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41.
The interaction of different metal oxides such as Co3O4, NiO, Al2O3, Cr2O3, Fe2O3 and SiO2 with Na2SO4 at a temperature of 1100 and 1200 K in flowing oxygen has been studied. The thermogravimetric studies for each system were
carried out as a function of Na2SO4 in the mixture. The presence of different constituents in the reaction products were identified by X-ray diffraction analysis
and the morphologies of the reaction products were characterized using metallography and scanning electron microscopy (SEM).
The formation of products was also investigated by thermodynamic computation of free energies of the reactions and the study
of relevant equilibrium phase diagrams. The soluble species in the aqueous solutions of the reaction products were determined
quantitatively using atomic absorption spectrophotometry.
The high temperature interaction products usually contain a 3-phase structure namely, Na2O·M2O
x
, M2O
x
and metal sulphide and/or metal sulphate. The formation of Na2O·M2O
x
depends upon the solid state solubility of metal oxide in the molten salt at high temperatures. Under limited solubility
conditions Na2O·M2O
x
is invariably formed, but as soon as this condition is relaxed the oxide. M2O
x
, precipitates and forms a separate phase. 相似文献
42.
RA Malik S Tesfaye SD Thompson A Veves AK Sharma AJ Boulton JD Ward 《Canadian Metallurgical Quarterly》1993,36(5):454-459
Twenty diabetic patients with neuropathy underwent clinical and neurophysiological evaluation together with a detailed morphometric assessment of capillary pathology in endoneurial and epineurial microvascular beds of the sural nerve. Morphological data were compared with ten non-diabetic control subjects. There were no significant differences in control subjects between basement membrane area, endothelial cell area, endothelial cell profile number or luminal area of endoneurial when compared with epineurial capillaries. In contrast, when compared with epineurial capillaries, endoneurial capillaries from diabetic patients demonstrated a significant increase in basement membrane (p < 0.001) and endothelial cell (p < 0.001) area and a significant reduction in luminal area (p < 0.001). There was no significant difference in endothelial cell profile number between endoneurial and epineurial capillaries amongst diabetic patients. Previous studies have demonstrated a good correlation between the degree of microangiopathy and measures of neuropathic severity. In the present study increased endoneurial capillary basement membrane area was significantly related to reduced peroneal nerve conduction velocity (p < 0.001), myelinated fibre density (p < 0.001) and elevated vibration (p < 0.05) and thermal (p < 0.001) perception. Increased endothelial cell area and reduced luminal size were related to a reduced peroneal nerve conduction (p < 0.05, p < 0.01, respectively), reduced myelinated fibre density (p < 0.05, p < 0.01) and elevated thermal perception (p < 0.05, p < 0.001). Epineurial capillary basement membrane, endothelial cell and luminal area failed to relate to measures of neuropathic severity.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
43.
Thomas L. Landers Melinda K. Beavers Malik Sadiq Don E. Stuart 《Computers & Industrial Engineering》1994,27(1-4):245-248
This paper describes an approach, conceptual framework, and software architecture for dynamic reconfiguration of the order picking system. The research and development project was sponsored by the Material Handling Research Center (MHRC), a National Science Foundation sponsored Cooperative Industry/University Research Center. The storage configuration is assumed to be an in-the-aisle order picking system in which stockkeeping units (SKUs) can occupy variable capacity storage locations and stock-splitting is allowed among zones (clusters). The product mix may include multiple product families with different life cycles, correlated demand within families and commonality of demand across families. 相似文献
44.
Muhammad Nabeel Ghayur Anwarul Hassan Gilani 《European Food Research and Technology》2007,224(4):477-481
In this study, we describe the tracheal-relaxant and tocolytic activities of the methanol (ME) and aqueous (AQ) crude extracts
of ginger (rhizome of Zingiber officinale) in an attempt to rationalize its traditional use in disorders of airways and uterine hyperactivity. Both of the ginger extracts
dose-dependently relaxed K+ (80 mM) and carbachol (CCh, 1 μM)-induced contractions with more potency against K+, similar to that elicited by verapamil, a Ca2+ channel blocker. In isolated uterine preparations, the extracts suppressed the K+-induced contractions with respective EC50 values of 0.03 mg/ml (0.02–0.05, 95% CI) and 0.05 mg/ml (0.04–0.06). Activity-directed fractionation of AQ yielded an organic
and an aqueous fraction with the activities concentrated in the former. Both the crude extracts were found safe in mice up
to the oral dose of 5 g/kg when tested for acute toxicity for 24 h. The study shows that ginger possesses tracheal and uterine
smooth muscle relaxant activity, possibility mediated via Ca2+ channel blockade, justifying its use in disorders such as asthma, cough as well as in dysmenorrhoea and uterine and menstrual
spasms and congestion. 相似文献
45.
