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Absorption Efficiency (absorption + efficiency)
Selected AbstractsThe effect of body size on food consumption, absorption efficiency, respiration, and ammonia excretion by the inland silverside, Menidia beryllina (Cope) (Osteichthyes: Atherinidae)JOURNAL OF APPLIED ICHTHYOLOGY, Issue 4 2003M. A. Peck Summary The inland silverside, Menidia beryllina (Cope), is an annual zooplanktivore that occurs in estuarine and freshwater habitats along the Atlantic and Gulf of Mexico coasts and drainages of the United States. Experiments were conducted at 25 ± 1°C to quantify the relationship between mean dry weight (WD) and rates of energy gain from food consumption (C), and energy losses as a result of respiration (R) and ammonia excretion (E) during routine activity and feeding by groups of fish. The absorption efficiency of ingested food energy (A) was also quantified. Rates of C, E, and R increased with WD by factors (b in the equation y = aWDb) equal to 0.462, 0.667, and 0.784, respectively. Mean (±SE) rates of energy loss during feeding were 1.6 ± 0.1 (R) and 3.4 ± 0.6 (E) times greater than those for unfed fish. Absorption efficiency was independent of WD and estimated to be 89% of C. From these measurements, the surplus energy available for growth and activity (G) and growth efficiency (K1) were estimated. Over the range in sizes of juveniles and adults (5,500 mg WD), predicted G and K1 values decreased from 7.42 to 0.20 J mg fish,1 day,1 and 63 to 21%, respectively. Measured and predicted bioenergetic parameters are discussed within an ecological context for a northern population of this species. [source] Dietary absorption efficiencies and toxicokinetics of polychlorinated biphenyls in ring doves following exposure to aroclor® mixturesENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 11 2000Ken G. Drouillard Abstract Ring doves (Streptotpelia risoria) were fed a meal of pellets spiked with an Aroclor® mixture. Feces were collected from birds after fasting 31 h postexposure and dietary absorption efficiencies (AbE) of polychlorinated biphenyls (PCBs) were determined by mass balance. Polychlorinated biphenyl AbEs ranged from 0.86 to 0.97 for individual congeners and were similar to the lipid AbE of 0.90. The AbEs exhibited a declining trend with increasing chemical hydrophobicity. The toxicokinetics of PCBs and dietary lipids in blood plasma were also followed in the exposed birds for 25 h after feeding the contaminated meal. Despite decreasing trends in net AbEs with increasing chemical hydrophobicity, all PCBs exhibited similar blood toxicokinetics as observed for dietary lipids. The PCB plasma uptake rate constants exhibited a positive correlation with chemical hydrophobicity such that the most hydrophobic congener PCB 180 approached the plasma uptake rate constant measured for dietary lipids. Trends in assimilation kinetics of PCBs in blood were not consistent with the general prediction that solubility limitations of chemicals in the unstirred water layer (UWL) contribute to declines in net AbEs for highly hydrophobic chemicals. The data are consistent with a micelle-mediated diffusion model, which indicates that dietary lipids and hydrophobic contaminants can cross the UWL and enter intestinal tissues at equivalent rates; however, solubility limitations of highly hydrophobic chemicals in mixed micelles may contribute to decline in net AbEs. [source] Association among growth, food consumption-related traits and amylase gene polymorphism in the Pacific oyster Crassostrea gigasANIMAL GENETICS, Issue 6 2008A. Huvet Summary To examine further a previously reported association between amylase gene polymorphism and growth in the Pacific oyster Crassostrea gigas, ecophysiological parameters and biochemical and molecular expression levels of ,-amylase were studied in Pacific oysters of different amylase genotypes. Genotypes that previously displayed significantly different growth were found to be significantly different for ingestion and absorption efficiency. These estimated parameters, used in a dynamic energy budget model, showed that observed ingestion rates (unlike absorption efficiencies) allowed an accurate prediction of growth potential in these genotypes. The observed association between growth and amylase gene polymorphism