Comparison of oxygen bomb method to other methods for measuring oxidative stability of peanuts and peanut products

The active oxygen method of the American Oil Chemists' Society has been used extensively to evaluate the oxidative stability of fats and oils. The AOM lacks versatility, however, in that it can be used for only a few products such as lard and vegetable oils. Experience in our laboratory has shown that results also can differ widely, even on the same sample. Recent work with the oxygen bomb at the National Peanut Research Laboratory has shown that it is both reliable and accurate when compared to other methods for measuring the oxidative stability of peanuts and peanut products. Results with the oxygen bomb were compared to the active oxygen method and iodine value of the peants.     

Synthesis and characterization of a PE-g-LCP copolymer

The possibility of reinforcing polyethylene (PE) by blending it with a liquid crystalline polymer (LCP) rests on the successful improvement of phase compatibility and interfacial adhesion of these two structurally unlike polymers. The approach that is being considered in our laboratories consists of the synthesis of PE–LCP block or graft copolymers and of their use as compatibilizing agents for PE/LCP blends. In this work, the melt polycon-densation of sebacic acid (S), 4,4′-dihydroxybiphenyl (B), and 4-hydroxybenzoic acid (H) has been carried out at temperatures up to 280°C in the presence of an oxidized low molar mass PE sample containing free carboxylic groups (PEox), with the main scope of demonstrating that a PE-g-LCP copolymer may be synthesized by this route. The polycon-densation product has been fractionated by successive extractions with boiling toluene and xylene. The soluble fractions and the residues have been characterized by IR and NMR spectroscopy, differential scanning calorimetry (DSC), thermogravimetric analysis (TG, DTG), and scanning electron microscopy (SEM). The extractions and the analyses have been repeated on a PEox/LCP blend prepared by melt mixing PEox and preformed LCP (SBH 112, by Eniricerche). The results show that, whereas for the blend a fairly clean separation of PEox and SBH can be obtained by solvent extraction, this is not so for the polycondensation product. All analytical procedures concordantly show that a PEox-g-SBH copolymer has, in fact, been obtained. In effect, both PEox and SBH chain segments are present, with different relative ratios, in all fractions of the polycondensate. Moreover, a fairly quantitative esterification of the PEox carboxyl groups has been shown by IR analysis to take place in the adopted conditions. Preliminary morphological investigations carried out by SEM have shown that the addition of the synthesized graft copolymer into HDPE/SBH blends leads to an improvement of the interfacial adhesion. © 1996 John Wiley & Sons, Inc.     

Dilatometric investigation of deformation mechanisms in polystyrene-polyethylene block copolymer blends: correlation between Poisson ratio and adhesion

To gain more insight into the deformation behaviour of blends containing polystyrene (PS), low density polyethylene(IdPE) and a PSPE block copolymer, tensile tests have been performed with simultaneous volume measurements. Assuming that shearing does not give rise to volume changes, it is shown that, after yielding, crazing is the only deformation mechanism of blends with a low PE and PSPE block copolymer content. Shearing becomes important at relatively high copolymer concentrations. This is explained by the formation of a semi-continuous low-modulus phase. The decrease of the Poisson ratio with PE content in PSPE blends, as opposed to an increase if some block copolymer has been added to these blends, shows that the Poisson ratio is very sensitive to adhesion between the components. Toughness of PSPE blends is discussed in terms of concentrations of craze nuclei. Too few craze nuclei give rise to brittle failure: the resulting low number of crazes cannot take over much of the deformation of the matrix. Too many craze nuclei cause brittle failure because chances are high that some of the high number of crazes formed will combine to produce a fatal crack. Therefore high toughness is only obtained at intermediate craze nuclei concentrations. The concentration of craze nuclei is shown to be dependent on the number of dispersed particles and the adhesion between these particles and the matrix.     

Influence of solid phase conductivity on spatial localization of electrochemical processes in flow-through porous electrodes: Part I: Electrodes with uniform conducting matrix

Mathematical simulation of the flow-through porous electrode (PE) operation on the basis of a one-dimensional model with a uniform conducting matrix and a cathodic process involving the main and side reactions (i.e., hydrogen evolution) has been made. The influence of current density and rate and direction of the solution flow on the depth of the main process penetration into the PE has been analysed for different relationships between phase conductivities. It has been shown that when the polarization curve of the side reaction is Tafelian, and the rate of solution circulation is high, there is a limit for the main process penetration into the PE. This limiting value is close to the thickness of the layer, Ld, capable of working at the limiting diffusion current obtained by Sioda's method. The dependence of the Ld layer thickness on phase conductivity has been analysed. In the limiting cases (low fractional conversion, high or identical phase conductivities) analytical expressions for Ld have been obtained. At low flow rates, the depth of the main process penetration increases up to the value of the entire thickness of the PE. It can be concluded that the possibility of increasing the PE efficiency for the uniform matrix by changing phase conductivities is limited.     

