棉酚的特性及在棉籽油生产中的工艺控制

棉酚是棉籽中色素腺体所含的一种黄色色素,其中游离棉酚具有毒性,长期食用游离棉酚超标的棉籽油对人体的神经、血管和部分器官均有毒害作用。棉酚在棉籽油的生产加工过程中有许多不利的影响。通过碱炼工艺,加水湿润蒸炒胚料、膨化浸出中水分控制等工艺都可有效降低油中的棉酚含量,从而提高棉籽油的精炼率。     

棉酚在棉籽油生产加工中解决方法

棉酚是棉籽中存在的一种天然色素,其中游离棉酚具有毒性,化学性质十分活波,在棉籽油的生产加工过程中对油脂和粕的品质都有一定的影响。通过采取湿润蒸炒、加稀碱液蒸炒、蒸炒料胚后膨化干燥处理、棉籽油碱炼等工序脱除棉酚,提高棉籽油和棉籽粕的使用价值。     

出口内涂罐包装的游离酚GC-MS法迁移分析

针对内涂环氧酚醛罐的出口食品包装产品,分析了国内外对材料中酚类等有害物迁移研究的差异.采用气相色谱质谱(GC-MS)技术,研究了内涂环氧酚醛罐中游离酚的定性定量分析检测,并通过模拟产品不同使用环境和条件,研究了游离酚向食品中的定向迁移特性.结果表明,所提方法不仅能检测出样品中的游离酚,背景干扰较少,还可对相应的游离酚化合物进行定性定量同步检测,且操作简单,灵敏度较高.该方法可为进一步补充和完善环氧酚醛内涂罐卫生标准的分析方法提供参考.     

鞋用纺织品中游离甲醛高效液相色谱法的运用与测定评价

本文首先针对当前鞋用纺织品甲醛检测中使用分光光度法检测存在的缺点与不足进行了研究,进而借鉴其他行业对甲醛进行检测的方法,对液相色谱法检测游离甲醛水平的原理进行了简要分析。重点通过实验的方式,研究了鞋用纺织品中游离甲醛应用高效液相色谱法进行检测的主要操作步骤,评价了本检测方法下检测游离甲醛数据的精确性,肯定了高效液相色谱法检测鞋用纺织品中游离甲醛含量的意义与价值,望引起业内人士的关注与重视。     

A new method for microcrack evaluation in concrete under compression

A method based on measurements of axial and transverse strains was developed for evaluation of the extent of microcracking in prismatic concrete specimens under uniaxial compression. The increase in the area of crack per unit cross-sectional area, which has the units of strain, was estimated from the transverse and axial strain measurements using a simple formula which involves the elastic Poisson’s ratio, determineda priori from the strain data.

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Resume On a mis au point une méthode de mesure des déformations axiales et transversales afin d’évaluer l’importance de la microfissuration dans des éprouvettes prismatiques de béton en compression uniaxiale. On a évalué l’accroissement dans l’aire de fissuration par unité de section transversale présentant une surface de déformation, d’après les mesures transversales et axiales de déformation en utilisant une formule simple qui comprend le coefficient de Poisson, déterminéa priori à partir des données de déformation.

     

A new particle method for simulation of incompressible free surface flow problems

A new Lagrangian particle method called the consistent particle method (CPM), which solves the Navier–Stokes equations in a semi‐implicit time stepping scheme, is proposed in this paper. Instead of using kernel function as in some particle methods, partial differential operators are approximated in a way consistent with Taylor series expansion. A boundary particle recognition method is applied to help define the changing liquid domain. The incompressibility condition of free surface particles is enforced by an adjustment scheme. With these improvements, the CPM is shown to be robust and accurate in long time simulation of free surface flow particularly for smooth pressure solution. Two types of free surface flow problems are presented to verify the CPM, that is, two‐dimensional dam break and liquid sloshing in a rectangular tank. In the dam break example, the CPM solutions of pressure and wave elevation are in good agreement with published experimental results. In addition, an experimental study of water sloshing in tank on a shake table was conducted to verify the CPM solutions. Copyright © 2011 John Wiley & Sons, Ltd.     

