Risk-based approach to developing a national residue sampling plan for testing under European Union regulation for veterinary medicinal products and coccidiostat feed additives in domestic animal production

A ranking system for veterinary medicinal products and coccidiostat feed additives has been developed as a tool to be applied in a risk-based approach to the residue testing programme for foods of animal origin in the Irish National Residue Control Plan (NRCP). Three characteristics of substances that may occur as residues in food are included in the developed risk ranking system: Potency, as measured by the acceptable daily intake assigned by the European Medicines Agency Committee for Medicinal Products for Veterinary Use, to each substance; Usage, as measured by the three factors of Number of Doses, use on Individual animals or for Group treatment, and Withdrawal Period; and Residue Occurrence, as measured by the number of Non-Compliant Samples in the NRCP. For both Number of Doses and Non-Compliant Samples, data for the 5-year period 2008–12 have been used. The risk ranking system for substances was developed for beef cattle, sheep and goats, pigs, chickens and dairy cattle using a scoring system applied to the various parameters described above to give an overall score based on the following equation: Potency × Usage (Number of Doses + Individual/Group Use + Withdrawal Period) × Residue Occurrence. Applying this risk ranking system, the following substances are ranked very highly: antimicrobials such as amoxicillin (for all species except pigs), marbofloxacillin (for beef cattle), oxytetracycline (for all species except chickens), sulfadiazine with trimethoprim (for pigs and chickens) and tilmicosin (for chickens); antiparasitic drugs, such as the benzimidazoles triclabendazole (for beef and dairy cattle), fenbendazole/oxfendazole (for sheep/goats and dairy cattle) and albendazole (for dairy cattle), the avermectin ivermectin (for beef cattle), and anti-fluke drugs closantel and rafoxanide (for sheep/goats); the anticoccidials monensin, narasin, nicarbazin and toltrazuril (for chickens). The risk ranking system described is a relatively simple system designed to provide a reliable basis for selecting the veterinary medicinal products and coccidiostat feed additives that might be prioritised for residue testing.     

Evaluating the effect of ration composition on income over feed cost and milk yield

Feed is generally the greatest expense for milk production. With volatility in feed and milk markets, income over feed cost (IOFC) is a more advantageous measure of profit than simply feed cost per cow. The objective of this study was to evaluate the effects of ration cost and ingredient composition on IOFC and milk yield. The Pennsylvania State Extension Dairy Team IOFC tool (http://extension.psu.edu/animals/dairy/business-management/financial-tools/income-over-feed-cost/introduction-to-iofc) was used to collect data from 95 Pennsylvania lactating dairy cow herds from 2009 to 2012 and to determine the IOFC per cow per day. The data collected included average milk yield, milk income, purchased feed cost, ration ingredients, ingredient cost per ton, and amount of each ingredient fed. Feed costs for home-raised feeds for each ration were based on market values rather than on-farm cost. Actual costs were used for purchased feed for each ration. Mean lactating herd size was 170 ± 10.5 and daily milk yield per cow was 31.7 ± 0.19 kg. The mean IOFC was $7.71 ± $1.01 cost per cow, ranging from −$0.33 in March 2009 to $16.60 in September 2011. Data were analyzed using a one-way ANOVA in SPSS (IBM Corp., Armonk, NY). Values were grouped by quartiles and analyzed with all years combined as well as by individual year. Purchased feed cost per cow per day averaged $3.16 ± $1.07 for 2009 to 2012. For 2009 to 2012 combined, milk yield and IOFC did not differ with purchased feed cost. Intermediate levels (quartiles 2 and 3) of forage cost per cow per day between $1.45 and $1.97 per cow per day resulted in the greatest average IOFC of $8.19 and the greatest average milk yield of 32.3 kg. Total feed costs in the fourth quartile ($6.27 or more per cow per day) resulted in the highest IOFC. Thus, minimizing feed cost per cow per day did not maximize IOFC. In 2010, the IOFC was highest at $8.09 for dairies that fed 1 or more commodity by-products. Results of the study indicated that intermediate levels of forage cost and higher levels of total feed cost per cow per day resulted in both higher milk yield and higher IOFC. This suggests that optimal ration formulation rather than least cost strategies may be key to increasing milk yield and IOFC, and that profit margin may be affected more by quality of the feed rather than the cost.     

