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Absorption
Kinds of Absorption Terms modified by Absorption Selected AbstractsIODINE-FORTIFIED RICE AND ITS ABSORPTIONJOURNAL OF FOOD BIOCHEMISTRY, Issue 2 2009VANNA TULYATHAN ABSTRACT Iodine deficiency remains a major health problem in many parts of Thailand with over 50% of the population lacking sufficient iodine in their diet. Since rice is the main staple for Thai people with rice consumed in one form or another in almost every meal, enrichment of rice with iodine offers an effective way to remedy this deficiency of iodine. The present paper investigates the enrichment of iodine in milled rice seeds using flour gel coating technique. Milled rice (Klong-laung 1 variety) was coated with iodine-enriched flour gel (rice : gel = 100:5 w/w) by mixing at 40 rpm and drying to less than 13% moisture. Washing or cooking of the iodine-enriched rice resulted in about 99% and 94% retention of original iodine, respectively. Sensory properties of the cooked rice were acceptable and almost comparable to non-iodine rice. When the iodine-fortified rice was fed to healthy male and female subjects, significant excretion of iodine in the urine was found. PRACTICAL APPLICATION A common form of rice consumed widely among Thai people (also popular in Laos and Cambodia) is a food known simply as "sticky rice." The reason for its popularity is the simple way it is prepared and, above all, its good taste. It is made from a short type of rice and when prepared, the resulting texture is quite sticky, thus its name. However, its nutritional value is quite low and is a good candidate for the introduction of iodine coating. It can be made by a quick steaming process and this simplicity in preparation makes it widely popular and can be a vehicle for the introduction of iodine to the local mass. [source] WATER ABSORPTION, LEACHING and COLOR CHANGES DURING the SOAKING FOR PRODUCTION of SOY-BULGURJOURNAL OF FOOD PROCESS ENGINEERING, Issue 2 2004MUSTAFA BAYRAM ABSTRACT In this study, the soaking process, which is the first step of soy-bulgur production to develop a new type food product, was investigated. the soaking operation was conducted at 30, 50 and 70C for 120 min and samples were taken from the soybean and soaking water at 10 min intervals. Moisture content and color (L, a, b and YI values) of soybean were measured, as well as soluble solids content and color (L, a, b and YI values) of soaking water during the soaking process. the results were analyzed by using ANOVA and Duncan test. Soaking time and temperature were significantly effective (P < 0.05) on all variables, except the time effect on the YI-value. During the soaking, moisture content, lightness (L) and yellowness (b) increased and, redness (a) and yellowness index (YI) of soybean decreased. Soluble solids content, yellowness and yellowness index increased in contrast to a decrease in the lightness and greenness of the soaking water. As a result, soluble solids content in the soaking water increased, which illustrated the leaching of soluble solids from soybean to water. Color of soybean turned to lights, in contrast to darkening and opaqueness of water during soaking. Results showed that the moisture content, soluble solid content, L, a, b and YI values can be successfully modeled using polynomial equations, which can be used to estimate their changes during the soaking operation. [source] PHOTOSYNTHETIC PERFORMANCE, LIGHT ABSORPTION, AND PIGMENT COMPOSITION OF MACROCYSTIS PYRIFERA (LAMINARIALES, PHAEOPHYCEAE) BLADES FROM DIFFERENT DEPTHS,JOURNAL OF PHYCOLOGY, Issue 6 2006María Florencia Colombo-Pallotta Macrocystis pyrifera (L.) C. Agardh is a canopy-forming species that occupies the entire water column. The photosynthetic tissue of this alga is exposed to a broad range of environmental factors, particularly related to light quantity and quality. In the present work, photosynthetic performance, light absorption, pigment composition, and thermal dissipation were measured in blades collected from different depths to characterize the photoacclimation and photoprotection responses of M. pyrifera according to the position of its photosynthetic tissue in the water column. The most important response of M. pyrifera was the enhancement of photoprotection in surface and near-surface blades. The size of the xanthophyll cycle pigment pool (XC) was correlated to the nonphotochemical quenching (NPQ) of chl a fluorescence capacity of the blades. In surface blades, we detected the highest accumulation of UV-absorbing compounds, photoprotective carotenoids, ,XC, and NPQ. These characteristics were important responses that allowed surface blades to present the highest maximum photosynthetic rate and the highest PSII electron transport rate. Therefore, surface blades made the highest contribution to algae production. In contrast, basal blades presented the opposite trend. These blades do not to contribute significantly to photosynthetate production of the whole organism, but they might be important for other functions, like nutrient uptake. [source] The Attentional Resource Allocation Scale (ARAS): psychometric properties of a composite measure for dissociation and absorption,DEPRESSION AND ANXIETY, Issue 8 2010R. N. Carleton M.A. Abstract Background: Differences in attentional processes have been linked to the development and maintenance of psychopathology. Shifts in such processes have been described by the constructs Dissociation and Absorption. Dissociation occurs when external and/or internal stimuli are excluded from consciousness due to discrepant, rather than unitary, manifestations of cognitive awareness [Erdelyi MH. 1994: Int J Clin Exp Hypnosis 42:379,390]. In contrast, absorption can be conceptualized