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排序方式: 共有302条查询结果,搜索用时 15 毫秒
191.
Ali Azhar Butt Iman Mirzadeh Susanna Toller Björn Birgisson 《International Journal of Pavement Engineering》2014,15(4):290-302
The construction, maintenance and disposal of asphalt pavements may lead to considerable environmental impacts, in terms of energy use and emissions during the life of the pavement. In order to enable quantification of the potential environmental impacts due to construction, maintenance and disposal of roads, an open life cycle assessment (LCA) framework for the asphalt pavements is presented in this paper. Emphasis was placed on the calculation and allocation of energy used for binder and additives at the project level. It was concluded from this study that when progressing from LCA to its corresponding life cycle cost, the feedstock energy of the binder becomes highly relevant as the cost of the binder will be reflected in its alternative value as fuel. Regarding additives like wax, a framework for energy allocation was suggested. The suggested project level LCA framework was demonstrated in a limited case study of a Swedish asphalt pavement. It was concluded that the asphalt production and transporting materials were the two most energy-consuming processes, emitting most greenhouse gases depending on the fuel type and electricity mix. 相似文献
192.
The article develops an oligopoly model to analyze the potential role of LNG in the liberalization of gas market. The assumptions of the model and its results are then discussed using the forecasts of gas demand and production for the next two or three decades. 相似文献
193.
Lynch SK Pai V Auxier J Stein AF Bennett EE Kemble CK Xiao X Lee WK Morgan NY Wen HH 《Applied optics》2011,50(22):4310-4319
In grating-based x-ray phase sensitive imaging, dark-field contrast refers to the extinction of the interference fringes due to small-angle scattering. For configurations where the sample is placed before the beamsplitter grating, the dark-field contrast has been quantified with theoretical wave propagation models. Yet when the grating is placed before the sample, the dark-field contrast has only been modeled in the geometric optics regime. Here we attempt to quantify the dark-field effect in the grating-before-sample geometry with first-principle wave calculations and understand the associated particle-size selectivity. We obtain an expression for the dark-field effect in terms of the sample material's complex refractive index, which can be verified experimentally without fitting parameters. A dark-field computed tomography experiment shows that the particle-size selectivity can be used to differentiate materials of identical x-ray absorption. 相似文献
194.
Photovoltaics: The Complete In‐Gap Electronic Structure of Colloidal Quantum Dot Solids and Its Correlation with Electronic Transport and Photovoltaic Performance (Adv. Mater. 6/2014) 下载免费PDF全文
Khabiboulakh Katsiev Alexander H. Ip Armin Fischer Iori Tanabe Xin Zhang Ahmad R. Kirmani Oleksandr Voznyy Lisa R. Rollny Kang Wei Chou Susanna M. Thon Graham H. Carey Xiaoyu Cui Aram Amassian Peter Dowben Edward H. Sargent Osman M. Bakr 《Advanced materials (Deerfield Beach, Fla.)》2014,26(6):822-822
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Janina Burk Anna Sassmann Cornelia Kasper Ariane Nimptsch Susanna Schubert 《International journal of molecular sciences》2022,23(3)
Matrix remodeling could be an important mode of action of multipotent mesenchymal stromal cells (MSC) in extracellular matrix (ECM) disease, but knowledge is limited in this respect. As MSC are well-known to adapt their behavior to their environment, we aimed to investigate if their mode of action would change in response to healthy versus pathologically altered ECM. Human MSC-derived ECM was produced under different culture conditions, including standard culture, culture on Matrigel-coated dishes, and stimulation with the pro-fibrotic transforming growth factor-β1 (TGFβ1). The MSC-ECM was decellularized, characterized by histochemistry, and used as MSC culture substrate reflecting different ECM conditions. MSC were cultured on the different ECM substrates or in control conditions for 2 days. Culture on ECM increased the presence of surface molecules with ECM receptor function in the MSC, demonstrating an interaction between MSC and ECM. In MSC cultured on Matrigel-ECM and TGFβ1-ECM, which displayed a fibrosis-like morphology, gene expression of collagens and decorin, as well as total matrix metalloproteinase (MMP) activity in the supernatant were decreased as compared with control conditions. These results demonstrated that MSC adapt to their ECM environment, which may include pathological adaptations that could compromise therapeutic efficacy. 相似文献
197.
