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排序方式: 共有242条查询结果,搜索用时 15 毫秒
31.
This paper presents the field-measured performance of two commercial photocontrolled lighting systems, continuous dimming and automatic on/off, as a function of various configurations of manual and photocontrolled automatic venetian blinds. The performance indicators considered were the space illumination and the electric lighting consumption as a function of blind slat angle and retraction area. The results showed that under clear sky and without blinds both lighting control systems reduced the lighting energy consumption on average by 50–60% when compared to lights fully on from 6 AM to 6 PM. These savings, however, dropped by 5–45% for the dimming system, and by 5–80% for the automatic on/off system with the introduction of various static window blind configurations. The savings in lighting energy were more significant when the lighting control systems were used with photocontrolled blinds. This was due to the capability of the blinds to adjust their position automatically in direct response to the variable daylight levels. 相似文献
32.
Computational modelling of shaped metal deposition 总被引:1,自引:0,他引:1
Andrés Anca Víctor D. Fachinotti Gustavo Escobar‐Palafox Alberto Cardona 《International journal for numerical methods in engineering》2011,85(1):84-106
Shaped metal deposition (SMD) is a novel process for rapid prototyping that employs tungsten inert gas (TIG) welding controlled by a robot inside an inert gas chamber to build parts by successive layer deposition. This process can be enhanced through modelling and control. Industries are interested in developing systematized models to explain observed phenomena and to predict processing conditions for process planning and optimization. In this work, thermal and mechanical finite element (FE) modelling of SMD is presented. The thermal problem is solved with linear tetrahedral finite FEs that take into account the liquid/solid phase change phenomenon. The mechanical problem is solved with hexahedral elements with tri‐linear interpolation of displacements and constant interpolation of mean stresses (Q1– P0). Special techniques to account for material addition were developed, based on activation/deactivation of FEs. Numerical tests were conducted to determine the heat source model parameters. An experiment using Ti‐6Al‐4V material was developed to validate the formulation. The test consisted of a TIG‐wash procedure (arc passing without wire feeding to preheat the plate) followed by a single welding layer. The results, including temperatures and residual displacements, are compared with those obtained with the finite element method (FEM) code. Finally, a multilayer SMD numerical example is presented. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
33.
Anca Hermenean Daniela Oatis Hildegard Herman Alina Ciceu Giovanbattista DAmico Maria Consiglia Trotta 《International journal of molecular sciences》2022,23(10)
Galectins are ten family members of carbohydrate-binding proteins with a high affinity for β galactose-containing oligosaccharides. Galectin-1 (Gal-1) is the first protein discovered in the family, expressed in many sites under normal and pathological conditions. In the first part of the review article, we described recent advances in the Gal-1 modulatory role on wound healing, by focusing on the different phases triggered by Gal-1, such as inflammation, proliferation, tissue repair and re-epithelialization. On the contrary, Gal-1 persistent over-expression enhances angiogenesis and extracellular matrix (ECM) production via PI3K/Akt pathway activation and leads to keloid tissue. Therefore, the targeted Gal-1 modulation should be considered a method of choice to treat wound healing and avoid keloid formation. In the second part of the review article, we discuss studies clarifying the role of Gal-1 in the pathogenesis of proliferative diabetic retinopathy, liver, renal, pancreatic and pulmonary fibrosis. This evidence suggests that Gal-1 may become a biomarker for the diagnosis and prognosis of tissue fibrosis and a promising molecular target for the development of new and original therapeutic tools to treat fibrosis in different chronic diseases. 相似文献
34.
We discuss some relationships between probability theory and statistics on one hand, and the theory of fuzzy sets on the other hand. We develop various statistical techniques for the analysis of imprecise data and for inference based on imprecise data. We study the estimation of fuzzy parameters, testing problems with fuzzy probabilities, and confidence estimation under uncertainty. Finally, we indicate some possible applications to the assessment of credibility in expert systems. 相似文献
35.
Lambertus M. van der Heijdt Fridolin van der Lecq Anand Lachmansingh Kees Versluis Anca van der Kerk-van Hoof Gerrit A. Veldink Johannes F. G. Vliegenthart 《Lipids》1993,28(9):779-782
The aim of this investigation was to determine whether the regioselectivity found for lipoxygenases in the formation of fatty
acid hydroperoxides from linoleic acid is reflected in the formation of dimeric products in secondary reactions involving
linoleic acid, product hydroperoxide and lipoxygenase. A method was therefore developed for the separation and identification
of dimers formed by fusion of two linoleic acid radicals or a linoleic acid radical and linoleate. The method includes solid-phase
extraction, preparative separation of products by thin-layer chromatography, derivatization to the corresponding fully hydrogenated
methyl esters and capillary gas chromatography (GC) coupled with electron impact mass spectrometry. We present evidence that
the formation of octadecadienoate dimers, during the secondary reaction of soybean lipoxygenase-1 or lipoxygenase-3, is a
nonenzymic process that can be envisaged by nonspecific association of intermediate fatty acid radicals (L*) that have dissociated from the enzyme. We could show that the relative amounts of different octadecadienoate dimers formed
remain unaltered, regard-less of pH and type of soybean isoenzyme used. Quantitative analysis by GC showed that under the
reaction conditions used, the formation of dimers branching at the 13-position is preferred. 相似文献
36.
