汽车顶棚面料浅谈

市场主流的汽车顶棚面料有针织复合品、针刺非织造布和缝边非织造布3种。分别从生产工艺、材料性能、成本和模压性等方面对不同的汽车顶棚面料进行了对比和分析,以期为汽车主机厂开发顶棚件提供参考。     

汽车装饰用非织造布的现状及分析

本文探讨了与我国汽车工业飞速发展形势相适应的汽车内饰材料的发展状况。对传统汽车内饰材料及新型汽车内饰材料做了比较。同时,着重分析并阐述了纺粘法长丝非织造布,逢编法非织造布,针刺法非织造布及经膜压处理后的非织造布等几种汽车内饰用非织造布的生产原理、特性、应用现状以及发展前景。     

非织造布购物袋热黏合接缝强力的测试方法探讨

超声波热黏合的非织造布接缝不同于普通机织物和针织物等的车缝接缝。运用正交试验设计方法,对纺粘法PP非织造布购物袋热黏合接缝断裂强力测试中的试样宽度、拉伸速率和隔距三个因素进行优化。试验结果表明,试样宽度对纺粘法PP非织造布热黏合接缝断裂强力的测试结果影响最大,并且接缝的断裂强力随着试样宽度的增加而增加。选用试样宽度为200mm、拉伸速率为50mm/min、隔距为100mm的组合所得出的测试结果能比较真实地反映实际的接缝断裂强力。     

汽车工业中的非织造布

汽车中 ,从空气过滤器、模压制椅到顶棚布、行李箱衬垫和地毯 ,到处都能见到非织造布产品 ,可见非织造布在汽车工业中扮演着重要的角色。非织造布在汽车制造业中大约有 40种以上的用途 ,起着隔音、滤气、绝热、加固及保护的作用 ,同时也增强了乘客的舒适感和安全性。由于非织造布有较大的强度和经久耐用的性能 ,使得汽车制造公司将它作为理想的使用材料。非织造布在汽车领域的应用越来越广泛 ,各模压制品制造商为了分一杯羹 ,竞争不断升温 ,导致制造商们针对这一市场的研究和开发投入不断加大。“在近几年 ,根据汽车制造商的需求 ,已经使得…     

不同宽度非织造布试样力学性能研究

分析了对不同宽度的热轧,针刺非织造布试样的断裂强力进行的一系列试验研究,并就非织造布力学性能测试试验中所采用的拉伸试样宽度提出了相关建议。     

汽车工业中的非织造布

汽车中，从空气过滤器、模压制椅到顶棚布、行李箱衬垫和地毯，到处都能见到非织造布产品，可见非织造布在汽车工业中扮演着重要的角色。非织造布在汽车制造业中大约有40种以上的用途，起着隔音、滤气、绝热、加固及保护的作用，同时也增强了乘客的舒适感和安全性。由于非织造布有较大的强度和经久耐用的性能，使得汽车     

水刺非织造布和机织布涂层及应用性能研究

采用铜粉和石墨作复合导电填料、水分散型丙烯酸酯共聚乳液作粘合剂自制一种导电涂料,分析比较涂覆法制备导电屏蔽涤纶水刺非织造布和机织布的性能。结果表明：涂覆后两种织物的透气性、柔软性都下降,拉伸断裂强力增大而断裂伸长减小;涂料在两种织物上的粘附强力相差不大;涂覆后水刺非织造布的耐磨性能较好且导电屏蔽性能更好。     

聚丙烯SMS非织造手术衣材料热处理温度研究

研究了聚丙烯纺粘-熔喷-纺粘复合(SMS)非织造手术衣材料在热处理过程中,材料结晶结构与结晶度的变化规律,以及热处理温度对力学性能的影响,结果表明:热处理温度的变化不会改变非织造布的内部晶型结构,非织造布的结晶度随热处理温度的升高而增大,晶粒尺寸随热处理温度升高先增大后减小.随热处理温度的升高,纵横向断裂强力和断裂伸长均呈现出先减小后增大的趋势,为获得更完善的晶型以及稳定的力学性能,合适的后整理温度为110～130℃.     

