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121.
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Helena Ribeiro Joana Marto Sara Raposo Maria Agapito Vera Isaac Bruna G. Chiari Pedro F. Lisboa Alexandre Paiva Susana Barreiros Pedro Simões 《European Journal of Lipid Science and Technology》2013,115(3):330-336
Spent coffee grounds (SCG), which are the residue obtained from the treatment of coffee with hot water or steam, can be used for industrial applications, due to the high content in lipids. The cosmetic products might be a suitable application for these types of residues because the barrier properties of the stratum corneum (SC) are largely dependent on the intactness of the lipid lamellae that surrounds the corneocytes. The purpose of this work was to assess the feasibility of using the lipid fraction of SCG extracted with supercritical carbon dioxide in the development of new cosmetic formulations with improved skin lipids (sebum) and hydration. The use of spent coffee lipid extract in cosmetic industry seems to be a suitable approach to recycle the wastes from coffee industry. Emulsion containing 10% of the lipid fraction of SCG (SpentCofOil cream) presented promising characteristics in the improvement of sebum skin levels with a good acceptance by consumers when compared to an emulsion containing 10% w/w of green coffee oil (GreenCofOil cream) and a placebo without coffee oil (NoCofOil cream). Practical applications: In this work, the authors develop and characterize a cream containing 10% of the lipid fraction of SCG extracted with supercritical carbon dioxide with improved skin lipids (sebum) and hydration. 相似文献
123.
Pasi Kaarakainen Helena Rintala Anne Hyvärinen Teija Meklin 《The Science of the total environment》2009,407(16):4673-4680
This study was designed to produce information about microbial concentrations using qPCR and their variation in different seasons and home environments with analyses of two types of house dust samples. Also the correlations between the two types of samples and the reproducibility of the parallel subsamples were studied. Two types of vacuumed house dust samples, rug dust and vacuum cleaner bag dust, were collected in 5 normal urban homes in four different seasons (N = 20 + 20). From all dust samples, five parallel subsamples were subjected to qPCR analyses of 17 microbial species or assay groups of microbes. The highest fungal concentrations were found for the Penicillium/Aspergillus/Paecilomyces variotii group, and for the species Aspergillus penicillioides, Aureobasidium pullulans, Cladosporium cladosporioides and Cladosporium herbarum. These species/groups were present in almost all samples. The two types of dust samples gave similar results for most microbial species or groups analyzed, but in general, concentrations were slightly higher in rug dust than in dust from vacuum cleaner bag. Microbial concentrations varied significantly between different seasons and hence the similarity of samples within home was mainly low. The concentrations varied significantly also between different home environments. The reproducibility of the parallel subsamples was good or moderate for most of the analyzed species or assay groups. However, further studies are needed to fully understand the factors causing variation in these methods. Nevertheless, in order to show actual differences in fungal concentrations between urban homes with no known microbial sources, all dust samples to be compared should be taken during the same season. 相似文献
124.
The exothermal character of cement hydration reactions causes concrete to endure temperature changes during the first days after casting, with associated volumetric deformations that may induce undesired cracking. The capability to predict temperature evolution in concrete since casting is thus important to back decisions that avoid detrimental thermal cracking in concrete structures. Even though several approaches exist to model the early age behavior of concrete, the laboratory or in situ verification of numerical predictions is scarce, and mostly done with embedded temperature sensors, with limited sampling points. The present research intends to evaluate the performance of the thermography technique in the continuous monitoring of surface temperatures of a hydrating 0.40 × 0.40 × 0.40 m3 concrete cube, in which embedded thermal sensors are also used. By using thermography, simultaneous monitoring of the visible surfaces of the specimen is possible, thus providing comprehensive information regarding the evolution of surface temperatures. The temperatures monitored with the thermography, as well as with the embedded temperature sensors, are finally used as a benchmark example for validation of a 3D finite element numerical code for thermal analysis developed by the authors. The use of thermography images for validation of finite element results is rather more advantageous than the use of standard single point temperature measurements, in view of the large facility and wide range of comparison provided by the simultaneous visualization of temperature surface color maps (measured and simulated). 相似文献
125.
126.
