Variability among peanut subsamples prepared for aflatoxin analysis with four mills

The variability in aflatoxin concentration among peanut subsamples ground with 4 different mills was evaluated. Twenty 2 kg samples of naturally contaminated peanuts were ground in a Dickens subsampling mill (DM), a Stephan model UM-12 vertical cutter mixer (SM), and a Robot Coupe model RS16Y-1 vertical cutter mixer (RC1). Twenty 4 kg samples were ground in the DM, SM, and a Robot Coupe model R10P vertical cutter mixer (RC2). From each 2 kg sample, ten 100 g subsamples were withdrawn, and from each 4 kg samples, ten 200 g subsamples were withdrawn. Subsamples were analyzed for aflatoxin by liquid chromatography. The coefficient of variation (CV) among each set of 10 subsamples was determined for each sample, and the CVs for each sample size were ranked and analyzed by the Kruskal-Wallis test of ranks. For 2 kg samples, the CVs for the samples ground in RC1 ranked significantly lower than those for samples ground in DM and SM. For 4 kg samples, the CVs for samples ground in RC2 and SM were significantly lower than that for samples ground in DM. The averages of the CVs for 2 kg samples were 17.2% (RC1), 32.8% (SM), and 40.6% (DM). The averages of the CVs for 4 kg samples were 21.2% (RC2), and 26.0% (SM), and 47.0% (DM).     

Determination and degradation of methomyl in tomatoes and green beans grown in greenhouses

A liquid chromatographic (LC) method using UV detection at 233 nm was used to study the degradation of methomyl in tomatoes and green beans grown in greenhouses. A liquid-liquid extraction with CH2Cl2-methanol (90 + 10, v/v) and a cleanup step with Florisil were combined with LC to isolate, recover, and quantitate the pesticide. Average recoveries obtained at spike levels of 0.03 and 0.40 mg/kg were 83.2-84.7% for tomatoes and 83.3-87.5% for green beans. Determination limits were 0.03 mg/kg for tomatoes and 0.01 mg/kg for green beans. Levels of methomyl residues were studied in tomatoes and green beans grown in an experimental greenhouse to establish the effect of the kind of greenhouse, application dose, species grown, and climatic conditions on the degradation of this pesticide. Analysis of variance showed that doses did not affect the response. The half-life, however, is greater in a flat-roof greenhouse than in an asymmetric-roof greenhouse and is significantly longer for green beans than for tomatoes and longer in winter than in spring. A preharvest time of about 5 days may be suitable for green beans sprayed with methomyl. Tomatoes show residue levels at the time of application lower than Spanish minimum residue levels.     

Friability and crushing strength of micrometer-size diamond abrasives used in microgrinding of optical glass

In abrasive grinding, the properties of the abrasives and their response to impact loading play a significant role in determining the results achievable. For micrometer-size diamond abrasives used for bound-abrasive microgrinding of optical glass, friability testing is used to estimate the related particle properties. Friability and crushing strength of diamond abrasives are estimated based on the data from comminution of sample powders on a commercial SPEX mixer/mill. Different diamond abrasives as well as a CBN abrasive are tested. Evolution of powder size and size distribution with comminution time is characterized with a HORIBA laser scattering analyzer. Correlation is established for the impact stress and the probability of fracture during comminution. This study demonstrates how to combine the ease of data acquisition found in a conventional friability test with the capability of predicting specific mechanical properties normally found only by crushing individual abrasive particles.     

八钢烧结利用炼钢污泥技术实践和探讨

八钢在烧结生产中利用炼钢污泥代替清水进行生石灰消化和混合机补水,针对存在的污泥管路堵塞、污泥泵故障、流量不稳定、污泥粘混合机筒体等技术问题,通过控制污泥浓度,改进污泥管路布置、混合机喷水管结构、布置,采用立式泥浆泵,提高设备自动化水平等措施,直接使用湿污泥量21.2万t/a以上,节约新水16.96万t/a,年直接经济效益超过1900万元。     

Factors related to the development of sensitization to green coffee and castor bean allergens among coffee workers

