浅析合理有效控制建筑工程造价

合理有效控制工程造价能够提高建筑施工企业的效益,有效控制建筑施工成本,文章主要对建筑工程造价的要点进行分析,从建筑工程施工图预算控制、招投标文件控制、现场签证变更控制、进度款确认控制和工程竣工结算控制等几方面进行阐述,尽量提高工程造价控制的合理性。     

客运专线预拌混凝土的质量控制

文章详细论述了客运专线混凝土拌合站对预拌混凝土质量的控制过程,要想提高预拌混凝土的质量,必须经过关键的四个控制过程即原材料质量控制、配合比质量控制、生产质量控制和运输质量控制。原材料质量控制关键是水泥、细骨料、粗骨料、外加剂、掺合料及拌合用水的选择。配合比质量控制关键是经过反复调配选定最优配合比。生产质量控制关键是搅拌过程中搅拌时间的控制。运输质量控制是在混凝土运输过程中采取各项措施保证混凝土拌合物各项指标满足施工现场需要。     

纺织品实验室化学检测领域内部质量控制的探讨

叙述纺织品实验室化学检测领域的内部质量控制的主要内容,介绍质量控制计划、空白试验、重复检测、比对、加标回收、实验室控制样品和质量控制图等化学检测常用的质量控制方法,结合纺织品化学检测项目,提出内部质量控制的应用指南。     

激光打印机原理及常见故障和维修(续)

三、控制系统部分 整机控制系统包括激光扫描系统的控制,静电记录(电子照相)系统的控制,与主机的接口控制,缓冲存储,脱机自检等控制。 激光扫描系统的控制主要是完成多面棱镜的稳速驱动,进行同步信号的检测、处理,半导体激光器的调制与驱动等。静电记录系统的控制与复印机相同,主要是控制和协调充电、曝光、显影、转     

早餐生产企业如何进行质量监控

对早餐生产企业的产品质量监控进行全面的综合分析,找出能最大范围控制产品质量的方法,从而达到对早餐产品质量的有效控制。其控制方法分三个阶段:事前控制、事中控制、事后控制。     

自动化控制技术在油脂精炼生产中的应用

结合油脂精炼工艺,介绍了自动化技术的组成与PLC设计,针对碱炼车间加碱量的控制、脱色车间白土添加量的控制、脱色车间过滤机的控制、回路的PID自动控制、冷却水风机的节能控制这几个关键点自动化控制技术的应用进行分析说明。     

达芬奇质量控制系统(QCS)在特种纸机上的应用

介绍了Honeywell达芬奇质量控制系统的测量部分和控制部分的解决方案和技术特点。测量部分包括传感器工作原理和维护方法;控制部分主要包括纸张定量、水分、灰分的纵向(MD)控制和纸张定量、水分、厚度的横向(CD)控制、横向优化控制以及施胶涂布量控制。     

蔬菜和水果农药残留检测中的质量控制措施

<正>本文从抽样过程质量控制、人员的质量控制、设施环境的质量控制、仪器设备的质量控制、检测材料的质量控制、标准物质的质量控制、检测过程质量控制与检测结果的质量控制等方面阐述了蔬菜与水果农药残留检测中的质量控制措施。蔬菜和水果农药残留检测目前是农产品质量安全风险监测工作的重要内容,承接该监测任务的检测机构肩负着极大的责任。农药残留检测是微     

新型人造毛皮提花编织机自动控制系统

针对市场对人造毛皮质量要求的不断提高和当前使用的人造毛皮编织机成本高、操作复杂、维护不便的缺点，提出了一种基于多单片机、DSP和配置触摸屏工业控制计算机的新型人造毛皮机自动控制系统的实现方案。其中工业控制计算机完成花型数据的处理功能、参数输入、控制与状态显示；DSP完成故障诊断、选针控制、喂毛控制和花型控制功能；系统共有18个梳理头，每个梳理头的喂毛控制和步进电机控制分别由一个单片机完成。编辑的花型数据通过U盘方便地传送给控制系统；工业控制计算机与DSP采用并口EPP模式进行通信；DSP与18路梳理头控制单片机采用串行通信模式。文中详细说明了选针器控制、喂毛控制、花型控制、故障诊断、数据通信等关键技术的实现方法。分析了停车线现象产生的原因，给出了基于密度补偿的具体补偿方式。该系统完成了1184针和1056针两种类型毛皮编织机的自动控制，编织质量好、效率高、操作简便、维护方便。     

