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排序方式: 共有485条查询结果,搜索用时 15 毫秒
101.
R. Zmeureanu T. Stathopoulos M. E. D. Schopmeijer F. Siret J. Payer 《Canadian Metallurgical Quarterly》2001,7(4):131-137
Exterior doors and entrances of nonresidential buildings are major sources of energy losses caused by air infiltration or exfiltration due to the frequent use of doors and the pressure difference across each door, created by the wind, stack effect, or ventilation systems. Information regarding the air leakage characteristics of manually or power-operated revolving doors is available in the American Society of Heating, Refrigerating and Air-Conditioning Engineers, Inc. (ASHRAE) publications, based on studies carried out in the 1950s and 1960s. This paper presents results from a recent study carried out to investigate the air leakage characteristics of four revolving doors of a large institutional building in Montreal. These results are compared with data available in ASHRAE publications, as well as with the specifications of the Model National Energy Code of Canada for Buildings and ASHRAE Standard 90.1. The impact of the quality of seals on the annual heating costs is also evaluated. 相似文献
102.
R. Zmeureanu 《Canadian Metallurgical Quarterly》2000,6(3):87-90
In a cold climate such as of Montreal, the air infiltration through the exterior envelope of a house has a significant impact on the heating energy consumption and cost. The renovation of existing houses for increasing the airtightness up to the level of new, well-built houses can lead to the reduction of heating energy cost. This paper estimates the cost-effectiveness of this type of renovation by considering (1) the life-cycle energy consumption; (2) the initial cost of renovation; and (3) the CO2 tax credits, which take into account the environmental impact of increasing the airtightness of existing houses. The results show that the increase of airtightness of existing houses is not always cost-effective in the Montreal area. 相似文献
103.
A higher order shear deformation theory is used to investigate the instability associated with delaminated composite plates
subject to dynamic loads. Both transverse shear and rotary inertia effects are taken into account. The procedure is implemented
using the finite element method. Delamination is modeled using the penalty parameter approach. The natural frequencies are
computed and compared with NASTRAN 3D results and available experimental data. The effect of delamination on the critical
buckling load and the first two instability regions is investigated for various loading conditions, plate thickness and boundary
conditions. As expected the natural frequencies and the critical buckling load of the delaminated plate are lower than those
of the nondelaminated plate. They decrease with increase in delamination length. Increase in delamination length causes instability
regions to be shifted to lower parametric resonance frequencies and the normalized width of the instability regions to increase. 相似文献
104.
Silvina Ilut Bianca O. Pirlog Radu Pirlog Andreea Nutu Vitalie Vacaras Sebastian M. Armean 《International journal of molecular sciences》2022,23(18)
Acute ischemic stroke (AIS) represents an important cause of disability and death. Since only a minor percentage of patients with AIS are eligible for acute therapy, the management of risk factors is mandatory. An important risk factor of AIS is hyperlipemia. The current guidelines recommend a strict correction of it. Statins are recommended as the first-line treatment, while proprotein convertase subtilin/kexin type 9 (PCSK-9) inhibitors are administered as a second or even third option when the goal for a low-density lipoprotein cholesterol (LDL-C) level is not achieved. PCSK-9 inhibitors effectively decrease the LDL-C levels through the inhibition of PCSK-9-LDL-receptor complex formation. The in-depth understanding of the PCSK-9 protein mechanism in the metabolism of LDL-C led to the development of effective targeted approaches. Furthermore, a better understanding of the LDL-C metabolic pathway led to the development of newer approaches, which increased the therapeutic options. This article aims to offer an overview of the PCSK-9 inhibitors and their mechanism in reducing the LDL-C levels. Moreover, we will present the main indications of the current guidelines for patients with hyperlipemia and for those who have suffered an acute ischemic stroke, as well as the importance of LDL-C reduction in decreasing the rate of a recurrence. 相似文献
105.
Ioana Rusu Radu Pirlog Paul Chiroi Andreea Nutu Vlad Radu Puia Alin Cornel Fetti Daniel Radu Rusu Ioana Berindan-Neagoe Nadim Al Hajjar 《International journal of molecular sciences》2022,23(20)
Nonalcoholic fatty liver disease (NAFLD) is the most prevalent liver pathology worldwide. Meanwhile, liver cancer represents the sixth most common malignancy, with hepatocellular carcinoma (HCC) as the primary, most prevalent subtype. Due to the rising incidence of metabolic disorders, NAFLD has become one of the main contributing factors to HCC development. However, although NAFLD might account for about a fourth of HCC cases, there is currently a significant gap in HCC surveillance protocols regarding noncirrhotic NAFLD patients, so the majority of NAFLD-related HCC cases were diagnosed in late stages when survival chances are minimal. However, in the past decade, the focus in cancer genomics has shifted towards the noncoding part of the genome, especially on the microRNAs (miRNAs) and long noncoding RNAs (lncRNAs), which have proved to be involved in the regulation of several malignant processes. This review aims to summarize the current knowledge regarding some of the main dysregulated, noncoding RNAs (ncRNAs) and their implications for NAFLD and HCC development. A central focus of the review is on miRNA and lncRNAs that can influence the progression of NAFLD towards HCC and how they can be used as potential screening tools and future therapeutic targets. 相似文献
106.
