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Sample records for chinese anti-fever cure

  1. Lipolysis and lipid oxidation during processing of Chinese traditional smoke-cured bacon.

    Science.gov (United States)

    Huang, Yechuan; Li, Hongjun; Huang, Tian; Li, Feng; Sun, Juan

    2014-04-15

    Lipolysis and lipid oxidation as well as the relationship between them during processing of Chinese traditional smoke-cured bacon were studied by evaluating the changes in physicochemical parameters, lipase and lipoxygenase (LOX) activities, lipid content, fatty acid composition, peroxide value (POV), and thiobarbituric acid reactive substances (TBARS). Besides phospholipids, triacylglycerols (TAG) were an important source of free fatty acids in bacon, resulting in an increase in free fatty acid content in the mid-late stage of processing, whilst phospholipids hydrolysed intensely in the early stage. Preferential lipolysis was observed for polyunsaturated fatty acids in phospholipids and for linoleic and palmitic acids in TAG. The lipolysis of TAG and phospholipids was independent and catalysed by acid lipase and phospholipase, respectively. ANOVA-partial least squares regression (APLSR) analysis showed that POV and TBARS were poorly related to LOX and closely associated with phospholipid degradation. Therefore, autoxidation may be the main cause of muscle lipid oxidation in smoke-cured bacon, which was promoted by phospholipid hydrolysis.

  2. 18C. Chinese Herbs Cured a Kidney Calculus—A Retrospective Case Report

    Science.gov (United States)

    2013-01-01

    Focus Areas: Integrative Approaches to Care Objective: Traditional Chinese medicine (TCM) is referred to as holistic or complementary and alternative medicine. Herbal remedy plays the main role of TCM. It has been widely used in preventive measures and treatment modalities for all stages of illness. Here is a retrospective case report about herb healing the kidney stone and improving type II diabetes and hypertension. Patient, Method and Result: A male, 46 years old, chief complaint: intermittent lumbago 6 years. The other symptoms were fatigue and slight thirst. He had been diagnosed with type II diabetes, hypertension of 2 years, and a small kidney stone (6 years). His blood pressure (BP) was between 140/85mmHg to 150/95mmHg; fasting plasma glucose was around 7mmol/L to 8 mmol/L. PE: BP 145/95 mmHg. Lab: 2hPG: 15.1mmol/L. Urinalysis: RBC: 5-6/HP, WBC: 2-4/ HP, GLU. Ultrasound: kidney stone, 0.3x 0.2 cm, at the inferior pole of the left kidney. This patient irregularly took Metformin, refused to control diet or use antihypertensives, but was open to using an herbal formula, 1 dose per day. After 1 year's treatment, his back pain, fatigue, and thirst gradually disappeared. BP was around130-120/85-75mmHg, 2h PG: 7.3mmol/L. FPG: 6mmol/L. Urinalysis: RBC: 0-2/HP, WBC: negative, Glu. Ultrasound: normal, no stone found. Discussion: Generally, there is no method to remove a small stone in the renal parenchyma. In this case, Chinese herbal tea achieved a dramatic curing result. At retrospective review after 8 years, no stone recurred. From the TCM theory, the stone is the result of heat congealing turbid dampness; the diabetes is Yin-deficient heat. The basic function of this formula is to tonify Qi and Yin, invigorate blood, clear heat, and resolve the stone. In conjunction with Metformin, the patient's diabetes and hypertension were improved. Conclusion: This Chinese herb formula dissolved the kidney stone and prevented a new stone from recurring. There is no obvious

  3. Searching for a Cure: The FDA's Regulatory Approach to Traditional Chinese Herbal Medicine

    OpenAIRE

    Kim, Anna L.

    1997-01-01

    I will begin this discussion by describing traditional Chinese medicine and how it compares to the Western medical tradition. Second, I will then examine why regulation is necessary given the impact of Chinese herbal medicine on American healthcare. Then, I will proceed to the problem of trying to fit a square peg into a round hole, namely, the issue of regulating Chinese herbal medicine under current statutory provisions. Fourth, I will analyze state and federal responses to alternative ther...

  4. 18C. Chinese Herbs Cured a Kidney Calculus—A Retrospective Case Report

    OpenAIRE

    Zhou, Xiaojing

    2013-01-01

    Focus Areas: Integrative Approaches to Care Objective: Traditional Chinese medicine (TCM) is referred to as holistic or complementary and alternative medicine. Herbal remedy plays the main role of TCM. It has been widely used in preventive measures and treatment modalities for all stages of illness. Here is a retrospective case report about herb healing the kidney stone and improving type II diabetes and hypertension. Patient, Method and Result: A male, 46 years old, chief complaint: intermit...

  5. Primary Study on the Volatile Flavor Compounds of Low-Salt Chinese Cured-Meat of Accelerated Maturtion%快速成熟低盐腊肉挥发性成分的初步研究

    Institute of Scientific and Technical Information of China (English)

    冯彩平; 刘美玉; 郑立红; 郭慧媛; 任发政

    2012-01-01

    To explore the volatile flavor compounds of low-salt Chinese cured-meat of accelerated maturation, lowsalt Chinese cured-meat was exposed under ultraviolet and O3 conditions to promote fat turning into flavor compounds. The volatile flavor compounds of traditional and low-salt Chinese cured-meat were analyaed using SPME-GC/MS. The result showed the amount of volatile flavor compounds of traditional Chinese cured-meat, low-salt Chinese cured-meat, low-salt Chinese cured-meat treated by ultraviolet, and low-salt one treated by O3 were 82, 85, 104, and 89, respectively. The treatment of active oxygen could change the volatile flavor compounds of low-salt Chinese cured-meat to some extent. The chief volatile flavor compounds were guaiacol, eugennol, palmitic acid, and oleic aid, etc. Which were similar with the chief flavor compounds of traditional Chinese cured-meat.%为了探明加快成熟后低盐腊肉挥发性成分的变化,采用紫外灯照射和O3发生器产生的活性氧促进低盐腊肉中脂肪快速氧化,用SPME-GC/MS对传统腊肉、低盐腊肉以及活性氧催熟的低盐腊肉样品的挥发性风味成分进行分析,结果表明,传统腊肉挥发性成分有82种,低盐腊肉挥发性成分有85种,经紫外灯照射处理的低盐腊肉有104种,经O3处理有89种.活性氧加快成熟的低盐腊肉风味成分有所改变,且形成一些新的风味物质,而主要呈味物质愈疮木酚、丁子香酚、棕榈酸、油酸等与传统腊肉一致.

  6. Cure SMA

    Science.gov (United States)

    ... SMA Europe and TREAT-NMD for Meeting with EMA Regulators Cure SMA will be participating in a one-day workshop with The European Medicines Agency (EMA—the European equivalent of the FDA), SMA... READ ...

  7. Curing Effects of Aqueous Extracts from Traditional Chinese Medicines on Yeast Prion [ PSI ^+]%中药水提物对酵母朊病毒[PSI^+]的治愈作用

    Institute of Scientific and Technical Information of China (English)

    钟正伟; 王冠蕾; 谢辉

    2012-01-01

    This paper aims to screen traditional Chinese medicines that could cure yeast prion [PSI^+] and provide foundations for developing anti-prion traditional Chinese medicines preparations. The serial two-fold dilutions method was used to determine the minimum inhibitory concentrations (MIC) of aqueous extracts from 18 traditional Chinese medicines for Saccharomyces cerevisiae, and the curing effects of these aqueous extracts on yeast prion [ PSI^+ ] were investigated by liquid culture method. The results showed that the aqueous extracts from Bletilla Striata and Schisandra Chinensis were active in curing yeast prion [ PSI^+ ] with a concentration of 125 mg/mL. After a 5- day treating with these two aqueous extracts, the curing rates of [ PSI^+ ] cells were 67.5% and 33. 2% respectively.%筛选能够治愈酵母朊病毒[PSI^+]的中药,为开发抗朊病毒中药制剂提供依据。采用试管二倍稀释法测定18种中药水提物的最小抑菌浓度,液体治愈法研究中药水提物对酵母朊病毒[PSI^+]的治愈作用。结果表明:白芨、五味子水提物质量浓度为125mg/mL时,对酵母朊病毒[PSI^+]均有治愈作用,同时,白芨、五味子水提物作用酵母朊病毒[PSI^+]5d的治愈率分别为67.5%和33.2%。

  8. Advance of the Prevention and the Cure of Mastit ies of Dairy Cow with Chinese Medicinal Herbs%中草药防制奶牛乳房炎的研究进展

    Institute of Scientific and Technical Information of China (English)

    付秀花; 王恬

    2001-01-01

    The mastities of dairy cow is one of the most com mon diseases that cause great economic loss in dairy production.The pa thogeny,th e influencing factors,and the methods of prevention and cure of the d isease were stated.Several problems in the traditional treatment,especially,the preven tion a nd cure of the mastities of dairy cow with Chinese medicinal herbs w ere demonstrated in this paper.%奶牛乳房炎是危害奶牛养殖业最常见的疾病之一,给 奶牛生产造成巨大的经济损失。文章对乳房炎的发病原因、影响因素、防治现状进行了分析 ,并对传统治疗方法中存在的一些问题,尤其是应用中草药防制奶牛乳房炎展开综述。

  9. Optimal Composite Curing System

    Science.gov (United States)

    Handel, Paul; Guerin, Daniel

    The Optimal Composite Curing System (OCCS) is an intelligent control system which incorporates heat transfer and resin kinetic models coupled with expert knowledge. It controls the curing of epoxy impregnated composites, preventing part overheating while maintaining maximum cure heatup rate. This results in a significant reduction in total cure time over standard methods. The system uses a cure process model, operating in real-time, to determine optimal cure profiles for tool/part configurations of varying thermal characteristics. These profiles indicate the heating and cooling necessary to insure a complete cure of each part in the autoclave in the minimum amount of time. The system coordinates these profiles to determine an optimal cure profile for a batch of thermally variant parts. Using process specified rules for proper autoclave operation, OCCS automatically controls the cure process, implementing the prescribed cure while monitoring the operation of the autoclave equipment.

  10. Meta Analysis on Chinese Patent Medicine in Prevention and Cure of Hepatic Lesion Caused by Anti-tuberculosis Drugs%中医成方防治抗结核药物致肝损害的Meta分析

    Institute of Scientific and Technical Information of China (English)

    魏华

    2012-01-01

    目的:系统评价中医成方防治抗结核药致肝损害的疗效和安全性.方法:电子检索2000年1月到2011年7月的Medline、Embase、Cochrane library、中国生物医学光盘数据库,万方、维普数据库,并手工检索相关文献,纳入治疗组为中医成方,对照组为常规保肝治疗,逐个对其进行质量评价和资料提取,用RevMan 4.2软件进行Meta分析.结果:最终纳入6个半随机对照试验,共372例患者,纳入研究质量均为C级.中医成方组肝功正常率优于常规l保肝治疗(P<0.01,OR-13.50,95%CI 6.89~26.46);未发现严重不良反应.结论:中医成方防治肝损害效果优于常规保肝治疗,且无明显不良反应.但由于纳入研究的方法学质量较低、观察时间较短,且存在中西医结合诊断不标准、中药使用不规范等问题,可能影响评价结果,尚需更多高质量、长周期、中西医结合规范化研究以系统评价其疗效.%Objective: To evaluate systemically the efficacy and safety of Chinese patent medicine in prevention and cure hepatic lesion caused by anti-tuberculosis drugs. Method :Medline, Embase, Cochrane Library, CBM, VIP and WanFang data from 2000 to May, 2011 were searched online and the literatures published or not were manually retrieved. The papers on Chinese patent medicine were divided into treatment group while routine treatment were in control group, all were undergoing the quality analysis and information extraction. RevMan 4.2 was used for data analysis. Finally six Quasi-randomized control trials involving 372 patients were recruited. Methodological qualities were all graded C. Result: After 1-6 months' treatment, normal rate of liver function in Chinese patent medicine group were higher than in routine treatment (P <0.01, OR=13.50, 95% CI 6.89-26.46) without serious side effects. Conclusion: Chinese patent medicine is better than routine treatment in prevention and cure hepatic lesion caused by anti-tuberculosis drugs

  11. Curing Behavior of Epoxy Asphalt

    Institute of Scientific and Technical Information of China (English)

    YU Jianying; CONG Peiliang; WU Shaopeng; CHENG Songbo

    2009-01-01

    The curing process of epoxy asphalt was analyzed by Fourier transform infrared (FT-IR)spectroscopy.Effect of curing temperature on viscosity of epoxy asphalt,and changes of mechanical properties with curing time were investigated.The evolution of concentration of epoxy band was followed as a function of the applied curing process.The experimental results indicate that the curing reaction rate of epoxy asphalt is invariable before 70 min at 120℃,and it decreases when curing time exceeds 70 min.The viscosity of epoxy asphalt increases slowly with curing time at initial curing stage.But it increases quickly after initial curing stage and the initial curing time decreases as the curing temperature increases.The tensile strength increases slowly at incipient curing stage and increases rapidly when curing time is form 20 min to 70 min.The elongation at break shows a decrease with curing time,but it exceeds 200%after cured.

  12. Radiation curing of epoxies

    Science.gov (United States)

    Dickson, Lawrence W.; Singh, Ajit

    The literature on radiation polymerization of epoxy compounds has been reviewed to assess the potential use of radiation for curing these industrially important monomers. Chemical curing of epoxies may proceed by either cationic or anionic mechanisms depending on the nature of the curing agent, but most epoxies polymerize by cationic mechanisms under the influence of high-energy radiation. Radiation-induced cationic polymerization of epoxy compounds is inhibited by trace quantities of water because of proton transfer from the chain-propagating epoxy cation to water. Several different methods with potential for obtaining high molecular weight polymers by curing epoxies with high-energy radiation have been studied. Polymeric products with epoxy-like properties have been produced by radiation curing of epoxy oligomers with terminal acrylate groups and mixtures of epoxies with vinyl monomers. Both of these types of resin have good potential for industrial-scale curing by radiation treatment.

  13. The Curing Meter

    DEFF Research Database (Denmark)

    Jensen, Ole Mejlhede

    2006-01-01

    Curing technology concerns adjustment and control of temperature and moisture conditions in hardening structures and elements of concrete. The curing technology comprises e.g. measurement, adjustment and control of the moisture conditions during the early hardening phase of the concrete to achiev...... from concrete surfaces in the early hardening phase. The Concrete Curing Meter is designed for simple and reliable monitoring of water loss from a wet surface of fresh concrete. This new measuring technique has been tested with several prototypes of the Curing Meter.......Curing technology concerns adjustment and control of temperature and moisture conditions in hardening structures and elements of concrete. The curing technology comprises e.g. measurement, adjustment and control of the moisture conditions during the early hardening phase of the concrete to achieve...... an optimal development of properties in the hardening concrete – so-called "moisture curing". Proper moisture curing is vital to concrete but laborious to accomplish and difficult to control at the construction site with present methods. This paper concerns a new method for site measurement of evaporation...

  14. C-CURE

    Data.gov (United States)

    US Agency for International Development — C-CURE system manages certain aspects of the access control system, including collecting employee and contractor names and photographs. The Office of Security uses...

  15. Radiation curing in the eighties

    Energy Technology Data Exchange (ETDEWEB)

    Vrancken, A. (UCB, Drogenbos (Belgium). Chemical Specialities Div.)

    1984-05-01

    The subject is discussed under the headings: introduction; what is radiation curing; history; radiation curable resins (with properties of products); ultraviolet and electron beam curing; photoinitiation and the ultraviolet light curing process; electron beam curing (initiation; electron beam accelerators); end uses (graphic arts; wood finishing; paper upgrading; adhesives; metal finishing; electronic chemical; floor coatings).

  16. Dual cure photocatalyst systems

    Energy Technology Data Exchange (ETDEWEB)

    DeVoe, R.J.; Brown-Wensley, K.A.; Holmes, G.L.; Mathis, M.D.; McCormick, F.B.; Palazzotto, M.C.; Spurgeon, K.M. (Minnesota Mining and Mfg. Co., St. Paul, MN (USA). Corporate Research Labs.)

    1990-01-01

    A family of dual cure photocatalyst systems is being developed to be used in the solventless processing of organic coatings. The photocatalyst systems consist of organometallic compounds often in combination with other agents. Upon photolysis, the photocatalyst system generates a Lewis acid and a free radical. The Lewis acid can initiate the polymerization of epoxies or the addition of isocyanates and polyols to form polyurethanes while the free radical can initiate the polymerization of acrylates. The performance of the various photocatalyst systems will be compared on the basis of the physical properties of the cured compositions they produce. 17 figs.

  17. Curing the queue

    NARCIS (Netherlands)

    Zonderland, Maartje Elisabeth

    2012-01-01

    In this dissertation we study several problems related to the management of healthcare and the cure of disease. In each chapter a hospital capacity distribution problem is analyzed using techniques from operations research, also known as mathematical decision theory. The problems considered are insp

  18. Modeling HIV Cure

    Science.gov (United States)

    Perelson, Alan; Conway, Jessica; Cao, Youfang

    A large effort is being made to find a means to cure HIV infection. I will present a dynamical model of post-treatment control (PTC) or ``functional cure'' of HIV-infection. Some patients treated with suppressive antiviral therapy have been taken off of therapy and then spontaneously control HIV infection such that the amount of virus in the circulation is maintained undetectable by clinical assays for years. The model explains PTC occurring in some patients by having a parameter regime in which the model exhibits bistability, with both a low and high steady state viral load being stable. The model makes a number of predictions about how to attain the low PTC steady state. Bistability in this model depends upon the immune response becoming exhausted when over stimulated. I will also present a generalization of the model in which immunotherapy can be used to reverse immune exhaustion and compare model predictions with experiments in SIV infected macaques given immunotherapy and then taken off of antiretroviral therapy. Lastly, if time permits, I will discuss one of the hurdles to true HIV eradication, latently infected cells, and present clinical trial data and a new model addressing pharmacological means of flushing out the latent reservoir. Supported by NIH Grants AI028433 and OD011095.

  19. Controversies in HIV cure research

    Directory of Open Access Journals (Sweden)

    Johnston Rowena

    2012-03-01

    Full Text Available Abstract Background Antiretroviral therapy significantly reduces HIV viral burden and prolongs life, but does not cure HIV infection. The major scientific barrier to a cure is thought to be the persistence of the virus in cellular and/or anatomical reservoirs. Discussion Most efforts to date, including pharmaco, immuno or gene therapy, have failed to cure patients, with the notable exception of a stem cell transplant recipient commonly known as the Berlin patient. This case has revived interest in the potential to cure HIV infection and has highlighted the need to resolve critical questions in the basic, pre-clinical and clinical research spheres as they pertain specifically to efforts to eradicate HIV from the body of an infected person (a sterilizing cure or at least render the need for lifelong antiretroviral therapy obsolete (functional cure. This paper describes ongoing debates in each of these research spheres as they were presented and discussed at a satellite session that took place at the 6th International AIDS Society Conference on HIV Pathogenesis, Treatment and Prevention in Rome in July 2011. Summary The resolution of these debates may have important implications for the search for a cure, the most efficient ways to identify and test promising interventions, and ultimately the availability of such a cure to diverse groups of HIV patients around the world.

  20. 对治疗糖尿病的传统中药中生命元素含量测定初步研究%Content Determination of Life Elements in Traditional Chinese Medicine to Cure Diabetes

    Institute of Scientific and Technical Information of China (English)

    郭玲玲; 吴红艳; 关艳丽; 李鑫; 宗玉丽; 孟双; 孙玉禄; 孙丽梅; 于广峰

    2011-01-01

    The contents of some elements such as zinc, magnesium, iron, copper, chromium, selenium in several Chinese medicines most in use to treat diabetes were determined with atomic absorption spectrophotometry.The results showed that these selected Chinese medicines for treating diabetes were rich of life elements in content that closely related to the ailment, and the determined contents of the elements assumed a negative reciprocity with those within the body of diabetes patients.These provided certain information and theoretical foundation to explore the effective mechanism and the preparation technology of Chinese medicine.It may also serve as reference for the treatment of diabetic patients.%利用原子吸收分光光度法对几味治疗糖尿病的常用中药进行锌、镁、铁、铜、铬、硒元素的含量测定.结果表明,实验选取的中药中与糖尿病关系密切的生命元素含量较丰富,且所测元素含量与糖尿病患者体内其含量呈负相关性.为探讨中药的作用机理、中药配制工艺提供一定的信息和理论依据,对于糖尿病患者治疗具有参考价值.

  1. CURING EFFICIENCY OF DUAL-CURE RESIN CEMENT UNDER ZIRCONIA WITH TWO DIFFERENT LIGHT CURING UNITS

    Directory of Open Access Journals (Sweden)

    Pınar GÜLTEKİN

    2015-04-01

    Full Text Available Purpose: Adequate polymerization is a crucial factor in obtaining optimal physical properties and a satisfying clinical performance from composite resin materials. The aim of this study was to evaluate the polymerization efficiency of dual-cure resin cement cured with two different light curing units under zirconia structures having differing thicknesses. Materials and Methods: 4 zirconia discs framework in 4 mm diameter and in 0.5 mm, 1 mm and 1.5 mm thickness were prepared using computer-aided design system. One of the 0.5 mm-thick substructures was left as mono-layered whereas others were layered with feldspathic porcelain of same thickness and ceramic samples with 4 different thicknesses (0.5, 1, 1.5 and 2.0 mm were prepared. For each group (n=12 resin cement was light cured in polytetrafluoroethylene molds using Light Emitting Diode (LED or Quartz-Tungsten Halogen (QHT light curing units under each of 4 zirconia based discs (n=96. The values of depth of cure (in mm and the Vickers Hardness Number values (VHN were evaluated for each specimen. Results: The use of LED curing unit produced a greater depth of cure compared to QTH under ceramic discs with 0.5 and 1 mm thickness (p<0.05.At 100μm and 300 μm depth, the LED unit produced significantly greater VHN values compared to the QTH unit (p<0.05. At 500 μm depth, the difference between the VHN values of LED and QTH groups were not statistically significant. Conclusion: Light curing may not result in adequate resin cement polymerization under thick zirconia structures. LED light sources should be preferred over QTH for curing dual-cure resin cements, especially for those under thicker zirconia restorations.

  2. Novel techniques for concrete curing

    DEFF Research Database (Denmark)

    Kovler, Konstantin; Jensen, Ole Mejlhede

    2005-01-01

    It is known that some high-strength/high-performance concretes (HSC/HPC) are prone to cracking at an early age unless special precautions are taken. The paper deals with the methods of curing as one of the main strategies to ensure good performance of concrete. Curing by both external (conventional......) and internal methods is reviewed and analyzed, among other methods of mitigating shrinkage and cracking of concrete. The focus is on the mitigation of autogenous shrinkage of low water to binder ratio (w/b) concrete by means of internal curing. The concepts of internal curing are based on using lightweight...... aggregate, superabsorbent polymers or water-soluble chemicals, which reduce water evaporation (so called "internal sealing"). These concepts have been intensively researched in the 90s, but still are not widespread among contractors and concrete suppliers. The differences between conventional methods...

  3. Correlation of cure monitoring techniques

    Science.gov (United States)

    Chang, S. S.; Mopsik, F. I.; Hunston, D. L.

    Six different composite matrix or neat resin cure-monitoring methods are presently used to follow the cure process in a model epoxy system, and the results obtained are compared. Differential scanning calorimetry, viscosity monitoring, the ultrasonic shear wave propagation technique, dielectric spectrometry, and two different fluorescence intensity techniques are compared with a view to common traits and differences. Dielectric fluorescence and ultrasonic measurement techniques are noted to be applicable to on-line process monitoring.

  4. 从气血水探讨中医药治疗慢性心力衰竭%To Cure Chronic Heart Failure by Qi Blood Water Theory of Chinese Medicine

    Institute of Scientific and Technical Information of China (English)

    郑国玉; 张明

    2011-01-01

    心力衰竭(简称心衰)是各种心脏疾病终末阶段的复杂临床综合征,5年存活率与恶性肿瘤相仿,正成为21世纪最重要的心血管疾病.慢性心衰严重影响病人的生活质量,同时也给国家和家庭带来沉重的经济负担.日本汉方医家吉益南涯继承家父衣钵,深研仲景著作,提出气血水理论,丰富和发展了中医辨证论治.为此,文章借鉴气血水理论,探讨中医药防治慢性心衰,发挥中医药特色,为人类健康做出贡献.%Heart failure (CHF)is the end stage of various heart diseases, the complex clinical syndrome similar to 5-year survival and cancer are the most important 21st century, cardiovascular disease.Heart failure not only seriously affects patients of quality life, but also results of a heavy economic burden for family and government. Japan Medicine, south career, inherit the mantle of his father, and deeply research of treatise on exogenous febrile diseases, put forward theory of blood water, enriched and developed the syndrome differentiation. Therefore, this article draw blood water theory of Chinese traditional medicine chronic heart failure, and play characteristics of Chinese traditional medicine, to contribute to human health.

  5. Curing units' ability to cure restorative composites and dual-cured composite cements under composite overlay.

    Science.gov (United States)

    Park, Sung-Ho; Kim, Su-Sun; Cho, Yong-Sik; Lee, Chang-Kyu; Noh, Byng-Duk

    2004-01-01

    This study compared the efficacy of using conventional low-power density QTH (LQTH) units, high-power density QTH (HQTH) units, argon (Ar) laser and Plasma arc curing (PAC) units for curing dual-cured resin cements and restorative resin composites under a pre-cured resin composite overlay. The microhardness of the two types of restorative resins (Z100 and Tetric Ceram) and a dual-cured resin cement (Variolink II) were measured after they were light cured for 60 seconds in a 2 mm Teflon mold. The recorded microhardness was determined to be the optimum microhard-ness (OM). Either one of the two types of restorative resins (Z100, Tetric Ceram) or the dual cured resin cement (Variolink II) were placed under a 1.5-mm thick and 8 mm diameter pre-cured Targis (Vivadent/Ivoclar AG, Schaan, Liechtenstein) overlay. The specimens that were prepared for each material were divided into four groups depending upon the curing units used (HQTH, PAC, Laser or LQTH) and were further subdi-vided into subgroups according to light curing time. The curing times used were 30, 60, 90 and 120 seconds for HQTH; 12, 24, 36 and 48 seconds for the PAC unit; 15, 30, 45 and 60 for the Laser and 60, 120 or 180 seconds for the LQTH unit. Fifteen specimens were assigned to each sub- group. The microhardness of the upper and and lower composite surfaces under the Targis overlay were measured using an Optidur Vickers hardness-measuring instrument (Göttfert Feinwerktechnik GmbH, Buchen, Germany). In each material, for each group, a three-way ANOVA with Tukey was used at the 0.05 level of significance to compare the microhardnesses of the upper and lower composite surfaces and the previously measured OM of the material. From the OM of each material, 80% OM was calculated and the time required for the microhardness of the upper and lower surface of the specimen to reach 100% and 80% of OM was determined. In Z100 and Tetric Ceram, when the composites were light cured for 120 seconds using the HQTH lamp

  6. Cold-Curing Structural Epoxy Resins: Analysis of the Curing Reaction as a Function of Curing Time and Thickness

    Directory of Open Access Journals (Sweden)

    Carola Esposito Corcione

    2014-09-01

    Full Text Available The curing reaction of a commercial cold-curing structural epoxy resin, specifically formulated for civil engineering applications, was analyzed by thermal analysis as a function of the curing time and the sample thickness. Original and remarkable results regarding the effects of curing time on the glass transition temperature and on the residual heat of reaction of the cold-cured epoxy were obtained. The influence of the sample thickness on the curing reaction of the cold-cured resin was also deeply investigated. A highly exothermal reaction, based on a self-activated frontal polymerization reaction, was supposed and verified trough a suitable temperature signal acquisition system, specifically realized for this measurement. This is one of the first studies carried out on the curing behavior of these peculiar cold-cured epoxy resins as a function of curing time and thickness.

  7. Curing efficiency of various types of light-curing units.

    Science.gov (United States)

    Rahiotis, Chris; Kakaboura, Afrodite; Loukidis, Michalis; Vougiouklakis, George

    2004-02-01

    This study compared monomer conversion (DC), the per cent linear polymerization shrinkage (%LS), the wall-to-wall contraction pattern (per cent of peripheral opening, %DM, and maximal marginal gap, MG) and depth of cure (DOC), of a hybrid resin composite (Spectrum TPH) exposed to different types of light-curing units and exposure modes (Virtuoso-PAC, Elipar TriLight-QTH, and FreeLight-LED). The QTH and LED units were used in two curing modes: the exponential ramp and the continuous output modes. Monomer conversion was investigated by micro Multiple Internal Reflection (MIR)-Fourier-transform infrared (FTIR) spectroscopy and %LS was measured by the deflective disc method. The wall-to-wall contraction method used a cylindrical cavity model in extracted human teeth. The per cent debonded margins relative to the cavity periphery (%DM) and the width of maximum gap (MG) was evaluated. The DOC was determined using Vickers microhardness measurements (200 g load, 20 s) at the top surface (H0), at 2 mm (H2) and at 4 mm (H4) depths, and the results expressed as H2/H0 and H4/H0 ratios. Significantly lower %DC and %LS values were provided by PAC and LED units. No differences were found in %DM among the curing units and PAC exhibited the highest MG. No significant differences were noted among light-curing groups in terms of H2/H0 microhardness values. The QTH, operated in exponential mode, resulted in the highest H4/H0 value. The exponential mode of the QTH demonstrated superior performance for the total of the characteristics evaluated.

  8. Breather cloth for vacuum curing

    Science.gov (United States)

    Reed, M. W.

    1979-01-01

    Finely-woven nylon cloth that has been treated with Teflon improves vacuum adhesive bonding of coatings to substrates. Cloth is placed over coating; entire assembly, including substrate, coating, and cloth, is placed in plastic vacuum bag for curing. Cloth allows coating to "breathe" when bag is evacuated. Applications include bonding film coatings to solar concentrators and collectors.

  9. Rapid Development of the Radiation Curing Sector

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    @@ Radiation curing is an advanced material surface treatment technology using ultraviolet (UV) radiation and electronic beams (EB). With the greater attention paid to environ mentel protection in recent years ,radiation curing has developed rapidly.

  10. Accelerated Cure Project for Multiple Sclerosis

    Science.gov (United States)

    ... main content Accelerating research toward a cure for multiple sclerosis Home Contact Us Search form Search Connect Volunteer ... is to accelerate efforts toward a cure for multiple sclerosis by rapidly advancing research that determines its causes ...

  11. Techniques for internal water curing of concrete

    DEFF Research Database (Denmark)

    Jensen, Ole Mejlhede; Pietro, Lura

    2003-01-01

    This paper gives an overview of different techniques for incorporation of internal curing water in concrete. Internal curing can be used to mitigate self-desiccation and self-desiccation shrinkage. Some concretes may need 50 kg/m3 of internal curing water for this purpose. The price of the internal...

  12. From HCV To HBV Cure.

    Science.gov (United States)

    Schinazi, Raymond F; Asselah, Tarik

    2017-01-01

    Approximately 170 million people are chronically infected with HCV and 350 million are chronically infected with HBV worldwide. It is estimated that more than one million patients die from complications related to chronic viral hepatitis, mainly HCC which is one of the most frequent cancers in many countries, especially Africa, the Middle East and Asia. HCV drug development has been impressive, and this revolution led to several direct-acting antiviral agents achieving an HCV cure after only 6-12 weeks. This progress could theorically lead to HCV global elimination making HCV and its consequences a rarity. HBV research and development programs can learn from the HCV experience, to achieve an HBV functional or sterilizing cure. This review will summarize key steps which have been realized for an HCV cure, and discuss the next steps to achieve for an HCV elimination. And also, how this HCV revolution has inspired scientists and clinicians to achieve the same for HBV.

  13. Freud's psychoanalysis: a moral cure.

    Science.gov (United States)

    Eriksson, Johan

    2014-08-01

    That psychoanalytical treatment in its classical Freudian sense is primarily a moral or ethical cure is not a very controversial claim. However, it is far from obvious how we are to understand precisely the moral character of psychoanalysis. It has frequently been proposed that this designation is valid because psychoanalysis strives neither to cure psychological symptoms pharmaceutically, nor to superficially modify the behaviour of the analysand, but to lead the analysand through an interpretive process during which he gradually gains knowledge of the unconscious motives that determine his behaviour, a process that might ideally liberate him to obtain, in relation to his inner desires, the status of a moral agent. There resides something appealing in these claims. But it is the author's belief that there is an even deeper moral dimension applying to psychoanalytical theory and praxis. Freudian psychoanalysis is a moral cure due to its way of thematizing psychological suffering as moral suffering. And this means that the moral subject - the being that can experience moral suffering - is not primarily something that the psychoanalytical treatment strives to realize, but rather the presupposition for the way in which psychoanalysis theorizes psychological problems as such.

  14. Composite cure monitoring with Bragg grating sensors

    Science.gov (United States)

    Slattery, Kerry T.; Corona-Bittick, Kelli; Dorr, Donald J.

    1998-03-01

    Residual stress is induced in fiber composite materials during the cure process because the thermal expansion coefficient of the fiber is generally much lower than that of the polymer matrix. The two materials are 'locked' together at the cure temperature. Then, as they cool, the matrix attempts to contract more than the fiber leading to tension in the matrix and compression in the fiber. This can lead to the formation of microcracks parallel to the fibers in thick composite piles or yarns. The magnitude of residual stress can be reduced by modifying the cure cycle; however, optimizing the cure cycle requires a complete understanding of the state of cure throughout the composite. This is a complex problem -- especially in thick composites. Pilot studies have been performed placing Bragg gratin sensors in glass fabric preforms and monitoring the response of the grating during resin infusion and cure. The typical response shows the initial thermal expansion of the Bragg grating, a rapid contraction of the grating as the resin gels, slower contraction during cure, and thermal contraction at the composite thermal expansion coefficient during cool down. This data is then sued with micromechanical models of the fiber/matrix interaction during cure to establish material parameters for cure simulation. Once verified, these cure simulation methods will be used to optimize tooling design and cure cycles in composite components.

  15. Cure-A-Phobia感

    Institute of Scientific and Technical Information of China (English)

    黄乔

    2015-01-01

    爵士乐源于二十世纪的非洲黑人音乐,被公认为欧洲现代流行音乐的开端,随着二十一世纪多元化文化的不断呈现,爵士乐在我国也愈来愈受到关注.特别是在各艺术类院校,相关爵士乐教学及演出活动也越来越多.本文在此将对瑞典爵士乐队Cure-A-Phobia的一场音乐会略抒己见.

  16. Interfacial Properties of Electron Beam Cured Composites

    Energy Technology Data Exchange (ETDEWEB)

    Eberle, C.C.

    1999-12-30

    The objectives of the CRADA are to: Confirm that fiber-resin adhesion is responsible for the observed poor shear properties; Determine the mechanism(s) responsible for poor adhesion between carbon fibers and epoxy resins after e-beam curing; Develop and evaluate resin systems and fiber treatments to improve the properties of e-beam cured, carbon-fiber-reinforced composites; and Develop refined methods for processing e-beam cured, carbon-fiber-reinforced composites.

  17. Microwave Cure of Phenol-Formaldehyde Adhesive

    OpenAIRE

    高谷, 政広; 田平, 英敏; 岡本, 忠

    2006-01-01

    [Synopsis] Phenol-formaldehyde resin has been used as a versatile material for adhesives and coatings of a wide range of adherends because of its excellent performance in water- resistance, strength against abrasion, and so on. However, it has a drawback of slow rate of cure and relevant emission of formaldehyde gas after bonding. We studied the curing performance under irradiation of microwave for the purpose of looking for a way of accelerating the cure rate of phenol formaldehyde resin. Th...

  18. Electron Beam Curing of Advanced Composites

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The fundamental concept of electron beam method and the application in cure of composites are elaborated in this paper. The components of electron beam curing system are introduced. The mechanisms of interaction between electron beam and polymer matrix composites are presented. Recent studies reported including work of authors themselves on electron beam curing of composites are also discussed. Moreover, the authors believe that it is necessary to do the basic research about understanding how electron beam affects cured network and the mechanical/physical properties of the composites, for establishing a quantitative or semi-quantitative formulation.

  19. Curing efficiency of three light emitting diode units at different curing profiles

    Directory of Open Access Journals (Sweden)

    Priyanka Verma

    2016-01-01

    Conclusions: Reduction of exposure time to 6 s with high-intensity curing light seemed to be clinically acceptable and should be recommended. Curing of metal brackets with single exposure from buccal side showed lower shear bond strength values.

  20. Prevention is better than cure

    CERN Multimedia

    Anaïs Schaeffer

    2012-01-01

    Throughout the year, members of the Safety Inspections Services section of HSE Unit devote themselves to ensuring the safety of all infrastructure and equipment that represent a specific hazard within the Organization. They regularly comb through all CERN's infrastructure to forestall any accidents and their potential impact, true to the adage that prevention is better than cure.   This site has a few (!) slight safety problems... Spot the mistakes! (Details of the game below.) Ensuring that an HV electrical installation is properly earthed, that a system under pressure has no weak points, that an item of lifting equipment can be used without risk, that safety valves operate at the right pressure threshold as well as checking that a heavy object that could inflict injury if it fell is not stored on top of a cupboard: such are the types of inspections performed by the Safety Inspection Service (DGS-SEE-SIS). "These checks reassure those in charge of equipment and infrastruct...

  1. Hepatitis C, stigma and cure.

    Science.gov (United States)

    Marinho, Rui Tato; Barreira, David Pires

    2013-10-28

    The infection with hepatitis C virus (HCV) is one of the most important global chronic viral infections worldwide. It is estimated to affect around 3% of the world population, about 170-200 million people. Great part of the infections are asymptomatic, the patient can be a chronic carrier for decades without knowing it. The most severe consequences of the chronic infection are liver cirrhosis and hepatocellular carcinoma, which appears in 20%-40% of the patients, leading to hepatic failure and death. The HCV was discovered 25 years ago in 1989, is a RNA virus and classified by the World Health Organization as an oncogenic one. Hepatocellular carcinoma is one of the most important cancers, the fifth worldwide in terms of mortality. It has been increasing in the Ocidental world, mainly due to chronic hepatitis C. Hepatitis C is not only a liver disease and a cause of cirrhosis, but also a mental, psychological, familiar, and social disease. The stigma that the infected person sometimes carries is tremendous having multiple consequences. The main cause is lack of adequate information, even in the health professionals setting. But, besides the "drama" of being infected, health professionals, family, society and the infected patients, must be aware of the chance of real cure and total and definitive elimination of the virus. The treatment for hepatitis C has begun in the last 80's with a percentage of cure of 6%. Step by step the efficacy of the therapy for hepatitis C is rapidly increasing and nowadays with the very new medications, the so called Direct Antiviral Agents-DAAs of new generation, is around 80%-90%.

  2. Curing Mechanism of Condensed Polynuclear Aromatic Resin and Thermal Stability of Cured Resin

    Institute of Scientific and Technical Information of China (English)

    Li Shibin; Sun Qiqian; Wang Yuwei; Wu Mingbo; Zhang Zailong

    2015-01-01

    In order to improve the thermal stability of condensed polynuclear aromatic (COPNA) resin synthesized from vacuum residue, 1,4-benzenedimethanol was added to cure COPNA resin. The curing mechanism was investigated by pro-ton nuclear magnetic resonance spectrometry, solid carbon-13 nuclear magnetic resonance spectrometry and Fourier trans-form infrared spectroscopy. Microstructures of the uncured and the cured COPNA resins were studied by scanning electron microscopy and X-ray diffractometry. The thermal stability of COPNA resins before and after curing was tested by thermo-gravimetric analysis. The element composition of the cured COPNA resin heated at different temperatures was analyzed by an element analyzer. The results showed that the uncured COPNA resin reacted with the cross-linking agent during the cur-ing process, and the curing mechanism was conifrmed to be the electrophilic substitution reaction. Compared with the un-cured COPNA resin, the cured COPNA resin had a smooth surface, well-ordered and streamlined sheet structure with more crystalline solids, better molecular arrangement and orientation. The weight loss process of the uncured and cured COPNA resins was divided into three stages. Carbon residue of the cured COPNA resin was 41.65%at 600℃, which was much higher than 25.02%of the uncured COPNA resin, which indicated that the cured COPNA resin had higher thermal stability.

  3. 7 CFR 29.6010 - Cured.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Cured. 29.6010 Section 29.6010 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... INSPECTION Standards Definitions § 29.6010 Cured. Tobacco dried of its sap by either natural or...

  4. Dental resin cure monitoring by inherent fluorescence

    Science.gov (United States)

    Li, Qun; Zhou, Jack X.; Li, Qingxiong; Wang, Sean X.

    2008-02-01

    It is demonstrated that the inherent fluorescence of a dental composite resin can be utilized to monitor the curing status, i.e. degree of conversion of the resin. The method does not require any sample preparation and is potentially very fast for real time cure monitoring. The method is verified by Raman spectroscopy analysis.

  5. 9 CFR 319.103 - Cured beef tongue.

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 2 2010-01-01 2010-01-01 false Cured beef tongue. 319.103 Section 319... Cured beef tongue. In preparing “Cured Beef Tongue,” the application of curing solution to the fresh beef tongue shall not result in an increase in the weight of the cured beef tongue of more than...

  6. Curing agent for polyepoxides and epoxy resins and composites cured therewith. [preventing carbon fiber release

    Science.gov (United States)

    Serafini, T. T.; Delvigs, P.; Vannucci, R. D. (Inventor)

    1981-01-01

    A curing for a polyepoxide is described which contains a divalent aryl radical such as phenylene a tetravalent aryl radical such as a tetravalent benzene radical. An epoxide is cured by admixture with the curing agent. The cured epoxy product retains the usual properties of cured epoxides and, in addition, has a higher char residue after burning, on the order of 45% by weight. The higher char residue is of value in preventing release to the atmosphere of carbon fibers from carbon fiber-epoxy resin composites in the event of burning of the composite.

  7. Pleuropulmonary paragonimiasis with migrated lesions cured by multiple therapies

    Directory of Open Access Journals (Sweden)

    Yun Hu

    2016-01-01

    Full Text Available Paragonimiasis is an infectious disease caused by Trematodes of the genus Paragonimus that is endemic in Asia, Africa, and South America. Most patients with paragonimiasis are cured by standard praziquantel treatment. However, several cases have been reported to have unsatisfactory responses to the standard praziquantel treatment. To probe the clinical characteristics, possible cause, and management of the paragonimiasis individuals improved by multiple therapies, we present a 12-year-old Chinese boy, who was infected with Paragonimus accompanied by arachnoid cyst involvement, as not having typical clinical symptoms, but repeatedly presenting with migrated lesions between the lung and pleura. He responded to treatment with 3 cycles of praziquantel and 1 cycle of albendazole.

  8. Curing efficiency of modern LED units.

    Science.gov (United States)

    Rencz, Adam; Hickel, Reinhard; Ilie, Nicoleta

    2012-02-01

    Recent reports claim that modern light-emitting diode (LED) curing units improve curing efficiency by increasing the units' irradiance. In this context also, short polymerisation times up to 5 s are proposed. The aim of this study was to examine whether there are differences in the curing efficiency of modern LED curing units by assessing their effect on two different composite materials and by varying the irradiation time. A nano- and a micro-hybrid resin-based composite (RBC) were polymerised for 5, 10 and 20 s with three commercial and a Prototype LED unit (Elipar™ S10). Cylindrical specimens (6 mm in depth, 4 mm in diameter) were prepared in three increments, each 2-mm thick, and were consecutively cured. Degree of cure was measured for 20 min in real time at the bottom of the samples, starting with the photoinitiation. The micro-mechanical properties (modulus of elasticity, E and Vickers hardness, HV) were measured as a function of depth, in 100-μm steps, on the above described samples stored in distilled water for 24 h at 37°C. Data were analysed with multivariate ANOVA followed by Tukey's test, t test and partial eta-squared statistics. In descending order of the strength of their effect, the type of RBC, depth, polymerisation time and curing unit were significant factors affecting the micro-mechanical parameters (p surface, a minimum of 20 s of irradiation is necessary for an adequate polymerisation 2 mm beyond the surface.

  9. One-step microwave foaming and curing

    Science.gov (United States)

    Gagliani, J.; Lee, R.; Sorathia, U. A. K.; Wilcoxson, A. L.

    1981-01-01

    Process that combines microwave foaming and curing of polyimide precursors in single step produces fire-resistant foam slabs of much larger volume than has previously been possible. By adding selected conductive fillers to powder precursors and by using high-power microwave oven, foam slabs with dimensions in excess of 61 by 61 by 7.6 cm are made. Typical foaming and curing and curing time is 35 minutes in microwave oven with additional 1 to 2 hour postcure in conventional oven.

  10. Acceleration of curing of resin composite at the bottom surface using slow-start curing methods.

    Science.gov (United States)

    Yoshikawa, Takako; Morigami, Makoto; Sadr, Alireza; Tagami, Junji

    2013-01-01

    The aim of this study was to evaluate the effect of two slow-start curing methods on acceleration of the curing of resin composite specimens at the bottom surface. The light-cured resin composite was polymerized using one of three curing techniques: (1) 600 mW/cm(2) for 60 s, (2) 270 mW/cm(2) for 10 s+0-s interval+600 mW/cm(2) for 50 s, and (3) 270 mW/cm(2) for 10 s+5-s interval+600 mW/cm(2) for 50 s. After light curing, Knoop hardness number was measured at the top and bottom surfaces of the resin specimens. The slow-start curing method with the 5-s interval caused greater acceleration of curing of the resin composite at the bottom surface of the specimens than the slow-start curing method with the 0-s interval. The light-cured resin composite, which had increased contrast ratios during polymerization, showed acceleration of curing at the bottom surface.

  11. [Mineral water as a cure].

    Science.gov (United States)

    Nocco, Priska Binz

    2008-01-01

    The treatment of diseases with mineral spring water belongs to the oldest medical therapies. The "remedy" mineral water is therefore of importance also within the pharmacy. The present pharmacy historical work examines the impact of the use of mineral waters, as well as of their dried components, as therapeutic agents in the 19th and early 20th centuries, i.e. from approx. 1810 to 1930, as well as the contributions given by pharmacists in the development and analysis of mineral water springs. Beside these aspects, the aim here is also to describe the role played by pharmacists in the production of artificial mineral water as well as in the sale and wholesale of natural and artificial mineral water. In the first part of this work the situation in Switzerland and its surrounding countries, such as Germany, France, Italy and Austria, is discussed. The second part contains a case-study of the particular situation in the Canton Tessin. It is known from the scientific literature published at that time that information on mineral water was frequently reported. Starting from the beginning of the 19th century the number of such publications increased tremendously. The major part of them were publications in scientific journals or contributions to medical and pharmaceutical manuals and reference books. In particular the spa-related literature, such as spa-guides, was of growing interest to a broad public. The inclusion of monographs into the Swiss, the Cantonal as well the foreign pharmacopoeias granted a legal frame for the mineral waters and their dried components. These works are of major importance from a pharmacy historical standpoint and represent a unique proof of historical evidence of the old medicinal drug heritage. The most frequently used therapies based on mineral waters were drinking and bath cures. Several diseases, particularly those of a chronic character, were treated with mineral waters. The positive influence of these cures on the recovery of the patients

  12. Light-cured resin for post patterns.

    Science.gov (United States)

    Waldmeier, M D; Grasso, J E

    1992-09-01

    A method of using light-cured acrylic resin as an alternative to the use of chemically-cured acrylic resins with elastomeric impressions for direct post patterns is presented. The GC Unifast LC acrylic resin is a powder/liquid type resin cured by exposure to visible light. The polymerization process has four stages before final curing: slurry, stringy, dough-like (plastic), and rubber-like (elastic). Advantages over current direct and indirect procedures include ease of manipulation of the material and no change in laboratory handling procedures. While in the dough-like state, the material can be contoured. In the rubber-like state, it is flexible to disengage from minor undercut areas.

  13. Fast Curing of Composite Wood Products

    Energy Technology Data Exchange (ETDEWEB)

    Dr. Arthur J. Ragauskas

    2006-04-26

    The overall objective of this program is to develop low temperature curing technologies for UF and PF resins. This will be accomplished by: • Identifying the rate limiting UF and PF curing reactions for current market resins; • Developing new catalysts to accelerate curing reactions at reduced press temperatures and times. In summary, these new curing technologies will improve the strength properties of the composite wood products and minimize the detrimental effects of wood extractives on the final product while significantly reducing energy costs for wood composites. This study is related to the accelerated curing of resins for wood composites such as medium density fiberboard (MDF), particle board (PB) and oriented strandboard (OSB). The latter is frequently manufactured with a phenol-formaldehyde resin whereas ureaformaldehyde (UF) resins are usually used in for the former two grades of composite wood products. One of the reasons that hinder wider use of these resins in the manufacturing of wood composites is the slow curing speed as well as inferior bondability of UF resin. The fast curing of UP and PF resins has been identified as an attractive process development that would allow wood to be bonded at higher moisture contents and at lower press temperatures that currently employed. Several differing additives have been developed to enhance cure rates of PF resins including the use of organic esters, lactones and organic carbonates. A model compound study by Conner, Lorenz and Hirth (2002) employed 2- and 4-hydroxymethylphenol with organic esters to examine the chemical basis for the reported enhanced reactivity. Their studies suggested that the enhance curing in the presence of esters could be due to enhanced quinone methide formation or enhanced intermolecular SN2 reactions. In either case the esters do not function as true catalysts as they are consumed in the reaction and were not found to be incorporated in the polymerized resin product. An

  14. EVALUATION OF DIELECTRIC CURING MONITORING INVESTIGATING LIGHT-CURING DENTAL FILLING COMPOSITES

    Directory of Open Access Journals (Sweden)

    Johannes Steinhaus

    2011-05-01

    Full Text Available The aim of this study is the evaluation of a dielectric analysis (DEA method monitoring the curing behaviour of a light curing dental filling material in real-time. The evaluation is to extract the influence of light intensity on the photo-curing process of dental composite filling materials. The intensity change is obtained by measuring the curing process at different sample depth. It could be shown that increasing sample thickness, and therefore exponentially decreasing light intensity, causes a proportional decrease in the initial curing rate. Nevertheless, the results give rise to the assumption that lower illumination intensities over a long period cause higher overall conversion, and thus better mechanical properties. This would allow for predictions of the impact of different curing-rates on the final mechanical properties.

  15. Effect of cure cycle on curing process and hardness for epoxy resin

    Directory of Open Access Journals (Sweden)

    2009-09-01

    Full Text Available A 3-dimensional finite element model is developed to simulate and analyze the temperature and degree of cure field of epoxy casting part during cure process. The present model based on general finite element software ABAQUS is verified by literature example and experimental data. The numerical results show good agreement with literature example and measured data, and are even more accurate than the simulation of literature. After modeling successfully, the influence of temperature cure cycle ramps have on the temperature and degree of cure gradient is investigated. Moreover, the effect of non-uniform temperature and degree of cure field within epoxy casting part on hardness is demonstrated. The present model provides an accurate and novel method that allows further insight into the process of cure for epoxy resin.

  16. High Power UV LED Industrial Curing Systems

    Energy Technology Data Exchange (ETDEWEB)

    Karlicek, Robert, F., Jr; Sargent, Robert

    2012-05-14

    UV curing is a green technology that is largely underutilized because UV radiation sources like Hg Lamps are unreliable and difficult to use. High Power UV LEDs are now efficient enough to replace Hg Lamps, and offer significantly improved performance relative to Hg Lamps. In this study, a modular, scalable high power UV LED curing system was designed and tested, performing well in industrial coating evaluations. In order to achieve mechanical form factors similar to commercial Hg Lamp systems, a new patent pending design was employed enabling high irradiance at long working distances. While high power UV LEDs are currently only available at longer UVA wavelengths, rapid progress on UVC LEDs and the development of new formulations designed specifically for use with UV LED sources will converge to drive more rapid adoption of UV curing technology. An assessment of the environmental impact of replacing Hg Lamp systems with UV LED systems was performed. Since UV curing is used in only a small portion of the industrial printing, painting and coating markets, the ease of use of UV LED systems should increase the use of UV curing technology. Even a small penetration of the significant number of industrial applications still using oven curing and drying will lead to significant reductions in energy consumption and reductions in the emission of green house gases and solvent emissions.

