Volatile components of peel and leaf oils of lemon and lime species

Peel and leaf oils of 43 taxa of lemons and limes were obtained from fruits and leaves collected from trees submitted to the same pedoclimatic and cultural conditions. Their chemical composition was investigated by capillary GC, GC-MS, and (13)C NMR, and the results were submitted to principal component analysis to check for chemical variability. Three major chemotypes were distinguished for lemon peel oils: limonene; limonene/beta-pinene/gamma-terpinene; and limonene/linalyl acetate/linalool. Two chemotypes were identified for lemon leaf oils: limonene/beta-pinene/geranial/neral and linalool/linalyl acetate/alpha-terpineol. In lime peel oils, four chemotypes were distinguished: limonene; limonene/gamma-terpinene; limonene/beta-pinene/gamma-terpinene; and limonene/gamma-terpinene/beta-pinene/oxygenated products. Four others were identified for lime leaf oils: beta-pinene/limonene; limonene/geranial/neral; limonene/linalool/citronellal; and limonene/sabinene/citronellal/linalool. These results were interpreted using principal component analysis.     

Biodegradation of ochratoxin A by fungi isolated from grapes

Ochratoxin A is a mycotoxin present in several food products for which levels should be reduced. Chemical, physical, and biological methods have been proposed for the detoxification of mycotoxins, biological methods being the more promising ones. In this report, filamentous fungi isolated from Portuguese grapes were assessed for ochratoxin A degradation capabilities. It was observed that 51 of the 76 tested strains, predominantly aspergillus species, were able to degrade more than 80% of ochratoxin A added to the culture medium and that the most potent species (more than 95% of initial amount) were the black aspergilli, A. clavatus, A. ochraceus, A. versicolor, and A. wentii. Other fungi frequently isolated from grapes, such as Alternaria, Botrytis, Cladosporium, and Penicillium, also showed significant degradation capabilities. It was observed that the compounds obtained from the degradation of ochratoxin A by black aspergilli and by A. ochraceus and A. wentii strains were different.     

水稻实生苗及腋芽苗试管快速繁殖技术的研究

试验研究不同浓度激动素（ＫＴ）、６－卞氨基嘌呤（６－ＢＡ）及奈乙酸（ＮＡＡ）对水稻不定芽诱导、增殖和发根的影响，结果表明：（１）６－ＢＡ对于不定芽的诱导及繁殖有明显的促进作用，其适宜浓度为２０～３０ｍｇ／Ｌ，ＫＴ在这方面的作用要比６－ＢＡ弱得多；（２）需要经过较长时间的培养才能诱导出不定芽，一般在４５ｄ以上；（３）０．５～１０ｍｇ／ＬＮＡＡ对于不定芽的发根有很强的促进作用。     

Vorticity analysis associated with drafting cylinders for pneumatic spinning

Traditional spinning systems have reached profitability limits in developed countries due to high production costs and low system productivity. Pneumatic spinning is seen as a developing system, because productivity is much higher than conventional systems. This study evaluates one of the main problems to increase productivity in pneumatic spinning, where air mass-flow is dragged by the drafting cylinders. This flow interacts with the incoming fibres deviating them from their expected path. Via laser anemometry, airflow velocity distribution around drafting cylinders has been measured and it has been found that vorticity is created at the cylinder’s inlet. Extensive CFD simulation on the air flow dragged by the cylinders has given a clear insight into the vortex created, producing valuable information on how cylinder design affects the vorticity created. Several drafting cylinder designs have been tested without giving any improvement in productivity. However, the use of a drafting cylinder with holes in it produced good results to the problem of air currents, strongly reducing them and therefore allowing a sharp increase in yarn quality, as well as an increase in productivity. An extensive study on vortex kinematics has been undertaken, bringing with it a better understanding of vortex creation, development and breakdown.     