by a focus on limited stimuli, to the exclusion of other stimuli, because of unifying, rather than discrepant, manifestations of cognitive awareness. The Dissociative Experiences Scale [DES; Bernstein EM, Putnam FW. 1986: J Nerv Ment Dis 174:727,735] and Tellegen Absorption Scale [TAS; Tellegen A, Atkinson G. 1974: J Abnorm Psychol 83:268,277] are common measures of each construct; however, no factor analyses are available for the TAS and despite accepted overlap, no one has assessed the DES and TAS items simultaneously. Previous research suggests the constructs and factor structures need clarification, possibly including more parsimonious item inclusion [Lyons LC, Crawford HJ. 1997: Person Individ Diff 23:1071,1084]. The purpose of this study was to evaluate the factor structure of the DES and TAS and create a psychometrically stable measure of Dissociation and Absorption. Methods: This study included data from an undergraduate (n=841; 76% women) and a community sample (n=233; 86% women) who each completed the DES and TAS. Results: Exploratory factor analyses [Osborne JW (ed). 2008: Best Practices in Quantitative Methods. Los Angeles: Sage Publications Inc.] with all DES and TAS items suggested a 15-item 3-factor solution (i.e., imaginative involvement, dissociative amnesia, attentional dissociation). Confirmatory factor analyses resulted in excellent fit indices for the same solution. Conclusions: The items and factors were conceptualized in line with precedent research as the Attentional Resource Allocation Scale (ARAS). Comprehensive results, implications, and future research directions are discussed. Depression and Anxiety, 2010. © 2010 Wiley-Liss, Inc. [source] Suppression of electromagnetic radiation noise from wireless modules in the millimeter-wave band by means of alumina containing carbon blackELECTRONICS & COMMUNICATIONS IN JAPAN, Issue 10 2010Yasuharu Takase Abstract Unwanted electromagnetic (EM) radiation generated from wireless modules in the millimeter-wave band used for car radar creates errors and results in performance degradation of electronic equipment. In this paper, to reduce these unwanted EM waves, an optimal design to add the function of EM wave absorption to the lid for the module is examined. Alumina-containing carbon black is used as a wave absorption material for the lid. Absorption of 20 dB or more is obtained as a measured result with the cover added for EM wave absorption at 60 GHz. The wireless module was also analyzed in the millimeter-wave band with the designed material used for the lid. The radiation and the reflection of electric power were greatly reduced by the loss electric power from the lid. Therefore, effective data for suppressing unwanted EM radiation noise from wireless modules in the millimeter-wave band can be provided. © 2010 Wiley Periodicals, Inc. Electron Comm Jpn, 93(10): 25,33, 2010; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/ecj.10216 3 [source] Absorption of H2S in NaOCl caustic aqueous solutionENVIRONMENTAL PROGRESS & SUSTAINABLE ENERGY, Issue 3 2001Luke Chen Pilot plant experimental data were collected to study the feasibility of H2S removal from air streams utilizing aqueous solutions. Solutions of NaOCl/NaOH were tested in a packed bed scrubber and found to be effective. An efficiency of 99.2% H2S removal was achieved at a gas flow rate of 790 lb/f2 -hr and liquid-gas ratio of 5.06. Sodium hydroxide was found to be the active ingredient in the absorption process. A minimum alkalinity of pH 11 in the scrubbing solution was required for the H2S to be efficiently absorbed in the packed bed scrubber. For gas flow rates up to 2,100 lb/f2 hr, the height of a transfer unit (HTU) varied from 1.8 ft to 2 ft with different proportions of NaOCl and NaOH in the solution. [source] Dynamics of 17,-Ethynylestradiol exposure in rainbow trout (Oncorhynchus mykiss): Absorption, tissue distribution, and hepatic gene expression patternENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 11 2006Ann D. Skillman Abstract 17,-Ethynylestradiol (EE2) is a synthetic estrogen identified in sewage effluents. To understand better the absorption kinetics of EE2 and the induction of vitellogenin (VTG) and estrogen receptor , (ER,) mRNA, we subjected male rainbow trout (Onchorynchus mykiss) to continuous water exposures of 125 ng/L of EE2 for up to 61 d. Trout were either repetitively sampled for blood plasma or serially killed at selected time intervals. Vitellogenin, ER, mRNA, and EE2 were measured using enzymelinked immunosorbent assay and using quantitative polymerase chain reaction and gas chromatography,mass spectrometry, respectively. In separate experiments, trout were exposed to EE2 for 7 d, and hepatic gene expression was assessed using a low- and high-density cDNA microarray. The EE2 was rapidly absorbed by the trout, with an apparent equilibrium at 16 h in plasma and liver. The ER, mRNA levels also increased rapidly, reaching near-peak levels by 48 h. In contrast, plasma levels of VTG continuously increased for 19 d. After 61 d, tissues with the highest levels of VTG were the liver, kidney, and testes. Microarray-based gene expression studies provided unexpected results. In some cases, known estrogen-responsive genes (e.g., ER,) were unresponsive, whereas many of the genes that have no apparent link to estrogen function or EE2 toxicity were significantly altered in expression. Of the two microarray approaches tested in the present study, the high-density array appeared to be superior because of the improved quality of the hybridization signal and the robustness of the response in terms of the number of genes identified as being EE2 responsive. [source] Absorption of copper(II) by creosote bush (Larrea tridentata): Use of atomic and