红外光谱法定性和定量分析聚烯烃中抗氧剂3114

研究了用红外光谱（IR）法定性和定量分析聚烯烃（聚乙烯、聚丙烯）中的抗氧剂3114的方法和准确度。分析了抗氧剂3114和PE、PP粉料的FTIR图,确定了抗氧剂3114在聚烯烃中的特征吸收峰为1695cm^-1,详细分析了不同含量抗氧剂3114的PE、PP样品的红外谱图和测试的准确度,同时根据抗氧剂3114的标准曲线可知,抗氧剂3114的含量与其特征峰的吸收强度呈良好的线性关系,相关系数达0．97以上,相对百分偏差最大为9．524％。表明红外光谱法可定性和定量分析聚乙烯、聚丙烯中的抗氧剂3114。     

Attaching Different Kinds of Proteinaceous Nanospheres to a Variety of Fabrics Using Ultrasound Radiation

The application of a rapid, non-destructive, cost-effective technique such as ultrasonic emulsification for the coating of different textiles was explored. The technical benefits for this research were the generation of multifunctional materials and their combinations through environmentally friendly processing technologies. We have shown for the first time that ultrasonic waves can be used to coat proteinaceous micro- and nanospheres (PM) of BSA (Bovine Serum Albumin) protein and casein on the surface of cotton and polyester (PE) fabrics. The creation and the anchoring of the microbubbles to the fabrics were performed by a one-step reaction, and the process is usually stopped after 3 min. The PM of bovine serum albumin (BSA) bonded to cotton and polyester fabrics has shown stability for ∼9 months. The PMs were shown to be attached more strongly to the polyester than to the cotton, and sustained stronger washing conditions on PE. The diameter of the BSA and the casein spheres on cotton was in the range of 0.8–1.0 μm, while on the PE it varied between 60 and 120 nm.     

小本体聚丙烯增韧研究

采用机械共混方法对小本体聚丙烯进行了增韧改性研究,探讨了增韧剂种类、含量以及有少量聚乙烯存在下对聚丙烯共混体系力学性能的影响,并与连续法聚丙烯进行了比较。实验结果表明,聚丙烯/增韧剂/聚乙烯三元共混体系可以获得理想的增韧效果。     

Ultrasonic Determination of the Cohesive Properties of Bonded Joints by Measurement of Reflection Coefficient and Bondline Transit Time

An ultrasonic nondestructive technique for the quantitative determination of the cohesive properties of adhesive joints based on the measurement of the reflection coefficient from the top adhesive/adherend interface and the bondline transit time has been developed. The method requires access to only one side of the joint and, for joints with typical aerospace geometries, it can be implemented using a single transducer with a centre frequency below 50 MHz. The technique has been used to determine the longitudinal bulk wave velocity in aluminium-epoxy-aluminium joints to within ±6% of the nominal values determined from bulk samples. The bondline thickness of the samples tested was evaluated to within micrometer accuracy, and thickness variations within the scan area were detected to much better than micrometer accuracy. The method has been tested successfully on joints made with two-part epoxies and with film adhesives containing a “scrim” carrier, and it has also been shown that the different standard adherend preparation procedures have a negligible effect on the results. The method, therefore, promises to provide a reliable, nondestructive means of measuring the cohesive properties of a bonded joint and represents a significant advance on the currently available technology.     

Ultrasonic Determination of the Cohesive Properties of Bonded Joints by Measurement of Reflection Coefficient and Bondline Transit Time

An ultrasonic nondestructive technique for the quantitative determination of the cohesive properties of adhesive joints based on the measurement of the reflection coefficient from the top adhesive/adherend interface and the bondline transit time has been developed. The method requires access to only one side of the joint and, for joints with typical aerospace geometries, it can be implemented using a single transducer with a centre frequency below 50 MHz. The technique has been used to determine the longitudinal bulk wave velocity in aluminium-epoxy-aluminium joints to within ±6% of the nominal values determined from bulk samples. The bondline thickness of the samples tested was evaluated to within micrometer accuracy, and thickness variations within the scan area were detected to much better than micrometer accuracy. The method has been tested successfully on joints made with two-part epoxies and with film adhesives containing a “scrim” carrier, and it has also been shown that the different standard adherend preparation procedures have a negligible effect on the results. The method, therefore, promises to provide a reliable, nondestructive means of measuring the cohesive properties of a bonded joint and represents a significant advance on the currently available technology.     