  17. Cure fraction estimation from the mixture cure models for grouped survival data.

    Science.gov (United States)

    Yu, Binbing; Tiwari, Ram C; Cronin, Kathleen A; Feuer, Eric J

    2004-06-15

    Mixture cure models are usually used to model failure time data with long-term survivors. These models have been applied to grouped survival data. The models provide simultaneous estimates of the proportion of the patients cured from disease and the distribution of the survival times for uncured patients (latency distribution). However, a crucial issue with mixture cure models is the identifiability of the cure fraction and parameters of kernel distribution. Cure fraction estimates can be quite sensitive to the choice of latency distributions and length of follow-up time. In this paper, sensitivity of parameter estimates under semi-parametric model and several most commonly used parametric models, namely lognormal, loglogistic, Weibull and generalized Gamma distributions, is explored. The cure fraction estimates from the model with generalized Gamma distribution is found to be quite robust. A simulation study was carried out to examine the effect of follow-up time and latency distribution specification on cure fraction estimation. The cure models with generalized Gamma latency distribution are applied to the population-based survival data for several cancer sites from the Surveillance, Epidemiology and End Results (SEER) Program. Several cautions on the general use of cure model are advised.

  18. Comparative study on compressive strength of Self cured SCC and Normally cured SCC

    Directory of Open Access Journals (Sweden)

    Ms. Akanksha A. Patil

    2014-11-01

    Full Text Available Curing is the process of maintaining proper moisture content particularly within 28 days to promote optimum cement hydration immediately after placement. Self-compacting concrete is made up of admixture i.e. superplasticizer. In recent years, self-compacting concrete (SCC has gained wide use for placement in congested reinforced concrete structures with difficult casting conditions. Also various curing methods are adopted in the construction industry especially for vertical structures, inaccessible areas s.a. high rise buildings, water scarce areas etc. In such structures conventional curing is not practically possible in most of the cases. But we need efficient curing which improves the strength and durability of concrete. In the present work, comparison of compressive strength of normally cured SCC and SCC cured with self curing material i.e. wax based, white pigmented, membrane forming concrete curing compound has been done. This study is investigating that weather the use of self curing compound is economical or not in remote areas of water without compromising with the compressive strength of concrete.

  19. 抗高热I号合剂对肺炎双球菌所致发热家兔脑脊液PGE、cAMP含量的影响%THE EFFECTS OF ANTI-FEVER MIXTURE I TO THE LEVELS OF PGE AND cAMP IN THE CEREBROSPINAL FLUID OF FEVER RABBITS INFECTED BY PNEUMOCOCCUS

    Institute of Scientific and Technical Information of China (English)

    蓝肇熙; 张进淘; 王杰龙; 张发荣; 谢春光; 刘宁; 孙鸿辉

    2001-01-01

    目的:观察抗高热I号合剂(AFMI)对发热家兔脑脊液前列腺素E(PGE)、环磷酸腺苷(cAMP)含量的影响。方法:用肺炎双球菌感染家兔,造成发热模型,提前应用AFMI合剂及以两种不同剂量于家兔体温达到高峰时应用,观测家兔脑脊液PGE、cAMP含量的变化并进行比较。结果:发热家兔脑脊液PGE、cAMP含量异常升高(P<0.01),AFMI可显著降低发热家兔脑脊液中异常升高的PGE和cAMP的含量(P<0.01),最佳剂量为26.25 g*kg-1, 提前应用AFMI,可阻抑感染家兔脑脊液中PGE、cAMP的合成释放。结论:AFMI具有良好的解热降温作用。%OBJECTIVE:To study effects of Anti-fever mixture I(AFMI,composed of Herba Ephedrae Decoction and Radix Puerariae Decoction) to the levels of PGE and cAMP in the cerebrospinal fluid of fever rabbits.METHODS:Rabbits were infected by pneumococcus to produce a fever model. Two different doses of AFMI were used when the rabbits' temperature reached its peak, and also used AFMI ahead of schedule. Survey the changes of PGE and cAMP levels and compared with each other.RESULTS:The levels of PGE and cAMP in fever rabbits' cerebrospinal fluid was rised abnormally(P<0.01), AFMI can lower the abnormally rised levels of PGE and cAMP in the cerebrospinal fluid(P<0.01), and the use of AFMI ahead of schedule can inhibit the synthesis and release of PGE and cAMP in the cerebrospinal fluid.CONCLUSION:The antipyretic and lowering temperature effects of AFMI are excellent.

  20. Things Chinese.

    Science.gov (United States)

    Law, Yip Wang

    Presented in this booklet are brief descriptions of items and activities that are symbolic of Chinese culture. Some of the items and activities described include a traditional Chinese child's outfit, dolls, sandalwood fans, writing and printing materials and techniques, toys and crafts, a Chinese abacus, and eating utensils. Several recipes for…

  1. HEAT-RESISTANT COMPOSITES CURED BY ELECTRON BEAM

    Institute of Scientific and Technical Information of China (English)

    Jian-wen Bao; Yang Li; Xiang-bao Chen; Feng-mei Li

    2001-01-01

    Electron beam (EB) curing of composites has many advantages. Heat-resistant EB-curing composites could substitute polyimide composites used in aeronautical engines. In this paper, the effects of catalyst and dose on the cured resin were investigated. The heat-resistance of the resin cured by EB was evaluated by dynamic mechanical analysis (DMA). The experimental results show that the mechanical properties of the composites cured by EB could meet the specifications of aeronautical engines at 250°C.

  2. Assessment of Curing Efficiency and Effect of Moist Curing on Performance of Fly Ash Concrete

    Institute of Scientific and Technical Information of China (English)

    LI Meili; QIAN Jueshi; WANG Lixia; XU Shanshan; JIA Xingwen; FAN Yunyan

    2011-01-01

    This study was conducted to evaluate the sensitivity of compressive strength,water permeability and electrical resistance of near-surface layer concrete with different fly ash contents to curing conditions. It is shown that the sensitivity to curing condition and fly ash content descends in the following order: difference between internal and surface resistivity (ρ)at 28 days, water permeability and compressive strength; both of longer duration of moist curing and use of fly ash in concrete enhanced the water penetration resistance. It is indicated that the resistivity difference p at 28 days can reflect accurately the curing history of fly ash concrete regardless of mix proportions; and use of fly ash in concrete requires longer moist curing duration.

  3. Curing mechanism of flexible aqueous polymeric coatings.

    Science.gov (United States)

    Irfan, Muhammad; Ahmed, Abid Riaz; Dashevskiy, Andriy; Kolter, Karl; Bodmeier, Roland

    2017-02-25

    The objective of this study was to explain curing phenomena for pellets coated with a flexible polymeric coating based on poly(vinyl acetate) (Kollicoat(®) SR 30D) with regard to the effect of starter cores, thickness of drug layer, adhesion of coating to drug-layered-cores as well as coating properties. In addition, appropriate approaches to eliminate the curing effect were identified. Sugar or MCC cores were layered with the model drugs carbamazepine, theophylline, propranolol HCl, tramadol HCl and metoprolol HCl using HPMC (5 or 25% w/w, based on drug) as a binder. Drug-layered pellets were coated with Kollicoat(®) SR 30D in a fluidized bed coater using TEC (10% w/w) as plasticizer and talc (35-100% w/w) as anti-tacking agent. Drug release, pellet properties (morphology, water uptake-weight loss and osmolality) and adhesion of the coating to the drug layer were investigated as a function of curing at 60 °C or 60 °C/75% RH for 24 h. The film formation of the aqueous dispersion of Kollicoat(®) SR 30D was complete, and therefore, a strong curing effect (decrease in drug release) at elevated temperature and humidity (60 °C/75% RH) could not be explained by the well-known hydroplasticization and the further gradual coalescence of the colloidal polymer particles. According to the provided mechanistic explanation, the observed curing effect was associated with 1) high flexibility of coating, 2) adhesion between coating and drug layer, 3) water retaining properties of the drug layer, and 4) osmotically active cores. Unwanted curing effects could be minimized/eliminated by the addition of talc or/and pore-forming water soluble polymers in the coating, increasing binder amount or applying an intermediate coating, by increasing the thickness of drug layer or using non-osmotic cores. A new insight into curing phenomena mainly associated with the adhesion between drug layer and coating was provided. Appropriate approaches to avoid unwanted curing effect were identified.

  4. Prevent and cure disuse bone loss

    Science.gov (United States)

    Jee, Webster S. S.

    1994-01-01

    Anabolic agents like parathyroid hormone and postagladin E-like substances were studied in dogs and rats to determine their effectiveness in the prevention and cure of bone loss due to immobilization. It was determined that postagladin E2 administration prevented immobilization while at the same time it added extra bone in a dose responsive manner. Although bone mass returns, poor trabecular architecture remains after normal ambulation recovery from immobilization. Disuse related bone loss and poor trabecular architecture were cured by post-immobilization postagladin E2 treatment.

  5. Production of cured meat color in nitrite-free Harbin red sausage by Lactobacillus fermentum fermentation.

    Science.gov (United States)

    Zhang, Xue; Kong, Baohua; Xiong, Youling L

    2007-12-01

    Lactobacillus fermentum was substituted for nitrite to produce cured pink color in a Chinese-style sausage. Treatments included inoculations (10(4), 10(6), and 10(8)CFU/g meat) followed by fermentation at 30°C for 8h and then at 4°C for 16h. Control sausage (with sodium nitrite, 60mg/kg meat) was cured at 4°C for 24h without L. fermentum. The UV-Vis spectra of pigment extract from L. fermentum-treated sausage were identical to that of nitrosylmyoglobin (NO-Mb) formed in nitrite-treated control. The NO-Mb concentration and the colorimetric a(∗) value of sausage treated with 10(8)CFU/g meat of L. fermentum essentially replicated those in nitrite-cured meat. Free amino acid content in sausage treated with L. fermentum was greater and the pH slightly lower compared with the nitrite-cured control sample. This study showed that L. fermentum has the potential to substitute for nitrite in the sausage production.

  6. Curing kinetics of visible light curing dental resin composites investigated by dielectric analysis (DEA).

    Science.gov (United States)

    Steinhaus, Johannes; Hausnerova, Berenika; Haenel, Thomas; Großgarten, Mandy; Möginger, Bernhard

    2014-03-01

    During the curing process of light curing dental composites the mobility of molecules and molecule segments is reduced leading to a significant increase of the viscosity as well as the ion viscosity. Thus, the kinetics of the curing behavior of 6 different composites was derived from dielectric analysis (DEA) using especially redesigned flat sensors with interdigit comb electrodes allowing for irradiation at the top side and measuring the ion viscosity at the bottom side. As the ion viscosities of dental composites change 1-3 orders of magnitude during the curing process, DEA provides a sensitive approach to evaluate their curing behavior, especially in the phase of undisturbed chain growth. In order to determine quantitative kinetic parameters a kinetic model is presented and examined for the evaluation of the ion viscosity curves. From the obtained results it is seen that DEA might be employed in the investigation of the primary curing process, the quality assurance of ingredients as well as the control of processing stability of the light curing dental composites.

  7. Light-Cured Self-Etch Adhesives Undergo Hydroxyapatite-Triggered Self-Cure.

    Science.gov (United States)

    Liu, Y; Bai, X; Liu, Y W; Wang, Y

    2016-03-01

    Light cure is a popular mode of curing for dental adhesives. However, it suffers from inadequate light delivery when the restoration site is less accessible, in which case a self-cure mechanism is desirable to salvage any compromised polymerization. We previously reported a novel self-cure system mediated by ethyl 4-(dimethylamino)-benzoate (4E) and hydroxyapatite (HAp). The present work aims to investigate if such self-cure phenomenon takes place in adhesives that underwent prior inadequate light cure and to elucidate if HAp released from the dental etching process is sufficient to trigger it. Model self-etch adhesives were formulated with various components, including bis[2-methacryloyloxy)ethyl]-phosphate (2MP) as acidic monomer and trimethylbenzoyl-diphenylphosphine oxide (TPO) as photoinitiator. In vitro evolution of degree of conversion (DC) of HAp-incorporated adhesives was monitored by infrared spectroscopy during light irradiation and dark storage. Selected adhesives were allowed to etch and extract HAp from enamel, light-cured in situ, and stored in the dark, after which Raman line mapping was used to obtain spatially resolved DC across the enamel-resin interface. Results showed that TPO+4E adhesives reached DC similar to TPO-only counterparts upon completion of light irradiation but underwent another round of initiation that boosted DC to ~100% regardless of HAp level or prior light exposure. When applied to enamel, TPO-only adhesives had ~80% DC in resin, which gradually descended to ~50% in enamel, whereas TPO+4E adhesives consistently scored ~80% DC across the enamel-resin interface. These observations suggest that polymerization of adhesives that underwent insufficient light cure is salvaged by the novel self-cure mechanism, and such salvaging effect can be triggered by HAp released from dental substrate during the etching process.

  8. Creep measurements on curing epoxy systems

    DEFF Research Database (Denmark)

    Kammer, Charlotte; Szabo, Peter

    1998-01-01

    The chemical curing of a stoichiometric mixture of the diglycidyl ether of bisphenol A and a 1,3-bis-(aminomethyl)-cyclohexane is studied.Creep experiments are combined with measurements in a Differential Scanning Calorimeter (DSC) to determine the change in bulk viscosity due to network formation....

  9. Mechanical characterization and modeling of curing thermosets

    NARCIS (Netherlands)

    Van 't Hof, C.

    2006-01-01

    Chemical shrinkage and simultaneous build-up of mechanical properties in curing thermosets leads to the build-up of residual stresses and strains. Depending on the constraints these may cause interface failure, dimensional inaccuracy or failure in the thermoset or its surrounding structure. The pre

  10. COMPARISON OF THE E44 EPOXY RESINS IN DIFFERENT CONTENTS OF CURING AGENT BY MICROWAVE AND THERMAL CURING METHODS

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    This paper discusses the fundamental principle of microwave heating, and based on the advantages of microwave heating, use maleic anhydride as curing agent.The technology of microwave curing E44 epoxy resins is investigated,the mechanical properties of cured epoxy resin samples in different contents of curing agent by microwave and thermal curing methods are measured respectively, and then some experimental results for which are obtained.At last, this paper analyses why microwave curing can improve mechanical property of epoxy resin.

  11. [Chinese phytotherapy: the power of synergy].

    Science.gov (United States)

    Rodríguez, Manuel

    2005-05-01

    Chinese pharmacology is ancient and very extensive. In reality, Chinese pharmacology is composed of matter having vegetable, animal and mineral origins; however, the dominance of vegetable and the exclusive restriction to vegetable matter which European legislation obliges us to follow makes the use of the term phyto-therapy which means curing via plants, as is reported in another article, "Phyto-therapy, a choice based on science and tradition" by Dr. Josep AlluPéCreus. (Rev ROL Enf 8(3):179-182).

  12. Thermal and Cure Kinetics of Epoxy Molding Compounds Cured with Thermal Latency Accelerators

    Directory of Open Access Journals (Sweden)

    Chean-Cheng Su

    2013-01-01

    Full Text Available The cure kinetics and mechanisms of a biphenyl type epoxy molding compounds (EMCs with thermal latency organophosphine accelerators were studied using differential scanning calorimetry (DSC. Although the use of triphenylphosphine-1,4-benzoquinone (TPP-BQ and triphenylphosphine (TPP catalysts in biphenyl type EMCs exhibited autocatalytic mechanisms, thermal latency was higher in the TPP-BQ catalyst in EMCs than in the TPP catalyst in EMCs. Analyses of thermal characteristics indicated that TPP-BQ is inactive at low temperatures. At high temperatures, however, TPP-BQ increases the curing rate of EMC in dynamic and isothermal curing experiments. The reaction of EMCs with the TPP-BQ latent catalyst also had a higher temperature sensitivity compared to the reaction of EMCs with TPP catalyst. In resin transfer molding, EMCs containing the TPP-BQ thermal latency accelerator are least active at a low temperature. Consequently, EMCs have a low melt viscosity before gelation, and the resins and filler are evenly mixed in the kneading process. Additionally, flowability is increased before the EMCs form a network structure in the molding process. The proposed kinetic model adequately describes curing behavior in EMCs cured with two different organophosphine catalysts up to the rubber state in the progress of curing.

  13. Bond strength of a light-cured and two auto-cured glass ionomer liners.

    Science.gov (United States)

    Holtan, J R; Nystrom, G P; Olin, P S; Rudney, J; Douglas, W H

    1990-10-01

    Ninety-nine extracted human molar teeth were used in this study comparing the shear bond strengths on dentine of one light-cured and two auto-cured polyalkenoate (glass ionomer) cements. Bond strength can be influenced by differences in tooth structure. A balanced-incomplete block design (Hull and Nie, 1981) was used to reduce variation attributable to such differences. Cements were applied to paired dentine surfaces in combinations such that 66 tooth sides were treated with each material. A light-cured dentinal adhesive and composite resin restorative material were then placed and shear bond strength testing was conducted exactly 24 h after the completion of each specimen. Mean forces (MPa) for the three materials were compared using an appropriate analysis of variance model (balanced-incomplete-blocks) The shear bond strengths (MPa) of the light-cured liner (Espe, Seefeld/Oberbay, FRG) was 4.71 +/- 1.16. Vitrabond showed the greatest variance of all three materials tested, however this material's average bond strength was greater than the maximum achieved for the other materials. Student-Newman-Keuls comparison of means showed that all cements differed significantly from each other (alpha = 0.05). It is concluded that the light-cured glass ionomer liner exhibited significantly better shear bond strength performance than the two auto-cured glass ionomers tested.

  14. [Dimensional accuracy of microwave-cured denture base resin].

    Science.gov (United States)

    Uchida, K; Okamoto, F; Ogata, K; Sato, T

    1989-02-01

    Recently, microwave-cured denture base resin was developed, and the resin solved the problem of internal porosity which had been generated by curing the conventional denture base resins with microwave irradiation. In this study, the dimensional accuracy of microwave-cured denture base resin was compared with that of other denture base resins, such as pour-type resin, heat-cured resin and heat-shock resin. From the experiment, the following results were obtained. 1. Dimensional accuracy of microwave-cured denture base resin was better than that of heat-cured resin and heat-shock resin, and was similar to that of pour-type resin. 2. Dimensional accuracy of microwave-cured denture base resin by slow cooling method and rapid cooling method was almost the same. Those findings suggest that microwave-cured denture base resin is valuable in clinic.

  15. Effect of curing on clinical retention. A 7-year evaluation

    DEFF Research Database (Denmark)

    van Dijken, Jan WV; Pallesen, Ulla

    Objective: To evaluate in a prospective evaluation the retention of Class V compomer and hybrid resin composite restorations placed with a 1-step self etch system and cured with continuous, soft-start and pulse-delay curing. Methods: 139 Class V restorations were placed and cured at random in 60...... subjects with a compomer (Dyract AP;68) or resin composite (Tetric Ceram:67) and cured for 40s with continuous, soft-start and pulse-delay modes. The restorations were evaluated with slightly modified USPHS criteria yearly during 7 years. Results: Of 135 restorations evaluated at 7 years, 29 were lost, 17...... compomer (25%) and 12 Tetric Ceram (18%). The cumulative loss rates for the compomer and resin composite restorations cured with the three curing modes were. continuous cure: 26.1%/18.2%, soft-start: 22.7%/19.0%, pulse delay: 26.1%/16.7%. No statistical difference were seen between the curing modes...

  16. Drinking Peroxide as 'Natural' Cure Leads to Dangerous Blood Clots

    Science.gov (United States)

    ... https://medlineplus.gov/news/fullstory_163513.html Drinking Peroxide as 'Natural' Cure Leads to Dangerous Blood Clots ... 9, 2017 (HealthDay News) -- Ingesting high-concentration hydrogen peroxide as a "natural cure" or cleansing agent may ...

  17. Electron Beam Curing of Polymer Matrix Composites - CRADA Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Janke, C. J. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Howell, Dave [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Norris, Robert E. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    1997-05-01

    The major cost driver in manufacturing polymer matrix composite (PMC) parts and structures, and one of the elements having the greatest effect on their quality and performance, is the standard thermal cure process. Thermal curing of PMCs requires long cure times and high energy consumption, creates residual thermal stresses in the part, produces volatile toxic by-products, and requires expensive tooling that is tolerant of the high cure temperatures.

  18. 7 CFR 29.6002 - Air-cured.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Air-cured. 29.6002 Section 29.6002 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... INSPECTION Standards Definitions § 29.6002 Air-cured. Tobacco cured under natural atmospheric...

  19. Alternative cancer cures: "unproven" or "disproven"?

    Science.gov (United States)

    Vickers, Andrew

    2004-01-01

    Oncology has always coexisted with therapies offered outside of conventional cancer treatment centers and based on theories not found in biomedicine. These alternative cancer cures have often been described as "unproven," suggesting that appropriate clinical trials have not been conducted and that the therapeutic value of the treatment is unknown. Contrary to much popular and scientific writing, many alternative cancer treatments have been investigated in good quality clinical trials, and they have been shown to be ineffective. In this article, clinical trial data on a number of alternative cancer cures including Livingston-Wheeler, Di Bella Multitherapy, antineoplastons, vitamin C, hydrazine sulfate, Laetrile, and psychotherapy are reviewed. The label "unproven" is inappropriate for such therapies; it is time to assert that many alternative cancer therapies have been "disproven."

  20. Cure of HCV related liver disease.

    Science.gov (United States)

    Shiffman, Mitchell L; Benhamou, Yves

    2015-01-01

    Chronic hepatitis C virus (HCV) causes chronic liver injury and can lead to cirrhosis and hepatocellular carcinoma (HCC). HCV can also interact with the immune system to cause several HCV related disorders including essential mixed cryoglobulinemia, vasculitis, dermatitis, glomerulonephritis and lymphoma. A strong association between HCV and diabetes mellitus also exists. These extrahepatic features may lead to increased fatigue and a reduced quality of life. It is now possible to cure most patients with chronic HCV using oral antiviral therapy. Many of these HCV-related disorders and symptoms can be cured when HCV is eradicated. However, some patients may have irreversible injury to extrahepatic sites, cirrhosis that cannot resolve, an increased risk for HCC, persistent fatigue and a reduced quality of life, despite achieving sustained virological response.

  1. Curing Reaction Model of Epoxy Asphalt Binder

    Institute of Scientific and Technical Information of China (English)

    QIAN Zhendong; CHEN Leilei; WANG Yaqi; SHEN Jialin

    2012-01-01

    In order to understand the strength developing law of the epoxy asphalt mixture,a curing reaction model of the epoxy asphalt binder was proposed based upon the thermokinetic analysis.Given some assumptions,the model was developed by applying the Kissinger law as well as Arrhenius equation,and the differential scanning calorimetry was performed for estimating the model parameters.To monitor the strength development of the epoxy asphalt mixture,a strength test program was employed and then results were compared to those produced from the proposed model.The comparative evaluation shows that a good consistency exists between the outputs from test program and the proposed model,indicating that the proposed model can be used effectively for simulating the curing reaction process for the epoxy asphalt binder and predicting the strength development for the epoxy asphalt mixture.

  2. Contactless optoelectronic technique for monitoring epoxy cure.

    Science.gov (United States)

    Cusano, A; Buonocore, V; Breglio, G; Calabrò, A; Giordano, M; Cutolo, A; Nicolais, L

    2000-03-01

    We describe a novel noninvasive optical technique to monitor the refractive-index variation in an epoxy-based resin that is due to the polymerization process. This kind of resin is widely used in polymer matrix composites. It is well known that the process of fabricating a thermoset-based composite involves mass and heat transfer coupled with irreversible chemical reactions that induce physical changes. To improve the quality and the reliability of these materials, monitoring the cure and optimization of the manufacturing process are of key importance. We discuss the basic operating principles of an optical system based on angle deflection measurements and present typical cure-monitoring results obtained from optical characterization. The method provides a flexible, high-sensitivity, material-independent, low-cost, noninvasive tool for monitoring real-time refractive-index variation.

  3. Light-Curing Adhesive Repair Tapes

    Science.gov (United States)

    Allred, Ronald; Haight, Andrea Hoyt

    2009-01-01

    Adhesive tapes, the adhesive resins of which can be cured (and thereby rigidized) by exposure to ultraviolet and/or visible light, are being developed as repair patch materials. The tapes, including their resin components, consist entirely of solid, low-outgassing, nonhazardous or minimally hazardous materials. They can be used in air or in vacuum and can be cured rapidly, even at temperatures as low as -20 C. Although these tapes were originally intended for use in repairing structures in outer space, they can also be used on Earth for quickly repairing a wide variety of structures. They can be expected to be especially useful in situations in which it is necessary to rigidize tapes after wrapping them around or pressing them onto the parts to be repaired.

  4. Fast curing ethylene vinyl acetate films with dual curing agent towards application as encapsulation materials for photovoltaic modules

    Directory of Open Access Journals (Sweden)

    W-H. Ruan

    2014-02-01

    Full Text Available To speed up curing of ethylene vinyl acetate (EVA films as encapsulation materials for photovoltaic modules, a dual curing agent of benzoyl peroxide (BPO and butylperoxy 2-ethylhexyl carbonate (TBEC was introduced in this work. The experimental results indicated that for the weight ratio of BPO/TBEC of 0.6/2.4, over 80% gel content of EVA was yielded after curing at 130°C for 12 min. Compared with the case of single curing agent, the present one obviously operated at much lower temperature with faster rate. By carefully studying the influence of curing agent proportion and curing conditions on gel content of EVA films, as well as rheology and curing kinetics, the mechanism involved was analyzed and verified. The results are believed to be useful for developing new curing system of EVA encapsulation films with improved processability.

  5. Using Sex to Cure the Genome.

    Directory of Open Access Journals (Sweden)

    Eduardo P C Rocha

    2016-03-01

    Full Text Available The diversification of prokaryotes is accelerated by their ability to acquire DNA from other genomes. However, the underlying processes also facilitate genome infection by costly mobile genetic elements. The discovery that cells can uptake DNA by natural transformation was instrumental to the birth of molecular biology nearly a century ago. Surprisingly, a new study shows that this mechanism could efficiently cure the genome of mobile elements acquired through previous sexual exchanges.

  6. Coating and curing apparatus and methods

    Energy Technology Data Exchange (ETDEWEB)

    Brophy, Brenor L.; Gonsalves, Peter R.; Maghsoodi, Sina; Colson, Thomas E.; Yang, Yu S.; Abrams, Ze' ev R.

    2016-04-19

    Disclosed is a coating apparatus including flow coating and roll-coating that may be used for uniform sol-gel coating of substrates such as glass, solar panels, windows or part of an electronic display. Also disclosed are methods for substrate preparation, flow coating and roll coating. Lastly, systems and methods for curing sol-gel coatings deposited onto the surface of glass substrates using high temperature air-knives, infrared emitters and direct heat applicators are disclosed.

  7. Photothermal Monitoring Of Curing Of Polymers

    Science.gov (United States)

    Rooney, Michael

    1993-01-01

    Time-resolved infrared radiometry (TRIR) adapted to monitoring curing of some polymers in production. Proposal part of continuing effort to perfect production of hydroxy-terminated polybutadiene for use in liners of solid-fuel rocket motors. Applicable to monitoring changing states of many other materials in process. TRIR, non-contact technique implemented with remotely situated equipment and better suited to use in production.

  8. Sage Gene Expression Profiles Characterizing Cure

    Science.gov (United States)

    2006-10-01

    therapies to improve breast cancer cure frequency. Down Regulation of VEGF in MTCL Cells. RNA interference has been a powerful genetic tool to study...Science 296, 550 (2002). 100. D. A. Rubinson et al., Nat Genet 33, 401 (2003). 101. E. Devroe, P. A. Silver, BMC Biotechnol 2 (2002). 102. J. P...double- plotted along the estrous cycle. Double plotting of rhythmic patterns is a standard chronobiological technique that allows visualization of

  9. An investigation on the effect of light cure and self cure composite resins on bonding strength of light cure glass ionomer to dentin (In-vitro

    Directory of Open Access Journals (Sweden)

    Pahlavan A

    2004-02-01

    Full Text Available Composite reins have recently become popular for posterior teeth restorations. Gap"nformation and subsequent microleakage are of the complications resulting from such restorations. One of the"ntechniques to overcome polymerization shrinkage of composite resins is sandwich technique (application of"nglass ionomer as a base beneath the composite resin. Since polymerization patterns in two types of composite"nresins (light cure and self cure differ from each other, various effects on the bond strength between glass"nionomer and dentin are expected."nPurpose: The aim of this in vitro study was to evaluate the effects of self- cure and light- cure composite"nresins in sandwich technique on the bond strength of light cure glass ionomer and dentin."nMaterials and Methods: 40 extracted human premolars were selected and divided into four groups:"nGroup 1: Light cure glass ionomer of 1mm thickness was placed on dentin."nGroup 2: 1mm thickness of light cure glass ionomer plus a mass of self cure composite resin of 2mm"nthickness were placed."nGroup 3: 1mm thickness of light cure glass ionomer plus light cure composite resin as two separate 1mm layer"nwere placed."nGroup 4: 1mm thickness of light cure glass ionomer with 37% phosphoric acid etching followed by two"nseparate layers of light cure composite resin of 1 mm thickness were placed."nSEM was used to determine gap size ai Gl- dentin and Gi- composite interlaces. The findings were analyzed"nby ANOVA and t-student tests."nResults: Groups 1 and 2 showed no gap at Gl-dentm interface and also cracks were not observed in all these"nspecimens. In group 3, there was gap between light cure GI and light cure composite resin and cracks were"nseen in GI, too. Group 4 showed gap at both interfaces and more cracks were seen in GI. Groups I and 2"nshowed the least gap formation and group 4 showed the most. Statistically significant difference was found"nbetween groups 3, 4 and group 1 (control, 2."nConclusion: Base

  10. Cure Behavior and Thermal Properties of Diepoxidized Cardanol Resin Cured by Electron Beam Process

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Donghwan; Cheon, Jinsil [Kumoh National Institute of Technology, Gumi (Korea, Republic of)

    2013-07-01

    Thermal curing of epoxy resin requires high temperature, time-consuming process and the volatilization of hardener. It has known that electron beam curing of epoxy resin is a fast process and occurs at low or room temperature that help reduce residual mechanical stresses in thermosetting polymers. Diepoxidized cardanol (DEC) can be synthesized by an enzymatic method from cashew nut shell liquid (CNSL), that constitutes nearly one-third of the total nut weight. A large amount of CNSL can be formed as a byproduct of the mechanical processes used to render the cashew kerneledible and its total production approaches one million tons annually, which can be bio-degradable and replace the industrial thermosetting plastics. It is expected that DEC may be cured as in an epoxy resin, which was constituted on two epoxide group and long alkyl chain, and two-types of onium salts (cationic initiator) were used as a photo-initiator. The experimental variables of this study are type and concentration of photo-initiators and electron beam dosage. In this study, the effects of initiator type and concentration on the cure behavior and the thermal properties of DEC resin processed by using electron beam technology were studied using FT-IR, TGA, TMA, DSC, and DMA. Figure 1 is the FT-IR results, showing the change of chemical structure of pure DEC and electron beam cured DEC. The characteristic absorption peak of epoxide group appeared at 850cm{sup -1}. The shape and the height were reduced when the sample was irradiated with electron beam. From this result, the epoxide groups is DEC were opened by electron beam and cured. After then, electron beam cured DEC was investigated the effect of forming 3-dimensional network.

  11. Accurate Cure Modeling for Isothermal Processing of Fast Curing Epoxy Resins

    Directory of Open Access Journals (Sweden)

    Alexander Bernath

    2016-11-01

    Full Text Available In this work a holistic approach for the characterization and mathematical modeling of the reaction kinetics of a fast epoxy resin is shown. Major composite manufacturing processes like resin transfer molding involve isothermal curing at temperatures far below the ultimate glass transition temperature. Hence, premature vitrification occurs during curing and consequently has to be taken into account by the kinetic model. In order to show the benefit of using a complex kinetic model, the Kamal-Malkin kinetic model is compared to the Grindling kinetic model in terms of prediction quality for isothermal processing. From the selected models, only the Grindling kinetic is capable of taking into account vitrification. Non-isothermal, isothermal and combined differential scanning calorimetry (DSC measurements are conducted and processed for subsequent use for model parametrization. In order to demonstrate which DSC measurements are vital for proper cure modeling, both models are fitted to varying sets of measurements. Special attention is given to the evaluation of isothermal DSC measurements which are subject to deviations arising from unrecorded cross-linking prior to the beginning of the measurement as well as from physical aging effects. It is found that isothermal measurements are vital for accurate modeling of isothermal cure and cannot be neglected. Accurate cure predictions are achieved using the Grindling kinetic model.

  12. Cure mechanisms in materials for use in esthetic dentistry.

    Science.gov (United States)

    Kwon, Tae-Yub; Bagheri, Rafat; Kim, Young K; Kim, Kyo-Han; Burrow, Michael F

    2012-02-01

    The current paper reviews the curing mechanisms found in resin-based materials used in dentistry. Historical aspects of dental products and the associated curing mechanisms are reviewed. In comparison with common industrial procedures, curing methods employed for dental materials are relatively limited because of the need to polymerize quickly in the oral cavity at an ambient temperature. Heat-cure and self-cure dental resins utilize benzoyl peroxide initiator alone with a tertiary amine co-initiator. At present, most dental restorative composites use a camphorquinone-amine complex initiation, visible light-cure, one-component systems, although alternative photoinitiators have been researched and developed. A multiple curing mode in a dual-cure material is a complex combination of various initiation systems. The use of aryl sulfinic acid sodium salt to overcome adverse chemical interactions between simplified adhesives and self- or dual-cure composites is based on another self-cure polymerization mechanism, sulfinic acid-initiated polymerization, proposed by Hagger in 1948. The sodium salt of aryl sulfinic acid reacts with an acidic monomer in simplified adhesives, and is believed to produce radicals. Clinically, it is important to try to optimize the degree of conversion of resin-based materials using proper manipulation and adequate light-curing techniques to ensure the best outcome for materials used to restore teeth.

  13. Rubber curing chemistry governing the orientation of layered silicate

    Directory of Open Access Journals (Sweden)

    2007-11-01

    Full Text Available The effect of curing systems on the orientation and the dispersion of the layered silicates in acrylonitrile butadiene rubber nanocomposite is reported. Significant differences in X-ray diffraction pattern between peroxide curing and sulfur curing was observed. Intense X-ray scattering values in the XRD experiments from peroxide cured vulcanizates indicate an orientation of the layers in a preferred direction as evinced by transmission electron micrographs. However, sulfur cured vulcanizates show no preferential orientation of the silicate particles. Nevertheless, a closer inspection of transmission electron microscopy (TEM images of peroxide and sulfur cured samples shows exfoliated silicate layers in the acrylonitrile butadiene rubber (NBR matrix. It was revealed in the prevailing study that the use of an excess amount of stearic acid in the formulation of the sulfur curing package leads to almost exfoliated type X-ray scattering pattern.

  14. Cure shrinkage effects in epoxy and polycyanate matrix composites

    Energy Technology Data Exchange (ETDEWEB)

    Spellman, G.P.

    1995-12-22

    A relatively new advanced composite matrix, polycyanate ester, was evaluated for cure shrinkage. The chemical cure shrinkage of composites is difficult to model but a number of clever experimental techniques are available to the investigator. In this work the method of curing a prepreg layup on top of a previously cured laminate of identical ply composition is utilized. The polymeric matrices used in advanced composites have been primarily epoxies and therefore a common system of this type, Fiberite 3501-6, was used as a base case material. Three polycyanate matrix systems were selected for the study. These are: Fiberite 954-2A, YLA RS-3, and Bryte Technology BTCy-1. The first three of these systems were unidirectional prepreg with carbon fiber reinforcement. The Bryte Technology material was reinforced with E-glass fabric. The technique used to evaluate cure shrinkage results in distortion of the flatness of an otherwise symmetric laminate. The first laminate is cured in a conventional fashion. An identical layup is cured on this first laminate. During the second cure all constituents are exposed to the same thermal cycles. However, only the new portion of the laminate will experience volumetric changes associate with matrix cure. The additional strain of cure shrinkage results in an unsymmetric distribution of residual stresses and an associated warpage of the laminate. The baseline material, Fiberite 3501-6, exhibited cure shrinkage that was in accordance with expectations. Cure strains were {minus}4.5E-04. The YLA RS-3 material had cure strains somewhat lower at {minus}3.2E-04. The Fiberite 954-2A cure strain was {minus}1.5E-04 that is 70% lower than the baseline material. The glass fabric material with the Bryte BTCy-1 matrix did not result in meaningful results because the processing methods were not fully compatible with the material.

  15. CURING OF POLYMERIC COMPOSITES USING MICROWAVE RESIN TRANSFER MOULDING (RTM

    Directory of Open Access Journals (Sweden)

    R. YUSOFF

    2007-08-01

    Full Text Available The main objective of this work is to compare the difference between microwave heating and conventional thermal heating in fabricating carbon/epoxy composites. Two types of epoxy resin systems were used as matrices, LY5052-HY5052 and DGEBA-HY917-DY073. All composite samples were fabricated using resin transfer moulding (RTM technique. The curing of the LY5052-HY5052-carbon and the DGEBA-HY917-DY073-carbon composite systems, were carried out at 100 °C and 120 °C, respectively. Microwave heating showed better temperature control than conventional heating, however, the heating rate of the microwave cured samples were slower than the conventionally cured samples. This was attributed to the lower power (250 W used when heating with microwaves compared to 2000 W used in conventional heating. Study of thermal characteristics as curing progressed showed that the polymerisation reaction occurred at a faster rate during microwave curing than in conventional curing for both the DGEBA and the LY/HY5052 carbon composite systems. The actual cure cycle was reduced from 60 minutes to 40 minutes when using microwaves for curing DGEBA-carbon composites. As for LY/HY5052-carbon composites, the actual cure cycle was reduced from 3 hours to 40 minutes. Both conventional and microwave heating yielded similar glass transition temperatures (120 °C for DGEBA systems and 130 °C for LY/HY5052 systems. Microwave cured composites had higher void contents than conventionally cured composites (2.2-2.8% and 1.8-2.4% for DGEBA and LY/HY5052 microwave cured composites, respectively, compared to 0.2-0.4% for both DGEBA and LY/HY5052 thermally cured composites. C-scan traces showed that all composites, regardless of methods of curing, had minimal defects.

  16. Curing Study of Epoxy/clay Nanocomposite by a New Aromatic Diamine Functional Curing Agent

    Directory of Open Access Journals (Sweden)

    Seyed Mahdi Saadati

    2013-12-01

    Full Text Available The curing behavior of an epoxy/clay nanocomposite system composed of diglycidyl ether of bisphenol A (DGEBA epoxy resin with a new aromatic diamine curing agent and organically modified clay was investigated. Epoxy/clay nanocomposite samples were prepared by mixing DGEBA, different percentages of nanoclay (1, 3, 5, 7, and 9% and 4-(4-(2,6-diphenylpyridin-4-ylphenoxybenzene-1,3-diamine (DAP. The optimum ratio of the epoxy/clay nanocomposite system (3% was investigated by total enthalpy of the curing reaction from differential scanning calorimetry (DSC thermograms. The kinetic parameters such as activation energy, pre-exponential factor, and rate constant were obtained from DSC data.

  17. Experimental Study on the Curing Effect of Dredged Sediments with Three Types of Curing Agents

    Directory of Open Access Journals (Sweden)

    Yan Lei-Ming

    2016-01-01

    Full Text Available Sediment solidification technology is widely used to dispose dredged sediment, three types of curing agents were used in this study to solidified the dredged sediment from shallows in Nantong with three types of curing agents: JY, ZL and FJ. The results showed that the optimal additive amounts of these three curing agents were 140g JY, 16g ZL, 2.0g FJ per 1000g of the dredged sediment respectively, their 28d USC were up to 2.48 MPa, 2.96 MPa and 3.00 MPa. JY has obvious early strength effect, which of FJ is not that obvious, but the later-stage strength of sediment solidified by FJ are relatively higher.

  18. CURING KINETICS AND PROPERTIES OF ACRYLIC RESIN CURED WITH AZIRIDINE CROSSLINKER

    Institute of Scientific and Technical Information of China (English)

    Fei Xie; Zong-hui Liu; De-qing Wei

    2002-01-01

    A kind of aziridine crosslinkers was synthesized and used to crosslink acrylate copolymers. The crosslinking properties and curing kinetics of the resin were studied. It was found that with the increase of the content of crosslinker in the emulsion, the mechanical properties and solvent resistance of the resin will be apparently improved, but its glass transition temperature (Tg) is very low. The lowest amount of crosslinker used in the acrylic resin emulsion is 0.25%. Curing kinetics studied by DSC show that this curing reaction occurs readily because the apparent activation energy of the reaction is low(65.1 KJ/mol). These results demonstrate that the aziridine crosslinker is indeed a low temperature crosslinking agent and can be used at room temperature.

  19. [Exploration of microcosmic Chinese medicine used by western medicine].

    Science.gov (United States)

    Zheng, Zhi-jing

    2015-02-01

    "Microcosmic syndrome", "treatment based on syndrome differentiation", and "combination of disease identification and syndrome differentiation" generally refer to a mode: following the syndrome if with no disease identified, following the disease if with no syndrome type differentiated. For example, Chinese medical treatment of hypertension, high blood lipids, increased transaminase, and so on candirectly use Chinese recipes, but no longer with syndrome differentiation. Clinical application of Chinese patent medicine can also obtain favorable clinical. Western doctors need not follow syndrome differentiation. The invention of artemisinin was screened from more than 40 000 kinds of compounds and herbs, but with no reference of any traditional Chinese medical theory. A lot of folk remedy and empirical recipes have obtained effective efficacy but unnecessarily with profound Chinese medical theories. Various evidences showed that disease can also be cured without syndrome differentiation. I held that it might be associated with the same mechanism of Chinese medicine and Western medicine. Any disease can be cured or alleviated by Chinese medicine is a result from its modern pharmacological effect, which is achieved by improving etiologies, and pathogeneses. I was inspired by whether we can directly use traditional Chinese medicine with modern pharmacological effects to treat symptomatic disease. So I raised an idea of microcosmic Chinese medicine used by Western medicine, i.e., we find and use Chinese herbs with relatively effective modern pharmacological effect to treat diseases targeting at patients' clinical symptoms and signs, as well as various positive laboratory results (collectively called as microscopic dialectical indicators). More Western doctors would use it to treat disease due to omission of complicated and mysterious syndrome differentiation. This will promote extensive application and expansion of Chi- nese medicine and pharmacy, enlarge the team of

  20. Improving a self-curing dental resin by eliminating oxygen, hydroquinone and water from its curing process.

    Science.gov (United States)

    Keh, En-Sheng; Hayakawa, Iwao; Takahashi, Hidekazu; Watanabe, Akihiko; Iwasaki, Yasuhiko; Akiyoshi, Kazunari; Nakabayashi, Nobuo

    2002-12-01

    Self-curing dental resins are always manipulated in the presence of curing inhibitory factors such as oxygen, hydroquinone, water and another contaminants such as saliva and blood. The purpose of this study was to elucidate the effects of eliminating these curing inhibitory factors on resin properties. Several clinically relevant characteristics of an experimental resin cured in the absence of inhibitory factors (purified group) were determined and compared with the resin cured conventionally (control group). The purified group showed a significantly shorter induction period and higher reaction exotherm. It also showed significantly higher tensile strength and lower strain to failure. With regard to the amount of residual monomer, fracture toughness and fatigue strength the improvements were not significant. These findings suggest that the polymerization outcomes and mechanical properties of the purified group resin can be improved in general. Dental clinicians should pay attention to the storage and curing environments while manipulating the self-curing resin.

  1. Cure behavior of epoxy polymers used in microelectronics

    Science.gov (United States)

    Taweeplengsangsuke, Jantrawan

    2000-10-01

    Underfill resins are used to reduce solder fatigue in flip-chip assemblies. Both underfilling and curing processes are critical to achieve reliable finished products. This study included two main themes; the development of processing diagrams for commercial underfill resins and the fundamental understanding of cure kinetics and evolution of cure stresses in model epoxies. A variety of techniques have been used to characterize the fundamental phenomena involved in the processing of underfill resins. The flow behavior, cure kinetics, cure stresses, outgassing phenomena and void formation of underfill resins were studied. Processing diagrams for underfill resins were developed by mapping fundamental phenomena involved to provide a guideline for underfilling and curing steps. With these processing diagrams one should be able to design his underfilling and curing process with scientific approach. Two commercial underfill resins, which were evaluated as part of a SEMATECH program, where shown to possess significantly different processing characteristics. However, the appropriate explanation could not be made without knowing the proprietary chemistry of the systems. Therefore, model epoxies were formulated. Three different systems were investigated; amine, imidazole, and anhydride curing agent systems. With the known chemistry, the reaction kinetics and developed cure stress can be explained more clearly. Vitrification, which severely retards the rate of reaction, was found in amine (N-aminoethylpiperazine) and anhydride (Hexahydro-4-methylphthalic anhydride) cured systems when the cure temperatures were lower than the glass transition temperature (T g) of fully cured samples; however, imidazole(2-ethyl-4-methyl-imidazole) did not show vitrification when it was cured at 20 degrees below the T g of fully cured sample due to the large exotherms. Interestingly for imidazole system, the higher cure temperature exhibited a lower Tg. This could possibly be explained by the

  2. Mechanical modeling of stress generation during cure of encapsulating resins

    Energy Technology Data Exchange (ETDEWEB)

    Lagasse, R.R.; Chambers, R.S.; Guess, T.R. (Sandia National Labs., Albuquerque, NM (USA)); Plazek, D.J.; Bero, C. (Pittsburgh Univ., PA (USA). Dept. of Materials Science and Engineering)

    1991-01-01

    We have developed a numerical model for calculating stresses generated during cure of shrinking encapsulating resins. Mechanical modeling of polymer encapsulated electronic devices usually focuses on stress generated during cooling after cure. The stress developed during cure, due to shrinkage of the encapsulant, is normally neglected. That assumption is valid if both the shear and bulk moduli of the encapsulant at the cure temperature are negligible with respect to the moduli at lower temperatures. Our measurements on a model epoxy encapsulant show that the shear modulus during cure, varying from 0 to 6 MPa, is at least 100 times smaller than that at ambient temperature. In contrast, the bulk modulus at the cure temperature is only 2.5 times smaller. Since the bulk modulus during cure cannot be neglected, significant stress can be produced if volume shrinkage is constrained by a stiff mold or embedded elements. In fact, mechanical failure of encapsulating materials during cure has been evident in some of our experiments. Using measurements of shear and bulk moduli plus volume shrinkage as inputs to a finite element model, we have successfully predicted the shrinkage strains and stresses developed during cure of a model epoxy resin inside a cylindrical tube. Consideration of cure shrinkage stress has led to a process modification that appears to reduce mechanical failures in a real encapsulated device. 6 refs., 6 figs.

  3. Critical parameters for electron beam curing of cationic epoxies and property comparison of electron beam cured cationic epoxies versus thermal cured resins and composites

    Energy Technology Data Exchange (ETDEWEB)

    Janke, C.J.; Norris, R.E.; Yarborough, K. [Oak Ridge National Lab., TN (United States). Oak Ridge Centers for Manufacturing Technology; Havens, S.J. [Oak Ridge Inst. for Science and Education, TN (United States); Lopata, V.J. [Atomic Energy of Canada Ltd., Pinawa, Manitoba (Canada). Whiteshell Labs.

    1997-01-16

    Electron beam curing of composites is a nonthermal, nonautoclave curing process offering the following advantages compared to conventional thermal curing: substantially reduced manufacturing costs and curing times; improvements in part quality and performance; reduced environmental and health concerns; and improvements in material handling. In 1994 a Cooperative Research and Development Agreement (CRADA), sponsored by the Department of Energy Defense Programs and 10 industrial partners, was established to advance electron beam curing of composites. The CRADA has successfully developed hundreds of new toughened and untoughened resins, offering unlimited formulation and processing flexibility. Several patent applications have been filed for this work. Composites made from these easily processable, low shrinkage material match the performance of thermal cured composites and exhibit: low void contents comparable to autoclave cured composites (less than 1%); superb low water absorption values in the same range as cyanate esters (less than 1%); glass transition temperatures rivaling those of polyimides (greater than 390 C); mechanical properties comparable to high performance, autoclave cured composites; and excellent property retention after cryogenic and thermal cycling. These materials have been used to manufacture many composite parts using various fabrication processes including hand lay-up, tow placement, filament winding, resin transfer molding and vacuum assisted resin transfer molding.

  4. Influence of curing protocol on selected properties of light-curing polymers

    DEFF Research Database (Denmark)

    Dewaele, Magali; Asmussen, Erik; Peutzfeldt, Anne;

    2009-01-01

    The purpose of this study was to investigate the effect of light-curing protocol on degree of conversion (DC), volume contraction (C), elastic modulus (E), and glass transition temperature (T(g)) as measured on a model polymer. It was a further aim to correlate the measured values with each other....

  5. Out-of-Autoclave Cure Composites

    Science.gov (United States)

    Hayes, Brian S.

    2015-01-01

    As the size of aerospace composite parts exceeds that of even the largest autoclaves, the development of new out-of-autoclave processes and materials is necessary to ensure quality and performance. Many out-of-autoclave prepreg systems can produce high-quality composites initially; however, due to long layup times, the resin advancement commonly causes high void content and variations in fiber volume. Applied Poleramic, Inc. (API), developed an aerospace-grade benzoxazine matrix composite prepreg material that offers more than a year out-time at ambient conditions and provides exceptionally low void content when out-of-autoclave cured. When compared with aerospace epoxy prepreg systems, API's innovation offers significant improvements in terms of out-time at ambient temperature and the corresponding tack retention. The carbon fiber composites developed with the optimized matrix technology have significantly better mechanical performance in terms of hot-wet retention and compression when compared with aerospace epoxy matrices. These composites also offer an excellent overall balance of properties. This matrix system imparts very low cure shrinkage, low coefficient of thermal expansion, and low density when compared with most aerospace epoxy prepreg materials.

  6. Radiation curing of carbon fibre composites

    Science.gov (United States)

    Spadaro, G.; Alessi, S.; Dispenza, C.; Sabatino, M. A.; Pitarresi, G.; Tumino, D.; Przbytniak, G.

    2014-01-01

    Epoxy/carbon fibre reinforced composites were produced by means of e-beam irradiation through a pulsed 10 MeV electron beam accelerator. The matrix consisted of a difunctional epoxy monomer (DGEBA) and an initiator of cationic polymerisation, while the reinforcement was a unidirectional high modulus carbon fibre fabric. Dynamic mechanical thermal analysis was carried out in order to determine the cross-linking degree. The analysis pointed out a nonuniformity in the cross-linking degree of the e-beam cured panels, with the formation of clusters at low Tg (glass transition temperature) and clusters at high Tg. An out-of-mould post irradiation thermal treatment on e-beam cured samples provides a higher uniformity in the network although some slight degradation effects. Mode I delamination fracture toughness and Interlaminar Shear Strength (ISS) were also investigated by means of Double Cantilever Beam (DCB) and Short Beam Shear tests, respectively. Results from this mechanical characterisation allowed to correlate fracture toughness of the bulk matrix resin, cross-linking density and fibre/matrix interaction to the delamination fracture behaviour of the fibre reinforced material.

  7. CURE: Clean use of reactor energy

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1990-05-01

    This paper presents the results of a joint Westinghouse Hanford Company (Westinghouse Hanford)-Pacific Northwest Laboratory (PNL) study that considered the feasibility of treating radioactive waste before disposal to reduce the inventory of long-lived radionuclides, making the waste more suitable for geologic disposal. The treatment considered here is one in which waste would be chemically separated so that long-lived radionuclides can be treated using specific processes appropriate for the nuclide. The technical feasibility of enhancing repository performance by this type of treatment is considered in this report. A joint Westinghouse Hanford-PNL study group developed a concept called the Clean Use of Reactor Energy (CURE), and evaluated the potential of current technology to reduce the long-lived radionuclide content in waste from the nuclear power industry. The CURE process consists of three components: chemical separation of elements that have significant quantities of long-lived radioisotopes in the waste, exposure in a neutron flux to transmute the radioisotopes to stable nuclides, and packaging of radionuclides that cannot be transmuted easily for storage or geologic disposal. 76 refs., 32 figs., 24 tabs.

  8. Modernization of Chinese herbal compound and the high performance liquid chromatography tandem mass spectrometry (HPLC-MS)

    Institute of Scientific and Technical Information of China (English)

    LI Wen-lan; SUN Zhi; DU Juan

    2008-01-01

    Chinese herbal compound is playing an important role on curing human diseases. And it has been a trend that Chinese herbal compound is being used all over the world in 21 century. However, our Chinese herbal compound is facing serious challenge for the lack of canonical system of quality criterion for Chinese herbal compound so it has been a urgent problem to set up the quality control standards and reveal therapeutic basis of Chinese herbal compound. In order to give full play to the advantages of Chinese herbal compound, modern scientific and technological is used to research of Chinese herbal compound, especially the high performance liquid chromatography tandem mass spectrometry(HPLC-MS), because it is high sensitive, rapid, and obtain more information. It is very necessary that HPLC-MS is uesed to elucidate the effective components of basic substances of Chinese Herbal Compound, and endow traditional Chinese medicine with modern scientific connotation.

