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Size Reduction (size + reduction)
Kinds of Size Reduction Selected AbstractsEffect of Grain Size Reduction and Geometrical Confinement in Fine Grained Copper: Potential Applications as a Material for Reversible Electrical Contacts,ADVANCED ENGINEERING MATERIALS, Issue 8 2010Yannick Champion The potential of ultrafine grained copper as a material for reversible electrical contact is investigated. The influence of grain size and sample size on strength and electrical properties is discussed. The existence of an optimal grain size and the relevance of size effects for the mechanical properties are analyzed. [source] Emergence of New Mechanical Functionality in Materials via Size ReductionADVANCED FUNCTIONAL MATERIALS, Issue 18 2009Julia R. Greer Abstract Julia R. Greer received her S.B. in Chemical Engineering from the Massachusetts Institute of Technology (1997) and a Ph.D. in Materials Science from Stanford University, where she worked on the nanoscale plasticity of gold with W. D. Nix (2005). She also worked at Intel Corporation in Mask Operations (2000,03) and was a post-doctoral fellow at the Palo Alto Research Center (2005,07), where she worked on organic flexible electronics with R. A. Street. Greer is a recipient of TR-35, Technology Review's Top Young Innovator award (2008), a NSF CAREER Award (2007), a Gold Materials Research Society Graduate Student Award (2004), and an American Association of University Women Fellowship (2003). Julia joined Caltech's Materials Science department in 2007 where she is developing innovative experimental techniques to assess mechanical properties of nanometer-sized materials. One such approach involves the fabrication of nanopillars with different initial microstructures and diameters between 25,nm and 1,µm by using focused ion beam and electron-beam lithography microfabrication. The mechanical response of these pillars is subsequently measured in a custom-built in situ mechanical deformation instrument, SEMentor, comprising a scanning electron microscope and a nanoindenter. Read our interview with Prof. Greer on MaterialsViews.com [source] Atrial Size Reduction as a Predictor of the Success of Radiofrequency Maze Procedure for Chronic Atrial Fibrillation in Patients Undergoing Concomitant Valvular SurgeryJOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 8 2001MIEN-CHENG CHEN M.D. Radiofrequency Maze Procedure and Atrial Size.Introduction: Previous studies showed that the surgical maze procedure can restore sinus rhythm and atrial transport function in patients with chronic atrial fibrillation (AF). However, no previous studies discussed the association of atrial size reduction and the success of sinus conversion by the radiofrequency (RF) maze procedure for chronic AF. Methods and Results: A total of 119 chronic AF patients undergoing valvular operations were included in this study. Sixty-one patients received RF and cryoablation to create lesions in both atria to simulate the surgical maze II or III procedure (RF maze II or RF maze III; 13 patients, group 1) or a modified maze pattern (RF maze "IV"; 48 patients, group 2). The other 58 patients who underwent valvular operations alone without the maze procedure served as control (group 3). At 3-month follow-up after operation, sinus rhythm was restored in 73%, 81%, and 11% of patients in groups 1, 2 and 3, respectively. Preoperative left and right atrial sizes were not statistically significant predictors of sinus conversion by the RF maze procedure. However, as a result of postoperative reduction of atrial sizes, postoperative left atrial diameter was significantly smaller in patients who had sinus conversion by the RF maze procedure than in patients who did not regain sinus rhythm (45.0 ± 7.0 mm vs 51.0 ± 8.0 mm; P = 0.03). Postoperative right atrial area of patients who had sinus conversion by the RF maze procedure also was significantly smaller than that of patients who did not regain sinus rhythm (18.1 ± 4.4 cm2 vs 28.5 ± 8.2 cm2; P = 0.008). Conclusion: Atrial size reduction appears to predict the success of sinus conversion with the RF maze procedure used in conjunction with valvular surgery. [source] The Effect of Protein Particle Size Reduction on the Physical Properties of CO2 -Precipitated Casein FilmsJOURNAL OF FOOD SCIENCE, Issue 4 2006Kirsten L. Dangaran ABSTRACT:, Casein precipitated with high pressure-CO2 (CO2CAS) has unique properties compared to commercial acid-precipitated casein. CO2CAS is less water-soluble and films made from it are less susceptible to high humidity environments; however, the films are also opaque and hazy. The appearance of CO2CAS films is important especially if applied as a food coating. To improve the appearance properties, the particle size of CO2CAS film plasticized with glycerol was reduced. The effect of protein particle size reduction on tensile properties, water vapor permeability (WVP), and gloss was studied using ASTM methodology. As particle size of the CO2CAS was reduced from 126 ,m to 111 ,m, tensile strength and modulus of the films increased, while WVP decreased. With the same particle reduction, gloss increased from 55.3 gloss units on average to 73 gloss units, but films were still hazy. With a particle size less than 86 ,m, CO2CAS films were glossy and transparent, however, tensile strength decreased and WVP increased. Depending on desired application, the properties of CO2CAS films can be optimized by changing particle size. [source] Density-Induced Plant Size Reduction and Size Inequalities in Ethylene-Sensing and Ethylene-Insensitive TobaccoPLANT BIOLOGY, Issue 2 2004R. Pierik Abstract: Plant competition for light is