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Selected AbstractsRecycling of nickel,metal hydride batteries.JOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 9 2004I: Dissolution, solvent extraction of metals Abstract Nickel,metal hydride batteries contain valuable metallic components and although they are not considered a hazardous waste, recovery of these materials is necessary from an economic point of view. In this work a hydrometallurgical method for the dissolution and separation of the metals from cylindrical nickel,metal hydride rechargeable batteries was investigated. Hydrochloric acid was employed as the leaching agent to dissolve the metals from the batteries. Dissolution of metals was investigated as a function of acid concentration, leaching time and temperature. Suitable conditions for maximum metal dissolution were 3 h leaching with 4.0 mol dm,3 hydrochloric acid solutions at 95 °C. Extraction of 98% of nickel, 100% of cobalt and 99% of rare earth elements was achieved under these conditions. Separation of the rare earths from nickel and cobalt was preliminarily investigated by single batch solvent extraction with 25% bis(2-ethylhexyl)phosphoric acid. Efficient separation via complete extraction of the rare earths was obtained at a pH of approximately 2.5 while leaving nickel and cobalt in the raffinate. A shrinking particle model which can enable, under certain conditions, evaluation of the extent of metal dissolution present in nickel,metal hydride batteries was developed. A proposed electrochemical recovery of nickel and cobalt is also briefly discussed. Copyright © 2004 Society of Chemical Industry [source] A study of twentieth-century extreme rainfall events in the United Kingdom with implications for forecastingMETEOROLOGICAL APPLICATIONS, Issue 1 2004William H. Hand Rainfall events in the United Kingdom during the twentieth century have been surveyed and those identified as extreme by the Flood Studies Report (1975) standards have been examined for common features. Events of duration up to 60 hours were considered in order to investigate those that could cause flash floods. More than half of the 50 events identified were short-period convective storms. The rainfall events were classified by meteorological situation, location and season, allowing the identification of conditions under which extreme rainfall occurred. Suitable conditions for extreme rainfall were split into three categories: orographic, frontal and convective. The frontal and convective classes were then divided into two sub-classes according to whether significant embedded instability was present in the frontal cases and the nature of the convection in the convective cases. The study revealed a lot of commonality between the cases. For example, all of the orographic events occurred in winter in moist west to southwest airflows, and 80% of the frontal cases involved a slow-moving depression to the south or east and also a slow moving frontal system. A conceptual airflow diagram has been developed for some of the frontal cases. The key result, however, was the discovery that each category of meteorological situation occupied a unique space in a rainfall amount versus duration diagram for each extreme event. This offers exciting opportunities for applying the results of this study and a framework for studying future events. Copyright © 2004 Royal Meteorological Society. [source] Highly-efficient Cd-free CuInS2 thin-film solar cells and mini-modules with Zn(S,O) buffer layers prepared by an alternative chemical bath processPROGRESS IN PHOTOVOLTAICS: RESEARCH & APPLICATIONS, Issue 6 2006A. Ennaoui Abstract Recent progress in fabricating Cd- and Se-free wide-gap chalcopyrite thin-film solar devices with Zn(S,O) buffer layers prepared by an alternative chemical bath process (CBD) using thiourea as complexing agent is discussed. Zn(S,O) has a larger band gap (Eg,=,3·6,3·8,eV) than the conventional buffer material CdS (Eg,=,2·4,eV) currently used in chalcopyrite-based thin films solar cells. Thus, Zn(S,O) is a potential alternative buffer material, which already results in Cd-free solar cell devices with increased spectral response in the blue wavelength region if low-gap chalcopyrites are used. Suitable conditions for reproducible deposition of good-quality Zn(S,O) thin films on wide-gap CuInS2 (,CIS') absorbers have been identified for an alternative, low-temperature chemical route. The thickness of the different Zn(S,O) buffers and the coverage of the CIS absorber by those layers as well as their surface composition were controlled by scanning electron microscopy, X-ray photoelectron spectroscopy, and X-ray excited Auger electron spectroscopy. The minimum thickness required for a complete coverage of the rough CIS absorber by a Zn(S,O) layer deposited by this CBD process was estimated to ,15,nm. The high transparency of this Zn(S,O) buffer layer in the short-wavelength region leads to an increase of ,1,mA/cm2 in the short-circuit current density of corresponding CIS-based solar cells. Active area efficiencies exceeding 11·0% (total area: 10·4%) have been achieved for the first time, with an open circuit voltage of 700·4,mV, a fill factor of 65·8% and a short-circuit current density of 24·5,mA/cm2 (total area: 22·5,mA/cm2). These results are comparable to the performance of CdS buffered reference cells. First integrated series interconnected mini-modules on 5,×,5,cm2 substrates have been prepared and already reach an