  9. In situ cure monitoring of advanced fiber reinforced composites

    Science.gov (United States)

    Powell, Graham R.; Crosby, Peter A.; Fernando, Gerard F.; France, Chris M.; Spooncer, Ronald C.; Waters, David N.

    1995-04-01

    This paper describes a comparative study of in-situ cure monitoring and cure modelling by three methods: (a) evanescent wave spectroscopy, (b) refractive index change, (c) near- infrared spectroscopy. Optical fibers were embedded into aerospace epoxy resins during the manufacturing process of the composite. The cure characteristics were then tracked in real- time during the processing of the material via evanescent wave interaction. This technique is based upon monitoring of characteristic infrared absorption bands of the resin system to find the concentration of the epoxy and amine hardener as a function of cure time. Hence this technique is suitable for on-line process monitoring and optimization. Results obtained from the optical fiber sensors were used to model the curing behavior of the resin system. The results were compared with near-infrared spectroscopy and differential scanning calorimetry experiments carried out under similar conditions. The feasibility of utilizing refractive index changes to monitor the extent of cure has also been demonstrated.

  10. Photoacoustic monitoring of inhomogeneous curing processes in polystyrene emulsions

    Energy Technology Data Exchange (ETDEWEB)

    Vargas-Luna, M.; Gutierrez-Juarez, G.; Rodriguez-Vizcaino, J.M.; Varela-Nsjera, J.B.; Rodriguez-Palencia, J.M.; Bernal-Alvarado, J.; Sosa, M. [Instituto de Fisica, Universidad de Guanajuato, Leon, Guanajuato (Mexico); Alvarado-Gil, J.J. [Centro de Investigacion y de Estudios Avanzados del IPN, Unidad Merida, Antigua Carretera a Progreso, Merida, Yucatan (Mexico)

    2002-07-07

    The time evolution of the inhomogeneous curing process of polystyrene emulsions is studied using a variant of the conventional photoacoustic (PA) technique. The thermal effusivity, as a function of time, is determined in order to monitor the sintering process of a styrene emulsion in different steps of the manufacturing procedure. PA measurements of thermal effusivity show a sigmoidal growth as a function of time during the curing process. The parameterization of these curves permits the determination of the characteristic curing time and velocity of the process. A decreasing of the curing time and an increasing curing velocity for the final steps of the manufacturing process are observed. The feasibility of our approach and its potentiality for the characterization of other curing process are discussed. (author)

  11. Process Formulations And Curing Conditions That Affect Saltstone Properties

    Energy Technology Data Exchange (ETDEWEB)

    Reigel, M. M.; Pickenheim, B. R.; Daniel, W. E.

    2012-09-28

    The first objective of this study was to analyze saltstone fresh properties to determine the feasibility of reducing the formulation water to premix (w/p) ratio while varying the amount of extra water and admixtures used during processing at the Saltstone Production Facility (SPF). The second part of this study was to provide information for understanding the impact of curing conditions (cure temperature, relative humidity (RH)) and processing formulation on the performance properties of cured saltstone.

  12. The curing process of layered silicate/epoxy nanocomposites

    OpenAIRE

    Nieminen, Ilkka

    2009-01-01

    The industrial methods of processing polymeric thermoset matrix nanocomposites require a good knowledge of the matrix curing process. The dispersion of nanoparticles in the matrix effects the curing process due to the interaction between nanoparticles and the matrix at the atomic level, especially when the nanoparticles have been treated with a surfactant agent ( alquilammonium) that is in competition with the reactive groups of the hardener. This thesis investigates the curing process o...

  13. Optical fibre grating refractometers for resin cure monitoring

    Science.gov (United States)

    Buggy, S. J.; Chehura, E.; James, S. W.; Tatam, R. P.

    2007-06-01

    The use of fibre grating refractometers as a means of monitoring the cure of a UV-cured epoxy resin is presented. The wavelength shift of the attenuation bands of a long period grating and the spectral response of a tilted fibre Bragg grating sensor were measured simultaneously during the cure of the resin and compared with measurements made using a fibre optic Fresnel-based refractometer. The results showed a good correlation (6 × 10-3 rius) and illustrate the potential of the techniques for non-invasive composite material cure monitoring.

  14. Curing Methods and Their Effects on The Strength of Concrete

    OpenAIRE

    Nuruddeen Usman; Muhammad Nura Isa

    2015-01-01

    There are a lot of arguments on which method of curing concrete gives good strength. These different opinions results into this study, which aim at investigating the effects of different curing methods on the strength of concrete. Laboratory test was employed for this study. Normal concretes were prepared using specified mix ratio of 1:2:4 and 1:3:6. The cubes tested for compressive strength at 3, 7, 21, and 28 days of curing respectively using four curing methods namely immersion...

  15. Study Progress of TCM Curing Methods%中药养护方法研究进展

    Institute of Scientific and Technical Information of China (English)

    罗文蓉; 杨扶德; 史彦斌

    2012-01-01

    对近年来中药养护的常见方法进行综述,提出中药养护在中药材生产、加工和贮藏过程中对确保中药的质量起到举足轻重的作用.不适当的中药养护,如过量硫磺熏蒸等会影响到中药材的品质和临床疗效.中药材安全、科学、经济和适当的养护方法学的研究可为中药的研制、生产和应用奠定质量基础.%We reviewed the common curing methods of traditional Chinese medicine in recent years and proposed that TCM curing played an important role in ensuring TCM quality during the production, processing and storage of TCM. Improper TCM curing method such as TCM fumigation with overdose sulfur has already affected the quality and curative effects of TCM. Study on scientific, economical and proper curing methods can lay quality foundation for the preparation, production and application of TCM.

  16. Ambient Cured Alkali Activated Flyash Masonry Units

    Science.gov (United States)

    Venugopal, K.; Radhakrishna; Sasalatti, Vinod M.

    2016-09-01

    Geopolymers belong to a category of non-conventional and non-Portland cement based cementitious binders which are produced using industrial by products like fly ash and ground granulated blast furnace slag (GGBFS). This paper reports on the development of geopolymer mortars for production of masonry units. The geopolymer mortars were prepared by mixing various by products with manufactured sand and a liquid mixture of sodium silicate and sodium hydroxide solutions. After curing at ambient conditions, the masonry units were tested for strength properties such as water absorption, initial rate of absorption, compression, shear- bond, and stress-strain behaviour etc. It was observed that the flexural strength of the blocks is more than 2 MPa and shear bond strength is more than 0.4MPa. It was found that the properties of geopolymer blocks were superior to the traditional masonry units. Hence they can be recommended for structural masonry.

  17. Helicobacter pylori: Basic Mechanisms to Clinical Cure

    Directory of Open Access Journals (Sweden)

    ABR Thomson

    1995-01-01

    Full Text Available Since its rediscovery 10 years ago, Helicobacter pylori has reshaped our thinking about the course of peptic ulcer disease. Our approach to the patient with a duodenal ulcer has become one of attempting eradication therapy at the time of first diagnosis, in the hope of curing the ulcer disease. Gastric and duodenal ulceration are only two of the manifestations of this chronic antral infection; other complications of H pylori include gastritis, gastric cancer and possible maltomas. Therapy of H pylori infection is complicated and involves dual therapy with an antibiotic plus a protein pump inhibitor, such as omeprazole 20 mg bid plus amoxicillin 1 g bid for two weeks, triple or quadruple therapy with bismuth, two antibiotics and an H2-receptor antagonist. Vaccination against H pylori is on the far horizon.

  18. Brane polarization is no cure for tachyons

    CERN Document Server

    Bena, Iosif

    2015-01-01

    Anti-M2 and anti-D3 branes placed in regions with charges dissolved in fluxes have a tachyon in their near-horizon region, which causes these branes to repel each other. If the branes are on the Coulomb branch this tachyon gives rise to a runaway behavior, but when the branes are polarized into five-branes this tachyon only appears to lower the energy of the polarized branes, without affecting its stability. We analyze brane polarization in the presence of a brane-brane-repelling tachyon and show that when the branes are polarized along the direction of the tachyon the polarized shell is unstable. This implies that tachyons cannot be cured by brane polarization and indicates that, at least in a certain regime of parameters, anti-D3 branes polarized into NS5 branes at the bottom of the Klebanov-Strassler solution have an instability.

  19. Stratospheric experiments on curing of composite materials

    Science.gov (United States)

    Chudinov, Viacheslav; Kondyurin, Alexey; Svistkov, Alexander L.; Efremov, Denis; Demin, Anton; Terpugov, Viktor; Rusakov, Sergey

    2016-07-01

    Future space exploration requires a large light-weight structure for habitats, greenhouses, space bases, space factories and other constructions. A new approach enabling large-size constructions in space relies on the use of the technology of polymerization of fiber-filled composites with a curable polymer matrix applied in the free space environment on Erath orbit. In orbit, the material is exposed to high vacuum, dramatic temperature changes, plasma of free space due to cosmic rays, sun irradiation and atomic oxygen (in low Earth orbit), micrometeorite fluence, electric charging and microgravitation. The development of appropriate polymer matrix composites requires an understanding of the chemical processes of polymer matrix curing under the specific free space conditions to be encountered. The goal of the stratospheric flight experiment is an investigation of the effect of the stratospheric conditions on the uncured polymer matrix of the composite material. The unique combination of low residual pressure, high intensity UV radiation including short-wave UV component, cosmic rays and other aspects associated with solar irradiation strongly influences the chemical processes in polymeric materials. We have done the stratospheric flight experiments with uncured composites (prepreg). A balloon with payload equipped with heater, temperature/pressure/irradiation sensors, microprocessor, carrying the samples of uncured prepreg has been launched to stratosphere of 25-30 km altitude. After the flight, the samples have been tested with FTIR, gel-fraction, tensile test and DMA. The effect of cosmic radiation has been observed. The composite was successfully cured during the stratospheric flight. The study was supported by RFBR grants 12-08-00970 and 14-08-96011.

  20. Curing of epoxy matrix composite in stratosphere

    Science.gov (United States)

    Kondyurin, Alexey; Kondyurina, Irina; Bilek, Marcela

    Large structures for habitats, greenhouses, space bases, space factories are needed for next stage of space exploitation. A new approach enabling large-size constructions in space relies on the use of the polymerization technology of fiber-filled composites with a curable polymer matrix applied in the free space environment. The polymerisation process is proposed for the material exposed to high vacuum, dramatic temperature changes, space plasma, sun irradiation and atomic oxygen (in low Earth orbit), micrometeorite fluence, electric charging and microgravitation. The stratospheric flight experiments are directed to an investigation of the curing polymer matrix under the stratospheric conditions on. The unique combination of low atmospheric pressure, high intensity UV radiation including short wavelength UV and diurnal temperature variations associated with solar irradiation strongly influences the chemical processes in polymeric materials. The first flight experiment with uncured composites was a part of the NASA scientific balloon flight program realised at the NASA stratospheric balloon station in Alice Springs, Australia. A flight cassette installed on payload was lifted with a “zero-pressure” stratospheric balloon filled with Helium. Columbia Scientific Balloon Facility (CSBF) provided the launch, flight telemetry and landing of the balloon and payload. A cassette of uncured composite materials with an epoxy resin matrix was exposed 3 days in the stratosphere (40 km altitude). The second flight experiment was realised in South Australia in 2012, when the cassette was exposed in 27 km altitude. An analysis of the chemical structure of the composites showed, that the space irradiations are responsible for crosslinking of the uncured polymers exposed in the stratosphere. The first prepreg in the world was cured successfully in stratosphere. The investigations were supported by Alexander von Humboldt Foundation, NASA and RFBR (12-08-00970) grants.

  1. Influence of curing tip distance on resin composite Knoop hardness number, using three different light curing units.

    Science.gov (United States)

    Caldas, Danilo Biazzetto de Menezes; de Almeida, Janaina Bertoncelo; Correr-Sobrinho, Lourenço; Sinhoreti, Mário Alexandre Coelho; Consani, Simonides

    2003-01-01

    This in vitro study evaluated the influence of curing tip distance on the Knoop Hardness Number (KHN) of a resin composite when using three different light curing units: (1) a halogen light (XL 1500 curing unit-3M), (2) a "softstart-polymerization" (Elipar Trilight curing in an exponential mode-ESPE) and (3) a PAC (Apolo 95E curing unit-DMD). The resin composite, Filtek Z250 (3M), was cured by these curing units at three light-tip distances from the resin composite: 0 mm, 6 mm and 12 mm. The resin composite specimens were flattened to their middle portion and submitted to 18 KHN measurements perspecimen. The results showed that for the Elipar Trilight unit, the hardness of the resin composite decreased as the light tip distance increased. The XL 1500 unit presented a significant decrease in hardness as the depth of cure of the resin composite increased. Apolo 95E caused a decrease in the resin composite hardness values when the depth of cure and light tip distance increased.

  2. Cure Kinetics of DGEBA with Hyperbranched Poly(3-hydroxyphenyl) Phosphate as Curing Agent Studied by Non-isothermal DSC

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The cure kinetics of diglycidyl ether of bisphenol A(DGEBA) with hyperbranched poly(3-hydroxyphenyl) phosphate(HHPP) as the curing agent was investigated by means of non-isothermal differential scanning calorimetry(DSC) at various heating rates. The results were compared with the corresponding results by using 1,3-dihydroxybenzene(DHB) as a model compound. The results show that HHPP can enhance the cure reaction of DGEBA, resulting in the decrease of the peak temperature of the curing curve as well as the decrease of the activation energy because of the flexible -P-O- groups in the backbone of HHPP. However, both the activation energy of the cured polymer and the peak temperature of the curing curve are increased with DHB as a curing agent. The cure kinetics of the DGEBA/HHPP system was calculated by using the isoconversional method given by Málek. It was found that the two-parameter autocatalytic model(esták-Berggren equation) is the most adequate one to describe the cure kinetics of the studied system at various heating rates. The obtained non-isothermal DSC curves from the experimental data show the results being accordant with those theoretically calculated.

  3. The effect of curing time and curing method on microleakge of conservative adhesive resin restorations: an in vitro study

    Directory of Open Access Journals (Sweden)

    Alireza Heidari

    2012-01-01

    Full Text Available Background and Aims: Using the conservative adhesive resin restoration (CAR in uncooperative children lead to numerous problems because of being time consuming. The purpose of this study was to compare the microleakage of conservative adhesive resin restoration under separate curing and co-curing.Materials and Methods: In this experimental study, 120 intact premolar teeth were collected and 120 vertical grooves were prepared on them. Then the teeth were divided into four groups: group 1, separated curing of bonding agent, flowable composite and sealant; group 2, co-curing of all materials for 60 seconds; group 3,co-curing of all materials for 40 seconds and group 4, co-curing of all materials for 20 seconds. Then the specimens were thermocycled and immersed in basic fuchsin solution. The teeth were sectioned horizontally and dye penetration was evaluated with stereomicroscope. Date were analyzed using one-way ANOVA and Scheffe test.Results: Mean value of dye penetration in groups 1, 2, 3, and 4 was 1.53±0.6, 2.06±0.6, 2.5±0.7 and 3.53±0.6, respectively. There was a statistically significant difference between group 1 and the other groups (P=0.0001.Conclusion: Considering the problems caused by microleakage in conservative resin adhesive restorations, co-curing method should not be used. In the case of using co-curing method, 60 second curing time is suggested for sufficient polymerization.

  4. Micromechanical properties of veneer luting resins after curing through ceramics.

    Science.gov (United States)

    Oztürk, Elif; Hickel, Reinhard; Bolay, Sükran; Ilie, Nicoleta

    2012-02-01

    The aim of this study was to assess the performance of light-cured luting resin after curing under the ceramic restoration in comparison to dual-cured luting resin, by evaluating the micromechanical properties. Two hundred seventy thin luting composite films of ca. 170 μm in thickness were prepared by using two light-cured luting resins (Variolink Veneer, Ivoclar Vivadent; RelyX Veneer, 3M ESPE) and a dual-cured luting resin (Variolink II, Ivoclar Vivadent). The composites were cured by using a LED-unit (Bluephase®, Ivoclar Vivadent) with three different curing times (10, 20, and 30 s) under two ceramics (IPS e.max Press, Ivoclar Vivadent; IPS Empress® CAD, Ivoclar Vivadent) of different thicknesses (0, 0.75, and 2 mm). Forty-five groups were included, each containing six thin films. The samples were stored after curing for 24 h at 37°C by maintaining moisture conditions with distilled water. Micromechanical properties of the composites were measured with an automatic microhardness indenter (Fisherscope H100C, Germany). For each sample, ten indentations were made, thus totalizing 60 measurements per group. Micromechanical properties of the luting resins were statistically analyzed (SPSS 17.0). Significant differences were observed between the micromechanical properties of the luting resins (p mechanical properties compared to the light-cured luting resins. The effect of luting resin type on the micromechanical properties of the luting resins was higher than the effect of curing time, ceramic type and ceramic thickness respectively (*The values of reference without ceramics for 30 s curing time).

  5. Hardening of a dual-cure resin cement using QTH and LED curing units

    OpenAIRE

    Santos,Maria Jacinta Moraes Coelho; Passos, Sheila Pestana; Encarnação, Monalisa Olga Lessa da; Santos Junior,Gildo Coelho; Bottino, Marco Antonio [UNESP

    2010-01-01

    p. 110-115 OBJECTIVE: This study evaluated the surface hardness of a resin cement (RelyX ARC) photoactivated through indirect composite resin (Cristobal) disks of different thicknesses using either a light-emitting diode (LED) or quartz tungsten halogen (QTH) light source. MATERIAL AND METHODS: Eighteen resin cement specimens were prepared and divided into 6 groups according to the type of curing unit and the thickness of resin disks interposed between the cement surface and light sourc...

  6. ACID RESISTANCE OF FLYASH BASED GEOPOLYMER MORTAR UNDER AMBIENT CURING AND HEAT CURING

    Directory of Open Access Journals (Sweden)

    V.Sreevidya

    2012-02-01

    Full Text Available An Experimental study was conducted to assess the Acid resistance of flyash based geopolymer mortar specimens of size 50x50x50mm with a ratio of flyash to sand as 1:3.The ratio between solution(Sodiumhydroxide and Sodium silicate solution to flyash were 0.376,0.386,0.396 and 0.416. After casting the specimens were subjected to both ambient curing and heat curing. In heat curing the specimens were kept continuously at 60oC for 24 hrs. Durability of specimens was assessed by immersing them in 5% of sulfuric acid and 5%hydrochloric acid for a period of 14 weeks. Evaluation of its resistance in terms of change in weight, compressive strength and visual appearance at regular intervals was carried out. After exposure in the acid solutions for 14 weeks, the samples showed very low weight loss. Results obtained from the present study indicate that Geopolymers are highly resistance to sulfuric acid and hydrochloric acid.

  7. Cure Behaviors of epoxy resin initiated by methylanilinium slats as latent cationic curing agent.

    Energy Technology Data Exchange (ETDEWEB)

    Park, S.J.; Kim, T.J.; Lee, C.J.; Lee, J.R. [Korea Research Institute of Chemical Technology, Taejeon (Korea); Park, J.K.; Shin, J.H. [Seoul National University, Seoul (Korea)

    2001-03-01

    The effect of novel N-crotyl-N, N-dimethyl-4-methylanilinium hexafluoroantimonate (CMH) curing agent as a thermal latent initiator on thermal behaviors, rheological properties, and thermal stability of diglycidylether of bisphenol A (DGEBA) epoxy cationic system was investigated. From DSC measurements of DGEBA/CMH system, it was shown that this system exhibits an excellent thermal latent characteristic at a given temperature. The conversion and conversion rate of DGEBA/CMH system increased with increasing the concentration of initiator, due to high activity of CMH. Rheological properties of the system were investigated under isothermal condition using a rheometer. The gelation time was obtained from the analysis of storage modulus (G'), loss modulus (G''), and damping factor (tan {delta}). As a result, the reduction of gelation time was affected by high curing temperature and concentration of CMH, resulting in high degree of network formation in cationic polymerization, due to difference of activity. The thermal stability of the cured epoxy resin was discussed in terms of the activation energy for decomposition and thermal factors determined from TGA measurements. (author). 29 refs., 3 tabs., 10 figs.

  8. Chinese Dream

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    The general managers of South Korean auto giants Hyundai and Kia have high hopes for the growing Chinese auto market. Both companies went through a painstaking period as the financial crisis first roared across the globe. Jin Shan-fa, General Manager of Hyundai Motor Group

  9. Improved method facilitates debulking and curing of phenolic impregnated asbestos

    Science.gov (United States)

    Gaines, P.

    1966-01-01

    Workpieces covered with phenolic impregnated asbestos tape and then wrapped with a specified thickness of nylon yarn under pressure, are debulked and cured in a standard oven. This method of debulking and curing is used in the fabrication of ablative chambers for the Gemini and Apollo attitude control engines.

  10. Isothermal epoxy-cure monitoring using nonlinear ultrasonics

    NARCIS (Netherlands)

    Koissin, V.; Demcenko, A.; Korneev, V.A.

    2014-01-01

    Isothermal curing of LY 1564SP resin in an aluminium-adhesive-aluminium laminate is investigated, using a nonlinear ultrasonic immersion technique, to prove its applicability for this type of dynamic material transformation. For verification and comparison, epoxy-cure kinetics and rheological behavi

  11. Shortest exposure time possible with LED curing lights

    NARCIS (Netherlands)

    Busemann, I.; Lipke, C.; Schattenberg, A.V.M.B.; Willershausen, B.; Ernst, C.P.

    2011-01-01

    PURPOSE: To investigate the shortest exposure time of different light emitting diode (LED)-curing devices for different resin composites in a clinically relevant laboratory model. METHODS: Nine LED curing devices (Bluephase, Bluephase 16i, Bluephase G2, Bluephase 20i/Ivoclar Vivadent, DEMI/sds Kerr,

  12. Curing mechanism of alkaline phenolic resin with organic ester

    Institute of Scientific and Technical Information of China (English)

    Huang Renhe; Wang Yanmin; Zhang Baoping

    2014-01-01

    To study the curing mechanism of alkaline phenolic resin with organic ester, three esters were chosen to react with three systems - alkaline phenolic resin, potassium hydroxide aqueous solution containing phenol, and potassium hydroxide aqueous solution. The variations of pH, heat release and gel pH during the reactions were monitored and measured. Infrared spectroscopy (IR) and thermal gravity analysis (TG) techniques were used to characterize the curing reaction. It was found that organic ester is only partial y hydrolyzed and resin can be cured through organic ester hydrolysis process as wel as the reaction with redundant organic ester. The sequential curing mechanism of alkaline phenolic resin cured by organic ester was identified as fol ows: a portion of organic ester is firstly hydrolyzed owing to the effect of the strong alkaline; the gel is then formed after the pH decreases to about 10.8-10.88, meanwhile, the redundant organic ester (i.e. non-hydrolysis ester) starts the curing reaction with the resin. It has also been found that the curing rate depends on the hydrolysis velocity of organic ester. The faster the hydrolysis speed of the ester, the faster the curing rate of the resin.

  13. Development of various curing effect of nominal strength Geopolymer concrete

    Directory of Open Access Journals (Sweden)

    S. Kumaravel

    2014-04-01

    Full Text Available Geopolymer concrete is an innovative method and is produced by complete elimination of ordinary Portland cement byproduced in fly ash. This study on different condition of curing in geopolymer concrete suitable for curing at ambient and heat-cured condition of temperature will widen its application to concrete structures. Low lime fly ash is used as the base material, which is reacted by alkaline solution and additional use of ground granulated blast furnace slag. Workability of fresh concrete and compressive strength of geopolymer concrete was investigated. The curing effect of geopolymer concrete is steam, hot air and ambient cubes specimens are tested in different days. Results are compared for various curing and strength of concrete.

  14. STUDY ON THE POST-CURE KINETICS OF EPOXY RESIN IRRADIATED BY AN ELECTRON BEAM

    Institute of Scientific and Technical Information of China (English)

    Jian-wen Bao; Ye Li; Xiang-yu Zhong; Xiang-bao Chen; Feng-mei Li

    2004-01-01

    The post-cure kinetics of electron beam (EB) curing of epoxy resin initiated by diaryiodinium was investigated.The post-cure reaction fits first order reaction kinetics. The reaction rate constant increases with increasing treatment temperature of post-cure. The reaction rate of post-cure is much lower than the rate of its reaction on electron beam treatment.

  15. Chinese Geography through Chinese Cuisine

    Science.gov (United States)

    Lipman, Jonathan

    2010-01-01

    China has the world's largest population, now over 1.3 billion, but its land area (much of it high mountains or desert) is about the same as that of the United States, which has less than one-fourth as many people. So Chinese farmers have learned to use every inch of their fertile land intensively. Pressure on the land has required extremely…

  16. Healing Without Waging War: Beyond Military Metaphors in Medicine and HIV Cure Research.

    Science.gov (United States)

    Nie, Jing-Bao; Gilbertson, Adam; de Roubaix, Malcolm; Staunton, Ciara; van Niekerk, Anton; Tucker, Joseph D; Rennie, Stuart

    2016-10-01

    Military metaphors are pervasive in biomedicine, including HIV research. Rooted in the mind set that regards pathogens as enemies to be defeated, terms such as "shock and kill" have become widely accepted idioms within HIV cure research. Such language and symbolism must be critically examined as they may be especially problematic when used to express scientific ideas within emerging health-related fields. In this article, philosophical analysis and an interdisciplinary literature review utilizing key texts from sociology, anthropology, history, and Chinese and African studies were conducted to investigate the current proliferation of military metaphors. We found the use of these metaphors to be ironic, unfortunate, and unnecessary. To overcome military metaphors we propose to (1) give them less aggressive meanings, and/or (2) replace them with more peaceful metaphors. Building on previous authors' work, we argue for the increased use of "journey" (and related) metaphors as meaningful, cross-culturally appropriate alternatives to military metaphors.

  17. Variation of Resin Properties Through the Thickness of Cured Samples

    Science.gov (United States)

    1984-01-01

    It is the purpose of this work to gain knowledge of the glassy materials used as matrices in composites and to study the homogeneity resulting from the curing process. An attempt is made to link the glass transition quantitatively with the presence of a given material. Expoxy resins containing various amounts of hardener (TGDDM/DDS system) were cured in a muffle furnace at 473 K for seven hours. The glass transition temperature, T sub g versus weight minus percent of hardener in the epoxy resin were measured. A limit was rapidly reached in T sub g at only two percent hardener. Thus, the glass transition of the fully cured epoxy-amine matrix seems not much different from the epoxide-epoxide cure. The T sub g versus cure-time for the epoxide-epoxide reaction was also studied. My 720 was cured by itself in an oil bath at 473 K for different lengths of time. The T sub g was found to increase exponentially with the cure time, and a maximum T sub g of about 450 K was reached after eleven hours. The reaction was found to be inhibited by running the sample under argon.

  18. Development of Geopolymer Concrete with Different Curing Conditions

    Directory of Open Access Journals (Sweden)

    M.F. Nuruddin Nuruddin

    2011-02-01

    Full Text Available Environmental issues resulted from cement production have become a major concern today. To develop a sustainable future it is encouraged to limit the use of this construction material that can affect the environment. Cement replacement material was proposed to partially replace cement portion in concrete. Geopolymer is a part of inorganic polymer material that has similar bonding function like cement in concrete. It consists of alkaline solutions and geological source material. Alkaline liquids used in this research are 8 M sodium hydroxide (NaOH solution and sodium silicate (Na2SiO3 solutions, while source materials are fly ash and microwave incinerated rice husk ash (MIRHA. Three different curing regimes, namely hot gunny curing, ambient curing, and external exposure curing, were applied to obtain suitable method that was suitable with cast in situ application. Geopolymer concrete samples were tested on their compressive strength and microstructure properties. It was found that external exposure curing had the highest compressive strength compared to other two curing methods. Scanning electron microscopy analysis also showed better improvement in interfacial transition zone for concrete sample with external exposure curing.

  19. Electron Beam Cured Epoxy Resin Composites for High Temperature Applications

    Science.gov (United States)

    Janke, Christopher J.; Dorsey, George F.; Havens, Stephen J.; Lopata, Vincent J.; Meador, Michael A.

    1997-01-01

    Electron beam curing of Polymer Matrix Composites (PMC's) is a nonthermal, nonautoclave curing process that has been demonstrated to be a cost effective and advantageous alternative to conventional thermal curing. Advantages of electron beam curing include: reduced manufacturing costs; significantly reduced curing times; improvements in part quality and performance; reduced environmental and health concerns; and improvement in material handling. In 1994 a Cooperative Research and Development Agreement (CRADA), sponsored by the Department of Energy Defense Programs and 10 industrial partners, was established to advance the electron beam curing of PMC technology. Over the last several years a significant amount of effort within the CRADA has been devoted to the development and optimization of resin systems and PMCs that match the performance of thermal cured composites. This highly successful materials development effort has resulted in a board family of high performance, electron beam curable cationic epoxy resin systems possessing a wide range of excellent processing and property profiles. Hundreds of resin systems, both toughened and untoughened, offering unlimited formulation and processing flexibility have been developed and evaluated in the CRADA program.

  20. A 'cure' for Down syndrome: what do parents want?

    Science.gov (United States)

    Inglis, A; Lohn, Z; Austin, J C; Hippman, C

    2014-10-01

    Recent advancements in molecular genetics raise the possibility that therapeutics or a 'cure' for Down syndrome (DS) may become available. However, there are no data regarding how parents of children with DS perceive the possibility of mitigating specific manifestations such as the intellectual disability (ID) associated with DS, or curing the condition entirely. To explore these issues, we distributed a questionnaire to members of the Lower Mainland Down Syndrome Society in British Columbia, Canada. Questionnaires were completed by 101 parents (response rate=41%). A majority (61%) viewed the possibility of reversing ID in DS positively, but only 41% said that they would 'cure' their child of DS if it were possible. Twenty-seven percent of respondents said they would not 'cure' their child, and 32% were unsure if they would 'cure' their child. The most commonly cited motivation for opting for a 'cure' was to increase their child's independence. However, parental attitudes' towards a 'cure' for DS were complex, affected by ethical issues, perceived societal values, and pragmatic factors such as the age of the individual and long-term care-giving burden. These findings could be used by healthcare professionals supporting families who include a member with DS and to direct future research.

  1. Composite depth of cure using four polymerization techniques

    Directory of Open Access Journals (Sweden)

    Ericson Janolio de Camargo

    2009-10-01

    Full Text Available The light-curing technique is relevant to reduce the degree of polymerization shrinkage, improving clinical and esthetic success of composite resin restorations. OBJECTIVE: To evaluate in vitro the effect of four light-curing techniques on depth of cure of a composite resin. MATERIAL AND METHODS: Ten specimens of a composite resin were made in cylindrical cavities prepared in PVC plates (3.0 X 7.0 mm for each light-curing technique. Four photoactivation methods were investigated: stepped, ramped, pulse-delay and traditional. Specimens were longitudinally sectioned and polished for microhardness measurements (kg/mm², which were made at 0.1, 1.0, 2.0 and 4.0 mm from the irradiated surface. Data were subjected to ANOVA and Tukey's test. RESULTS: The effect of factors studied (curing method and distance from the surface and the interaction of these factors was statistically significant (p<0.05. The traditional method of cure provided higher microhardness values (69.6 ± 2.5 than the stepped (63.5 ± 3.1 and pulsed (63.9 ± 3.2 methods at all depths evaluated, but it did not differ from the ramped method (66.7± 4.4 at 0.1 and 1.0 mm of depth. CONCLUSION: All techniques employed provided satisfactory cure of the composite resin up to the depth of 2.0 mm from the irradiated surface.

  2. Development of a resin curing model for UV nanoimprint.

    Science.gov (United States)

    Lee, Jin Woo; Cho, Dong-Woo

    2005-10-01

    UV nanoimprint lithography uses UV light as an energy source. It is performed at room temperature and low pressure, and has its own merits as compared to thermal nanoimprint. In this paper, a measurement system was developed to measure the degree of resin curing in UV nanoimprint to improve our understanding of the resin solidification phenomenon. A curing model was then established based on the measurement results. The measurement system measured the degree of cure in real time and was composed of a Fourier transform infrared spectroscopy system, a UV light source, and an optical guide. Also, new UV-curable resins that had low viscosity values were developed for the UV nanoimprint process, and imprint tests using these resins were performed successfully. The curing model considered the UV irradiation time, power, and curing temperature, which are important parameters in the UV nanoimprint process. The degree of cure had an exponential relation to UV irradiation time, power, and temperature; thus, the curing model was expressed as an exponential function of the UV irradiation time, power, and temperature. The developed model was verified for various UV-curable resins.

  3. LEARNING CHINESE

    Institute of Scientific and Technical Information of China (English)

    1995-01-01

    Vocabulary: 银行 yin hang bank 邮局 you jǔ (you as in "slow") post office 电报 dian bao telegram 邮票 you piao (you as in "know") stamp 信 xin letter 信封 xin feng envelope 航空 hang kong airmail 包裹 bao guo parcel 元 yuan a unit of currency in China 人民币 ren min bi RMB (the name of Chinese currency)

  4. Chinese Weddings

    Institute of Scientific and Technical Information of China (English)

    1997-01-01

    ACCORDING to the Marriage Law of the People’s Republic of China, marital kinship is established and protected by law when a couple registers at tile local marriage registration office. The newly-weds usually hold a wedding feast in celebration at home or in a restaurant. The big red Chinese character, "Double Happiness," would be pasted on walls at the ceremonial hall to

  5. Pharmacodynamic study on insomnia-curing effects of Shuangxia Decoction in Drosophila melanogaster.

    Science.gov (United States)

    Zhang, Zhi-Qian; Degejin; Geng, Di; Zhang, Qi; Tian, Yan; Xi, Yuan; Wang, Wen-Qi; Tang, Hua-Qi; Xu, Bing; Lin, Hong-Ying; Sun, Yi-Kun

    2016-09-01

    The present study aimed to establish a pharmacodynamic method using the pySolo software to explore the influence of freeze-dried powders of Shuangxia Decoction (SXD) on the sleep of normal Drosophila melanogaster and the Drosophila melanogaster whose sleep was divested by light. The dose-effect and the time-effect relationships of SXD on sleep were examined. The effect-onset concentration of SXD was 0.25%, the plateau appeared at the concentration of 2.5% and the total sleep time showed a downtrend when the concentration was greater than 2.5%. The sleep time was the longest on the fourth day after SXD was given. The fruit fly sleep deprivation model was repeated by light stimulation at night. The middle dosage group (2.5%) had the best insomnia-curing effect. In conclusion, using the pySolo software, an approach for the pharmacodynamics study was established with Drosophila melanogaster as a model organism to determine the insomnia-curing effects of the traditional Chinese medicine (TCM). Our results demonstrated the reliability of this method. The freeze-dried powders of SXD could effectively improve the sleep quality of Drosophila melanogaster.

  6. Changes on degree of conversion of dual-cure luting light-cured with blue LED

    Science.gov (United States)

    Bandéca, M. C.; El-Mowafy, O.; Saade, E. G.; Rastelli, A. N. S.; Bagnato, V. S.; Porto-Neto, S. T.

    2009-05-01

    The indirect adhesive procedures constitute recently a substantial portion of contemporary esthetic restorative treatments. The resin cements have been used to bond tooth substrate and restorative materials. Due to recently introduction of the self-bonding resin luting cement based on a new monomer, filler and initiation technology has become important to study the degree of conversion of these new materials. In the present work the polymerization reaction and the filler content of dual-cured dental resin cements were studied by means of infra-red spectroscopy (FT-IR) and thermogravimetry (TG). Twenty specimens were made in a metallic mold (8 mm diameter × 1 mm thick) from each of 2 cements, Panavia® F2.0 (Kuraray) and RelyX™ Unicem Applicap (3M/ESPE). Each specimen was cured with blue LED with power density of 500 mW/cm2 for 30 s. Immediately after curing, 24 and 48 h, and 7 days DC was determined. For each time interval 5 specimens were pulverized, pressed with KBr and analyzed with FT-IR. The TG measurements were performed in Netzsch TG 209 under oxygen atmosphere and heating rate of 10°C/min from 25 to 700°C. A two-way ANOVA showed DC (%) mean values statistically significance differences between two cements ( p 0.05). The Relx-Y™ Unicem mean values were significantly higher than Panavia® F 2.0. The degree of conversion means values increasing with the storage time and the filler content showed similar for both resin cements.

  7. Chinese Culture and Leadership.

    Science.gov (United States)

    Wong, Kam-Cheung

    2001-01-01

    Describes essential characteristics of Chinese philosophical tradition; Discusses Western perspectives on value leadership in education, particularly moral leadership. Discuses moral leadership from a Chinese philosophical perspective, especially Confucianism. Draws implications for using Chinese cultural and philosophical traditions to develop…

  8. CHINESE JOURNAL OF CHEMISTRY

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    @@Chinese Journal of Chemistry is an international journal published in English by the Chinese Chemical Society with its editorial office hosted by Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences.

  9. Experimental observation of internal water curing of concrete

    DEFF Research Database (Denmark)

    Lura, Pietro; Jensen, Ole Mejlhede

    2007-01-01

    Internal water curing has a significant effect on concrete. In addition to affecting hydration and moisture distribution, it influences most concrete properties, such as strength, shrinkage, cracking, and durability. The following paper is an overview of experimental methods to study internal water...... curing of concrete and its consequences. The special techniques needed to study internal water curing are dealt with along with the consequences of this process. Examples of applications are given and new measuring techniques that may potentially be applied to this field are addressed....

  10. The Chinese Banking System

    OpenAIRE

    2012-01-01

    The Chinese banking system is critical to the functioning of the Chinese economy, being the main conduit through which savings are allocated to investment opportunities. Banking activity in China has grown rapidly over the past decade in association with the expansion of the Chinese economy, and the Chinese banking system now includes some of the world’s largest banks. Chinese banks have become more commercially orientated over this period, although the Chinese Government retains considerable...

  11. Micro-leakage of a Fissure Sealant Cured Using Quartz-tungsten-halogen and Plasma Arc Light Curing Units.

    Science.gov (United States)

    Bahrololoomi, Zahra; Soleimani, Ali Asghar; Jafari, Najmeh; Varkesh, Bentolhoda

    2014-01-01

    Background and aims. Newer curing units such as plasma arc can polymerize the sealants in much shorter curing times. The aim of this study was to compare the effect of two different curing units on the micro-leakage of a fissure sealant material. Materials and methods. Sixty two extracted premolars without caries were randomly divided into two groups of 31 samples. Occlusal surfaces of all teeth were cleansed. Then, teeth surfaces were etched by 37% phosphoric acid. After rinsing and drying, occlusal surfaces of teeth were sealed by a fissure sealant. The sealant was then cured using either a halogen light curing unit or a plasma arc curing light. After sealing, the teeth were thermocycled for 500 cycles. The teeth were then sectioned and examined for micro-leakage. Statistical analyses were performed with Mann-Whitney test. Results. There was no significant difference between two groups regarding micro-leakage (P = 0.42). Conclusion. Results showed that there was no significant difference between two different curing units. Therefore, plasma arc unit might be a useful alternative for sealant polymerization.

  12. Measuring Vapors To Monitor the State of Cure of a Resin

    Science.gov (United States)

    Cramer, Elliott; Perey, Daniel F.; Yost, William T.

    2006-01-01

    A proposed noninvasive method of monitoring the cure path and the state of cure of an epoxy or other resin involves measurement of the concentration( s) of one or more compound(s) in the vaporous effluent emitted during the curing process. The method is based on the following general ideas: (1) The concentrations of the effluent compounds in the vicinity of the curing resin are approximately proportional to the instantaneous rate of curing. (2) As curing proceeds at a given temperature, subsequent decreases in the concentrations are indicative of approaching completion of cure; that is, the lower are the concentrations, the more nearly complete is the cure.

  13. The effect of curing light and chemical catalyst on the degree of conversion of two dual cured resin luting cements.

    Science.gov (United States)

    Souza-Junior, Eduardo José; Prieto, Lúcia Trazzi; Soares, Giulliana Panfiglio; Dias, Carlos Tadeu dos Santos; Aguiar, Flávio Henrique Baggio; Paulillo, Luís Alexandre Maffei Sartini

    2012-01-01

    The aim of this study was to evaluate the influence of different curing lights and chemical catalysts on the degree of conversion of resin luting cements. A total of 60 disk-shaped specimens of RelyX ARC or Panavia F of diameter 5 mm and thickness 0.5 mm were prepared and the respective chemical catalyst (Scotchbond Multi-Purpose Plus or ED Primer) was added. The specimens were light-cured using different curing units (an argon ion laser, an LED or a quartz-tungsten-halogen light) through shade A2 composite disks of diameter 10 mm and thickness 2 mm. After 24 h of dry storage at 37°C, the degree of conversion of the resin luting cements was measured by Fourier-transformed infrared spectroscopy. For statistical analysis, ANOVA and the Tukey test were used, with p ≤ 0.05. Panavia F when used without catalyst and cured using the LED or the argon ion laser showed degree of conversion values significantly lower than RelyX ARC, with and without catalyst, and cured with any of the light sources. Therefore, the degree of conversion of Panavia F with ED Primer cured with the quartz-tungsten-halogen light was significantly different from that of RelyX ARC regardless of the use of the chemical catalyst and light curing source. In conclusion, RelyX ARC can be cured satisfactorily with the argon ion laser, LED or quartz-tungsten-halogen light with or without a chemical catalyst. To obtain a satisfactory degree of conversion, Panavia F luting cement should be used with ED Primer and cured with halogen light.

  14. CHINESE LACQUER – SHORT OVERVIEW OF TRADITIONAL TECHNIQUES AND MATERIAL CHARACTERISATION FOR CONSERVATION PURPOSES

    Directory of Open Access Journals (Sweden)

    Xin You LIU

    2014-12-01

    Full Text Available Chinese lacquer (urushi is an ancient natural finishing material obtained from the sap of the lacquer trees (Rhus vernicifera. This has been used for millennia to protect and decorate furniture and various artefacts made of wood or other materials. Lacquered objects are important components of Chinese and world cultural heritage and their conservation imposes a good knowledge and understanding of the material and traditional techniques. This paper presents basic information on the Chinese lacquer as material and lacquering techniques in their historic evolution during different dynasties. The experimental part looked at the physical properties of raw urushi lacquer, respectively aspect, solids content and miscibility with different solvents. A limited compatibility with white spirit as potential thinner was demonstrated. Furthermore, the microstructure of the cured film and characteristic chemical features of raw urushi lacquer as liquid and cured film were investigated. The cured film of raw urushi presents a characteristic microstructural pattern. FTIR spectroscopy revealed a partial oxidation and polymerization following processing by Kuromisation. The further curing accentuated these changes, visible as a decrease of hydroxyl absorptions bands (3400 and 1360cm-1 occurring in parallel with an increase of carbonyl band (1740cm-1 . A strong decrease of the absorption band at 1270cm-1 , which nearly disappears for the cured film, was also observed

  15. Comparative Study of Alkali-Activated Fly Ash Manufactured Under Pulsed Microwave Curing and Thermal Oven Curing

    OpenAIRE

    Shi, Shi; Bai, Yun; Li, H.; Xu, D. L.; Basheer, P. A. Muhammed

    2014-01-01

    This paper compares the alkali-activated fly ash (AAFA) manufactured with thermal oven curing and pulsed microwave curing methods. Fly ash activated by 8M NaOH solution at a liquid to solid ratio of 0.3 was cured by thermal oven at 85°C and domestic microwave oven, respectively. Apart from compressive strength test, the temperature profiles of AAFA samples were captured by thermal camera. Reaction products of AAFA were characterised with XRD, FTIR and TG/DTG, while the microstructure of AAFA ...

  16. Chemistry and technology of Cured and Smoked Meat Products

    Directory of Open Access Journals (Sweden)

    V. K. Mathur

    1967-05-01

    Full Text Available Recent developments in the chemistry and technology of cured and smoked meat products are reviewed. Various factors physical, chemical and microbiological affecting water holding capacity of cured meats and cured colour formation and its stability during storage are discussed. Methods of preparation of various types of cured and smoked meat products have been briefly described. Developments in the use of synthetic casings and skinless sausages have been mentioned. Smoke constituents, their role and physico-chemical aspects of mechanism and functions of smoking are discussed. Advancements in the methods of smoke generation, conventional smoking and some kilns, electrostatic smoking and smoking by use of liquid smokes have been described. Some of the methods of preparation of liquid smokes are also given.

  17. Cure monitoring using ultrasonic guided waves in wires

    Science.gov (United States)

    Vogt, T.; Lowe, M.; Cawley, P.

    2003-09-01

    The possibility of using ultrasonic guided waves for monitoring the cure process of epoxy resins is investigated. The two techniques presented use a wire waveguide which is partly embedded in the resin. The first technique is based on the measurement of attenuation due to leakage of bulk waves into the resin surrounding the waveguide. The second technique measures the reflection of the guided wave that occurs at the point where the waveguide enters the resin. Both the attenuation and the reflection coefficient change significantly during cure, and the numerical methods to relate these to the material properties of the curing resin are presented in this paper. The results from the modeling are experimentally verified and show good agreement. The applicability of each testing method is discussed, and typical cure-monitoring curves are presented.

  18. Curing of Epoxy Resin Induced by Femtosecond Laser Pulse

    Institute of Scientific and Technical Information of China (English)

    LI Yubin; ZHANG Zuoguang

    2005-01-01

    The possibility of curing of epoxy resin induced by femtosecond laser beam was explored through choosing different initiators . Absorption spectroscopy, infrared spectroscopy (IR), stereomicroscopy and scanning electron microscopy (SEM) were applied to analyze the structure of epoxy resin systems after irradiation with a femtosecond laser beam. The experimental results show that the epoxy resin systems containing diaryliodonium salts can be cured by irradiation of Jemtosecond laser pulse, while the systems containing benzoin can not be cured. It is found that diaryliodonium salts decompose under the irradiation of femtosecond laser pulse through multi ( two ) -photon absorption, initiating the ring-opening polymerization of epoxy resin. And the appearance of cured area has a sheet structure consisting of many tiny lamellar structures.

  19. GENERAL ENVIRONMENTAL CORPORATION; CURE ELECTROCOAGULATION TECHNOLOGY: INNOVATIVE TECHNOLOGY EVALUATION REPORT

    Science.gov (United States)

    The CURE electrocoagulation technology was demonstrated under the Superfund Innovative Technology Evaluation (SITE) program at the U.S. Department of Energy (DOE) Rocky Flats Environmental Technology Site (RFETS), where water from the solar evaporation ponds (SEPs) was contaminat...

  20. Cure monitoring using ultrasonic guided waves in wires.

    Science.gov (United States)

    Vogt, T; Lowe, M; Cawley, P

    2003-09-01

    The possibility of using ultrasonic guided waves for monitoring the cure process of epoxy resins is investigated. The two techniques presented use a wire waveguide which is partly embedded in the resin. The first technique is based on the measurement of attenuation due to leakage of bulk waves into the resin surrounding the waveguide. The second technique measures the reflection of the guided wave that occurs at the point where the waveguide enters the resin. Both the attenuation and the reflection coefficient change significantly during cure, and the numerical methods to relate these to the material properties of the curing resin are presented in this paper. The results from the modeling are experimentally verified and show good agreement. The applicability of each testing method is discussed, and typical cure-monitoring curves are presented.

  1. Factors affecting dry-cured ham consumer acceptability.

    Science.gov (United States)

    Morales, R; Guerrero, L; Aguiar, A P S; Guàrdia, M D; Gou, P

    2013-11-01

    The objectives of the present study were (1) to compare the relative importance of price, processing time, texture and intramuscular fat in purchase intention of dry-cured ham through conjoint analysis, (2) to evaluate the effect of dry-cured ham appearance on consumer expectations, and (3) to describe the consumer sensory preferences of dry-cured ham using external preference mapping. Texture and processing time influenced the consumer preferences in conjoint analysis. Red colour intensity, colour uniformity, external fat and white film presence/absence influenced consumer expectations. The consumer disliked hams with bitter and metallic flavour and with excessive saltiness and piquantness. Differences between expected and experienced acceptability were found, which indicates that the visual preference of consumers does not allow them to select a dry-cured ham that satisfies their sensory preferences of flavour and texture.

  2. The Prevention and Cure of Cervical Vertebra Disease

    Institute of Scientific and Technical Information of China (English)

    1994-01-01

    CERVICAL vertebra problems are common and usually occur in middleaged and elderly people, especially those who often bend over. The symptoms patients might encounter are dizziness, headache, neck and shoulder pain and numbness, and even viscera trouble. The following exercises are a simple and convenient way to prevent and cure cervical vertebra problems. If you continue doing the exercises, you can prevent and cure them. Here are the exercises step by step:

  3. Cure Characteristics of Tricyanate Ester High Temperature Composite Resins (PREPRINT)

    Science.gov (United States)

    2011-02-09

    isothermal DSC data were analyzed via the Kissinger [17], Ozawa [18], and Friedman [19] methods, as described in the recent analysis of dicyanate ester...7 present the graphical analysis that underlies the Kissinger [17], Ozawa [18], and Friedman [19] methods, respectively, of non-isothermal DSC cure...where β is the heating rate and Tp the absolute temperature at the peak cure rate, is proportional to the activation energy. For the Ozawa method

  4. In-situ cure monitoring of epoxy resin systems

    OpenAIRE

    Powell, Graham

    1998-01-01

    This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University. This thesis describes the work carried out at Brunel University to develop novel optical fibre sensors capable of monitoring the cure state of an epoxy/amine resin system. The sensors were of simple construction, consisting of an optical fibre from which the silicone cladding layer had been removed over a short length. This stripped length was embedded into the curing resin system. The sensor...

  5. Absolutely Chinese

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    <正>Ink painting animation - an exquisite art form that ends up in a museum Little Tadpole Looking for Mummy Little Tadpole Looking for Mummy, China’s first ink painting animation, was produced in 1961. With innovation in painting, photography and production technology, it was the first effort at ’animating’ ink paintings. Fishes, shrimps, frogs and crabs in the film resemble those in Qi Baishi’s works. By any shot, it’s an animated painting of fishes and insects, one that is suffused with a taste of Chinese ink-and-wash painting.

  6. Fifty-Four Infantile Intractable Diarrhea Patients Treated with Integrated Traditional Chinese and Western Medicine

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Infantile intractable diarrhea (IID) was usually complicated with malnutrition, growth retardation and pulmonary infection, etc. It is difficult to cure, and mortality is rather high. The authors used integrated traditional Chinese and western medicine therapy to treat it, and satisfactory result has been obtained and reported as follows.

  7. CURING PROCESS OF PHOTOPOLYMER RESIN BOND DIAMOND TOOLS

    Institute of Scientific and Technical Information of China (English)

    GAO Tao; PENG Wei; YAO Chunyan

    2007-01-01

    Analytical simulation and corresponding proof-test are adopted to study the principle of the curing process of photopolymer resin diamond tools. The influence of the diamond as abrasives in photopolymer resin owing to the absorptivity of the diamond for the UV light on the photopolymer resin curing process is discussed. Based on the above, a kind of diamond tool-dicing blade is selected to analyze the curing process of photopolymer bond diamond tools. An analytical model of curing process is developed and a correlation curve between the depth of polymerization of the photopolymer resin diamond tools and the exposure time to represent the curing process of photopolymer bond dicing blade. A test is done to proof-test the validity of the analytical model and the correlation curve. The simulated data fit the experimental results, which demonstrates the analytical models and numerical algorithm are of high reliability. The analytical simulation method could possibly be used to optimize the curing cycle and improve the quality of the photopolymers resin bond diamond tools.

  8. Monitoring the Cure State of Thermosetting Resins by Ultrasound

    Directory of Open Access Journals (Sweden)

    Alfonso Maffezzoli

    2013-09-01

    Full Text Available The propagation of low intensity ultrasound in a curing resin, acting as a high frequency oscillatory excitation, has been recently proposed as an ultrasonic dynamic mechanical analysis (UDMA for cure monitoring. The technique measures sound velocity and attenuation, which are very sensitive to changes in the viscoelastic characteristics of the curing resin, since the velocity is related to the resin storage modulus and density, while the attenuation is related to the energy dissipation and scattering in the curing resin. The paper reviews the results obtained by the authors’ research group in the last decade by means of in-house made ultrasonic set-ups for both contact and air-coupled ultrasonic experiments. The basics of the ultrasonic wave propagation in polymers and examples of measurements of the time-evolution of ultrasonic longitudinal modulus and chemical conversion of different thermosetting resins are presented. The effect of temperature on the cure kinetics, the comparison with rheological, low frequency dynamic mechanical and calorimetric results, and the correlation between ultrasonic modulus and crosslinking density will be also discussed. The paper highlights the reliability of ultrasonic wave propagation for monitoring the physical changes taking place during curing and the potential for online monitoring during polymer and polymer matrix composite processing.

