烧碱预处理对莫代尔织物数码印花的影响

研究聚焦于100%莫代尔织物的预处理,以及随后的数码印花中烧碱(NaOH)对印花质量,即印花深度、印花亮度和织物实用价值的影响。结果显示烧碱对织物的外观和舒适度有总体影响。研究还给出了莫代尔织物预处理中烧碱的最优用量。     

烧碱、纯碱用于压榨花生油脱酸的比较研究

为降低酸值,将烧碱与纯碱分别用于高酸值压榨花生油的脱酸过程,通过对比研究了不同条件对两种方法脱酸的影响,并确定纯碱脱酸的最佳条件为:碱液浓度20%~25%,加碱量小于理论值的1.5倍,温度20~30℃,搅拌时间20~25 min。综合比较来看,纯碱脱酸效果要优于烧碱。     

针织物丝光水洗淡碱液的回用

在针织物丝光水洗淡碱液中，NaOH和渗透剂残余量较高，尤其是前端水洗阶段，若作为废水排放，会增加污水处理难度和费用。通过测试各个水洗槽中淡碱液的COD、色度和酸碱度，经处理后，将其回用于织物煮漂，再染色。由于丝光残液中含有大量的渗透剂，回用时煮练效果较好，且不会影响织物的染色。     

食品级烧碱在脱皮芝麻生产中的应用

以平舆康博汇鑫油脂有限公司芝麻脱皮生产线为基础,运用机械法快速有效地对芝麻进行湿法脱皮。在保持脱皮芝麻产品口感、风味的条件下,研究加碱量对脱皮率的影响,分析湿法脱皮过程中水洗时间与脱皮率及碱残留的关系。确定最佳加碱量为1.4%~1.5%;在最佳加碱量条件下,无碱残留的最佳水洗时间为30 min。     

The role of heat exchangers in the contamination of milk with Bacillus cereus in dairy processing plants

In the dairy industry microbiological contamination may arise from equipment used for handling or processing. In this study it was demonstrated that Bacillus cereus spores could adhere stainless steel, germinate and/or multiply in a tube heat exchanger. The levels of B cereus detect in the tubes, after 24 h at 20°C, varied from less than 1 to 2600 cm^-2. Adhering cells and/or spores were more resistant to cleaning with K500 and sodium hydroxide, determined by laboratory suspension tests and surface tests on stainless steel. This was confirmed in a field trial with a tube heat exchanger after cleaning B cereus could still be isolated from all tubes determined by swab samples of individual tubes. The identity of the isolates was checked by polymerase chain reaction/randomly amplified polymorphic DNA typing to confirm that the organisms found on the surfaces were the same as the bacteria in the ingoing milk.     

棉在烧碱溶液中溶胀的结构变化研究

介绍了棉的溶胀机理和棉在烧碱溶液中溶胀产生的形态结构和超分子结构变化.在烧碱溶液中,棉纤维溶胀程度低,初生胞壁不能溶解,呈均匀的膨胀状态.施加张力会降低棉纤维在烧碱溶液中的溶胀,丝光只能将纤维素I部分转变成纤维素Ⅱ,产生的横截面尺寸和长度上的变化可以保留在干态.     

Membrane cleaning in the dairy industry: a review

Membrane separation processes have become part of the set of basic unit operations for dairy process design and product development. These processes are employed in a variety of separation and concentration duties, but in all cases, the membranes must be cleaned regularly to remove both organic and inorganic material deposited on the surface from the fluid stream being processed. Cleaning is a vital step in maintaining the permeability and selectivity of the membrane and is necessary to return the plant to its original capacity, to minimize risks of bacteriological contamination, and to produce acceptable products. Caustic-, acidic-, and enzyme-based cleaners may be used for membrane cleaning and are usually formulated with additives to best match the specific cleaning duty. Cleaning generates significant volumes of wastewater and reduces membrane life and plant productivity, so each regime must be optimized with respect to concentration, order and duration of cleaning steps, temperature, pressure, and flow rate. This article reviews the key mechanisms governing cleaning performance and suggests directions by which further optimization may be achieved.     

The role of organic agriculture in the dairy industry

A small, but high added-value and growing market exists for dairy produce manufactured from milk produced organically. This paper describes the philosophy and practice of organic agriculture and suggests its relation to the dairy industry.     