efficiency (active area: 17·2,cm2) of above 8%. Copyright © 2006 John Wiley & Sons, Ltd. [source] Structural analysis of human hair fibers under the ultra-high voltage electron microscopeINTERNATIONAL JOURNAL OF COSMETIC SCIENCE, Issue 2 2005K. Koike Three-dimensional structural analyses of human hair fibers and comparison of the different fibers were tried by using the Ultra-high Voltage Electron Microscope (UHVEM). The analysis condition, sample preparation, and a machine state were adjusted to the suitable condition for tilting observation of from ,70° to +70°, at 2° intervals. The tomography of hair fiber was successfully reconstructed from the different angle pictures with IMODE software in a computer. By using UHVEM, the various human hair fibers from Japanese and Caucasians were investigated and discussed about their structures. [source] Technical and non-technical skills can be reliably assessed during paramedic simulation trainingACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 1 2009T. VON WYL Background: Medical teams depend on technical skills (TS) as well as non-technical skills (NTS) for successful management of critical events. Simulated scenarios are an opportunity for presentation of similar crisis situations. The aim of this study was to test whether TS and NTS are assessable with satisfactory interrater reliability (IRR) during a regular paramedic training. Methods: Thirty paramedics were rated by two independent observers using video-recording and previously validated checklists while managing two simulated emergency scenarios as a team of two. The observed items of the team's TS included type, order, and time of adequate medical care. The NTS were restricted to six team-oriented dimensions. The IRR was quantified by calculating the intraclass correlation coefficient (ICC). The z -transformed values of the TS and NTS were correlated by Pearson's correlation. Internal consistency was controlled using Cronbach's ,. Results: The average measures ICC for the IRR was between 0.97 [95% confidence interval (CI) 0.91,0.99] and 0.98 (95% CI 0.94,0.99) for the TS sum-score, and was 0.94 (95% CI 0.87,0.97) for the NTS sum-score; the Cronbach's , of this NTS sum-score was 0.86. There is a positive correlation between the normalised TS and NTS sum-scores (r=0.53; P<0.05). Conclusion: Assessment of TS and NTS is feasible and reliable during paramedic training in emergency scenarios. TS can be reliably assessed by one trained observer; for NTS, two trained raters provide a suitable condition for excellent observations. There is a significant positive correlation between TS and NTS. [source] Photoreactive nanomatrix structure formed by graft-copolymerization of 1,9-nonandiol dimethacrylate onto natural rubberJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 11 2010Yoshimasa Yamamoto Abstract Formation of photoreactive nanomatrix structure was investigated by graft-copolymerization of an inclusion complex of 1,9-nonandiol dimethacrylate (NDMA) with ,-cyclodextrin (,-CD) onto natural rubber particle using potassium persulfate (KPS), tert -butyl hydroperoxide/tetraethylenepentamine (TBHPO/TEPA), cumene hydroperoxide/tetraethylenepentamine (CHPO/TEPA), and benzoyl peroxide (BPO) as an initiator. The graft copolymer was characterized by 1H NMR and FTIR after coagulation. The conversion of NDMA and the amount of residual methacryloyl group were found to be 58.5 w/w % and 1.81 w/w %, respectively, under the suitable condition of the graft-copolymerization. The morphology of the film specimen, prepared from the graft copolymer, was observed by transmission electron microscopy (TEM) after staining the film with OsO4. Natural rubber particle of about 1.0 ,m in diameter was dispersed in poly(NDMA) matrix of about 10 nm in thickness. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 2418,2424, 2010 [source] Functional Interpretations of Constructive Set Theory in All Finite TypesDIALECTICA, Issue 2 2008Justus Diller Gödel's dialectica interpretation of Heyting arithmetic HA may be seen as expressing a lack of confidence in our understanding of unbounded quantification. Instead of formally proving an implication with an existential consequent or with a universal antecedent, the dialectica interpretation asks, under suitable conditions, for explicit ,interpreting' instances that make the implication valid. For proofs in constructive set theory CZF - , it may not always be possible to find just one such instance, but it must suffice to explicitly name a set consisting of such interpreting instances. The aim of eliminating unbounded quantification in favor of appropriate constructive functionals will still be obtained, as our ,-interpretation theorem for constructive set theory in all finite types CZF, - shows. By changing to a hybrid interpretation ,q, we show closure of CZF, - under rules that , in stronger forms , have already been studied in the context of Heyting arithmetic. In a similar spirit, we briefly survey modified realizability of CZF, - and its hybrids. Central results of this paper have been proved by Burr 2000a and Schulte 2006, however, for different translations. We use a simplified interpretation that goes back to Diller and Nahm 1974. A novel element is a lemma on absorption of bounds which is essential for the smooth operation of our translation. [source] Electrochemical Approach to the Radical Anion Formation from 2,-Hydroxy Chalcone DerivativesELECTROANALYSIS, Issue 5 2006P. Quintana-Espinoza