drawback of lower thermal conductivity, so a new shape-stabilized PCM with high thermal conductivity, which is suitable for thermal control of electronic devices, is prepared. The thermal properties of n-octadecane-based shape-stabilized PCM are tested and analyzed. The heat storage/release performance is studied by numerical simulation. Its thermal control effect for electronic devices is also discussed. The results show that the expanded graphite (EG) can greatly improve the thermal conductivity of the material with little effect on latent heat and phase change temperature. When the mass fraction of EG is 5%, thermal conductivity has reached 1.76 W/(m K), which is over 4 times than that of the original one. Moreover, the material has larger latent heat and good thermal stability. The simulation results show that the material can have good heat storage/release performance. The analysis of the effect of thermal parameters on thermal control effect for electronic devices provides references to the design of phase change thermal control unit. - Highlights: ► A new shape-stabilized PCM with higher thermal conductivity is prepared. ► The material overcomes the packaging difficulty of traditional PCMs used in thermal control unit. ► The EG greatly improves thermal conductivity with little effect on latent heat. ► The material has high thermal stability and good heat storage/release performance. ► The effectiveness of the material for electronic device thermal control is proved.

  8. Dihedral angle control to improve the charge transport properties of conjugated polymers in organic field effect transistors

    Science.gov (United States)

    Dharmapurikar, Satej S.; Chithiravel, Sundaresan; Mane, Manoj V.; Deshmukh, Gunvant; Krishnamoorthy, Kothandam

    2018-03-01

    Diketopyrrolopyrrole (DPP) and i-Indigo (i-Ind) are two monomers that are widely explored as active materials in organic field effect transistor and solar cells. These two molecules showed impressive charge carrier mobility due to better packing that are facilitated by quadrupoles. We hypothesized that the copolymers of these monomers would also exhibit high charge carrier mobility. However, we envisioned that the dihedral angle at the connecting point between the monomers will play a crucial role in packing as well as charge transport. To understand the impact of dihedral angle on charge transport, we synthesized three copolymers, wherein the DPP was sandwiched between benzenes, thiophenes and furans. The copolymer of i-Indigo and furan comprising DPP showed a band gap of 1.4 eV with a very high dihedral angle of 179°. The polymer was found to pack better and the coherence length was found to be 112 Å. The hole carrier mobility of these polymer was found to be highest among the synthesized polymer i.e. 0.01 cm2/vs. The copolymer comprising benzene did not transport hole and electrons. The dihedral angle at the connecting point between i and Indigo and benzene DPP was 143 Å, which the packing and consequently charge transport properties.

  9. Effect of controlling recrystallization from the melt on the residual stress and structural properties of the Silica-clad Ge core fiber

    Science.gov (United States)

    Zhao, Ziwen; Cheng, Xueli; He, Ting; Xue, Fei; Zhang, Wei; Chen, Na; Wen, Jianxiang; Zeng, Xianglong; Wang, Tingyun

    2017-09-01

    Effect of controlling recrystallization from the melt (1000 °C) on the residual stress and structural properties of a Ge core fiber via molten core drawing (MCD) method is investigated. Ge core fibers is investigated using Raman spectroscopy, scanning electron microscope (SEM), and X-ray diffraction (XRD). Compared with the as-drawn Ge fiber, the Raman peak of the recrystallized Ge fiber shift from 300 cm-1 to 300.6 cm-1 and full width at half maximum (FWHM) decreased from 5.36 cm-1 to 4.48 cm-1. The Ge crystal grains which sizes are of 200-600 nm were formed during the process of recrystallization; the XRD peak of (1 1 1) plane is observed after recrystallization. These results show that controlling recrystallization allows the release of the thermal stress, and improvement of the crystal quality of Ge core.

  10. Acute effects of combined exercise and oscillatory positive expiratory pressure therapy on sputum properties and lung diffusing capacity in cystic fibrosis: a randomized, controlled, crossover trial.

    Science.gov (United States)

    Radtke, Thomas; Böni, Lukas; Bohnacker, Peter; Maggi-Beba, Marion; Fischer, Peter; Kriemler, Susi; Benden, Christian; Dressel, Holger

    2018-06-14

    Regular airway clearance by chest physiotherapy and/or exercise is critical to lung health in cystic fibrosis (CF). Combination of cycling exercise and chest physiotherapy using the Flutter® device on sputum properties has not yet been investigated. This prospective, randomized crossover study compared a single bout of continuous cycling exercise at moderate intensity (experiment A, control condition) vs a combination of interval cycling exercise plus Flutter® (experiment B). Sputum properties (viscoelasticity, yield stress, solids content, spinnability, and ease of sputum expectoration), pulmonary diffusing capacity for nitric oxide (DLNO) and carbon monoxide (DLCO) were assessed at rest, directly and 45 min post-exercise (recovery) at 2 consecutive visits. Primary outcome was change in sputum viscoelasticity (G', storage modulus; G", loss modulus) over a broad frequency range (0.1-100 rad.s - 1 ). 15 adults with CF (FEV 1 range 24-94% predicted) completed all experiments. No consistent differences between experiments were observed for G' and G" and other sputum properties, except for ease of sputum expectoration during recovery favoring experiment A. DLNO, DLCO, alveolar volume (V A ) and pulmonary capillary blood volume (V cap ) increased during experiment A, while DLCO and V cap increased during experiment B (all P < 0.05). We found no differences in absolute changes in pulmonary diffusing capacity and its components between experiments, except a higher V A immediately post-exercise favoring experiment A (P = 0.032). The additional use of the Flutter® to moderate intensity interval cycling exercise has no measurable effect on the viscoelastic properties of sputum compared to moderate intensity continuous cycling alone. Elevations in diffusing capacity represent an acute exercise-induced effect not sustained post-exercise. ClinicalTrials.gov; No.: NCT02750722 ; URL: clinical.trials.gov; Registration date: April 25th, 2016.

  11. Preliminary investigation of the effect of air-pollution-control residue from waste incineration on the properties of cement paste and mortar

    DEFF Research Database (Denmark)

    Geiker, Mette Rica; Kjeldsen, Ane Mette; Galluci, Emmanuel

    2006-01-01

    For preliminary assessment of the engineering properties of concrete with air-pollution-control residue from waste incineration (APC) the possible reactivity of APC and the effect of APC on cement hydration were investigated by isothermal calorimetry, chemical shrinkage (pychnometry), thermal...... analysis (TG), X-ray diffraction (XRD) and scanning electron microscopy (SEM). Furthermore, compressive strength development was measured and impregnated plane sections were prepared. The APC was from a Danish wet process plant. Although the APC contained high amounts of chloride (approx. 10%) and heavy......% and 20% APC showed a major retarding effect of APC on the development of hydration. The APC was found to be pozzolanic. Chemical shrinkage measurements indicated early expansive reactions of pastes with the APC including evolution of air. Crack formation was observed in mortars with APC, and strength...

  12. Effect of pulsed duty cycle control on tribological and corrosion properties of AISI-316 in cathodic cage plasma nitriding

    Science.gov (United States)

    Naeem, M.; Raza, H. A.; Shafiq, M.; Zaka-ul-Islam, M.; Iqbal, Javed; Díaz-Guillén, J. C.; Zakaullah, M.

    2017-11-01

    Austenitic stainless steels are of prime importance in many industrial sectors because of their excellent corrosion resistance; however, their poor mechanical and tribological features lead to their reduced applicability. In this regard, low-temperature cathodic cage plasma nitriding (CCPN) can be used to improve surface properties of steels without scarifying the inherent corrosion resistance. In this study, AISI-316 samples are processed in CCPN reactor at a temperature of 400 °C, for the treatment time of 4 h, at a pressure of 150 Pa and variable pulsed duty cycle (15-75%). The microstructure and mechanical features are analyzed using x-ray diffraction, scanning electron microscopy, microhardness tester and ball-on-disc wear tester. The anodic polarization test in 3.5% NaCl is conducted to examine the corrosion properties. The results show that hardness is enhanced up to 1327 HV at low duty cycle, which is considerably higher than base material (278 HV). The wear rate is found to be reduced up to 90% over base material by processing at low duty cycle. The base material exhibits severe abrasive wear, and the nitrided sample has dominant adhesive wear. The corrosion rate is found to be reduced up to 95% over base material for the sample nitrided at low duty cycle. This study shows that wear and corrosion resistance in CCPN can be significantly boosted by reducing the pulsed duty cycle.

  13. Controllable Interfacial Coupling Effects on the Magnetic Dynamic Properties of Perpendicular [Co/Ni]5/Cu/TbCo Composite Thin Films.

    Science.gov (United States)

    Tang, Minghong; Zhao, Bingcheng; Zhu, Weihua; Zhu, Zhendong; Jin, Q Y; Zhang, Zongzhi

    2018-02-07

    Dynamic magnetic properties in perpendicularly exchange-coupled [Co/Ni] 5 /Cu (t Cu = 0-2 nm)/TbCo structures show strong dependences on the interfacial antiferromagnetic strength J ex , which is controlled by the Cu interlayer thickness. The precession frequency f and effective damping constant α eff of a [Co/Ni] 5 multilayer differ distinctly for parallel (P) and antiparallel (AP) magnetization orientation states. For samples with a thin t Cu , f of the AP state is apparently higher, whereas α eff is lower than that in the P state, owing to the unidirectional exchange bias effect (H EB ) from the TbCo layer. The differences in f and α eff between the two states gradually decrease with increasing t Cu . By using a uniform precession model including an additional H EB term, the field-dependent frequency curves can be well-fitted, and the fitted H EB value is in good agreement with the experimental data. Moreover, the saturation damping constant α 0 displays a nearly linear correlation with J ex . It decreases significantly with J ex and eventually approaches a constant value of 0.027 at t Cu = 2 nm where J ex vanishes. These results provide a better understanding and effective control of magnetization dynamics in exchange-coupled composite structures for spintronic applications.

  14. How gluten properties are effected by pentosans

    NARCIS (Netherlands)

    Wang, M.; Vliet, van T.; Hamer, R.J.

    2004-01-01

    During the wet separation of starch and gluten, both water extractable pentosans (WEP) and water unextractable solids (WUS) have a negative effect on gluten yield. Gluten properties are also affected: the gluten becomes less extensible. In comparison to the control, addition of WUS or WEP resulted

  15. Optimization of biodegradable sponges as controlled release drug matrices. I. Effect of moisture level on chitosan sponge mechanical properties.

    Science.gov (United States)

    Foda, Nagwa H; El-laithy, Hanan M; Tadros, Mina I

    2004-04-01

    Cross-linked chitosan sponges as controlled release drug carrier systems were developed. Tramadol hydrochloride, a centrally acting analgesic, was used as a model drug. The sponges were prepared by freeze-drying 1.25% and 2.5% (w/w) high and low M.wt. chitosan solutions, respectively, using glutaraldehyde as a cross-linking agent. The hardness of the prepared sponges was a function of glutaraldehyde concentration and volume where the optimum concentration that offered accepted sponge consistency was 5%. Below or above 5%, very soft or very hard and brittle sponges were obtained, respectively. The determined drug content in the prepared sponges was uniform and did not deviate markedly from the calculated amount. Scanning electron microscopy (SEM) was used to characterize the internal structures of the sponges. The SEM photos revealed that cross-linked high M.wt. chitosan sponges have larger size surface pores that form connections (channels) with the interior of the sponge than cross-linked low M.wt. ones. Moreover, crystals of the incorporated Tramadol hydrochloride were detected on the lamellae and within pores in both chitosan sponges. Differences in pore size and dissolution medium uptake capacity were crucial factors for the more delayed drug release from cross-linked low M.wt. chitosan sponges over high M.wt. ones at pH 7.4. Kinetic analysis of the release data using linear regression followed the Higuchi diffusion model over 12 hours. Setting storage conditions at room temperature under 80-92% relative humidity resulted in soft, elastic, and compressible sponges.

  16. Effect of Three Species of Mycorrhiza Inoculation on Yield and Some Physiological properties of Two Potato Cultivars under Drought Stress in Controlled Conditions

    Directory of Open Access Journals (Sweden)

    S. Khaninejad

    2017-03-01

    Full Text Available Introduction In recent years, rainfall deficiency was an increasing problem in most countries; which limited the production of agricultural crops. Among abiotic stresses the plants encountered, drought stress is considered as the most important limiting factor in plants growth and reproduction in natural and agricultural systems through most parts of the world; while drought stress causes 45% increase in the crops among various stress making factors (biotic and abiotic. A suitable procedure for controlling drought stress in agriculture is making the symbiotic relation between plants and mycorrhizal fungi. Mycorrhizal fungi decrease the plant ability in absorbing nutrients, ion balance, keeping enzyme activity, increasing chlorophyll density and root-soil connection; they decline the hazards caused by stress and decrease the plant tolerance to biotic and abiotic stresses. Potato is one of the most valuable sources to provide human food in the developing countries and is one of the most productive crops, while its production is twofold to rice and wheat. Producing more than 5 million tones potato makes this crop as the first utilizable nutrient after wheat, in this country. Potato is sensitive to soil humidity caused by limited and low-deep root system. Materials and Methods Thus, an investigation was conducted to examine the effect of three of mycorrhizal fungi (Glomus mosseae, Glomus intraradices and Glomus fasciculatum on two potato cultivars (Agria and Fontana under drought stress and control conditions, in factorial experiment based on complete randomize block with three repetitions in research greenhouse of Ferdowsi University in 2012. In control treatment, irrigating was done when field capacity got 80% and it was conducted to 100% field capacity. Stress treatment was done when the field capacity got 60% and continued to 80% field capacity. Fungus treatment was done with a 100g mixture of inoculum including mycorrhizal root sections of corn

  17. Controlled synthesis and electrochemical properties of vanadium ...

    Indian Academy of Sciences (India)

    Vanadium oxides (V3O7·H2O and VO2) with different morphologies have been selectively synthesized ... appeared at around 68 ◦C. Furthermore, the electrochemical properties of V3O7·H2O nanobelts, VO2(B) .... morphologies of shape-controlled orthorhombic V3O7·H2O ..... condition, as shown in figures S14i and j.

  18. 48 CFR 1245.511 - Audit of property control system.

    Science.gov (United States)

    2010-10-01

    ... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false Audit of property control... 1245.511 Audit of property control system. (a) The property administrator (or other Government official authorized by the contracting officer) shall audit the contractor's property control system whenever there...

  19. Effect of a controlled burn on the thermophysical properties of a dry soil using a new model of soil heat flow and a new high temperature heat flux sensor

    Science.gov (United States)

    W. J. Massman; J. M. Frank

    2004-01-01

    Some fires can be beneficial to soils but, if a fire is sufficiently intense, soil can be irreversible altered. We measured soil temperatures and heat fluxes at several soil depths before, during, and after a controlled surface burn at Manitou Experimental Forest (southern Colorado, USA) to evaluate its effects on the soil's thermophysical properties (thermal...

  20. Controlled retting of hemp fibres: Effect of hydrothermal pre-treatmen tand enzymatic retting on the mechanical properties of unidirectiona lhemp/epoxy composites

    DEFF Research Database (Denmark)

    Liu, Ming; Silva, Diogo Alexandre Santos; Fernando, Dinesh

    2016-01-01

    The objective of this work was to investigate the use of hydrothermal pre-treatment and enzymatic retting to remove non-cellulosic compounds and thus improve the mechanical properties of hemp fibre/epoxy composites. Hydrothermal pre-treatment at 100 kPa and 121 °C combined with enzymatic retting...... produced fibres with the highest ultimate tensile strength (UTS) of 780 MPa. Compared to untreated fibres, this combined treatment exhibited a positive effect on the mechanical properties of hemp fibre/epoxy composites, resulting in high quality composites with low porosity factor (αpf) of 0.08.Traditional...

  1. Effect of food on the pharmacokinetic properties of the oral sarpogrelate hydrochloride controlled-release tablet in healthy male Korean subjects.

    Science.gov (United States)

    Jung, Jin Ah; Kim, Jung-Ryul; Kim, Tae-Eun; Lee, Soo-Youn; Huh, Wooseong; Lee, Jae Won; Jun, Hun; Ko, Jae-Wook

    2013-07-01

    A new controlled-release formulation of sarpogrelate, a 5-hydroxytryptamine receptor subtype 2 antagonist that blocks serotonin-induced platelet aggregation, has been developed for once-daily administration. This study evaluated the effect of food on the pharmacokinetic properties of controlled-release sarpogrelate (sarpogrelate CR) in healthy volunteers. A randomized, open-label, two-period, two-treatment crossover study was performed in healthy male Korean subjects. Following an overnight fast, a single dose of sarpogrelate CR 300 mg was administered either in the fasted condition or immediately after a high-fat breakfast. Pharmacokinetic parameters were calculated using a noncompartmental analysis. Tolerability was determined using clinical laboratory testing and physical examination, including vital sign measurements, electrocardiography, and interviews with the volunteers regarding adverse events (AEs). A total of 24 healthy subjects were enrolled, 23 of whom completed the study (mean [range] age, 26 years [21-45]; weight, 68.1 kg [56.0-79.9]; body mass index, 22.1 kg/m(2) [18.8-25.0]). Sarpogrelate C(max) and AUC(last) were decreased In the fed condition compared with those in the fasted condition, with geometric mean ratios (90% CI) of 0.4868 (0.4041-0.5864) and 0.7394 (0.6809-0.8028), respectively. T(max) was delayed from 0.75 to 4.0 hours after a high-fat meal, but the fed condition exhibited a similar elimination profile to that of the fasted condition. The most commonly reported AE was headache (n = 2), and other AEs were reported in 1 subject each. All of the AEs were considered mild in intensity, and the participants recovered without treatment. Compared with the administration of sarpogrelate CR 300 mg in the fasted condition, administration with food was associated with a decreased rate and extent of absorption, as assessed by C(max) and AUC(last), respectively. The drug was well-tolerated by the healthy subjects in this study. Copyright © 2013

  2. Effects of irradiation on mechanical properties

    International Nuclear Information System (INIS)

    Server, W.L.; Griesbach, T.J.; Dragunov, Y.; Amaev, A.

    1998-01-01

    As a result of the popularity of the Agencies report 'Neutron Irradiation Embrittlement of Reactor Pressure Vessel Steels' of 1975, it was decided that another report on this broad subject would be of use. In this report, background and contemporary views on specially identified areas of the subject are considered as self-contained chapters, written by experts. The effects of irradiation on the mechanical properties of reactor pressure vessel steels are explained. This chapter provides some background on the critical elements controlling neutron damage effects. Distinction is made between vessels made in the USA and in the former USSR

  3. Effects of hydrogen irradiation on the optical and electronic properties of site-controlled InGaAsN V-groove quantum wires

    International Nuclear Information System (INIS)

    Felici, M.; Pettinari, G.; Polimeni, A.; Lavenuta, G.; Tartaglini, E.; De Luca, M.; Capizzi, M.; Carron, R.; Gallo, P.; Dwir, B.; Rudra, A.; Kapon, E.; Notargiacomo, A.; Fekete, D.; Christianen, P. C. M.; Maan, J. C.

    2013-01-01

    The properties of InGaAsN V-groove quantum wires (QWRs) –both untreated and irradiated with atomic hydrogen– are probed via micro-magneto-photoluminescence (PL) and polarization-dependent PL. As generally observed in dilute-nitride materials, H irradiation is found to fully passivate nitrogen, thus allowing us to accurately assess –and to precisely control– the effects of N incorporation in the QWRs

  4. HYDRAULIC CONCRETE COMPOSITION AND PROPERTIES CONTROL SYSTEM

    Directory of Open Access Journals (Sweden)

    O. M. Pshinko

    2015-08-01

    Full Text Available Purpose. Scientific work aims at the development and testing of information system to meet the challenges of concrete composition design and control (for railway structures and buildings based on the physico-analytical method algorithm for hydraulic concrete composition calculation. Methodology. The proposed algorithm of hydraulic concrete composition calculation is based on the physicochemical mechanics and in particular on the rheology of elastic–viscous–plastic bodies. The system of canonical equations consists of the equations for concrete strength, absolute volume, concrete mix consistency as well as the equation for optimal concrete saturation with aggregates while minimizing cement content. The joint solution of these four equations related to composition allows determining for the materials the concrete composition of required strength, concrete workability with minimum cement content. The procedure for calculation of hydraulic concrete composition according to the physico-analytical method consists of two parts: 1 physical, which is laboratory testing of concrete mix components in different concrete compositions; 2 analytical, which represents the calculation algorithm for concrete compositions equivalent in concrete strength and workability that comply with the specific conditions of concrete placing. Findings. To solve the problem of designing the concrete composition with the desired properties for railway structures and buildings it was proposed to use the information technology in the form of a developed computer program whose algorithm includes the physico-analytical method for hydraulic concrete composition determination. Originality. The developed concrete composition design method takes into account the basic properties of raw materials, concrete mix and concrete, which are pre-determined. The distinctive feature of physico-analytical method is obtaining of a set of equivalent compositions with a certain concrete mix

  5. 48 CFR 3045.511 - Audit of property control system.

    Science.gov (United States)

    2010-10-01

    ... 48 Federal Acquisition Regulations System 7 2010-10-01 2010-10-01 false Audit of property control system. 3045.511 Section 3045.511 Federal Acquisition Regulations System DEPARTMENT OF HOMELAND SECURITY... Government Property in the Possession of Contractors 3045.511 Audit of property control system. (a) The...

  6. 25 CFR 900.54 - Should the property management system prescribe internal controls?

    Science.gov (United States)

    2010-04-01

    ... System Standards § 900.54 Should the property management system prescribe internal controls? Yes. Effective internal controls should include procedures: (a) For the conduct of periodic inventories; (b) To... 25 Indians 2 2010-04-01 2010-04-01 false Should the property management system prescribe internal...

  7. The Effects of Fungicide, Soil Fumigant, Bio-Organic Fertilizer and Their Combined Application on Chrysanthemum Fusarium Wilt Controlling, Soil Enzyme Activities and Microbial Properties

    Directory of Open Access Journals (Sweden)

    Shuang Zhao

    2016-04-01

    Full Text Available Sustained monoculture often leads to a decline in soil quality, in particular to the build-up of pathogen populations, a problem that is conventionally addressed by the use of either fungicide and/or soil fumigation. This practice is no longer considered to be either environmentally sustainable or safe. While the application of organic fertilizer is seen as a means of combating declining soil fertility, it has also been suggested as providing some control over certain soil-borne plant pathogens. Here, a greenhouse comparison was made of the Fusarium wilt control efficacy of various treatments given to a soil in which chrysanthemum had been produced continuously for many years. The treatments comprised the fungicide carbendazim (MBC, the soil fumigant dazomet (DAZ, the incorporation of a Paenibacillus polymyxa SQR21 (P. polymyxa SQR21, fungal antagonist enhanced bio-organic fertilizer (BOF, and applications of BOF combined with either MBC or DAZ. Data suggest that all the treatments evaluated show good control over Fusarium wilt. The MBC and DAZ treatments were effective in suppressing the disease, but led to significant decrease in urease activity and no enhancement of catalase activity in the rhizosphere soils. BOF including treatments showed significant enhancement in soil enzyme activities and microbial communities compared to the MBC and DAZ, evidenced by differences in bacterial/fungi (B/F ratios, Shannon–Wiener indexes and urease, catalase and sucrase activities in the rhizosphere soil of chrysanthemum. Of all the treatments evaluated, DAZ/BOF application not only greatly suppressed Fusarium wilt and enhanced soil enzyme activities and microbial communities but also promoted the quality of chrysanthemum obviously. Our findings suggest that combined BOF with DAZ could more effectively control Fusarium wilt disease of chrysanthemum.

  8. Effect of process control agent on the porous structure and mechanical properties of a biomedical Ti-Sn-Nb alloy produced by powder metallurgy.

    Science.gov (United States)

    Nouri, A; Hodgson, P D; Wen, C E

    2010-04-01

    The influence of different amounts and types of process control agent (PCA), i.e., stearic acid and ethylene bis-stearamide, on the porous structure and mechanical properties of a biomedical Ti-16Sn-4Nb (wt.%) alloy was investigated. Alloy synthesis was performed on elemental metal powders using high-energy ball milling for 5h. Results indicated that varying the PCA content during ball milling led to a drastic change in morphology and particle-size distribution of the ball-milled powders. Porous titanium alloy samples sintered from the powders ball milled with the addition of various amounts of PCA also revealed different pore morphology and porosity. The Vickers hardness of the sintered titanium alloy samples exhibited a considerable increase with increasing PCA content. Moreover, the addition of larger amounts of PCA in the powder mixture resulted in a significant increase in the elastic modulus and peak stress for the sintered porous titanium alloy samples under compression. It should also be mentioned that the addition of PCA introduced contamination (mainly carbon and oxygen) into the sintered porous product. Crown Copyright 2009. Published by Elsevier Ltd. All rights reserved.

  9. Effects of composition on waste glass properties

    International Nuclear Information System (INIS)

    Mellinger, G.B.; Chick, L.A.

    1979-01-01

    The electrical conductivity, viscosity, chemical durability, devitrification, and crystallinity of a defense waste glass were measured. Each oxide component in the glass was varied to determine its effect on these properties. A generic study is being developed which will determine the effects of 26 oxides on the above and additional properties of a wide field of possible waste glasses. 5 figures, 2 tables

  10. Nanosilicon properties, synthesis, applications, methods of analysis and control

    CERN Document Server

    Ischenko, Anatoly A; Aslalnov, Leonid A

    2015-01-01

    Nanosilicon: Properties, Synthesis, Applications, Methods of Analysis and Control examines the latest developments on the physics and chemistry of nanosilicon. The book focuses on methods for producing nanosilicon, its electronic and optical properties, research methods to characterize its spectral and structural properties, and its possible applications. The first part of the book covers the basic properties of semiconductors, including causes of the size dependence of the properties, structural and electronic properties, and physical characteristics of the various forms of silicon. It presents theoretical and experimental research results as well as examples of porous silicon and quantum dots. The second part discusses the synthesis of nanosilicon, modification of the surface of nanoparticles, and properties of the resulting particles. The authors give special attention to the photoluminescence of silicon nanoparticles. The third part describes methods used for studying and controlling the structure and pro...

  11. Effect of anti-sclerostin therapy and osteogenesis imperfecta on tissue-level properties in growing and adult mice while controlling for tissue age.

    Science.gov (United States)

    Sinder, Benjamin P; Lloyd, William R; Salemi, Joseph D; Marini, Joan C; Caird, Michelle S; Morris, Michael D; Kozloff, Kenneth M

    2016-03-01

    Bone composition and biomechanics at the tissue-level are important contributors to whole bone strength. Sclerostin antibody (Scl-Ab) is a candidate anabolic therapy for the treatment of osteoporosis that increases bone formation, bone mass, and bone strength in animal studies, but its effect on bone quality at the tissue-level has received little attention. Pre-clinical studies of Scl-Ab have recently expanded to include diseases with altered collagen and material properties such as osteogenesis imperfecta (OI). The purpose of this study was to investigate the role of Scl-Ab on bone quality by determining bone material composition and tissue-level mechanical properties in normal wild type (WT) tissue, as well as mice with a typical OI Gly➔Cys mutation (Brtl/+) in type I collagen. Rapidly growing (3-week-old) and adult (6-month-old) WT and Brtl/+ mice were treated for 5weeks with Scl-Ab. Fluorescent guided tissue-level bone composition analysis (Raman spectroscopy) and biomechanical testing (nanoindentation) were performed at multiple tissue ages. Scl-Ab increased mineral to matrix in adult WT and Brtl/+ at tissue ages of 2-4wks. However, no treatment related changes were observed in mineral to matrix levels at mid-cortex, and elastic modulus was not altered by Scl-Ab at any tissue age. Increased mineral-to-matrix was phenotypically observed in adult Brtl/+ OI mice (at tissue ages>3wks) and rapidly growing Brtl/+ (at tissue ages>4wks) mice compared to WT. At identical tissue ages defined by fluorescent labels, adult mice had generally lower mineral to matrix ratios and a greater elastic modulus than rapidly growing mice, demonstrating that bone matrix quality can be influenced by animal age and tissue age alike. In summary, these data suggest that Scl-Ab alters the matrix chemistry of newly formed bone while not affecting the elastic modulus, induces similar changes between Brtl/+ and WT mice, and provides new insight into the interaction between tissue age and

  12. Ride control of surface effect ships using distributed control

    Directory of Open Access Journals (Sweden)

    Asgeir J. Sørensen

    1994-04-01

    Full Text Available A ride control system for active damping of heave and pitch accelerations of Surface Effect Ships (SES is presented. It is demonstrated that distributed effects that are due to a spatially varying pressure in the air cushion result in significant vertical vibrations in low and moderate sea states. In order to achieve a high quality human comfort and crew workability it is necessary to reduce these vibrations using a control system which accounts for distributed effects due to spatial pressure variations in the air cushion. A mathematical model of the process is presented, and collocated sensor and actuator pairs are used. The process stability is ensured using a controller with appropriate passivity properties. Sensor and actuator location is also discussed. The performance of the ride control system is shown by power spectra of the vertical accelerations obtained from full scale experiments with a 35 m SES.

  13. Theoretical analysis and real time implementation of a classical controller with intelligent properties

    Directory of Open Access Journals (Sweden)

    Essam Hendawi

    2018-05-01

    Full Text Available This paper presents theoretical analysis and experimental implementation of a classical controller with intelligent properties. The controller has constant parameters, but it performs as an intelligent controller. The controller design mimics the fuzzy logic controller in a classical form and combines the advantages of classical controllers and properties of intelligent controllers. The designed controller parameters force the controlled variable to behave such as a first order system with a desired time constant. DC motor practical system is used to demonstrate the effectiveness of the presented controller. Root locus and frequency response using Bode diagram are used to help the design of the controller parameters. Simulation and experimental results verify the high performance of the presented controller. Keywords: Classical controller, DC motor, Root locus, Frequency response, Arduino microcontroller

  14. Effect of cryogel on soil properties

    Science.gov (United States)

    Altunina, L. K.; Fufaeva, M. S.; Filatov, D. A.; Svarovskaya, L. I.; Rozhdestvenskii, E. A.; Gan-Erdene, T.

    2014-05-01

    Samples from the A1 and A1A2 horizons of sandy loamy gray forest soil containing 3.1% organic matter have been mixed with a 5% solution of polyvinyl alcohol (PVA) at a ratio of 7 : 1 under laboratory conditions. The samples were frozen at -20°C in a refrigerator; after a freezing-thawing cycle, the evaporation of water from their surface, their thermal conductivity coefficient, their elasticity modulus, and other properties were studied. It has been experimentally found that the thermal conductivity coefficient of cryostructured soil is lower than that of common soil by 25%. It has been shown that the cryostructured soil retains water for a longer time and that the water evaporation rate from its surface is significantly lower compared to the control soil. Cryogel has no negative effect on the catalase activity of soil; it changes the physical properties of soils and positively affects the population of indigenous soil microflora and the growth of the sown plants.

  15. Control Properties of Bottom Fired Marine Boilers

    DEFF Research Database (Denmark)

    Solberg, Brian; Andersen, Palle; Karstensen, Claus M. S.

    2005-01-01

    This paper focuses on model analysis of a dynamic model of a bottom fired one-pass smoke tube boiler. Linearised versions of the model are analysed to determine how gain, time constants and right half plane zeros (caused by the shrink-and-swell phenomenon) depend on the steam flow load. Furthermore...... the interactions in the system are inspected to analyse potential benefit from using a multivariable control strategy in favour of the current strategy based on single loop theory. An analysis of the nonlinear model is carried out to further determine the nonlinear characteristics of the boiler system...... and to verify whether nonlinear control is needed. Finally a controller based on single loop theory is used to analyse if input constraints become active when rejecting transient behaviour from the disturbance steam flow. The model analysis shows large variations in system gains at steady state as function...

  16. Effect of mixing on properties of SCC

    DEFF Research Database (Denmark)

    Geiker, Mette Rica; Ekstrand, John Peter; Hansen, Rune

    2007-01-01

    agglomerates will remain. The paper focuses on the effect of mixing schedule on self-compacting concrete properties. Workability and micro structure of a typical Danish self-compacting concrete mixed at varying intensity and with addition of superplasticizer in either one or two batches are described....... The observations indicate that the most homogeneous concrete does not necessarily exhibit the lowest rheological properties....

  17. Effectiveness of Property Tax Relief in Oregon.

    Science.gov (United States)

    Hartman, William T.; Hwang, C. S.

    This study examines the effects of the 1979 Oregon Property Tax Relief Plan on 1980-81 school district budget decisions by comparing the available tax relief, the school expenditures, and the tax levies in the state for the years 1975-81. The history of direct and indirect property tax relief in Oregon is sketched for the years prior to 1979; the…

  18. ENVIRONMENTAL EFFECTS OF ABANDONED PROPERTIES IN ...

    African Journals Online (AJOL)

    Osondu

    Effects observed include pollution, health problem, city's financial loss, obscenity, crime, property value decline, ... fundamental preoccupation of planning for public purpose; is to ... are found with slum characteristics. ... Results and Discussion.

  19. Hydraulic concrete composition and properties control system

    OpenAIRE

    PSHINKO O.M.; KRASNYUK A.V.; HROMOVA O.V.

    2015-01-01

    Purpose. Scientific work aims at the development and testing of information system to meet the challenges of concrete composition design and control (for railway structures and buildings) based on the physico-analytical method algorithm for hydraulic concrete composition calculation. Methodology. The proposed algorithm of hydraulic concrete composition calculation is based on the physicochemical mechanics and in particular on the rheology of elastic–viscous–plastic bodies. The system of canon...

  20. Control Properties of Bottom Fired Marine Boilers

    DEFF Research Database (Denmark)

    Solberg, Brian; Andersen, Palle; Karstensen, Claus M. S.

    2005-01-01

    This paper focuses on model analysis of a dynamic model of a bottom fired one-pass smoke tube boiler. Linearised versions of the model are analysed to determine how gain, time constants and right half plane zeros (caused by the shrink-and-swell phenomenon) depend on the steam flow load. Furthermore...... the interactions in the system are inspected to analyse potential benefit from using a multivariable control strategy in favour of the current strategy based on single loop theory. An analysis of the nonlinear model is carried out to further determine the nonlinear characteristics of the boiler system...

  1. Equilibrium properties of proximity effect

    International Nuclear Information System (INIS)

    Esteve, D.; Pothier, H.; Gueron, S.; Birge, N.O.; Devoret, M.

    1996-01-01

    The proximity effect in diffusive normal-superconducting (NS) nano-structures is described by the Usadel equations for the electron pair correlations. We show that these equations obey a variational principle with a potential which generalizes the Ginzburg-Landau energy functional. We discuss simple examples of NS circuits using this formalism. In order to test the theoretical predictions of the Usadel equations, we have measured the density of states as a function of energy on a long N wire in contact with a S wire at one end, at different distances from the NS interface. (authors)

  2. Equilibrium properties of proximity effect

    Energy Technology Data Exchange (ETDEWEB)

    Esteve, D.; Pothier, H.; Gueron, S.; Birge, N.O.; Devoret, M.

    1996-12-31

    The proximity effect in diffusive normal-superconducting (NS) nano-structures is described by the Usadel equations for the electron pair correlations. We show that these equations obey a variational principle with a potential which generalizes the Ginzburg-Landau energy functional. We discuss simple examples of NS circuits using this formalism. In order to test the theoretical predictions of the Usadel equations, we have measured the density of states as a function of energy on a long N wire in contact with a S wire at one end, at different distances from the NS interface. (authors). 12 refs.

  3. Spectral radiative property control method based on filling solution

    International Nuclear Information System (INIS)

    Jiao, Y.; Liu, L.H.; Hsu, P.-F.

    2014-01-01

    Controlling thermal radiation by tailoring spectral properties of microstructure is a promising method, can be applied in many industrial systems and have been widely researched recently. Among various property tailoring schemes, geometry design of microstructures is a commonly used method. However, the existing radiation property tailoring is limited by adjustability of processed microstructures. In other words, the spectral radiative properties of microscale structures are not possible to change after the gratings are fabricated. In this paper, we propose a method that adjusts the grating spectral properties by means of injecting filling solution, which could modify the thermal radiation in a fabricated microstructure. Therefore, this method overcomes the limitation mentioned above. Both mercury and water are adopted as the filling solution in this study. Aluminum and silver are selected as the grating materials to investigate the generality and limitation of this control method. The rigorous coupled-wave analysis is used to investigate the spectral radiative properties of these filling solution grating structures. A magnetic polaritons mechanism identification method is proposed based on LC circuit model principle. It is found that this control method could be used by different grating materials. Different filling solutions would enable the high absorption peak to move to longer or shorter wavelength band. The results show that the filling solution grating structures are promising for active control of spectral radiative properties. -- Highlights: • A filling solution grating structure is designed to adjust spectral radiative properties. • The mechanism of radiative property control is studied for engineering utilization. • Different grating materials are studied to find multi-functions for grating

  4. Quadrotor Control in the Presence of Unknown Mass Properties

    Science.gov (United States)

    Duivenvoorden, Rikky Ricardo Petrus Rufino

    Quadrotor UAVs are popular due to their mechanical simplicity, as well as their capability to hover and vertically take-off and land. As applications diversify, quadrotors are increasingly required to operate under unknown mass properties, for example as a multirole sensor platform or for package delivery operations. The work presented here consists of the derivation of a generalized quadrotor dynamic model without the typical simplifying assumptions on the first and second moments of mass. The maximum payload capacity of a quadrotor in hover, and the observability of the unknown mass properties are discussed. A brief introduction of L1 adaptive control is provided, and three different L 1 adaptive controllers were designed for the Parrot AR.Drone quadrotor. Their tracking and disturbance rejection performance was compared to the baseline nonlinear controller in experiments. Finally, the results of the combination of L1 adaptive control with iterative learning control are presented, showing high performance trajectory tracking under uncertainty.

  5. Scale dependence of effective media properties

    International Nuclear Information System (INIS)

    Tidwell, V.C.; VonDoemming, J.D.; Martinez, K.

    1992-01-01

    For problems where media properties are measured at one scale and applied at another, scaling laws or models must be used in order to define effective properties at the scale of interest. The accuracy of such models will play a critical role in predicting flow and transport through the Yucca Mountain Test Site given the sensitivity of these calculations to the input property fields. Therefore, a research programhas been established to gain a fundamental understanding of how properties scale with the aim of developing and testing models that describe scaling behavior in a quantitative-manner. Scaling of constitutive rock properties is investigated through physical experimentation involving the collection of suites of gas permeability data measured over a range of discrete scales. Also, various physical characteristics of property heterogeneity and the means by which the heterogeneity is measured and described are systematically investigated to evaluate their influence on scaling behavior. This paper summarizes the approach that isbeing taken toward this goal and presents the results of a scoping study that was conducted to evaluate the feasibility of the proposed research

  6. Beyond local effective material properties for metamaterials

    Science.gov (United States)

    Mnasri, K.; Khrabustovskyi, A.; Stohrer, C.; Plum, M.; Rockstuhl, C.

    2018-02-01

    To discuss the properties of metamaterials on physical grounds and to consider them in applications, effective material parameters are usually introduced and assigned to a given metamaterial. In most cases, only weak spatial dispersion is considered. It allows to assign local material properties, e.g., a permittivity and a permeability. However, this turned out to be insufficient. To solve this problem, we study here the effective properties of metamaterials with constitutive relations beyond a local response and take strong spatial dispersion into account. This research requires two contributions. First, bulk properties in terms of eigenmodes need to be studied. We particularly investigate the isofrequency surfaces of their dispersion relation are investigated and compared to those of an actual metamaterial. The significant improvement to effectively describe it provides evidence for the necessity to use nonlocal material laws in the effective description of metamaterials. Second, to be able to capitalize on such constitutive relations, also interface conditions need to be known. They are derived in this contribution for our form of the nonlocality using a generalized (weak) formulation of Maxwell's equations. Based on such interface conditions, Fresnel expressions are obtained that predict the amplitude of the reflected and transmitted plane wave upon illuminating a slab of such a nonlocal metamaterial. This all together offers the necessary means for the in-depth analysis of metamaterials characterized by strong spatial dispersion. The general formulation we choose here renders our approach applicable to a wide class of metamaterials.

  7. Effect of geometry structure on critical properties

    Science.gov (United States)

    Jiang, Qing; Jiang, Xue-fan

    1997-02-01

    The effective-field renormalization group (EFRG) scheme is utilized to compute critical properties of the transverse Ising model (TIM) in a quantum-spin system. We distinguish differences between lattices of the same coordination number but of different structures and take effects of the first fluctuation correction into account. The improved results for the critical transverse field are obtained for several lattice structures even by considering the smallest possible cluster, which is in good agreement with series results.

  8. Effect of process control agent on the structural and magnetic properties of nano/amorphous Fe0.7Nb0.1Zr0.1Ti0.1 powders prepared by high energy ball milling

    Science.gov (United States)

    Khazaei Feizabad, Mohammad Hossein; Sharafi, Shahriar; Khayati, Gholam Reza; Ranjbar, Mohammad

    2018-03-01

    In this study, amorphous Fe0.7Nb0.1Zr0.1Ti0.1 alloy without metalloids was produced by mechanical alloying of pure mixture elements. Miedema's semi-empirical model was employed to predict the possibility of amorphous phase formation in proposed alloying system. The effect of Hexane as process control agent (PCA) on the structural, magnetic, morphological and thermal properties of the products was investigated. The results showed that the presence of PCA was necessary for the formation of amorphous phase as well as improved its soft magnetic properties. The PCA addition causes an increase of the saturation magnetization (about 43%) and decrease of the coercivity (about 50%). Moreover, the sample milled without PCA, showed a wide particle size distribution as well as relatively spherical geometry. While, in the presence of PCA the powders were aspherical and Polygon. In addition, the crystallization and Curie temperatures were found to be around 800 °C and 650 °C, respectively which are relatively high values for these kinds of alloys.

  9. Effective Optical Properties of Plasmonic Nanocomposites

    Directory of Open Access Journals (Sweden)

    Christoph Etrich

    2014-01-01

    Full Text Available Plasmonic nanocomposites find many applications, such as nanometric coatings in emerging fields, such as optotronics, photovoltaics or integrated optics. To make use of their ability to affect light propagation in an unprecedented manner, plasmonic nanocomposites should consist of densely packed metallic nanoparticles. This causes a major challenge for their theoretical description, since the reliable assignment of effective optical properties with established effective medium theories is no longer possible. Established theories, e.g., the Maxwell-Garnett formalism, are only applicable for strongly diluted nanocomposites. This effective description, however, is a prerequisite to consider plasmonic nanocomposites in the design of optical devices. Here, we mitigate this problem and use full wave optical simulations to assign effective properties to plasmonic nanocomposites with filling fractions close to the percolation threshold. We show that these effective properties can be used to properly predict the optical action of functional devices that contain nanocomposites in their design. With this contribution we pave the way to consider plasmonic nanocomposites comparably to ordinary materials in the design of optical elements.

  10. Effective elastic properties of damaged isotropic solids

    International Nuclear Information System (INIS)

    Lee, U Sik

    1998-01-01

    In continuum damage mechanics, damaged solids have been represented by the effective elastic stiffness into which local damage is smoothly smeared. Similarly, damaged solids may be represented in terms of effective elastic compliances. By virtue of the effective elastic compliance representation, it may become easier to derive the effective engineering constants of damaged solids from the effective elastic compliances, all in closed form. Thus, in this paper, by using a continuum modeling approach based on both the principle of strain energy equivalence and the equivalent elliptical micro-crack representation of local damage, the effective elastic compliance and effective engineering constants are derived in terms of the undamaged (virgin) elastic properties and a scalar damage variable for both damaged two-and three-dimensional isotropic solids

  11. Elevated temperature effects on concrete properties

    International Nuclear Information System (INIS)

    Grant, P.R.; Gruber, R.S.; Van Katwijk, C.

    1993-08-01

    The design of facilities to process or store radioactive wastes presents many challenging engineering problems. Such facilities must not only provide for safe storage of radioactive wastes but they must also be able to maintain confinement of these materials during and after natural phenomena events. Heat generated by the radioactive decay of the wastes will cause the temperature of the concrete containment structure to increase to a magnitude higher than that found in conventional structures. These elevated temperatures will cause strength-related concrete properties to degrade over time. For concrete temperatures less than 150 degree F, no reduction in strength is taken and the provisions of ACI 349, which states that higher temperatures are allowed if tests are provided to evaluate the reduction in concrete strength properties, apply. Methods proposed in a Pacific Northwest Laboratory (PNL) report, Modeling of Time-Variant Concrete Properties at Elevated Temperatures, can be used to evaluate the effects of elevated temperatures on concrete properties. Using these modified concrete properties the capacity of a concrete structure, subjected to elevated temperatures, to resist natural phenomena hazards can be determined

  12. Alcohol's Effects on Lipid Bilayer Properties

    Science.gov (United States)

    Ingólfsson, Helgi I.; Andersen, Olaf S.

    2011-01-01

    Alcohols are known modulators of lipid bilayer properties. Their biological effects have long been attributed to their bilayer-modifying effects, but alcohols can also alter protein function through direct protein interactions. This raises the question: Do alcohol's biological actions result predominantly from direct protein-alcohol interactions or from general changes in the membrane properties? The efficacy of alcohols of various chain lengths tends to exhibit a so-called cutoff effect (i.e., increasing potency with increased chain length, which that eventually levels off). The cutoff varies depending on the assay, and numerous mechanisms have been proposed such as: limited size of the alcohol-protein interaction site, limited alcohol solubility, and a chain-length-dependent lipid bilayer-alcohol interaction. To address these issues, we determined the bilayer-modifying potency of 27 aliphatic alcohols using a gramicidin-based fluorescence assay. All of the alcohols tested (with chain lengths of 1–16 carbons) alter the bilayer properties, as sensed by a bilayer-spanning channel. The bilayer-modifying potency of the short-chain alcohols scales linearly with their bilayer partitioning; the potency tapers off at higher chain lengths, and eventually changes sign for the longest-chain alcohols, demonstrating an alcohol cutoff effect in a system that has no alcohol-binding pocket. PMID:21843475

  13. Functionally-interdependent shape-switching nanoparticles with controllable properties

    Science.gov (United States)

    Halman, Justin R.; Satterwhite, Emily; Roark, Brandon; Chandler, Morgan; Viard, Mathias; Ivanina, Anna; Bindewald, Eckart; Kasprzak, Wojciech K.; Panigaj, Martin; Bui, My N.; Lu, Jacob S.; Miller, Johann; Khisamutdinov, Emil F.; Shapiro, Bruce A.; Dobrovolskaia, Marina A.

    2017-01-01

    Abstract We introduce a new concept that utilizes cognate nucleic acid nanoparticles which are fully complementary and functionally-interdependent to each other. In the described approach, the physical interaction between sets of designed nanoparticles initiates a rapid isothermal shape change which triggers the activation of multiple functionalities and biological pathways including transcription, energy transfer, functional aptamers and RNA interference. The individual nanoparticles are not active and have controllable kinetics of re-association and fine-tunable chemical and thermodynamic stabilities. Computational algorithms were developed to accurately predict melting temperatures of nanoparticles of various compositions and trace the process of their re-association in silico. Additionally, tunable immunostimulatory properties of described nanoparticles suggest that the particles that do not induce pro-inflammatory cytokines and high levels of interferons can be used as scaffolds to carry therapeutic oligonucleotides, while particles with strong interferon and mild pro-inflammatory cytokine induction may qualify as vaccine adjuvants. The presented concept provides a simple, cost-effective and straightforward model for the development of combinatorial regulation of biological processes in nucleic acid nanotechnology. PMID:28108656

  14. Environmental effects on properties of structural alloys

    International Nuclear Information System (INIS)

    Chopra, O.K.; Smith, D.L.

    1984-01-01

    Corrosion data are presented for several austenitic and ferritic steels exposed at temperatures between 700 and 755 K in flowing lithium and Pb-17Li environments. The results indicate that dissolution rates for both steels are an order of magnitude greater in Pb-Li than in lithium. Tensile data for cold-worked type 316 stainless steel show that a flowing environment has no effect on the tensile properties of type 316 stainless steel at temperatures between 473 and 773 K

  15. Controlling the scattering properties of thin, particle-doped coatings

    Science.gov (United States)

    Rogers, William; Corbett, Madeleine; Manoharan, Vinothan

    2013-03-01

    Coatings and thin films of small particles suspended in a matrix possess optical properties that are important in several industries from cosmetics and paints to polymer composites. Many of the most interesting applications require coatings that produce several bulk effects simultaneously, but it is often difficult to rationally formulate materials with these desired optical properties. Here, we focus on the specific challenge of designing a thin colloidal film that maximizes both diffuse and total hemispherical transmission. We demonstrate that these bulk optical properties follow a simple scaling with two microscopic length scales: the scattering and transport mean free paths. Using these length scales and Mie scattering calculations, we generate basic design rules that relate scattering at the single particle level to the film's bulk optical properties. These ideas will be useful in the rational design of future optically active coatings.

  16. Magnetic Nanoparticles: Surface Effects and Properties Related to Biomedicine Applications

    OpenAIRE

    Issa, Bashar; Obaidat, Ihab M.; Albiss, Borhan A.; Haik, Yousef

    2013-01-01

    Due to finite size effects, such as the high surface-to-volume ratio and different crystal structures, magnetic nanoparticles are found to exhibit interesting and considerably different magnetic properties than those found in their corresponding bulk materials. These nanoparticles can be synthesized in several ways (e.g., chemical and physical) with controllable sizes enabling their comparison to biological organisms from cells (10–100 μm), viruses, genes, down to proteins (3–50 nm). The opti...

  17. [Prebiotics: concept, properties and beneficial effects].

    Science.gov (United States)

    Corzo, N; Alonso, J L; Azpiroz, F; Calvo, M A; Cirici, M; Leis, R; Lombó, F; Mateos-Aparicio, I; Plou, F J; Ruas-Madiedo, P; Rúperez, P; Redondo-Cuenca, A; Sanz, M L; Clemente, A

    2015-02-07

    Prebiotics are non-digestible food ingredients (oligosaccharides) that reach the colon and are used as substrate by microorganisms producing energy, metabolites and micronutrients used for the host; in addition they also stimulate the selective growth of certain beneficial species (mainly bifidobacteria and lactobacilli) in the intestinal microbiota. In this article, a multidisciplinary approach to understand the concept of prebiotic carbohydrates, their properties and beneficial effects in humans has been carried out. Definitions of prebiotics, reported by relevant international organizations and researchers, are described. A comprehensive description of accepted prebiotics having strong scientific evidence of their beneficial properties in humans (inulin-type fructans, FOS, GOS, lactulose and human milk oligosaccharides) is reported. Emerging prebiotics and those which are in the early stages of study have also included in this study. Taken into account that the chemical structure greatly influences carbohydrates prebiotic properties, the analytical techniques used for their analysis and characterization are discussed. In vitro and in vivo models used to evaluate the gastrointestinal digestion, absorption resistance and fermentability in the colon of prebiotics as well as major criteria to design robust intervention trials in humans are described. Finally, a comprehensive summary of the beneficial effects of prebiotics for health at systemic and intestinal levels is reported. The research effort on prebiotics has been intensive in last decades and has demonstrated that a multidisciplinary approach is necessary in order to claim their health benefits. Copyright AULA MEDICA EDICIONES 2014. Published by AULA MEDICA. All rights reserved.

  18. Effectiveness of the “What’s Up!” Intervention to Reduce Stigma and Psychometric Properties of the Youth Program Questionnaire (YPQ: Results from a Cluster Non-randomized Controlled Trial Conducted in Catalan High Schools

    Directory of Open Access Journals (Sweden)

    Laura Andrés-Rodríguez

    2017-09-01

    Full Text Available Mental disorders are highly prevalent in the general population, and people who experience them are frequently stigmatized. Stigma has a very negative impact on social, academic/professional, and personal life. Considering the high rates of mental disorders among children and adolescents (13.4% and how critical this age is in the formation of nuclear beliefs, many campaigns to combat stigma have been developed in the last decade, with mixed results. The OBERTAMENT initiative has produced various anti-stigma campaigns in Catalonia (Spain. In the present study, the main objective was to report on the effectiveness of the OBERTAMENT “What’s up!” intervention, a curricular intervention including education and social contact conducted by the teachers in the classroom with teenagers aged between 14 and 18. Prior to this, we examined the psychometric properties of the Youth Program Questionnaire (YPQ, our main outcome measure, in terms of dimensionality, reliability, and validity. A cluster non-randomized controlled trial was conducted to assess this intervention, which was tested in nine high schools situated in the Barcelona region. A convenience sample of 261 students formed the intervention group and 132 the control group (52% women, mean age = 14, SD = 0.47. The assignment to study conditions was conducted by Departament d’Ensenyament (Department of Education, Generalitat de Catalunya (Catalan Government. Participants were evaluated at baseline, post-intervention, and 9-month follow-up. The main outcome measure of this study was the YPQ. The Reported and Intended Behavior Scale (RIBS was used as secondary outcome measure. The statistical analysis indicated that the YPQ possesses a two-factor structure (stereotypical attitudes and intended behavior and sound psychometric properties. The multilevel mixed-effects models revealed statistically significant interactions for both study measures and post hoc intragroup analyses revealed a

  19. Access and control of information and intellectual property

    Science.gov (United States)

    Lang, Gerald S.

    1996-03-01

    This paper introduces the technology of two pioneering patents for the secure distribution of information and intellectual property. The seminal technology has been used in the control of sensitive material such as medical records and imagery in distributed networks. It lends itself to the implementation of an open architecture access control system that provides local or remote user selective access to digital information stored on any computer system or storage medium, down to the data element, pixel, and sub-pixel levels. Use of this technology is especially suited for electronic publishing, health care records, MIS, and auditing.

  20. Engine control techniques to account for fuel effects

    Science.gov (United States)

    Kumar, Shankar; Frazier, Timothy R.; Stanton, Donald W.; Xu, Yi; Bunting, Bruce G.; Wolf, Leslie R.

    2014-08-26

    A technique for engine control to account for fuel effects including providing an internal combustion engine and a controller to regulate operation thereof, the engine being operable to combust a fuel to produce an exhaust gas; establishing a plurality of fuel property inputs; establishing a plurality of engine performance inputs; generating engine control information as a function of the fuel property inputs and the engine performance inputs; and accessing the engine control information with the controller to regulate at least one engine operating parameter.

  1. The Effect of Bedding Structure on Mechanical Property of Coal

    Directory of Open Access Journals (Sweden)

    Zetian Zhang

    2014-01-01

    Full Text Available The mechanical property of coal, influencing mining activity considerably, is significantly determined by the natural fracture distributed within coal mass. In order to study the effecting mechanism of bedding structure on mechanical property of coal, a series of uniaxial compression tests and mesoscopic tests have been conducted. The experimental results show that the distribution characteristic of calcite particles, which significantly influences the growth of cracks and the macroscopic mechanical properties of coal, is obviously affected by the bedding structure. Specifically, the uniaxial compression strength of coal sample is mainly controlled by bedding structure, and the average peak stress of specimens with axes perpendicular to the bedding planes is 20.00 MPa, which is 2.88 times the average amount of parallel ones. The test results also show a close relationship between the bedding structure and the whole deformation process under uniaxial loading.

  2. Controlling the Casimir force via the electromagnetic properties of materials

    International Nuclear Information System (INIS)

    Yang Yaping; Chen Hong; Zeng Ran; Zhu Shiyao; Zubairy, M. Suhail

    2010-01-01

    The control of the Casimir force between two parallel plates can be achieved through adjusting the frequency-dependent electromagnetic properties of materials of the two plates. We show that, for different plate separations, the main contribution to the Casimir force comes from different frequency regions: For smaller (larger) separation, it comes from the higher (lower) frequency region. When the separation of the plates increases, the Casimir force can vary from attractive to repulsive and/or vice versa, by selecting the two plates with suitable electromagnetic properties. We discuss how a restoring Casimir force, which varies from repulsive to attractive by increasing the separation, can be realized and that the stable equilibrium is formed at zero Casimir force.

  3. Pairing properties of realistic effective interactions

    Directory of Open Access Journals (Sweden)

    Gargano A.

    2016-01-01

    Full Text Available We investigate the pairing properties of an effective shell-model interaction defined within a model space outside 132Sn and derived by means of perturbation theory from the CD-Bonn free nucleon-nucleon potential. It turns out that the neutron pairing component of the effective interaction is significantly weaker than the proton one, which accounts for the large pairing gap difference observed in the two-valence identical particle nuclei 134Sn and 134Te. The role of the contribution arising from one particle-one hole excitations in determining the pairing force is discussed and its microscopic structure is also analyzed in terms of the multipole decomposition.

  4. Effective spectral index properties for Fermi blazars

    Science.gov (United States)

    Yang, JiangHe; Fan, JunHui; Liu, Yi; Zhang, YueLian; Tuo, ManXian; Nie, JianJun; Yuan, YuHai

    2018-05-01

    Blazars are a special subclass of active galactic nuclei with extreme observation properties. This subclass can be divided into two further subclasses of flat spectrum radio quasars (FSRQs) and BL Lacertae objects (BL Lacs) according to their emission line features. To compare the spectral properties of FSRQs and BL Lacs, the 1.4 GHz radio, optical R-band, 1 keV X-ray, and 1 GeV γ-ray flux densities for 1108 Fermi blazars are calculated to discuss the properties of the six effective spectral indices of radio to optical ( α RO), radio to X-ray ( α RX), radio to γ ray ( α Rγ), optical to X-ray ( α OX), optical to γ ray ( α Oγ), and X-ray to γ ray ( α Xγ). The main results are as follows: For the averaged effective spectral indices, \\overline {{α _{OX}}} > \\overline {{α _{Oγ }}} > \\overline {{α _{Xγ }}} > \\overline {{α _{Rγ }}} > \\overline {{α _{RX}}} > \\overline {{α _{RO}}} for samples of whole blazars and BL Lacs; \\overline {{α _{Xγ }}} ≈ \\overline {{α _{Rγ }}} ≈ \\overline {{α _{RX}}} for FSRQs and low-frequency-peaked BL Lacs (LBLs); and \\overline {{α _{OX}}} ≈ \\overline {{α _{Oγ }}} ≈ \\overline {{α _{Xγ }}} for high-synchrotron-frequency-peaked BL Lacs (HBLs). The distributions of the effective spectral indices involving optical emission ( α RO, α OX, and α Oγ) for LBLs are different from those for FSRQs, but if the effective spectral index does not involve optical emission ( α RX, α Rγ, and α Xγ), the distributions for LBLs and FSRQs almost come from the same parent population. X-ray emissions from blazars include both synchrotron and inverse Compton (IC) components; the IC component for FSRQs and LBLs accounts for a larger proportion than that for HBLs; and the radiation mechanism for LBLs is similar to that for FSRQs, but the radiation mechanism for HBLs is different from that for both FSRQs and LBLs in X-ray bands. The tendency of α Rγ decreasing from LBLs to HBLs suggests that the synchrotron self

  5. Multichannel Selective Femtosecond Coherent Control Based on Symmetry Properties

    International Nuclear Information System (INIS)

    Amitay, Zohar; Gandman, Andrey; Chuntonov, Lev; Rybak, Leonid

    2008-01-01

    We present and implement a new scheme for extended multichannel selective femtosecond coherent control based on symmetry properties of the excitation channels. Here, an atomic nonresonant two-photon absorption channel is coherently incorporated in a resonance-mediated (2+1) three-photon absorption channel. By proper pulse shaping, utilizing the invariance of the two-photon absorption to specific phase transformations of the pulse, the three-photon absorption is tuned independently over an order-of-magnitude yield range for any possible two-photon absorption yield. Noticeable is a set of ''two-photon dark pulses'' inducing widely tunable three-photon absorption

  6. 23 CFR 750.705 - Effective control.

    Science.gov (United States)

    2010-04-01

    ... 23 Highways 1 2010-04-01 2010-04-01 false Effective control. 750.705 Section 750.705 Highways... BEAUTIFICATION Outdoor Advertising Control § 750.705 Effective control. In order to provide effective control of... of applicable control requirements will apply; (h) Develop laws, regulations, and procedures to...

  7. Effect of nanoparticles on tensile, impact and fatigue properties of ...

    Indian Academy of Sciences (India)

    Administrator

    military, marine and automotive applications. Polymer nanocomposites ... manufacturing techniques (LM) and measured the mechanical properties. The measurement .... withstand application force and as a quality control check of materials.

  8. Effect of Chitosan Properties on Immunoreactivity

    Science.gov (United States)

    Ravindranathan, Sruthi; Koppolu, Bhanu prasanth; Smith, Sean G.; Zaharoff, David A.

    2016-01-01

    Chitosan is a widely investigated biopolymer in drug and gene delivery, tissue engineering and vaccine development. However, the immune response to chitosan is not clearly understood due to contradicting results in literature regarding its immunoreactivity. Thus, in this study, we analyzed effects of various biochemical properties, namely degree of deacetylation (DDA), viscosity/polymer length and endotoxin levels, on immune responses by antigen presenting cells (APCs). Chitosan solutions from various sources were treated with mouse and human APCs (macrophages and/or dendritic cells) and the amount of tumor necrosis factor-α (TNF-α) released by the cells was used as an indicator of immunoreactivity. Our results indicate that only endotoxin content and not DDA or viscosity influenced chitosan-induced immune responses. Our data also indicate that low endotoxin chitosan (chitosan in preclinical studies in order for this valuable biomaterial to achieve widespread clinical application. PMID:27187416

  9. Optoelectronic properties of valence-state-controlled amorphous niobium oxide

    Science.gov (United States)

    Onozato, Takaki; Katase, Takayoshi; Yamamoto, Akira; Katayama, Shota; Matsushima, Koichi; Itagaki, Naho; Yoshida, Hisao; Ohta, Hiromichi

    2016-06-01

    In order to understand the optoelectronic properties of amorphous niobium oxide (a-NbO x ), we have investigated the valence states, local structures, electrical resistivity, and optical absorption of a-NbO x thin films with various oxygen contents. It was found that the valence states of Nb ion in a-NbO x films can be controlled from 5+  to 4+  by reducing oxygen pressure during film deposition at room temperature, together with changing the oxide-ion arrangement around Nb ion from Nb2O5-like to NbO2-like local structure. As a result, a four orders of magnitude reduction in the electrical resistivity of a-NbO x films was observed with decreasing oxygen content, due to the carrier generation caused by the appearance and increase of an oxygen-vacancy-related subgap state working as an electron donor. The tunable optoelectronic properties of a-NbO x films by valence-state-control with oxygen-vacancy formation will be useful for potential flexible optoelectronic device applications.

  10. 23 CFR 751.9 - Effective control.

    Science.gov (United States)

    2010-04-01

    ... 23 Highways 1 2010-04-01 2010-04-01 false Effective control. 751.9 Section 751.9 Highways FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RIGHT-OF-WAY AND ENVIRONMENT JUNKYARD CONTROL AND ACQUISITION § 751.9 Effective control. (a) In order to provide effective control of junkyards located within 1...

  11. Controlling the properties of graphene produced by electrochemical exfoliation

    International Nuclear Information System (INIS)

    Hofmann, Mario; D Nguyễn, Tuân; Chiang, Wan-Yu; Hsieh, Ya-Ping

    2015-01-01

    The synthesis of graphene with controllable electronic and mechanical characteristics is of significant importance for its application in various fields ranging from drug delivery to energy storage. Electrochemical exfoliation of graphite has yielded graphene with widely varying behavior and could be a suitable approach. Currently, however the limited understanding of the exfoliation process obstructs targeted modification of graphene properties. We here investigate the process of electrochemical exfoliation and the impact of its parameters on the produced graphene. Using in situ optical and electrical measurements we determine that solvent intercalation is the required first step and the degree of intercalation controls the thickness of the exfoliated graphene. Electrochemical decomposition of water into gas bubbles causes the expansion of graphite and controls the functionalization and lateral size of the exfoliated graphene. Both process steps proceed at different time scales and can be individually addressed through application of pulsed voltages. The potential of the presented approach was demonstrated by improving the performance of graphene-based transparent conductors by 30times. (paper)

  12. Effects of ageing and moisture content on thermal properties of ...

    African Journals Online (AJOL)

    Effects of ageing and moisture content on thermal properties of cassava roots ... after harvest coupled with non-‐availability of acceptable storage alternatives. ... the properties simultaneously based on the transient line heat source method.