BACKGROUND: Occupational allergic respiratory symptoms in coffee workers have been frequently reported, but the ultimate cause of sensitization is still debated, castor bean being considered besides green coffee beans. Atopy and cigarette smoking have been suggested as promoting factors of sensitization for several occupational allergens. OBJECTIVE: This study was carried out to assess the prevalence of allergic respiratory symptoms and of sensitization to both green coffee beans and castor bean in the whole workforce of a coffee manufacturing plant. Furthermore we wanted to ascertain both the presence of castor bean antigens in the settled dust of the green coffee beans warehouse and the possible crossreactivity between the two beans. Meanwhile, the effect of smoking and atopy was considered. METHOD: Two-hundred and eleven workers were examined. A questionnaire on oculorhinitis and asthma was administered and skin-prick tests for green coffee beans, castor bean and 15 common inhalant allergens were carried out. Isoelectric focusing, isoelectric focusing immunoblot and radioallergosorbent assay (RAST) inhibition were performed on samples of settled environmental dust from the green coffee area, as well as on castor bean and green coffee beans. RESULTS: Ten per cent of the workers complained of oculorhinitis alone and 16% of asthma (nearly always associated with oculorhinitis). The overall prevalence of skin-sensitization was: 15% for green coffee beans, 22% for castor bean, 22% for common allergens. Evidence of sensitization to occupational allergens was more common in smokers, with a more than twofold increase in relative risk. The strong association between skin positivity to common and occupational allergens suggests that atopy acts as an enhancing host factor towards occupational sensitization. The analysis of the dust confirmed the presence of castor bean antigens. CONCLUSION: Our findings indicate that castor bean is the major cause of occupational sensitization among coffee workers, whereas smoking and atopy act as enhancing factors.     

Effect of carbon recycle materials on properties of bench scale prebaked anodes for aluminum smelting

Bench scale aluminum smelting anodes were produced from aggregates having butts contents of 0 to 40 wt pct, from 100 pct mixer scrap or 100 pct green anode scrap, and from aggregates having used potlining contents of 0 to 25 pct to determine effects on important properties. Butts additions increased baked apparent density, decreased electrical resistivity, baking shrinkage, and thermal shock cracking resistance, and had little effect on excess carbon consumption. Use of 100 pct mixer scrap was equivalent to use of freshly blended coke and pitch. Use of 100 pct green anode scrap increased baked apparent density, decreased electrical resistivity, and may have reduced carbon consumption. Additions of used potlining increased carbon consumption, had little effect on electrical resistivity, and had a variable effect on thermal shock cracking resistance.     

Effect of distribution of B4C on the mechanical behaviour of Al-6061/B4C composite

In this work, the effect of mixing parameters on the distribution of B₄C in 6061-Al alloy and its correlation with mechanical behaviour was studied. 6061-Al alloy powder was mixed with 10 mass-% B₄C powder in a ball mill and powder rotator mixer by varying mixing time from 1 to 5?h. Mixing was performed in both wet and dry conditions in a ball mill while only dry condition was used in the powder rotator mixer. The green compacts were sintered at 630°C. The quadrat method was used to quantify the distribution of B₄C particles in the microstructures of sintered Al/B₄C composite. The results showed that the distribution was improved with mixing time but the density, hardness and compression strength of Al/B₄C composites were reduced with time during ball milling. On the other hand, the distribution of reinforcement, density, hardness and compressive strength of Al/B₄C composites was improved with mixing time in the powder rotator mixer.     

Effects of mixed rare earth fertilizer on yield and nutrient quality of leafy vegetables during different seasons

Using Chinese cabbage and rape as test material and examining the same soil conditions at different seasons(spring and autumn), the effects of mixed rare earth fertilizer on the yield and nutrient quality of leafy vegetables were studied to provide a theoretical basis for the application of mixed rare earth fertilizer in agriculture. Results showed a seasonal difference in the nutrient quality of Chinese cabbage and rape. For crops planted in autumn, the soluble sugar and vitamin C content were higher, the titratable acid and nitrate content were lower, and the sugar acid ratio was higher relative to crops planted in spring. Mixed rare earth treatments promoted growth of both crops during both seasons. The plot yield, stem and leaf fresh and dry matter weight, and dry and fresh ratio increased. These increases for Chinese cabbage were greater in autumn than in spring while for rape, the increases were greater in spring than autumn. The soluble sugar content, titratable acid content and sugar acid ratio were increased and the nitrate content decreased, in autumn the effects were more obvious than in spring. In spring, the vitamin C content was increased, and the increase was greater for Chinese cabbage than rape. In autumn, the vitamin C content decreased, and the decrease was greater for rape than Chinese cabbage. At the same time, the content of heavy metals such as Cu, Zn, Cd, Pb and Ni in stems and leaves decreased. This decrease was greater in spring for Chinese cabbage and in autumn for rape.     