is therefore more likely to be related to ingestion than to absorption efficiency. Additionally, relative mRNA levels of the two amylase cDNAs were also strongly associated with amylase gene polymorphism, possibly reflecting variation in an undefined regulatory region, although no corresponding variation was observed in specific amylase activity. Amylase gene sequences were determined for each genotype, showing the existence of only synonymous or functionally equivalent non-synonymous polymorphisms. The observed associations among growth, food consumption-related traits and amylase gene polymorphism are therefore more likely to be related to variation in the level of amylase gene expression than to functional enzymatic variants. [source] Experimental study of flue gas desulfurization using landfill leachateENVIRONMENTAL PROGRESS & SUSTAINABLE ENERGY, Issue 1 2007Ding Sang-lan Abstract Because of the complexity of landfill leachate's composition, the reaction mechanism of SO2 in flue gas with landfill leachate was studied. The experimental results indicated that the factors influencing SO2 absorption efficiency using landfill leachate as the scrubbing medium were, in decreasing order of importance, pH, Fe2+, Mn2+, and Cl, as catalysts and the concentration of toluene and ethanol. Experiments showed that the pH of landfill leachate was the key factor governing both SO2 absorption and ammonia stripping. With the initial pH of 8.5, the terminal pH 6.0 and L/G ratio 3 L/m3, experimental results showed that average absorption efficiency of SO2 and the stripping efficiency of ammonia were 85 and 44%, respectively. The use of catalysts such as Fe2+ and Mn2+ was important for SO2 absorption when the pH value was below 7.0. The catalytic activity of Mn2+ was greater than that of Fe2+ although the reaction steps were very similar. Ethanol inhibits HSO3,/SO32, oxidation. The HSO3,/SO32, oxidation process improves the solubility of organics such as toluene in the leachate. The solute products of organics were water-soluble and biodegradable and could be used as substrates for bacteria in the post biotreatment. The factorial experiment results showed the effect of Cl,, Fe2+, and Mn2+ as catalysts on the HSO3,/SO32, oxidation has a greater positive impact than ethanol's inhibitory effect on the HSO3,/SO32, oxidation. © 2006 American Institute of Chemical Engineers Environ Prog 26:25,32, 2007 [source] Light acclimation of Chlamydomonas acidophila accumulating in the hypolimnion of an acidic lake (pH 2.6)FRESHWATER BIOLOGY, Issue 8 2005ANTJE GERLOFF-ELIAS Summary 1. The unicellular green alga Chlamydomonas acidophila accumulates in a thin phytoplankton layer in the hypolimnion (deep chlorophyll maximum, DCM) of an extremely acidic lake (Lake 111, pH 2.6, Lusatia, Germany), in which the underwater light spectrum is distorted and red-shifted. 2. Chlamydomonas acidophila exhibited a significantly higher absorption efficiency and a higher cellular chlorophyll b content when incubated in the red shifted underwater light of Lake 111 than in a typical, blue-green dominated, light spectrum. 3. Chlamydomonas acidophila has excellent low light acclimation properties (increased chlorophyll b content, increased oxygen yield and a low light saturation point for photosynthesis) that support survival of the species in the low light climate of the DCM. 4. In situ acclimation to the DCM under low light and temperature decreased maximum photosynthetic rate in autotrophic C. acidophila cultures, whereas the presence of glucose under these conditions enhanced photosynthetic efficiency and capacity. 5. The adaptive abilities of C. acidophila to light and temperature shown in this study, in combination with the absence of potent competitors because of low lake pH, most probably enable the unusual dominance of the green alga in the DCM of Lake 111. [source] Quantifying anomalous intestinal sterol uptake, lymphatic transport, and biliary secretion in Abcg8,/, mice,,HEPATOLOGY, Issue 4 2007Helen H. Wang Sitosterolemia is caused by mutations in either ABCG5 or ABCG8, but simultaneous mutations of these genes have never been observed. To explore whether ABCG8, the sterol efflux (hemi-)transporter, plays a major role in determining intestinal absorption efficiency and hepatic secretion rates of cholesterol and