a commonly occurring phenomenon in natural and agricultural vegetations. It is typically size-asymmetric, meaning that slightly larger individuals receive a disproportionate share of the light, leaving a limited amount of light for the initially smaller individuals. As a result, size inequalities of such stands increase with competition intensity. A plant's ability to respond morphologically to the presence of neighbour plants with enhanced shoot elongation, the so-called shade avoidance response, acts against the development of size inequalities. This has been shown experimentally with transgenic plants that cannot sense neighbours and, therefore, show no shade avoidance responses. Stands of such transgenic plants showed a much stronger development of size inequalities at high plant densities than did wild type (WT) stands. However, the transgenic plants used in these experiments displayed severely hampered growth rates and virtually no response to neighbours. In order to more precisely study the impact of this phenotypic plasticity on size inequality development, experiments required plants that have normal growth rates and reduced, but not absent, shade avoidance responses. We made use of an ethylene-insensitive, transgenic tobacco genotype (Tetr) that has wild type growth rates and moderately reduced shade avoidance responses to neighbours. Here, we show that the development of size inequalities in monocultures of these plants is not affected unambiguously different from wild type monocultures. Plots of Tetr plants developed higher inequalities for stem length than did WT, but monocultures of the two genotypes had identical CV (Coefficient of Variance) values for shoot biomass that increased with plant density. Therefore, even though reduced shade avoidance capacities led to the expected higher size inequalities for stem length, this does not necessarily lead to increased size inequalities for shoot biomass. [source] The effect of an enzymatic pretreatment on the hydrolysis and size reduction of fat particles in slaughterhouse wastewaterJOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 6 2001L Masse Abstract The effect of an enzymatic pretreatment, Pancreatic Lipase 250 (PL-250), on the hydrolysis and size reduction of fat particles in slaughterhouse wastewater was characterised for enzyme doses ranging from 125 to 1000,mg,dm,3 and initial particle sizes (Din) varying between 53 and 383,µm. Treatment with PL-250 significantly reduced the size of pork fat particles in slaughterhouse wastewater. Particle size reduction increased with Din, possibly due to the more filamentous and plate-like configuration of the larger fat particles, which could be easily broken at weak points. The smaller particles were observed to be denser and more spherical. Size reduction also increased with enzyme concentration, but the benefit of adding more enzyme diminished greatly as enzyme dose was increased. The maximum long-chain fatty acid (LCFA) concentration in filtered samples was detected after 4,7,h of treatment and ranged from 8.2 to 34.9,mg,dm,3. The linear rate of LCFA released in solution during enzymatic pretreatment ranged from 39.4 to 169.9,mg,dm,3 d,1, and increased with enzyme concentration up to 500,mg,dm,3. At a PL-250 concentration of 1000,mg,dm,3, the LCFA release rate decreased, maybe due to excessive layering of adsorbed enzyme on the fat particles or increased degradation of released LCFAs. The pretreatment appeared to be more efficient with beef than pork fat particles. However, the effect of an enzymatic pretreatment on a downstream anaerobic treatment of slaughterhouse wastewater containing fat particles remains to be tested. © 2001 Society of Chemical Industry [source] Size reduction of microwave and millimeter-wave passive circuits by UC-PBG in standard 0.18-,m CMOS technologyMICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 9 2008Shuiyang Lin Abstract Size reduction of microwave and millimeter-wave (mm-wave) passive circuits incorporating a defective uniplanar compact photonic bandgap (UC-PBG) slow-wave structure is investigated. Benefited from the multilayer mental technology of the standard 0.18-,m CMOS process, thin film microstrip structure is properly constructed on the lossy silicon substrate to reduce substrate loss. Defected periodic patterns on the ground plane are used to contribute to an enhancement of the effective dielectric constant and the slow-wave factor is 14% increased by the use of UC-PBG ground. Microwave and mm-wave passive circuits including resonator and filter are designed and fabricated. Measured results show that the use of UC-PBG ground has induced a frequency drop of 14% and validate the size reduction concept by using UC-PBG. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 2251,2254, 2008; Published online in Wiley InterScience (www.interscience.wiley.com).DOI 10.1002/mop.23643 [source] Size reduction and harmonic suppression of microstrip branch-line coupler using defected ground structureMICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 10 2006Santanu Dwari Abstract A new method, with branches having an equivalent series inductance using defected ground structure, is proposed for size reduction and harmonic suppression of branch-line coupler. The proposed structure is 35% of the conventional branch-line coupler at 1 GHz and the measured third harmonic signal is less than ,30 dB. