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71.
A BABANEJHAD M HASHEMI Y RAHMATALLAHPUR SH A NOZAD 《Bulletin of Materials Science》2012,35(4):561-566
The present work aims to study effect of lactic acid concentration as complexing agent on surface roughness and nucleation morphology of electroless N?CP deposition. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) have been used to study nucleation morphology and surface roughness of deposition. Deposition process started at some initial priority growing centres independently distributed on the substrate. We found that the morphology and surface roughness of deposition strongly depends on the complexing agent concentration. Morphology of initial deposited centres with no concentration of lactic acid was in coniform structure. By increasing the complexing agent concentration, the structure of initial growing centres changed from coniform to nodular shape and the surface roughness of depositions decreased. 相似文献
72.
Amir Mowla Mehrez Agnaou Tanyakarn Treeratanaphitak Hector M. Budman Nasser M. Abukhdeir Marios A. Ioannidis 《American Institute of Chemical Engineers》2020,66(6):e16959
We quantify the ability of the two-fluid Euler–Euler model to predict the overall gas hold-up during two-phase flow in vertical columns using a combination of experiments and simulations. Gas hold-up in a bubble column and gas hold-up in the less-frequently studied co-current flow are investigated. For homogeneous flow characterized by nearly uniform bubble size, Euler–Euler model predictions are within 10% of the experimental values for both modes of operation, if the bubble diameter supplied as input to the model is the average bubble diameter in the physical system. This also holds true for heterogeneous flow in bubble columns despite the presence of a broad distribution of bubble sizes, if turbulence and bubble swarm effects on momentum exchange between phases are properly accounted for. Swarm corrections adequate for bubble columns, are less successful for co-current heterogeneous flow, for which gas hold-up predictions are least accurate (average error of 22%). 相似文献
73.
介绍了真空缓冷炉渣的工艺矿物学特性。试验研究结果表明,该炉渣属于中等可碎性偏难,硬度系数在8 ̄16之间,在磨矿细度为-0.016mm占89%时,粗、扫选抛尾粗精矿再磨再选,以Z-200、SN-9和丁胺为混合捕收剂,最终得到铜精矿产率为4.59%,精矿含铜23.48%,含金5.8g/t,铜回收率为83.70%;尾矿含铜0.22%,含金0.18g/t。 相似文献
74.
Gain-scheduling has proven to be a successful design methodology in many engineering applications. However, in the absence of a sound theoretical analysis, these designs come with no guarantees of robust stability, performance or even nominal stability of the overall gain-scheduled deign.This paper presents such an analysis for one type of nonlinear gain-scheduled control system based on the process input for nonlinear chemical processes. A methodology is also proposed for the design and optimization of the robust gain-scheduled PI controller. Conditions which guarantee robust stability and performance are formulated as a finite set of linear matrix inequalities (LMIs) and hence, the resulting problem is numerically tractable. Issues of modeling error and input-saturation are explicitly incorporated into the analysis. A simulation study of a nonlinear continuous stirred tank reactor (CSTR) process indicates that this approach can produce efficient sub-optimal robust gain-scheduled controllers. 相似文献
75.
Butler Stephen F.; Newman Frederick L.; Cacciola John S.; Frank Arlene; Budman Simon H.; McLellan A. Thomas; Ford Sabrina; Blaine Jack; Gastfriend David; Moras Karla; Salloum Ihsan M.; Barber Jacques P. 《Canadian Metallurgical Quarterly》1998,10(4):399
The Addiction Severity Index (ASI) is a reliable and valid measure of problem severity among addicted patients. Concerns have been raised about the reliability of the Interviewer Severity Rating (ISR), a summary score for each of 7 domains. As part of an effort to build a computer-administered ASI, regression equations were developed to predict the ISR. Repeated resampling of a large dataset, consisting of 1,124 ASIs conducted by trained interviewers, permitted derivation of stable regression equations predicting the ISR for each ASI domain from patients' answers to preselected interview items. The resulting 7 Predicted Severity Ratings (PSRs) were tested on 8, standardized vignettes, with "gold standard," expert-generated ISRs. Reliabilities compared well with those of intensively trained interviewers. The PSRs could provide an alternative to potentially unreliable interviewer ratings, enhancing the ASI's role in treatment planning and treatment matching and make possible a computer-administered version of the ASI. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
76.
