Absorption Capacity (absorption + capacity)

Distribution by Scientific Domains
Distribution within Chemistry

Kinds of Absorption Capacity

  • water absorption capacity


  • Selected Abstracts


    Energy absorption capacity; a new concept for stability analysis of nonlinear dynamic systems,

    ASIAN JOURNAL OF CONTROL, Issue 1 2009
    Ali Akbar Jamshidifar
    Abstract Stability is the main concern considered for every system. Generally the well-known Lyapunov and input-output stability methods are utilized for the stability analysis of nonlinear systems. These methods face serious difficulties as the size and complexity of the systems increases. In this paper a new approach is presented to overcome this problem by introducing a new concept "Energy Absorption Capacity" (EAC) for every component. The EAC of the system can be derived from its component EACs considering their interaction. It is shown that the stability of every individual component is assured if its EAC has a positive value. The proposed approach is less conservative compared to a Lyapunov-based approach. This is due to its reliance on EAC as the extreme value of energy function rather than the function itself. Some examples are given to support the proposed approach. Copyright © 2009 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society [source]


    Composition and functional properties of raw and electron beam-irradiated Mucuna pruriens seeds

    INTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 8 2008
    Rajeev Bhat
    Summary The proximate, nutritional and functional properties of raw and electron beam-irradiated (0,30 kGy) Mucuna seeds were investigated. Irradiation increased crude protein and crude carbohydrates significantly than crude lipid, crude fibre and energy. Raw seeds were rich in minerals and were not affected by irradiation except for magnesium and phosphorus. Amino acids of raw seeds were comparable to soyabean and FAO/WHO reference pattern and except for 30 kGy, no significant changes were seen in amino acid profile. Raw seeds were rich in unsaturated fatty acids and some of them decreased on irradiation, while linoleic acid steadily elevated (0,14.35 mg g,1 lipid). In vitro protein digestibility was dose dependent and significantly increased up to 15 kGy. Water and oil absorption capacities and foaming capacity significantly increased on irradiation, while protein solubility decreased (15 and 30 kGy) with an improvement of gelation property of seed flour. The cooking time of seeds significantly reduced on irradiation. [source]


    Chemical composition, functional properties and baking potential of African breadfruit kernel and wheat flour blends

    INTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 2 2004
    Peter I. Akubor
    Summary The chemical composition and functional properties of African breadfruit kernel flour (ABKF), wheat flour (WF) and their blends were determined. Cookies prepared from the blends were evaluated for their protein contents, physical and sensory characteristics. The flour blends had higher protein, fat and ash contents than WF. The level of these nutrients improved with increased amounts of ABKF in the blends. Foaming, water and oil absorption capacities of the flour blends increased, while the foam stability decreased with increased level of ABKF. The protein contents of the composite flour cookies were higher than that of the all WF cookie. There were no significant differences (P > 0.05) in the flavour of the composite flour cookies and that of all WF cookies. However, sensory scores differed significantly (P < 0.05) amongst them for colour, texture and overall acceptability. [source]


    Perovskite oxide absorbents for oxygen separation

    AICHE JOURNAL, Issue 12 2009
    Yufeng He
    Abstract The fixed-bed oxygen absorption processes of the series of Ba1,xSrxCo0.8Fe0.2O3,, oxides were studied by oxygen partial pressure swing absorption in the temperature range of 300,850°C. The results show that SrCo0.8Fe0.2O3,,, with the smallest A-site ion radius, has the largest oxygen absorption capacity (0.402 mmol/g) at 500°C. The oxygen absorption and desorption kinetics fit well with the pseudo-second-order kinetics model. Comparing the modeling absorption rate coefficient k2 with the desorption rate coefficient k2,, all the oxides studied had higher oxygen absorption rates than oxygen desorption ones. In addition, the combined results of X-ray diffraction analysis, O2 -TPD, room temperature iodometric titration, and thermogravimetric analysis explained the relationship between the oxygen absorption capacities and the average radii of the A-site ions for this series of Ba1,xSrxCo0.8Fe0.2O3,, in the temperature range of 300,600°C. © 2009 American Institute of Chemical Engineers AIChE J, 2009 [source]


