Affine-based registration of CT and MR modality images of human brain using multiresolution approaches: comparative study on genetic algorithm and particle swarm optimization

We present a non-linear 2-D/2-D affine registration technique for MR and CT modality images of section of human brain. Automatic registration is achieved by maximization of a similarity metric, which is the correlation function of two images. The proposed method has been implemented by choosing a realistic, practical transformation and optimization techniques. Correlation-based similarity metric should be maximal when two images are perfectly aligned. Since similarity metric is a non-convex function and contains many local optima, choice of search strategy for optimization is important in registration problem. Many optimization schemes are existing, most of which are local and require a starting point. In present study we have implemented genetic algorithm and particle swarm optimization technique to overcome this problem. A comparative study shows the superiority and robustness of swarm methodology over genetic approach.     

Performance Evaluation and Biodegradation Study of Polyvinyl Chloride Films with Castor Oil-based Plasticizer

In the present study, a renewable resource-based plasticizer was synthesized by the lipase-catalyzed esterification reaction of furfuryl alcohol (FA) and castor oil fatty acid (COFA). The resultant ester (FA-COFA ester) was used as secondary plasticizers to the polyvinyl chloride (PVC) films. The PVC films were formulated using the combination of a conventional plasticizer di-butyl phthalate (DBP) and FA-COFA ester as a secondary plasticizer at different concentrations. Films were characterized by X-ray diffraction analysis, scanning electron microscopy, thermal analysis, mechanical performance, and migration stability. A biodegradability study of the PVC films showed increased degradability with increasing concentration of the FA-COFA ester in the PVC film. The study showed that ester of FA and COFA could be a substitute of DBP by as much as 80% of the total plasticizer with improved elongation and tensile properties, and such a kind of sustainable resource-based PVC blend films could be used as a good packaging material with biodegradable property.     

A novel method for synthesis of α-Si3N4 nanowires by sol–gel route

Silicon nitride (Si₃ N₄) nanowires have been prepared by carbothermal reduction followed by the nitridation (CTRN) of silica gel containing ultrafine excess carbon obtained by the decomposition of dextrose over the temperature range of 1200–1350 °C. This innovative process involves repeated evacuation followed by purging of nitrogen gas so that the interconnected nanopores of the gel are filled with nitrogen gas prior to heat treatment. During heat treatment at higher temperatures, the presence of nitrogen gas in the nanopores of the gel starts the CTRN reaction simultaneously throughout the bulk of the gel, leading to the formation of Si₃ N₄ nanowires. The in situ generated ultrafine carbon obtained by the decomposition of dextrose decreases the partial pressure of oxygen in the system to stabilize the nanowires. The nanowires synthesized by this process are of ∼500 nm diameter and ∼0.2 mm length. The product was characterized by scanning electron microscope (SEM), energy dispersive x-ray analysis (EDX), x-ray diffraction (XRD) and infrared (IR) spectra.     

米糠油加工最新进展

米糠油中富含不皂化物,如维生素E、γ-谷维素、植物甾醇、植物多酚以及角鲨烯等微量成分。但因米糠油中游离脂肪酸（FFA）和丙酮不溶物含量高,导致其加工困难。近年来,为了获得高质量、低炼耗的米糠油,人们对其加工产生了浓厚的兴趣。综述了米糠油加工工艺,包括膜加工技术。     

Enzymatic interesterification of blends of castor oil and some oils rich in saturated fatty acids

Interesterification of castor oil blended with some oils rich in saturated fatty acids was done with the help of 1,3-specific lipase from Mucor miehei in order to alter its viscosity characteristics and adhesion properties by the introduction of saturated fatty acid molecules. The interesterification was done by an oil blend ratio of 50 : 50. 10% enzyme were used. Temperature was kept at 60 °C under 2—5 mm Hg pressure with constant stirring, and the reactions were carried out for 6 h. The products were filtered to remove the enzyme and then analyzed for slip point, specific gravity, and kinematic viscosity. The slip point of the interesterified products was found to be much lower than the parent blend and was in the range of 15—25 °C. Specific gravity and iodine value of the products were in comparison with the theoretical ones. A very large depression in kinematic viscosity was found with every interesterified product from original castor oil and also from the blends at three different temperatures.     