x-ray absorption spectroscopyENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 11 2001Jorge Luis Gardea-Torresdey Abstract Larrea tridentata (creosote bush), a common North American native desert shrub, exhibits the ability to take up copper(II) ions rapidly from solution. Following hydroponic studies, U.S. Environmental Protection Agency method 200.3 was used to digest the plant samples, and flame atomic absorption spectroscopy (FAAS) was used to determine the amount of copper taken up in different parts of the plant. The amount of copper(II) found within the roots, stems, and leaves was 13.8, 1.1, and 0.6 mg/g, respectively, after the creosote bush was exposed to a 63.5-ppm copper(II) solution for 48 h. When the plant was exposed to a 635-ppm copper(II) solution, the roots, stems, and leaves contained 35.0, 10.5, and 3.8 mg/g, respectively. In addition to FAAS analysis, x-ray microfluorescence (XRMF) analysis of the plant samples provided further confirmation of copper absorption by the various plant parts. X-ray absorption spectroscopy (XAS) elucidated the oxidation state of the copper absorbed by the plants. The copper(II) absorbed from solution remained as copper(II) bound to oxygen-containing ligands within the plant samples. The results of this study indicate that creosote bush may provide a useful and novel method of removing copper(II) from contaminated soils in an environmentally friendly manner. [source] Effect of bile salts, lipid, and humic acids on absorption of benzo[a]pyrene by isolated channel catfish (Ictalurus punctatus) intestine segmentsENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 5 2001Lynn P. Weber Abstract Dietary absorption of lipophilic contaminants may be a significant route of exposure in aquatic organisms. Bile salts, lipids, and humic acids are important factors that may influence the intestinal absorption of a contaminant such as benzo[a]pyrene (BaP). We hypothesized that bile salts, monoglycerides, and free fatty acids would increase BaP intestinal absorption, while triglycerides, humic acids, and sediment would decrease BaP intestinal absorption. We have established and validated an in vitro model to examine modification of 3H-BaP absorption in everted intestinal segments from channel catfish (Ictalurus punctatus). Uptake of BaP into the everted intestinal segments continued to increase over the times examined in this study (60 min) and apparently occurs passively; thus, fugacity-based models of uptake are supported. Absorption of BaP into intestinal cells was significantly decreased by the addition of monoglycerides and free fatty acids to bile salts in the incubation media. Addition of triglycerides decreased BaP absorption even further. Humic acids may have decreased BaP intestinal absorption, while natural sediment may have increased BaP absorption. The results of this study suggest that all lipids may decrease intestinal uptake of lipophilic contaminants if they remain in unabsorbable excess in the intestinal lumen by retaining BaP in lipid/bile micelles. In contrast, if triglycerides are hydrolyzed into monoglycerides/free fatty acids prior to absorption, lipophilic contaminant uptake will likely be facilitated. Thus, it may be the hydrolytic state of lipids that determines its effects on BaP absorption. Humic acids alone may decrease dietary uptake of BaP, but our results suggest that other components in natural sediment may counteract this effect to cause a slight enhancement of BaP uptake. Further studies are needed to determine the dietary conditions necessary for bio-accumulation to contribute significantly to lipophilic contaminant body burdens in benthivorous fish. Finally, the everted intestinal segment technique has the potential to be used in other species and with different contaminants. [source] Rectal Absorption of Lamotrigine Compressed TabletsEPILEPSIA, Issue 7 2000Angela K. Birnbaum Summary: Purpose: Interruption of oral drug administration poses a significant clinical problem for antiepileptic drugs that have no parenteral formulation. If a drug is absorbed rectally, rectal administration can be a useful alternative when the oral route of administration is not possible. The purpose of this study was to compare the single-dose pharmacokinetics of la-motrigine (LTG) compressed tablets after rectal and oral administration in healthy volunteers. Methods: A single LTG compressed tablet (100 mg) was administered orally and rectally to 12 volunteers in this single-dose, two-period, crossover study with a 2-week washout between doses. For rectal administration, tablets were crushed and suspended in 10 mL of water. Plasma samples were collected from 0 to 120 hr after each dose and analyzed for LTG by an HPLC method developed for this investigation. Results: LTG plasma concentrations were lower after rectal administration versus oral administration. The average area under the curve was 28.90 ± 9.5 ,g/mL/hr after rectal administration and 51.71 ± 19.2 ,g/mL/hr after oral administration. The average maximum LTG concentration was 0.53 ± 0.14 ,g/mL after rectal administration and 1.45 ± 0.35 ,g/mL after oral administration. The relative bioavailability for LTG compressed tablets was 0.63 ± 0.33 for rectal administration. There were no drug-related rashes or serious side effects. Conclusions: LTG suspension prepared from LTG compressed tablets is absorbed rectally, although not to the same extent or rate as when given orally. [source] A Ferromagnetically Coupled, Bent, Trinuclear Copper(II) Complex: Synthesis, Structure, Hydrogen-Bonding Network, Magnetic Properties and DNA Interaction StudyEUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 17 2006Sumana Sarkar Abstract A bent trinuclear copper(II) complex (1) incorporating ,-phenoxo, ,- syn - syn carboxylato, and ,3 -chloro bridges and an O,N,N -coordinated reduced Schiff-base ligand is reported. The complex shows an intramolecular ferromagnetic interaction in the solid state. The EPR spectra also support the magnetic behaviour of the complex. In the compound, each copper centre has a square-pyramidal geometry. The separation between the adjacent copper ions is about 3.05 Å and that between the terminal copper ions is about 5.0 Å. The complex forms a supramolecular architecture through N,H···Cl hydrogen bonding between the amine group of the reduced Schiff-base ligand and the counter chloride anions. Absorption and fluorescence spectral studies and viscosity measurements have been performed to determine the type of interaction with calf-thymus DNA. The nuclease activity of the complex with plasmid DNA is also studied. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006) [source] A Theoretical Investigation of Substituent Effects on the Absorption and Emission Properties of a Series of Terpyridylplatinum(II) Acetylide ComplexesEUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 10 2005Xiao-Juan Liu Abstract A comprehensive calculational investigation has been carried out on a series of complexes of the type [(terpyridyl-R1)Pt(C,C-R2)], where terpyridyl-R1 is a series of substituted 2,2':6',2"-terpyridyl ligands and C,C-R2 is a series of substituted acetylide ligands. In one series of complexes (I), the energy of the electronic excited state is varied by changing the substituents on the terpyridyl ligand (R1). In a second series of complexes (II), this electronic structure variation is obtained by changing the para substituents (R2) of the acetylide ligand. The effect of varying the substituents on the lowest-energy excited states of the complexes has been assessed by calculating their electronic structures and excitation energies. We anticipated that introduction of electron-withdrawing substituents on the terpyridyl ligand will benefit the LLCT (or MLCT) and prohibit the nonradiative pathways via d-d transitions in these complexes; introduction of electron-donating substituents on the acetylide ligand can also prohibit the nonradiative pathways by increasing the energy gaps between the HOMO,LUMO and d-d transitions. The results also reveal that the lowest-energy excitations of all complexes of series I and IIa,b complexes are dominated by a ,(C,C),,,,*(terp) (LLCT) transition mixed with some energetically d,(Pt),,,terpyridyl (MLCT) transition. However, for the complexes IIc,IId, in which phenyl rings are introduced on the acetylide ligand, the lowest-lying absorptions of IIc and IId are predominately LLCT in character, with less MLCT mixture, due to a lower contribution of the Pt(d) orbital to the HOMO, while for IIe, with a stronger donor on the acetylide, the lowest-lying absorption is completely LLCT in character. The absorption and emission calculations using the TDDFT method are based on the optimized geometries obtained at the B3LYP/LanL2DZ and CIS/LanL2DZ levels, respectively. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005) [source] Novel TRIP-Steel/Mg-PSZ Composite,Open Cell Foam Structures for Energy AbsorptionADVANCED ENGINEERING MATERIALS, Issue 3 2010Christos G. Aneziris Porous materials have received extensive attention for energy absorption in the last years. In terms of this study austenitic TRIP-steel/Mg-PSZ composite,open cell foam structures are formed based on replicas using open-celled polyurethane foam as a skeleton with and without a supporting dense face (jacket) coating. Their compression strength as well as their specific energy absorption SEA has been registered as a function of the compressive strain. The zirconia addition has reinforced the composite material with the face coating up to a compressive strain of 50%. The stress-induced martensitic transformation of partially stabilized zirconia phases has been investigated as a function of the compressive strain by EBSD. The zirconia phase transformation is triggered already at low compressive strains below 2%. [source] Comparison of pharmacokinetics and metabolism of desloratadine, fexofenadine, levocetirizine and mizolastine in humansFUNDAMENTAL & CLINICAL PHARMACOLOGY, Issue 4 2004M. Molimard Abstract Absorption, distribution, metabolism and excretion of desloratadine, fexofenadine, levocetirizine, and mizolastine in humans have been compared. The time required to reach peak plasma levels (tmax) is shortest for levocetirizine (0.9 h) and longest for desloratadine (,3 h). Steady-state plasma levels are attained after about 6 days for desloratadine, 3 days for fexofenadine, 2,3 days for mizolastine and by the second day for levocetirizine. The apparent volume of distribution is limited for levocetirizine (0.4 L/kg) and mizolastine (1,1.2 L/kg), larger for fexofenadine (5.4,5.8 L/kg) and particularly large for desloratadine (, 49 l/kg). Fexofenadine and levocetirizine appear to be very poorly metabolized (, 5 and 14% of the total oral dose, respectively). Desloratadine and mizolastine are extensively metabolized. After administration of 14C-levocetirizine to healthy volunteers, 85 and 13% of the radioactivity are recovered in urine and faeces, respectively. In contrast, faeces are the preferential route of excretion for 14C-fexofenadine (80% vs. 11% of the radioactive dose in urine). The corresponding values are 41% (urine) and 47% (faeces) for 14C-desloratadine, 84,95% (faeces) and 8,15% (urine) for 14C-mizolastine. The absolute bioavailability is 50,65% for mizolastine; it is high for levocetirizine as the percentage of the drug eliminated unchanged in the 48 h urine is 77% of the oral dose; the estimation for fexofenadine is at least 33%; no estimation was