Sara Conti Giuseppe Remuzzi Ariela Benigni Susanna Tomasoni 《International journal of molecular sciences》2022,23(3)
Transmission electron microscopy (TEM) remains the gold standard for renal histopathological diagnoses, given its higher resolving power, compared with light microscopy. However, it imposes several limitations on pathologists, including longer sample preparation time and a small observation area. To overcome these, we introduced a scanning electron microscopy (SEM) technique for imaging resin-embedded semi-thin sections of renal tissue. We developed a rapid tissue preparation protocol for experimental models and human biopsies which, alongside SEM digital imaging acquisition of secondary electrons (SE–SEM), enables fast electron microscopy examination, with a resolution similar to that achieved by TEM. We used this unconventional SEM imaging approach to investigate the subpodocyte space (SPS) in BTBR ob/ob mice with type 2 diabetes. Analysis of semi-thin sections with secondary electrons revealed that the SPS had expanded in volume and covered large areas of the glomerular basement membrane, forming wide spaces between the podocyte body and the underlying filtering membrane. Our results show that SE–SEM is a valuable tool for imaging the kidney at the ultrastructural level, filling the magnification gap between light microscopy and TEM, and reveal that in diabetic mice, the SPS is larger than in normal controls, which is associated with podocyte damage and impaired kidney function. 相似文献
198.
Robert M. Carey Helmy M. Siragy John J. Gildea Susanna R. Keller 《International journal of molecular sciences》2022,23(4)
Angiotensin II (Ang II) type-2 receptors (AT2R) are expressed in the adult kidney, prominently in renal proximal tubule cells (RPTCs), and play an important role in opposing renal sodium (Na+) retention induced by Ang II stimulation of Ang II type-1 receptor (AT1R). Natriuresis induced by AT1R blockade is due at least in part to AT2R activation and whole body deletion of AT2Rs reduces the natriuretic response to increased blood pressure (BP). The major endogenous AT2R agonist mediating the natriuretic response is Ang III, the Ang II heptapeptide metabolite generated by aminopeptidase A, and the principal nephron site mediating inhibition of Na+ reabsorption by the AT2R is the renal proximal tubule (RPT). AT2Rs induce natriuresis via a bradykinin, nitric oxide and cyclic GMP (cGMP) signaling cascade. Recent studies demonstrated a key role for protein phosphatase 2A (PP2A) in the AT2R-mediated natriuretic response upstream of cGMP. By inducing natriuresis, AT2Rs lower BP in the Ang II-infusion model of hypertension. PP2A activation and the natriuretic response to AT2R stimulation are defective in spontaneously hypertensive rats, a model of primary hypertension in humans. AT2R agonists are candidates for proximal tubule natriuretic agents in Na+ and fluid retention disorders. 相似文献
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200.
To investigate the ejection of liquid steel and slag from gas‐stirred melts in view of minimum formation of dusts and accretions, studies were performed combining laboratory experiments on single bubble/melt interactions with bench‐scale tests on 150 kg heats and with observations in metallurgical production facilities. Fine droplets are created when single bubbles burst on the melt surface or on the surface of bigger drops to form film (< 20 mm) and jet (0.1‐2 mm) droplets. At gas exit velocities of ≥ 0.1 m/s, gas flow tends to become turbulent leading to the ejection of splashes > 2 mm. In secondary metallurgy, the gas throughput is relatively small keeping the amount of small droplets (dust) low. On the other hand, the conditions for splashing are frequently met, and splashing is in fact observed in practice. An explanation model for the mechanisms of dust generation in the BOF process is derived from the lab results. 相似文献