  9. Depth of cure of bulk-fill flowable composite resins.

    Science.gov (United States)

    Pedalino, Inaam; Hartup, Grant R; Vandewalle, Kraig S

    2015-01-01

    In recent years, manufacturers have introduced flowable composite resins that reportedly can be placed in increments of 4 mm or greater. The purpose of this study was to evaluate the depth of cure of bulk-fill flowable composite resins (SureFil SDR Flow, Grandio Flow, and Venus Bulk Fill) and a conventional flowable composite resin (Revolution Formula 2). Depth of cure was measured in terms of bottom-maximum Knoop hardness number (KHN) ratios and the International Organization for Standardization (ISO) 4049 scrape technique. Shades A2 and A3 of SureFil SDR Flow, Grandio Flow, and Revolution Formula 2 were tested. Venus Bulk Fill was tested in its only available shade (universal). Specimens in thicknesses of 2, 3, 4, 5, and 6 mm were polymerized for 20 or 40 seconds, and a hardness tester was used to determine the hardness ratios for each shade at each thickness. For the scraping technique, after specimens were exposed to the curing light, unpolymerized composite resin was removed with a plastic instrument, the polymerized composite was measured, and the length was divided by 2 per ISO guidelines. According to the KHN ratios and the scrape test, Venus Bulk Fill predictably exceeded the manufacturer's claim of a 4-mm depth of cure at both 20 and 40 seconds of curing time. The overall results for depth of cure showed that Venus Bulk Fill ≥ SureFil SDR Flow ≥ Grandio Flow ≥ Revolution Formula 2.

  10. Treatment of Severe Post-kidney-transplant Lung Infection by Integrative Chinese and Western Medicine

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Objective: To explore treatments of severe post-kidney-transplant lung infection by integrative Chinese and Western medicine (ICWM), in order to elevate the curing rate as well as to lower the death rate. Methods: Based on conventional ways of Western medical treatments of 18 cases of severe post-kidney-transplant lung infection, such as putting the patients in single individual ward, antibiotics to prevent infection, respiratory machines, blood filtration, nutritional support, steroids, and maintaining electrolytes balance, we applied integrated Chinese medicinal treatments, like altering conventional prescription "pneumonia Ⅲ ", and conducted clinical observation of effectiveness, and indexes including white blood cell (WBC), neutrophilic granulocyte, blood urea nitrogen (BUN), blood creatinine (Cr), etc. Results: Of the 18cases studied, 7 were already cured, 8 proved the treatment effective, 3 died. All clinical indexes had statistically significant changes compared with those of before treatment (P<0.01). Conclusion: ICWM can increase curing rate and lower death rate.

  11. Degree of cure-dependent modelling for polymer curing processes at small-strain. Part I: consistent reformulation

    Science.gov (United States)

    Hossain, M.; Steinmann, P.

    2014-04-01

    A physically-based small strain curing model has been developed and discussed in our previous contribution (Hossain et al. in Comput Mech 43:769-779, 2009a) which was extended later for finite strain elasticity and viscoelasticity including shrinkage in Hossain et al. (Comput Mech 44(5):621-630, 2009b) and in Hossain et al. (Comput Mech 46(3):363-375, 2010), respectively. The previously proposed constitutive models for curing processes are based on the temporal evolution of the material parameters, namely the shear modulus and the relaxation time (in the case of viscoelasticity). In the current paper, a thermodynamically consistent small strain constitutive model is formulated that is directly based on the degree of cure, a key parameter in the curing (reaction) kinetics. The new formulation is also in line with the earlier proposed hypoelastic approach. The curing process of polymers is a complex phenomenon involving a series of chemical reactions which transform a viscoelastic fluid into a viscoelastic solid during which the temperature, the chemistry and the mechanics are coupled. Part I of this work will deal with an isothermal viscoelastic formulation including shrinkage effects whereas the following Part II will give emphasis on the thermomechanical coupled approach. Some representative numerical examples conclude the paper and show the capability of the newly proposed constitutive formulation to capture major phenomena observed during the curing processes of polymers.

  12. Chinese letterkunde. Een inleiding

    NARCIS (Netherlands)

    Idema, Wilt; Haft, Lloyd

    2005-01-01

    De Chinese cultuur mag zich verheugen in een groeiende belangstelling. Chinese films bereiken in Nederland een steeds omvangrijker publiek en ook de moderne Chinese literatuur, die sinds de jaren tachtig een grote bloei doormaakt, wordt door veel liefhebbers op de voet gevolgd. Chinese Letterkunde b

  13. UV-cured methacrylic-silica hybrids: Effect of oxygen inhibition on photo-curing kinetics

    Energy Technology Data Exchange (ETDEWEB)

    Corcione, C. Esposito; Striani, R.; Frigione, M., E-mail: mariaenrica.frigione@unisalento.it

    2014-01-20

    Highlights: • The kinetic behavior of novel photopolymerizable organic–inorganic hybrid system was studied as a function of the composition and of the atmosphere for reactions. • The UV-curing reaction of the hybrid mixture was found fast and complete. • The combined presence of thiol monomer and nanostructured silica allows to reduce the effect of inhibition of oxygen towards the radical photopolymerization. - Abstract: The kinetic behavior of innovative photopolymerizable UV-cured methacrylic–silica hybrid formulations, previously developed, was studied and compared to that of a reference control system. The organic–inorganic (O–I) hybrids proposed in this study are obtained from organic precursors with a high siloxane content mixed with tetraethoxysilane (TEOS) in such a way to produce co-continuous silica nano-domains dispersed within a cross-linked organic phase, as a result of the hydrolysis and condensation reactions. The kinetics of the radical photopolymerization mechanism induced by UV-radiations, in presence of a suitable photoinitiator, was studied by calorimetric, FTIR and Raman spectroscopic analyses, by varying the composition of the mixtures and the atmosphere for reactions. The well known effect of oxygen on the kinetic mechanism of the free radical photopolymerization of the methacrylic–siloxane based monomers was found to be strongly reduced in the hybrid system, especially when a proper thiol was used. The experimental calorimetric data were fitted using a simple kinetic model for radical photopolymerization reactions, obtaining a good agreement between the experimental data and the theoretical model. From the comparison of the kinetic constants calculated for control and hybrid systems, it was possible to assess the effect of the composition, as well as of the atmosphere used during the photo-polymerization process, on the kinetic of photopolymerization reaction.

  14. SENSORY CHARACTERISTICS OF NATIVE CHICKEN QUEEN PINEAPPLE-CURED HAM

    Directory of Open Access Journals (Sweden)

    Dr. Lilibeth A. Roxas

    2015-01-01

    Full Text Available The potential of Native Chicken to be processed into palatable ham was conducted making use of Queen Pineapple (QP crude extract as one of the curing ingredients. Primarily, the main goal is to develop a protocol in the manufacture of processed native chicken ham and determine the organoleptic quality of native chicken ham product. The age of the bird and maturity of the fruit were considered for the best organoleptic quality of chicken ham. In this study, the combine injection and dry cure (CIDC method of the conventional formula was adopted. The desired amount of QP crude extract was first determined for the pump pickle. Curing salt was used for the control while different volume of pineapple crude extract was used in two treatments. The protocols for processing native chicken were developed using slaughter native chicken, and QP crude extract as curing ingredient for ham making. Color, flavor, juiciness and tenderness were among the desirable characteristics considered in this study. The sensory evaluation by trained panelists on QP-cured ham samples demonstrated comparable results. All the cooked meat samples were apparently acceptable to the sensory panel. The mean scores for flavor, juiciness and tenderness of meat samples have slight differences; however, they are not statistically significant. Indeed, native chicken can be processed into palatable ham with queen pineapple (Formosa variety extract that served as curing ingredient, flavor enhancer and tenderizer. Native Chicken QP-Cured ham is a commendable value-added product for both native chicken and queen pineapple by-products (butterball size.

  15. Influence of argon laser curing on resin bond strength.

    Science.gov (United States)

    Hinoura, K; Miyazaki, M; Onose, H

    1993-04-01

    Light cured resin composites are usually cured with halogen lamps whose light output decreases with time and distance to the resin surface. This study compared bond strengths of resins to tooth structure cured with either an argon laser or a conventional halogen light. The enamel and dentin of bovine incisors were ground on the buccal surface with wet #600 grit SiC paper. A 4 x 2 mm mold was placed on the tooth surface and Scotchbond 2/Silux and Clearfil Photobond/Photo Clearfil A were placed into the molds and cured using a Quick Light or an argon laser for exposure times of 10, 20, and 30 seconds, and distances of 0.0, 0.5, 1.0, and 1.5 mm from the resin surface. The intensity of the Quick Light was measured as 510 mW/cm2 at 470 +/- 15 nm and the intensity of the argon laser was adjusted to 510 mW/cm2 before curing. Shear bond tests at a crosshead speed of 1.0 mm/min were performed after 24 hours of storage in water. The bond strengths obtained with the halogen lamp and the laser were not significantly different at the same exposure times and at 0.0 or 0.5 mm from the resin surface. The laser cured bond strengths did not decrease with increasing distance whereas there was a significant decrease in halogen bond strengths at distances greater than 0.5 mm for both resins. The use of the laser might provide a clinical advantage in cases where the curing light source cannot be brought into proximity to the surface of the resin.

  16. Management of Chinese restaurant

    OpenAIRE

    Cui , Longbo

    2009-01-01

    With Chinese economy developing rapidly, the Chinese restaurant is under the spotlight, but the management of Chinese restaurant is weak at the moment, especially on the service management, which is an important part of service management in the Chinese restaurant. On the other hand, the managers of Chinese restaurant should pay more attention on the service management for instance brand, service innovation. Service management is core and essential concept for every service company recently, ...

  17. Photothermal radiometry monitoring of light curing in resins

    Energy Technology Data Exchange (ETDEWEB)

    Zambrano-Arjona, M A [Applied Physics Department, Cinvestav-Unidad Merida, A.P. 73 Cordemex, Merida, 97310 (Mexico); Medina-Esquivel, R [Cinvestav-Unidad Queretaro, Libramiento Norponiente 2000 Fracc. Real de Juriquilla, CP 76230, Queretaro (Mexico); Alvarado-Gil, J J [Applied Physics Department, Cinvestav-Unidad Merida, A.P. 73 Cordemex, Merida, 97310 (Mexico)

    2007-10-07

    Real time measurement of thermal diffusivity during the evolution of the light curing process in dental resins is reported using photothermal radiometry. The curing is induced by a non-modulated blue light beam, and at the same time, a modulated red laser beam is sent onto the sample, generating a train of thermal waves that produce modulated infrared radiation. The monitoring of this radiation permits to follow the time evolution of the process. The methodology is applied to two different commercially available light curing resin-based composites. In all cases thermal diffusivity follows a first order kinetics with similar stabilization characteristic times. Analysis of this kinetics permits to exhibit the close relationship of increase in thermal diffusivity with the decrease in monomer concentration and extension of the polymerization in the resin, induced by the curing light. It is also shown that the configuration in which the resin is illuminated by the modulated laser can be the basis for the development of an in situ technique for the determination of the degree of curing.

  18. Caul and method for bonding and curing intricate composite structures

    Science.gov (United States)

    Willden, Kurtis S. (Inventor); Goodno, Kenneth N. (Inventor)

    1993-01-01

    The invention disclosed here is a method for forming and curing an intricate structure of criss-crossing composite stringers and frames that are bonded to a skin panel. A structure constructed in accordance with the invention would be well-suited for use as a portion of an aircraft fuselage, a boat hull, or the like. The method is preferably practiced by applying uncured composite stringers to an uncured composite sheet panel. This is followed by placing cured frames crosswise over the stringers. The frames have openings at the locations where they intersect with the stringers which enables the frames to come into direct contact with the skin along most of their length. During the forming and curing process, the stringers are covered with a plurality of cauls, and the entire assembly of skin panel, stringers, frames and cauls is subjected to a vacuum bagging and curing process. The cauls serve to maintain both part shape and to control the flow of resin within the stringers as they are cured. Further, they probably eliminate the need for intermediate protective materials between the vacuum bag and the stringers.

  19. Fiber-Matrix Interface Studies on Electron Beam Cured Composites

    Energy Technology Data Exchange (ETDEWEB)

    Drazel, L.T.; Janke, C.J.; Yarborough, K.D.

    1999-05-23

    The recently completed Department of Energy (DOE) and industry sponsored Cooperative Research and Development Agreement (CRADA) entitled, ''Electron Beam Curing of Polymer Matrix Composites,'' determined that the interlaminar shear strength properties of the best electron beam cured IM7/epoxy composites were 19-28% lower than autoclave cured IM7/epoxy composites (i.e. IM7/977-2 and IM7/977-3). Low interlaminar shear strength is widely acknowledged as the key barrier to the successful acceptance and implementation of electron beam cured composites in the aircraft/aerospace industry. The objective of this work was to improve the interlaminar shear strength properties of electron beam cured composites by formulating and evaluating several different fiber sizings or coating materials. The researchers have recently achieved some promising results by having discovered that the application of epoxy-based, electron beam compatible sizings or coatings onto surface-treated, unsized IM7 carbon fibers improved the composite interlaminar shear strength properties by as much as 55% versus composites fabricated from surface-treated, unsized IM7 fibers. In addition, by applying these same epoxy-based sizings or coatings onto surface-treated, unsized IM7 fibers it was possible to achieve an 11% increase in the composite interlaminar shear strength compared to composites made from surface-treated, GP-sized IM7 fibers. Work is continuing in this area of research to further improve these properties.

  20. Thermal stability and curing kinetics of polycarbosilane fibers

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Thermal stability and curing kinetics of polycarbosilane (PCS) fibers were studied by thermogravimetry (TG), Fourier transform infrared spectroscopy(FT-IR). Curing is an essential step in the preparation of SiC fibers and the properties of SiC fibers are affected greatly by curing conditions. TG measurement performed in air shows that mass gain starts at approximately 200℃ and PCS fibers are sensitive to oxygen. Curing with oxygen, which results in crosslinking on the surface, enabled PCS fibers to retain its shape during high-temperature pyrolysis. The curing of PCS fibers is oxidation of Si-H and Si-CH3, then Si-O-Si and Si-O-C bonds are formed. This is a first order reaction, with activation energy of 79.27 kJ/mol, and the pre-exponential factor is calculated as 3.07 × 106.The kinetics model was obtained and the experimental data of PCS fibers show good agreement with the kinetics model.

  1. Mining Compatibility Rules from Irregular Chinese Traditional Medicine Database by Apriori Agorithm

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    This paper aims to mine the knowledge and rules on compatibility of drugs from the prescriptions for curing arrhythmia in the Chinese traditional medicine database by Apriori algorithm. For data preparation, 1 113 prescriptions for arrhythmia, including 535herbs (totally 10884 counts of herbs) were collected into the database. The prescription data were preprocessed through redundancy reduction, normalized storage, and knowledge induction according to the pretreatment demands of data mining. Then the Apriori algorithm was used to analyze the data and form the related technical rules and treatment procedures. The experimental result of compatibility of drugs for curing arrhythmia from the Chinese traditional medicine database shows that the prescription compatibility obtained by Apriori algorithm generally accords with the basic law of traditional Chinese medicine for arrhythmia. Some special compatibilities unreported were also discovered in the experiment, which may be used as the basis for developing new prescriptions for arrhythmia.

  2. Characterization of Moisture Diffusion in Cured Concrete Slabs at Early Ages

    OpenAIRE

    Xiao Zhang; Hongduo Zhao

    2015-01-01

    The objective of this paper is to investigate the characterization of moisture diffusion inside early-age concrete slabs subjected to curing. Time-dependent relative humidity (RH) distributions of three mixture proportions subjected to three different curing methods (i.e., air curing, water curing, and membrane-forming compounds curing) and sealed condition were measured for 28 days. A one-dimensional nonlinear moisture diffusion partial differential equation (PDE) based on Fick’s second law,...

  3. Prediction of 28-day Compressive Strength of Concrete from Early Strength and Accelerated Curing Parameters

    OpenAIRE

    T.R. Neelakantan; S. Ramasundaram; Shanmugavel, R.; R. Vinoth

    2013-01-01

    Predicting 28-day compressive strength of concrete is an important research task for many years. In this study, concrete specimens were cured in two phases, initially at room temperature for a maximum of 30 h and later at a higher temperature for accelerated curing for a maximum of 3 h. Using the early strength obtained after the two-phase curing and the curing parameters, regression equations were developed to predict the 28-day compressive strength. For the accelerated curing (higher temper...

  4. Comparative evaluation of surface porosities in conventional heat polymerized acrylic resin cured by water bath and microwave energy with microwavable acrylic resin cured by microwave energy

    Directory of Open Access Journals (Sweden)

    Sunint Singh

    2013-01-01

    Full Text Available Background: Conventional heat cure poly methyl methacrylate (PMMA is the most commonly used denture base resin despite having some short comings. Lengthy polymerization time being one of them and in order to overcome this fact microwave curing method was recommended. Unavailability of specially designed microwavable acrylic resin made it unpopular. Therefore, in this study, conventional heat cure PMMA was polymerized by microwave energy. Aim and Objectives: This study was designed to evaluate the surface porosities in PMMA cured by conventional water bath and microwave energy and compare it with microwavable acrylic resin cured by microwave energy. Materials and Methods: Wax samples were obtained by pouring molten wax into a metal mold of 25 mm × 12 mm × 3 mm dimensions. These samples were divided into three groups namely C, CM, and M. Group C denotes conventional heat cure PMMA cured by water bath method, CM denotes conventional heat cure PMMA cured by microwave energy, M denotes specially designed microwavable acrylic denture base resin cured by microwave energy. After polymerization, each sample was scanned in three pre-marked areas for surface porosities using the optical microscope. As per the literature available, this instrument is being used for the first time to measure the porosity in acrylic resin. It is a reliable method of measuring area of surface pores. Portion of the sample being scanned is displayed on the computer and with the help of software area of each pore was measured and data were analyzed. Results: Conventional heat cure PMMA samples cured by microwave energy showed maximum porosities than the samples cured by conventional water bath method and microwavable acrylic resin cured by microwave energy. Higher percentage of porosities was statistically significant, but well within the range to be clinically acceptable. Conclusion: Within the limitations of this in-vitro study, conventional heat cure PMMA can be cured by

  5. Influence of light curing units on failure of directcomposite restorations

    Directory of Open Access Journals (Sweden)

    Sameer Jadhav

    2011-01-01

    Full Text Available Light polymerizable tooth colored restorative materials are most widely preferred for advantages such as esthetics, improved physical properties and operator′s control over the working time. Since the introduction of these light polymerizable restorative materials, there has been a concern about the depth of appropriate cure throughout the restoration. Photopolymerization of the composite is of fundamental importance because adequate polymerization is a crucial factor for optimization of the physical and mechanical properties and clinical results of the composite material. Inadequate polymerization results in greater deterioration at the margins of the restoration, decreased bond strength between the tooth and the restoration, greater cytotoxicity, and reduced hardness. Therefore, the dentist must use a light curing unit that delivers adequate and sufficient energy to optimize composite polymerization. Varying light intensity affects the degree of conversion of monomer to polymer and depth of cure.

  6. Temperature and curing time affect composite sorption and solubility

    Directory of Open Access Journals (Sweden)

    Fabrício Luscino Alves de Castro

    2013-04-01

    Full Text Available Objective: This study evaluated the effect of temperature and curing time on composite sorption and solubility. Material and Methods: Seventy five specimens (8×2 mm were prepared using a commercial composite resin (ICE, SDI. Three temperatures (10°C, 25°C and 60°C and five curing times (5 s, 10 s, 20 s, 40 s and 60 s were evaluated. The specimens were weighed on an analytical balance three times: A: before storage (M1; B: 7 days after storage (M2; C: 7 days after storage plus 1 day of drying (M3. The storage solution consisted of 75% alcohol/25% water. Sorption and solubility were calculated using these three weights and specimen dimensions. The data were analyzed using the Kruskal-Wallis and Mann-Whitney U Tests (α=5%. Results: The results showed that time, temperature and their interaction influenced the sorption and solubility of the composite (p0.05. The 60°C composite temperature led to lower values of sorption for all curing times when compared with the 10°C temperature (p0.05. Solubility was similar at 40 s and 60 s for all temperatures (p>0.05, but was higher at 10°C than at 60°C for all curing times (p0.05. Conclusions: In conclusion, higher temperatures or longer curing times led to lower sorption and solubility values for the composite tested; however, this trend was only significant in specific combinations of temperature and curing times.

  7. Synthesis and curing of alkyd enamels based on ricinoleic acid

    Directory of Open Access Journals (Sweden)

    Jovičić Mirjana C.

    2010-01-01

    Full Text Available A combination of an alkyd resin with a melamine-formaldehyde resin gives a cured enamel film with the flexibility of the alkyd constituent and the high chemical resistance and hardness of the melamine resin at the same time. The melamine resin is a minor constituent and plays the role of a crosslinking agent. In this paper, alkyd resins of high hydroxyl numbers based on trimethylolpropane, ricinoleic acid and phthalic anhydride were synthesized. Two alkyds having 30 and 40 wt% of ricinoleic acid were formulated by calculation on alkyd constant. Alkyds were characterized by FTIR and by the determination of acid and hydroxyl numbers. Then synthesized alkyds were made into baking enamels by mixing with melamine-formaldehyde resins (weight ratio of 70:30 based on dried mass. Two types of commercial melamine resins were used: threeisobutoxymethyl melamine-formaldehyde resin (TIMMF and hexamethoxymethyl melamine resin (HMMMF. Prepared alkyd/melamine resin mixtures were cured in a differential scanning calorimeter (DSC under non-isothermal mode. Apparent degree of curing as a function of temperature was calculated from the curing enthalpies. Kinetic parameters of curing were calculated using Freeman-Carroll method. TIMMF resin is more reactive with synthesized alkyds than HMMMF resin what was expected. Alkyd resin with 30 wt% of ricinoleic acid is slightly more reactive than alkyd with 40 wt% of ricinoleic acid, probably because it has the high contents of free hydroxyl and acid groups. The gel content, Tg, thermal stability, hardness, elasticity and impact resistance of coated films cured at 150°C for 60 min were measured. Cured films show good thermal stability since the onset of films thermal degradation determined by thermogravimetric analysis (TGA is observed at the temperatures from 281 to 329°C. Films based on alkyd 30 are more thermal stable than those from alkyd 40, with the same melamine resin. The type of alkyd resin has no significant

  8. Grey Disorder in Field Flue—Cured Tobacco

    Institute of Scientific and Technical Information of China (English)

    ZHANGXIN; ZHAOQIBO; 等

    1999-01-01

    A field study was carried out on the grey disorder in flue-cured tobacco( Nicotiana tabacum L.) leaves.The results showed that low Eh and high available Fe content in the soils were responsible for the grey tobacco and dead roots.Grey disorder leaves produced low quality lamina,which was low in N,nicotine,reduced sugar and K contents,In this study,soil available Mn and leaf Mn contents were in a relatively low level and should not be an important factor in the occurrence of grey disorder in flue-cured tobacco.

  9. Magnetoactive elastomeric composites: Cure, tensile, electrical and magnetic properties

    Indian Academy of Sciences (India)

    K Sasikumar; G Suresh; K A Thomas; Reji John; V Natarajan; T Mukundan; R M R Vishnubhatla

    2006-11-01

    Magnetically active elastomer materials were prepared by incorporating nickel powder in synthetic elastomeric matrices, polychloroprene and nitrile rubber. Cure characteristics, mechanical, electrical and magnetic properties were experimentally determined for different volume fractions of magnetoactive filler. The cure time decreases sharply for initial filler loading and the decrease is marginal for additional loading of filler. The tensile strength and modulus at 100% strain was found to increase with increase in the volume fraction of nickel due to reinforcement action. The magnetic impedance and a.c. conductivity are found to increase with increase in volume fraction of nickel as well as frequency.

  10. Realtime 3D stress measurement in curing epoxy packaging

    DEFF Research Database (Denmark)

    Richter, Jacob; Hyldgård, A.; Birkelund, Karen;

    2007-01-01

    This paper presents a novel method to characterize stress in microsystem packaging. A circular p-type piezoresistor is implemented on a (001) silicon chip. We use the circular stress sensor to determine the packaging induced stress in a polystyrene tube filled with epoxy. The epoxy curing process...... is monitored by stress measurements. From the stress measurements we conclude that the epoxy cures in 8 hours at room temperature. We find the difference in in-plane normal stresses to be sigmaxx-sigmayy=6.7 MPa and (sigmaxx+sigmayy-0.4sigmazz)=232 MPa....

  11. Optimization of the curing process of a sandwich panel

    Science.gov (United States)

    Phyo Maung, Pyi; Tatarnikov, O.; Malysheva, G.

    2016-10-01

    This study presented finite element modelling and experimental measurements of temperatures during the autoclave curing of the T-50 aircraft wing sandwich panel. This panel consists of upper and lower carbon fibre based laminates and an aluminium foil honeycomb. The finite element modelling was performed using the Femap-Nastran product. During processing, the temperature at various points on the surface of the panel was measured using the thermocouples. The finite element method simulated the thermal conditions and determined the temperatures in the different parts of the panel for a full cycle of the curing process. A comparison of the calculated and experimental data shows that their difference does not exceed 6%.

  12. Preliminary toxicological study of Sylgard 184 curing agent

    Energy Technology Data Exchange (ETDEWEB)

    Smith, D.M.; London, J.E.; Drake, G.A.; Thomas, R.G.

    1978-06-01

    The acute oral LD/sub 50//sup 30/ values for mice and rats receiving Sylgard 184 curing agent were greater than 5 g/kg. According to classical guidelines, the compound would be considered slightly toxic or practically nontoxic in both species. Skin application studies in the rabbit demonstrated the compound to be mildly irritating. Eye irritation studies, also in the rabbit, showed that Sylgard 184 curing agent was a mild but transitory irritant. The sensitization study in guinea pigs did not show the resin to be deleterious.

  13. Emergent Cure Chemistry in the Development of Aerospace Materials

    Science.gov (United States)

    2015-03-25

    R4 R3-SHR3-S-CH2-CH2-R4Product Anti-Markovnikov • Thiol-ene chemistry is a hybrid of free radical and condensation chemistry . It combines the speed...Charts 3. DATES COVERED (From - To) March 2015-March 2015 4. TITLE AND SUBTITLE Emergent cure chemistry in the development of aerospace materials...cure chemistry in the development of aerospace materials Joseph M. Mabry, Ph.D. Air Force Research Laboratory joseph.mabry@us.af.mil (661) 275-5857

  14. Cure Monitoring and Control with Combined Dielectric/Temperature Probes.

    Science.gov (United States)

    1983-01-10

    DGEBA with expressions include an additional menthane diamine at 90*C were used parameter, 8, which accounts for to make the plots (the actual data...parameters to match Fig. 2 data. DGEBA cured with menthane diamine at Frequencies are 1,10,100 and 1000 Rz 900C. -5- ally with time (following the to slow down...mum. An example of such a result ure 2 shows plots correspondizg to is presented in Section 3.1 below. the model curves of Fig. 1 for DGEBA cured

  15. Effects of feeding high protein or conventional canola meal on dry cured and conventionally cured bacon.

    Science.gov (United States)

    Little, K L; Bohrer, B M; Stein, H H; Boler, D D

    2015-05-01

    Objectives were to compare belly, bacon processing, bacon slice, and sensory characteristics from pigs fed high protein canola meal (CM-HP) or conventional canola meal (CM-CV). Soybean meal was replaced with 0 (control), 33, 66, or 100% of both types of canola meal. Left side bellies from 70 carcasses were randomly assigned to conventional or dry cure treatment and matching right side bellies were assigned the opposite treatment. Secondary objectives were to test the existence of bilateral symmetry on fresh belly characteristics and fatty acid profiles of right and left side bellies originating from the same carcass. Bellies from pigs fed CM-HP were slightly lighter and thinner than bellies from pigs fed CM-CV, yet bacon processing, bacon slice, and sensory characteristics were unaffected by dietary treatment and did not differ from the control. Furthermore, testing the existence of bilateral symmetry on fresh belly characteristics revealed that bellies originating from the right side of the carcasses were slightly (P≤0.05) wider, thicker, heavier and firmer than bellies from the left side of the carcass.

  16. Volatile compounds of dry-cured Iberian ham as affected by the length of the curing process.

    Science.gov (United States)

    Ruiz, J; Ventanas, J; Cava, R; Andrés, A; García, C

    1999-05-01

    Volatile compounds from 10 dry-cured Iberian hams ripened for two different processing times, a prolonged traditional one (600 days) and a shortened process (420 days), were analysed by purge and trap coupled to gas chromatography-mass spectroscopy. Eighty-three compounds were identified which agreed with the major classes found in other ham types. The amount of methyl branched alkanes was much higher than in other dry-cured ham types, probably due to the feeding regime. The percentages of 2- and 3-methylbutanal were higher (p<0.0001 and p<0.0003, respectively) in the longer aged hams, whereas the amounts of some compounds from lipid oxidation decreased from 420 to 600 days aging. In agreement with these observations, 600-day hams had higher scores for those odour and flavour traits usually considered to be positive attributes and lower scores for rancidity. A positive and significant correlation between 2-methyl butanal and cured flavour was found.

  17. Effects of cement-curing mode and light-curing unit on the bond durability of ceramic cemented to dentin

    Directory of Open Access Journals (Sweden)

    Sheila Pestana Passos

    2013-04-01

    Full Text Available The aim of this study was to evaluate the effects of different light-curing units and resin cement curing types on the bond durability of a feldspathic ceramic bonded to dentin. The crowns of 40 human molars were sectioned, exposing the dentin. Forty ceramic blocks of VITA VM7 were produced according to the manufacturer's recommendations. The ceramic surface was etched with 10% hydrofluoric acid / 60s and silanized. The dentin was treated with 37% phosphoric acid / 15s, and the adhesive was applied. The ceramic blocks were divided and cemented to dentin according to resin cement / RC curing type (dual- and photo-cured, light-curing unit (halogen light / QTH and LED, and storage conditions (dry and storage / 150 days + 12,000 cycles / thermocycling. All blocks were stored in distilled water (37°C / 24h and sectioned (n = 10: G1 - QTH + RC Photo, G2 - QTH + RC Dual, G3 - LED + RC Photo, G4 - LED + RC Dual. Groups G5, G6, G7, and G8 were obtained exactly as G1 through G4, respectively, and then stored and thermocycled. Microtensile bond strength tests were performed (EMIC, and data were statistically analyzed by ANOVA and Tukey's test (5%. The bond strength values (MPa were: G1 - 12.95 (6.40ab; G2 - 12.02 (4.59ab; G3 - 13.09 (5.62ab; G4 - 15.96 (6.32a; G5 - 6.22 (5.90c; G6 - 9.48 (5.99bc; G7 - 12.78 (11.30ab; and G8 - 8.34 (5.98bc. The same superscript letters indicate no significant differences. Different light-curing units affected the bond strength between ceramic cemented to dentin when the photo-cured cement was used, and only after aging (LED > QTH. There was no difference between the effects of dual- and photo-cured resin-luting agents on the microtensile bond strength of the cement used in this study.

  18. Happy (Chinese) New Year!

    Science.gov (United States)

    Johnson, Georgia G.

    1979-01-01

    Suggestions are made for a classroom celebration of Chinese New Year, including discussion of the Chinese calendar and customs, a short list of appropriate children's stories, and food ideas, including a recipe for fortune cookies. (SJL)

  19. Recidivism and Self-Cure of Smoking and Obesity

    Science.gov (United States)

    Schacter, Stanley

    1982-01-01

    Data indicate that addictive-appetitive disorders such as obesity, opiate use, and cigarette smoking are not (as most professionals believe) markedly resistant to long-term modification. Studies of nontherapeutic populations indicate that long-term self-cures of smoking, obesity, and drug use are relatively common events. (Author/GC)

  20. 21 CFR 177.2400 - Perfluorocarbon cured elastomers.

    Science.gov (United States)

    2010-04-01

    ... (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) INDIRECT FOOD ADDITIVES: POLYMERS Substances for Use Only... generally recognized as safe (GRAS) in food or food packaging. (2) Substances used in accordance with a... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Perfluorocarbon cured elastomers. 177.2400...

  1. Hot embossing of microstructures on addition curing polydimethylsiloxane films

    DEFF Research Database (Denmark)

    Vudayagiri, Sindhu; Yu, Liyun; Hassouneh, Suzan Sager;

    2013-01-01

    The aim of this research work is to establish a hot embossing process for addition curing vinyl-terminated polydimethylsiloxane (PDMS), which are thermosetting elastomers, based on the existing and widely applied technology for thermoplasts. To our knowledge, no known technologies or processes...

  2. Sodium nitrite: the "cure" for nitric oxide insufficiency.

    Science.gov (United States)

    Parthasarathy, Deepa K; Bryan, Nathan S

    2012-11-01

    This process of "curing" food is a long practice that dates back thousands of years long before refrigeration or food safety regulations. Today food safety and mass manufacturing are dependent upon safe and effective means to cure and preserve foods including meats. Nitrite remains the most effective curing agent to prevent food spoilage and bacterial contamination. Despite decades of rigorous research on its safety and efficacy as a curing agent, it is still regarded by many as a toxic undesirable food additive. However, research within the biomedical science community has revealed enormous therapeutic benefits of nitrite that is currently being developed as novel therapies for conditions associated with nitric oxide (NO) insufficiency. Much of the same biochemistry that has been understood for decades in the meat industry has been rediscovered in human physiology. This review will highlight the fundamental biochemistry of nitrite in human physiology and highlight the risk benefit evaluation surrounding nitrite in food and meat products. Foods or diets enriched with nitrite can have profound positive health benefits.

  3. Gout: why is this curable disease so seldom cured?

    NARCIS (Netherlands)

    Doherty, M.; Jansen, T.L.Th.A.; Nuki, G.; Pascual, E.; Perez-Ruiz, F.; Punzi, L.; So, A.K.; Bardin, T.

    2012-01-01

    Gout is the most common inflammatory arthritis and one in which pathogenesis and risk factors are best understood. One of the treatment objectives in current guidelines is 'cure'. However, audits show that only a minority of patients with gout receive adequate advice and treatment. Suboptimal care a

  4. A consensus on criteria for cure of acromegaly

    NARCIS (Netherlands)

    A. Giustina (Andrea); P. Chanson (Philippe); M.D. Bronstein; A. Klibanski; S.W.J. Lamberts (Steven); F.F. Casanueva; P. Trainer; E. Ghigo (Ezio); K.K.Y. Ho; S. Melmed (Shlomo)

    2010-01-01

    textabstractObjective: The Acromegaly Consensus Group met in April 2009 to revisit the guidelines on criteria for cure as defined in 2000. Participants: Participants included 74 neurosurgeons and endocrinologists with extensive experience of treating acromegaly. Evidence/Consensus Process: Relevant

  5. Specific pretreatments reduce curing period of vanilla (Vanilla planifolia) beans.

    Science.gov (United States)

    Sreedhar, R V; Roohie, K; Venkatachalam, L; Narayan, M S; Bhagyalakshmi, N

    2007-04-18

    With the aiming of reducing the curing period, effects of pretreatments on flavor formation in vanilla beans during accelerated curing at 38 degrees C for 40 days were studied. Moisture loss, change in texture, levels of flavoring compounds, and activities of relevant enzymes were compared among various pretreatments as well as the commercial sample. Use of naphthalene acetic acid (NAA; 5 mg/L) or Ethrel (1%) with blanching pretreatment resulted in 3-fold higher vanillin on the 10th day. Other flavoring compounds-vanillic acid, p-hydroxybenzoic acid, and p-hydroxybenzaldehyde-fluctuated greatly, showing no correlation with the pretreatments. Scarification of beans resulted in nearly 4- and 3.6-fold higher vanillin formations on the 10th day in NAA- and Ethrel-treated beans, respectively, as compared to control with a significant change in texture. When activities of major relevant enzymes were followed, addition of NAA or Ethrel helped to retain higher levels of cellulase throughout the curing period and higher levels of beta-glucosidase on the 20th day that correlated with higher vanillin content during curing and subsequent periods. Peroxidase, being highest throughout, did not correlate with the change in levels of major flavoring compounds. The pretreatment methods of the present study may find importance for realizing higher flavor formation in a shorter period because the major quality parameters were found to be comparable to those of a commercial sample.

  6. Student Actor Ailments: Ten Ills and How To Cure Them.

    Science.gov (United States)

    Bishop, Barbara Long

    2000-01-01

    Lists the top ten acting ailments often encountered in student actors, and offers advice to cure these ailments: the split personality, the beauty queen and the leading man, the comedian, the director in training, the moody one, the character-clueless, the loner, the mimic, the stage-frightened, and the opening night artist. (SR)

  7. Nutidig mental sundhedsfremme i et historisk Mind-Cure perspektiv

    DEFF Research Database (Denmark)

    Wistoft, Karen

    2014-01-01

    the tradition, while also retaining the limitations noted by James. Three examples of this are mindfulness, religious coping and learned optimism. This article discusses how James’s critique can challenge these current Mind-Cure methods. The point is that illness, suffering and mental disorder have...

  8. LED Curing Lights and Temperature Changes in Different Tooth Sites

    Directory of Open Access Journals (Sweden)

    E. Armellin

    2016-01-01

    Full Text Available Objectives. The aim of this in vitro study was to assess thermal changes on tooth tissues during light exposure using two different LED curing units. The hypothesis was that no temperature increase could be detected within the dental pulp during polymerization irrespective of the use of a composite resin or a light-curing unit. Methods. Caries-free human first molars were selected, pulp residues were removed after root resection, and four calibrated type-J thermocouples were positioned. Two LED lamps were tested; temperature measurements were made on intact teeth and on the same tooth during curing of composite restorations. The data was analyzed by one-way analysis of variance (ANOVA, Wilcoxon test, Kruskal-Wallis test, and Pearson’s χ2. After ANOVA, the Bonferroni multiple comparison test was performed. Results. Polymerization data analysis showed that in the pulp chamber temperature increase was higher than that without resin. Starlight PRO, in the same condition of Valo lamp, showed a lower temperature increase in pre- and intrapolymerization. A control group (without composite resin was evaluated. Significance. Temperature increase during resin curing is a function of the rate of polymerization, due to the exothermic polymerization reaction, the energy from the light unit, and time of exposure.

  9. Bacterial spoilage of meat and cured meat products

    NARCIS (Netherlands)

    Borch, E.; Kant-Muermans, M.L.T.; Blixt, Y.

    1996-01-01

    The influence of environmental factors (product composition and storage conditions) on the selection, growth rate and metabolic activity of the bacterial flora is presented for meat (pork and beef) and cooked, cured meat products. The predominant bacteria associated with spoilage of refrigerated bee

  10. Scanorama in Chinese

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    @@ Scanorama, the SAS on-board magazine,is now also available in Chinese. Table-tennis star,J-O Waldner, Scandinavian design and delicious Norwegian seafood are what SAS Chinese customers can read about while sitting on board SAS flights on the Copenhagen - Beijing and Copenhagen-Shanghai routes. The magazine uses the written Chinese language that is read by nearly one billion mainland Chinese.

  11. On Chinese Character

    Institute of Scientific and Technical Information of China (English)

    杨文娟

    2016-01-01

    Just as the long history of our country, Chinese characters also have their long histories through thousands of years. There have been many great scientific works or documents studying on the origin of Chinese characters. From them, it can easily be found that each Chinese character has its own history. If we study on the history of a specific Chinese character, its motivation will be found.

  12. Curing Reaction Kinetics of Epoxy Resin Using Dicyandiamide Modified by Aromatic Amines

    Institute of Scientific and Technical Information of China (English)

    CHEN Lianxi; TIAN Hua; LIU Quanwen; Wang Jun

    2007-01-01

    The curing reaction and reaction mechanism of epoxy resin E-44, for which aromatic amine modified dicyandiamide was used as a curing reagent, were investigated by means of differential scanning calorimetry (DSC). The results showed that the modified dicyandiamide had better curing characteristic than ummodified dicyandiamide for epoxy resin E-44, and the curing reaction could be carried out at moderate temperature. Apparent activation energy of the curing reaction was decreased appreciably from 123.829 kJ/mol to 61.550-64.405 kJ/mol, and reaction order was decreased from 0.941 to 0.896-0.900. Curing reaction mechanism also was discussed.

  13. Application conditions for ester cured alkaline phenolic resin sand

    Institute of Scientific and Technical Information of China (English)

    Ren-he Huang; Bao-ping Zhang; Yao-ji Tang

    2016-01-01

    Five organic esters with different curing speeds: propylene carbonate (i.e. high-speed ester A); 1, 4-butyrolactone; glycerol triacetate (i.e. medium-speed ester B); glycerol diacetate; dibasic ester (DBE) (i.e. low-speed ester C), were chosen to react with alkaline phenolic resin to analyze the application conditions of ester cured alkaline phenolic resin. The relationships between the curing performances of the resin (including pH value, gel pH value, gel time of resin solution, heat release rate of the curing reaction and tensile strength of the resin sand) and the amount of added organic ester and curing temperature were investigated. The results indicated the folowing: (1) The optimal added amount of organic ester should be 25wt.%-30wt.% of alkaline phenolic resin and it must be above 20wt.%-50 wt.% of the organic ester hydrolysis amount. (2) High-speed ester A (propylene carbonate) has a higher curing speed than 1, 4-butyrolactone, and they were both used as high-speed esters. Glycerol diacetate is not a high-speed ester in alkaline phenolic resin although it was used as a high-speed ester in ester cured sodium silicate sand; glycerol diacetate and glycerol triacetate can be used as medium-speed esters in alkaline phenolic resin. (3) High-speed ester A, medium-speed ester B (glycerol triacetate) and low-speed ester C (dibasic ester, i.e., DBE) should be used below 15 ºC, 35 ºC and 50 ºC, respectively. High-speed ester A or low-speed ester C should not be used alone but mixed with medium-speed ester B to improve the strength of the resin sand. (4) There should be a suitable solid content (generaly 45wt.%-65wt.% of resin), alkali content (generaly 10wt.%-15wt.% of resin) and viscosity of alkaline phenolic resin (generaly 50-300 mPa·s) in the preparation of alkaline phenolic resin. Finaly, the technique conditions of alkaline phenolic resin preparation and the application principles of organic ester were discussed.

  14. TRADITIONAL CHINESE HERBAL MEDICINE

    NARCIS (Netherlands)

    ZHU, YP; WOERDENBAG, HJ

    1995-01-01

    Herbal medicine, acupuncture and moxibustion, and massage and the three major constituent parts of traditional Chinese medicine. Although acupuncture is well known in many Western countries, Chinese herbal medicine, the mos important part of traditional Chinese medicine, is less well known in the We

  15. Chinese restaurant syndrome

    Directory of Open Access Journals (Sweden)

    Balachandran C

    1991-01-01

    Full Text Available A 24-year-old Chinese student with history of recurrent attacks of flushing with burning and dryness of face of 4 years duration showed exacerbation of the symptoms after oral provocation with 1 mg of Chinese salt. Patient was treated with 50 mg pyridoxine daily and restriction of the Chinese salt in diet with moderate improvement.

  16. Comparative study of optical fiber cure-monitoring methods

    Science.gov (United States)

    Crosby, Peter A.; Powell, Graham R.; Fernando, Gerard F.; Waters, David N.; France, Chris M.; Spooncer, Ronald C.

    1997-06-01

    This paper reports on a comparative study undertaken for different types of optical fiber sensor developed to monitor the cure of an epoxy resin system. The optical fiber sensors used to monitor the cure process were based on transmission spectroscopy, evanescent wave spectroscopy and refractive index monitoring. The transmission sensor was prepared by aligning two optical fibers within a specially prepared sleeve with a gap between the optical fiber end-faces. During cure, resin from the specimen flowed into the gap between the optical fibers allowing transmission spectra of the resin to be obtained. The evanescent wave sensor was prepared by stripping the cladding from a high refractive index core optical fiber. The prepared sensor was embedded in the sample and attenuated total reflectance spectra recorded from the resin/core boundary. Refractive index monitoring was undertaken using a high refractive index core optical fiber which had a small portion of its cladding removed. The prepared sensor was embedded in the resin specimen and light from a single wavelength source was launched into the fiber. Changes in the guiding characteristics of the sensor due to refractive index changes at the resin/core boundary were used to monitor the progress of the cure reaction. The transmission and evanescent wave spectroscopy sensors were used to follow changes in characteristic near-infrared absorption bands of the resin over the range 1450 - 1700 nm during the cure reaction. Consequently these techniques required tunable wavelength sources covering specific wavelength ranges. However, the refractive index based sensor used a single wavelength source. Therefore the equipment costs for this type of sensor were considerably less. Additionally, the refractive index sensor did not require a single wavelength source at any particular wavelength and could be applied to any spectral region in which the optical fiber would transmit light. The advantages and disadvantages of these

  17. Microwave and thermal curing of an epoxy resin for microelectronic applications

    Energy Technology Data Exchange (ETDEWEB)

    Johnston, K. [Institute of Chemical Sciences, School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh EH14 4AS (United Kingdom); Pavuluri, S.K.; Leonard, M.T.; Desmulliez, M.P.Y. [MIcroSystems Engineering Centre (MISEC), Institute of Signals, Sensors and Systems, School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh EH14 4AS (United Kingdom); Arrighi, V., E-mail: v.arrighi@hw.ac.uk [Institute of Chemical Sciences, School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh EH14 4AS (United Kingdom)

    2015-09-20

    Graphical abstract: - Highlights: • Thermal and microwave curing of a commercial epoxy resin EO1080 are compared. • Microwave curing increases cure rate and does not adversely affect properties. • The curing of EO1080 is generally autocatalytic but deviates at high conversion. • Microwave radiation has a more complex effect on curing kinetics. - Abstract: Microwave curing of thermosetting polymers has a number of advantages to natural or thermal oven curing and is considered a cost-effective alternative. Here we present a detailed study of a commercially available epoxy resin, EO1080. Samples that are thermally cured are compared to curing using a recently developed modular microwave processing system. For commercial purposes it is crucial to demonstrate that microwave curing does not adversely affect the thermal and chemical properties of the material. Therefore, the kinetics of cure and various post cure properties of the resin are investigated. Attenuated Total Reflectance Fourier-Transform Infrared (ATR-FTIR) analysis shows no significant difference between the conventionally and microwave cured samples. Differential scanning calorimetry (DSC) is used to monitor the kinetics of the curing reaction, as well as determine the thermal and ageing properties of the material. As expected, the rate of curing is higher when using microwave energy and we attempt to quantify differences compared to conventional thermal curing. No change in glass transition temperature (T{sub g}) is observed. For the first time, enthalpy relaxation measurements performed on conventional and microwave cured samples are reported and these indicate similar ageing properties at any given temperature under T{sub g}.

  18. The Chinese Medicine Treatment of Impotence%简述阳痿中医治疗

    Institute of Scientific and Technical Information of China (English)

    田耀军

    2016-01-01

    目的:研究运用中医辨证分型治疗阳痿的效果。方法对本卫生所自2013年至今收治的阳痿患者进行中医辨证分型治疗。结果中医辨证分型治疗阳痿效果十分理想。结论精准的中医辨证分型治疗阳痿有助于体现中医临床效果的优越性。%Objective To study the application of TCM treatment for impotence effect.MethodsThe China health center from 2013 to date, the fingers of impotence patients with TCM syndrome differentiation.by Chinese medicine dialectics cent type cures.Results The effect Chinese medicine dialectics cent type cures of treating impotent is very ideal.Conclusion The accurate conclusion of Chinese medicine dialectics cent type cures for impotence can help to reflect the clinical effect of traditional Chinese medicine.

  19. Influence of curing rate on softening in ethanol, degree of conversion, and wear of resin composite

    DEFF Research Database (Denmark)

    Benetti, Ana Raquel; Peutzfeldt, Anne; Asmussen, Erik

    2011-01-01

    PURPOSE: To investigate the effect of curing rate on softening in ethanol, degree of conversion, and wear of resin composites. METHOD: With a given energy density and for each of two different light-curing units (QTH or LED), the curing rate was reduced by modulating the curing mode. Thus......, the irradiation of resin composite specimens (Filtek Z250, Tetric Ceram, Esthet-X) was performed in a continuous curing mode and in a pulse-delay curing mode. Wallace hardness was used to determine the softening of resin composite after storage in ethanol. Degree of conversion was determined by infrared...... exposed to the pulse-delay curing mode were softer than resin composites exposed to continuous cure (Pconversion (P

  20. STUDY ON CO-CURING REACTION IN CHAIN PROLONGED BISMALEIMIDE-UNSATURATED POLYMER RESIN SYSTEM

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The curing process of chemical reacton between flexible unsaturated polymer resin and diphenylmethane bismaleimides which have been chain-prolonged by diaminodiphenylmethane is presented, also the kinetics parameters and curing technology are investigated.

  1. Chinese Lunar Calendar

    Institute of Scientific and Technical Information of China (English)

    方陵生

    2005-01-01

    @@ Background and Concept The Chinese animal signs2 are a 12-year cycle used for dating the years. They represent a cyclical concept of time, rather than the Western linear concept of time. The Chinese Lunar Calendar is based on the cycles of the moon, and is constructed in a different fashion than the Western solar calendar3. In the Chinese calendar, the beginning of the year falls somewhere between late January and early February. The Chinese have adopted the Western calendar since 1911,but the lunar calendar is still used for festive occasions such as the Chinese New Year. Many Chinese calendars will print both the solar dates and the Chinese lunar dates.

  2. Finding a cure for HIV: will it ever be achievable?

    Directory of Open Access Journals (Sweden)

    Lewin Sharon R

    2011-01-01

    Full Text Available Abstract Combination antiretroviral therapy (cART has led to a major reduction in HIV-related mortality and morbidity. However, HIV still cannot be cured. With the absence of an effective prophylactic or therapeutic vaccine, increasing numbers of infected people, emerging new toxicities secondary to cART and the need for life-long treatment, there is now a real urgency to find a cure for HIV. There are currently multiple barriers to curing HIV. The most significant barrier is the establishment of a latent or "silent" infection in resting CD4+ T cells. In latent HIV infection, the virus is able to integrate into the host cell genome, but does not proceed to active replication. As a consequence, antiviral agents, as well as the immune system, are unable to eliminate these long-lived, latently infected cells. Reactivation of latently infected resting CD4+ T cells can then re-establish infection once cART is stopped. Other significant barriers to cure include residual viral replication in patients receiving cART, even when the virus is not detectable by conventional assays. In addition, HIV can be sequestered in anatomical reservoirs, such as the brain, gastrointestinal tract and genitourinary tract. Achieving either a functional cure (long-term control of HIV in the absence of cART or a sterilizing cure (elimination of all HIV-infected cells remains a major challenge. Several studies have now demonstrated that treatment intensification appears to have little impact on latent reservoirs. Some potential and promising approaches that may reduce the latent reservoir include very early initiation of cART and the use of agents that could potentially reverse latent infection. Agents that reverse latent infection will promote viral production; however, simultaneous administration of cART will prevent subsequent rounds of viral replication. Such drugs as histone deacetylase inhibitors, currently used and licensed for the treatment of some cancers, or

  3. Variable frequency microwave (VFM) curing, processing of thermoset prepreg laminates. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Paulauskas, F.L.

    1996-09-30

    The objective of this work was to investigate the beneficial effect of the variable frequency microwave (VFM) technology to cure thermosetting prepreg laminates. Further, it was to investigate the interrelationship and effect on the curing process of frequency, band width, and curing time with different types of laminates. Previous studies of microwave-assisted curing of neat resins (epoxy) and unidirectional glass and carbon fiber laminates with a fixed frequency of 2.45 GHz, have shown that a substantial reduction in the curing time was obtained. Results of this earlier work indicate that the microwave-assisted curing of multidirectional glass fiber laminates also show a substantial reduction of the required curing time. This may be explained by the penetration of microwave energy directly and throughout the laminate with enhancement of the kinetics of the chemical reaction. The fixed frequency microwave radiation of 2.45 GHz has been demonstrated to be a partially acceptable method to cure unidirectional carbon fiber laminates. Multidirectional carbon fiber/epoxy laminates demonstrate a lack of coupling during the curing process. A direct curing of these laminates was not possible by microwave radiation with the experimental approach used in agreement with previous work. In addition to this short coming, the unidirectional laminate samples cured with the fixed frequency are visually nonuniform. Localized areas of darker colors (burn, hot spots, overheating) are attributed to the formation of standing waves within the microwave cavity. For this reason, the laminates are subject to proper rotation while curing through fixed frequency. The present research indicates that variable frequency microwave technology is a sound and acceptable processing method to effectively cure uni-, bi- or multi-directional thermosetting glass fiber laminates. Also, this methodology will effectively cure unidirectional thermosetting carbon fiber laminates. For all these cases, this

  4. Cure Cycle Effect on High-Temperature Polymer Composite Structures Molded by VARTM

    OpenAIRE

    Ahmed Khattab

    2013-01-01

    This paper presents an analytical and experimental investigation of cure cycle effect on carbon-fiber reinforced high-temperature polymer composite structures molded by vacuum assisted resin transfer molding (VARTM). The molded composite structure consists of AS4-8 harness carbon-fiber fabrics and a high-temperature polymer (Cycom 5250-4-RTM). Thermal and resin cure analysis is performed to model the cure cycle of the VARTM process. The temperature and cure variations with time are determined...

