Boron concentrations in selected foods from borate‐producing regions in Turkey

As part of a large‐scale programme to investigate the health effects of exposure to borate minerals in Turkey, boron concentrations in vegetables, fruits and some other foods were determined. From all borate‐producing regions of the country, 22 species of fruit, 17 species of vegetable, 12 species of cereal, legume and oilseed, three species of herbs and six types of other food were collected in 1999 and analysed for boron concentrations using the Azomethine H method. The results were compared with 37 types of food collected from areas well distant from the borate‐producing areas. The total number of samples evaluated was 420. Pistachio (67.0 mg kg^?1) had the highest concentration of boron, followed by grape leaf (60.48 mg kg^?1), sour cherry (57.03 mg kg^?1), quince (38.78 mg kg^?1), peach (34.49 mg kg^?1), grape (20.70 mg kg^?1), green beans (19.49 mg kg^?1), unripe peach (18.92 mg kg^?1) and parsley (10.24 mg kg^?1) from the borate‐producing regions. A large number of foods contained boron at higher concentrations than those reported in the literature, most probably due to the high boron content of these Turkish soils. According to the results of t‐tests, the area itself does not have a significant effect (p > 0.05) on boron concentration in all foods evaluated so far. Copyright © 2003 Society of Chemical Industry     

Ozone Applications in Fruit and Vegetable Processing

Ozone, a powerful oxidant, is effective against various kinds of microorganisms on fruits and vegetables. Promising results have been revealed in solving the problems of the food industry like mycotoxin and pesticide residues by ozone application. Spontaneous decomposition without forming hazardous residues in the treatment medium makes ozone safe in food applications. If improperly used, ozone can cause some deleterious effects on products, such as losses in sensory quality. Treatment conditions should be specifically determined for all kinds of products for effective and safe use of ozone.     

Effects of cooking methods on chlorophylls, pheophytins and colour of selected green vegetables

The effect of microwave and conventional cooking methods on chlorophyll pigments and colour properties of squash, green beans, peas, leek, broccoli and spinach were studied, by HPLC and colorimetry, respectively. In five of six vegetables, chlorophyll a was found more heat resistant compared with chlorophyll b, except in peas. Chlorophylls in peas were retained to the 80–90%, the highest in all vegetables evaluated. Chlorophylls were retained to 19–100%, depending on the vegetable type and cooking method. Pheophytins increased in all vegetables after cooking. Highest chlorophyll a and chlorophyll b losses were observed in boiled leek while microwaved peas and boiled peas retained the most chlorophyll a and chlorophyll b, respectively. Pheophytin a and pheophytin b formation was highest at boiled squash and boiled green beans, which were fifty‐ninefold and twenty‐onefold compared with fresh ones, respectively. Most of the pheophytin formations occurred in boiled and the least in microwaved vegetables. Surface colour changed depending on the type of vegetable and cooking method.     

A new MAC protocol for broadband wireless communications and its performance evaluation

This paper presents a new Time Division Multiple Access/Frequency Division Duplexing (TDMA/FDD) based Medium Access Control (MAC) protocol for broadband wireless networks, supporting Quality of Service (QoS) for real-time multimedia applications. It also gives the Call Blocking Probability (CBP), packet end-to-end delay and utilization analysis of different service classes, as they are most essential performance criterions in broadband wireless network assessment. The Connection Admission Control (CAC) mechanism in the proposed MAC efficiently organizes the bandwidth allocation for different service classes by means of a fairness based scheduling algorithm. In addition, the simulation model of the proposed MAC scheme is realized by using OPNET Modeler network simulator. The results of the analytical calculations for the CBPs are compared to those of the simulation of the proposed MAC, thus validity of the MAC protocol is proved.     

Light microscope based analysis of three-dimensional structure: Applications to the study of Drosophila salivary gland nuclei. I. Data collection and analysis

Many biological structures of interest are large enough that they may be viewed by light microscope methods, yet they are sufficiently complicated that interpretation of what is seen is quite difficult. The salivary gland nuclei from Dipterans are an example of this. Previous attempts at determining the path of the giant chromosomes in these nuclei have depended on the laborious construction of models by hand. A unified Computer Aided Modelling and Analysis system (CAMA) has been implemented, allowing data collection and analysis of structures visible by light microscopy. This system is extendible to the analysis of electron micrographs of serial sections or of other data consisting of images present in a stack.     

Ettringite formation in historic bath brick-lime plasters

Two types of historic hydraulic brick-lime plasters from a selected Ottoman bath are examined to characterize their technology and the appropriateness of their use in bath. The first type of plaster is original and structurally sound, while the historic repair plaster is the second type and is found to have deteriorated despite being exposed to the same environment. This difference is investigated by comparing their raw material compositions and the pozzolanic activities of the brick powders used in the plasters. Although these results showed no significant differences, ettringite crystals are detected in the historic repair ones by XRD, FTIR, and SEM-EDS analysis. The repair plaster may have lost its integrity owing to the expansion generated by the growth of ettringite crystals in the plaster. In this study, the ettringite formation is discussed in relation to hydration reaction products of lime-brick plasters, possible sources of gypsum, and the climatic conditions of historic bath building.     