  13. Ultrafast control and monitoring of material properties using terahertz pulses

    Energy Technology Data Exchange (ETDEWEB)

    Bowlan, Pamela Renee [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Lab. for Ultrafast Materials Optical Science (LUMOS)

    2016-05-02

    These are a set of slides on ultrafast control and monitoring of material properties using terahertz pulses. A few of the topics covered in these slides are: How fast is a femtosecond (fs), Different frequencies probe different properties of molecules or solids, What can a THz pulse do to a material, Ultrafast spectroscopy, Generating and measuring ultrashort THz pulses, Tracking ultrafast spin dynamics in antiferromagnets through spin wave resonances, Coherent two-dimensional THz spectroscopy, and Probing vibrational dynamics at a surface. Conclusions are: Coherent two-dimensional THz spectroscopy: a powerful approach for studying coherence and dynamics of low energy resonances. Applying this to graphene we investigated the very strong THz light mater interaction which dominates over scattering. Useful for studying coupled excitations in multiferroics and monitoring chemical reactions. Also, THz-pump, SHG-probe spectoscopy: an ultrafast, surface sensitive probe of atomic-scale symmetry changes and nonlinear phonon dymanics. We are using this in Bi2Se3 to investigate the nonlinear surface phonon dynamics. This is potentially very useful for studying catalysis.

  14. Magnetic nanoparticles: surface effects and properties related to biomedicine applications.

    Science.gov (United States)

    Issa, Bashar; Obaidat, Ihab M; Albiss, Borhan A; Haik, Yousef

    2013-10-25

    Due to finite size effects, such as the high surface-to-volume ratio and different crystal structures, magnetic nanoparticles are found to exhibit interesting and considerably different magnetic properties than those found in their corresponding bulk materials. These nanoparticles can be synthesized in several ways (e.g., chemical and physical) with controllable sizes enabling their comparison to biological organisms from cells (10-100 μm), viruses, genes, down to proteins (3-50 nm). The optimization of the nanoparticles' size, size distribution, agglomeration, coating, and shapes along with their unique magnetic properties prompted the application of nanoparticles of this type in diverse fields. Biomedicine is one of these fields where intensive research is currently being conducted. In this review, we will discuss the magnetic properties of nanoparticles which are directly related to their applications in biomedicine. We will focus mainly on surface effects and ferrite nanoparticles, and on one diagnostic application of magnetic nanoparticles as magnetic resonance imaging contrast agents.

  15. Effect of Chitosan Properties on Immunoreactivity

    Directory of Open Access Journals (Sweden)

    Sruthi Ravindranathan

    2016-05-01

    Full Text Available Chitosan is a widely investigated biopolymer in drug and gene delivery, tissue engineering and vaccine development. However, the immune response to chitosan is not clearly understood due to contradicting results in literature regarding its immunoreactivity. Thus, in this study, we analyzed effects of various biochemical properties, namely degree of deacetylation (DDA, viscosity/polymer length and endotoxin levels, on immune responses by antigen presenting cells (APCs. Chitosan solutions from various sources were treated with mouse and human APCs (macrophages and/or dendritic cells and the amount of tumor necrosis factor-α (TNF-α released by the cells was used as an indicator of immunoreactivity. Our results indicate that only endotoxin content and not DDA or viscosity influenced chitosan-induced immune responses. Our data also indicate that low endotoxin chitosan (<0.01 EU/mg ranging from 20 to 600 cP and 80% to 97% DDA is essentially inert. This study emphasizes the need for more complete characterization and purification of chitosan in preclinical studies in order for this valuable biomaterial to achieve widespread clinical application.

  16. Magnetic tunnel structures: Transport properties controlled by bias, magnetic field, and microwave and optical radiation

    International Nuclear Information System (INIS)

    Volkov, N.V.; Eremin, E.V.; Tarasov, A.S.; Rautskii, M.V.; Varnakov, S.N.; Ovchinnikov, S.G.; Patrin, G.S.

    2012-01-01

    Different phenomena that give rise to a spin-polarized current in some systems with magnetic tunnel junctions are considered. In a manganite-based magnetic tunnel structure in CIP geometry, the effect of current-channel switching was observed, which causes bias-driven magnetoresistance, rf rectification, and the photoelectric effect. The second system under study, ferromagnetic/insulator/semiconductor, exhibits the features of the transport properties in CIP geometry that are also related to the current-channel switching effect. The described properties can be controlled by a bias, a magnetic field, and optical radiation. At last, the third system under consideration is a cooperative assembly of magnetic tunnel junctions. This system exhibits tunnel magnetoresistance and the magnetic-field-driven microwave detection effect.

  17. Effect of soil properties on the toxicity of Pb: Assessment of the appropriateness of guideline values

    NARCIS (Netherlands)

    Romero Freire, A.; Martin Peinado, F.J.; van Gestel, C.A.M.

    2015-01-01

    Soil contamination with lead is a worldwide problem. Pb can cause adverse effects, but its mobility and availability in the terrestrial environment are strongly controlled by soil properties. The present study investigated the influence of different soil properties on the solubility of lead in

  18. Low temperature carrier transport properties in isotopically controlled germanium

    Energy Technology Data Exchange (ETDEWEB)

    Itoh, Kohei [Univ. of California, Berkeley, CA (United States)

    1994-12-01

    Investigations of electronic and optical properties of semiconductors often require specimens with extremely homogeneous dopant distributions and precisely controlled net-carrier concentrations and compensation ratios. The previous difficulties in fabricating such samples are overcome as reported in this thesis by growing high-purity Ge single crystals of controlled 75Ge and 70Ge isotopic compositions, and doping these crystals by the neutron transmutation doping (NTD) technique. The resulting net-impurity concentrations and the compensation ratios are precisely determined by the thermal neutron fluence and the [74Ge]/[70Ge] ratios of the starting Ge materials, respectively. This method also guarantees unprecedented doping uniformity. Using such samples the authors have conducted four types of electron (hole) transport studies probing the nature of (1) free carrier scattering by neutral impurities, (2) free carrier scattering by ionized impurities, (3) low temperature hopping conduction, and (4) free carrier transport in samples close to the metal-insulator transition.

  19. Degrading radiation effects on properties of bromobutyl rubber compounds

    Energy Technology Data Exchange (ETDEWEB)

    Scagliusi, Sandra R.; Cardoso, Elisabeth C.L.; Pozenato, Cristina A.; Lugao, Ademar B., E-mail: srscagliusi@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2013-07-01

    The understanding of chemistry involved in degradation induced radiation is becoming more and more relevant in the re-use of polymeric materials, as well in beneficial radiation uses. Degrading radiation effects have been considered from viewpoint of controlled degradation for isoprene/isobutene in rubbers for recycling purposes. Bromobutyl rubber (BIIR) is an isobutylene/isoprene copolymer comprising 1.9 to 2.1% bromine and has a lot of applications including in tires air-chambers. In this work there were evaluated gamma-irradiation effects for re-use or recycling objectives in elastomeric bromobutyl compositions irradiated at 5, 15, 25, 50, 100,150 and 200 kGy. Mechanical properties, hardness and swelling were assessed in non-vulcanized and vulcanized rubber, non-irradiated and irradiated at different doses. The major gamma radiation effect in butyl rubber is the generation of free radicals along changes in mechanical properties. Irradiation effects in bromobutyl rubber compounds were comprehensively investigated, demonstrated and discussed. (author)

  20. Degrading radiation effects on properties of bromobutyl rubber compounds

    International Nuclear Information System (INIS)

    Scagliusi, Sandra R.; Cardoso, Elisabeth C.L.; Pozenato, Cristina A.; Lugao, Ademar B.

    2013-01-01

    The understanding of chemistry involved in degradation induced radiation is becoming more and more relevant in the re-use of polymeric materials, as well in beneficial radiation uses. Degrading radiation effects have been considered from viewpoint of controlled degradation for isoprene/isobutene in rubbers for recycling purposes. Bromobutyl rubber (BIIR) is an isobutylene/isoprene copolymer comprising 1.9 to 2.1% bromine and has a lot of applications including in tires air-chambers. In this work there were evaluated gamma-irradiation effects for re-use or recycling objectives in elastomeric bromobutyl compositions irradiated at 5, 15, 25, 50, 100,150 and 200 kGy. Mechanical properties, hardness and swelling were assessed in non-vulcanized and vulcanized rubber, non-irradiated and irradiated at different doses. The major gamma radiation effect in butyl rubber is the generation of free radicals along changes in mechanical properties. Irradiation effects in bromobutyl rubber compounds were comprehensively investigated, demonstrated and discussed. (author)

  1. Tillage Effects on Soil Properties & Respiration

    Science.gov (United States)

    Rusu, Teodor; Bogdan, Ileana; Moraru, Paula; Pop, Adrian; Duda, Bogdan; Cacovean, Horea; Coste, Camelia

    2015-04-01

    Soil tillage systems can be able to influence soil compaction, water dynamics, soil temperature and soil structural condition. These processes can be expressed as changes of soil microbiological activity, soil respiration and sustainability of agriculture. Objectives of this study were: 1) to assess the effects of tillage systems (Conventional System-CS, Minimum Tillage-MT, No-Tillage-NT) on soil compaction, soil temperature, soil moisture and soil respiration and 2) to establish the relationship that exists in changing soil properties. Three treatments were installed: CS-plough + disc; MT-paraplow + rotary grape; NT-direct sowing. The study was conducted on an Argic-Stagnic Faeoziom. The MT and NT applications reduce or completely eliminate the soil mobilization, due to this, soil is compacted in the first year of application. The degree of compaction is directly related to soil type and its state of degradation. The state of soil compaction diminished over time, tending toward a specific type of soil density. Soil moisture was higher in NT and MT at the time of sowing and in the early stages of vegetation and differences diminished over time. Moisture determinations showed statistically significant differences. The MT and NT applications reduced the thermal amplitude in the first 15 cm of soil depth and increased the soil temperature by 0.5-2.20C. The determinations confirm the effect of soil tillage system on soil respiration; the daily average was lower at NT (315-1914 mmoli m-2s-1) and followed by MT (318-2395 mmoli m-2s-1) and is higher in the CS (321-2480 mmol m-2s-1). Comparing with CS, all the two conservation tillage measures decreased soil respiration, with the best effects of no-tillage. An exceeding amount of CO2 produced in the soil and released into the atmosphere, resulting from aerobic processes of mineralization of organic matter (excessive loosening) is considered to be not only a way of increasing the CO2 in the atmosphere, but also a loss of

  2. Biomaterial property-controlled stem cell fates for cardiac regeneration

    Directory of Open Access Journals (Sweden)

    Yanyi Xu

    2016-09-01

    Full Text Available Myocardial infarction (MI affects more than 8 million people in the United States alone. Due to the insufficient regeneration capacity of the native myocardium, one widely studied approach is cardiac tissue engineering, in which cells are delivered with or without biomaterials and/or regulatory factors to fully regenerate the cardiac functions. Specifically, in vitro cardiac tissue engineering focuses on using biomaterials as a reservoir for cells to attach, as well as a carrier of various regulatory factors such as growth factors and peptides, providing high cell retention and a proper microenvironment for cells to migrate, grow and differentiate within the scaffolds before implantation. Many studies have shown that the full establishment of a functional cardiac tissue in vitro requires synergistic actions between the seeded cells, the tissue culture condition, and the biochemical and biophysical environment provided by the biomaterials-based scaffolds. Proper electrical stimulation and mechanical stretch during the in vitro culture can induce the ordered orientation and differentiation of the seeded cells. On the other hand, the various scaffolds biochemical and biophysical properties such as polymer composition, ligand concentration, biodegradability, scaffold topography and mechanical properties can also have a significant effect on the cellular processes.

  3. Clinical Ion Beam Applications: Basic Properties, Application, Quality Control, Planning

    International Nuclear Information System (INIS)

    Kraft, Gerhard

    2009-01-01

    Heavy-ion therapy using beam scanning and biological dose optimization is a novel technique of high-precision external radiotherapy. It yields a better perspective for tumor cure of radio-resistant tumors. However, heavy-ion therapy is not a general solution for all types of tumors. As compared to conventional radiotherapy, heavy-ion radiotherapy has the advantages of higher tumor dose, improved sparing of normal tissue in the entrance channel, a more precise concentration of the dose in the target volume with steeper gradients to the normal tissue, and a higher radiobiological effectiveness for tumors which are radio-resistant in conventional therapy. These properties make it possible to treat radio-resistant tumors with great success, including those in close vicinity to critical organs.

  4. Effect of different fibers on dough properties and biscuit quality.

    Science.gov (United States)

    Blanco Canalis, María S; Steffolani, María E; León, Alberto E; Ribotta, Pablo D

    2017-03-01

    This study forms part of a broader project aimed at understanding the role of fibers from different sources in high-fat, high-sugar biscuits and at selecting the best fibers for biscuit quality. The main purpose of this work was to understand the rheological and structural properties involved in fiber-enriched biscuit dough. High-amylose corn starch (RSII), chemically modified starch (RSIV), oat fiber (OF) and inulin (IN) were used at two different levels of incorporation (6 and 12 g) in dough formulation. The influence of fiber on the properties of biscuit dough was studied via dynamic rheological tests, confocal microscopy and spreading behavior. Biscuit quality was assessed by width/thickness factor, texture and surface characteristics, total dietary fiber and sensory evaluation. Main results indicated that IN incorporation increased the capacity of dough spreading during baking and thus improved biscuit quality. OF reduced dough spreading during baking and strongly increased its resistance to deformation. RSII and RSIV slightly affected the quality of the biscuits. Sensory evaluation revealed that the panel liked IN-incorporated biscuits as much as control biscuits. The increase in total dietary fiber modified dough behavior and biscuit properties, and the extent of these effects depended on the type of fiber incorporated. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  5. Manufacturing of hydrogel biomaterials with controlled mechanical properties for tissue engineering applications.

    Science.gov (United States)

    Vedadghavami, Armin; Minooei, Farnaz; Mohammadi, Mohammad Hossein; Khetani, Sultan; Rezaei Kolahchi, Ahmad; Mashayekhan, Shohreh; Sanati-Nezhad, Amir

    2017-10-15

    Hydrogels have been recognized as crucial biomaterials in the field of tissue engineering, regenerative medicine, and drug delivery applications due to their specific characteristics. These biomaterials benefit from retaining a large amount of water, effective mass transfer, similarity to natural tissues and the ability to form different shapes. However, having relatively poor mechanical properties is a limiting factor associated with hydrogel biomaterials. Controlling the biomechanical properties of hydrogels is of paramount importance. In this work, firstly, mechanical characteristics of hydrogels and methods employed for characterizing these properties are explored. Subsequently, the most common approaches used for tuning mechanical properties of hydrogels including but are not limited to, interpenetrating polymer networks, nanocomposites, self-assembly techniques, and co-polymerization are discussed. The performance of different techniques used for tuning biomechanical properties of hydrogels is further compared. Such techniques involve lithography techniques for replication of tissues with complex mechanical profiles; microfluidic techniques applicable for generating gradients of mechanical properties in hydrogel biomaterials for engineering complex human tissues like intervertebral discs, osteochondral tissues, blood vessels and skin layers; and electrospinning techniques for synthesis of hybrid hydrogels and highly ordered fibers with tunable mechanical and biological properties. We finally discuss future perspectives and challenges for controlling biomimetic hydrogel materials possessing proper biomechanical properties. Hydrogels biomaterials are essential constituting components of engineered tissues with the applications in regenerative medicine and drug delivery. The mechanical properties of hydrogels play crucial roles in regulating the interactions between cells and extracellular matrix and directing the cells phenotype and genotype. Despite

  6. Controlled swelling and adsorption properties of polyacrylate/montmorillonite composites

    Energy Technology Data Exchange (ETDEWEB)

    Natkanski, Piotr [Faculty of Chemistry, Jagiellonian University, Ingardena 3, 30-060 Krakow (Poland); Kustrowski, Piotr, E-mail: kustrows@chemia.uj.edu.pl [Faculty of Chemistry, Jagiellonian University, Ingardena 3, 30-060 Krakow (Poland); Bialas, Anna; Piwowarska, Zofia [Faculty of Chemistry, Jagiellonian University, Ingardena 3, 30-060 Krakow (Poland); Michalik, Marek [Institute of Geological Sciences, Jagiellonian University, Oleandry 2a, 30-063 Krakow (Poland)

    2012-10-15

    A series of novel polyacrylate/montmorillonite composites was synthesized by in situ polymerization in aqueous slurry of clay. Dissociated (obtained by adding ammonium or sodium hydroxide) and undissociated forms of acrylic acid were used as monomers in the hydrogel synthesis. The structure and composition of the samples were studied by powder X-ray diffraction, diffuse reflectance infra-red Fourier transform spectroscopy, thermogravimetry and elemental analysis. It has been found that the kind of monomer influences strongly the location of a polymer chain in the formed composite. Complete intercalation of hydrogel into the interlayer space of montmorillonite was observed for sodium polyacrylate, whereas polyacrylic acid and ammonium polyacrylate mainly occupied the outer surface of the clay. The position of hydrogel determined the swelling and adsorption properties of the studied composites. The important factor influencing the kinetics of Fe(III) cation adsorption was pH. The analysis of adsorption isotherms allowed to propose the mechanism of Fe(III) cation adsorption. Highlights: Black-Right-Pointing-Pointer Polyacrylate hydrogels can be introduced into the interlayers of clay. Black-Right-Pointing-Pointer The position of hydrogel in the composite depends on the polymer type. Black-Right-Pointing-Pointer Ammonium polyacrylate places outside the clay, sodium one is intercalated into it. Black-Right-Pointing-Pointer Swelling and adsorption capacities can be controlled by the polymer position. Black-Right-Pointing-Pointer High adsorption efficiency in Fe(III) removal was observed.

  7. Effects of scalp dermatitis on chemical property of hair keratin

    Science.gov (United States)

    Kim, Kyung Sook; Shin, Min Kyung; Park, Hun-Kuk

    2013-05-01

    The effects of scalp dermatitis (seborrheic dermatitis (SD), psoriasis, and atopic dermatitis (AD)) on chemical properties of hair keratin were investigated by Fourier transform infrared (FT-IR) spectroscopy. Hairs were collected from lesional regions affected by SD, psoriasis, and AD and non-lesional regions separately. The hairs with SD were taken from patients with ages of 16-80 years. The ages of patients with psoriasis ranged from 8 to 67 years, and all patients exhibited moderate disease. Hairs with AD were taken from the patients with ages of 24-45 years and the average SCORing atopic dermatitis (SCORAD) was 48.75. Hairs from 20 normal adults were collected as a control. The FT-IR absorbance bands were analyzed by the Gaussian model to obtain the center frequency, half width, height, and area of each band. The height and area of all bands in the spectra were normalized to the amide I centered at 1652 cm-1 to quantitatively analyze the chemical composition of keratin. The spectra of hair with scalp dermatitis were different with that of control, the amide A components centered at 3278 cm-1 were smaller than those of the control. The psoriasis hair showed a large difference in the IR absorbance band between lesional and non-lesional hairs indicating good agreement with the morphological changes. The hairs with diseases did not show differences in the content of cystine, which was centered at 1054 cm-1, from the control. The chemical properties of keratin were not significantly different between the hairs affected by SD, psoriasis, and AD. However, the changes induced by scalp dermatitis were different with weathering. Therefore, FT-IR analysis could be used to screen differences between the physiological and pathological conditions of scalp hair.

  8. Nuclear medium effects on the nucleon properties

    International Nuclear Information System (INIS)

    Gerard, A.

    1986-06-01

    The idea that the nuclear medium may modify the properties of the nucleon is not really a new one. But until these last few years the intrinsic properties of the nucleon such as its mass, baryonic or electromagnetic size, magnetic moments, were hardly suspected to be substantially modified by the nuclear environment. The question raised essentially from two categories of experimental investigations, in quite different kinematical regimes and it remains at the present time a controversal subject. In this paper I try to review the present status of experimental investigations and some of the recent theoretical developments relevant to this topic

  9. Convergence properties of the effective interaction

    International Nuclear Information System (INIS)

    Ellis, P.J.; Engeland, T.; Hjorth-Jensen, M.; Holt, A.; Osnes, E.

    1994-01-01

    The convergence properties of two perturbative schemes to sum the so-called folded diagrams are critically reviewed in this work, with an emphasis on the intruder state problem. The methods we study are the approaches of Kuo and co-workers and Lee and Suzuki. The suitability of the two schemes for shell-model calculations is discussed. ((orig.))

  10. Convergence properties of the effective interaction

    International Nuclear Information System (INIS)

    Ellis, P.J.; Engeland, T.; Hjorth-Jensen, M.; Holt, A.; Osnes, E.

    1993-10-01

    The convergence properties of two perturbative schemes to sum the so called folded diagrams are critically reviewed with an emphasis on the intruder state problem. The methods studied are the approaches of Kuo and co-workers and Lee and Suzuki. The suitability of the two schemes for shell-model calculations is discussed. 11 refs., 3 figs., 1 tab

  11. Structural properties and neutron irradiation effects of ceramics

    International Nuclear Information System (INIS)

    Yano, Toyohiko

    1994-01-01

    In high temperature gas-cooled reactors and nuclear fusion reactors being developed at present, various ceramics are to be used in the environment of neutron irradiation for undertaking important functions. The change of the characteristics of those materials by neutron irradiation must be exactly forecast, but it has been known that the response of the materials is different respectively. The production method of ceramics and the resulted structures of ceramics which control their characteristics are explained. The features of covalent bond and ionic bond, the synthesis of powder and the phase change by heating, sintering and sintering agent, and grain boundary phase are described. The smelling of ceramics by neutron irradiation is caused by the formation of the clusters of Frenkel defects and minute spot defects. Its restoration by annealing is explained. The defects remaining in materials after irradiation are the physical defects by flipping atoms cut due to the collision with high energy particles and the chemical defects by nuclear transformation. Some physical defects can be restored, but chemical defects are never restored. The mechanical properties of ceramics and the effect of irradiation on them, and the thermal properties of ceramics and the effect of irradiation on them are reported. (K.I.)

  12. Constraining the surface properties of effective Skyrme interactions

    Science.gov (United States)

    Jodon, R.; Bender, M.; Bennaceur, K.; Meyer, J.

    2016-08-01

    Background: Deformation energy surfaces map how the total binding energy of a nuclear system depends on the geometrical properties of intrinsic configurations, thereby providing a powerful tool to interpret nuclear spectroscopy and large-amplitude collective-motion phenomena such as fission. The global behavior of the deformation energy is known to be directly connected to the surface properties of the effective interaction used for its calculation. Purpose: The precise control of surface properties during the parameter adjustment of an effective interaction is key to obtain a reliable and predictive description of nuclear properties. The most relevant indicator is the surface-energy coefficient asurf. There are several possibilities for its definition and estimation, which are not fully equivalent and require a computational effort that can differ by orders of magnitude. The purpose of this study is threefold: first, to identify a scheme for the determination of asurf that offers the best compromise between robustness, precision, and numerical efficiency; second, to analyze the correlation between values for asurf and the characteristic energies of the fission barrier of 240Pu; and third, to lay out an efficient and robust procedure for how the deformation properties of the Skyrme energy density functional (EDF) can be constrained during the parameter fit. Methods: There are several frequently used possibilities to define and calculate the surface energy coefficient asurf of effective interactions built for the purpose of self-consistent mean-field calculations. The most direct access is provided by the model system of semi-infinite nuclear matter, but asurf can also be extracted from the systematics of binding energies of finite nuclei. Calculations can be carried out either self-consistently [Hartree-Fock (HF)], which incorporates quantal shell effects, or in one of the semiclassical extended Thomas-Fermi (ETF) or modified Thomas-Fermi (MTF) approximations. The

  13. Tuning electronic properties of In2O3 nanowires by doping control

    International Nuclear Information System (INIS)

    Lei, B.; Li, C.; Zhang, D.; Tang, D.; Zhou, C.

    2004-01-01

    We present two effective routes to tune the electronic properties of single-crystalline In 2 O 3 nanowires by controlling the doping. The first method involves using different O 2 concentrations during the synthesis. Lightly (heavily) doped nanowires were produced by using high (low) O 2 concentrations, respectively, as revealed by the conductances and threshold voltages of nanowire-based field-effect transistors. Our second method exploits post-synthesis baking, as baking heavily doped nanowires in ambient air led to suppressed conduction and a positive shift of the threshold voltage, whereas baking lightly doped nanowires in vacuum displayed the opposite behavior. Our approaches offer viable ways to tune the electronic properties of many nonstoichiometric metal oxide systems such as In 2 O 3 , SnO 2 , and ZnO nanowires for various applications

  14. Physical properties of beryllium oxide - Irradiation effects

    International Nuclear Information System (INIS)

    Elston, J.; Caillat, R.

    1958-01-01

    This work has been carried out in view of determining several physical properties of hot-pressed beryllium oxide under various conditions and the change of these properties after irradiation. Special attention has been paid on to the measurement of the thermal conductivity coefficient and thermal diffusivity coefficient. Several designs for the measurement of the thermal conductivity coefficient have been achieved. They permit its determination between 50 and 300 deg. C, between 400 and 800 deg. C. Some measurements have been made above 1000 deg. C. In order to measure the thermal diffusivity coefficient, we heat a perfectly flat surface of a sample in such a way that the heat flux is modulated (amplitude and frequency being adjustable). The thermal diffusivity coefficient is deduced from the variations of temperature observed on several spots. Tensile strength; compressive strength; expansion coefficient; sound velocity and crystal parameters have been also measured. Some of the measurements have been carried out after neutron irradiation. Some data have been obtained on the change of the properties of beryllium oxide depending on the integrated neutron flux. (author) [fr

  15. Effect of Mechanical Alloying Atmospheres and Oxygen Concentration on Mechanical Properties of ODS Ferritic Steels

    International Nuclear Information System (INIS)

    Noh, Sanghoon; Choi, Byoungkwon; Han, Changhee; Kim, Kibaik; Kang, Sukhoon; Chun, Youngbum; Kim, Taekyu

    2013-01-01

    Finely dispersed nano-oxide particles with a high number density in the homogeneous grain matrix are essential to achieve superior mechanical properties at high temperatures, and these unique microstructures can be obtained through the mechanical alloying (MA) and hot consolidation process. The microstructure and mechanical property of ODS steel significantly depends on its powder property and the purity after the MA process. These contents should be carefully controlled to improve the mechanical property at elevated temperature. In particular, appropriate the control of oxygen concentration improves the mechanical property of ODS steel at high temperature. An effective method is to control the mechanical alloying atmosphere by high purity inert gas. In the present study, the effects of mechanical alloying atmospheres and oxygen concentration on the mechanical property of ODS steel were investigated. ODS ferritic alloys were fabricated in various atmospheres, and the HIP process was used to investigate the effects of MA atmospheres and oxygen concentration on the microstructure and mechanical property. ODS ferritic alloys milled in an Ar-H 2 mixture, and He is effective to reduce the excess oxygen concentration. The YH 2 addition made an extremely reduced oxygen concentration by the internal oxygen reduction reaction and resulted in a homogeneous microstructure and superior creep strength

  16. Effect of monohydric alcohols on structural properties of macromolecular solutions

    International Nuclear Information System (INIS)

    Giordano, R.; Wanderlingh, F.; Cordone, L.; Cupane, A.

    1983-01-01

    A report on the effects of monohydric alcohols on the thixotropic properties of a 1% (by weight) BSA solution is given. The presence of alcohols in the solution medium, even in a very small amount, weakens the structure responsible for the thixotropic properties: this effect increases with increasing alcohol concentration and alkyl group size. Indirect evidence relating the observed effects to the alteration, in the presence of alcohol, of protein-solvent hydrophobic interactions is also presented

  17. Effect of refractive error on temperament and character properties

    Institute of Scientific and Technical Information of China (English)

    Emine; Kalkan; Akcay; Fatih; Canan; Huseyin; Simavli; Derya; Dal; Hacer; Yalniz; Nagihan; Ugurlu; Omer; Gecici; Nurullah; Cagil

    2015-01-01

    AIM: To determine the effect of refractive error on temperament and character properties using Cloninger’s psychobiological model of personality.METHODS: Using the Temperament and Character Inventory(TCI), the temperament and character profiles of 41 participants with refractive errors(17 with myopia,12 with hyperopia, and 12 with myopic astigmatism) were compared to those of 30 healthy control participants.Here, temperament comprised the traits of novelty seeking, harm-avoidance, and reward dependence, while character comprised traits of self-directedness,cooperativeness, and self-transcendence.RESULTS: Participants with refractive error showed significantly lower scores on purposefulness,cooperativeness, empathy, helpfulness, and compassion(P <0.05, P <0.01, P <0.05, P <0.05, and P <0.01,respectively).CONCLUSION: Refractive error might have a negative influence on some character traits, and different types of refractive error might have different temperament and character properties. These personality traits may be implicated in the onset and/or perpetuation of refractive errors and may be a productive focus for psychotherapy.

  18. Effect of Precuring Warming on Mechanical Properties of Restorative Composites

    Directory of Open Access Journals (Sweden)

    Kareem Nada

    2011-01-01

    Full Text Available To investigate the effect of prepolymerization warming on composites' mechanical properties, three composites were evaluated: Clearfil Majesty (CM (Kuraray, Z-100 (3M/ESPE, and Light-Core (LC (Bisco. Specimens were prepared from each composite at room temperature as control and 2 higher temperatures (37∘C and 54∘C to test surface hardness (SH, compressive strength (CS, and diametral tensile strength (DTS. Data were statistically analyzed using ANOVA and Fisher's LSD tests. Results revealed that prewarming CM and Z100 specimens significantly improved their SH mean values (P<0.05. Prewarming also improved mean CS values of Z100 specimens (P<0.05. Furthermore, DTS mean value of CM prepared at 52∘ was significantly higher than that of room temperature specimens (P<0.05. KHN, CS, and DTS mean values varied significantly among the three composites. In conclusion, Prewarming significantly enhanced surface hardness of 2 composites. Prewarming also improved bulk properties of the composites; however, this improvement was significant in only some of the tested materials.

  19. Local Government Planning Tool to Calculate Institutional and Engineering Control Costs for Brownfield Properties

    Science.gov (United States)

    This cost calculator is designed as a guide for municipal or local governments to assist in calculating their expected costs of implementing and conducting long-term stewardship of institutional controls and engineering controls at brownfield properties.

  20. Effect of polyacrylamide on soil physical and hydraulic properties

    Science.gov (United States)

    Albalasmeh, Ammar; Gharaibeh, Mamoun; Hamdan, Enas

    2017-04-01

    The effect of polyacrylamide (PAM), as a soil conditioner, on selected soil physical and hydraulic properties (infiltration rate (f(t)), hydraulic conductivity (HC), soil moisture content, aggregate stability (AS), and soil aggregation) was studied. Two types of anionic PAM were used: Low molecular weight (LPAM) (1×105 g/mol) with medium charge density (33-43) and high molecular weight (HPAM) (1-6×106 g/mol) with medium charge density (33-43). Sandy loam soil was packed into plastic columns; PAM solutions at different concentrations (100, 250, 500, and 1000 mg L-1) were used every two weeks in four wetting and drying cycles. The highest infiltration rate value was 0.16 mm s-1 at 1000 mg/L low molecular weight PAM while the highest value of infiltration rate in high PAM molecular weight was 0.11 mm s-1 compared to the control (0.01 mm s-1). Soil HC was about 3.00 cm h-1 for LPAM at 1000 mg L-1 PAM, while the highest value for HPAM was about 2 cm h-1 for the same concentration, compared to the control. The amount of water that can be held by soil increased with the addition of PAM compared to the control. Differences in water content were more pronounced in LPAM compared to HPAM. The addition of LPAM increased aggregate stability proportional to PAM concentration. Moreover, 1000 mg L-1 produced the highest aggregate stability (19{%}) compared to HPAM and control (7{%} and 5{%}), respectively. As PAM concentration increased, the geometric mean diameter (GMD) increased for both PAM molecular weights compared to control (0.4 mm). At 1000 mg L-1 the GMD values were 0.88 mm and 0.79 mm for LPAM and HPAM, respectively. The addition of PAM improved soil physical and hydraulic properties, with an advantage to LPAM owing that to its ability to penetrate soil aggregates and therefore stabilizing them.

  1. Effect of antimicrobial agents on cellulose acetate nano composites properties

    International Nuclear Information System (INIS)

    Rodriguez, Francisco J.; Bruna, Julio E.; Galotto, Maria J.; Guarda, Abel; Sepulveda, Hugo

    2011-01-01

    Nano composites based on cellulose acetate, Cloisite 30B, triethyl citrate and thymol or cinnamaldehyde were prepared using a dissolution casting technique. The effect of thymol and cinnamaldehyde on the cellulose acetate nano composite properties was evaluated by XRD and DSC. Important changes on the thermal properties and morphological structure were observed according to thymol and cinnamaldehyde content. (author)

  2. Effect Of Formulating Additives On The Properties Of Ibuprofen Tablets

    African Journals Online (AJOL)

    A study of the comparative effects of different formulating additives and film coating on the properties of ibuprofen tablets was made. The tested properties were hardeness (H), friability (F), the disintegration time (D) and dissolution characteristics of ibuprofen tablets. The hardeness, friability, the hardeness friability ratio ...

  3. Effect of Sucrose Esters on the Physicochemical Properties of Wheat ...

    African Journals Online (AJOL)

    HP

    Purpose: To investigate the effect of sucrose esters on the physicochemical properties of wheat starch. Methods: Sucrose ester was mixed with wheat starch extracted from normal soft wheat cultivars and heated. Change in starch properties arising from the interaction between were assessed for starch blue value, viscosity ...

  4. Effect of ozone gas processing on physical and chemical properties ...

    African Journals Online (AJOL)

    Purpose: To investigate the effects of ozone treatment on chemical and physical properties of wheat (Triticum aestivum L.) gluten, glutenin and gliadin. Methods: Wheat proteins isolated from wheat flour were treated with ozone gas. The physical and chemical properties of gluten proteins were investigated after treatment ...

  5. Effect of antimicrobial agents on cellulose acetate nano composites properties

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez, Francisco J.; Bruna, Julio E.; Galotto, Maria J.; Guarda, Abel; Sepulveda, Hugo, E-mail: francisco.rodriguez.m@usach.cl [Center for the Development of Nanoscience and Nanotechnology (CEDENNA). Universidad de Santiago de Chile. Faculty of Technology. Department of Food Science and Technology. Food Packaging Laboratory. Santiago (Chile)

    2011-07-01

    Nano composites based on cellulose acetate, Cloisite 30B, triethyl citrate and thymol or cinnamaldehyde were prepared using a dissolution casting technique. The effect of thymol and cinnamaldehyde on the cellulose acetate nano composite properties was evaluated by XRD and DSC. Important changes on the thermal properties and morphological structure were observed according to thymol and cinnamaldehyde content. (author)

  6. Radiation effect on polyethylene tube operational properties

    International Nuclear Information System (INIS)

    Kagan, D.F.; Kantor, L.A.; Sokolov, I.A.; Pogrebetskij, G.E.; Perlova, N.A.; Chumakov, V.V.

    1975-01-01

    The operational properties (stability on prolonged usage and creeping) were determined for pressure pipes made of high-density and low-density polyethylene subjected to γ-radiation. The dependence of the period up to the breaking point on the radiation dosage was extreme in character, with a maximum being near 25 Mrad. With an increase in the irradiation dosage the character of the breaking changes from plastic (at 0-15 Mrad) to brittle (at higher dosages). The plots of creepage, indepent from the amount of radiation, can be described by logarithmic equation epsilon=epsilonsub(0)+K lgt (where, epsilon-deformation of creepage, %; epsilonsub(0)- and K - creepage constants). Therefore creepage can be considered as a criterion determining the carrying capacity of the γ-irradiated polyethylene. It was established that only radiation-grafted high-density polyethylene is suitable for hot water supply pipes

  7. The porosity effect on properties of sintered materials as their conductivity and Youngs modulus of elasticity

    International Nuclear Information System (INIS)

    Ondracek, G.; Thuemmler, F.

    1979-01-01

    A set of equations derived demonstrates quantitatively the influence of closed pores on the conductivity as well as on Youngsmodulus of elasticity of sintered materials. There are three microstructural parameters following from the theoretical derivation controlling the porosity effect on the properties, which are the total porosity, the form factor and the orientation factor of the pores. By quantitative microstructure analysis these factors become available providing together with the equations the tool - to calculate the conductivity and Youngs modulus of elasticity from microstructural quantities of sintered materials thus substituting direct property measurements by quantitative microstructure analysis if desired - to endeaver technologically optimum microstructures to obtain theoretically predicted special property values and to precalculate property alterations by microstructure variations ('taylor-made-materials') - to supplement the conventional microstructural quality control by calculated property data. (orig.) [de

  8. Design and Performance of Property Gradient Ternary Nitride Coating Based on Process Control.

    Science.gov (United States)

    Yan, Pei; Chen, Kaijie; Wang, Yubin; Zhou, Han; Peng, Zeyu; Jiao, Li; Wang, Xibin

    2018-05-09

    Surface coating is an effective approach to improve cutting tool performance, and multiple or gradient coating structures have become a common development strategy. However, composition mutations at the interfaces decrease the performance of multi-layered coatings. The key mitigation technique has been to reduce the interface effect at the boundaries. This study proposes a structure design method for property-component gradient coatings based on process control. The method produces coatings with high internal cohesion and high external hardness, which could reduce the composition and performance mutations at the interface. A ZrTiN property gradient ternary nitride coating was deposited on cemented carbide by multi-arc ion plating with separated Ti and Zr targets. The mechanical properties, friction behaviors, and cutting performances were systematically investigated, compared with a single-layer coating. The results indicated that the gradient coating had better friction and wear performance with lower wear rate and higher resistance to peeling off during sliding friction. The gradient coating had better wear and damage resistance in cutting processes, with lower machined surface roughness Ra. Gradient-structured coatings could effectively inhibit micro crack initiation and growth under alternating force and temperature load. This method could be extended to similar ternary nitride coatings.

  9. Effect of processing on functional properties of animal blood plasma.

    Science.gov (United States)

    Del Hoyo, P; Rendueles, M; Díaz, M

    2008-04-01

    A number of functional and physical properties such as solubility, foam capacity, emulsifying stability and interfacial tension were compared for standard plasma, plasma decationed by ion exchange and plasma deionized by ultrafiltration (UF). The changes in functional properties can determine the use of a protein as an additive to a food product or invalidate its use. All samples had good functional properties and hence could be used in the formulation of food products. Results showed that ion exchange and UF improved emulsifying capacity while having little effect on the other functional properties.

  10. Tuning the Properties of Polymer Bulk Heterojunction Solar Cells by Adjusting Fullerene Size to Control Intercalation

    KAUST Repository

    Cates, Nichole C.; Gysel, Roman; Beiley, Zach; Miller, Chad E.; Toney, Michael F.; Heeney, Martin; McCulloch, Iain; McGehee, Michael D.

    2009-01-01

    We demonstrate that intercalation of fullerene derivatives between the side chains of conjugated polymers can be controlled by adjusting the fullerene size and compare the properties of intercalated and nonintercalated poly(2,5-bis(3-hexadecylthiophen-2-yl)thieno[3,2-b]thiophene (pBTTT):fullerene blends. The intercalated blends, which exhibit optimal solar-cell performance at 1:4 polymer:fullerene by weight, have better photoluminescence quenching and lower absorption than the nonintercalated blends, which optimize at 1:1. Understanding how intercalation affects performance will enable more effective design of polymer:fullerene solar cells. © 2009 American Chemical Society.

  11. Tuning the Properties of Polymer Bulk Heterojunction Solar Cells by Adjusting Fullerene Size to Control Intercalation

    KAUST Repository

    Cates, Nichole C.

    2009-12-09

    We demonstrate that intercalation of fullerene derivatives between the side chains of conjugated polymers can be controlled by adjusting the fullerene size and compare the properties of intercalated and nonintercalated poly(2,5-bis(3-hexadecylthiophen-2-yl)thieno[3,2-b]thiophene (pBTTT):fullerene blends. The intercalated blends, which exhibit optimal solar-cell performance at 1:4 polymer:fullerene by weight, have better photoluminescence quenching and lower absorption than the nonintercalated blends, which optimize at 1:1. Understanding how intercalation affects performance will enable more effective design of polymer:fullerene solar cells. © 2009 American Chemical Society.

  12. Effects of botulinum toxin on strength-duration properties.

    Science.gov (United States)

    Yerdelen, Deniz; Koc, Filiz; Sarica, Yakup

    2007-10-01

    Axonal excitability studies have been used in several diseases to investigate the underlying pathophysiology. The threshold tracking technique was developed to measure noninvasively several indices of axonal excitability, such as strength-duration properties. This study investigated the possible effects of botulinum toxin on strength-duration time constant (SDTC) in patients with the symptoms and signs of botulism. The clinical and electrophysiological findings of 13 patients who were admitted to the authors' clinic with botulism signs and symptoms were evaluated in a 5-day period after exposure to the toxin prospectively. After routine diagnostic electroneuromyographic examinations and electromyogram with repetitive nerve stimulation at 20-50 Hz, SDTC was studied. The results were compared with 13 age- and sex-matched healthy volunteers. The SDTCs were 381 +/- 60 micros and 471 +/- 84 micros in patients and controls, respectively. There was a statistical difference between the two groups (p = .003, Mann Whitney U test). These findings suggest a possible effect of botulinum toxin, known to be effective at neuromuscular junction, on Na(+)/K(+) pump activity, and Na(+) or K(+) conductance.

  13. effects of sulphur addition on addition on and mechanical properties

    African Journals Online (AJOL)

    User

    234-8034714355. 8034714355. 1. EFFECTS OF SULPHUR ADDITION ON. ADDITION ON. 2. AND MECHANICAL PROPERTIES O. 3. 4. C. W. Onyia. 5. 1DEPT. OF METALLURGICAL AND MATERIALS. 6. 2, 4DEPT. OF METALLURGICAL ...

  14. The effective use of property tax incentives for economic development

    OpenAIRE

    Daphne A. Kenyon; Adam H. Langley; Bethany P. Paquin

    2013-01-01

    To make property-tax incentives for business more effective, do not approve every incentive request, target use of incentives, avoid incentive wars, cooperate with surrounding localities, and conduct regular evaluations.

  15. Niobium effect on the Pzt ceramic properties

    International Nuclear Information System (INIS)

    Gimenes, R.; Zaguete, M.A.; Varela, J.A.; Cilense, M.; Paiva-Santos, C.O.; Las, W.C.

    1996-01-01

    Lead zirconate titanate, PZT, was prepared with Zr/Ti ratio of 50/50. The powder was prepared by the Pechini method with addition of 0,3; 0,5 e 0,7 mol % of Nb +5 ions. The precursors obtained were calcined at 700 deg C for 3 hs and milled with zirconia balls in a medium of isopropilic alcohol for 6 hs. The powders were characterized by XRD. For the sintering studies powders were isostatically pressed (230 MPa) into pellets and which were put inside a box furnace at 1200 deg C for 2 hs and 1100 deg C for 4 hs in a closed system containing 5 % of atmospheric powder (Pb Zr O 3 + 5% Pb O) relative to all pellets'mass. It was verified that the best densification rate was obtained for PZT with addition of 0,5 mol % of Nb +5 ions and sintered at 1100 deg C for 4 hs. Sintered samples at 1100 deg C for 4 hs were characterized as to dielectric (k, P r and E c ) and piezoelectric properties. (author)

  16. A comparison between acoustic properties and heat effects in biogenic (magnetosomes) and abiotic magnetite nanoparticle suspensions

    International Nuclear Information System (INIS)

    Józefczak, A.; Leszczyński, B.; Skumiel, A.; Hornowski, T.

    2016-01-01

    Magnetic nanoparticles show unique properties and find many applications because of the possibility to control their properties using magnetic field. Magnetic nanoparticles are usually synthesized chemically and modification of the particle surface is necessary. Another source of magnetic nanoparticles are various magnetotactic bacteria. These biogenic nanoparticles (magnetosomes) represent an attractive alternative to chemically synthesized iron oxide particles because of their unique characteristics and a high potential for biotechnological and biomedical applications. This work presents a comparison between acoustic properties of biogenic and abiotic magnetite nanoparticle suspensions. Experimental studies have shown the influence of a biological membrane on the ultrasound properties of magnetosomes suspension. Finally the heat effect in synthetic and biogenic magnetite nanoparticles is also discussed. The experimental study shows that magnetosomes present good heating efficiency. - Highlights: • A biogenic and abiotic magnetite nanoparticle suspensions are investigated. • A comparison between ultrasonic properties and heat effects is presented. • Magnetosomes and abiotic magnetite nanoparticles exhibit good heating efficiency.

  17. Tropospheric ozone. Formation, properties, effects. Expert opinion

    International Nuclear Information System (INIS)

    Elstner, E.F.

    1996-01-01

    The formation and dispersion of tropospheric ozone are discussed only marginally in this expert opinion; the key interest is in the effects of ground level ozone on plants, animals, and humans. The expert opinion is based on an analysis of the available scientific publications. (orig./MG) [de

  18. Health effects estimation for contaminated properties

    International Nuclear Information System (INIS)

    Marks, S.; Denham, D.H.; Cross, F.T.; Kennedy, W.E. Jr.

    1984-05-01

    As part of an overall remedial action program to evaluate the need for and institute actions designed to minimize health hazards from inactive tailings piles and from displaced tailings, methods for estimating health effects from tailings were developed and applied to the Salt Lake City area. 2 references, 2 tables

  19. Topological and statistical properties of quantum control transition landscapes

    International Nuclear Information System (INIS)

    Hsieh, Michael; Wu Rebing; Rabitz, Herschel; Rosenthal, Carey

    2008-01-01

    A puzzle arising in the control of quantum dynamics is to explain the relative ease with which high-quality control solutions can be found in the laboratory and in simulations. The emerging explanation appears to lie in the nature of the quantum control landscape, which is an observable as a function of the control variables. This work considers the common case of the observable being the transition probability between an initial and a target state. For any controllable quantum system, this landscape contains only global maxima and minima, and no local extrema traps. The probability distribution function for the landscape value is used to calculate the relative volume of the region of the landscape corresponding to good control solutions. The topology of the global optima of the landscape is analysed and the optima are shown to have inherent robustness to variations in the controls. Although the relative landscape volume of good control solutions is found to shrink rapidly as the system Hilbert space dimension increases, the highly favourable landscape topology at and away from the global optima provides a rationale for understanding the relative ease of finding high-quality, stable quantum optimal control solutions

  20. Effect of boron waste on the properties of mortar and concrete.

    Science.gov (United States)

    Topçu, Iker Bekir; Boga, Ahmet Raif

    2010-07-01

    Utilization of by-products or waste materials in concrete production are important subjects for sustainable development and industrial ecology concepts. The usages as mineral admixtures or fine aggregates improve the durability properties of concrete and thus increase the economic and environmental advantages for the concrete industry. The effect of clay waste (CW) containing boron on the mechanical properties of concrete was investigated. CW was added in different proportions as cement additive in concrete. The effect of CW on workability and strength of concrete were analysed by fresh and hardened concrete tests. The results obtained were compared with control concrete properties and Turkish standard values. The results showed that the addition of CW had a small effect upon the workability of the concrete but an important effect on the reduction of its strength. It was observed that strength values were quite near to that of control concrete when not more than 10% CW was used in place of cement. In addition to concrete specimens, replacing cement with CW produced mortar specimens, which were investigated for their strength and durability properties. The tests of SO( 4) (2-) and Cl(-) effect as well as freeze-thaw behaviour related to the durability of mortar were performed. Consequently, it can be said that some improvements were obtained in durability properties even if mechanical properties had decreased with increasing CW content.

  1. Effects of Basalt Fibres on Mechanical Properties of Concrete

    Directory of Open Access Journals (Sweden)

    El-Gelani A. M.

    2018-01-01

    Full Text Available This paper presents the results of an experimental program carried out to investigate the effects of Basalt Fibre Reinforced Polymers (BFRP on some fundamental mechanical properties of concrete. Basalt fibres are formed by heating crushed basalt rocks and funnelling the molten basalt through a spinneret to form basalt filaments. This type of fibres have not been widely used till recently. Two commercially available chopped basalt fibres products with different aspect ratios were investigated, which are dry basalt (GeoTech Fibre and basalt pre-soaked in an epoxy resin (GeoTech Matrix .The experimental work included compression tests on 96 cylinders made of multiple batches of concrete with varying amounts of basalt fibre additives of the two mentioned types, along with control batches containing no fibres. Furthermore, flexural tests on 24 prisms were carries out to measure the modulus of rupture, in addition to 30 prisms for average residual strength test. Results of the research indicated that use of basalt fibres has insignificant effects on compressive strength of plain concrete, where the increase in strength did not exceed about 5%. On the other hand, results suggest that the use of basalt fibres may increase the compressive strength of concrete containing fly as up top 40%. The rupture strength was increased also by 8% to 28% depending on mix and fibre types and contents. Finally, there was no clear correlation between the average residual strength and ratios of basalt fibres mixed with the different concrete batches.

  2. Controlled change of transport properties of poly(ethylene terephthalate) track membranes by plasma method

    International Nuclear Information System (INIS)

    Kravets, L I; Dmitriev, S N; Drachev, A I; Gilman, A B; Lazea, A; Dinescu, G

    2007-01-01

    A process of plasma polymerization of dimethylaniline and acrylic acid vapours on the surface of poly(ethylene terephthalate) track membranes has been investigated. The surface and hydrodynamic properties of the composite membranes produced in this case have been studied. It is shown that the water permeability of the obtained polymeric membranes can be controlled by changing the filtrate pH. Membranes with such properties can be used for controllable drug delivery and in sensor control

  3. Intrinsic control of electroresponsive properties of transplanted mammalian brain neurons

    DEFF Research Database (Denmark)

    Hounsgaard, J; Yarom, Y

    1985-01-01

    The present study presents the first analysis of neurons in mammalian brain transplants based on intracellular recording. The results, obtained in brain slices including both donor and host tissue, showed that neuronal precursor cells in embryonic transplants retained their ability to complete...... their normal differentiation of cell-type-specific electroresponsive properties. Distortions in cell aggregation and synaptic connectivity did not affect this aspect of neuronal differentiation....

  4. The effects and control of radiation

    International Nuclear Information System (INIS)

    Saunders, P.A.H.

    1982-12-01

    The subject is discussed under the headings: introduction; ionising radiation (alpha and beta particles, gamma- and X-radiation, neutrons, half-life, sources of radiation); biological effects; risk estimates (somatic) (early effects, delayed effects); risk estimates (hereditary); control of radiation; risk estimates (accidents). (U.K.)

  5. Asymptotic stability and disturbance attenuation properties for a class of networked control systems

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    In this paper, stability and disturbance attenuation issues for a class of Networked Control Systems (NCSs)under uncertain access delay and packet dropout effects are considered. Our aim is to find conditions on the delay and packet dropout rate, under which the system stability and H∞ disturbance attenuation properties are preserved to a desired level. The basic idea in this paper is to formulate such Networked Control System as a discrete-time switched system. Then the NCSs' stability and performance problems can be reduced to the corresponding problems for switched systems, which have been studied for decades and for which a number of results are available in the literature. The techniques in this paper are based on recent progress in the discrete-time switched systems and piecewise Lyapunov functions.

  6. Effect of extrusion processing on the microstructure, mechanical properties, biocorrosion properties and antibacterial properties of Ti-Cu sintered alloys

    International Nuclear Information System (INIS)

    Zhang, Erlin; Li, Shengyi; Ren, Jing; Zhang, Lan; Han, Yong

    2016-01-01

    Ti-Cu sintered alloys, Ti-Cu(S) alloy, have exhibited good anticorrosion resistance and strong antibacterial properties, but low ductility in previous study. In this paper, Ti-Cu(S) alloys were subjected to extrusion processing in order to improve the comprehensive property. The phase constitute, microstructure, mechanical property, biocorrosion property and antibacterial activity of the extruded alloys, Ti-Cu(E), were investigated in comparison with Ti-Cu(S) by X-ray diffraction (XRD), optical microscopy (OM), scanning electronic microscopy (SEM) with energy disperse spectroscopy (EDS), mechanical testing, electrochemical testing and plate-count method in order to reveal the effect of the extrusion process. XRD, OM and SEM results showed that the extrusion process did not change the phase constitute but refined the grain size and Ti 2 Cu particle significantly. Ti-Cu(E) alloys exhibited higher hardness and compressive yield strength than Ti-Cu(S) alloys due to the fine grain and Ti 2 Cu particles. With the consideration of the total compressive strain, it was suggested that the extrusion process could improve the ductility of Ti-Cu alloy(S) alloys. Electrochemical results have indicated that the extrusion process improved the corrosion resistance of Ti-Cu(S) alloys. Plate-count method displayed that both Ti-Cu(S) and Ti-Cu(E) exhibited strong antibacterial activity (> 99%) against S. aureus. All these results demonstrated that hot forming processing, such as the extrusion in this study, refined the microstructure and densified the alloy, in turn improved the ductility and strength as well as anticorrosion properties without reduction in antibacterial properties. - Highlights: • Hot extrusion refined the grain size and Ti 2 Cu phase significantly. • Hot extrusion increased the mechanical properties and the corrosion resistance. • The antibacterial properties was not affected by the hot process.

  7. Which key properties controls the preferential transport in the vadose zone under transient hydrological conditions

    Science.gov (United States)

    Groh, J.; Vanderborght, J.; Puetz, T.; Gerke, H. H.; Rupp, H.; Wollschlaeger, U.; Stumpp, C.; Priesack, E.; Vereecken, H.

    2015-12-01

    Understanding water flow and solute transport in the unsaturated zone is of great importance for an appropriate land use management strategy. The quantification and prediction of water and solute fluxes through the vadose zone can help to improve management practices in order to limit potential risk on our fresh water resources. Water related solute transport and residence time is strongly affected by preferential flow paths in the soil. Water flow in soils depends on soil properties and site factors (climate or experiment conditions, land use) and are therefore important factors to understand preferential solute transport in the unsaturated zone. However our understanding and knowledge of which on-site properties or conditions define and enhance preferential flow and transport is still poor and mostly limited onto laboratory experimental conditions (small column length and steady state boundary conditions). Within the TERENO SOILCan lysimeter network, which was designed to study the effects of climate change on soil functions, a bromide tracer was applied on 62 lysimeter at eight different test sites between Dec. 2013 and Jan. 2014. The TERENO SOILCan infrastructure offers the unique possibility to study the occurrence of preferential flow and transport of various soil types under different natural transient hydrological conditions and land use (crop, bare and grassland) at eight TERENO SOILCan observatories. Working with lysimeter replicates at each observatory allows defining the spatial variability of preferential transport and flow. Additionally lysimeters in the network were transferred within and between observatories in order to subject them to different rainfall and temperature regimes and enable us to relate the soil type susceptibility of preferential flow and transport not only to site specific physical and land use properties, but also to different transient boundary conditions. Comparison and statistical analysis between preferential flow indicators 5

  8. WOOD PROPERTIES AND EFFECT OF WOOD PROPERTIES ON THE WOOD FINISHING

    Directory of Open Access Journals (Sweden)

    Abdulkadir Malkoçoğlu

    2006-04-01

    Full Text Available Wood is basic raw material for furniture and joinery industries with wood structures. Wood is a biological material that has widely different properties depending on species, geographic area where the tree grew, the growth condition, size of the tree at harvest, sawing, and other manufacturing processes. Wood properties have been characterized within two groups as natural and manufacturing factors that effects finishing performance. Grow rate, density, knots, moisture content, extractives and juvenile wood are natural characteristics. Grain orientation, texture, drying and performance expectations are manufacturing characteristics. In this review, the effects of natural and manufacturing characteristics are discussed on the surface finishing performance of wood.

  9. Effect of starch binder on charcoal briquette properties

    Science.gov (United States)

    Borowski, Gabriel; Stępniewski, Witold; Wójcik-Oliveira, Katarzyna

    2017-10-01

    The paper shows the results of a study on the effect of starch binder on the mechanical, physical and burning properties of charcoal briquettes. Two types of binders were repeatedly used to make briquettes of native wheat starch and modified wheat starch, at 8% of the whole. Briquetting was performed in a roller press unit, and pillow-shaped briquettes were made. The moisture of the mixed material ranged from 28 to 32%. The product, whether the former or the latter, was characterized by very good mechanical properties and satisfactory physical properties. Moreover, the type of starch binder had no effect on toughness, calorific heating value, volatiles, fixed carbon content and ash content. However, the combustion test showed quite different burning properties. As briquettes should have short firing up time and lower smokiness, as well as high maximum temperature and long burning time, we have concluded that briquettes with native wheat starch as a binder are more appropriate for burning in the grill.

  10. Artificial immune system for effective properties optimization of magnetoelectric composites

    Science.gov (United States)

    Poteralski, Arkadiusz; Dziatkiewicz, Grzegorz

    2018-01-01

    The optimization problem of the effective properties for magnetoelectric composites is considered. The effective properties are determined by the semi-analytical Mori-Tanaka approach. The generalized Eshelby tensor components are calculated numerically by using the Gauss quadrature method for the integral representation of the inclusion problem. The linear magnetoelectric constitutive equation is used. The effect of orientation of the electromagnetic materials components is taken into account. The optimization problem of the design is formulated and the artificial immune system is applied to solve it.

  11. Effect of irradiation on functional properties of Gum Tragacanth

    Directory of Open Access Journals (Sweden)

    Neda Mollakhalili meybodi

    2017-03-01

    Full Text Available Background and objective: irradiation is a physical treatment in which products are exposed to ionized radiation such as gamma and x rays to improve the security and quality. Hydrocolloids are components that are used in food science to improve texture properties. Exposing to irradiation treatment may change structural and functional properties. By regard to the importance of irradiation on decontaminating of hydrocolloids in food application, the aim of this study is studying the effect of irradiation at different doses on functional properties of Gum Tragacanth in food application. Material and methods: effect of irradiation treatment was studied on the rheological properties, zeta potential, particle size distribution and surface tension of dispersion systems contained 0/5% w/ w gum tragacanth that is irradiated at different doses (0, 0.75. 3, 5 kGy. The effect of irradiation on rheological properties was monitored by rheometer. In order to monitor the effect of irradiation treatment on particle size distribution, zeta potential and surface tension, particle sizer, Brookhaven zeta plus and tensiometer sere used respectively. All treatments were performed three times and the data were analyzed by one way ANOVA. Significant differences between means were identified (P values < 0.05 using Duncan test. Results: Irradiation, change rheologiacal properties and particle size distribution of dispersion contained gum tragacanth. Irradiation treatment up to 0.75 kGy increase zeta potential, but irradiating at higher doses decrease it again. Results of studying parameters showed that irradiation changes the functional properties by affecting on structure. These changes depend on irradiation dose Conclusion: Gum tragacanth irradiation may improve the functional properties by affecting on structure.

  12. Effect of mucin extraction method on some properties of ...

    African Journals Online (AJOL)

    Effect of mucin extraction method on some properties of metronidazole mucoadhesive loaded patches. MI Arhewoh, SO Eraga, PF Builders, MA Ibobiri. Abstract. To evaluate the effects of mucin extraction method and plasticizer concentration on the bioadhesive strength and metronidazole release profile from mucin-based ...

  13. Properties of Strange Matter in a Model with Effective Lagrangian

    Institute of Scientific and Technical Information of China (English)

    WANG Ping; SU Ru-Keng; SONG Hong-Qiu; ZHANG Li-Liang

    2001-01-01

    The strange hadronic matter with nucleons, A-hyperons and E-hyperons is studied by using an effective nuclear model in a mean-field approximation. The density and strangeness fraction dependence of the effective baryon masses as well as the saturation properties and stabilities of the strange hadronic matter are discussed.``

  14. Hydration Control of the Mechanical and Dynamical Properties of Cellulose

    Energy Technology Data Exchange (ETDEWEB)

    Petridis, Loukas; O’Neill, Hugh M.; Johnsen, Mariah [Ripon College, Ripon, Wisconsin 54971, United States; Fan, Bingxin [Department; Schulz, Roland [Department; Mamontov, Eugene; Maranas, Janna [Department; Langan, Paul [Department; Smith, Jeremy C. [Department

    2014-10-13

    The mechanical and dynamical properties of cellulose, the most abundant biomolecule on earth, are essential for its function in plant cell walls and advanced biomaterials. Cellulose is almost always found in a hydrated state, and it is therefore important to understand how hydration influences its dynamics and mechanics. Here, the nanosecond-time scale dynamics of cellulose is characterized using dynamic neutron scattering experiments and molecular dynamics (MD) simulation. The experiments reveal that hydrated samples exhibit a higher average mean-square displacement above ~240 K. The MD simulation reveals that the fluctuations of the surface hydroxymethyl atoms determine the experimental temperature and hydration dependence. The increase in the conformational disorder of the surface hydroxymethyl groups with temperature follows the cellulose persistence length, suggesting a coupling between structural and mechanical properties of the biopolymer. In the MD simulation, 20% hydrated cellulose is more rigid than the dry form, due to more closely packed cellulose chains and water molecules bridging cellulose monomers with hydrogen bonds. This finding may have implications for understanding the origin of strength and rigidity of secondary plant cell walls. The detailed characterization obtained here describes how hydration-dependent increased fluctuations and hydroxymethyl disorder at the cellulose surface lead to enhancement of the rigidity of this important biomolecule.

  15. Control of amorphous films properties in the case of combined sputtering of targets

    International Nuclear Information System (INIS)

    Okunev, V.D.; Yurov, A.G.

    1979-01-01

    A possibility of controlling amorphous film properties produced by combined sputtering of two targets: was investigated one of the targets was made of a basis material-polycrystalline CdGeAs 2 , the other one was made of a material of additives. As the additives the Ni,Co elements with low chemical activity and the Cu,Te additives with high chemical activity were used. Besides, to study the effect of deviation from amorphous CdGeAs 2 stoichiometry on film properties, the Gd,Ge,As additives were investigated. The various additives influence on electric conductivity of amorphous films has been studied. It is shown that approximately 1 at% Ni or Co contents results in reducing film specific resistance by 6 orders. Cu and Te introduction results in the change of the structure and type of amorphous layer conductivity. The conclusion has been drawn, that introduction of the elements with high chemical activity can be used as the method of producing films with new physicochemical properties

  16. Rheological behaviour and physical properties of controlled-release gluten-based bioplastics.

    Science.gov (United States)

    Gómez-Martínez, D; Partal, P; Martínez, I; Gallegos, C

    2009-03-01

    Bioplastics based on glycerol, water and wheat gluten have been manufactured in order to determine the effect that mechanical processing and further thermal treatments exert on different thermo-mechanical properties of the biomaterials obtained. An "active agent", KCl was incorporated in these matrices to develop controlled-release formulations. Oscillatory shear, dynamic mechanical thermal analysis (DMTA), diffusion and water absorption tests were carried out in order to study the influence of the above-mentioned treatments on the physico-chemical characteristics and rheological behaviour of these bioplastic samples. Wheat gluten protein-based bioplastics studied in this work present a high ability for thermosetting modification, due to protein denaturation, which may favour the development of a wide variety of biomaterials. Bioplastic hygroscopic properties depend on plasticizer nature and processing procedure, and may be a key factor for industrial applications where water absorption is required. On the other hand, high water absorption and slow KCl release from bioplastic samples (both of them suitable properties in agricultural applications) may be obtained by adding citric acid to a given formulation, at selected processing conditions.

  17. Cost effective material control and accountability training

    International Nuclear Information System (INIS)

    Robichaux, J.J.; Shull, L.M.; Salizzoni, L.M.