  5. Experimental investigation of interface curing stresses between PMMA and composite using digital speckle correlation method

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    This paper studies the interface curing stresses between polymethyl methacrylate (PMMA) and composite by means of digital speckle correlation method (DSCM).A new method by combining DSCM with the marker points is developed to measure the interface curing stresses,and the measurement principle is introduced.The interface curing stresses between PMMA and composite with different curing bonding conditions are measured and analyzed,this indicates that the residual stress for furnace heating and furnace cooling ...

  6. Progress Toward HIV Eradication: Case Reports, Current Efforts, and the Challenges Associated with Cure.

    Science.gov (United States)

    Martin, Alyssa R; Siliciano, Robert F

    2016-01-01

    An estimated 35 million people worldwide are infected with HIV, yet a widely applicable cure strategy remains elusive. Recent case reports have suggested that curing HIV infection is possible, renewing excitement about research efforts. We describe those cases and discuss their relevance to the global HIV epidemic. We also review ongoing cure strategies that are transitioning from the lab to the clinic, and the assays and clinical assessments that can be used to evaluate cure interventions.

  7. Implications of prioritizing HIV cure: new momentum to overcome old challenges in HIV

    OpenAIRE

    Tucker, JD; Gilbertson, A; Lo, YR; Vitória, M

    2016-01-01

    Background Curing HIV is a new strategic priority for several major AIDS organizations. In step with this new priority, HIV cure research and related programs are advancing in low, middle, and high-income country settings. This HIV cure momentum may influence existing HIV programs and research priorities. Discussion Despite the early stage of ongoing HIV cure efforts, these changes have directly influenced HIV research funding priorities, pilot programs, and HIV messaging. The building moment...

  8. Study of catalytic effect of ammonium molybdate on the bisphthalonitrile resins curing reaction with aromatic amine

    Institute of Scientific and Technical Information of China (English)

    Wen Ting Li; Fang Zuo; Kun Jia; Xiao Bo Liu

    2009-01-01

    A kind of catalyst, ammonium molybdate was developed in this paper to promote the curing reaction of bisphthalonitrile resins with aromatic amine as curing agent, and the catalytic effect was studied by differential scanning calorimetry (DSC), rheometric measurements and thermogravimetric analysis (TGA). The results indicated that the catalyst could improve the curing rate and increase the curing degree, which could be regulated by the content of the catalyst used in the reaction.

  9. Ionizing radiation post-curing of objects produced by stereolithography and other methods

    Science.gov (United States)

    Howell, David H.; Eberle, Claude C.; Janke, Christopher J.

    2000-01-01

    An object comprised of a curable material and formed by stereolithography or another three-dimensional prototyping method, in which the object has undergone initial curing, is subjected to post-curing by ionizing radiation, such as an electron beam having a predetermined beam output energy, which is applied in a predetermined dosage and at a predetermined dose rate. The post-cured object exhibits a property profile which is superior to that which existed prior to the ionizing radiation post-curing.

  10. Chinese Wrestling,Chinese Traditional Spirit to Be Succeeded

    Institute of Scientific and Technical Information of China (English)

    Sun Yongjian; Guo Yan

    2006-01-01

    @@ Chinese Wrestling which has been exercised for thousands of years, has a history of as long as the Chinese People China's Foreign Trade exclusively interviewed 72-year old Mr. Li Baoru, Head of the Chinese Wrestling Team. He stressed: "Chinese Wrestling will not become extinct, because it is the symbol of the Chinese Spirit."

  11. Influence of Cure Shrinkage on Process-Induced Stress and Deformation in Thick Thermosetting Composites

    Science.gov (United States)

    1992-07-01

    unidirectional composite micromechanics model The constituent fiber properties (constant), the resin properties and chemical shrinkage (cure dependent...during cure. Changes in the resin properties directly influence the mechanical properties in the composite, and chemical shrinkage represents a...xA (5) The expansion coefficients, otL and or, are based on the micromechanics model utilizing constant fiber properties. cure dependent resin

  12. Curing lights for orthodontic bonding: A systematic review and meta-analysis

    NARCIS (Netherlands)

    Fleming, P.S.; Eliades, T.; Katsaros, C.; Pandis, N.

    2013-01-01

    INTRODUCTION: Light cure of resin-based adhesives is the mainstay of orthodontic bonding. In recent years, alternatives to conventional halogen lights offering reduced curing time and the potential for lower attachment failure rates have emerged. The relative merits of curing lights in current use,

  13. Curing Behavior and Viscoelasticity of Dual-Curable Adhesives Based on High-Reactivity Azo Initiator

    Science.gov (United States)

    Lee, Jong-Gyu; Shim, Gyu-Seong; Park, Ji-Won; Kim, Hyun-Joong; Moon, Sang-Eun; Kim, Young-Kwan; No, Dong-Hun; Kim, Jong-Hwan; Han, Kwan-Young

    2016-07-01

    We have investigated the curing behavior of dual-curable acrylic resin to solve problems associated with curing of adhesives in shaded areas during display manufacture. A low-temperature curing-type thermal initiator, 2,2'-azobis (4-methoxy-2,4-dimethylvaleronitrile), with a 30°C half-life decomposition temperature was used in the investigation. Dual-curable adhesives were prepared according to the thermal initiator content and ultraviolet (UV) radiation dose. The effects of thermal initiator and UV irradiation on the curing behavior and viscoelasticity were investigated. Using Fourier-transform infrared spectroscopy and gel-fraction analysis, an evaluation was carried out to determine the degree of curing after dual UV/thermal curing. In addition, the real-time curing behavior was evaluated using thermogravimetric analysis, differential scanning calorimetry, and a UV/advanced rheometric expansion system. A lift-off test was carried out to verify the effects of dual curing on adhesion performance. Application of UV irradiation before thermal curing suppressed the thermal curing efficiency. Also, the network structure formed after dual curing with low UV dose showed higher crosslinking density. Therefore, the thermal initiator radical effectively influenced uncured areas with low curing temperature and initiator content without causing problems in UV-curable zones.

  14. Characterization of Moisture Diffusion in Cured Concrete Slabs at Early Ages

    Directory of Open Access Journals (Sweden)

    Xiao Zhang

    2015-01-01

    Full Text Available The objective of this paper is to investigate the characterization of moisture diffusion inside early-age concrete slabs subjected to curing. Time-dependent relative humidity (RH distributions of three mixture proportions subjected to three different curing methods (i.e., air curing, water curing, and membrane-forming compounds curing and sealed condition were measured for 28 days. A one-dimensional nonlinear moisture diffusion partial differential equation (PDE based on Fick’s second law, which incorporates the effect of curing in the Dirichlet boundary condition using a concept of curing factor, is developed to simulate the diffusion process. Model parameters are calibrated by a genetic algorithm (GA. Experimental results show that the RH reducing rate inside concrete under air curing is greater than the rates under membrane-forming compound curing and water curing. It is shown that the effect of water-to-cement (w/c ratio on self-desiccation is significant. Lower w/c ratio tends to result in larger RH reduction. RH reduction considering both effect of diffusion and self-desiccation in early-age concrete is not sensitive to w/c ratio, but to curing method. Comparison between model simulation and experimental results indicates that the improved model is able to reflect the effect of curing on moisture diffusion in early-age concrete slabs.

  15. Gene Therapy to Cure HIV: Where to from Here?

    Science.gov (United States)

    Johnston, Rowena

    2016-12-01

    A variety of approaches are being tested to cure HIV, but with the exception of the Berlin patient case, none has been successful. The Berlin patient, positive for both HIV and acute myeloid leukemia (AML), received two stem cell transplants from a donor homozygous for the CCR5delta32 mutation. In the 8 years since his second transplant, he has remained free of both HIV and AML. This case provides strong proof-of-principle that a cure for HIV is possible and might be achieved through gene therapy. Several technological barriers must be resolved and are discussed here, including the safe delivery of the intervention throughout the body of the infected person, increased efficiency of gene editing, and avoidance of resistance to the therapy. Delivery of a gene therapy intervention to HIV-infected people around the world will also be a considerable challenge.

  16. Monolithic growth of partly cured polydimethylsiloxane thin film layers

    DEFF Research Database (Denmark)

    Yu, Liyun; Skov, Anne Ladegaard

    2014-01-01

    to enable interlayer crosslinking reactions either by application of an adhesion promoter or by ensuring that there are reactive, complementary sites available on the two surfaces. Polydimethylsiloxane (PDMS) is a widely used polymer for DEAPs. In this work, two-layered PDMS films are adhered together...... at different curing times. The monolithic films are investigated by rheology, scanning electron microscope, mechanical testing, dielectric relaxation spectroscopy, thermal gravimetric analysis (TGA) and differential scanning calorimetry (DSC). The morphology, mechanical and dielectric properties, as well...... as thermal stabilities of the bilayer elastomer films are observed to change with the curing time of the monolayers before lamination. The objective of this work is to create adhesion of two layers without destroying the original viscoelastic properties of the PDMS films, and hence enable, for example...

  17. Social desirability in personality inventories: symptoms, diagnosis and prescribed cure.

    Science.gov (United States)

    Bäckström, Martin; Björklund, Fredrik

    2013-04-01

    An analysis of social desirability in personality assessment is presented. Starting with the symptoms, Study 1 showed that mean ratings of graded personality items are moderately to strongly linearly related to social desirability (Self Deception, Impression formation, and the first Principal Component), suggesting that item popularity may be a useful heuristic tool for identifying items which elicit socially desirable responding. We diagnose the cause of socially desirable responding as an interaction between the evaluative content of the item and enhancement motivation in the rater. Study 2 introduced a possible cure; evaluative neutralization of items. To test the feasibility of the method lay psychometricians (undergraduates) reformulated existing personality test items according to written instructions. The new items were indeed lower in social desirability while essentially retaining the five factor structure and reliability of the inventory. We conclude that although neutralization is no miracle cure, it is simple and has beneficial effects.

  18. Properties of Cement Mortar with Phosphogpysum under Steam Curing Condition

    Directory of Open Access Journals (Sweden)

    Kyoungju Mun

    2008-01-01

    Full Text Available The purpose of this study is to utilize waste PG as an admixture for concrete products cured by steam. For the study, waste PG was classified into 4 forms (dehydrate, β-hemihydrate, III-anhydrite, and II-anhydrite, which were calcined at various temperatures. Also, various admixtures were prepared with PG, fly-ash (FA, and granulated blast-furnace slag (BFS. The basic properties of cement mortars containing these admixtures were analyzed and examined through X-ray diffraction, scanning electron microscopy, compressive strength, and acid corrosion resistance. According to the results, cement mortars made with III-anhydrite of waste PG and BFS exhibited strength similar to that of cement mortars made with II-anhydrite. Therefore, III-anhydrite PG calcined at lower temperature can be used as a steam curing admixture for concrete second production.

  19. Epoxy-silicate nanocomposites: Cure monitoring and characterization

    Energy Technology Data Exchange (ETDEWEB)

    Hussain, Farzana [Aerospace Manufacturing Technology Center (AMTC), Institute for Aerospace Research (IAR), National Research Council Canada - NRC, Montreal, QC (Canada)]. E-mail: farzssain@gmail.com; Chen, Jihua [Aerospace Manufacturing Technology Center (AMTC), Institute for Aerospace Research (IAR), National Research Council Canada -NRC, Montreal, QC (Canada); Hojjati, Mehdi [Aerospace Manufacturing Technology Center (AMTC), Institute for Aerospace Research (IAR), National Research Council Canada - NRC, Montreal, QC (Canada)

    2007-02-15

    Epoxy-clay nanocomposites were prepared with organically modified layered clay with varying clay contents (1-8 wt.%). Neat resin and nanocomposite were characterized using different techniques. At first, the effect of nanoclay concentration on the cure behaviour was investigated using an on-line dielectric cure monitoring technique. Differential scanning calorimetry (DSC) was used to verify the dielectric measurement results. Furthermore, mechanical and thermal properties were studied using tensile test and Dynamic Mechanical Analysis (DMA), respectively. Experimental results showed that properties of the epoxy were changed evidently because of the nanoclay loading. The tensile modulus of the nanocomposites increased by 47%, however, no improvement in tensile strength and glass transition temperature (T {sub g}) was observed. Fracture surface of the tensile samples were analyzed by Scanning Electron Microscope (SEM). The nanocomposites structures were characterized with Wide Angle X-Ray Diffraction (WAXD) and Transmission Electron Microscopy (TEM), which revealed the intercalated morphology of clay layers in the epoxy resin systems.

  20. Synthesis, characterization and photoinduced curing of polysulfones with (methacrylate functionalities

    Directory of Open Access Journals (Sweden)

    Cemil Dizman

    2010-06-01

    Full Text Available The UV-curable telechelic polysulfones with (methacrylate functionalities were synthesized by condensation polymerization and subsequent esterification. The final polymers and intermediates at various stages were characterized by 1H NMR, FT-ATR, and GPC. The oligomeric films prepared from the appropriate solutions containing these telechelics and 2,2-dimethoxy-2-phenylacetophenone (DMPA as the photoinitiator undergo rapid polymerization upon irradiation forming insoluble networks. The photo-curing behavior was investigated by photo-DSC and the effects of the molecular weight of the polysulfone precursor and type of functionality on the rate of polymerization and conversion were evaluated. Thermal properties of the photochemically cured films were studied by differential scanning calorimeter (DSC and thermal gravimetric analysis (TGA.

  1. PERBEDAAN KANDUNGAN SENYAWA VOLATIL DAUN SALAM (Eugenia polyantha Wight) PADA BEBERAPA PROSES CURING The Difference of Volatile Compounds of Bay Leaf (Eugenia polyantha Wight.) in Several Curing Processes

    OpenAIRE

    2012-01-01

    The influence of curing process toward flavour substances of bay leaf has been conducted. Bay leaves were cured with three different time of process: 0, 2 and 4 days and extracted by simultaneous distillation-extraction using n- hexane. Flavour extract was evaporated by vacuum rotary evaporator and remained solvent was flushed with nitrogen gas. Flavour compounds of the bay leaf extract were analysed using GC-MS. The result showed that curing process affected the composition of bay leaf flavo...

  2. Compaction and Cure of Resin Film Infusion Prepregs

    OpenAIRE

    Thompson, Joseph E.

    2004-01-01

    Gutowski et al.'s model has been employed to describe the cure and consolidation of prepregs used for resin film infusion. Resin kinetics, rheology, flow and fiber deformation are considered. Resin kinetics are simulated with an isothermal autocatalytic-1 type relation. The non-Newtonian viscosity of the Cytec™ 754 resin is represented with a gel type expression. The one dimensional flow of resin through a deformable, partially saturated porous medium is studied. A nonlinear partial...

  3. On the probability of cure for heavy-ion radiotherapy.

    Science.gov (United States)

    Hanin, Leonid; Zaider, Marco

    2014-07-21

    The probability of a cure in radiation therapy (RT)-viewed as the probability of eventual extinction of all cancer cells-is unobservable, and the only way to compute it is through modeling the dynamics of cancer cell population during and post-treatment. The conundrum at the heart of biophysical models aimed at such prospective calculations is the absence of information on the initial size of the subpopulation of clonogenic cancer cells (also called stem-like cancer cells), that largely determines the outcome of RT, both in an individual and population settings. Other relevant parameters (e.g. potential doubling time, cell loss factor and survival probability as a function of dose) are, at least in principle, amenable to empirical determination. In this article we demonstrate that, for heavy-ion RT, microdosimetric considerations (justifiably ignored in conventional RT) combined with an expression for the clone extinction probability obtained from a mechanistic model of radiation cell survival lead to useful upper bounds on the size of the pre-treatment population of clonogenic cancer cells as well as upper and lower bounds on the cure probability. The main practical impact of these limiting values is the ability to make predictions about the probability of a cure for a given population of patients treated to newer, still unexplored treatment modalities from the empirically determined probability of a cure for the same or similar population resulting from conventional low linear energy transfer (typically photon/electron) RT. We also propose that the current trend to deliver a lower total dose in a smaller number of fractions with larger-than-conventional doses per fraction has physical limits that must be understood before embarking on a particular treatment schedule.

  4. Screening and cervical cancer cure: population based cohort study

    OpenAIRE

    Andrae, B.; Andersson, T. M.-L.; Lambert, P C; Kemetli, L.; Silfverdal, L.; Strander, B.; Ryd, W.; Dillner, J.; Tornberg, S.; Sparen, P.

    2012-01-01

    Objective To determine whether detection of invasive cervical cancer by screening results in better prognosis or merely increases the lead time until death. Design Nationwide population based cohort study. Setting Sweden. Participants All 1230 women with cervical cancer diagnosed during 1999-2001 in Sweden prospectively followed up for an average of 8.5 years. Main outcome measures Cure proportions and five year relative survival ratios, stratified by screening history, mode of detection, age...

  5. Adherend Surface Effects on Epoxy Cure by NMR

    Science.gov (United States)

    1994-05-11

    questions. 3 2. Summary of results. The structure and dynamics of the cure of the epoxy resin system based on the diglycidyl ether of bisphenol-A ( DGEBA ) is... DGEBA ), obtained from Dow Chemical Co. (der 332) was heated in the oven at temperature 160 OC until completely melted. The sample was cooled and at the...epoxy to ether conversion with the NMR analysis. (b) Results and Interpretation. The mixture of DGEBA with DDS was studied at temperature 1600C. The

  6. Wormholes as a cure for black hole singularities

    CERN Document Server

    Olmo, Gonzalo J; Sanchez-Puente, Antonio

    2016-01-01

    Using exactly solvable models, it is shown that black hole singularities in different electrically charged configurations can be cured. Our solutions describe black hole space-times with a wormhole giving structure to the otherwise point-like singularity. We show that geodesic completeness is satisfied despite the existence of curvature divergences at the wormhole throat. In some cases, physical observers can go through the wormhole and in other cases the throat lies at an infinite affine distance.

  7. Targeting the brain reservoirs: towards an HIV cure

    Directory of Open Access Journals (Sweden)

    Celine Marban

    2016-09-01

    Full Text Available One of the top research priorities of the international AIDS society by the action Towards an HIV Cure is the purge or the decrease of the pool of all latently infected cells. This strategy is based on reactivation of latently reservoirs (the shock followed by an intensifying Combination Antiretroviral Therapy (cART to kill them (the kill. The Central Nervous System (CNS has potential latently infected cells i.e. perivascular macrophages, microglial cells and astrocytes which will need to be eliminate. However the CNS has several characteristics that may preclude the achievement of a cure. In this review we discuss several limitations to the eradication of brain reservoirs and how we could circumvent these limitations by making it efforts in 4 directions: (i designing efficient Latency-Reversal Agents for CNS-cell types (ii improving cART by targeting HIV transcription (iii improving delivery of HIV drugs in the CNS and in the CNS-cell types (iv developing therapeutic immunization. As a prerequisite to these efforts we also believe that a better comprehension of molecular mechanisms involved in establishment and persistence of HIV latency in brain reservoirs are essential to design new molecules for strategies aiming to achieve a cure for instance the shock and kill strategy.

  8. [Can we cure autism? From outcome to intervention].

    Science.gov (United States)

    Alessandri, M; Thorp, D; Mundy, P; Tuchman, R F

    2005-01-15

    Outcome in autism is variable but with a significant trend toward a poor prognosis and despite reports that outcome in individuals with autism may be improving secondary to early intensive interventions there is still much to be learned about the natural history and the effects of intervention in autism spectrum disorders. While there may not be a known cure for autism, there are a number of viable treatment options available. The primary models of treatment are non pharmacological interventions that include intervention models such as applied behavior analysis and developmental and structured teaching. The role of pharmacological interventions is limited to treating specific symptoms that may be interfering with a child's ability to learn or function within a particular environment. The question of whether or not we can cure autism needs to be discussed in terms of the need to overcome the as of yet poorly understood fundamental disturbance in autism and the need to develop treatment protocols specifically targeting social deficits. At the present time, it is more appropriate to speak of our quest to understand autism than it is to speak of a cure.

  9. A 50-Year Journey to Cure Childhood Acute Lymphoblastic Leukemia

    Science.gov (United States)

    Pui, Ching-Hon; Evans, William E.

    2013-01-01

    The 50th anniversary of Seminars in Hematology coincides with the 50th of St. Jude Children’s Research Hospital, and both milestones are inexorably linked to studies contributing to the cure of childhood acute lymphoblastic leukemia (ALL). We thought it fitting, therefore, to mark these events by traveling back in time to point out some of the achievements, institutions, study groups and individuals that have made cure of childhood ALL a reality. In many instances, progress was driven by new ideas, while in others it was driven by new experimental tools that allowed more precise assessment of the biology of leukemic blasts and their utility in selecting therapy. We also discuss a number of contemporary advances that point the way to exciting future directions. Whatever pathways are taken, a clear challenge will be to use emerging genome-based or immunologic-based treatment options in ways that will enhance, rather than duplicate or compromise, recent gains in outcome with classic cytotoxic chemotherapy. The theme of this journey serves as a reminder of the chief ingredient of any research directed to a catastrophic disease such as ALL. It is the audacity of a small group of investigators who confronted a childhood cancer with the goal of cure, not palliation, as their mindset. PMID:23953334

  10. CURING AND MECHANICAL PROPERTIES OF CHLOROSULPHONATED POLYETHYLENE RUBBER BLEND

    Directory of Open Access Journals (Sweden)

    Jaroslava Budinski-Simendić

    2011-09-01

    Full Text Available In this paper, the curing and mechanical properties of two series of prepared blends, i.e., chlorosulphonated polyethylene (CSM/isobutylene-co-isoprene (IIR rubber blends and chlorosulphonated polyethylene (CSM/chlorinated isobutylene-co-isoprene (CIIR rubber blends were carried out. Blends were prepared using a two-roll mill at a temperature of 40-50 °C. The curing was assessed using a Monsanto oscillating disc rheometer R-100. The process of vulcanization accelerated sulfur of pure rubbers and their blends was carried out in an electrically heated laboratory hydraulic press under a pressure of about 4 MPa and 160 °C. The stress-strain experiments were performed using a tensile tester machine (Zwick 1425. Results indicate that the scorch time, ts2, and optimum cure time, tc90, increase with increasing CSM content in both blends. The value of modulus at 100 and 300% elongation and tensile strength increases with increasing CSM content, whereas elongation at break shows a decreasing trend. The enhancement in mechanical properties was supported by data of crosslink density in these samples obtained from swelling measurement and scanning electron microscopy studies of the rubber blends fractured surfaces

  11. The electron beam cure of epoxy paste adhesives

    Energy Technology Data Exchange (ETDEWEB)

    Farmer, J.D. [Air Force Advanced Composites Program office, McClellan AFB, CA (United States); Janke, C.J. [Oak Ridge National Lab., TN (United States). Oak Ridge Centers for Manufacturing Technology; Lopata, V.J. [Atomic Energy of Canada Ltd., Pinawa, Manitoba (Canada). Whiteshell Labs.

    1998-07-01

    Recently developed epoxy paste adhesives were electron beam cured and experimentally explored to determine their suitability for use in an aerospace-quality aircraft component. There were two major goals for this program. The first was to determine whether the electron beam-curable past adhesives were capable of meeting the requirements of the US Air Force T-38 supersonic jet trainer composite windshield frame. The T-38 windshield frame`s arch is currently manufactured by bonding thin stainless steel plies using an aerospace-grade thermally-cured epoxy film adhesive. The second goal was to develop the lowest cost hand layup and debulk process that could be used to produce laminated steel plies with acceptable properties. The laminate properties examined to determine adhesive suitability include laminate mechanical and physical properties at room, adhesive tack, out-time capability, and the debulk requirements needed to achieve these properties. Eighteen past adhesives and four scrim cloths were experimentally examined using this criteria. One paste adhesive was found to have suitable characteristics in each of these categories and was later chosen for the manufacture of the T-38 windshield frame. This experimental study shows that by using low-cost debulk and layup processes, the electron beam-cured past adhesive mechanical and physical properties meet the specifications of the T-38 composite windshield frame.

  12. Persistent Comorbidities in Cushing’s Syndrome after Endocrine Cure

    Directory of Open Access Journals (Sweden)

    Eugenia Resmini

    2014-01-01

    Full Text Available It was assumed that resolution of hypercortisolism in Cushing syndrome (CS was followed by normalization of morbidity; however, in the last decade evidence is accumulating that patients with cured CS still have increased morbidity and mortality after the biochemical control of hypercortisolism. Patients with CS have an increased cardiovascular and metabolic risk and persistent accumulation of central fat, with an unfavorable adipokine profile, not only during the active phase of the disease but also long after biochemical remission. Clinical management should be particularly careful in identifying global cardiovascular risk, as a primary goal during the followup of these patients, aimed at improving global vascular morbidity. Moreover bone mass is reduced not only due to the endogenous hypercortisolism but also due to duration and dose of exogenous glucocorticoid (GC replacement therapy after surgery. Thus, therapy in operated patients with inhibition of the hypothalamic-pituitary-adrenal axis should be reduced to the lowest dose and duration possible. Specific treatments should be considered in patients with decreased bone mass, aimed at reducing the increased fracture incidence. Finally, cognitive and health related quality of life impairments, described in active disease, are still abnormal after endocrine cure. Thus, residual morbidity persists in cured CS, suggesting irreversibility of GC-induced phenomena, typical of chronic hypercortisolism.

  13. Microwaves energy in curing process of water glass molding sands

    Directory of Open Access Journals (Sweden)

    Granat K.

    2007-01-01

    Full Text Available This work presents the results of investigation of microwave heating on hardening process of water glass molding sands. Essential influence of this heating process on basic properties such as: compression, bending and tensile strength as well as permeability and abrasion resistance has been found. It has been proved, that all investigated sorts of sodium water glass with a module between 2.0 and 3.3 can be used as a binder of molding sands in microwave curing process. It has been found during analysis of research results of sands with 2.5 % water glass addition that they are practically the same as in case of identical molding sands dried for 120 minutes at the temperature of 110°C, used for comparative purposes. Application of microwave curing of molding sands with water glass, however, guarantees reduction of hardening time (from 120 to 4 minutes as well as significant reduction of energy consumption. Attempts of two stage hardening of the investigated water glass molding sands have also been carried out, that is after an initial hardening during a classical CO2 process (identical sands have also been tested for comparison after CO2 blowing process and additional microwave heating. It has been found that application of this kind of treatment for curing sands with 2.5 % sodium water glass content and module from 2.0 up to 3.3 results in the improvement of properties in comparison to classical CO2 process.

  14. Dataset of producing and curing concrete using domestic treated wastewater.

    Science.gov (United States)

    Asadollahfardi, Gholamreza; Delnavaz, Mohammad; Rashnoiee, Vahid; Fazeli, Alireza; Gonabadi, Navid

    2016-03-01

    We tested the setting time of cement, slump and compressive and tensile strength of 54 triplicate cubic samples and 9 cylindrical samples of concrete with and without a Super plasticizer admixture. We produced concrete samples made with drinking water and treated domestic wastewater containing 300, 400 kg/m(3) of cement before chlorination and then cured concrete samples made with drinking water and treated wastewater. Second, concrete samples made with 350 kg/m(3) of cement with a Superplasticizer admixture made with drinking water and treated wastewater and then cured with treated wastewater. The compressive strength of all the concrete samples made with treated wastewater had a high coefficient of determination with the control concrete samples. A 28-day tensile strength of all the samples was 96-100% of the tensile strength of the control samples and the setting time was reduced by 30 min which was consistent with a ASTMC191 standard. All samples produced and cured with treated waste water did not have a significant effect on water absorption, slump and surface electrical resistivity tests. However, compressive strength at 21 days of concrete samples using 300 kg/m(3) of cement in rapid freezing and thawing conditions was about 11% lower than concrete samples made with drinking water.

  15. Effect of base monomer's refractive index on curing depth and polymerization conversion of photo-cured resin composites.

    Science.gov (United States)

    Fujita, Kou; Nishiyama, Norihiro; Nemoto, Kimiya; Okada, Tamami; Ikemi, Takuji

    2005-09-01

    In this study, we examined the effect of the transmitted amount of visible light through a resin composite on the curing depth and polymerization conversion. Transmitted amount of visible light was strongly dependent on the magnitude of refractive index difference that existed between the resin and silica filler. More specifically, the differences arose from the type of base monomer used. The transmitted amount of visible light exhibited a good correlation with the curing depth and Knoop hardness ratio of the bottom surface against the top surface of the resin composite. To improve the polymerization conversion of the cavity floor, it is important to reduce the refractive index difference that exists between the base resin and silica filler.

  16. Electron beam curing of dimer acid-based urethane acrylates for pressure sensitive adhesives

    Energy Technology Data Exchange (ETDEWEB)

    Sasaki, Takashi [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment; Takeda, Satoe; Shiraishi, Katsutoshi

    1995-03-01

    Polyester urethane diacrylate prepolymers prepared from dimer acids (DUA) were cured with low energy electron beams to investigate adhesive properties of cured films. Among various type monomers added, monofunctional methacrylates such as isobornyl methacrylate (IBXMA) were effective for higher peel strength cured films although the dose-to-cure for the mixtures increased to 100 kGy or more. The increase in the molecular weight of prepolymers resulted in lower curing rates but higher peel strength. Aging tests up to 80degC for four weeks proved good stability in peel strength of the stored products. (author).

  17. CHINESE OF HUMANITY

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    A discussion of chinese curriculum of primary school under the background of new curriculum reform Mao xinjuan Feng haiying [Abstract] in recent years, Chinese learning received more and more attention by people article mainly from the national studies this course concepts, the curriculum reform of elementary school curriculum requirements and how to effective implementation of primary national studies course several aspects under the background of curriculum reform of Chinese primary curriculum the new school

  18. Natural products as antidepressants documented in Chinese patents from 1992 to 2013.

    Science.gov (United States)

    Sun, Chang-Li; Geng, Chang-An; Yin, Xiu-Juan; Huang, Xiao-Yan; Chen, Ji-Jun

    2015-01-01

    Depressive disorder is a severe psychiatric problem all over the world. Clinical therapeutic agents for the treatment of depression in the market targeting on monoamine neurotransmitters are far from satisfaction due to their adverse effects. Novel classes of antidepressant agents with different mechanisms and low toxicity are needed. Natural products from traditional Chinese medicines have been revealed as new sources to cure the depressive symptoms with various chemical structures and promising activities. This paper reviews natural products as antidepressants documented in Chinese patents so far.

  19. Efficiency of Sodium Polyacrylate to Improve Durability of Concrete under Adverse Curing Condition

    Directory of Open Access Journals (Sweden)

    Tanvir Manzur

    2015-01-01

    Full Text Available The conventional external curing process requires supply of large amount of water in addition to mixing water as well as strict quality control protocol. However, in a developing country like Bangladesh, many local contractors do not have awareness and required knowledge on importance of curing which often results in weaker concrete with durability issues. Moreover, at times it is difficult to maintain proper external curing process due to nonavailability of water and skilled laborer. Internal curing can be adopted under such scenario since this method is simple and less quality intensive. Usually, naturally occurring porous light weight aggregates (LWA are used as internal curing agent. However, naturally occurring LWA are not available in many countries like Bangladesh. Under these circumstances, Super Absorbent Polymer (SAP can be utilized as an alternative internal curing agent. In this study, sodium polyacrylate (SP as SAP has been used to produce internally cured concrete. Desorption isotherm of SP has been developed to investigate its effectiveness as internal curing agent. Test results showed that internally cured concrete with SP performed better in terms of both strength and durability as compared to control samples when subjected to adverse curing conditions where supply of additional water for external curing was absent.

  20. Energy saving estimation on radiation process. Electron beam curing of paint

    Energy Technology Data Exchange (ETDEWEB)

    Kaneko, Hideaki (Nihon Parkerizing Co., Ltd., Tokyo); Maekawa, H.; Ito, Y.; Nishikawa, I.; Fujii, H.; Murata, K.

    1982-01-01

    When the quantity of paint used for industrial coating is assumed to be 420,000 tons, it is estimated that the area being coated is 2.8 billion m/sup 2/, the petroleum required for pretreatment steam, drying and baking is 1.68 million tons, and the required amount of energy saving is 120,000 tons per year in terms of petroleum. The authors examined how the adoption of electron beam curing for surface coating contributes to the energy saving. So far, it has been said that electron beam curing is more efficient than thermal or light curing in energy consumption, but the premise condition was not clear. The theoretical energy requirement for thermal curing, light curing and electron beam curing was calculated and compared. The comparison of the measured values was also performed. The amount of energy required for thermal curing, UV light curing and electron beam curing was roughly 100:10:1, and the cost of energy for them was 50:5:1. In spite of the large merit of electron beam curing, it has not spread as expected, because of the repayment cost of the facility and the cost of inert gas required for the process. Energy saving is brought about by electron beam curing, but the overall cost must be examined case by case.

  1. Effects of light curing method and resin composite composition on composite adaptation to the cavity wall.

    Science.gov (United States)

    Yoshikawa, Takako; Morigami, Makoto; Sadr, Alireza; Tagami, Junji

    2014-01-01

    This study aimed to evaluate the effects of the light curing method and resin composite composition on marginal sealing and resin composite adaptation to the cavity wall. Cylindrical cavities were prepared on the buccal or lingual cervical regions. The teeth were restored using Clearfil Liner Bond 2V adhesive system and filled with Clearfil Photo Bright or Palfique Estelite resin composite. The resins were cured using the conventional or slow-start light curing method. After thermal cycling, the specimens were subjected to a dye penetration test. The slow-start curing method showed better resin composite adaptation to the cavity wall for both composites. Furthermore, the slow-start curing method resulted in significantly improved dentin marginal sealing compared with the conventional method for Clearfil Photo Bright. The light-cured resin composite, which exhibited increased contrast ratios duringpolymerization, seems to suggest high compensation for polymerization contraction stress when using the slow-start curing method.

  2. A cure shrinkage model for analyzing the stresses and strains in encapsulated assemblies

    Science.gov (United States)

    Chambers, R. S.; Lagasse, R. R.; Guess, T. R.; Plazek, D. J.; Bero, C.

    Electrical component assemblies are encapsulated to provide delicate parts with voltage isolation and protection against damage caused by shock, vibration, and harsh atmospheric environments. During cure, thermosetting resins shrink and harden simultaneously. If the natural deformation of the resin is constrained by adhesion to the mold or to relatively stiff embedded components, cure shrinkage stresses are generated in the encapsulant. Subsequent cooling or thermal cycling produces additional stresses that are caused by the mismatches in thermal strains among the materials in the encapsulated assembly. Although cure shrinkage stresses frequently are neglected because they are considerably smaller than thermal stresses, cure shrinkage stresses can cause delamination or fractures in the encapsulant, since the partially cured resin is not as tough as the fully cured material. Cracks generated during cure can compromise performance (e.g., permit dielectric breakdown), degrade a component's protection, and grow under subsequent thermal cycling producing residual stresses that differ from those found in uncracked assemblies.

  3. A cure shrinkage model for analyzing the stresses and strains in encapsulated assemblies

    Energy Technology Data Exchange (ETDEWEB)

    Chambers, R.S.; Lagasse, R.R.; Guess, T.R. [Sandia National Labs., Albuquerque, NM (United States); Plazek, D.J.; Bero, C. [Pittsburgh Univ., PA (United States). Dept. of Materials Science and Engineering

    1992-12-31

    Electrical component assemblies are encapsulated to provide delicate parts with voltage isolation and protection against damage caused by shock, vibration, and harsh atmospheric environments. During cure, thermosetting resins shrink and harden simultaneously. If the natural deformation of the resin is constrained by adhesion to the mold or to relatively stiff embedded components, cure shrinkage stresses are generated in the encapsulant. Subsequent cooling or thermal cycling produces additional stresses that are caused by the mismatches in thermal strains among the materials in the encapsulated assembly. Although cure shrinkage stresses frequently are neglected because they are considerably smaller than thermal stresses, cure shrinkage stresses can cause delamination or fractures in the encapsulant, since the partially cured resin is not as tough as the fully cured material. Cracks generated during cure can compromise performance (e. g., permit dielectric breakdown), degrade a component`s protection, and grow under subsequent thermal cycling producing residual stresses that differ from those found in uncracked assemblies. 3 refs., 11 figs.

  4. [Effects of silicon carbide on the cure depth, hardness and compressive strength of composite resin].

    Science.gov (United States)

    Wang, Ke; Lin, Yi'na; Liu, Xiaoqing

    2009-08-01

    The hardness, compressive strength and cure depth are important indices of the composite resin. This investigation was made with regard to the effects of silicon carbide on the cure depth, hardness and compressive strength of the light-curing composite resin. Different amounts of silicon carbide were added to the light-curing composite resin, which accounted for 0 wt%, 1 wt%, 0.6 wt%, 0.3 wt%, 0.1 wt%, 0.05 wt% and 0.005 wt% of the composite resin, respectively. The hardness, compressive strength and cure depth of the six afore-mentioned groups of composite resin were measured by the vernier caliper, the vickers hardness tester and the tensile strength of machine, respectively. The results showed that silicon carbide improved the hardness and compressive strength of the light-curing composite resin,when the concentration was 0.05 wt%. And the cure depth was close to that of control.

  5. Traditional Chinese Medicine Takes Effect in Treating AIDS

    Institute of Scientific and Technical Information of China (English)

    1995-01-01

    SINCE the first case of AIDS was found in the United States in June 1981, AIDS patients and persons infected with HIV have reached 17.41 million in the world. Among the more than four million AIDS patients, over two million have died. Currently, China has 1,435 patients infected with HIV. AIDS is a serious threat to health and the development of social economy, especially to women and children. Since there is still no effective cure for AIDS the death rate of AIDS patients is nearly 100 percent, many countries are trying to find medicines to combat this disease. Chinese doctors and researchers have made some progress in treating AIDS with traditional Chinese medicine. After numerous selections and

  6. History of Chinese medicinal wine.

    Science.gov (United States)

    Xia, Xun-Li

    2013-07-01

    Chinese medicinal wine is one type of a favorable food-drug product invented by Chinese ancestors for treating and preventing diseases, promoting people's health and corporeity, and enriching people's restorative culture. In the course of development of the millenary-old Chinese civilization, Chinese medicinal wine has made incessant progress and evolution. In different historical periods, Chinese medicinal wine presented different characteristics in basic wine medical applications, prescriptions, etc. There are many medical and Materia Medica monographs which have systemically and specifically reported on Chinese medicinal wine in past Chinese dynasties. By studying leading medical documents, this article made an outline review on the invention, development, and characteristics of Chinese medicinal wine.

  7. An exponential chemorheological model for viscosity dependence on degree-of-cure of a polyfurfuryl alcohol resin during the post-gel curing stage

    DEFF Research Database (Denmark)

    Dominguez, J.C.; Oliet, M.; Alonso, María Virginia

    2016-01-01

    In the present study, the chemorheological behavior of a bio-based polyfurfuryl alcohol (PFA) resin has been determined by rheological isothermal tests at different curing temperatures for the post-gel curing stage of the resin, using three different amounts of catalyst (2, 4 and 6 wt %). Instead...

  8. The effects of halogen and light-emitting diode light curing on the depth of cure and surface microhardness of composite resins

    Directory of Open Access Journals (Sweden)

    Batu Can Yaman

    2011-01-01

    Full Text Available Aim : Light-emitting diode light curing units (LED LCUs have become more popular than halogen LCUs in routine dental restorative treatment. The aim of the study was to compare the effects of two conventional halogen (Hilux Plus and VIP and two LED (Elipar FreeLight 2 and Smart Lite light curing units on the depth of cure and the microhardness of various esthetic restorative materials. Materials and Methods : The curing depth and microhardness of a compomer (Dyract Extra, a resin-modified glass ionomer (Vitremer, a packable composite (Sculpt It, an ormocer (Admira, a hybrid composite (Tetric Ceram, two microhybrid composites (Miris and Clearfil Photo Posterior and, a nanofil composite (Filtek Supreme were determined using a scraping method and a hardness tester. A total of 320 samples were prepared using the eight different materials (n = 10 samples for each subgroup. The scraping test was based on ISO 4049:2000. Vicker′s microhardness testing was carried out using hardness tester (Zwick 3212. Data were analyzed using one-way analysis of variance (ANOVA, Bonferroni and the Kolmogorov-Smirnov tests. Results : Best microhardness results were obtained with the LED light curing units and Tetric EvoCeram and Filtek Supreme achieved the highest hardness values. The nanofil composite, Filtek Supreme, showed the best curing depth results in all the tested light curing systems. Conclusions : The LEDs were found to be more successful than the halogen units with respect to both curing depth and microhardness properties.

  9. 烤房类型对烤后烟叶质量的影响%Effect of Differont Types of Curing Barns on Tobacoo Leaf Quantity after Curing

    Institute of Scientific and Technical Information of China (English)

    黄维

    2012-01-01

    [目的]考察3种类型烤房在烟叶鲜叶初加工过程中的整体效果.[方法]采用云南烟区普遍使用的气流下降式密集烤房密集型烤房、气流上升式密集烤房和普通立式炉小烤房3种烤房,分析比较不同类型烤房烤后烟叶的主要化学成分、物理特性、外观等级、评吸质量的差异.[结果]不同类型烤房烤后烟叶中上等烟叶比例气流下降式密集烤房比普通立式炉小烤房密集烤房分别高出2.86%和0.87%,比气流上升式密集烤房高出7.75%和4.29%;不同类型烤房烤后烟叶根据多数化学指标均为气流下降式密集烤房烤房烤后烟叶化学成分最为协调,气流上升式密集烤房次之,普通立式炉小烤房较差;不同类型烤房烤后上中下部位烟叶感官质量和物理特性均为气流下降式密集烤房最好,气流上升式密集烤房次之,普通立式炉小烤房效果较差.[结论]气流下降式密集电烤房结构设计合理可以推广应用.%[ Objective] To investigate the effect of three types of curing bams on the primary processing quality of fresh tobacco leaves. [ Method] Airflow-descending dense curing barna,airflow-ascending dense curing bams and common vertical furnace-curing bams in Yunnan tobacco area were adopted for analyzing and comparing the difference of main chemical components,physical characteristics,appearance grade and smoking quality of tobaccos cured by the three types of curing bamB. [ Result ] The medium and high-grade tobacco proportions after being cured by the airflow-descending dense curing barns were higher than that by the common vertical furnace min-curing bams and dense curing bams by 2.86% and 0.87% respectively,and higher than that by airflow-ascending dense curing bams hy 7.75% and 4.29%. According to a majority of chemical indicators,the tobacco chemical components cured by airflow-descending dense curing bams were the most coordinate,followed by the airflow

  10. Cure-WISE: HETDEX Data Reduction with Astro-WISE

    Science.gov (United States)

    Snigula, J. M.; Drory, N.; Fabricius, M.; Landriau, M.; Montesano, F.; Hill, G. J.; Gebhardt, K.; Cornell, M. E.

    2014-05-01

    The Hobby-Eberly Telescope Dark Energy Experiment (HETDEX, Hill et al. 2012b) is a blind spectroscopic survey to map the evolution of dark energy using Lyman-alpha emitting galaxies at redshifts 1.9currently receives a wide-field upgrade (Hill et al. 2012a) to accomodate the spectrographs and to provide the needed field of view. Over the projected five year run of the survey we expect to obtain approximately 170 GB of data each night. For the data reduction we developed the Cure pipeline, to automatically find and calibrate the observed spectra, subtract the sky background, and detect and classify different types of sources. Cure employs rigorous statistical methods and complete pixel-level error propagation throughout the reduction process to ensure Poisson-limited performance and meaningful significance values. To automate the reduction of the whole dataset we implemented the Cure pipeline in the Astro-WISE framework. This integration provides for HETDEX a database backend with complete dependency tracking of the various reduction steps, automated checks, and a searchable interface to the detected sources and user management. It can be used to create various web interfaces for data access and quality control. Astro-WISE allows us to reduce the data from all the IFUs in parallel on a compute cluster. This cluster allows us to reduce the observed data in quasi real time and still have excess capacity for rerunning parts of the reduction. Finally, the Astro-WISE interface will be used to provide access to reduced data products to the general community.

  11. [Stress profile during curing contraction of composite resin adhesives].

    Science.gov (United States)

    Kunzelmann, K H; Hickel, R

    1990-11-01

    The wall-to-wall curing contraction of thin composite resin layers was recorded with a tensometer. The composite resin was applied to cylindrically shaped ceramic sample holders with diameters of 3 mm, 4 mm and 8 mm. The distances of the sample holders was set at 50 microns, 100 microns, 150 microns, 200 microns and 300 microns. The shrinkage stress recordings clearly show that the shrinkage forces are governed by the distance of the sample holders and not by the volume or the configuration factor of the composite resin layers.

  12. Invasive Scedosporium sternal osteomyelitis following lung transplant: Cured

    Directory of Open Access Journals (Sweden)

    E.J. Denton

    2016-06-01

    Full Text Available Scedosporium is an important pathogen in cystic fibrosis (CF and post-transplant but rarely causes invasive infection. Treatment remains challenging, particularly due to inherent resistance to multiple antifungal agents. We present a young man with CF who developed invasive sternal and rib infection 10-months following lung transplant. The infection has been clinically and radiologically cured with extensive surgery and triazole therapy. This case highlights the importance of adjunctive surgery in addition to prolonged triazole treatment to manage invasive Scedosporium infections in immunosuppressed patients.

  13. Chosen quality parameters of pork sausage produced without curing mixture

    Directory of Open Access Journals (Sweden)

    Adam Kostecki

    2015-09-01

    Full Text Available Background. The aim of this study was to determine the infl uence of the dried celeriac juice addition, as a nitrogenous compounds sources, on the quality of the experimental pork sausage. Material and methods. In the sausages with vegetable preparation addition and in traditionally cured sausages amount of the sodium nitrate (III and sodium nitrate (V was determined (in the batter and 24 h after production. Moreover the total number of aerobic bacteria, number of coli forms, anaerobic survived bacteria, coagulase positive staphylococci, Listeria monocytogenes and occurrence of Salmonella in 25 g (according to Polish Standards was determined during sausages storing (after 2, 14 and 21 days. Also sensory evaluation was carried out (after 2 and 14 days. After 2, 7, 14 and 21 days the amount of drip loss in the package was determined. Result. In the experimental sausage produced with the addition of vegetable preparation (E0, the content was 2.2 times higher of sodium nitrate (V while sodium nitrate (III three times lower, compared to traditionally cured sausages (K. In the E0 sausages faster aerobic microorganisms proliferation was observed. However, in these products, in comparison to the control group (K, no higher contamination with coliform bacteria, anaerobic sporulating bacteria, coagulase positive Staphylococci, Listeria monocytogenes or Salmonella was found. The sensory evaluation (colour in cross-section, fl avour, taste, consistency showed no statistically significant difference between the experimental sausages. Conclusions. In the sausages produced with dried celeriac juice addition there was above twice more sodium nitrate (V and threefold less sodium nitrate (III in comparison to traditionally cured sausages and faster growth of aerobic bacteria was demonstrated. Sensory quality of ‘cold’ and ‘hot’ sausages without curing salt was worse, but the score number was never lower than 4,1, so the sausages were accepted. In the

  14. Solid Rocket Fuel Constitutive Theory and Polymer Cure

    Science.gov (United States)

    Ream, Robert

    2006-01-01

    Solid Rocket Fuel is a complex composite material for which no general constitutive theory, based on first principles, has been developed. One of the principles such a relation would depend on is the morphology of the binder. A theory of polymer curing is required to determine this morphology. During work on such a theory an algorithm was developed for counting the number of ways a polymer chain could assemble. The methods used to develop and check this algorithm led to an analytic solution to the problem. This solution is used in a probability distribution function which characterizes the morphology of the polymer.

  15. Resin flow and void formation in an autoclave cure cycle

    Science.gov (United States)

    Lionetto, Francesca; Lucia, Massimo; Dell'Anna, Riccardo; Maffezzoli, Alfonso

    2016-05-01

    A finite element (FE) model able to evaluate both the evolution of resin flow, degree of reaction and void formation during autoclave cure cycles was developed. The model was implemented using a commercial epoxy matrix widely used in aeronautic field. The FE model also included a kinetic and rheological model whose input parameters were experimentally determined by Differential Scanning Calorimetry and rheological analysis. The FE model was able to predict the evolution of degree of reaction with very good agreement with the experimental data. Moreover, the predicted resin losses were lower than 3% of the overall composite resin content.

  16. Preliminary toxicological study of Sylgard 184 encapsulating resin: curing agent

    Energy Technology Data Exchange (ETDEWEB)

    Smith, D.M.; Drake, G.A.; London, J.E.; Thomas, R.G.

    1978-06-01

    The acute oral LD/sub 50//sup 30/ values for Sylgard 184 (100 parts encapsulating resin plus 10 parts curing agent) were greater than 5 g/kg in rats and mice. According to classical guidelines, the mixture would be considered slightly toxic or practically nontoxic in both species. Skin application studies in the rabbit demonstrated the mixture to be mildly irritating. Eye irritation tests, also in the rabbit, showed the Sylgard 184 mixture to be a mild but transitory irritant. The sensitization study in the guinea pig demonstrated the mixture to be a very mild sensitizer in two of six animals.

  17. Chemical Interpretation of the Relaxed Permittivity during Epoxy Resin Cure.

    Science.gov (United States)

    1984-11-30

    contributions of other polar groups and their time variation are included. The isothermal cure of a stoichiometric mixture of a DGEBA epoxy resin, EPON 825. with...the DGEBA molecule, and since it contains only a single epoxide. this material does not crosslink. At low temperatures and at all frequencies, the...ratios of DGEBA and DDS gave an epoxy dipole moment of 8.SE-30 C-u and an amine dipole moment of 19.8E-30 C-m [10]. The experimental data and the curves

  18. Curing characteristics of chlorosulphonated polyethylene and natural rubber blends

    OpenAIRE

    M. MARINOVIC-CINCOVIC; J. BUDINSKI SIMENDIC; Markovic, G.; Radovanovic, B.

    2005-01-01

    The dependence of the Mooney scorch time and cure index on the blend ratio of chlorosulphonated polyethylene/natural rubber (CSM/SMR 20 CV) and chlorosulphonated polyethylene/chlorinated natural rubber (CSM/Pergut S 40) blends were determined in the temperature range from 120 oC to 160 oC using a Monsanto Mooney viscometer. Semi-efficient vulcanization systems were used for the study. The morphology of the fracture surface of the crosslinked systems was determined by Scanning Electron Microsc...

  19. Low toxicity aromatic diamine curing agents for adhesives

    Energy Technology Data Exchange (ETDEWEB)

    Dorsey, G.F.

    1993-08-24

    Increasing severity of regulations for handling of hazardous materials has led to formulation of adhesives with considerably lowered toxicities for use at the Oak Ridge Y-12 Plant. Fundamental was the development of Asilamine aromatic diamines, a family of liquid aromatic diamines useful as substitutes for methylenedianiline (MDA), a widely used adhesives curing agent. The use of Asilamine has allowed us to continue operations without dealing with expensive measures for regulation of MDA as a carcinogen promulgated by the Occupational Safety and Health Administration (OSHA).