非织造布购物袋接缝强力测试影响因素探讨

通过设定不同的试样宽度、拉伸速率和隔距尺寸测试纺粘法PP非织造布购物袋接缝强力。对测试结果进行分析得知,非织造布购物袋的接缝强力随着试样宽度的增加而线性增加,拉伸速率和隔距尺寸对接缝强力测试结果的影响不显著。     

低面密度PE/PP双组分纺粘非织造布的制备及其性能

为获得具有优异柔软度和透气性的卫生用纺粘非织造布,通过改变聚合物原料和工艺参数控制纺粘非织造布的纤维类型、纤维细度和面密度,制备不同纤维细度和面密度的单/双组分纺粘非织造布,研究面密度对纺粘非织造布性能的影响。结果表明：纺粘非织造布的断裂强力、断裂伸长率、厚度随面密度的增加而增加,不匀率、透气性、柔软度随面密度的增大而减小;同一面密度下,聚乙烯/聚丙烯(PE/PP)双组分纺粘非织造布的厚度、断裂伸长率、柔软度和透气性均优于聚丙烯(PP)纺粘非织造布,而断裂强力相对略低。低面密度(15 g/m²)PE/PP双组分纺粘非织造布的纤维原料细度为21.6μm,织物弯曲长度为1.28 cm,透气量为6 995.1 mm/s,其柔软度、透气性有显著提高,可用作一次性卫生用品包覆材料。     

Evaluation of a cocktail of three bacteriophages for the biocontrol of Salmonella of wastewater

Salmonella serovars are increasing in importance as significant pathogens of both human and animals. Although water and wastewater are treated to eliminate pathogenic microorganisms, they still play an important role in the transmission of Salmonella spp. In this study, bacteriophages infecting Salmonella spp. were isolated from wastewater and evaluated; for their potential to lyse environmental Salmonella strains in vitro at different MOIs and temperatures; and to control the wastewater bacterial community. Three distinct phages designated sww65, sww275, and sww297; as defined by plaque morphology, electron microscopy and host range; were obtained from wastewater. Challenge tests were performed at 37, and 30 °C with the infection of the Salmonella cultures with individual phage, a mixture of two phages, and cocktail of three phages at MOIs of 10⁰, 10², and 10⁴ PFU/CFU. At 30, and 37 °C, a cocktail of three phages reduced all of the Salmonella cultures tested. These results required a high multiplicity of infection. However, when infected with only one phage or a mixture of two phages at MOIs of 10⁰ or 10 ² PFU/CFU, an emergence of bacterial resistance was observed. The dynamic monitoring of wastewater enterobacterial community was conducted using Enterobacterial Repetitive Intergenic Consensus-PCR (ERIC-PCR). The number of bands decreased gradually with the use of individual phage or phage cocktails. Moreover, the dynamic monitoring of Salmonella community during wastewater treatment was performed using PCR detection of virulence gene invA. The results correlated with the ERIC-PCR fingerprints, and suggested that Salmonella community was affected by the phage treatment. Indeed, in wastewater, bacteriophages are reducing Salmonella and other members of the Enterobacteriaceae. These results indicated that dynamic changes are closely related with the process of treatment. The introduction of wide host range bacteriophages in wastewater can have a potential impact on the dynamics of the microbial communities, manifested by the reduction or the elimination of microbial species.     

Including Records of Daughters of Selected Bulls in Estimation of Sire Component of Variance

Methods to account for selection in estimation of variance components are computationally difficult and require inclusion of records on which selection was based. The last criterion often cannot be met. Within a time records of daughters in the small sample set for a bull should be relatively free of effects of selection. If only such records are used, many herd-year-season subclasses, however, contain only one record, so that those records are eliminated when herd-year-season effects are absorbed. Including records of daughters of few but heavily used and selected bulls would provide more comparisons within herd-year-seasons, but treating effects of such sires as random and unselected would bias estimates of variance components. Effects for proved sires can be treated as fixed and for sampling sires as random for estimation of sire and residual variances. For example. Method 3 estimates for an operational model including fixed herd-year-season effects (h), fixed effects of proved sires (s₁), and random effects of sampling sires (s₂) are:

${\stackrel{?}{\sigma }}_{\text{e}}^2=[\text{y}\prime \text{y}?\text{R}(\text{h},{\text{s}}_1,{\text{s}}_2)]/(\text{N}?\text{c})$

and

${\stackrel{?}{\sigma }}_{\text{s}}^2=[\text{R}({\text{s}}_2|\text{h},{\text{s}}_1)?(\text{r}?1){\stackrel{?}{\sigma }}_{\text{e}}^2]/\text{tr}(\text{Z}\prime \text{WZ})$

where y′y is total sum of squares, R( ) indicates a least squares reduction in sum of squares, N is number of records, c is rank of full coefficient matrix, r is rank, and tr(Z′WZ) is trace of coefficient matrix after absorption of effects of herd-year-seasons and proved sires.     