Nonlinear parameter estimation through particle swarm optimization

Parameter estimation procedures are very important in the chemical engineering field for development of mathematical models, since design, optimization and advanced control of chemical processes depend on model parameter values obtained from experimental data. Model nonlinearity makes the estimation of parameter and the statistical analysis of parameter estimates more difficult and more challenging. In this work, it is shown that many of these difficulties can be overcome with the use of heuristic optimization methods, such as the particle swarm optimization (PSO) method. Parameter estimation problems are solved here with PSO and it is shown that the PSO method is efficient for both minimization and construction of the confidence region of parameter estimates. Moreover, it is shown that the elliptical approximation of confidence regions of nonlinear model parameters can be very poor sometimes and that more accurate likelihood confidence regions can be constructed with PSO, allowing for more reliable statistical analysis of the significance of parameter estimates.     

Quantitative investigation of electromechanical coupling of potassium sodium niobate-based thin films

High-performance environment-friendly piezoelectric potassium sodium niobate (KNN)-based thin films have been emerged as promising lead-free candidates, while their substrate-dependent piezoelectricity faces the lack of high-quality information due to restraints in measurements. Although piezoresponse force microscopy (PFM) is a potential measuring tool, still its regular mode is not considered as a reliable characterization method for quantification. After combining machine-learning enabled analysis using PFM datasets, it is possible to measure piezoelectric properties quantitatively. Here we utilized advanced PFM technology empowered by machine learning to measure and compare the piezoelectricity of KNN based thin films on different substrates. The results provide a better understanding of the relationship between structures and piezoelectric properties of the thin films.     

Semiautomatic analysis of serum triglycerides and cholesteryl esters by infrared absorption

An instrument has been developed for the semiautomatic analysis of mixtures of triglycerides and cholesteryl esters. The method is based on high-resolution infrared spectrophotometry, and has previously been shown to be applicable to the determination of these components in the nonionic fraction of human serum lipids. A simple nonrecording grating spectrophotometer has been suitably modified to carry out this analysis; and appropriate computing circuitry has been coupled with it for performing the two-component calculation. The supplementary electronics consist of operational amplifiers, a logarithmic conversion circuit, a digital voltmeter, and a printer. Automatic operation is accomplished by a control mechanism, which programs the measurements, the steps in the calculations, and print-out of the results. Sample preparation consists of an extraction of lipids from serum in such a way as to exelude phospholipids. This may be done in a single step, although a two-step procedure—total lipid extraction followed by adsorption separation of the phospholipids—appears to be more reliable. Measurements are made on a solution of the neutral lipid fraction in carbon tetrachloride.     

Upcycling of polypropylene—the influence of polyethylene impurities

Long chain branching (LCB)—a well‐known industrial process—is shown as an innovative tool for the treatment of PP post‐consumer waste. The introduction of LCB by reactive extrusion does not only compensate the degradation during product life (e.g., thermally and UV‐induced chain scission), it also improves the melt properties (e.g., melt strength, strain hardening). Thus, not only a re‐cycling process, even a real “up‐cycling” can be achieved. Compared with virgin material, PP from post‐consumer waste contains impurities like other polyolefines (PE‐HD, PE‐LD, PE‐LLD, copolymers), the total removal is economically not viable. Hence, the focus of this work was the influence of PE‐HD on the LCB formation of PP. Based on model mixtures with virgin PP and 10% PE‐HD, it is shown that PE‐HD influences the mechanical properties and gel content of the chemically modified blend but has no detrimental effect on the improved melt properties. POLYM. ENG. SCI., 57:1374–1381, 2017. © 2017 Society of Plastics Engineers     

Evaluation of the homogenization properties of masterbatches

Appearance is a very important property for many different products, therefore it is important to investigate what types of parameters and processing conditions influence their appearance. The proper investigation of this property requires a reliable and repeatable measurement method. Recently, a novel evaluation method has been developed to evaluate the colour inhomogeneity of injection molded specimens. In this study, this novel inhomogeneity evaluation method was used to compare the homogenization properties of different masterbatches. It was shown using this technique that the homogenization properties of different masterbatch recipes can be evaluated and developed. The results of this method were validated by a group of trained technicians and their results were correlated with the inhomogeneity levels derived from the new method.     

