Soybean and castor oil based monomers: Synthesis and copolymerization with styrene

In this study, castor oil was alcoholyzed with both aliphatic alcohols, such as glycerol and pentaerythritol, and an aromatic alcohol, bisphenol A propoxylate. The resulting alcoholysis products were then malinated and cured in the presence of styrene. Soybean oil pentaerythritol glyceride maleates were also prepared for a direct comparison of the properties of the castor oil and soybean oil based resins. Castor oil was directly malinated as well to see the effect of the alcoholysis step on the properties of the castor oil based resins. The monomers synthesized were characterized by ¹H‐NMR spectroscopy, and the styrenated resin liquid properties, such as viscosity and surface energy values, were determined. The conversion of polymerization was determined using time resolved FTIR analysis for the styrenated soybean oil pentaerythritol glyceride maleates, castor oil maleates, and castor oil pentaerythritol glyceride maleates. The effect of monomer identity and styrene content on the conversion of polymerization was explored. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 2433–2447, 2006     

Kinetic of thermal degradation of poly(isobornyl methacrylate)

The kinetic of the thermal degradation of poly(isobornyl methacrylate) (PIBORNMA) was investigated by thermo gravimetric (TG) analysis at different heating rates. TG curves showed that the thermal decomposition of PIBORNMA occurred in one stage. The apparent activation energies of thermal decomposition of PIBORNMA was determined by Tang, Flynn-Wall-Ozawa (FWO), Kissenger–Akahira–Sunose (KAS) and Coats-Redfern methods and the values were 80.30, 84.69, 79.81 and 84.413 kJ/mol, respectively. The mechanism function and pre-exponential factor was determined by master plots method.     

Improved cache utilization and preconditioner efficiency through use of a space-filling curve mesh element- and vertex-reordering technique

Solving partial differential equations using finite element (FE) methods for unstructured meshes that contain billions of elements is computationally a very challenging task. While parallel implementations can deliver a solution in a reasonable amount of time, they suffer from low cache utilization due to unstructured data access patterns. In this work, we reorder the way the mesh vertices and elements are stored in memory using Hilbert space-filling curves to improve cache utilization in FE methods for unstructured meshes. This reordering technique enumerates the mesh elements such that parallel threads access shared vertices at different time intervals, reducing the time wasted waiting to acquire locks guarding atomic regions. Further, when the linear system resulting from the FE analysis is solved using the preconditioned conjugate gradient method, the performance of the block-Jacobi preconditioner also improves, as more nonzeros are present near the stiffness matrix diagonal. Our results show that our reordering reduces the L1 and L2 cache miss-rates in the stiffness matrix assembly step by about 50 and 10 %, respectively, on a single-core processor. We also reduce the number of iterations required to solve the linear system by about 5 %. Overall, our reordering reduces the time to assemble the stiffness matrix and to solve the linear system on a 4-socket, 48-core multi-processor by about 20 %.     

Utilization of trommel sieve waste as an additive in Portland cement production

Large quantities of industrial wastes form in boron industry in Turkey every year. These wastes have dual problems of disposal and health hazards. The wastes such as borax slime, tincal waste, concentration wastes and thromel sieve waste (TSW) contain impurities that accelerate the normal setting and hardening of building materials produced from them. In this study, it was aimed to stabilize TSW produced during manufacture of borax from tincal. The effects of TSW added on the mechanical properties of Portland cement prepared by adding TSW to clinker were investigated. The utilization of TSW in cement industry as an additive was tested and compared with other materials.     

当代潘天寿研究中的问题剖析

潘天寿作为中国20世纪绘画史上的一面旗帜,一直是当代中国画研究领域的热点,对于他的指墨画研究、艺术教育研究、篆刻画研究等方面的文章不下百篇,其中对潘先生的艺术成就、人格修养、思想观点等各方面做了全面的分析,但是对潘天寿的研究中还存在一些研究者对潘天寿研究欠缺、过多掺杂个人观点以及缺乏时代语境的问题值得我们关注。     

Development of intestinal alkaline sphingomyelinase in rat fetus and newborn rat

Sphingomyelin metabolism is a novel signal transduction pathway related to cell differentiation, proliferation, and apoptosis. Alkaline sphingomyelinase (alk-SMase) is specifically present in the intestinal tract of many species. The enzyme is important in digestion of dietary sphingomyelin. Milk is the ony exogenous source of sphingomyelin for an infant, and digestion of milk sphingomyelin may be important for development of intestinal mucosa. It is unknown whether alk-SMase is present before birth and whether it changes after birth and during the suckling period. We studied activities, expression, and distribution of alk-SMase in rat fetus and newborn. The changes of acid and neutral SMase as well as alkaline phosphatase were analyzed for comparison. Little activity of alk-SMase was identified up to gestation day 20, but increased 10 times during the following 2 d. After birth, the activity continused to increase during the following 4 wk. Western blot using IgY antibody against rat alk-SMase failed to identify the enzyme at gestation day 20 but clearly showed the protein at day 22. The distribution pattern of the enzyme along the intestinal tract in fetus was largely the same as in adult animals, but became more pronounced after birth. Short-term weaning had no effect on alk-SMase activity. The activities of acid and neutral SMase were high at gestation day 20 and decreased significantly before birth. The changes of alk-SMase also differed from those of alkaline phosphatase, another brush border enzyme. Thus, we conclude that alk-SMase is rapidly expressed during the last days of gestation and that the newborn rat acquires the ability to digest milk sphingomyelin early in life.     