    EFFECT OF VARIETAL DIFFERENCES AND POLISHING OF RICE ON QUALITY PARAMETERS OF IDLI

    JOURNAL OF SENSORY STUDIES, Issue 5 2005
    CHANDINI S. KUMAR
    ABSTRACT The effect of varietal differences and polishing of rice on quality parameters of "idli," an Indian fermented product, were studied. In addition, the functional properties of decorticated (whole and split) black gram (Phaseolus mungo Roxb.), were also determined. Two varieties of raw rice, "Jaya" and "Minilong," and one variety of parboiled rice "Ponni" with two degrees of polishing (high and low) were selected. Idlis were prepared following standard procedures. Variations were observed in water and fat absorption capacities of two black gram samples. Emulsification capacity ranged from 102 to 110 mL/100 g. Foam capacities at different pH range were similar, but foam stability differed as a function of time. The pH of the fermented batter was between 4.1 and 4.8. Rice with a lesser degree of polishing fermented better with higher batter volume and microbial count, lesser shear value and gave softer idlis. However, sensory analysis revealed that idlis prepared with low-polish rice scored significantly lower for appearance and color quality compared with products prepared with high-polish rice. Significant differences were observed in the quality of flavor of all products. It can be concluded that the quality characteristics of Idli were influenced by the variety of rice and the degree of polishing, but the two types of black gram used, whole and split, had no effect. [source]


    Collapse of Reinforced Concrete Column by Vehicle Impact

    COMPUTER-AIDED CIVIL AND INFRASTRUCTURE ENGINEERING, Issue 6 2008
    Hing-Ho Tsang
    The column slenderness ratio can be in the order of 6,9. Some of these buildings are right next to busy streets and hence continuously exposed to the potential hazard of a vehicle impacting on a column in an accident. In the early part of this study, the ultimate energy absorption capacity of a reinforced concrete column is compared to the kinetic energy embodied in the moving vehicle. The energy-absorption capacity is calculated from the force-displacement curve of the column as determined from a nonlinear static (push-over) analysis. The ultimate displacement of the column is defined at the point when the column fails to continue carrying the full gravitational loading. Results obtained from the nonlinear static analysis have been evaluated by computer simulations of the dynamic behavior of the column following the impact. Limitations in the static analysis procedure have been demonstrated. The effects of strain rate have been discussed and the sensitivity of the result to changes in the velocity function and stiffness of the impacting vehicle has also been studied. [source]


    Processing of urea-formaldehyde-based particleboard from hazelnut shell and improvement of its fire and water resistance

    FIRE AND MATERIALS, Issue 8 2009
    M. Gürü
    Abstract The purpose of this study was to manufacture urea-formaldehyde-based particleboard from hazelnut shell and eliminate its disadvantages such as flammability, water absorption, swelling thickness by using fly ash and phenol-formaldehyde. Synthesized urea-formaldehyde and grained hazelnut shells were blended at different ratios ranging from 0.8 to 3.2 hazelnut shell/urea-formaldehyde and dried at 70°C in an oven until constant weight was reached. In addition, other parameters affecting polymer composite particleboard from hazelnut shell and urea-formaldehyde were investigated to be the amount of fly ash, amount of phenol formaldehyde and the effects of these parameters on bending stress, limit oxygen index, water absorption capacity and swelling in the thickness. The optimization results showed that the maximum bending strength was 4.1N/mm2, at urea-formaldehyde ratio of 1.0, reaction temperature of 70°C, reaction time of 25,min, hazelnut shell/urea-formaldehyde resin of 2.4 and mean particle size of 0.1,mm. Although the limited oxygen index and smoke density of composite particleboard without fly ash has 22.3 and 1.62, with fly ash of 16% (w/w) according to the filler has 38.2 and 1.47, respectively. Water absorption and increase in the swelling thickness exponentially decreased with increasing phenol formaldehyde. Copyright © 2009 John Wiley & Sons, Ltd. [source]


    Recharge of aquifers by flood events in an arid region

    HYDROLOGICAL PROCESSES, Issue 4 2003
    Isabella Shentsis
    Abstract The process of aquifer recharge by flood events in an arid region was investigated as applied to the Hazeva Formation (the Karkom graben, the Wadi Paran watershed, Israel). The hydrological model was established as a complex system, with due regard for groundwater and transmission losses of surface runoff. It was based on a previously outlined hydrogeological model of the Karkom graben and a model of transmission losses in arid watercourses under conditions of data deficiency. Proceeding from calculation of groundwater balances, the contribution of surface runoff as a decisive balance component was confirmed. The main characteristics of aquifer regimes, such as changes in storage volume and groundwater level, as well as lateral flow, were all found to be dependent upon the net extraction rate, i.e. pumpage discounting replenishment by flood events. Analysis and physical interpretation of model parameters enabled assessment of the influence of groundwater extraction on aquifer recharge. This became apparent as increasing absorption capacity and recharge availability of the aquifer as a result of the groundwater abstraction. Copyright © 2002 John Wiley & Sons, Ltd. [source]