37.
Although long-chain fatty acyl-coenzyme A (LCFA-CoA) thioesters are specific high-affinity ligands for hepatocyte nuclear
factor-4α (HNF-4α) and peroxisome proliferator-activated receptor-α (PPARα), X-ray crystals of the respective purified recombinant
ligand-binding domains (LBD) do not contain LCFA-CoA, but instead exhibit bound LCFA or have lost all ligands during the purification
process, respectively. As shown herein: (i) The acyl chain composition of LCFA bound to recombinant HNF-4α reflected that
of the bacterial LCFA-CoA pool, rather than the bacterial LCFA pool. (ii) Bacteria used to produce the respective HNF-4α and
PPARα contained nearly 100-fold less LCFA-CoA than LCFA. (iii) Under conditions used to crystallize LBD (at least 3 wk at
room temperature in aqueous buffer), 16∶1-CoA was very unstable in buffer alone. (iv) In the presence of the respective nuclear
receptor (i.e., HNF-4α and PPARα), LBD 70–75% of 16∶1-CoA was degraded after 1 d at room temperature in the crystallization
buffer, whereas as much as 94–97% of 16∶1-CoA was degraded by 3 wk. (v) Cytoplasmic LCFA-CoA binding proteins such as acyl-CoA
binding protein, sterol carrier protein-2, and liver-FA binding protein slowed the process of 16∶1-CoA degradation proportional
to their respective affinities for this ligand. Taken together, these data for the first time indicated that the absence of
LCFA-CoA in the crystallized HNF-4α and PPARα was due to the paucity of LCFA-CoA in bacteria as well as to the instability
of LCFA-CoA in aqueous buffers and the conditions used for LBD crystallization. Furthermore, instead of protecting bound LCFA-CoA
from autohydrolysis like several cytoplasmic LCFA-CoA binding proteins, these nuclear receptors facilitated LCFA-CoA degradation. 相似文献
38.
Coralia Cotoraci Alina Ciceu Alciona Sasu Anca Hermenean 《International journal of molecular sciences》2021,22(4)
Anemia, characterized by a decrease of the hemoglobin level in the blood and a reduction in carrying capacity of oxygen, is a major public health problem which affects people of all ages. The methods used to treat anemia are blood transfusion and oral administration of iron-based supplements, but these treatments are associated with a number of side effects, such as nausea, vomiting, constipation, and stomach pain, which limit its long-term use. In addition, oral iron supplements are poorly absorbed in the intestinal tract, due to overexpression of hepcidin, a peptide hormone that plays a central role in iron homeostasis. In this review, we conducted an analysis of the literature on biologically active compounds and plant extracts used in the treatment of various types of anemia. The purpose of this review is to provide up-to-date information on the use of these compounds and plant extracts, in order to explore their therapeutic potential. The advantage of using them is that they are available from natural resources and can be used as main, alternative, or adjuvant therapies in many diseases, such as various types of anemia. 相似文献
39.
Catalin Croitoru Anca Maria Varodi Maria Cristina Timar Ionut Claudiu Roata Elena Manuela Stanciu Alexandru Pascu 《Journal of Materials Science》2018,53(6):4132-4143
The improvement of wood-plastic composites properties by additives and compatibilizers is a critical issue to produce value-added materials. High-density polyethylene-wood composites have been obtained through compression molding at 140 °C, using two types of additives, namely methyltrioctylammonium bis (trifluoromethylsulfonyl)imide and trihexyltetradecylphosphonium bis (2,4,4-trimethylpentyl) phosphinate room temperature ionic liquids. The ionic liquids improve the interfacial adhesion between the wood and the polymer phases, contributing to an increased stability of the material to water action and to an improved impact resistance and tensile strength in comparison with the reference. Also, the FTIR spectroscopy tests have proven a higher resistance of the ionic liquid-containing composites to accelerated photooxidation. Preliminary screening tests have also proven the antifungal character of the ionic liquids used in this study against brown rot (Postia placenta). This study opens new insights in the domain of polymeric composite materials, through documenting the possibility of blending new types of chemically distinct materials, difficult to be achieved by traditional functionalization/derivatization routes. 相似文献
40.
The purpose of this study was to investigate the photocatalytic oxidation of a reactive azo dye. The photocatalytic activity of the TiO2 was studied using a reactor equipped with UV-A sources, with maximum emission at 365 nm. The photocatalytic activity of the TiO2 powder (99.9% anatase) and thin films has been measured through the decomposition of methyl orange solutions. The thin film was prepared by doctor blade and spray pyrolysis deposition (SPD). The TiO2 suspensions were prepared at 1 g/L concentration, and the initial methyl orange concentration was fixed at 7.8125 mg/L. The influence of the TiO2 (powder or thin films) and/or O2 and H2O2 on the photobleaching rate, was tested under different experiments, at pH = 5. Thin films (doctor blade) of TiO2 formed of mezo-sized aggregates formed of nanosized anatase crystallites show better photobleaching efficiency than thin film (SPD) due to their large internal surface. The rate is even higher in H2O2 compared to oxygen environment. 相似文献