  20. FROM THE CHINESE PRESS

    Institute of Scientific and Technical Information of China (English)

    1998-01-01

    Equality and harmony are mainstream in Chinese marriage. The conclusion was made by a systematic investigation in 1996 on love and marriage relations between couples in Shanghai, Harbin, Guangdong, Gansu and other regions. Six thousand couples were surveyed in a multi-period, separated level probability sampling; the research was conducted by the study group, "Marriage quality during the period of Chinese social

  1. About Chinese Characters

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The Chinese pictographs for 土 tǔ (earth) are "(?)", "(?)" and "(?)", reflecting the Chinese people of remote antiquity’s understanding of earth. They divided it into two layers, upper and subterranean, and used the "二" in "土" to represent both layers, the central "(?)" representing the plants that

  2. Not Your Father's Chinese

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The government's first annual report on the evolution of the Chinese language contains some surprisesThe Chinese people are proud of their language, which they consider the most essential part of their civilization of 5,000 years. The charm of the language includes its ideographic writing system, in which the structure of the characters is directly related

  3. Danish-accented Chinese

    DEFF Research Database (Denmark)

    Wang, Lei; Sloos, Marjoleine 莱娜; Zhang, Chun

    In search for a linguistic basis for the education of Chinese as a foreign language CFL in Denmark, we set up a new line of investigation into CFL. This research focuses on the phonetics and phonology of Mandarin Chinese as compared to Danish. Considering the sound systems of both languages, we...

  4. Predicate Movements in Chinese

    Science.gov (United States)

    Shou-hsin, Teng

    1975-01-01

    The movements of such higher predicates as time, locative, and complementation verbs are studied, and Tai's Predicate Placement Constraint is rejected as an incorrect account of predicate movements in Chinese. It is proposed, on the other hand, that there is only leftward movement involving predicates in Chinese. (Author)

  5. Why I Learn Chinese

    Institute of Scientific and Technical Information of China (English)

    Keltoum; Otamani

    2013-01-01

    <正>I am eighteen years old. I have learned Chinese at the FFCA NordPas-de Calais for three years. I will continue to study Chinese during my five-year university life and try to get a job dealing with China in the future. I became interested in China at the age of 13, and my interest grew year by year.

  6. Doorway to Chinese Civilization

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    Xi’an,the ancient Chinese capital and modern day metropolis,offers an exciting array of historic attractions and tourist charms The long and extensive history of Xi’an,an ancient Chinese capital,has endowed it with an abundant variety of cultural sites and artifacts,including the

  7. Chinese Conversation Structure

    Institute of Scientific and Technical Information of China (English)

    LIU Yan

    2016-01-01

    This paper aims to describe the features of Chinese conversation structure. Specifically speaking, the structure will be analyzed from the following four aspects:openings and pre-sequence, adjacency pairs, pre-closing and closing. Generally speak-ing, Chinese conversation structure is similar to English conversation structure. But still a lot of differences are found due to cul-tural factors.

  8. Courting Chinese Investors

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Inviting Chinese business delegations. Participating in trade fairs in China.Building an industrial park for Chinese investors. Poland is doing all theseand more to attract investment from China, according to Krzysztof Szumski,Poland ’s Ambassador to Chi

  9. AfricaonChineseDream

    Institute of Scientific and Technical Information of China (English)

    2013-01-01

    At the opening of the 2013 Understanding and Cooperation Dialogue held by the Chinese Association for International Understanding (CAFIU) on July 23 in Beijing, former President of the Federal Repub-lic of Nigeria Olusegun Obasanjo expounded on his understanding of the Chinese dream and its implications for Africa. The ful text of his thoughts follow.

  10. Chinese Children's Songs.

    Science.gov (United States)

    Kwok, Irene, Comp.

    Singing can be an enjoyable and effective way to motivate children to learn a second language. This booklet consists of contemporary and folk songs that are related to Chinese festivals, transportation, the family, seasons, Christmas and other topics. Each page gives the music to a song with the words in Chinese and in English. The songs are…

  11. The Mechanism of Carotenoid Degradation in Flue-Cured Tobacco and Changes in the Related Enzyme Activities at the Leaf-Drying Stage During the Bulk Curing Process

    Institute of Scientific and Technical Information of China (English)

    SONG Zhao-peng; LI Tong-shuai; ZHANG Yong-gang; CAO Hui-jing; GONG Chang-rong; ZHANG Wei-jian

    2010-01-01

    The mechanism of carotenoid degradation and the changes in the activities of related enzymes in flue-cured tobacco at the leaf-drying stage during the bulk-curing process were studied in order to provide theoretical basis for optimization of curing technology.The effect of different rising speeds of temperature on the carotenoid degradation and the related enzymes activities at the color-fixing stage during the bulk curing process was studied by using the electric-heated fluecuring barn designed by Henan Agricultural University,China,based on curing technology with yellowing at low temperature and moderate humidity and leaf drying at moderate humidity.The results showed that the carotenoid degradation components(β-carotene,lutein,neoxanthin,and violaxthin)decreased gradually at the color-fixing stage during the bulk curing process.The carotenoid degradation components viz.,β-carotene,lutein,neoxanthin,and violaxthin at the slow heating curing(T1)were relatively higher than the rapid heating curing(T2)accounting for 10,2,32 and 32%respectively,but there were no differences among treatments(P>0.05).The effect of different conditions of curing on the activities of enzymes related to carotenoids degradation were significant.The lipoxygenase,phenylalanine ammonialyase,peroxidase,and polyphenol oxidase enzymes had a bidirectional effect on the quality of tobacco leaves and it was beneficial to form more premise matter of aroma based on the higher enzyme activities at the early leaf-drying stage.The slow heating could regulate the change in various enzymes' activities reasonably,making cell redox reaction to reach the dynamic balance and make the degradation of carotenoids adequately.Meanwhile,it could avoid the occurrence of browning reaction and provide foundation for improving the quality of tobacco and optimization of technology for bulk curing and further enhancing aroma.

  12. Influence of curing rate of resin composite on the bond strength to dentin

    DEFF Research Database (Denmark)

    Benetti, Ana Raquel; Asmussen, E; Peutzfeldt, A

    2007-01-01

    @ 1000 mW/cm2) for all groups. A split Teflon mold was clamped to the treated dentin surface and filled with resin composite. The rate of cure was varied, using one of four LED-curing units of different power densities. The rate of cure was also varied using the continuous or pulse-delay mode....... In continuous curing mode, in order to give an energy density totaling 16 J/cm2, the power densities (1000, 720, 550, 200 mW/cm2) emitted by the various curing units were compensated for by the light curing period (16, 22, 29 or 80 seconds). In the pulse-delay curing mode, two seconds of light curing at one...... of the four power densities was followed by a one-minute interval, after which light cure was completed (14, 29, 27 or 78 seconds), likewise, giving a total energy density of 16 J/cm2. The specimens produced for each of the eight curing protocols and two resin composites (Tetric EvoCeram, Ivoclar Vivadent...

  13. Benefits of Sealed-Curing on Compressive Strength of Fly Ash-Based Geopolymers

    Directory of Open Access Journals (Sweden)

    Sujeong Lee

    2016-07-01

    Full Text Available There is no standardized procedure for producing geopolymers; therefore, many researchers develop their own procedures for mixing and curing to achieve good workability and strength development. The curing scheme adopted is important in achieving maximum performance of resultant geopolymers. In this study, we evaluated the impact of sealed and unsealed curing on mechanical strength of geopolymers. Fly ash-based geopolymers cured in sealed and unsealed moulds clearly revealed that retention of water during curing resulted in superior strength development. The average compressive strength of sealed-cured geopolymers measured after 1 day of curing was a modest 50 MPa, while after 7 day curing the average compressive strength increased to 120~135 MPa. In the unsealed specimens the average compressive strength of geopolymers was lower; ranging from 60 to 90 MPa with a slight increase as the curing period increased. Microcracking caused by dehydration is postulated to cause the strength decrease in the unsealed cured samples. These results show that water is a crucial component for the evolution of high strength three-dimensional cross-linked networks in geopolymers.

  14. Synergistic effect of graphene-oxide-doping and microwave-curing on mechanical strength of cement

    Science.gov (United States)

    Qin, Hao; Wei, Wei; Hang Hu, Yun

    2017-04-01

    In this communication, efficient reinforcement of cement matrix was obtained by graphene-oxide (GO) doping and curing treatments. The compressive strength of plain cement is 14.3±0.2 MPa. When the cement contained 0.5 wt% GO, its strength reached 19.4±0.9 MPa. The strength can be further enhanced by curing, which follows the sequence: Microwave-cured GO-cement > Microwave and water-cured GO-cement > Water-cured GO-cement > GO-cement without curing. The highest compressive strength (32.4±0.7 MPa), which was achieved by combining GO-doping and microwave curing, is 126.6±8.1% higher than that without GO-doping and microwave curing. This demonstrates a synergistic effect of GO doping and microwave-curing on the strength of cement composite materials. Furthermore, X-ray diffraction (XRD), Fourier transform Infrared Spectroscopy (FTIR), and field emission scanning electron microscope (FESEM) characterizations revealed that the combination of GO doping and microwave-curing remarkably accelerated cement hydration, leading to the regular and compact structure and thus a high compressive strength. This work provides a new way to improve the mechanical properties of cement composites.

  15. Comparative efficiency of plasma and halogen light sources on composite micro-hardness in different curing conditions

    OpenAIRE

    Dietschi, Didier; Marret, N; Krejci, Ivo

    2003-01-01

    Recent developments have led to the introduction of high power curing lights, which are claimed to greatly reduce the total curing time. This study evaluated the effectiveness of a plasma-curing device (Apollo 95 E) and a halogen device (Heliolux DLX), in different curing conditions.

  16. Effect of In-Situ Curing on Compressive Strength of Reactive Powder Concrete

    Directory of Open Access Journals (Sweden)

    Bali Ika

    2016-01-01

    Full Text Available A development of Reactive Powder Concrete (RPC currently is the use of quartz powder as a stabilizing agent with the content to cement ratio of 30% and steam curing method in an autoclave temperature of 250ºC which produced a high compressive strength of 180 MPa. That RPC can be generated due to one reason for using the technique of steam curing in an autoclave in the laboratory. This study proposes in-situ curing method in order the curing can be applied in the field and with a reasonable compressive strength results of RPC. As the benchmarks in this study are the curing methods in laboratory that are steam curing of 90°C for 8 hours (C1, and water curing for 28 days (C2. For the in-situ curing methods that are covering with tarpaulins and flowed steam of 3 hours per day for 7 days (C3, covering with wet sacks for 28 days (C4, and covering with wet sacks for 28 days for specimen with unwashed sand as fine aggregate (C5. The comparison of compressive strength of the specimens in this study showed compressive strength of RPC with in-situ steam curing (101.64 MPa close to the compressive strength of RPC with steam curing in the laboratory with 8.2% of different. While in-situ wet curing compared with the water curing in laboratory has the different of 3.4%. These results indicated that the proposed in-situ curing methods are reasonable good in term of the compressive strength that can be achieved.

  17. Modern Chinese History Studies

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    Famous Foreign Scholars' Lecture Tours in China Around the May Fourth Movement and Changes in Chinese Intellectual Circles From 1919 to 1924, John Dewey and four other famous foreign scholars came to China on lecture tours. These tours were great cultural undertakings to spread Western learning to the East after the First World War. The lectures these schol- ars gave helped to deepen the thoughts of Chinese people, and at the same time encouraged the diversification and evolution of Chinese intellectual circles. Firstly, the lectures hastened the birth of a contemporary Chinese wave of reflection on mo- dernity, and provided a basis for the theoretical views and cultural appeals of Liang Qichao and other members of the socalled "Orient Culture Faction," thereby increasing the tension intrinsic to the development of the New Culture Movement and to the expansion of intellectual horizons in Chinese intellectual circles.

  18. Bond strength between composite resin and resin modified glass ionomer using different adhesive systems and curing techniques

    OpenAIRE

    Alireza Boruziniat; Samineh Gharaei

    2014-01-01

    Aim: To evaluate bond strength between RMGI and composite using different adhesive systems and curing techniques. Materials and Methods: Sixty prepared samples of RMGI were randomly divided into six groups according to adhesive systems (total-etch, two-step self-etch and all-in-one) and curing techniques (co-curing and pre-curing). In co-curing technique, the adhesive systems were applied on uncured RMGI samples and co-cured together. In the pre-curing technique, before application of adh...

  19. Study on Translating Chinese into Chinese Sign Language

    Institute of Scientific and Technical Information of China (English)

    徐琳; 高文

    2000-01-01

    Sign language is a visual-gestural language mainly used by hearing impaired people to communicate with each other. Gesture and facial expression are important grammar parts of sign language. In this paper, a text-based transfor mation method of Chinese-Chinese sign language machine translation is proposed.Gesture and facial expression models are created. And a practical system is im plemented. The input of the system is Chinese text. The output of the system is "graphics person" who can gesticulate Chinese sign language accompanied by facial expression that corresponds to the Chinese text entered so as to realize automatic translation from Chinese text to Chinese sign language.

  20. Effect of Different Thicknesses of Pressable Ceramic Veneers on Polymerization of Light-cured and Dual-cured Resin Cements

    Science.gov (United States)

    Cho, Seok-Hwan; Lopez, Arnaldo; Berzins, David W.; Prasad, Soni; Ahn, Kwang Woo

    2015-01-01

    Aim This study evaluated the effects of ceramic veneer thicknesses on the polymerization of two different resin cements. Materials and Methods A total of 80 ceramic veneer discs were fabricated by using a pressable ceramic material (e.max Press; Ivoclar Vivadent) from a Low Translucency (LT) ingot (A1 shade). These discs were divided into light-cured (LC; NX3 Nexus LC; Kerr) and dual-cured (DC; NX3 Nexus DC; Kerr) and each group was further divided into 4 subgroups, based on ceramic disc thickness (0.3 mm, 0.6 mm, 0.9 mm, and 1.2 mm). The values of Vickers microhardness (MH) and degree of conversion (DOC) were obtained for each specimen after a 24-hour storage period. Association between ceramic thickness, resin cement type, and light intensity readings (mW/cm2) with respect to microhardness and degree of conversion was statistically evaluated by using ANOVA. Results For the DOC values, there was no significant difference observed among the LC resin cement subgroups, except in the 1.2 mm subgroup; only the DOC value (14.0 ± 7.4%) of 1.2 mm DC resin cement had significantly difference from that value (28.9 ± 7.5%) of 1.2 mm LC resin cement (P.05). Conclusion The degree of conversion and hardness of the resin cement was unaffected with veneering thicknesses between 0.3 and 0.9 mm. However, the DC resin cement group resulted in a significantly lower DOC and MH values for the 1.2 mm subgroup. Clinical Significance While clinically adequate polymerization of LC resin cement can be achieved with a maximum 1.2 mm of porcelain veneer restoration, the increase of curing time or light intensity is clinically needed for DC resin cements at the thickness of more than 0.9 mm. PMID:26162252

  1. Preparation, curing kinetic and properties of a novel amine with flexible polyoxypropylene side chain curing agent for epoxy resin

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Guiyou, E-mail: guiyouwang@ecust.edu.cn; Jiang, Guanlan; Zhang, Jie

    2014-08-10

    Highlights: • Novel amines with different length of flexible polyoxypropylene side chain (AFPE) were synthesized. • The non-isothermal curing kinetics of DGEBA/AFPEs were studied in detail. • Structure, morphology and physical properties of AFPEs modified diethylenetriamine/DGEBA systems were studied, and results showed that AFPE was a novel and effective toughening agent for epoxy resins. - Abstract: A novel amine with flexible polyoxypropylene side chain (AFPE) was synthesized and characterized with FT-IR and NMR. Then, AFPEs with different molecular weight were used as a curing agent for diglycidyl ether of bisphenol A (DGEBA), and non-isothermal reaction was detected with DSC. The kinetic parameters of the curing process were determined by Málek method. A two-parameter (m, n) autocatalytic model (Šesták–Berggren equation) was found to be adequate to describe the reaction-controlled kinetics of the studied epoxy resins, yet was insufficient in depicting the diffusion-controlled kinetics of the epoxy resins. The values of E{sub a} depended on the molecular weight of AFPEs, and increased with longer polyoxypropylene chain length in the AFPE. Dynamic mechanical analysis of AFPEs modified DGEBA/diethylenetriamine systems found that with the increasing molecular weight of AFPEs, α relaxation temperature, β relaxation temperature and crosslinking density decreased, while impact strength and elongation at break improved. From scanning electron microscope, tensile surfaces were rougher and sizes of cavities in the surface became larger with the increasing molecular weight of AFPEs. Our study showed that AFPE was a novel and effective toughening agent for epoxy resins.

  2. The Mexican asthma cure. Systemic steroids for gullible gringos.

    Science.gov (United States)

    Rubin, B K; LeGatt, D F; Audette, R J

    1990-04-01

    Asthmatic patients from western Canada and the United States have reported that after visits to an asthma clinic in Mexicali, Mexico, they return home substantially improved or cured having received "a bronchodilator medication unavailable in the United States or Canada because of the big drug companies." Analysis of these medications reveals that the most commonly prescribed combination is the glucocorticoid triamcinolone (unscored white tablets) and the antihistamine chlorpheniramine (coated biconvex orange or red tablets). Occasionally benzodiazepines are added to these medications. The patients are assured that the medications which they have been given are free of side effects and specifically, that corticosteroids are not used. Such therapy is dangerous to the patient who not only is unaware of the medications that he or she is taking, but is unlikely to mention this therapy to his or her physician. These patients risk drug interactions, medication side effects, and the possibility of adrenal failure either with a stress to their system or on withdrawal of drug treatment. Patients are also at risk of abandoning safer forms of asthma therapy for the miracle cure. We, too, are partially responsible for these unethical practices by avoiding the use of steroids and undertreating our patients at times, leaving them unnecessarily restricted and eager for any form of relief.

  3. Definition of Cure in Childhood Acute Myeloid Leukemia

    Science.gov (United States)

    Rubnitz, Jeffrey E.; Inaba, Hiroto; Leung, Wing; Pounds, Stanley; Cao, Xueyuan; Campana, Dario; Ribeiro, Raul C.; Pui, Ching-Hon

    2014-01-01

    Background A better understanding of when cure can be declared in childhood acute myeloid leukemia (AML) would reduce anxiety and improve quality of life of AML survivors. We determined the likelihood of patients with AML to maintain long-term remission after completion of therapy. Patients and Methods The cumulative risk of relapse, time to relapse, event-free survival and overall survival were analyzed for 604 patients with AML enrolled in seven successive clinical trials, divided into 3 treatment eras (1976–1991, 1991–1997, 2002–2008). Results The median time to relapse did not change over time (0.93 years vs. 0.76 vs. 0.8 years for each consecutive era, P = .22) but the risk of relapse decreased significantly (5-year cumulative incidence of relapse 52.6% ± 3.1% vs. 31.5% ± 3.9% vs. 22.0% ± 3.0%, P < .001). Among patients who were in remission 4 years from diagnosis, the probabilities of relapse were 1.7%, 2.9%, and 0.9%, respectively. In the most recent era, all 44 relapses except one occurred within four years of diagnosis. Conclusion Children with AML who are treated with contemporary therapy and remain in remission four years from diagnosis are likely cured. Although late relapses and late deaths from other causes are rare, long-term follow up of survivors is necessary for timely management of late adverse effects. PMID:24798038

  4. Blue light curing units--a dermatological hazard?

    Science.gov (United States)

    Chadwick, R G; Traynor, N; Moseley, H; Gibbs, N

    1994-01-08

    The setting reactions of a large number of dental materials are activated upon exposure to visible blue light emitted from a curing unit. Although the wavelength (lambda) from such devices is principally in the visible spectrum (lambda > 400 nm) a small amount of ultraviolet radiation (UV) is also present. Little attention has been paid to the consequences of such exposure upon the skin of dental surgeons' fingers. This investigation studied the level of UVA I (lambda = 340-400 nm) emitted by three commonly used polymerisation sources and assessed the level of protection afforded by six brands of surgical glove. The integrated irradiances of the Translux, Topaz T100 and Heliomat units in the UVA I range were 15861, 3611 and 305 mW/m2 respectively. For all gloves the mean % transmission, at lambda = 400 nm, was less than 4% with the exception of one brand where, in the stretched state, the level of transmission was 7%. It is concluded that the risk of initiating adverse dermatological consequences as a result of exposure to UVA I, emitted by light polymerisation units, is minimal in normal usage. The combined effects of exposure to radiation of this type and contamination of the fingers with quantities of irritant chemicals, such as found in many dental materials, are unknown. Due to the ability of the gloves to shield the skin from both chemicals and UVA I it is recommended that gloves are routinely worn for all light curing procedures.

  5. Modern Medicine: Towards Prevention, Cure, Well-being and Longevity

    Directory of Open Access Journals (Sweden)

    Singh Ajai

    2010-01-01

    Full Text Available Modern medicine has done much in the fields of infectious diseases and emergencies to aid cure. In most other fields, it is mostly control that it aims for, which is another name for palliation. Pharmacology, psychopharmacology included, is mostly directed towards such control and palliation too. The thrust, both of clinicians and research, must now turn decisively towards prevention and cure. Also, longevity with well-being is modern medicine′s other big challenge. Advances in vaccines for hypertension, diabetes, cancers etc, deserve attention; as also, the role of meditation, yoga, spirituality etc in preventing disease at various levels. Studies on longevity, life style changes and healthy centenarians deserve special scrutiny to find what aids longevity with wellbeing. A close look at complementary and alternative medicine is needed to find any suitable models they may have, cutting aside their big talk and/or hostility towards mainstream medical care. Medicine is a manifestation of the human eros, and should not become a means of its thanatos. It must realise its true potential, so that eros prevails, and thanatos prevails only ultimately, not prematurely.

  6. Curing characteristics of chlorosulphonated polyethylene and natural rubber blends

    Directory of Open Access Journals (Sweden)

    M. MARINOVIC-CINCOVIC

    2005-05-01

    Full Text Available The dependence of the Mooney scorch time and cure index on the blend ratio of chlorosulphonated polyethylene/natural rubber (CSM/SMR 20 CV and chlorosulphonated polyethylene/chlorinated natural rubber (CSM/Pergut S 40 blends were determined in the temperature range from 120 oC to 160 oC using a Monsanto Mooney viscometer. Semi-efficient vulcanization systems were used for the study. The morphology of the fracture surface of the crosslinked systems was determined by Scanning Electron Microscopy (SEM. The results showed that the scorch time decreased with increasing SMR 20 CV and Pergut S 40 contents. This observation is attributed to the increasing solubility of sulfur, as the content of SMR 20 CV and Pergut S 40 in the composition increased. For temperatures greater than 140 oC, the dependence of the scorch time on blend ratios diminishes, as enough thermal energy is available to overcome the activation energy of vulcanization. The differing curing characteristics of the two blends is explained by the compatibility factor of the respective blend. Morphological analysis of the blends shows a very satisfactory agreement.

  7. The Danger of Chinese Exceptionalism

    DEFF Research Database (Denmark)

    Li, Xin

    2016-01-01

    In the movement of Chinese indigenous management research, a sort of ‘Chinese exceptionalism’ (as critiqued by Peng, 2005: 133) seems to have been emerging, namely, some Chinese scholars see Chinese culture, philosophy, and way of thinking are unique and cannot be accounted for by some...

  8. Research in Ancient Chinese Language

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    JIANG Ji-cheng, A Brief Study of Arabian-Chinese Diaphone in Huihui Prescription Abstract: Based on meterials of Arabian- Chinese diaphone in Huihui Prescription, this paper studies all Chinese phonetic initials and finals in Yuan dynasty, including 21 initials and 34 finals. Key Words: Huihui Prescription, Arabian- Chinese diaphone, transferred sound, International Phonetic Alphabet

  9. Effects of Amine and Anhydride Curing Agents on the VARTM Matrix Processing Properties

    Science.gov (United States)

    Grimsley, Brian W.; Hubert, Pascal; Song, Xiaolan; Cano, Roberto J.; Loos, Alfred C.; Pipes, R. Byron

    2002-01-01

    To ensure successful application of composite structure for aerospace vehicles, it is necessary to develop material systems that meet a variety of requirements. The industry has recently developed a number of low-viscosity epoxy resins to meet the processing requirements associated with vacuum assisted resin transfer molding (VARTM) of aerospace components. The curing kinetics and viscosity of two of these resins, an amine-cured epoxy system, Applied Poleramic, Inc. VR-56-4 1, and an anhydride-cured epoxy system, A.T.A.R.D. Laboratories SI-ZG-5A, have been characterized for application in the VARTM process. Simulations were carried out using the process model, COMPRO, to examine heat transfer, curing kinetics and viscosity for different panel thicknesses and cure cycles. Results of these simulations indicate that the two resins have significantly different curing behaviors and flow characteristics.

  10. UV curing of a liquid based bismaleimide-containing polymer system

    Directory of Open Access Journals (Sweden)

    2007-06-01

    Full Text Available A new liquid formulation of commercial bismaleimide and n-acryloylmorpholine was prepared that could be UV cured as an alternative to traditional thermal cure methods presently used for BMI in the industry. UV curing was shown to be an efficient method which promoted the reaction rate significantly and was able to achieve this at low temperatures (30–50°C. A free radical polymerization approach has been used to explain the cure mechanism and cure kinetics, using data elucidated from the DPC and FTIR. The cured thin film was shown to achieve very high thermal stability (~400°C, with the BMI shown to retard the thermal degradation temperature and rate.

  11. Activities of RILEM Technical Committee: Internal Curing of Concrete and Anticipated Research

    DEFF Research Database (Denmark)

    Kovler, Konstantin; Jensen, Ole Mejlhede

    of Concrete” of the International Union of Laboratories and Experts in Construction Materials, Systems and Structures (RILEM). The authors of this short communication served as a chair (K. Kovler) and secretary (O.M. Jensen) of the TC. The regular and corresponding members were acknowledged RILEM experts......Novel methods of shrinkage mitigation, based on special advanced methods of internal curing (IC), are currently being intensively studied in research groups in several countries. They have been the focus of the State-of-the-Art report prepared by the Technical Committee TC 196-ICC “Internal Curing...... in ACI, JCI (Japan Concrete Institute) and other well-known research associations in the field of concrete science and engineering. Internal curing, as well as external curing, can be classified into two categories: • Internal water curing (sometimes called “water entrainment”), when the curing agent...

  12. Dynamic cure measurement of dental polymer composites using optical coherence tomography

    Science.gov (United States)

    Tomlins, Peter H.; Palin, Will M.; Shortall, Adrian C.

    2008-02-01

    Dental amalgam is being increasingly replaced by Light-activated resin-based dental composites. However, these materials are limited by inefficient setting reactions as a function of depth, constraining the maximum extent of cure and reducing biocompatibility. In this paper we demonstrate a novel metrological tool for dynamic monitoring of refractive index and thickness change through curing resins using spectral-domain optical coherence tomography. We present real-time measurements from pre- to post-cure of a series of un-filled bisphenol-A diglycidyl ether dimethacrylate (bisGMA) and triethylene glycol dimethacrylate (TEGDMA) resins with different inhibitor concentrations. Our results demonstrate that refractive index measurements are sensitive to the extent of cure of such resins and that the inhibitor concentration strongly affects the cure dynamics and final extent of cure.

  13. Effect of Curing Procedure on the Properties of Copper-Powder-Filled Conductive Adhesives

    Institute of Scientific and Technical Information of China (English)

    ZHENG Xiaoling; ZHANG Lulu; YOU Min; WU Jianhao; YU Haizhou; YANG Derong; MAO Yuping

    2008-01-01

    By means of testing the shear strength with single lap joint, measuring electrical resistivity for cured products and the curing strain with strain gauges, the effect of cure parameters on the properties of HT1012 conductive adhesive filled with copper powder was investigated, and the residual stress in the conductive adhesives was also estimated. The experimental results show that the properties such as shear strength of the adhesives, electrical resistivity of products as well as the residual stress of cured HT1012 copper-filled conductive adhesive were evidently affected by curing temperature and time. The diagrams of scanning electron microscopy (SEM) and Fourier transform infrared (FT-IR) were also used to determine the properties. The higher mechanical property was achieved under the condition of curing the adhesive 3h at 60℃ as the density of the hydrogen links or linkages existed in the adhesive was relatively higher and the lower electrical resistivity occurred at 80℃.

  14. Influence of Curing Condition on the Adhesive Strength of EVA Modified Mortar to Tile

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The reducing water effectiveness of EVA latex and powder was observed. Adhesive strength of EVA modified mortar to tile under different curing condition was studied. And the adhesive strengths of mortars modified by EVA latex and by EVA powder were compared. The results show that the reducing water effectiveness is improved by 36.12% and 21.55%, respectively, when the content of EVA latex and powder are 8% and 4%. EVA latex and powder can improve the adhesive strength of modified mortar to tile under the standard curing, high temperature curing, and freeze-thaw circle curing.EVA latex can improve the water resistance obviously, besides improve the adhesive strengths of standard curing and high temperature curing, comparing with EVA powder.

  15. Semiparametric Bayesian estimation of quantile function for breast cancer survival data with cured fraction.

    Science.gov (United States)

    Gupta, Cherry; Cobre, Juliana; Polpo, Adriano; Sinha, Debjayoti

    2016-09-01

    Existing cure-rate survival models are generally not convenient for modeling and estimating the survival quantiles of a patient with specified covariate values. This paper proposes a novel class of cure-rate model, the transform-both-sides cure-rate model (TBSCRM), that can be used to make inferences about both the cure-rate and the survival quantiles. We develop the Bayesian inference about the covariate effects on the cure-rate as well as on the survival quantiles via Markov Chain Monte Carlo (MCMC) tools. We also show that the TBSCRM-based Bayesian method outperforms existing cure-rate models based methods in our simulation studies and in application to the breast cancer survival data from the National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) database.

  16. Effect of curing conditions and ionic additives on properties of fly ash–lime compacts

    Indian Academy of Sciences (India)

    Saikat Maitra; Farooq Ahmad; Ananta K Das; Santanu Das; Binay K Dutta

    2010-04-01

    In the present work the reaction between fly ash and lime in fly ash–lime compacts under water curing and steam curing conditions was studied thoroughly in relation to the processing conditions. Fly ash from different sources were collected, characterized, mixed with lime in different ratios and compacted. The compacts were cured with water and steam separately. The reduction in the free CaO content in these compacts was measured as a function of curing time and curing process. Role of two ionic additives, FeCl3 and MgCl2, on the reaction between fly ash and lime was also investigated by measuring the free CaO content. Kinetics of these reactions was studied by determining the reaction order and rate constants with respect to the free CaO content and it was observed that the curing conditions and additives affected the reaction kinetics significantly.

  17. ENGINEERED INTERFACE CHEMISTRY TO IMPROVE THE MECHANICAL PROPERTIES OF CARBON FIBER COMPOSITES CURED BY ELECTRON BEAM

    Energy Technology Data Exchange (ETDEWEB)

    Vautard, Frederic [ORNL; Grappe, Hippolyte A. [Oak Ridge Institute for Science and Education (ORISE); Ozcan, Soydan [ORNL

    2014-01-01

    A reactive sizing was designed to achieve high levels of interfacial adhesion and mechanical properties with a carbon fiber-acrylate system cured by electron beam (EB). The sizing was made of a partially cured epoxy sizing with a high density of pendant functional groups (acrylate functionality) able to generate a covalent bonding with the matrix. The interlaminar shear strength was clearly improved from 61 MPa to 81 MPa (+ 33 %) without any post-processing, reaching a similar value to the one obtained with the same system cured by a thermal treatment. Observation of the fracture profiles clearly highlighted a change in the fracture mechanism from a purely adhesive failure to a cohesive failure. Such improvements of the mechanical properties of carbon fiber composites cured by EB, without any post-cure, have not been reported previously to the best of our knowledge. This constitutes a breakthrough for the industrial development of composites EB curing.

  18. Swelling of radiation-cured polymer precursor powder for silicon carbide by pyrolysis

    Directory of Open Access Journals (Sweden)

    Akinori Takeyama

    2015-12-01

    Full Text Available Ceramic yield, density, volume change and pore size distribution were measured for radiation- and thermally cured PCS powder when they were pyrolyzed in the temperature range of 673–973 K. Higher ceramic yield was obtained for radiation-cured powder due to smaller amount of evolved gas. Temperature dependence of volume change and the total pore volume show that the formation and disappearance of pores in the powders were determined by the volume shrinkage and evolution of decomposed gases. Volume shrinkage narrowed the pore size distribution for radiation-cured powder. For thermally cured powder, the narrowing of size distribution was disturbed by aggregated pores. Smaller amount of evolved gas from radiation-cured powder relative to thermally cured powder prevented the aggregation of pores and provided the narrow size distribution.

  19. A comparative study to evaluate the effect of fluoride releasing sealant cured by visible light, argon laers, and light emitting diode curing units: An in vitro study

    Directory of Open Access Journals (Sweden)

    Das U

    2009-09-01

    Full Text Available In Pediatric Dentistry, the use of pit and fissure sealant is one of the essential forms of prevention. Pit and fissure caries may be substantially decreased by obliteration of these developmental defects in occlusal, buccal and lingual surfaces with resin based dental sealants. Visible light-curing units, or LCUs, are an integral part of modern adhesive dentistry" They are used to cure resin based composite restoration materials, resin modified glass-ionomer and pit and fissure sealants, as well as to bond orthodontic teeth. Most recently, the argon laser has been approved for initiating the setting reaction with visible light cured-resins. Argon curing of resin materials has been show to enhance the physical properties and degree of polymerization of the resin, while reducing the polymerization time by 75 percent. The study is undertaken considering the inadequate research reports of regarding the comparison of curing ability using argon laser. LEDs and visible light as well as the resistant towards caries activity of the preventive fluoride releasing pit and fissure sealant cured by above mentioned curing units.

  20. Performing "Chinese-ness" in Singkawang

    NARCIS (Netherlands)

    Ong, C.E.; Ormond, M.E.; Sulianti, Dian

    2017-01-01

    Through an examination of two festivals – Qing Ming and Cap Go Meh – in the town of Singkawang in Indonesian Borneo (Kalimantan), we show how Singkawang-bound Chinese Indonesian tourists and their Singkawang-based relatives produce a diasporic heritage network through ‘moorings’ generated by both tr

  1. Thermal analysis of bulk filled composite resin polymerization using various light curing modes according to the curing depth and approximation to the cavity wall

    Directory of Open Access Journals (Sweden)

    Hoon-Sang Chang

    2013-07-01

    Full Text Available OBJECTIVE: The purpose of this study was to investigate the polymerization temperature of a bulk filled composite resin light-activated with various light curing modes using infrared thermography according to the curing depth and approximation to the cavity wall. MATERIAL AND METHODS: Composite resin (AeliteFlo, Bisco, Schaumburg, IL, USA was inserted into a Class II cavity prepared in the Teflon blocks and was cured with a LED light curing unit (Dr's Light, GoodDoctors Co., Seoul, Korea using various light curing modes for 20 s. Polymerization temperature was measured with an infrared thermographic camera (Thermovision 900 SW/TE, Agema Infra-red Systems AB, Danderyd, Sweden for 40 s at measurement spots adjacent to the cavity wall and in the middle of the cavity from the surface to a 4 mm depth. Data were analyzed according to the light curing modes with one-way ANOVA, and according to curing depth and approximation to the cavity wall with two-way ANOVA. RESULTS: The peak polymerization temperature of the composite resin was not affected by the light curing modes. According to the curing depth, the peak polymerization temperature at the depth of 1 mm to 3 mm was significantly higher than that at the depth of 4 mm, and on the surface. The peak polymerization temperature of the spots in the middle of the cavity was higher than that measured in spots adjacent to the cavity wall. CONCLUSION: In the photopolymerization of the composite resin, the temperature was higher in the middle of the cavity compared to the outer surface or at the internal walls of the prepared cavity.

  2. Thermal curing of PBI membranes for high temperature PEM fuel cells

    DEFF Research Database (Denmark)

    Aili, David; Cleemann, Lars N.; Li, Qingfeng

    2012-01-01

    to solubility, phosphoric acid doping, radical-oxidative resistance and mechanical strength indicated that the PBI membranes were irreversibly cured by the thermal treatment. After curing, the PBI membranes demonstrated features that are fundamental characteristics of a thermoset resin including complete...... insolubility, high resistance to swelling and improved mechanical toughness. Additionally, the thermal treatment was found to increase the degree of crystallinity of the membranes. The improved physicochemical characteristics of the membranes after curing were further illustrated by a dramatically improved...

  3. CURE OF A MICROGEL-EPOXY RESIN TWO-PHASE POLYMER WITH ETHYLENE DIAMINE

    Institute of Scientific and Technical Information of China (English)

    SONG Aiteng; HUANG Wei; YU Yunzhao

    1992-01-01

    The curing of a microgel-epoxy resin two phase polymer prepared by in situ copolymerization of unsaturated polyester with acrylic monomer was studied. The unsaturated unit reacted with N- H during the cure of the resin with ethylene diamine. The Michael type reaction was ten times more rapid than the addition of N -H to epoxide .This was accounted for the lower apparent activation energy of the curing of the two phase resin.

  4. Degree of Conversion and Mechanical Properties of Resin Cements Cured Through Different All-Ceramic Systems

    OpenAIRE

    Lopes, Camila de Carvalho Almança; Rodrigues, Renata Borges; André Luis Faria e Silva; Paulo Cézar SIMAMOTO JÚNIOR; Soares, Carlos José; Novais,Veridiana Resende

    2015-01-01

    Abstract: The aim of this study was to verify the degree of conversion (DC), Vickers microhardness (VH) and elastic modulus (E) of resin cements cured through different ceramic systems. One 1.5-mm-thick disc of each ceramic system (feldspathic, lithium dissilicate and zircônia veneered with feldspathic) was used. Three dual-cured (Allcem, Variolink II and RelyX U200) and one chemically-cured (Multilink) resin cements were activated through ceramic discs. For dual-cured resin cements was used ...

  5. Evaluation of light curing units used for polymerization of orthodontic bonding agents.

    Science.gov (United States)

    Oyama, Nanako; Komori, Akira; Nakahara, Rizako

    2004-12-01

    This study evaluated the light intensity of various light curing units, the effect of distance of the light guide, and the validity of a tapered light guide. Light curing units tested included (1) four blue light-emitting diode curing units, Lux-O-Max, LEDemetronl, Ortholux LED, and The Cure; (2) two tungsten-quartz halogen curing units, Optilux 501 and Co-bee; and (3) one plasma arc curing unit, Apollo95E. The Optilux 501 was also evaluated for combinations of normal mode and boost mode and Standard tip and Turbo tip light guide. The spectral output of each unit was measured from 300 to 600 nm with a spectroradiometer. The light intensities at distances of zero, five, 10, 15, and 20 mm were determined with the radiometer. The peak value of Ortholux LED and The Cure surpassed that of Apollo95E. The light intensity significantly decreased with distance. Although The Cure showed a higher light intensity than the LEDemetron1 at zero-mm distance, the light intensity of the LEDemetron1 was higher than that of The Cure at five to 20 mm, resulting in no significant difference. The boost mode increased light intensity at any distance. Although the Turbo tip enhanced light intensity at zero-mm distance, reduction of light intensity by Turbo tip was demonstrated at five- to 20-mm distance.

  6. Influence of sample composition and processing parameters on the UV cure of clear coatings

    Science.gov (United States)

    Ruiz, C. S. B.; Machado, L. D. B.; Volponi, J. E.; Pino, E. S.

    2003-08-01

    Photocurable systems consist of functional macromolecules, which undergo polymerization and a photoinduced crosslinking reaction under UV irradiation. Radiation-curable coatings have gained importance because they are environmentally friendly and save more energy than conventional heat-curable processes. The performance of UV-curable coatings depends on their formulation and cure quality. The quality of UV radiation cure depends on lamp characteristics, photoinitiator (PI) content, film thickness, curing environment, substrate and temperature. The aim of this study was to evaluate the influence of coating thickness and UV radiation dose, as well as coating characteristics such as PI content and stabilizer additive composition, on the curing process.

  7. Study on Curing Kinetics of Heat-resistant Flexible Polyamide Modified Epoxy Resin Adhesive

    Directory of Open Access Journals (Sweden)

    Hua Li

    2015-04-01

    Full Text Available In order to study the effects of numerous variables affecting the reaction rate of heat-resistant flexible modified epoxy resin adhesive, the curing kinetics of polyamide modified epoxy resin was studied. The heat-resistant flexible modified epoxy resin adhesive cured at room-temperature was prepared with epoxy resin, polysulfide rubber and organosilicone as adhesive component, polyamide as main curing agent and addition of different modified filler and the curing agent containing benzene ring structure. The curing kinetics of polyamide modified epoxy resin was studied by Differential Scanning Calorimetry (DSC at different heating speeds and the characteristic temperatures of the curing process were analyzed and confirmed. the kinetics parameters of activation energy was calculated using Flynn-Wall-Ozawa equation and Kissinger equation, respectively, then the kinetic model of curing reaction was built as d&alpha/dt = 4.38×107 exp (-57740/RT (1-&alpha0.93, the results show that the two-parameter model is adequate to represent the curing reaction process, the model can well describe the curing reaction process of the studied resin. The DSC curves obtained using the experimental data show a good agreement with that theoretically calculated. The research results will provide theoretical basis for the choice of manufacturing process and the optimization of processing window.

  8. Influence of curing regimes on compressive strength of ultra high performance concrete

    Indian Academy of Sciences (India)

    Prabhat Ranjan Prem; B H Bharatkumar; Nagesh R Iyer

    2013-12-01

    The present paper is aimed to identify an efficient curing regime for ultra high performance concrete (UHPC), to achieve a target compressive strength more than 150 MPa, using indigenous materials. The thermal regime plays a vital role due to the limited fineness of ingredients and low water/binder ratio. By activation of the reaction kinetics, the effectiveness of the binder is enhanced which leads to improvements in mechanical as well as durability properties. The curing cycle employed are ambient air curing, water curing and hot air curing. The specimens were exposed to thermal regime at (90°C/150°C/200°C) for duration of 24, 48 or 72 hours at the age of 3rd and 7th day followed with air curing or water curing till 28 days. The results showed a marked difference in compressive strength ranging from 217 to 142 MPa with change in curing regimes. The samples when thermally cured at the age of 3rd and 7th day produced an average ultimate strength of 217–152 MPa and 196–150 MPa, respectively.

  9. Effect of In-Situ Curing on Compressive Strength of Reactive Powder Concrete

    OpenAIRE

    Bali Ika; Kushartomo Widodo; Jonathan

    2016-01-01

    A development of Reactive Powder Concrete (RPC) currently is the use of quartz powder as a stabilizing agent with the content to cement ratio of 30% and steam curing method in an autoclave temperature of 250ºC which produced a high compressive strength of 180 MPa. That RPC can be generated due to one reason for using the technique of steam curing in an autoclave in the laboratory. This study proposes in-situ curing method in order the curing can be applied in the field and with a reasonable c...

  10. Study on catalysis effect of TEPB on the curing reaction of HTPB binder system

    Science.gov (United States)

    Chang, S. J.; Tang, J.; Liu, X.; Yan, W.

    2016-07-01

    The catalysis effect of tri (exhoxyphenyl) bismuthine (TEPB) on the curing reaction of HTPB binder system was studied by using DSC method. The curing peak temperatures of the catalyst systems were measured to calculate kinetic parameters by using Kissinger and Crane methods, respectively. Two curing reaction kinetic equations were established. The results show that TEPB has high catalytic activity and can decrease the curing temperature of HTPB binder system, down to 35 °C, in which the optimum volume of TEPB is 0.5% of HTPB binder system.

  11. Hard and soft computing models of composite curing process looking toward monitoring and control

    Science.gov (United States)

    Rubino, F.; Carlone, P.; Aleksendrić, D.; Ćirović, V.; Sorrentino, L.; Bellini, C.

    2016-10-01

    The curing process of thermosetting resins plays a key role on the final quality of the composite material components. Soft computing techniques proved to be an efficient method to control and optimize the curing process, replacing the conventional experimental and numerical approaches. In this paper artificial neural network (ANN) and fuzzy logic control (FLC) were implemented together to predict and control the temperature and degree of cure profile during the autoclave curing process. The obtained outcomes proved the capability of ANNs and FLC with respect to the hard computing methods.

  12. The plants, rituals and spells that 'cured' helminthiasis in Sicily

    Directory of Open Access Journals (Sweden)

    Napoli Mariangela

    2008-09-01

    Full Text Available Abstract Background The author reports on the plants, rituals and spells used against worms and the so-called scantu (fright in some areas of Sicily. The work is based on ethnobotanical research carried out, prevalently, between 2002-2006, in some areas of Eastern, South-Eastern, North-Central and South-Central Sicily. Methods This research is based on dialogue. Senior 'healers' were contacted; furthermore, doctors, teachers, farmers and in general 'experts' with herbs and 'magic' rituals. Information was collected about the way the plants of folk medicine are prepared. The interviewees were also invited to recite prayers and spells against helminthiasis. Results The author has highlighted the importance of how, in some parts of Sicily, some ailments like helminthiasis and other correlated pathologies like scantu are 'treated' and, especially within the rural social classes, by folk medicine remedies, herbal practises, particular prayers, rituals and spells. Conclusion As regards health/illness, it should be noted that in the last ten years conventional medicine has provided very satisfactory results even resolving potentially mortal pathologies. However, in certain social classes, there is no real collaboration between conventional and folk medicine; so for some senior citizens, the 'healer' with his rituals and empirical and magical herbs is still the person to turn to for the 'cure' of particular ailments. Interest in these practises from ancestral heritage in an advanced country like Italy, is only relevant if the aim is to recoup a cultural identity which is already in decline. It is significant to report a piece: on 14 October 2007 the news on a well-known national Italian TV channel reported an interview with a 94 year-old man from Arbatax (Sardinia referred to as a 'healer' because both his townspeople and others from all over the world go to him for his cures. He is not paid except in kind and has been known to cure St. Anthony's fire

  13. 番茄红素有效成分的提取工艺及其解酒机理的研究%Extraction of Lycopene Active Ingredients and Study on Its Hangover-Cure Mechanism

    Institute of Scientific and Technical Information of China (English)

    张卫佳; 陈家树

    2016-01-01

    探讨番茄提取物解酒作用机理,为中药解酒保肝药物的开发提供依据.观察比较番茄提取物与解酒护肝胶囊对小鼠肝脏匀浆中ADH、SOD的酶活力的影响.结果表明,番茄提取物能够明显提高ADH、SOD活力.番茄红素提取物通过提高ADH、SOD活力以达到其解酒的作用,并能减缓酒精进入血液中的速度,进而对抗酒精性肝损伤.%The hangover-cure mechanism of tomato extracts was explored to provide reference for the development of traditional Chinese medi-cine with hangover-cure and hepato-protective functions. In the experiments, the effects of tomato extracts and hangover-cure&hepato-protec-tive capsule on the activities of ADH and SOD in liver homogenates were compared. The results suggested that, tomato extracts could signifi-cantly improve ADH and SOD vitality and further achieve satisfactory hangover-cure effects, and slow down the speed of alcohol into the bloodstream and further prevent alcohol-induced liver damage.

  14. Cultural Characteristics of Chinese Cuisine:From Contrastive Studies of English and Chinese

    Institute of Scientific and Technical Information of China (English)

    乞聪妮

    2014-01-01

    Chinese cuisine plays an important role in Chinese culture. The paper illustrates the features of Chinese cuisine in Chi-nese dish naming from different perspectives, and analyze them from contrastive studies of English and Chinese.

  15. The surface finish of light-cured composite resin materials.

    Science.gov (United States)

    Sidhu, S K; Henderson, L J

    1993-01-01

    A necessity for any dental restorative material is its ability to take and maintain a smooth surface finish. Composite resin restorative materials with fillers and matrix of differing hardness are difficult to finish and polish. The use of aluminum trioxide discs is a popular and acceptable method of finishing composite restorative materials where the material is accessible. Burs and stones are used for finishing and polishing inaccessible areas. This study was undertaken to compare the surface finish of composite resin restorative material when finished with white stones, superfine diamond burs and aluminum trioxide discs. The finished surface was measured with a profilometer and the roughness average value used to compare the surfaces. The aluminum trioxide discs gave the best and most consistent results. It was possible to attain similar results with the superfine diamond bur. However, the results were highly variable. None of the methods used achieved the smoothness of composite resin cured against a transparent matrix.

  16. Curing critical links in oscillator networks as power grid models

    CERN Document Server

    Rohden, Martin; Timme, Marc; Meyer-Ortmanns, Hildegard

    2015-01-01

    Modern societies crucially depend on the robust supply with electric energy. Blackouts of power grids can thus have far reaching consequences. During a blackout, often the failure of a single infrastructure, such as a critical transmission line, results in several subsequent failures that spread across large parts of the network. Preventing such large-scale outages is thus key for assuring a reliable power supply. Here we present a non-local curing strategy for oscillatory power grid networks based on the global collective redistribution of loads. We first identify critical links and compute residual capacities on alternative paths on the remaining network from the original flows. For each critical link, we upgrade lines that constitute bottlenecks on such paths. We demonstrate the viability of this strategy for random ensembles of network topologies as well as topologies derived from real transmission grids and compare the nonlocal strategy against local back-ups of critical links. These strategies are indep...

  17. Radiation oxidation and subsequent thermal curing of polyacrylonitrile fiber

    Science.gov (United States)

    Liu, Weihua; Wang, Mouhua; Xing, Zhe; Wu, Guozhong

    2014-01-01

    Polyacrylonitrile (PAN) fibers were exposed to gamma-ray irradiation at room temperature under vacuum, air and oxygen to investigate the radiation oxidation effects on PAN fibers. Radiation-induced oxidation degradation and crosslinking was evaluated by measuring the gel fraction. It was found that radiation oxidation took place mainly on the fiber surface due to the limited penetration of oxygen into PAN fibers from the surface, and the oxidation thickness increased with the oxygen pressure. Chain scission was dominant in the oxidized area, and crosslinking occurred in the inner part of the fibers. However, the oxidized regions of the fibers can be converted to gel via crosslinking by thermal curing at 160 °C in a N2 atmosphere. Higher extents of radiation oxidation degradation led to a greater increase in the gel fraction. These results suggest that the radiation treatment of PAN fibers prior to thermal oxidation may be useful for manufacturing carbon fibers.

  18. HIV therapeutic vaccines: moving towards a functional cure.

    Science.gov (United States)

    Mylvaganam, Geetha H; Silvestri, Guido; Amara, Rama Rao

    2015-08-01

    Anti-viral T-cell and B-cell responses play a crucial role in suppressing HIV and SIV replication during chronic infection. However, these infections are rarely controlled by the host immune response, and most infected individuals need lifelong antiretroviral therapy (ART). Recent advances in our understanding of how anti-HIV immune responses are elicited and regulated prompted a surge of interest in harnessing these responses to reduce the HIV 'residual disease' that is present in ART-treated HIV-infected individuals. Novel approaches that are currently explored include both conventional therapeutic vaccines (i.e., active immunization strategies using HIV-derived immunogens) as well as the use of checkpoint blockers such as anti-PD-1 antibodies. These approaches appear promising as key components of complex therapeutic strategies aimed at curing HIV infection.

  19. Critique and cure: a dream of uniting psychoanalysis and philosophy.

    Science.gov (United States)

    Webster, Jamieson

    2013-06-01

    Critical theory, whose aim was to historicize philosophy through integrating it with the social sciences, turned to psychoanalysis to find its way through an accounting of philosophy after the Second World War. Over 50 years after this initial project, the rift between philosophy and psychoanalysis has never been greater. If Jacques Lacan could be considered one of the few psychoanalysts to maintain and foster links to philosophical thought in the latter half of the 20th century, his work has sadly remained marginal in the clinical field throughout America and Europe. Both critical theory and Lacan remain skeptical of the direction taken by psychoanalysis after Freud. Reflecting on the history of these two disciplines, as well as through an examination of Theodor Adorno's posthumously published dream journal, critique and cure emerge as two dialectically intertwined themes that gain momentum in the dream of the unification of the philosophical and psychoanalytic projects.

  20. Chinese remainder codes

    Institute of Scientific and Technical Information of China (English)

    ZHANG Aili; LIU Xiufeng

    2006-01-01

    Chinese remainder codes are constructed by applying weak block designs and the Chinese remainder theorem of ring theory.The new type of linear codes take the congruence class in the congruence class ring R/I1 ∩ I2 ∩…∩ In for the information bit,embed R/Ji into R/I1 ∩ I2 ∩…∩ In,and assign the cosets of R/Ji as the subring of R/I1 ∩ I2 ∩…∩ In and the cosets of R/Ji in R/I1 ∩ I2 ∩…∩ In as check lines.Many code classes exist in the Chinese remainder codes that have high code rates.Chinese remainder codes are the essential generalization of Sun Zi codes.

  1. Chinese Remainder Codes

    Institute of Scientific and Technical Information of China (English)

    张爱丽; 刘秀峰; 靳蕃

    2004-01-01

    Chinese Remainder Codes are constructed by applying weak block designs and Chinese Remainder Theorem of ring theory. The new type of linear codes take the congruence class in the congruence class ring R/I1∩I2∩…∩In for the information bit, embed R/Ji into R/I1∩I2∩…∩In, and asssign the cosets of R/Ji as the subring of R/I1∩I2∩…∩In and the cosets of R/Ji in R/I1∩I2∩…∩In as check lines. There exist many code classes in Chinese Remainder Codes, which have high code rates. Chinese Remainder Codes are the essential generalization of Sun Zi Codes.

