Influence of Eriophyid mites (Aculus olearius Castagnoli and Aceria oleae (Nalepa) (Acarina: Eriophyidae)) on some physical and chemical characteristics of Ayvalık variety olive fruit

BACKGROUND: Aculus olearius Castagnoli is a recently recorded species that damages olive fruits in the Mediterranean basin of Turkey. Thus, the effects of Eriophyid mites (Aculus olearius Castagnoli and Aceria oleae (Nalepa) (Acarina: Eriophyidae) on the olive fruits from Ayval?k variety in southern Turkey were studied for the first time in terms of some physical parameters and chemical constituents including some individual phenolics. RESULTS: The Eriophyid damaged fruits had higher L* values (lighter colour) and tyrosol level (37.53 mg kg^?1) than the undamaged fruits (28.51 mg kg^?1) in August. In contrast, Eriophyid damaged fruits were darker in colour and had lower levels (25.77 mg kg^?1) of tyrosol than those of undamaged fruits (79.14 mg kg^?1) in October. Eriophyid damaged samples had higher values of vanillic acid than the undamaged samples. An increase in the average concentrations of hydroxytyrosol and p‐coumaric acid was observed in the fruits harvested in August, whilst the oleuropein content decreased. CONCLUSION: The harvest in October can be recommended regarding the higher dimensional values, total oil, dry matter and oleuropein contents. But the interaction between harvest time and Eriophyid damage was found effective in terms of tyrosol content and skin colour; as tyrosol values were lower in the fruits harvested in October and the fruits were darker. The resistance of undamaged fruits against Eriophyid damage can be linked to high tyrosol content of these fruits. Copyright © 2010 Society of Chemical Industry     

Survey of Italian honeys for the presence of foreign matter using the filth test

Honey is an ancient food that has always been considered a natural and healthy product, free of contaminants. However, it can contain toxic substances, such as antibiotics, pesticides and heavy metals, as well as foreign matter (e.g. arthropod body parts and microbial contaminants), working as allergens and vectors of human pathogens. In this study we used the filth test to evaluate the abundance of foreign matter in 70 Italian honeys, including Castanea sativa, Robinia pseudoacacia and multi-floral honeys, the latter both from small beekeeping farms and industrial producers. The abundance of different foreign matter varied in honeys, with a higher number of carbon particles and other inorganic fragments, followed by fragments of animal origin. This latter included insects (Diptera Brachycera larvae and Strepsiptera), their cuticular fragments (mainly Coleoptera, Hymenoptera and Lepidoptera), mites (mainly Glycyphagidae, Acaridae and Tarsonemidae) and mammal hairs. No differences were recorded in the abundance of foreign matter among different kinds of honey, as well as between honeys from small and large-sized producers. Foreign matter found in honey provided functional information to evaluate honey quality standards in apiary, honey extraction and packaging phases. Overall, the filth test method applied to honey quality control can be considered an excellent tool, also for small beekeeping farms, since it allows rapid and frequent quality checking of the production process. This method is cheap, requires minimal instrumental equipment and results can be interpreted quickly.     

微重力条件下粉尘燃烧机理研究

由落塔仓产生的微重力提供了一种独特的环境 ,可克服粉尘云在地面实验时因受重力影响而产生的沉降现象 ,使封闭容器内的整个燃烧过程能维持粉尘云的稳定悬浮 ,保证粉尘燃烧机理的实验研究中粉尘的实际浓度与初始名义浓度相符 ,令粉尘浓度名符其实地成为一个独立参变量。在 12 m落塔提供的 10 - 2 g,1.2 s微重力环境下对球形铝粉 (d50 =7μm)与球形玉米粉 (d50 =2 0μm)两种粉尘的等容燃烧特性进行了系统的实验研究。实验结果经与地面实验结果进行比较与分析后定量给出了粉尘浓度保持不变时 ,粉尘爆炸特性随扬尘湍流强度衰减而变化的规律以及在地面上重力沉降令粉尘浓度变小后对粉尘爆炸特性的影响。最后还讨论了实验容器过小而引起的部分实验数据失真的原因。     

On the investigation of photovoltaic output power reduction due to dust accumulation and weather conditions