Characterization of germination of spores of Clostridium estertheticum,the primary causative agent of blown pack spoilage of vacuum packaged beef

The aim of this study was to investigate the effect of various factors on the germination of Clostridium estertheticum endospores (spores) in relation to beef. The effect of heat on germination was determined by recovering C. estertheticum on Columbia agar from spore suspensions not heated or heated at 63, 70 or 80 °C for various times. The effects of pH, temperature and oxygen were determined, by enumeration of remaining ungerminated spores during incubation in Meat Juice medium (MJM). Amino acids and lactate were tested for their ability to trigger germination of C. estertheticum spores by monitoring dipicolinic acid (DPA) release. Heat treatment of spores at 80 °C for ≤ 20 min significantly (p < 0.05) increased the numbers of spores recovered on blood agar. Neither incubation temperature nor oxygen affected germination in MJM. The optimal pH for germination was 7.0 to 7.5. Incubation with leucine or aspartic acid caused a 1.3% release of DPA, the highest among all amino acids tested. Incubation with lactate resulted in a 4.1% release of DPA, which was significantly (p < 0.05) higher than those from incubation with amino acids. The DPA release from incubation with lactate, lactate with amino acids, or MJM was similar (p > 0.05).     

Effect of Sources of Fibre on Performance of Growing Snail

The proximate and physicochemical properties of cassava leaf and peel meals were evaluated with a view to possible replacement of wheat offal which is the conventional source of fibre in animal feed, with these meals. The effect of feeds produced with cassava leaf and peel meals on the performance of growing snails was also investigated. Feeds (F1, F2 and F3) were formulated to contain 240, 235 and 230 g/kg cassava root meal each and 85, 85 and 90 g/kg cassava peel meal, wheat offal meal and cassava leaf meal respectively. The formulated feeds contain approximately 18.0% crude protein, 7.5% ash, 3% fat, 6.0% crude fibre 8%, calcium, 0.7% phosphorus, and energy level of 2400 kcal ME / kg. A total of 54 growing snails (Archachatina marginata) were used to investigate the nutritive potential of the formulated feeds on performance of growing snails for 15 weeks. Concentrations of the crude protein, crude fat, crude fibre, ash and calcium in cassava leaf meal were higher than those of wheat offal and cassava peel meal, with the exception of nitrogen free extract which was highest (70.01%) in cassava peel meal. Feed intake was 576 g 569 g and 581 g for snails fed with cassava leaf meal, cassava peel meal and wheat offal respectively but the corresponding weight gain ranged between 123.35 and 134.81 % being highest for F1. The feed conversion ratio shows that F1 > F3 > F2 indicating better conversion of feed to edible meat in F1. The results show that cassava leaves and peels have a strong potential to substitute the traditional wheat offal and can therefore be adapted as commercial feed ingredients.     

Occurrence of fumonisins and aflatoxins in cereals from markets of Hebei province of China

Fumonisins B₁, B₂ and B₃ (FB₁, FB₂ and FB₃) and aflatoxins B₁ (AFB₁), B₂ (AFB₂), G₁ (AFG₁) and G₂ (AFG₂) are both major mycotoxins of food concern, because of their wide range of concentration and possible co-occurrence. Therefore, a contamination survey in corn and wheat flour by liquid chromatography–tandem mass spectrometry was carried out. Quantification of fumonisins and aflatoxins was based on internal calibration (by the use of ¹³C₃₄-fumonisin) and external calibration, respectively. Fumonisins were detected in 95% of corn samples and in 7% of wheat flour samples, with the mean level (FB₁?+?FB₂?+?FB₃) of 441?µg?kg^?1 and 0.09?µg?kg^?1, respectively. Low levels of aflatoxins were detected in 37% of the samples with a mean level (B₁?+?B₂?+?G₁?+?G₂) of 0.12?µg?kg^?1. Fumonisins and aflatoxins were not detected in 29% of the samples analysed. Simultaneous occurrence of fumonisins and aflatoxins was observed in 12% of samples.     

