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101.
Experimental testing was completed to study the load/displacement and energy-absorption characteristics of AA6061-T6 round extrusions under a cutting deformation mode. A heat-treated 4140 steel alloy cutter was designed and manufactured with four cutting blades of approximate average thickness of 1.18 mm to penetrate through the round AA6061-T6 extrusions. The specimens utilized in this experimental investigation were tubes of lengths 200 and 300 mm with a nominal wall thickness of 3.175 and an external diameter of 50.8 mm. Results from the experimental tests showed that the cutting deformation mode exhibited a high average crush force efficiency of 0.95 compared to average values of 0.66 and 0.20 for progressive folding and global bending deformation modes, respectively. An almost constant cutting force was observed during the cutting deformation process. For both the 200 and 300 mm length tubes, the average total energy absorption was observed to be 6.11 kJ, which was independent of tube length. The mean steady-state cutting force observed was 45.58 kN and a fair correspondence was found between the theoretical predictions and the experimental results. 相似文献
102.
Sudesh Jood Bhag Mal Chauhan Amin C. Kapoor 《Journal of the science of food and agriculture》1987,39(2):145-149
The effects of soaking, cooking, autoclaving and sprouting on the polyphenol contents of eight cultivars of chickpea (Cicer arietinum) and four of blackgram (Vigna mungo) were studied. All the treatments reduced the polyphenols of the legume seeds, but to a varying extent. Sprouting and autoclaving had the most pronounced effect; ordinary cooking and soaking were relatively less effective. 相似文献
103.
MG Hobart CS Modlin A Kapoor N Boparai B Mastroianni D Papajcik SM Flechner DA Goldfarb R Fischer KJ O'Malley AC Novick 《Canadian Metallurgical Quarterly》1998,66(12):1689-1694
BACKGROUND: To maximize the renal donor pool, cadaveric pediatric en bloc kidneys have been transplanted as a dual unit by some transplant centers. We compared the short- and long-term outcomes of adult recipients of cadaveric pediatric en bloc renal transplants versus those of matched recipients of cadaveric adult kidneys. METHODS: Thirty-three adults who received pediatric en bloc kidney transplants between April 1990 and September 1997 were retrospectively identified and were compared with 33 matched adults who received adult cadaveric kidney transplants. The groups were identical for transplantation era, immunosuppression, recipient sex, race, cause of renal failure, mean weight, and follow-up duration (37.8 vs. 37.5 months). The mean recipient age study versus control was lower (36.3 vs. 48.9 years, P=0.0003). Results. There was no difference between the en bloc and adult donor groups in the 3-year patient survival rates (95% vs. 87%, P=0.16) or the 3-year graft survival rates (87.3% vs. 84.2%, P=0.35). Further, there was no difference in en bloc patient or en bloc graft survival time stratified by recipient age (14-44 vs. >45 years, P=0.11), en bloc donor age (<24 vs. >24 months, P=0.39), or recipient weight (<60, 61-75, >75 kg; P=0.60). Differences in serum creatinine (mg/dl) for the en bloc versus the control group at the time of discharge (3.0 vs. 7.8 mg/dl, P=0.06), at 1 year (1.4 vs. 2.0 mg/dl, P=0.06), and at 2 years (1.1 vs. 1.6 mg/dl, P=0.14) had dissipated by the time of the 5-year follow-up examination (1.1 vs. 1.6 mg/dl, P=0.14). Vascular complications were more prevalent in the en bloc group: renal vein thrombosis (one case), thrombosis of donor aorta (two cases), arterial thrombosis of one renal moiety (two cases), and renal artery stenosis (two cases). There were no differences between groups in delayed graft function, acute or chronic rejection, posttransplant hypertension, posttransplant protein-uria, or long-term graft function. CONCLUSIONS: Collectively, these data indicate that transplanting pediatric en bloc kidneys into adult recipients results in equivalent patient and graft survival compared with adult cadaveric kidneys. Further, the data also suggest that pediatric en bloc kidneys need not be strictly allocated based on recipient weight or age criteria. 相似文献
104.