sitostanol, we performed direct measurements of the absorption and lymphatic transport of these sterols in mice with chronic biliary and lymphatic fistulae, as well as the transport rates of radiolabeled cholesterol and sitostanol from plasma high-density lipoprotein (HDL) into bile in male Abcg8,/, and wild-type mice. We observed that the absorption and lymphatic transport rates of radiolabeled cholesterol and sitostanol were increased by ,40% and ,500%, respectively, in Abcg8,/, mice in the setting of constant intraduodenal infusion of micellar taurocholate and lecithin. Both strains displayed identical intestinal Npc1l1 expression levels and small intestinal transit rates. After 45 minutes of intraduodenal infusion, acute intestinal uptake rates of trace [14C]cholesterol and [3H]sitostanol were essentially similar in both groups of mice with intact biliary secretion. Furthermore, in wild-type mice, mass transport rate of [3H]sitostanol from plasma HDL into bile was significantly faster than that of [14C]cholesterol; however, no [3H]sitostanol and only traces of [14C]cholesterol were detected in bile of Abcg8,/, mice. Conclusion: Deletion of the Abcg8 gene alone significantly increases the mass of intestinal cholesterol and sitostanol absorption and reduces but does not eliminate hepatic secretion of cholesterol. Moreover, the mutation has no influence on acute uptake of cholesterol and sitostanol by the enterocyte nor small intestinal transit time. (HEPATOLOGY 2007;45:998,1006.) [source] Chromium nanoparticle exhibits higher absorption efficiency than chromium picolinate and chromium chloride in Caco-2 cell monolayersJOURNAL OF ANIMAL PHYSIOLOGY AND NUTRITION, Issue 2 2008L.-Y. Zha Summary This study was conducted to determine whether chromium nanoparticle (CrNano) exhibited higher absorption efficiency and possessed unique absorption mechanism in comparison to chromium picolinate (CrPic) and chromium chloride (CrCl3), as was postulated by previous reports. Twenty-one-day-old Caco-2 cell monolayers grown on semipermeable membranes in Snapwell tissue culture bichambers were incubated with CrNano, CrPic or CrCl3 to examine their transport and uptake respectively. In the concentration range of 0.2,20 ,mol/l, transport of CrNano, CrPic and CrCl3 across Caco-2 monolayers both in apical-to-basolateral and basolateral-to-apical direction was concentration-, and time-dependent, and temperature independent. The apparent permeability coefficient (Papp) of CrNano was between 5.89 and 7.92 × 10,6 cm/s and that of CrPic and CrCl3 was between 3.52 and 5.31 × 10,6 cm/s and between 0.97 and 1.37 × 10,6 cm/s respectively. Uptake of CrNano, CrPic and CrCl3 by both apical and basolateral membranes was concentration- and time-dependent. Uptake of CrNano by apical membrane was significantly (p < 0.05) decreased when the incubation temperature was reduced from 37 °C to 4 °C. The transport efficiency of CrNano, CrPic and CrCl3 after incubation for 120 min at 37 °C was 15.83% ± 0.76%, 9.08% ± 0.25% and 2.11% ± 0.53% respectively. The uptake efficiency of CrNano, CrPic and CrCl3 was 10.08% ± 0.76%, 4.73% ± 0.60% and 0.88% ± 0.08% respectively. It was concluded that the epithelial transport of CrNano, CrPic and CrCl3 across the Caco-2 cell monolayers was mainly via passive transport pathways. In addition, CrNano exhibited considerably higher absorption efficiency than both CrPic and CrCl3 in Caco-2 cell monolayers. [source] The effect of body size on food consumption, absorption efficiency, respiration, and ammonia excretion by the inland silverside, Menidia beryllina (Cope) (Osteichthyes: Atherinidae)JOURNAL OF APPLIED ICHTHYOLOGY, Issue 4 2003M. A. Peck Summary The inland silverside, Menidia beryllina (Cope), is an annual zooplanktivore that occurs in estuarine and freshwater habitats along the Atlantic and Gulf of Mexico coasts and drainages of the United States. Experiments were conducted at 25 ± 1°C to quantify the relationship between mean dry weight (WD) and rates of energy gain from food consumption (C), and energy losses as a result of respiration (R) and ammonia excretion (E) during routine activity and feeding by groups of fish. The absorption efficiency of ingested food energy (A) was also quantified. Rates of C, E, and R increased with WD by factors (b in the equation y = aWDb) equal to 