    Increasing transmission losses from flood events due to groundwater extraction

    HYDROLOGICAL PROCESSES, Issue 4 2003
    Isabella Shentsis
    Abstract This study continues the examination of the influence of groundwater exploitation upon the process of aquifer recharge by flood events. In the course of the developing an earlier hydrological model for the Hazeva Formation aquifer (the Wadi Paran watershed, southern Israel), it became apparent that groundwater extraction influenced absorption capacity of sub-aquifers and regulated the distribution of percolating surface water between units. The present study lends numerical proof regarding the influence of Hazeva aquifer exploitation upon the regime of runoff and enhancement of transmission losses from flood events in Wadi Paran, and, as a result, upon increased recharge to the aquifer. Copyright © 2002 John Wiley & Sons, Ltd. [source]


    Structure, lymphatic vascularization and lymphocyte migration in mucosa-associated lymphoid tissue

    IMMUNOLOGICAL REVIEWS, Issue 1 2003
    Giacomo Azzali
    Summary:, In this review, we consider the morphological aspects and topographical arrangement of gut-associated lymphoid tissue (GALT) (solitary and aggregate lymph nodules or Peyer's patches) and of vermiform appendix in the human child and in some mammals. The spatial arrangement of the vessels belonging to apparatus lymphaticus periphericus absorbens (ALPA) and of blood vessels within each lymphoid follicle as well as the ultrastructural characteristics of the lymphatic endothelium with high absorption capacity are considered. Particular attention is also paid to the morphological and biomolecular mechanisms inducing lymphocyte transendothelial migration to the bloodstream by means of lymphatic vessels as well as their passage from blood into lymphoid tissue through the high endothelial venules (HEVs). The preferential transendothelial passage of lymphocytes and polymorphonuclear neutrophils within ALPA vessels of the interfollicular area does not occur following the opening of intercellular contacts, but rather it occurs by means of ,intraendothelial channels'. In HEVs, on the contrary, the hypothesis is plausible that lymphocyte transendothelial migration into lymphoid tissue occurs through a channel-shaped endothelial invagination entirely independent of interendothelial contacts. The lymph of ALPA vessels of the single Peyer's patch is conveyed into precollector lymphatic vessels and into prelymph nodal collectors, totally independent of the ALPA vessels of the gut segments devoid of lymphoid tissue. The quantitative distribution of T lymphocytes in the lymph of mucosal ALPA vessels suggests a prevalent function of fluid uptake, whereas a reservoir and supply function is implicated for the vessels of interfollicular area. The precollector lymphatic vessels and prelymph nodal collectors are considered to be vessels with low absorption capacity, whose main function is lymph conduction and flow. [source]


    The hydrophilic, foaming and emulsifying properties of casein concentrates produced by various methods

    INTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 6 2006
    Janesca A. Roman
    Summary The hydrophilic and surfactant properties of casein concentrates made by different processes such as isoelectric precipitation and neutralization (commercial casein, CC) coagulation by rennet (casein clots, COC) and microfiltration/diafiltration (casein micelles, CM) were studied. Water absorption capacity (WAC), water solubility (WS) and water-holding capacity (WHC) were highest for CM and lowest for COC. Solubility was higher in water and in pH 5.5, 0.10 m NaCl solution for both CM and COC. Foaming capacity was better for CM than for CC at pH 4.0 and for CC at pH 6.0 and 8.0. Foam stability was low for both CM and CC at pH 4.0 but it was high for CM at pH 6.0 and 8.0 and for CC in the absence of salt. Emulsifying capacity was higher for CC at pH 4.0 and 7.0. Stability of emulsion was high for CC at pH 4.0 and for CM at pH 7.0. [source]


    The functional properties of popped, flaked, extruded and roller-dried foxtail millet (Setaria italica)

    INTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 9 2004
    Singh R. Ushakumari
    Summary Foxtail millet grains were decorticated in rice-milling machinery and the decorticated millet was processed to prepare flaked, extrusion cooked and roller-dried products, whereas the native grains were subjected to high-temperature, short-time treatment to prepare popped millet. The nutrient composition and some of the functional properties of the products were determined, principally solubility and swelling power in water, oil absorption capacity and pasting characteristics. Carbohydrate and lipid profiles of the products were also studied. The changes in the starch granular structure caused by heat treatment were examined by scanning electron microscopy. The degree of starch gelatinization was highest in the case of roller-dried millet followed by popped, flaked and extruded products. It was concluded that the cereal processing technologies that were investigated could be successfully applied to foxtail millet to prepare ready-to-eat or use products, thereby increasing its utilization as a food. [source]


    Metal ion-imprinted polymer microspheres derived from copper methacrylate for selective separation of heavy metal ions