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 1966,1969, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21830 [source] Size reduction of donor organs in pediatric lung transplantationPEDIATRIC TRANSPLANTATION, Issue 3 2010Carsten Mueller Mueller C, Hansen G, Ballmann M, Schwerk N, Simon AR, Goerler H, Strueber M. Size reduction of donor organs in pediatric lung transplantation. Pediatr Transplantation 2010:14: 364,368. © 2009 John Wiley & Sons A/S. Abstract:, Lobar transplantation and peripheral segmental resection allow downsizing of larger lungs for use in smaller recipients, particularly with regard to pediatric patients on the high urgency waiting list. We studied the safety and outcome of these techniques in children. All pediatric patients who underwent reduced size LTx between January 2000 and March 2009 were retrospectively reviewed and compared with pediatric patients who underwent full size LTx during the same period. Patient characteristics, intra-operative variables, and post-operative morbidity and mortality were compared. Among 28 primary LTxs, 16 (57%) were performed in reduced size technique. Preoperatively, there was a trend toward a higher rate of mechanical ventilation and a higher capillary pCO2 in the reduced size group. Surgical procedures tended to be longer in that group. Post-operative complications, survival and functional parameters were comparable between both groups. Our study demonstrates that reduced size LTx in children is a reliable therapeutic option that provides results comparable to full size LTx. This technique might help to reduce waiting list mortality by expanding the donor pool in pediatric LTx. [source] Further evidence that post-traumatic stress disorder but not dissociative disorders are related to amygdala and hippocampal size reduction in trauma-exposed individualsACTA PSYCHIATRICA SCANDINAVICA, Issue 4 2009E. Irle No abstract is available for this article. [source] Application feasibility of permittivity graded FGM (functionally graded materials) for gas-insulated equipmentELECTRICAL ENGINEERING IN JAPAN, Issue 2 2008Hideki Shumiya Abstract For the size reduction of electric power equipment, the electric field stress around solid insulators is to be carefully designed. This concern will be solved by the application of FGM (Functionally Graded Materials). In this paper, we investigated an application feasibility of FGM from numerical simulation, and the fabrication technique for gas insulated equipment. Finally, we could confirm the significant effect of FGM application for gas insulated equipment. © 2007 Wiley Periodicals, Inc. Electr Eng Jpn, 162(2): 39,45, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.20363 [source] Brood size reduction in Nicrophorus vespilloides after usurpation of carrion from Nicrophorus quadripunctatus (Coleoptera: Silphidae)ENTOMOLOGICAL SCIENCE, Issue 3 2004Seizi SUZUKI Abstract Burying beetles bury small vertebrate carcasses, which become food for their larvae. They sometimes usurp carcasses occupied and buried by other beetles. Brood sizes of intraspecific and interspecific intruders were examined using Nicrophorus quadripunctatus as the resident. The brood sizes of usurpers were not reduced relative to control brood sizes when the usurper was conspecific, but were reduced when the usurper was heterospecific (N. vespilloides). [source] The mitochondrial genome of the wine yeast Hanseniaspora uvarum: a unique genome organization among yeast/fungal counterpartsFEMS YEAST RESEARCH, Issue 1 2006Paraskevi V. Pramateftaki Abstract The complete sequence of the apiculate wine yeast Hanseniaspora uvarum mtDNA has been determined and analysed. It is an extremely compact linear molecule containing the shortest functional region ever found in fungi (11 094 bp long), flanked by Type 2 telomeric inverted repeats. The latter contained a 2704-bp-long subterminal region and tandem repeats of 839-bp units. In consequence, a population of mtDNA molecules that differed at the number of their telomeric reiterations was detected. The functional region of the mitochondrial genome coded for 32 genes, which included seven subunits of respiratory complexes and ATP synthase (the genes encoding for NADH oxidoreductase subunits were absent), two rRNAs and 23 tRNA genes which recognized codons for all amino acids. A single intron interrupted the cytochrome oxidase subunit 1 gene. A number of reasons contributed towards its strikingly small size, namely: (1) the remarkable size reduction (by >40%) of the rns and rnl genes; (2) that most tRNA genes and five of the seven protein-coding genes were the shortest among known yeast homologs; and (3) that the noncoding regions were restricted to 5.1% of the genome. In addition, the genome showed multiple changes in the orientation of transcription and the gene order differed drastically from other yeasts. When all protein coding gene sequences were considered as one unit and were compared with the corresponding molecules from all other complete mtDNAs of yeasts, the phylogenetic trees constructed robustly supported its placement basal to the yeast species of the ,Saccharomyces complex', demonstrating the advantage of this approach over single-gene or multigene approaches of unlinked genes. [source] Impact of a tick size reduction on liquidity: evidence from the Sydney Futures ExchangeACCOUNTING & FINANCE, Issue 1 2009Kiril Alampieski G12 Abstract This paper examines the impact of a reduction in the minimum price increment on liquidity and execution costs in a futures market setting. In 2006, the Sydney Futures Exchange halved the minimum tick in the 3 Year Commonwealth Treasury Bond Futures. Results indicate that bid-ask spreads are significantly reduced after the change. Quoted depth, both at the best quotes and visible in the limit order book, is significantly lower after the tick reduction. Further analysis reveals that execution costs are significantly reduced after the change. We conclude that a