圆盘造球机旋转刮刀参数的仿真优化

对圆盘造球机旋转刮刀运行轨迹不理想,盘面不平整的问题进行了分析,找出了其主要原因是圆盘转速与刮刀转速不匹配。为此对刮刀参数进行了仿真优化并将优化结果用于刮刀转速控制。使用结果表明,仿真优化后生球质量得到了明显改善。     

国际粉碎工程领域的新进展（续九）

评述了国际粉碎工程领域尤其是设备方面的最新进展、主要发展动向和特点,内容涉及粉碎理论研究、破碎、粉磨、筛分、分级、耐磨材料、超细磨、超细分级、特殊粉碎方法及设备等。介绍和评述了目前国际上最先进、最著名和最大规格的粉碎工程设备的最新发展,包括瑞典Sandvik集团的液压圆锥破碎机和芬兰Metso集团的Symons体系圆锥破碎机、我国与俄罗斯合作制造的惯性圆锥破碎机、德国KruppPolysius公司和KHD公司的辊压机、芬兰Metso集团的Nordberg Barmac B系列立式冲击破碎机、瑞典Mogensen公司的振动筛、世界最大规格的自磨机、球磨机和搅拌球磨机、美国Krebs公司的水力旋流器和美国Derrick公司的高频振动细筛。评述了我国粉碎工程的发展现状以及与先进国家的差距,介绍了新近出现的、有发展前途的粉碎方法和设备。     

Composite Behavior of Lath Martensite Steels Induced by Plastic Strain,a New Paradigm for the Elastic-Plastic Response of Martensitic Steels

Based on high-resolution neutron diffraction experiments, we will show that in lath martensite steels, the initially homogeneous dislocation structure, i.e., homogeneous on the length scale of grain size, is disrupted by plastic deformation, which, in turn, produces a composite on the length scale of martensite lath packets. The diffraction patterns of plastically strained martensitic steel reveal characteristically asymmetric peak profiles in the same way as has been observed in materials with heterogeneous dislocation structures. The quasi homogeneous lath structure, formed by quenching, is disrupted by plastic deformation producing a composite structure. Lath packets oriented favorably or unfavorably for dislocation glide become soft or hard. Two lath packet types develop by work softening or work hardening in which the dislocation densities become smaller or larger compared to the initial average dislocation density. The decomposition into soft and hard lath packets is accompanied by load redistribution and the formation of long-range internal stresses between the two lath packet types. The composite behavior of plastically deformed lath martensite opens a new way to understand the elastic-plastic response in this class of materials.     

国际粉碎工程领域的新进展

评述了国际粉碎工程领域尤其是设备方面的最新进展、主要发展动向和特点，内容涉及粉碎理论研究、破碎、粉磨、筛分、分级、耐磨材料、超细磨、超细分级、特殊粉碎方法及设备等。介绍和评述了目前国际上最先进、最著名和最大规格的粉碎工程设备的最新发展，包括瑞典Sandvik集团的液压圆锥破碎机和芬兰Metso集团的Symons体系圆锥破碎机、我国与俄罗斯合作制造的惯性圆锥破碎机、德国KruppPolysius公司和KHD公司的辊压机、芬兰Metso集团的NordbergBarmacB系列立式冲击破碎机、瑞典Mogensen公司的振动筛、世界最大规格的自磨机、球磨机和搅拌球磨机、美国Krebs公司的水力旋流器和美国Derrick公司的高频振动细筛。评述了我国粉碎工程的发展现状以及与先进国家的差距，介绍了一些新近出现的、有发展前途的粉碎方法和设备。     

国际粉碎工程领域的新进展(续三)

评述了国际粉碎工程领域尤其是设备方面的最新进展、主要发展动向和特点,内容涉及粉碎理论研究、破碎、粉磨、筛分、分级、耐磨材料、超细磨、超细分级、特殊粉碎方法及设备等。介绍和评述了目前国际上最先进、最著名和最大规格的粉碎工程设备的最新发展,包括瑞典Sandvik集团的液压圆锥破碎机和芬兰Metso集团的Symons体系圆锥破碎机、我国与俄罗斯合作制造的惯性圆锥破碎机、德国Krupp Polysius公司和KHD公司的辊压机、芬兰Metso集团的Nordberg Barmac B系列立式冲击破碎机、瑞典Mogensen公司的振动筛、世界最大规格的自磨机、球磨机和搅拌球磨机、美国Krebs公司的水力旋流器和美国Derrick公司的高频振动细筛。评述了我国粉碎工程的发展现状以及与先进国家的差距,介绍了新近出现的、有发展前途的粉碎方法和设备。     

国际粉碎工程领域的新进展(续二)

评述了国际粉碎工程领域尤其是设备方面的最新进展、主要发展动向和特点，内容涉及粉碎理论研究、破碎、粉磨、筛分、分级、耐磨材料、超细磨、超细分级、特殊粉碎方法及设备等。介绍和评述了目前国际上最先进、最著名和最大规格的粉碎工程设备的最新发展，包括瑞典Sandvik集团的液压圆锥破碎机和芬兰Metso集团的Symons体系圆锥破碎机、我国与俄罗斯合作制造的惯性圆锥破碎机、德国Krupp Polysius公司和KHD公司的辊压机、芬兰Metso集团的Nordberg Barmac B系列立式冲击破碎机、瑞典Mogensen公司的振动筛、世界最大规格的自磨机、球磨机和搅拌球磨机、美国Krebs公司的水力旋流器和美国Derrick公司的高频振动细筛。评述了我国粉碎工程的发展现状以及与先进国家的差距．介绍了新近出现的、有发展前途的粉碎方法和设备。     