    JOURNAL OF APPLIED POLYMER SCIENCE, Issue 1 2008
    Anh Hoang Dam
    Abstract Microbeads of metal ion-imprinted polymers (MIIPs) were prepared by a novel precipitation polymerization technique, in which copper methacrylate monomer and ethylene glycol dimethacrylate crosslinker were copolymerized in a rotary evaporator. The prepared microbeads had mono- or narrow size dispersity, and their sizes increased from 1 to 4 ,m with decreasing solvent amount or increasing initiator concentration. The absorption capacity and selectivity of the imprinted polymer for copper ion were determined in the presence of various competitive metal ions. As results, adsorption equilibrium was quickly achieved in about 10 min with high absorbability (about 90%). The effects of pH, initial metallic ion concentration, and MIIP bead size on the absorption capacity were investigated. The Cu(II)-imprinted polymers exhibited extremely high selectivity, which was much higher than that of corresponding blank polymers. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2008 [source]


    Silicone oil: An effective absorbent for the removal of hydrophobic volatile organic compounds

    JOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 3 2010
    Guillaume Darracq
    Abstract BACKGROUND: Hydrophobic volatile organic compounds (VOCs), such as toluene, dimethyl sulfide (DMS) and dimethyl disulfide (DMDS), are poorly soluble in water and classical air treatment processes like chemical scrubbers are not efficient. An alternative technique involving an absorption step in an organic solvent followed by a biodegradation phase was proposed. The solvent must fulfil several characteristics, which are key factors of process efficiency, and a previous study allowed polydimethylsiloxane (or PDMS, i.e. silicone oil) to be selected for this purpose. The aim of this paper was to determine some of its characteristics like absorption capacity and velocity performances (Henry's constant, diffusivity and mass transfer coefficient), and to verify its non-biodegradability. RESULTS: For the three targeted VOCs, Henry's constants in silicone oil were very low compared to those in water, and solubility was infinite. Diffusivity values were found to be in the range 10,10 to 10,11 m2 s,1 and mass transfer coefficients did not show significant differences between the values in pure water and pure silicone oil, in the range 1.0 × 10,3 to 4.0 × 10,3 s,1 for all the VOCs considered. Silicone oil was also found to be non-biodegradable, since its biological oxygen demand (BOD5) value was zero. CONCLUSION: Absorption performances of silicone oil towards toluene, DMS and DMDS were determined and showed that this solvent could be used during the first step of the process. Moreover, its low biodegradability and its absence of toxicity justify its use as an absorbent phase for the integrated process being considered. Copyright © 2010 Society of Chemical Industry [source]


    Effect of High Pressure Pasteurization on Bacterial Load and Bioactivity of Echinacea Purpurea

    JOURNAL OF FOOD SCIENCE, Issue 7 2010
    Xiu-Min Chen
    Abstract:, High hydrostatic pressure (HHP) technology was applied to organic Echinacea purpurea (E. purpurea) roots and flowers to determine the feasibility of using this technology for cold herb pasteurization, to produce microbiologically safe and shelf-stable products for the natural health products (NHPs) industry. HHP significantly (P < 0.01) reduced microbial contamination in both roots and flowers without affecting the phytochemical retention of chicoric and chlorogenic acids, and total alkamide contents. The antioxidant activity of E. purpurea methanol-derived extracts, evaluated in both chemical (2,2,-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) [ABTS] and oxygen radical absorption capacity [ORAC] assay) and in cell culture models (RAW264, 7 macrophage, H2O2 -induced intracellular oxidation, and lipopolysaccharide [LPS]-induced nitric oxide production), was not adversely affected by the application of HHP at both 2 and 5 min at 600 mPa. Furthermore, HHP did not affect the capacity of E. purpurea extracts to suppress nitric oxide production in LPS-activated macrophage cells. Therefore, our results show that HHP is an effective pasteurization process treatment to reduce microbial-contamination load while not adversely altering chemical and bioactive function of active constituents present in organic E. purpurea. Practical Application:, Our study reports for the first time, the effectiveness of using high hydrostatic pressure (HHP) technology pressure to pasteurize E. purpurea root and flower, and the comparative retention of bioactive phytochemicals. Therefore, this technique can be used in food and natural health product industries to produce high-quality, microbiologically safe, and shelf-stable products. [source]