tick size reduction improves liquidity and reduces execution costs in a futures market setting. [source] Body condition, growth rates and diet of Skylark Alauda arvensis nestlings on lowland farmlandIBIS, Issue 3 2001PAUL F. DONALD Factors affecting the diet, body condition and growth rates of Skylark chicks were assessed to examine their relationship to their agricultural environment during a critical period in the life cycle of this rapidly declining species. Rainfall explained the greatest amount of variation in body condition and growth rates and had a negative effect on both. Body condition indices were a good predictor of the likelihood of future partial brood loss to starvation. Low body condition in grass fields was related to a low diversity in the diet. Chicks fed insect larvae had higher body condition indices than those not fed larvae. Larger broods tended to have higher growth rates than smaller ones, whereas smaller broods tended to have higher body condition indices. Natural brood size reduction through the non-hatching of eggs resulted in higher body condition indices than were found in nests with the same number of chicks where all eggs hatched, this effect being independent of absolute brood size. There was no significant difference between crop types in the distance adult birds flew to forage for food for nestlings and foraging crop destination had no effect on chick development. Differences between crop types in chick diet could be related to the documented effects of pesticides on different prey species. We suggest that recent agricultural changes have affected diet and possibly body condition, but that these effects are unlikely to have been an important factor in recent population declines. [source] Evolution of M1 crown size and cusp proportions in the genus HomoJOURNAL OF ANATOMY, Issue 5 2009Rolf Quam Abstract Previous research into tooth crown dimensions and cusp proportions has proved to be a useful way to identify taxonomic differences in Pliocene and Pleistocene fossil hominins. The present study has identified changes in both M1 crown size and cusp proportions within the genus Homo, with M1 overall crown size reduction apparently occurring in two main stages. The first stage (a reduction of ca. 17%) is associated with the emergence of Homo ergaster and Homo erectus sensu stricto. The second stage (a reduction of ca. 10%) occurs in Homo sapiens, but the reduced modern human M1 tooth crown size was only attained in Upper Paleolithic times. The absolute sizes of the individual cusps are highly positively correlated with overall crown size and dental reduction produces a reduction in the absolute size of each of the cusps. Most of the individual cusps scale isometrically with crown size, but the paracone shows a negative allometric relationship, indicating that the reduction in paracone size is less than in the other M1 cusps. Thus, the phylogenetically oldest cusp in the upper molars also seems to be the most stable cusp (at least in the M1). The most striking change in M1 cusp proportions is a change in the relative size of the areas of the paracone and metacone. The combination of a small relative paracone and a large relative metacone generally characterizes specimens attributed to early Homo, and the presence of this character state in Australopithecus and Paranthropus suggests it may represent the primitive condition for the later part of the hominin clade. In contrast, nearly all later Homo taxa, with the exception of Homo antecessor, show the opposite condition (i.e. a relatively large paracone and a relatively small metacone). This change in the relationship between the relative sizes of the paracone and metacone is related to an isometric reduction of the absolute size of the metacone. This metacone reduction occurs in the context of relative stability in the paracone as crown size decreases. Among later Homo taxa, both Homo heidelbergensis and Homo neanderthalensis show a further reduction of the metacone and an enlargement of the hypocone. Fossil and contemporary H. sapiens samples show a trend toward increasing the relative size of the protocone and decreasing the relative size of the hypocone. In Europe, modern human M1 cusp proportions are essentially reached during the Upper Paleolithic. Although some variation was documented among the fossil taxa, we suggest that the relative size of the M1 paracone and metacone areas may be useful for differentiating the earliest members of our genus from subsequent Homo species. [source] Mixing immiscible blends in an intermeshing counter-rotating twin screw extruderADVANCES IN POLYMER TECHNOLOGY, Issue 2 2006Ramesh Potluri Abstract Domain size of 10% dispersed polystyrene in polyethylene was followed in a 34-mm intermeshing counter-rotating twin screw extruder. Variables studied included the effects of barrel temperature, screw speed, viscosity ratio of dispersed-to-continuous phase, and parallel melt versus preblended solids feeds. After steady state was achieved, die samples were quenched for later photomicrographing. The extruder was then stopped and quenched, with subsequent pulling of the screws. From 7 to 12 additional samples were taken along the 18/1 L/D extruder for determination of the mechanism of dispersion and dispersed phase domain size by optical microscopy. At low temperatures, the polystyrene tended to fracture with sharp edges. The fine particles formed in the initial breakup underwent no further size reduction. At higher temperatures, fractured segments had rounder edges, but the size of the small domains remained constant throughout the axial length. There was some evidence of flocculation and coalescence prior to exit through the die. © 2006 Wiley Periodicals, Inc. Adv Polym Techn 25: 81,89, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/adv.20065 [source] Crystal structure of cobalt-substituted calcium hydroxyapatite nanopowders prepared by hydrothermal processingJOURNAL OF APPLIED CRYSTALLOGRAPHY, Issue 2 2010Ljiljana Veselinovi A series of cobalt-exchanged hydroxyapatite (CoHAp) powders with different Ca/Co ratios and nominal unit-cell contents Ca10,xCox(PO4)6(OH)2, x = 0, 0.5, 1.0, 1.5 and 2.0, were synthesized by hydrothermal treatment of a precipitate at 473,K for 8,h. Based on ICP (inductively coupled plasma) emission spectroscopy analysis, it was established that the maximum amount of cobalt incorporation saturated at ,12,at.