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排序方式: 共有563条查询结果,搜索用时 15 毫秒
61.
Huseyin Yavuz 《国际水资源开发杂志》1997,13(4):561-566
In spite of the fact that abundance of water creates problems and sometimes disasters, much of the problem with water lies with its scarcity. Water shortages in a region occur mainly for two reasons. The most important one is associated with climatic conditions, whereas the other has to do with the fact that the location of the water resource does not coincide with where it is needed. This is where engineering and technology come into play along with a handsome amount of capital requirement. As is the case for almost all engineering projects, project economy entails both technical and economic feasibility, which in turn requires that water should be treated as an economic commodity. 相似文献
62.
Management of non-resectable pelvic tumours by intra-arterial local chemotherapy was shown to be beneficial but systemic toxicity limits its use. To overcome this problem isolated pelvic perfusion (IPP) was introduced as an alternative. This study summarizes our preliminary experience with IPP in the treatment of 18 non-resectable pelvic tumours [recurrent rectal adenocarcinoma (six), soft tissue sarcoma (STS) (five), bone tumour (three), epidermoid carcinoma (two), prostatic adenocarcinoma (one), malignant melanoma (one)]. Results of IPP were regarded as complete remission (CR), partial remission (PR), stable disease (SD) and disease progression (DP) according to the changes in three parameters including; scoring in pain, tumour marker and tumour size measurements. Complete and partial remission were established in five (27%) and seven (39%) patients respectively indicating a benefit ratio of 66%. Objective pain relief was encountered in 53% of the cases. All patients with STS had undergone further surgical treatment after IPP with successful curative resections in four. No residual tumour was found at the laparotomy of the fifth patient. Presenting symptom of the prostatic adenocarcinoma patient was symptomatic hypoglycaemia which resolved completely after IPP. To our knowledge, this represents the first case reported in the English literature in whom tumour related hypoglycaemia was successfully managed by IPP. In conclusion; management of non-resectable pelvic tumours by IPP seems to offer serious palliation and increase in the quality of life without any systemic toxicity. Our preliminary experience suggests even resectability may be achieved in a number of patients especially in those with STS. 相似文献
63.
Huseyin Sehitoglu X. Y. Zhang T. Kotil D. Canadinc Y. Chumlyakov H. J. Maier 《Metallurgical and Materials Transactions A》2002,33(12):3661-3672
We present experimental and theoretical evidence of thermoelastic martensites in Fe29Ni18Co4Ti alloys. In this class of alloys,
the high strength in the austenite domains limits the slip deformation as verified with transmission electron microscopy.
The restriction of slip permits a higher degree of recoverability of the transformation. Using both single crystals with [123]
orientation and polycrystals, the appearance of martensite plates upon deformation, and their reversion back to austenite
upon heating (the shape memory effect), is revealed with in-situ optical microscopy. Theoretical results for the transformation strains and the detwinning of martensite are presented, which
demonstrate convincingly the potential of these classes of alloys. Electrical resistance measurements identified the stress
and temperature levels at the onset of forward and reverse transformations in isothermal deformation and thermal cycling experiments,
respectively. The return of the electrical resistance to its reference value, upon austenite to martensite followed by martensite
to austenite transformation, verified the recovery in the transformation strains measured in the experiments. 相似文献
64.
Accurate and reliable modelling of protein–protein interaction networks for complex diseases such as colorectal cancer can help better understand mechanism of diseases and potentially discover new drugs. Different machine learning methods such as empirical mode decomposition combined with least square support vector machine, and discrete Fourier transform have been widely utilised as a classifier and for automatic discovery of biomarkers for the diagnosis of the disease. The existing methods are, however, less efficient as they tend to ignore interaction with the classifier. In this study, the authors propose a two‐stage optimisation approach to effectively select biomarkers and discover interactions among them. At the first stage, particle swarm optimisation (PSO) and differential evolution (DE) are used to optimise parameters of support vector machine recursive feature elimination algorithm, and dynamic Bayesian network is then used to predict temporal relationship between biomarkers across two time points. Results show that 18 and 25 biomarkers selected by PSO and DE‐based approach, respectively, yields the same accuracy of 97.3% and F1‐score of 97.7 and 97.6%, respectively. The stratified analysis reveals that Alpha‐2‐HS‐glycoprotein was a dominant hub gene with multiple interactions to other genes including Fibrinogen alpha chain, which is also a potential biomarker for colorectal cancer.Inspec keywords: cancer, proteins, particle swarm optimisation, evolutionary computation, support vector machines, recursive functions, Bayes methods, genetics, molecular biophysics, medical computingOther keywords: colorectal cancer metastasis, two‐stage optimisation approach, protein–protein interaction networks, biomarkers, particle swarm optimisation, differential evolution, support vector machine recursive feature elimination, dynamic Bayesian network, stratified analysis, Alpha‐2‐HS‐glycoprotein, hub gene, Fibrinogen alpha chain 相似文献
65.