Abstract Three 2,-hydroxy chalcone derivatives were electrochemically reduced to the radical anion by a reversible one-electron transfer followed by a chemical dimerization reaction. Under suitable conditions of the medium, the one-electron reduction produces very well resolved cyclic voltammograms due to the formation of the radical anion. By using appropriately the wide versatility of the cyclic voltammetric technique, was possible to study the generation of the radical anion and its stability. [source] Undesirable side-effects of water hyacinth control in a shallow tropical reservoirFRESHWATER BIOLOGY, Issue 6 2007DENISE DE C. BICUDO Summary 1. Based on a comprehensive data set collected monthly during 8 years (1997,2004), we evaluated the effects of mechanical removal of Eichhornia crassipes on the limnological characteristics and algal biomass of a polymictic shallow tropical reservoir. 2. Interrupted time series analyses indicated that the limnological responses to macrophyte removal can be classified as an ,abrupt permanent impact' implying that the overall mean of the time-series shifted promptly after intervention. These analyses indicated a significant increase for pH, total phosphorus, total phytoplankton and cyanobacterial biomass, and a decrease in water transparency and CO2 concentrations in the surface water; also, the increase in water stability, increase of bottom soluble reactive phosphorus (SRP) and decrease in bottom oxygen levels. 3. Cyclic anoxic periods previously observed during springs and summers were replaced by a persistent period of anoxic conditions in the sediment overlying water. Anoxic conditions were suitable for SRP release from sediments. Heavy cyanobacterial blooms became more persistent, maximum biomass (4229 mm3 L,1) was 30 times larger, the blooms frequently reached 2 m and sometimes the bottom of the reservoir, contrasting to the preremoval period in which it reached at most 1 m deep. 4. The long-term P dynamics in the system, initially driven by allochthonous nutrient loadings were replaced by internal ecological processes. Water hyacinth removal markedly accelerated the process of eutrophication due to internal feedback mechanisms, leading to a switch to a more turbid state. Biological feedback mechanisms were driven by cyanobacterial blooms by enhancing water stability, oxygen anoxia at the bottom and by increasing suitable conditions for P internal loading. These data support the hypothesis of the role of cyanobacterial blooms as an important factor impairing water quality and driving the ecosystem towards a stable degraded state. 5. These findings have important implications for the restoration of shallow stratifying eutrophic lakes, as the alternative degraded state is most likely to occur when compared with their non-stratifying counterparts. Moreover, feedback mechanisms in tropical and subtropical shallow lakes seem to be stronger than in temperate ones, as stratification events are more likely to occur over the year, intensifying system resilience to restorative strategies. [source] Differences in seed mass between hydric and xeric plants influence seed bank dynamics in a dryland riparian ecosystemFUNCTIONAL ECOLOGY, Issue 2 2008J. C. Stromberg Summary 1Dryland riparian zones have steep spatial gradients of soil moisture and flood disturbance, and the component hydrogeomorphic surfaces support hydric to xeric plant species. These systems undergo extremes of flood and drought, a dynamic that may select for persistent soil seed banks. We asked if reliance on this strategy differed among plants in three moisture groups (hydric, mesic and xeric), and if patterns were related to diaspore traits. 2We assessed the composition of soil and litter seed banks (emergence method) and extant vegetation along a riparian hydrogradient, and measured seed persistence (using an indirect method) and diaspore mass and shape variance of the component species. 3Hydroriparian species had smaller diaspores than xeroriparian species, corresponding to differences in selective pressures on seedlings in their respective habitats, but the two groups formed persistent seed banks at approximately equal percentages. Persistent seeds were smaller than transient seeds, but within the persistent seed group there was separation between the smaller-diaspored hydrophytes and larger-diaspored xerophytes. 4Distribution patterns of extant vegetation, in concert with diaspore trait differences among moisture-affinity groups, gave rise to divergent spatial patterns of diaspores within the soil: hydroriparian diaspores were abundant not only along wet channel bars but also in deep soils under floodplain forests and shrublands, presumably owing to dispersal by flood waters. Xeroriparian diaspores were largely restricted to the litter and upper soil layers of their drier, higher, floodplain habitats. With increasing depth in the soil of floodplain forests and shrublands, viable diaspores became smaller and rounder, and plant composition shifted from xeroriparian to hydroriparian species. 