    1995-01-01

    DOE Order 5630.15, ''Safeguards and Security Training Program'' is being implemented at the Savannah River Site within the Westinghouse Savannah River Company's material control and accountability program. This paper reviews the development of a material control and accountability task analysis, the development of specific material control and accountability courses, and the cost effective and innovative strategies employed to implement the training program. The paper also discusses how the site material control and accountability policies and procedures are incorporated into the Westinghouse Savannah River Company training program to ensure that personnel receive the most current information

  18. Composition-controlled optical properties of colloidal CdSe quantum dots

    International Nuclear Information System (INIS)

    Ayele, Delele Worku; Su, Wei-Nien; Chou, Hung-Lung; Pan, Chun-Jern; Hwang, Bing-Joe

    2014-01-01

    Graphical abstract: - Highlights: • The surface of CdSe QDs are modified with cadmium followed by selenium. • The optical properties of CdSe QDs can be controlled by manipulating the composition. • Surface compositional change affects the surface defects or traps and recombination. • The surface trapping state can be controlled by tuning the surface composition. • A change in composition shows a change in the carrier life time. - Abstract: A strategy with respect to band gap engineering by controlling the composition of CdSe quantum dots (QDs) is reported. After the CdSe QDs are prepared, their compositions can be effectively manipulated from 1:1 (Cd:Se) CdSe QDs to Cd-rich and then to Se-rich QDs. To obtain Cd-rich CdSe QDs, Cd was deposited on equimolar CdSe QDs. Further deposition of Se on Cd-rich CdSe QDs produced Se-rich CdSe QDs. The compositions (Cd:Se) of the as-prepared CdSe quantum dots were acquired by Energy-dispersive X-ray spectroscopy (EDX). By changing the composition, the overall optical properties of the CdSe QDs can be manipulated. It was found that as the composition of the QDs changes from 1:1 (Cd:Se) CdSe to Cd-rich and then Se-rich CdSe, the band gap decreases along with a red shift of UV–vis absorption edges and photoluminescence (PL) peaks. The quantum yield also decreases with surface composition from 1:1 (Cd:Se) CdSe QDs to Cd-rich and then to Se-rich, largely due to the changes in the surface state. Because of the involvement of the surface defect or trapping state, the carrier life time increased from the 1:1 (Cd:Se) CdSe QDs to the Cd-rich to the Se-rich CdSe QDs. We have shown that the optical properties of CdSe QDs can be controlled by manipulating the composition of the surface atoms. This strategy can potentially be extended to other semiconductor nanocrystals to modify their properties

  19. Composition-controlled optical properties of colloidal CdSe quantum dots

    Energy Technology Data Exchange (ETDEWEB)

    Ayele, Delele Worku [Department of Chemical Engineering, National Taiwan University of Science and Technology, Taipei 106, Taiwan (China); Department of Chemistry, Bahir Dar University, Bahir Dar (Ethiopia); Su, Wei-Nien, E-mail: wsu@mail.ntust.edu.tw [Graduate Institute of Applied Science and Technology, National Taiwan University of Science and Technology, Taipei 106, Taiwan (China); Chou, Hung-Lung [Graduate Institute of Applied Science and Technology, National Taiwan University of Science and Technology, Taipei 106, Taiwan (China); Pan, Chun-Jern [Department of Chemical Engineering, National Taiwan University of Science and Technology, Taipei 106, Taiwan (China); Hwang, Bing-Joe, E-mail: bjh@mail.ntust.edu.tw [Department of Chemical Engineering, National Taiwan University of Science and Technology, Taipei 106, Taiwan (China); National Synchrotron Radiation Research Center, Hsinchu 300, Taiwan (China)

    2014-12-15

    Graphical abstract: - Highlights: • The surface of CdSe QDs are modified with cadmium followed by selenium. • The optical properties of CdSe QDs can be controlled by manipulating the composition. • Surface compositional change affects the surface defects or traps and recombination. • The surface trapping state can be controlled by tuning the surface composition. • A change in composition shows a change in the carrier life time. - Abstract: A strategy with respect to band gap engineering by controlling the composition of CdSe quantum dots (QDs) is reported. After the CdSe QDs are prepared, their compositions can be effectively manipulated from 1:1 (Cd:Se) CdSe QDs to Cd-rich and then to Se-rich QDs. To obtain Cd-rich CdSe QDs, Cd was deposited on equimolar CdSe QDs. Further deposition of Se on Cd-rich CdSe QDs produced Se-rich CdSe QDs. The compositions (Cd:Se) of the as-prepared CdSe quantum dots were acquired by Energy-dispersive X-ray spectroscopy (EDX). By changing the composition, the overall optical properties of the CdSe QDs can be manipulated. It was found that as the composition of the QDs changes from 1:1 (Cd:Se) CdSe to Cd-rich and then Se-rich CdSe, the band gap decreases along with a red shift of UV–vis absorption edges and photoluminescence (PL) peaks. The quantum yield also decreases with surface composition from 1:1 (Cd:Se) CdSe QDs to Cd-rich and then to Se-rich, largely due to the changes in the surface state. Because of the involvement of the surface defect or trapping state, the carrier life time increased from the 1:1 (Cd:Se) CdSe QDs to the Cd-rich to the Se-rich CdSe QDs. We have shown that the optical properties of CdSe QDs can be controlled by manipulating the composition of the surface atoms. This strategy can potentially be extended to other semiconductor nanocrystals to modify their properties.

  20. Controlling attribute effect in linear regression

    KAUST Repository

    Calders, Toon; Karim, Asim A.; Kamiran, Faisal; Ali, Wasif Mohammad; Zhang, Xiangliang

    2013-01-01

    In data mining we often have to learn from biased data, because, for instance, data comes from different batches or there was a gender or racial bias in the collection of social data. In some applications it may be necessary to explicitly control this bias in the models we learn from the data. This paper is the first to study learning linear regression models under constraints that control the biasing effect of a given attribute such as gender or batch number. We show how propensity modeling can be used for factoring out the part of the bias that can be justified by externally provided explanatory attributes. Then we analytically derive linear models that minimize squared error while controlling the bias by imposing constraints on the mean outcome or residuals of the models. Experiments with discrimination-aware crime prediction and batch effect normalization tasks show that the proposed techniques are successful in controlling attribute effects in linear regression models. © 2013 IEEE.

  1. Controlling attribute effect in linear regression

    KAUST Repository

    Calders, Toon

    2013-12-01

    In data mining we often have to learn from biased data, because, for instance, data comes from different batches or there was a gender or racial bias in the collection of social data. In some applications it may be necessary to explicitly control this bias in the models we learn from the data. This paper is the first to study learning linear regression models under constraints that control the biasing effect of a given attribute such as gender or batch number. We show how propensity modeling can be used for factoring out the part of the bias that can be justified by externally provided explanatory attributes. Then we analytically derive linear models that minimize squared error while controlling the bias by imposing constraints on the mean outcome or residuals of the models. Experiments with discrimination-aware crime prediction and batch effect normalization tasks show that the proposed techniques are successful in controlling attribute effects in linear regression models. © 2013 IEEE.

  2. Modelling the electrical properties of concrete for shielding effectiveness prediction

    International Nuclear Information System (INIS)

    Sandrolini, L; Reggiani, U; Ogunsola, A

    2007-01-01

    Concrete is a porous, heterogeneous material whose abundant use in numerous applications demands a detailed understanding of its electrical properties. Besides experimental measurements, material theoretical models can be useful to investigate its behaviour with respect to frequency, moisture content or other factors. These models can be used in electromagnetic compatibility (EMC) to predict the shielding effectiveness of a concrete structure against external electromagnetic waves. This paper presents the development of a dispersive material model for concrete out of experimental measurement data to take account of the frequency dependence of concrete's electrical properties. The model is implemented into a numerical simulator and compared with the classical transmission-line approach in shielding effectiveness calculations of simple concrete walls of different moisture content. The comparative results show good agreement in all cases; a possible relation between shielding effectiveness and the electrical properties of concrete and the limits of the proposed model are discussed

  3. Physical property control in core/shell inorganic nanostructures for fluorescence and magnetic targeting applications

    Science.gov (United States)

    Roberts, Stephen K.

    Nanomaterials show immense promise for the future in numerous areas of application. Properties that are unique from the bulk material and are tunable allow for innovation in material design. This thesis will focus on controlling the physical properties of core/shell nanostructures to enhance the utility of the materials. The first focus is on the impact of different solvent mixtures during the shell growth phase of SILAR based core/shell quantum dot synthesis is studied. Gaining insight into the mechanism for SILAR growth of core/shell nanoparticles allows improved synthetic yields and precursor binding, providing enhanced control to synthesis of core/shell nanoparticles. The second focus of this thesis is exploring the use of magnetic nanoparticles for magnetic drug targeting for cardiovascular conditions. Magnetic targeting for drug delivery enables increased local drug concentration, while minimizing non-specific interactions. In order to be effective for magnetic targeting, it must be shown that low magnetic strength is sufficient to capture flowing nanoparticles. By demonstrating the binding of a therapeutic agent to the surface at medicinal levels, the viability for use as a nanoparticle drug delivery system is improved.

  4. Controlling microstructure of pentacene derivatives by solution processing: impact of structural anisotropy on optoelectronic properties.

    Science.gov (United States)

    James, David T; Frost, Jarvist M; Wade, Jessica; Nelson, Jenny; Kim, Ji-Seon

    2013-09-24

    The consideration of anisotropic structural properties and their impact on optoelectronic properties in small-molecule thin films is vital to understand the performance of devices incorporating crystalline organic semiconductors. Here we report on the important relationship between structural and optoelectronic anisotropy in aligned, functionalized-pentacene thin films fabricated using the solution-based zone-casting technique. The microstructure of thin films composed of 6,13-bis(triisopropylsilylethynyl)pentacene (TIPS-pentacene) and 6,13-bis(triethylsilylethynyl)pentacene (TES-pentacene) is systematically controlled by varying the casting speed. By controlling the structural alignment, we were able to experimentally decouple, for the first time in these films, an intramolecular absorption transition dipole (at ∼440 nm) oriented close to the pentacene short axis and an intermolecular absorption transition dipole (at ∼695 nm) oriented predominantly along the conjugated pentacene-pentacene core stacking axis (crystallographic a-axis) in both films. Using the intermolecular absorption as a signature for intermolecular delocalization, much higher optical dichroism was obtained in TES-pentacene (16 ± 6) than TIPS-pentacene (3.2 ± 0.1), which was attributed to the 1D packing structure of TES-pentacene compared to the 2D packing structure of TIPS-pentacene. This result was also supported by field-effect mobility anisotropy measurements of the films, with TES-pentacene exhibiting a higher anisotropy (∼21-47, depending on the casting speed) than TIPS-pentacene (∼3-10).

  5. Size Effect of Defects on the Mechanical Properties of Graphene

    Science.gov (United States)

    Park, Youngho; Hyun, Sangil

    2018-03-01

    Graphene, a two-dimensional material, has been studied and utilized for its excellent material properties. In reality, achieving a pure single-crystalline structure in graphene is difficult, so usually graphene may have various types of defects in it. Vacancies, Stone-Wales defects, and grain boundaries can drastically change the material properties of graphene. Graphene with vacancy defects has been of interest because it is a two-dimensional analogy of three-dimensional porous materials. It has efficient material properties, and can function as a part of modern devices. The mechanical properties have been studied by using molecular dynamics for either a single vacancy defect with various sizes or multiple vacancy defects with same defect ratios. However, it is not clear which one has more influence on the mechanical properties between the size of the defects and the defect ratio. Therefore, we investigated the hole-size effect on the mechanical properties of single-crystalline graphene at various defect ratios. A void defect with large size can have a rather high tensile modulus with a low fracture strain compared to a void defect with small size. We numerically found that the tensile properties of scattered single vacancies is similar to that of amorphous graphene. We suspect that this is due to the local orbital change of the carbon atoms near the boundary of the void defects, so-called the interfacial phase.

  6. 48 CFR 2945.104 - Review and correction of contractors' property control systems.

    Science.gov (United States)

    2010-10-01

    ... 48 Federal Acquisition Regulations System 7 2010-10-01 2010-10-01 false Review and correction of... contractors' property control systems. When the Government's property administrator determines that review and... administrator must review the system to determine whether the contractor will be able to meet the requirements...

  7. Effect of the crone suspension control system on braking

    Energy Technology Data Exchange (ETDEWEB)

    Moreau, X.; Oustaloup, A. [Bordeaux-1 Univ., Talence (France). Lab. d' Automatique et de Productique; Nouillant, C. [Bordeaux-1 Univ., Talence (France). Lab. d' Automatique et de Productique]|[DRIA-PSA Peugeot Citroen, Velizy - Villacoublay (France)

    2001-07-01

    Semi-active or active suspensions not only increase driving comfort, but also permit the control system to be switched over if required in order to improve the transmission of forces at the points of contact between tire and road surface by minimizing the dynamic wheel loads. It may also be possible to use these systems to control wheel load distribution and, thus, influence braking or steering performance by changing the distribution of normal forces between the front and rear axles. This article examines the effect of the CRONE suspension control system on braking. The central idea is to use continuously variable dampers and fast load levelling devices to distribute the normal forces of tire between the front and rear axles. The basis principle is explained using known dynamic properties of active suspension, vehicles and tires. The effect of active suspension on vehicle response during braking is then evaluated using computer simulations from a two-wheel vehicle model. (orig.)

  8. Fetal health locus of control: Scale properties and applications in preconception health programs.

    Science.gov (United States)

    Soliday, Elizabeth; Strahm, Anna; Mammenga, Stefani

    2016-04-01

    Preconception health programs have resulted in improved health behaviors among participants and have shown promise in reducing adverse birth outcomes. However, the role of health beliefs in preconception health program outcomes has been overlooked but warrants attention due to reported positive associations between women's views of control over fetal health and health behavior in pregnancy. Towards an ultimate aim of improving preconception health program reach and effectiveness, we examined properties of a fetal health locus of control (FHLC; Labs & Wurtele, 1986) measure in nulliparous, childbearing aged university women and men. Students (n=1467) completed an online survey that included the FHLC subscales maternal, powerful others', and chance control over fetal health. Factor analyses and correlations with related scales supported the soundness of FHLC constructs in both women and men. All participants rated maternal control in fetal health nearly twice as highly as powerful others' and chance. We therefore recommend that FHLC be integrated into preconception health program evaluation as personal agency in fetal health likely has an important role in women's and men's preconception health behavior and health behavior change. Copyright © 2015 Elsevier Ltd. All rights reserved.

  9. Waterproofing of porous carbonate rocks: Efficiency-controlling its properties

    Directory of Open Access Journals (Sweden)

    Esbert, R. M.

    1995-03-01

    Full Text Available The aim of this study is to establish which physical properties may be used, in a routine way, in order to know the efficacy rate of a treatment applied on a specific rocky substrate. Whit this purpose, two types of carbonated rocks, the limestone of Hontoria (Burgos and the dolomite of Laspra (Asturias have been chosen, with a very different configuration of their porosity systems. Three protection products, with silico-organic nature and widely used have been used, to wit: two siloxenes and a copolymer. Tue properties chosen (contact angle and water vapour permeability have been the proper ones in order to determine the efficacy level of the different treatments. This level was demonstrated to be conditioned by the chemical characteristics of this product, and the influence of the characteristics is practically null. Other investigations are being carried out with the same rocks and treatment products in order to establish the corelationships between the efficacy rate of these treatments and the durability of the rock-treatment systems.

    La finalidad del presente estudio es la de tratar de establecer que propiedades físicas pueden ser empleadas de una forma rutinaria para conocer el grado de eficacia de un tratamiento aplicado sobre un determinado sustrato pétreo. Con esta finalidad se han seleccionado dos tipos de rocas carbonatadas, la caliza de Hontoria (Burgos y la dolomía de Laspra (Asturias, con una configuración del sistema poroso muy diferente. Se han empleado tres productos protectores de naturaleza silicoorgánica, ampliamente utilizados, dos siloxanos y un copolímero. Las propiedades seleccionadas (ángulo de contado y permeabilidad al vapor de agua han resultado idóneas para determinar el grado de eficacia de los distintos tratamientos. Se ha comprobado que dicho grado está condicionado por las características químicas del producto, siendo prácticamente nula la influencia de las características de la roca. Se

  10. Effect of extrusion processing on the microstructure, mechanical properties, biocorrosion properties and antibacterial properties of Ti-Cu sintered alloys.

    Science.gov (United States)

    Zhang, Erlin; Li, Shengyi; Ren, Jing; Zhang, Lan; Han, Yong

    2016-12-01

    Ti-Cu sintered alloys, Ti-Cu(S) alloy, have exhibited good anticorrosion resistance and strong antibacterial properties, but low ductility in previous study. In this paper, Ti-Cu(S) alloys were subjected to extrusion processing in order to improve the comprehensive property. The phase constitute, microstructure, mechanical property, biocorrosion property and antibacterial activity of the extruded alloys, Ti-Cu(E), were investigated in comparison with Ti-Cu(S) by X-ray diffraction (XRD), optical microscopy (OM), scanning electronic microscopy (SEM) with energy disperse spectroscopy (EDS), mechanical testing, electrochemical testing and plate-count method in order to reveal the effect of the extrusion process. XRD, OM and SEM results showed that the extrusion process did not change the phase constitute but refined the grain size and Ti2Cu particle significantly. Ti-Cu(E) alloys exhibited higher hardness and compressive yield strength than Ti-Cu(S) alloys due to the fine grain and Ti2Cu particles. With the consideration of the total compressive strain, it was suggested that the extrusion process could improve the ductility of Ti-Cu alloy(S) alloys. Electrochemical results have indicated that the extrusion process improved the corrosion resistance of Ti-Cu(S) alloys. Plate-count method displayed that both Ti-Cu(S) and Ti-Cu(E) exhibited strong antibacterial activity (>99%) against S. aureus. All these results demonstrated that hot forming processing, such as the extrusion in this study, refined the microstructure and densified the alloy, in turn improved the ductility and strength as well as anticorrosion properties without reduction in antibacterial properties. Copyright © 2016 Elsevier B.V. All rights reserved.

  11. Frequency Properties Research of Elevator Drive System with Direct Torque Control-Pulse with Modulation

    Directory of Open Access Journals (Sweden)

    A. S. Koval

    2008-01-01

    Full Text Available In the article problems of frequency properties research for electric drive system with direct torque control and pulse width modulator are described. The mathematical description of elevator is present. Simplified mathematical description of direct torque control - pulse width modulator electric drive system is shown. Transfer functions for torque and speed loops are determined. Logarithmic frequency characteristics are computed. Damping properties of elevator drive system are estimated.

  12. Food Service Guideline Policies on State Government-Controlled Properties.

    Science.gov (United States)

    Zaganjor, Hatidza; Bishop Kendrick, Katherine; Warnock, Amy Lowry; Onufrak, Stephen; Whitsel, Laurie P; Ralston Aoki, Julie; Kimmons, Joel

    2016-09-13

    Food service guideline (FSG) policies can impact millions of daily meals sold or provided to government employees, patrons, and institutionalized persons. This study describes a classification tool to assess FSG policy attributes and uses it to rate FSG policies. Quantitative content analysis. State government facilities in the United States. Participants were from 50 states and District of Columbia in the United States. Frequency of FSG policies and percentage alignment to tool. State-level policies were identified using legal research databases to assess bills, statutes, regulations, and executive orders proposed or adopted by December 31, 2014. Full-text reviews were conducted to determine inclusion. Included policies were analyzed to assess attributes related to nutrition, behavioral supports, and implementation guidance. A total of 31 policies met the inclusion criteria; 15 were adopted. Overall alignment ranged from 0% to 86%, and only 10 policies aligned with a majority of the FSG policy attributes. Western states had the most FSG policies proposed or adopted (11 policies). The greatest number of FSG policies were proposed or adopted (8 policies) in 2011, followed by the years 2013 and 2014. The FSG policies proposed or adopted through 2014 that intended to improve the food and beverage environment on state government property vary considerably in their content. This analysis offers baseline data on the FSG landscape and information for future FSG policy assessments. © The Author(s) 2016.

  13. Food Service Guideline Policies on State Government Controlled Properties

    Science.gov (United States)

    Zaganjor, Hatidza; Bishop Kendrick, Katherine; Warnock, Amy Lowry; Onufrak, Stephen; Whitsel, Laurie P.; Ralston Aoki, Julie; Kimmons, Joel

    2017-01-01

    Purpose Food service guidelines (FSG) policies can impact millions of daily meals sold or provided to government employees, patrons, and institutionalized persons. This study describes a classification tool to assess FSG policy attributes and uses it to rate FSG policies. Design Quantitative content analysis. Setting State government facilities in the U.S. Subjects 50 states and District of Columbia. Measures Frequency of FSG policies and percent alignment to tool. Analysis State-level policies were identified using legal research databases to assess bills, statutes, regulations, and executive orders proposed or adopted by December 31, 2014. Full-text reviews were conducted to determine inclusion. Included policies were analyzed to assess attributes related to nutrition, behavioral supports, and implementation guidance. Results A total of 31 policies met inclusion criteria; 15 were adopted. Overall alignment ranged from 0% to 86%, and only 10 policies aligned with a majority of FSG policy attributes. Western States had the most FSG policy proposed or adopted (11 policies). The greatest number of FSG policies were proposed or adopted (8 policies) in 2011, followed by the years 2013 and 2014. Conclusion FSG policies proposed or adopted through 2014 that intended to improve the food and beverage environment on state government property vary considerably in their content. This analysis offers baseline data on the FSG landscape and information for future FSG policy assessments. PMID:27630113

  14. Controlling of morphology and electrocatalytic properties of cobalt oxide nanostructures prepared by potentiodynamic deposition method

    Energy Technology Data Exchange (ETDEWEB)

    Hallaj, Rahman [Department of Chemistry, University of Kurdistan, P.O. Box 416, Sanandaj (Iran, Islamic Republic of); Akhtari, Keivan [Department of Chemistry, University of Kurdistan, P.O. Box 416, Sanandaj (Iran, Islamic Republic of); Research Center for Nanotechnology, University of Kurdistan, P.O.Box 416, Sanandaj (Iran, Islamic Republic of); Salimi, Abdollah, E-mail: absalimi@uok.ac.ir [Department of Chemistry, University of Kurdistan, P.O. Box 416, Sanandaj (Iran, Islamic Republic of); Research Center for Nanotechnology, University of Kurdistan, P.O.Box 416, Sanandaj (Iran, Islamic Republic of); Soltanian, Saied [Department of Physics, University of Kurdistan, P.O. Box 416, Sanandaj (Iran, Islamic Republic of)

    2013-07-01

    Electrodeposited cobalt oxide nanostructures were prepared by Repetitive Triangular Potential Scans (RTPS) as a simple, remarkably fast and scalable potentiodynamic method. Electrochemical deposition of cobalt oxide nanostructures onto GC electrode was performed from aqueous Co(NO{sub 3}){sub 2}, (pH 6) solution using cyclic voltammetry method. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) were used to characterize the morphology of fabricated nanostructures. The evaluation of electrochemical properties of deposited films was performed using cyclic voltametry (CV) and impedance spectroscopy (IS) techniques. The analysis of the experimental data clearly showed that the variations of potential scanning ranges during deposition process have drastic effects on the geometry, chemical structure and particle size of cobalt oxide nanoparticles. In addition, the electrochemical and electrocatalytic properties of prepared nanostructures can be controlled through applying different potential windows in electrodeposition process. The imaging and voltammetric studies suggested to the existence of at least three different shapes of cobalt-oxide nanostructures in various potential windows applied for electrodeposition. With enlarging the applied potential window, the spherical-like cobalt oxide nanoparticles with particles sizes about 30–50 nm changed to the grain-like structures (30 nm × 80 nm) and then to the worm-like cobalt oxide nanostructures with 30 nm diameter and 200–400 nm in length. Furthermore, the roughness of the prepared nanostructures increased with increasing positive potential window. The GC electrodes modified with cobalt oxide nanostructures shows excellent electrocatalytic activity toward H{sub 2}O{sub 2} and As (III) oxidation. The electrocatalytic activity of cobalt oxide nanostructures prepared at more positive potential window toward hydrogen peroxide oxidation was increased, while for As(III) oxidation the electrocatalytic

  15. Controlling of morphology and electrocatalytic properties of cobalt oxide nanostructures prepared by potentiodynamic deposition method

    International Nuclear Information System (INIS)

    Hallaj, Rahman; Akhtari, Keivan; Salimi, Abdollah; Soltanian, Saied

    2013-01-01

    Electrodeposited cobalt oxide nanostructures were prepared by Repetitive Triangular Potential Scans (RTPS) as a simple, remarkably fast and scalable potentiodynamic method. Electrochemical deposition of cobalt oxide nanostructures onto GC electrode was performed from aqueous Co(NO 3 ) 2 , (pH 6) solution using cyclic voltammetry method. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) were used to characterize the morphology of fabricated nanostructures. The evaluation of electrochemical properties of deposited films was performed using cyclic voltametry (CV) and impedance spectroscopy (IS) techniques. The analysis of the experimental data clearly showed that the variations of potential scanning ranges during deposition process have drastic effects on the geometry, chemical structure and particle size of cobalt oxide nanoparticles. In addition, the electrochemical and electrocatalytic properties of prepared nanostructures can be controlled through applying different potential windows in electrodeposition process. The imaging and voltammetric studies suggested to the existence of at least three different shapes of cobalt-oxide nanostructures in various potential windows applied for electrodeposition. With enlarging the applied potential window, the spherical-like cobalt oxide nanoparticles with particles sizes about 30–50 nm changed to the grain-like structures (30 nm × 80 nm) and then to the worm-like cobalt oxide nanostructures with 30 nm diameter and 200–400 nm in length. Furthermore, the roughness of the prepared nanostructures increased with increasing positive potential window. The GC electrodes modified with cobalt oxide nanostructures shows excellent electrocatalytic activity toward H 2 O 2 and As (III) oxidation. The electrocatalytic activity of cobalt oxide nanostructures prepared at more positive potential window toward hydrogen peroxide oxidation was increased, while for As(III) oxidation the electrocatalytic activity decreased

  16. Effects of irradiation on the gelation properties of muscle protein

    International Nuclear Information System (INIS)

    Lin Xianping; Yang Wenge

    2014-01-01

    Gel properties of muscle protein are the important functional characteristics in meat and its products. which determine the meat products' unique quality. such as texture. Juiciness. fat content and sensory characteristics As a novel food preservation technique, irradiation may lead to changes in the composition and structure of protein molecule. and impact the gel forming ability and gelation properties of muscle protein. Based on the introduction of gel forming mechanism of muscle protein, effects of irradiation on the water holding capacity, mechanical properties and structure of muscle protein gel were reviewed in detail. High-dose irradiation could weaken the water holding capacity of muscle protein and result in the loss of meat juice. With different irradiation conditions or raw materials, influences of irradiation on the texture and theological properties of muscle protein gels are varied, and effects on the structure of muscle protein and its gel are more complex. Finally, the research trend of irradiation effects on the gelation properties of muscle protein is put forward. (authors)

  17. By passing microbial resistance: xylitol controls microorganisms growth by means of its anti-adherence property.

    Science.gov (United States)

    Ferreira, Aline S; Silva-Paes-Leme, Annelisa F; Raposo, Nádia R B; da Silva, Sílvio S

    2015-01-01

    Xylitol is an important polyalcohol suitable for use in odontological, medical and pharmaceutical products and as an additive in food. The first studies on the efficacy of xylitol in the control and treatment of infections started in the late 1970s and it is still applied for this purpose, with safety and very little contribution to resistance. Xylitol seems to act against microorganisms exerting an anti-adherence effect. Some research studies have demonstrated its action against Gram-positive and Gram-negative bacteria and yeasts. However, a clear explanation of how xylitol is effective has not been completely established yet. Some evidence shows that xylitol acts on gene expression, down-regulating the ones which are involved in the microorganisms' virulence, such as capsule formation. Another possible clarification is that xylitol blocks lectin-like receptors. The most important aspect is that, over time, xylitol bypasses microbial resistance and succeeds in controlling infection, either alone or combined with another compound. In this review, the effect of xylitol in inhibiting the growth of a different microorganism is described, focusing on studies in which such an anti-adherent property was highlighted. This is the first mini-review to describe xylitol as an anti-adherent compound and take into consideration how it exerts such action.

  18. Controlled release of antibiotics encapsulated in the electrospinning polylactide nanofibrous scaffold and their antibacterial and biocompatible properties

    International Nuclear Information System (INIS)

    Wang, Shu-Dong; Zhang, Sheng-Zhong; Liu, Hua; Zhang, You-Zhu

    2014-01-01

    In this research, the drug loaded polylactide nanofibers are fabricated by electrospinning. Morphology, microstructure and mechanical properties are characterized. Properties and mechanism of the controlled release of the nanofibers are investigated. The results show that the drug loaded polylactide nanofibers do not show dispersed phase, and there is a good compatibility between polylactide and drugs. FTIR spectra show that drugs are encapsulated inside the polylactide nanofibers, and drugs do not break the structure of polylcatide. Flexibility of drug loaded polylactide scaffolds is higher than that of the pure polylactide nanofibers. Release rate of the drug loaded nanofibers is significantly slower than that of the drug powder. Release rate increases with the increase of the drugs’ concentration. The research mechanism suggests a typical diffusion-controlled release of the three loaded drugs. Antibacterial and cell culture show that drug loaded nanofibers possess effective antibacterial activity and biocompatible properties. (papers)

  19. Controlled synthesis and magnetic properties of monodispersed ceria nanoparticles

    Directory of Open Access Journals (Sweden)

    Sumeet Kumar

    2015-02-01

    Full Text Available In the present study, monodispersed CeO2 nanoparticles (NPs of size 8.5 ± 1.0, 11.4 ± 1.0 and 15.4 ± 1.0 nm were synthesized using the sol-gel method. Size-dependent structural, optical and magnetic properties of as-prepared samples were investigated by X-ray diffraction (XRD, field emission scanning electron microscope (FE-SEM, high resolution transmission electron microscopy (HR-TEM, ultra-violet visible (UV-VIS spectroscopy, Raman spectroscopy and vibrating sample magnetometer (VSM measurements. The value of optical band gap is calculated for each particle size. The decrease in the value of optical band gap with increase of particle size may be attributed to the quantum confinement, which causes to produce localized states created by the oxygen vacancies due to the conversion of Ce4+ into Ce3+ at higher calcination temperature. The Raman spectra showed a peak at ∼461 cm-1 for the particle size 8.5 nm, which is attributed to the 1LO phonon mode. The shift in the Raman peak could be due to lattice strain developed due to variation in particle size. Weak ferromagnetism at room temperature is observed for each particle size. The values of saturation magnetization (Ms, coercivity (Hc and retentivity (Mr are increased with increase of particle size. The increase of Ms and Mr for larger particle size may be explained by increase of density of oxygen vacancies at higher calcination temperature. The latter causes high concentrations of Ce3+ ions activate more coupling between the individual magnetic moments of the Ce ions, leading to an increase of Ms value with the particle size. Moreover, the oxygen vacancies may also produce magnetic moment by polarizing spins of f electrons of cerium (Ce ions located around oxygen vacancies, which causes ferromagnetism in pure CeO2 samples.

  20. Effect of glycemic control on diabetic dyslipidemia

    International Nuclear Information System (INIS)

    Ahmed, W.; Arshad, A.R.

    2010-01-01

    To determine whether good glycemic control has an effect on lipid profile in diabetics After taking relevant history and physical examination, serum urea, creatinine, thyroid stimulating hormone, bilirubin, alanine transaminase and HbA1c were measured. Blood samples for determination of fasting plasma glucose, serum total cholesterol, triglycerides, HDL and LDL levels were collected in a fasting state. Patients were divided into two groups based on HbA1c levels. They were compared using SPSS 13. 42 patients had good glycemic control and 58 had poor control. The two groups were age and weight matched. 43 patients had abnormal lipid profiles. Serum total cholesterol and triglycerides were lower and HDL levels higher in the good control group but serum LDL levels were equal. Conclusion: Good glycemic control improves lipid profile in patients with type 2 diabetes mellitus. (author)

  1. Effect of glycemic control on diabetic dyslipidemia

    Energy Technology Data Exchange (ETDEWEB)

    Ahmed, W [Military Hospital Rawalpindi, Rawalpindi (Pakistan); Arshad, A R [Combined Military Hospital, Lahore (Pakistan)

    2010-03-15

    To determine whether good glycemic control has an effect on lipid profile in diabetics After taking relevant history and physical examination, serum urea, creatinine, thyroid stimulating hormone, bilirubin, alanine transaminase and HbA1c were measured. Blood samples for determination of fasting plasma glucose, serum total cholesterol, triglycerides, HDL and LDL levels were collected in a fasting state. Patients were divided into two groups based on HbA1c levels. They were compared using SPSS 13. 42 patients had good glycemic control and 58 had poor control. The two groups were age and weight matched. 43 patients had abnormal lipid profiles. Serum total cholesterol and triglycerides were lower and HDL levels higher in the good control group but serum LDL levels were equal. Conclusion: Good glycemic control improves lipid profile in patients with type 2 diabetes mellitus. (author)

  2. Optical properties of individual site-controlled Ge quantum dots

    Energy Technology Data Exchange (ETDEWEB)

    Grydlik, Martyna, E-mail: moritz.brehm@jku.at, E-mail: martyna.grydlik@jku.at [Institute of Semiconductor and Solid State Physics, Johannes Kepler University Linz, Altenbergerstrasse 69, 4040 Linz (Austria); Institute for Integrative Nanosciences, IFW Dresden, Helmholtzstr. 20, Dresden 01069 (Germany); Center for Advancing Electronics Dresden, CfAED, TU Dresden (Germany); Brehm, Moritz, E-mail: moritz.brehm@jku.at, E-mail: martyna.grydlik@jku.at [Institute of Semiconductor and Solid State Physics, Johannes Kepler University Linz, Altenbergerstrasse 69, 4040 Linz (Austria); Institute for Integrative Nanosciences, IFW Dresden, Helmholtzstr. 20, Dresden 01069 (Germany); Tayagaki, Takeshi [Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011 (Japan); Research Center for Photovoltaics, National Institute of Advanced Industrial Science and Technology, 1-1-1 Umezono, Tsukuba, Ibaraki 305-8568 (Japan); Langer, Gregor; Schäffler, Friedrich [Institute of Semiconductor and Solid State Physics, Johannes Kepler University Linz, Altenbergerstrasse 69, 4040 Linz (Austria); Schmidt, Oliver G. [Institute for Integrative Nanosciences, IFW Dresden, Helmholtzstr. 20, Dresden 01069 (Germany); Center for Advancing Electronics Dresden, CfAED, TU Dresden (Germany)

    2015-06-22

    We report photoluminescence (PL) experiments on individual SiGe quantum dots (QDs) that were epitaxially grown in a site-controlled fashion on pre-patterned Si(001) substrates. We demonstrate that the PL line-widths of single QDs decrease with excitation power to about 16 meV, a value that is much narrower than any of the previously reported PL signals in the SiGe/Si heterosystem. At low temperatures, the PL-intensity becomes limited by a 25 meV high potential-barrier between the QDs and the surrounding Ge wetting layer (WL). This barrier impedes QD filling from the WL which collects and traps most of the optically excited holes in this type-II heterosystem.

  3. Output Feedback Stabilization with Nonlinear Predictive Control: Asymptotic properties

    Directory of Open Access Journals (Sweden)

    Lars Imsland

    2003-07-01

    Full Text Available State space based nonlinear model predictive control (NM PC needs the state for the prediction of the system behaviour. Unfortunately, for most applications, not all states are directly measurable. To recover the unmeasured states, typically a stable state observer is used. However, this implies that the stability of the closed-loop should be examined carefully, since no general nonlinear separation principle exists. Recently semi-global practical stability results for output feedback NMPC using a high-gain observer for state estimation have been established. One drawback of this result is that (in general the observer gain must be increased, if the desired set the state should converge to is made smaller. We show that under slightly stronger assumptions, not only practical stability, but also convergence of the system states and observer error to the origin for a sufficiently large but bounded observer gain can be achieved.

  4. Analysis of physical properties controlling steady-state infiltration rates on tropical savannah soils

    International Nuclear Information System (INIS)

    Mbagwu, J.S.C.

    1993-10-01

    A knowledge of physical properties influencing the steady-state infiltration rates (ic) of soils is needed for the hydrologic modelling of the infiltration process. In this study evidence is provided to show that effective porosity (Pe) (i.e. the proportion of macro pore spaces with equivalent radius of > 15 μm) and dry bulk density are the most important soil physical properties controlling the steady-state infiltration rates on a tropical savannah with varying land use histories. At a macro porosity value of ≤ 5.0% the steady-state infiltration rate is zero. Total porosity and the proportion of water-retaining pores explained only a small fraction of the variation in this property. Steady-state infiltration rates can also be estimated from either the saturated hydraulic conductivity (Ks) by the equation, i c = 31.1 + 1.06 (Ks), (R 2 = 0.8104, p ≤ 0.001) or the soil water transmissivity (A) by the equation, i c = 30.0 + 29.9(A), (R 2 = 0.8228, ρ ≤ 0.001). The Philip two-parameter model under predicted steady-state infiltration rates generally. Considering the ease of determination and reliability it is suggested that effective porosity be used to estimate the steady-state infiltration rates of these other soils with similar characteristics. The model is, i c 388.7(Pe) - 10.8(R 2 = 0.7265, p ≤ 0.001) where i c is in (cm/hr) and Pe in (cm 3 /cm 3 ). (author). 20 refs, 3 figs, 4 tabs

  5. Effect of machining damage on tensile properties of beryllium

    International Nuclear Information System (INIS)

    Hanafee, J.E.

    1976-01-01

    It is well established that damage introduced at the surface of beryllium during machining operations can lower its mechanical properties. Tensile tests were conducted to illustrate this on beryllium presently being used for parts in the W79 program and similar to the new powder-processed beryllium specified for production (tentative specification MEL 76-001319). The objective of this study is to quantitatively illuminate the importance of controlling machining damage in this particular grade of powder-processed beryllium

  6. Effects of a Chitosan Coating Layer on the Surface Properties and Barrier Properties of Kraft Paper

    Directory of Open Access Journals (Sweden)

    Shanhui Wang

    2016-01-01

    Full Text Available Biodegradable chitosan can be applied as a coating on the surface of kraft paper in order to improve its barrier properties against water vapor and air. The food packaging industry can benefit from the addition of chitosan to its current packaging, and in turn reduce pollution from plastic packaging plants. This paper discusses the film formation of chitosan, the permeability of paper coated with a chitosan layer, and the influence on the paper’s surface and barrier properties under different process conditions. SEM (scanning electron microscope, AFM (atomic force microscope, ATR-FTIR (Fourier transmission infrared spectroscope with attenuated total reflection, and PDA (penetration dynamics analysis were used to analyze the properties of chitosan’s film formation and permeability. A controlled experiment showed that the chitosan layer was smoother than the surface of the uncoated kraft paper, had better film formation, and that there was no chitosan penetration through the kraft paper. The barrier properties against water vapor were strongest when there was a higher concentration of chitosan solution at the optimum pH, stirring speed, and those with a thicker coating on the kraft paper.

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

    Science.gov (United States)

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

    2015-12-01

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

  8. [Effect of soybean lipoxygenae on baking properties of wheat flour].

    Science.gov (United States)

    Permiakova, M D; Trufanov, V A

    2011-01-01

    Changes in bread-baking properties of wheat flour caused by soybean lipoxygenase and polyunsaturated fatty acids were studied. A positive effect of soybean flour added during dough kneading in an amount of 2% was demonstrated. A method for dough fermentation increasing the loaf volume and improving organoleptic characteristics and total bread-baking estimate is recommended.

  9. Effect of oxygen on the hydrogenation properties of magnesium films

    DEFF Research Database (Denmark)

    Ostenfeld, Christopher Worsøe; Chorkendorff, Ib

    2006-01-01

    The effect of magnesium oxide on the magnesium and hydrogen desorption properties of magnesium films have been investigated. We find that by capping metallic magnesium films with oxide overlayers the apparent desorption energy of magnesium is increased from 146 kJ/mol to 314 kJ/mol. The results...... are discussed in light of previous investigations of ball-milled magnesium powders....

  10. Effects of automobile battery wastes on physicochemical properties ...

    African Journals Online (AJOL)

    Difference in soil qualities has been noticeable in many soils due to anthropogenic sources, especially of automobile battery wastes. This study examines the effects of automobile battery wastes on the physicochemical properties of the soil. Soil samples for this study were collected in triplicates from three battery chargers' ...

  11. Effect of drying methods on the physicochemical properties of ...

    African Journals Online (AJOL)

    This study investigated the effects of sun drying and oven drying at three different temperatures (60 0C, 70 0C and 80 0C) on the physicochemical and sensory properties of waterleaf (Talinum triangulare). About 2000 g of freshly harvested leaves were obtained, sorted, chopped into small pieces and sub-divided into five ...

  12. Effect of Cassava Processing Effluent on Soil Properties, Growth and ...

    African Journals Online (AJOL)

    A study, comprising a survey, greenhouse and field experiments was conducted to examine the effect of Cassava Processing Effluent (CPE) on soil chemical properties, maize growth performances and grain yield. In the survey, soil samples were taken (0-15 and 15 – 30cm) of CPE contaminated and non contaminated ...

  13. Effect of animal manures on selected soil chemical properties (1 ...

    African Journals Online (AJOL)

    The effects of animal manures on selected soil properties were studied in the laboratory. Manures of Rabbit (RBM), Swine (SWM), Poultry (POM), Goat, (GTM) and Cow (COM) were added at 10, 20, 30 and 40 t/ha to an acidic Ultisol. The amended soils were incubated at 70% water holding capacity for 3 weeks.

  14. Geotechnical Properties of Makurdi Shale and Effects on Foundations

    African Journals Online (AJOL)

    Geotechnical Properties of Makurdi Shale and Effects on Foundations. IO Agbede, P Smart ... Ten disturbed soil samples were collected from a third site of a proposed site for a light building and subjected to engineering classification tests. Based on the outcome of the second set of experiments, a foundation other than the ...

  15. Effect of skin tumor properties on laser penetration

    CSIR Research Space (South Africa)

    Karsten, AE

    2009-06-01

    Full Text Available Computer modeling can be a valuable tool to determine the absorption of laser light in different skin layers. For this study, the optical properties of three different skin tumors were used in the model to evaluate the effect on penetration depth...

  16. The Effects of Moisture Content on Mechanical Properties of Soybean

    African Journals Online (AJOL)

    Some mechanical properties were determined for four varieties of soybean (TGX 297-129C, Samsoy1, TGX 306-636C and TGX 536-02D). The hardness, compressive and tensile strength determination were carried out using a Rockwell Hardness machine and tensometer. The effect of moisture content on the hardness ...

  17. Effects of carbonization conditions on properties of bamboo pellets

    Science.gov (United States)

    Zhijia Liu; Zehui Jiang; Zhiyong Cai; Benhua Fei; Yan Yu; Xing' e Liu

    2013-01-01

    Bamboo is a biomass material and has great potential as a bio-energy resource of the future in China. Bamboo pellets were successfully manufactured using a laboratory pellet mill in preliminary work. This study was therefore carried out to investigate the effect of carbonization conditions (temperature and time) on properties of bamboo pellets and to evaluate product...

  18. Effect of Honey as Partial Sugar Substitute on Pasting Properties ...

    African Journals Online (AJOL)

    The effect of partial substitution of sugar with liquid honey on the pasting properties of cooked dough made from cassava-wheat composite (10:90) flour as well as the sensory preference and shelf stability of its bread was investigated. Sucrose (S) in the bread recipe formulation was substituted with honey (H) at levels 0, 10, ...

  19. Effects of iron supply on the rheological properties and sensory ...

    African Journals Online (AJOL)

    The most basic is the world wheat crops. In Iran Bread is a staple food staple Food and because, as a bearer of good food to enrich bread with iron has been considered. The effect of flour fortification star with iron, folic acid, the chemical properties (dry gluten, wet gluten, gluten-free number, protein and Ddzlny) Rheological ...

  20. Effect of annealing time on structural and magnetic properties of ...

    Indian Academy of Sciences (India)

    We studied the effects on the structural and magnetic properties of Fe3O4 thin films. The films have been characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and vibrating sample magnetometry (VSM). XRD studies showed pure single phase spinel cubic structure of Fe3O4 with a preferential [111] ...

  1. Effect of animal manures on soil properties, growth, nutrients status ...

    African Journals Online (AJOL)

    A comparative field study was carried out at two sites in Akure, Southwest Nigeria to determine effect of different animal manures on soil physical and chemical properties and performance of tomato (Lycopersicm esculentus Mill). Analysis of cattle (CM), goat (GM), pig (PG) and poultry (PM) manures showed that N, K, Ca ...

  2. Effect of Bulk and Interfacial Rheological Properties on Bubble Dissolution

    NARCIS (Netherlands)

    Kloek, W.; Vliet, van T.; Meinders, M.

    2001-01-01

    This paper describes theoretical calculations of the combined effect of bulk and interracial rheological properties on dissolution behavior of a bubble in an infinite medium at saturated conditions. Either bulk or interracial elasticity can stop the bubble dissolution process, and stability criteria

  3. Effect of surfactants on the mechanical properties of acetaminophen ...

    African Journals Online (AJOL)

    The purpose of this study was to investigate the effect of non ionic surfactant on the mechanical properties of acetaminophen-wax matrix tablet and hence its implication on dissolution profile. Acetaminophen-wax matrix granules were prepared by melt granulation technique. This was formed by triturating acetaminophen ...

  4. Effect of Cement Grades on some properties of Sandcrete ...

    African Journals Online (AJOL)

    The purpose of this study is to investigate the effects of cement grade on some properties of sandcrete. The cement used for this work was Ordinary Portland cement (Dangote brand) of grade 42.5 and 32.5 meeting the requirement of ASTM C150 type 1 cement. Three types of fine aggregate was also used to produce ...

  5. Effect of acrylic acid on the properties of polyvinylpyrrolidone ...

    African Journals Online (AJOL)

    Hydrogels based on polyvinylpyrrolidone (PVP) networks grafted with acrylic acid (AAc) was prepared by using γ-rays from a Co-60 source at room temperature. The parameters like effect of radiation dose and concentration of AAc were studied. The properties such as gel content, swelling behavior and thermal stability ...

  6. Effect of heat treatment on structure and magnetic properties

    Indian Academy of Sciences (India)

    Fe46Co35Ni19/CNTs nanocomposites have been prepared by an easy two-step route including adsorption and heat treatment processes. We investigated the effect of heat treatment conditions on structure, morphology, nanoparticle sizes and magnetic properties of the Fe46Co35Ni19 alloy nanoparticles attached on the ...

  7. Environmental Effects of Abandoned Properties in Ogbomoso and ...

    African Journals Online (AJOL)

    ... reptiles, accident and vagrancy. The brunt of abandonment is found to be more in the medium residential density. The study thus recommends an aggressive environmental management that offsets blighted conditions in the environment. Keywords: Effects, Buildings, Lots, Abandonment, Landed Properties, Environment ...

  8. Effect of biosolids application on soil chemical properties and uptake ...

    African Journals Online (AJOL)

    Effect of biosolids application on soil chemical properties and uptake of some heavy metals by Cercis siliquastrum. ... and municipal solid waste compost (50% CM + 50% MC) at three levels of 0, 2.5 and 5 kg/shrub and three replicates in calcareous sandy loam soil at the botanical garden of Mobarekeh steel company.

  9. Effects of irradiation on the physicochemical properties of carioca beans

    International Nuclear Information System (INIS)

    Lima, Damaris Carvalho

    2016-01-01

    The common bean is an important component in the diet of the average Brazilian person. Each harvest of beans, losses occur due to attacks of insects and rodents. One of the ways to preserve the beans, and at the same time keep its nutritional characteristics, is the use of gamma radiation. This study aimed to evaluate the effects of different doses of gamma radiation on the physical and chemical properties of the carioca variety of common beans subject to cooking of soaked and unsoaked beans. Portions of raw beans were used as control and the other was subject to ionizing radiation at doses of 1, 5 and 10 kGy. Following irradiation, a portion of the samples (control and irradiated) were soaked and the other was not, then all beans were cooked. The cooked samples were lyophilized, milled and then accommodated in pots and stored at -23 deg C temperatures. The analysis of chemical composition, determination of protein digestibility, condensed tannin and phytic acid content were performed using the milled samples. Using whole grains, were performed analysis of expansion capability and hydration, cooking time and instrumental color. Irradiation did not alter the chemical composition of soaked and unsoaked samples. The condensed tannin levels did not reduce according to increased doses. The phytic acid concentrations were reduced at the doses of 5 and 10 kGy for soaked samples, whereas for the not soaked beans, gamma irradiation did not influence the phytate content. The protein digestibility decreased on soaked samples, at doses of 1 kGy and in the other doses, the reduction was not significant. As for not soaked beans, increases in digestibility were observed at dose of 10 kGy. As the doses increased, reduction in cooking time on soaked and unsoaked beans was noted. At a dose of 10 kGy, the bean expansion capability increased. The samples' color did not change significantly, as the doses increased. Therefore, it is concluded that ionizing radiation has no effect

  10. Effect of notch and alloying on steel properties during extension

    International Nuclear Information System (INIS)

    Vinokur, B.B.; Pilyushenko, U.L.; Kasatkin, O.G.

    1985-01-01

    A study was made on change of strength and plastic characteristics during extension of notched steel samples of 15 compositions containing often-used alloying elements in various amounts and combinations. The notch causes increase of strength and decrease of plastic properties of structural steels during extension. The most pronounced change of properties takes place for the notched sample with expansion angle close to 180 deg. Reduction of notch expansion angle below 150 deg causes slower decrease of the rate of property change. Nickel alloying and vanadium, titanium microalloying assist the improvement of steel plasticity despite the increase of strength properties. Introduction of these elements in steel compensate partially for the negative notch effect. Alloying by silicon, molybdenum and tungsten results in steel strengthening and chromium alloying causes some loss of strength. Manse, chromium, silicon, molybdenum and tungsten cause decrease of plasticity, which intensifies the negative notch effect. When determining concentration ranges of carbon and alloying elements within the limits of quality composition it is necessary to consider both technology and possibility of sufficient change of properties especially in the case of stress concentrator presence in structures

  11. Synergistic effect of casein glycomacropeptide on sodium caseinate foaming properties.

    Science.gov (United States)

    Morales, R; Martinez, M J; Pilosof, A M R

    2017-11-01

    Several strategies to improve the interfacial properties and foaming properties of proteins may be developed; among them, the use of mixtures of biopolymers that exhibit synergistic interactions. The aim of the present work was to evaluate the effect of casein glycomacropeptide (CMP) on foaming and surface properties of sodium caseinate (NaCas) and to establish the role of protein interactions in the aqueous phase. To this end particles size, interfacial and foaming properties of CMP, NaCas and NaCas-CMP mixtures at pH 5.5 and 7 were determined. At both pH, the interaction between CMP and NaCas induced a decrease in the aggregation state of NaCas. Single CMP foams showed the highest and NaCas the lowest foam overrun (FO) and the mixture exhibited intermediate values. CMP foam quickly drained. The drainage profile of mixed foams was closer to NaCas foams; at pH 5.5, mixed foams drained even slower than NaCas foam, exhibiting a synergistic performance. Additionally, a strong synergism was observed on the collapse of mixed foams at pH 5.5. Finally, a model to explain the synergistic effect observed on foaming properties in CMP-NaCas mixtures has been proposed; the reduced aggregation state of NaCas in the presence of CMP, made it more efficient for foam stabilization. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. Elucidation and control of electronic properties related to organic semiconductors

    International Nuclear Information System (INIS)

    Yamane, Hiroyuki; Ueno, Nobuo; Seki, Kazuhiko

    2009-01-01

    The electronic structure of organic solids and interfaces plays a crucial role in the performance of optoelectronic devices using organic semiconductors such as light-emitting diodes, field-effect transistors, and photovoltaic cells. The functionality of these organic devices is seriously dominated by the geometric structure, which varies depending on the molecular structure and the sample preparation condition. Due to the rapid progress in sample preparation methods and surface science techniques, we can now discuss in detail the correlation of the electronic structure with the geometric structure of organic solids, films, and interfaces. This paper reviews the recent progress of studies in the geometric and electronic structures related to organic semiconductors. (author)

  13. Effect of ?-cyclodextrin on Rheological Properties of some Viscosity Modifiers

    OpenAIRE

    Rao, G. Chandra Sekhara; Ramadevi, K.; Sirisha, K.

    2014-01-01

    Cyclodextrins are a group of novel excipients, extensively used in the present pharmaceutical industry. Sometimes they show significant interactions with other conventional additives used in the formulation of dosage forms. The effect of β-cyclodextrin on the rheological properties of aqueous solutions of some selected viscosity modifiers was studied in the present work. β-cyclodextrin showed two different types of effects on the rheology of the selected polymers. In case of natural polymers ...

  14. Morphology Control of Platinum Nanoparticles and their Catalytic Properties

    International Nuclear Information System (INIS)

    Miyazaki, Akane; Balint, Ioan; Nakano, Yoshio

    2003-01-01

    Platinum nanoparticles with different morphology were prepared by reduction of K 2 PtCl 4 solution in the presence of different capping polymers. It was found that the shapes and the sizes of the Pt nanocrystals resulted were related to the kind of capping polymer used. When poly(vinylpyrrolidon) (PVP), poly(N-isopropylacrylamide) (NIPA) and sodium poly(acrylate) (SPA) were used as capping agents, the dominant shapes of the Pt nanocrystals observed by transmission electron microscopy were hexagonal (∼62%), square (∼67%) and triangular (∼41%), respectively. The average sizes of Pt nanocrystals were 6.9, 13.6 and 14.6 nm for capping polymers of PVP, NIPA and SPA, respectively. The colloidal Pt nanoparticles with different morphologies were supported on γ-Al 2 O 3 (1 wt.% Pt) and then their catalytic activity for NO reduction by CH 4 was tested in the 350-600 deg. C temperature range. Additionally, the catalytic activities of these alumina-supported Pt nanocrystals were compared with a conventional catalyst having the average size of Pt particles of ∼2.4 nm. Over the alumina-supported Pt nanocrystals as compared with the conventional Pt/Al 2 O 3 , it was observed that the NO/CH 4 reaction yields to NH 3 and CO decreased significantly and on the other hand, the yield to N 2 O increased. The experimental results are suggesting that the catalytic behavior can be tuned in a convenient way through the morphological control of the metal nanoparticles

  15. Morphology Control of Platinum Nanoparticles and their Catalytic Properties

    Energy Technology Data Exchange (ETDEWEB)

    Miyazaki, Akane [Tokyo Institute of Technology, Department of Environmental Chemistry and Engineering, Interdisciplinary Graduate School of Science and Technology (Japan)], E-mail: akanem@chemenv.titech.ac.jp; Balint, Ioan [Institute of Physical Chemistry, Romanian Academy (Romania); Nakano, Yoshio [Tokyo Institute of Technology, Department of Environmental Chemistry and Engineering, Interdisciplinary Graduate School of Science and Technology (Japan)

    2003-04-15

    Platinum nanoparticles with different morphology were prepared by reduction of K{sub 2}PtCl{sub 4} solution in the presence of different capping polymers. It was found that the shapes and the sizes of the Pt nanocrystals resulted were related to the kind of capping polymer used. When poly(vinylpyrrolidon) (PVP), poly(N-isopropylacrylamide) (NIPA) and sodium poly(acrylate) (SPA) were used as capping agents, the dominant shapes of the Pt nanocrystals observed by transmission electron microscopy were hexagonal ({approx}62%), square ({approx}67%) and triangular ({approx}41%), respectively. The average sizes of Pt nanocrystals were 6.9, 13.6 and 14.6 nm for capping polymers of PVP, NIPA and SPA, respectively. The colloidal Pt nanoparticles with different morphologies were supported on {gamma}-Al{sub 2}O{sub 3} (1 wt.% Pt) and then their catalytic activity for NO reduction by CH{sub 4} was tested in the 350-600 deg. C temperature range. Additionally, the catalytic activities of these alumina-supported Pt nanocrystals were compared with a conventional catalyst having the average size of Pt particles of {approx}2.4 nm. Over the alumina-supported Pt nanocrystals as compared with the conventional Pt/Al{sub 2}O{sub 3}, it was observed that the NO/CH{sub 4} reaction yields to NH{sub 3} and CO decreased significantly and on the other hand, the yield to N{sub 2}O increased. The experimental results are suggesting that the catalytic behavior can be tuned in a convenient way through the morphological control of the metal nanoparticles.

  16. Electrospray synthesis and properties of hierarchically structured PLGA TIPS microspheres for use as controlled release technologies.

    Science.gov (United States)

    Malik, Salman A; Ng, Wing H; Bowen, James; Tang, Justin; Gomez, Alessandro; Kenyon, Anthony J; Day, Richard M

    2016-04-01

    Microsphere-based controlled release technologies have been utilized for the long-term delivery of proteins, peptides and antibiotics, although their synthesis poses substantial challenges owing to formulation complexities, lack of scalability, and cost. To address these shortcomings, we used the electrospray process as a reproducible, synthesis technique to manufacture highly porous (>94%) microspheres while maintaining control over particle structure and size. Here we report a successful formulation recipe used to generate spherical poly(lactic-co-glycolic) acid (PLGA) microspheres using the electrospray (ES) coupled with a novel thermally induced phase separation (TIPS) process with a tailored Liquid Nitrogen (LN2) collection scheme. We show how size, shape and porosity of resulting microspheres can be controlled by judiciously varying electrospray processing parameters and we demonstrate examples in which the particle size (and porosity) affect release kinetics. The effect of electrospray treatment on the particles and their physicochemical properties are characterized by scanning electron microscopy, confocal Raman microscopy, thermogravimetric analysis and mercury intrusion porosimetry. The microspheres manufactured here have successfully demonstrated long-term delivery (i.e. 1week) of an active agent, enabling sustained release of a dye with minimal physical degradation and have verified the potential of scalable electrospray technologies for an innovative TIPS-based microsphere production protocol. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  17. The Effect of Moisture Content on Physical Properties of Berberis

    Directory of Open Access Journals (Sweden)

    E Velayati

    2011-03-01

    Full Text Available In order to enhance the mechanization level of harvest and post-harvest operations of Berberis fruit, as one of the major and local crops of south Khorasan province, some of its physical properties were investigated. Different dimensions, geometrical mean diameter, sphericity, surface area, mass of thousand fruit, true density, bulk density, porosity, static coefficient of friction and the repose angles were determined. The properties and the effect of moisture content on them were studied by the completely randomized designs statistical method. Analysis of data indicated that the change of moisture content caused significant difference (P

  18. Effect of sonication on technological properties of beef

    Directory of Open Access Journals (Sweden)

    Z. J. Dolatowski

    2007-06-01

    Full Text Available Ultrasound treatment during rigor mortis period led to an acceleration of aging processes. No significant influence of sonication on acidity during ageing was observed. Ultrasound treatment did not influence the lightness, but according to the shear force measurements, improve meat tenderness. Differentiated technological properties of examined samples may result from influence of ultrasound on protein structures of meat. As a result of ultrasound treatment an increase of free calcium ions concentration occurred. Obtained results pointed out that sonication may be an effective method of formation of technological properties of beef during ageing.

  19. Effect of surfactant for magnetic properties of iron oxide nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Haracz, S. [Faculty of Chemistry, Adam Mickiewicz University, Umultowska 89B, 61-614 Poznań (Poland); Hilgendorff, M. [Freie Universität Berlin, Fachbereich Physik, Arnimalle 14, 14195 Berlin (Germany); Rybka, J.D. [Faculty of Chemistry, Adam Mickiewicz University, Umultowska 89B, 61-614 Poznań (Poland); Giersig, M. [Faculty of Chemistry, Adam Mickiewicz University, Umultowska 89B, 61-614 Poznań (Poland); Freie Universität Berlin, Fachbereich Physik, Arnimalle 14, 14195 Berlin (Germany)

    2015-12-01

    Highlights: • Dynamic behavior of magnetic nanoparticles. • Synthesis of iron oxide nanoparticles. • Effect of surfactant for magnetic properties. - Abstract: For different medical applications nanoparticles (NPs) with well-defined magnetic properties have to be used. Coating ligand can change the magnetic moment on the surface of nanostructures and therefore the magnetic behavior of the system. Here we investigated magnetic NPs in a size of 13 nm conjugated with four different kinds of surfactants. The surface anisotropy and the magnetic moment of the system were changed due to the presence of the surfactant on the surface of iron oxide NPs.

  20. Improved antimicrobial property and controlled drug release kinetics of silver sulfadiazine loaded ordered mesoporous silica

    Directory of Open Access Journals (Sweden)

    Suman Jangra

    2016-09-01

    Full Text Available The present study deals with the loading of silver sulfadiazine into ordered mesoporous silica material by post-impregnation method and its effect on the in vitro release kinetics and antimicrobial property of the drug. The formulated SBA-15 silica material with rope-like morphology and SBA-15-silver sulfadiazine (SBA-AgSD were characterized by UV–visible spectrophotometer, small and wide-angle powder X-ray diffraction (PXRD, field emission scanning electron microscope (FESEM and high resolution transmission electron microscope (HRTEM. Thermo-gravimetric analysis of SBA-AgSD revealed a high loading amount of 52.87%. Nitrogen adsorption–desorption analysis confirmed the drug entrapment into host material by revealing a reduced surface area (214 m2/g and pore diameter (6.7 nm of the SBA-AgSD. The controlled release of silver sulfadiazine drug from the mesoporous silica to simulated gastric, intestinal and body fluids was evaluated. The Korsmeyer–Peppas model fits the drug release data with the non-Fickian diffusion model and zero order kinetics of SBA-AgSD. The antibacterial performance of the SBA-AgSD was evaluated with respect to Staphylococcus aureus, Bacillus subtilis and Pseudomonas aeruginosa. The controlled drug delivery of the SBA-AgSD revealed improved antibacterial activity, thus endorsing its applicability in effective wound dressing.

  1. Ethanolamine properties and use for feedwater pH control: A pressurized water reactor case study

    International Nuclear Information System (INIS)

    Keeling, D.L.; Polidoroff, C.T.; Cortese, S.; Cushner, M.C.

    1995-01-01

    Ethanolamine (ETA) as a feedwater pH control additive has been recently used to minimize corrosion of secondary water components in the nuclear power industry pressurized water reactors (PWRs). The use of ETA is compared with ammonia. Relative volatility effects on various parts of the system are analyzed and chemistry changes are presented. Materials of construction and the use of existing plant equipment for ETA service are discussed. Properties of ETA as well as safety, storage and handling issues are compared with ammonia. Health d aquatic toxicity are reviewed. warnings, safety, handling guidelines, biodegradability an Diablo Canyon Power Plant used ammonia for pH control from 1985 until a change over to ETA in 1993/1994. Full flow condensate polishers that are required to protect the plant from saltwater cooling incursions limit the amount of pH additive. Iron levels in the secondary water systems are compared before and after changing to ETA and replacement of corrosion-susceptible piping. Iron reduction benefits are assessed along with other effects on the feedwater nozzles, low pressure turbine, polisher resin capacity and polisher regeneration system

  2. Predicting, monitoring and controlling geomechanical effects of CO2 injection

    International Nuclear Information System (INIS)

    Streit, J.E.; Siggins, A.F.

    2005-01-01

    A key objective of geological carbon dioxide (CO 2 ) storage in porous rock is long-term subsurface containment of CO 2 . Fault stability and maximum sustainable pore-fluid pressures should be estimated in geomechanical studies in order to avoid damage to reservoir seals and fault seals of storage sites during CO 2 injection. Such analyses rely on predicting the evolution of effective stresses in rocks and faults during CO 2 injection. However, geomechanical analyses frequently do not incorporate poroelastic behaviour of reservoir rock, as relevant poroelastic properties are rarely known. The knowledge of rock poroelastic properties would allow the use of seismic methods for the accurate measurement of the effective stress evolution during CO 2 injection. This paper discussed key geomechanical effects of CO 2 injection into porous rock, and in particular, focused on the effects that the poroelasticity of reservoir rocks and pore pressure/stress coupling have on effective stresses. Relevant geophysical monitoring techniques were also suggested. The paper also outlined how these techniques could be applied to measure stress changes related to poroelastic rock behaviour during CO 2 injection and to test the predictions of sustainable changes in effective stress in CO 2 storage sites. It was concluded that a combination of predictive geomechanical techniques and application of geophysical monitoring techniques is a valid new concept for controlling and monitoring the geomechanical effects of CO 2 storage. 36 refs., 5 figs

  3. Structural properties of the material control and accounting system

    International Nuclear Information System (INIS)

    1978-12-01

    A unified digraph approach is proposed for the assessment of the structure of the MC and A System. The approach emphasizes the two structural aspects of the system: vulnerability and reliability. Vulnerability is defined as a possibility of loosing connectedness in a given structure due to line and/or node removals. It is purely deterministic notion which leads to a qualitative analysis of redundancy of connections in the corresponding system. Reliability of the MC and A System structure provides a more quantitative way of assessing how safe the system is to random failures of the links representing lines of communication, material paths, monitors, and the components of the power supply network. By assigning probabilities to the lines and nodes of the corresponding digraph, the least reliable path can be used as a measure of the goodness of the system, which can be computed by efficient shortest path algorithms. Both vulnerability and reliability considerations are important in determining the effect of tampering of an adversary with the elements of the MC and M System

  4. Controlling the properties of ferroelectric-nickelate interfaces

    Science.gov (United States)

    Marshall, Matthew S. J.; Malashevich, Andrei; Disa, Ankit; Han, Myung-Geun; Zhu, Yimei; Ismail-Beigi, Sohrab; Walker, Frederick; Ahn, Charles

    2015-03-01

    Ferroelectrics are a class of materials that exhibit a stable, reversible polarization making them useful for non-volatile electronic devices. In devices consisting of thin film ferroelectric PZT acting as a gate and a thin film of the conductive oxide LaNiO3 grown on LaAlO3(001) acting as a channel, we have realized a large change in room temperature channel resistance by switching the ferroelectric polarization. The effect of switching the polarization of the ferroelectric is to modify the electronic structure of the interface between the gate and channel, resulting in conduction in the otherwise insulating ferroelectric. Here, we discuss how changing the epitaxial strain and interface termination of LaNiO3 can result in larger changes in resistivity. The epitaxial strain is varied by growing the devices on LaAlO3 for tensile strain and SrTiO3 for compressive strain. An interface termination of either an atomic layer of NiO2 or LaO is achieved via atomic layering using oxygen plasma assisted molecular beam epitaxy (MBE).