主汽轮机控制系统(MTC)功能简介

主汽轮机控制系统是通过自动调节进入汽轮机的蒸汽流量来控制汽轮机转速及负荷的设备。它具有升速控制、阀门切换控制、关闭所有阀门、调节器控制以及快速减负荷等控制功能。     

Food safety and legislation in the dairy industry*

The legal and commercial controls on milk and milk products in the United Kingdom are reviewed. Although these controls have generally provided milk and milk products with a good food safety record, the UK government is actively working in several areas which are described in this paper to maintain and improve standards. A major revision of existing UK regulations will probably be required if the proposals for regulations on milk and milk products from the European Commission, currently under discussion, are agreed. Other factors, and particularly those concerning public health, may also lead to changes.     

Binding, Sensory and Storage Properties of Algin/Calcium Structured Beef Steaks

Structured beef steaks formed with the algin/calcium binder and with or without glucono-delta-lactone were compared with 100% beef controls and with structured steaks formed with salt and phosphate. Algin/calcium-treated products exhibited better binding and color in the raw state, but had lower palatability scores in the cooked state than salt/phosphate controls. Shelf-life of both algin/calcium products under aerobic conditions was similar to the all-beef control. In vacuum packages, however, the algin/calcium products showed more rapid gas production and microbial growth than all-beef and salt/phosphate controls. The algin/calcium treatment will allow increased marketing alternatives for meat products.     

Quantitative analysis of pork dry-cured sausages to quality control by NIR spectroscopy

Near infrared spectroscopy technology (diode array instrument) was used to study the feasibility of applying quality controls to typical Spanish sausages by performing a proximate analysis (fat, moisture and protein) on the finished product (intact and homogenized). This could be used to provide quality controls at various stages once the finished product was obtained: finished product, storage, distribution and marketing. The selected models were calibrated and evaluated by cross and external validation. For intact products, coefficients of determination for calibration (R²) for fat, moisture and protein were 0.98, 0.93 and 0.97, respectively. These values for homogenised products were 0.99, 0.98 and 0.97, respectively. The standard errors of prediction (SEP) for external validation in intact products were 1.47%, 0.97% and 1.08% for fat, moisture and protein, respectively. In homogenised products, these values were lower: 0.71%, 0.41% and 0.95%, respectively.     

Active and intelligent packaging for food: Is it the future?

This paper gives an overview of the legal consequences of a new EU framework regulation on food contact materials which includes controls on active and intelligent packaging. Recent developments in active and intelligent packaging systems are described, two examples of which aim at achieving improvements in quality and safety of food products. The first one is an on-command preservative-releasing packaging system. The second system is an intelligent concept, based on the development of a non-invasive microbial growth sensor to monitor the sterility of food products.     

Acceptability of Flavor, Texture, and Appearance in Mutton Processed Meat Products Made by Smoking, Curing, Spicing, Adding Starter Cultures and Modifying Fat Source

Mutton meat was tested as the main ingredient, in different processed meat items to obtain prototype products lacking objectionable mutton off-flavors. Four consumer-preference sensory panel sessions were conducted to rate these products against beef or pork controls. Sensory panel results indicated that compared to texture and appearance parameters, flavor had more effect on overall acceptability of these products. Objectionable mutton flavor was apparently reduced by: (1) reducing mutton fat to a level of 10% or less, and (2) using spices, smoking, and/or curing.     

EFFECT OF GAMMA RADIATION ON WHEAT STARCH AND ITS COMPONENTS

SUMMARY– Studies on the susceptibility of irradiated wheat starch, amylose and amylopectin to alpha- and beta-amylolysis reveal that they are more susceptible to enzyme actions, compared to their unirradiated controls; however, irradiated amylose seems to be comparatively more vulnerable. From irradiated starch, series of oligosaccharides of the maltose series are discernible, while glucose appears only above 200 Krad dose level. Quantitative analysis of the radiolytic breakdown products of starch reveal that at high dose levels (1 Mrad) maltose, maltotriose and maltotetrose are the main products. Results on the separation of radiolytic breakdown products suggest they resemble those produced by alpha-amylolysis of starch.     