% under these conditions. The effects of cobalt content on the CoHAp powders were investigated using ICP emission spectroscopy, particle size analysis, transmission electron microscopy (TEM) and high-resolution transmission electron microscopy (HRTEM) analyses as well as X-ray powder diffraction (XRPD) including Rietveld analysis. According to XRPD, all the materials are single-phase HAp and CoHAp of low crystallinity. Rietveld analysis shows that Co enrichment causes the c cell parameter to decrease at a faster rate than the a cell parameter. A microstructural analysis showed anisotropic X-ray line broadening due to crystallite size reduction. In CoHAp there is significant crystal elongation in [001], and the average size decreases with increasing cobalt content. The crystallite morphology transforms from rod-like for the pure HAp to lamellae at the highest degree of Co substitution. The results of Rietveld refinement (symmetry, size and morphology of the crystallites) were confirmed by TEM and HRTEM analysis. [source] Atrial Size Reduction as a Predictor of the Success of Radiofrequency Maze Procedure for Chronic Atrial Fibrillation in Patients Undergoing Concomitant Valvular SurgeryJOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 8 2001MIEN-CHENG CHEN M.D. Radiofrequency Maze Procedure and Atrial Size.Introduction: Previous studies showed that the surgical maze procedure can restore sinus rhythm and atrial transport function in patients with chronic atrial fibrillation (AF). However, no previous studies discussed the association of atrial size reduction and the success of sinus conversion by the radiofrequency (RF) maze procedure for chronic AF. Methods and Results: A total of 119 chronic AF patients undergoing valvular operations were included in this study. Sixty-one patients received RF and cryoablation to create lesions in both atria to simulate the surgical maze II or III procedure (RF maze II or RF maze III; 13 patients, group 1) or a modified maze pattern (RF maze "IV"; 48 patients, group 2). The other 58 patients who underwent valvular operations alone without the maze procedure served as control (group 3). At 3-month follow-up after operation, sinus rhythm was restored in 73%, 81%, and 11% of patients in groups 1, 2 and 3, respectively. Preoperative left and right atrial sizes were not statistically significant predictors of sinus conversion by the RF maze procedure. However, as a result of postoperative reduction of atrial sizes, postoperative left atrial diameter was significantly smaller in patients who had sinus conversion by the RF maze procedure than in patients who did not regain sinus rhythm (45.0 ± 7.0 mm vs 51.0 ± 8.0 mm; P = 0.03). Postoperative right atrial area of patients who had sinus conversion by the RF maze procedure also was significantly smaller than that of patients who did not regain sinus rhythm (18.1 ± 4.4 cm2 vs 28.5 ± 8.2 cm2; P = 0.008). Conclusion: Atrial size reduction appears to predict the success of sinus conversion with the RF maze procedure used in conjunction with valvular surgery. [source] The effect of an enzymatic pretreatment on the hydrolysis and size reduction of fat particles in slaughterhouse wastewaterJOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 6 2001L Masse Abstract The effect of an enzymatic pretreatment, Pancreatic Lipase 250 (PL-250), on the hydrolysis and size reduction of fat particles in slaughterhouse wastewater was characterised for enzyme doses ranging from 125 to 1000,mg,dm,3 and initial particle sizes (Din) varying between 53 and 383,µm. Treatment with PL-250 significantly reduced the size of pork fat particles in slaughterhouse wastewater. Particle size reduction increased with Din, possibly due to the more filamentous and plate-like configuration of the larger fat particles, which could be easily broken at weak points. The smaller particles were observed to be denser and more spherical. Size reduction also increased with enzyme concentration, but the benefit of adding more enzyme diminished greatly as enzyme dose was increased. The maximum long-chain fatty acid (LCFA) concentration in filtered samples was detected after 4,7,h of treatment and ranged from 8.2 to 34.9,mg,dm,3. The linear rate of LCFA released in solution during enzymatic pretreatment ranged from 39.4 to 169.9,mg,dm,3 d,1, and increased with enzyme concentration up to 500,mg,dm,3. At a PL-250 concentration of 1000,mg,dm,3, the LCFA release rate decreased, maybe due to excessive layering of adsorbed enzyme on the fat particles or increased degradation of released LCFAs. The pretreatment appeared to be more efficient with beef than pork fat particles. However, the effect of an enzymatic pretreatment on a downstream anaerobic treatment of slaughterhouse wastewater containing fat particles remains to be tested. © 2001 Society of Chemical Industry [source] Pre-dispersal acorn predation in mixed oak forests: interspecific differences are driven by the interplay among seed phenology, seed size and predator sizeJOURNAL OF ECOLOGY, Issue 6 2009Josep M. Espelta Summary 1.,Pre-dispersal seed predation (PSP) often occurs in multi-host,predator systems (e.g. several plant species exposed to a common array of granivorous insects). However, whether the interaction among seed phenology, seed size and predator size accounts for interspecific differences in PSP remains elusive. 