Studying the role of common membrane surface functionalities on adsorption and cleaning of organic foulants using QCM-D

Adsorption of organic foulants on nanofiltration (NF) and reverse osmosis (RO) membrane surfaces strongly affects subsequent fouling behavior by modifying the membrane surface. In this study, impact on organic foulant adsorption of specific chemistries including those in commercial thin-film composite membranes was investigated using self-assembled monolayers with seven different ending chemical functionalities (-CH(3), -O-phenyl, -NH(2), ethylene-glycol, -COOH, -CONH(2), and -OH). Adsorption and cleaning of protein (bovine serum albumin) and polysaccharide (sodium alginate) model foulants in two solution conditions were measured using quartz crystal microbalance with dissipation monitoring, and were found to strongly depend on surface functionality. Alginate adsorption correlated with surface hydrophobicity as measured by water contact angle in air; however, adsorption of BSA on hydrophilic -COOH, -NH(2), and -CONH(2) surfaces was high and dominated by hydrogen bond formation and electrostatic attraction. Adsorption of both BSA and alginate was the fastest on -COOH, and adsorption on -NH(2) and -CONH(2) was difficult to remove by surfactant cleaning. BSA adsorption kinetics was shown to be markedly faster than that of alginate, suggesting its importance in the formation of the conditioning layer. Surface modification to render -OH or ethylene-glycol functionalities are expected to reduce membrane fouling.     

Influence of the pre-rinse on the efficiency of circulation cleaning milking machines

The effect of volume and temperature of pre-rinse water on the cleaning efficiency of five circulation cleaned recorder milking machines was investigated. A hot (> 75 °C) pre-rinse gave the lowest bacteriological rinse total colony counts. As the rinse count differences were small, the least expensive cold water pre-rinse is considered satisfactory for most farms. A pre-rinse volume of 16 litres per unit removed more residual milk than eight litres per unit but gave no significant difference in rinse counts. For most plants 8–10 litres per unit is considered a satisfactory pre-rinse volume     

纸机白水应用浮选柱净化的效果

介绍了加拿大制浆造纸研究所进行浮选柱净化纸机白水的研究.结果是增加了油墨和抽出物的除去,改进了循环用白水的质量,增加了白水循环利用后纸机的可运行性和产品的质量.     

Characteristics of biological aerosols in dairy processing plants

The viable aerosol in dairy processing plant environments was characterized by using an Andersen six-stage sieve sampler and a Reuter centrifugal sampler. Artificially introduced Serratia marcescens were detected in the air during drain flooding and after rinsing the floor with a pressured water hose, thus illustrating the ability of a specific microorganism to be disseminated from drains and wet surfaces via physical disruption activities often observed in food plants. Once a high concentration of wet viable aerosol was generated, it took 40 or more min to return to the background level in the absence of forced ventilation or other activity. The greatest reduction in viable particles occurred during the first 10 min. Estimated mean aerosol particle sizes were decreased from approximately 4.6 to 3.2 mu with time lapse. The estimated mean aerosol particle sizes from actual dairy processing plant environments ranged from approximately 4.3 to 5.3 mu. In addition, a more heavily contaminated dairy processing environment contained larger aerosol particles. These results indicate that the RCS sampler will often overestimate the true aerosol concentration in highly contaminated air, because mean particle sizes are over 4 mu in diameter.     

有机酸化学清洗在化肥厂的应用

论述了有机酸在大化肥装置上化学清洗的原理,介绍了有机酸化学清洗的工艺流程和工艺参数。     

Effect of gum arabic on the surface tension and surface dilational rheology of trisiloxane surfactant

The surface tension and surface dilational properties of trisiloxane surfactant silwet408, gum arabic, and their mixed solutions are reported. The dilational rheological properties are measured by means of oscillating drop method. The influences of dilational frequency, bulk concentration and aging time on dilational rheology properties have been investigated. The adsorption films of silwet408 behave elastic in nature at low bulk concentration. With increasing concentration, the dilational modulus becomes more frequency dependent and reaches a maximum value. The addition of 1 wt% gum arabic has no remarkable influence on the silwet408 films since the adsorption ability of silwet408 is much better than that of gum arabic. However, the maximum of dilational modulus and dilational elasticity are shifted toward a higher concentration, which has been correlated with the decreased molecular exchange in the presence of 1 wt% gum arabic.     

The genetic and biological basis of feed efficiency in mid-lactation Holstein dairy cows