    Functional Properties of Glycated Soy 11S Glycinin

    JOURNAL OF FOOD SCIENCE, Issue 4 2005
    Allaoua Achouri
    ABSTRACT: 11S-rich glycinin fraction was extracted from defatted soy flakes and glycated using glucose (at a 1:44 molar ratio of protein to sugar) through the Maillard reaction. The glycation was done at 50°C and 65% relative humidity for varying incubation periods (6, 16, 24, and 48 h). Fluorescamine and trinitrobenzenesulfonic acid (TNBS) methods both revealed a gradual increase in % glycation from 34.8% to 39.6%, 42.6%, and 46.5%, as samples were glycated from 6 to 48 h. Functional studies of the glycated 11S-rich glycinin fraction showed an initial increase in solubility during the early stages of glycation and a decrease as glycation progressed beyond 24 h. Glycation in the 1st hour of incubation also decreased protein surface hydrophobicity and fat absorption capacity (FAC). This was mainly attributed to an increase in the net negative charge induced by the introduction of the sugar moiety. As the Maillard reaction progressed (24 h and 48 h of incubation), an increase in FAC and surface hydrophobicity was observed. The results further showed an increase in foaming properties and emulsifying activity of the 11S-rich glycinin fraction with glycation (compared with control), especially at the early and middles stages of the Maillard reaction. [source]


    Characteristics of Tortillas Prepared from Dry Extruded Masa Flour Added with Maize Pericarp

    JOURNAL OF FOOD SCIENCE, Issue 4 2002
    V.G. Arámbula
    ABSTRACT Corn flour produced by extrusion was used to evaluate the effect of added maize pericarp (0 to 6%, w/w) on the following parameters: water absorption capacity of dry extruded masa flour (DEMF); weight loss during cooking and dehydration rate (DR) in fresh masa (FM), as well as rollability (R), puffing degree (PD), and cutting force (CF) of tortillas. CF was evaluated after 1 and 24 h of preparation. The viscoamylogram profiles, x-ray diffraction, and crystallinity of DEMF and powdered tortillas were also obtained. The DEMF with 3% (w/w) of pericarp produced the highest tortilla yield, improved the PD, DR, R, and CF characteristics of FM and tortillas, and developed the highest viscosity and a structure with adequate crystallinity to make tortillas with commercial quality. [source]


    Effects of simvastatin on hepatic cholesterol metabolism, bile lithogenicity and bile acid hydrophobicity in patients with gallstones

    JOURNAL OF GASTROENTEROLOGY AND HEPATOLOGY, Issue 8 2000
    Jeffery L Smith
    Abstract Background and Aims: There is limited information available on the effects of 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors on hepatic and biliary cholesterol metabolism in patients with gallstones. The aims of this study were to determine the effect of simvastatin on the regulatory elements of cholesterol metabolism that determine the concentrations of cholesterol in plasma and bile. Methods: Thirty-one gallstone patients were enrolled in the study; 17 were treated with 20 mg simvastatin daily for 3 weeks prior to cholecystectomy and 14 served as controls. Samples of blood, liver, gall-bladder bile and bile from the common bile duct (CBD) were collected and analysed. Results: The plasma cholesterol (,30%), triacylglycerol (,23%) and low-density lipoprotein (LDL) cholesterol (,42%) concentrations were significantly lowered by simvastatin treatment, as was the plasma lathosterol : cholesterol (,70%), which reflects whole-body cholesterol synthesis. Despite these changes, the hepatic LDL receptor protein and LDL receptor activity in circulating mononuclear cells were similar in both groups. There were no differences in the plasma phytosterol : cholesterol, which reflects the intestinal cholesterol absorption capacity or in the activity of hepatic acyl-coenzyme A : cholesterol acyltransferase. There were however, lower cholesterol concentrations in CBD (,68%) and gall bladder (,41%) bile, and decreased lithogenic (,47%) and bile acid hydrophobicity (,22%) indices of CBD bile in the simvastatin group. Conclusions: These data indicate that simvastatin reduced plasma and biliary cholesterol levels primarily by reducing cholesterol synthesis. The reduction in CBD bile lithogenicity and bile acid hydrophobicity by simvastatin suggests that this agent may be useful for people who have early stages of cholesterol gallstone development and in whom a choleretic effect is required. [source]


    Perovskite oxide absorbents for oxygen separation

    AICHE JOURNAL, Issue 12 2009
    Yufeng He
    Abstract The fixed-bed oxygen absorption processes of the series of Ba1,xSrxCo0.8Fe0.2O3,, oxides were studied by oxygen partial pressure swing absorption in the temperature range of 300,850°C. The results show that SrCo0.8Fe0.2O3,,, with the smallest A-site ion radius, has the largest oxygen absorption capacity (0.402 mmol/g) at 500°C. The oxygen absorption and desorption kinetics fit well with the pseudo-second-order kinetics model. Comparing the modeling absorption rate coefficient k2 with the desorption rate coefficient k2,, all the oxides studied had higher oxygen absorption rates than oxygen desorption ones. In addition, the combined results of X-ray diffraction analysis, O2 -TPD, room temperature iodometric titration, and thermogravimetric analysis explained the relationship between the oxygen absorption capacities and the average radii of the A-site ions for this series of Ba1,xSrxCo0.8Fe0.2O3,, in the temperature range of 300,600°C. © 2009 American Institute of Chemical Engineers AIChE J, 2009 [source]


