Effect of minimal neutralization at optimal conditions on minor components and oxidation stability of sunflower oil

In this study, oxidatively stable minimal neutralized sunflower seed oils were produced using three chemicals (Ca(OH)₂, MgO, and Na₂SiO₃) under previously determined optimal process conditions. Lipid oxidation rates at these optimum conditions were compared to the oils neutralized with NaOH (0.20%, 40°C, 15 min). It was concluded that the oils neutralized by NaOH had the shortest hydroperoxide and hexanal lag phases, thus were the least stable oils. Oils neutralized by Ca(OH)₂, MgO, and Na₂SiO₃ had lower FFA and higher oxidative stability than oil neutralized by NaOH. The study focused on which weak alkaline has higher oxidation stability and minimum FFA content and maximum acceptable tocopherol content. The oil neutralized by Ca(OH)₂ had the lowest FFA value and highest total phenolics and α-tocopherol contents and it had better oxidative stability than oil neutralized by NaOH. It suggests that Ca(OH)₂ could be more effective in producing a high quality oil.     

环氧化天然橡胶玻璃化转变温度与环氧化程度的关系

根据Ｖａｎ Ｋｒｅｖｅｌｅｎ 等提出的一些高聚物物理参数加合性原则，推导了环氧化天然橡胶（ＥＮＲ） 的玻璃化转变温度（Ｔｇ） 与环氧化程度（Ｂ） 的关系，并根据经验公式计算了不同环氧化程度ＥＮＲ 的Ｔｇ 。     

Assessing the natural ventilation cooling potential of office buildings in different climate zones in China

This paper presents an investigation of the natural ventilation cooling potential (NVCP) of office buildings in the five generally recognised climate zones in China using the Thermal Resistance Ventilation (TRV) model, which is a simplified, coupled, thermal and airflow model. The acceptable operative temperature for naturally conditioned space supplied by the ASHARE Standard 55-2004 has been used for the comfort temperature setting. Dynamic simulations for a typical office room in the five representative cities, which are Harbin, Beijing, Shanghai, Kunming and Guangzhou, have been carried out. The study demonstrates that the NVCP depends on the multiple impacts of climate, the building's thermal characteristics, internal gains, ventilation profiles and regimes. The work shows how the simplified method can be used to generate detailed, indoor, operative temperature data based on the various building conditions and control profiles which are used to investigate the NVCP at the strategic design stage. The simulation results presented in this paper can be used as a reference guideline for natural ventilation design in China.     

Investigation of a windvent passive ventilation device against current fresh air supply recommendations

Recent ecological and political developments have created an increased focus on sustainable energy sources. The purpose of this paper is to examine a passive ventilation device, the windvent, and evaluate its potential against current British Standards BS5952:1991 [British Standards, Ventilation principles and designing for natural ventilation, BS5925:1991 (1991)] recommended fresh air delivery rates. The results provide useful information for both engineers and architects when examining ways to reduce new and existing buildings running costs, and conform to new legislation. Numerical analysis is carried out using a commercial Computational Fluid Dynamics (CFD) code, to investigate the effect of various external wind velocities (1–5 m/s) and directions (concurrent and counter current) on the device performance. The results show that the windvent is capable of providing recommended rates of fresh air supply even at relatively low incident wind velocities. The performance indications show that the device warrants further analysis and provides a sustainable alternative ventilation system.     

低CO2排放自然通风建筑的设计与评价——英国谢菲尔德大学学生健康中心

2005年，在约克郡举行的英国皇家建筑师协会RIBA2005庆典上，谢菲尔德大学学生健康中心获得两个奖项？该建筑在设计上特别注重自然采光和自然通风，并使用了低CO2排放环境友好的构件和装饰材料，本文从建筑设计过程阐述其低排放设计策略的发展和贯彻情况，并通过使用后研究评价最初的设计目标是否实现？实际使用效果是否符合预期设计要求，评价内容包括监测部分房间的室内物理状况．了解用户的反应和开窗通风策略的实施情况，评价得到了计算机虚拟环境模拟工具的支持，将现状与现状之外的其他状况进行多方案比较，以提供新的方案解决当前存在的问题，监测和调查显示，该建筑在设计和实际使用方面的确存在一些问题，因此，在计算机模拟和现状监测调查的基础上，本文给用户提出了改进后的自然采光和自然通风操作建议。     

山西省水体中天然放射性核素浓度调查研究

本文报道了山西省河流、湖泊、水库、泉、井、自来水中的天然放射性核素浓度的调查结果。调查结果表明,山西省各类水体中天然放射性核素浓度属正常本底水平;全省南部高于北部,西部黄河水系高于东部海河水系,平水期高于枯水期。     

Keypoint Detection and Local Feature Matching for Textured 3D Face Recognition

In this study we concentrate on qualitative topological analysis of the local behavior of the space of natural images. To this end, we use a space of 3 by 3 high-contrast patches ℳ. We develop a theoretical model for the high-density 2-dimensional submanifold of ℳ showing that it has the topology of the Klein bottle. Using our topological software package PLEX we experimentally verify our theoretical conclusions. We use polynomial representation to give coordinatization to various subspaces of ℳ. We find the best-fitting embedding of the Klein bottle into the ambient space of ℳ. Our results are currently being used in developing a compression algorithm based on a Klein bottle dictionary.     

Evaluation of sodium acetylacetonate as a synergist for arylamine antioxidants in synthetic lubricants

Differential scanning calorimetry (DSC) was employed to evaluate the performance of an ester lubricant containing sodium acetylacetonate. In the isothermal DSC oxidation test, sodium acetylacetonate is an effective synergist for arylamine antioxidant p,p′-dioctyldiphenylamine (DODPA). When combining with arylamine antioxidants, sodium acetylacetonate can also effectively reduce the increases in viscosity and acid number of the ester oil in oxidation–corrosion test. The electron paramagnetic resonance (EPR) results indicated that sodium acetylacetonate can reduce the free radical contents in the oxidized oil with arylamine antioxidants present.     

Improving thermal performance of the roof enclosure of heavy construction buildings

High heat flux through the enclosures of heavy building constructions during summer and winter seasons is of great concern with respect to energy-related economics and environmental issues. This paper demonstrates the importance of quantitative evaluation of enclosure design and proves the potential for substantial energy savings by minor alterations of conventional roof designs. These modifications include adding insulation layer(s), removing construction details and obstructing fluid flow within the attic cavity by partial or full vertical partition within the cavity. The CFD approach adopted for this purpose is based on a numerical study of steady, conjugate natural convection in the cavity of an attic of heavy construction buildings. Because of the flow characteristics, laminar and turbulent models were employed for summer and winter day boundary conditions, respectively. Steady state results based on the finite-volume method were obtained for Rayleigh number in the range 10⁸–10¹⁰. Representative results illustrating the effects of the proposed design modifications on the local and total Nusselt numbers at the indoor surfaces are presented and discussed for summer and winter day boundary conditions. The results show that considerable energy saving may be achieved via relatively simple design changes. It is also shown that adding an insulation layer does not necessarily translate into energy conservation, and that eliminating a minor design detail might have significant rewards in terms of energy savings.