The kinetics of enzyme catalyzed synthesis of sterol ester

The production of sterol ester by transesterification of β‐sitosterol with fish oil (TAG) catalyzed by Thermomyces lanuginosus immobilized lipase enzyme with varied reaction parameters such as temperature, substrate molar ratio, concentration of enzyme to deduce the enzyme kinetics for the reaction was investigated. For this transesterification reaction, the kinetic model was derived by using Ping Pong Bi Bi Mechanism. The K_m value from the first plot containing fish oil as substrate was 1.31 ± 0.05, while K_m from the second plot containing β‐sitosterol as substrate was 1.01 ± 0.04; identical V_max (0.213 ± 0.06) values were obtained by keeping one of the substrate concentration constant and varying the other. Practical applications : Deduction of reaction kinetics is an important criterion to ascertain the viability of any chemical process. Enzymatic processes need special attention to set model reaction parameters which could help in optimization or design of the actual process. In the present study we have derived the enzyme kinetics for the production sterol ester, an important nutraceutical, and calculated its K_m and V_max values along with the Arhenius activation energy to establish the viability of the reaction.     

Multifunctional greener additives for lubricating oil

In an anticipation to produce biodegradable additives with multifunctional performance for a cost‐effective lubricant composition, copolymers are synthesized by incorporating rice bran oil, peanut oil, β‐pinene in the backbone of isodecyl acrylate through microwave irradiation method using AIBN (azobisisobutyronitrile) as radical initiator. The prepared polymers are characterized by spectral techniques (IR, NMR) and SEC‐GPC analysis, thermal stability was determined by thermogravimetric analysis. Performance of the polymers as antiwear (AW), pour point depressant (PPD), viscosity modifier/viscosity index improver (VII) in different mineral base oils (SN1 and SN2) were done by standard ASTM methods. Biodegradability test of the polymers was carried out by disk diffusion (DD) and soil burial test methods. The copolymers of rice bran oil showed better viscosity index values and AW property, whereas the copolymers of peanut oil found to be most effective as PPD. Copolymers with higher concentration of green units showed better performance as viscosity modifier, pour point depressant and AW performance along with excellent biodegradability. POLYM. ENG. SCI., 2017. © 2017 Society of Plastics Engineers     

Tb—Dy—Fe—M四元系超磁致伸缩材料的磁性

研究了Ｔｂ０．２７Ｄｙ０．７３Ｆｅｘ（ｘ＝１．８，１．９，２，２．１）三元系和Ｔｂ０．２７Ｄｙ０．７３Ｆｅ１．８Ｍ０．１（Ｍ＝Ｚｎ，Ｔｉ，Ａｌ，Ｃｒ）四元系超磁致伸缩材料的磁性。合金在氩气保护的真空电弧炉中熔炼，铸锭在１０００℃真空热处理７天，用法拉第磁秤测定居里温度，用ＬＤＪ９５００振动样品磁强计测磁化曲线，用电阻应变计测量磁致伸缩。Ｔｂ０．２７Ｄｙ０．７３Ｆｅｘ合金的居里温度在３５５～３７５℃范围内，加入Ｚｎ、Ｔｉ、Ａｌ和Ｃｒ降低合金的居里温度，加Ｃｒ增加合金的磁致伸缩，加Ａｌ增加合金在低磁场下的磁致伸缩，加Ｚｎ，Ｔｉ降低磁致伸缩。除加Ｃｒ外，热处理也能提高合金的磁致伸缩。     

碟状氧化锌气相生长及机理的研究

采用气相沉积法制备了碟状的氧化锌,并基于自催化的气-液-固机理及气-固机理结合温度及过饱和度等生长因素对碟状氧化锌的生长机理进行了研究,结果表明,较高的生长温度及适中的过饱和度被归结为碟状氧化锌形成的原因。     

Resonance parameters based analysis for metallic thickness optimization of a bimetallic plasmonic structure

Metallic film thickness optimization in mono- and bimetallic plasmonic structures has been carried out in order to determine the correct device parameters. Different resonance parameters, such as reflectivity, phase, field enhancement, and the complex amplitude reflectance Argand diagram (CARAD), have been investigated for the proposed optimization procedure. Comparison of mono- and bimetallic plasmonic structures has been carried out in the context of these resonance parameters with simultaneous angular and spectral interrogation. Differential phase analysis has also been performed and its application to sensing has been discussed along with a proposed interferometric set-up.