  5. Autonomous Control, Climate and Environmental Changes Effects ...

    African Journals Online (AJOL)

    Autonomous Control, Climate and Environmental Changes Effects on Trypanosomiasis in Sub-Saharan Africa: A Review. ... African trypanosomiasis is a parasitic disease that causes serious economic losses in livestock due to anemia, loss of condition and emaciation. The disease when neglected is lethal and untreated ...

  6. Effectiveness of weed control methods on pavement

    NARCIS (Netherlands)

    Vermeulen, G.D.; Verwijs, B.R.; Kempenaar, C.

    2007-01-01

    The policy in the Netherlands is to signifiantly reduce the use of herbicides, also on pavements. Existing non-chemical methods to control weeds are much less effective than spot spraying, the usual method at this moment. Therefore, the cost of non-chemical weed management is often estimated to be 4

  7. Effect of decompression drying treatment on physical properties of solid foods.

    Science.gov (United States)

    Morikawa, Takuya; Takada, Norihisa; Miura, Makoto

    2017-04-01

    This study used a decompression drying instrument to investigate the effects of a drying treatment on the physical properties of solid foods. Commercial tofu was used as a model food and was treated at different temperature and pressure conditions in a drying chamber. Overall, high temperatures resulted in better drying. Additionally, pressure in the chamber influenced the drying conditions of samples. Differences in physical properties, such as food texture, shrinkage, and color were observed among some samples, even with similar moisture content. This was caused by differences in moisture distribution in the food, which seems to have manifested as a thin, dried film on the surfaces of samples. It caused inefficient drying and changes in physical properties. Control of the drying conditions (i.e. pressure and heat supply) has relations with not only physical properties, but also the drying efficiency of solid foods.

  8. Effect of magnetic field on the physical properties of water

    Science.gov (United States)

    Wang, Youkai; Wei, Huinan; Li, Zhuangwen

    2018-03-01

    In this study, the effect of magnetic field (MF) on the partial physical properties of water are reported, tap water (TW) and 4 types of magnetized water (MW) were measured in the same condition. It was found that the properties of TW were changed following the MF treatment, shown as the increase of evaporation amount, the decrease of specific heat and boiling point after magnetization, the changes depend on the magnetization effect. In addition, magnetic field strength (MFS) has a marked influence on the magnetization effect, the optimal magnetizing condition was determined as the MFS of 300 mT. The findings of this study offered a facile approach to improve cooling and power generation efficiency in industrial.

  9. Effect of disorder on the superconducting properties of materials

    International Nuclear Information System (INIS)

    Brouers, F.; Derenne, M.

    1982-01-01

    The effect of the variation of the density states at the Fermi level on the critical superconductivity temperature TC of transition metal compounds is studied. This paper suggests using the technique of calculating the 5-fold degenerate d-band density of states from a continued fraction extension of a tight-binding Green function to study the relative importance of one dimensionality chain coupling, three dimensional interactions and the effect of disorder on the electronic and superconducting properties of complex phase and in particular A15 phases. The first results obtained for A15 phases density of states indicate that an extension of the suggested method can be of great interest to analyze the effect of disorder on superconductivity properties of complex phases

  10. Effect of transglutaminase treatment on skimmed yogurt properties

    Directory of Open Access Journals (Sweden)

    Iuliana BANU

    2012-12-01

    Full Text Available The aim of the present study was to evaluate the effect of microbial transglutaminase on the stability and rheological properties of skimmed yogurt. The fermentation was carried out with Streptococus theromophilus and Lactobacillus delbrueckii subsp. Bulgaricus after incubating the milk with various enzyme concentrations ranging from 0 to 0.04%, at different setting temperatures (30, 40 and 50°C, for 60, 90 and 120 min. The postacidification process and the stability of the yogurt samples were influenced by the degree of polymerization of the milk proteins which depended on the conditions of the milk treated with microbial transglutaminase. The best results in terms of whey separation and rheological properties were obtained when preincubating the milk with 0.04% transglutaminase for 120 min setting at 40°C. The results indicate that transglutaminase may be successfully used for enhancing the functional properties of yogurt with low fat content.

  11. Aluminium effect on the physical properties of titanium

    International Nuclear Information System (INIS)

    Nazimov, O.P.; Il'in, A.A.; Zvonova, L.N.

    1977-01-01

    The effect of aluminium on the physical properties of titanium was investigated. Within the framework of the configuration model of matter it is shown that a change in physical properties with an aluminium content of up to 7.5 wt.% in alloys depends on the phase composition and electron structure. In interacting with titanium, aluminium exhibits acceptor properties, causing d→s electron transitions. The electrons which have shifted to the s-state are partly collectivized and partly localized into quasistable sp 3 configurations, with the resulting increase of the interatomic forces. An intensification of d→s transitions in alloying of titanium with aluminium stabilizes the α-phase. Predominance of d 1 configurations in the intermediate spectrum in the region of the α-solution increases the ratio of the axes of the HCP lattice and determines the electron type of conduction of alloys of the Ti-Al system

  12. Effect of current pulsing on tensile properties of titanium alloy

    International Nuclear Information System (INIS)

    Balasubramanian, V.; Jayabalan, V.; Balasubramanian, M.

    2008-01-01

    Titanium and its alloys have been considered as one of the best engineering metals for industrial applications. This is due to the excellent combination of properties such as elevated strength to weight ratio, high toughness, excellent resistance to corrosion and good fatigue properties make them attractive for many industrial applications. Recently, considerable research has been performed on pulsed current gas tungsten arc welding process and reported advantages include improved bead contour, lower heat input requirements, reduced residual stresses and distortion. Metallurgical advantages of pulsed current welding frequently reported in literature include refinement of fusion zone grain size, reduced width of heat affected zone, etc. All these factors will help in improving the mechanical properties. Hence, in this investigation an attempt has been made to study the effect of pulsed current gas tungsten arc welding parameters on Ti-6Al-4V titanium alloy

  13. Effect of current pulsing on tensile properties of titanium alloy

    Energy Technology Data Exchange (ETDEWEB)

    Balasubramanian, V. [Department of Manufacturing Engineering, Annamalai University, Annamalai Nagar 608 002 (India)], E-mail: visvabalu@yahoo.com; Jayabalan, V. [Department of Manufacturing Engineering, Anna University, Guindy, Chennai 600 025 (India)], E-mail: jbalan@annauniv.edu; Balasubramanian, M. [Department of Mechanical Engineering, Maamallan Institute of Technology, Sriperumpudur 602 105 (India)], E-mail: manianmb@rediffmail.com

    2008-07-01

    Titanium and its alloys have been considered as one of the best engineering metals for industrial applications. This is due to the excellent combination of properties such as elevated strength to weight ratio, high toughness, excellent resistance to corrosion and good fatigue properties make them attractive for many industrial applications. Recently, considerable research has been performed on pulsed current gas tungsten arc welding process and reported advantages include improved bead contour, lower heat input requirements, reduced residual stresses and distortion. Metallurgical advantages of pulsed current welding frequently reported in literature include refinement of fusion zone grain size, reduced width of heat affected zone, etc. All these factors will help in improving the mechanical properties. Hence, in this investigation an attempt has been made to study the effect of pulsed current gas tungsten arc welding parameters on Ti-6Al-4V titanium alloy.

  14. Observer-based attitude controller for lifting re-entry vehicle with non-minimum phase property

    Directory of Open Access Journals (Sweden)

    Wenming Nie

    2017-05-01

    Full Text Available This article concentrates on the attitude control problem for the lifting re-entry vehicle with non-minimum phase property. A novel attitude control method is proposed for this kind of lifting re-entry vehicle without assuming the internal dynamics to be measurable. First, an internal dynamics extended state observer is developed to deal with the unmeasurable problem of the internal dynamics. And then, the control scheme which adopts output feedback method is proposed by modifying the traditional output redefinition technique with internal dynamics extended state observer. This control scheme only requires the system output to be measurable, and it can still stabilize the unstable internal dynamics and track attitude commands. Besides, because of the inherent property of extended state observer in rejecting uncertainties and disturbances, the control precision of the proposed controller is higher than the controller designed with traditional output redefinition technique. Finally, the effectiveness and robustness of the proposed attitude controller are demonstrated by the simulation results.

  15. Radio-Frequency-Controlled Cold Collisions and Universal Properties of Unitary Bose Gases

    Science.gov (United States)

    Ding, Yijue

    This thesis investigates two topics: ultracold atomic collisions in a radio-frequency field and universal properties of a degenerate unitary Bose gas. One interesting point of the unitary Bose gas is that the system has only one length scale, that is, the average interparticle distance. This single parameter determines all properties of the gas, which is called the universality of the system. We first introduce a renormalized contact interaction to extend the validity of the zero-range interaction to large scattering lengths. Then this renormalized interaction is applied to many-body theories to determined those universal relations of the system. From the few-body perspective, we discuss the scattering between atoms in a single-color radio-frequency field. Our motivation is proposing the radio-frequency field as an effective tool to control interactions between cold atoms. Such a technique may be useful in future experiments such as creating phase transitions in spinor condensates. We also discuss the formation of ultracold molecules using radio-freqency fields from a time-dependent approach.

  16. Release Properties and Cellular Uptake in Caco-2 Cells of Size-Controlled Chitosan Nanoparticles.

    Science.gov (United States)

    Je, Hyun Jeong; Kim, Eun Suh; Lee, Ji-Soo; Lee, Hyeon Gyu

    2017-12-20

    The influences of particle size on the physicochemical, release, and cellular uptake properties of chitosan nanoparticles (CSNPs) were investigated. Ionotropic CSNPs of different sizes (200-1000 nm) loaded with two model core materials (resveratrol or coumarin-6) were prepared using tripolyphosphate and carrageenan as cross-linkers. With an increase of particle size, zeta potential (34.6 ± 0.5 to 51.1 ± 0.9) and entrapment efficiency (14.9 ± 1.4 to 40.9 ± 1.9) of the CSNPs were significantly (p cellular uptake of CSNPs were significantly increased from 3.70 ± 0.03 to 5.24 ± 0.20 with an increase of particle size from 200 to 600 nm, whereas those significantly decreased from 5.24 ± 0.20 to 4.55 ± 0.2 for particles larger than 600 nm in transwell assay. Moreover, much the same uptake patterns were also observed in confocal microscopy and flow cytometry. Investigation of cellular uptake of CSNPs revealed positive correlations between ZP and EE and indicated the effects of complex factors of nanoparticles other than size. These results provide a better understanding of CSNPs absorption and raises the possibility of controlling alternative nanoparticle properties to enhance bioavailability.

  17. Effects of humidity on the mechanical properties of gecko setae.

    Science.gov (United States)

    Prowse, Michael S; Wilkinson, Matt; Puthoff, Jonathan B; Mayer, George; Autumn, Kellar

    2011-02-01

    We tested the hypothesis that an increase in relative humidity (RH) causes changes in the mechanical properties of the keratin of adhesive gecko foot hairs (setae). We measured the effect of RH on the tensile deformation properties, fracture, and dynamic mechanical response of single isolated tokay gecko setae and strips of the smooth lamellar epidermal layer. The mechanical properties of gecko setae were strongly affected by RH. The complex elastic modulus (measured at 5 Hz) of a single seta at 80% RH was 1.2 GPa, only 39% of the value when dry. An increase in RH reduced the stiffness and increased the strain to failure. The loss tangent increased significantly with humidity, suggesting that water absorption produces a transition to a more viscous type of deformation. The influence of RH on the properties of the smooth epidermal layer was comparable with that of isolated seta, with the exception of stress at rupture. These values were two to four times greater for the setae than for the smooth layer. The changes in mechanical properties of setal keratin were consistent with previously reported increases in contact forces, supporting the hypothesis that an increase in RH softens setal keratin, which increases adhesion and friction. Copyright © 2010 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  18. Gate Control Coefficient Effect on CNFET Characteristic

    International Nuclear Information System (INIS)

    Sanudin, Rahmat; Ma'Radzi, Ahmad Alabqari; Nayan, Nafarizal

    2009-01-01

    The development of carbon nanotube field-effect transistor (CNFET) as alternative to existing transistor technology has long been published and discussed. The emergence of this device offers new material and structure in building a transistor. This paper intends to do an analysis of gate control coefficient effect on CNFET performance. The analysis is based on simulation study of current-voltage (I-V) characteristic of ballistic CNFET. The simulation study used the MOSFET-like CNFET mathematical model to establish the device output characteristic. Based on the analysis of simulation result, it is found that the gate control coefficient contributes to a significant effect on the performance of CNFET. The result also shown the parameter could help to improve the device performance in terms of its output and response as well. Nevertheless, the characteristic of the carbon nanotube that acts as the channel is totally important in determining the performance of the transistor as a whole.

  19. Controlling In–Ga–Zn–O thin films transport properties through density changes

    Energy Technology Data Exchange (ETDEWEB)

    Kaczmarski, Jakub, E-mail: kaczmarski@ite.waw.pl [Institute of Electron Technology, al. Lotników 32/46, 02-668 Warsaw (Poland); Boll, Torben [Department of Applied Physics, Chalmers University of Technology, Fysikgränd 3, SE-412 96 Gothenburg (Sweden); Borysiewicz, Michał A. [Institute of Electron Technology, al. Lotników 32/46, 02-668 Warsaw (Poland); Taube, Andrzej [Institute of Electron Technology, al. Lotników 32/46, 02-668 Warsaw (Poland); Institute of Microelectronics & Optoelectronics, Warsaw University of Technology, ul. Koszykowa 75, 00-662 Warsaw (Poland); Thuvander, Mattias; Law, Jia Yan [Department of Applied Physics, Chalmers University of Technology, Fysikgränd 3, SE-412 96 Gothenburg (Sweden); Kamińska, Eliana [Institute of Electron Technology, al. Lotników 32/46, 02-668 Warsaw (Poland); Stiller, Krystyna [Department of Applied Physics, Chalmers University of Technology, Fysikgränd 3, SE-412 96 Gothenburg (Sweden)

    2016-06-01

    In the following study we investigate the effect of the magnetron cathode current (I{sub c}) during reactive sputtering of In–Ga–Zn–O (a-IGZO) on thin-films nanostructure and transport properties. All fabricated films are amorphous, according to X-ray diffraction measurements. However, High Resolution Transmission Electron Microscopy revealed the a-IGZO fabricated at I{sub C} = 70 mA to contain randomly-oriented nanocrystals dispersed in amorphous matrix, which disappear in films deposited at higher cathode current. These nanocrystals have the same composition as the amorphous matrix. One can observe that, while I{sub C} is increased from 70 to 150 mA, the carrier mobility improves from μ{sub Hall} = 6.9 cm{sup 2}/Vs to μ{sub Hall} = 9.1 cm{sup 2}/Vs. Additionally, the increase of I{sub C} caused a reduction of the depletion region trap states density of the Ru–Si–O/In–Ga–Zn–O Schottky barrier. This enhancement in transport properties is attributed to the greater overlapping of s-orbitals of the film-forming cations caused by increased density, evidenced by X-ray reflectivity, at a fixed chemical composition, regardless nanostructure of thin films. - Highlights: • Magnetron cathode current (I{sub C}) controls the transport properties of In–Ga–Zn–O (IGZO). • Low I{sub C} results in IGZO films with nanocrystalline inclusions in amorphous matrix. • High I{sub C} reduces the number of trap states in depletion region of Schottky contacts.

  20. Controlled fabrication of PANI/CNF hybrid films: molecular interaction induced various micromorphologies and electrochemical properties.

    Science.gov (United States)

    Xu, Guiheng; Xu, Dongdong; Zhang, Jianan; Wang, Kaixi; Chen, Zhimin; Chen, Jiafu; Xu, Qun

    2013-12-01

    In this paper, a facile and efficient method is reported to prepare polyaniline/carbon nanofiber (PANI/CNF) hybrid films by in situ chemical polymerization of aniline. The various morphologies and microstructures of PANI/CNF hybrid films can be controlled by adjusting the concentration of aniline and different acids as the protonation reagent, and the formation mechanism is illustrated in this study. The surface morphologies and chemical structure of the PANI/CNF hybrid films are characterized by scanning electron microscope (SEM), transmission electron microscope (TEM), water contact angle (CA), FT-IR, Raman, and UV-vis spectrophotometers. The different morphology of uniformly coated, twist-tangled, and needle-like PANI built on CNF films are obtained by using HCl, H2SO4, and HClO4 as protonation reagent and the obtained hybrid films are labeled as PANI/CNF-f1, PANI/CNF-f2, and PANI/CNF-f3, respectively. We demonstrated that the different protonation reagent has the determined effect on the surface properties of the obtained hybrid films that can transfer from hydrophilic to hydrophobic. Besides, the various morphologies of PANI play an important role in their electrochemical properties. PANI/CNF-f3 exhibits higher specific capacitance and better stability than that of the PANI/CNF-f1 and PANI/CNF-f2. Considering its unique needle-like structure, this work is a proof of concept that micro-structure and morphology can determine the macro-properties. And this study supplies a facile method to fabricate PANI/CNF hybrid films that can be used as electrode materials in supercapacitors. Copyright © 2013 Elsevier Inc. All rights reserved.

  1. Effect of cold drawing on mechanical properties of biodegradable fibers.

    Science.gov (United States)

    La Mantia, Francesco Paolo; Ceraulo, Manuela; Mistretta, Maria Chiara; Morreale, Marco

    2017-01-26

    Biodegradable polymers are currently gaining importance in several fields, because they allow mitigation of the impact on the environment related to disposal of traditional, nonbiodegradable polymers, as well as reducing the utilization of oil-based sources (when they also come from renewable resources). Fibers made of biodegradable polymers are of particular interest, though, it is not easy to obtain polymer fibers with suitable mechanical properties and to tailor these to the specific application. The main ways to tailor the mechanical properties of a given biodegradable polymer fiber are based on crystallinity and orientation control. However, crystallinity can only marginally be modified during processing, while orientation can be controlled, either during hot drawing or cold stretching. In this paper, a systematic investigation of the influence of cold stretching on the mechanical and thermomechanical properties of fibers prepared from different biodegradable polymer systems was carried out. Rheological and thermal characterization helped in interpreting the orientation mechanisms, also on the basis of the molecular structure of the polymer systems. It was found that cold drawing strongly improved the elastic modulus, tensile strength and thermomechanical resistance of the fibers, in comparison with hot-spun fibers. The elastic modulus showed higher increment rates in the biodegradable systems upon increasing the draw ratio.

  2. Effect of the carbonyl iron particles on acoustic absorption properties of magnetic polyurethane foam

    Science.gov (United States)

    Geng, Jialu; Wang, Caiping; Zhu, Honglang; Wang, Xiaojie

    2018-03-01

    Elastomeric matrix embedded with magnetic micro-sized particles has magnetically controllable properties, which has been investigated extensively in the last decades. In this study we develop a new magnetically controllable elastomeric material for acoustic applications at lower frequencies. The soft polyurethane foam is used as matrix material due to its extraordinary elastic and acoustic absorption properties. One-step method is used to synthesize polyurethane foam, in which all components including polyether polyols 330N, MDI, deionized water, silicone oil, carbonyl iron particle (CIP) and catalyst are put into one container for curing. Changing any component can induce the change of polyurethane foam's properties, such as physical and acoustic properties. The effect of the content of MDI on acoustic absorption is studied. The CIPs are aligned under extra magnetic field during the foaming process. And the property of polyurethane foam with aligned CIPs is also investigated. Scanning electron microscope (SEM) is used to observe the structure of pore and particle-chain. The two-microphone impedance tube and the transfer function method are used to test acoustic absorption property of the magnetic foams.

  3. Electrostatic control of the coffee stain effect

    Science.gov (United States)

    Wray, Alex; Papageorgiou, Demetrios; Sefiane, Khellil; Matar, Omar

    2013-11-01

    The ``coffee stain effect,'' as first explained by Deegan et al. 1997, has received a great deal of attention amongst modellers and experimentalists in recent years, perhaps due in part to its obvious casual familiarity. However, it maintains interest because of its intriguing reliance on an interplay of a trio of effects: contact line pinning, inhomogeneous mass flux, and resulting capillarity-driven flow. What is more, the effect, and especially its suppression or reversal, find applications in fields as diverse as sample recovery, mass spectroscopy and the printing of Organic LEDs. We examine the motion a nanoparticle-laden droplet deposited on a precursor film, incorporating the effects of capillarity, concentration-dependent rheology, together with a heated substrate and resultant mass flux and Marangoni effects. We allow the substrate to act as an electrode and incorporate a second electrode above the droplet. The potential difference together with a disparity in electrical properties between the two regions results in electrical (Maxwell) stresses at the interface. We show via lubrication theory and via direct numerical simulations that the ring effect typically observed may be suppressed or augmented via appropriate use of electric fields. EPSRC DTG

  4. Effects of model layer simplification using composite hydraulic properties

    Science.gov (United States)

    Kuniansky, Eve L.; Sepulveda, Nicasio; Elango, Lakshmanan

    2011-01-01

    Groundwater provides much of the fresh drinking water to more than 1.5 billion people in the world (Clarke et al., 1996) and in the United States more that 50 percent of citizens rely on groundwater for drinking water (Solley et al., 1998). As aquifer systems are developed for water supply, the hydrologic system is changed. Water pumped from the aquifer system initially can come from some combination of inducing more recharge, water permanently removed from storage, and decreased groundwater discharge. Once a new equilibrium is achieved, all of the pumpage must come from induced recharge and decreased discharge (Alley et al., 1999). Further development of groundwater resources may result in reductions of surface water runoff and base flows. Competing demands for groundwater resources require good management. Adequate data to characterize the aquifers and confining units of the system, like hydrologic boundaries, groundwater levels, streamflow, and groundwater pumping and climatic data for recharge estimation are to be collected in order to quantify the effects of groundwater withdrawals on wetlands, streams, and lakes. Once collected, three-dimensional (3D) groundwater flow models can be developed and calibrated and used as a tool for groundwater management. The main hydraulic parameters that comprise a regional or subregional model of an aquifer system are the hydraulic conductivity and storage properties of the aquifers and confining units (hydrogeologic units) that confine the system. Many 3D groundwater flow models used to help assess groundwater/surface-water interactions require calculating ?effective? or composite hydraulic properties of multilayered lithologic units within a hydrogeologic unit. The calculation of composite hydraulic properties stems from the need to characterize groundwater flow using coarse model layering in order to reduce simulation times while still representing the flow through the system accurately. The accuracy of flow models with

  5. Confinement Effect on Material Properties of RC Beams Under Flexure

    Science.gov (United States)

    Kulkarni, Sumant; Shiyekar, Mukund Ramchandra; Shiyekar, Sandip Mukund

    2017-12-01

    In structural analysis, especially in indeterminate structures, it becomes essential to know the material and geometrical properties of members. The codal provisions recommend elastic properties of concrete and steel and these are fairly accurate enough. The stress-strain curve for concrete cylinder or a cube specimen is plotted. The slope of this curve is modulus of elasticity of plain concrete. Another method of determining modulus of elasticity of concrete is by flexural test of a beam specimen. The modulus of elasticity most commonly used for concrete is secant modulus. The modulus of elasticity of steel is obtained by performing a tension test of steel bar. While performing analysis by any software for high rise building, cross area of plain concrete is taken into consideration whereas effects of reinforcement bars and concrete confined by stirrups are neglected. Present aim of study is to determine elastic properties of reinforced cement concrete beam. Two important stiffness properties such as AE and EI play important role in analysis of high rise RCC building idealized as plane frame. The experimental program consists of testing of beams (model size 150 × 150 × 700 mm) with percentage of reinforcement varying from 0.54 to 1.63% which commensurate with existing Codal provisions of IS:456-2000 for flexural member. The effect of confinement is considered in this study. The experimental results are verified by using 3D finite element techniques.

  6. Effect of Board Type on Some Properties of Bamboo Strandboard

    Directory of Open Access Journals (Sweden)

    Ihak Sumardi

    2015-03-01

    Full Text Available The objective of this study was to evaluate the properties of bamboo strandboard (OSB by comparing different board types and strand-lengths. Bamboo strandboards with nominal dimensions of 37 mm by 37 mm by 12 mm and target density 0.65 g/cm3 were manufactured using moso bamboo (Pyllostachys pubescent Mezel and MDI resin to produce two types of strandlength. Two types of strand length and MDI resin were used to produce three types of strandboard. The bending properties and dimensional stability of the strandboards were evaluated according to the Japanese Industrial Standard (JIS for particleboard. The results of this experiment indicate that the bending properties and internal bond strength were affected by both board type and strand-length. The distribution of resin inside the 80 mm strandboard was less homogenous than in the 50 mm strandboard, which affects the internal bond strength. Thickness swelling of the RAND board was the highest and linear stability was affected substantially by strand alignment. The RAND board and cross-oriented 3LAY board effectively restrained linear expansion in the direction perpendicular to the strand alignment. A cross-oriented core may be the most effective way to reduce dimensional change and bending property values in perpendicular directions.

  7. Effect of Somatosensory Impairments on Balance Control

    Directory of Open Access Journals (Sweden)

    Alireza Hassanpour

    2012-10-01

    Full Text Available Background and Aim: The somatosensory system is one of the most effective systems in balance control. It consists of peripheral and central components. Knowing the role of these components in balance control assists the developing of effective rehabilitation protocols. In some diseases peripheral components and in others central components are impaired. This paper reviews the effect of impairment of peripheral and central components of the somatosensory system on balance control.Methods: In this study publication about somatosensory impairments from 1983 through 2011 in PubMed, Scopus, ProQuest, Google Scholar, Iran Medex, Iran Doc and Magiran were reviewed. Medical subject headings terms and keywords related to balance, somatosensory, somatosensory loss, and sensory integration/processing were used to perform the searches.Conclusion: Somatosensory impairments either with peripheral or central origin, can cause problems in balance control. However, these problems are not considered in some patients. In these impairments, balance training is recommended to be used alongside other routine treatments in the patients' rehabilitation programs.

  8. Anomalous Josephson effect controlled by an Abrikosov vortex

    Science.gov (United States)

    Mironov, S.; Goldobin, E.; Koelle, D.; Kleiner, R.; Tamarat, Ph.; Lounis, B.; Buzdin, A.

    2017-12-01

    The possibility of a fast and precise Abrikosov vortex manipulation by a focused laser beam opens the way to create laser-driven Josephson junctions. We theoretically demonstrate that a vortex pinned in the vicinity of the Josephson junction generates an arbitrary ground state phase which can be equal not only to 0 or π but to any desired φ0 value in between. Such φ0 junctions have many peculiar properties and may be effectively controlled by the optically driven Abrikosov vortex. Also we theoretically show that the Josephson junction with the embedded vortex can serve as an ultrafast memory cell operating at sub THz frequencies.

  9. Piezo Voltage Controlled Planar Hall Effect Devices.

    Science.gov (United States)

    Zhang, Bao; Meng, Kang-Kang; Yang, Mei-Yin; Edmonds, K W; Zhang, Hao; Cai, Kai-Ming; Sheng, Yu; Zhang, Nan; Ji, Yang; Zhao, Jian-Hua; Zheng, Hou-Zhi; Wang, Kai-You

    2016-06-22

    The electrical control of the magnetization switching in ferromagnets is highly desired for future spintronic applications. Here we report on hybrid piezoelectric (PZT)/ferromagnetic (Co2FeAl) devices in which the planar Hall voltage in the ferromagnetic layer is tuned solely by piezo voltages. The change of planar Hall voltage is associated with magnetization switching through 90° in the plane under piezo voltages. Room temperature magnetic NOT and NOR gates are demonstrated based on the piezo voltage controlled Co2FeAl planar Hall effect devices without the external magnetic field. Our demonstration may lead to the realization of both information storage and processing using ferromagnetic materials.

  10. Effects of salting treatment on the physicochemical properties, textural properties, and microstructures of duck eggs

    Science.gov (United States)

    Xu, Lilan; Zhao, Yan; Xu, Mingsheng; Yao, Yao; Nie, Xuliang; Du, Huaying

    2017-01-01

    In order to illuminate the forming process of salted egg, the effects of the brine solution with different salt concentrations on the physicochemical properties, textural properties, and microstructures of duck eggs were evaluated using conventional physicochemical property determination methods. The results showed that the moisture contents of both the raw and cooked egg whites and egg yolks, the springiness of the raw egg yolks and cooked egg whites exhibited a decreasing trend with the increase in the salting time and salt concentration. The salt content, oil exudation and the hardness of the raw egg yolks showed a constantly increasing trend. Viscosity of the raw egg whites showed an overall trend in which it first deceased and then increased and decreased again, which was similar to the trend of the hardness of the cooked egg whites and egg yolks. As the salting proceeded, the pH value of the raw and cooked egg whites declined remarkably and then declined slowly, whereas the pH of the raw and cooked egg yolks did not show any noticeable changes. The effect of salting on the pH value varied significantly with the salt concentration in the brine solution. Scanning electron microscopy (SEM) revealed that salted yolks consist of spherical granules and embedded flattened porosities. It was concluded that the treatment of salt induces solidification of yolk, accompanied with higher oil exudation and the development of a gritty texture. Different salt concentrations show certain differences. PMID:28797071

  11. Regulatory properties of 6-phosphofructokinase and control of glycolysis in boar spermatozoa.

    Science.gov (United States)

    Kamp, G; Schmidt, H; Stypa, H; Feiden, S; Mahling, C; Wegener, G

    2007-01-01

    Glycolysis is crucial for sperm functions (motility and fertilization), but how this pathway is regulated in spermatozoa is not clear. This prompted to study the location and the regulatory properties of 6-phosphofructokinase (PFK, EC 2.7.1.11), the most important element for control of glycolytic flux. Unlike some other glycolytic enzymes, PFK showed no tight binding to sperm structures. It could readily be extracted from ejaculated boar spermatozoa by sonication and was then chromatographically purified. At physiological pH, the enzyme was allosterically inhibited by near-physiological concentrations of its co-substrate ATP, which induced co-operativity, i.e. reduced the affinity for the substrate fructose 6-phosphate. Inhibition by ATP was reinforced by citrate and H+. Above pH 8, PFK lost all its regulatory properties and showed maximum activity. However, in the physiological pH range, PFK activity was very sensitive to small changes in effectors. At near-physiological substrate concentrations, PFK activity requires activators (de-inhibitors) of which the combination of AMP and fructose 2,6-bisphosphate (F2,6P2) was most efficient as a result of synergistic effects. The kinetics of PFK suggest AMP, F2,6P2, H+, and citrate as allosteric effectors controlling PFK activity in boar spermatozoa. Using immunogold labeling, PFK was localized in the mid-piece and principal piece of the flagellum as well as in the acrosomal area at the top of the head and in the cytoplasmic droplets released from the mid-piece after ejaculation.

  12. The effect of clay amendment on substrate properties and growth of woody plants

    Directory of Open Access Journals (Sweden)

    Tomáš Meisl

    2012-01-01

    Full Text Available This work deals with the effect of two clay products differing in particle size distribution on properties of growing substrate and on growth of containerized woody plants in substrates amended with these clay products. Fine and coarse clay were added to a peat substrate, each at two rates. The peat substrate without clay was used as a control. The substrates were tested in experiments with two woody ornamentals (Thuja occidentalis ’Smaragd’ and Prunus cistena. Chemical and physical properties of the substrates were measured according to European Standards before planting. Proportion of water categories differing in availability to the plants were calculated from retention curves measured on the sand box. Properties of substrates in containers with and without plants were evaluated in the same way at the end of the culture. Clay addition changed chemical and physical properties of the tested substrates in terms: available nutrients content, particle density, bulk density, total pore volume, easy available water, water buffering capacity, air capacity, and shrinkage. The effect of fine clay was much stronger. In comparison with the clear effect of clay addition on the substrate chemical and physical properties, the effect on the growth and quality of model woody plants was not so explicit.

  13. Effect of ionizing radiation on structural and conductive properties of copper nanotubes

    Science.gov (United States)

    Zdorovets, M. V.; Borgekov, D. B.; Kenzhina, I. E.; Kozlovskiy, A. L.

    2018-01-01

    The use of electron radiation is an effective tool for stimulating a controlled modification of structural and conductive properties of nanomaterials in modern materials science. The paper presents the results of studies of the influence of various types of radiation on structural and conductive properties of copper nanotubes obtained by electrochemical synthesis in pores of templates based on polyethylene terephthalate. Such methods as SEM, X-ray diffraction and EDS show that irradiation with a stream of high-energy electrons with doses of 50-250 kGy makes it possible to modify the crystal structure of nanotubes, increasing their conductivity and decreasing the resistance of nanostructures without destroying the structure.

  14. A Percolation Study of Wettability Effect on the Electrical Properties of Reservoir Rocks

    DEFF Research Database (Denmark)

    Zhou, Dengen; Arbabi, Sepehr; Stenby, Erling Halfdan

    1997-01-01

    Measurements of the electrical resistivity of oil reservoirs are commonly used to estimate other properties of reservoirs, such as porosity and hydrocarbon reserves. However, the interpretation of the measurements is based on empirical correlations, because the underlying mechanisms that control...... the electrical properties of oil bearing rocks have not been well understood. In this paper, we employ percolation concepts to investigate the effect of wettability on the electrical conductivity of a reservoir formation. A three-dimensional simple cubic network is used to represent an ideal reservoir formation...

  15. Microstructure and orientation effects on properties of discontinuous silicon carbide/aluminum composites

    Science.gov (United States)

    Mcdanels, D. L.; Hoffman, C. A.

    1984-01-01

    Composite panels containing up to 40 vol % discontinuous silicon carbide SiC whisker, nodule, or particulate reinforcement in several aluminum matrices are commercially fabricated and the mechanical properties and microstructual characteristics are evaluated. The yield and tensile strengths and the ductility are controlled primarily by the matrix alloy, the temper condition, and the reinforcement content. Particulate and nodule reinforcements are as effective as whisker reinforcement. Increased ductility is attributed to purer, more uniform starting materials and to more mechanical working during fabrication. Comparing mechanical properties with those of other aluminum alloys shows that these low cost, lightweight composites demonstrate very good potential for application to aerospace structures.

  16. Effects of surface properties on droplet formation inside a microfluidic device

    Science.gov (United States)

    Steinhaus, Ben; Shen, Amy

    2004-11-01

    Micro-fluidic devices offer a unique method of creating and controlling droplets on small length scales. A microfluidic device is used to study the effects of surface properties on droplet formation of a 2-phase flow system. Four phase diagrams are generated to compare the dynamics of the 2 immiscible fluid system (silicone oil and water) inside microchannels with different surface properties. Results show that the channel surface plays an important role in determining the flow patterns and the droplet formation of the 2-phase fluid system.

  17. The effect of long-term oxidation on the rheological properties of polymer modified asphalts

    Energy Technology Data Exchange (ETDEWEB)

    Yonghong Ruan; Richard R. Davison; Charles J. Glover [Texas A & M University, College Station, TX (United States). Department of Chemical Engineering

    2003-10-01

    The effect of long-term aging on rheological properties of polymer modified asphalt binders was studied. Modifiers included diblock poly(styrene-b-butadiene) rubber, triblock poly(styrene-b-butadiene-b-styrene), and tire rubber. Asphalt aging was carried out either at 60{sup o}C in a controlled environmental room or at 100{sup o}C in a pressure aging vessel (AASHTO Provisional Standards, 1993). Both dynamic shear properties and extensional properties were investigated. Polymer modification resulted in increased asphalt complex modulus at high temperatures, decreased asphalt complex modulus at low temperatures, broadened relaxation spectra, and improved ductility. Oxidative aging decreased asphalt temperature susceptibility, damaged the polymer network in binders, further broadened the relaxation spectrum, and diminished polymer effectiveness in improving asphalt ductility. 27 refs., 8 figs., 3 tabs.

  18. The Effects of Shallow Cryogenic Process On The Mechanical Properties of AISI 4140 Steel

    Directory of Open Access Journals (Sweden)

    Eşref KIZILKAYA

    2018-03-01

    Full Text Available In this study, shallow cryogenic treatments were carried out for various holding time to AISI 4140 steel and the effects of heat treatment parameters on wear behavior, impact strength and tensile strength were investigated. Three different holding times were used for cryogenic heat treatments. After the cryogenic process, single tempering was applied. In addition, the abrasion tests were carried out at three different forces (5N, 10N and 15N at a constant slip speed (3.16 m / s and at three different slip distances (95 m, 190 m, 285 m. It has been determined that the shallow cryogenic process parameters significantly influence the mechanical properties of the AISI 4140 steel as a result of experimental studies., Low heat treatment times in cryogenic heat treatment have been found to have a positive effect on many mechanical properties, especially wear. The mechanical properties of the AISI 4140 steel can be optimized by controlling the shallow cryogenic heat treatment parameters.

  19. Finite amplitude effects on drop levitation for material properties measurement

    Science.gov (United States)

    Ansari Hosseinzadeh, Vahideh; Holt, R. Glynn

    2017-05-01

    The method of exciting shape oscillation of drops to extract material properties has a long history, which is most often coupled with the technique of acoustic levitation to achieve non-contact manipulation of the drop sample. We revisit this method with application to the inference of bulk shear viscosity and surface tension. The literature is replete with references to a "10% oscillation amplitude" as a sufficient condition for the application of Lamb's analytical expressions for the shape oscillations of viscous liquids. Our results show that even a 10% oscillation amplitude leads to dynamic effects which render Lamb's results inapplicable. By comparison with samples of known viscosity and surface tension, we illustrate the complicating finite-amplitude effects (mode-splitting and excess dissipation associated with vorticity) that can occur and then show that sufficiently small oscillations allow us to recover the correct material properties using Lamb's formula.

  20. Characterization of cookies made from wheat flour blended with buckwheat flour and effect on antioxidant properties.

    Science.gov (United States)

    Jan, Ulfat; Gani, Adil; Ahmad, Mudasir; Shah, Umar; Baba, Waqas N; Masoodi, F A; Maqsood, Sajid; Gani, Asir; Wani, Idress Ahmed; Wani, S M

    2015-10-01

    Buckwheat flour was incorporated into wheat flour at different levels (0, 20, 40, 60, 80, and 100 %) and the physicochemical, functional and antioxidant properties of the blended flour were studied. This study also investigated the effect of buckwheat on the retention of antioxidant properties of cookies during baking. The results showed significant variation in physicochemical and functional properties of the blended flour. The addition of buckwheat flour into wheat flour also increased the antioxidant properties of blended flour proportionally, but metal chelating properties decreased. The incorporation of buckwheat in wheat flour helped in better retention of antioxidant potential of cookies during baking process as buckwheat cookies (100 % buckwheat) showed greater percentage increase in antioxidant properties than control (100 % wheat). Quality characteristics of cookies such as hardness and spread ratio decreased, while as non-enzymatic browning (NEB) increased significantly with increase in the proportion of buckwheat flour in wheat flour. The Overall acceptability of cookies by sensory analysis was highest at 40 % level of blending. This study concluded that addition of buckwheat in wheat flour, may not only improve the physico-chemical and functional properties of the blended flour but may also enhance the nutraceutical potential of the product prepared from it.

  1. Effect of Toothpaste Application Prior to Dental Bleaching on Whitening Effectiveness and Enamel Properties.

    Science.gov (United States)

    Vieira-Junior, W F; Lima, D A N L; Tabchoury, C P M; Ambrosano, G M B; Aguiar, F H B; Lovadino, J R

    2016-01-01

    The purpose of this study was to investigate the effects on the enamel properties and effectiveness of bleaching using 35% hydrogen peroxide (HP) when applying toothpastes with different active agents prior to dental bleaching. Seventy enamel blocks (4 × 4 × 2 mm) were submitted to in vitro treatment protocols in a tooth-brushing machine (n=10): with distilled water and exposure to placebo gel (negative control [NC]) or HP bleaching (positive control [PC]); and brushing with differing toothpastes prior to HP bleaching, including potassium nitrate toothpaste (PN) containing NaF, conventional sodium monofluorophosphate toothpaste (FT), arginine-based toothpastes (PA and SAN), or a toothpaste containing bioactive glass (NM). Color changes were determined using the CIE L*a*b* system (ΔE, ΔL, Δa, and Δb), and a roughness (Ra) analysis was performed before and after treatments. Surface microhardness (SMH) and cross-sectional microhardness (CSMH) were analyzed after treatment. Data were analyzed with repeated measures ANOVA for Ra, one-way ANOVA (SMH, ΔE, ΔL, Δa, and Δb), split-plot ANOVA (CSMH), and Tukey post hoc test (α PA = SAN > all other groups) or decreased HP effects (CSMH). Ra increased in all bleached groups, with the exception of NM, which did not differ from the NC. The variation in the color variables (ΔL, Δa, and Δb) explained 21% of the variation in the physical surface variables (Ra and SMH). The application of toothpaste prior to dental bleaching did not interfere with the effectiveness of treatment. The bioactive glass based toothpaste protected the enamel against the deleterious effects of dental bleaching.

  2. Dielectric properties of perbunan rubber: γ-irradiation effects

    International Nuclear Information System (INIS)

    El-Nour, K.N.A.; Fouda, I.M.; Migahed, M.D.

    1987-01-01

    A systematic dielectric study over a frequency range extending from 200 Hz to 100 kHz and temperature ranging from 20 0 to 60 0 C has been carried out on perbunan rubber. The acrylonitrile content of the rubber samples was 28% and 38%. The effect of 15 MR γ-irradiation on the dielectric properties of both samples was studied and the results are interpreted. The study revealed that NBR-38 is better than NBR-28 for insulating purposes. (author)

  3. Effective thermoelastic properties of composites with periodicity in cylindrical coordinates

    KAUST Repository

    Chatzigeorgiou, George

    2012-09-01

    The aim of this work is to study composites that present cylindrical periodicity in the microstructure. The effective thermomechanical properties of these composites are identified using a modified version of the asymptotic expansion homogenization method, which accounts for unit cells with shell shape. The microscale response is also shown. Several numerical examples demonstrate the use of the proposed approach, which is validated by other micromechanics methods. © 2012 Elsevier Ltd. All rights reserved.

  4. Effect of radiation damage on the infrared properties of apatite

    International Nuclear Information System (INIS)

    Anis Faridah Md Nori; Yusof Mohd Amin; Rosli Mahat; Burhanuddin Kamaluddin

    1991-01-01

    Apatites are known to contain radioactive elements such as uranium and thorium at a few ppm in concentration. These elements decay and produce fission tracks inside the crystals. The presence of such tracks have been known to affect the thermoluminescence (TL) properties of apatites. These fission tracks can be removed by annealing the crystals in air. In this paper we present the result of a preliminary study on the effect of radiation damage on the infrared transmission of apatites

  5. Effects of Bi doping on dielectric and ferroelectric properties

    Indian Academy of Sciences (India)

    [Pb0.95(La1−Bi)0.05][Zr0.53Ti0.47]O3 (PLBZT) ferroelectric thin films have been synthesized on indium tin oxide (ITO)-coated glass by sol–gel processing. PLBZT thin films were annealed at a relatively low temperature of 550 °C in oxygen ambient. Effects of Bi doping on structure, dielectric and ferroelectric properties of ...

  6. Strontium effects on root dentin tubule occlusion and nanomechanical properties.

    Science.gov (United States)

    Saeki, Kuniko; Marshall, Grayson W; Gansky, Stuart A; Parkinson, Charles R; Marshall, Sally J

    2016-02-01

    Dentin hypersensitivity often is treated by promotion of dentin tubule occlusion. In this in vitro study we evaluated nanomechanical properties and degree of tubule occlusion conferred to sound and demineralized human root dentin following treatment with a 10% (w/w) strontium acetate solution and its relation to the treatment duration and delivery method. 24 human cervical root dentin disks (8 groups of 3) were polished through 0.25 μm. 12 disks were subjected to an acid challenge (1% citric acid, pH 3.8) for 2 min. The specimens were incubated in artificial saliva, treated by soaking or brushing with deionized (DI) water or a solution of 10% strontium acetate for 2 min twice a day for 28 days. The occlusion percent and nanomechanical properties were determined at the baseline, 5, 14 and 28 days. Cross-sectioned specimens were prepared to evaluate the depth affected by strontium acetate / dentin interaction by SEM. Statistical analysis was performed using linear mixed effects models. A 10% strontium acetate treatment over 5-28 days significantly increased tubule occlusion for normal root dentin and to a lesser extent for demineralized dentin and increased the AFM based nanomechanical properties of demineralized dentin. Brushing was more effective than soaking in recovery of properties of demineralized dentin when treated with strontium. No difference in tubuleocclusion was found between the two delivery methods. Strontium acetate itself proved to have the ability to occlude dentin tubules and result in small changes in the mechanical properties of dentin. Copyright © 2015 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  7. Effects of prescribed fires on soil properties: A review.

    Science.gov (United States)

    Alcañiz, M; Outeiro, L; Francos, M; Úbeda, X

    2018-02-01

    Soils constitute one of the most valuable resources on earth, especially because soil is renewable on human time scales. During the 20th century, a period marked by a widespread rural exodus and land abandonment, fire suppression policies were adopted facilitating the accumulation of fuel in forested areas, exacerbating the effects of wildfires, leading to severe degradation of soils. Prescribed fires emerged as an option for protecting forests and their soils from wildfires through the reduction of fuels levels. However such fires can serve other objectives, including stimulating the regeneration of a particular plant species, maintaining biological diversity or as a tool for recovering grasslands in encroached lands. This paper reviews studies examining the short- and long- term impacts of prescribed fires on the physical, chemical and biological soil properties; in so doing, it provides a summary of the benefits and drawbacks of this technique, to help determine if prescribed fires can be useful for managing the landscape. From the study conducted, we can affirm that prescribed fires affects soil properties but differ greatly depending on soil initial characteristics, vegetation or type of fire. Also, it is possible to see that soil's physical and biological properties are more strongly affected by prescribed fires than are its chemical properties. Finally, we conclude that prescribed fires clearly constitute a disturbance on the environment (positive, neutral or negative depending on the soil property studied), but most of the studies reviewed report a good recovery and their effects could be less pronounced than those of wildfires because of the limited soil heating and lower fire intensity and severity. Copyright © 2017. Published by Elsevier B.V.

  8. Effects of pore design on mechanical properties of nanoporous silicon

    International Nuclear Information System (INIS)

    Winter, Nicholas; Becton, Matthew; Zhang, Liuyang; Wang, Xianqiao

    2017-01-01

    Nanoporous silicon has been emerging as a powerful building block for next-generation sensors, catalysts, transistors, and tissue scaffolds. The capability to design novel devices with desired mechanical properties is paramount to their reliability and serviceability. In order to bring further resolution to the highly variable mechanical characteristics of nanoporous silicon, here we perform molecular dynamics simulations to study the effects of ligament thickness, relative density, and pore geometry/orientation on the mechanical properties of nanoporous silicon, thereby determining its Young's modulus, ultimate strength, and toughness as well as the scaling laws versus the features of interior ligaments. Results show that pore shape and pattern dictate stress accumulation inside the designed structure, leading to the corresponding failure signature, such as stretching-dominated, bending-dominated, or stochastic failure signatures, in nanoporous silicon. The nanostructure of the material is also seen to drive or mute size effects such as “smaller is stronger” and “smaller is ductile”. This investigation provides useful insight into the behavior of nanoporous silicon and how one might leverage its promising applications. - Graphical abstract: Molecular dynamics simulations are performed to study the effects of ligament thickness, relative density, and pore geometry/orientation on the mechanical properties of nanoporous silicon, thereby determining its Young's modulus, ultimate strength, and toughness as well as the scaling trends versus the features of interior ligaments.

  9. Acid deposition: sources, effects and controls

    Energy Technology Data Exchange (ETDEWEB)

    Longhurst, J.W.S. (ed.)

    1989-01-01

    The purpose of this collection of 19 papers is to review our understanding of the cause and effect of acid deposition, to present new data that assist in the provision of a fuller understanding of cause, process and implication and thus to assist in defining the research agenda of the future. The materials presented are European in perspective, drawn from the Federal Republic of Germany, Hungary, Norway, Sweden and the United Kingdom. The current position as regards deposition monitoring, ecological effects and control technologies is presented in five sections: acid deposition monitoring, freshwater acidification, soils and forest systems, structural materials and control technologies. Each section is introduced by an overview paper outlining the contemporary understanding and identifying areas requiring future work. Specialist papers presenting new data or re-interpretations of existing information comprise the remainder of each section. Four of the papers have been abstracted separately.

  10. Effect of fluoride addition on the properties of dental alginate impression materials.

    Science.gov (United States)

    Lee, Yong-Keun; Lim, Bum-Soon; Kim, Cheol-We

    2004-03-01

    Fluoride-containing dental alginate impression materials can exert a considerable reduction in enamel solubility. The objective was to evaluate the effects of fluoride addition in the alginate impression materials on the properties and subsequent release of fluoride. Four experimental alginate impression materials were studied. Materials were mixed with distilled water (control) or 100-ppm fluoride solution. One or two percent NaF, or 1% SnF2 was added to the materials, which were mixed with distilled water. Fluoride release, flexibility, recovery from deformation, setting time, compressive strength and elastic modulus were determined in accordance with the ISO 1563 and ANSI/ADA Spec. 18. Fluoride release increased after addition of fluoride, and the released amount was 0.762-14.761 ppm. Addition of NaF or SnF2 resulted in higher fluoride release than the control group (p alginate impression material may result in effective release of fluoride without deteriorating the properties of material itself.

  11. Effective regulatory control of radioactive sources

    International Nuclear Information System (INIS)

    Meserve, R.A.

    2001-01-01

    This paper provides an overview of the situation in the USA regarding government control over use of radiation sources, the challenges it faces and the potential paths to their resolution. In the light of the large number of radiation sources in use worldwide, the safety record on balance is remarkably good. But there is still considerable room for improvement. The IAEA has an important role to play, and it is playing it effectively

  12. Effect of γ-ray irradiation on the properties of concrete

    International Nuclear Information System (INIS)

    Muraoka, Susumu; Murase, Yoshinobu; Yamada, Kiyotsugu

    1983-02-01

    In order to obtain the fundamental data of concretes which are used in the construction of storange facilities of HLW, the effect of γ-ray irradiation on the properties of concretes was evaluated. After curing in water for about 4 weeks, concretes were stored under three different condition; 1) heating with γ-ray irradiation, 2) heating without γ-ray irradiation, and 3) controlled at 20 0 C, Relative Humidty of 90%; for 300, 600, and 1200 hours. Then, concretes were tested about the changes of weight, compressive strength, modulus of elasticity, Poisson's ratio, dimension and carbonation depth. Heating temperature were 100, 160 and 190 0 C. Consequently, it was concluded that the effect of γ-ray irradiation within the range of 1.0 x 10 9 R on the properties of concrete was uncertain, and that the effect of heating was more distinguished than γ-ray irradiation effect. (author)

  13. Rheological Properties of Extreme Pressure Greases Measured Using a Process Control Rheometer

    DEFF Research Database (Denmark)

    Glasscock, Julie; Smith, Robin S.

    2012-01-01

    A new process control rheometer (PCR) designed for use in industrial process flows has been used to measure the rheological properties of three extreme-pressure greases. The rheometer is a robust yet sensitive instrument designed to operate in an industrial processing environment in either in......-line or on-line configurations. The PCR was able to measure the rheological properties including the elastic modulus, viscous modulus, and complex viscosity of the greases which in an industrial flow application could be used as variables in a feedback system to control the process and the quality...

  14. Control properties of hybrid distillation processes for the separation of biobutanol

    DEFF Research Database (Denmark)

    Sánchez-Ramírez, Eduardo; Alcocer-García, Heriberto; Quiroz-Ramírez, Juan José

    2017-01-01

    value decomposition technique and a closed-loop dynamic analysis was performed on several hybrid distillation processes including conventional, thermally coupled, thermodynamically equivalent and intensified designs. The results indicated that under the closed-loop control policy, an intensified design...... which is integrated for only two distillation columns instead of three distillation columns, showed good dynamic properties. In addition, thermally coupled sequence A showed better control properties under open-loop analysis. CONCLUSIONS: Using both SVD analysis and closed-loop tests the dynamics...

  15. Effect of activated carbon and electrolyte on properties of supercapacitor

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Effect of activated carbon and electrolyte on electrochemical properties of organic supercapacitor was investigated. The results show that specific surface area and mesoporosity of activated carbon influence specific capacitance. If specific surface area is larger and mesoporosity is higher, the specific capacitance will become bigger. Specific surface area influences resistance of carbon electrode and consequently influences power property and pore size distribution. If specific surface area is smaller and mesoporosity is higher, the power property will become better. Ash influences leakage current and electrochemical cycling stability. If ash content is lower, the performance will become better. The properties of supercapacitor highly depend on the electrolyte. The compatibility of electrolyte and activated carbon is a determining factor of supercapacitor's working voltage. LiPF6/(EC+EMC+DMC) is inappropriate for double layer capacitor. MeEt3NPF4/PC has higher specific capacitance than EtnNPFn/PC because methyl's electronegativity value is lower than ethyl and MeEt3N+ has more positive charges and stronger polarizability than Et4N+ when an ethyl is substituted by methyl.

  16. Effect of Surface Treatment on the Properties of Wool Fabric

    Science.gov (United States)

    Kan, C. W.; Yuen, C. W. M.; Chan, C. K.; Lau, M. P.

    Wool fiber is commonly used in textile industry, however, it has some technical problems which affect the quality and performance of the finished products such as felting shrinkage, handle, lustre, pilling, and dyeability. These problems may be attributed mainly in the presence of wool scales on the fiber surface. Recently, chemical treatments such as oxidation and reduction are the commonly used descaling methods in the industry. However, as a result of the pollution caused by various chemical treatments, physical treatment such as low temperature plasma (LTP) treatment has been introduced recently because it is similarly capable of achieving a comparable descaling effect. Most of the discussions on the applications of LTP treatment on wool fiber were focused on applying this technique for improving the surface wettability and shrink resistance. Meanwhile, little discussion has been made on the mechanical properties, thermal properties, and the air permeability. In this paper, wool fabric was treated with LTP treatment with the use of a non-polymerizing gas, namely oxygen. After the LTP treatment, the fabrics low-stress mechanical properties, air permeability, and thermal properties were evaluated and discussed.

  17. Effects of Coal Gangue on Cement Grouting Material Properties

    Science.gov (United States)

    Liu, J. Y.; Chen, H. X.

    2018-05-01

    The coal gangue is one of the most abundant industrial solid wastes and pollute source of air and water. The use of coal gangue in the production of cement grouting material comforms to the basic state policy of environment protection and the circular using of natural resources. Through coal gangue processing experiment, coal gangue cement grouting materials making test, properties detection of properties and theoretical analysis, the paper studied the effects of coal gangue on the properties of cement grouting materials. It is found that at the range of 600 to 700 °C, the fluidity and the compressive and flexural strengths of the cement grouting materials increase with the rising up of the calcination temperatures of coal gangue. The optimum calcination temperature is around 700 °C. The part substitution of cement by the calcined coal gangue in the cement grouting material will improve the mechanical properties of the cement grouting material, even thought it will decrease its fluidity. The best substitution amount of cement by coal gangue is about 30%. The fluidity and the long term strength of the ordinary silicate cement grouting material is obviously higher than that of the sulphoaluminate cement one as well as that of the silicate-sulphoaluminate complex cement one.

  18. Effect of Melting Techniques on Ductile Iron castings Properties

    Directory of Open Access Journals (Sweden)

    Bockus, S.

    2006-01-01

    Full Text Available The study was designed to investigate the effects of the charge, melting conditions, nodularizing and inoculation on the ductile iron castings properties. Results showed that the temperature and holding time of the melt in an induction furnace and the intensity of spheroidizing effect on the carbon and residual magnesium contents in the ductile iron castings. The same grade of ductile iron may be obtained using different chemical compositions. The castings of ductile iron will be ferritic as-cast only when large amount of pig iron in the charge and in addition some-steps inoculating treatment are used.

  19. Effect of smelt aluminium on mechanical properties of steels

    International Nuclear Information System (INIS)

    Ryabov, V.R.; Dykhno, I.S.; Deev, G.F.; Karikh, V.V.

    1987-01-01

    Effect of smelt aluminium on mechanical properties of armco-iron and 12 Kh18N10T steel is studied. It is stated that in smelt aluminium and aluminium alloy contact with armco-iron the sample ductility is decreased. Corrosion effect of smelt alluminium on (18Kh15N5AM3) steel in the form of reinforced wire in aluminium-steel KAS-1A composite material is investigted. It is stated in experiment that during smelt alluminium-steel contact interaction of heterogeneous phases takes place

  20. Heat treatment effect on the mechanical properties of industrial drawn copper wires

    International Nuclear Information System (INIS)

    Beribeche, Abdellatif; Boumerzoug, Zakaria; Ji, Vincent

    2013-01-01

    In this present investigation, the mechanical properties of industrial drawn copper wires have been studied by tensile tests. The effect of prior heat treatments at 500°C on the drawn wires behavior was the main goal of this investigation. We have found that the mechanical behavior of drawn wires depends strongly on those treatments. SEM observations of the wire cross section after tensile tests have shown that the mechanism of rupture was mainly controlled by the void formation

  1. Solar Sail Material Performance Property Response to Space Environmental Effects

    Science.gov (United States)

    Edwards, David L.; Semmel, Charles; Hovater, Mary; Nehls, Mary; Gray, Perry; Hubbs, Whitney; Wertz, George

    2004-01-01

    The National Aeronautics and Space Administration's (NASA) Marshall Space Flight Center (MSFC) continues research into the utilization of photonic materials for spacecraft propulsion. Spacecraft propulsion, using photonic materials, will be achieved using a solar sail. A solar sail operates on the principle that photons, originating from the sun, impart pressure to the sail and therefore provide a source for spacecraft propulsion. The pressure imparted to a solar sail can be increased, up to a factor of two, if the sun-facing surface is perfectly reflective. Therefore, these solar sails are generally composed of a highly reflective metallic sun-facing layer, a thin polymeric substrate and occasionally a highly emissive back surface. Near term solar sail propelled science missions are targeting the Lagrange point 1 (Ll) as well as locations sunward of L1 as destinations. These near term missions include the Solar Polar Imager and the L1 Diamond. The Environmental Effects Group at NASA s Marshall Space Flight Center (MSFC) continues to actively characterize solar sail material in preparation for these near term solar sail missions. Previous investigations indicated that space environmental effects on sail material thermo-optical properties were minimal and would not significantly affect the propulsion efficiency of the sail. These investigations also indicated that the sail material mechanical stability degrades with increasing radiation exposure. This paper will further quantify the effect of space environmental exposure on the mechanical properties of candidate sail materials. Candidate sail materials for these missions include Aluminum coated Mylar[TM], Teonex[TM], and CPl (Colorless Polyimide). These materials were subjected to uniform radiation doses of electrons and protons in individual exposures sequences. Dose values ranged from 100 Mrads to over 5 Grads. The engineering performance property responses of thermo-optical and mechanical properties were

  2. Foam property tests to evaluate the potential for longwall shield dust control.

    Science.gov (United States)

    Reed, W R; Beck, T W; Zheng, Y; Klima, S; Driscoll, J

    2018-01-01

    Tests were conducted to determine properties of four foam agents for their potential use in longwall mining dust control. Foam has been tried in underground mining in the past for dust control and is currently being reconsidered for use in underground coal longwall operations in order to help those operations comply with the Mine Safety and Health Administration's lower coal mine respirable dust standard of 1.5 mg/m 3 . Foams were generated using two different methods. One method used compressed air and water pressure to generate foam, while the other method used low-pressure air generated by a blower and water pressure using a foam generator developed by the U.S. National Institute for Occupational Safety and Health. Foam property tests, consisting of a foam expansion ratio test and a water drainage test, were conducted to classify foams. Compressed-air-generated foams tended to have low expansion ratios, from 10 to 19, with high water drainage. Blower-air-generated foams had higher foam expansion ratios, from 30 to 60, with lower water drainage. Foams produced within these ranges of expansion ratios are stable and potentially suitable for dust control. The test results eliminated two foam agents for future testing because they had poor expansion ratios. The remaining two foam agents seem to have properties adequate for dust control. These material property tests can be used to classify foams for their potential use in longwall mining dust control.

  3. Surface effects on the mechanical properties of nanoporous materials

    International Nuclear Information System (INIS)

    Lu Zixing; Zhang Cungang; Liu Qiang; Yang Zhenyu

    2011-01-01

    In this paper, surface effects on the mechanical behaviour of nanoporous materials are investigated using the theory of surface elasticity and Timoshenko beam theory based on the tetrakaidecahedron (or Kelvin) open-cell foam model. Meanwhile, the influence of surface elasticity and residual surface stress on the mechanical properties of nanoporous materials is discussed. In addition, the results derived from the theory of Euler-Bernoulli beam model are also provided for comparison. Theoretical results show that the effective Young's modulus of the nanoporous materials increases as the diameter of the strut decreases, but in contrast Poisson's ratio and the brittle collapse strength decrease with the diameter of the strut. The contribution of shear deformation to surface effects on elastic properties is more significant, while the surface effects on brittle collapse strength are not sensitive to shear deformation, and it can even be neglected. As the strut size increases, the present results can be reduced to the cases without considering surface effects, which verifies the efficiency of the present model to a certain extent.

  4. Materials science in microelectronics II the effects of structure on properties in thin films

    CERN Document Server

    Machlin, Eugene

    2005-01-01

    The subject matter of thin-films - which play a key role in microelectronics - divides naturally into two headings: the processing / structure relationship, and the structure / properties relationship. Part II of 'Materials Science in Microelectronics' focuses on the latter of these relationships, examining the effect of structure on the following: Electrical properties Magnetic properties Optical properties Mechanical properties Mass transport properties Interface and junction properties Defects and properties Captures the importance of thin films to microelectronic development Examines the cause / effect relationship of structure on thin film properties.

  5. Numerical calculations of effective elastic properties of two cellular structures

    International Nuclear Information System (INIS)

    Tuncer, Enis

    2005-01-01

    Young's moduli of regular two-dimensional truss-like and eye-shaped structures are simulated using the finite element method. The structures are idealizations of soft polymeric materials used in ferro-electret applications. In the simulations, the length scales of the smallest representative units are varied, which changes the dimensions of the cell walls in the structures. A power-law expression with a quadratic as the exponent term is proposed for the effective Young's moduli of the systems as a function of the solid volume fraction. The data are divided into three regions with respect to the volume fraction: low, intermediate and high. The parameters of the proposed power-law expression in each region are later represented as a function of the structural parameters, the unit-cell dimensions. The expression presented can be used to predict a structure/property relationship in materials with similar cellular structures. The contribution of the cell-wall thickness to the elastic properties becomes significant at concentrations >0.15. The cell-wall thickness is the most significant factor in predicting the effective Young's modulus of regular cellular structures at high volume fractions of solid. At lower concentrations of solid, the eye-shaped structure yields a lower Young's modulus than a truss-like structure with similar anisotropy. Comparison of the numerical results with those of experimental data for poly(propylene) show good agreement regarding the influence of cell-wall thickness on elastic properties of thin cellular films

  6. Effects of Charcoal Addition on the Properties of Carbon Anodes

    Directory of Open Access Journals (Sweden)

    Asem Hussein

    2017-03-01

    Full Text Available Wood charcoal is an attractive alternative to petroleum coke in production of carbon anodes for the aluminum smelting process. Calcined petroleum coke is the major component in the anode recipe and its consumption results in a direct greenhouse gas (GHG footprint for the industry. Charcoal, on the other hand, is considered as a green and abundant source of sulfur-free carbon. However, its amorphous carbon structure and high contents of alkali and alkaline earth metals (e.g., Na and Ca make charcoal highly reactive to air and CO2. Acid washing and heat treatment were employed in order to reduce the reactivity of charcoal. The pre-treated charcoal was used to substitute up to 10% of coke in the anode recipe in an attempt to investigate the effect of this substitution on final anode properties. The results showed deterioration in the anode properties by increasing the charcoal content. However, by adjusting the anode recipe, this negative effect can be considerably mitigated. Increasing the pitch content was found to be helpful to improve the physical properties of the anodes containing charcoal.