5The wide distribution of hydroriparian diaspores in floodplain soils influences disturbance dynamics, increasing the probability that ephemeral wetland communities will develop wherever suitable conditions are stochastically created by floods. Persistent seed banks also allow many xeric annuals to be maintained in dryland riparian zones throughout extended drought, similar to processes that occur in desert uplands. [source] Recent decay of a single palsa in relation to weather conditions between 1996 and 2000 in Laivadalen, northern SwedenGEOGRAFISKA ANNALER SERIES A: PHYSICAL GEOGRAPHY, Issue 2 2002Frieda Sjoukje Zuidhoff This study presents the decay of a small palsa complex between 1996 and 2000 in Sweden's southernmost major palsa bog. The outline of the palsa was mapped during three summers in 1996, 1999 and 2000 and an automatic weather station measured air temperature, precipitation, snow depth, wind speed and wind direction between 1997 and 2000. The decay of the palsa was enormous in the dome,shaped part of the palsa complex: the height decreased during the observation period from 2.3 m to 0.5 m. In 2000, the palsa dome had almost totally disappeared: only some peat blocks in a palsa pond were left. The decay of the palsa was complex with a number of degradational processes, of which the main processes were block erosion, thermokarst and wind erosion. Thermal melting has occurred along the edges of the palsa and possibly below the frozen core of the palsa since 1998/99. Wind erosion was observed during summer and the maximum estimated deflation was 80 cm. The decay of the palsa dome was especially large between 1999 and 2000, probably due to a high mean annual temperature, high summer precipitation and the warming influence of the large pond surrounding the palsa. The present climate in the palsa bog with a mean annual temperature of ,0.8°C is not favourable for palsa development and maintenance, despite a strong wind regime which can provide suitable conditions for snowdrift. [source] Molecular dynamics of the generation process of double-walled carbon nanotubes from peapodsHEAT TRANSFER - ASIAN RESEARCH (FORMERLY HEAT TRANSFER-JAPANESE RESEARCH), Issue 4 2006Yasushi Shibuta Abstract The generation process of a double-walled carbon nanotube (DWNT) from a "peapod" was studied by classical molecular dynamics simulation. Starting from a peapod structure, defined by five C60 molecules inside a (10,10) single-walled carbon nanotube (SWNT), polymerized fullerenes, a peanut-like structure and an almost nanotube-like structure were obtained under suitable conditions of temperature control. The mean distance between the two layers of the DWNT agreed with an experimental report that it is larger than the interlayer spacing found in multi-walled carbon nanotubes (MWNTs). In addition, the chirality dependence of the potential energy of a DWNT on the relative chirality of its constituent tubes was examined using a 6-12 Lennard-Jones potential. It was found that the potential energy depends only on the distance between the two layers, not on the relative chiralities. © 2006 Wiley Periodicals, Inc. Heat Trans Asian Res, 35(4): 254,264, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/htj.20115 [source] Unified formulation of radiation conditions for the wave equationINTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING, Issue 2 2002Steen Krenk Abstract A family of radiation boundary conditions for the wave equation is derived by truncating a rational function approximation of the corresponding plane wave representation, and it is demonstrated how these boundary conditions can be formulated in terms of fictitious surface densities, governed by second-order wave equations on the radiating surface. Several well-established radiation boundary conditions appear as special cases, corresponding to different choices of the coefficients in the rational approximation. The relation between these choices is established, and an explicit formulation in terms of selected directions with ideal transmission is presented. A mechanical interpretation of the fictitious surface densities enables identification of suitable conditions at corners and boundaries of the radiating surface. Numerical examples illustrate excellent results with one or two fictitious layers with suitable corner and boundary conditions. Copyright © 2001 John Wiley & Sons, Ltd. [source] Treatment of beverage-processing wastewater in a three-phase fluidised bed biological reactorINTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 6 2008Samwel Victor Manyele Summary This paper presents a study on treatment of beverage-processing wastewater (BPWW) in a three-phase fluidised bed bioreactor (TPFBB). Wastewater samples were introduced in the TPFBB and aerated at optimum liquid and gas flow rates while measuring wastewater parameters [pH, chemical oxygen demand (COD), total suspended solids (TSS), total Kjehldahl nitrogen (TKN) and ammonia-nitrogen (NH3 -N)]. Two different initial pH levels were studied, i.e. 9.0 and 11.5. The pH of the wastewater was observed to level off at 9.3 after 1 day. The TSS dropped by 95% after 5 days, for both initial pH levels. The NH3 -N and TKN dropped to similar final concentration independent of initial pH. The COD removal efficiency was observed to depend on the initial pH level. A highest efficiency of 98% and lowest efficiency of 50% were observed at initial pH of 9.0 and 11.5, respectively. The study results show that TPFBB is capable of treating food-processing wastewater under suitable conditions. [source] Commercial considerations in tissue engineeringJOURNAL OF ANATOMY, Issue 4 2006Jonathan Mansbridge Abstract Tissue engineering is a field with immense promise. Using the example of an early tissue-engineered skin implant, Dermagraft, factors involved in the successful commercial development of devices of this type are explored. Tissue engineering