    ROLE OF GLUTAMATE DEHYDROGENASE AND GLUTAMINE SYNTHETASE IN CHLORELLA VULGARIS DURING ASSIMILATION OF AMMONIUM WHEN JOINTLY IMMOBILIZED WITH THE MICROALGAE-GROWTH-PROMOTING BACTERIUM AZOSPIRILLUM BRASILENSE,

    JOURNAL OF PHYCOLOGY, Issue 5 2008
    Luz E. De-Bashan
    Enzymatic activities of glutamate dehydrogenase (GDH) and glutamine synthetase (GS) participating in the nitrogen metabolism and related ammonium absorption were assayed after the microalga Chlorella vulgaris Beij. was jointly immobilized with the microalgae-growth-promoting bacterium Azospirillum brasilense. At initial concentrations of 3, 6, and 10 mg · L,1 NH4+, joint immobilization enhances growth of C. vulgaris but does not affect ammonium absorption capacity of the microalga. However, at 8 mg · L,1 NH4+, joint immobilization enhanced ammonium absorption by the microalga without affecting the growth of the microalgal population. Correlations between absorption of ammonium per cell and per culture showed direct (negative and positive) linear correlations between these parameters and microalga populations at 3, 6, and 10 mg · L,1 NH4+, but not at 8 mg · L,1 NH4+, where the highest absorption of ammonium occurred. In all cultures, immobilized and jointly immobilized, having the four initial ammonium concentrations, enzymatic activities of Chlorella are affected by A. brasilense. Regardless of the initial concentration of ammonium, GS activity in C. vulgaris was always higher when jointly immobilized and determined on a per-cell basis. When jointly immobilized, only at an initial concentration of 8 mg · L,1 NH4+ was GDH activity per cell higher. [source]


    COMPARISON OF INSTRUMENTAL METHODS FOR MEASURING SEED HARDNESS OF FOOD-GRADE SOYBEAN

    JOURNAL OF TEXTURE STUDIES, Issue 1 2008
    BO ZHANG
    ABSTRACT Breeding specialty soybeans for the soyfood market requires proper methodology in evaluation of seed quality attributes. In this study, efficient methods that could be potentially used for testing soybean seed hardness were developed by examining different instruments and seed parameters. Five food-grade soybean genotypes with different seed sizes were used to determine seed water-absorption capacity and hardness. Water absorption capacity was expressed by swell ratios for seed weight, seed dimension, and volume of water changes before and after soaking. Seed hardness test was conducted by a one-bite method using a food texture analyzer equipped with five different probes. The results showed that hardness testing by a 75 mm cylinder with 10 steamed seeds, single blade with five steamed seeds, and shear cell with 30 g steamed seeds produced dependable and consistent results with low coefficient of variance. However, shear cell may not be practical for early plant selection in a breeding program due to a relatively large sample requirement. Seed size can be used as indirect selection indicators for seed hardness. PRACTICAL APPLICATIONS Seed hardness is an important factor in determining soybean suitability for natto production. This study used two texture analyzers equipped with five different probes to test hardness of five soybean genotypes with different seed size. The methodologies for testing the seed texture of soybean have been established, which can help regulate the seed hardness testing for commercial production and provide consistent hardness references for natto breeding programs and the seed industry. [source]


    Formation and Densification Behavior of MgAl2O4 Spinel: The Influence of Processing Parameters

    JOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 6 2008
    Ibram Ganesh
    Different types of dense stoichiometric and nonstoichiometric magnesium aluminate (MgAl2O4) spinel (MAS) ceramics were prepared following a conventional double-stage firing process using different commercially available alumina and magnesia raw materials. Stoichiometric, magnesia-rich, and alumina-rich spinels were sintered at 1500°,1800°C for 1,2.5 h. The influence of the different processing parameters (average particle size, degree of spinel phase, green density, mass of the powder compact, sintering temperature, holding time at the peak temperature, and starting composition) on the densification behavior of MAS was assessed by measuring the bulk density, apparent porosity, and water absorption capacity, and microstructural observations. Most of the MAS compositions tested exhibited excellent sintering properties. [source]


    Accumulation of Mycosporine-like Amino Acids in Asparagopsis armata Grown in Tanks with Fishpond Effluents of Gilthead Sea Bream, Sparus aurata