Influence of type of muscles on nutritional value of foal meat

The effect of type of muscle on nutritional characteristic (fatty acid profile, amino acid content, cholesterol and major and minor mineral) of foal meat was investigated. Six muscles: longissimus dorsi (LD), semimembranosus (SM), semitendinosus (ST), biceps femoris (BF), triceps brachii (TB) and psoas major & minor (PM) from twelve foals slaughtered at 15 months from an extensive production system in freedom regimen were extracted for this study. Horse meat is characterized by low fat, low cholesterol content, rich in iron and in vitamin B. Statistical analysis showed that the cholesterol content did not show significant differences (P > 0.05) among muscle with mean value range between 0.62 and 0.57 mg/100 g. Most fatty acid presented significant differences (P < 0.05) with respect to the type of muscle. The obtained results showed that except for the polyunsaturated linoleic acid, the highest contents of fatty acids were found in the hindquarter muscles. Regarding amino acid profile, significant differences (P < 0.05) were observed among muscles and our results indicated that, 100 g of foal meat covered from 80.6 to 86.7% for the daily requirement for an adult man weighing 70 kg for essential amino acids for ST and LD muscles, respectively. Statistical analysis showed significant differences (P = 0.050) for the EAA (essential amino acids) index, which was highest for TB muscle, followed by BF and SM muscles, while the lowest values were reported by ST muscle. Finally, foal meat seems to be a very good nutritional source of major and minor minerals. The higher nutritional value of foal meat will be of great importance in the promotion of this meat.     

Effects of rapid chilling of carcasses and time of deboning on weight loss and technological quality of pork semimembranosus muscle

The effect of rapid air chilling of carcasses in the first 3 h of chilling at −31 °C (then at 2–4 °C, till 24 h post-mortem) and the possibility of earlier deboning (8 h post-mortem) after rapid air chilling, compared to conventional air chilling (at 2–4 °C, till 24 h post-mortem) on weight loss and technological quality (pH value, tenderness, drip loss, cooking loss and colour - L^*a^*b^* values) of pork M. semimembranosus was investigated. Under the rapid chilling conditions, weight loss was 0.8% at 8 h post-mortem and increased to 1.4% at 24 h post-mortem when weight loss was 2.0% under conventional chilling. Carcasses that were rapid chilled had significantly lower (P < 0.001) internal temperature in the deep leg at 4 (25.7 °C), 6 (13.0 °C), 8 (6.2 °C) and 24 h (3.8 °C) post-mortem compared to conventional chill treatment (32.7, 24.2, 19.1 and 5.1 °C, respectively). Rapid chilling reduced significantly (P < 0.05) the rate of pH value decline at 8 h (6.02) post-mortem in M. semimembranosus compared to conventional chill treatment (5.88). Compared to conventional chilling, in M. semimembranosus deboned in different time post-mortem, rapid chilling had a positive significant effect on drip loss (P < 0.05, muscles deboned 8 h post-mortem), cooking loss (P < 0.001) and incidence of pale colour (L^* value). Rapid chilling i.e. rapid chilling and earlier deboning had neither positive nor negative significant effects (P > 0.05) on other investigated technological quality parameters of M. semimembranosus (tenderness, a^* value and b^* value) compared to conventional chilling.     

Evaluation of rheological properties of date syrup

Rheological behavior of date syrup is an important factor affecting the efficiency of sugar production and refining processes such as boiling, crystallization, separation and pumping. A rotational viscometer was used to characterize the flow behavior of date syrup solution at four different temperatures (20 °C, 40 °C, 60 °C and 80 °C) and four concentrations (17, 24, 31 and 39 °Brix). The samples were subjected to a programmed shear rate increasing from 10 to 100 s⁻¹ in 2 min, held constant at 100 s⁻¹ for 10 min and linearly decreasing to 10 during 2 min. The power law model was fitted to shear stress vs. shear rate data to obtain the consistency coefficient (m) and the flow behavior index (n). Both m and n were sensitive to changes in temperature and concentration. The apparent viscosity increases with increasing concentration of date syrup and a decrease in temperature.     

Development Changes in Fine Structure of Starches of Several Endosperm Mutants of Maize

Distribution of components of maize starches from several endosperm mutants sampled at three stages of development were investigated by gel filtration after debranching by isoamylase. The waxy (wx) starches consisted of only amylopectin, and the distribution of components did not change during development. In other starches: normal, amylose-extender (ae), dull (du), sugary-1 (su₁) and sugary-2 (su₂) starches, amylose contents increased during the 20–35 days after pollination (DAP) period of development. The ae, du, su₁ and su₂ mutants produced high-amylose starches, while amylopectin of su₂ was normal type and those of ae, du and su₁ were novel type, and ae starches possessed longer average chain-lengths of amylopectin. Phytoglycogens were prepared from su₁ kernels during development and their characteristics were compared with those of su₁ starches. The characteristics of phytoglycogens did not change during the developmental phase studied and the average chain-lengths of phytoglycogens were shorter than those of amylopectin of su₁ starches at each stage of development.