has to strike a balance between tissue culture, which is a resource-intensive activity, and business considerations that are concerned with minimizing cost and maximizing customer convenience. Bioreactor design takes place in a highly regulated environment, so factors to be incorporated into the concept include not only tissue culture considerations but also matters related to asepsis, scaleup, automation and ease of use by the final customer. Dermagraft is an allogeneic tissue. Stasis preservation, in this case cryopreservation, is essential in allogeneic tissue engineering, allowing sterility testing, inventory control and, in the case of Dermagraft, a cellular stress that may be important for hormesis following implantation. Although the use of allogeneic cells provides advantages in manufacturing under suitable conditions, it raises the spectre of immunological rejection. Such rejection has not been experienced with Dermagraft. Possible reasons for this and the vision of further application of allogeneic tissues are important considerations in future tissue-engineered cellular devices. This review illustrates approaches that indicate some of the criteria that may provide a basis for further developments. Marketing is a further requirement for success, which entails understanding of the mechanism of action of the procedure, and is illustrated for Dermagraft. The success of a tissue-engineered product is dependent on many interacting operations, some discussed here, each of which must be performed simultaneously and well. [source] Microporous activated carbon spheres prepared from resole-type crosslinked phenolic beads by physical activationJOURNAL OF APPLIED POLYMER SCIENCE, Issue 5 2008Arjun Singh Abstract Microporous activated carbon spheres (ACSs) with a high specific Brunauer,Emmet,Teller (BET) surface area were prepared from resole-type spherical crosslinked phenolic beads (PBs) by physical activation. The PBs used as precursors were synthesized in our laboratory through the mixing of phenol and formaldehyde in the presence of an alkaline medium by suspension polymerization. The effects of the gasification time, temperature, and flow rate of the gasifying agent on the surface properties of ACSs were investigated. ACSs with a controllable pore structure derived from carbonized PBs were prepared by CO2 gasification. Surface properties of ACSs, such as the BET surface area, pore volume, pore size distribution, and pore diameters, were characterized with BET and Dubinin,Reduchkevich equations based on N2 adsorption isotherms at 77 K. The results showed that ACSs with a 32,88% extent of burn-off with CO2 gasification exhibited a BET surface area ranging from 574 to 3101 m2/g, with the pore volume significantly increased from 0.29 to 2.08 cm3/g. The pore size and its distribution could be tailored by the selection of suitable conditions, including the gasification time, temperature, and flow rate of the gasifying agents. The experimental results of this analysis revealed that ACSs obtained under different conditions were mainly microporous. The development of the surface morphology of ACSs was also studied with scanning electron microscopy. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 [source] Breeding latitude and timing of spring migration in songbirds crossing the Gulf of MexicoJOURNAL OF AVIAN BIOLOGY, Issue 3 2009Kathryn M. Langin Each spring, millions of songbirds migrate across the Gulf of Mexico on their way to breeding sites in North America. Data from radar and migration monitoring stations have revealed broad patterns in the spatial and temporal course of trans-Gulf migration. Unfortunately, we have limited information on where these birds have previously spent the winter and where they are migrating to breed. Here we measure stable-hydrogen isotopes in feathers (,Df) to infer the breeding latitude of five species of songbirds , hooded warblers Wilsonia citrina, American redstarts Setophaga ruticilla, black-and-white warblers Mniotilta varia, ovenbirds Seiurus aurocapilla, and northern waterthrushes S. noveboracensis, that were captured at a stopover site along the coast of southwestern Louisiana in spring 2004. Values of ,Df across all species ranged from ,163 to ,35, (n=212), and within most species the range was consistent with the latitudinal extent of known breeding sites in central and eastern North America. Individuals that arrived first along the northern Gulf coast had ,Df values indicative of southerly breeding sites in hooded warblers, American redstarts, black-and-white warblers, and ovenbirds, but no relationship was found between passage timing and ,Df for northern waterthrushes. Our findings suggest that spring passage is often timed to coincide with the emergence of suitable conditions on breeding areas, with southern breeding birds migrating first. [source] The effect of the extent of the study region on GIS models of species geographic distributions and estimates of niche evolution: preliminary tests with montane rodents (genus Nephelomys) in VenezuelaJOURNAL OF BIOGEOGRAPHY, Issue 7 2010Robert P. Anderson Abstract Aim, Various techniques model a species' niche and potential distribution by comparing the environmental conditions of occurrence localities with those of the overall study region (via a background or pseudoabsence sample). Here, we examine how changes in the extent of the study region (ignored or under-appreciated in most studies) affect models of two rodents, Nephelomys