A. Catarina Guedes Luís A. Meireles Helena M. Amaro F. Xavier Malcata 《Journal of the American Oil Chemists' Society》2010,87(7):791-801
Aquaculture is a growing commercial activity worldwide, which resorts more and more often to microalgae as feed; the lipid
composition of such microalgae is a critical factor with regard to the fish growth rate upon ingestion. The aim of this work
was thus to study the influence of light intensity on the lipid profile of a known microalga, Pavlova lutheri. Several semi-continuous cultures were carried out, and biochemical parameters such as lipid, protein, carbohydrate, and
chlorophyll contents were quantified. Lipids were specifically fractionated into classes by TLC, and those in each class were
subjected to GC afterwards in an attempt to ascertain their fatty acid profile. Evidence was consequently provided which showed
that cultures grown under low light intensity (9 W m−2) possess a higher fraction of eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids esterified in polar classes—which are
those with a more favorable role in aquaculture. It was also demonstrated that intermediate levels of light intensity (19 W m−2) may be misleading in terms of favorable effects upon EPA and DHA contents—because there is an increase in their total yields
and productivities, but they appear mostly esterified into triacylglycerols; this may be a favorable deed for production and
purification, but is metabolically not so effective in aquaculture. The highest EPA and DHA productivities attained were 1.29
and 0.69 mg L−1 day−1, respectively, at intermediate levels of light intensity (19 W m−2). 相似文献
127.
Gessia Momoe Shida Aruana Rocha Barros Cristiane Marques dos Reis Eduardo Lucena Cavalcante de Amorim Márcia Helena Rissato Zamariolli Damianovic Edson Luiz Silva 《International Journal of Hydrogen Energy》2009,34(9):3679-3688
This study evaluates the stability of hydrogen and organic acids production in an anaerobic fluidized-bed reactor (AFBR) that contains expanded clay (2.8–3.35 mm in diameter) as a support medium and is operated on a long-term basis. The reactor was inoculated with thermally pre-treated anaerobic sludge and operated with decreasing hydraulic retention time (HRT), from 8 h to 1 h, at a controlled temperature of 30 °C and a pH of about 3.8. Glucose (2000 mg L?1) was used as the substrate, generating conversion rates of 92–98%. Decreasing the HRT from 8 h to 1 h led to an increase in average hydrogen-production rates, with a maximum value of 1.28 L h?1 L?1 for an HRT of 1 h. In general, hydrogen yield production increased as HRT decreased, reaching 2.29 mol of H2/mol glucose at an HRT of 2 h and yielding a maximum hydrogen content of 37% in the biogas. No methane was detected in the biogas throughout the period of operation. The main soluble metabolites (SMP) were acetic acid (46.94–53.84% of SMP) and butyric acid (34.51–42.16% of SMP), with less than 15.49% ethanol. The steady performance of the AFBR may be attributed to adequate thermal treatment of the inoculum, the selection of a suitable support medium for microbial adhesion, and the choice of satisfactory environmental conditions imposed on the system. The results show that stable hydrogen production and organic acids production were maintained in the AFBR over a period of 178 days. 相似文献
128.
Lederberg Amy R.; Ryan Helena B.; Robbins Bonnie L. 《Canadian Metallurgical Quarterly》1986,22(5):691
14 deaf 54–83 mo olds were videotaped playing once with each of 4 partners: a familiar deaf playmate, a familiar hearing playmate, an unfamiliar hearing child who was a playmate of another deaf child, and an unfamiliar hearing child who had little experience playing with deaf children. 21 hearing and 7 deaf playmates participated. Deaf Ss rarely used language, and formal language use was not related to measures of interaction or play even when playing with another deaf child. Instead, interaction and pretense seemed to be related to the deaf Ss' nonlinguistic communication abilities. Partner hearing status primarily affected communication, with communication between deaf playmates being more visual (both linguistic and nonlinguistic) and less object-based than communication between deaf and hearing playmates. Familiarity played a larger role than experience in improving interaction between deaf and hearing children. The hearing children were more responsive to and used more visual communication devices with their deaf playmate than an unfamiliar deaf child. But the hearing playmates were no better at playing with an unfamiliar deaf child than were hearing children who had little experience playing with deaf children. Implications for the understanding of young children's communication abilities and for deaf educational programs are discussed. (20 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
129.
Study of self-stratifying compositions 总被引:2,自引:0,他引:2
Helena Kuczyńska Ewa Langer Elżbieta Kamińska-Tarnawska Dmitry A. Kulikov Eugene A. Indeikin 《Journal of Coatings Technology and Research》2009,6(3):345-352
Paint applied as a single layer, and its spontaneous separation to form a primer and a top coat, is one of the newest concepts
of the effective and economical application of two layers in one step. The influence of the molecular weight of epoxy oligomer
and acrylic polymer and their ratio on self-stratification was investigated. The degree of stratification depending on molecular
weight and their mutual ratio was determined using ATR-FTIR spectroscopy, differential scanning calorimetry, microscopy techniques,
adhesion tests, and surface tension measurements. Phase separation and self-stratification of two-component homogenous mixtures
were followed using FTIR technique and surface tension measurements. As a result of these investigations, optimal oligomeric/polymeric
composition was selected. The obtained coating system showed good mechanical properties, gloss, and interlayer adhesion. 相似文献
130.