Malik Mary L.; Beutler Larry E.; Alimohamed Shabia; Gallagher-Thompson Dolores; Thompson Larry 《Canadian Metallurgical Quarterly》2003,71(1):150
The definition of an empirically supported treatment (EST) arguably embodies 2 untested assumptions: (a) that different manualized renditions of the same therapy are functionally equivalent and (b) that therapies can be reliably applied independently of therapist, setting, and format. These assumptions were tested as applied to cognitive therapy (CT), using process data from a large multisite study (N=235) that included 3 cognitive and 6 alternative therapies. Although the non-CTs were more variable than the CTs on 2 of 4 dimensions studied (directiveness and emotional arousal), there was considerable variation among the 3 CTs, even when implemented in the current context of rigorous training, manualization, and adherence checks. Results are discussed as related to the assumptions underlying EST criteria. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
46.
47.
N‐p‐Bromophenylmaleimide (BrPMI) does not polymerize in solution by conventional free radical mechanism. However, it readily polymerized in bulk when mixed with a free radical initiator and heated in a microwave oven for 7–8 min. Copolymerization of ethyl methacrylate or butyl methacrylate with BrPMI was conducted in dioxane. The copolymers were characterized by IR and 1H NMR spectroscopy and gel permeation chromatography. The monomer reactivity ratios were calculated by a non‐linear least‐square analysis. Thermal analysis indicated a great improvement in thermal stability of the copolymers compared with the methacrylate homopolymers. BrPMI was also polymerized in bulk in the DSC pan, which allowed the calculation of the activation energy of its polymerization. Copyright © 2003 Society of Chemical Industry 相似文献
48.
It has been shown that tilt and exercise elicit significant changes in autonomic activity in normal subjects and that submaximal exercise causes a greater reduction in heart rate variability (HRV) in animals susceptible to ventricular fibrillation (VF). Whether there is an abnormal HRV response to tilt and exercise in patients at risk of sudden cardiac death (SCD) remains unknown. Short-term HRV before and during passive tilt and exercise was studied in 12 survivors of out-of-hospital cardiac arrest with documented VF and compared with 12 age- and sex-matched normal controls. No patient had significant structural heart disease or left ventricular dysfunction. HRV was computed as total-frequency (TF, 0.01 to 1.00 Hz), low-frequency (LF, 0.04 to 0.15 Hz) and high-frequency (HF, 0.15 to 0.40 Hz) components. There was no significant difference between normal controls and SCD survivors in HRV before or during tilt or submaximal exercise testing. The HF component was significantly decreased during tilt compared with that in the supine position in both normal controls (5.85 +/- 0.61 vs 5.08 +/- 0.95 In(msec2), p = 0.005) and patients (5.58 +/- 1.49 versus 4.74 +/- 1.18 In(msec2), p = 0.003). There was again no significant change in the TF or LF components during tilt in either patients or controls. All frequency components were significantly decreased during submaximal exercise testing in both patients and controls. However, there was no significant difference in any of these tilt- and exercise-induced changes in HRV between normal controls and SCD survivors.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
49.
This paper describes the implementation and experimental studies of an adaptive self-optimizing pole shifting power system stabilizer. Using an Intel iSBC386/21 single-board computer, the adaptive power system stabilizer has been tested on a physical model of a single-machine infinite-bus power system. Under different operating conditions and disturbances, the behavior of the proposed adaptive stabilizer was investigated. Comparison has also been made to a digital-type conventional fixed-parameter power system stabilizer. Results of the experimental studies show that the proposed adaptive stabilizer outperforms the conventional stabilizer. 相似文献
50.
Schubert E.F. Hunt N.E.J. Malik R.J. Micovic M. Miller D.L. 《Lightwave Technology, Journal of》1996,14(7):1721-1729
Resonant-cavity light-emitting diodes (RCLED) are novel, high-efficiency light-emitting diodes which employ optical microcavities. These diodes have higher intensities and higher spectral purity as compared to conventional LEDs. Analytical formulas are derived for the enhancement of the spontaneous emission along the optical axis of the cavity. The design rules for high-efficiency operation of RCLEDs are established. The temperature dependence of the emission intensity is analyzed in the range 20-80° and it is described by an exponential dependence with a characteristic temperature of 112 K. The modulation characteristics of RCLEDs exhibit 3 dB frequencies of 580 MHz. Eye diagrams at transmission rates of 622 Mb/s are wide open indicating the suitability of RCLEDs for high-speed data transmission 相似文献