found for desloratadine. Fexofenadine is a P-glycoprotein (P-gp) substrate and P-gp is certainly involved both in the poor brain penetration by the compound and, at least partially, in a number of observed drug interactions. An interaction of desloratadine with P-gp has been suggested in mice, whereas the information on mizolastine is very poor. The fact that levocetirizine is a substrate of P-gp, although weak in an in vitro model, could contribute to prevent drug penetration into the brain, whereas it is unlikely to be of any clinical relevance for P-gp-mediated drug interactions. [source] Neutron Activation Analysis, Atomic Absorption and X-Ray Fluorescence Spectrometry Review for 2006,2007GEOSTANDARDS & GEOANALYTICAL RESEARCH, Issue 4 2008L. Paul Bédard These mature analytical techniques do not show any change in publication level from the previous two years and AAS remains dominant in terms of the number of publications. The last two years have seen fewer technical improvements than in the previous review period. Some interesting papers dealing with uncertainty and quality assurance in INAA were published during 2006,2007. It is suggested that photon activation should be reconsidered because the source of electron accelerators has recently improved. A technique to preconcentrate Se for INAA determination has also been proposed. In the case of AAS, papers on analyte preconcentration continue to be more abundant than those relating to instrumental modification. Sample preparation for AAS is also active and ultrasound-assisted leaching shows some promising applications. There were an unusual number of reviews concerned with AAS and those important to geological samples are cited here. A technique to preconcentrate Cr in water is presented and a new device to determine As and Se is showing some potential uses. Confocal X-ray mapping continues to show interesting developments. One group developed a technique to perform XRF inside an oyster and an interesting application of ,-XRF mapping of sediments is presented. Determination of platinum-group elements (at ,g g1 concentrations) can be carried out very quickly with an improved XRF technique. [source] Neutron Activation Analysis, Atomic Absorption and X-Ray Fluorescence Spectrometry Review for 2003GEOSTANDARDS & GEOANALYTICAL RESEARCH, Issue 1 2005L. Paul Bédard This review for the year 2003 deals with three relatively well-established, mature, analytical techniques (neutron activation analysis, atomic absorption spectrometry and X-ray fluorescence spectrometry) that nevertheless remain very important for the characterisation of geological and environmental samples. Developments in neutron activation analysis included modification to the technique in relation to the determination of platinum-group elements, as well as consideration of sample size in ore grade estimation. A considerable body of literature was published on the application of atomic absorption spectrometry in the analysis of environmental samples. Many of these proposed technical and methodological improvements, notably in extraction procedures. X-ray fluorescence spectrometry saw developments in in situ analysis, synchrotron micro-XRF (,-SRXRF) and a confocal X-ray set-up for 3D elemental imaging. XRF technologies were used in the analysis of geological samples, reference materials, glasses, solutes and environmental materials. [source] Preparation of Functional Hybrid Glass Material from Platinum (II) Complexes for Broadband Nonlinear Absorption of LightADVANCED FUNCTIONAL MATERIALS, Issue 2 2009Roman Zieba Abstract The synthesis of trans -di(arylalkynyl)diphosphine platinum(II) complexes bearing trialkoxysilane groups is described, as well as the preparation of siloxane-based hybrid materials from organometallic chromophores through a modified sol,gel process. Glass materials prepared from trans -[P(n,Bu)3]2Pt[(C,C,p,C6H4,C,C,p,C6H4,CH2O(CO)NH(CH2)3Si(OC2H5)3]2 generally show spectral transmittance, absorption and luminescence similar to that of solutions reported in the literature. Measurements of optical power limiting for the hybrid glass are carried out, and show broadband nonlinear absorption throughout the whole visible wavelength range with clamping values in the range 0.2,7,µJ at 120,mM chromophore concentration. The sol,gel process using urethane-propyltriethoxysilane-functionalized chromophores as precursors appears to be a valid method for formation of robust silicate materials with grafted diarylethynyl Pt(II) complexes for OPL devices. [source] Accounting for Interference, Scattering, and Electrode Absorption to Make Accurate Internal Quantum Efficiency Measurements in Organic and Other Thin Solar CellsADVANCED MATERIALS, Issue 30 2010George F. Burkhard Accurately measuring internal quantum efficiency requires knowledge of absorption in the active layer of a solar cell. The experimentally accessible total absorption includes significant contributions from the electrodes and other non-active layers. We suggest a straightforward method for calculating the active layer contribution that minimizes error by subtracting optically-modeled electrode absorption from experimentally measured total absorption. [source] Organoselenium-substituted poly(p -phenylenevinylene)HETEROATOM CHEMISTRY, Issue 7 2005Nicolai Stuhr-Hansen A new type of conjugated polymer, organoselenium substituted poly(p -phenyleneviny- lene) (PPV), was synthesized from the corresponding alkylselenenyl p -xylylene dibromide via a Gilch route using potassium tert -butoxide in THF. The p -xylylene dibromide precursors were synthesized by reacting lithiated bis(methoxymethyl)benzenes with elemental selenium, followed by alkylation of the generated selenolates. As a final demasking step, the bromomethyl