A new method of producing high strength oil palm shell lightweight concrete

This paper presents a new method to produce high strength lightweight aggregate concrete (HSLWAC) using an agricultural solid waste, namely oil palm shell (OPS). This method is based on crushing large old OPS. Crushed OPS are hard and have a strong physical bond with hydrated cement paste. The 28 and 56 days compressive strength achieved in this study were about 53 and 56 MPa, respectively. Furthermore, it was observed that it was possible to produce grade 30 OPS concrete without the addition of any cementitious materials. Compared to previous studies, significantly lower cement content was used to produce this grade of concrete. Unlike OPS concrete incorporating uncrushed OPS aggregate, this study found that there is a strong correlation between the short term and 28-day compressive strength.     

A new method for evaluation of stress intensities for interface cracks

A new method is presented for calculating the values of K_I and K_II in the elasticity solution at the tip of an interface crack. The method is based on an evaluation of the J-integral by the virtual crack extension method. Expressions for calculating K_I and K_II by using the displacements and the stiffness derivative of the finite element solution and asymptotic crack tip displacements are derived. The method is shown to produce very accurate solutions even with coarse element mesh.     

A new method of investigating the causes of blistering of metal in oil refining equipment

A new method of investigating the causes of blistering of metal in oil refining plant was developed. The method, which is based on making an artificial void (micro-collector) in steel and inducing segregation of hydrogen in this collector, may be used to study the blistering of metals as a result of hydrogen charging.     

A new method for the evaluation of stabilization index of polyacrylonitrile fibers

A new method for the evaluation of stabilization index (SI) using X-ray diffraction is described. The strongest diffraction peak from PAN fibers arises from the (100) plane whose intensity decreases gradually and markedly with the progress of stabilization, and complete stabilization results in the disappearance of the peak. The peak does not become superposed with others and its center hardly moves. This indicates that the SI can be characterized by intensity changes of the (100) peak. The feasibility of this was verified by elemental analysis and density measurements.     

基于价值工程的可适应性评价方法

可适应设计是为适应用户需求不断变化、降低资源消耗而提出的一种新的设计方法,对产品的可适应性进行评价是其关键技术之一.在分析可适应设计原则及实现途径的基础上,给出了一种基于价值工程的产品可适应性的评价方法.该方法将产品的资源消耗总量、产品性能以及用户的使用环境等因素综合考虑,将用户使用产品后获得的效益与在完成这一系列任务时所消耗的资源量的比值作为评价产品可适应性的指标.通过该方法,可以选择使用户在产品的全生命周期内资源消耗量最少的产品设计方案.最后,将该可适应性评价方法用于高效圆柱齿轮机床的设计中,验证了该方法的有效性.     

A new method to obtain Fourier transform infrared spectra free from water vapor disturbance

Infrared absorption bands due to water vapor in the mid-infrared regions often obscure important spectral features of the sample. Here, we provide a novel method to collect a qualified infrared spectrum without any water vapor interference. The scanning procedure for a single-beam spectrum of the sample is divided into two stages under an atmosphere with fluctuating humidity. In the first stage, the sample spectrum is measured with approximately the same number of scans as the background. If the absorbance of water vapor in the spectrum is positive (or negative) at the end of the first stage, then the relative humidity in the sample compartment of the spectrometer is changed by a dry (or wet) air blow at the start of the second stage while the measurement of the sample spectrum continues. After the relative humidity changes to a lower (or higher) level than that of the previously collected background spectrum, water vapor peaks will become smaller and smaller with the increase in scanning number during the second stage. When the interfering water lines disappear from the spectrum, the acquisition of a sample spectrum is terminated. In this way, water vapor interference can finally be removed completely.     

Preparation of purpurin-18 loaded magnetic nanocarriers in cottonseed oil for photodynamic therapy

Purpurin-18 loaded magnetic silica nanocarriers for photodynamic therapy (PDT) were prepared in cottonseed oil by W/O micro-emulsion method. The size of the nanocarriers was ranged from 20 to 30 nm obtained from transmission electron micrograph observation. The photodynamic drug purpurin-18 was successfully enwrapped in the nanocarriers characterized by ultraviolet–visible absorption and Fourier transform infrared spectroscopy spectra. The generation of singlet oxygen (¹O₂) was followed by N,N-dimethyl-4-nitrosoaniline (RNO) bleaching assay. The loss of RNO absorbance at 440 nm versus irradiation time displayed that purpurin-18 could play a role in normal.