撞击型触发器对帽形薄壁截面轴向挤压影响的数值分析

主要介绍了触发器的设计和性能。为了分析撞击型触发器的几何特征对于轴向冲击荷载作用下耗能构件的抗挤压性能的影响,对其进行数值分析。该耗能构件由一个平盖加一个帽形顶部剖面构成。将触发器视为一个在帽形剖面上具有半圆形横截面的突起物,采用有限元软件LS-DYNA模拟所有的挤压作用。结果显示：在挤压力峰值和轴向冲击荷载作用下的构件耗能能力上,触发器的引入非常有效。同时发现,通过改变触发器的位置和几何尺寸,可以控制构件的挤压响应。     

Production and anodising of highly porous Ti–Ta–Zr–Co alloy for biomedical implant applications

In the present study, beta-type low elastic modulus Ti–Ta–Zr–Co alloy foams were manufactured by powder metallurgy-mechanical alloying based space holder route for hard tissue implant purposes. Ta was included to the alloy for low elastic modulus beta-Ti phase stabilisation in order to prevent stress shielding effect between implant and bone. Zr was introduced for corrosion resistance. Co addition was lowered the sintering temperature of the alloy, provided easier machining, and introduced aging capacity. Electrochemical anodisation (oxidation) surface treatment was carried out to produce a surface oxide film in order to improve the corrosion resistance and bioactivity. Corrosion properties of the surface passive oxide film were investigated in artificial saliva. Digital radiography and computed tomography studies were used for three-dimensional defect and pore structure characterisation.     

Determination and Improvement of Deposition Parameters of TiO2 Thin Films via ALD

In recent years,with the development of technology,interest in microelectronics and thin film devices has increased considerably.Future improvements in microele...     

Correction to: Evaluation of publication delays in the orthopedic surgery manuscript review process from 2010 to 2015

Scientometrics - In the original publication of the article, the author’s name “Shai Shemesh” was missed. The complete author group is given in this Correction.     

Electro-oxidation of pistachio processing wastewater using Ti/Pt mesh-type anodes in batch system

In this study, the treatment of pistachio processing wastewater (PPW) by electro-oxidation method was investigated. Ti/Pt-plated electrodes were used for the anode material, and stainless steel electrodes were used for cathode material. Experimental studies were carried out in batch mode. Stirring speed, supporting electrolyte species and concentration, initial pH value, current density, temperature and dilution ratio were selected as experimental parameters effecting removal efficiency. In Ti/Pt electrode experimental studies on the optimum conditions, chemical oxygen demand (COD), total organic carbon (TOC) and total phenols (TP) removal efficiencies were obtained, respectively, as 99.98%, 70.74% and 100%, and energy consumption value was obtained as 297.5 kW-h/m³ (12.39 kW-h/kg COD, 51.29 kW-h/kg TOC and 64.68 kW-h/kg TP). As a result of the experimental studies, the PPW can be treated by electro-oxidation. Given the results of removal efficiency and energy consumption values, it was concluded the electro-oxidation using Ti/Pt anode very appropriate treatment of PPW.     

Investigation of Lake Sapanca water pollution,Adapazari, Turkey

Lake Sapanca has been the only source of drinking and recreational water for the city of Adapazari, Turkey. This paper reports a study of the variation of nutrient loading and trophic state of the lake, and also water quality parameters of Lake Sapanca compared to those of the neighbouring Lake Iznik. Through one year, samples were taken every three months from 15 different points on the streams feeding and draining off the lake. Nitrate, NO₂‐N, NH₃‐N, TKN, PO₄‐P concentrations on the 12 streams fe and three draining off points were determined. Then, loading, discharge, and accumulation amounts of nitrogen and phosphorus causing eutrophication were calculated and the trophic state of the lake was determined. A simple model was used to analyse the response of Lake Sapanca when the phosphorus loading rate was changed. Through this model, the variation of different parameters (t, M, K, Q, V and A) with respect to phosphorus concentration (C) was studied to identify effects and results. The consequences of an eutrophic state and measures to protect the lake are also discussed.     

Progressive and explicit refinement of scheduling for multidimensional data-flow applications using uml marte

Process networks and data-flow graphs are used to capture data-dependencies in computation-intensive embedded systems. Their simplicity allows the computation of static schedules that reduce the dynamic overhead and increase predictability. The resulting schedule is a total ordering of actor computations and communications. It can therefore become an over-specification of the initial system when several schedules are valid. This is particularly the case for multidimensional data-flow applications. We propose a methodology to avoid such an over-specification. We propose to use logical time to capture explicitly all the valid schedules for a given multi-dimensional data-flow model. Then, we show that the proposed approach allows for a progressive and explicit refinement of computation scheduling that also captures constraints imposed by the environment and the execution platform. All this is achieved by using uml marte concepts and the resulting models can be considered for simulation and analysis with existing tools for early design validation. The whole approach is validated on a typical application devoted to radar signal processing.     

Energy analysis and modeling of a solar assisted house heating system with a heat pump and an underground energy storage tank

An analytical model is presented and analyzed to predict the long term performance of a solar assisted house heating system with a heat pump and an underground spherical thermal energy storage tank. The system under investigation consists of a house, a heat pump, solar collectors and a storage tank. The present analytical model is based on a proper coupling of the individual energy models for the house, the heat pump, useful solar energy gain, and the transient heat transfer problem for the thermal energy storage tank. The transient heat transfer problem outside the energy storage tank is solved using a similarity transformation and Duhamel’s superposition principle. A computer code based on the present model is used to compute the performance parameters for the system under investigation. Results from the present study indicate that an operational time span of 5–7 years will be necessary before the system under investigation can attain an annually periodic operating condition. Results also indicate a decrease in the annually minimum value of the storage tank temperature with a decrease in the energy storage tank size and/or solar collector area.     

Radioactivity and heavy metal concentrations in food samples from Rize, Turkey

BACKGROUND: Rize in Turkey was contaminated by the Chernobyl accident in 1986. A comprehensive study was planned and carried out to determine the radioactivity levels and heavy metal concentrations in four food categories collected in Rize in 2008, 2009 and 2010. RESULTS: Tomato showed the highest concentration of ²³⁸U, at 9.43 ± 0.128 Bq kg^?1, whereas the lowest concentration of 0.20 ± 0.02 Bq kg^?1 was measured in aubergine samples. The highest concentration of ²³²Th was measured at 3.22 ± 0.29 Bq kg^?1 in grape samples. ⁴⁰K was found to contribute the highest activity in all the food samples. The highest activity concentration of ¹³⁷Cs was 10.20 ± 4.19 Bq kg^?1, for parsley. The average contribution range of each of the heavy metals to the dietary intake was 0.13–9.14, 0.27–34.63, 0.05–3.62, 0.11–14.97, 0.78–8.51 and 0.01–1.57 mg, respectively, for Mn, Fe, Cu, Zn, Ni and As. CONCLUSION: The range of radioactivity levels in food samples of the present study is of no risk to public health. Heavy metal concentrations of Mn, Fe, Cu, Zn, Ni and As obtained were far below the established values by FAO/WHO limits. Copyright © 2011 Society of Chemical Industry