高压下无规聚甲基丙烯酸甲酯的玻璃化转变

采用PVT～100分析仪测试了无规聚甲基丙烯酸甲酯(a-PMMA)在30～180℃，20～180MPa下的压力-体积-温度(PVT)曲线。与常压下玻璃化转变是某一点不同，高压下a-PMMA的玻璃化出现一个反常的转变区，并且随着压力增加，该转变区逐渐加宽。PVT实验后，a-PMMA的数均和重均摩尔质量均明显下降；由DSC测试的Tg和TGA测定的Td也明显降低，说明这一测试的复杂温度和压力历史对样品的结构有显著影响。     

The effect of moisture content and air-drying on spontaneous combustion characteristics of two Turkish lignites

The results of an experimental study aimed at evaluating the spontaneous combustion characteristics of two Turkish lignites moistured and air-dried at varying times are discussed. The spontaneous combustion characteristics of the coals were determined using Crossing Point Methods adapted to our laboratories conditions. The content of three predominant oxygen functional groups (carboxyl, hydroxyl, and carbonyl) of untreated, moisten and air-dried coal samples were also determined with wet chemical methods. The content of oxygen functional groups in moisten coal samples do not differ significantly that of untreated coal samples, for realized in vacuum desicator to moistured of coal samples. The liability of spontaneous combustion of the two coals was reduced when moisture content increased with increase in contacted time to water vapour. The moisten coal samples was dried in laboratory during 24 and 48 h time period. The concentration of oxygen contain functional groups of drying coal samples increased with increase of contact time with air and decrease of particle size. The liability of spontaneous combustion of the air-dried coal samples increased with increase of contacted time with air and with decrease of moisture content.     

Synthesis of oligo‐ortho‐azomethinephenol and its oligomer–metal complexes: Characterization and application as anti‐microbial agents

The oxidative polycondensation reaction conditions and optimum parameters of o‐phenylazomethinephenol (PAP) with oxygen (air) and NaOCl were determined in an aqueous alkaline solution at 60–98°C. The properties of oligo‐o‐phenylazomethinephenol (OPAP) were studied by chemical and spectra analyses. PAP was converted to dimers and trimers (25–60%) by oxidation in an aqueous alkaline medium. The number average molecular weight (M_n), mass average molecular weight (M_w), and polydispersity index (PDI) values were 1180 g mol^?1, 1930 g mol^?1, and 1.64, respectively. According to these values, 20–33% of PAP turned into OPAP. During the polycondensation reaction, a part of the azomethine (? CH?N? ) groups oxidized to carboxylic (? COOH) group. Thus, a water‐soluble fraction of OPAP was incorporated in the carboxylic (? COOH); (2–20%) group. Also, the structure and properties of oligomer–metal complexes of OPAP with Cu(II), Ni(II), Zn(II), and Co(II) were studied. Antimicrobial activites of the oligomer and its oligomer–metal complexes were tested against B. cereus, L. monocytogenes, B. megaterium, B. subtilis, E. coli, Str. thermophilus, M. smegmatis, B. brevis, E. aeroginesa, P. vulgaris, M. luteus, S. aureus, and B. jeoreseens. Also, according to differential thermal analysis and thermogravimetric analysis, OPAP and its oligomer–metal complexes were stable throughout to temperature and thermo‐oxidative decomposition. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 2004–2013, 2002     

华北煤田陷落柱区域成因探讨

综合分析了华北石炭二叠地层特点、岩溶陷落柱总体特征以及煤田岩溶陷落柱区域分布规律,运用区域古构造应力场发展演化史——中生代印支、燕山期受欧亚构造域板块挤压和太平洋板块俯冲影响,认为华北地区基本处于构造压应力状态,构造活动强烈,发育诸多造山带、隆起带和深大断裂带,新生代的喜山运动时期,印度洋板块与亚欧板块碰撞,同时,太平洋板块回弹,在中国大陆东部,华北地区压应力释放,处于构造张扭应力状态,形成了大量张性NNE走向正断层,提出岩溶陷落柱分两期发展,最终形成于新生界喜山运动时期,得出古构造应力场是岩溶陷落柱成因的主要控制因素.