  7. Immediate effect of exercise on achilles tendon properties: systematic review.

    Science.gov (United States)

    Obst, Steven J; Barrett, Rod S; Newsham-West, Richard

    2013-08-01

    Understanding the mechanical and morphological adaptation of the Achilles tendon (AT) in response to acute exercise could have important implications for athletic performance, injury prevention, and rehabilitation. The purpose of this study was to conduct a systematic review and critical evaluation of the literature to determine the immediate effect of a single bout of exercise on the mechanical and morphological properties of the AT in vivo. Five electronic research databases were systematically searched for intervention-based studies reporting mechanical and morphological properties of the AT after a single bout of exercise. Searches revealed 3292 possible articles; 21 met the inclusion criteria. There is evidence that maximal isometric contractions and prolonged static stretching (>5 min) of the triceps surae complex cause an immediate decrease in AT stiffness, whereas prolonged running and hopping have minimal effect. Limited but consistent evidence exists, indicating that AT hysteresis is reduced after prolonged static stretching. Consistent evidence supports a reduction in free AT diameter (anterior-posterior) after dynamic ankle exercise, and this change appears most pronounced in the healthy tendon and after eccentric exercise. The mechanical and morphological properties of the AT in vivo are affected by acute exercise in a mode- and dose-dependent manner. Transient changes in AT stiffness, hysteresis, and diameter after unaccustomed exercise modes and doses may expose the tendon to increased risk of strain injury and impact on the mechanical function of the triceps surae muscle-tendon unit.

  8. Effects of weather and tailings properties on tailings drying times

    Energy Technology Data Exchange (ETDEWEB)

    Gantzer, C.; Fasking, T.; Costello, M.; Greenwood, J. [Barr Engineering, Calgary, AB (Canada)

    2010-07-01

    This PowerPoint presentation presented the results of a study conducted to determine the effects of weather and tailings properties on tailings drying times. Weather conditions have a significant impact the potential evaporation (PE) and actual evaporation (AE) of oil sands tailings. A 2-stage drying of slurry at a constant PE was conducted to determine the shrinkage limit of untreated mature fine tailings (MFT). An evaporation and seepage model was used to determine maximum first-stage drying rates. Measurements were also taken in a wind tunnel. Potential evaporation rates were calculated and evaporative water losses from the MFT were determined. Estimated drying times were presented. Results of the approach were compared with field measurements conducted in a previous study. Results of the study showed that evaporative water loss rates for May through August were limited by the properties of the tailings. Water loss rates were limited by weather for other months in the year-long study. tabs., figs.

  9. Effect of helium on tensile properties of vanadium alloys

    Energy Technology Data Exchange (ETDEWEB)

    Chung, H.M.; Billone, M.C.; Smith, D.L. [Argonne National Lab., IL (United States)

    1997-08-01

    Tensile properties of V-4Cr-4Ti (Heat BL-47), 3Ti-1Si (BL-45), and V-5Ti (BL-46) alloys after irradiation in a conventional irradiation experiment and in the Dynamic Helium Charging Experiment (DHCE) were reported previously. This paper presents revised tensile properties of these alloys, with a focus on the effects of dynamically generated helium of ductility and work-hardening capability at <500{degrees}C. After conventional irradiation (negligible helium generation) at {approx}427{degrees}C, a 30-kg heat of V-4Cr-4Ti (BL-47) exhibited very low uniform elongation, manifesting a strong susceptibility to loss of work-hardening capability. In contrast, a 15-kg heat of V-3Ti-1Si (BL -45) exhibited relatively high uniform elongation ({approx}4%) during conventional irradiation at {approx}427{degrees}C, showing that the heat is resistant to loss of work-hardening capability.

  10. Effects of gamma radiation on sensorial properties in black tea

    Energy Technology Data Exchange (ETDEWEB)

    Silveira, Ana Paula M.; Fanaro, Gustavo B.; Costa, Helbert S.F.; Silva, Priscila V.; Santillo, Amanda G.; Villavicencio, Anna Lucia C.H., E-mail: ana.paula.silveira@usp.b, E-mail: villavic@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2009-07-01

    The black tea (Camellia sinensis) is the most consumed beverage in the world and its consumption has increased, manly in occidental countries, due to the fact that this drink has large antioxidants quantities. In this type of tea, the taste determines the product qualities and its final value. Several studies reported that food irradiation is an excellent process to disinfect food, reducing storage losses and extended its shelf life. This treatment can inhibit cellular division, promoting a molecular and DNA structural modification. Depending on the dose applied, the irradiation can modify sensorial properties, influencing the marked cost. The sensorial analysis is one of the main tests to detect any better or worse changes, by consumers. The aim of this study is to evaluate the effect of ionizing radiation on sensorial properties in black tea. Samples will be irradiated with a {sup 60}Co source, at doses of 0, 5, and 10 kGy. (author)

  11. Effects of gamma radiation on sensorial properties in black tea

    International Nuclear Information System (INIS)

    Silveira, Ana Paula M.; Fanaro, Gustavo B.; Costa, Helbert S.F.; Silva, Priscila V.; Santillo, Amanda G.; Villavicencio, Anna Lucia C.H.

    2009-01-01

    The black tea (Camellia sinensis) is the most consumed beverage in the world and its consumption has increased, manly in occidental countries, due to the fact that this drink has large antioxidants quantities. In this type of tea, the taste determines the product qualities and its final value. Several studies reported that food irradiation is an excellent process to disinfect food, reducing storage losses and extended its shelf life. This treatment can inhibit cellular division, promoting a molecular and DNA structural modification. Depending on the dose applied, the irradiation can modify sensorial properties, influencing the marked cost. The sensorial analysis is one of the main tests to detect any better or worse changes, by consumers. The aim of this study is to evaluate the effect of ionizing radiation on sensorial properties in black tea. Samples will be irradiated with a 60 Co source, at doses of 0, 5, and 10 kGy. (author)

  12. Numerical Simulation of Effective Properties of 3D Piezoelectric Composites

    Directory of Open Access Journals (Sweden)

    Ri-Song Qin

    2014-01-01

    Full Text Available The prediction of the overall effective properties of fibre-reinforced piezocomposites has drawn much interest from investigators recently. In this work, an algorithm used in two-dimensional (2D analysis for calculating transversely isotropic material properties is developed. Since the finite element (FE meshing patterns on the opposite areas are the same, constraint equations can be applied directly to generate appropriate load. The numerical results derived using this model have found a good agreement with those in the literature. The 2D algorithm is then modified and improved in such a way that it is valid for three-dimensional (3D analysis in the case of random distributed shorts and inclusions. Linear interpolation of displacement field is employed to establish constraint equations of nodal displacements between two adjacent elements.

  13. Effect of localized polycrystalline silicon properties on solar cell performance

    Science.gov (United States)

    Leung, D.; Iles, P. A.; Hyland, S.; Kachare, A.

    1984-01-01

    Several forms of polycrystalline silicon, mostly from cast ingots, (including UCP, SILSO and HEM) were studied. On typical slices, localized properties were studied in two ways. Small area (about 2.5 sq mm) mesa diodes were formed, and localized photovoltaic properties were measured. Also a small area (about .015 sq mm) light spot was scanned across the cells; the light spot response was calibrated to measure local diffusion length directly. Using these methods, the effects of grain boundaries, or of intragrain imperfections were correlated with cell performance. Except for the fine grain portion of SILSO, grain boundaries played only a secondary role in determining cell performance. The major factor was intra-grain material quality and it varied with position in ingots and probably related to solidification procedure.

  14. Gamma radiation effect study in polycarbonate optical and mechanics properties

    International Nuclear Information System (INIS)

    Araujo, E.S. de.

    1991-02-01

    Polycarbonates (PC) are used in different industrial applications due to their excellent dielectric characteristics, impact resistance, and high temperature resistance. In some of these applications, the polycarbonates are exposed to gamma radiation which produces molecular scissions, causing changes in the polycarbonate properties. To estimate the radiation effects in the Durolon polycarbonate, samples were irradiated with 60 Co gamma rays with doses between 0,2 kGy and 300 kGy. The results obtained showed that the PC mechanical properties are not changed due to the gamma radiation. However the results showed an expressive variation in the yellowness index for doses above 1 kGy. The results showed that it is possible to use the gamma sterilization of PC in applications where the coloration of PC is not critical. (author). 21 refs, 25 figs, 3 tabs

  15. Transformation properties of the effective action for gauge theories

    International Nuclear Information System (INIS)

    Otten, C.M.E.

    1978-01-01

    The main purpose of this thesis is to investigate the gauge invariance properties of the effective action. In fact, the Slavnov-Taylor identities for the effective action are nothing but a compact formulation of the gauge symmetry properties of the theory. Chapter II of this thesis focuses on the derivation of the Slavnov-Taylor identities for a general gauge theory, especially the identities for proper vertices. An analysis of the group- and invariance structure of the effective action is given, using both diagrammatic and functional techniques. Moreover, the Slavnov-Taylor identities are written out explicitely up to the order g 4 , where g is the coupling constant of the theory. The general theory outlined in chapter II is applied to an SU(2) model containing vector bosons, scalar particles and leptons. Specifically, the interplay between finite one-loop effects and the invariance structure of the model is studied in a certain limit (the so-called large Higgs mass limit). It is shown that the results can be fully interpreted on the basis of the Slavnov-Taylor identities for proper vertices. This is done in chapter III. (Auth.)

  16. Interface engineering for oxide electronics: tuning electronic properties by atomically controlled growth

    NARCIS (Netherlands)

    Huijben, Mark

    2006-01-01

    The main aim of this thesis is to develop a controlled growth with atomic precision for the realization of artificial perovskite structures, to exploit the exceptional physical properties of complex oxide materials such as high-temperature superconductors and conducting interfaces between band

  17. Effect of brief heat-curing on microstructure and mechanical properties in fresh cement based mortars

    International Nuclear Information System (INIS)

    Ballester, P.; Hidalgo, A.; Marmol, I.; Morales, J.; Sanchez, L.

    2009-01-01

    The effect of temperature on fresh mortar and cement paste was evaluated by simulating the curing conditions of external buildings plastering applied under extremely hot weather. The specimens were heated at controlled temperatures in the 40-80 o C range by exposure to IR radiation over short periods. The effect of soaking for a short time was also examined. The results of compressive strength tests, scanning electron microscopy, infrared spectroscopy and mercury porosimetry helped to characterize the mechanical and physico-chemical properties of the studied sample. Early age behaviour (28 days) in neat cement was barely affected by the temperature. By contrast, exposure to high temperatures caused significant microstructural changes in the mortar. However, successive soaking over short periods was found to reactivate the mechanism of curing and restore the expected mechanical properties. Based on the results, application of cement based mortar at high temperatures is effective when followed by a short, specific soaking process.

  18. The effect of listing the lesser prairie chicken as a threatened species on rural property values.

    Science.gov (United States)

    Wietelman, Derek C; Melstrom, Richard T

    2017-04-15

    This paper estimates the effect of Endangered Species Act protections for the lesser prairie chicken (Tympanuchus pallidicinctus) on rural property values in Oklahoma. The political and legal controversy surrounding the listing of imperiled species raises questions about the development restrictions and opportunity costs the Endangered Species Act imposes on private landowners. Examining parcel-level sales data before and after the listing of the endemic lesser prairie chicken, we employ difference-in-differences (DD) regression to measure the welfare costs of these restrictions. While our basic DD regression provides evidence the listing was associated with a drop in property values, this finding does not hold up in models that control for latent county and year effects. The lack of a significant price effect is confirmed by several robustness checks. Thus, the local economic costs of listing the lesser prairie chicken under the Endangered Species Act appear to have been small. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Effects of C3+ ion irradiation on structural, electrical and magnetic properties of Ni nanotubes

    Science.gov (United States)

    Shlimas, D. I.; Kozlovskiy, A. L.; Zdorovets, M. V.; Kadyrzhanov, K. K.; Uglov, V. V.; Kenzhina, I. E.; Shumskaya, E. E.; Kaniukov, E. Y.

    2018-03-01

    Ion irradiation is an attractive method for obtaining nanostructures that can be used under extreme conditions. Also, it is possible to control the technological process that allows obtaining nanomaterials with new properties at ion irradiation. In this paper, we study the effect of irradiation with 28 MeV C3+ ions and fluences up to 5 × 1011 cm-2 on the structure and properties of template-synthesized nickel nanotubes with a length of 12 μm, with diameters of 400 nm, and a wall thickness of 100 nm. It is demonstrated that the main factor influencing the degradation of nanostructures under irradiation in PET template is the processes of mixing the material of nanostructures with the surrounding polymer. The influence of irradiation with various fluences on the crystal structure, electrical and magnetic properties of nickel nanotubes is studied.

  20. The preparation of UO2 powder: effect of ammonium uranate properties

    International Nuclear Information System (INIS)

    Woolfrey, J.L.

    1978-01-01

    Ammonium uranate (AU) powders were precipitated from a uranyl nitrate solution with gaseous ammonia. The decomposition of the powders in hydrogen was studied to determine those properties of AU which affect the decomposition reactions and influence the properties of the final UO 2 powder. The thermal decomposition was affected by the initial composition (ammonia and nitrate content) and the morphology of the AU powders. The amount of self-reduction increased with increasing combined ammonia content and decreased with increasing nitrate content. The specific surface area of the decomposed powder increased with increasing total ammonia content and initial surface area of the precursor AU powder. Thermal treatment of the decomposed powder can be used to modify such effects and, in commercial powder production, is used to control the properties of the final UO 2 powder. (Auth.)

  1. Effect of Al-doped YCrO3 on structural, electronic and magnetic properties

    Science.gov (United States)

    Durán, A.; Verdín, E.; Conde, A.; Escamilla, R.

    2018-05-01

    Structural, dielectric and magnetic properties were investigated in the YCr1-xAlxO3 with 0 cell volume of the orthorhombic structure without changes in the oxidation state of the Cr3+ ions. We discuss two mechanisms that could have a significant influence on the magnetic properties. The first is related to local deformation occurring for x structure. The local deformation is controlled by the inclination of the octahedrons and the octahedral distortion having a strong effect on the TN and the coercive field at low Al concentrations. On the other hand, the decreasing of the magnetization values (Mr and Hc) is ascribed to changes in the electronic structure, which is confirmed by a decreasing of the contribution of Cr 3d states at Fermi level due to increasing Al3+ content. Thus, we analyzed and discussed that both mechanisms influence the electronic properties of the YCr1-xAlxO3 solid solution.

  2. Effect of THI on milk coagulation properties of Holstein-Friesian dairy cattle

    Directory of Open Access Journals (Sweden)

    Simone Beux

    Full Text Available ABSTRACT The objective of this study was to evaluate the effect of temperature-humidity index (THI on the milk coagulation properties of Holstein-Friesian dairy cattle from northeast part of Italy. A total of 592 individual milk samples from six dairy herds were evaluated. The milk coagulation properties traits analysed were milk rennet coagulation time and curd firmness, as well as the fat, protein, and casein contents, pH, milk aptitude to coagulate (IAC, and the somatic cell count. The THI was determined during the periods of sample collection. The THI results showed that values of up to 75 did not significantly change the IAC values; however, when the THI values were above 75, the IAC decreased significantly. The control of THI can be used to guarantee appropriate milk coagulation properties.

  3. Effect of PVA fiber content on creep property of fiber reinforced high-strength concrete columns

    Science.gov (United States)

    Xu, Zongnan; Wang, Tao; Wang, Weilun

    2018-04-01

    The effect of PVA (polyvinyl alcohol) fiber content on the creep property of fiber reinforced high-strength concrete columns was investigated. The correction factor of PVA fiber content was proposed and the creep prediction model of ACI209 was modified. Controlling the concrete strength as C80, changing the content of PVA fiber (volume fraction 0%, 0.25%, 0.5%, 1% respectively), the creep experiment of PVA fiber reinforced concrete columns was carried out, the creep coefficient of each specimen was calculated to characterize the creep property. The influence of PVA fiber content on the creep property was analyzed based on the creep coefficient and the calculation results of several frequently used creep prediction models. The correction factor of PVA fiber content was proposed to modify the ACI209 creep prediction model.

  4. Effect of soil properties on the toxicity of Pb: assessment of the appropriateness of guideline values.

    Science.gov (United States)

    Romero-Freire, A; Martin Peinado, F J; van Gestel, C A M

    2015-05-30

    Soil contamination with lead is a worldwide problem. Pb can cause adverse effects, but its mobility and availability in the terrestrial environment are strongly controlled by soil properties. The present study investigated the influence of different soil properties on the solubility of lead in laboratory spiked soils, and its toxicity in three bioassays, including Lactuca sativa root elongation and Vibrio fischeri illumination tests applied to aqueous extracts and basal soil respiration assays. Final aim was to compare soil-dependent toxicity with guideline values. The L. sativa bioassay proved to be more sensitive to Pb toxicity than the V. fischeri and soil respiration tests. Toxicity was significantly correlated with soil properties, with soil pH, carbonate and organic carbon content being the most important factors. Therefore, these variables should be considered when defining guideline values. Copyright © 2015 Elsevier B.V. All rights reserved.

  5. Effects of plant cover on properties of rhizosphere and inter-plant soil in a semiarid valley, SW China

    NARCIS (Netherlands)

    Qu, Laiye; Huang, Yuanyuan; Ma, Keming; Zhang, Yuxin; Biere, A.

    2016-01-01

    Plant establishment is widely recognized as an effective way to prevent soil erosion in arid and semiarid ecosystems. Artemisia gmelinii, a pioneering species in many degraded ecosystems in China, is effective in improving soil properties and controlling runoff and soil loss, but mechanisms

  6. The Hawthorne Effect: a randomised, controlled trial

    Directory of Open Access Journals (Sweden)

    van Haselen Robbert

    2007-07-01

    Full Text Available Abstract Background The 'Hawthorne Effect' may be an important factor affecting the generalisability of clinical research to routine practice, but has been little studied. Hawthorne Effects have been reported in previous clinical trials in dementia but to our knowledge, no attempt has been made to quantify them. Our aim was to compare minimal follow-up to intensive follow-up in participants in a placebo controlled trial of Ginkgo biloba for treating mild-moderate dementia. Methods Participants in a dementia trial were randomised to intensive follow-up (with comprehensive assessment visits at baseline and two, four and six months post randomisation or minimal follow-up (with an abbreviated assessment at baseline and a full assessment at six months. Our primary outcomes were cognitive functioning (ADAS-Cog and participant and carer-rated quality of life (QOL-AD. Results We recruited 176 participants, mainly through general practices. The main analysis was based on Intention to treat (ITT, with available data. In the ANCOVA model with baseline score as a co-variate, follow-up group had a significant effect on outcome at six months on the ADAS-Cog score (n = 140; mean difference = -2.018; 95%CI -3.914, -0.121; p = 0.037 favouring the intensive follow-up group, and on participant-rated quality of life score (n = 142; mean difference = -1.382; 95%CI -2.642, -0.122; p = 0.032 favouring minimal follow-up group. There was no significant difference on carer quality of life. Conclusion We found that more intensive follow-up of individuals in a placebo-controlled clinical trial of Ginkgo biloba for treating mild-moderate dementia resulted in a better outcome than minimal follow-up, as measured by their cognitive functioning. Trial registration Current controlled trials: ISRCTN45577048

  7. Thermodynamic properties and transport coefficients of a two-temperature polytetrafluoroethylene vapor plasma for ablation-controlled discharge applications

    Science.gov (United States)

    Wang, Haiyan; Wang, Weizong; Yan, Joseph D.; Qi, Haiyang; Geng, Jinyue; Wu, Yaowu

    2017-10-01

    Ablation-controlled plasmas have been used in a range of technical applications where local thermodynamic equilibrium (LTE) is often violated near the wall due to the strong cooling effect caused by the ablation of wall materials. The thermodynamic and transport properties of ablated polytetrafluoroethylene (PTFE) vapor, which determine the flowing plasma behavior in such applications, are calculated based on a two-temperature model at atmospheric pressure. To our knowledge, no data for PTFE have been reported in the literature. The species composition and thermodynamic properties are numerically determined using the two-temperature Saha equation and the Guldberg-Waage equation according to van de Sanden et al’s derivation. The transport coefficients, including viscosity, thermal conductivity and electrical conductivity, are calculated with the most recent collision interaction potentials using Devoto’s electron and heavy-particle decoupling approach but expanded to the third-order approximation (second-order for viscosity) in the frame of the Chapman-Enskog method. Results are computed for different degrees of thermal non-equilibrium, i.e. the ratio of electron to heavy-particle temperatures, from 1 to 10, with electron temperature ranging from 300 to 40 000 K. Plasma transport properties in the LTE state obtained from the present work are compared with existing published results and the causes for the discrepancy analyzed. The two-temperature plasma properties calculated in the present work enable the modeling of wall ablation-controlled plasma processes.

  8. Thermodynamic properties and transport coefficients of a two-temperature polytetrafluoroethylene vapor plasma for ablation-controlled discharge applications

    International Nuclear Information System (INIS)

    Wang, Haiyan; Qi, Haiyang; Wang, Weizong; Yan, Joseph D; Geng, Jinyue; Wu, Yaowu

    2017-01-01

    Ablation-controlled plasmas have been used in a range of technical applications where local thermodynamic equilibrium (LTE) is often violated near the wall due to the strong cooling effect caused by the ablation of wall materials. The thermodynamic and transport properties of ablated polytetrafluoroethylene (PTFE) vapor, which determine the flowing plasma behavior in such applications, are calculated based on a two-temperature model at atmospheric pressure. To our knowledge, no data for PTFE have been reported in the literature. The species composition and thermodynamic properties are numerically determined using the two-temperature Saha equation and the Guldberg–Waage equation according to van de Sanden et al ’s derivation. The transport coefficients, including viscosity, thermal conductivity and electrical conductivity, are calculated with the most recent collision interaction potentials using Devoto’s electron and heavy-particle decoupling approach but expanded to the third-order approximation (second-order for viscosity) in the frame of the Chapman–Enskog method. Results are computed for different degrees of thermal non-equilibrium, i.e. the ratio of electron to heavy-particle temperatures, from 1 to 10, with electron temperature ranging from 300 to 40 000 K. Plasma transport properties in the LTE state obtained from the present work are compared with existing published results and the causes for the discrepancy analyzed. The two-temperature plasma properties calculated in the present work enable the modeling of wall ablation-controlled plasma processes. (paper)

  9. Enhancing the photoresponse and photocatalytic properties of TiO2 by controllably tuning defects across {101} facets

    Science.gov (United States)

    Wan, Piaopiao; Hood, Zachary D.; Adhikari, Shiba P.; Xu, Yunfan; Yang, Shize; Wu, Sujuan

    2018-03-01

    Introducing defects into semiconductors with well-controlled exposed facets offers an effective route for the development of photocatalytic materials with greatly improved properties. Here, we report a facile ethylene glycol reduction procedure to make anatase titanium dioxide (TiO2) with different concentrations of exposed {001} and {101} facets, leading to different surficial defects. TiO2 with increased concentrations of {101} facets shows a 5-fold improvement in photocurrent generation as well as improved photocatalytic activity towards water splitting under visible light irradiation. The improved activity is ascribed to the oxygen vacancies as well as the variable surface chemical states, which collectively induce a slower recombination rate of photo-induced electron-hole pairs. This work also highlights a feasible strategy to obtain the defective TiO2 and explore the synergistic effect of surface defects and different concentrations of exposed {001} and {101} facets for photocurrent and photocatalytic properties under visible light irradiation.

  10. Surface effects on the mechanical properties of nanoporous materials

    International Nuclear Information System (INIS)

    Xia Re; Li Xide; Feng Xiqiao; Qin Qinghua; Liu Jianlin

    2011-01-01

    Using the theory of surface elasticity, we investigate the mechanical properties of nanoporous materials. The classical theory of porous materials is modified to account for surface effects, which become increasingly important as the characteristic sizes of microstructures shrink to nanometers. First, a refined Timoshenko beam model is presented to predict the effective elastic modulus of nanoporous materials. Then the surface effects on the elastic microstructural buckling behavior of nanoporous materials are examined. In particular, nanoporous gold is taken as an example to illustrate the application of the proposed model. The results reveal that both the elastic modulus and the critical buckling behavior of nanoporous materials exhibit a distinct dependence on the characteristic sizes of microstructures, e.g. the average ligament width.

  11. Surface effects on the mechanical properties of nanoporous materials

    Energy Technology Data Exchange (ETDEWEB)

    Xia Re [School of Power and Mechanical Engineering, Wuhan University, Wuhan 430072 (China); Li Xide; Feng Xiqiao [AML, Department of Engineering Mechanics, Tsinghua University, Beijing 100084 (China); Qin Qinghua [School of Engineering, Australian National University, Canberra, ACT 0200 (Australia); Liu Jianlin, E-mail: fengxq@tsinghua.edu.cn [Department of Engineering Mechanics, China University of Petroleum, Qingdao 266555 (China)

    2011-07-01

    Using the theory of surface elasticity, we investigate the mechanical properties of nanoporous materials. The classical theory of porous materials is modified to account for surface effects, which become increasingly important as the characteristic sizes of microstructures shrink to nanometers. First, a refined Timoshenko beam model is presented to predict the effective elastic modulus of nanoporous materials. Then the surface effects on the elastic microstructural buckling behavior of nanoporous materials are examined. In particular, nanoporous gold is taken as an example to illustrate the application of the proposed model. The results reveal that both the elastic modulus and the critical buckling behavior of nanoporous materials exhibit a distinct dependence on the characteristic sizes of microstructures, e.g. the average ligament width.

  12. Micromagnetic modeling of the effects of stress on magnetic properties

    International Nuclear Information System (INIS)

    Zhu, B.; Lo, C. C. H.; Lee, S. J.; Jiles, D. C.

    2001-01-01

    A micromagnetic model has been developed for investigating the effect of stress on the magnetic properties of thin films. This effect has been implemented by including the magnetoelastic energy term into the Landau - Lifshitz - Gilbert equation. Magnetization curves of a nickel film were calculated under both tensile and compressive stresses of various magnitudes applied along the field direction. The modeling results show that coercivity increased with increasing compressive stress while remanence decreased with increasing tensile stress. The results are in agreement with the experimental data in the literature and can be interpreted in terms of the effects of the applied stress on the irreversible rotation of magnetic moments during magnetization reversal under an applied field. [copyright] 2001 American Institute of Physics

  13. Effect of dielectric confinement on optical properties of colloidal nanostructures

    Energy Technology Data Exchange (ETDEWEB)

    Rodina, A. V., E-mail: anna.rodina@mail.ioffe.ru [Russian Academy of Sciences, Ioffe Physicotechnical Institute (Russian Federation); Efros, Al. L., E-mail: efros@nrl.navy.mil [Naval Research Laboratory (United States)

    2016-03-15

    We review the effects caused by a large difference in the dielectric constants of a semiconductor and its surrounding in colloidal semiconductor nanostructures (NSs) with various shapes, e.g., nanocrystals, nanorods, and nanoplatelets. The difference increases the electron–hole interaction and consequently the exciton binding energy and its oscillator transition strength. On the other hand, this difference reduces the electric field of a photon penetrating the NS (the phenomenon is called the local field effect) and reduces the photon coupling to an exciton. We show that the polarization properties of the individual colloidal NSs as well as of their randomly oriented ensemble are determined both by the anisotropy of the local field effect and by the symmetry of the exciton states participating in optical transitions. The calculations explain the temperature and time dependences of the degree of linear polarization measured in an ensemble of CdSe nanocrystals.

  14. Effect of metallurgical factors on the bulk magnetic properties of non-oriented electrical steels

    Energy Technology Data Exchange (ETDEWEB)

    Ghosh, Pampa, E-mail: pampaghosh@gmail.com [Department of Mining and Materials Engineering, McGill University, 3610 University Street, Montreal, Que., Canada H3A 0C5 (Canada); Chromik, Richard R., E-mail: richard.chromik@mcgill.ca [Department of Mining and Materials Engineering, McGill University, 3610 University Street, Montreal, Que., Canada H3A 0C5 (Canada); Knight, Andrew M. [Department of Electrical and Computer Engineering, University of Alberta, Edmonton, Alta., Canada T6G 2V4 (Canada); Wakade, Shekhar G. [GM Powertrain, General Motors Company, 823 Joslyn Avenue, Building B, 4AJ35, Pontiac, MI 48340-2920 (United States)

    2014-04-01

    Non-oriented electrical steel (NOES) is one of the most common material used in electrical motors. Core loss and permeability are the most important properties that the motor manufacturers look for. Both these properties are structure sensitive and depend on several metallurgical factors; such as chemistry, grain size, crystallographic texture, cleanliness and stress states in non-oriented electrical steels. It has been observed in this course of the study that the grain size and Si content of NOES are the primary controlling factors to core loss, especially at higher frequencies. On the contrary, crystallographic texture plays an important role at lower frequencies. At higher frequency, core loss increases with increasing grain size and decreasing Si content of the steels. Small difference in grain size (∼50 μm) at lower frequency range has little influence on the magnetic properties but has significant adverse effect as frequency reaches high enough. - Highlights: • Magnetic properties of a set of electrical steels were measured. • Crystallographic texture, chemistry and grain size were studied for their effects on core loss and permeability. • Structure–magnetic property relationships were identified for the electrical steels.

  15. Evaluation of nutritional properties and effect of storage conditions ...

    African Journals Online (AJOL)

    Soy-coconut blends were formulated from extracts of soybeans and coconut using different blends or ratios of 90:10; 85:15; 80:20; and 70:30, while 100% Soymilk served as control. The blends were analyzed for nutritional and sensory qualities. The sample blend with the highest sensory scores was used to study the effect ...

  16. Effect of chain extender on properties of silicone rubber sealant

    Science.gov (United States)

    Liu, Jiesheng; Wu, Shaopeng; Mi, Yixuan; Zhu, Guojun; Zheng, Shaoping

    2010-03-01

    The room-temperature vulcanizing silicone rubber sealant was prepared with chain extender. The effect of chain extender on the properties of silicone rubber sealant was discussed. The composite samples with chain extender were investigated from the aspects of tack-free time, cross-linkage density, hardness (penetration number) and adhesive strength with the concrete slab. It was found that the adding of the chain extender effectively makes the molecular chain length increase and causes the mechanical properties improvement. In addition, the increase in the amount of the chain extender reduces the cross-linkage density and hardness of silicone rubber sealant, which is accompanied with a decrease in the tack-free time. Adhesive strength is one of the most important requirements for sealant. The effect of chain extender on the adhesive strength was also investigated in this study. It was found that the increase in the amount of the chain extender makes the adhesive strength between the sealant and the concrete slab decrease.

  17. Habitat structure mediates biodiversity effects on ecosystem properties.

    Science.gov (United States)

    Godbold, J A; Bulling, M T; Solan, M

    2011-08-22

    Much of what we know about the role of biodiversity in mediating ecosystem processes and function stems from manipulative experiments, which have largely been performed in isolated, homogeneous environments that do not incorporate habitat structure or allow natural community dynamics to develop. Here, we use a range of habitat configurations in a model marine benthic system to investigate the effects of species composition, resource heterogeneity and patch connectivity on ecosystem properties at both the patch (bioturbation intensity) and multi-patch (nutrient concentration) scale. We show that allowing fauna to move and preferentially select patches alters local species composition and density distributions, which has negative effects on ecosystem processes (bioturbation intensity) at the patch scale, but overall positive effects on ecosystem functioning (nutrient concentration) at the multi-patch scale. Our findings provide important evidence that community dynamics alter in response to localized resource heterogeneity and that these small-scale variations in habitat structure influence species contributions to ecosystem properties at larger scales. We conclude that habitat complexity forms an important buffer against disturbance and that contemporary estimates of the level of biodiversity required for maintaining future multi-functional systems may need to be revised.

  18. Effect of deformation diagram on molybdenum structure and properties

    International Nuclear Information System (INIS)

    Larin, Eh.N.; Abalikhin, A.A.; Kolikov, A.P.; Ushakova, N.E.

    1984-01-01

    Effect of deformation diagram on a tendency to lamination and mechanical properties of disks made of molybdenum alloy is studied. Investigated samples were subjected to hot rolling or forging. X-ray structural analysis of texture is carried out along with estimation of the level of mechanical properties across item cross section. Sample mechanical bending tests were conducted. Sample microstructure is also studied. It is shown that rolled molybdenum has a tendency to lamination, but forged molybdenum is free of such a tendency. Forged sample ductility is practically equal in all directionse but rolled sample ductility in a surface layer is high and decreases with depth. A conclusion is drawn that forged sample grains in a setting surface are equiaxial, but distinct deformation texture is observed for rolled samples and their grains are elongated in the direction of rolling. A conclusion is made that a flow diagram of the process of disk fabrication by forging or stamping ppovides a necessary complex of physicomechanical properties of metal as compared to polling, and metal discharge coefficient decreases sharply in this case

  19. Antidiabetic Effects of Aronia melanocarpa and Its Other Therapeutic Properties

    Directory of Open Access Journals (Sweden)

    Ines Banjari

    2017-11-01

    Full Text Available Diabetes is a global pandemic which warrants urgent attention due to its rising prevalence and economic burden. Thus, many alternative therapies are being researched for antidiabetic properties, given the inefficacy of current medicinal treatments. From this perspective, Aronia melanocarpa or black chokeberry has been investigated for its therapeutic properties in many studies, especially for its ability to combat hyperglycemia-induced oxidative stress and the macrovascular complications of diabetes including cardiovascular disease. Though A. melanocarpa is native to the eastern areas of North America, it has been planted extensively in Europe and Asia as well. Several in vivo studies have displayed the antioxidant properties of A. melanocarpa berry juice and plant extract in rat models where oxidative stress markers were observed to have significant reductions. Some of the potent bioactive compounds present in the fruits and other parts of the plant were identified as (−-epicatechin, chlorogenic acid, neochlorogenic acid, and cyanidin-3-galactoside. Overall, A. melanocarpa could be considered a good source of antioxidants which is effective in combating hyperglycemia-induced oxidative stress.

  20. Confining dyon gas with finite-volume effects under control

    Energy Technology Data Exchange (ETDEWEB)

    Bruckmann, Falk [Regensburg Univ. (Germany). Institut fuer Theoretische Physik; Dinter, Simon [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany). John von Neumann-Inst. fuer Computing NIC; Humboldt-Universitaet, Berlin (Germany). Inst. fuer Physik; Ilgenfritz, Ernst-Michael [Humboldt-Universitaet, Berlin (Germany). Inst. fuer Physik; Joint Institute for Nuclear Research, VBLHEP, Dubna (Russian Federation); Maier, Benjamin; Mueller-Preussker, Michael [Humboldt-Universitaet, Berlin (Germany). Inst. fuer Physik; Wagner, Marc [Humboldt-Universitaet, Berlin (Germany). Inst. fuer Physik; Frankfurt Univ. (Germany). Inst. fuer Theoretische Physik

    2011-11-15

    As an approach to describe the long-range properties of non-Abelian gauge theories at non-zero temperature Teffects. Therefore, we demonstrate the application of Ewald's summation method to this system. Finite-volume effects are shown to be under control, which is a crucial requirement for numerical studies of interacting dyon ensembles. (orig.)

  1. Confining dyon gas with finite-volume effects under control

    International Nuclear Information System (INIS)

    Bruckmann, Falk; Maier, Benjamin; Mueller-Preussker, Michael; Wagner, Marc; Frankfurt Univ.

    2011-11-01

    As an approach to describe the long-range properties of non-Abelian gauge theories at non-zero temperature T c , we consider a non-interacting ensemble of dyons (magnetic monopoles) with non-trivial holonomy. We show analytically, that the quark-antiquark free energy from the Polyakov loop correlator grows linearly with the distance, and how the string tension scales with the dyon density. In numerical treatments, the long-range tails of the dyon fields cause severe finite-volume effects. Therefore, we demonstrate the application of Ewald's summation method to this system. Finite-volume effects are shown to be under control, which is a crucial requirement for numerical studies of interacting dyon ensembles. (orig.)

  2. Annealing effect on restoration of irradiation steel properties

    International Nuclear Information System (INIS)

    Vishkarev, O.M.; Kolesova, T.N.; Myasnikova, K.P.; Pecherin, A.M.; Shamardin, V.K.

    1986-01-01

    The effect of temperature and annealing time on the restoration of properties of the 15Kh2NMFAA and 15Kh2MFA steels after irradiation at 285 deg with the fluence of 6x10 23 neutr/m 2 (E>0.5 MeV) is studied. Microhardness (H μ ) restoration in the irradiated 15Kh2NMFAA steel is shown to start from 350 deg C annealing temperature. The complete microhardness restoration is observed at the annealing temperature of 500 deg C for 10 hours

  3. Effect of irradiation on biochemistry properties of shrimp allergen

    International Nuclear Information System (INIS)

    Gu Kefei; Gao Meixu; Li Chunhong; Li Shurong; Pan Jiarong

    2007-01-01

    Study on the effects of 60 Co γ-rays irradiation at the dose of 0,3,5,7,10 kGy on shrimp allergen biochemistry properties was conducted. The results indicated that the allergen protein molecule can be broken down to smaller molecules or coagulated to larger molecules by irradiation. The hydrophobicity and turbidity of irradiated allergen increased with the increase of absorbed dose. The results also show that allergen solution is more sensitive to irradiation than allergen in solid state or in the whole shrimp. (authors)

  4. Surface effects in controlled thermonuclear fusion

    International Nuclear Information System (INIS)

    Kaminsky, M.

    1975-08-01

    During the operation of large size plasma facilities and future controlled thermonuclear fusion reactors the surfaces of such major components as container walls, beam limiters, diverter walls and beam-dump walls of the injector region will be exposed to particle and photon bombardment from primary plasma radiations and from secondary radiations. Such radiations can cause, for example, physical and chemical sputtering, blistering, particle- and photon-impact induced desorption, secondary electron and x-ray emission, backscattering, nuclear reactions, photo-decomposition of surface compounds, photocatalysis, and vaporization. Such effects in turn can (a) seriously damage and erode the bombarded surface and (b) release major quantities of impurities which will contaminate the plasma. The effects of some of the major surface phenomena on the operation of plasma facilities and future fusion reactors are discussed

  5. Control of crystal structure, morphology and optical properties of ceria films by post deposition annealing treatments

    International Nuclear Information System (INIS)

    Eltayeb, Asmaa; Vijayaraghavan, Rajani K.; McCoy, Anthony P.; Cullen, Joseph; Daniels, Stephen; McGlynn, Enda

    2016-01-01

    In this paper, the effects of post-deposition annealing temperature and atmosphere on the properties of pulsed DC magnetron sputtered ceria (CeO_2) thin films, including crystalline structure, grain size and shape and optical properties were investigated. Experimental results, obtained from X-ray diffraction (XRD), showed that the prepared films crystallised predominantly in the CeO_2 cubic fluorite structure, although evidence of Ce_2O_3 was also seen and this was quantified by a Rietveld refinement. The anneal temperature and oxygen content of the Ar/O_2 annealing atmosphere both played important roles on the size and shape of the nanocrystals as determined by atomic force microscopy (AFM). The average grain size (determined by an AFM) as well as the out of plane coherence length (obtained from XRD) varied with increasing oxygen flow rate (OFR) in the annealing chamber. In addition, the shape of the grains seen in the AFM studies transformed from circular to triangular as the OFR was raised from 20 sccm to 30 sccm during an 800 °C thermal anneal. X-ray photoelectron spectroscopy was used to measure near-surface oxidation states of the thin-films with varying OFR in the annealing chamber. The bandgap energies were estimated from the ultra-violet and visible absorption spectra and low-temperature photoluminescence. An extracted bandgap value of 3.04 eV was determined for as-deposited CeO_2 films and this value increased with increasing annealing temperatures. However, no difference was observed in bandgap energies with variation of annealing atmosphere. - Highlights: • Deposition of ceria thin films by pulsed DC magnetron sputtering • Effect of annealing temperature and gas ambient on film crystalline structure • Evidence for control of the film roughness and grain size and shape is achieved. • Investigation of the effect of post-deposition annealing on the film stoichiometry • Films showed blue shifts in bandgap energies with increasing annealing

  6. Effects of material properties on soft contact dynamics

    International Nuclear Information System (INIS)

    Khurshid, A.; Malik, M.A.; Ghafoor, A.

    2009-01-01

    The superiority of deformable human fingertips as compared to hard robot gripper fingers for grasping and manipulation has led to a number of investigations with robot hands employing elastomers or materials such as fluids or powders beneath a membrane at the fingertips. In this paper, to analyze the stability of dynamic control of an object grasped between two soft fingertips through a soft interface using the viscoelastic material between the manipulating fingers and a manipulated object is modeled through bond graph method (BGM). The fingers are made viscoelastic by using springs and dampers. Detailed bond graph modeling (BGM) of the contact phenomenon with two soft-finger contacts considered to be placed against each other on the opposite sides of the grasped object as is generally the case in a manufacturing environment is presented. The stiffness of the springs is exploited in order to achieve the stability in the soft-grasping which includes friction between the soft finger contact surfaces and the object, The paper also analyses stability of dynamic control through a soft interface between a manipulating finger and a manipulated object. It is shown in the paper that the system stability depends on the visco-elastic material properties of the soft interface. Method of root locus is used to analyze this phenomenon. The paper shows how the weight of the object coming downward is controlled by the friction between the fingers and the object during the application of contact forces by varying the damping and the stiffness in the soft finger. (author)

  7. Nanomanufacturing of titania interfaces with controlled structural and functional properties by supersonic cluster beam deposition

    Energy Technology Data Exchange (ETDEWEB)

    Podestà, Alessandro, E-mail: alessandro.podesta@mi.infn.it, E-mail: pmilani@mi.infn.it; Borghi, Francesca; Indrieri, Marco; Bovio, Simone; Piazzoni, Claudio; Milani, Paolo, E-mail: alessandro.podesta@mi.infn.it, E-mail: pmilani@mi.infn.it [Centro Interdisciplinare Materiali e Interfacce Nanostrutturati (C.I.Ma.I.Na.), Dipartimento di Fisica, Università degli Studi di Milano, via Celoria 16, 20133 Milano (Italy)

    2015-12-21

    Great emphasis is placed on the development of integrated approaches for the synthesis and the characterization of ad hoc nanostructured platforms, to be used as templates with controlled morphology and chemical properties for the investigation of specific phenomena of great relevance in interdisciplinary fields such as biotechnology, medicine, and advanced materials. Here, we discuss the crucial role and the advantages of thin film deposition strategies based on cluster-assembling from supersonic cluster beams. We select cluster-assembled nanostructured titania (ns-TiO{sub 2}) as a case study to demonstrate that accurate control over morphological parameters can be routinely achieved, and consequently, over several relevant interfacial properties and phenomena, like surface charging in a liquid electrolyte, and proteins and nanoparticles adsorption. In particular, we show that the very good control of nanoscale morphology is obtained by taking advantage of simple scaling laws governing the ballistic deposition regime of low-energy, mass-dispersed clusters with reduced surface mobility.

  8. Nanomanufacturing of titania interfaces with controlled structural and functional properties by supersonic cluster beam deposition

    International Nuclear Information System (INIS)

    Podestà, Alessandro; Borghi, Francesca; Indrieri, Marco; Bovio, Simone; Piazzoni, Claudio; Milani, Paolo

    2015-01-01

    Great emphasis is placed on the development of integrated approaches for the synthesis and the characterization of ad hoc nanostructured platforms, to be used as templates with controlled morphology and chemical properties for the investigation of specific phenomena of great relevance in interdisciplinary fields such as biotechnology, medicine, and advanced materials. Here, we discuss the crucial role and the advantages of thin film deposition strategies based on cluster-assembling from supersonic cluster beams. We select cluster-assembled nanostructured titania (ns-TiO 2 ) as a case study to demonstrate that accurate control over morphological parameters can be routinely achieved, and consequently, over several relevant interfacial properties and phenomena, like surface charging in a liquid electrolyte, and proteins and nanoparticles adsorption. In particular, we show that the very good control of nanoscale morphology is obtained by taking advantage of simple scaling laws governing the ballistic deposition regime of low-energy, mass-dispersed clusters with reduced surface mobility

  9. Nanomanufacturing of titania interfaces with controlled structural and functional properties by supersonic cluster beam deposition

    Science.gov (United States)

    Podestà, Alessandro; Borghi, Francesca; Indrieri, Marco; Bovio, Simone; Piazzoni, Claudio; Milani, Paolo

    2015-12-01

    Great emphasis is placed on the development of integrated approaches for the synthesis and the characterization of ad hoc nanostructured platforms, to be used as templates with controlled morphology and chemical properties for the investigation of specific phenomena of great relevance in interdisciplinary fields such as biotechnology, medicine, and advanced materials. Here, we discuss the crucial role and the advantages of thin film deposition strategies based on cluster-assembling from supersonic cluster beams. We select cluster-assembled nanostructured titania (ns-TiO2) as a case study to demonstrate that accurate control over morphological parameters can be routinely achieved, and consequently, over several relevant interfacial properties and phenomena, like surface charging in a liquid electrolyte, and proteins and nanoparticles adsorption. In particular, we show that the very good control of nanoscale morphology is obtained by taking advantage of simple scaling laws governing the ballistic deposition regime of low-energy, mass-dispersed clusters with reduced surface mobility.

  10. Thermophysical Properties Measurement of High-Temperature Liquids Under Microgravity Conditions in Controlled Atmospheric Conditions

    Science.gov (United States)

    Watanabe, Masahito; Ozawa, Shumpei; Mizuno, Akotoshi; Hibiya, Taketoshi; Kawauchi, Hiroya; Murai, Kentaro; Takahashi, Suguru

    2012-01-01

    Microgravity conditions have advantages of measurement of surface tension and viscosity of metallic liquids by the oscillating drop method with an electromagnetic levitation (EML) device. Thus, we are preparing the experiments of thermophysical properties measurements using the Materials-Science Laboratories ElectroMagnetic-Levitator (MSL-EML) facilities in the international Space station (ISS). Recently, it has been identified that dependence of surface tension on oxygen partial pressure (Po2) must be considered for industrial application of surface tension values. Effect of Po2 on surface tension would apparently change viscosity from the damping oscillation model. Therefore, surface tension and viscosity must be measured simultaneously in the same atmospheric conditions. Moreover, effect of the electromagnetic force (EMF) on the surface oscillations must be clarified to obtain the ideal surface oscillation because the EMF works as the external force on the oscillating liquid droplets, so extensive EMF makes apparently the viscosity values large. In our group, using the parabolic flight levitation experimental facilities (PFLEX) the effect of Po2 and external EMF on surface oscillation of levitated liquid droplets was systematically investigated for the precise measurements of surface tension and viscosity of high temperature liquids for future ISS experiments. We performed the observation of surface oscillations of levitated liquid alloys using PFLEX on board flight experiments by Gulfstream II (G-II) airplane operated by DAS. These observations were performed under the controlled Po2 and also under the suitable EMF conditions. In these experiments, we obtained the density, the viscosity and the surface tension values of liquid Cu. From these results, we discuss about as same as reported data, and also obtained the difference of surface oscillations with the change of the EMF conditions.

  11. Effect of diblock copolymer properties on the photophysical properties of dendrimer silicon phthalocyanine nanoconjugates

    Science.gov (United States)

    Chen, Kuizhi; Pan, Sujuan; Zhuang, Xuemei; Lv, Hafei; Que, Shoulin; Xie, Shusen; Yang, Hongqin; Peng, Yiru

    2016-07-01

    1-2 generation poly(benzyl aryl ether) dendrimer silicon phthalocyanines with axially disubstituted cyano terminal functionalities (G n -DSiPc(CN)4 n , (G n = n-generation dendrimer, n = 1-2)) were synthesized. Their structures were characterized by elemental analysis, IR, 1H NMR, and ESI-MS. Polymeric nanoparticles (G n -DSiPc(CN)4 n /m) were formed through encapsulating G n -DSiPc(CN)4 n into three monomethoxyl poly(ethylene glycol)-poly(ɛ-caprolactone) diblock copolymers (MPEG-PCL) with different hydrophilic/hydrophobic proportion, respectively. The effect of dendritic generation and the hydrophilic/hydrophobic proportion of diblock copolymers on the UV/Vis and fluorescence spectra of G n -DSiPc(CN)4 n and G n -DSiPc(CN)4 n /m were studied. The photophysical properties of polymeric nanoparticles exhibited dendritic generation and hydrophilic/hydrophobic proportion dependence. The fluorescence intensities and lifetimes of G n -DSiPc(CN)4 n /m were lower than the corresponding free dendrimer phthalocyanines. G n -DSiPc(CN)4 n encapsulated into MPEG-PCL with hydrophilic/hydrophobic molecular weight ratio 2000:4000 exhibited excellent photophysical property. The mean diameter of MPEG2000-PCL2000 micelles was about 70 nm, which decreased when loaded with G n -DSiPc(CN)4 n .

  12. Nitrile functionalized halloysite nanotubes/poly(arylene ether nitrile) nanocomposites: Interface control, characterization, and improved properties

    International Nuclear Information System (INIS)

    Wan, Xinyi; Zhan, Yingqing; Zeng, Guangyong; He, Yi

    2017-01-01

    Highlights: • Novel nitrile functionalized HNTs were realized through the covalent bonding. • Then modified HNTs showed good dispersion and interfacial adhesion with PEN. • The modified HNTs exhibited excellent reinforcement effect on PEN. • The chemical crosslinking between HNTs and PEN further enhanced the performance of nanocomposites. - Abstract: To develop high-performance halloysite nanotube (HNT)-based nanocomposites, the two key issues need to be considered: precise interface control and the dispersal of HNTs. This study presents an efficient way to functionalize halloysite nanotubes with 3-aminophenoxy-phthalonitrile, followed by compounding with poly(arylene ether nitrile) (PEN), to prepare functional nanocomposite films. The surface functionalization of HNTs was characterized and confirmed by Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), X-ray photoelectron spectroscopy (XPS), and transmission electron microscopy (TEM). Compared with neat PEN, the tensile strength and modulus of the resulting PEN nanocomposites with 3 wt% functionalized HNTs were found to increase by 25.7% and 20.7%, respectively. The good dispersion and high capacitance of the dielectric layer resulted in PEN/HNTs nancomposites with enhanced dielectric permittivity and relatively low dielectric loss. Moreover, the addition of functional HNTs greatly improved the thermal stability of PEN, which could be further enhanced through the chemical cross-linking reaction between the functional HNTs and the PEN matrix. This work provides a new path toward obtaining advanced polymer-based nanocomposites with functional properties.

  13. Nitrile functionalized halloysite nanotubes/poly(arylene ether nitrile) nanocomposites: Interface control, characterization, and improved properties

    Energy Technology Data Exchange (ETDEWEB)

    Wan, Xinyi [School of Chemistry and Chemical Engineering, Southwest Petroleum University, 8 Xindu Avenue, Chengdu, Sichuan, 610500 (China); Zhan, Yingqing, E-mail: 201599010032@swpu.edu.cn [School of Chemistry and Chemical Engineering, Southwest Petroleum University, 8 Xindu Avenue, Chengdu, Sichuan, 610500 (China); Oil & Gas Field Applied Chemistry Key Laboratory of Sichuan Province, Southwest Petroleum University, Chengdu, Sichuan, China, 610500 (China); Zeng, Guangyong [School of Chemistry and Chemical Engineering, Southwest Petroleum University, 8 Xindu Avenue, Chengdu, Sichuan, 610500 (China); He, Yi, E-mail: heyi007@163.com [School of Chemistry and Chemical Engineering, Southwest Petroleum University, 8 Xindu Avenue, Chengdu, Sichuan, 610500 (China); Oil & Gas Field Applied Chemistry Key Laboratory of Sichuan Province, Southwest Petroleum University, Chengdu, Sichuan, China, 610500 (China); State Key Lab of Oil and Gas Reservoir Geology and Exploitation, Southwest Petroleum University, 8Xindu Avenue, Chengdu, Sichuan, 610500 (China)

    2017-01-30

    Highlights: • Novel nitrile functionalized HNTs were realized through the covalent bonding. • Then modified HNTs showed good dispersion and interfacial adhesion with PEN. • The modified HNTs exhibited excellent reinforcement effect on PEN. • The chemical crosslinking between HNTs and PEN further enhanced the performance of nanocomposites. - Abstract: To develop high-performance halloysite nanotube (HNT)-based nanocomposites, the two key issues need to be considered: precise interface control and the dispersal of HNTs. This study presents an efficient way to functionalize halloysite nanotubes with 3-aminophenoxy-phthalonitrile, followed by compounding with poly(arylene ether nitrile) (PEN), to prepare functional nanocomposite films. The surface functionalization of HNTs was characterized and confirmed by Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), X-ray photoelectron spectroscopy (XPS), and transmission electron microscopy (TEM). Compared with neat PEN, the tensile strength and modulus of the resulting PEN nanocomposites with 3 wt% functionalized HNTs were found to increase by 25.7% and 20.7%, respectively. The good dispersion and high capacitance of the dielectric layer resulted in PEN/HNTs nancomposites with enhanced dielectric permittivity and relatively low dielectric loss. Moreover, the addition of functional HNTs greatly improved the thermal stability of PEN, which could be further enhanced through the chemical cross-linking reaction between the functional HNTs and the PEN matrix. This work provides a new path toward obtaining advanced polymer-based nanocomposites with functional properties.

  14. Formation of Nanoparticles Controlled by the Yield and Properties of the γ-Generated Radicals

    International Nuclear Information System (INIS)

    Chen, Q.

    2009-01-01

    In the past two decades, nanoparticles have attracted much attention because of their novel properties. Among the numerous synthetic methods, ionizing irradiation, which is simple and can take at normal temperature and pressure, even at low temperature, is a powerful method for preparing metals, alloys, metal oxides, metal chalcogenides, metal halides and insoluble sulphate nanoparticles. In this method, dose rate is always used to affect the shape, component and size of synthesized nanoparticles. In addition, to eliminate the effect of ·OH on the formation of nanoparticles, alcohol (such as isopropyl alcohol) is always added and a lot of reductive radicals with wide range of reduction potentials are generated. At the same time, these radicals transformed from ·OH can also reduce the reactant, which have been used to control the growth of nanoparticles. However, so far, most nanoparticles synthesized by ionizing irradiation are spherical. In our previous work, ''solid'' BaSO 4 microspheres, mainly consisting of quasi-spherical nanoparticles, have been synthesized by precipitating Ba 2+ ions with SO 4 2- ions, which were generated from the reduction of K 2 S 2 O 8 in the presence of EDTA under N 2 atmosphere by γ-irradiation

  15. Formation of Nanoparticles Controlled by the Yield and Properties of the γ-Generated Radicals

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Q. [Department of Applied Chemistry, College of Chemistry and Molecular Engineering, Peking University, Beijing (China)

    2009-07-01

    In the past two decades, nanoparticles have attracted much attention because of their novel properties. Among the numerous synthetic methods, ionizing irradiation, which is simple and can take at normal temperature and pressure, even at low temperature, is a powerful method for preparing metals, alloys, metal oxides, metal chalcogenides, metal halides and insoluble sulphate nanoparticles. In this method, dose rate is always used to affect the shape, component and size of synthesized nanoparticles. In addition, to eliminate the effect of ·OH on the formation of nanoparticles, alcohol (such as isopropyl alcohol) is always added and a lot of reductive radicals with wide range of reduction potentials are generated. At the same time, these radicals transformed from ·OH can also reduce the reactant, which have been used to control the growth of nanoparticles. However, so far, most nanoparticles synthesized by ionizing irradiation are spherical. In our previous work, ''solid'' BaSO{sub 4} microspheres, mainly consisting of quasi-spherical nanoparticles, have been synthesized by precipitating Ba{sup 2+} ions with SO{sub 4}{sup 2-} ions, which were generated from the reduction of K{sub 2}S{sub 2}O{sub 8} in the presence of EDTA under N{sub 2} atmosphere by γ-irradiation.

  16. Antioxidant and signal modulation properties of plant polyphenols in controlling vascular inflammation.

    Science.gov (United States)

    Kostyuk, Vladimir A; Potapovich, Alla I; Suhan, Tatyana O; de Luca, Chiara; Korkina, Liudmila G

    2011-05-11

    Oxidized low-density lipoproteins (oxLDL) play a critical role in the initiation of atherosclerosis through activation of inflammatory signaling. In the present work we investigated the role of antioxidant and signal modulation properties of plant polyphenols in controlling vascular inflammation. Significant decrease in intracellular NO level and superoxide overproduction was found in human umbilical vein endothelial cells (HUVEC) treated with oxLDL, but not with LDL. The redox imbalance was prevented by the addition of quercetin or resveratrol. Expression analysis of 14 genes associated with oxidative stress and inflammation revealed oxLDL-mediated up-regulation of genes specifically involved in leukocyte recruitment and adhesion. This up-regulation could be partially avoided by the addition of verbascoside or resveratrol, while treatment with quercetin resulted in a further increase in the expression of these genes. Lipopolysaccharide (LPS)-treated HUVEC were also used for the evaluation of anti-inflammatory potency of plant polyphenols. Significant differences between HUVEC treaded with oxLDL and LPS were found in both the expression pattern of inflammation-related genes and the effects of plant polyphenols on cellular responses. The present data indicate that plant polyphenols may affect vascular inflammation not only as antioxidants but also as modulators of inflammatory redox signaling pathways. Crown Copyright © 2011. Published by Elsevier B.V. All rights reserved.

  17. Effect of tumor therapeutic irradiation on the mechanical properties of teeth tissue

    International Nuclear Information System (INIS)

    Fraenzel, W.; Gerlach, R.; Hein, H.J.; Schaller, H.G.

    2006-01-01

    Tumor irradiation of the head-neck area is accompanied by the development of a so-called radiation caries in the treated patients. In spite of conservative therapeutic measures, the process results in tooth destruction. The present study investigated the effects of irradiation on the demineralization and remineralization of the dental tissue. For this purpose, retained third molars were prepared and assigned either to a test group, which was exposed to fractional irradiation up to 60 Gy, or to a non-irradiated control group. Irradiated and non-irradiated teeth were then demineralized using acidic hydroxyl-cellulose gel; afterwards the teeth were remineralized using either Bifluorid12 registered or elmex gelee registered . The nanoindentation technique was used to measure the mechanical properties, hardness and elasticity, of the teeth in each of the conditions. The values were compared to the non-irradiated control group. Irradiation decreased dramatically the mechanical parameters of enamel and dentine. In non-irradiated teeth, demineralization had nearly the same effects of irradiation on the mechanical properties. In irradiated teeth, the effects of demineralization were negligible in comparison to non-irradiated teeth. Remineralization with Bifluorid12 registered or elmex gelee registered led to a partial improvement of the mechanical properties of the teeth. The enamel was more positively affected, by remineralization than the dentine. (orig.)

  18. Effect of tumor therapeutic irradiation on the mechanical properties of teeth tissue

    Energy Technology Data Exchange (ETDEWEB)

    Fraenzel, W. [Dept. of Physics, Martin Luther Univ. Halle (Germany); Gerlach, R. [Univ. Clinic and Policlinic for Radiation Therapy, Martin Luther Univ. Halle (Germany); Hein, H.J. [Univ. Clinic and Policlinic for Orthopaedics and Physical Medicine, Martin Luther Univ. Halle (Germany); Schaller, H.G. [Dept. of Operative Dentistry and Periodontology, Martin Luther Univ. Halle (Germany)

    2006-07-01

    Tumor irradiation of the head-neck area is accompanied by the development of a so-called radiation caries in the treated patients. In spite of conservative therapeutic measures, the process results in tooth destruction. The present study investigated the effects of irradiation on the demineralization and remineralization of the dental tissue. For this purpose, retained third molars were prepared and assigned either to a test group, which was exposed to fractional irradiation up to 60 Gy, or to a non-irradiated control group. Irradiated and non-irradiated teeth were then demineralized using acidic hydroxyl-cellulose gel; afterwards the teeth were remineralized using either Bifluorid12 {sup registered} or elmex gelee {sup registered}. The nanoindentation technique was used to measure the mechanical properties, hardness and elasticity, of the teeth in each of the conditions. The values were compared to the non-irradiated control group. Irradiation decreased dramatically the mechanical parameters of enamel and dentine. In non-irradiated teeth, demineralization had nearly the same effects of irradiation on the mechanical properties. In irradiated teeth, the effects of demineralization were negligible in comparison to non-irradiated teeth. Remineralization with Bifluorid12 {sup registered} or elmex gelee {sup registered} led to a partial improvement of the mechanical properties of the teeth. The enamel was more positively affected, by remineralization than the dentine. (orig.)

  19. Metallurgical Mechanisms Controlling Mechanical Properties of Aluminum Alloy 2219 Produced By Electron Beam Freeform Fabrication

    Science.gov (United States)

    Domack, Marcia S.; Taminger, Karen M. B.; Begley, Matthew

    2006-01-01

    The electron beam freeform fabrication (EBF3) layer-additive manufacturing process has been developed to directly fabricate complex geometry components. EBF3 introduces metal wire into a molten pool created on the surface of a substrate by a focused electron beam. Part geometry is achieved by translating the substrate with respect to the beam to build the part one layer at a time. Tensile properties have been demonstrated for electron beam deposited aluminum and titanium alloys that are comparable to wrought products, although the microstructures of the deposits exhibit features more typical of cast material. Understanding the metallurgical mechanisms controlling mechanical properties is essential to maximizing application of the EBF3 process. In the current study, mechanical properties and resulting microstructures were examined for aluminum alloy 2219 fabricated over a range of EBF3 process variables. Material performance was evaluated based on tensile properties and results were compared with properties of Al 2219 wrought products. Unique microstructures were observed within the deposited layers and at interlayer boundaries, which varied within the deposit height due to microstructural evolution associated with the complex thermal history experienced during subsequent layer deposition. Microstructures exhibited irregularly shaped grains, typically with interior dendritic structures, which were described based on overall grain size, morphology, distribution, and dendrite spacing, and were correlated with deposition parameters. Fracture features were compared with microstructural elements to define fracture paths and aid in definition of basic processing-microstructure-property correlations.

  20. Effective Materials Property Information Management for the 21st Century

    Science.gov (United States)

    Ren, Weiju; Cebon, David; Arnold, Steve

    2009-01-01

    This paper discusses key principles for the development of materials property information management software systems. There are growing needs for automated materials information management in various organizations. In part these are fueled by the demands for higher efficiency in material testing, product design and engineering analysis. But equally important, organizations are being driven by the need for consistency, quality and traceability of data, as well as control of access to sensitive information such as proprietary data. Further, the use of increasingly sophisticated nonlinear, anisotropic and multi-scale engineering analyses requires both processing of large volumes of test data for development of constitutive models and complex materials data input for Computer-Aided Engineering (CAE) software. And finally, the globalization of economy often generates great needs for sharing a single "gold source" of materials information between members of global engineering teams in extended supply chains. Fortunately, material property management systems have kept pace with the growing user demands and evolved to versatile data management systems that can be customized to specific user needs. The more sophisticated of these provide facilities for: (i) data management functions such as access, version, and quality controls; (ii) a wide range of data import, export and analysis capabilities; (iii) data "pedigree" traceability mechanisms; (iv) data searching, reporting and viewing tools; and (v) access to the information via a wide range of interfaces. In this paper the important requirements for advanced material data management systems, future challenges and opportunities such as automated error checking, data quality characterization, identification of gaps in datasets, as well as functionalities and business models to fuel database growth and maintenance are discussed.