  2. Chinese implicit leadership theory.

    Science.gov (United States)

    Ling, W; Chia, R C; Fang, L

    2000-12-01

    In a 1st attempt to identify an implicit theory of leadership among Chinese people, the authors developed the Chinese Implicit Leadership Scale (CILS) in Study 1. In Study 2, they administered the CILS to 622 Chinese participants from 5 occupation groups, to explore differences in perceptions of leadership. Factor analysis yielded 4 factors of leadership: Personal Morality, Goal Efficiency, Interpersonal Competence, and Versatility. Social groups differing in age, gender, education level, and occupation rated these factors. Results showed no significant gender differences, and the underlying cause for social group differences was education level. All groups gave the highest ratings to Interpersonal Competence, reflecting the enormous importance of this factor, which is consistent with Chinese collectivist values.

  3. Ancient Chinese Dress

    Institute of Scientific and Technical Information of China (English)

    1992-01-01

    Chinese archaeologists discov- ered in Zhoukoudian on theoutskirts of Beijing the firstneedle made by Chinese about 18,000years ago.It was about 82 mm longand 3.3 mm in diameter,polishedcarefully and had a hole,showing thatthe Chinese of that time had masteredthe skill of polishing and drilling andcould make clothes ont of animalskins.It Is recorded in The Book of Rites(one of the Confucian classics,includ- ing essays on rites and etiquette of theQin and Han dynasties),compiled byDai Sheng of the Western Han Dy- nasty(206 B.C.-A.D.24),that therehad been no flax or silk in the pastand people wore animal skins or feathers as clothes.That proves that appa-rel appeared earlier than textiles in theChinese culture.

  4. CHINESE OF HUMANITY

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    The feature and development direction of ecological garden city; The problem and countermeasures in urban construction audio-visual file management task;Youth network moral education is imperative;A shallow discussion about moral education penetration in Chinese classroom;

  5. Chinese Female Creativity

    Institute of Scientific and Technical Information of China (English)

    VALERIE; SARTOR

    2011-01-01

    "Many foreigners mistakenly believe that Chinese women are creatively oppressed,that they have been oppressed for centuries," Teacher Yang said,glancing at me wryly."That’s correct," I replied, lifting my eyebrows.

  6. FROM THE CHINESE PRESS

    Institute of Scientific and Technical Information of China (English)

    1994-01-01

    Compiled by the Central Document Compiling Committee of the Chinese Communist Party (CPC), the third volume of the Selected Works of Deng Xiaoping was published by the People’s Publishing House and was issued nationwide on November 2, 1993.

  7. The Chinese Olympic Committee

    Institute of Scientific and Technical Information of China (English)

    余信波

    2008-01-01

    The Chinese Olympic Committee (COC) is a non-governmental,non-profit national sports organization of a mass character,with the objective of developing sports and promoting the Olympic Movement in the country.

  8. Ancient Chinese Architecture

    Institute of Scientific and Technical Information of China (English)

    1993-01-01

    CHINESE people have accu-mulated a great deal ofexperience in architecture,constantly improving building ma-terials and thus creating uniquebuilding styles.The history of ancient Chinesearchitechtural development can be

  9. Expats rank Chinese cities

    Institute of Scientific and Technical Information of China (English)

    By Lv Dong

    2012-01-01

    Beijing, April The results of the "2011 Amazing China- The Most Attractive Chinese Cities for Foreigners" election are released. Expats choose Beijing, Shanghai, Tianjin and other cities as Chinas 10 most attractive cities for foreigners.

  10. Chinese Ecosystem Research Network

    Institute of Scientific and Technical Information of China (English)

    Huang Tieqing; Liu Jian; Chen Panqin; Fu Bojie

    2002-01-01

    The article analyzes the development of the Chinese Ecosystem Research Network, and its mission, mandate, and management mechanisms, with examples of research, demonstration and consultation for policy-setting.

  11. Traditional Chinese Biotechnology

    Science.gov (United States)

    Xu, Yan; Wang, Dong; Fan, Wen Lai; Mu, Xiao Qing; Chen, Jian

    The earliest industrial biotechnology originated in ancient China and developed into a vibrant industry in traditional Chinese liquor, rice wine, soy sauce, and vinegar. It is now a significant component of the Chinese economy valued annually at about 150 billion RMB. Although the production methods had existed and remained basically unchanged for centuries, modern developments in biotechnology and related fields in the last decades have greatly impacted on these industries and led to numerous technological innovations. In this chapter, the main biochemical processes and related technological innovations in traditional Chinese biotechnology are illustrated with recent advances in functional microbiology, microbial ecology, solid-state fermentation, enzymology, chemistry of impact flavor compounds, and improvements made to relevant traditional industrial facilities. Recent biotechnological advances in making Chinese liquor, rice wine, soy sauce, and vinegar are reviewed.

  12. The interaction between the atmosphere and curing concrete bridge decks

    Science.gov (United States)

    Wojcik, Gary S.

    The long-term durability of concrete can be compromised by excessive concrete temperatures or temperature gradients and lack of moisture during the first few days after placement. Because the concrete binder components undergo temperature-dependent hydration reactions during this period, atmospheric and construction conditions influence the ultimate concrete quality. To understand this interaction, curing concrete bridge energy balances were estimated with meteorological techniques and calorimetry and model experiments were performed. The agreement of concrete hydration heat estimates from the energy balances, calorimetry experiments, and model simulations validates our methodology and results. In Chapter 2, we estimate from meteorological measurements and techniques the energy balances of four curing concrete bridge decks. One challenge is to determine fluxes from small surfaces (largest horizontal dimension exchange coefficients for small areas is developed. Chapter 3, we improve with calorimetry experiments a simple bimolecular heat generation expression for hydrating binder. We show that this expression, with a new parameterization accounting for retarder effects on hydration rates, simulates temperatures to within 2°C and 72 h heat generation (˜265 kJ kg-1) to within 10% of the observed. In Chapter 4, we present models developed with the field and laboratory work and show that the highest concrete temperatures occur at high initial concrete temperatures and air temperatures and humidities, and at low wind speeds and cloud cover fractions. Peak bridge concrete temperatures can exceed 60°C. Large concrete temperature gradients (˜2°C cm-1 ) occur at the concrete top surface and the support beam top. An application of the 1D model with input from a weather forecast model predicts concrete temperatures within 2°C of the observed and so is a suitable operational model.

  13. The Chinese Politeness Scale

    Institute of Scientific and Technical Information of China (English)

    王喜凤

    2012-01-01

    In order to make sense of what is said in an interaction,we have to look at various factors which relate to social distance and closeness.Generally,these factors include the specific situation language takes place,the relative status of the two participants,the message being delivered and finally the age of the participants.In this article,the Chinese Politeness Scale,based on Chinese social values and tradition,will be explained and demonstrated in detail.

  14. Traditional Chinese Medicine

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    2009013 Clinical observation on treatment of active rheumatoid arthritis with Chinese herbal medicine. SHENG Zhenghe(盛正和), et al.Dept TCM, 5th Affili Hosp, Guangxi Med Univ, Guangxi 545001. Chin J Integr Tradit West Med 2008;28(11):990-993. Objective To study the efficacy and safety of Chinese drugs for expelling evil-wind, removing dampness, promoting blood circulation and invigorating yin in treating active rheumatoid arthritis (RA).

  15. The Magic of Chinese

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    One of the world's oldest languages appears to have a vibrant futureClassical Greek and Latin, two languages that share an ancient history with Chinese, have been threatened with extinction, being used primarily in classic books or for special purposes. Chinese, on the other hand, is thriving as more and more people develop an interest in learning the language, and its charm has been noticed by linguists.

  16. Chinese New Year

    Institute of Scientific and Technical Information of China (English)

    王芳

    2005-01-01

    The Chinese New Year is now known as the Spnng Festival because it starts trom the beginning otspring. Though there are some sayings about its origin (起源), all agree that the word Nian, which inmodern Chinese means “year”, was originally the name of a beast (野兽) that started to eat people thenight before the beginning of a new year.

  17. Simultaneous monitoring of curing shrinkage and degree of cure of thermosets by attenuated total reflection Fourier transform infrared (ATR FT-IR) spectroscopy.

    Science.gov (United States)

    Fernàndez-Francos, Xavier; Kazarian, Sergei G; Ramis, Xavier; Serra, Àngels

    2013-12-01

    We present a novel methodology to simultaneously monitor of the degree of cure and curing shrinkage of thermosetting formulations. This methodology is based on the observation of changes in the infrared absorption of reactive functional groups and the groups used as a standard reference for normalization. While the optical path length is exact and controlled in transmission infrared spectroscopy, in attenuated total reflection Fourier transform infrared (ATR FT-IR), the exact determination of volume changes requires the measurement of the refractive indices of the studied system throughout the curing process or at least an indirect parallel measurement of this property. The methodology presented here allows one to achieve quantitative measurements of the degree of cure and shrinkage for thermosets using in situ ATR FT-IR spectroscopy.

  18. Comparison of the fracture toughness and wear resistance of indirect composites cured by conventional post curing methods and electron beam irradiation

    Directory of Open Access Journals (Sweden)

    Vaishnavi C

    2010-01-01

    Full Text Available Aim : To compare the fracture toughness and wear resistance of indirect composites cured by conventional post curing methods and electron beam irradiation. Materials and Methods : Forty specimens were randomly assigned into four groups of ten each and were subjected to various post curing methods. Fracture toughness and wear resistance tests were performed and the results were tabulated and analyzed statistically using Kruskal Wallis and Mann-Whitney U test. Results : It was found that Inlay system showed higher values followed by electron beam irradiation. Conclusion : Electron beam irradiation of dental composites gives comparable mechanical properties to other post curing systems. It can be concluded that further studies with increased radiation dose should be performed to improve the mechanical properties of indirect composites.

  19. Curing behavior and kinetic analysis of epoxy resin/multi-walled Carbon nanotubes composites

    Institute of Scientific and Technical Information of China (English)

    FANG Zhengping; WANG Jianguo; GU Aijuan; TONG Lifang

    2007-01-01

    The effect of multi-walled carbon nanotubes (MWNTs).both amino-functionalized(f-MWNTs) and unfunctionalized (p-MWNTs) on the curing behavior of epoxy resin (EP) cured with triethanolamine (TEA),was investigated using differential scanning calorimetry(DSC).Because the triethylenetetramine (TETA) grafted on the f-MWNTs could act as curing agent and the produced tertiary amine as negative ionic catalysts of curing reaction of EP so the activation energy of the EP/TEA system was decreased by the addition of f-MWNTs.Viscosity played a key role in the curing behavior of the EP/TEA/MWNTs system,for high viscosity of the EP/TEA/MWNTs system could hinder the motion of the functional grows.The curing heat in EP/TEA/f-MWNTs (weight ratio 1/0.1/0.01) system was higher than the neat EP/TEA(weight ratio 1/0.1) system,while the curing heat in EP/TEA/p-MWMTs (weight ratio 1/0.1/0.01) was lower than the neat system.When the content of f-MWNTs was increased to 2 phr(weight ratio of 1/0.1/0.02).the curing heat became lower than that of the neat EP/TEA system,which was the result of the higher viscosity of the EP/f-MWNTs/TEA system.Since the curing heat indicated the curing degree of the system generally,the addition of the f-MWNTs was thought to increase the curing degree of the epoxy matrix at a relatively low content.

  20. Curing kinetics and thermomechanical properties of latent epoxy/carbon fiber composites

    Science.gov (United States)

    Dalle Vacche, S.; Michaud, V.; Demierre, M.; Bourban, P.-E.; Månson, J.-A. E.

    2016-07-01

    In this work, resins based on diglycidyl ether of bisphenol A (DGEBA) epoxy and a latent hardener, dicyandiamide (DICY), as well as carbon fiber (CF) composites based on them, were prepared with three commercial accelerators: a methylene bis (phenyl dimethyl urea), a cycloaliphatic substituted urea, and a modified polyamine. The curing kinetics of the three DGEBA/DICY/accelerator systems were investigated by chemorheology and differential scanning calorimetry (DSC), in isothermal and over temperature change conditions. Differences in the reaction onset temperature, and in the glass transition temperature (Tg) were highlighted. For curing of thick resin samples, a slow curing cycle at the lowest possible temperature was used, followed by high temperature (160 - 180 °C) post-curing. Indeed, fast curing at higher temperatures caused the formation of hot spots and led to local burning of the samples. The obtained thermomechanical properties, assessed by ultimate tensile testing and dynamic mechanical analysis (DMA) in single cantilever configuration, were all in the expected range for epoxy resins, with tensile moduli close to 3 GPa and Tg > 140 °C. The longterm stability of these resins at room temperature was verified by DSC. Composite samples were prepared by hand lay-up by manually impregnating four layers of 5-harness satin CF textile, and curing in vacuum bag. Impregnation quality and void content were assessed by optical microscopy. The flexural properties of the post-cured composites were assessed by three-point bending test at room temperature and showed no relevant differences, all composites having bending moduli of 45 - 50 GPa. Finally, composites cured with a faster high temperature curing cycle (20 min at 140 °C) were prepared with the DGEBA/DICY/ methylene bis (phenyl dimethyl urea) system, obtaining similar properties as with the slower curing cycle, showing that the prepreg system allowed more flexibility in terms of curing cycle than the bulk resin

  1. State of art an Overview on the Tensile Strength and Flexural Strength of Concrete in different Curing Methods

    Directory of Open Access Journals (Sweden)

    J. Allen Paul Edson

    2014-11-01

    Full Text Available The concrete is made of different ingredients such as cement, fine aggregate, and coarse aggregate but it is a homogeneous material when it is in a harden concrete. The strength of concrete decides the life span of any concrete structure. The factors which affect the strength of concrete are the type of material used, size of aggregate, water cement ratio, improper compaction and improper curing. Curing is one of the major factors in the failure of concrete. Curing is defined as the process of promoting the hydration of cement. The grade used in the manufacture of concrete may be M20, M30 grade. This paper deals with the overview on the tensile strength and flexural strength of concrete when the concrete is exposed to various curing methods such as Water curing (Ponding and Immersion, Air Curing (Dry air curing, and plastic film curing at 3 days, 7 days, 28 days and 56 days. It is studied that the tensile and flexural strength of concrete during immersion method is high when compared with Air curing and plastic film curing. It is found that the water curing is the most effective method of curing with the maximum of 10% increase in tensile strength and 15% increase in flexural strength of concrete when compared with other curing methods. On comparison with self compacting concrete (SCC and Normal cement concrete (NCC under different curing methods the tensile strength and flexural strength of SCC is high than NCC.

  2. Chinese Advertising and Advanced Chinese Culture

    Institute of Scientific and Technical Information of China (English)

    Liu Fan

    2006-01-01

    @@ Chinese advertising has long been inseparable from the Chinese national culture from late Shang Dynasty and early Zhou Dynasty when Jiang Ziya beat sword to spread sound to the 21st century when the badge of Beijing 2008 Olympic Games sweeps the whole world. With cultural trait as one of its fundamental character,advertising naturally becomes one of the most important cultural industries in contemporary era. In recent years because of prevalent theme, "Rediscover the Brilliance of Ancient Cities," promoted by the 39th IAA World Congress and the 12th China Advertising Festival held in China, Beijing and Xi'an, two ancient cities, had been splendidly presented to the whole world.

  3. Criteria for cure in acromegaly: report of a case apparently cured in which persisting tumor was found at autopsy.

    Science.gov (United States)

    Wrightson, P; Holdaway, I M; Synek, B J

    1984-06-01

    A 49-year-old man with acromegaly underwent the apparently complete removal of a pituitary microadenoma by the transsphenoidal route. There was complete remission of the biochemical abnormalities for 2 1/2 years, with basal plasma growth hormone (GH) levels of less than 1 ng/ml and normal somatomedin levels. The patient then died after the rupture of a cerebral aneurysm. Serial sections of the pituitary fossa showed persistent tumor with a volume of about 6% of the remaining normal gland. It is concluded that current endocrine tests are limited in their ability to detect residual GH-secreting tumor. Their sensitivity is likely to depend on the mass of tumor and on the GH secretion rate. Predictions of long term cure based on these tests are only tentative.

  4. CURING KINETICS AND THERMAL STABILITY OF EPOXY BLENDS CONTAINING PHOSPHOROUS-OXIRANE WITH AROMATIC AMIDE-AMINE AS CURING AGENTS

    Institute of Scientific and Technical Information of China (English)

    Geeta Durga; A.K.Narula

    2012-01-01

    This article describes the synthesis of a series of aromatic amide-amines and their potential use as epoxy hardeners.These amines were synthesized by the reaction of L-phenylalanine (PA) with diamines of different structures i.e.1,4-phenylene diamine (PD),1,5-diamino naphthalene (N),4,4′-(9-fluorenyllidene)-dianiline (F),4,4′-diaminodiphenyl sulphide (DS) and 3,4′-oxydianiline (O) in a stoichiometric ratio (1∶1).Structural characterization of synthesized amide-amines was done with the help of elemental analysis and spectroscopic techniques viz.FT-IR,1H-NMR and 13C-NMR.An epoxy blend was prepared by mixing tris(glycidyloxy) phosphine oxide (TGPO) with conventional epoxy i.e.diglycidyl ether of bisphenol-A (DGEBA) in an equivalent ratio of 2∶3 to incorporate phosphorous into the main chain.The curing kinetics of the epoxy blend with synthesized aromatic amide-amines was investigated by non-isothermal DSC technique using multiple heating rate method (5,10,15 and 20 K/min.).The activation energies were determined by fitting the experimental data into Kissinger and Ozawa kinetic models.The activation energies obtained through Ozawa method were slightly higher than those of Kissinger method but were comparable.However,both the energies were found to be dependent on the structure of amines.The thermal stability and weight loss behavior of isothermally cured thermosets were also investigated using thermogravimetric analysis (TGA) in nitrogen atmosphere.All the samples showed improved thermal stability in terms of char yield than using only amines as hardeners.

  5. In vitro analysis of shear bond strength and adhesive remnant index comparing light curing and self-curing composites

    Directory of Open Access Journals (Sweden)

    Murilo Gaby Neves

    2013-06-01

    Full Text Available OBJECTIVE: To evaluate, in vitro, the shear bond strength of self-curing (ConciseTM - 3M and Alpha Plast - DFL and light-curing composites (TransbondTM XT - 3M and Natural Ortho - DFL used in orthodontics bonding, associated to Morelli metal brackets, with further analysis of adhesive remnant index (ARI and enamel condition in scanning electron microscopy (SEM. METHODS: Forty human premolars, just extracted and stored in physiologic solution 0.9 % were used. Randomly, these samples were divided in four groups: G1 group, the brackets were bonded with ConciseTM - 3M composite; in G2 group, Alpha Plast - DFL composite was used; in G3 group, TransbondTM XT - 3M was used; in G4 group, Natural Ortho - DFL composite was used. These groups were submitted to shear strength tests in universal testing machine, at 0.5 mm per minute speed. RESULTS: Statistical difference between G3 and G4 groups was recorded, as G4 showing higher strength resistance than G3. In the other hand, there were no statistical differences between G1, G2 and G3 and G1, G2 and G4 groups. ARI analysis showed that there was no statistical difference between the groups, and low scores were recorded among then. The scanning electron microscopy (SEM analysis revealed the debonding spots and the enamel surface integrity. CONCLUSIONS: Shear bond strength was satisfactory and similar between the composites, however Natural Ortho - DFL revealed best comparing to TransbondTM XT - 3M.

  6. Thirty-two Cases of Acne Treated with Blood-letting Puncture,Cupping and Chinese-Drug Facemask

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    To observe the therapeutic effect on acne treated with blood-letting puncture, cupping and Chinese-drug facemask. Thirty-two patients with acne were treated with above-mentioned therapeutic method. Cure,improvement and ineffectiveness were respectively found in 24, 7 and 1 case, with a curative rate of 75.0% and a total effective rate of 96.8%. The combination of blood-letting puncture, cupping and external application of Chinese-drug facemask is effective in treating acne.

  7. Can immediate postoperative random growth hormone levels predict long-term cure in patients with acromegaly?

    Directory of Open Access Journals (Sweden)

    Pinaki Dutta

    2016-01-01

    Conclusion: Early postoperative GH values may be used to predict long-term cure. A value of ≤1.5 ng/ml at 6 h following surgery may predict long-term cure in two-thirds of the patients with acromegaly who undergo TSS.

  8. Changes in scattering and absorption during curing of denta-resin composites: silorane and nanocomposite

    Science.gov (United States)

    del Mar Pérez, Maria; Ghinea, Razvan; Ionescu, Ana-Maria; de la Cruz Cardona, Juan

    2011-05-01

    Photocured polymers are widely used in dental applications. The optical properties of the dental composites change during curing; the appearance of the composites also changes. Recently, a new silorane-based composite resin and dental nanocomposite have been introduced. However, research regarding the effect of the silorane monomers or the size filler on appearance after curing of the resin composite is limited. This work aims to examine the optical properties of silorane-based composite and nanocomposite, in terms of scattering and absorption during curing. Six dimethacrylate-based dental resin composite (five universal and one nanocomposite) and one silorane-based dental resin composite (all shades A2 and T) were studied. The curing irradiance was 1100mW/cm2. The spectral reflectance of 1mm thick composite samples against white and black backgrounds were measured both before and after curing, and were converted to scattering and absorption coefficients using the Kubelka-Munk Theory. Both for pre and post-curing dental resin composites, the Albedo coefficient (K/S) shows that absorption prevails over the scattering for short wavelengths while for medium and large wavelengths, the scattering becomes more important, except for the T shade of the nanocomposite. After curing, the scattering and absorption values decreased for both types of materials. Changes in the absorption coefficient values should be caused by changes in the camphorquinone (CQ) absorption, whereas the scattering changes found should be directly attributable to index of refraction changes of the resin during curing.

  9. Studies on thermal degradation kinetics of thermal and UV cured N-(4-hydroxy phenyl) maleimide derivatives

    Energy Technology Data Exchange (ETDEWEB)

    Pitchaimari, G.; Vijayakumar, C.T., E-mail: ctvijay22@yahoo.com

    2014-01-10

    Graphical abstract: - Highlights: • UV cure materials are more thermally stable than the thermally cured materials. • Cyanate ester functionalization offers better thermal stability. • The Ea values for Poly NVPs are low compared to other materials investigated. • The UV cured materials showed higher Ea values than the thermally cured materials. - Abstract: The results of the studies concerning the thermal and photo initiated copolymerization of N-(4-acryloyloxy phenyl) maleimide (AX), N-(4-methacryloyloxy phenyl) maleimide (MAX) and N-(4-cyanato phenyl) maleimide (CNX) with N-vinyl-2-pyrrolidone (NVP) were presented. The structures of all the copolymers prepared were confirmed by FTIR studies. The thermogravimetric studies of both the thermal and UV cured materials indicated that the UV cured materials were comparatively thermally more stable than the thermally polymerized materials during thermal degradation. Of all the materials investigated, liquid composition having NVP and CNX cured by UV irradiation showed better thermal stability. The degradation kinetic studies using Flynn–Wall–Ozawa, Vyazovkin and Friedman methods showed that the activation energies (Ea) for the thermal degradation of polymeric materials cured by UV irradiation were slightly higher than the Ea values calculated for the thermally polymerized materials.

  10. 9 CFR 327.23 - Compliance procedure for cured pork products offered for entry.

    Science.gov (United States)

    2010-01-01

    ... procedure for cured pork products offered for entry. (a) Definitions. For the purposes of this section: (1... group. (5) The Absolute Minimum PFF Requirement is that no laboratory result of an individual sample for... of all cured pork products from the country must be equal to or greater than zero. The count for...

  11. Managing the care of health and the cure of disease--Part II: Integration.

    Science.gov (United States)

    Glouberman, S; Mintzberg, H

    2001-01-01

    The development of appropriate levels of integration in the system of health care and disease cure will require stronger collective cultures and enhanced communication among the key actors. Part II of this paper uses this line of argument to reframe four major issues in this system: coordination of acute cure and of community care, and collaboration in institutions and in the system at large.

  12. Influence of nanoclay-carbon black hybrid fillers on cure and properties of natural rubber compounds

    NARCIS (Netherlands)

    Sapkota, J.; Poikelispää, M.; Das, A.; Dierkes, W.K.; Vuorinen, J.

    2013-01-01

    The influence of organically modified nanoclay-carbon black (CB) hybrid filler on the curing behavior of natural rubber (NR) was explored in this investigation. Here an effort was paid to understand the curing kinetics of organomodified nanoclay filled rubber compounds. On the basis of two different

  13. Cure kinetics characterization and monitoring of an epoxy resin for thick composite structures

    Science.gov (United States)

    Hardis, Ricky

    The use of fiber-reinforced polymers (FRPs) is increasing for numerous industrial applications. In-situ cure monitoring is very important to directly observe the cure process of FRPs during the manufacturing process. In this work, the possible use for in-situ cure monitoring of an epoxy resin was investigated by means of Raman spectroscopy and dielectric analysis (DEA). The cure behavior was first characterized using differential scanning calorimetry (DSC) as a baseline comparison, and the best-fit phenomenological reaction model was determined to describe the cure behavior of the epoxy resin as well as the kinetic parameters. The relationship between T g and degree of cure was also established. The degree of cure obtained from the Raman spectroscopy and DEA under isothermal conditions was compared to the one obtained from the DSC. A good agreement was observed among the three methods, supporting in-situ cure monitoring during manufacturing. An implementation plan for in-plant monitoring was also discussed.

  14. Production of Pastırma with Different Curing Methods and Using Starter Culture

    OpenAIRE

    AKSU, Muhammet İrfan; Kaya, Mükerrem

    2002-01-01

    The effects of starter culture (Staphylococcus carnosus + Lactobacillus pentosus) on some physical, chemical and microbiological properties of pastırma produced with brine and dry curing methods were investigated. The curing method significantly affected the contents of salt, nitrite, nitrite/nitrate rate at the level of P

  15. Curing Kinetics, Mechanical Properties and Thermal Stability of Epoxy/Graphene Nanoplatelets (GNPs) Powder Coatings

    Institute of Scientific and Technical Information of China (English)

    ZHI Maoyong; HUANG Wanxia

    2016-01-01

    Epoxy/graphene nanoplatelets (GNPs) powder coatings were fabricated using ultrasonic pre-dispersion of GNPs and melt-blend extrusion method. The isothermal curing kinetics of epoxy/GNPs powder coating were monitored by means of real-time Fourier transform infrared spectroscopy (FT-IR) with a heating cell. The mechanical properties of the epoxy/GNPs cured coatings had been investigated, by evaluating their fracture surfaces with ifeld-emission scanning electron microscopy (FE-SEM) after three-point-bending tests. The thermal stability of the epoxy/GNPs cured coatings was studied by thermo-gravimetric analysis (TGA). The isothermal curing kinetics result showed that the GNPs would not affect the autocatalytic reaction mechanism, but the loading of GNPs below 1.0 wt % additive played a prompting role in the curing of the epoxy/GNPs powder coatings. The fracture strain, fracture toughness and impact resistance of the epoxy/GNPs cured coatings increased dramatically at low levels of GNPs loading (1 wt %), indicating that the GNPs could improve the toughness of the epoxy/GNPs powder coatings. Furthermore, from FE-SEM studies of the fracture surfaces, the possible toughening mechanisms of the epoxy/GNPs cured coatings were proposed. TGA result showed that the incorporation of GNPs improved the thermal stability of the cured coatings. Hence, the GNPs modiifed epoxy can be an efifcient approach to toughen epoxy powder coating along with improving their thermal stability.

  16. Mathematical modelling of simultaneous solvent evaporation and chemical curing in thermoset coatings: A parameter study

    DEFF Research Database (Denmark)

    Kiil, Søren

    2011-01-01

    A mathematical model, describing the curing behaviour of a two-component, solvent-based, thermoset coating, is used to conduct a parameter study. The model includes curing reactions, solvent intra-film diffusion and evaporation, film gelation, vitrification, and crosslinking. A case study with a ...

  17. Two-step method for curing Escherichia coli of ColE1-derived plasmids

    DEFF Research Database (Denmark)

    Hove-Jensen, Bjarne

    2008-01-01

    To cure Escherichia coli for plasmids derived from the ColE1 replicon advantage is taken of the fact that maintenance of this replicon requires a wild-type allele of polA, encoding DNA polymerase I. Curing is achieved by cotransduction of a mutant polA allele with metE::Tn10, fadAB::Tn10 or other...

  18. Cure monitoring of epoxy resin by using fiber bragg grating sensor

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jin Hyuk [KEPCO, Naju (Korea, Republic of); Kim, Dae Hyun [Dept. of Mechanical and Automotive Engineering, Seoul National University of Science and Technology, Seoul (Korea, Republic of)

    2016-06-15

    In several industrial fields, epoxy resin is widely used as an adhesive for co-curing and manufacturing various structures. Controlling the manufacturing process is required for ensuring robust bonding performance and the stability of the structures. A fiber optic sensor is suitable for the cure monitoring of epoxy resin owing to the thready shape of the sensor. In this paper, a fiber Bragg grating (FBG) sensor was applied for the cure monitoring of epoxy resin. Based on the experimental results, it was demonstrated that the FBG sensor can monitor the status of epoxy resin curing by measuring the strain caused by volume shrinkage and considering the compensation of temperature. In addition, two types of epoxy resin were used for the cure-monitoring; moreover, when compared to each other, it was found that the two types of epoxy had different cure-processes in terms of the change of strain during the curing. Therefore, the study proved that the FBG sensor is very profitable for the cure-monitoring of epoxy resin.

  19. Novel co-agents for improved properties in peroxide cure of saturated elastomers

    NARCIS (Netherlands)

    Alvarez Grima, Maria Montserrat

    2007-01-01

    Peroxide vulcanisation is a widely used cure system for elastomers and offers many possibilities for use, mainly because of the availability of co-agents and scorch retarders. The range of applications of peroxide cure could significantly be widened, if certain mechanical properties could be improve

  20. International AIDS Society global scientific strategy: towards an HIV cure 2016.

    Science.gov (United States)

    Deeks, Steven G; Lewin, Sharon R; Ross, Anna Laura; Ananworanich, Jintanat; Benkirane, Monsef; Cannon, Paula; Chomont, Nicolas; Douek, Daniel; Lifson, Jeffrey D; Lo, Ying-Ru; Kuritzkes, Daniel; Margolis, David; Mellors, John; Persaud, Deborah; Tucker, Joseph D; Barre-Sinoussi, Françoise; Alter, Galit; Auerbach, Judith; Autran, Brigitte; Barouch, Dan H; Behrens, Georg; Cavazzana, Marina; Chen, Zhiwei; Cohen, Éric A; Corbelli, Giulio Maria; Eholié, Serge; Eyal, Nir; Fidler, Sarah; Garcia, Laurindo; Grossman, Cynthia; Henderson, Gail; Henrich, Timothy J; Jefferys, Richard; Kiem, Hans-Peter; McCune, Joseph; Moodley, Keymanthri; Newman, Peter A; Nijhuis, Monique; Nsubuga, Moses Supercharger; Ott, Melanie; Palmer, Sarah; Richman, Douglas; Saez-Cirion, Asier; Sharp, Matthew; Siliciano, Janet; Silvestri, Guido; Singh, Jerome; Spire, Bruno; Taylor, Jeffrey; Tolstrup, Martin; Valente, Susana; van Lunzen, Jan; Walensky, Rochelle; Wilson, Ira; Zack, Jerome

    2016-08-01

    Antiretroviral therapy is not curative. Given the challenges in providing lifelong therapy to a global population of more than 35 million people living with HIV, there is intense interest in developing a cure for HIV infection. The International AIDS Society convened a group of international experts to develop a scientific strategy for research towards an HIV cure. This Perspective summarizes the group's strategy.

  1. Cationic concentration effects on electron beam cured of carbon-epoxy composites

    Science.gov (United States)

    Nishitsuji, D. A.; Marinucci, G.; Evora, M. C.; Silva, L. G. A.

    2010-03-01

    Electron beam (e-beam) curing is a technology that offers advantages over the thermal curing process, that usually requires high temperature and are time-consuming. E-beam curing is faster and occurs at low temperatures that help reduce residual mechanical stresses in a thermoset composite. The aim of the present study is to analyze the effects of cationic initiator (diaryliodonium hexafluoroantimonate) ranged from 1 to 3 wt% in DGEBA (diglycidyl ether of bisphenol A) epoxy resin when cured by a 1.5 MeV electron beam. The specimens were cured to a total dose of 200.4 kGy for 40 min. Analyses by dynamic mechanical thermal analysis (DMTA) and differential scanning calorimetry (DSC) show that the e-beam irradiated samples with 2 wt% cationic initiator were 96% cured obtained a glass transition temperature (tan δ) of 167 °C. The same epoxy resin, thermally cured for 16 h with an anhydride hardener, reached a Tg (tan δ) of 136 °C. So, the irradiated sample had its Tg increased approximately 20% and the curing process was much less time consuming.

  2. Cationic concentration effects on electron beam cured of carbon-epoxy composites

    Energy Technology Data Exchange (ETDEWEB)

    Nishitsuji, D.A., E-mail: delmo_amari@yahoo.com.b [Brazilian Navy Technological Center, Sao Paulo (Brazil); Marinucci, G. [Brazilian Navy Technological Center, Sao Paulo (Brazil); Energetic and Nuclear Research Institute-IPEN-CNEN/SP, Av. Prof. Lineu Prestes, 2242-Cidade Universitaria, 05508-000 Sao Paulo/SP (Brazil); Evora, M.C. [Institute of Advanced Studies/CTA, Sao Jose dos Campos/SP (Brazil); Silva, L.G.A. [Energetic and Nuclear Research Institute-IPEN-CNEN/SP, Av. Prof. Lineu Prestes, 2242-Cidade Universitaria, 05508-000 Sao Paulo/SP (Brazil)

    2010-03-15

    Electron beam (e-beam) curing is a technology that offers advantages over the thermal curing process, that usually requires high temperature and are time-consuming. E-beam curing is faster and occurs at low temperatures that help reduce residual mechanical stresses in a thermoset composite. The aim of the present study is to analyze the effects of cationic initiator (diaryliodonium hexafluoroantimonate) ranged from 1 to 3 wt% in DGEBA (diglycidyl ether of bisphenol A) epoxy resin when cured by a 1.5 MeV electron beam. The specimens were cured to a total dose of 200.4 kGy for 40 min. Analyses by dynamic mechanical thermal analysis (DMTA) and differential scanning calorimetry (DSC) show that the e-beam irradiated samples with 2 wt% cationic initiator were 96% cured obtained a glass transition temperature (tan delta) of 167 deg. C. The same epoxy resin, thermally cured for 16 h with an anhydride hardener, reached a T{sub g} (tan delta) of 136 deg. C. So, the irradiated sample had its T{sub g} increased approximately 20% and the curing process was much less time consuming.

  3. Quality of life in patients after long-term biochemical cure of cushing's disease

    NARCIS (Netherlands)

    M.O. van Aken (Maarten); A.M. Pereira (Alberto); N.R. Biermasz; S.W. van Thiel (Sjoerd); H. Hoftijzer (Hendrieke); J.W. Smit (Johannes); F. Roelfsema (Ferdinand); S.W.J. Lamberts (Steven); J.A. Romijn (Johannes)

    2005-01-01

    textabstractTo evaluate the long-term impact of cured Cushing's disease on subjective well-being, we assessed quality of life by validated health-related questionnaires in 58 patients cured from Cushing's disease by transsphenoidal surgery (n = 58), some of whom received additional radiotherapy (n =

  4. Effect of curing with a plasma light on the properties of polymerizable dental restorative materials.

    Science.gov (United States)

    Millar, B J; Nicholson, J W

    2001-06-01

    Specimens of light-curable dental restoratives have been prepared using either a conventional dental curing lamp (for 20 or 30 s) or a plasma light (for 1 or 2 s). The specimens were then stored in water until their mass equilibrated, then dried to constant mass. Most specimens lost material in this process but the losses in all specimens cured with the plasma light were significantly greater than those cured with the conventional lights (P cure times gave slightly reduced losses in water in most cases. The specimens were then returned to water and allowed to re-equilibrate and their equilibrium water uptake determined. There was no simple trend in this latter property because elution of loosely bound hydrophilic species may have resulted in a less hydrophilic specimen, whose equilibrium water content was therefore correspondingly lower. Overall, the losses through dissolution in water suggest that plasma curing is less effective for these materials than conventional light curing, as it probably results in material with lower molar mass. The losses for the resin-modified glass-ionomer were much greater than for other materials, and it was concluded that the more rapid polymerization with plasma light caused a significant inhibitation of the acid-base part of the setting process. These findings suggest that long-term durability of materials may be compromised by employing plasma light cure rather than a conventional cure system and further studies of this point are recommended.

  5. Simulation-Based Optimization of Cure Cycle of Large Area Compression Molding for LED Silicone Lens

    Directory of Open Access Journals (Sweden)

    Min-Jae Song

    2015-01-01

    Full Text Available Three-dimensional heat transfer-curing simulation was performed for the curing process by introducing a large area compression molding for simultaneous forming and mass production for the lens and encapsulants in the LED molding process. A dynamic cure kinetics model for the silicone resin was adopted and cure model and analysis result were validated and compared through a temperature measurement experiment for cylinder geometry with cure model. The temperature deviation between each lens cavity could be reduced by implementing a simulation model on the large area compression mold and by optimizing the location of heat source. A two-step cure cycle was constructed to reduce excessive reaction peak at the initial stage and cycle time. An optimum cure cycle that could reduce cycle time by more than 29% compared to a one-step cure cycle by adjusting dwell temperature, heating rate, and dwell time was proposed. It was thus confirmed that an optimization of large area LED lens molding process was possible by using the present experiment and the finite element method.

  6. An Electron Microscopic Study of the Morphology of Cured Epoxy Resin

    Science.gov (United States)

    1986-12-01

    inhomogeneity. Luttgert and BOnart27 have postulated that the size of the heterogeneity in the cured resin depends on the rate of microgel formation or...nucleation and the rate of growth of the gel particles. At high curing temperatures, the rate of nucleation will be fast and the great number of microgels

  7. Studies on Treating Eczema by Chinese Herbal Medicine with Anti-Type Ⅳ Allergic Activity

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Objective: To study Chinese herbal prescription for treatment of eczema on the basis of the suppressive effect of Chinese herbal medicine with type Ⅳ allergic reaction. Methods: Various formulae composed of Chinese herbal medicines possessing suppressive effect on murine allergic contact dermatitis were formed following the therapeutic principles of traditional Chinese medicine in treating eczema, and their effect on ear swelling, ear flake weight, dermal inflammatory infiltration cell count and plasma level of calcitonin gene related peptide ( CGRP) were examined in mice with dinitrofluorobenzene induced dermatitis. The prescription, Composite Poria Decoction was formulated and made into granule form, which was used to treat 63 cases of eczema (atopic dermatitis was excluded), and compared with 59 cases treated with antihistaminic that was aimed at the type I allergic reaction. Results: Experimental study showed that all the 4 Chinese prescriptions had the effect of anti-type Ⅳ allergic reaction, among them, the formula for cooling blood and removing Heat, Wind and Dampness evil possessed the most potent effect in suppressing murine dermatitis, and it was also able to up-regulate the plasma CGRP concentration. The clinical cure rate of Composite Poria Granule treatment was 47.6%, and that of the control was 22.0%. The difference was significant between the two groups (u=2.9555, P<0.01). Conclusions: Chinese herbal medicine has the effect of anti-type Ⅳ allergic reaction. Composite Poria Granule has good effect in treating eczema.

  8. Optical and Thermal Analysis of the Time Evolution of Curing in Resins by Photothermal Techniques

    Science.gov (United States)

    Martínez-Torres, P.; Zambrano-Arjona, M.; Aguilar, G.; Alvarado-Gil, J. J.

    2012-11-01

    Four shades of a commercial visible-light curing dental resin are analyzed using photothermal techniques. The thermal effusivities of the dental resin shades before curing are measured using a variant of the conventional photoacoustic technique. The thermal diffusivities before and after curing are measured using infrared photothermal radiometry in the forward emission configuration. The time evolution process of the photocuring resin is monitored by photothermal radiometry in the forward and backward emission configurations. Inversion of the time evolution signal of the different configurations used permits one to obtain the time evolution of the thermal and optical properties during the photocuring. The thermal effusivity and thermal diffusivity exhibit exponential growth, while the optical absorption decreases exponentially due to the curing process. The relationship of these phenomena with the decrease of monomer concentration induced by the curing is discussed.

  9. Mechanical properties, volumetric shrinkage and depth of cure of short fiber-reinforced resin composite.

    Science.gov (United States)

    Tsujimoto, Akimasa; Barkmeier, Wayne W; Takamizawa, Toshiki; Latta, Mark A; Miyazaki, Masashi

    2016-01-01

    The mechanical properties, volumetric shrinkage and depth of cure of a short fiber-reinforced resin composite (SFRC) were investigated in this study and compared to both a bulk fill resin composite (BFRC) and conventional glass/ceramic-filled resin composite (CGRC). Fracture toughness, flexural properties, volumetric shrinkage and depth of cure of the SFRC, BFRC and CGRC were measured. SFRC had significantly higher fracture toughness than BFRCs and CGRCs. The flexural properties of SFRC were comparable with BFRCs and CGRCs. SFRC showed significantly lower volumetric shrinkage than the other tested resin composites. The depth of cure of the SFRC was similar to BFRCs and higher than CGRCs. The data from this laboratory investigation suggests that SFRC exhibits improvements in fracture toughness, volumetric shrinkage and depth of cure when compared with CGRC, but depth of cure of SFRC was similar to BFRC.

  10. The influence of curing time on the shear strength of fluidized fly ash

    Directory of Open Access Journals (Sweden)

    Gruchot Andrzej

    2015-06-01

    Full Text Available The paper presents results of research on the influence of compaction and air and water curing on angle of internal friction and cohesion of fluidized fly ash from “Połaniec” Power Plant. It was stated that the increase in compaction resulted in an insignificant increase of the angle of internal friction and a quite significant increase of cohesion. While the type and time of curing had a great influence on the angle of internal friction and cohesion. The highest values of angle of internal friction were obtained in the air curing, and the lowest in the water curing whereas in case of cohesion there was an inverse relation. The rise of curing time resulted in largely increased cohesion and small changes of angle of internal friction.

  11. Experimental and mumerical validation of the technique for concrete cure monitoring using piezoelectric admittance measurement

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Wan Cheol; Park, Gyu Hae [Dept. of Mechanical Engineering, Chonnam National University, Gwangju (Korea, Republic of)

    2016-06-15

    This paper presents a new technique for monitoring the concrete curing process using embedded piezoelectric transducers via admittance measurements. When a piezoelectric transducer is embedded in a structure, the electrical impedance (admittance) of the transducer is coupled with the mechanical impedance of the host structure, which allows monitoring of the structural condition. In this study, the admittance signatures are used for monitoring the concrete curing process. This new method is based on an admittance-based sensor diagnostic process, in which the capacitance values of the piezoelectric transducers are dependent on the strength of the host structure. We numerically and experimentally investigated the variations in capacitive value during the curing process. The results demonstrate that there is a clear relationship between the concrete curing status and the slope, this indicates that the proposed method could be efficiently used for monitoring the curing status of a concrete structure.

  12. Cure Behaviors and Water Up-take Evaluation of a New Waterborne Epoxy Resin

    Institute of Scientific and Technical Information of China (English)

    WAN Tao; ZANG Tianshun; ZHANG Rui; SUN Xianchang

    2012-01-01

    Cure behaviors and water up-take evaluation of a low cost,ecofriendly and water soluble epoxy resin prepared by reaction between epichlorohydrin and PEG400,PEG600 and PEG1000,respectively,were investigated using non-isothermal differential scanning calorimetry (DSC) and gravimetrical method,respectively.Factors affecting the cure behaviors as well as water up-take of waterborne epoxy resins,such as amount of triethylenetetramine (TETA) and triethylene diamine (TEDA),PEG molecular weight,curing temperature,were systematically investigated.The prepared water soluble epoxy resins can be cured under room temperature with the shape of the curing curves similar to that expected for an autocatalytic reaction.

  13. Cures for the Expansion Shock and the Shock Instability of the Roe Scheme

    CERN Document Server

    Li, Xue-song; Gu, Chun-wei

    2016-01-01

    A common defect of the Roe scheme is the production of non-physical expansion shock and shock instability. An improved method with several advantages was presented to suppress the shock instability. However, this method cannot prevent expansion shock and is incompatible with the traditional curing method for expansion shock. Therefore, the traditional curing mechanism is analyzed. The discussion explains the effectiveness of the traditional curing method and identifies several defects, one of which leads to incompatibility between curing the shock instability and expansion shock. Consequently, a new improved Roe scheme is proposed in this study. This scheme is concise, easy to implement, low computational cost, and robust. More importantly, the scheme can simultaneously cure the shock instability and expansion shock without additional costs.

  14. Cure effects on microcracking in IM7 fiber/Matrimid 5292{reg_sign} BMI composites

    Energy Technology Data Exchange (ETDEWEB)

    Wilenski, M.S.; Shin, E.; Morgan, R.J.; Drzal, L.T. [Michigan State Univ., East Lansing, MI (United States)

    1995-12-31

    Initial results from a study of the microcracking behavior of the Matrimid 5292{reg_sign} BMI/IM7 carbon fiber system are presented. Studies were performed to determine the composite`s Stress Free Temperature (SFT) which is seen to control the presence and extent of microcracking. The SFT was determined using asymmetric laminates [0{sub 2}/90{sub 2}]. Varied post-cure cycles were utilized and it was found that until complete cure is obtained, the SFT is a function of the highest temperature experienced by the laminate, with little effect of previous thermal history. The reactions necessary to fully cure this system are not active at temperatures below 250 C, ruling out the possibility of obtaining a fully cured composite with a low SFT through extended post-cures at lower temperatures.

  15. Enhanced microactuation with magnetic field curing of magnetorheological elastomers based on iron–natural rubber nanocomposites

    Indian Academy of Sciences (India)

    M P Vasudevan; P M Sudeep; I A Al-Omari; Philip Kurian; P M Ajayan; T N Narayanan; M R Anantharaman

    2015-06-01

    The incorporation of nanoparticles of iron in a natural rubber matrix leads to flexible magnetorheological (MR) materials. Rod-shaped MR elastomers based on natural rubber and nanosized iron have been moulded both with and without the application of an external magnetic field during curing. These MR elastomer rods and filler material were characterized by X-ray powder diffraction, scanning electron microscopy and transmission electron microscopy. Magnetic properties were investigated by using vibrating sample magnetometry. Microactuation studies were carried ou t by employing a laser Doppler vibrometer. It is seen that microactuation of field cured samples have been enhanced by two times when compared with that of zero field cured samples. The effect of alignment of magnetic particles during field-assisted curing was also studied by using a dynamic mechanical analyzer. A plausible model is put forwarded to explain the observed enhancement of actuation for field cured samples.

  16. A Cure for HIV Infection: "Not in My Lifetime" or "Just Around the Corner"?

    Science.gov (United States)

    Lederman, Michael M; Cannon, Paula M; Currier, Judith S; June, Carl H; Kiem, Hans Peter; Kuritzkes, Daniel R; Lewin, Sharon R; Margolis, David M; McCune, Joseph M; Mellors, John W; Schacker, Timothy W; Sekaly, Rafick P; Tebas, Pablo; Walker, Bruce D; Douek, Daniel C

    2016-01-01

    With the advent and stunning success of combination antiretroviral therapy (ART) to prolong and improve quality of life for persons with HIV infection, HIV research has been afforded the opportunity to pivot towards studies aimed at finding "a cure." The mere idea that cure of HIV might be possible has energized researchers and the community towards achieving this goal. Funding agencies, both governmental and private, have targeted HIV cure as a high priority; many in the field have responded to these initiatives and the cure research agenda is robust. In this "salon" two editors of Pathogens and Immunity, Michael Lederman and Daniel Douek ask whether curing HIV is a realistic, scalable objective. We start with an overview perspective and have asked a number of prominent HIV researchers to add to the discussion.

  17. Salt and intramuscular fat modulate dynamic perception of flavour and texture in dry-cured hams.

    Science.gov (United States)

    Lorido, Laura; Estévez, Mario; Ventanas, Jesús; Ventanas, Sonia

    2015-09-01

    The present study aimed to evaluate the influence of salt and intramuscular fat (IMF) content on the sensory characteristics of two different types of dry-cured hams (Iberian and Serrano) using the time-intensity (TI) method. All studied TI parameters of flavour attributes (overall flavour, saltiness, cured and rancid flavours) were significantly (p < 0.05) affected by variations in the salt and/or IMF content. However, regarding texture attributes only the maximum intensity (Imax) of hardness was significantly (p < 0.05) affected by the salt content of hams. Compared to Iberian dry-cured hams, the dynamic perception of the flavour and texture of Serrano dry-cured hams was less influenced by variations in salt and/or IMF content. The dynamic sensory techniques may be helpful to guarantee the quality of dry-cured products subjected to strategies of salt and fat reduction.

  18. The role of curing stresses in subsequent response, damage and failure of textile polymer composites

    Science.gov (United States)

    Heinrich, Christian; Aldridge, Michael; Wineman, Alan S.; Kieffer, John; Waas, Anthony M.; Shahwan, Khaled W.

    2013-05-01

    An integrated computational framework for textile polymer composites is introduced. A novel polymer curing model is used in connection with modeling the polymer curing process during manufacturing of textile composites. The model is based on the notion of polymer networks that are continuously formed in a body of changing shape due to changes in temperature, chemistry and external loads. Nonlinear material behavior is incorporated through nonlocal continuum damage mechanics that preserves mesh objectivity in calculations that go beyond maximum loads. The integrated model is applied to the curing of plain weave textile composites made from carbon fiber tows and Epon™862 resin. The mechanical and chemical properties are measured during curing using concurrent Brillouin and Raman light scattering. It is shown that significant stresses can develop during cure. The effect of these stresses on the manufactured part performance, when subsequent service loads are applied, is evaluated and a reduction in ultimate load, in agreement with experimental observations, is observed.

  19. [Improvement of light-cured indirect inlays durability by means of electromagnetic field].

    Science.gov (United States)

    Nidzel'skiĭ, M Ia; Korotetskaia-Zinkevich, V L

    2014-01-01

    The main strength characteristics of light-cured resins used for replacement of dental hard tissues defects are destructive stress by compression, microhardness, resistance to abrasion, impact and water absorption. The study focuses on some strength features of composite materials for inlays processed by electromagnetic field. Four sample series of light cured resin (Charisma, Heraus Kulzer, Germany) were used to assess strength features changes in various curing methods: 10 control samples were polymerized by conventional light-curing device, while 30 were additionally processed by electromagnetic field of various intensity (60, 80 and 100 Oe, 10 samples for each group). The obtained results confirm the positive effects of electromagnetic field on strength features of light-cured resins which improves the quality of inlays.

  20. Significant and sustaining elevation of blood oxygen induced by Chinese cupping therapy as assessed by near-infrared spectroscopy

    OpenAIRE

    Li, Ting; Li, Yaoxian; Lin, Yu; Li, Kai

    2016-01-01

    Cupping therapy has been used in traditional Chinese medicine for thousands of years to relieve muscle pain/tendency/fatigue and to cure or reduce symbols of other diseases. However, its therapeutic effect is sparsely interpreted in the language of modern physiology. To objectively evaluate its therapeutic effect, we focused on dry cupping treatment and utilized near-infrared spectroscopy (NIRS) to assess the concentration change in oxy-hemoglobin ([HbO2]), deoxy-hemoglobin ([Hb]), and blood ...