The objective of this study was to identify genomic regions and candidate genes associated with feed efficiency in lactating Holstein cows. In total, 4,916 cows with actual or imputed genotypes for 60,671 single nucleotide polymorphisms having individual feed intake, milk yield, milk composition, and body weight records were used in this study. Cows were from research herds located in the United States, Canada, the Netherlands, and the United Kingdom. Feed efficiency, defined as residual feed intake (RFI), was calculated within location as the residual of the regression of dry matter intake (DMI) on milk energy (MilkE), metabolic body weight (MBW), change in body weight, and systematic effects. For RFI, DMI, MilkE, and MBW, bivariate analyses were performed considering each trait as a separate trait within parity group to estimate variance components and genetic correlations between them. Animal relationships were established using a genomic relationship matrix. Genome-wide association studies were performed separately by parity group for RFI, DMI, MilkE, and MBW using the Bayes B method with a prior assumption that 1% of single nucleotide polymorphisms have a nonzero effect. One-megabase windows with greatest percentage of the total genetic variation explained by the markers (TGVM) were identified, and adjacent windows with large proportion of the TGVM were combined and reanalyzed. Heritability estimates for RFI were 0.14 (±0.03; ±SE) in primiparous cows and 0.13 (±0.03) in multiparous cows. Genetic correlations between primiparous and multiparous cows were 0.76 for RFI, 0.78 for DMI, 0.92 for MBW, and 0.61 for MilkE. No single 1-Mb window explained a significant proportion of the TGVM for RFI; however, after combining windows, significance was met on Bos taurus autosome 27 in primiparous cows, and nearly reached on Bos taurus autosome 4 in multiparous cows. Among other genes, these regions contain β-3 adrenergic receptor and the physiological candidate gene, leptin, respectively. Between the 2 parity groups, 3 of the 10 windows with the largest effects on DMI neighbored windows affecting RFI, but were not in the top 10 regions for MilkE or MBW. This result suggests a genetic basis for feed intake that is unrelated to energy consumption required for milk production or expected maintenance as determined by MBW. In conclusion, feed efficiency measured as RFI is a polygenic trait exhibiting a dynamic genetic basis and genetic variation distinct from that underlying expected maintenance requirements and milk energy output.     

The decline in digestive efficiency of US dairy cows from 1970 to 2014

Since the year 1970, US milk production per cow has more than doubled, in part because of large increases in feed intake. It is well established that increasing feed intake reduces diet digestibility in dairy cattle. Our objective was to determine whether the digestive efficiency of US dairy cows had also changed. We assembled a data set consisting of diet digestibility measured either by total collection of feces or by use of indigestible neutral detergent fiber (NDF) in lactating dairy cow studies published in the Journal of Dairy Science from July 1970 to July 2014. The data set contained 575 treatment means from 154 individual research trials conducted at 26 US institutions. Based on regression analysis, mean milk yield and dry matter intake (DMI) between 1970 and 2014 increased by 19.7 and 10.3 kg/d, respectively. Temporal effects on digestibility [dry matter (DM), crude protein (CP), and NDF] were determined using the regression model Y_i = YEAR_1970i + CP_i + NDF_i + e_i, where YEAR_1970i is the publication year minus 1970, CP_i and NDF_i are diet constituents (% of diet DM) that were included to account for their known effects on digestibility, and e_i is the residual error. Dry matter digestibility decreased 0.07 percentage units/yr for a total reduction of 3.08 percentage units since 1970. Furthermore, CP and NDF digestibilities decreased 0.04 and 0.17 percentage units/yr, respectively. To account for the potential effect of feed intake on digestibility, DMI as a percentage of body weight was added to the regression model. With DMI as a percentage of body weight in the model, temporal changes in DM, CP, and NDF digestibilities were no longer significant. This suggested that the apparent decline in DM digestibility could be mostly accounted for by simultaneous increases in level of feed intake. Despite lower apparent digestive efficiency, the modern dairy cow has greater production efficiency than the 1970s dairy cow because she produces more milk per unit of feed consumed and digested.     

Application of turbulent pulsating flows to the bacterial removal during a cleaning in place procedure. Part 2: Effects on cleaning efficiency

Pulsating turbulent flows effects on cleaning in place procedure of straight pipes were investigated for various pulsations parameters (frequency and amplitude) and mean velocities of the flow. Pulsations generation was made with a new system which allows high amplitude of pulsations. Experiments showed the contribution of the different pulsation parameters, in the removal of adhered bacterial spores, in addition to the effect of the mean velocity of the flow. A high level of the cleaning rate is observed despite the reduction of the magnitude of the mean velocity. This result can be explained by the effect of the two pulsations parameters (amplitude and frequency) which ensure a high wall shear rate. The study of the cleaning kinetics has shown the increase of the removal constant rate of spores using pulsed flow in comparison with the use of a steady turbulent flow.     

Determinants of technical efficiency among dairy farms in Wisconsin

The US dairy sector is facing structural changes including a geographical shift in dairy production and a tendency toward the implementation of more intensive production systems. These changes might significantly affect farm efficiency, profitability, and the long-term economic sustainability of the dairy sector, especially in more traditional dairy production areas. Consequently, the goal of this study was to examine the effect of practices commonly used by dairy farmers and the effect of intensification on the performance of the farms. We used a sample of 273 Wisconsin dairy farms to estimate a stochastic production frontier simultaneously with a technical inefficiency model. The empirical analysis showed that at a commercial level the administration of bovine somatotropin hormone to lactating cows increased milk production. In addition, we found that production exhibits constant returns to scale and that farm efficiency is positively related to farm intensification, the level of contribution of family labor in the farm activities, the use of a total mixed ration feeding system, and milking frequency.