Passenger thermal comfort and behavior: a field investigation in commercial aircraft cabins

Passengers' behavioral adjustments warrant greater attention in thermal comfort research in aircraft cabins. Thus, a field investigation on 10 commercial aircrafts was conducted. Environment measurements were made and a questionnaire survey was performed. In the questionnaire, passengers were asked to evaluate their thermal comfort and record their adjustments regarding the usage of blankets and ventilation nozzles. The results indicate that behavioral adjustments in the cabin and the use of blankets or nozzle adjustments were employed by 2/3 of the passengers. However, the thermal comfort evaluations by these passengers were not as good as the evaluations by passengers who did not perform any adjustments. Possible causes such as differences in metabolic rate, clothing insulation and radiation asymmetry are discussed. The individual difference seems to be the most probable contributor, suggesting possibly that passengers who made adjustments had a narrower acceptance threshold or a higher expectancy regarding the cabin environment. Local thermal comfort was closely related to the adjustments and significantly influenced overall thermal comfort. Frequent flying was associated with lower ratings for the cabin environment.     

秸秆饰面墙体砌砖成型机的设计及其应用分析

阐述了秸秆饰面墙体砌砖成型机的设计方案,具体包括基本结构及工作原理。为满足秸秆墙体砌砖在建筑用材上较高强度和密实度的要求,关键对于成型装置和进料装置进行了设计和装配,使一次挤压中得以实现二次进料以及隔层中玻纤维添加的连续过程。并将秸秆饰面墙体砌砖在主要性能指标上与水泥砖进行对比分析,剖析秸秆墙体砌砖的优势和竞争力,而且通过经济指标上具体产值和节能效益的计算,分析得出该设备及其产品较大的市场价值和发展前景。     

超声振动铣削2A12表面粗糙度实验研究

利用小径立铣刀对铝合金进行超声振动铣削实验,重点探讨了超声振幅与每齿进给量对工件槽底表面粗糙度的影响.实验结果表明:槽底表面粗糙随着超声振幅的增大而增大,在每齿进给量fZ<4μm/z时槽超声振幅为主要影响因素;每齿进给量fZ>6μm/z时每齿进给量为主要影响因素.在超声振动铣削加工中应尽量选择小进给量可获得较小槽底表面粗糙度.通过扫面电镜对工件微观形貌观测证实了施加振动后脉冲切削和断续切削双重作用导致槽底表面粗糙度增大.     

硬车代磨表面粗糙度试验研究

使用硬质合金刀具、陶瓷刀具和PCBN刀具对渗碳淬硬钢20CrMnTi进行干式车削试验,通过测量不同切削条件下的表面粗糙度值,得出切削速度、进给量对表面粗糙度的影响规律,验证了以车代磨的干式切削渗碳淬硬钢20CrMnTi的可行性.     

返料式立辊磨粉机的设计研究

目前市场上应用比较广泛的中速立式磨机处理量都在30t/h以上,而且存在磨矿效率低、耗能高和故障率高等缺点,不适合小型企业应用。针对此现状,提出了连续返料均布分料立辊式磨粉机。该磨机对粉碎机理进行了改进,大大提高了效率,降低了能耗,并且加入了风选,保证了出料的颗粒度。     

矿用救生舱舱门锁紧机构设计

分析了舱门在矿用救生舱设计中的重要性,并利用齿轮与齿条的啮合原理设计了舱门锁紧机构;舱门的四周对应闩板端分布有4个闩孔,闩板的伸出端呈楔形状,通过齿轮与齿条啮合带动闩板进入相应的闩孔中,在压紧力的作用下舱门处于四周压紧密封状态,确保舱门紧扣在舱体上,从而保证了舱内温度和空气免受外界直接影响;通过手柄的旋转角度判断出锁紧程度,确保了舱门对舱体的密封性能;解决了加工和安装中由于误差大而导致闩板不能对准闩孔的问题。     

煤矿井下救生系统

煤矿井下救生系统由井下救生舱,井上设备和连接线缆等三部分组成,为矿井发生事故后无法及时撤离的矿工提供一个安全的密闭空间,对外抵御爆炸冲击、高温烟气、冒顶坍塌、隔绝有毒有害气体;对内为被困矿工提供氧气、食物、水,赢得较长的生存时间;同时通过舱内应急电话,引导外界救援。     

紫金洗煤厂絮凝剂自动添加系统的研究

针对紫金洗煤厂煤泥水处理的实际情况,设计了絮凝剂自动添加控制系统。系统根据实时检测到的煤泥水浓度、流量以及溢流水浊度,通过前馈和反馈相结合的方法,自动控制絮凝剂添加量。工业试验表明:使用该系统降低了药耗,稳定了溢流水浊度,改善了循环水质量。