Critical density index for the solar production of bittern from seawater

Solar extraction of common salt from seawater has been practiced for centuries in a rather crude manner because the process was not performed in stages to obtain a pure salt. The common practice in developing countries is to carry through with the evaporation process to the stage of dryness to facilitate harvesting the salt mix. If salt is harvested prior to the deposition of impurities during the evaporation process then the resulting bittern would provide chemicals which could have many commercial applications particularly in treatment industries. This paper describes an effective procedure for the separation of common salt and impurities. Sufficiently sensitive indicators that would signal the start and deposition of impurities in the course of the solar evaporation process were established. These indicators are particularly useful in regions where advanced desalting technology is not readily available.     

Nonlinear Analysis of Reinforced Concrete Beam–Columns with Bond-Slip

This paper presents a new model for nonlinear analysis of reinforced concrete beam–columns with bond–slip. The model is derived from a two-field mixed formulation with independent approximation of forces and displacements. The state determination algorithm for the implementation of the model in a general purpose nonlinear finite-element analysis program is presented and its stability characteristics are discussed. Both, bond–slip and pull-out effects, are represented in the model. The paper concludes with a correlation study to investigate the validity of the model. The study confirmed the accuracy of the model in representing global and particularly local parameters.     

Development of methodology in biomechanical simulation of manual lifting

The purpose of this paper is to introduce some techniques of biomechanical simulation through an example — simulation of manual lifting. The motivation for developing biomechanical simulation is discussed. Biomechanical simulation is defined and compared with the traditional biomechanical modeling. The formulation of biomechanical simulation of manual lifting is presented, and some practical techniques used to conduct a simulation of manual lifting are provided.     

Carcinoma of the lung in three brothers and two sisters

SETTING: Patients were recruited from Siriraj, Bamrasnaradura, and Central Chest Hospitals, the three major hospitals responsible for tuberculosis patients in Bangkok, Thailand, and vicinity. OBJECTIVE: To evaluate a new rapid serologic test, the MycoDot test, for diagnosis of tuberculosis (TB). DESIGN: The study was conducted as a cross-sectional survey. A total of 594 patients were tested with the MycoDot test. This included 142 human immunodeficiency virus (HIV) seropositive patients with active TB, 144 HIV seronegative patients with active TB, 153 HIV seropositive controls, and 155 HIV seronegative controls. RESULTS: The sensitivity of the MycoDot test for detection of TB was 40.1% in HIV seropositive patients, compared with 63.2% in HIV seronegative patients (P < 0.001). If only patients with laboratory proven TB were evaluated, the sensitivity was 40.6% in seropositive and in 70.8% seronegative patients. The sensitivity of the MycoDot test was similar in TB patients with pulmonary and extra-pulmonary disease. The sensitivity of the test in patients with CD4 counts > or = 200 cells/mm3 was significantly higher than in those with CD4 counts < 200 cells/mm3. The specificity of the test was 97.4%, and was identical in HIV seropositive and seronegative individuals. CONCLUSION: The MycoDot test had a higher sensitivity for the diagnosis of TB among HIV seronegative than HIV seropositive patients. Although the MycoDot test has a less than optimal sensitivity, the test specificity approaches 100%. It may be useful in patients with suspected TB and negative smears and in extra-pulmonary TB.     

Chilled ceiling and displacement ventilation system for energy savings: A case study

This paper studies the design and performance of cooled ceiling and displacement ventilation (CC/DV) systems application for buildings in Beirut for the purpose of saving energy. The transient thermal response of spaces cooled by the combined CC/DV system is needed for performance assessment. For that reason, the plume‐multi‐layer model of CC/DV cooled spaces is extended to transient applications. A design procedure for the combined CC/DV system in Beirut humid climate and buildings is developed to insure that both indoor air quality and comfort are satisfied within the conditioned zone. The contribution of the proposed procedure is that it guarantees that the stratification height (occupied zone) is at 1.1 m taking into consideration the plumes from internal sources and non‐isothermal walls. The design procedure is applied to a case study in Beirut to design a system for a typical office space at 85 W m^?2 sensible cooling load. The CC/DV system size is compared with the size of a conventional mixed convection system. It is found that the size of the CC/DV system is 10.2 kW compared to conventional system size of 7.9 and 13.4 kW at the 30 and 100% fresh air supply, respectively. For the same indoor air quality and thermal comfort level, the CC/DV system consumed 21% less cooling energy than the conventional 100% fresh air system over the cooling season. The initial cost of the CC/DV system is higher, but the pay back period based on transient operation is less than 5 yr. Copyright © 2006 John Wiley & Sons, Ltd.     

Biomechanics of manual material handling through simulation: Computational aspects

Computerized human motion simulation allows generation of dynamic human motions on computers. Biomechanical stresses can be estimated using the motions generated on a computer without actually collecting joint coordinate data. A two-dimensional whole-body lifting simulation model is presented in this paper. The model assumes that humans perform lifting activities based on minimization of physical work, subject to various constraints. The simulation method contains three major computation units: trajectory formation unit, dynamics of motion unit, and nonlinear optimization unit. The trajectory formation unit generates smooth polynomials representing motion characteristics of human lifting. Kinematics and kinetics are calculated in the dynamics unit. Objective and constraint functions are evaluated in the optimization unit. Optimal motions are generated by minimizing the objective function, subject to the constraints. Computation methods of the three units and simulation results are presented.     

火灾中混凝土与钢筋之间粘结力的模拟

采用非线性程序,模拟火灾中钢筋混凝土结构中混凝土与钢筋之间的粘结机理。通过1个梁的拉拔力试验、1个特定温度下的梁试验和在两种标准火灾中的4个足尺梁试验,证明数值模型的准确可靠性。该模型对火灾中钢筋混凝土构件和结构响应的预测满足精度要求,粘结连接单元也能满足火灾中钢筋混凝土结构3维分析的计算精度和计算效率的要求。结果表明:混凝土与钢筋之间的粘结条件对钢筋混凝土结构的耐火性能有重要影响,尤其当钢筋的温度较高(大于500°C)时。目前使用的火灾中钢筋混凝土结构粘结条件的假设是偏不安全的。     

Synthesis of a graft copolymer from an ozonized polycarbonate and its application as a compatibilizer

The polycarbonate (PC)/polystyrene (PS) blend is an immiscible system. The use of copolymers as compatibilizers in blends is one approach that is being developed within the larger field of polymer alloys. In this study, PC was ozonized to create peroxides and hydroperoxides on the polymer chain. These functional groups under heating conditions were used to initiate the radical polymerization of styrene (vinyl monomers) to give graft copolymers. The first part of this study was dedicated to the examination of the kinetics of the styrene polymerization initiated by an ozonized PC. However, the structure of the graft copolymers was confirmed by IR spectroscopy, and the molecular weight of the PS graft chain was determined by gel permeation chromatography. The compatibilized bends were prepared by melt blending in an internal mixer. The morphologies of the PC/PS/graft copolymer blend were examined by transmission electron microscopy and were finer than those of an uncompatibilized blend. The tensile properties of these blends were also investigated. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013