0.462, 0.667, and 0.784, respectively. Mean (±SE) rates of energy loss during feeding were 1.6 ± 0.1 (R) and 3.4 ± 0.6 (E) times greater than those for unfed fish. Absorption efficiency was independent of WD and estimated to be 89% of C. From these measurements, the surplus energy available for growth and activity (G) and growth efficiency (K1) were estimated. Over the range in sizes of juveniles and adults (5,500 mg WD), predicted G and K1 values decreased from 7.42 to 0.20 J mg fish,1 day,1 and 63 to 21%, respectively. Measured and predicted bioenergetic parameters are discussed within an ecological context for a northern population of this species. [source] Relating the ontogeny of functional morphology and prey selection with larval mortality in Amphiprion frenatusJOURNAL OF MORPHOLOGY, Issue 6 2010Justin Anto Abstract Survival during the pelagic larval phase of marine fish is highly variable and is subject to numerous factors. A sharp decline in the number of surviving larvae usually occurs during the transition from endogenous to exogenous feeding known as the first feeding stage in fish larvae. The present study was designed to evaluate the link between functional morphology and prey selection in an attempt to understand how the relationship influences mortality of a marine fish larva, Amphiprion frenatus, through ontogeny. Larvae were reared from hatch to 14 days post hatch (DPH) with one of four diets [rotifers and newly hatched Artemia sp. nauplii (RA); rotifers and wild plankton (RP); rotifers, wild plankton, and newly hatched Artemia nauplii (RPA); wild plankton and newly hatched Artemia nauplii (PA)]. Survival did not differ among diets. Larvae from all diets experienced mass mortality from 1 to 5 DPH followed by decreased mortality from 6 to 14 DPH; individuals fed RA were the exception, exhibiting continuous mortality from 6 to 14 DPH. Larvae consumed progressively larger prey with growth and age, likely due to age related increase in gape. During the mass mortality event, larvae selected small prey items and exhibited few ossified elements. Cessation of mass mortality coincided with consumption of large prey and ossification of key elements of the feeding apparatus. Mass mortality did not appear to be solely influenced by inability to establish first feeding. We hypothesize the interaction of reduced feeding capacities (i.e., complexity of the feeding apparatus) and larval physiology such as digestion or absorption efficiency contributed to the mortality event during the first feeding period. J. Morphol., 2010. © 2010 Wiley-Liss, Inc. [source] Rigorous modeling of UV absorption by TiO2 films in a photocatalytic reactorAICHE JOURNAL, Issue 7 2000Z. Zhang The radiation absorption profiles on the surfaces of TiO2 films in a corrugated-plate photocatalytic reactor were modeled based on first principles. A new term, the local-area-specific rate of energy absorption (LASREA), was adopted to describe the catalyst surface radiation in heterogeneous photoreactors. The LASREA and the energy absorption efficiency were both quite sensitive to the dimensions of the corrugated plates. Due to the multiple photon reflections between the opposing surfaces, corrugated plates possess a superior capability for recapturing longer wavelength photons that would otherwise be reflected out of some reactor designs. This results in higher energy absorption efficiency and more uniform LASREA on the catalyst films. Compared to a flat plate, corrugations are predicted to enhance the energy absorption efficiency by up to 50% for UV-A fluorescent-lamp-powered systems and more than 100% for solar-powered systems. [source] 2-Ethylhexyl-2,4,5-trimethoxycinnamate and di-(2-ethylhexyl)-2,4,5-trimethoxybenzalmalonate as novel UVA filtersJOURNAL OF PHARMACY AND PHARMACOLOGY: AN INTERNATI ONAL JOURNAL OF PHARMACEUTICAL SCIENCE, Issue 2 2007Thitinun Monhaphol A series of 2-ethylhexylmethoxy substituted cinnamates and benzalmalonates have been synthesized and characterized. 