Effect of zinc supplementation and high-protein rice on the growth of preschool children on a rice-based diet

A six-month feeding trial was undertaken in a children's home in Manila on three groups of 27 preschool Filipino children, each on a diet in which rice contributed about 50% of the energy. Total zinc intake of 4–6 mg daily was obtained from analyses of food composites of the institutional diet. Supplementation of this diet with 5 mg zinc and substitution of high-protein (10.4%) rice for average-protein rice (~7.4%) together resulted in significantly faster height and weight increases in the experimental group than in the control group. Zinc supplementation alone, however, did not improve the growth of the children.     

Comparative study of anatomy and lignin distribution in normal and tension wood of Salix gordejecii

Fibre morphology, anatomy and ultrastructure in cell wall of Salix gordejecii normal wood were examined by transmission electron microscopy (TEM). S. gordejecii tension wood can be recognized anatomically by the presence of gelatinous (G) fibres, which contain a conspicuously thickened inner cell wall layer. TEM images showed that cell wall of S. gordejecii normal wood was typically divided into three layers including the primary wall (P), the middle lamellar (ML) and the secondary wall (S₁, S₂ and S₃). Lignin distribution was determined by using confocal laser scanning microscopy (CLSM) and transmission electron microscopy with energy dispersive X-ray analysis (TEM-EDXA). Confocal images (530 nm) of S. gordejecii normal wood showed strongly lignified CCML, and weakly lignified ML and S2 layer. Weakly lignified fibres (F) and strongly lignified vessels (V) were also detected by using CLSM. Results obtained from confocal microscopy were further confirmed by using TEM-EDXA, indicating that the ratio of lignin concentration in CCML, ML and S2 is 1.72 (1321):1.31 (1006):1 (768). Lignin distribution in tension wood is similar to that in normal wood, except for the non-lignified G layer.     

Field efficacy of imidacloprid and Steinernema carpocapsae in a chitosan formulation against the red palm weevil Rhynchophorus ferrugineus (Coleoptera: Curculionidae) in Phoenix canariensis

BACKGROUND: The invasive red palm weevil, Rhynchophorus ferrugineus (Olivier), has become the major pest of palms in the Mediterranean Basin. Chemical control against this species is difficult because of its cryptic habits and is mainly based on the repeated application of large quantities of synthetic insecticides. The aim of this work has been to evaluate in the field the efficacy of imidacloprid (Confidor^® 240 OD) and Steinernema carpocapsae Weiser with chitosan (Biorend R^® Palmeras) as soil and stipe treatments respectively, alone or in combination, against this pest. RESULTS: All treatments significantly reduced the mean number of immature stages of R. ferrugineus per palm. However, there were no significant differences among the different treatments considered. Efficacies ranged from 83.8 to 99.7% for the mean number of immature stages found in the palms and resulted in a significant increase in palm survival compared with the untreated control (75.0–90.0% versus 16.5% respectively). CONCLUSION: Both imidacloprid and S. carpocapsae in a chitosan formulation proved highly effective against R. ferrugineus in the field, and their efficacies did not significantly change when used in combination. Copyright © 2009 Society of Chemical Industry     

高温季节种鸡饲养管理技术措施

夏季高温环境对种鸡造成的热应激影响极为显著,种鸡由于饮水量增加,采食量下降而导致产蛋率、蛋品质以及种蛋受精率下降.高温高湿的环境造成鸡舍有害气体含量过高,高温条件下有利于病原微生物的滋生或存活,长期热应激引起机体免疫力下降,诱发疾病,严重影响到种鸡的生产性能发挥.为了避免上述现象的发生,高温季节种鸡饲养管理要抓好以下技术措施:     

化工原理实验教学改革的实践与体会

化工原理实验课作为化工原理课程的一个重要教学环节 ,其基本任务是使学生加深理解和巩固化工原理课程中阐述的理论 ,培养学生解决工程问题的能力并掌握一定的实验操作技能 ,通过对实验现象的观察、分析和讨论来培养学生独立思考问题和解决问题的能力。经过多年的教学实践和改革起到了一定的效果 ,特别是组织学生兴趣小组先后开发了化工原理实验的实验数据处理软件和化工原理实验仿真软件 ,在实验内容和实验手段方面进行了改革 ,提高了学生参与实验的积极性 ,从多方面培养了学生的动手能力。