2.,We studied PSP in a mixed-oak forest with two oaks (the larger-seeded Quercus humilis and the smaller-seeded Q. ilex), both depredated by two acorn weevils (the smaller Curculio glandium and the larger C. elephas). We intensively monitored acorn production and infestation phenology and we identified the weevil species depredating acorns by means of DNA taxonomy. 3.,The minimum acorn size required for infestation was lower for C. glandium than for C. elephas, in accordance with their different body sizes. This resulted in an earlier infestation phenology in C. glandium and the ability of this species to infest both smaller and larger acorns. Above a minimum acorn size threshold, no selection for larger acorns by weevils was observed. 4.,Initial acorn crop size was similar in the two oaks. Nonetheless, the earlier acorn phenology and the production of larger acorns in Q. humilis favoured the earlier infestation by C. glandium and the predation by both small and large weevils. Smaller acorns of Q. ilex almost excluded infestation by the larger C. elephas. 5.,Although larger acorns of Q. humilis could better survive infestation (preserve the embryo), higher PSP in this species finally resulted in a lower mature acorn crop size than in Q. ilex. 6.,Synthesis. In a multi-host,predator system, smaller-seeded species may benefit from a reduced PSP because they exclude larger granivorous insects, but also by means of a ,free-rider effect', if larger-seeded heterospecifics earlier reach a critical size to be depredated. These results also highlight the benefits of a small body size in granivorous insects to depredate seeds earlier and to forage on a wider range of seed sizes. Whether the advantage of ,being small' in this antagonistic plant,animal interaction is offset by other processes, or whether it results in a pressure towards seed and insect size reduction, deserves further attention. [source] The Effect of Protein Particle Size Reduction on the Physical Properties of CO2 -Precipitated Casein FilmsJOURNAL OF FOOD SCIENCE, Issue 4 2006Kirsten L. Dangaran ABSTRACT:, Casein precipitated with high pressure-CO2 (CO2CAS) has unique properties compared to commercial acid-precipitated casein. CO2CAS is less water-soluble and films made from it are less susceptible to high humidity environments; however, the films are also opaque and hazy. The appearance of CO2CAS films is important especially if applied as a food coating. To improve the appearance properties, the particle size of CO2CAS film plasticized with glycerol was reduced. The effect of protein particle size reduction on tensile properties, water vapor permeability (WVP), and gloss was studied using ASTM methodology. As particle size of the CO2CAS was reduced from 126 ,m to 111 ,m, tensile strength and modulus of the films increased, while WVP decreased. With the same particle reduction, gloss increased from 55.3 gloss units on average to 73 gloss units, but films were still hazy. With a particle size less than 86 ,m, CO2CAS films were glossy and transparent, however, tensile strength decreased and WVP increased. Depending on desired application, the properties of CO2CAS films can be optimized by changing particle size. [source] Modeling and simulation of polymeric nanocapsule formation by emulsion diffusion methodAICHE JOURNAL, Issue 8 2009M. Hassou Abstract The objective of this work is to develop a predictive dynamical model of a nanoencapsulation process using an emulsion diffusion method. This model describes the formation of the polymeric membrane around the oil droplet and its size reduction due to the solvent diffusion. To this end, we assume that the phase separation is only due to purely diffusive mechanism. This work is illustrated on the formation of poly-,-caprolactone (PCL) around the oily core formed of labrafac from the initial homogeneous polymer-solvent-nonsolvent solution (PCL, ethyl acetate, and labrafac). The polymeric membrane formation, the size reduction of the nanocapsule after the solvent diffusion, and the morphology of nanocapsules are experimentally investigated. It is shown that the results obtained in simulation from the dynamical model are in agreement with the experimental ones. The model is then used to predict the effect of the initial composition on the nanocapsule morphology. © 2009 American Institute of Chemical Engineers AIChE J, 2009 [source] Progress of actinolite-forming reactions in mafic schists during retrograde metamorphism: an example from the Sanbagawa metamorphic belt in central Shikoku, JapanJOURNAL OF METAMORPHIC GEOLOGY, Issue 5 2005A. OKAMOTO Abstract Hydration reactions are direct evidence of fluid,rock interaction during regional metamorphism. In this study, hydration reactions to produce retrograde actinolite in mafic schists are investigated to evaluate the controlling factors on the reaction progress. Mafic schists in the Sanbagawa belt contain amphibole coexisting with epidote, chlorite, plagioclase and quartz. Amphibole typically shows two types of compositional zoning from core to rim: barroisite , hornblende , actinolite in the high-grade zone, and winchite , actinolite in the low-grade zone. Both types indicate that amphibole grew during the exhumation stage of the metamorphic belt. Microstructures of amphibole zoning