    JOURNAL OF THE WORLD AQUACULTURE SOCIETY, Issue 5 2008
    Félix L. Figueroa
    Both the effects of total ammonium nitrogen (TAN) fluxes and the algal densities on MAA accumulation were investigated. MAAs increased with the TAN flux, but only until values lower than 100 ,M/h. Above this flux, the MAA content decreased, whereas algal yield increased. The content of individual MAAs was related to nitrogen (N) status, that is, shinorine percentage slightly decreased and palythine increased with increasing N fluxes. The decrease of MAAs at high flux of N (up to 100 ,M/h) is related to the decrease of water residence time and the decrease of the biofiltration efficiency. Under different TAN fluxes and algal densities, MAA content was negatively related to algal yield indicating that MAAs were accumulated only under a high ammonium-N availability. Thus, an energy allocation between growth (primary metabolism) and MAA accumulation (secondary metabolism) is regulated by the absorption capacity of inorganic N. In conclusion, A. armata, in addition to its high biofiltration capacity of nutrients, is a good source of MAAs as potential UV screen photoprotectors. [source]


    Evaluation of the performance of iron-based oxygen scavengers, with comments on their optimal applications

    PACKAGING TECHNOLOGY AND SCIENCE, Issue 1 2005
    Joseph Miltz
    Abstract Oxygen scavengers are commonly used in packaged foods in Japan and much less so in other developed countries, in spite of the advantages that they offer in maintaining quality and extending shelf-life. The reason stems from the additional cost involved, and even more so because of the lack of sufficient technical information on their performance and the lack of understanding of how to apply them effectively. In the present study the performance of iron-based oxygen-scavenging sachets was evaluated. It was found that the actual scavenging capacity is much higher than the ,nominal' capacity provided by the manufacturers. Also, a significant distribution in the oxygen absorption capacity exists, even in the same scavenger type. The rate of oxygen scavenging was found to depend on the scavenger type and capacity. It was also found that in an atmosphere containing CO2 (as in MAP applications) the iron-based oxygen scavengers also absorb CO2. Copyright © 2004 John Wiley & Sons, Ltd. [source]


    Accumulated p53 protein and UVA protection level of sunscreens

    PHOTODERMATOLOGY, PHOTOIMMUNOLOGY & PHOTOMEDICINE, Issue 1 2000
    S. Seité
    Nuclear p53 expression is a sensitive parameter for the detection of ultraviolet (UV)-induced skin damage, and it has been used as an endpoint to evaluate the effectiveness of sunscreens. In this study, we compared the protection provided by two sunscreens having identical sun protection factors (SPF) but different UVA protection factors (UVA-PF) measured by the persistent pigment darkening method (PPD). The SPF of the sunscreens was 7 and the UVA-PF were respectively 7 and 3. Nuclear p53 protein was quantified in human skin biopsies treated with sunscreens and exposed 8 times to 5 MED of solar simulated radiation (SSR). The results showed that both sunscreens offered only partial protection against the increased expression of nuclear p53 protein induced by repetitive SSR exposures. However, a significantly lower level of p53-positive cells was found in areas protected with the sunscreen having the higher UVA-PF compared to the other sunscreen protected areas. In order to verify whether the difference in efficacy of these products was due to the difference in UVA absorption capacity, we quantified epidermal p53 protein accumulation after 8 exposures to either UVA (320,400 nm) or UVA1 (340,400 nm). We showed that as with SSR, repetitive exposures to 12.5 and 25 J/cm2 of UVA or UVA1 induced a significant increase in p53-positive cells in the human epidermis. These results confirmed that SPF determined on the basis of an acute erythemal reaction does not predict the level of protection against cumulative damage. They also showed that the protection provided by two sunscreens with different UVA protection factors is different (based on nuclear p53 protein accumulation), and that the PPD method can distinguish varying levels of sunscreen efficacy against UVA-induced cell damage. [source]


    Differences in the structure, growth and survival of Parasenecio yatabei ramets with contrasting water relations on the slope of a stream bank

    PLANT SPECIES BIOLOGY, Issue 2 2009
    HAJIME TOMIMATSU
    Abstract Parasenecio yatabei (Asteraceae), a summer-green perennial herb, is widely distributed on sloping mountain stream banks in cool-temperate zone forests of Japan. We investigated the growth pattern, leaf longevity and leaf water relations of vegetatively independent plants (ramets) growing in two contrasting soil water conditions, that is, upper and lower stream banks (U ramets and L ramets, respectively). The objective of the present study was to clarify the physiological and morphological responses of the ramets to soil water conditions. Dry matter allocation to subterranean parts was higher in U ramets than in L ramets. The U ramet leaves survived for approximately 2 months longer than L ramet leaves. The ratio of subterranean part to aerial part dry matter was greater in U ramets than L ramets. Leaf mass per leaf area (LMA) tended to be greater in U ramets than L ramets throughout the growing season. The leaf bulk modulus of elasticity at full hydration was significantly higher in U ramets. Thus, ramet growth patterns and morphological traits varied with changing soil water conditions. The greater longevity of U ramet leaves may play a role in compensating for the reduced annual net carbon gain caused by lower photosynthetic activity. U ramets growing in environments with less water availability achieved high water-use efficiency by a high passive water absorption capacity via a progressed root system and high productivity via longer leaf longevity with higher LMA and elasticity. Therefore, P. yatabei growing along mountain streams could have the ability to colonize the upper bank through higher survivorship based on these traits. [source]


