Effective Thermal Conductivity of a Packed Bed of Hollow Zirconia Microspheres, under Vacuum and under 100 kPa of Argon

Measurements have been made of the effective thermal conductivity of a packed bed of hollow, yttria-stabilized zirconia microspheres, under vacuum and under 100 kPa of argon gas. Above 1400 K the spheres begin to sinter together. Before this occurs, the conductivity is given under vacuum by A ₁ T ³+ A ₂ with A ₁= 2 × 10⁻¹¹ W · m⁻¹· K⁻⁴ and A ₂= 0.01 W · m⁻¹· K⁻¹. The thermal conductivity increases strongly with both the gas pressure and the degree of sintering of the spheres. The measured values can be fitted reasonably well by a model developed by Takegoshi et al. These results may have some applicability to the development of high-temperature thermal insulation.     

Relationship between endocrine, immune, and clinical variables in patients with systemic lupus erythematosus

OBJECTIVE: To assess the frequency of increased plasma prolactin (PRL) in patients with systemic lupus erythematosus (SLE) and to evaluate its relationship to other hormonal and immune variables. METHODS: Thirty-five patients with SLE with various levels of disease activity were studied. Plasma PRL, cortisol, growth hormone (GH) were determined by radioimmunoassay and interleukin 6 (IL-6) by ELISA: SLE activity was evaluated using the European Consensus Lupus Activity Measurement (ECLAM). RESULTS: Increased plasma PRL concentration (> 20 ng/ml) was recorded in 11 patients (31%). No correlation was found between plasma PRL and GH, IL-6, cortisol, or C-reactive protein, nor was any significant correlation observed between plasma PRL and the ECLAM score. Patients with hyperprolactinemia were, however, found to have been treated with higher doses of prednisone therapy than patients with normal plasma PRL. Further analysis of the relationship of plasma PRL and therapy showed that patients with SLE selected by the attending physician for prednisone therapy in doses > or = 10 mg/day were more frequently hyperprolactinemic. CONCLUSION: Our findings that patients with SLE with a more active form of the disease and who are less responsive to therapy had increased plasma PRL levels more frequently may be indicative of a potential relationship of hyperprolactinemia to severity of disease.     

What determines initial feeling of knowing? Familiarity with question terms, not with the answer.

How do people know whether they have an answer to a question before they actually find it in their memory? Two experiments explored this question. Ss were trained on relatively novel 2-digit?×?2-digit arithmetic problems (e.g., 23?×?27). Before answering each problem, Ss made a quick feeling of knowing judgment as to whether they could directly retrieve the answer from memory or had to compute it. Knowing the answer initially appeared to be linearly related to having a feeling of knowing the answer; however, when the frequency of exposure to complete problems and the frequency of exposure to parts of the problems were separately varied, feeling of knowing was better predicted by the frequency of presentation of the problem parts, not by knowledge of the answer. This suggests that the processes involved in knowing the answer are different from those involved in having a feeling of knowing. Specifically, an early feeling of knowing is not just based on an early read of the answer. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

POROSITY: III. WATER AS AN ABSORPTION LIQUID

Classes of absorption method .—The ordinary immersion method has been shown by previous investigators to be unreliable. Simple immersion in low vacuo without boiling is also shown theoretically to be unreliable. An analysis of the results of previous investigators indicates the presence of unsuspected sources of error. Effect of adsorbed gases upon dry weights of test pieces .—Dry air is shown to be without appreciable influence. Depending upon the humidity of the atmosphere, adsorbed water vapor may cause errors up to 2 per cent in the porosity value. Perfectly dry fired clay will remove water from conc. H₂SO₄, and from fused CaCl₂. Saturation by boiling at atmospheric pressure .—A one hour's (and in one instance a 5 hours') boiling failed to saturate completely. On continued boiling the saturated weight increases linearly with the time and this in spite of the fact that appreciable quantities of dissolved materials are removed from the test piece by the hot water. This result is shown to be due to a gradual and continuous rehydration of the clay by the hot water. The error from this factor may amount to as much as 3% and the error from dissolved materials to as much as 2%, during a 3 hours' boiling. The nature of the dissolved material was determined. Method of cooling the test piece .—It is recommended that the test piece be kept in a closed vessel over 95% sulphuric acid for several hours before its dry weight is taken. Saturation procedure .—A vacuum method is described in which water may be employed as the saturation liquid under conditions where the above sources of error are reduced to a minimum. The method is not however recommended as a primary standard. Necessity of a soaking period .—It is shown from theoretical considerations that a soaking period is necessary and methods are given for calculating and for measuring the minimum soaking period required for a given test piece and a given liquid of known penetrativity.     

无噪驱动

随着节能及其他优势的发展,可调速驱动在驱动设计和安装过程中必须最小化驱动发出的分裂电噪声。     

A Scalable System Architecture for High-Throughput Turbo-Decoders

The need for higher data rates is ever rising as wireless communications standards move from the third to the fourth generation. Turbo-Codes are the prevalent channel codes for wireless systems due to their excellent forward error correction capability. So far research has mainly focused on components of high throughput Turbo-Decoders. In this paper we explore the Turbo-Decoder design space anew, both under system design and deep-submicron implementation aspects. Our approach incorporates all levels of design, from I/O behavior down to floorplaning taking deep-submicron effects into account. Its scalability allows to derive optimized architectures tailored to the given throughput and target technology. We present results for 3GPP compliant Turbo-Decoders beyond 100 Mbit/s synthesized on a 0.18 μm standard cell library.     

Individual differences in output variability as a function of job complexity.

The hypothesis was tested that the standard deviation of employee output as a percentage of mean output (SDp) increases as a function of the complexity level of the job. The data examined were adjusted for the inflationary effects of measurement error and the deflationary effects of range restriction on observed SDp figures, refinements absent from previous studies. Results indicate that SDp increases as the information-processing demands (complexity) of the job increase; the observed progression was approximately 19%, 32%, and 48%, from low to medium to high complexity nonsales jobs, respectively. SDp values for sales jobs are considerably larger. These findings have important implications for the output increases that can be produced through improved selection. They may also contribute to the development of a theory of work performance. In addition, there may be implications in labor economics. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Auswirkungen einer Kalziumbehandlung auf die Entstehung und Zusammensetzung von nichtmetallischen Einschlüssen bei der Erzeugung von aluminiumberuhigten Stählen für Langprodukte

The treatment of liquid steel with calcium is an often used practice, if the melt has been killed with aluminium. Thus high melting aluminium oxides are being modified to calcium aluminates with a lower melting point. This improves the castability in the continuous casting process. Therefore experiments have been carried out at Voestalpine Stahl Donawitz to determine the effects of a calcium treatment on the inclusion composition and morphology Tests of the steel purity and SEM/EDX-analyses of nonmetallic inclusions have been carried out. Main interest of the investigations were the influence of a high sulphur content in the melt and bigger amounts of calcium. By means of the results, the formation of inclusions (calcium aluminates, calcium sulphides) could be reproduced and influences on the steel purity could be shown.