and mass-balance relations suggest that: (1) the actinolite-forming reactions proceeded at the expense of the preexisting amphibole; and (2) the breakdown reaction of hornblende consumed more H2O fluid than that of winchite, when one mole of preexisting amphibole was reacted. Reaction progress is indicated by the volume fraction of actinolite to total amphibole, Yact, with the following details: (1) reaction proceeded homogeneously in each mafic layer; (2) the extent of the hornblende breakdown reaction is commonly low (Yact < 0.5), but it increases drastically in the high-grade part of the garnet zone (Yact,>,0.7); and (3) the extent of the winchite breakdown reaction is commonly high (Yact,>,0.7). Many microcracks are observed within hornblende, and the extent of hornblende breakdown reaction is correlated with the size reduction of the hornblende core. Brittle fracturing of hornblende may have enhanced retrograde reaction progress by increasing of influx of H2O and the surface area of hornblende. In contrast to high-grade rocks, the winchite breakdown reaction is well advanced in the low-grade rocks, where reaction progress is not associated with brittle fracturing of winchite. The high extent of the reaction in the low-grade rocks may be due to small size of winchite before the reaction. [source] Modeling for size reduction of agglomerates in nanoparticle fluidizationAICHE JOURNAL, Issue 11 2004Satoru Matsuda Abstract Nanoparticle fluidization was studied in a centrifugal fluidized bed (CenFB) with variable gravitational acceleration (Gg) conditions. Agglomerate size variation in CenFB nanoparticles (7 nm) was examined with G and fluidization time. With increasing fluidization time, the agglomerate size was found to decrease and reach an equilibrium value after several hours. Higher G reduced agglomerate size. To elucidate these phenomena, a comprehensive model was developed based on the energy balance model with respect to energy consumption for disintegration of agglomerates. Experimental results showed good agreement with the proposed model. Effects of high G on agglomerate fluidization are clarified as follows. The critical minimum size of agglomerates, which is the agglomerate size estimated by the force balance model, is reduced by high G. Attainable energy for disintegration of agglomerates is increased, leading to decreased agglomerate size. © 2004 American Institute of Chemical Engineers AIChE J, 50: 2763,2771, 2004 [source] Longitudinal quantitative evaluation of lesion size change in femoral head osteonecrosis using three-dimensional magnetic resonance imaging and image registrationJOURNAL OF ORTHOPAEDIC RESEARCH, Issue 6 2006Masaki Takao Abstract It remains controversial whether some lesions of femoral head osteonecrosis regress during the natural course of the disease. With image registration, accurately matched image sets of the same subject can be acquired at different times. We applied image registration to evaluate lesion size change and assessed accuracy and usefulness compared to volume measurements and a conventional method. We also investigated whether lesions regress with this technique and with volume measurements. Baseline and 1 year minimum follow-up scans were conducted on 25 patients (31 hips) without radiological evidence of collapse. A three-dimensional (3D) spoiled gradient recalled echo sequence was used in the coronal direction (slice thickness,=,2 mm; slice pitch,=,1 mm). Size change was evaluated on all contiguous pairs of matched images after image registration. As a conventional method, coronal images (slice thickness,=,5 mm) were reconstructed, and size change was evaluated on the five representative coronal slices. Evaluation with the conventional method identified eight lesions with apparent reduction; assessments using image registration and volume measurements identified three lesions, all within a year of initial steroid treatment and remaining at ARCO stage I at follow up. Evaluation of lesion size change using image registration was comparable to volume measurements. Inaccurate estimation of lesion size change due to mismatching of slice planes can be excluded. We demonstrated that some early lesions detected less than a year after initial steroid treatment can show size reduction with image registration as well as with volume measurements. © 2006 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 24:1231,1239, 2006 [source] Quantifying effects of particulate properties on powder flow properties using a ring shear testerJOURNAL OF PHARMACEUTICAL SCIENCES, Issue 9 2008Hao Hou Abstract Effects of particle size, morphology, particle density, and surface silicification, on powder flow properties were investigated using a ring shear tester. Flow properties were quantified by flow function (FF), that is, unconfined yield strength, fc, as a function of major principal stress. A total of 11 powders from three series of microcrystalline cellulose (MCC): Avicel (regular MCC, elongated particles), Prosolv (silicified MCC, elongated particles), and Celphere (spherical MCC), were studied. Particle size distribution in each type of MCC was systematically different. Within each series, smaller particles always led to poorer powder flow properties. The slope of FF line was correlated to degree of powder consolidation by external stress. A key mechanism of the detrimental effect of particle size reduction on flow properties was the larger powder specific surface area. Flow properties of Celphere were significantly better than Avicel of comparable particles size, suggesting spherical morphology promoted better powder flow properties. Flow properties of powders different in densities but