caracolus and Nephelomys meridensis. Location, North-central South America. Methods, We used Maxent to model the species' potential distributions via two methods of defining the study region. In Method 1 (typical of most studies to date), we calibrated the model in a large study region that included the ranges of both species. In Method 2, we calibrated the model using a smaller study region surrounding the localities of the focal species, and then applied it to the larger region. Because the study region of Method 1 is likely to include areas of suitable conditions that are unoccupied because of dispersal limitations and/or biotic interactions, this approach is prone to overfitting to conditions found near the occupied localities. In contrast, Method 2 should avoid such problems but may require further assumptions (,clamping' in Maxent) to make predictions for areas with environmental conditions beyond those found in the smaller study region. For each method, we calculated several measures of geographic interpredictivity between predictions for the species (cross-species AUC, cross-species omission rate, and proportional geographic overlap). Results, Compared with Method 1, Method 2 revealed a larger predicted area for each species, less concentrated around known localities (especially for N. caracolus). It also led to higher cross-species AUC values, lower cross-species omission rates and higher proportions of geographic overlap. Clamping was minimal and occurred primarily in regions unlikely to be suitable. Main conclusions, Method 2 led to more realistic predictions and higher estimates of niche conservatism. Conclusions reached by many studies depend on the selection of an appropriate study region. Although detailed information regarding dispersal limitations and/or biotic interactions will typically be difficult to obtain, consideration of coarse distributional patterns, topography and vegetational zones often should permit delimitation of a much more reasonable study region than the extremely large ones currently in common use. [source] Recovery of Components from Shrimp (Xiphopenaeus kroyeri) Processing Waste by Enzymatic HydrolysisJOURNAL OF FOOD SCIENCE, Issue 5 2006Helenice Duarte De Holanda ABSTRACT:, Industrial shrimp waste is a good source of protein, chitin, and carotenoids. In general, this waste is discarded with no attempt to use it, thus contributing to environmental pollution. This study was aimed at recovering the 3 main components of industrial shrimp waste, protein, chitin, and astaxanthin, using enzymatic treatment with Alcalase and pancreatin. An increase in the degree of hydrolysis (DH) from 6% to 12% resulted in 26% to 28% protein recovery. Alcalase was more efficient than pancreatin, increasing the recovery of protein from 57.5% to 64.6% and of astaxanthin from 4.7 to 5.7 mg astaxanthin/100 g of dry waste, at a DH of 12%. The enzymatic hydrolysis of the industrial waste from Xiphopenaeus kroyeri shrimp using Alcalase allowed for 65% protein recovery in the form of hydrolysates, in addition to providing suitable conditions for the recovery of astaxanthin and chitin. [source] Laparoscopic excision of large ovarian cystsJOURNAL OF OBSTETRICS AND GYNAECOLOGY RESEARCH (ELECTRONIC), Issue 6 2002Hesham A.F. Salem Abstract Objective: The aim of this study was to check the ability of operative laparoscopy to help in the management of large ovarian cysts that may reach above the level of the umbilicus. Material and methods: Fifteen cases oflarge ovarian cysts reaching above the level of the umbilicus were chosen. Clinical and ultrasonic diagnosis denied any signs of malignancy. Pneumoperitoneum and a 5 mm trocar were inserted safely in the left midclavicular line below the ninth costal margin. This trocar allowed us to inspect the peritoneal cavity thoroughly. Another 5 mm trocar was inserted suprapubically in the contralateral side of the cyst and better inspection of the cyst and peritoneal cavity was then done. In the case of an apparently benign cyst, aspiration of the cyst fluid was done after puncturing its wall, then the cyst was removed as usual. Results: In all of these cases, there was no laparoconversion and no other complications were recorded. Nine cases were mucinous and six were serous cystadenomas. The mean operation time was 53.66 ± 14.7 min. Conclusion: Laparoscopic excision of large ovarian cysts is possible, and safe in suitable conditions, with immediate laparoconversion at hand at any time. [source] Direct functionalization of polyisobutylene by living initiation with ,-methylstyrene epoxideJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 8 2002J. Song Abstract This article describes the synthesis and characterization of polyisobutylene (PIB) carrying one primary hydroxyl head group and a tertiary chloride end group, [PhC(CH3)(CH2OH),PIB,CH2C(CH3)2Cl] prepared with direct functionalization via initiation. The polymerization of isobutylene was initiated with the ,-methylstyrene epoxide/titanium tetrachloride system. Living conditions were obtained from ,75 to ,50 °C (198,223 K). Low molecular weight samples (number-average molecular weight , 4000 g/mol) were prepared under suitable conditions and characterized by Fourier transform infrared and 1H NMR spectroscopy. The presence of primary hydroxyl head groups in PIB was verified by both methods. Quantitative Fourier transform infrared with 2-phenyl-1-propanol calibration and 1H NMR performed on both the hydroxyl-functionalized PIB and its reaction product with trimethylchlorosilane showed that each polymer chain carried one primary hydroxyl head group. The synthetic methodology presented here is an effective and simple route for the direct functionalization of PIB. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 1005,1015, 2002 [source] GELLING BEHAVIOR OF RICE FLOUR DISPERSIONS AT DIFFERENT CONCENTRATIONS OF SOLIDS AND TIME OF HEATINGJOURNAL OF TEXTURE STUDIES, Issue 3 2008ALKA KAPRI ABSTRACT Rice flour dispersions, under suitable conditions of processing, can form a gel. The effect of concentration of solids (10,18%) and time (0,75 min) of processing on textural attributes, and viscoelasticity were investigated along with sensory attributes. The textural attribute determined is gel strength, while viscoelasticity was determined in terms of mechanical spectra like storage modulus (G,), loss modulus (G,), complex viscosity (,*) and loss factor (tan ,) during a frequency sweep varying from 0.01 to 40 Hz at a constant stress of 25 Pa. Microstructural observation indicates the swelling of starch granules in the beginning of heating, while damaged granule and leached-out materials are visible at the end of the gelling process. Desirability function analysis has been applied to obtain a rice gel with acceptable textural attributes; a solid concentration of 15.2% and a heating time of 75 min can lead to the development of a gel with a satisfaction level of 0.6. PRACTICAL APPLICATIONS Rice flour gels in the form of hard-set gels, porridges and spreads are popular in several parts of the world particularly for feeding of infants and children. The application of the present study lies in understanding the role of major processing variables on the quality attributes and viscoelasticity of a product, characterization of cooked gels and for developing rice flour-based food gels. The findings may also be extended for the development of other cereal-based gels. [source] RHEOLOGICAL, TEXTURAL AND MICROSTRUCTURE ANALYSIS OF THE HIGH-METHOXY PECTIN/GELATIN MIXED SYSTEMSJOURNAL OF TEXTURE STUDIES, Issue 5 2007H. LIU ABSTRACT The aim of this research was to evaluate the interaction between high-methoxy pectin and gelatin in solution and mixed gel utilizing rheological, texture profile and microstructure analysis. The results showed that the phase separation and association might both exist depending on the ratio of pectin to gelatin in the mixed system. After the pectin addition to the mixed system, the gelation properties of gelatin were improved at suitable conditions. The structure development rate, gel hardness and gel brittleness of the pectin/gelatin mixed system were positively affected by the addition of pectin and from there to expand the application of the mixed system in food industry. PRACTICAL APPLICATIONS Structure-forming polysaccharides and protein provide desired functional properties to a wide range of foods such as gel confectionery products, milk products and fat replacers. As an academic paper, this article provided the information that high-methoxy (HM) pectin could prove the gelation properties of gelatin to corporate audiences. We could find that the ratio of HM pectin to gelatin, and the concentration of these two polymers, dictate the texture properties of the mixed system. The pectin addition to the gelatin system affected the structure development rate, which might save time when the products are processed in practice. The melting temperature was increased with the pectin addition to the gelatin system, which is favorable if it is to be kept under higher temperature. [source] Autoregressive processes with data-driven regime switchingJOURNAL OF TIME SERIES ANALYSIS, Issue 5 2009Joseph Tadjuidje Kamgaing Abstract., We develop a switching-regime vector autoregressive model in which changes in regimes are governed by an underlying Markov process. In contrast to the typical hidden Markov approach, we allow the transition probabilities of the underlying Markov process to depend on past values of the time series and exogenous variables. Such processes have potential applications in finance and neuroscience. In the latter, the brain activity at time t (measured by electroencephalograms) will be modelled as a function of both its past values as well as exogenous variables (such as visual or somatosensory stimuli). In this article, we establish stationarity, geometric ergodicity and existence of moments for these processes under suitable conditions on the parameters of the model. Such properties are important for understanding the stability properties of the model as well as for deriving the asymptotic behaviour of various statistics and model parameter estimators. [source] Blow up for a Cauchy viscoelastic problem with a nonlinear dissipation of cubic convolution typeMATHEMATICAL METHODS IN THE APPLIED SCIENCES, Issue 15 2009Shengqi Yu Abstract In this paper, we consider a Cauchy viscoelastic problem with a nonlinear source of polynomial type and a nonlinear dissipation of cubic convolution type involving a singular kernel. Under suitable conditions on the initial data and the relaxation functions, it is proved that the solution of this particular problem blows up in finite time. Copyright © 2009 John Wiley & Sons, Ltd. [source] Cokernel bundles and Fibonacci bundlesMATHEMATISCHE NACHRICHTEN, Issue 4 2008Maria Chiara Brambilla Abstract We are interested in those bundles C on ,N which admit a resolution of the form 0 , ,s , E ,t , F , C , 0. In this paper we prove that, under suitable conditions on (E, F), a generic bundle with this form is either simple or canonically decomposable. As applications we provide an easy criterion for the stability of such bundles on ,2 and we prove the stability when E = ,,, F = ,,(1) and C is an exceptional bundle on ,N for N , 2. