Modeling of Melt Flow and Surface Standing Waves in a Continuous Casting Mold

Majority of surface and subsurface defects in the continuously cast steel may be attributed to surface standing waves and turbulence. A lot of work has been done on surface defects and on understanding the behavior of the surface waves but there is a dearth of literature connecting the two. Also 3‐D modeling of surface waves with heat transfer and solidification has received little attention. In the present study, a 3‐dimensional mathematical model incorporating turbulent fluid flow, heat transfer, and solidification using a commercial code, FLOW3D, was developed. Using the model, the applicability of Froude criterion for scaling down industrial flow systems was analyzed. Although the small scale models, using this criterion, correctly predict the general fluid flow but the prediction of surface waves is not very accurate. Also, the effect of temperature is difficult to incorporate in water models. The model was used to study the effect of temperature on surface waves and verify the water modeling results. The effects of casting and SEN parameters on the fluid flow and surface waves were studied.     

Studies on Processing of Low Grade Indian Molybdenum Sulphide Concentrate

In India, a low grade molybdenum sulphide concentrate containing 25–30% molybdenum is recovered as a by-product of uranium operations at Jaduguda. This concentrate contains a high association of copper and nickel. If it is processed by the conventional route, both copper and nickel would decrease molybdenum recovery. Such concentrates need a different processing route. Various processes such as soda ash roasting, lime roasting, oxychlorination, and electro-oxidation have been studied. The processes aimed at converting molybdenum into a soluble form, then purified by chemical processing as well as by carbon adsorption-desorption route to yield pure molybdic oxide. The oxide was then reduced to metal with hydrogen. In an alternate scheme, molybdenum values in solution have been converted into molybdenum intermediates such as calcium molybdate/ferrimolybdate. This paper presents the result of these investigations.     

液-液萃取气相色谱法测定四氯化钛水解体系中痕量四氯化碳的不同萃取剂萃取能力对比

比较了液-液萃取气相色谱测定精四氯化钛水解样品中四氯化碳方法中使用的庚烷、正己烷、正辛烷、异辛烷4种萃取剂对痕量四氯化碳的萃取效果。结果表明:4种萃取剂对四氯化碳都有较好的响应, 色谱图上的峰位和峰形都较好, 而且四氯化钛中三氯甲烷、一氯乙酰氯、三氯乙酰氯共存杂质对四氯化碳的测定没有干扰。对于庚烷、正己烷、正辛烷、异辛烷, 校准曲线的线性相关系数分别为0.990 8、0.997 2、0.998 7、0.999 5, 检出限分别为0.003 2、0.001 5、0.004 4、0.001 1, 样品加标平均回收率分别为95.4%、98.8%、96.4%、99.6%, 相对标准偏差分别为2.6%、4.0%、4.6%、1.6%。因此, 4种萃取剂对四氯化碳都有较好的萃取能力, 但异辛烷的萃取能力最强, 稳定性也较好。     

Effect of External Forced Flow and Boiling Film on Heat Transfer of AISI 4140 Steel Horizontal Rod During Direct Quenching

 The effects of rod falling and moving, external flow field, boiling film and radiation were investigated on fluid flow and heat transfer of AISI 4140 steel horizontal rod during direct quenching by mathematical modeling. The flow field and heat transfer in quenching tank were simulated by computational fluid dynamics (CFD) method considering falling and moving of rods during process. Therefore, modeling of flow field was done by a fixed-mesh method for general moving objects equations, and then, energy equation was solved with a numerical approach so that effect of boiling film heat flux was considered as a source term in energy equation for solid-liquid boundary. Simulated results were verified by comparing with published and experimental data and there was a good agreement between them. Also, the effects of external forced flow and film boiling were investigated on heat flux output, temperature distribution and heat transfer coefficient of rod. Also simulated results determined optimum quenching time for this process.     

A General Formulation for Unidimensional Unfolding and Pairwise Preference Models: Making Explicit the Latitude of Acceptance

Probabilistic unfolding models for direct responses of persons to statements are characterised by single peaked response functions. The range in which a positive response is most likely is termed the latitude of acceptance, a well known but little researched concept in the modelling of attitude measurement. This paper derives a general form for probabilistic unfolding models in which a natural parameter characterises the latitude of acceptance. It is shown that a number of already known models for unfolding can be reexpressed in this general form with different operational functions and that, in doing so, the implied latitude of acceptance for these models is identified. It is also shown that other unfolding models can be generated readily by specifying the operational function of the general form. A general form for pairwise preference models is also presented. A discussion on the latitude of acceptance parameter as a scale parameter is also provided. Copyright 1998 Academic Press.     