  1. Extinction properties of metallic nanowires: Quantum diffraction and retardation effects

    Energy Technology Data Exchange (ETDEWEB)

    Moradi, Afshin, E-mail: a.moradi@kut.ac.ir [Department of Engineering Physics, Kermanshah University of Technology, Kermanshah (Iran, Islamic Republic of); Department of Nano Sciences, Institute for Studies in Theoretical Physics and Mathematics (IPM), Tehran (Iran, Islamic Republic of)

    2015-10-09

    The standard Mie theory for the extinction of electromagnetic radiation by a metal cylinder that is irradiated by a normally incident plane wave is extended to the case of a metallic nanowire, where two quantum longitudinal waves are excited. The modification of the Mie theory due to quantum diffraction effects is included by employing the quantum hydrodynamic approximation and applying the appropriate quantum additional boundary conditions. The extinction properties of the system and their differences with previous treatments based on the standard local and nonlocal models are shown. Also, as an example the validity of the nonretarded approximation in the quantum nonlocal optical response of a sodium nanowire is discussed. - Highlights: • Extinction properties of metallic nanowires in the presence of quantum diffraction and retardation effects are studied. • The differences of new results with previous findings based on the standard local and nonlocal models are shown. • The validity of the nonretarded approximation in the quantum nonlocal optical response of a sodium nanowire is discussed.

  2. Gamma radiation effects on the structure and properties of polystyrene

    International Nuclear Information System (INIS)

    Lima, Ivania Soares de

    1996-01-01

    Polystyrene is a linear thermoplastic with a molecular weight ranging from 130,000 to 300,000 g/mole. This polymer has wide industrial applications. In medicine it is used to manufacture medical supplies which can be sterilized by ionizing radiation. The sterilization of medical instruments by ionizing radiation was introduced in the 60's as an alternative method to the conventional treatment with ethylene oxide gas. Radiosterilization is now worldwide standard procedure, as it is cheaper and cleaner. Some polymers, however, may show some changes in their physical properties following irradiation. These changes are due to the prevailing crosslinking and main chain scission induced by the irradiation of the polymeric system. In the present work, Brazilian-made polystyrene Lustrex was irrigated with γ rays in the presence of air at room temperature. Under these conditions, the analysis of viscosimetric essays showed the prevalence of crosslinking effects at doses up to 25 kGy and of main scission effects at does from 25 to 200 kGy. Observed G values (number of events per 100 eV of absorbed energy) pointed to low degrees of both crosslinking (Gx ∼ 0.15) and main chain scission (Gs ∼ 0.09). Therefore, the minor changes in Lustrex's molecular structure induced by irradiation have not influenced significantly its mechanical, thermal, and optical properties. As a result, Lustrex can be used in applications involving radiation without the need to introduce radioprotective to the polymeric system. (author)

  3. Effect of polybutenes on mechanical and physical properties of polypropylene

    International Nuclear Information System (INIS)

    Nascimento, Uedson A. do; Timoteo, Gustavo Arante V.; Rabello, Marcelo S.

    2009-01-01

    This study investigated the effect of polybutene (PIB) of molecular weights ranging from 480 the 1.600 g/mol in polypropylene homopolymer. Compositions with 0, 3, 5 and 7% of PIB were prepared in internal mixer and compression moulded. The properties evaluated were: tensile strength, scanning electron microscopy (SEM), FTIR, X-ray diffraction (XRD) and melt flow index (IF). The results of mechanical tests showed that the presence of the plasticizer reduced the tensile strength, elastic modulus and hardness. The analysis of XRD showed a drop in the degree of crystallinity of PP/PIB blends. The micrographs obtained by SEM did not reveal the occurrence of the phase separation. The IF analysis confirm the effect of PIB as internal lubricant's, by increasing the rate of flow. (author)

  4. International Workshop on Stratospheric Aerosols: Measurements, Properties, and Effects

    Science.gov (United States)

    Pueschel, Rudolf F. (Editor)

    1991-01-01

    Following a mandate by the International Aerosol Climatology Program under the auspices of International Association of Meteorology and Atmospheric Physics International Radiation Commission, 45 scientists from five nations convened to discuss relevant issues associated with the measurement, properties, and effects of stratospheric aerosols. A summary is presented of the discussions on formation and evolution, transport and fate, effects on climate, role in heterogeneous chemistry, and validation of lidar and satellite remote sensing of stratospheric aerosols. Measurements are recommended of the natural (background) and the volcanically enhanced aerosol (sulfuric acid and silica particles), the exhaust of shuttle, civil aviation and supersonic aircraft operations (alumina, soot, and ice particles), and polar stratospheric clouds (ice, condensed nitric and hydrochloric acids).

  5. Effect of irradiated pork on physicochemical properties of meat emulsions

    Science.gov (United States)

    Choi, Yun-Sang; Sung, Jung-Min; Jeong, Tae-Jun; Hwang, Ko-Eun; Song, Dong-Heon; Ham, Youn-Kyung; Kim, Hyun-Wook; Kim, Young-Boong; Kim, Cheon-Jei

    2016-02-01

    The effect of pork irradiated with doses up to 10 kGy on meat emulsions formulated with carboxy methyl cellulose (CMC) was investigated. Raw pork was vacuums packaged at a thickness of 2.0 cm and irradiated by X-ray linear accelerator (15 kW, 5 MeV). The emulsion had higher lightness, myofibrillar protein solubility, total protein solubility, and apparent viscosity with increasing doses, whereas cooking loss, total expressible fluid separation, and hardness decreased. There were no significant differences in fat separation, sarcoplasmic protein solubility, springiness, and cohesiveness. Our results indicated that it is treatment by ionizing radiation which causes the effects the physicochemical properties of the final raw meat product.

  6. Effect of twinning plane on superconductor magnetic properties

    International Nuclear Information System (INIS)

    Buzdin, A.I.; Kuptsov, D.A.

    1989-01-01

    Effect of twinning planes on pinning of the Abrikosov vortices in superconductors of the second order with the Ginsburg-Landau parameter, κ >> 1, is considered. The modified Ginsburg-Landau functional, where the effect of superconducting properties improvement near the twinning plane is taken into account by adding the additional δ-function component, is used to descibe superconductivity of twinning plane. Force of interaction of a vortex filament and the twinning plane is calculated. It is shown that in case of the twinning plane opaque to electrons, additional attractive force, being analogous to that occurring in the problem on the surface Been-Livingston barrier, affects the vortex filament. The results can explain anisotropy of vortex pinning observed in the periodic twinning structure in high-temperature superconductors

  7. Effect of Ground Waste Concrete Powder on Cement Properties

    Directory of Open Access Journals (Sweden)

    Xianwei Ma

    2013-01-01

    Full Text Available The paste/mortar attached to the recycled aggregate decreases the quality of the aggregate and needs to be stripped. The stripped paste/mortar is roughly 20% to 50% in waste concrete, but relevant research is very limited. In this paper, the effects of ground waste concrete (GWC powder, coming from the attached paste/mortar, on water demand for normal consistency, setting time, fluidity, and compressive strength of cement were analyzed. The results show that the 20% of GWC powder (by the mass of binder has little effect on the above properties and can prepare C20 concrete; when the sand made by waste red clay brick (WRB replaces 20% of river sand, the strength of the concrete is increased by 17% compared with that without WRB sand.

  8. Effects of biochars on hydraulic properties of clayey soil

    Science.gov (United States)

    Zhen, Jingbo; Palladino, Mario; Lazarovitch, Naftali; Bonanomi, Giuliano; Battista Chirico, Giovanni

    2017-04-01

    Biochar has gained popularity as an amendment to improve soil hydraulic properties. Since biochar properties depend on feedstocks and pyrolysis temperatures used for its production, proper selection of biochar type as soil amendment is of great importance for soil hydraulic properties improvement. This study investigated the effects of eight types of biochar on physical and hydraulic properties of clayey soil. Biochars were derived from four different feedstocks (Alfalfa hay, municipal organic waste, corn residues and wood chip) pyrolyzed at two different temperatures (300 and 550 °C). Clayey soil samples were taken from Leone farm (40° 26' 15.31" N, 14° 59' 45.54" E), Italy, and were oven-dried at 105 °C to determine dry bulk density. Biochars were mixed with the clayey soil at 5% by mass. Bulk densities of the mixtures were also determined. Saturated hydraulic conductivities (Ks) of the original clayey soil and corresponding mixtures were measured by means of falling-head method. Soil water retention measurements were conducted for clayey soil and mixtures using suction table apparatus and Richards' plate with the pressure head (h) up to 12000 cm. van Genuchten retention function was selected to evaluate the retention characteristics of clayey soil and mixtures. Available water content (AWC) was calculated by field capacity (h = - 500 cm) minus wilting pointing (h = -12000 cm). The results showed that biochar addition decreased the bulk density of clayey soil. The Ks of clayey soil increased due to the incorporation of biochars except for waste and corn biochars pyrolyzed at 550 °C. AWC of soils mixed with corn biochar pyrolyzed at 300 °C and wood biochar pyrolyzed at 550 °C, increased by 31% and 7%, respectively. Further analysis will be conducted in combination of biochar properties such as specific surface area and total pore volume. Better understanding of biochar impact on clayey soil will be helpful in biochar selection for soil amendment and

  9. Effect of glycemic index on obesity control.

    Science.gov (United States)

    Pereira, Elisângela Vitoriano; Costa, Jorge de Assis; Alfenas, Rita de Cássia Gonçalves

    2015-06-01

    Evaluate the effect of glycemic index (GI) on biochemical parameters, food intake, energy metabolism, anthropometric measures and body composition in overweight subjects. Simple blind study, in which nineteen subjects were randomly assigned to consume in the laboratory two daily low GI (n = 10) or high GI (n = 9) meals, for forty-five consecutive days. Habitual food intake was assessed at baseline. Food intake, anthropometric measures and body composition were assessed at each 15 days. Energy metabolism and biochemical parameters were evaluated at baseline and the end of the study. Low GI meals increased fat oxidation, and reduced waist circumference and HOMA-IR, while high GI meals increased daily dietary fiber and energy intake compared to baseline. There was a higher reduction on waist circumference and body fat, and a higher increase on postprandial fat oxidation in response to the LGI meals than after high GI meals. High GI meals increased fasting respiratory coefficient compared to baseline and low GI meals. The results of the present study showed that the consumption of two daily low GI meals for forty-five consecutive days has a positive effect on obesity control, whereas, the consumption of high GI meals result has the opposite effect.

  10. The effects of topology on the structural, dynamic and mechanical properties of network-forming materials

    International Nuclear Information System (INIS)

    Wilson, Mark

    2012-01-01

    The effects of network topology on the static structural, mechanical and dynamic properties of MX 2 network-forming liquids (with tetrahedral short-range order) are discussed. The network topology is controlled via a single model parameter (the anion polarizability) which effectively constrains the inter-tetrahedral linkages in a physically transparent manner. Critically, it is found to control the balance between the stability of corner- and edge-sharing tetrahedra. A potential rigidity transformation is investigated. The vibrational density of states is investigated, using an instantaneous normal model analysis, as a function of both anion polarizability and temperature. A low frequency peak is seen to appear and is shown to be correlated with the fraction of cations which are linked through solely edge-sharing structural motifs. A modified effective mean atom coordination number is proposed which allows the appearance of the low frequency feature to be understood in terms of a mean field rigidity percolation threshold. (paper)

  11. Establishing whether the structural feature controlling the mechanical properties of starch films is molecular or crystalline.

    Science.gov (United States)

    Li, Ming; Xie, Fengwei; Hasjim, Jovin; Witt, Torsten; Halley, Peter J; Gilbert, Robert G

    2015-03-06

    The effects of molecular and crystalline structures on the tensile mechanical properties of thermoplastic starch (TPS) films from waxy, normal, and high-amylose maize were investigated. Starch structural variations were obtained through extrusion and hydrothermal treatment (HTT). The molecular and crystalline structures were characterized using size-exclusion chromatography and X-ray diffractometry, respectively. TPS from high-amylose maize showed higher elongation at break and tensile strength than those from normal maize and waxy maize starches when processed with 40% plasticizer. Within the same amylose content, the mechanical properties were not affected by amylopectin molecular size or the crystallinity of TPS prior to HTT. This lack of correlation between the molecular size, crystallinity and mechanical properties may be due to the dominant effect of the plasticizer on the mechanical properties. Further crystallization of normal maize TPS by HTT increased the tensile strength and Young's modulus, while decreasing the elongation at break. The results suggest that the crystallinity from the remaining ungelatinized starch granules has less significant effect on the mechanical properties than that resulting from starch recrystallization, possibly due to a stronger network from leached-out amylose surrounding the remaining starch granules. Copyright © 2014 Elsevier Ltd. All rights reserved.

  12. 36 CFR 1280.2 - What property is under the control of the Archivist of the United States?

    Science.gov (United States)

    2010-07-01

    ... 36 Parks, Forests, and Public Property 3 2010-07-01 2010-07-01 false What property is under the control of the Archivist of the United States? 1280.2 Section 1280.2 Parks, Forests, and Public Property NATIONAL ARCHIVES AND RECORDS ADMINISTRATION NARA FACILITIES USE OF NARA FACILITIES What Are the General...

  13. Topological effects on the mechanical properties of polymer knots

    Science.gov (United States)

    Zhao, Yani; Ferrari, Franco

    2017-11-01

    The mechanical properties of knotted polymer rings under stretching in a bad or good solvent are investigated by applying a force F to a point of the knot while keeping another point fixed. The Monte Carlo sampling of the polymer conformations is performed on a simple cubic lattice using the Wang-Landau algorithm. The specific energy, specific heat capacity, gyration radius and the force-elongation curves are computed for several knot topologies with lengths up to 120 lattice units. The common features of the mechanical and thermal behavior of stretched short polymer rings forming knots of a given topological type are analyzed as well as the differences arising due to topology and size effects. It is found that these systems admit three different phases depending on the values of the tensile force F and the temperature T. The transitions from one phase to the other are well characterized by the peaks of the specific heat capacity and by the data of the gyration radius and specific energy. At very low temperatures the force-elongation curves show that the stretching of a knot is a stepwise process, which becomes smooth at higher temperatures. Criteria for distinguishing topological and size effects are provided. It turns out from our study that the behavior of short polymer rings is strongly influenced by topological effects. In particular, the swelling and the swelling rate of knots are severely limited by the topological constraints. Several other properties that are affected by topology, like the decay of the specific energy at high tensile forces, are discussed. The fading out of the influences of topological origin with increasing knot lengths has been verified. Some anomalies detected in the plots of the specific heat capacity of very short and complex knots have been explained by the limitations in the number of accessible energy states due to the topological constraints.

  14. The Effect of Cold Work on Properties of Alloy 617

    Energy Technology Data Exchange (ETDEWEB)

    Wright, Richard [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2014-08-01

    Alloy 617 is approved for non-nuclear construction in the ASME Boiler and Pressure Vessel Code Section I and Section VIII, but is not currently qualified for nuclear use in ASME Code Section III. A draft Code Case was submitted in 1992 to qualify the alloy for nuclear service but efforts were stopped before the approval process was completed.1 Renewed interest in high temperature nuclear reactors has resulted in a new effort to qualify Alloy 617 for use in nuclear pressure vessels. The mechanical and physical properties of Alloy 617 were extensively characterized for the VHTR programs in the 1980’s and incorporated into the 1992 draft Code Case. Recently, the properties of modern heats of the alloy that incorporate an additional processing step, electro-slag re-melting, have been characterized both to confirm that the properties of contemporary material are consistent with those in the historical record and to increase the available database. A number of potential issues that were identified as requiring further consideration prior to the withdrawal of the 1992 Code Case are also being re-examined in the current R&D program. Code Cases are again being developed to allow use of Alloy 617 for nuclear design within the rules of the ASME Boiler and Pressure Vessel Code. In general the Code defines two temperature ranges for nuclear design with austenitic and nickel based alloys. Below 427°C (800°F) time dependent behavior is not considered, while above this temperature creep and creep-fatigue are considered to be the dominant life-limiting deformation modes. There is a corresponding differentiation in the treatment of the potential for effects associated with cold work. Below 427°C the principal issue is the relationship between the level of cold work and the propensity for stress corrosion cracking and above that temperature the primary concern is the impact of cold work on creep-rupture behavior.

  15. Effect of neutron irradiation on mechanical properties of ferritic steels

    International Nuclear Information System (INIS)

    Kass, S.B.; Murty, K.L.

    1995-01-01

    Effect of neutron radiation exposure was investigated in various ferritic steels with the main emphasis being the effects of thermal neutrons on radiation hardening. Pure iron of varied grain sizes was also used for characterizing the grain size effects on the source hardening before and after neutron irradiation. While many steels are considered in the overall study, the results on 1020, A516 and A588 steels are emphasized. Radiation hardening due to fast neutrons was seen to be sensitive to the composition of the steels with A354 being the least resistant and A490 the least sensitive. Majority of the radiation hardening stems from friction hardening, and source hardening term decreased with exposure to neutron radiation apparently due to the interaction of interstitial impurities with radiation produced defects. Inclusion of thermal neutrons along with fast resulted in further decrease in the source hardening with a slight increase in the friction hardening which revealed a critical grain size below which exposure to total (fast and thermal) neutron spectrum resulted in a slight reduction in the yield stress compared to the exposure to only fast neutrons. This is the first time such a grain size effect is reported and this is shown to be consistent with known radiation effects on friction and source hardening terms along with the observation that low energy neutrons have a nonnegligible effect on the mechanical properties of steels. In ferritic steels, however, despite their small grain size, exposure to total neutron spectrum yielded higher strengths than exposure to only fast neutrons. This behavior is consistent with the fact that the source hardening is small in these alloys and radiation effect is due only to friction stress

  16. The Effect of Water Harvesting Techniques on Runoff, Sedimentation, and Soil Properties

    Science.gov (United States)

    Al-Seekh, Saleh H.; Mohammad, Ayed G.

    2009-07-01

    This study addressed the hydrological processes of runoff and sedimentation, soil moisture content, and properties under the effect of different water harvesting techniques (treatments). The study was conducted at three sites, representing environmental condition gradients, located in the southern part of the West Bank. For each treatment, the study evaluated soil chemical and physical properties, soil moisture at 30 cm depth, surface runoff and sedimentation at each site. Results showed that runoff is reduced by 65-85% and sedimentation by 58-69% in stone terraces and semi-circle bunds compared to the control at the semi-humid site. In addition, stone terraces and contour ridges significantly reduced the amount of total runoff by 80% and 73%, respectively, at the arid site. Soil moisture content was significantly increased by water harvesting techniques compared to the control in all treatments at the three study sites. In addition, the difference between the control and the water harvesting structures were higher in the arid and semi-arid areas than in the semi-humid area. Soil and water conservation, via utilization of water harvesting structures, is an effective principle for reducing the negative impact of high runoff intensity and subsequently increasing soil moisture storage from rainfall. Jessour systems in the valley and stone terraces were effective in increasing soil moisture storage, prolonging the growing season for natural vegetation, and decreasing the amount of supplemental irrigation required for growing fruit trees.

  17. The effect of water harvesting techniques on runoff, sedimentation, and soil properties.

    Science.gov (United States)

    Al-Seekh, Saleh H; Mohammad, Ayed G

    2009-07-01

    This study addressed the hydrological processes of runoff and sedimentation, soil moisture content, and properties under the effect of different water harvesting techniques (treatments). The study was conducted at three sites, representing environmental condition gradients, located in the southern part of the West Bank. For each treatment, the study evaluated soil chemical and physical properties, soil moisture at 30 cm depth, surface runoff and sedimentation at each site. Results showed that runoff is reduced by 65-85% and sedimentation by 58-69% in stone terraces and semi-circle bunds compared to the control at the semi-humid site. In addition, stone terraces and contour ridges significantly reduced the amount of total runoff by 80% and 73%, respectively, at the arid site. Soil moisture content was significantly increased by water harvesting techniques compared to the control in all treatments at the three study sites. In addition, the difference between the control and the water harvesting structures were higher in the arid and semi-arid areas than in the semi-humid area. Soil and water conservation, via utilization of water harvesting structures, is an effective principle for reducing the negative impact of high runoff intensity and subsequently increasing soil moisture storage from rainfall. Jessour systems in the valley and stone terraces were effective in increasing soil moisture storage, prolonging the growing season for natural vegetation, and decreasing the amount of supplemental irrigation required for growing fruit trees.

  18. Effect of Inulin and Stevia on Some Physical Properties of Chocolate Milk

    Directory of Open Access Journals (Sweden)

    Mohammad Asghari Jafarabadi

    2012-07-01

    Full Text Available Background: The aim of this study was to assess physical properties of dietetic chocolate milkproduced by stevia as a sugar replacer and inulin. Along with having prebiotic effect, inulin canalso participate in enhancing textural properties of beverages. Therefore, this novel food will beuseful for all people especially for diabetics.Methods: This study was carried out in Quality Control Laboratory of Food Science and TechnologyDepartment, Health and Nutrition Faculty, Tabriz University of Medical Science, during2011-2012. The assay was performed on nine treatments with three replications. Sugar was substitutedwith stevia in two proportions of sucrose to stevia; 50:50 and 0:100. Inulin, in four levelsof 0%, 2%, 4% and 6%, was added to the treatments of 50% and 100% stevia. The control samplecontained no stevia and no inulin, such as commercial ones. Precipitation amount and viscositywere measured 24 hours after production. Data analyzed by one-way ANOVA, at the significantlevel of 0.05, using SPSS software ver. 17.Results: Sugar replacement with stevia caused significant increase in precipitation and significantdecrease in viscosity (P0.05. The sample containing50% stevia and 6% inulin had the lowest precipitation while having a non-significantlydifference with the control.Conclusion: A thickener agent, such as inulin, should be used in the chocolate milk sweetenedby stevia to improve physical properties of the product.

  19. Control of Mechanical Properties of Thermoplastic Polyurethane Elastomers by Restriction of Crystallization of Soft Segment

    Directory of Open Access Journals (Sweden)

    Sadaharu Nakamura

    2010-12-01

    Full Text Available Mechanical properties of thermoplastic polyurethane elastomers based on either polyether or polycarbonate (PC-glycols, 4,4’-dipheylmethane diisocyanate (1,1’-methylenebis(4-isocyanatobenzene, 1,4-butanediol, were controlled by restriction of crystallization of polymer glycols. For the polyether glycol based-polyurethane elastomers (PUEs, poly(oxytetramethylene glycol (PTMG, and PTMG incorporating dimethyl groups (PTG-X and methyl side groups (PTG-L were employed as a polymer glycol. For the PC-glycol, the randomly copolymerized PC-glycols with hexamethylene (C6 and tetramethylene (C4 units between carbonate groups with various composition ratios (C4/C6 = 0/100, 50/50, 70/30 and 90/10 were employed. The degree of microphase separation and mechanical properties of both the PUEs were investigated using differential scanning calorimetry, dynamic viscoelastic property measurements and tensile testing. Mechanical properties could be controlled by changing the molar ratio of two different monomer components.

  20. Semi-degradable poly(β-amino ester) networks with temporally controlled enhancement of mechanical properties.

    Science.gov (United States)

    Safranski, David L; Weiss, Daiana; Clark, J Brian; Taylor, W Robert; Gall, Ken

    2014-08-01

    Biodegradable polymers are clinically used in numerous biomedical applications, and classically show a loss of mechanical properties within weeks of implantation. This work demonstrates a new class of semi-degradable polymers that show an increase in mechanical properties through degradation via a controlled shift in a thermal transition. Semi-degradable polymer networks, poly(β-amino ester)-co-methyl methacrylate, were formed from a low glass transition temperature crosslinker, poly(β-amino ester), and high glass transition temperature monomer, methyl methacrylate, which degraded in a manner dependent upon the crosslinker chemical structure. In vitro and in vivo degradation revealed changes in mechanical behavior due to the degradation of the crosslinker from the polymer network. This novel polymer system demonstrates a strategy to temporally control the mechanical behavior of polymers and to enhance the initial performance of smart biomedical devices. Copyright © 2014 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  1. Thermoelectric properties control due to doping level and sintering conditions for FGM thermoelectric element

    CERN Document Server

    Kajikawa, T; Shiraishi, K; Ohmori, M; Hirai, T

    1999-01-01

    Thermoelectric performance is determined with three factors, namely, Seebeck coefficient, electrical resistivity and thermal conductivity. For metal and single crystalline semiconductor, those factors have close interrelation each $9 other. However, as the sintered thermoelectric element has various levels of superstructure from macro scale and micro scale in terms of the thermoelectric mechanism, the relationship among them is more complex than that for the $9 melt- grown element, so it is suggested that the control of the temperature dependence of thermoelectric properties is possible to enhance the thermoelectric performance for wide temperature range due to FGM approach. The research $9 objective is to investigate the characteristics of the thermoelectric properties for various doping levels and hot-pressed conditions to make the thermoelectric elements for which the temperature dependence of the performance is $9 controlled due to FGM approach varying the doping levels and sintering conditions. By usage ...

  2. Price game and chaos control among three oligarchs with different rationalities in property insurance market.

    Science.gov (United States)

    Ma, Junhai; Zhang, Junling

    2012-12-01

    Combining with the actual competition in Chinese property insurance market and assuming that the property insurance companies take the marginal utility maximization as the basis of decision-making when they play price games, we first established the price game model with three oligarchs who have different rationalities. Then, we discussed the existence and stability of equilibrium points. Third, we studied the theoretical value of Lyapunov exponent at Nash equilibrium point and its change process with the main parameters' changes though having numerical simulation for the system such as the bifurcation, chaos attractors, and so on. Finally, we analyzed the influences which the changes of different parameters have on the profits and utilities of oligarchs and their corresponding competition advantage. Based on this, we used the variable feedback control method to control the chaos of the system and stabilized the chaos state to Nash equilibrium point again. The results have significant theoretical and practical application value.

  3. Price game and chaos control among three oligarchs with different rationalities in property insurance market

    Science.gov (United States)

    Ma, Junhai; Zhang, Junling

    2012-12-01

    Combining with the actual competition in Chinese property insurance market and assuming that the property insurance companies take the marginal utility maximization as the basis of decision-making when they play price games, we first established the price game model with three oligarchs who have different rationalities. Then, we discussed the existence and stability of equilibrium points. Third, we studied the theoretical value of Lyapunov exponent at Nash equilibrium point and its change process with the main parameters' changes though having numerical simulation for the system such as the bifurcation, chaos attractors, and so on. Finally, we analyzed the influences which the changes of different parameters have on the profits and utilities of oligarchs and their corresponding competition advantage. Based on this, we used the variable feedback control method to control the chaos of the system and stabilized the chaos state to Nash equilibrium point again. The results have significant theoretical and practical application value.

  4. Effect of diblock copolymer properties on the photophysical properties of dendrimer silicon phthalocyanine nanoconjugates

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Kuizhi [Fujian Normal University, College of Materials Science & Engineering, Fujian Provincial Key Laboratory of Polymer Materials (China); Pan, Sujuan [Fujian Normal University, College of Chemistry & Engineering (China); Zhuang, Xuemei [Fuzhou No.2 Hospital (China); Lv, Hafei; Que, Shoulin [Fujian Normal University, College of Chemistry & Engineering (China); Xie, Shusen; Yang, Hongqin, E-mail: hqyang@fjnu.edu.cn [Fujian Normal University, Key Laboratory of Optoelectronic Science and Technology for Medicine of Ministry of Education (China); Peng, Yiru, E-mail: yirupeng@fjnu.edu.cn [Fujian Normal University, College of Chemistry & Engineering (China)

    2016-07-15

    1–2 generation poly(benzyl aryl ether) dendrimer silicon phthalocyanines with axially disubstituted cyano terminal functionalities (G{sub n}-DSiPc(CN){sub 4n}, (G{sub n} = n-generation dendrimer, n = 1–2)) were synthesized. Their structures were characterized by elemental analysis, IR, {sup 1}H NMR, and ESI-MS. Polymeric nanoparticles (G{sub n}-DSiPc(CN){sub 4n}/m) were formed through encapsulating G{sub n}-DSiPc(CN){sub 4n} into three monomethoxyl poly(ethylene glycol)-poly(ε-caprolactone) diblock copolymers (MPEG–PCL) with different hydrophilic/hydrophobic proportion, respectively. The effect of dendritic generation and the hydrophilic/hydrophobic proportion of diblock copolymers on the UV/Vis and fluorescence spectra of G{sub n}-DSiPc(CN){sub 4n} and G{sub n}-DSiPc(CN){sub 4n}/m were studied. The photophysical properties of polymeric nanoparticles exhibited dendritic generation and hydrophilic/hydrophobic proportion dependence. The fluorescence intensities and lifetimes of G{sub n}-DSiPc(CN){sub 4n}/m were lower than the corresponding free dendrimer phthalocyanines. G{sub n}-DSiPc(CN){sub 4n} encapsulated into MPEG–PCL with hydrophilic/hydrophobic molecular weight ratio 2000:4000 exhibited excellent photophysical property. The mean diameter of MPEG{sub 2000}–PCL{sub 2000} micelles was about 70 nm, which decreased when loaded with G{sub n}-DSiPc(CN){sub 4n}.Graphical abstract .

  5. THE EFFECT OF TRANSGLUTAMINASE ON THE RHEOLOGICAL PROPERTIES OF YOGURT

    Directory of Open Access Journals (Sweden)

    Iuliana Aprodu

    2011-05-01

    Full Text Available The aim of this study was to investigate the rheological characteristics of yogurts obtained from milk treated with transglutaminase prior to fermentation with Streptococus theromophilus and Lactobacillus delbrueckii subsp. Bulgaricus. A set of 36 experiments were carried out to test the influence of various enzyme concentrations ranging from 0 to 0.04%, different setting temperatures (35, 40 and 45 oC, and setting time (60, 90 and 120 min. The cross-linking of milk proteins influenced the post-acidification process as well as the stability of the yogurt samples. The enzymatic treatment of milk allowed avoiding the syneresis phenomena during yogurt storage at 4 oC; the water holding capacity during centrifugation was also improved. Concerning the rheological properties, the apparent viscosity of yogurt increased by increasing the enzyme concentration and the setting time for the entire tested domain of shear rates. The results indicate that transglutaminase catalyzed cross-linking is an effective tool for improving functional properties of yogurt.

  6. Effect of wastewater on properties of Portland pozzolana cement

    Science.gov (United States)

    Babu, G. Reddy

    2017-07-01

    This paper presents the effect of wastewaters on properties of Portland pozzolana cement (PPC). Fourteen water treatment plants were found out in the Narasaraopet municipality region in Guntur district, Andhra Pradesh, India. Approximately, from each plant, between 3500 and 4000 L/day of potable water is selling to consumers. All plants are extracting ground water and treating through Reverse Osmosis (RO) process. During water treatment, plants are discharging approximately 1,00,000 L/day as wastewater in side drains in Narasaraopet municipality. Physical and chemical analysis was carried out on fourteen plants wastewater and distilled water as per producer described in APHA. In the present work, based on the concentrations of constituent's in wastewater, four typical plants i.e., Narasaraopeta Engineering College (NECWW), Patan Khasim Charitable Trust (PKTWW), Mahmadh Khasim Charitable Trust (MKTWW) and Amara (ARWW) were considered. The performance of four plants wastewater on physical properties i.e., setting times, compressive strength, and flexural strength of Portland pozzolana Cement (PPC) were performed in laboratories and compared same with reference specimens i.e., made with Distilled Water (DW) as mixing water. No significant change was observed in initial and finial setting time but setting times of selected wastewaters were retarded as compared to that of reference water. Almost, no change was observed in 90 days compressive and flexural strengths in four plants wastewaters specimens compared to that of reference water specimens. XRD technique was employed to find out main hydration compounds formed in the process.

  7. Effects of liquid lead on 316l tensile properties

    International Nuclear Information System (INIS)

    Ionescu, V.; Pitigoi, V.; Nitu, A.; Hororoi, M.; Voicu, F.; Cojocaru, V.

    2016-01-01

    The lead-cooled fast reactor (LFR) is one of the concepts of the Generation IV reactor systems. Compatibility of the candidate structural materials with the liquid lead is known to be one of the critical issues to allow development of the LFR reactors. In contact with the liquid metal, the mechanical integrity of the structural materials can be affected. The steel.s mechanical properties are assessed by tensile testing as a function of temperature in heavy liquid metal and in an air environment. RATEN ICN is involved in several European projects aimed to Generation IV research activities. In a first stage an Experimental Facility for Tensile Tests in Liquid Lead environment has been set up. This installation is adapted on the Instron testing machine, already existing in institute. 316L alloy is one of a candidate structural material for this type of reactor. This document presents the effect of liquid lead on tensile properties of 316L material tested in liquid lead (in static conditions) and in air environment at 500°C, without oxygen monitoring system. When solid metals are placed in contact to liquid metals and stress is applied, they may undergo abrupt brittle failure. Stress-strain curves of slow strain rate tests have been obtained in conformity with ASTM, E-8. Mechanical characteristics determined are in accordance with literature. (authors)

  8. Radiation Effects on Mechanical Properties of LDPE/EVA blend

    International Nuclear Information System (INIS)

    Lee, Chung; Kim, Ki Yup; Im, Don Sun; Ryu, Boo Hyung

    2005-01-01

    Restricted properties and a limited use of homopolymers alone, have given rise to an exploration of composites, copolymers, blends, etc. Copolymers such as poly(ethylene-co-vinyl acetate) (EVA), poly(ethylene-co-butyl acrylate), poly(ethylene-co-ethyl acrylate) (EEA) have wide usages in different industry. Among the numerous ethylene copolymers, due to its wide range of properties depending on its vinyl acetate content, EVA has become one of the most useful copolymers in the electrical industry as a cable insulator, and in many other industries as a hot melt adhesive, a coating, etc. Several works looked at the influence of gamma rays on polymers. Zhang et al have blended EVA with PE because crosslinked PE has a low flexibility for use as a cable insulation. It was reported that the blend showed have a better elongation, flexibility and heat aging effect than PE, but its hardness and softening point were lower. In this study, the radiation degradation of LDPE/EVA blends as a function of the vinyl acetate contents was investigated by using TGA, gelation and elongation

  9. Effect of vacancies on the mechanical properties of phosphorene nanotubes

    Science.gov (United States)

    Sorkin, V.; Zhang, Y. W.

    2018-06-01

    Using density functional tight-binding method, we studied the mechanical properties, deformation and failure of armchair (AC) and zigzag (ZZ) phosphorene nanotubes (PNTs) with monovacancies and divacancies subjected to uniaxial tensile strain. We found that divacancies in AC PNTs and monovacancies in ZZ PNTs possess the lowest vacancy formation energy, which decreases with the tube diameter in AC PNTs and increases in ZZ PNTs. The Young’s modulus is reduced, while the radial and thickness Poisson’s ratios are increased by hosted vacancies. In defective AC PNTs, deformation involves fracture of the intra-pucker bonds and formation of the new inter-pucker bonds at a critical strain, and the most stretched bonds around the vacancy rupture first, triggering a sequence of the structural transformations terminated by the ultimate failure. The critical strain of AC PNTs is reduced significantly by hosted vacancies, whereas their effect on the critical stress is relatively weaker. Defective ZZ PNTs fail in a brittle-like manner once the most stretched bonds around a vacancy rupture, and vacancies are able to significantly reduce the failure strain but only moderately reduce the failure stress of ZZ PNTs. The understandings revealed here on the mechanical properties and the deformation and failure mechanisms of PNTs provide useful guidelines for their design and fabrication as building blocks in nanodevices.

  10. Effect of substrate temperature and deposition rate on the morphology and optical properties of Ti films

    Energy Technology Data Exchange (ETDEWEB)

    Einollahzadeh-Samadi, M.; Dariani, R.S., E-mail: dariani@alzahra.ac.ir

    2013-09-01

    Titanium films are deposited on transparent fluorine-doped tin oxide (FTO) glass substrates by DC magnetron sputtering process. Influences imposed by sputtering rate and substrate temperature on surface morphology and optical properties of the deposited Ti films are investigated. We observed that all the sputtered films exhibit uniform and compact surface morphology without peeling and cracking. Morphology of the films is studied using atomic force microscopy (AFM) and X-ray diffraction (XRD). The optical properties of the films are investigated using UV–vis spectroscopy. The morphological studies indicate that by increasing the substrate temperature from room temperature to 250 °C and/or decreasing sputtering rate from 660 Å/min to 540 Å/min the surface roughness decreased from 73.4 to 31.0 nm and the grain size increases from 50.76 nm to 163.93 nm. An important effect of the root mean square (RMS) surface roughness and grain size is modification of the films optical properties. In fact, an enhancement of refractive index n for the Ti films deposited at high substrate temperature and/or high deposition rate is observed, that is attributed to reduction of RMS roughness. This effect is attributed to increment of fractional volume which leads to an increase in density of deposited film. Thus, by controlling the sputtering conditions one can reach to the desired morphological and optical properties.

  11. Inhibitory effect on Streptococcus mutans and mechanical properties of the chitosan containing composite resin

    Directory of Open Access Journals (Sweden)

    Ji-Sun Kim

    2013-02-01

    Full Text Available Objectives This study evaluated the antibacterial effect and mechanical properties of composite resins (LCR, MCR, HCR incorporating chitosan with three different molecular weights (L, Low; M, Medium; H, High. Materials and Methods Streptococcus (S. mutans 100 mL and each chitosan powder were inoculated in sterilized 10 mL Brain-Heart Infusion (BHI solution, and was centrifuged for 12 hr. Absorbance of the supernatent was measured at OD660 to estimate the antibacterial activities of chitosan. After S. mutans was inoculated in the disc shaped chitosan-containing composite resins, the disc was cleansed with BHI and diluted with serial dilution method. S. mutans was spread on Mitis-salivarius bacitracin agar. After then, colony forming unit (CFU was measured to verify the inhibitory effect on S. mutans biofilm. To ascertain the effect on the mechanical properties of composite resin, 3-point bending and Vickers hardness tests were done after 1 and 3 wk water storage, respectively. Using 2-way analysis of variance (ANOVA and Scheffe test, statistical analysis was done with 95% significance level. Results All chitosan powder showed inhibition effect against S. mutans. CFU number in chitosan-containing composite resins was smaller than that of control resin without chitosan. The chitosan containing composite resins did not show any significant difference in flexural strength and Vickers hardness in comparison with the control resin. However, the composite resin, MCR showed a slightly decreased flexural strength and the maximum load than those of control and the other composite resins HCR and LCR. Conclusions LCR and HCR would be recommended as a feasible antibacterial restorative due to its antibacterial nature and mechanical properties.

  12. Electronic properties of mesoscopic graphene structures: Charge confinement and control of spin and charge transport

    Energy Technology Data Exchange (ETDEWEB)

    Rozhkov, A.V., E-mail: arozhkov@gmail.co [Advanced Science Institute, RIKEN, Wako-shi, Saitama, 351-0198 (Japan); Institute for Theoretical and Applied Electrodynamics, Russian Academy of Sciences, 125412, Moscow (Russian Federation); Giavaras, G. [Advanced Science Institute, RIKEN, Wako-shi, Saitama, 351-0198 (Japan); Bliokh, Yury P. [Advanced Science Institute, RIKEN, Wako-shi, Saitama, 351-0198 (Japan); Department of Physics, Technion-Israel Institute of Technology, Haifa 32000 (Israel); Freilikher, Valentin [Advanced Science Institute, RIKEN, Wako-shi, Saitama, 351-0198 (Japan); Department of Physics, Bar-Ilan University, Ramat-Gan 52900 (Israel); Nori, Franco [Advanced Science Institute, RIKEN, Wako-shi, Saitama, 351-0198 (Japan); Department of Physics, University of Michigan, Ann Arbor, MI 48109-1040 (United States)

    2011-06-15

    This brief review discusses electronic properties of mesoscopic graphene-based structures. These allow controlling the confinement and transport of charge and spin; thus, they are of interest not only for fundamental research, but also for applications. The graphene-related topics covered here are: edges, nanoribbons, quantum dots, pn-junctions, pnp-structures, and quantum barriers and waveguides. This review is partly intended as a short introduction to graphene mesoscopics.

  13. THE PROBLEMS OF ACCOUNTING AND CONTROL OF PROPERTY OF BUDGET LOW VALUE IN EDUCATIONAL INSTITUTIONS

    OpenAIRE

    Efimova S.B.; Sobachko A.I.

    2012-01-01

    Purpose. Consideration of the treatment facilities, which are debited from the balance, but continue to participate in the activities of the institutio. We used a systematic approach to the study of the issues, analysis, synthesis, observation, group, etc. The article focuses on the issues arising in the course of accounting and control system development. The key issues in this respect are property valuation and classification, ways of entity identification and writing them off from offbalan...

  14. Microwave absorption properties of carbon nanocoils coated with highly controlled magnetic materials by atomic layer deposition.

    Science.gov (United States)

    Wang, Guizhen; Gao, Zhe; Tang, Shiwei; Chen, Chaoqiu; Duan, Feifei; Zhao, Shichao; Lin, Shiwei; Feng, Yuhong; Zhou, Lei; Qin, Yong

    2012-12-21

    In this work, atomic layer deposition is applied to coat carbon nanocoils with magnetic Fe(3)O(4) or Ni. The coatings have a uniform and highly controlled thickness. The coated nanocoils with coaxial multilayer nanostructures exhibit remarkably improved microwave absorption properties compared to the pristine carbon nanocoils. The enhanced absorption ability arises from the efficient complementarity between complex permittivity and permeability, chiral morphology, and multilayer structure of the products. This method can be extended to exploit other composite materials benefiting from its convenient control of the impedance matching and combination of dielectric-magnetic multiple loss mechanisms for microwave absorption applications.

  15. Control of clay minerals effect in flotation. A review

    Directory of Open Access Journals (Sweden)

    Taner Hasan Ali

    2016-01-01

    Full Text Available The increased exposure to low grade ores highlights the importance of understanding phyllosilicate gangue mineralogy which consists of common gangue minerals. To improve the flotation performance and ore quality the negative effect of the clay minerals on flotation should be identified. The presence of clay minerals leads to problems, such as changing the froth stability, which are related to swelling behaviour, increase in pulp viscosity, overconsumption of reagents, slime coating and mechanical entrainment. The clay content in the ore is changing from time to time and it is necessary to provide quick solutions to the issues caused by the new ore composition. The objective of this paper is to give an overview how to control the colloidal properties of clay minerals on flotation.

  16. Effect of mechanical properties on erosion resistance of ductile materials

    Science.gov (United States)

    Levin, Boris Feliksovih

    incorporating this parameter into a new erosion model, good correlation was observed with experimentally measured erosion rates. An increase in area under the microhardness curve led to an increase in erosion resistance. It was shown that an increase in hardness below the eroded surface occurs mainly due to the strain-rate hardening effect. Strain-rate sensitivities of tested materials were estimated from the nanoindentation tests and showed a decrease with an increase in materials hardness. Also, materials combining high hardness and strain-rate sensitivity may offer good erosion resistance. A methodology is presented to determine the proper mechanical properties to incorporate into the erosion parameter based on the physical model of the erosion mechanism in ductile materials.

  17. Effective thermo-mechanical properties and shape memory effect of CNT/SMP composites

    Science.gov (United States)

    Yang, Qingsheng; Liu, Xia; Leng, Fangfang

    2009-07-01

    Shape memory polymer (SMP) has been applied in many fields as intelligent sensors and actuators. In order to improve the mechanical properties and recovery force of SMP, the addition of minor amounts of carbon nanotubes (CNT) into SMP has attracted wide attention. A micromechanical model and thermo-mechanical properties of CNT/SMP composites were studied in this paper. The thermo-mechanical constitutive relation of intellectual composites with isotropic and transversely isotropic CNT was obtained. Moreover, the shape memory effect of CNT/SMP composites and the effect of temperature and the volume fraction of CNT were discussed. The work shows that CNT/SMP composites exhibit excellent macroscopic thermo-mechanical properties and shape memory effect, while both of them can be affected remarkably by temperature and the microstructure parameters.

  18. Effect of Solar Radiation on Viscoelastic Properties of Bovine Leather: Temperature and Frequency Scans

    Science.gov (United States)

    Nalyanya, Kallen Mulilo; Rop, Ronald K.; Onyuka, Arthur S.

    2017-04-01

    This work presents both analytical and experimental results of the effect of unfiltered natural solar radiation on the thermal and dynamic mechanical properties of Boran bovine leather at both pickling and tanning stages of preparation. Samples cut from both pickled and tanned pieces of leather of appropriate dimensions were exposed to unfiltered natural solar radiation for time intervals ranging from 0 h (non-irradiated) to 24 h. The temperature of the dynamic mechanical analyzer was equilibrated at 30°C and increased to 240°C at a heating rate of 5°C \\cdot Min^{-1}, while its oscillation frequency varied from 0.1 Hz to 100 Hz. With the help of thermal analysis (TA) control software which analyzes and generates parameter means/averages at temperature/frequency range, the graphs were created by Microsoft Excel 2013 from the means. The viscoelastic properties showed linear frequency dependence within 0.1 Hz to 30 Hz followed by negligible frequency dependence above 30 Hz. Storage modulus (E') and shear stress (σ ) increased with frequency, while loss modulus (E''), complex viscosity (η ^{*}) and dynamic shear viscosity (η) decreased linearly with frequency. The effect of solar radiation was evident as the properties increased initially from 0 h to 6 h of irradiation followed by a steady decline to a minimum at 18 h before a drastic increase to a maximum at 24 h. Hence, tanning industry can consider the time duration of 24 h for sun-drying of leather to enhance the mechanical properties and hence the quality of the leather. At frequencies higher than 30 Hz, the dynamic mechanical properties are independent of the frequency. The frequency of 30 Hz was observed to be a critical value in the behavior in the mechanical properties of bovine hide.

  19. Soil organic carbon dynamics jointly controlled by climate, carbon inputs, soil properties and soil carbon fractions.

    Science.gov (United States)

    Luo, Zhongkui; Feng, Wenting; Luo, Yiqi; Baldock, Jeff; Wang, Enli

    2017-10-01

    Soil organic carbon (SOC) dynamics are regulated by the complex interplay of climatic, edaphic and biotic conditions. However, the interrelation of SOC and these drivers and their potential connection networks are rarely assessed quantitatively. Using observations of SOC dynamics with detailed soil properties from 90 field trials at 28 sites under different agroecosystems across the Australian cropping regions, we investigated the direct and indirect effects of climate, soil properties, carbon (C) inputs and soil C pools (a total of 17 variables) on SOC change rate (r C , Mg C ha -1  yr -1 ). Among these variables, we found that the most influential variables on r C were the average C input amount and annual precipitation, and the total SOC stock at the beginning of the trials. Overall, C inputs (including C input amount and pasture frequency in the crop rotation system) accounted for 27% of the relative influence on r C , followed by climate 25% (including precipitation and temperature), soil C pools 24% (including pool size and composition) and soil properties (such as cation exchange capacity, clay content, bulk density) 24%. Path analysis identified a network of intercorrelations of climate, soil properties, C inputs and soil C pools in determining r C . The direct correlation of r C with climate was significantly weakened if removing the effects of soil properties and C pools, and vice versa. These results reveal the relative importance of climate, soil properties, C inputs and C pools and their complex interconnections in regulating SOC dynamics. Ignorance of the impact of changes in soil properties, C pool composition and C input (quantity and quality) on SOC dynamics is likely one of the main sources of uncertainty in SOC predictions from the process-based SOC models. © 2017 John Wiley & Sons Ltd.

  20. Advanced manufacturing of microdisk vaccines for uniform control of material properties and immune cell function.

    Science.gov (United States)

    Zeng, Qin; Zhang, Peipei; Zeng, Xiangbin; Tostanoski, Lisa H; Jewell, Christopher M

    2017-12-19

    The continued challenges facing vaccines in infectious disease and cancer highlight a need for better control over the features of vaccines and the responses they generate. Biomaterials offer unique advantages to achieve this goal through features such as controlled release and co-delivery of antigens and adjuvants. However, many synthesis strategies lead to particles with heterogeneity in diameter, shape, loading level, or other properties. In contrast, advanced manufacturing techniques allow precision control of material properties at the micro- and nano-scale. These capabilities in vaccines and immunotherapies could allow more rational design to speed efficient design and clinical translation. Here we employed soft lithography to generate polymer microdisk vaccines with uniform structures and tunable compositions of vaccine antigens and toll like receptor agonists (TLRas) that serve as molecular adjuvants. Compared to conventional PLGA particles formed by emulsion, microdisks provided a dramatic improvement in the consistency of properties such as diameter. During culture with primary dendritic cells (DCs) from mice, microdisks were internalized by the cells without toxicity, while promoting co-delivery of antigen and TLRa to the same cell. Analysis of DC surface activation markers by flow cytometry revealed microdisk vaccines activated dendritic cells in a manner that depended on the level of TLRa, while antigen processing and presentation depended on the amount of antigen in the microdisks. Together, this work demonstrates the use of advanced manufacturing techniques to produce uniform vaccines that direct DC function depending on the composition in the disks.

  1. Controlling the optical properties of monocrystalline 3C-SiC heteroepitaxially grown on silicon at low temperatures

    Science.gov (United States)

    Colston, Gerard; Myronov, Maksym

    2017-11-01

    Cubic silicon carbide (3C-SiC) offers an alternative wide bandgap semiconductor to conventional materials such as hexagonal silicon carbide (4H-SiC) or gallium nitride (GaN) for the detection of UV light and can offer a closely lattice matched virtual substrate for subsequent GaN heteroepitaxy. As 3C-SiC can be heteroepitaxially grown on silicon (Si) substrates its optical properties can be manipulated by controlling the thickness and doping concentrations. The optical properties of 3C-SiC epilayers have been characterized by measuring the transmission of light through suspended membranes. Decreasing the thickness of the 3C-SiC epilayers is shown to shift the absorbance edge to lower wavelengths, a result of the indirect bandgap nature of silicon carbide. This property, among others, can be exploited to fabricate very low-cost, tuneable 3C-SiC based UV photodetectors. This study investigates the effect of thickness and doping concentration on the optical properties of 3C-SiC epilayers grown at low temperatures by a standard Si based growth process. The results demonstrate the potential photonic applications of 3C-SiC and its heterogeneous integration into the Si industry.

  2. Effect of aging on properties of pressure vessel steels

    Energy Technology Data Exchange (ETDEWEB)

    Druce, S.G.; Gage, G.; Jordan, G.

    1986-04-01

    Manganese-molybdenum-nickel steels are used in nuclear pressure vessels operating at temperatures up to 350/sup 0/C. The effects of thermal ageing in the temperature range 300-550/sup 0/C for durations up to 2 x 10/sup 4/ h have been studied in conventionally quenched and tempered and simulated heat-affected-zone (HAZ) microstructural conditions. Quantitative fractography and Auger spectroscopy have been used to relate changes in mechanical properties with changes in fracture mode and grain boundary chemistry. Aging increases the ductile-brittle transition temperature by an amount dependent on material, prior heat treatment, aging temperature and time. Embrittlement is associated with segregation of phosphorus to grain boundaries and is modelled using McLean's approach to equilibrium segregation.

  3. Effect of precipitation route on the properties of antimony trioxide

    International Nuclear Information System (INIS)

    Abdullah, Abdul Halim; Noor, Nor Hayati Mohd; Ramli, Irmawati; Hashim, Mansor

    2008-01-01

    Antimony trioxide was prepared, using antimony potassium tartarate as starting material, via forward and reverse precipitation technique. The characteristics of the resulting antimony oxides were determined by BET surface area method, differential thermogravimetry analysis (DTG), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR) and SEM. The DTG curves for all uncalcined samples showed only a single endothermic peak which indicated that the sample is antimony trioxide. Unlike forward precipitation technique which resulted in a single antimony trioxide phase which is senarmontite, reverse precipitation technique produced antimony trioxide with both senarmontite and valentinite phase. Upon calcinations at 723 K, a small amount of Sb 2 O 4 with cervantite phase was formed at the expense of Sb 2 O 3 senarmontite phase as detected from the XRD pattern and infrared spectrum of RSb. The effect of preparation route on the properties of the antimony trioxide produced was clearly demonstrated

  4. Effect of temperature on tribological properties of palm biodiesel

    Energy Technology Data Exchange (ETDEWEB)

    Haseeb, A.S.M.A.; Sia, S.Y.; Fazal, M.A.; Masjuki, H.H. [Department of Mechanical Engineering, University of Malaya, 50603 Kuala Lumpur (Malaysia)

    2010-03-15

    Biodiesel, as an alternative fuel is steadily gaining attention to replace petroleum diesel partially or completely. The tribological performance of biodiesel is crucial for its application in automobiles. In the present study, effect of temperature on the tribological performance of palm biodiesel was investigated by using four ball wear machine. Tests were conducted at temperatures 30, 45, 60 and 75 C, under a normal load of 40 kg for 1 h at speed 1200 rpm. For each temperature, the tribological properties of petroleum diesel (B0) and three biodiesel blends like B10, B20, B50 were investigated and compared. During the wear test, frictional torque was recorded on line. Wear scars in tested ball were investigated by optical microscopy. Results show that friction and wear increase with increasing temperature. (author)

  5. Quantum confinement effects on superconducting properties of Lead nanocrystals

    Science.gov (United States)

    Aubin, Herve; Moreira, Helena; Mahler, Benoit; Dubertret, Benoit

    2008-03-01

    We developed a new chemical synthesis method for producing large quantities of monodispersed lead (Pb) nanocrystals. They are obtained from the alcohol reduction of a mixture of two lead carboxylates with alkyl chains of different lengths, dissolved in a high temperature solvent. The nanocrystals obtained are protected from oxydation and aggregation by long chain fatty acids and their diameter can be tuned to reach values as low as 10 nm. Our results suggest that monodispersed particules are obtained when nucleation and growth occur at distincts temperatures, possibly as a consequence of different reactivities of the two lead carboxylates used in the solution. Owing to the large quantities of monodispersed particles produced, thermodynamics studies as function of particles diameter become possible. In particular, we will present a study of the effect of quantum confinement on superconducting properties of these Pb particles through SQUID magnetometry measurements.

  6. Effect of Superfine Grinding on Physicochemical Properties of Apple Pomace

    International Nuclear Information System (INIS)

    Liang, X.; Sun, J.; Ma, H.

    2016-01-01

    The effect of superfine grinding on the physicochemical properties of apple pomace was investigated in this study. The optimal ultrafine powder could be obtained under the conditions of motor speed 450 rpm and fan speed 300 rpm, whose particle size, water-solubility index, angle of repose, total phenolic content and total sugar content were 10.23±0.42 micro m, 33.65±0.91 percent, 39.36±1.59 degree, 12.62±0.34 mg GAE/g and 136.14±3.1 mg/g, respectively. Compared with the traditional powder, the significant increase of water-solubility, total phenolic content and total sugar content could be found while the decrease of angle of repose could be observed. It could be concluded that the bioavailability of functional and nutritional ingredients of apple pomace could be significantly improved by superfine grinding. (author)

  7. Drying effects on the antioxidant properties of tomatoes and ginger.

    Science.gov (United States)

    Gümüşay, Özlem Aktürk; Borazan, Alev Akpınar; Ercal, Nuran; Demirkol, Omca

    2015-04-15

    In this study, the effects of four different drying processes, sun drying (SD), oven drying (OD), vacuum oven drying (VOD) and freeze drying (FD) for tomatoes (Solanum lycopersicum) and ginger (Zingiber officinale) in terms of thiolic and phenolic contents have been studied. Thiol content, total phenolic content (TPC), ascorbic acid (AA) content, and cupric ion reducing antioxidant capacity (CUPRAC) were determined in fresh and dried samples. Glutathione (GSH) and cysteine (Cys) were determined as the thiol contents of tomatoes and ginger. Significant losses were observed in the contents of TPC, AA, GSH and Cys and CUPRAC values in all samples that were dried using the thermal method. There was a statistically significant difference in the losses of the TPC, AA, and thiol contents between the use of thermal drying and freeze drying (except Cys in tomatoes) methods. Freeze dried tomato and ginger samples have been found to have better antioxidant properties. Copyright © 2014 Elsevier Ltd. All rights reserved.

  8. Effects of biodrying process on municipal solid waste properties.

    Science.gov (United States)

    Tambone, F; Scaglia, B; Scotti, S; Adani, F

    2011-08-01

    In this paper, the effect of biodrying process on municipal solid waste (MSW) properties was studied. The results obtained indicated that after 14d, biodrying reduced the water content of waste, allowing the production of biodried waste with a net heating value (NHV) of 16,779±2,074kJ kg(-1) wet weight, i.e. 41% higher than that of untreated waste. The low moisture content of the biodried material reduced, also, the potential impacts of the waste, i.e. potential self-ignition and potential odors production. Low waste impacts suggest to landfill the biodried material obtaining energy via biogas production by waste re-moistening, i.e. bioreactor. Nevertheless, results of this work indicate that biodrying process because of the partial degradation of the organic fraction contained in the waste (losses of 290g kg(-1) VS), reduced of about 28% the total producible biogas. Copyright © 2011 Elsevier Ltd. All rights reserved.

  9. Effect of coal soluble constituents on caking property of coal

    Energy Technology Data Exchange (ETDEWEB)

    Hengfu Shui; Mingdong Zheng; Zhicai Wang; Xunming Li [Anhui University of Technology, Maanshan (China). School of Chemistry and Chemical Engineering, Key Laboratory of Anhui Educational Department

    2007-07-15

    Three cokemaking bituminous coals were extracted by the CS{sub 2}/NMP mixed solvents with different content of NMP, and the effect of the amount and the component of coal soluble constituents on the caking property of the extracted residues of coals were investigated in this study. The CS{sub 2}/NMP mixed solvent (1:1 by volume) was found to give the maximal extraction yields for the three coals, and the fat coal gave the highest extraction yield of 78.6% (daf) corresponding to its highest caking index of 101. It was found that for coking coal, when the extraction yield got to the maximum of 25.3% in the 1:1 by volume of CS{sub 2}/NMP mixed solvent, the residue extracted still had caking property with the caking index of 19. This means parts of the caking constituents of coal are un-extractible because of covalent bonding or strong associative cross-links. The soluble components extracted by the CS{sub 2}/NMP mixed solvent and their effects on the caking indexes of the residues at a similar extraction yield quite differed depending on the NMP content in the mixed solvent. The coal solubles extracted by the CS{sub 2}/NMP mixed solvent with NMP less than 50% contained less light constituents with less of oxygen groups. This may lead to the decrease in the caking indexes for the residues obtained at the similar extraction yields compared to those of the CS{sub 2}/NMP mixed solvent with NMP more than 50%. 11 refs., 5 figs., 3 tabs.

  10. Morphology controlled Y{sub 2}O{sub 3}:Eu{sup 3+} nanophosphors with enhanced photoluminescence properties

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Deepak [School of Physics and Materials Science, Thapar University, Patiala 147003, Punjab (India); Sharma, Manoj, E-mail: manojnarad@sggswu.org [Department of Nanotechnology, Sri Guru Granth Sahib World University, Fatehgarh Sahib 140406, Punjab (India); Pandey, O.P., E-mail: oppandey@thapar.edu [School of Physics and Materials Science, Thapar University, Patiala 147003, Punjab (India)

    2015-02-15

    Eu{sup 3+} doped Y{sub 2}O{sub 3} is prepared by a co-precipitation method using ammonium hydrogen carbonate as precipitating agent. In the present work we studied the effect of different molar concentrations of Poly vinyl pyrrolidone (PVP) and 1-Thio-glycerol (TG) as capping agents to enhance the optical and morphological properties of Y{sub 2}O{sub 3}:Eu{sup 3+} nanophosphors. In addition, variation of pH was studied to control the particle size of the synthesized product. The polymer concentration (TG and PVP) was also optimized at different pH to get higher luminescence of Eu{sup 3+} doped Y{sub 2}O{sub 3} nanoparticles (NPs). It was observed that pH of solution during synthesis and also its concentration affect the morphological and optical properties of Y{sub 2}O{sub 3}:Eu{sup 3+}. The structural, morphological and optical properties were studied by an X-ray diffraction, transmission electron microscopy, Fourier transform infrared spectroscopy and photoluminescence spectroscopy. XRD studies followed by Rietveld refinement confirmed the body-centered cubic structure of doped nanophosphors. It was observed that at optimized pH and polymer concentration the nanoparticles of Y{sub 2}O{sub 3}:Eu{sup 3+} have narrow size distribution and exhibited enhanced photoluminescent properties. - highlights: • Nano-sized Y{sub 2}O{sub 3}:Eu{sup 3+} were synthesized by a co-precipitation method using PVP and TG as capping agents. • Effect of polymers (PVP and TG) on morphological properties of Y{sub 2}O{sub 3}:Eu{sup 3+} has been explained in detail. • Improvement in PL intensity for Y{sub 2}O{sub 3}:Eu{sup 3+} prepared with polymers has been explained in detail.

  11. Effect of aggregate grain size distribution on properties of permeable ...

    African Journals Online (AJOL)

    ) ratio on the mechanical properties of permeable concrete is investigated. The aim of this study is to prepare permeable concrete mixture with optimum properties in terms of strength and permeability. For this purpose, five different permeable ...

  12. Uranium: properties and biological effects after internal contamination

    International Nuclear Information System (INIS)

    Souidi, M.; Tissandie, E.; Racine, R.; Ben Soussan, H.; Rouas, C.; Grignard, E.; Dublineau, I.; Gourmelon, P.; Lestaevel, P.; Gueguen, Y.

    2009-01-01

    Uranium is a radionuclide present in the environment since the origin of the Earth. In addition to natural uranium, recent deposits from industrial or military activities are acknowledged. Uranium's toxicity is due to a combination of its chemical (heavy metal) and radiological properties (emission of ionizing radiations). Acute toxicity induces an important weight loss and signs of renal and cerebral impairment. Alterations of bone growth, modifications of the reproductive system and carcinogenic effects are also often seen. On the contrary, the biological effects of a chronic exposure to low doses are unwell known. However, results from different recent studies suggest that a chronic contamination with low levels of uranium induces subtle but significant levels. Indeed, an internal contamination of rats for several weeks leads to detection of uranium in many cerebral structures, in association with an alteration of short-term memory and an increase of anxiety level. Biological effects of uranium on the metabolisms of xenobiotics, steroid hormones and vitamin D were described in the liver, testis and kidneys. These recent scientific data suggest that uranium could participate to increase of health risks linked to environmental pollution. (authors)

  13. PLASTIC SHRINKAGE CONTROLLING EFFECT BY POLYPROPYLENE SHORT FIBER WITH HYDROPHILY

    Science.gov (United States)

    Hosoda, Akira; Sadatsuki, Yoshitomo; Oshima, Akihiro; Ishii, Akina; Tsubaki, Tatsuya

    The aim of this research is to clarify the mechanism of controlling plastic shrinkage crack by adding small amout of synthetic short fiber, and to propose optimum polypropylene short fiber to control plastic shrinkage crack. In this research, the effect of the hydrophily of polypropylene fiber was investigated in the amount of plastic shrinkage of mortar, total area of plastic shrinkage crack, and bond properties between fiber and mortar. The plastic shrinkage test of morar was conducted under high temperature, low relative humidity, and constant wind velocity. When polypropylene fiber had hydrophily, the amount of plastic shrinkage of mortar was restrained, which was because cement paste in morar was captured by hydrophilic fiber and then bleeding of mortar was restrained. With hydrophily, plastic shrinkage of mortar was restrained and bridging effect was improved due to better bond, which led to remarkable reduction of plastic shrinkage crack. Based on experimental results, the way of developing optimum polypropylene short fiber for actual construction was proposed. The fiber should have large hydrophily and small diameter, and should be used in as small amount as possible in order not to disturb workability of concrete.

  14. Ropivacaine alters the mechanical properties of hamstring tendons: In vitro controlled mechanical testing of tendons from living donors.