Certain environmental conditions such as accumulation of dust and change in weather conditions affect the amount of solar radiation received by photovoltaic (PV) panel surfaces and thus have a significant effect on panel efficiency. This study conducted an experimental investigation in Surabaya, Indonesia, on the effect of these factors on output PV power reduction from the surface of a PV module. The module was exposed to outside weather conditions and connected to a measurement system developed using a rule-based model to identify different environmental conditions. The rule-based model, a clear sky solar irradiance model that included solar position, and a PV temperature model were then used to estimate the PV output power, and tests were also conducted using an ARM Cortex-M4 microcontroller STM32F407 as a standalone digital controller equipped with voltage, current, temperature, and humidity sensors to measure real time PV output power. In this system, humidity was monitored to identify dusty, cloudy, and rainy conditions. Validated test results demonstrate that the prediction error of PV power output based on the model is 3.6% compared to field measurements under clean surface conditions. The effects of dust accumulation and weather conditions on PV panel power output were then analyzed after one to four weeks of exposure. Results revealed that two weeks of dust accumulation caused a PV power output reduction of 10.8% in an average relative humidity of 52.24%. Results of the experiment under rainy conditions revealed a decrease in PV output power of more than 40% in average relative humidity of 76.32%, and a decrease in output power during cloudy conditions of more than 45% in an average relative humidity of 60.45% was observed. This study reveals that local environmental conditions, i.e., dust, rain, and partial cloud, significantly reduce PV power output.     

Numerical modelling of wind and dust patterns around a full-scale paraboloidal solar dish

This study reports on numerical predictions of velocity and pressure fields, and dust particles trajectories in steady and unsteady flows around a full-scale paraboloidal solar dish. Calculations are performed for three wind speeds of 4.16, 9.72, and 15.2 m s⁻¹, and dish pitch angles from 0° to 180°. The flow field structure, lift and drag coefficients are calculated for each flow configuration. Using the predicted mean flow velocity field, analytical expressions for the aerodynamic coefficients, as a function of the pitch angle, are developed. The unsteady-state flow is characterised by formation of stable vortices behind the dish for most flow configurations, except at 60° and 150° pitch angles. At these angles vortex-shedding occurred with a strong flow oscillation extending downstream the dish. The calculations of dust particles trajectories provide a qualitative assessment of the deposition rate, dish orientation, and surface locations where dust accumulation is most likely to occur. The study also presents an initial assessment of the effectiveness of various windbreaks installed upstream of the dish in reducing aerodynamics drag.     

移动颗粒层过滤除尘的数值模拟及实验对比

通过建立离散颗粒运动数学模型,对移动颗粒层过滤除尘器中粉尘颗粒与过滤介质颗粒碰撞以及对除尘效率的影响进行了初步研究。模拟计算了碰撞次数与系统风速之间的变化关系,与实验结果对比发现,随系统风速的变化,颗粒碰撞频次与除尘效率之间存在定性的一致。颗粒间碰撞作用对移动颗粒层的除尘性能起着重要作用。     

炼铁厂出铁口烟尘综合利用的研究

本文分析了炼铁厂出铁口烟尘的性质,并用选矿方法对烟尘进行提纯,通过重选、磁选、浮选的试验研究,结果表明;“分级一磁选”效果最好,可获得铁品位为68．78％的超级铁精矿,回收率为66．22％;另一铁精矿品位为57．93％,回收率为32．86％;尾矿铁损失率仅为0．92％。文章还对后续深加工提出了具体建议。     

Consideration of the stress dependence of the bulk density in silo storage of dusts from dry off-gas cleaning

In this study the influence of the consolidation stress on the bulk density of dusts separated from the off-gas of a broad variety of industrial processes was investigated. With the exception of very small values of the stress this dependence can be approximated very well by a simple function. One coefficient in this function correlates very well with the bulk density measured according to EN ISO 60, while the other coefficient shows a good correlation with a function, combining several dust properties. Using this approximation function equations for the vertical stress and bulk density in the shaft of a cylindrical silo as a function of the distance from the surface were derived. The results for the vertical stress and the mass of the bulk obtained with these equations were compared with those acquired on the basis of Janssen’s equation assuming constant bulk density according to EN ISO 60 and a constant average bulk density. Up to a certain distance from the surface of the bulk the values for the stress and for the mass were between the results obtained by the two variants with constant bulk density, whereas for greater distances the resulting values were higher.     

塑料厂除尘系统的设计分析

除尘系统是捕集、输送、净化含尘气体直至干净气体排放的整个系统,它由集气吸尘罩、除尘管路、除尘设备、除尘风机等组成。提出了除尘系统的设计原则和计算方法,为正确选择、合理配置除尘系统提供了设计依据     

溴氟菊酯等几种农药防治害虫的药效试验

通过1990－1993年的小区试验和大田示范说明上海中西药业公司新研制的拟除虫菊酯农药溴氟菊酯，是一种广谱性的杀虫杀螨剂，其药效与三氟氯氰菊酯，甲氰菊酯相似，优于常用农药久效磷，氧乐果和三氯杀螨醇，10％溴氟菊酯在1000－1500倍浓度下，对蚜虫，叶螨，棉铃虫和地老虎等害虫的防效，喷药后10天均在95％以上，且初效快，药效可长达15天左右。