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Identification of 21 polymorphic microsatellites in the African parasitoid wasp, Psyttalia lounsburyi (Silvestri) (Hymenoptera: Braconidae)MOLECULAR ECOLOGY RESOURCES, Issue 4 2008M. C. BON Abstract We have developed 21 dinucleotide repeat microsatellite loci from African populations of Psyttalia lounsburyi (Silvestri) (Hymenoptera: Braconidae), a parasitoid wasp of the olive fruit fly, as part of a study assessing the role of introgression/hybridization in the success of a biological control introduction. We proposed suitable conditions for polymerase chain reaction multiplexing. All 21 loci were polymorphic with two to 21 alleles per locus within the Kenyan and South African populations tested. Most of them were successfully amplified in two other Psyttalia species. [source] A modified modulus method for symmetric positive-definite linear complementarity problemsNUMERICAL LINEAR ALGEBRA WITH APPLICATIONS, Issue 2 2009Jun-Liang Dong Abstract By reformulating the linear complementarity problem into a new equivalent fixed-point equation, we deduce a modified modulus method, which is a generalization of the classical one. Convergence for this new method and the optima of the parameter involved are analyzed. Then, an inexact iteration process for this new method is presented, which adopts some kind of iterative methods for determining an approximate solution to each system of linear equations involved in the outer iteration. Global convergence for this inexact modulus method and two specific implementations for the inner iterations are discussed. Numerical results show that our new methods are more efficient than the classical one under suitable conditions. Copyright © 2008 John Wiley & Sons, Ltd. [source] Alternately linearized implicit iteration methods for the minimal nonnegative solutions of the nonsymmetric algebraic Riccati equationsNUMERICAL LINEAR ALGEBRA WITH APPLICATIONS, Issue 8 2006Zhong-Zhi Bai Abstract For the non-symmetric algebraic Riccati equations, we establish a class of alternately linearized implicit (ALI) iteration methods for computing its minimal non-negative solutions by technical combination of alternate splitting and successive approximating of the algebraic Riccati operators. These methods include one iteration parameter, and suitable choices of this parameter may result in fast convergent iteration methods. Under suitable conditions, we prove the monotone convergence and estimate the asymptotic convergence factor of the ALI iteration matrix sequences. Numerical experiments show that the ALI iteration methods are feasible and effective, and can outperform the Newton iteration method and the fixed-point iteration methods. Besides, we further generalize the known fixed-point iterations, obtaining an extensive class of relaxed splitting iteration methods for solving the non-symmetric algebraic Riccati equations. Copyright © 2006 John Wiley & Sons, Ltd. [source] Response of pine natural regeneration to small-scale spatial variation in a managed Mediterranean mountain forestAPPLIED VEGETATION SCIENCE, Issue 4 2009Ignacio Barbeito Abstract Questions: What influence do management practices and previous tree and shrub stand structure have on the occurrence and development of natural regeneration of Pinus sylvestris in Mediterranean mountain forests? How are the fine-scale and environmental patterns of resources affected and what impact does this have on the distribution of the regeneration? Location: A Pinus sylvestris Mediterranean mountain forest in central Spain. Methods: Upperstory trees and regeneration (seedlings and saplings) were mapped in four 0.5-ha plots located in two types of stand with different management intensities (even-aged and uneven-aged stands). Environmental variables were recorded at the nodes of a grid within the plots. The relationships between the upperstory and regeneration were evaluated by bivariate point pattern analysis; redundancy analysis ordination and variation partitioning were performed to characterize regeneration niches and the importance of the spatial component. Results: Seedlings and saplings presented a clumped structure under both types of management and their distribution was found to be related to the spatial distribution of favourable microsites. Regeneration was positively related to conditions of partial cover with high soil water content during the summer. More than half of the explained variance was spatially structured in both types of stand. This percentage was particularly high in the even-aged stands where the pattern of regeneration was highly influenced by the gaps created by harvesting. Conclusions: The spatial distribution of the tree and shrub upperstory strongly influences regeneration patterns of P. sylvestris. Current management practices, promoting small gaps, partial canopy cover and moderate shade in even-aged stands, or favouring tree and shrub cover in the case of uneven-aged stands, appears to provide suitable conditions for the natural regeneration of P. sylvestris in a Mediterranean climate. [source] | |||||||||||||||||||||||||||||||