similar in particle size, shape, and surface properties were similar. When corrected for density effect, higher particle density corresponded to better flow behavior. Surface silicification significantly improved flow properties of finer MCC, but did not improve those of coarser. © 2008 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 97:4030,4039, 2008 [source] Formulations generated from ethanol-based proliposomes for delivery via medical nebulizersJOURNAL OF PHARMACY AND PHARMACOLOGY: AN INTERNATI ONAL JOURNAL OF PHARMACEUTICAL SCIENCE, Issue 7 2006Abdelbary M. A. Elhissi Multilamellar and oligolamellar liposomes were produced from ethanol-based soya phosphatidylcholine proliposome formulations by addition of isotonic sodium chloride or sucrose solutions. The resultant liposomes entrapped up to 62% of available salbutamol sulfate compared with only 1.23% entrapped by conventionally prepared liposomes. Formulations were aerosolized using an air-jet nebulizer (Pari LC Plus) or a vibrating-mesh nebulizer (Aeroneb Pro small mesh, Aeroneb Pro large mesh, or Omron NE U22). All vibrating-mesh nebulizers produced aerosol droplets having larger volume median diameter (VMD) and narrower size distribution than the air-jet nebulizer. The choice of liposome dispersion medium had little effect on the performance of the Pari nebulizer. However, for the Aeroneb Pro small mesh and Omron NE U22, the use of sucrose solution tended to increase droplet VMD, and reduce aerosol mass and phospholipid outputs from the nebulizers. For the Aeroneb Pro large mesh, sucrose solution increased the VMD of nebulized droplets, increased phospholipid output and produced no effect on aerosol mass output. The Omron NE U22 nebulizer produced the highest mass output (approx. 100%) regardless of formulation, and the delivery rates were much higher for the NaCl-dispersed liposomes compared with sucrose-dispersed formulation. Nebulization produced considerable loss of entrapped drug from liposomes and this was accompanied by vesicle size reduction. Drug loss tended to be less for the vibrating-mesh nebulizers than the jet nebulizer. The large aperture size mesh (8,m) Aeroneb Pro nebulizer increased the proportion of entrapped drug delivered to the lower stage of a twin impinger. This study has demonstrated that liposomes generated from proliposome formulations can be aerosolized in small droplets using air-jet or vibrating-mesh nebulizers. In contrast to the jet nebulizer, the performance of the vibrating-mesh nebulizers was greatly dependent on formulation. The high phospholipid output produced by the nebulizers employed suggests that both air-jet and vibrating-mesh nebulization may provide the potential of delivering liposome-entrapped or solubilized hydrophobic drugs to the airways. [source] Characterization of A New Almond Witches' Broom Phytoplasma in IranJOURNAL OF PHYTOPATHOLOGY, Issue 7-8 2006M. Salehi Abstract Almond witches' broom (AlmWB) is a destructive disease in several provinces in Iran. Association of phytoplasma with the disease has been established previously. In the present work two phytoplasmas from Khafr (KAlmWB) and Neyriz (NAlmWB) in the Fars Province were compared by biological and molecular analysis. Both infected bitter almond, wild almond, peach and nectarine but not apple and pear, by grafting. In bitter almond the symptoms induced by KAlmWB consisted of severe proliferation, internode shortening and leaf size reduction. In contrast, NAlmWB caused leaf necrosis, dieback and death. KAlmWB was transmitted to periwinkle and eggplant and from experimentally infected periwinkle to almond by dodder. It was also transmitted from eggplant to eggplant, ornamental eggplant and tomato by grafting. Under similar test conditions, NAlmWB was not transmitted to herbaceous plants by dodder. Phylogenetic analysis of 16S,23S rDNA spacer region (SR) sequences placed both strains in the pigeon pea witches' broom (PPWB) group. However, based on phylogenetic and putative restriction site analyses and sequence homology, NAlmWB was identical with the Lebanese AlmWB phytoplasma, while KAlmWB was closer to the Knautia arvensis phyllody (KAP) agent. Clustering of KAlmWB with KAP was confirmed by analysis of full length 16S rDNA sequence. On the basis of host range, dodder transmission, host range, symptomatology and molecular analyses of 16S rDNA and SR, two different phytoplasmas related to PPWB group were associated with AlmWB disease in Iran. KAlmWB phytoplasma is being reported as a new phytoplasma of AlmWB disease. [source] A strategic response to class size reduction: Combination classes and student achievement in CaliforniaJOURNAL OF POLICY ANALYSIS AND MANAGEMENT, Issue 3 2008David Sims The California class size reduction program provided schools with cash rewards for K,3 classes of 20 or fewer students. I show how program rules made it possible for schools to save money by using mixed-grade classes to meet class size reduction obligations while maintaining larger average class sizes. I also show that this smoothing of students across grades is associated with a significant test score gap for certain second and third grade students. My estimates suggest that class size reduction may lead to lower test scores for students placed in combination classes. Alternative explanations of teacher experience and credentialing changes cannot explain the test score pattern. This result spotlights both the underappreciated role of age heterogeneity in classroom learning and the difficulty of replicating the success of policy experiments in statewide reform. © 2008 by the Association for Public Policy Analysis and Management. [source] | |||||||||||||||||||||||||||||||