    Science.gov (United States)

    Ollivier, M; Sbihi, J; Sbihi, A; Pithioux, M; Parratte, S; Argenson, J-N

    2017-11-01

    Intraarticular or periarticular injection of ropivacaine (RI) is an element of current knee surgery practices. The goal of this study was to determine the effects of RI on the mechanical properties of hamstring tendons. We hypothesized that RI would have a detrimental effect on the mechanical properties of periarticular soft tissues METHODS: A tensile test to failure was performed on 120 hamstring tendon segments harvested during ACL reconstruction surgery in 120 patients. Two sets of tensile tests were done. The first evaluated the effect of RI itself on the mechanical properties of tendons: 30 samples were soaked for 1hour in a 2% RI solution and compared to 30 samples soaked in a saline solution (control group). The second evaluated the effect of RI concentration on the mechanical properties of hamstring tendons: 30 samples were soaked for 1hour in a 2% RI solution and 30 samples were soaked in a 7.5% RI solution. In the first test, 29 samples from each group were analyzed as two samples (one in each group) failed at the grip interface. The specimens exposed to 2% RI had lower ultimate tensile strength (Δ=4.4MPa, P=0.001), strain energy (Δ=13MPa, P=0.001) and Young's modulus (Δ=1.6MPa, P=0.02) than the specimens in the control group. There was no significant difference in the strain at failure between groups (Δ=5%, P=0.3). In the second test, one specimen from the 7.5% RI group failed during the preloading and was excluded. There was no significant difference in terms of the load at failure and ultimate tensile stress (Δ=0.45MPa, P=0.6) and strain energy (Δ=0.49MPa, P=0.49) between the two groups. There were significant differences in terms of elongation at failure (Δ=28%, P=0.0003) and Young's modulus (Δ=2.6MPa, P=0.005), with the specimens exposed to 7.5% RI undergoing greater deformation and having a lower Young's modulus. While local RI injections are widely performed in clinical practice, the results of this in vitro study point to short

  15. Measurement and control of detailed electronic properties in a single molecule break junction.

    Science.gov (United States)

    Wang, Kun; Hamill, Joseph; Zhou, Jianfeng; Guo, Cunlan; Xu, Bingqian

    2014-01-01

    The lack of detailed experimental controls has been one of the major obstacles hindering progress in molecular electronics. While large fluctuations have been occurring in the experimental data, specific details, related mechanisms, and data analysis techniques are in high demand to promote our physical understanding at the single-molecule level. A series of modulations we recently developed, based on traditional scanning probe microscopy break junctions (SPMBJs), have helped to discover significant properties in detail which are hidden in the contact interfaces of a single-molecule break junction (SMBJ). For example, in the past we have shown that the correlated force and conductance changes under the saw tooth modulation and stretch-hold mode of PZT movement revealed inherent differences in the contact geometries of a molecular junction. In this paper, using a bias-modulated SPMBJ and utilizing emerging data analysis techniques, we report on the measurement of the altered alignment of the HOMO of benzene molecules with changing the anchoring group which coupled the molecule to metal electrodes. Further calculations based on Landauer fitting and transition voltage spectroscopy (TVS) demonstrated the effects of modulated bias on the location of the frontier molecular orbitals. Understanding the alignment of the molecular orbitals with the Fermi level of the electrodes is essential for understanding the behaviour of SMBJs and for the future design of more complex devices. With these modulations and analysis techniques, fruitful information has been found about the nature of the metal-molecule junction, providing us insightful clues towards the next step for in-depth study.

  16. Lithology and Bedrock Geotechnical Properties in Controlling Rock and Ice Mass Movements in Mountain Cryosphere

    Science.gov (United States)

    Karki, A.; Kargel, J. S.

    2017-12-01

    Landslides and ice avalanches kill >5000 people annually (D. Petley, 2012, Geology http://dx.doi.org/10.1130/G33217.1); destroy or damage homes and infrastructure; and create secondary hazards, such as flooding due to blocked rivers. Critical roles of surface slope, earthquake shaking, soil characteristics and saturation, river erosional undercutting, rainfall intensity, snow loading, permafrost thaw, freeze-thaw and frost shattering, debuttressing of unstable masses due to glacier thinning, and vegetation burn or removal are well-known factors affecting landslides and avalanches. Lithology-dependent bedrock physicochemical-mechanical properties—especially brittle elastic and shear strength, and chemical weathering properties that affect rock strength, are also recognized controls on landsliding and avalanching, but are not commonly considered in detail in landslide susceptibility assessment. Lithology controls the formation of weakened, weathered bedrock; the formation and accumulation of soils; soil saturation-related properties of grain size distribution, porosity, and permeability; and soil creep related to soil wetting-drying and freeze-thaw. Lithology controls bedrock abrasion and glacial erosion and debris production rates, the formation of rough or smoothed bedrock surface by glaciation, fluvial, and freeze-thaw processes. Lithologic variability (e.g., bedding; fault and joint structure) affects contrasts in chemical weathering rates, porosity, and susceptibility to frost shattering and chemical weathering, hence formation of overhanging outcrops and weakened slip planes. The sudden failure of bedrock or sudden slip of ice on bedrock, and many other processes depend on rock lithology, microstructure (porosity and permeability), and macrostructure (bedding; faults). These properties are sometimes considered in gross terms for landslide susceptibility assessment, but in detailed applications to specific development projects, and in detailed mapping over

  17. Hydrophilic magnetic nanoclusters with thermo-responsive properties and their drug controlled release

    International Nuclear Information System (INIS)

    Meerod, Siraprapa; Rutnakornpituk, Boonjira; Wichai, Uthai; Rutnakornpituk, Metha

    2015-01-01

    Synthesis and drug controlled release properties of thermo-responsive magnetic nanoclusters grafted with poly(N-isopropylacrylamide) (poly(NIPAAm)) and poly(NIPAAm-co-poly(ethylene glycol) methyl ether methacrylate) (PEGMA) copolymers were described. These magnetic nanoclusters were synthesized via an in situ radical polymerization in the presence of acrylamide-grafted magnetic nanoparticles (MNPs). Poly(NIPAAm) provided thermo-responsive properties, while PEGMA played a role in good water dispersibility to the nanoclusters. The ratios of PEGMA to NIPAAm in the (co)polymerization in the presence of the MNPs were fine-tuned such that the nanoclusters with good water dispersibility, good magnetic sensitivity and thermo responsiveness were obtained. The size of the nanoclusters was in the range of 50–100 nm in diameter with about 100–200 particles/cluster. The nanoclusters were well dispersible in water at room temperature and can be suddenly agglomerated when temperature was increased beyond the lower critical solution temperature (LCST) (32 °C). The release behavior of an indomethacin model drug from the nanoclusters was also investigated. These novel magnetic nanoclusters with good dispersibility in water and reversible thermo-responsive properties might be good candidates for the targeting drug controlled release applications. - Highlights: • Nanoclusters with good water dispersibility and magnetic response were prepared. • They were grafted with thermo-responsive poly(NIPAAm) and/or poly(PEGMA). • Poly(NIPAAm) provided thermo-responsive properties to the nanoclusters. • Poly(PEGMA) provided good water dispersibilityto the nanoclusters. • Accelerated and controllable releases of a drug from the nanoclusters were shown

  18. Effect of guar and xanthan gums on functional properties of mango (Mangifera indica) kernel starch.

    Science.gov (United States)

    Nawab, Anjum; Alam, Feroz; Haq, Muhammad Abdul; Hasnain, Abid

    2016-12-01

    The effects of different concentrations of guar and xanthan gums on functional properties of mango kernel starch (MKS) were studied. Both guar and xanthan gum enhanced the water absorption of MKS. The addition of xanthan gum appeared to reduce the SP (swelling power) and solubility at higher temperatures while guar gum significantly enhanced the SP as well as solubility of MKS. The addition of both gums produced a reinforcing effect on peak viscosity of MKS as compared to control. Pasting temperature of MKS was higher than that of starch modified by gums indicating ease of gelatinization. Guar gum played an accelerative effect on setback but xanthan gum delayed the setback phenomenon during the cooling of the starch paste. Both gums were found to be effective in reducing the syneresis while gel firmness was markedly improved. Copyright © 2016 Elsevier B.V. All rights reserved.

  19. Dynamic mechanical analysis of compatibilizer effect on the mechanical properties of wood flour/high-density polyethylene composites

    Science.gov (United States)

    Mehdi Behzad; Medhi Tajvidi; Ghanbar Ehrahimi; Robert H. Falk

    2004-01-01

    In this study, effect of MAPE (maleic anhydride polyethylene) as the compatibilizer on the mechanical properties of wood-flour polyethylene composites has been investigated by using Dynamic Mechanical Analysis (DMA). Composites were made at 25% and 50% by weight fiber contents and 1% and 2% compatibilizer respectively. Controls were also made at the same fiber contents...

  20. Effects of pig slurry application on soil physical and chemical properties and glyphosate mobility

    Directory of Open Access Journals (Sweden)

    Daniela Aparecida de Oliveira

    2014-10-01

    Full Text Available Pig slurry applied to soil at different rates may affect soil properties and the mobility of chemical compounds within the soil. The purpose of this study was to evaluate the effects of rates of pig slurry application in agricultural areas on soil physical and chemical properties and on the mobility of glyphosate through the soil profile. The study was carried out in the 12th year of an experiment with pig slurry applied at rates of 0 (control, 50, 100 and 200 m³ ha-1 yr-1 on a Latossolo Vermelho distrófico (Hapludox soil. In the control, the quantities of P and K removed by harvested grains were replaced in the next crop cycle. Soil physical properties (bulk density, porosity, texture, and saturated hydraulic conductivity and chemical properties (organic matter, pH, extractable P, and exchangeable K were measured. Soil solution samples were collected at depths of 20, 40 and 80 cm using suction lysimeters, and glyphosate concentrations were measured over a 60-day period after slurry application. Soil physical and chemical properties were little affected by the pig slurry applications, but soil pH was reduced and P levels increased in the surface layers. In turn, K levels were increased in sub-surface layers. Glyphosate concentrations tended to decrease over time but were not affected by pig slurry application. The concentrations of glyphosate found in different depths show that the pratice of this application in agricultural soils has the potential for contamination of groundwater, especially when the water table is the surface and heavy rains occur immediately after application.

  1. Effect of Sewage Sludge on Some Macronutrients Concentration and Soil Chemical Properties

    Directory of Open Access Journals (Sweden)

    Sakine Vaseghi

    2005-03-01

    Full Text Available Sewage sludge as an organic fertilizer has economic benefits. Land application of sewage sludge improves some soil chemical and physical properties. The objective of this study was to evaluate the effect of sewage sludge on soil chemical properties and macronutrient concentration in acid and calcareous soils. The study was carried out in a greenhouse using factorial experiment design as completely randomized with three replications. Treatments included : four levels of 0 or control, 50, and 100, 200 ton ha-1 sludge and one level of chemical fertilizer (F consisting of 250 kg ha-1 diammonium phosphate and 250 kg ha-1 urea, and soil including soils of Langroud, Lahijan, Rasht, and Isfahan. As a major vegetable , crop spinach (Spinacea oleracea was grown in the treated soils. Soils samples were analyzed for their chemical properties after crop narvesting. Application of sewage sludge significantly increased plant available k, P, total N, organic matter, electrical conductivity and cation exchange in the soils. Soils pH significantly decreased as a result sewage sludge application. The effect of sewage sludge on plant yield was significant. Overall, the results indicated that sewage sludge is potentially a valuable fertilizer. However, the sludge effect on soil EC and heavy metals should be taken into consideration before its widespread use on cropland.

  2. Effect of 60Co-gamma radiation on the binding properties in furs

    International Nuclear Information System (INIS)

    Raina, R.K.

    1992-01-01

    New Zealand white rabbit pelts were pickled by the usual procedure and were tanned with basic aluminium sulphate, basic chromium sulphate and their combinations. Tanned furs were irradiated with 60 Co-gamma radiations in the dose range of 5.0-114.0 kGy. The effect of radiation on the binding properties of various added substances like mineral tannins, fats, moisture and shrinkage temperature has been assessed by their comparison with the control samples. The results of these investigations show that radiation on furs causes detannage, increases the moisture and bound fat content and decreases the shrinkage temperature of the furs. (author)

  3. Effect of [sup 60]Co-gamma radiation on the binding properties in furs

    Energy Technology Data Exchange (ETDEWEB)

    Raina, R K [Regional Research Lab., Srinagar (India)

    1992-09-01

    New Zealand white rabbit pelts were pickled by the usual procedure and were tanned with basic aluminium sulphate, basic chromium sulphate and their combinations. Tanned furs were irradiated with [sup 60]Co-gamma radiations in the dose range of 5.0-114.0 kGy. The effect of radiation on the binding properties of various added substances like mineral tannins, fats, moisture and shrinkage temperature has been assessed by their comparison with the control samples. The results of these investigations show that radiation on furs causes detannage, increases the moisture and bound fat content and decreases the shrinkage temperature of the furs. (author).

  4. γ-irradiation effect on electronic properties in hydrogenated amorphous silicon

    International Nuclear Information System (INIS)

    Shirafuji, J.; Nagata, S.; Shirakawa, K.

    1986-01-01

    γ-irradiation effect on electron transport and photoelectric properties in glow-discharge hydrogenated amorphous silicon is investigated mainly by means of time-of-flight measurement. Although the electron transport changes from non-dispersive to dispersive when the total dose on γ-rays is increased, the electron mobility at room temperature is affected only slightly by γ-irradiation. The γ-irradiation introduces dominantly Si dangling bonds, allowing to study the recombination characteristic as a function of dangling bond density under controllable conditions. It is found that the electron recombination lifetime is inversely proportional to the dangling bond density. (author)

  5. Neutron irradiation effect on thermomechanical properties of shape memory alloys

    International Nuclear Information System (INIS)

    Abramov, V.Ya.; Ionajtis, R.R.; Kotov, V.V.; Loguntsev, E.N.; Ushakov, V.P.

    1996-01-01

    Alloys of Ti-Ni, Ti-Ni-Pd, Fe-Mn-Si, Mn-Cu-Cr, Mn-Cu, Cu-Al-Mn, Cu-Al-Ni systems are investigated after irradiation in IVV-2M reactor at various temperatures with neutron fluence of 10 19 - 10 20 cm -2 . The degradation of shape memory effect in titanium nickelide base alloys is revealed after irradiation. Mn-Cu and Mn-Cu-Cr alloys show the best results. Trends in shape memory alloy behaviour depending on irradiation temperature are found. A consideration is given to the possibility of using these alloys for components of power reactor control and protection systems [ru

  6. Adaptive Controller Effects on Pilot Behavior

    Science.gov (United States)

    Trujillo, Anna C.; Gregory, Irene M.; Hempley, Lucas E.

    2014-01-01

    Adaptive control provides robustness and resilience for highly uncertain, and potentially unpredictable, flight dynamics characteristic. Some of the recent flight experiences of pilot-in-the-loop with an adaptive controller have exhibited unpredicted interactions. In retrospect, this is not surprising once it is realized that there are now two adaptive controllers interacting, the software adaptive control system and the pilot. An experiment was conducted to categorize these interactions on the pilot with an adaptive controller during control surface failures. One of the objectives of this experiment was to determine how the adaptation time of the controller affects pilots. The pitch and roll errors, and stick input increased for increasing adaptation time and during the segment when the adaptive controller was adapting. Not surprisingly, altitude, cross track and angle deviations, and vertical velocity also increase during the failure and then slowly return to pre-failure levels. Subjects may change their behavior even as an adaptive controller is adapting with additional stick inputs. Therefore, the adaptive controller should adapt as fast as possible to minimize flight track errors. This will minimize undesirable interactions between the pilot and the adaptive controller and maintain maneuvering precision.

  7. Glycolic Acid Physical Properties, Impurities, And Radiation Effects Assessment

    International Nuclear Information System (INIS)

    Pickenheim, B.; Bibler, N.

    2010-01-01

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

  8. Modeling the temperature dependence of thermophysical properties: Study on the effect of temperature dependence for RFA.

    Science.gov (United States)

    Watanabe, Hiroki; Kobayashi, Yo; Hashizume, Makoto; Fujie, Masakatsu G

    2009-01-01

    Radio frequency ablation (RFA) has increasingly been used over the past few years and RFA treatment is minimally invasive for patients. However, it is difficult for operators to control the precise formation of coagulation zones due to inadequate imaging modalities. With this in mind, an ablation system using numerical simulation to analyze the temperature distribution of the organ is needed to overcome this deficiency. The objective of our work is to develop a temperature dependent thermophysical liver model. First, an overview is given of the development of the thermophysical liver model. Second, a simulation to evaluate the effect of temperature dependence of the thermophysical properties of the liver is explained. Finally, the result of the simulation, which indicated that the temperature dependence of thermophysical properties accounts for temperature differences influencing the accuracy of RFA treatment is described.

  9. Effect of physicochemical action on the aggregative properties of detonation-synthesized nanodiamonds

    Science.gov (United States)

    Fan, Z. W.; Ilnitska, H.; Lysakovskyi, V.; Ivakhnenko, S.; Kovalenko, T.

    2018-01-01

    The results of researches of physicochemical action on aggregate properties of nanodiamond are presented. The kinetics of aggregation of nanodiamond powder was studied as a function of time, temperature, and pH of the solution. The effect of the sp2-sp3 hybridization ratio of carbon in nanodiamond powders on their aggregation was studied. It is shown that the presence of non-diamond carbon in detonation synthesis nanodiamond powders leads to the increase of the mean diameters of particles, i.e., their agglomeration. The theoretical justification of the aggregation mechanism is proposed. It is shown that it is possible to control aggregative properties of nanodiamond powders by physicochemical influences, e.g., gas-phase thermal treatment to reduce the size of agglomerates and to create a well-developed reconstructed surface of diamond particles with a low content of functional groups on their surface.

  10. Method of manipulating the chemical properties of water to improve the effectiveness of a desired process

    Science.gov (United States)

    Hawthorne, Steven B.; Miller, David J.; Lagadec, Arnaud Jean-Marie; Hammond, Peter James; Clifford, Anthony Alan

    2002-01-01

    The method of the present invention is adapted to manipulate the chemical properties of water in order to improve the effectiveness of a desired process. The method involves heating the water in the vessel to subcritical temperatures between 100.degree. to 374.degree. C. while maintaining sufficient pressure to the water to maintain the water in the liquid state. Various physiochemical properties of the water can be manipulated including polarity, solute solubility, surface tension, viscosity, and the disassociation constant. The method of the present invention has various uses including extracting organics from solids and semisolids such as soil, selectively extracting desired organics from liquids, selectively separating organics using sorbent phases, enhancing reactions by controlling the disassociation constant of water, cleaning waste water, removing organics from water using activated carbon or other suitable sorbents, and degrading various compounds.

  11. EFFECT OF ALTERNATIVE MULTINUTRIENT SOURCES ON SOIL CHEMICAL PROPERTIES

    Directory of Open Access Journals (Sweden)

    Vanessa Martins

    2015-02-01

    Full Text Available The current high price of potassium chloride and the dependence of Brazil on imported materials to supply the domestic demand call for studies evaluating the efficiency of alternative sources of nutrients. The aim of this work was to evaluate the effect of silicate rock powder and a manganese mining by-product, and secondary materials originated from these two materials, on soil chemical properties and on brachiaria production. This greenhouse experiment was conducted in pots with 5 kg of soil (Latossolo Vermelho-Amarelo distrófico - Oxisol. The alternative nutrient sources were: verdete, verdete treated with NH4OH, phonolite, ultramafic rock, mining waste and the proportion of 75 % of these K fertilizers and 25 % lime. Mixtures containing 25 % of lime were heated at 800 ºC for 1 h. These sources were applied at rates of 0, 150, 300, 450 and 600 kg ha-1 K2O, and incubated for 45 days. The mixtures of heated silicate rocks with lime promoted higher increases in soil pH in decreasing order: ultramafic rock>verdete>phonolite>mining waste. Applying the mining waste-lime mixture increased soil exchangeable K, and available P when ultramafic rock was incorporated. When ultramafic rock was applied, the release of Ca2+ increased significantly. Mining subproduct released the highest amount of Zn2+ and Mn2+ to the soil. The application of alternative sources of K, with variable chemical composition, altered the nutrient availability and soil chemical properties, improving mainly plant development and K plant uptake, and are important nutrient sources.

  12. Effect of oxygen implantation on the electrochemical properties of palladium

    International Nuclear Information System (INIS)

    Fujihana, T.; Ueshima, M.; Takahashi, K.; Iwaki, M.

    1995-01-01

    Hydrogen presence in metals has significant effects on their properties. A stress caused by hydrogen migration leads to cracks in metals. The suppression of hydrogen incorporation for the protection of such hydrogen embrittlement is one of the most important subjects for industrial engineering. In contrast, the development of active materials for hydrogen absorption and desorption reactions is expected to make a potable storage of hydrogen which is clean and virtually inexhaustible fuel. The electrochemical properties of O + -implanted Pd measured by cyclic voltammetry in a 0.25 mol dm -3 H 2 SO 4 solution were investigated in relation to their composition and structure. Implantation of 16 O + was performed with doses between 10 17 and 10 18 ions cm -2 at 150 keV, and at nearly room temperature. SIMS, ERD combined with RBS, and XRD were used to analyze the composition depth profile and structure of O + -implanted Pd surface layers. The H atoms were accumulated with a gaussian distribution and carbon materials containing the solid solution of PdCx (x = 0.13--0.15) were also formed in the near surface layers during O + -implantation. The distribution of implanted oxygen changed from gaussian to trapezoidal as the dose increased, accompanied by the crystal growth of Pd(OH) 2 , and simultaneously, the amount of accumulated H atoms increased. The voltammetric measurements revealed that with an increase in the dose, the hydrogen absorption was suppressed at the early stage of sweep cycles, and at the final stage, the redox reaction of both hydrogen and Pd was activated. From these results, the authors propose that the carbon materials containing the PdCx formed during O + -implantation suppress the hydrogen absorption, and the metallic Pd like a Pd-black formed by the reduction of Pd(OH) 2 during voltammetric measurements causes the electrochemical activation of O + -implanted Pd

  13. Effect of sodium fluorosilicate on the properties of Portland cement.

    Science.gov (United States)

    Appelbaum, Keith S; Stewart, Jeffrey T; Hartwell, Gary R

    2012-07-01

    Mineral trioxide aggregate (MTA) satisfies most of the ideal properties of a surgical root-end filling and perforation repair material. It has been found to be nontoxic, noncarcinogenic, nongenotoxic, biocompatible, insoluble in tissue fluids, and dimensionally stable and promotes cementogenesis. The major disadvantages are its long setting time and difficult handling characteristics during placement when performing endodontic procedures. MTA is similar to Portland cement (PC) in both composition and properties. The cement industry has used many additives to decrease the setting time of PC. Proprietary formulas of PC additives include fluorosilicates, which decrease setting time. The purpose of this pilot study was to determine whether sodium fluorosilicate (SF) could be used to decrease the setting time without adversely affecting the compressive strength of PC. To determine the most appropriate amount of SF to add to PC to decrease its setting time, 1%, 2%, 3%, 4%, 5%, 10%, and 15% SF by weight were added to PC and compared with PC without SF. Setting times were measured by using a Gilmore needle, and compressive strengths were determined by using a materials testing system at 24 hours and 21 days. Statistical analysis was performed by using one-way analysis of variance with post hoc Games-Howell test. None of the percentages of SF were effective in changing the setting time of PC (P > .05), and the SF additives were found to decrease the compressive strength of PC (P < .001). On the basis of the conditions of this study, SF should not be used to decrease setting time and increase the compressive strength of PC and as such does not warrant further testing with MTA. Copyright © 2012 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  14. Cover Crops Effects on Soil Chemical Properties and Onion Yield

    Directory of Open Access Journals (Sweden)

    Rodolfo Assis de Oliveira

    2016-01-01

    Full Text Available ABSTRACT Cover crops contribute to nutrient cycling and may improve soil chemical properties and, consequently, increase crop yield. The aim of this study was to evaluate cover crop residue decomposition and nutrient release, and the effects of these plants on soil chemical properties and on onion (Allium cepa L. yield in a no-tillage system. The experiment was carried out in an Inceptisol in southern Brazil, where cover crops were sown in April 2012 and 2013. In July 2013, shoots of weeds (WD, black oats (BO, rye (RY, oilseed radish (RD, oilseed radish + black oats (RD + BO, and oilseed radish + rye (RD + RY were cut at ground level and part of these material from each treatment was placed in litter bags. The litter bags were distributed on the soil surface and were collected at 0, 30, 45, 60, 75, and 90 days after distribution (DAD. The residues in the litter bags were dried, weighed, and ground, and then analyzed to quantify lignin, cellulose, non-structural biomass, total organic carbon (TOC, N, P, K, Ca, and Mg. In November 2012 and 2013, onion crops were harvested to quantify yield, and bulbs were classified according to diameter, and the number of rotted and flowering bulbs was determined. Soil in the 0.00-0.10 m layer was collected for chemical analysis before transplanting and after harvesting onion in December 2012 and 2013. The rye plant residues presented the highest half-life and they released less nutrients until 90 DAD. The great permanence of rye residue was considered a protection to soil surface, the opposite was observed with spontaneous vegetation. The cultivation and addition of dry residue of cover crops increased the onion yield at 2.5 Mg ha-1.

  15. Effect of high pressure on physicochemical properties of meat.

    Science.gov (United States)

    Buckow, Roman; Sikes, Anita; Tume, Ron

    2013-01-01

    The application of high pressure offers some interesting opportunities in the processing of muscle-based food products. It is well known that high-pressure processing can prolong the shelf life of meat products in addition to chilling but the pressure-labile nature of protein systems limits the commercial range of applications. High pressure can affect the texture and gel-forming properties of myofibrillar proteins and, hence, has been suggested as a physical and additive-free alternative to tenderize and soften or restructure meat and fish products. However, the rate and magnitude at which pressure and temperature effects take place in muscles are variable and depend on a number of circumstances and conditions that are still not precisely known. This review provides an overview of the current knowledge of the effects of high pressure on muscle tissue over a range of temperatures as it relates to meat texture, microstructure, color, enzymes, lipid oxidation, and pressure-induced gelation of myofibrillar proteins.

  16. Effect of temperature to the properties of sago starch

    Science.gov (United States)

    Mustafa Kamal, M.; Baini, R.; Mohamaddan, S.; Selaman, O. S.; Zauzi, N. Ahmad; Rahman, M. R.; Rahman, N. Abdul; Chong, K. H.; Atan, M. F.; Samat, N. A. S. Abdul; Taib, S. N. L.; Othman, A. K.

    2017-06-01

    Recently, the importance of sago starch has increased, as it has become one of the main economically important agricultural crops to the most Southeast Asia countries. In the present work, an analysis on drying process of sago starch (Metroxylon sagu Rottb.) underwent various temperature has been made by using four empirical equations. The main goal of this analysis is to suggest the most accurate equation, in order to model and simulate the mechanical drying of sago starch. The experimental investigations were carried out in a gravity convection lab oven; and ±50g of sago starch (sample heights of 1 cm) was dried through four different temperatures, which were 50, 60, 70 and 80ºC. The effect of drying temperature on the drying kinetics, as well as various qualities attributes of sago starch, such as microstructure, colour and functional properties were investigated. The results suggested that drying temperature has significant effect on sago starch drying kinetic; therefore, drying temperature would be the basis to select drying condition. Meanwhile, it was found that the various drying temperature ranging from 50 to 80ºC affected the product quality especially in term of colour.

  17. Effects of Hydrostatic Pressure on Carcinogenic Properties of Epithelia.

    Science.gov (United States)

    Tokuda, Shinsaku; Kim, Young Hak; Matsumoto, Hisako; Muro, Shigeo; Hirai, Toyohiro; Mishima, Michiaki; Furuse, Mikio

    2015-01-01

    The relationship between chronic inflammation and cancer is well known. The inflammation increases the permeability of blood vessels and consequently elevates pressure in the interstitial tissues. However, there have been only a few reports on the effects of hydrostatic pressure on cultured cells, and the relationship between elevated hydrostatic pressure and cell properties related to malignant tumors is less well understood. Therefore, we investigated the effects of hydrostatic pressure on the cultured epithelial cells seeded on permeable filters. Surprisingly, hydrostatic pressure from basal to apical side induced epithelial stratification in Madin-Darby canine kidney (MDCK) I and Caco-2 cells, and cavities with microvilli and tight junctions around their surfaces were formed within the multi-layered epithelia. The hydrostatic pressure gradient also promoted cell proliferation, suppressed cell apoptosis, and increased transepithelial ion permeability. The inhibition of protein kinase A (PKA) promoted epithelial stratification by the hydrostatic pressure whereas the activation of PKA led to suppressed epithelial stratification. These results indicate the role of the hydrostatic pressure gradient in the regulation of various epithelial cell functions. The findings in this study may provide clues for the development of a novel strategy for the treatment of the carcinoma.

  18. Effect of Carboxymethylation on the Rheological Properties of Hyaluronan.

    Science.gov (United States)

    Wendling, Rian J; Christensen, Amanda M; Quast, Arthur D; Atzet, Sarah K; Mann, Brenda K

    2016-01-01

    Chemical modifications made to hyaluronan to enable covalent crosslinking to form a hydrogel or to attach other molecules may alter the physical properties as well, which have physiological importance. Here we created carboxymethyl hyaluronan (CMHA) with varied degree of modification and investigated the effect on the viscosity of CMHA solutions. Viscosity decreased initially as modification increased, with a minimum viscosity for about 30-40% modification. This was followed by an increase in viscosity around 45-50% modification. The pH of the solution had a variable effect on viscosity, depending on the degree of carboxymethyl modification and buffer. The presence of phosphates in the buffer led to decreased viscosity. We also compared large-scale production lots of CMHA to lab-scale and found that large-scale required extended reaction times to achieve the same degree of modification. Finally, thiolated CMHA was disulfide crosslinked to create hydrogels with increased viscosity and shear-thinning aspects compared to CMHA solutions.

  19. Property.

    Science.gov (United States)

    Piele, Philip K.

    Numerous cases in this year's chapter dealt with the same topics of previous years--contracts and bids for building construction, and detachment and annexation of a portion of a school district. The courts continued to attribute board discretionary authority to school boards in school property matters. Intergovernmental disputes over ownership or…

  20. Controlled biomineralization of electrospun poly(ε-caprolactone) fibers to enhance their mechanical properties.

    Science.gov (United States)

    Xie, Jingwei; Zhong, Shaoping; Ma, Bing; Shuler, Franklin D; Lim, Chwee Teck

    2013-03-01

    Electrospun polymeric fibers have been investigated as scaffolding materials for bone tissue engineering. However, their mechanical properties, and in particular stiffness and ultimate tensile strength, cannot match those of natural bones. The objective of the study was to develop novel composite nanofiber scaffolds by attaching minerals to polymeric fibers using an adhesive material - the mussel-inspired protein polydopamine - as a "superglue". Herein, we report for the first time the use of dopamine to regulate mineralization of electrospun poly(ε-caprolactone) (PCL) fibers to enhance their mechanical properties. We examined the mineralization of the PCL fibers by adjusting the concentration of HCO(3)(-) and dopamine in the mineralized solution, the reaction time and the surface composition of the fibers. We also examined mineralization on the surface of polydopamine-coated PCL fibers. We demonstrated the control of morphology, grain size and thickness of minerals deposited on the surface of electrospun fibers. The obtained mineral coatings render electrospun fibers with much higher stiffness, ultimate tensile strength and toughness, which could be closer to the mechanical properties of natural bone. Such great enhancement of mechanical properties for electrospun fibers through mussel protein-mediated mineralization has not been seen previously. This study could also be extended to the fabrication of other composite materials to better bridge the interfaces between organic and inorganic phases. Copyright © 2012 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  1. Enhancement of mechanical properties of a TRIP-aided austenitic stainless steel by controlled reversion annealing

    Energy Technology Data Exchange (ETDEWEB)

    Hamada, A.S., E-mail: atef.hamada@suezuniv.edu.eg [Centre for Advanced Steels Research, Box 4200, University of Oulu, 90014 Oulu (Finland); Metallurgical and Materials Engineering Department, Faculty of Petroleum & Mining Engineering, Suez University, Box 43721, Suez (Egypt); Kisko, A.P. [Centre for Advanced Steels Research, Box 4200, University of Oulu, 90014 Oulu (Finland); Sahu, P. [Department of Physics, Jadavpur University, Kolkata 700032 (India); Karjalainen, L.P. [Centre for Advanced Steels Research, Box 4200, University of Oulu, 90014 Oulu (Finland)

    2015-03-25

    Controlled martensitic reversion annealing was applied to a heavily cold-worked metastable austenitic low-Ni Cr–Mn austenitic stainless steel (Type 201) to obtain different ultrafine austenite grain sizes to enhance the mechanical properties, which were then compared with the conventional coarse-grained steel. Characterization of the deformed and reversion annealed microstructures was performed by electron back scattered diffraction (EBSD), X-ray diffraction (XRD) and light and transmission electron microscopy (TEM). The steel with a reverted grain size ~1.5 μm due to annealing at 800 °C for 10 s showed significant improvements in the mechanical properties with yield stress ~800 MPa and tensile strength ~1100 MPa, while the corresponding properties of its coarse grained counterpart were ~450 MPa and ~900 MPa, respectively. However, the fracture elongation of the reversion annealed steel was ~50% as compared to ~70% in the coarse grained steel. A further advantage is that the anisotropy of mechanical properties present in work-hardened steels also disappears during reversion annealing.

  2. Use of alcohol vinegar in the inhibition of Candida spp. and its effect on the physical properties of acrylic resins

    OpenAIRE

    de Castro, Ricardo Dias; Mota, Ana Carolina Loureiro Gama; de Oliveira Lima, Edeltrudes; Batista, Andr? Ulisses Dantas; de Ara?jo Oliveira, Julyana; Cavalcanti, Alessandro Leite

    2015-01-01

    Background Given the high prevalence of oral candidiasis and the restricted number of antifungal agents available to control infection, this study investigated the in vitro antifungal activity of alcohol vinegar on Candida spp. and its effect on the physical properties of acrylic resins. Methods Tests to determine the Minimum Inhibitory Concentration (MIC) and Minimum Fungicidal Concentration (MFC) of vinegar alcohol (0.04?g/ml of acetic acid) and nystatin (control) were performed. The antifu...

  3. Oral mouth rinses from Costa Rican natural substances with antibacterial properties applied to biofilm control in 2013

    International Nuclear Information System (INIS)

    Bermudez Vargas, Silvia; Garita Herrera, Andrea; Porras Monge, Gerardo

    2013-01-01

    The antibacterial properties of three natural substances were analyzed for the control of the dental biofilm in Costa Rica in 2013. The studied plants are the cypress, the star anise flower and the guava leaves which were chosen after being studied, demonstrating antimicrobial properties. An extract of each sample by distillation process by steam drag in the Centro de Investigaciones de Productos Naturales of the Universidad de Costa Rica. Chlorhexidine in vitro tests were performed on the three plants in different concentrations, pure, 50% and 25%, against a population of streptococcus mutans. The flower of anis lacked activity against S. mutans in the microbiological tests, the cypress showed effectiveness against S. mutans, using the pure extract and at 50% concentration. The guava leaves, an inhibitory halo was obtained. 10 mm, when using the extract in its pure form and a 7 mm halo when using it at 50% concentration, so they are effective against S. mutans. Comparing the antimicrobial activity of the three plants with that of chlorhexidine, chlorhexidine showed a greater activity, being more effective against S. mutans. The essential oil of the cypress and guava leaves showed antimicrobial activity against S. mutans, however, more tests are needed to prove its effectiveness as a mouthwash. The star anise in a steam extract did not show antimicrobial activity against S. mutans. (author) [es

  4. Effect of electromagnetic fields on some biomechanical and biochemical properties of rat’s blood

    Science.gov (United States)

    Mohaseb, M. A.; Shahin, F. A.; Ali, F. M.; Baieth, H. A.

    2017-06-01

    In order to study the effect of electromagnetic fields (0.3 mT, 50 Hz) on some biomechanical and biochemical properties of rats’ blood, healthy thirty male albino rats of 150 ± 10 g were divided into three equal groups namely A, B1, B2. Group A used as a control group, group B1 was continuously exposed to a magnetic field of (0.3 mT, 50 Hz) for a period of 21 days for direct effect studies. Group B2 was continuously exposed to the same magnetic field for the same period of time, then was housed away from the magnetic field for a period of 45 days for delayed effects studies. After examination, the results indicated that the apparent viscosity and the consistency index increased significantly and very high significantly for groub B1 and B2 compared to control at Pbone marrow functions. These results are supported by the blood film image, where irregularities and deformations in the RBCs membranes had been occurred. We conclude that the cell membrane properties are highly affected by the extremely low frequency (ELF) magnetic fields, which proved to be biologically toxic.

  5. Effect of Partial Pre-Extraction of Hemicelluloses on the Properties of Pinus radiata Chemimechanical Pulps

    Directory of Open Access Journals (Sweden)

    Pablo Reyes

    2015-09-01

    Full Text Available Extraction of hemicelluloses prior to pulping and conversion of the extracted hemicelluloses to other bioproducts could provide additional revenue to traditional pulp and paper industries. The effect of hemicelluloses pre-extraction with a hydrothermal (HT process on Pinus radiata chemimechanical pulp (CMP properties was investigated in this study. The HT extraction resulted in a release of 7% to 58% of the initial amount of hemicelluloses from the wood. The extraction yield increased with temperature and extraction time. This hemicellulosic fraction was in the form of low molar mass oligomers with molecular weights varying from 1.5 to 100 kDa. Compared with the control (unextracted CMP pulp, the HT pre-extraction significantly reduced the refining energy to obtain a given fibrillation degree (freeness. The pulp yield with the HT/CMP process was in the range of 56% to 75%. Fiber properties of the pulps from pre-extracted wood, such as fiber length, were reduced, while increases in fiber width, fines content, fiber coarseness, and kink index were observed in comparison with the control pulps. The strength properties of CMP pulps decreased with increasing amounts of hemicellulose removal during the stage prior to pulping.

  6. Effects of ethyl cellulose on the crystallization and mechanical properties of poly(β-hydroxybutyrate).

    Science.gov (United States)

    Chen, Jianxiang; Wu, Defeng; Pan, Keren

    2016-07-01

    Ethyl cellulose (EC) was blended with poly(β-hydroxybutyrate) (PHB), aiming at controlling crystallization and mechanical properties of PHB. The obtained PHB/EC blend is an immiscible system, and the discrete EC phase behaves dual characteristics in the PHB matrix, as the viscoelastic droplets during processing, and as the rigid filler particles during shear flow. This is confirmed by the rheological tests. The presence of EC domains acts as the tackifier, sharply increasing system viscosity from 1000Pas to 5000Pas, and as a result, has large influence on the spherulite morphology of PHB and its crystallization kinetics. The PHB spherulite growth rate reduces in the presence of inert EC, accompanied by decreased degree of crystallinity and reduced lamella defects. These affect the mechanical properties of PHB strongly, together with reinforcing effect of EC itself. At the lower content level, EC can act as both reinforcement and toughener. The presence of 1wt% EC enhances the tensile strength of PHB by about 22%, from 27.5MPa to 33.3MPa, accompanied by 15% increase of impact strength. This work provide an easy way to control the structure and properties of PHB using EC. Copyright © 2016 Elsevier B.V. All rights reserved.

  7. Effect of pulsed electric field on the rheological and colour properties of soy milk.

    Science.gov (United States)

    Xiang, Bob Y; Simpson, Marian V; Ngadi, Michael O; Simpson, Benjamin K

    2011-12-01

    The effects of pulsed electric field (PEF) treatments on rheological and colour properties of soy milk were evaluated. Flow behaviour, viscosity and rheological parameters of PEF-treated soy milk were monitored using a controlled stress rheometer. For PEF treatments, electric field intensity of 18, 20 and 22 kV cm(-1) and number of pulses of 25, 50, 75 and 100 were used. For the measurements of rheological properties of soy milk shear rates between 0 and 200 s(-1) was used. The rheological behaviour of control and the PEF-treated soy milk were described using a power law model. The PEF treatments affected the rheological properties of soy milk. Apparent viscosity of soy milk increased from 6.62 to 7.46 (10(-3) Pa s) with increase in electric field intensity from 18 to 22 kV cm(-1) and increase in the number of pulses from 0 to 100. The consistency index (K) of soy milk also changed with PEF treatments. Lightness (L*), red/greenness (a*) and yellowness/blueness (b*) of soy milk were affected by PEF treatments.

  8. Effect of high-pressure food processing on the physical properties of synthetic and biopolymer films.

    Science.gov (United States)

    Galotto, M J; Ulloa, P A; Guarda, A; Gavara, R; Miltz, J

    2009-08-01

    The effect of high-pressure processing on 2 plastic food packaging films, a biopolymer (PLASiOx/PLA) and a synthetic polymer (PET-AlOx), was studied. Samples in direct contact with olive oil, as a fatty food simulant, and distilled water, as an aqueous simulant, were subjected to a pressure of 500MPa for 15 min at 50 degrees C. The mechanical, thermal, and gas barrier properties of both films were evaluated after the high-pressure processing (HPP) and compared to control samples that have not undergone this treatment. Significant changes in all properties were observed in both films after the HPP treatment and in contact with the food simulants. In both films an induced crystallization was noticed. In the PLASiOx/PLA film the changes were larger when in contact with water that probably acted as a plasticizer. In the PET-AlOx film the changes in properties were attributed to the formation of pinholes and cracks during the HPP treatment. In this film, most of the properties changed more in the presence of oil as the food simulant.

  9. Effect of nanocomposite gate-dielectric properties on pentacene microstructure and field-effect transistor characteristics.

    Science.gov (United States)

    Lee, Wen-Hsi; Wang, Chun-Chieh

    2010-02-01

    In this study, the effect of surface energy and roughness of the nanocomposite gate dielectric on pentacene morphology and electrical properties of pentacene OTFT are reported. Nanoparticles TiO2 were added in the polyimide matrix to form a nanocomposite which has a significantly different surface characteristic from polyimide, leading to a discrepancy in the structural properties of pentacene growth. A growth mode of pentacene deposited on the nanocomposite is proposed to explain successfully the effect of surface properties of nanocomposite gate dielectric such as surface energy and roughness on the pentacene morphology and electrical properties of OTFT. To obtain the lower surface energy and smoother surface of nanocomposite gate dielectric that is responsible for the desired crystalline, microstructure of pentacene and electrical properties of device, a bottom contact OTFT-pentacene deposited on the double-layer nanocomposite gate dielectric consisting of top smoothing layer of the neat polyimide and bottom layer of (PI+ nano-TiO2 particles) nanocomposite has been successfully demonstrated to exhibit very promising performance including high current on to off ratio of about 6 x 10(5), threshold voltage of -10 V and moderately high filed mobility of 0.15 cm2V(-1)s(-1).

  10. Effect of friction on anodic polarization properties of metallic biomaterials.

    Science.gov (United States)

    Okazaki, Yoshimitsu

    2002-05-01

    The effect of friction on the anodic polarization properties of metallic biomaterials in a physiological saline solution was investigated. The current density during friction becomes higher than during the static condition. The fluctuation range of the current density caused by the destruction and formation of passive film was observed. For SUS316L stainless steel and Co-Cr-Mo casting alloy, the fluctuation range was observed in the passivity zone. Otherwise, for Ti alloys, the fluctuation range was observed in both the activity and passivity zones. The decrease of the corrosion potential for Ti alloys due to friction was much larger than that of SUS316L stainless steel and Co-Cr-Mo casting alloy. From this result, it was considered that in a the frictional environment, the stressing zone turned anodic and its periphery cathodic, and corrosion tended to progress more than in the static environment. The effect of wear on the anodic polarization curves also changed depending on the frictional load, potential zone and the pH of the solution. A rapid increase in current density due to corrosion starting from the frictional area was found in the Ti-6Al-4V and Ti-15Mo-5Zr-3Al alloys containing Al. However, for the new Ti-15Zr-4Nb-4Ta alloy, this rapid increase was not seen in the high-potential region. The effect of the lateral reciprocal speed was also negligible for the new Ti alloy. It was found that the new Ti-15Zr-4Nb-4Ta alloy exhibited excellent corrosion resistance under friction.

  11. Steel impurity element effects on postirradiation properties recovery by annealing

    International Nuclear Information System (INIS)

    Hawthorne, J.R.

    1987-01-01

    The influence of copper content and phosphorus content on notch ductility recovery by 399 0 C postirradiation heat treatment was explored for A 533-B and A 302-B pressure vessel steels. Charpy-V (C/sub V/) specimens for the investigation were obtained from ten plates produced from four (4-way split) laboratory melts. The plates were 15.2 mm thick but were heat treated to reproduce the microstructure of 150-mm and thicker A 302-B plates at the quarter-thickness location. The C/sub V/ specimens were irradiated in two assemblies at 288 0 C (550 0 F) to a fluence of --2.5 x 10/sup 19/ n/cm/sup 2/ in a light-water-cooled and moderated test reactor. Notch ductility properties in the asirradiated and 399 0 C, 168 h postirradiation-annealed conditions were determined. In addition, separate sets of specimens were thermally conditioned at 288 0 C and at 288 0 C followed by 399 0 C to benchmark the effects of temperature in the absence of irradiation. The results indicate that copper has a significant influence on the magnitude of residual embrittlement after annealing. In contrast, phosphorus contents in the range of 0.002 to 0.025% were found not to have an effect on residual embrittlement either in high or low copper steels. Essentially full recovery in 41-J transition temperature was observed for high phosphorus, low copper content steels. Effects of nickel alloying on recovery behavior were also investigated through data comparisons for A 302-B versus A 533-B plates

  12. Impact of a low intensity controlled-fire in some chemical soil properties.

    Science.gov (United States)

    Martínez-Murillo, Juan F.; Hueso-González, Paloma; Aranda-Gómez, Francisco; Damián Ruiz-Sinoga, José

    2014-05-01

    Some changes in chemical soil properties can be observed after fires of low intensities. pH and electric conductivity tend to increase, while C/N ratio decrease. In the case of organic matter, the content can increase due to the massive incorporation of necromass including, especially, plants and roots. The aim of this study is to assess the impact of low intensity and controlled fire in some soil properties in field conditions. El Pinarillo experimental area is located in South of Spain. Two set of closed plots were installed (24 m2: 12 m length x 2 m width). One of them was remained as control with the original vegetation cover (Mediterranean matorral: Rosmarinus officinalis, Cistus clusii, Lavandula stoechas, Chamaeropos humilis, Thymus baetica), and the other one was burnt in a controlled-fire in 2011. Weather conditions and water content of vegetation influenced in the intensity of fire (low). After the controlled-fire, soil surface sample (0-5 cm) were taken in both set of plots (B, burnt soil samples; C, control soil samples). Some soil chemical properties were analysed: organic matter content (OM), C/N ratio, pH and electrical conductivity (EC). Some changes were observed in B corroborating a controlled-fire of low intensity. pH remained equal after fire (B: pH=7.7±0.11; C: pH=7.7±0.04). An increment was obtained in the case of EC (B: EC=0.45 mScm-1±0.08 mScm-1; C: EC=0.35 mScm-1±0.07 mScm-1) and OM (B: OM=8.7%±3.8%; C: pH=7.3%±1.5%). Finally, C/N ratio decreased after fire respect to the control and initial conditions (B: C/N=39.0±14.6; C: C/N =46.5±10.2).

  13. Automatic control algorithm effects on energy production

    Science.gov (United States)

    Mcnerney, G. M.

    1981-01-01

    A computer model was developed using actual wind time series and turbine performance data to simulate the power produced by the Sandia 17-m VAWT operating in automatic control. The model was used to investigate the influence of starting algorithms on annual energy production. The results indicate that, depending on turbine and local wind characteristics, a bad choice of a control algorithm can significantly reduce overall energy production. The model can be used to select control algorithms and threshold parameters that maximize long term energy production. The results from local site and turbine characteristics were generalized to obtain general guidelines for control algorithm design.

  14. Critical properties of effective gauge theories for novel quantum fluids

    Energy Technology Data Exchange (ETDEWEB)

    Smoergrav, Eivind

    2005-07-01

    Critical properties of U(1) symmetric gauge theories are studied in 2+1 dimensions, analytically through duality transformations and numerically through Monte Carlo simulations. Physical applications range from quantum phase transitions in two dimensional insulating materials to superfluid and superconducting properties of light atoms such as hydrogen under extreme pressure. A novel finite size scaling method, utilizing the third moment M{sub 3} of the action, is developed. Finite size scaling analysis of M{sub 3} yields the ratio (1 + alpha)/ny and 1/ny separately, so that critical exponents alpha and ny can be obtained independently without invoking hyperscaling. This thesis contains eight research papers and an introductory part covering some basic concepts and techniques. Paper 1: The novel M{sub 3} method is introduced and employed together with Monte Carlo simulations to study the compact Abelian Higgs model in the adjoint representation with q = 2. Paper 2: We study phase transitions in the compact Abelian Higgs model for fundamental charge q = 2; 3; 4; 5. Various other models are studied to benchmark the M{sub 3} method. Paper 3: This is a proceeding paper based on a talk given by F. S. Nogueira at the Aachen EPS HEP 2003 conference. A review of the results from Paper 1 and Paper 2 on the compact Abelian Higgs model together with some results on q = 1 obtained by F. S. Nogueira, H. Kleinert, and A. Sudboe is given. Paper 4: The effect of a Chern-Simons (CS) term in the phase structure of two Abelian gauge theories is studied. Paper 5: We study the critical properties of the N-component Ginzburg-Landau theory. Paper 6: We consider the vortices in the 2-component Ginzburg-Landau model in a finite but low magnetic field. The ground state is a lattice of co centered vortices in both order parameters. We find two novel phase transitions. i) A 'vortex sub-lattice melting' transition where vortices in the field with lowest phase stiffness (&apos

  15. Traffic Accident Propagation Properties and Control Measures for Urban Links Based on Cellular Automata

    Directory of Open Access Journals (Sweden)

    Xian-sheng Li

    2013-01-01

    Full Text Available With the rapid development of urban transport and the sharp increase in vehicle population, traffic accidents form one of the most important causes of urban traffic congestion other than the imbalance between traffic supply and demand. Traffic congestion causes severe problems, such as environment contamination and energy dissipation. Therefore, it would be useful to analyze the congestion propagation characteristics after traffic accidents. Numerical analysis and computer simulation were two of the typical methods used at present to study the traffic congestion propagation properties. The latter was more widespread as it is more consistent with the actual traffic flow and more visual than the former. In this paper, an improved cellular automata (CA model was presented to analyze traffic congestion propagation properties and to evaluate control strategies. In order to apply them to urban traffic flow simulation, the CA models have been improved and expanded on. Computer simulations were built for congestion not only extending to the upstream intersection, but also the upstream intersection and the entire road network, respectively. Congestion propagation characteristics after road traffic accidents were obtained, and controls of different severities and durations were analyzed. The results provide the theoretical foundation and practical means for the control of congestion.

  16. Two-dimensional tantalum disulfide: controlling structure and properties via synthesis

    Science.gov (United States)

    Zhao, Rui; Grisafe, Benjamin; Krishna Ghosh, Ram; Holoviak, Stephen; Wang, Baoming; Wang, Ke; Briggs, Natalie; Haque, Aman; Datta, Suman; Robinson, Joshua

    2018-04-01

    Tantalum disulfide (TaS2) is a transition metal dichalcogenide (TMD) that exhibits phase transition induced electronic property modulation at low temperature. However, the appropriate phase must be grown to enable the semiconductor/metal transition that is of interest for next generation electronic applications. In this work, we demonstrate direct and controllable synthesis of ultra-thin 1T-TaS2 and 2H-TaS2 on a variety of substrates (sapphire, SiO2/Si, and graphene) via powder vapor deposition. The synthesis process leads to single crystal domains ranging from 20 to 200 nm thick and 1-10 µm on a side. The TaS2 phase (1T or 2H) is controlled by synthesis temperature, which subsequently is shown to control the electronic properties. Furthermore, this work constitutes the first demonstration of a metal-insulator phase transition in directly synthesized 1T-TaS2 films and domains by electronic means.

  17. Effect of land use change on soil properties and functions

    Science.gov (United States)

    Tonutare, Tonu; Kõlli, Raimo; Köster, Tiina; Rannik, Kaire; Szajdak, Lech; Shanskiy, Merrit

    2014-05-01

    , and pedo-ecological conditions. LUC from natural to arable is accompanied by different regulations: (1) regular restoration of plant available nutrition elements' stocks in soil, (2) regulation (if needed) of water regime of gleyed and gley soils, (3) optimizing of soil actual acidity by liming, and (4) forming a suitable for crops seed bed instead of natural epipedon. Principal changes are occurred in fabric and agrochemical properties of topsoil and in soil functioning. The connected with LUC changes in soil functioning are: (1) increase of openness level of chemical elements cycling and nutrition elements concentration in phytomass, and (2) decrease of total phytomass, species diversity, amount of annual falling litter and content of mortmass in soil cover. These changes lead to decreasing of biological control on soil resources, flux of energy and substances to soil processes, and volume of cycling. At the same time the intensity of organic matter decomposition and outflow of nutrition elements are increased. All these changes are resulted by alteration of food chains and exhausting of nutrition elements' stocks. The changes in soil functioning (decrease or increase of productivity) depend much on soil type. The aspects of functioning, which do not changed with LUC are chemical-textural potential of soil cover and functioning character of subsoil. The sound matching of soil and plant cover is of decisive importance for sustainable functioning of ecosystem and in attaining a good environmental status of the area.

  18. Physicochemical and antimicrobial properties of copaiba oil: implications on product quality control.

    Science.gov (United States)

    Fonseca, Renata G; Barros, Francisco M; Apel, Miriam A; Poser, Gilsane L von; Andriolli, Jo O L; Filho, Pedro C Campos; Sousa, Dhierlate F; Lobo, Ivon P; Conceiç O, Aline O

    2015-01-01

    The copaiba oil is a common natural product used in cosmetic industry and as a nutraceutical product. However, lack of quality control and scarce knowledge about its antimicrobial activity is a point of concern. The proposal of this study was to investigate the physicochemical properties and the antimicrobial activity of five commercial brands of copaiba oil. Acidity and ester index, refractory index, solubility in alcohol, and thin layer chromatography were performed to verify the physicochemical properties of five commercial copaiba oils sold in local pharmacies. Ultra performance liquid chromatography coupled with diode-array detection and electrospray ionization quadrupole time-of-flight mass spectrometry (UPLC-DAD/ESI-Q-TOF-MS) was used to investigate diterpene acids while the volatile compounds were analysed by gas chromatography-mass spectrometry (GC-MS). Antibacterial and antifungal activities were also evaluated by agar diffusion technique; and minimal inhibitory concentration and maximal bactericidal concentration were defined for each sample and bacteria. The physical-chemical analysis revealed heterogeneity between all samples analysed. The A1 sample showed characteristics of copaiba oil and was mainly composed by hydrocarbon sesquiterpenes (29.95% β-bisabolene, 25.65% Z-α-bergamotene and 10.27% β-cariophyllene). Among diterpene acids, the UPLCDAD/ESI-Q-TOF-MS data are compatible with presence of copalic and/or kolavenic acid (m/z 305 [M + H]+). Candida albicans was sensitive to almost all samples at high concentration and Saccaromyces. Cerevisiae showed sensitivity to A1 sample at 100 mg/mL. Although variable, all samples showed antibacterial activity. Significant activity was seen for A3 (19.0 ±0 and 15.6 ±0.5 mm), A4 (16.6 ±0.5 and 15.6 ±0 mm), and A5 (17.1 ±0 and 17.1 ±0 mm) on Staphylococcus saprophyticus and S. aureus, respectively. All samples were active against Klebsiella pneumoniae showing ≥15 mm diameter halo inhibition; and only A

  19. [Effects of biochar and PAM application on saline soil hydraulic properties of coastal reclamation region].

    Science.gov (United States)

    Cao, Yu Tong; She, Dong Li

    2017-11-01

    Disc infiltration tests were carried out to study the soil infiltration characteristics under different rates of soil amendments application, and to investigate the effects of biochar and polyacrylamide (PAM) application on saline soil hydraulic properties, pore characteristics and contribution of each pore to soil water flow in coastal reclamation region. The results showed that soil satura-ted hydraulic conductivity increased by 46.4% when biochar was applied at 2% compared with the control, and decreased with increasing PAM application. The total effective soil porosity and r>100 μm pores were increased by 8.3% and 10.2% (PPAM application. Particularly, the total effective soil porosity decreased markedly when PAM was applied at 1‰ and the reduction was up to 88%. With the application of biochar and PAM, the contribution of r500 μm played a major role in determining water flows.

  20. Effectiveness of Fiber Reinforcement on the Mechanical Properties and Shrinkage Cracking of Recycled Fine Aggregate Concrete

    Science.gov (United States)

    Nam, Jeongsoo; Kim, Gyuyong; Yoo, Jaechul; Choe, Gyeongcheol; Kim, Hongseop; Choi, Hyeonggil; Kim, Youngduck

    2016-01-01

    This paper presents an experimental study conducted to investigate the effect of fiber reinforcement on the mechanical properties and shrinkage cracking of recycled fine aggregate concrete (RFAC) with two types of fiber—polyvinyl alcohol (PVA) and nylon. A small fiber volume fraction, such as 0.05% or 0.1%, in RFAC with polyvinyl alcohol or nylon fibers was used for optimum efficiency in minimum quantity. Additionally, to make a comparative evaluation of the mechanical properties and shrinkage cracking, we examined natural fine aggregate concrete as well. The test results revealed that the addition of fibers and fine aggregates plays an important role in improving the mechanical performance of the investigated concrete specimens as well as controlling their cracking behavior. The mechanical properties such as compressive strength, splitting tensile strength, and flexural strength of fiber-reinforced RFAC were slightly better than those of non-fiber-reinforced RFAC. The shrinkage cracking behavior was examined using plat-ring-type and slab-type tests. The fiber-reinforced RFAC showed a greater reduction in the surface cracks than non-fiber-reinforced concrete. The addition of fibers at a small volume fraction in RFAC is more effective for drying shrinkage cracks than for improving mechanical performance. PMID:28773256

  1. Production of bone cement composites: effect of fillers, co-monomer and particles properties

    Energy Technology Data Exchange (ETDEWEB)

    Santos Junior, J.G.F.; Melo, P.A.; Pinto, J.C., E-mail: jjunior@peq.coppe.ufrj.b, E-mail: melo@peq.coppe.ufrj.b, E-mail: pinto@peq.coppe.ufrj.b [Coordenacao dos Programas de Pos-Graduacao de Engenharia. (PEQ/COPPE/UFRJ), RJ (Brazil). Programa de Engenharia Quimica; Pita, V.J.R.R., E-mail: vjpita@ima.ufrj.b [Universidade Federal do Rio de Janeiro (IMA/UFRJ), RJ (Brazil). Inst. de Macromoleculas Eloisa Mano; Nele, M. [Universidade Federal do Rio de Janeiro (EQ/UFRJ), RJ (Brazil). Escola de Quimica

    2011-04-15

    Artificial bone cements (BCs) based on poly(methyl methacrylate) (PMMA) powders and methyl methacrylate (MMA) liquid monomer also present in their formulation small amounts of other substances, including a chemical initiator compound and radiopaque agents. Because inadequate mixing of the recipe components during the manufacture of the bone cement may compromise the mechanical properties of the final pieces, new techniques to incorporate the fillers into the BC and their effect upon the mechanical properties of BC pieces were investigated in the present study. PMMA powder composites were produced in situ in the reaction vessel by addition of X-ray contrasts to the reacting MMA mixture. It is shown that this can lead to much better mechanical properties of test pieces, when compared to standard bone cement formulations, because enhanced dispersion of the radiopaque agents can be achieved. Moreover, it is shown that the addition of hydroxyapatite (HA) and acrylic acid (AA) to the bone cement recipe can be beneficial for the mechanical performance of the final material. It is also shown that particle morphology can exert a tremendous effect upon the performance of test pieces, indicating that the suspension polymerization step should be carefully controlled when optimization of the bone cement formulation is desired. (author)

  2. Production of bone cement composites: effect of fillers, co-monomer and particles properties

    Directory of Open Access Journals (Sweden)

    J. G. F. Santos Jr.

    2011-06-01

    Full Text Available Artificial bone cements (BCs based on poly(methyl methacrylate (PMMA powders and methyl methacrylate (MMA liquid monomer also present in their formulation small amounts of other substances, including a chemical initiator compound and radiopaque agents. Because inadequate mixing of the recipe components during the manufacture of the bone cement may compromise the mechanical properties of the final pieces, new techniques to incorporate the fillers into the BC and their effect upon the mechanical properties of BC pieces were investigated in the present study. PMMA powder composites were produced in-situ in the reaction vessel by addition of X-ray contrasts to the reacting MMA mixture. It is shown that this can lead to much better mechanical properties of test pieces, when compared to standard bone cement formulations, because enhanced dispersion of the radiopaque agents can be achieved. Moreover, it is shown that the addition of hydroxyapatite (HA and acrylic acid (AA to the bone cement recipe can be beneficial for the mechanical performance of the final material. It is also shown that particle morphology can exert a tremendous effect upon the performance of test pieces, indicating that the suspension polymerization step should be carefully controlled when optimization of the bone cement formulation is desired.

  3. Effect of tooth bleaching agents on protein content and mechanical properties of dental enamel.

    Science.gov (United States)

    Elfallah, Hunida M; Bertassoni, Luiz E; Charadram, Nattida; Rathsam, Catherine; Swain, Michael V

    2015-07-01

    This study investigated the effect of two bleaching agents, 16% carbamide peroxide (CP) and 35% hydrogen peroxide (HP), on the mechanical properties and protein content of human enamel from freshly extracted teeth. The protein components of control and treated enamel were extracted and examined on sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). Marked reduction of the protein matrix and random fragmentation of the enamel proteins after bleaching treatments was found. The mechanical properties were analyzed with Vickers indentations to characterize fracture toughness, and nanoindentation to establish enamel hardness, elastic modulus and creep deformation. Results indicate that the hardness and elastic modulus of enamel were significantly reduced after treatment with CP and HP. After bleaching, the creep deformation at maximum load increased and the recovery upon unloading reduced. Crack lengths of CP and HP treated enamel were increased, while fracture toughness decreased. Additionally, the microstructures of fractured and indented samples were examined with field emission gun scanning electron microscopy (FEG-SEM) showing distinct differences in the fracture surface morphology between pre- and post-bleached enamel. In conclusion, tooth bleaching agents can produce detrimental effects on the mechanical properties of enamel, possibly as a consequence of damaging or denaturing of its protein components. Copyright © 2015 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  4. Effectiveness of Fiber Reinforcement on the Mechanical Properties and Shrinkage Cracking of Recycled Fine Aggregate Concrete.

    Science.gov (United States)

    Nam, Jeongsoo; Kim, Gyuyong; Yoo, Jaechul; Choe, Gyeongcheol; Kim, Hongseop; Choi, Hyeonggil; Kim, Youngduck

    2016-02-26

    This paper presents an experimental study conducted to investigate the effect of fiber reinforcement on the mechanical properties and shrinkage cracking of recycled fine aggregate concrete (RFAC) with two types of fiber-polyvinyl alcohol (PVA) and nylon. A small fiber volume fraction, such as 0.05% or 0.1%, in RFAC with polyvinyl alcohol or nylon fibers was used for optimum efficiency in minimum quantity. Additionally, to make a comparative evaluation of the mechanical properties and shrinkage cracking, we examined natural fine aggregate concrete as well. The test results revealed that the addition of fibers and fine aggregates plays an important role in improving the mechanical performance of the investigated concrete specimens as well as controlling their cracking behavior. The mechanical properties such as compressive strength, splitting tensile strength, and flexural strength of fiber-reinforced RFAC were slightly better than those of non-fiber-reinforced RFAC. The shrinkage cracking behavior was examined using plat-ring-type and slab-type tests. The fiber-reinforced RFAC showed a greater reduction in the surface cracks than non-fiber-reinforced concrete. The addition of fibers at a small volume fraction in RFAC is more effective for drying shrinkage cracks than for improving mechanical performance.

  5. GEOMETRIC PROPERTIES OF A MECHANICAL FORWARD MOTION COMPENSATION SYSTEM CONTROLLED BY A PIEZOELECTRIC DRIVE

    Directory of Open Access Journals (Sweden)

    F. Collette

    2012-07-01

    Full Text Available Forward Motion Compensation (FMC systems have been designed to ensure the radiometric quality of motion acquisition in airborne cameras. If the radiometric benefits of FMC have been acknowledged, what are its effects on the geometrical properties of the camera? This paper demonstrates that FMC significantly improves geometrical properties of a camera. Aspects of FMC theory are discussed, with a focus on the near-lossless implementation of this technology into digital aerial camera systems. Among mechanical FMC technologies, the piezoelectric drive is proving to excel in dynamic positioning in both accuracy and repeatability. The patented piezoelectric drive integrated into Optech aerial camera systems allows for continuous and precise sensor motion to ensure exact compensation of the aircraft's forward motion. This paper presents findings that demonstrate the validity of this assertion. The paper also discusses the physical principles involved in motion acquisition. Equations are included that define the motion effect at image level and illustrate how FMC acts to prevent motion effects. The residual motion effect or compensation error is formulated and a practical computation applied to the more restrictive camera case. The assessment concludes that, in the range of airborne camera utilization, the mechanical FMC technique is free of "visible" error at both human eye and computer assessment level. Lastly, the paper proceeds to a detailed technical discussion of piezoelectric drives and why they have proven to be so effective as nanopositioning devices for optical applications. The effectiveness of the patented piezoelectric drives used to achieve FMC in Optech cameras is conclusively demonstrated.