2-Ethylhexyl-2,4,5-trimethoxycinnamate (E8) and di-(2-ethylhexyl)-2,4,5-trimethoxybenzalmalonate (B8) show UVA absorption with high molar absorption coefficients (12000-14000 cm,1 M,1 at 350 nm). E8 undergoes trans to cis photoisomerization under UVA exposure causing the decrease in UV absorption efficiency. E8 is more photostable than butyl methoxydibenzoylmethane (BMDBM). For example, 41.64 J cm,2 UVA irradiation produces 20 ± 2% and 25 ± 2% loss in UV absorption for E8 and BMDBM, respectively. Similar irradiation produces no change in the UV absorption of B8. Both the oily liquid E8 and the yellow solid B8 can be dissolved in various organic solvents, ranging from methanol to hexane, various silicone fluids and 2-ethylhexyl-4-trimethoxycinnamate (EHMC, a widely used UVB filter). A liquid broadband filter comprising B8 and EHMC shows excellent photostability in both UVB and UVA regions. [source] Edge-pumped asymmetric Yb:YAG/YAG thin disk laserLASER PHYSICS LETTERS, Issue 10 2007Q. Liu Abstract An edge-pumping scheme for a quasi-three-level solid-state laser using asymmetric crystal is reported. The scheme uses a thin disk laser configuration with the pump light incident from disk edges. The pump light propagates through the disk along the zigzag path and repeatedly passes the gain medium, thus improving the pump uniformity and absorption efficiency. A maximum output power of over 123 W was achieved from an edge-pumped composite Yb:YAG/YAG thin disk laser, with slope efficiency of 34.8% and beam quality M2 , 20. (© 2007 by Astro Ltd., Published exclusively by WILEY-VCH Verlag GmbH & Co. KGaA) [source] Temperature-tuning Yb:YAG microchip lasersLASER PHYSICS LETTERS, Issue 9 2005Jun Dong Abstract Based on the quasi-three-level system, a theoretical model of diode-laser end-pumped fundamental continuous-wave (CW) Yb3+:YAG microchip lasers is proposed. The fluorescence concentration quenching effect, the temperature dependent mechanical and optical properties and the absorption efficiency of the host have been taken into account in the model. The theoretical results of the numerical calculations are in good agreement with those of experiments. The effects of the concentration of the Yb3+:YAG crystal, the thickness of the Yb3+:YAG crystal, the temperature and the transmission of the output coupler on the laser performance (threshold and output power) are addressed. The optimization of the concentration and the thickness for the Yb3+:YAG crystal microchip laser is presented. The effects of the temperature and the pump power intensity on the optical-tooptical efficiency are discussed. The output power can be scaled by increase the working area of the laser gain medium. This modeling is not only applicable to Yb3+:YAG crystal microchip laser but also to other quasi-three-level microchip lasers. (© 2005 by Astro, Ltd. Published exclusively by WILEY-VCH Verlag GmbH & Co. KGaA) [source] Comparison between laser-induced nucleation of ZnS and CdS nanocrystals directly into polymer matricesPOLYMER COMPOSITES, Issue 6 2010Athanassia Athanassiou The nucleation of two kinds of crystalline nanoparticles, zinc sulfide (ZnS), and cadmium sulfide (CdS), is achieved directly into specific sites of polymer matrices after their irradiation with UV laser pulses. The starting samples consist of polymers doped with precursors of Zn or Cd thiolate that are proved to decompose after the absorption of UV light, resulting into the nanoparticles formation. The growth of the crystalline nanostructures is followed throughout the irradiation of the samples with successive incident pulses, by different methods, such as transmission electron microscopy, atomic force microscopy, confocal microscopy, and X-ray diffraction. Special attention is paid to the difference of the formation pathways of the two kinds of nanoparticles studied, because the Cd thiolate precursor exhibits much higher absorption efficiency than the Zn thiolate one, at the applied UV wavelength. Indeed, CdS nanoparticles become evident after the very first incident UV pulses, whereas the formation of ZnS nanocrystals requires rather prolonged irradiation, always through a macroscopically nondestructive procedure for the polymer matrix. POLYM. COMPOS., 2010. © 2009 Society of Plastics Engineers [source] Association among growth, food consumption-related traits and amylase gene polymorphism in the Pacific oyster Crassostrea gigasANIMAL GENETICS, Issue 6 2008A. Huvet Summary To examine further a previously reported association between amylase gene polymorphism and growth in the Pacific oyster Crassostrea gigas, ecophysiological parameters and biochemical and molecular expression