functions were liberated by ether cleavage using boron tribromide. Bis-alkylselenenyl PPV was obtained with an average molecular weight Mw of approximately 300,000 g/mol and with polydispersity Mw/Mn = 2. Due to low solubility, monoalkylselenenyl PPV was obtained with a considerably lower average molecular weight in the proximity of 16,000 g/mol and with a polydispersity slightly larger than 3. Absorption and fluorescence spectroscopy revealed that the bis-alkylselenenyl PPV is extensively conjugated. © 2005 Wiley Periodicals, Inc. Heteroatom Chem 16:656,662, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.20167 [source] Enhanced Two-Photon Absorption of Organic Chromophores: Theoretical and Experimental Assessments,ADVANCED MATERIALS, Issue 24 2008Francesca Terenziani Abstract Functional organic materials with enhanced two-photon absorption lead to new technologies in the fields of chemistry, biology, and photonics. In this article we review experimental and theoretical methodologies allowing detailed investigation and analysis of two-photon absorption properties of organic chromophores. This includes femtosecond two-photon excited fluorescence experimental setups and quantum-chemical methodologies based on time-dependent density functional theory. We thoroughly analyze physical phenomena and trends leading to large two-photon absorption responses of a few series of model chromophores focusing on the effects of symmetric and asymmetric donor/acceptor substitution and branching. [source] Transdermal delivery of two antioxidants from different cosmetic formulationsINTERNATIONAL JOURNAL OF COSMETIC SCIENCE, Issue 1-2 2003S. Richert Synopsis The efficacy of any cosmetic product containing a functional ingredient is determined by the skin delivery of the active molecule, which is influenced by the type of the vehicle and the molecule itself. This study was designed to compare the percutaneous absorption habits of the antioxidants carcinine and lipoic acid out of various formulations by means of the porcine skin model. Initial evaluation of the in vitro porcine skin model has demonstrated its feasibility for various substances and formulations [1, 2]. Increasing legal requirements for risk assessment in the cosmetic industry have led to the development of this alternative test method. The penetration properties are determined by the OECD Guideline TG 428: Skin Absorption: in vitro Method [3, 4], which allows the use of porcine skin for penetration studies. Porcine skin is used because of its similarity to human skin in terms of its morphology and the essential permeation characteristics [5]. The mass balances for each tested formulation type of the antioxidants show individual penetration behaviours with significant differences. The presented data plainly demonstrate that the lipophilic lipoic acid has a distinct higher penetration potential than the hydrophilic carcinine. The chosen vehicle can enhance or reduce the transdermal delivery of both tested antioxidants. Modern effective cosmetic formulations will work only, if the active ingredients penetrate into the epidermis. In conclusion, the correct selection of a suitable formulation plays an important role during product development. Résumé L'efficacité d'un produit cosmétique ou de son principe actif est définie par l'absorption du principe actif par la peau. Cette action est influencée par la structure moléculaire du principe actif ainsi que par la galénique du produit. Dans cette étude, les taux d'absorption percutanée des agents anti-oxydants Carcinine et Acide Lipoïque intégrés dans différentes formulations cosmétiques ont été comparés avec le modèle de peau porcine. La phase de validation sur plusieurs années du modèle peau porcine in vitro a prouvé qu'il se prête très bien à la détermination de la pénétration percutanée de différentes substances et formulations. Des exigences légales de plus en plus sévères concernant la pratique des tests de sécurité pour les produits cosmétiques ont mené au développement de cette méthode qui remplace les essais sur animaux. La définition des qualités de pénétration se fait selon la directive OECD TG 428 : Skin Absorption : in vitro Method [3, 4] qui permet l'utilisation de la peau porcine provenant des abattoirs pour l'exécution des études de pénétration. Les bilans quantitatifs des formulations testées montrent que les agents anti-oxydants ont des comportements de pénétration différant de manière significative. Les données présentées démontrent très clairement que l'acide Lipoïque, lipophile, possède un potentiel de pénétration bien plus élevé que la Carcinine, hydrophile. La base cosmétique peut aussi réduire ou augmenter le potentiel de pénétration des agents anti-oxydant testés. En résumé, le choix correct d'un type de formulation joue un rôle très important dans le développement d'un produit cosmétique. [source] Molecule,Surface Plasmon Interactions in Hole Arrays: Enhanced Absorption, Refractive Index Changes, and All-Optical Switching,ADVANCED MATERIALS, Issue 10 2006J. Dintinger Enhanced molecular absorption of dyes in the visible range, mediated by surface plasmon excitations on metallic hole arrays, is reported. The combination of these structures with a photochromic cover layer can be used to create an all-optical switching system, essential for the development of active plasmonic devices. The figure shows transmission images of the coated hole array before (left) and after (right) UV irradiation. [source] Operational results of an intermittent absorption cooling unitINTERNATIONAL JOURNAL OF ENERGY RESEARCH, Issue 9 2002Ali R. El-GhalbanArticle first published online: 15 JUL 200 Abstract The concept of solar cooling is appealing because the cooling load is in phase with the