  6. Edge effects on the electronic properties of phosphorene nanoribbons

    International Nuclear Information System (INIS)

    Peng, Xihong; Copple, Andrew; Wei, Qun

    2014-01-01

    Two dimensional few-layer black phosphorus crystal structures have recently been fabricated and have demonstrated great potential in electronic applications. In this work, we employed first principles density functional theory calculations to study the edge and quantum confinement effects on the electronic properties of the phosphorene nanoribbons (PNR). Different edge functionalization groups, such as H, F, Cl, OH, O, S, and Se, in addition to a pristine case were studied for a series of ribbon widths up to 3.5 nm. It was found that the armchair-PNRs (APNRs) are semiconductors for all edge groups considered in this work. However, the zigzag-PNRs (ZPNRs) show either semiconductor or metallic behavior in dependence on their edge chemical species. Family 1 edges (i.e., H, F, Cl, OH) form saturated bonds with P atoms in the APNRs and ZPNRs, and the edge states keep far away from the band gap. However, Family 2 edges (pristine, O, S, Se) form weak unsaturated bonds with the p z orbital of the phosphorus atoms and bring edge states within the band gap of the ribbons. For the ZPNRs, the edge states of Family 2 are present around the Fermi level within the band gap, which close up the band gap of the ZPNRs. For the APNRs, these edge states are located at the bottom of the conduction band and result in a reduced band gap.

  7. Effect of dose rate on radical and property of gelatin

    International Nuclear Information System (INIS)

    Geng Shengrong; Chen Yuxia; Zu Xiaoyan; Li Xin; Jiang Hongyou

    2015-01-01

    The gelatin was irradiated respectively in the range of 0-32 kGy by dose rates of 60 Gy/min 60 Co, 480 Gy/min 60 Co and 12000 Gy/min accelerator, and the relationships of the radical character and gelatin property with dose rate were investigated through electron spin resonance (ESR) and gelatin permeation chromatogram. The results show that there is weak ESR signal from unirradiated gelatin, but irradiated one presents typical double peak. The order of ESR signal intensity of gelatin with the same absorbed dosage from high to low is 60 Gy/min 60 Co, 480 Gy/min 60 Co and 12000 Gy/min accelerator. The linear relationship between ESR signal intensity from 60 Co irradiated gelatin and absorbed dose is y= 26.983x 2 +1 641.8x-205.69. The intrinsic viscosity, average relative molecular weight, gelatin strength and breaking elongation of irradiated gelatin from high to low are 480 Gy/min 60 Co, 12000 Gy/min accelerator and 60 Gy/min 60 Co. The protection mechanism of high dose rate radiation on gelatin degradation is that the production of effective long life free radicals reduces. (authors)

  8. Effect of Rheological Properties on Liquid Curtain Coating

    Science.gov (United States)

    Mohammad Karim, Alireza; Suszynski, Wieslaw; Griffith, William; Pujari, Saswati; Carvalho, Marcio; Francis, Lorraine; Dow Chemical Company Collaboration; PUC-Rio Collaboration

    2017-11-01

    Curtain coating is one of the preferred methods for high-speed precision application of single-layer and multi-layer coatings in technology. However, uniform coatings are only obtained in a certain range of operating parameters, called coating window. The two main physical mechanisms that limit successful curtain coating are liquid curtain breakup and air entrainment. The rheological properties of the liquid play an important role on these mechanisms, but the fundamental understanding of these relations is still not complete. The effect of rate-dependent shear and extensional viscosities on the stability of viscoelastic and shear thinning liquid curtains were explored by high-speed visualization. Aqueous solutions of polyethylene oxide (PEO) and polyethylene glycol (PEG) were used as viscoelastic liquids. Xanthan Gum in water and glycerol solutions with a range of compositions were used as shear thinning liquids. The critical condition was determined by examining flow rate below which curtain broke. In this work, we also analyze relative importance of rate-dependent shear and extensional viscosity on both curtain breakup and air entrainment. We would like to acknowledge the financial support from the Dow Chemical Company.

  9. Effect of pressure on the physical properties of magnetorheological fluids

    Directory of Open Access Journals (Sweden)

    A. Spaggiari

    2013-01-01

    Full Text Available To date, several applications of magnetorheological (MR fluids are present in the industrial world, nonetheless system requirements often needs better material properties. In technical literature a previous work shows that MR fluids exhibit a pressure dependency called squeeze strengthen effect. Since a lot of MR fluid based devices are rotary devices, this paper investigates the behaviour of MR fluids under pressure when a rotation is applied to shear the fluid. The system is designed in order to apply both the magnetic field and the pressure and follows a Design of Experiment approach. The experimental apparatus comprises a cylinder in which a piston is used both to apply the pressure and to shear the fluid. The magnetic circuit is designed to provide a nearly constant induction field in the MR fluid. The experimental apparatus measures the torque as a function of the variables considered and the yield shear stress is computed. The analysis of the results shows that there is a positive interaction between magnetic field and pressure, which enhances the MR fluid performances more than twice.

  10. Effect of Concrete Waste Form Properties on Radionuclide Migration

    International Nuclear Information System (INIS)

    Mattigod, Shas V.; Bovaird, Chase C.; Wellman, Dawn M.; Skinner, De'Chauna J.; Cordova, Elsa A.; Wood, Marcus I.

    2009-01-01

    Assessing long-term performance of Category 3 waste cement grouts for radionuclide encasement requires knowledge of the radionuclide-cement interactions and mechanisms of retention (i.e., sorption or precipitation) the mechanism of contaminant release, the significance of contaminant release pathways, how waste form performance is affected by the full range of environmental conditions within the disposal facility, the process of waste form aging under conditions that are representative of processes occurring in response to changing environmental conditions within the disposal facility, the effect of waste form aging on chemical, physical, and radiological properties and the associated impact on contaminant release. This knowledge will enable accurate prediction of radionuclide fate when the waste forms come in contact with groundwater. Numerous sets of tests were initiated in fiscal years (FY) 2006-2009 to evaluate (1) diffusion of iodine (I) and technetium (Tc) from concrete into uncontaminated soil after 1 and 2 years, (2) I and rhenium (Re) diffusion from contaminated soil into fractured concrete, (3) I and Re (set 1) and Tc (set 2) diffusion from fractured concrete into uncontaminated soil, (4) evaluate the moisture distribution profile within the sediment half-cell, (5) the reactivity and speciation of uranium (VI) (U(VI)) compounds in concrete porewaters, (6) the rate of dissolution of concrete monoliths, and (7) the diffusion of simulated tank waste into concrete.

  11. Effect of radiation on the optical properties of some ferroelectrics

    International Nuclear Information System (INIS)

    Pirogova, G.N.; Kritskaya, V.E.; Malov, N.A.; Ryabov, A.I.; Voronin, Y.V.

    1986-01-01

    This paper studies the effect of gamma-irradiation and impulsive irradiation with electrons on the optical properties of crystals used in nonlinear optics: potassium dihydrophosphate KH 2 PO 4 , and cesium dihydroarsenate CsH 2 AsO 4 . The authors used two types of crystals obtained by extraction of the condensate, lowering of the temperature and recirculation. The content of iron-group impurity atoms (A1, Cu, and Mg) were determined with the help of atomic absorption spectrometry and was less than 1.10 -3 mole %. The samples were irradiated with a Co 60 gamma-ray source and impulsive irradiation with electrons was performed with a U-12 linear accelerator. A comparison of the spectra of gamma-irradiated single crystals and crystals irradiated with electrons shows that they are identical in the UV region. The impulse technique, however, enables observing the absorption bands which under gamma-irradiation are lost owing to the large increment of the optical density in the ultraviolet region and the shift of the absorption edge into the long-wavelength region

  12. Effects of magnetic atoms on the properties of ternary superconductors

    International Nuclear Information System (INIS)

    Dunlap, B.D.; Shenoy, G.K.

    1980-01-01

    Until recently it has been commonly accepted that small impurities of magnetic atoms were severely detrimental to superconductivity, and that superconductivity and long-range magnetic ordering could not occur in the same materials. In known binary and pseudo-binary compounds, this is still the case. However, many recent experiments on ternary superconductors have shown that the effects of magnetism are considerably more complex. In some cases, the addition of magnetic atoms has been found to enhance superconducting properties by increasing the superconducting critical field, without significantly lowering the transition temperature. In many cases, compounds will show both superconducting and long range magnetic ordering transitions. The destruction of superconductivity by ferromagnetic ordering and the coexistence of superconductivity with antiferromagnetic ordering is now well established. Hyperfine interaction measurements have played a significant role in the investigations of these materials, including measurement of the magnitude of the exchange interaction between rare-earth spin and conduction electron spin, elucidation of the mechanism for critical field enhancement, specification of crystalline field ground states, and studies of the nature of magnetic ordering

  13. Nanoconfinement: an effective way to enhance PVDF piezoelectric properties.

    Science.gov (United States)

    Cauda, Valentina; Stassi, Stefano; Bejtka, Katarzyna; Canavese, Giancarlo

    2013-07-10

    The dimensional confinement and oriented crystallization are both key factors in determining the piezoelectric properties of a polymeric nanostructured material. Here we prepare arrays of one-dimensional polymeric nanowires showing piezoelectric features by template-wetting two distinct polymers into anodic porous alumina (APA) membranes. In particular, poly(vinylidene fluoride), PVDF, and its copolymer poly(vinylidene fluoride-trifluoroethylene), PVTF, are obtained in commercially available APA, showing a final diameter of about 200 nm and several micrometers in length, reflecting the templating matrix features. We show that the crystallization of both polymers into a ferroelectric phase is directed by the nanotemplate confinement. Interestingly, the PVDF nanowires mainly crystallize into the β-phase in the nanoporous matrix, whereas the reference thin film of PVDF crystallizes in the α nonpolar phase. In the case of the PVTF nanowires, needle-like crystals oriented perpendicularly to the APA channel walls are observed, giving insight on the molecular orientation of the polymer within the nanowire structure. A remarkable piezoelectric behavior of both 1-D polymeric nanowires is observed, upon recording ferroelectric polarization, hysteresis, and displacement loops. In particular, an outstanding piezoelectric effect is observed for the PVDF nanowires with respect to the polymeric thin film, considering that no poling was carried out. Current versus voltage (I-V) characteristics showed a consistent switching behavior of the ferroelectric polar domains, thus revealing the importance of the confined and oriented crystallization of the polymer in monodimensional nanoarchitectures.

  14. Edge effects on the electronic properties of phosphorene nanoribbons

    Energy Technology Data Exchange (ETDEWEB)

    Peng, Xihong, E-mail: xihong.peng@asu.edu [School of Letters and Sciences, Arizona State University, Mesa, Arizona 85212 (United States); Copple, Andrew [Department of Physics, Arizona State University, Tempe, Arizona 85287 (United States); Wei, Qun [School of Letters and Sciences, Arizona State University, Mesa, Arizona 85212 (United States); School of Physics and Optoelectronic Engineering, Xidian University, Xi' an 710071 (China)

    2014-10-14

    Two dimensional few-layer black phosphorus crystal structures have recently been fabricated and have demonstrated great potential in electronic applications. In this work, we employed first principles density functional theory calculations to study the edge and quantum confinement effects on the electronic properties of the phosphorene nanoribbons (PNR). Different edge functionalization groups, such as H, F, Cl, OH, O, S, and Se, in addition to a pristine case were studied for a series of ribbon widths up to 3.5 nm. It was found that the armchair-PNRs (APNRs) are semiconductors for all edge groups considered in this work. However, the zigzag-PNRs (ZPNRs) show either semiconductor or metallic behavior in dependence on their edge chemical species. Family 1 edges (i.e., H, F, Cl, OH) form saturated bonds with P atoms in the APNRs and ZPNRs, and the edge states keep far away from the band gap. However, Family 2 edges (pristine, O, S, Se) form weak unsaturated bonds with the p{sub z} orbital of the phosphorus atoms and bring edge states within the band gap of the ribbons. For the ZPNRs, the edge states of Family 2 are present around the Fermi level within the band gap, which close up the band gap of the ZPNRs. For the APNRs, these edge states are located at the bottom of the conduction band and result in a reduced band gap.

  15. On the properties and mechanisms of microjet arrays in crossflow for the control of flow separation

    Science.gov (United States)

    Fernandez, Erik J.

    By utilizing passive and active methods of flow control, the aerodynamic performance of external and internal components can be greatly improved. Recently however, the benefits of applying active flow control methods to turbomachinery components for improved fuel efficiency, reduced engine size, and greater operational envelope has sparked a renewed interest in some of these flow control techniques. The more attractive of these, is active control in the form of jets in cross flow. With their ability to be turned on and off, as well as their negligible effect on drag when not being actuated, they are well suited for applications such as compressor and turbine blades, engine inlet diffusers, internal engine passages, and general external aerodynamics. This study consists of two parts. The first is the application of active control on a low-pressure turbine (LPT) cascade to determine the effectiveness of microjet actuators on flow separation at relatively low speeds. The second study, motivated by the first, involves a parametric study on a more canonical model to examine the effects of various microjet parameters on the efficacy of separation control and to provide a better understanding of the relevant flow physics governing this control approach. With data obtained from velocity measurements across the wide parametric range, correlations for the growth of the counter-rotating vortex pairs generated by these actuators are deduced. From the information and models obtained throughout the study, basic suggestions for microjet actuator design are presented.

  16. Controllable growth and magnetic properties of nickel nanoclusters electrodeposited on the ZnO nanorod template

    International Nuclear Information System (INIS)

    Tang Yang; Zhao Dongxu; Shen Dezhen; Zhang Jiying; Wang Xiaohua

    2009-01-01

    The ZnO nanorods were used as a template to fabricate nickel nanoclusters by electrodeposition. The ZnO nanorod arrays act as a nano-semiconductor electrode for depositing metallic and magnetic nickel nanoclusters. The growth sites of Ni nanoclusters could be controlled by adjusting the applied potential. Under -1.15 V the Ni nanoclusters could be grown on the tips of ZnO nanorods. On increasing the potential to be more negative the ZnO nanorods were covered by Ni nanoclusters. The magnetic properties of the electrodeposited Ni nanoclusters also evolved with the applied potentials.

  17. Controllable growth and magnetic properties of nickel nanoclusters electrodeposited on the ZnO nanorod template

    Energy Technology Data Exchange (ETDEWEB)

    Tang Yang; Zhao Dongxu; Shen Dezhen; Zhang Jiying [Key Laboratory of Excited State Processes, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, 16 East Nan-Hu Road, Open Economic Zone, Changchun 130033 (China); Wang Xiaohua, E-mail: dxzhao2000@yahoo.com.c [National Key Laboratory of High Power Semiconductor Laser, Changchun University of Science and Technology, 7089 WeiXing Road, ChangChun 130022 (China)

    2009-12-09

    The ZnO nanorods were used as a template to fabricate nickel nanoclusters by electrodeposition. The ZnO nanorod arrays act as a nano-semiconductor electrode for depositing metallic and magnetic nickel nanoclusters. The growth sites of Ni nanoclusters could be controlled by adjusting the applied potential. Under -1.15 V the Ni nanoclusters could be grown on the tips of ZnO nanorods. On increasing the potential to be more negative the ZnO nanorods were covered by Ni nanoclusters. The magnetic properties of the electrodeposited Ni nanoclusters also evolved with the applied potentials.

  18. Controlling steady-state and dynamical properties of atomic optical bistability

    CERN Document Server

    Joshi, Amitabh

    2012-01-01

    This book provides a comprehensive introduction to the theoretical and experimental studies of atomic optical bistability and multistability, and their dynamical properties in systems with two- and three-level inhomogeneously-broadened atoms inside an optical cavity. By making use of the modified linear absorption and dispersion, as well as the greatly enhanced nonlinearity in the three-level electromagnetically induced transparency system, the optical bistablity and efficient all-optical switching can be achieved at relatively low laser powers, which can be well controlled and manipulated. Un

  19. Controlling the Local Electronic Properties of Si(553)-Au through Hydrogen Doping

    Science.gov (United States)

    Hogan, C.; Speiser, E.; Chandola, S.; Suchkova, S.; Aulbach, J.; Schäfer, J.; Meyer, S.; Claessen, R.; Esser, N.

    2018-04-01

    We propose a quantitative and reversible method for tuning the charge localization of Au-stabilized stepped Si surfaces by site-specific hydrogenation. This is demonstrated for Si(553)-Au as a model system by combining density functional theory simulations and reflectance anisotropy spectroscopy experiments. We find that controlled H passivation is a two-step process: step-edge adsorption drives excess charge into the conducting metal chain "reservoir" and renders it insulating, while surplus H recovers metallic behavior. Our approach illustrates a route towards microscopic manipulation of the local surface charge distribution and establishes a reversible switch of site-specific chemical reactivity and magnetic properties on vicinal surfaces.

  20. Kinetic Control of Aqueous Hydrolysis: Modulating Structure/Property Relationships in Inorganic Crystals

    Science.gov (United States)

    Neilson, James R.

    2011-12-01

    A grand challenge in materials science and chemistry revolves around the preparation of materials with desired properties by controlling structure on multiple length scales. Biology approaches this challenge by evolving tactics to transform soluble precursors into materials and composites with macro-scale and atomic precision. Studies of biomineralization in siliceous sponges led to the discovery of slow, catalytic hydrolysis of molecular precursors in the biogenesis of silica skeletal elements with well defined micro- and nano-scale architectures. However, the role of aqueous hydrolysis in the limit of kinetic control is not well understood; this allows us to form a central hypothesis: that the kinetics of hydrolysis modulate the structures of materials and their properties. As a model system, the diffusion of a simple hydrolytic catalyst (such as ammonia) across an air-water interface into a metal salt solution reproduces some aspects of the chemistry found in biomineralization, namely kinetic and vectorial control. Variation of the catalyst concentration modulates the hydrolysis rate, and thus alters the resulting structure of the inorganic crystals. Using aqueous solutions of cobalt(II) chloride, each product (cobalt hydroxide chloride) forms with a unique composition, despite being prepared from identical mother liquors. Synchrotron X-ray total scattering methods are needed to locate the atomic positions in the material, which are not aptly described by a traditional crystallographic unit cell due to structural disorder. Detailed definition of the structure confirms that the hydrolysis conditions systematically modulate the arrangement of atoms in the lattice. This tightly coupled control of crystal formation and knowledge of local and average structures of these materials provides insight into the unusual magnetic properties of these cobalt hydroxides. The compounds studied show significant and open magnetization loops with little variation with composition

  1. Neutron irradiation effects on magnetic properties of some Heusler alloys

    International Nuclear Information System (INIS)

    Onodera, Hideya; Shinohara, Takeshi; Yamamoto, Hisao; Watanabe, Hiroshi

    1975-01-01

    The neutron irradiation effects were studied with measurements of temperature dependence of magnetization in ordered and disordered Heusler alloys. The irradiation was carried out in JMTR with a total flux of fast neutrons of 10 20 nvt. Fully ordered Cu 2 MnIn, partially ordered Cu 2 MnAl and completely disordered Cu 2 MnSn were prepared with various temperature treatments. The magnetization-temperature curves of each specimen were measured before and after irradiation. In the irradiated Cu 2 MnIn, the disordering by the irradiation gave rise to a decrease of magnetization, and the temperature dependence of magnetization showed that the disordered region contained various regions with different degrees of disorder. For the distribution of the disordered region, the calculation based on the theory of temperature spike by Seitz and Koekler gave a feasible result that a disordered region comprised a central core with a radius of 5.4 A which was completely disordered and a periphery of 3.3 A thickness which was partially disordered. From the magnetization-temperature curves of Cu 2 MnAl, it was considered that the disordered regions induced by the irradiation had different properties from those induced by the heat treatment. The former were the localized and comprised regions corresponding to various degrees of disorder, while the latter spread spatially in a wide range with a certain degree of disorder. The ordering by enhanced diffusion occurred simultaneously to an extent comparable to the disordering, and so it played an important role in the magnetization in the partially disordered Cu 2 MnAl. In the disordered Cu 2 MnSn, however, the ordering effect was very small. It is supposed to be difficult for the A2 structure to transform into the L2 1 structure by the enhanced diffusion. (auth.)

  2. Inhibitory effects of Urtica dioica L. root on electrophysiological properties of isolated rabbit atrioventricular node

    Directory of Open Access Journals (Sweden)

    A. Enayati

    2017-11-01

    Full Text Available Background and objectives: The ideal drug for treatment of a wide range of supraventricular arrhythmia hasn't yet been developed. Previous studies have shown antihypertensive and negative inotropic effects of the Urtica dioica L. (nettle. Therefore, the aim of present study is to determine the rate dependent inhibitory effects of ethanol extract of nettle root and investigate the role of adrenoceptors in the anti-arrhythmic mechanism of nettle on the isolated rabbit atrio-ventricular node. Methods: Urtica dioica roots were collected from Gorgan (Golestan, Iran. Male New Zealand rabbits (n=7 were used in all of the experiments. Experimental stimulation protocols (WBCL; Recovery, Facilitation, Fatigue were applied to assess electrophysiological properties of Node. All protocols were repeated in the presence and absence (control of different concentration (0.25-0.5 w/v % of nettle and 1 μM nadolol. Data were shown as Mean±SE, difference between groups statistically were assessed by SPSS software. Results: Nettle (0.5 w/v significantly decreased basic and functional properties of node as WBCL, ERP, FRP, AVCT and magnitude of fatigue (∆AH significantly increased but ∆FRP significantly decreased. In the presence of nadolol (1μM as a nonselective β-blocker, nettle (0.3 mg/L could not repeat its effects on electrophysiological properties of AV-node. Conclusion: The results showed the modifying properties of Urtica dioica root extract. It may be considered as a candidate for the treatment of supraventicular arrhythmias.

  3. Effect of Sucrose Esters on the Physicochemical Properties of Wheat ...

    African Journals Online (AJOL)

    In addition, the structure and thermodynamic properties of the modified starch were analyzed by Fourier transform infrared spectroscopy (FITR), scanning electron microscopy (SEM) and differential scanning calorimetry (DSC). Results: The properties of wheat starch changed greatly by adding different sucrose esters to their ...

  4. Effects of moisture on the mechanical properties of glass fibre ...

    Indian Academy of Sciences (India)

    However, the properties were relatively inferior when treated with boiling water for longer hours attributing to ingress of moisture by capillary action through the interface between the fibre and the resin matrix. Considering the rates of moisture absorption and correlating with the mechanical properties, it was observed that the ...

  5. The effects of cryopreservation on red blood cell rheologic properties

    NARCIS (Netherlands)

    Henkelman, Sandra; Lagerberg, Johan W. M.; Graaff, Reindert; Rakhorst, Gerhard; van Oeveren, Willem

    2010-01-01

    BACKGROUND: In transfusion medicine, frozen red blood cells (RBCs) are an alternative for liquid-stored RBCs. Little is known about the rheologic properties (i.e., aggregability and deformability) of thawed RBCs. In this study the rheologic properties of high-glycerol frozen RBCs and postthaw stored

  6. Effect of pentosans on gluten formation and properties.

    NARCIS (Netherlands)

    Wang, M.

    2003-01-01

    Keywords: pentosans, gluten yield, gluten properties, glutenin macropolymerThe gluten protein polymeric network plays a pivotal role in determining the end-use quality of wheat in many food products. The properties of this polymeric network are strongly affected by wheat flour

  7. Boron nitride elastic and thermal properties. Irradiation effects

    International Nuclear Information System (INIS)

    Jager, Bernard.

    1977-01-01

    The anisotropy of boron nitride (BN) and especially thermal and elastic properties were studied. Specific heat and thermal conductivity between 1.2 and 300K, thermal conductivity between 4 and 350K and elastic constants C 33 and C 44 were measured. BN was irradiated with electrons at 77K and with neutrons at 27K to determine properties after irradiation [fr

  8. Effective properties of a viscoplastic constitutive model obtained by homogenisation

    NARCIS (Netherlands)

    Sluis, van der O.; Schreurs, P.J.G.; Meijer, H.E.H.

    1999-01-01

    Heterogeneous materials are used more and more frequent due to their enhanced mechanical properties. If the relation between the microscopic deformation and the macroscopic mechanical behaviour can be obtained, it can be used to design new materials with desired properties such as high strength,

  9. Effects of Polyethylene Glycol on the Mechanical Properties of ...

    African Journals Online (AJOL)

    Akorede

    investigate the mechanical properties and microstructural evaluation of steel. The test ... quenchant on the properties of steel (Eshraghi-Kakhki et al, ... Alloy Steel ... Table 1: Chemical composition of the steel used in this experiment. Elements. C. Si. S ... Cu. W. As. Composition 0.0555 0.00180 0.0029 0.3031 0.0003 0.0060.

  10. Effects of porcine somatotropin and dietary phosphorus on growth performance and bone properties of gilts.

    Science.gov (United States)

    Weeden, T L; Nelssen, J L; Goodband, R D; Hansen, J A; Fitzner, G E; Friesen, K G; Laurin, J L

    1993-10-01

    One hundred eight gilts (initial weight = 58.5 kg) were used to determine the effects of porcine somatotropin (pST) and dietary P on growth performance and bone mechanical properties and mineralization during the finishing phase (58 to 105 kg) and a 35-d postfinishing phase. Gilts were injected daily with placebo (control) or 4 mg of pST and fed diets containing .4, .8, or 1.2% P in a 2 x 3 factorial arrangement. From 58 to 105 kg, administration of pST increased (P properties and bone ash. A pST x P interaction was observed (P < .05) for rib bending moment and modulus of elasticity; maximum rib bending moment was attained by control gilts at .8% P and rib modulus of elasticity values remained constant across P levels, whereas rib bending moment and modulus of elasticity increased as dietary P increased from .4 to 1.2% in pST-treated gilts. Administration of pST decreased (P < .05) stress of the rib, femur, and metacarpals compared with control gilts. Increasing dietary P resulted in a linear (P < .10) increase in bending moment, stress, and ash content for rib, femur, and metacarpal bones. The remaining 54 gilts were individually fed 1.8 kg/d of a common diet for 35 d postfinishing.(ABSTRACT TRUNCATED AT 250 WORDS)

  11. Effect of incorporation of zinc oxide nanoparticles on mechanical properties of conventional glass ionomer cements.

    Science.gov (United States)

    Panahandeh, Narges; Torabzadeh, Hassan; Aghaee, Mohammadamin; Hasani, Elham; Safa, Saeed

    2018-01-01

    The aim of this study is to investigate the physical properties of conventional and resin-modified glass ionomer cements (GICs) compared to GICs supplemented with zinc oxide (ZnO) nanofiller particles at 5% (w/w). In this in vitro study, ZnO nanoparticles of different morphologies (nanospherical, nanorod, and nanoflower) were incorporated to glass ionomer powder. The samples were subjected to the flexural strength ( n = 20) and surface hardness test ( n = 12) using a universal testing machine and a Vickers hardness machine, respectively. Surface analysis and crystal structure of samples were performed with scanning electron microscope and X-radiation diffraction, respectively. The data were analyzed using one-way ANOVA, Shapiro-Wilk, and Tukey's tests ( P glass ionomer containing nanoparticles was not significantly different from the control group ( P > 0.05). The surface hardness of the glass ionomer containing nanospherical or nanoflower ZnO was significantly lower than the control group ( P glass ionomer containing nanorod ZnO was not significantly different from the control group ( P = 0.868). Incorporation of nanospherical and nanoflower ZnO to glass ionomer decreased their surface hardness, without any changes on their flexural strength. Incorporation of nanorod ZnO particles caused no effect on the mechanical properties.

  12. Intelligent sensor in control systems for objects with changing thermophysical properties

    Science.gov (United States)

    Belousov, O. A.; Muromtsev, D. Yu; Belyaev, M. P.

    2018-04-01

    The control of heat devices in a wide temperature range given thermophysical properties of an object is a topical issue. Optimal control systems of electric furnaces have to meet strict requirements in terms of accuracy of production procedures and efficiency of energy consumption. The fulfillment of these requirements is possible only if the dynamics model describing adequately the processes occurring in the furnaces is used to calculate the optimal control actions. One of the types of electric furnaces is the electric chamber furnace intended for heat treatment of various materials at temperatures from thousands of degrees Celsius and above. To solve the above-mentioned problem and to determine its place in the system of energy-efficient control of dynamic modes in the electric furnace, we propose the concept of an intelligent sensor and a method of synthesizing variables on sets of functioning states. The use of synthesis algorithms for optimal control in real time ensures the required accuracy when operating under different conditions and operating modes of the electric chamber furnace.

  13. Psychometric properties of the Spanish version of the Controlling Coach Behaviors Scale in the sport context.

    Science.gov (United States)

    Castillo, Isabel; Tomás, Inés; Ntoumanis, Nikos; Bartholomew, Kimberley; Duda, Joan L; Balaguer, Isabel

    2014-01-01

    The purpose of this research was to translate into Spanish and examine the psychometric properties of the Spanish version of the Controlling Coach Behaviors Scale (CCBS) in male soccer players. The CCBS is a questionnaire designed to assess athletes' perceptions of sports coaches' controlling interpersonal style from the perspective of the self-determination theory. Study 1 tested the factorial structure of the translated scale using confirmatory factor analysis (CFA) and provided evidence of discriminant validity. Studies 2 and 3 examined the invariance across time and across competitive level via multi-sample CFA. Reliability analyses were also conducted. The CFA results revealed that a four-factor model was acceptable, indicating that a controlling interpersonal style is a multidimensional construct represented by four separate and related controlling coaching strategies. Further, results supported the invariance of the CCBS factor structure across time and competitive level and provided support for the internal consistency of the scale. Overall, the CCBS demonstrated adequate internal consistency, as well as good factorial validity. The Spanish version of the CCBS represents a valid and reliable adaptation of the instrument, which can be confidently used to measure soccer players' perceptions of their coaches' controlling interpersonal style.

  14. Surface orientation effects on bending properties of surgical mesh are independent of tensile properties.

    Science.gov (United States)

    Simon, David D; Andrews, Sharon M; Robinson-Zeigler, Rebecca; Valdes, Thelma; Woods, Terry O

    2018-02-01

    Current mechanical testing of surgical mesh focuses primarily on tensile properties even though implanted devices are not subjected to pure tensile loads. Our objective was to determine the flexural (bending) properties of surgical mesh and determine if they correlate with mesh tensile properties. The flexural rigidity values of 11 different surgical mesh designs were determined along three textile directions (machine, cross-machine, and 45° to machine; n = 5 for each) using ASTM D1388-14 while tracking surface orientation. Tensile testing was also performed on the same specimens using ASTM D882-12. Linear regressions were performed to compare mesh flexural rigidity to mesh thickness, areal mass density, filament diameter, ultimate tensile strength, and maximum extension. Of 33 mesh specimen groups, 30 had significant differences in flexural rigidity values when comparing surface orientations (top and bottom). Flexural rigidity and mesh tensile properties also varied with textile direction (machine and cross-machine). There was no strong correlation between the flexural and tensile properties, with mesh thickness having the best overall correlation with flexural rigidity. Currently, surface orientation is not indicated on marketed surgical mesh, and a single mesh may behave differently depending on the direction of loading. The lack of correlation between flexural stiffness and tensile properties indicates the need to examine mesh bending stiffness to provide a more comprehensive understanding of surgical mesh mechanical behaviors. Further investigation is needed to determine if these flexural properties result in the surgical mesh behaving mechanically different depending on implantation direction. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 854-862, 2018. © 2017 Wiley Periodicals, Inc.

  15. Control of microstructure and mechanical properties of laser solid formed Inconel 718 superalloy by electromagnetic stirring

    Science.gov (United States)

    Liu, Fencheng; Cheng, Hongmao; Yu, Xiaobin; Yang, Guang; Huang, Chunping; Lin, Xin; Chen, Jing

    2018-02-01

    The coarse columnar grains and special interface in laser solid formed (LSFed) Inconel 718 superalloy workpieces seriously affect their mechanical properties. To improve the microstructure and mechanical properties of LSFed Inconel 718 superalloy, electromagnetic stirring (EMS) was introduced to alter the solidification process of the molten pool during LSF. The results show that EMS could not completely eliminate the epitaxially growing columnar grains, however, the strong convection of liquid metals can effectively influence the solid-liquid interface growing mode. The segregation of alloying elements on the front of solid-liquid interface is inhibited and the degree of constitutional supercooling decreases correspondingly. Comparing the microstructures of samples formed under different process parameters, the size and amount of the γ+Laves eutectic phases formed in interdendritic area decrease along with the increasing magnetic field intensity, resulting in more uniformly distributed alloying elements. The residual stress distribution is proved to be more uniform, which is beneficial to the grain refinement after recrystallilzaiton. Mechanical properties testing results show an improvement of 100 MPa in tensile strength and 22% in elongation was obtained after EMS was used. The high cycle fatigue properties at room temperature was also improved from 4.09 × 104 cycles to 8.21 × 104 cycles for the as-deposited samples, and from 5.45 × 104 cycles to 12.73 × 104 cycles for the heat treated samples respectively.

  16. Controlled Living Nanowire Growth: Precise Control over the Morphology and Optical Properties of AgAuAg Bimetallic Nanowires

    Science.gov (United States)

    2015-01-01

    Inspired by the concept of living polymerization reaction, we are able to produce silver–gold–silver nanowires with a precise control over their total length and plasmonic properties by establishing a constant silver deposition rate on the tips of penta-twinned gold nanorods used as seed cores. Consequently, the length of the wires increases linearly in time. Starting with ∼210 nm × 32 nm gold cores, we produce nanowire lengths up to several microns in a highly controlled manner, with a small self-limited increase in thickness of ∼4 nm, corresponding to aspect ratios above 100, whereas the low polydispersity of the product allows us to detect up to nine distinguishable plasmonic resonances in a single colloidal solution. We analyze the spatial distribution and the nature of the plasmons by electron energy loss spectroscopy and obtain excellent agreement between measurements and electromagnetic simulations, clearly demonstrating that the presence of the gold core plays a marginal role, except for relatively short wires or high-energy modes. PMID:26134470

  17. A Spatial Hedonic Analysis of the Effects of Wind Energy Facilities on Surrounding Property Values in the United States

    Energy Technology Data Exchange (ETDEWEB)

    Hoen, Ben [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Wiser, Ryan [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Cappers, Peter [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Brown, Jason P. [Federal Reserve Bank of Kansas City, MO (United States); Jackson, Thomas [Real Analytics Inc. and Texas A & M Univ., College Station, TX (United States); Thayer, Mark A. [San Diego State Univ., CA (United States)

    2013-08-21

    This report summarizes a new analysis, building on previously published research, about wind energy’s effects on residential property values. This study helps fill research gaps by collecting and analyzing data from 27 counties across nine U.S. states, related to 67 different wind facilities, and constructs a pooled model that investigates average effects near the turbines across the sample while controlling for local variables, such as sale prices of nearby homes.

  18. Litter decay controlled by temperature, not soil properties, affecting future soil carbon.

    Science.gov (United States)

    Gregorich, Edward G; Janzen, Henry; Ellert, Benjamin H; Helgason, Bobbi L; Qian, Budong; Zebarth, Bernie J; Angers, Denis A; Beyaert, Ronald P; Drury, Craig F; Duguid, Scott D; May, William E; McConkey, Brian G; Dyck, Miles F

    2017-04-01

    Widespread global changes, including rising atmospheric CO 2 concentrations, climate warming and loss of biodiversity, are predicted for this century; all of these will affect terrestrial ecosystem processes like plant litter decomposition. Conversely, increased plant litter decomposition can have potential carbon-cycle feedbacks on atmospheric CO 2 levels, climate warming and biodiversity. But predicting litter decomposition is difficult because of many interacting factors related to the chemical, physical and biological properties of soil, as well as to climate and agricultural management practices. We applied 13 C-labelled plant litter to soil at ten sites spanning a 3500-km transect across the agricultural regions of Canada and measured its decomposition over five years. Despite large differences in soil type and climatic conditions, we found that the kinetics of litter decomposition were similar once the effect of temperature had been removed, indicating no measurable effect of soil properties. A two-pool exponential decay model expressing undecomposed carbon simply as a function of thermal time accurately described kinetics of decomposition. (R 2  = 0.94; RMSE = 0.0508). Soil properties such as texture, cation exchange capacity, pH and moisture, although very different among sites, had minimal discernible influence on decomposition kinetics. Using this kinetic model under different climate change scenarios, we projected that the time required to decompose 50% of the litter (i.e. the labile fractions) would be reduced by 1-4 months, whereas time required to decompose 90% of the litter (including recalcitrant fractions) would be reduced by 1 year in cooler sites to as much as 2 years in warmer sites. These findings confirm quantitatively the sensitivity of litter decomposition to temperature increases and demonstrate how climate change may constrain future soil carbon storage, an effect apparently not influenced by soil properties. © 2016 Her Majesty

  19. WEED CONTROL EFFECTS ON SOIL CHEMICAL CHARACTERISTICS

    Directory of Open Access Journals (Sweden)

    Paulo Sérgio Lima e Silva

    2008-01-01

    Full Text Available The weed control procedures are known to affect the soil physical attributes and the nutrient amount taken up by weed roots. This work hypothesis is that weed control methods might also affect soil chemical attributes. Four experiments were carried out, three with maize (E-1, E-2 and E-3 and one with cotton (E-4, in randomized complete blocks design arranged in split-plots, with five replications. In E-1 experiment, the plots consisted of two weed control treatments: no-weed control and weed shovel-digging at 20 and 40 days after sowing; and the subplots consisted of six maize cultivars. In the three other experiments, the plots consisted of plant cultivars: four maize cultivars (E-2 and E-3 and four cotton cultivars (E-4. And, the subplots consisted of three weed control treatments: (1 no-weed control; (2 weed shovel-digging at 20 and 40 days after sowing; and (3 intercropping with cowpea (E-2 or Gliricidia sepium (Jacq. Walp. (E-3 and E-4. In all experiments, after harvest, eight soil samples were collected from each subplot (0-20 cm depth and composed in one sample. Soil chemical analysis results indicated that the weed control by shovel-digging or intercropping may increase or decrease some soil element concentrations and the alterations depend on the element and experiment considered. In E-2, the weed shovel-dug plots showed intermediate soil pH, lower S (sum of bases values and higher soil P concentrations than the other plots. In E-4, soil K and Na concentrations in plots without weed control did not differ from plots with intercropping, and in both, K and Na values were higher than in weed shovel-dug plots. Maize and cotton cultivars did not affect soil chemical characteristics.

  20. Effect of dietary garlic bulb and husk on the physicochemical properties of chicken meat.

    Science.gov (United States)

    Kim, Y J; Jin, S K; Yang, H S

    2009-02-01

    This study was carried out to compare the physicochemical and sensory properties of chicken thigh muscles from broilers fed different levels of garlic bulb (GB) and garlic husk (GH). Two hundred male Arbor Acre broiler chickens were fed either a control diet (based on corn and soybean meal) or the control diet supplemented with 2 and 4% of GB and GH powder for 5 wk. There were no differences among diets in moisture and ash contents. However, dietary supplementation with GB and GH resulted in significantly greater protein content and lower fat content in chicken thigh muscle compared with muscle from birds fed nonsupplemented diets (Pchicken diets with garlic can produce chicken meat with favorable lipid profiles and can enhance eating quality because sensory panels found that thigh meat from chickens fed a garlic-supplemented diet had better texture and flavor. Therefore, the treatment with the most significant effects in this study was that with the high level of garlic husk.

  1. Effects of consolidation process on microstructure and mechanical properties of commingled glass/polypropylene composites

    International Nuclear Information System (INIS)

    Tufail, M.; Long, A.C.; Rudd, C.D.

    2001-01-01

    The thermal history of a thermoplastic composite material during forming and consolidation is critical to the quality of the component. Attempts to process outside the normal melt region will result in incomplete consolidation and voidage. Clearly then, the preheat phase plays a key role in successful processing. Too low a preheat temperature results in insufficient matrix flow while, if the temperature is increased too much, degradation of the matrix occurs, again resulting in poor quality of the composite. In particular polypropylene has poor chemical (oxidative) resistance, and oxidative degradation reduces the average molecular weight of the materials. If excessive, this can result in a dramatic reduction in mechanical properties. Flat plaques of braided, commingled glass/polypropylene yarn were produced to examine these effects using both isothermal and non-isothermal consolidation. Woven plaques were also produced from commingled yarn in a similar fashion as control samples in order to identify any effects specific to the braiding process. This paper describes the effect of heating and stamping cycles on the properties of these composites, concentrating on the effects of temperature, heating time and compaction rate. (author)

  2. Laser grade CaF2 with controllable properties: growing conditions and structural imperfection

    International Nuclear Information System (INIS)

    Mouchovski, J T; Temelkov, K A; Vuchkov, N K; Sabotinov, N V

    2007-01-01

    Optical properties of CaF 2 , grown by a controlled Bridgman-Stockbarger technique, are studied by CuBr and SrBr 2 vapour lasers. Absorption losses are determined as a function of the grown crystal volume, the crystallization front (CF), and the real crystallization rate. It is found that the absorption losses are relatively independent of the transmitted wavelengths in a wide spectral range from the deep ultraviolet (DUV) to the middle infrared (MIR) spectral region and their minimum corresponds to CF positions within the upper half of the adiabatic furnace zone, where the CR reaches a constant value slightly higher than the speed of crucible movement. The crystal quality conforms to laser grade CaF 2 for the DUV, visible and MIR spectral regions and may be controlled efficiently by introducing an appropriate systematic correction in the furnace temperature field, which shifts the CF position

  3. Physical and chemical properties of gels. Application to protein nucleation control in the gel acupuncture technique

    Science.gov (United States)

    Moreno, Abel; Juárez-Martínez, Gabriela; Hernández-Pérez, Tomás; Batina, Nikola; Mundo, Manuel; McPherson, Alexander

    1999-09-01

    In this work, we present a new approach using analytical and optical techniques in order to determine the physical and chemical properties of silica gel, as well as the measurement of the pore size in the network of the gel by scanning electron microscopy. The gel acupuncture technique developed by García-Ruiz et al. (Mater. Res. Bull 28 (1993) 541) García-Ruiz and Moreno (Acta Crystallogr. D 50 (1994) 484) was used throughout the history of crystal growth. Several experiments were done in order to evaluate the nucleation control of model proteins (thaumatin I from Thaumatococcus daniellii, lysozyme from hen egg white and catalase from bovine liver) by the porous network of the gel. Finally, it is shown how the number and the size of the crystals obtained inside X-ray capillaries is controlled by the size of the porous structure of the gel.

  4. Effects of soil properties on the uptake of pharmaceuticals into earthworms

    International Nuclear Information System (INIS)

    Carter, Laura J.; Ryan, Jim J.; Boxall, Alistair B.A.

    2016-01-01

    Pharmaceuticals can enter the soil environment when animal slurries and sewage sludge are applied to land as a fertiliser or during irrigation with contaminated water. These pharmaceuticals may then be taken up by soil organisms possibly resulting in toxic effects and/or exposure of organisms higher up the food chain. This study investigated the influence of soil properties on the uptake and depuration of pharmaceuticals (carbamazepine, diclofenac, fluoxetine and orlistat) in the earthworm Eisenia fetida. The uptake and accumulation of pharmaceuticals into E. fetida changed depending on soil type. Orlistat exhibited the highest pore water based bioconcentration factors (BCFs) and displayed the largest differences between soil types with BCFs ranging between 30.5 and 115.9. For carbamazepine, diclofenac and fluoxetine BCFs ranged between 1.1 and 1.6, 7.0 and 69.6 and 14.1 and 20.4 respectively. Additional analysis demonstrated that in certain treatments the presence of these chemicals in the soil matrices changed the soil pH over time, with a statistically significant pH difference to control samples. The internal pH of E. fetida also changed as a result of incubation in pharmaceutically spiked soil, in comparison to the control earthworms. These results demonstrate that a combination of soil properties and pharmaceutical physico-chemical properties are important in terms of predicting pharmaceutical uptake in terrestrial systems and that pharmaceuticals can modify soil and internal earthworm chemistry which may hold wider implications for risk assessment. - Highlights: • Uptake of pharmaceuticals into earthworms is influenced by soil parameters. • Presence of pharmaceuticals in the terrestrial environment influences soil pH. • Uptake of pharmaceuticals by earthworms changes internal earthworm pH. - The uptake of pharmaceuticals into soil invertebrates is dependent on the complex interplay between pharmaceutical physico-chemical properties and soil

  5. Experimental control of the beam properties of laser-accelerated protons and carbon ions

    International Nuclear Information System (INIS)

    Amin, Munib

    2008-12-01

    The laser generation of energetic high quality beams of protons and heavier ions has opened up the door to a plethora of applications. These beams are usually generated by the interaction of a short pulse high power laser with a thin metal foil target. They could already be applied to probe transient phenomena in plasmas and to produce warm dense matter by isochoric heating. Other applications such as the production of radioisotopes and tumour radiotherapy need further research to be put into practice. To meet the requirements of each application, the properties of the laser-accelerated particle beams have to be controlled precisely. In this thesis, experimental means to control the beam properties of laser-accelerated protons and carbon ions are investigated. The production and control of proton and carbon ion beams is studied using advanced ion source designs: Experiments concerning mass-limited (i.e. small and isolated) targets are conducted. These targets have the potential to increase both the number and the energy of laser-accelerated protons. Therefore, the influence of the size of a plane foil target on proton beam properties is measured. Furthermore, carbon ion sources are investigated. Carbon ions are of particular interest in the production of warm dense matter and in cancer radiotherapy. The possibility to focus carbon ion beams is investigated and a simple method for the production of quasi-monoenergetic carbon ion beams is presented. This thesis also provides an insight into the physical processes connected to the production and the control of laser-accelerated ions. For this purpose, laser-accelerated protons are employed to probe plasma phenomena on laser-irradiated targets. Electric fields evolving on the surface of laser-irradiated metal foils and hollow metal foil cylinders are investigated. Since these fields can be used to displace, collimate or focus proton beams, understanding their temporal and spatial evolution is crucial for the design of

  6. Experimental control of the beam properties of laser-accelerated protons and carbon ions

    Energy Technology Data Exchange (ETDEWEB)

    Amin, Munib

    2008-12-15

    The laser generation of energetic high quality beams of protons and heavier ions has opened up the door to a plethora of applications. These beams are usually generated by the interaction of a short pulse high power laser with a thin metal foil target. They could already be applied to probe transient phenomena in plasmas and to produce warm dense matter by isochoric heating. Other applications such as the production of radioisotopes and tumour radiotherapy need further research to be put into practice. To meet the requirements of each application, the properties of the laser-accelerated particle beams have to be controlled precisely. In this thesis, experimental means to control the beam properties of laser-accelerated protons and carbon ions are investigated. The production and control of proton and carbon ion beams is studied using advanced ion source designs: Experiments concerning mass-limited (i.e. small and isolated) targets are conducted. These targets have the potential to increase both the number and the energy of laser-accelerated protons. Therefore, the influence of the size of a plane foil target on proton beam properties is measured. Furthermore, carbon ion sources are investigated. Carbon ions are of particular interest in the production of warm dense matter and in cancer radiotherapy. The possibility to focus carbon ion beams is investigated and a simple method for the production of quasi-monoenergetic carbon ion beams is presented. This thesis also provides an insight into the physical processes connected to the production and the control of laser-accelerated ions. For this purpose, laser-accelerated protons are employed to probe plasma phenomena on laser-irradiated targets. Electric fields evolving on the surface of laser-irradiated metal foils and hollow metal foil cylinders are investigated. Since these fields can be used to displace, collimate or focus proton beams, understanding their temporal and spatial evolution is crucial for the design of

  7. Gelatin Scaffolds with Controlled Pore Structure and Mechanical Property for Cartilage Tissue Engineering.

    Science.gov (United States)

    Chen, Shangwu; Zhang, Qin; Nakamoto, Tomoko; Kawazoe, Naoki; Chen, Guoping

    2016-03-01

    Engineering of cartilage tissue in vitro using porous scaffolds and chondrocytes provides a promising approach for cartilage repair. However, nonuniform cell distribution and heterogeneous tissue formation together with weak mechanical property of in vitro engineered cartilage limit their clinical application. In this study, gelatin porous scaffolds with homogeneous and open pores were prepared using ice particulates and freeze-drying. The scaffolds were used to culture bovine articular chondrocytes to engineer cartilage tissue in vitro. The pore structure and mechanical property of gelatin scaffolds could be well controlled by using different ratios of ice particulates to gelatin solution and different concentrations of gelatin. Gelatin scaffolds prepared from ≥70% ice particulates enabled homogeneous seeding of bovine articular chondrocytes throughout the scaffolds and formation of homogeneous cartilage extracellular matrix. While soft scaffolds underwent cellular contraction, stiff scaffolds resisted cellular contraction and had significantly higher cell proliferation and synthesis of sulfated glycosaminoglycan. Compared with the gelatin scaffolds prepared without ice particulates, the gelatin scaffolds prepared with ice particulates facilitated formation of homogeneous cartilage tissue with significantly higher compressive modulus. The gelatin scaffolds with highly open pore structure and good mechanical property can be used to improve in vitro tissue-engineered cartilage.

  8. Magnetic, structural and magnetocaloric properties of Ni-Si and Ni-Al thermoseeds for self-controlled hyperthermia.

    Science.gov (United States)

    Pandey, Sudip; Quetz, Abdiel; Aryal, Anil; Dubenko, Igor; Mazumdar, Dipanjan; Stadler, Shane; Ali, Naushad

    2017-11-01

    Self-controlled hyperthermia is a non-invasive technique used to kill or destroy cancer cells while preserving normal surrounding tissues. We have explored bulk magnetic Ni-Si and Ni-Al alloys as a potential thermoseeds. The structural, magnetic and magnetocaloric properties of the samples were investigated, including saturation magnetisation, Curie temperature (T C ), and magnetic and thermal hysteresis, using room temperature X-ray diffraction and magnetometry. The annealing time, temperature and the effects of homogenising the thermoseeds were studied to determine the functional hyperthermia applications. The bulk Ni-Si and Ni-Al binary alloys have Curie temperatures in the desired range, 316 K-319 K (43 °C-46 °C), which is suitable for magnetic hyperthermia applications. We have found that T C strictly follows a linear trend with doping concentration over a wide range of temperature. The magnetic ordering temperature and the magnetic properties can be controlled through substitution in these binary alloys.

  9. The effect of intrinsic soil properties on soil quality assessments

    Directory of Open Access Journals (Sweden)

    Alessandro Samuel-Rosa

    2013-10-01

    Full Text Available The assessment of soil quality is based on indicators and indices derived from soil properties. However, intrinsic soil properties may interfere with other soil properties that vary under different land uses and are used to calculate the indices. The aim of this study was to assess the extent to which intrinsic soil properties (clay and iron oxide contents explain variable soil properties (sum of bases, potential acidity, organic carbon, total porosity, and bulk density under different land uses (native forest, no-tillage and conventional agriculture on small family farms in Southern Brazil. The results showed that the five properties evaluated can be included in soil quality assessments and are not influenced by the clay and iron oxide contents. It was concluded that for little weathered 1:1 and 2:1 phyllosilicate rich-soils, if the difference between the maximum and the minimum clay content under the different land uses is less than about 200 g kg-1 and the iron oxide content less than about 15 g kg-1, the physico-chemical soil properties in the surface layer are determined mostly by the land use.

  10. Effect of prostaglandin E2 injection on the structural properties of the rat patellar tendon

    Directory of Open Access Journals (Sweden)

    Ferry Scott T

    2012-01-01

    Full Text Available Abstract Background Increased tendon production of the inflammatory mediator prostaglandin E2 (PGE2 has been suggested to be a potential etiologic agent in the development of tendinopathy. Repeated injection of PGE2 into tendon has been proposed as a potential animal model for studying treatments for tendinopathy. In contrast, nonsteroidal anti-inflammatory drugs (NSAIDs which inhibit PGE2 production and are commonly prescribed in treating tendinopathy have been shown to impair the healing of tendon after acute injury in animal models. The contradictory literature suggests the need to better define the functional effects of PGE2 on tendon. Our objective was to characterize the effects of PGE2 injection on the biomechanical and biochemical properties of tendon and the activity of the animals. Our hypothesis was that weekly PGE2 injection to the rat patellar tendon would lead to inferior biomechanical properties. Methods Forty rats were divided equally into four groups. Three groups were followed for 4 weeks with the following peritendinous injection procedures: No injection (control, 4 weekly injections of saline (saline, 4 weekly injections of 800 ng PGE2 (PGE2-4 wks. The fourth group received 4 weekly injections of 800 ng PGE2 initially and was followed for a total of 8 weeks. All animals were injected bilaterally. The main outcome measurements included: the structural and material properties of the patellar tendon under tensile loading to failure, tendon collagen content, and weekly animal activity scores. Results The ultimate load of PGE2-4 wks tendons at 4 weeks was significantly greater than control or saline group tendons. The stiffness and elastic modulus of the PGE2 injected tendons at 8 weeks was significantly greater than the control or saline tendons. No differences in animal activity, collagen content, or mean fibril diameter were observed between groups. Conclusions Four weekly peritendinous injections of PGE2 to the rat patellar

  11. 25 CFR 900.58 - Do the same accountability and control procedures described above apply to Federal property?

    Science.gov (United States)

    2010-04-01

    ... 25 Indians 2 2010-04-01 2010-04-01 false Do the same accountability and control procedures described above apply to Federal property? 900.58 Section 900.58 Indians BUREAU OF INDIAN AFFAIRS... Organization Management Systems Property Management System Standards § 900.58 Do the same accountability and...

  12. Effect of diamond blend on the gas-separation properties of composite membranes

    Science.gov (United States)

    Kryuchkova, S. V.; Kostina, Yu. V.; Yablokova, M. Yu.; Gasanova, L. G.; Kepman, A. V.

    2017-10-01

    The morphological structure and gas transport properties of polyimide- and polyamide-imidebased rigid-chain polymers containing a fine carbon filler (a diamond blend) are studied. Gas transport properties are measured, and the effect exerted on these properties by intermolecular interaction between the functional groups of polymer chains and the fine filler is analyzed.

  13. EFFECT OF SOIL PROPERTIES ON LEAD BIOAVAILABILITY AND TOXCITY TO EARTHWORMS

    Science.gov (United States)

    Soil properties are important factors modifying metal bioavailability to ecological receptors. Twenty-one soils with a wide range of soil properties were amended with a single concentration of Pb (2000 mg/kg) to determine the effects of soil properties on Pb bioavailability and ...

  14. Chloride ion addition for controlling shapes and properties of silver nanorods capped by polyvinyl alcohol synthesized using polyol method

    Energy Technology Data Exchange (ETDEWEB)

    Junaidi, E-mail: junaidi.1982@fmipa.unila.ac.id [Department of Physics, Universitas Gadjah Mada, Yogyakarta, 55281 (Indonesia); Department of Physics, Lampung University, Bandar Lampung (Indonesia); Yunus, Muhammad, E-mail: muhammad.yunus@mail.ugm.ac.id [Department of Physics, Universitas Gadjah Mada, Yogyakarta, 55281 (Indonesia); Triyana, Kuwat, E-mail: triyana@ugm.ac.id; Harsojo,, E-mail: harsojougm@ugm.ac.id; Suharyadi, Edi, E-mail: esuharyadi@ugm.ac.id [Department of Physics, Universitas Gadjah Mada, Yogyakarta, 55281 (Indonesia); Nanomaterials Research Group, Universitas Gadjah Mada, Yogyakarta, 55281 (Indonesia)

    2016-04-19

    We report our investigation on the effect of chloride ions on controlling the shapes and properties of silver nanorods (AgNRs) synthesized using a polyol method. In this study, we used polyvinyl alcohol (PVA) as a capping agent and sodium chloride (NaCl) as a salt precursor and performed at the oil bath temperature of 140°C. The chloride ions originating from the NaCl serve to control the growth of the silver nanorods. Furthermore, the synthesized silver nanorods were characterized using SEM and XRD. The results showed that besides being able to control the growth of AgCl atoms, the chloride ions were also able to control the growth of multi-twinned-particles into the single crystalline of silver nanorods by micrometer-length. At an appropriate concentration of NaCl, the diameter of silver nanorods decreased significantly compared to that of without chloride ion addition. This technique may be useful since a particular diameter of silver nanorods affects a particular application in the future.

  15. Chloride ion addition for controlling shapes and properties of silver nanorods capped by polyvinyl alcohol synthesized using polyol method

    International Nuclear Information System (INIS)

    Junaidi; Yunus, Muhammad; Triyana, Kuwat; Harsojo,; Suharyadi, Edi

    2016-01-01

    We report our investigation on the effect of chloride ions on controlling the shapes and properties of silver nanorods (AgNRs) synthesized using a polyol method. In this study, we used polyvinyl alcohol (PVA) as a capping agent and sodium chloride (NaCl) as a salt precursor and performed at the oil bath temperature of 140°C. The chloride ions originating from the NaCl serve to control the growth of the silver nanorods. Furthermore, the synthesized silver nanorods were characterized using SEM and XRD. The results showed that besides being able to control the growth of AgCl atoms, the chloride ions were also able to control the growth of multi-twinned-particles into the single crystalline of silver nanorods by micrometer-length. At an appropriate concentration of NaCl, the diameter of silver nanorods decreased significantly compared to that of without chloride ion addition. This technique may be useful since a particular diameter of silver nanorods affects a particular application in the future.

  16. Carbofuran biodegradation in brackish groundwater and its effect on the hydraulic properties of the porous medium

    Science.gov (United States)

    Amiaz, Yanai; Ronen, Zeev; Adar, Eilon; Weisbrod, Noam

    2015-04-01

    A chalk fractured aquitard beneath an industrial site is subjected to intense contamination due to percolation of contaminants from the different facilities operating at the site. In order to reduce further contamination, draining trenches were excavated and filled with coarse gravel (3-4 cm in diameter) forming a porous medium, to which the contaminated groundwater discharges from the fractures surrounding the trenches. This research is aimed at establishing a biodegrading process of high efficiency and performance within the draining trenches. The research includes both field and laboratory experiments. An experimental setup of five columns (50 cm length and 4.5 cm in diameter) was constructed under highly controlled conditions. Over the course of the experiments, the columns were filled with different particle sizes and placed in a temperature controlled chamber. Filtered groundwater (0.2 µm) from the site groundwater, enriched by a model contaminant carbofuran (CRF), was injected to the columns; as two of the columns were inoculated by CRF degrading microorganisms native in the site's groundwater, two columns were inoculated by CRF degrading bacteria from the external environment, and one column was used as a control. During the experiment, measurements were taken from different locations along each column. These include: (a) CRF concentration and (b) hydraulic pressure and solution viscosity (in order to obtain the changes in permeability). A tracer test using uranine was carried out in parallel, in order to obtain the changes in hydraulic parameters. Correlating CRF concentration variations to changes of hydraulic parameters enable the deduction due to the effect that biological activity (under different temperature regimes) has on the hydraulic properties of the porous medium and its effect on the process of contaminant groundwater bodies' remediation. Preliminary results suggest that although biodegradation occurs, microbial activity has minor effect on

  17. Preparation and hygrothermal properties of composite phase change humidity control materials

    International Nuclear Information System (INIS)

    Chen, Zhi; Qin, Menghao

    2016-01-01

    Highlights: • A new kind of phase change humidity control material (PCHCM) was prepared. • The PCHCM can moderate both the indoor temperature and humidity. • The silicon dioxide shell can improve the thermal properties of the composite. • The PCM microcapsules can improve the moisture buffer ability of the composite. • The CPCM/vesuvianite composite has a better hygrothermal performance than pure hygroscopic material. - Abstract: A novel phase change humidity control material (PCHCM) was prepared by using PCM microcapsules and different hygroscopic porous materials. The PCHCM composite can regulate the indoor hygrothermal environment by absorbing or releasing both heat and moisture. The PCM microcapsules were synthesized with methyl triethoxysilane by the sol–gel method. The vesuvianite, sepiolite and zeolite were used as hygroscopic materials. The scanning electron microscopy (SEM) was used to measure the morphology profiles of the microcapsules and PCHCM. The differential scanning calorimetry (DSC) and the thermal gravimetric analysis (TGA) were used to determine the thermal properties and thermal stability. Both the moisture transfer coefficient and moisture buffer value (MBV) of different PCHCMs were measured by the improved cup method. The DSC results showed that the SiO 2 shell can reduce the super-cooling degree of PCM. The super-cooling degrees of microcapsules and PCHCM are lower than that of the pure PCM. The onset temperature of thermal degradation of the microcapsules and PCHCMs is higher than that of pure PCM. Both the moisture transfer coefficient and MBV of PCHCMs are higher than that of the pure hygroscopic materials. The results indicated the PCHCMs have better thermal properties and moisture buffer ability.

  18. PEGylated lipid nanocapsules with improved drug encapsulation and controlled release properties.

    Science.gov (United States)

    Hervella, Pablo; Alonso-Sande, Maria; Ledo, Francisco; Lucero, Maria L; Alonso, Maria J; Garcia-Fuentes, Marcos

    2014-01-01

    Drugs with poor lipid and water solubility are some of the most challenging to formulate in nanocarriers, typically resulting in low encapsulation efficiencies and uncontrolled release profiles. PEGylated nanocapsules (PEG-NC) are known for their amenability to diverse modifications that allow the formation of domains with different physicochemical properties, an interesting feature to address a drug encapsulation problem. We explored this problem by encapsulating in PEG-NC the promising anticancer drug candidate F10320GD1, used herein as a model for compounds with such characteristics. The nanocarriers were prepared from Miglyol(®), lecithin and PEG-sterate through a solvent displacement technique. The resulting system was a homogeneous suspension of particles with size around 200 nm. F10320GD1 encapsulation was found to be very poor (<15%) if PEG-NC were prepared using water as continuous phase; but we were able to improve this value to 85% by fixing the pH of the continuous phase to 9. Interestingly, this modification also improved the controlled release properties and the chemical stability of the formulation during storage. These differences in pharmaceutical properties together with physicochemical data suggest that the pH of the continuous phase used for PEG-NC preparation can modify drug allocation, from the external shell towards the inner lipid core of the nanocapsules. Finally, we tested the bioactivity of the drug-loaded PEG-NC in several tumor cell lines, and also in endothelial cells. The results indicated that drug encapsulation led to an improvement on drug cytotoxicity in tumor cells, but not in non-tumor endothelial cells. Altogether, the data confirms that PEG-NC show adequate delivery properties for F10320GD1, and underlines its possible utility as an anticancer therapy.

  19. Controlled Synthesis of Hierarchically Assembled Porous ZnO Microspheres with Enhanced Gas-Sensing Properties

    Directory of Open Access Journals (Sweden)

    Shengsheng You

    2015-01-01

    Full Text Available The ZnO microspheres constructed by porous nanosheets were successfully synthesized by calcinating zinc hydroxide carbonate (ZHC microspheres obtained by a sample hydrothermal method. The samples were characterized in detail with scanning electron microscopy (SEM, transmission electron microscopy (TEM, X-ray diffraction (XRD, and thermogravimetric and differential scanning calorimetry (TG-DSC. The results indicated that the prepared ZnO microspheres were well crystalline with wurtzite hexagonal phase. The effects of reaction time, temperature, the amount of trisodium citrate, and urea on the morphology of ZnO microspheres were studied. The formation mechanism of porous ZnO microspheres was discussed. Furthermore, the gas-sensing properties for detection of organic gas of the prepared porous ZnO microspheres were investigated. The results indicated that the prepared porous ZnO microspheres exhibited high gas-sensing properties for detection of ethanol gas.

  20. High temperature superconductor bulk materials. Fundamentals - processing - properties control - application aspects

    International Nuclear Information System (INIS)

    Krabbes, G.; Fuchs, G.; Canders, W.R.; May, H.; Palka, R.

    2006-01-01

    This book presents all the features of bulk high temperature superconducting materials. Starting from physical and chemical fundamentals, the authors move on to portray methods and problems of materials processing, thoroughly working out the characteristic properties of bulk superconductors in contrast to long conductors and films. The authors provide a wide range of specific materials characteristics with respect to the latest developments and future applications guiding from fundamentals to practical engineering examples. This book contains the following chapters: 1. Fundamentals 2. Growth and melt processing of YBCO 3. Pinning-relevant defects in bulk YBCO 4. Properties of bulk YBCO 5. Trapped fields 6. Improved YBCO based bulk superconductors and functional elements 7. Alternative systems 8. Peak effect 9. Very high trapped fields in YBCO permanent magnets 10. Engineering aspects: Field distribution in bulk HTSC 11. Inherently stable superconducting magnetic bearings 12. Application of bulk HTSCs in electromagnetic energy converters 13. Applications in magnet technologies and power supplies