BACKGROUND: Tacrolimus (FK506) may represent a major advance in the management of allograft rejection after solid organ transplantation. In August 1994 a European heart transplantation pilot study was initiated to assess the efficacy and safety of tacrolimus when administered exclusively through an oral route. METHODS: Eighty-two heart transplant recipients were randomized to treatment (2:1 ratio) with either tacrolimus- (n=54) or cyclosporine-based therapy (n=28). RESULTS: No significant differences were evident between the two treatment groups in either rejection or survival rates at 1 year. Kaplan-Meier estimates of the freedom from rejection were 26.3% and 18.5%, respectively, for the tacrolimus and cyclosporine treatment groups (p=.444). Survival rates were 79.6% and 92.9% (p=.125). At 3 of the 5 centers, patients received antithymocyte globulin during the immediate postoperative period and fared better than those who did not (with acute rejection-free rates of 49.2% and 26.7% for tacrolimus and cyclosporine, respectively [p=.080], as opposed to 7.1% and 8.3% [p=.965]; patient survival rates of 84.6% and 93.3% [p=.382] vs 75.0% and 92.3% [p=.243]). The overall rates of infection, impaired renal function (31.5% vs 21.4%), and glucose intolerance (7.0% vs 4.3%) did not differ significantly between the tacrolimus and cyclosporine treatment groups. Tacrolimus seemed to possess an advantage with regard to a reduced requirement for antihypertensive therapy (59.5% vs 87.5%, p=.025). CONCLUSIONS: Immunosuppression with oral tacrolimus provides a viable alternative to treatment with cyclosporine, particularly when administered in conjunction with antibody therapy. Further studies are warranted to optimize the administration of tacrolimus in this indication. 相似文献
77.
Cummings Nicholas A.; Budman Simon H.; Thomas J. Lawrence 《Canadian Metallurgical Quarterly》1998,29(5):460
A recent series of articles purported that brief psychotherapy is mostly ineffective, that managed care's use of brief interventions constitutes invisible rationing, and that it is ethically mandatory to disclose this information to the patient. In response, the authors of this article demonstrate that health care rationing is multifaceted and universal in modern society, and patient disclosure is far from the simplistic, one-sided matter purported by the previous articles. It may even be deleterious. The authors advocate effective psychotherapy as a viable response to scarce resources and urge the profession to train future practitioners in the full range of emerging innovative and effective psychotherapies. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
78.
C Küchler SH Heywang-K?brunner U Schauml?ffel P Viehweg H H?fer J Buchmann D Lampe 《Canadian Metallurgical Quarterly》1997,37(8):621-628
PURPOSE: To test the capabilities of vacuum core biopsy (VCB) in the diagnosis of mammographically indeterminate lesions. MATERIALS AND METHODS: 120 patients (131 lesions) were examined using VCB with 14G or 11G vacuum core. RESULTS: VCB was mostly performed because of indeterminate microcalcifications (67 cases) or soft tissue densities/architectural distortion (64 cases). 112 benign changes, 14 DCIS and 5 invasive carcinomas were found. Excellent accuracy was achieved (presently 100%), since complete excision of small lesions/areas (< or = 1 cm) or partial excision of larger lesions was possible. No relevant hematomas or infections occurred. Patients tolerated the painless procedure very well. DISCUSSION: This report confirms our previous experiences. This method promises to replace diagnostic open biopsy of indeterminate or suspicious nonpalpable lesions. 相似文献
79.
MG Wysoki CJ Nassar RA Koenigsberg RA Novelline SH Faro EN Faerber 《Canadian Metallurgical Quarterly》1998,208(1):125-128
The determination of diagnostic features in recorded heart sounds was investigated with Carpentier-Edwards (CE) bioprosthetic valves. Morphological features, extracted using the Choi-Williams distribution, achieved between 96 and 61% correct classification. The time-scale wavelet-transform feature set achieved 100% correct classification with native valve populations, and 87% with the CE replacements. 相似文献
80.