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排序方式: 共有100条查询结果,搜索用时 15 毫秒
1.
GS Wengler A Lanfranchi T Frusca R Verardi A Neva D Brugnoni S Giliani M Fiorini P Mella F Guandalini E Mazzolari S Pecorelli LD Notarangelo F Porta AG Ugazio 《Canadian Metallurgical Quarterly》1996,348(9040):1484-1487
BACKGROUND: X-linked severe combined immunodeficiency (SCIDXI) is an inherited immune defect which leads to death in infancy from severe infections. The defect is caused by mutations of the IL-2RG gene that encodes for the common gamma chain shared by several cytokine receptors. The disease is characterised by lack of T and NK cells with normal numbers of B cells. SCIDXI can be cured by bone marrow transplantation (BMT) or prevented by abortion after prenatal diagnosis. METHODS: A male fetus was diagnosed as having SCIDXI by molecular, immunophenotypic, and functional analyses. The fetus was injected intraperitoneally under ultrasound guidance with CD34 haematopoietic progenitor cells purified from paternal bone marrow and T-cell depleted by E rosetting. Chimerism analysis was by HLA-DQ alpha typing and gamma-chain staining on cord blood. FINDINGS: A healthy 3.6 kg boy was delivered by caesarean section at 38 weeks of gestation with no clinical or laboratory signs of graft-versus-host disease. Engraftment of donor-derived CD2 cells was found at birth. At 3.5 months of age the infant is well and his T-cell counts and function are normal. INTERPRETATION: In-utero transplantation of haematopoietic progenitor cells allowed immune reconstitution of a fetus with SCIDXI and may be an alternative to elective abortion. Our report should encourage applications of this method to other inherited disorders curable by BMT. 相似文献
2.
A methodology, incorporating the use of an automated polariscope together with three-dimensional photoelasticity, is described and employed to determine mode III stress intensity factors. A series of angled cracks in a modified compact tension specimen were examined. The cracks were at an angle to the face of the specimen so that mode I and III displacements were produced. The results of the experiments were compared with the standard expressions for KI and KIII, and some recent modifications to the expressions. The results support the findings of recent finite element analyses and fracture work by others that the expressions are not accurate and that the stress intensity factors vary along the crack front. 相似文献
3.
Cloud computing is a very attractive research topic. Many studies have examined the infrastructure as a service and software as a service aspects of cloud computing; however, few studies have focused on platform as a service (PaaS). According to recent reports, demand for enterprise PaaS solutions will increase continuously. However, different sectors require different types of PaaS applications and computing resources. Therefore, an evaluation and ranking framework for PaaS solutions according to application needs is required. To address this need, this study presents the most essential aspects of PaaS solutions and provides a framework for evaluating the performance of PaaS providers. It also proposes a suitable set of benchmarking algorithms that can help determine the most appropriate PaaS provider based on different resource needs and application requirements. Performance evaluations of three well-known cloud computing PaaS providers were conducted using the analytic hierarchy process and the logic scoring of preference methods. 相似文献
4.
In this study, Generalized Regression Neural Networks (GRNN) and Feed Forward Neural Networks (FFNN) approaches are used to predict the scour depth around circular bridge piers. Hundred and sixty five data collected from various experimental studies, are used to predict equilibrium scour depth. The model consisting of the combination of dimensional data involving the input variables is constructed. The performance of the models in training and testing sets are compared with observations. Then, the model is also tested by Multiple Linear Regression (MLR) and empirical formula. The results of all approaches are compared in order to get more reliable comparison. The results indicated that GRNN can be applied successfully for prediction of scour depth around circular bridge piers. 相似文献
5.
The effect of porosity on the microstructural damping response of 6061 aluminium alloy 总被引:4,自引:0,他引:4
The paper reports on the results of a systematic study of the effects of micrometre-sized pores on the damping response of 6061 aluminium alloy. Spray atomization and deposition processing was utilized for the present study as a result of its ability to produce a material with a pre-determined amount of non-interconnected, micrometre-sized pores. The amount and distribution of pores present in the material may be systematically altered through variations in the processing parameters by using this synthesis approach. The damping measurements were conducted on cantilever beam specimens by using free vibration decay and resonant vibration techniques. Experimental results showed that the porosity increased with increasing average pore size; the damping capacity, in terms of logarithmic decrement , of the as-spray-deposited 6061 Al alloy, increased from 1.8 to 2.9% as the amount of porosity increased from 4 to 10%. Comparisons show that the damping capacity of the as-spray-deposited 6061 Al alloy is higher than those reported by other investigators using the same alloy but with different processing techniques. The loading damping mechanisms are discussed in the light of data from the characterization of microstructure and damping capacity. 相似文献
6.