Computer models of personality: implications for measurement

Computer models of human behavior have long existed in the world of science fiction; however, in reality, progress has been slow. Research has concentrated, in recent years, on the simulation of memory and cognition. Computer models of personality, although fascinating and potentially useful, have been neglected. This paper reviewed the research done to date, categorizing it under five headings: (a) models of belief systems; (b) models of interpersonal behavior; (c) models of decision-making processes; (d) prediction models; and (e) theory-based simulations of specific processes. One practical application was then explored in depth, that of using the computer models in personality measurement. Although some practical development of the working simulations would have to precede their application to personality measurement, it was felt that such an application would be feasible and useful.     

Characterization of Models for Time-Dependent Behavior of Soils

Different classes of constitutive models have been developed to capture the time-dependent viscous phenomena (creep, stress relaxation, and rate effects) observed in soils. Models based on empirical, rheological, and general stress-strain-time concepts have been studied. The first part is a review of the empirical relations, which apply only to problems of specific boundary conditions and frequently involve natural time alone. The second part deals with different rheological models used for describing the viscous effects in the field of solid mechanics. The rheological models are typically developed for metals and steel but are, to some extent, used to characterize time effects in geomaterials. The third part is a review of constitutive laws that describe not only viscous effects but also the inviscid (rate-independent) behavior of soils, in principle, under any possible loading condition. Special attention is paid to elastoviscoplastic models that combine inviscid elastic and time-dependent plastic behavior. Various general elastoviscoplastic models can roughly be divided into two categories: Models based on the concept of overstress and models based on nonstationary flow surface theory. Although general in structure, both have shortcomings when used for modeling of soils.     

Changes in supervision as counselors and therapists gain experience: A review.

Considerable research relevant to counselor and therapist development has been done since E. L. Worthington's (see record 1988-21517-001) review. Additional support has surfaced for Worthington's conclusions: There is support for general developmental models, perceptions of supervisors and supervisees are consistent with developmental theories, the behaviors of supervisors change as counselors gain experience, and the supervision relationship changes as counselors gain experience. Although the types of research used and the sophistication of data analysis have improved somewhat, too few studies directly address changes over time for trainees in supervision. Suggestions are given for future research in supervision to reflect the level of specificity necessary to investigate developmental models. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Proliferative disorders of the breast as risk factors for breast cancer in a self-selected screened population: pathologic markers

A study was done to quantify the pathologic risk of subsequent breast cancer in women whose biopsies demonstrated proliferative histologic conditions. Out of a total of 10,530 patients, 1,408 had biopsies which were classified as either bland fibrocystic or hyperplastic. The behavior of the disease in these patients was compared to that of the general screened population. It was concluded that women whose biopsies reveal hyperplastic disorder, primarily atypical hyperplasia and fibroadenoma, run the greatest risk of getting cancer. For women with atypical hyperplasia, the risk is 13 times that of the general population, and for those with fibroadenoma it is three times greater.     

Convexity of Yield Surface with Directional Distortional Hardening Rules

The present paper examines the convexity of the yield surface in the directional distortional hardening models by Feigenbaum and Dafalias. In these models anisotropy develops through kinematic and directional distortional hardening, supplemented by the classical isotropic hardening, and the associative flow rule is used. However, the issue of convexity, which naturally arises due to the distortion of the yield surface, was not fully addressed. The present paper derives the necessary and sufficient conditions to ensure convexity of the yield surface for the simpler Feigenbaum and Dafalias models, but it is not as straightforward to derive corresponding conditions for convexity of the Feigenbaum and Dafalias model version which contains an evolving fourth-order tensor. In this case convexity will be addressed first in general and then at the limit state for which simple restrictions on the material constants to ensure convexity are derived. Numerical examples will show that some of the yield surfaces simulated in the original Feigenbaum and Dafalias publication will not stay convex if loaded beyond what was done in these publications. Therefore the material constants for these cases are recalibrated based on the derived relations for satisfaction of the convexity requirement, and the fitting of the yield surfaces is repeated with the new set of constants and compared with the previous case.     