All‐Carbon Nanoarchitectures as High‐Performance Separation Membranes with Superior Stability
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Kunli Goh Wenchao Jiang Huseyin Enis Karahan Shengli Zhai Li Wei Dingshan Yu Anthony G. Fane Rong Wang Yuan Chen 《Advanced functional materials》2015,25(47):7348-7359
The application of graphene‐based membranes is hindered by their poor stability under practical hydrodynamic conditions. Here, nanocarbon architectures are designed by intercalating surface‐functionalized, small‐diameter, multi‐walled carbon nanotubes (MWCNTs) into reduced graphene oxide (rGO) sheets to create highly stable membranes with improved water permeability and enhanced membrane selectivity. With the intercalation of 10 nm diameter MWCNTs, the water permeability reaches 52.7 L m?2 h?1 bar?1, which is 4.8 times that of pristine rGO membrane and five to ten times higher than most commercial nanofiltration membranes. The membrane also attains almost 100% rejection for three organic dyes of different charges. More importantly, the membrane can endure a turbulent hydrodynamic flow with cross‐flow rates up to 2000 mL min?1 and a Reynolds number of 4667. Physicochemical characterization reveals that the inner graphitic walls of the MWCNTs can serve as spacers, while nanoscale rGO foliates on the outer walls interconnect with the assimilated rGO sheets to instill superior membrane stability. In contrast, intercalating with single‐walled nanotubes fails to reproduce such stability. Overall, this nanoarchitectured design is highly versatile in creating both graphene‐rich and CNT‐rich all‐carbon membranes with engineered nanochannels, and is regarded as a general approach in obtaining stable membranes for realizing practical applications of graphene‐based membranes. 相似文献
66.
Mohamed S EL-Genk Huseyin Bostanci 《International Journal of Heat and Mass Transfer》2003,46(10):1841-1854
Experiments are performed, which investigated the effect of inclination angle, θ, on saturation pool boiling of HFE-7100 dielectric liquid from a smooth, 10×10 mm copper surface, simulating a microelectronic chip. For θ?90° and surface superheats, ΔTsat>20 K, nucleate boiling heat flux decreases with increased θ, but increases with θ for ΔTsat<20 K. Similarly, at higher inclinations and ΔTsat>13 K, nucleate boiling heat flux decreases with increased inclination, but at lower surface superheats the trend is inconclusive. The developed nucleate boiling correlation is within ±10% of the data and the developed correlations for critical heat flux (CHF) and the surface superheat at CHF are within ±3% and ±8% of the data, respectively. Results show that CHF decreases slowly from 24.45 W/cm2 at 0° to 21 W/cm2 at 90°, then decreases fast with increased θ to 4.30 W/cm2 at 180°. The surface superheat at CHF also decreases with θ, from 31.7 K at 0° to 19.9 K at 180°. Still photographs are recorded of pool boiling at different heat fluxes and θ=0°, 30°, 60°, 90, 120°, 150° and 180°. The measured average departure bubble diameter from the photographs taken at the lowest nucleate boiling heat flux of ∼0.5 W/cm2 and θ=0° is 0.55±0.07 mm and the calculated departure frequency is ∼100 Hz. 相似文献
67.
In this investigation, the influence of filler type and filler content on the mechanical properties of nylon‐6 is investigated. The mineral fillers were selected on the basis of their shape and size: flake‐like kaolin and talc, spherical glass beads or fibrous wollastonite. These fillers were added to nylon‐6 individually or in mixed combinations. They were added at different percentages varying between 10 and 30% w/w. Samples of the composites were prepared by the injection moulding process. Uniaxial tensile, Izod impact and flexural tests were carried out. Tensile strength, elongation at break, modulus of elasticity and impact energy were obtained and compared. In case of single fillers the results showed that the tensile strength, modulus of elasticity and their flexural values for nylon‐6 composite improve with the increase in filler content while mixed compounds showed no significant changes above 15% + 15% w/w filler. However, for single and mixed filler up to 10% w/w, the impact strength and maximum elongation at break showed significant decrease. In general, the maximum improvement in mechanical the addition of 10–15% w/w filler. Copyright © 2003 Society of Chemical Industry 相似文献
68.
In this study, superheating and sub‐cooling heat exchangers in vapor‐compressed refrigeration system are analyzed from thermodynamics and economical (refrigeration system operation cost, investment cost) viewpoints. Using four different refrigerants (R22, R502, R134a and R404a), the temperature of condenser at the interval of (35–55°C) and temperature of evaporator at the interval of (?10 to 10°C) have been obtained from the calculation process. The second law analysis (analysis of irreversibility) of a refrigeration system is carried out and then the whole system is optimized thermo‐economically. As a result of calculations, optimum superheating and sub‐cooling temperatures of heat exchanger (superheating, sub‐cooling) areas corresponding to these temperatures are obtained. Copyright © 2007 John Wiley & Sons, Ltd. 相似文献
69.
Unal C.M.H. Snoeij P. Swart P.J.F. 《Geoscience and Remote Sensing, IEEE Transactions on》1991,29(4):621-626
A series of airborne scatterometer measurements carried out with the DUTSCAT multifrequency airborne scatterometer are discussed. This study deals with the first results obtained from the analysis of these measurements. The objective of this activity is to establish a multifrequency dual-polarization radar signature database, and with it a multidimensional version of the current CMOD1 model. The main features of the data set are the following. The wind exponent of the upwind normalized radar cross section (NRCS) increases with frequency and incidence angle in the case of HH polarization. The upwind/downwind ratio is mainly negative at 20° of incidence angle, always at C -, X -, and Ku 1-bands 相似文献
70.
A life prediction model is developed for crack nucleation and early crack growth based on fatigue, environment (oxidation),
and creep damage. The model handles different strain-temperature phasings(i.e., in-phase and out-of-phase thermomechanical fatigue, isothermal fatigue, and others, including nonproportional phasings).
Fatigue life predictions compare favorably with experiments in 1070 steel for a wide range of test conditions and strain-temperature
phasings. An oxide growth (oxide damage) model is based on the repeated microrupture process of oxide observed from microscopic
measurements. A creep damage expression, which is stress-based, is coupled with a unified constitutive equation. A set of
interrupted tests was performed to provide valuable damage progression information. Tests were performed in air and in helium
atmospheres to isolate creep damage from oxidation damage. 相似文献