intensity of solar energy. Many system arrangements or cycles are employed to achieve solar cooling, such as Absorption, desiccant or Rankine-vapour compression systems. The technical feasibility of driving an absorption-cooling unit by a low-temperature heat source (such as solar energy using a simple flat-plate collector) for air-conditioning applications is investigated in this work. This study aims to design and construct a prototype for an intermittent absorption refrigeration system and to examine its implementation. The operating characteristics of the considered unit are extensively investigated. In order to accomplish this strategy, the prototype was integrated in a test rig designed for this purpose and equipped with the necessary measuring instruments to determine the required operating criteria of the unit. The energy added or extracted to or from the different unit components is calculated and the system performance is analysed. The C.O.P of the unit is found to be 19% which is 2% lower than the designed value, which could be regarded as an encouraging result for more studies in this field. Copyright © 2002 John Wiley & Sons, Ltd. [source] Theoretical electronic spectra of 2-aminopurine in vapor and in waterINTERNATIONAL JOURNAL OF QUANTUM CHEMISTRY, Issue 13 2006Antonio Carlos Borin Abstract The accurate quantum chemical CASSCF and CASPT2 methods combined with a Monte Carlo procedure to mimic solvation effects have been used in the calculation of the spectroscopic properties of two tautomers of 2-aminopurine (2AP). Absorption and emission spectra have been simulated both in vacuum and in aqueous environment. State and transition energies and properties have been obtained with high accuracy, leading to the assignment of the most important spectroscopic features. The lowest-lying 1(,,,*) (1La) state has been determined as responsible for the first band in the absorption spectrum and also for the strong fluorescence observed for the system in water. The combined approach used in the present work gives quantitatively accurate results. © 2006 Wiley Periodicals, Inc. Int J Quantum Chem, 2006 [source] Absorption, resonance, and near-resonance Raman studies of the tetracyanoquinodimethane neutral and its monoanion in terms of density functional theory and complete active space self-consistent field methodsINTERNATIONAL JOURNAL OF QUANTUM CHEMISTRY, Issue 8 2006Marcin Makowski Abstract The electronic structure of the 11B1u and 12B3u excited electronic states of the tetracyanoquinodimethane (TCNQ) neutral and its charged derivative are studied within the framework of complete active space self-consistent field (CASSCF) and Becke's three-parameter hybrid method with Lee,Yang,Parr correlation functional (B3LYP) methods applied to the level aug-cc-p-VDZ basis set. Both CASSCF/aug-cc-p-VDZ and B3LYP/aug-cc-p-VDZ treatments provide the ground-state and the excited state geometries; these are then used to assess the Franck,Condon (FC) parameters in the 11B1u state of the neutral TCNQ and in the 12B3u state of the TCNQ monoanion. The quality of numerical results is then tested on the base of available experimental near-resonance and resonance Raman data. The studies are performed in terms of the vibronic model, which takes both FC and mode-mixing (Dushinsky) effects into account. This somewhat simplified vibronic model leads to very good agreement between the theory and the Raman experiments concerning both neutral TCNQ and its monoanion. In particular, the calculated excitation profiles of the ,2 = 2215 cm,1, ,4 = 1389 cm,1, ,5 = 1195 cm,1, and ,9 = 336 cm,1 fundamentals are shown to be in excellent agreement with those for the TCNQ monoanion. © 2006 Wiley Periodicals, Inc. Int J Quantum Chem, 2006 [source] The Effect of Linguistic Distance and Country of Origin on Immigrant Language Skills: Application to IsraelINTERNATIONAL MIGRATION, Issue 3 2001Michael Beenstock This article is concerned with identifying, for the first time, the separate effects of linguistic distance (language of origin) and country of origin on the destination language proficiency of immigrants. The determinants of Hebrew language proficiency (fluency and literacy) among immigrants in Israel are studied using the 1972 Census of Israel and the Immigration Absorption (panel) Surveys conducted in the 1970s. Country of origin and language of origin matter for proficiency in Hebrew, especially in the longer term. By country of origin, those from North Africa are the least proficient. By language of origin, Arabic speakers are the most proficient, suggesting a small linguistic distance from Hebrew. Immigrants from English-speaking origins are the least proficient in Hebrew. This may reflect a large linguistic distance or, more likely, the unique role of English as the international language, which reduces incentives for investments in Hebrew. Immigrants from dual-language countries of origin are more proficient in Hebrew than those from single language origins. [source] Enhanced Infrared Absorption of C60 on Thin Evaporated Pd Island FilmsISRAEL JOURNAL OF CHEMISTRY, Issue 3 2006Toshimasa Wadayama Infrared transmission spectra of C60 multilayers on thin Pd films deposited onto surface-oxidized Si(100) and hydrogen-terminated Si(111) substrates are reported. In both cases, the spectra in the 1500,1100 cm,1 region exhibited bands at 1444, 1429, and 1182 cm,1 due, respectively, to the Ag (2), T1u (4), and T1u (3) modes. The appearance of the Ag (2) mode, which is originally infrared inactive (Raman active), reveals electron transfer from the metal to chemisorbed C60. Indeed, increasing the thickness of C60, the Ag (2) mode intensity saturated more rapidly than the T1u (4) and T1u (3) modes. The originally infrared active T1u (4) and T1u (3) modes were enhanced in intensity depending upon the Pd thickness. Actually, while both substrates gave nearly the same magnitude of enhancement, the optimum Pd thickness was smaller on the hydrogen-terminated surface than on the surface-oxidized surface. On the other hand, the Ag (2) mode was less intense on the hydrogen-terminated surface than on the oxidized surface, suggestive of a shortage of chemisorbed C60 and thus pointing out the importance of the metal film morphology. Indeed, Pd films deposited on the two substrates gave rise to quite different AFM images. We also show that, regardless of the substrate, the Ag (2) mode is an order of magnitude smaller than for Ag deposition, though no remarkable intensity differences were observed with respect to the T1u (4) and T1u (3) modes. [source] Absorption, disposition and metabolism of di-isononyl phthalate (DINP) in F-344 ratsJOURNAL OF APPLIED TOXICOLOGY, Issue 5 2002R. H. McKee Abstract Di-isononyl phthalate (DINP; CAS no. 68515-48-0) is a general-purpose plasticizer for polyvinyl chloride. It produced liver and kidney effects when given to rodents at high oral doses, but there were no target organ effects in primates treated under similar conditions. To assist in understanding the basis for these species differences, the pharmacokinetic properties of DINP were evaluated in rodents following both oral and dermal administration. These studies demonstrated that the pharmacokinetic properties of DINP are similar to those of other high-molecular-weight phthalates. When orally administered to rodents, DINP is rapidly metabolized in the gastrointestinal tract to the corresponding monoester, absorbed and excreted, primarily in the urine. Shortly after administration, DINP is found primarily in liver and kidneys, but it does not persist or accumulate in any organ or tissue. It is very poorly absorbed from the skin, but once absorbed it behaves in the same way as the orally administered material. The results of these rodent studies contrast with data from studies involving humans or other primates, which indicate low absorption at low oral doses and much more limited total absorption at high doses. It appears that many, if not all, of the effects of DINP in rodent studies are associated with internal doses that would be difficult, if not impossible, to achieve in humans under any circumstances. Thus, the results of rodent studies may not be very useful in assessing the potential risks to humans from high-molecular-weight phthalates. Copyright © 2002 John Wiley & Sons, Ltd. [source] Effect of Piperine, a Major Component of Black Pepper, on the Intestinal Absorption of Fexofenadine and Its Implication on Food,Drug InteractionJOURNAL OF FOOD SCIENCE, Issue 3 2010Ming-Ji Jin ABSTRACT:, The present study aimed to investigate the effect of piperine, a major component of black pepper, on the oral exposure of fexofenadine in rats. Pharmacokinetic parameters of fexofenadine were determined in rats following an oral (10 mg/kg) or intravenous (5 mg/kg) administration of fexofenadine in the presence and absence of piperine (10 or 20 mg/kg, given orally). Compared to the control group given fexofenadine alone, the combined use of piperine increased the oral exposure (AUC) of fexofenadine by 180% to 190% while there was no significant change in,Cmax and,T1/2 of fexofenadine in rats. The bioavailability of fexofenadine was increased by approximately 2-folds via the concomitant use of piperine. Furthermore,,Tmax tends to be increased which might be attributed to the delayed gastric emptying in the presence of piperine. In contrast, piperine did not alter the intravenous pharmacokinetics of fexofenadine, implying that piperine may increase mainly the gastrointestinal absorption of fexofenadine rather than reducing hepatic extraction. In conclusion, piperine significantly enhanced the oral exposure of fexofenadine in rats likely by the inhibition of P-glycoprotein-mediated cellular efflux during the intestinal absorption, suggesting that the combined use of piperine or piperine-containing diet with fexofenadine may require close monitoring for potential drug,diet interactions. [source] Reduction of Oil Absorption in Deep-Fried, Battered, and Breaded Chicken Patties Using Whey Protein Isolate as a Postbreading Dip: Effect on Flavor, Color, and TextureJOURNAL OF FOOD SCIENCE, Issue 1 2009E. Mah ABSTRACT:, The effect of the application of whey protein isolate (WPI) solution as a postbreading dip to reduce oil absorption in deep-fried, battered, and breaded chicken patties on sensory properties was investigated. Chicken patties were battered, breaded with either crackermeal (CMP) or Japanese breadcrumbs (JBP), and dipped into WPI solutions at varying protein concentrations (0%, 2.5%, 5%, and 10%[w/w] WPI) and pH levels (pH 2, 3, and 8). A trained descriptive sensory panel evaluated the patties for 16 attributes relating to appearance, texture, and flavor. Instrumental analysis on the color and texture of the patties was also performed. The only perceivable changes in treated patties were related to color, hardness, and crunchiness. Increasing WPI concentration caused darkening of JBP but made CMP lighter. Patties treated at pH 8 were significantly darker across all WPI concentrations. The presence of WPI increased hardness and crust fracture for CMP but not JBP. Variations in pH levels did not affect texture. Thus, JBP that showed the highest lipid reduction (10% WPI at pH 2) were observed to be darker, less yellow, but did not produce any perceivable changes in hardness or crunchiness, while CMP with the lowest lipid content (5% WPI at pH 2) were lighter, more yellow, harder, and crunchier. [source] | ||||||||||||||||||||||||||||||||||||||||||||||