国际粉碎工程领域的新进展（续六）

评述了国际粉碎工程领域尤其是设备方面的最新进展、主要发展动向和特点，内容涉及粉碎理论研究、破碎、粉磨、筛分、分级、耐磨材料、超细磨、超细分级、特殊粉碎方法及设备等。介绍和评述了目前国际上最先进、最著名和最大规格的粉碎工程设备的最新发展，包括瑞典Sandvik集团的液压圆锥破碎机和芬兰Metso集团的Symons体系圆锥破碎机、我国与俄罗斯合作制造的惯性圆锥破碎机、德国Krupp Polysius公司和KHD公司的辊压机、芬兰Met8。集团的Nordberg Barmac B系列立式冲击破碎机、瑞典Mogensen公司的振动筛、世界最大规格的自磨机、球磨机和搅拌球磨机、美国Krebs公司的水力旋流器和美国Derrick公司的高频振动细筛。评述了我国粉碎工程的发展现状以及与先进国家的差距，介绍了新近出现的、有发展前途的粉碎方法和设备。     

国际粉碎工程领域的新进展（续八）

评述了国际粉碎工程领域尤其是设备方面的最新进展、主要发展动向和特点,内容涉及粉碎理论研究、破碎、粉磨、筛分、分级、耐磨材料、超细磨、超细分级、特殊粉碎方法及设备等。介绍和评述了目前国际上最先进、最著名和最大规格的粉碎工程设备的最新发展,包括瑞典Sandvik集团的液压圆锥破碎机和芬兰Metso集团的Symons体系圆锥破碎机、我国与俄罗斯合作制造的惯性圆锥破碎机、德国Krupp Polysius公司和KHD公司的辊压机、芬兰Metso集团的Nordberg Barmac B系列立式冲击破碎机、瑞典Mogensen公司的振动筛、世界最大规格的自磨机、球磨机和搅拌球磨机、美国Krebs公司的水力旋流器和美国Derrick公司的高频振动细筛。评述了我国粉碎工程的发展现状以及与先进国家的差距,介绍了新近出现的、有发展前途的粉碎方法和设备。     

国际粉碎工程领域的新进展(续五)

评述了国际粉碎工程领域尤其是设备方面的最新进展、主要发展动向和特点，内容涉及粉碎理论研究、破碎、粉磨、筛分、分级、耐磨材料、超细磨、超细分级、特殊粉碎方法及设备等。介绍和评述了目前国际上最先进、最著名和最大规格的粉碎工程设备的最新发展，包括瑞典Sandvik集团的液压圆锥破碎机和芬兰Metso集团的Symons体系圆锥破碎机、我国与俄罗斯合作制造的惯性圆锥破碎机、德国Krupp Polysius公司和KHD公司的辊压机、芬兰Metso集团的Nordberg Barmac B系列立式冲击破碎机、瑞典Mogensen公司的振动筛、世界最大规格的自磨机、球磨机和搅拌球磨机、美国Krebs公司的水力旋流器和美国Derrick公司的高频振动细筛。评述了我国粉碎工程的发展现状以及与先进国家的差距，介绍了新近出现的、有发展前途的粉碎方法和设备。     

Vertical fracture dislocation of the tarsal navicular

An isolated vertical fracture dislocation of the left tarsal navicular with some comminution was successfully treated with open reduction and internal fixation with a screw. The surgical treatment is described, and early mobilization strongly recommended.     

Modeling of Wrinkling in Compression Molding of Composites

A model has been developed for the prediction of wrinkling during the compression molding process for composites with thick cross sections. The onset of wrinkling is modeled as a localized bifurcation model, which produces additional solutions in the form of wrinkles in a single layer or group of neighboring layers. Average mechanical, thermal, and cure properties of the composite material needed for simulation of compression molding processes are developed.     

高精度直径轴承圈的车圆弧工具

对太原重型集团公司大型轴承圈的制造，由于其材料为不锈钢，由于其导轨为圆弧辊边，刀具加工难度大，所以根据其导轨特点，设计金属切削机床上使用专用工具，工具使用要求具有刀架的立车，使用时拉杆夹固定于立车一个刀架上，刀杆装在另一个架上，加工时，固定刀杆的刀架找正后固定不动，移动另一刀架，通过拉杆连接带动齿条，齿条传动带动轴旋转，实现自动旋转走刀。