Abdulkadir Kocer Ismet Faruk Yaka Afsin Gungor 《International Journal of Hydrogen Energy》2017,42(36):23244-23249
In this study, a modeling study was carried out to investigate the potential of hydrogen production from greenhouse tomato and pepper residues blending in different rates (0%, 25%, 50%, 75% and 100%) by air-steam gasification. The numerical model developed for the gasification system assumes that all carbon in the mixture is gasified. Air to fuel rate and steam to fuel rates are 0.05 due to high content of O2 in biomass residues. The gasifier temperature is 877 °C (1150 K) for developed model. According to the result of this study, increasing tomato residues blending rate increases hydrogen content of syngas. It is mainly caused by the content of O2 in tomato residues being higher than content of O2 in pepper residues. This study shows that the O2 content of greenhouse residues is an important factor in syngas production, especially in H2 production. 相似文献
7.
Afsin Gungor Nurdil Eskin 《Journal of the Chinese Institute of Chemical Engineers》2008,39(6):541-556
A well-designed CFBC can burn coal with high efficiency and within acceptable levels of gaseous emissions. In this theoretical study effects of operational parameters on combustion efficiency and the pollutants emitted have been estimated using a developed dynamic 2D (two-dimensional) model for CFBCs. Model simulations have been carried out to examine the effect of different operational parameters such as excess air and gas inlet pressure and coal particle size on bed temperature, the overall CO, NOx and SO2 emissions and combustion efficiency from a small-scale CFBC. It has been observed that increasing excess air ratio causes fluidized bed temperature decrease and CO emission increase. Coal particle size has more significant effect on CO emissions than the gas inlet pressure at the entrance to fluidized bed. Increasing excess air ratio leads to decreasing SO2 and NOx emissions. The gas inlet pressure at the entrance to fluidized bed has a more significant effect on NOx emission than the coal particle size. Increasing excess air causes decreasing combustion efficiency. The gas inlet pressure has more pronounced effect on combustion efficiency than the coal particle size, particularly at higher excess air ratios. The developed model is also validated in terms of combustion efficiency with experimental literature data obtained from 300 kW laboratory scale test unit. The present theoretical study also confirms that CFB combustion allows clean and efficient combustion of coal. 相似文献
8.
Yasin Gormez Zafer Aydin Ramazan Karademir Vehbi C. Gungor 《International Journal of Communication Systems》2020,33(11)
Detecting malicious behavior is important for preventing security threats in a computer network. Denial of Service (DoS) is among the popular cyber attacks targeted at web sites of high‐profile organizations and can potentially have high economic and time costs. In this paper, several machine learning methods including ensemble models and autoencoder‐based deep learning classifiers are compared and tuned using Bayesian optimization. The autoencoder framework enables to extract new features by mapping the original input to a new space. The methods are trained and tested both for binary and multi‐class classification on Digiturk and Labris datasets, which were introduced recently for detecting various types of DDoS attacks. The best performing methods are found to be ensembles though deep learning classifiers achieved comparable level of accuracy. 相似文献
9.
Temporal fluctuations of the speckle pattern formed upon backscattering of a laser beam from an interface between gold and nonlinear polymer film have been observed as a function of optical power. The instability can be explained by coupling of laser light to surface plasmons and other guided modes, which experience multiple scattering while propagating in the film along the interface. The speckle pattern produced in this process is extremely sensitive to fluctuations of the scattering potential near the interface. 相似文献
10.
Robust microencapsulated phase change materials in concrete mixes for sustainable buildings 下载免费PDF全文
Beyza Beyhan Kemal Cellat Yeliz Konuklu Caner Gungor Okan Karahan Cengiz Dundar Halime Paksoy 《国际能源研究杂志》2017,41(1):113-126
For passive building applications, phase change materials (PCMs) are microencapsulated to avoid leakage of PCM from concrete structure. The primary challenge of using microencapsulated PCM (MPCM) is its weak shell structure. New MPCMs with different shell compositions to prevent breakage during mixing in fresh concrete are needed. In this study, free radical polymerization method to microencapsulate capric acid–myristic acid mixture as PCM with two different methyl methacrylate co‐polymers is proposed to produce robust MPCMs for building applications. Two new microcapsules (MPCM‐1 and MPCM‐2) having latent heats of 91.9 and 97.3 J/g were synthesized. SEM analyses showed the size of microcapsules being in the range of 400–850 nm for MPCM‐1 and 250–475 nm for MPCM‐2. Analyses also reveal that the shells of MPCMs were not harmed, as they were added into concrete mixes. The microsphere's geometry was preserved, and distribution was homogeneous. The MPCMs were also studied under thermal tests of 1000 heating/cooling cycles. No significant changes in thermal properties were observed after thermal cycling tests. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献