Facial changes in extraction and nonextraction patients

BACKGROUND: An invitational conference was held in Dearborn, MI, in April of 1998 to discuss technical and conceptual issues related to the general topic of using outcomes data to compare plans, networks, and providers. Approximately 150 researchers, clinicians, purchasers, and representatives of accreditation bodies and government agencies attended. SURVEY OF PARTICIPANTS: At the opening session, attendees participated in an electronic survey exercise designed to identify areas of agreement or disagreement on controversial issues related to the main conference topic. MAIN FINDINGS: There was general agreement about the basic concept of health plan and provider accountability for health outcomes, and about the need for further development of data sources and case-mix adjustment models. There was disagreement about other issues, including questions of who should bear the cost of collecting outcomes data and whether results should be analyzed at health plan, network, or individual clinician level. CONCLUSION: A group of experts agreed on the importance of reporting comparative outcomes data, but disagreed on many of the technical details of how that could best be done.     

220 kV总降压变电站33 kV系统设备运行分析及改造

叙述了天津钢管公司220kV总降压变电站33kV系统设备运行的概况。在消化吸收引进先进技术的基础上，针对国外设备存在的一些问题进行了分析及技术改造。     

Tasks of hygienic science and sanitation practices in relation to the resolution of the Central Committee of CPSU and of the Soviet of Ministers of the USSR on "Measures for averting pollution of the Black and Azov Sea basins"

A survey was done of the attitude of 4,852 patients to the presence of students in general practitioners' consulting rooms during the 5th year general practice apprenticeship in Queensland. Overall acceptance was 94 per cent. This was remarkably consistent with the results of a similar study in Aberdeen in 1970. Students were more welcome in country practices than in practices in provincial cities and Brisbane, and were also more welcome in solo than in group practices. A plea is made for general practitioners to cooperate, not only as preceptors in the apprenticeship scheme, but also to take part in the collection of basic data for research projects initiated by the sub-Department of Community Practice, Department of Social and Preventive Medicine.     

A study of the pharmacological actions of Dioclea grandiflora Martius ex Bentham

Dioclea grandiflora Mart. ex Bent., known as Mucuna or Mucuna of stone, is a member of the Leguminosae family, popularly used for its possible effects on the Central Nervous System (CNS). Reports mention sedative, tonic, and also antiepileptic properties for this plant. In this paper a screening for CNS action was done with aqueous extracts of the seeds. This study was carried out using some animal models for the study of sedative, hypnotic, anxiolytic, anticonvulsive and neuroleptic activity. The results showed that Dioclea grandiflora Mart. ex Bent. demonstrates the general profile of a CNS depressant drug. However, the extract did not exhibit any of the specific profiles tested. Moreover, the results suggest a possible toxicity stemming from the popular or folk use of this plant.     

配煤炼焦试验研究

济钢焦化厂利用7kg小焦炉进行张庄气肥煤和邹县煤的炼焦试验及不同配比的炼焦试验，将试验结果用于指导生产，扩大了炼焦煤资源，降低了配煤成本，稳定了焦炭质量。     

改进湿法炼锌工艺的新设想

鉴于湿法炼锌在湿法冶金中的重要地位及目前湿法炼锌流程存在的缺陷，提出一个全湿法及采用溶剂萃取技术的新工艺流程，该新工艺流程较现行湿法炼锌流程有一系列优点，但要工业实现该新工艺流程，还需要进行大量的研究工作。     

Application of the Phase Transfer Catalysis in Rare Earth Solvent Extraction

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Criterion models and construct validity for criteria.

Reviews methods for measuring criteria and ascertaining underlying criterion constructs. 3 criterion measurement models (the ultimate criterion model, the multiple criterion model, and a "general" criterion model) for the determinants of managerial effectiveness were examined and attempts made toward integration. The 3 models were than compared to a formal construct validation model. Strengths and weaknesses in both the constructs provided by each of the criterion models and the construct validation procedures are discussed. It is recommended that future criterion research utilize an integrated multiple and general criterion model, and construct validation procedures more extensive than the multitrait-multimethod matrix. (39 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

中厚板控轧模型中待温时间的算法分析

数学模型是轧钢过程进行自动控制的基础,引进的自动控制生产线包含许多先进的数学模型,结合实际的物理过程对程序中数学模型的算法进行分析是消化吸收引进技术的一种方法。本文通过对轧件待温时传热现象的研究,对现有轧钢模型中待温时间的算法进行了分析。     

Implementing the Agency for Health Care Policy and Research pain management pediatric guideline in a multicultural practice setting

This article describes the implementation, monitoring, and evaluation of a clinical practice guideline for managing pediatric patient pain. The standard of care used was the Agency for Health Care Policy and Research acute pain management guideline. It was used to assess current levels of care and to make recommendations for improvements. Information was gathered from a sample of 240 pediatric patients aged 1 week to 14 years. Recommendations for improving care are given. The guideline was found to be clinically useful as a general standard of care, but more work needs to be done to individualize care for specific populations, age groups, and cultures.