    Modified suspension-PVC particles as absorbents of ortho -dichlorobenzene from water

    POLYMERS FOR ADVANCED TECHNOLOGIES, Issue 2 2003
    M. Shach-Caplan
    Abstract Modified porous PVC particles are studied as absorbents of o-dichlorobenzene (DCB), from water. The modified particles were produced by an in-situ stabilizer-free polymerization/crosslinking of a monomer/crosslinker/peroxide solution absorbed within commercial porous suspension-type PVC particles. The modifying monomers used include styrene with divinyl benzene (DVB) as a crosslinking comonomer, methyl methacrylate (MMA), butyl acrylate (BA), or ethylhexyl acrylate (EHA) with ethylene glycol dimethacrylate (EGDMA) as a crosslinking comonomer. The effect of the nature of the monomers, morphology, porosity, surface area and composition of the modified PVC particles on DCB absorption was studied. Batch experiments (absorption rate and isotherms) were used to screen the PVC absorbents on the basis of absorption rate and absorption capacity. Continuous absorption column experiments were conducted to study the parameters characterizing the absorption process. Both the unmodified and modified PVC particles absorb DCB from water. The PBA and PEHA-modified PVC particles approach equilibrium capacity faster and have greater absorption capacity than neat PVC, PS-modified PVC and PMMA-modified PVC particles. The absorption characteristics are influenced by the modifying polymer's Tg. The rubbery nature of PBA and PEHA yields better absorption in spite of the significantly lower surface area and porosity obtained in the modified PVC particles. Thus, indicating that fast adsorption followed by bulk absorption of DCB is taking place. A clear influence of the crosslinking effect was not established. The continuous absorption experiments were found more efficient than the batch absorption experiments. Copyright © 2003 John Wiley & Sons, Ltd. [source]


    Performance of four carbon dioxide absorbents in experimental and clinical settings

    ANAESTHESIA, Issue 3 2009
    M. Yamakage
    Summary To evaluate the performance of four kinds of carbon dioxide (CO2) absorbents (Medisorb® GE Healthcare, Amsorb® Plus Armstrong Medical, YabashiLime® Yabashi Industries, and Sodasorb® LF Grace Performance Chemicals), we measured their dust production, acceptability of colour indicator, and CO2 absorption capacity in in vitro experimental settings and the concentration of compound A in an inspired anaesthetic circuit during in vivo clinical practice. In vitro, the order of the dust amount was Sodasorb LF > Medisorb > Amsorb Plus = YabashiLime both before and after shaking. The order of the color acceptability was similar: Sodasorb LF > Amsorb Plus = Medisorb > YabashiLime both initially and 16 h after CO2 exhaustion. During exposure to 200 ml.min,1 CO2 in vitro, the period until 1 kg of fresh soda lime allowed inspired CO2 to increase to 0.7 kPa (as a mark of utilisation of the absorbent) was longer with Medisorb (1978 min) than with the other absorbents (1270,1375 min). In vivo, compound A (1.0% inspired sevoflurane) was detected only when using Medisorb. While Medisorb has the best ability to absorb CO2, it alone produces compound A. [source]


    Energy absorption capacity; a new concept for stability analysis of nonlinear dynamic systems,

    ASIAN JOURNAL OF CONTROL, Issue 1 2009
    Ali Akbar Jamshidifar
    Abstract Stability is the main concern considered for every system. Generally the well-known Lyapunov and input-output stability methods are utilized for the stability analysis of nonlinear systems. These methods face serious difficulties as the size and complexity of the systems increases. In this paper a new approach is presented to overcome this problem by introducing a new concept "Energy Absorption Capacity" (EAC) for every component. The EAC of the system can be derived from its component EACs considering their interaction. It is shown that the stability of every individual component is assured if its EAC has a positive value. The proposed approach is less conservative compared to a Lyapunov-based approach. This is due to its reliance on EAC as the extreme value of energy function rather than the function itself. Some examples are given to support the proposed approach. Copyright © 2009 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society [source]