levels of ,-amylase were studied in Pacific oysters of different amylase genotypes. Genotypes that previously displayed significantly different growth were found to be significantly different for ingestion and absorption efficiency. These estimated parameters, used in a dynamic energy budget model, showed that observed ingestion rates (unlike absorption efficiencies) allowed an accurate prediction of growth potential in these genotypes. The observed association between growth and amylase gene polymorphism is therefore more likely to be related to ingestion than to absorption efficiency. Additionally, relative mRNA levels of the two amylase cDNAs were also strongly associated with amylase gene polymorphism, possibly reflecting variation in an undefined regulatory region, although no corresponding variation was observed in specific amylase activity. Amylase gene sequences were determined for each genotype, showing the existence of only synonymous or functionally equivalent non-synonymous polymorphisms. The observed associations among growth, food consumption-related traits and amylase gene polymorphism are therefore more likely to be related to variation in the level of amylase gene expression than to functional enzymatic variants. [source] Influence of dietary polar lipids' quantity and quality on ingestion and assimilation of labelled fatty acids by larval gilthead seabreamAQUACULTURE NUTRITION, Issue 3 2001Izquierdo Dietary supplementation of phospholipids seems to be extremely important to promote growth and survival in fish larvae. Several studies also suggest the importance of n-3 highly unsaturated fatty acids (HUFA) rich phospholipids to further enhance larval performance. In the present study, four different diets were formulated in order to compare the effect of total dietary polar lipid contents, of soya bean lecithin supplementation and of feeding n-3 HUFA in the form of neutral or polar lipids on ingestion and incorporation of labelled fatty acids in gilthead seabream larvae. These diets were prepared including radiolabelled fatty acids from palmitoyl phosphatidylcholine, glycerol trioleate, free oleic acid (FOA) and free eicosapentaenoic acid (FEPA) and were fed to 25 day-old larvae. The results of these experiments showed that the elevation of the dietary polar lipid levels significantly improved microdiet ingestion, regardless of the origins of the polar lipids. This effect caused an improved incorporation of phosphatidylcholine fatty acids to the larval polar and total lipids (TL) as the dietary polar lipids increased. Nevertheless, a better incorporation of fatty acids from dietary polar lipids in comparison with that of fatty acids from dietary triglycerides into larval lipids was found in gilthead seabream, whereas a better utilization of dietary triglycerides fatty acids than dietary free fatty acids could also be observed. Besides, the presence of n-3 HUFA rich neutral lipids (NL) significanlty increased the absorption efficiency of labelled oleic acid from dietary triglycerides, but the presence of n-3 HUFA rich polar lipids, particularly improved the incorporation of FEPA. This fatty acid was preferentially incorporated into larval polar lipids in comparison with FOA. [source] Simulation of the Carbonate Looping Process for Post-Combustion CO2 Capture from a Coal-Fired Power PlantCHEMICAL ENGINEERING & TECHNOLOGY (CET), Issue 3 2009J. Ströhle Abstract The present contribution focuses on the carbonate looping process, i.e., post-combustion CO2 capture by means of CaO containing solid sorbents in a system of two circulating fluidized bed reactors. Material and energy balances were performed using the ASPEN PLUSTM software. Two different modeling approaches are applied to the carbonator. First, the entire active fraction of CaO is assumed to be converted; second, the CO2 absorption efficiency in the circulating fluidized bed is calculated using an analytical 1D model for fast fluidization. The absorption of SO2 by CaO is taken into account. The overall plant efficiency depends on the mass flows of fresh limestone and circulating CaO. The process is shown to be economically feasible, having low energy penalties in comparison with other CO2 capture technologies and it seems to be suited for retro-fitting existing power plants. [source] | |||||||||||||||||||