105.
Microstrip discontinuities are analyzed using Wheeler's waveguide model and the finite-difference time-domain (FDTD) method. Wheeler's model employs a conformal transformation to convert a microstrip into an enclosed waveguide structure. This permits the mapping of a discontinuous microstrip into a discontinuous, but enclosed, waveguide. The enclosed waveguide eliminates the difficulties usually associated with analysis of an open domain geometry. The FDTD technique is then used to calculate the scattering coefficients of the discontinuous waveguide. The features of this approach are: (1) it yields a smaller computational domain than that required to analyze the untransformed geometry; (2) it yields results over a band of frequencies; and (3) it is simple to implement. Results obtained using this scheme show good agreement with previously published results 相似文献
106.
V. K. Bhatia K. G. Mittal R. P. Mehrotra V. K. Garg M. Mehrotra R. K. Sarin V. B. Kapoor S. C. Gupta 《Fuel》1988,67(12):1708-1709
The latex of Euphorbia neriifolia has been studied with a view to its development as a potential petrocrop. Hydrocracking of biocrude afforded 72% conversion to products (C5 and larger molecules), comprising up to 35% gasoline (b.p. 65–150 °C) and 15% kerosene (150–260 °C) in addition to other products. About 70% of the hydrocarbon material present in the gasoline fraction has been characterized. 相似文献
107.
108.
SS Sikora A Kumar R Saxena VK Kapoor SP Kaushik 《Canadian Metallurgical Quarterly》1995,19(6):858-860
The possibility of conversion to open cholecystectomy (OC) always exists while performing a laparoscopic cholecystectomy (LC). This study has been performed with the aim of identifying factors predicting conversion to OC. From October 1992-April 1994, LC was attempted in 150 patients and conversion to OC was required in 29 (19%) patients. Ten preoperative factors were analyzed retrospectively to identify parameters significantly correlating with conversion to OC. Preoperative factors analyzed were age, sex, duration of symptoms, BMI (Body Mass Index), past history of jaundice, previous abdominal surgery, associated medical risk factors, palpable lump on clinical examination, USG, and OCG findings. Univariate and multiple stepwise regression analysis identified male sex, USG finding of contracted/thick-walled gall bladder, and a palpable gall bladder lump on examination as significant preoperative factors predicting conversion to OC. 相似文献
109.
In the mammalian brain, kynurenine aminotransferase (KAT) is pivotal to the synthesis of kynurenic acid, a preferential antagonist at the strychnine-insensitive NMDA-glycine site. As NMDA receptors are involved in autonomic function, we have examined the immunohistochemical localization of KAT in the medulla and spinal cord of the rat. KAT immunoreactivity (KAT-li) was found throughout these areas, in both glia and neurons. Unlike the mainly astrocytic localization in forebrain structures, KAT-li was predominantly neuronal, notably in areas important for blood pressure and heart rate regulation: ventral medulla, nucleus ambiguus, nucleus of the solitary tract and intramediolateral cell column of the spinal cord. The presence of KAT in these nuclei supports a neuromodulatory role for kynurenic acid in NMDA-mediated autonomic function. 相似文献
110.
Contact angle measurements on silicon-nitride substrates were conducted on tin-based alloys, containing titanium and zirconium,
to determine the suitability of these alloys as filler metals for low-temperature joining of ceramics. Titanium-containing
alloys exhibited excellent wettability characterized by contact angles less than 20 deg, whereas the Zr-containing alloys
exhibited contact angles around 50 deg. The superior wettability of the Sn−Ti alloys is attributed to the higher activity
coefficient of Ti in Sn−Ti alloys. The liquidus temperature of the Sn−Ti alloys is in the 400°C to 600°C range. Hence, these
alloys are expected to reduce the residual stress problem. 相似文献