Use of octanoic acid as a postlethality treatment to reduce Listeria monocytogenes on ready-to-eat meat and poultry products

The antilisterial efficacy and organoleptic impact of an octanoic acid (OA)-based treatment for ready-to-eat (RTE) meat and poultry products were investigated. Whole-muscle and comminuted RTE products were inoculated with a five-strain mixture of Listeria monocytogenes. The OA treatments were applied to the surface of RTE products by dispensing a specific volume of solution directly into the final package prior to vacuum sealing. Once sealed, the vacuum-packaged RTE products containing OA were immersed in water heated to 93.3 degrees C (200 degrees F) for 2 s to effect adequate film shrinkage. Extending the time at which the packaged, treated RTE products were exposed to water heated to 93.3 degrees C was also evaluated with a commercial cascading shrink tunnel fitted with a modified drip pan. Once treated, RTE products were examined for survivor populations of L. monocytogenes after 24 h of storage at 5 degrees C. Sensory evaluation was conducted with a 60-member trained panel on 11 uninoculated, treated RTE products. The OA treatment of RTE products reduced L. monocytogenes numbers to between 0.85 log CFU per sample (oil-browned turkey) and 2.89 log CFU per sample (cured ham) when compared with controls. The antilisterial activity of OA was improved by increasing the duration of the heat shrink exposure. Specifically, reductions of L. monocytogenes ranged from 1.46 log CFU per sample (oil-browned turkey) to 3.34 log CFU per sample (cured ham). Results from the sensory evaluation demonstrated that 10 of the 11 treated RTE products were not perceived as different (P < or = 0.05) from the untreated controls. Panelists detected reduced (P < or = 0.05) smoke flavor intensity with treated mesquite turkey, although the treated product was viewed as acceptable. Results demonstrate the effectiveness of OA as a postlethality treatment meeting U.S. Food Safety and Inspection Service regulatory guidelines for RTE meat and poultry products with minimal impact on sensory quality.     

Dietary Supplementation of Vitamin E to Feedlot Cattle Affects Beef Retail Display Properties

Beef products from carcasses (n = 20) of cattle fed supplemental vitamin E and beef products from commodity carcasses (n = 20), used as controls, were compared to determine effects of increased vitamin E tissue levels on display appearance of fresh beef held in supermarket and simulated retail conditions. Meat from cattle fed supplemental vitamin E contained higher levels of α-tocopherol (P < 0.05) and, over time, exhibited less lipid oxidation, brighter lean color and lower discoloration. Monitoring supermarkets for discounted retail meats showed increased levels of α-tocopherol in beef extended caselife and decreased the incidence of discounted beef products.     

反射法测定芦荟制品中乳酸的含量

芦荟制品中乳酸的含量反映芦荟制品加工过程中微生物控制情况,也反映芦荟制品品质的变化情况。本文建立了一种反射计量测定乳酸含量的新方法。实验结果表明,该方法快速灵敏、操作简单、重复性好,可用于芦荟制品生产过程中乳酸含量的测定及其产品质量的评价。     

Sensory and Microbial Quality of Irradiated Crab Meat Products

Low dose gamma irradiation has proved effective in reducing pathogenic and spoilage microorganisms in a variety of seafood products. However, little information is available on the effect of irradiation on the sensory quality and consumer acceptance of such products. We compared microbial and sensory quality of irradiated (2 kGy or less) crab products (white lump, claw, and fingers) through 14-days of ice-storage. Irradiation effectively reduced spoilage bacteria extending shelf-life by more than 3 days beyond control samples. During storage, fresh crab odor and flavor were similar for treated and control samples, while off-flavors and odors developed more rapidly in controls. Overall acceptability scores for irradiated crab samples were higher than for control samples throughout 14-days ice storage.