轴对称热弹性问题杂交基本解Trefftz有限元分析

针对稳态热弹性问题,提出一种杂交基本解Trefftz有限元计算格式.数值求解过程中,温度荷载导致单元刚度方程出现域积分,使杂交基本解有限元法只含边界积分的优势消失.通过将问题的真实解分解为特解和齐次解两部分达到消除域积分的目的.数值算例表明,杂交基本解Trefftz有限元法计算结果与商业软件ABAQUS吻合,可验证本文方法的准确性与高效性.     

A fractal conductivity-based approach to mobile sensor networks in a potential field

This paper presents the design of multi-robots or multiple mobile sensors and gives the results of the team behavior of them in a potential field in a collaborative manner. The aim is to prove the concept of the fractal conductivity-based approach to mobile sensor networks in a potential field. We attempted to create multi-robots having similar inherent nature, similar background knowledge, and the same mission as relevant bodies, the creation of some sort of attraction force between them is achieved with the application of fractal conductivity of belief functions. We attempted to develop multi-robots capable of carrying out an orchestrated movement in an environment having some kind of potential field such as a chemical substance contaminated into sea or lake water. The basis of the theory of behavior in a potential field is established. The fractal conductivity approach is explained. A mobile sensor structure having an input, output, and internal belief functions is designed. Internal structures of mobile sensors are implemented by software. A mobile sensor network composed of mobile sensor nodes is developed. Two communities of interest groups have been constituted. Collaborative behaviors of multi-robots in a potential field are investigated. The mobile sensors move towards a target by sensing the potential field at their locations, broadcasting the information composed of locally sensed intensity of the potential field around them and the infrastructure knowledge of themselves to other sensors and receiving the information of the potential field intensities together with the identity information that is being broadcasted from the other mobile sensors inside the potential field. The target is a source creating the potential field. A mobile sensor is a body incorporating a prior knowledge base that is the identity information in the form of a fractal belief function inside itself. After developing the theoretical basis for sensing potential field and movement, a fractal conductivity approach, which is based on fractal natures of the belief functions, is applied to this basic approach to obtain the movements of the multi-robots as a coordinated team, i.e., grouped as relevant bodies. The operation of mobile sensors based on time division multiple access method is achieved. The results of coordinated movement and obstacle avoidance have been demonstrated by the simulation results.     

The effect of crystallographic orientation and solution aging on the electrical properties of sol–gel derived Pb(Zr0.45Ti0.55)O3 thin films

Lead zirconate titanate—Pb(Zr_0.45Ti_0.55)O₃ thin films are grown on Pt_1 1 1/Ti/SiO₂/Si_1 0 0 substrates by a sol–gel method with 1 0 0/0 0 1 and 1 1 1 preferred orientations. Film orientation was controlled mainly by the annealing process and temperature. Films with 1 0 0/0 0 1 orientation consist of a uniform microstructure with micron size grains, whereas films with 1 1 1 orientation contain sub-micron grains. The electrical properties were influenced markedly by the microstructure and orientation of the films. The 1 1 1 oriented films exhibit a square-like hysteresis loop with remnant polarization (P_r) reaching 46 μC/cm² under 550 kV/cm, whereas 1 0 0/0 0 1 oriented films have a P_r of 20 μC/cm² with more slim hysteresis curves. Aging of the precursor solutions resulted in films growing with 1 0 0/0 0 1 texture and displaying inferior electrical properties.     

页岩储层标准等温吸附曲线的建立——以鄂尔多斯盆地长7页岩储层为例

页岩的矿物成分复杂、孔隙结构多样,导致页岩吸附性能差异大,同一储层中不同岩样的等温吸附曲线形态变化大,有必要针对页岩建立标准等温吸附曲线。对来自鄂尔多斯盆地长7油层组的页岩储层样品进行了低温液氮等温吸附实验,将实验所得曲线进行初步标准化后按照BET理论中的常数C值取2为底的指数进行分类并标准化。再将所有样品的标准等温吸附曲线使用4种吸附层厚度方程在Matlab数值分析软件中进行参数拟合,用以验证标准等温吸附曲线。按拟合精度从小到大排列的4种吸附层厚度方程的顺序为：Carbon Black 2次方程 < Carbon Black 3次方程 < Halsey方程 < De Bore方程。最后通过参数平均得出了每一类型的页岩标准等温吸附曲线。所得页岩储层的标准等温吸附曲线代表了一系列表面性质相似的储层的吸附特征,可直接用于油藏数值模拟或油藏工程计算,简化了大量的繁琐计算过程,降低了岩样随机选择所导致的数据不确定性,且使计算结果具有较强的代表性。