Tiberiu Roman Daniel Ghercă Adrian-Iulian Borhan Marian Grigoraș George Stoian Nicoleta Lupu Ina Turcan Nicanor Cimpoesu Bogdan Istrate Ioana Radu Raluca-Ștefania Dănilă Aurel Pui 《Ceramics International》2021,47(13):18177-18187
Quaternary Ni1-xCuxFe2-yCeyO4 complex nano-ferrites system with different cerium content ratio and copper substitution degree were synthesized via co-precipitation wet chemical technique. The newly obtained nanoparticles, with general formula Ni1-xCuxFe2-yCeyO4 (where x = 0.0, 0.3, 0.6 and y = 0.00, 0.03, 0.05, 0.08 and 0.10) were heated up to 600 °C to stabilize the specific crystalline spinel structure. The limit of cerium content was quantitively determined to be around 0.08 and up to 0.10. Furthermore, the powders were pelletized in a 13 mm wide pellets and thermally treated at 950 °C. The thermal treatment affected even more the phases segregation process, as CeO2 was identified in the sample with lowest degree of cerium insertion – 0.03. Also, a difference in color and size of pelletized samples was noticed after the 950 °C thermal treatment. The Rietveld refinement, crystal structure confirmation, morphology magnetic and electrical properties of samples have been deeply studied. The cation distribution carried out from Rietveld refinement confirms the occupancy of (Fe3+) on tetrahedral sites and [Ni2+], [Cu2+], [Fe3+] and [Ce2+] on octahedral sites in the crystal lattice. Preliminary information regarding the cation distribution in spinel structures were suggested by FTIR spectral results, precisely in the 650-520 cm?1 region, as a consequence of peak shape and lack of shiftiness of MTd – O bond. Spherical-shaped quaternary nano-ferrites of 17–28 nm were determined from FE-SEM analysis and the samples composition was confirmed by EDX analysis. Hysteresis loops shows modifications in coercivity, magnetization and magnetic remanence with Ni2+ and Cu2+ ions doping in Ni1-xCuxFe2-yCeyO4 complex systems with typical ferrimagnetic behavior. Dielectric measurements were employed in order to determine the electrical permittivity, dielectric losses and conductivity values in a 10 Hz – 1 MHz frequency range. 相似文献
107.
Karthik Srinivasan Cosmin Radu Dario Bilardello Peter Solheid Bethanie J. H. Stadler 《Advanced functional materials》2020,30(15)
One of the best magneto‐optical claddings for optical isolators in photonic integrated circuits is sputter deposited cerium‐doped terbium iron garnet (Ce:TbIG) which has a large Faraday rotation (≈?3500° cm?1 at 1550 nm). Near‐ideal stoichiometry of Ce0.5Tb2.5Fe4.75O12 is found to have a 44 nm magnetic dead layer that can impede the interaction of propagating modes with garnet claddings. The effective anisotropy of Ce:TbIG on Si is also important, but calculations using bulk thermal mismatch overestimate the effective anisotropy. Here, X‐ray diffraction measurements yield highly accurate measurements of strain that show anisotropy favors an in‐plane magnetization in agreement with the positive magnetostriction of Ce:TbIG. Upon doping TbIG with Ce, a slight decrease in compensation temperature occurs which points to preferential rare‐earth occupation in dodecahedral sites and an absence of cation redistribution between different lattice sites. The high Faraday rotation, large remanent ratio, large coercivity, and preferential in‐plane magnetization enable Ce:TbIG to be an in‐plane latched garnet, immune to stray fields with magnetization collinear to direction of light propagation. 相似文献
108.
Polyhedral object recognition by indexing 总被引:1,自引:0,他引:1
In computer vision, the indexing problem is the problem of recognizing a few objects in a large database of objects while avoiding the help of the classical image-feature-to-object-feature matching paradigm. In this paper we address the problem of recognizing three-dimensional (3-D) polyhedral objects from 2-D images by indexing. Both the objects to be recognized and the images are represented by weighted graphs. The indexing problem is therefore the problem of determining whether a graph extracted from the image is present or absent in a database of model graphs. We introduce a novel method for performing this graph indexing process which is based both on polynomial characterization of binary and weighted graphs and on hashing. We describe in detail this polynomial characterization and then we show how it can be used in the context of polyhedral object recognition. Next we describe a practical recognition-by-indexing system that includes the organization of the database, the representation of polyhedral objects in terms of 2-D characteristic views, the representation of this views in terms of weighted graphs and the associated image processing. Finally, some experimental results allow the evaluation of the system performance. 相似文献
109.
A study was conducted to estimate the prevalence of Salmonella among broilers retailed at wet-markets and processing plants. Litter and feed samples obtained from both broiler and breeder farms were also examined for Salmonella. A total of 158 out of 445 (35.5%) and 52 out of 104 (50.0%) broiler carcasses obtained from wet-markets and processing plants were contaminated with Salmonella, respectively. Salmonella was isolated from 14 out of 98 (14.3%) samples of intestinal content. Litter samples from broiler and breeder farms were positive for Salmonella, 8/40 (20%) and 2/10 (20%), respectively. Salmonella isolates (230) belonging to 15 different serovars were isolated. Predominant serovars were S. enteritidis, S. muenchen, S. kentucky and S. blockley. 相似文献
110.
Xiaohua Kong Radu Negulescu Larry Weidong Ying 《International Journal on Software Tools for Technology Transfer (STTT)》2003,4(3):359-370
In this paper we propose a refinement-based technique to formally verify data transfer in a heterogeneous timing framework.
Novel data transfer models are proposed to represent data communication between two locally independent clock domains via
an asynchronous handshake environment. As a case study, we apply our technique to automatically verify data transfer in a
previously published architecture for globally asynchronous locally synchronous on-chip systems. In this case study, we find
several race conditions, hazards, and other dangers that were not mentioned in the original publication, and we find additional
delay constraints that avoid some of the detected dangers.
Published online: 17 December 2002 相似文献