基于压电陶瓷优化工艺的设计

压电陶瓷是将机械能与电能进行转化的关键材料,已经应用到了军事、医学、电子信息、汽车工业等多个领域,但是含铅陶瓷有危害性。。通过实验,结果发现铅含量对压电性能影响可以实现优化。这一研究对于国家环保材料的发展有一定的参考价值。     

Morphology development,melt linear viscoelastic properties and crystallinity of polylactide/polyethylene/organoclay blend nanocomposites

Polylactide/polyethylene blends (PLA/PE) and their nanocomposites were prepared via the melt blending process. The effects of organoclay, compatibilizer (PE‐g‐MA), and PE content on morphology, linear viscoelastic properties of the melt and cold crystallization of the samples have been studied. The Palierne model is applied to predict the rheological behavior of unfilled blends. It implies that there is a quantitative agreement between model and experimental data for low PE content blend. From WAXD and the rheological behavior, it is shown that organoclay exhibits a higher extent of intercalation and dispersion in PLA/PE/organoclay nanocomposite than in PLA/organoclay nanocomposite. The DSC results present that the addition of compatibilizer into blend nanocomposite increases cold crystallization temperature of PLA by about 3°C. This can be explained by the role of compatibilizer in transfer of a part of organoclay from PLA matrix to droplets resulting in increase of PLA chain mobility and, therefore, slightly greater cold crystallization temperature. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41300.     

聚乙烯管材应变硬化模量与裂纹扩展速率相关性研究

采用应变硬化试验和锥体试验分别得到不同聚乙烯100（PE100）管材试样的应变硬化模量和裂纹扩展速率,并对它们之间的相关性进行研究,以期验证应变硬化试验法评价PE管材耐慢速裂纹扩展性能的正确性。结果表明,锥体试验中PE管材试样的裂纹扩展程度随着试验时间的增加而增大;应变硬化试验和锥体试验对不同PE管材试样的耐慢速裂纹扩展性能评价结果完全相同,应变硬化试验法评价PE管材耐慢速裂纹扩展性能的正确性得到验证;应变硬化试验不仅误差较小,而且可以区分不同牌号PE100管材耐慢速裂纹扩展性能的细微差异,评价结果相对于锥体试验要更加可靠。     

The capacitance effect method of measuring moisture and salt content of concrete

A new electrical method called “capacitance effect” is described for determination of the degree of saturation and salt content of concrete. The method involves applying a constant electric field (voltage) between two embedded steel electrodes and measuring the resultant current at two frequencies, from which change in capacitance can be calculated. Small concrete specimens were used to develop and test the method. Statistical evaluation of the experimental data has shown that a good relationship exists between the degree of saturation and the capacitance effect. A less well defined relationship has been found to exist between salt content and the capacitance effect. The laboratory derived statistical predictive models of the degree of saturation have been applied to field measurements on a highway barrier wall. A comparison between the calculated degree of saturation and the actual degree of saturation obtained by chiseling samples from the highway barrier wall has shown that this new technique of measurement is reliable.     

Effect of viscosity in ternary polymer blends displaying partial wetting phenomena

Partial wetting in a ternary polymer blend is the thermodynamic state where all three phases meet at a three-phase line of contact. Pickering emulsions, where solid particles situate at the interface of two other phases is a classic example of this state. This paper studies the presence of partial wetting in PE/PP/PS and in PE/PP/PC ternary polymer blends and examines, in particular, the influence of polyethylene viscosity on PS droplet formation at the PE/PP interface. Quantitative analysis of PS droplet growth and coverage at the PE/PP interface during static annealing were obtained by image analysis. A new approach was established to estimate the co-continuous PE/PP coarsening rate and was found to be in agreement with previous studies. In this work it is shown that the polyethylene viscosity can be of significant importance in ternary partial wetting when the interfacial driving force for partial wetting is weak and viscosity directly affects the quantity and size of PS droplets at the interface during annealing. The equilibrium between droplet stability at the interface, as predicted by spreading theory, and the interfacial mobility generated by coarsening determines the PS droplet size and surface coverage at the PE/PP interface.A ternary PE/PP/PC system, which displays a strong partial wetting driving force, was also investigated. The morphology of the blend system studied demonstrated a clear dominance of partial wetting over complete wetting.     

聚乙烯及其复合管道安全检测与评价方法

聚乙烯及其复合管道广泛应用于油气输送、城市燃气等能源领域,其安全性至关重要。焊接接头的安全检测及评价是聚乙烯及其复合管道系统安全的关键技术。介绍了聚乙烯管道焊接接头的无损检测原理及方法、冷焊检测技术以及缺陷分类与失效模式三方面内容。对电熔和热熔焊接接头分别采用超声相控阵和耦合聚焦技术进行超声检测,并给出了缺陷剖切与检测结果的对比图。提出了物理概念清晰、工程应用方便的冷焊超声检测方法。将电熔接头中的缺陷分为熔合面缺陷、孔洞、结构畸变和过焊。分别对含不同类型和大小缺陷的电熔接头进行力学性能测试,发现电熔接头存在三种典型的失效模式,即沿电熔套筒壁贯穿裂纹失效、熔合面失效以及沿电阻丝所在平面贯穿裂纹失效。根据试验测试与理论分析结果,提出了相应的安全评定方法。所提出的方法,填补了国内外在聚乙烯管道安全检测与评价方法方面的技术空白,提高了燃气管道的本质安全性。