  1. Influence of cure via network structure on mechanical properties of a free-radical polymerizing thermoset

    Science.gov (United States)

    Ganglani, Manisha Sachin

    The matrix of a composite material exerts influence over composite properties. The hypothesis is that control of molecular architecture of the matrix allows for the control of resin properties and therefore impacts composite properties. The objective of this research is to define the relationship between cure chemistry, network structure, and final physical properties of vinyl ester-styrene (VE/S) resin, a free-radical polymerizing thermoset polymer often used as the matrix of fiber reinforced polymers. Tensile and fracture properties of the polymer are found to depend on both cure schedule and cure formulation. The possibilities of phase separation and microgel formation being the cause for the differences in mechanical properties are examined. This research shows that the VE/S system does not phase separate under the conditions studied. This proven, the research examines changes in network architecture under different cure conditions. It is found that though bulk properties of the resin are unaffected by the details of the cure, the microscopic morphology, in particular the type of crosslink formed (intermolecular bond or intramolecular bond), is sensitive to both cure temperature and initiation mechanism as determined by cure formulation. Thus, the molecular architecture of the network is responsible for the bulk mechanical properties of the resin. A kinetic analysis shows that both temperature and initiation mechanism affect the apparent "reaction order" of the VE/S system as determined by the autoacceleration equation. This apparent reaction order is interpreted as being an indication of the degree of heterogeneity in the resin. By controlling cure temperature and cure formulation, it is possible to minimize the apparent reaction order and thereby optimize physical properties. Finally, a theory is adapted from other non-network polymer systems to describe qualitatively how cure temperature and initiation mechanism may alter the heterogeneity in network

  2. Vickers Hardness of Composite Resins Cured with LED and QTH Units

    Directory of Open Access Journals (Sweden)

    Alaghemand H

    2016-03-01

    Full Text Available Statement of Problem: One of the factors affecting the degree of polymerization of light-cured composites is the type of light-curing unit used. In addition, physicomechanical properties of the composite resins depend on the degree of conversion and polymerization. Objectives: Since the type of initiator in new composite resins is not explained by manufacturers, this study is an attempt to compare the depth of hardening, with two LED and QTH light-curing units. Materials and Methods: Fifteen samples prepared from Gradia Direct and Filtek Z250, both of which being universal, were cured with QTH (Astralis 7 and LED (Bluephase C8 light-curing units. All the samples were molded in polyester resin and cut from the middle by a disk. The hardness of the cut area was evaluated at 0, 0.5, 1, 1.5, 2, 2.5, 3, 3.5 and 4-mm depth intervals and also at the same interval as the width of the sample, with Vickers hardness machine, while the samples were placed in a darkroom. Data were statistically analyzed using one-way ANOVA, two-way ANOVA, t-test and post Hoc Tukey’s tests in SPSS, version 16. Results: Filtek Z250 was harder than Gradia Direct at all the depth with both light-curing units. The hardness of Filtek Z250 sample cured with Astralis 7 was higher than that cured with LED, but with Gradia Direct the LED unit resulted in higher hardness. Curing depth was not significantly different between the groups (p = 0.109. Conclusions: Vickers hardness number for both composites used in this study is in an acceptable range for clinical implications. The composites’ composition is important to be considered for selection of light unit. Based on the findings of the present study, LED did not present more curing depth compared with QTH.

  3. Role of Oxides of Nitrogen in Tobacco-Specific Nitrosamine Formation in Flue-Cured Tobacco

    Directory of Open Access Journals (Sweden)

    Nestor TB

    2014-12-01

    Full Text Available Tobacco is known to contain a class of nitrosamines known as tobacco-specific nitrosamines or TSNA. Nitrosation of naturally occurring tobacco alkaloids is commonly accepted as the mechanism of TSNA formation in tobacco. Because green and freshly harvested tobaccos are virtually free of TSNA, formation and accumulation of TSNA are generally considered to occur during the curing process. Most recent hypotheses have focused on microbial reduction of nitrate to nitrite and other oxides of nitrogen (NOcompounds that react with tobacco alkaloids to form TSNA during curing. This natural microbial process remains the prevalent hypothesis for TSNA formation in burley and other air-cured tobaccos. However, a different mechanism for the formation of TSNA in flue-cured tobacco, independent of microbial activity, is documented in this paper. It is common practice to flue-cure Virginia or blonde tobacco in bulk barns that incorporate forced air ventilation and temperature control. For the last thirty-five years, many modern bulk barns in North America generally have used liquid propane gas (LPG with direct-fired burners that exhaust combustion gases directly into the barn where the tobacco is exposed to those gases. Our studies indicate that LPG combustion by-products in the exhaust stream, namely NO, react with naturally occurring tobacco alkaloids to form TSNA. Heat exchange curing methods preclude exposure of the tobacco to combustion gases and by-products, thereby eliminating this significant source of TSNA formation, without degrading leaf quality or smoking character. Research findings from 1998 and 1999 are presented to demonstrate the role of NOgases in TSNA formation and the significance of direct-fired curing as a primary source of TSNA formation in flue-cured tobacco. Also, data from an extensive barn conversion program in 2000, which resulted in a 94% average reduction in TSNA levels in cured flue-cured leaf, are presented.

  4. Preliminary Study of the Influence of Post Curing Parameters to the Particle Reinforced Composite's Mechanical and Physical Properties

    Directory of Open Access Journals (Sweden)

    Aare ARUNIIT

    2012-09-01

    Full Text Available This study examines the effect of different post cure parameters to a polymer matrix particulate reinforced composite material. The goal is to evaluate the importance of different factors and to suggest a well-balanced post cure mode that supports the application of the material.Polymer matrix composites are post cured at elevated temperature to increase the amount of cross linking to achieve better chemical and heat resistance and mechanical properties. Every material has an individual post cure process that depends from the raw materials. Post curing variables include temperature, duration of cure, the time between initial curing and post curing and temperature profile gradient.There are several ways to determine the cure state of a polymer. It can be evaluated based on the mechanical and physical properties, residual styrene content, glass transition temperature, residual exotherm or solvent swelling test. For the determination of the suitable post cure parameters test slabs were casted and post cured with varying time and temperature. Glass transition temperature, residual exotherm, softening in ethanol, surface hardness, flexural strength and flexural modulus were determined. It is shown that the material should be cured at 60 °C – 80 °C. With higher temperature and extended time of cure the glass transition temperature raises but the material becomes too brittle.DOI: http://dx.doi.org/10.5755/j01.ms.18.3.2435

  5. UV-cured adhesives for carbon fiber composite applications

    Science.gov (United States)

    Lu, Hsiao-Chun

    Carbon fiber composite materials are increasingly used in automobile, marine, and aerospace industries due to their unique properties, including high strength, high stiffness and low weight. However, due to their brittle characteristic, these structures are prone to physical damage, such as a bird strike or impact damage. Once the structure is damaged, it is important to have fast and reliable temporary repair until the permanent repair or replacement can take place. In this dissertation, UV-based adhesives were used to provide a bonding strength for temporary repair. Adhesively bonded patch repair is an efficient and effective method for temporary repair. In this study, precured patches (hard patches) and dry fabric patches with laminating resins (soft patches) were performed. UV-based epoxy adhesives were applied to both patch repair systems. For precured patch repair, the bonding strengths were investigated under different surface treatments for bonding area and different adhesives thicknesses. The shear stresses of different UV exposure times and curing times were tested. Besides, the large patch repair was investigated as well. For soft patch repair, the hand wet lay-up was applied due to high viscosity of UV resins. A modified single lap shear testing (ASTM D5868) was applied to determine the shear stress. The large patches used fiber glass instead of carbon fiber to prove the possibility of repair with UV epoxy resin by hand wet lay-up process. The hand lay-up procedure was applied and assisted by vacuum pressure to eliminate the air bubbles and consolidate the patches. To enhance the bonding strength and effective soft patch repair, vacuum assisted resin transferring molding (VaRTM) is the better option. However, only low viscosity resins can be operated by VaRTM. Hence, new UV-based adhesives were formulated. The new UV-based adhesives included photoinitiator (PI), epoxy and different solvents. Solvents were used to compound the photoinitiator into epoxy

  6. ISOPAR L RELEASE FROM SALTSTONE CURED AT 55 C

    Energy Technology Data Exchange (ETDEWEB)

    Cozzi, A; Cora Berry, C; Michael Bronikowski, M; Russell Eibling, R; Jack Zamecnik, J

    2006-05-16

    The decontaminated salt solution waste stream from the Modular Caustic Side Solvent Extraction Unit and the Salt Waste Processing Facility is anticipated to contain entrained extraction solvent. The decontaminated salt solution is scheduled to be processed through Tank 50 into the Saltstone Production Facility. This study, among others, has been undertaken because the solvent concentration in the decontaminated salt solution may cause flammability issues within the Saltstone Disposal Facility that may need to be addressed prior to operation. Previous work at the Savannah River National Laboratory determined the release of Isopar{reg_sign} L from saltstone prepared with a simulated DSS with Isopar{reg_sign} L concentrations ranging from 50 to 200 {micro}g/g in the salt fraction and with test temperatures ranging from ambient to 95 C. The results from the curing of the saltstone showed that the Isopar{reg_sign} L release data can be treated as a percentage of initial concentration in the concentration range studied. The majority of the Isopar{reg_sign} L that was released over the test duration was released in the first few days. The release of Isopar{reg_sign} L begins immediately and the rate of release decreases over time. At higher temperatures the immediate release is larger than at lower temperatures. In this study, saltstone was prepared using a simulated decontaminated salt solution containing Isopar{reg_sign} L concentrations of 50 {micro}L/L (30 {micro}g/g) and 100 {micro}L/L (61 {micro}g/g) and cured at 55 C. The headspace of each sample was purged and the Isopar{reg_sign} L was trapped on a coconut shell carbon tube. The amount of Isopar{reg_sign} L captured was determined using NIOSH Method 1501. The percentage of Isopar{reg_sign} L released after 20 days was 1.4 - 3.7% for saltstone containing 50 {micro}L/L concentration and 2.1 - 4.3% for saltstone containing 100 {micro}L/L concentration. Given the measurement uncertainties in this work there is no

  7. Cure of experimental botulism and antibotulismic effect of toosendanin

    Institute of Scientific and Technical Information of China (English)

    Yu-liang SHI; Zhong-feng WANG

    2004-01-01

    Botulinum neurotoxins (BoNTs), a group of bacterial proteins that comprise a light chain disulfide linked aheavy chain, are the most lethal biotoxins known to mankind. By inhibiting neurotransmitter release, BoNTs causesevere neuroparalytic disease, botulism. A series of important findings in the past 10 years which displayed themolecular targets of BoNTs and hence proposed a four-step action mechanism to explain BoNT intoxication greatlyadvanced the study of antibotulismic drug. In this article, we reviewed these progresses and anti-botulismiccompounds found in recent years. These compounds function due to their facilitation on neurotransmitter releaseor to their interference on the binding, internalization, translocation, and endopeptidase activity of the toxins.Toosendanin is a triterpenoid derivative extracted from a digestive tract-parasiticide in Chinese traditional medicine.Chinese scientists have found that the compound is a selective prejunctional blocker. In spite of sharing somesimilar action with BoNT, toosendanin can protect botulism animals that have been administrated with lethal dosesof BoNT/A or BoNT/B for several hours from death and make them restore normal activity. The neuromuscularjunction preparations isolated from the rats that have been injected with toosendanin tolerate BoNT/A challenge.Toosendanin seems to have no effect on endopeptidase activity of BoNT, but blocks the toxin approach to itsenzymatic substrate.

  8. Contemporary American Chinese Studies

    Institute of Scientific and Technical Information of China (English)

    Qiu Huafei

    2008-01-01

    The rise of modern American scholarship on China was largely attributed to the establishment of the American Joint Committee on Contemporary China (JCCC) in 1959 which sponsored all kinds of activities to promote Chinese studies, ranging from institutional support and financial resources to training courses. Since then, American study of China has entered into a period of sustainability that features academic and group-oriented research. It has become a mainstream discipline in American social science studies.1 There are some distinctive differences between early sinology and modern Chinese Studies: the latter is much more concentrated on the study of issues, comparative historical studies, and contemporary Chinese society. American Chinese studies stresses empirical research, textual data, and the application of theory to practice.Shanghai. He was a Fulbright visiting professor at State University of New York at Geneseo from 2006-2007. This treatise is one of a series of studies for China's National Research Foundation of Philosophy and Social Science (05BGJ012), "American Chinese Studies."

  9. Chinese Affixes and Word Formation

    Directory of Open Access Journals (Sweden)

    Fu Ruomei

    2014-05-01

    Full Text Available Chinese language is one of the typical isolated languages. It lacks morphological variation; part of speech has no morphological signs; the additional component of word formation is less; and the roots never change their forms. The major method of Chinese word formation is the combination of roots according to certain grammatical relations. Although the affix word formation is not part of mainstream Chinese word formation, affix-formation is still an integral part of the Chinese word-formation. Article used literature review, summarized the types and meanings of Chinese affixes. And meanwhile, article analyzed word formation function of Chinese Affixes and quasi-affixes. The Chinese quasi-affixes have stronger capabilities in forming new words, but development direction of Chinese quasi-affixes has to stand the test of time.

  10. IMPACT OF TIME / TEMPERATURE CURING CONDITIONS AND ALUMINATE CONCENTRATIONS ON SALTSTONE PROPERTIES

    Energy Technology Data Exchange (ETDEWEB)

    Harbour, J.; Edwards, T.; Williams, V.

    2009-05-05

    This report addresses the impact of (1) the time and temperature curing conditions (profile) and (2) the impact of higher aluminate concentrations in the decontaminated salt solution on Saltstone processing and performance properties. The results demonstrate that performance properties as well as some of the processing properties of Saltstone are highly sensitive to the conditions of time and temperature under which curing occurs. This sensitivity is in turn dependent on the concentration of aluminate in the salt feed solution. In general, the performance properties and indicators (Young's modulus, compressive strength and total porosity) are reduced when curing is initially carried out under high temperature. However, this reduction in performance properties is dependent on the sequence of temperatures (the time/temperature profile) experienced during the curing process. That is, samples that are subjected to a 1, 2, 3 or 4 day curing time at 60 C followed by final curing at 22 C lead to performance properties that are significantly different than the properties of grouts allowed to cure for 1, 2, 3 or 4 days at 22 C followed by a treatment at 60 C. The performance properties of Saltstone cured in the sequence of higher temperature first are generally less (and in some cases significantly less) than performance properties of Saltstone cured only at 22 C. This loss in performance was shown to be mitigated by increased slag content or cement content in the premix at the expense of fly ash. For the sequence in which the Saltstone is initially cured at 22 C followed by a higher temperature cure, the performance properties can be equal to or greater than the properties observed with curing only at 22 C curing. The results in this report indicate that in order to meaningfully measure and report the performance properties of Saltstone, one has to know the time/temperature profile conditions under which the Saltstone will be cured. This will require thermal modeling

  11. Effect of cross infection control barriers used on the light-curing device tips on the cure depth of a resin composite

    Directory of Open Access Journals (Sweden)

    Isabel Cristina Celerino de Moraes Porto

    2013-01-01

    Full Text Available Background: Among the advice on prevent cross-infection was included usage of mechanical barriers on tips of photoactivation units. However, questions about the use of protective barriers placed on the light-curing unit′s tips and the possibility of interference with the ability of guaranteeing an effective polymerization of composite resins need to be clarified. Aims: The aim of this study was to evaluate the effect of cross infection control barriers used on the light-curing device tips on the cure depth of composite resin. Materials and Methods: Power density measurements from the light-cure unit were recorded with a radiometer on ten separate occasions with different types and placement modes of each barrier (low-density polyethylene and polyvinyl chloride (PVC film - smooth and folds and no-barrier (control. Cure depth of TPH™ Spectrum™ resin, A2-A4, was evaluated by the scraping test. Statistical Analysis: The data were analyzed using Student′s t-test or ANOVA one-way with Tukey′s test (α =0.05. Results: Same type of barrier and different shades (A2, A4 of composite exhibited significant difference in the cure depth among all groups (P < 0.05. Both low-density polyethylene and PVC film folded barriers produced a significant reduction in the light intensity (P < 0.05. Conclusions: Regarding the resin shade, there was a significant reduction in the cure depth of A4 composite resin (dark shade but this reduction is not enough to cause any adverse effect on the material′s clinical performance. Therefore, disposable barriers can be recommended for use over the end of the light guide.

  12. Evaluation of the Effect of Porcelain Laminate Thickness on Degree of Conversion of Light Cure and Dual Cure Resin Cements Using FTIR

    Science.gov (United States)

    Hoorizad Ganjkar, Maryam; Heshmat, Haleh; Hassan Ahangari, Reza

    2017-01-01

    Statement of the Problem: Increasing the thickness of the veneering porcelain may affect the polymerization of resin cements. Incomplete polymerization of resin cements can lead to compromised quality of restoration and decrease the longevity of indirect restorations. Purpose: This study sought to assess the effect of IPS Empress porcelain thickness on the degree of conversion of light-cure and dual-cure resin cements using Fourier transform infrared spectroscopy. Materials and Method: In this experimental study, IPS Empress porcelain discs (A2 shade) with 10mm diameter and 0.5, 1 and 1.5 mm thicknesses were fabricated. Choice2 (Bisco, USA) and Nexus3 (Kerr, USA) resin cements were light cured through the three porcelain thicknesses in two groups of 3 samples using a LED light-curing unit (LEDemetron II; Kerr, USA). The control group samples were cured individually with no porcelain disc. The degree of conversion of resin cements was determined using FTIR (Bruker; Equinox55, Germany). The data were analyzed using Dunn’s test. Results: The degree of conversion (in percent) beneath the 0.5, 1.5 and 2 mm thicknesses of IPS Empress was 68.67±0.88, 71.06±0.94 and 72.51±0.41 for Choice2 resin cement and 69.60±2.12, 69.64±1.63 and 69.24±2.12 for Nexus3, respectively. Porcelain thickness and type of resin cement had no significant effect on degree of conversion (p≥ 0.05). Conclusion: It seems that increasing the porcelain thickness by up to 1.5 mm has no adverse effect on degree of conversion of both dual cure and light cure resin cements evaluated in this study. PMID:28280757

  13. The Loading Density of Pre-air-curing Flue-cured Tobacco%预先晾制烤烟的装烟密度研究

    Institute of Scientific and Technical Information of China (English)

    刘卉; 周清明; 邓小华; 谢鹏飞; 张万良; 翟争光; 刘涛

    2013-01-01

    为明确预先晾制烤烟的装烟密度,以烤烟品种云烟97为试材,研究了预先晾制烤烟不同装烟密度对上部叶品质的影响.结果表明:4 000 kg装烟量烤后烟叶除外观质量与对照3 000kg装烟量差异不显著外,在物理性状、化学性状、经济性状及能耗方面均劣于对照;而3 500 kg装烟量烤后烟叶在外观质量、物理性状、化学性状、经济性状、能耗方面均优于对照3 000 kg装烟量.3 500 kg装烟量是上部叶预先晾制后最合适的装烟密度.%In order to explore the loading density of pre-air-curing flue-cured tobacco,Yunyan97 was taken as test material to explore the effects of different loading densities of pre-air-curing flue-cured tobacco on quality of upper leaves.The results showed that in comparison with control (loading density of 3 000 kg),the flue-cured tobacco leaves with 4 000 kg of loading density was worse in physical characteristics,chemical characteristics,economic characteristics and energy consumption,only the difference in appearance quality was not significant; the flue-cured tobacco leaves with 3 500 kg of loading density was better in all aspects (appearance quality,physical characteristics,chemical characteristics,economic characteristics and energy consumption).Therefore,the 3 500 kg of loading density is the optimum loading density for pre-air-curing upper tobacco leaves.

  14. Good Reasons to Choose Chinese

    Institute of Scientific and Technical Information of China (English)

    1996-01-01

    TASTE, texture and aroma all act as food’s aphrodisiacs. Chinese food combines each of these elements, creating an art for the senses. Diet has long been recognized as a way of preserving and enhancing health. From ancient times, the Chinese noticed people’s moods change with the seasons. Using a delicately woven tapestry, food and Chinese medicine go hand in hand. According to traditional Chinese medicine, people should change their

  15. Effects of postharvest curing treatment on flesh colour and phenolic metabolism in fresh-cut potato products.

    Science.gov (United States)

    Wang, Qingguo; Cao, Yu; Zhou, Lili; Jiang, Cai-Zhong; Feng, Yanyan; Wei, Shaochong

    2015-02-15

    The flesh colour and phenolic metabolism in potato tuber during curing and after cut were investigated. Result indicated that postharvest curing not only changed phenolic metabolism during curing, but also improved fresh-cut colour for 12 days after fresh cut. Significantly lower PAL and higher phenolic content and PPO activities during curing treatment and fresh-cut potatoes were detected compared to the control, which lead to the lower browning in the slices from curing treated potatoes. HPLC analysis revealed that amounts of total phenolics, chlorogenic acid, gallic acid and protocatechuic acid were induced by curing and highly accumulated in the curing treated potatoes. Our results demonstrated that phenolic metabolism played an important role in the control of browning of fresh cut potato after curing.

  16. Cure shrinkage in epoxy grouts for grouted repairs

    Science.gov (United States)

    Shamsuddoha, Md.; Islam, Md. Mainul; Aravinthan, Thiru; Manalo, Allan; Lau, Kin-tak

    2013-08-01

    Structures can go through harsh environmental adversity and can experience material loss and cracks during their service lives. Infill material is used to ensure a supporting bed for a grouted repair. Epoxy grouts are used for repairing and rehabilitating structures, such as foundations, bridges, piers, transportation pipelines, etc., because they are resistant to typical chemicals and possess superior mechanical properties than other grouts. The resin based infill used inside the void or cracked space of the repair is vulnerable to shrinkage. When these filled grouts have high resin content, cracks can develop from residual stresses, which can affect the load transfer performance. It follows that interlayer separation and cracking of infill layer can occur in a grouted repair. In this study, volumetric shrinkage of two epoxy grouts was measured over 28 days using a Pycnometer. The highest volumetric shrinkage measured after 7 days was found to be 2.72%. The results suggest that the volumetric shrinkage can be reduced to 1.1% after 7 days, through the introduction of a coarse aggregate filler; a 2.5 times reduction in shrinkage. About 98% and 92% of the total shrinkage over the 28 day period, of the unfilled and filled grouts respectively, was found to occur within 7 days of mixing. The gel-time shrinkages were also calculated, to determine the "postgel" part of the curing contraction which subsequently produces residual stresses in the hardened grout systems.

  17. Barriers to a cure for HIV in women

    Science.gov (United States)

    Gianella, Sara; Tsibris, Athe; Barr, Liz; Godfrey, Catherine

    2016-01-01

    Introduction Distinct biological factors exist that affect the natural history of HIV and the host immune response between women and men. These differences must be addressed to permit the optimal design of effective HIV eradication strategies for much of the HIV-positive population. Methods and results Here, we review the literature on sex-based differences in HIV pathogenesis and natural history in tissues and anatomic compartments, HIV latency and transcriptional activity, and host immunity including the role of sex hormones. We then outline the potential effects of these differences on HIV persistence, and on the safety and efficacy of HIV eradication and curative interventions. Finally, we discuss the next steps necessary to elucidate these factors to achieve a cure for HIV, taking in account the complex ethical issues and the regulatory landscape in the hopes of stimulating further research and awareness in these areas. Conclusions Targeted enrolment of women in clinical trials and careful sex-based analysis will be crucial to gain further insights into sex-based differences in HIV persistence and to design sex-specific approaches to HIV eradication, if required. PMID:26900031

  18. On the radiation dose required to cure intracranial germinoma

    Energy Technology Data Exchange (ETDEWEB)

    Shibamoto, Yuta [Kyoto Univ. (Japan). Inst. for Frontier Medical Sciences

    1999-09-01

    Despite its high radiosensitivity, intracranial germinoma has most often been treated with a radiation dose of 50 Gy. Relatively old literature suggested that 50 Gy was appropriate, but several newer studies indicate that 40-45 Gy may be sufficient. Regarding this issue, we conducted a phase II study in which the total dose to the primary site was planned to be 40 Gy to tumors <2.5 cm in diameter, 45 Gy to 2.5-4 cm tumors, and 50 Gy to tumors >4 cm, using 1.6-1.8 Gy daily fractions. Thirty-eight patients were enrolled. Within a median follow-up period of 116 months, no patients developed local recurrence, and only two developed CSF dissemination. Intracranial germinoma <4 cm in diameter can be cured with radiation doses of 40-45 Gy. Radiotherapy alone with these reduced doses should be compared with the ongoing protocols of chemotherapy plus further reduced dose (24-30 Gy) radiation in future studies. (author)

  19. Drawing cure: children's drawings as a psychoanalytic instrument.

    Science.gov (United States)

    Wittmann, Barbara

    2010-01-01

    This essay deals with the special case of drawings as psychoanalytical instruments. It aims at a theoretical understanding of the specific contribution made by children's drawings as a medium of the psychical. In the influential play technique developed by Melanie Klein, drawing continuously interacts with other symptomatic (play) actions. Nonetheless, specific functions of drawing within the play technique can be identified. The essay will discuss four crucial aspects in-depth: 1) the strengthening of the analysis's recursivity associated with the graphic artifact; 2) the opening of the analytic process facilitated by drawing; 3) the creation of a genuinely graphic mode of producing meaning that allows the child to develop a "theory" of the workings of his own psychic apparatus; and 4) the new possibilities of symbolization associated with the latter. In contrast to classical definitions of the psychological instrument, the child's drawing is a weakly structured tool that does not serve to reproduce psychic processes in an artificial, controlled setting. The introduction of drawing into the psychoanalytic cure is by no means interested in replaying past events, but in producing events suited to effecting a transformation of the synchronic structures of the unconscious.

  20. Plasmid interference for curing antibiotic resistance plasmids in vivo

    Science.gov (United States)

    Kamruzzaman, Muhammad; Shoma, Shereen; Thomas, Christopher M.; Partridge, Sally R.

    2017-01-01

    Antibiotic resistance increases the likelihood of death from infection by common pathogens such as Escherichia coli and Klebsiella pneumoniae in developed and developing countries alike. Most important modern antibiotic resistance genes spread between such species on self-transmissible (conjugative) plasmids. These plasmids are traditionally grouped on the basis of replicon incompatibility (Inc), which prevents coexistence of related plasmids in the same cell. These plasmids also use post-segregational killing (‘addiction’) systems, which poison any bacterial cells that lose the addictive plasmid, to guarantee their own survival. This study demonstrates that plasmid incompatibilities and addiction systems can be exploited to achieve the safe and complete eradication of antibiotic resistance from bacteria in vitro and in the mouse gut. Conjugative ‘interference plasmids’ were constructed by specifically deleting toxin and antibiotic resistance genes from target plasmids. These interference plasmids efficiently cured the corresponding antibiotic resistant target plasmid from different Enterobacteriaceae in vitro and restored antibiotic susceptibility in vivo to all bacterial populations into which plasmid-mediated resistance had spread. This approach might allow eradication of emergent or established populations of resistance plasmids in individuals at risk of severe sepsis, enabling subsequent use of less toxic and/or more effective antibiotics than would otherwise be possible, if sepsis develops. The generalisability of this approach and its potential applications in bioremediation of animal and environmental microbiomes should now be systematically explored. PMID:28245276

  1. Cure kinetics of epoxy matrix resin by differential scanning calorimetry

    Science.gov (United States)

    Cizmecioglu, M.; Gupta, A.

    1982-01-01

    A study was made on the cure kinetics of an epoxy neat-resin (Narmco 5208) using Differential Scanning Calorimetry (DSC). Two interrelated analytical methods were applied to dynamic DSC data for evaluating the kinetic parameters, such as activation energy, E, the order of reaction, n, and the total heat of polymerization (or crosslinking), delta H sub t. The first method was proposed by Ellerstein (1968), and uses a thorough differential-integral analysis of a single DSC curve to evaluate the kinetic parameters. The second method was proposed by Kissinger (1957), and uses multiple DSC curves obtained at various heating rates to evaluate E regardless of n. Kinetic analysis of Narmco 5208 epoxy resin showed that the reaction order, n, is substantially affected by the rate of heating; i.e., n is approximately 2 at slow scan rates but is reduced to 1.5 at higher scan rates. The activation energy, E, is not affected by the scan rate, and the average value of E is 25.6 + or - 1.8 kcal/mole.

  2. Curing dark energy instability with parametrized post-Friedmann treatment

    CERN Document Server

    Richarte, Martín G

    2014-01-01

    We review the parametrized post-Friedmann (PPF) method within the framework of interacting dark energy model for a FRW background. We assess the possibility of using such treatment for curing a "bad" interaction from its large-scale instabilities, usually presented within the standard linear perturbation theory. Regarding the Markov Chain Monte-Carlo analysis, our global fitting combines several cosmological probes including the cosmic microwave background (WMAP9+Planck) data, barion acoustic oscillation (BAO) measurements, JLA sample of supernovae, Hubble constant (HST), and redshift-space distorsion (RSD) measurements through the ${\\rm f}\\sigma_{8}{\\rm (z)}$ data points. The joint observational analysis of ${\\rm Planck+WP+JLA+BAO+HST+RSD}$ data leads to a coupling parameter, $\\xi_{c}=0.00140_{-0.00080}^{+0.00079}$ at $1\\sigma$ level for vanishing momentum transfer potential, whereas the aforesaid value is reduced in a $0.022\\%$ when the momentum transfer potential is switched on. The CMB power spectrum show...

  3. Bacterial spoilage of meat and cured meat products.

    Science.gov (United States)

    Borch, E; Kant-Muermans, M L; Blixt, Y

    1996-11-01

    The influence of environmental factors (product composition and storage conditions) on the selection, growth rate and metabolic activity of the bacterial flora is presented for meat (pork and beef) and cooked, cured meat products. The predominant bacteria associated with spoilage of refrigerated beef and pork, are Brochothrix thermosphacta, Carnobacterium spp., Enterobacteriaceae, Lactobacillus spp., Leuconostoc spp., Pseudomonas spp. and Shewanella putrefaciens. The main defects in meat are off-odours and off-flavours, but discolouration and gas production also occur. Bacteria associated with the spoilage of refrigerated meat products, causing defects such as sour off-flavours, discolouration, gas production, slime production and decrease in pH, consist of B. thermosphacta, Carnobacterium spp. Luctobacillus spp. Leuconostoc spp. and Weissella spp. Analysis of spoilage as measured by bacterial and chemical indicators is discussed. It is concluded that a multivariate approach based on spectra of chemical compounds, may be helpful in order to analyse spoilage, at least for spoilage caused by lactic acid bacteria. The consequences of bacteria bacteria interactions should be evaluated more.

  4. Generalized Poisson-Lindely Distribution in Promotion Time Cure Model

    Directory of Open Access Journals (Sweden)

    Ahmad Reza Baghestani

    2014-12-01

    Full Text Available 1024x768 Long-term survival analysis has been improved in the last decade and most of the models concentrate on the promotion time cure model that proposed by Chen (1999. These models are based on the distribution of latent variable N, number of initiated node cells. In this paper we proposed a Generalized Poisson-Lindely distribution that is another option instead of Negative Binomial distribution when there is overdispersion. The results indicated a better fitness compared to others, because of its more flexibility. Parameter estimation has been done by Bayesian approach, in a real data set and a simulation study has shown the advantages of proposed model. Normal 0 false false false /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Times New Roman"; mso-ansi-language:#0400; mso-fareast-language:#0400; mso-bidi-language:#0400;}

  5. Equilibria of Chinese Auctions

    DEFF Research Database (Denmark)

    Branzei, Simina; Forero, Clara; Larson, Kate

    for asymmetric games when some valuations are zero. In that case we prove that the auctioneer can stabilize the game by placing his own ticket in each basket. On the other hand, when all the valuations are strictly positive, a pure Nash equilibrium is guaranteed to exist, and the equilibrium strategies......Chinese auctions are a combination between a raffle and an auction and are held in practice at charity events or festivals. In a Chinese auction, multiple players compete for several items by buying tickets, which can be used to win the items. In front of each item there is a basket...... are symmetric when both valuations and budgets are symmetric. We also study Chinese auctions with discrete budgets, for which we give both existence results and counterexamples. While the literature on rent-seeking contests traditionally focuses on continuous costly tickets, the discrete variant is very natural...

  6. Ancient Chinese Landscape Architecture

    Institute of Scientific and Technical Information of China (English)

    1993-01-01

    IN the past decade,the worldhas suddenly discovered thewonders of Chinese landscapegardening and garden architecture,and places like New York,Singaporeand London have all built Chinese-style gardens.The architectural stylespecial to Chinese gardens has,infact,developed·a“school”of itsown.In China,the landscaped gardenhas long been a part of culture,andliterature,painting,philosophy,cal-ligraphy and folk customs have alldealt with it at one time or another.Two categories of garden architec-ture exist:the imperial garden andthe private garden.The former is,ofcourse,grand and palatial and occu-pies large tracts of land,while the

  7. Knowing Chinese character grammar.

    Science.gov (United States)

    Myers, James

    2016-02-01

    Chinese character structure has often been described as representing a kind of grammar, but the notion of character grammar has hardly been explored. Patterns in character element reduplication are particularly grammar-like, displaying discrete combinatoriality, binarity, phonology-like final prominence, and potentially the need for symbolic rules (X→XX). To test knowledge of these patterns, Chinese readers were asked to judge the acceptability of fake characters varying both in grammaticality (obeying or violating reduplication constraints) and in lexicality (of the reduplicative configurations). While lexical knowledge was important (lexicality improved acceptability and grammatical configurations were accepted more quickly when also lexical), grammatical knowledge was important as well, with grammaticality improving acceptability equally for lexical and nonlexical configurations. Acceptability was also higher for more frequent reduplicative elements, suggesting that the reduplicative configurations were decomposed. Chinese characters present an as-yet untapped resource for exploring fundamental questions about the nature of the human capacity for grammar.

  8. Concepts of Chinese Folk Happiness

    Science.gov (United States)

    Ip, Po Keung

    2011-01-01

    Discourses on Chinese folk happiness are often based on anecdotal narratives or qualitative analysis. Two traditional concepts of happiness popular in Chinese culture are introduced. The paper constructs a concept of Chinese folk happiness on basis of the findings of a scientific survey on the Taiwanese people regarding their concepts of…

  9. Chinese Colleges Need More Endowment

    Institute of Scientific and Technical Information of China (English)

    杨瑞

    2014-01-01

    In this paper I talk about the importance of increased college endowments. First I will introduce the limited financial situation of current Chinese colleges. Second, I will present an analysis on the financial reports of STU and Yale. Thirdly, I will describe the current Chinese College endowment situation. In conclusion I will present four suggestions for enhancing current Chinese college endowments.

  10. How Iconic Are Chinese Characters?

    Science.gov (United States)

    Luk, Gigi; Bialystok, Ellen

    2005-01-01

    The study explores the notion that some Chinese characters contain pictorial indications of meanings that can be used to help retrieve the referent. Thirty adults with no prior knowledge of Chinese guessed the meanings of twenty Chinese characters by choosing between one of two photographs. Half of the characters were considered to be iconic and…

  11. Directory of Chinese American Librarians.

    Science.gov (United States)

    Chinese American Librarians Association, River Forest, IL.

    This directory was compiled by the Chinese American Librarians Association based on replies to questionnaires sent to more than 500 Chinese American librarians in the United States and research based on secondary sources. Information provided on each person includes: name, name in Chinese, position/title, institution, institution's address, field…

  12. Chinese Contemporary Art: Ink Experiment

    Institute of Scientific and Technical Information of China (English)

    PiDaojian

    2003-01-01

    Chinese ink painting is an age-old art tradition that embodies distinctive characteristics of Chinese culture. In these exquisite paintings, artists integrate nature and everyday life to show how the two exist in harmonyalso a frequent theme in Chinese philosophy.

  13. In Situ Monitoring of UV-Curing Kinetics of Acrylate Coatings by Combined Ultrasound Reflectometry and Near-Infrared Spectroscopy

    OpenAIRE

    Agarwal, Suman

    2011-01-01

    UV radiation curing is a novel technology in the field of organic coatings. It involves curing of reactive resin using the energy of photons in the wavelength region 200-400 nm. The most attractive feature of this method is its low space, low capital and low energy consumption. Free radical polymerizable acrylate resins are the most commonly used resins in UV curing. The UV curable acrylates are mainly used as protective and decorative coatings. In general curing displays a complex interdepen...

  14. Chinese Literature,Anyone?

    Institute of Scientific and Technical Information of China (English)

    ALI; ALIZADEH

    2007-01-01

    Like many other ancient cultures,China possesses an impressive and celebrated literary heritage. The master poets of the medieval Tang Dynasty(618-907), for example, are rightfully known as some of the world’s best lyric poets; the adventures of the Monkey King and his company—as told in the classical Chinese narrative Journey to the West—have achieved a global following (in part due to TV adaptations and the like); and novels, short story collections and memoirs by expat Chinese authors living in the West have won major literary prizes and become international bestsellers.

  15. Polymerization and curing kinetics of furan resins under conventional and microwave heating

    Energy Technology Data Exchange (ETDEWEB)

    Lopez de Vergara, Unai, E-mail: bergara@gaiker.es [Plastics and Composites Department, Gaiker IK4 Research Centre, Parque Tecnológico, Ed. 202, 48170 Zamudio Spain (Spain); Mechanical Engineering and Industrial Manufacturing Department, Mondragón Unibertsitatea, Loramendi 4, 20500 Mondragón Spain (Spain); Sarrionandia, Mariasun [Mechanical Engineering and Industrial Manufacturing Department, Mondragón Unibertsitatea, Loramendi 4, 20500 Mondragón Spain (Spain); Gondra, Koldo [Plastics and Composites Department, Gaiker IK4 Research Centre, Parque Tecnológico, Ed. 202, 48170 Zamudio Spain (Spain); Aurrekoetxea, Jon [Mechanical Engineering and Industrial Manufacturing Department, Mondragón Unibertsitatea, Loramendi 4, 20500 Mondragón Spain (Spain)

    2014-04-01

    Graphical abstract: - Highlights: • The furan resin structure was investigated using IR and RMN techniques. • The polymerization of furan resins was developed based on multistage kinetics. • Vyazovkin numerical analysis was found the most accurate kinetic method. • Microwave curing of furan resins was much faster than thermal curing. - Abstract: The challenge of this work is the microwave curing study of low free-furfuryl alcohol content furan resins. The chemical characterization of the furan resins has been made by infrared spectroscopy and nuclear magnetic resonance spectroscopy. The chemical composition of the resin and its reactions with p-toluensulfonic acid are proposed, with the aim of understanding the mechanism responsible for the main reactions. The results show the presence of methyl and ether bridges between the furan rings, and the formation of ketone and conjugated structures. Furthermore, the curing kinetics of the furan resins has been characterized by differential scanning calorimetry. Different methods have been applied in order to obtain and compare the activation energy of the process. Vyazovkin numerical analysis was found the most accurate method. Finally, microwave and conventional curing processes has been compared. The analysis showed that microwave curing of furan resins was twice faster than thermal curing.

  16. Influence of Curing on the Strength Development of Calcium-Containing Geopolymer Mortar

    Directory of Open Access Journals (Sweden)

    Zhenzhen Jiao

    2013-11-01

    Full Text Available This paper investigated the curing effects on the mechanical properties of calcium-containing geopolymer mortar. Three precursors are used: Class C fly ash, Class F fly ash plus calcium hydroxide and Class F fly ash plus slag. Curing conditions included: (1 standard curing at 20 ± 3 °C and RH 95% (C; (2 steam curing at 60 °C for 24 h (S; (3 steam curing at 60 °C for 6 h (S6; and (4 oven curing at 60 °C for 24 h (O, then the latter three followed by the standard curing. Under the standard conditions, the flexural strength and compressive strength of Class C fly ash geopolymer mortars developed quickly until the age of 7 days, followed by a gradual increase. Specimens with Class F fly ash plus Ca(OH2 showed slow increase till the age of 28 days. Under these non-standard conditions (2–4, all specimens showed higher 3-day strength, while later strengths were either higher or lower than those in standard conditions, depending on the type of the precursor.

  17. Characteristics of an Extrusion Panel Made by Applying a Modified Curing Method

    Directory of Open Access Journals (Sweden)

    Haseog Kim

    2016-05-01

    Full Text Available CO2 emitted from building materials and the construction materials industry has reached about 67 million tons. Controls on the use of consumed fossil fuels and the reduction of emission gases are essential for the reduction of CO2 in the construction area as one reduces the second and third curing to emit CO2 in the construction materials industry. In this study, a new curing method was addressed by using a low energy curing admixture (LA in order to exclude autoclave curing. The new curing method was applied to make panels. Then, its physical properties, depending on the mixed amount of fiber, type of fiber and mixed ratio of fiber, were observed. The type of fiber did not appear to be a main factor that affected strength, while the LA mixing ratio and mixing amount of fiber appeared to be major factors affecting the strength. Applying the proposed new curing method can reduce carbon and restrain the use of fossil fuels through a reduction of the second and third curing processes, which emit CO2 in the construction materials industry. Therefore, it will be helpful to reduce global warming.

  18. Inorganic polymers from alkali activation of metakaolin: Effect of setting and curing on structure

    Energy Technology Data Exchange (ETDEWEB)

    Lancellotti, Isabella, E-mail: isabella.lancellotti@unimore.it [Deparment of Engineering “Enzo Ferrari”, University of Modena and Reggio Emilia, Via Vignolese 905/A, Modena I-41125 (Italy); Catauro, Michelina [Department of Aerospace and Mechanical Engineering, Second University of Naples, Via Roma 29, Aversa (CE) I-81031 (Italy); Ponzoni, Chiara [Deparment of Engineering “Enzo Ferrari”, University of Modena and Reggio Emilia, Via Vignolese 905/A, Modena I-41125 (Italy); Bollino, Flavia [Department of Aerospace and Mechanical Engineering, Second University of Naples, Via Roma 29, Aversa (CE) I-81031 (Italy); Leonelli, Cristina [Deparment of Engineering “Enzo Ferrari”, University of Modena and Reggio Emilia, Via Vignolese 905/A, Modena I-41125 (Italy)

    2013-04-15

    Geopolymers, obtained by chemical reaction between aluminosilicate oxides and silicates under highly alkaline conditions, are studied in this paper. The proposed mechanism of geopolymer setting and hardening or curing consists of a dissolution, a transportation or an orientation, as well as a polycondensation step. The aim of this paper is to investigate the influence of the curing time and temperature, the relative humidity and the reagents temperature on the geopolymerization process in order to obtain a resistant matrix usable for inertization of hazardous wastes. The evolution of the process from the precursors dissolution to final geopolymer matrix hardening has been followed by FTIR spectroscopy, X-ray diffractometry, SEM/EDS and leaching tests. The results show the significant influence of both curing temperature in the curing stage and of the mould materials on the matrix stability. The easy-to-run preparation procedure for a chemically stable metakaolin geopolymer individuated can be summarized as reagents setting and curing at room temperature and material mould which permits moisture level around 40%. - Graphical abstract: Chemical stability as a function of curing conditions. Highlights: ► Metakaolin in highly alkaline solutions produced solid materials at room temperature. ► Curing time and temperature, relative humidity, reagents temperature were optimized. ► Leaching tests were used to confirm final hardening. ► FTIR spectroscopy, SEM analysis and X-ray diffractometry were used to interpret matrix stability.

  19. A cure shrinkage model for analyzing the stresses and strains in encapsulated assemblies

    Energy Technology Data Exchange (ETDEWEB)

    Chambers, R.S.; Lagasse, R.R.; Guess, T.R. (Sandia National Labs., Albuquerque, NM (United States)); Plazek, D.J.; Bero, C. (Pittsburgh Univ., PA (United States). Dept. of Materials Science and Engineering)

    1992-01-01

    Electrical component assemblies are encapsulated to provide delicate parts with voltage isolation and protection against damage caused by shock, vibration, and harsh atmospheric environments. During cure, thermosetting resins shrink and harden simultaneously. If the natural deformation of the resin is constrained by adhesion to the mold or to relatively stiff embedded components, cure shrinkage stresses are generated in the encapsulant. Subsequent cooling or thermal cycling produces additional stresses that are caused by the mismatches in thermal strains among the materials in the encapsulated assembly. Although cure shrinkage stresses frequently are neglected because they are considerably smaller than thermal stresses, cure shrinkage stresses can cause delamination or fractures in the encapsulant, since the partially cured resin is not as tough as the fully cured material. Cracks generated during cure can compromise performance (e. g., permit dielectric breakdown), degrade a component's protection, and grow under subsequent thermal cycling producing residual stresses that differ from those found in uncracked assemblies. 3 refs., 11 figs.

  20. Isothermal curing of polymer layered silicate nanocomposites based upon epoxy resin by means of anionic homopolymerisation

    Energy Technology Data Exchange (ETDEWEB)

    Román, Frida, E-mail: roman@mmt.upc.edu; Calventus, Yolanda, E-mail: calventus@mmt.upc.edu; Colomer, Pere, E-mail: colomer@mmt.upc.edu; Hutchinson, John M., E-mail: hutchinson@mmt.upc.edu

    2013-12-20

    Highlights: • The nanocomposite with low content of clay displayed improved thermal properties. • The vitrification was observed in the isothermal curing. • Dielectric relaxations outside and inside of the clay galleries were detected. - Abstract: The use of an initiator, 4-(dimethylamino) pyridine (DMAP), to promote an anionic homopolymerisation reaction for the isothermal cure of polymer layered silicate (PLS) nanocomposites based on an epoxy resin, as well as the effect of the nanoclay content, have been studied by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), dielectric relaxation spectroscopy (DRS) and transmission electron microscopy (TEM). The vitrification phenomenon was observed during the isothermal cure process, and it was found that the nanocomposite with a low clay content (2 wt%), denoted EDM2, shows improved thermal properties with respect to the unreinforced resin (denoted ED), while the nanocomposite with a higher clay content (5 wt%), denoted EDM5, displayed inferior properties. The cure kinetics were analysed by different methods, and it was observed that the activation energy and kinetic parameters of EDM2 were lower compared to the other two systems. Examination of the nanostructure of the cured EDM2 nanocomposite showed partial exfoliation, while the EDM5 system retains an intercalated nanostructure. In the DRS studies of the curing process of the EDM2 system, two dielectric relaxations were detected, which are associated with the molecular mobility in the curing reaction which takes place both outside and inside the clay galleries.

  1. Correlation between the state of cure of thermosetting resins and their properties

    Energy Technology Data Exchange (ETDEWEB)

    Haffane, N.; Benameur, T.; Granger, R.; Vergnaud, J.M. [Faculty of Sciences, University of St Etienne (France)

    1996-01-01

    Thermosetting resins, in the same way as polymers, are more and more used for coating metal sheets, in order to bring various interesting properties. An important problem arises with the cure of the thermoset, the process of cure being complex with heating conduction and convection and the heat generated by the cure reaction. The kinetics of the heat evolved from the overall cure reaction is determined through calorimetry experiments in scanning mode. The state of cure at time t is expressed by the heat generated by reaction up to time t as a fraction of the total heat generated. A numerical model taking all the facts into account is able to evaluate the profile of the state of cure developed through the thickness of the thermoset. The state of cure which derives from a theoretical point of view is correlated with some properties of interest for the coating, such as the hardness and the resistance to liquids. The resistance to water and ethanol is evaluated by determining the kinetics of absorption which is controlled by diffusion. {copyright} {ital 1996 American Institute of Physics.}

  2. Influence of curing agents on gelation and exotherm behaviour of an unsaturated polyester resin

    Indian Academy of Sciences (India)

    Raghu Raja Pandiyan Kuppusamy; Swati Neogi

    2013-12-01

    A judicious choice of curing agents such as initiator and promoter and their ratio to the resin can avoid reduced gel-time and shortened exothermic reactions in applications such as liquid compositemoulding processes. In this study, effects of different ratio of initiator and promoter to the unsaturated polyester resin on curing of the resin were investigated by measuring gel-time and peak exotherm using ASTM D2471 standards. Methyl ethyl ketone peroxide (MEKP) was used as an initiator and a cobalt salt was employed as an accelerator for the free radical polymerization of curing resin at ambient temperatures. It was observed that the resin gelation starts closely with the initial rise in exotherm temperature and time of gelation decreases with the increase in initiator or accelerator volume proportions. It was also found that the exotherm-peak and rate of temperature rise indicating that the curing rate increases with the initiator or accelerator proportions also increased. A nonlinear regression analysis of all geltime and cure data were performed to quantify the dependence of curing parameters on the volume proportions of accelerator and initiator. Thus, for this polymerization initiation system, the gel-time and cure parameters can be predicted for any initiator and cobalt levels within the ranges studied.

  3. Photoacoustic study of curing time by UV laser radiation of a photoresin with different thickness

    Energy Technology Data Exchange (ETDEWEB)

    Pincel, P. Vieyra [UPIITA IPN, Avenida Instituto Politécnico Nacional, No. 2580, Col. Barrio la Laguna Ticomán, Delegación Gustavo A. Madero, C.P. 07340 México, D.F. (Mexico); Jiménez-Pérez, J.L., E-mail: jimenezp@fis.cinvestav.mx [UPIITA IPN, Avenida Instituto Politécnico Nacional, No. 2580, Col. Barrio la Laguna Ticomán, Delegación Gustavo A. Madero, C.P. 07340 México, D.F. (Mexico); Cruz-Orea, A. [Departamento de Física, CINVESTAV-IPN, Av. Instituto Politécnico Nacional 2508, Col. San Pedro Zacatenco, C.P. 07360 México, D.F. (Mexico); Correa-Pacheco, Z.N. [Instituto Politécnico Nacional-Centro de Desarrollo de Productos Bióticos (CEPROBI). Carr. Yautepec–Jojutla, km 6. San Isidro, C.P. 62730 Yautepec, Morelos (Mexico); Rosas, J. Hernández [UPIITA IPN, Avenida Instituto Politécnico Nacional, No. 2580, Col. Barrio la Laguna Ticomán, Delegación Gustavo A. Madero, C.P. 07340 México, D.F. (Mexico)

    2015-04-20

    Highlights: • The curing of a resin in the presence of a UV laser radiation was studied. • Open photoacoustic cell technique was used to characterize the curing of the resin. • The curing of the resin as a function of time was studied. • A parabolic behavior of the resin thickness, as a function of time was observed. • UV–vis and FTIR spectroscopy were employed to characterize the resin. - Abstract: This paper deals with the study of the cure of a resin in the presence of a UV laser radiation used as the excitation source, operated at λ = 405 nm, with an output power of 20 mW. The open photoacoustic cell (OPC) technique was used to study the curing of the resins as a function of time. The curing characteristic time values were τ = 10.43, 20.99, 30.18, 45.84, 67.59 and 89.55 s for the resin thicknesses of 1000, 2000, 3000, 4000, 5000 and 6000 μm, respectively. A parabolic behavior of the resin thickness, as a function of the curing characteristic time, was obtained. UV–vis spectroscopy and infrared Fourier transform spectroscopy (FTIR) techniques were employed to characterize the resin in order to study the optical absorption and the chemical bonds, respectively. Our work has applications in the manufacture of 3D printing parts for applications, among others, in medicine.

  4. An Optimal Cure Process to Minimize Residual Void and Optical Birefringence for a LED Silicone Encapsulant

    Directory of Open Access Journals (Sweden)

    Min-Jae Song

    2014-05-01

    Full Text Available Silicone resin has recently attracted great attention as a high-power Light Emitting Diode (LED encapsulant material due to its good thermal stability and optical properties. In general, the abrupt curing reaction of the silicone resin for the LED encapsulant during the curing process induces reduction in the mechanical and optical properties of the LED product due to the generation of residual void and moisture, birefringence, and residual stress in the final formation. In order to prevent such an abrupt curing reaction, the reduction of residual void and birefringence of the silicone resin was observed through experimentation by introducing the multi-step cure processes, while the residual stress was calculated by conducting finite element analysis that coupled the heat of cure reaction and cure shrinkage. The results of experiment and analysis showed that it was during the three-step curing process that the residual void, birefringence, and residual stress reduced the most in similar tendency. Through such experimentation and finite element analysis, the study was able to confirm that the optimization of the LED encapsulant packaging process was possible.

  5. The Effect of Using Modified Flask on the Porosity of Processed Heat- Cure Acrylic Resin

    Directory of Open Access Journals (Sweden)

    Mohammed T. Al-Khafagy

    2013-04-01

    Full Text Available Porosity is an important property of acrylic resin material because it affect other properties like strength, esthetic and cause bacterial or fungal growth lead to unhealthy dentures. This paper Study the possibility of reducing the porosity of heat- cure acrylic resin by making a modification in the flask of processing .The processing flask was modified by constructing a tongue like projection fixed to the upper half of the flask in order to spread the high temperature occurred in the center of the muffle. In the this research; forty lower denture base with bite rim samples were prepared from heat-cure acrylic resin denture base. The study include 4 testing groups depending on the type of curing cycle and using of ordinary traditional and modified flask in curing process, each group contain 10 samples. One way ANOVA with Tukey's test between tested groups in regarding the type of flasking and curing cycle are indicated, the results revealed a significant difference at (P=0.05 when compare between group 2(I.I.O.Fand 3(S.C.M.F and between group2and 4(S.C.O.F, and also between group 3and 4. While there was a non significant differences between group 1,2 and1,3 and finally between group1and4. Less Porosity was observed in the group of samples that cured with slow curing cycle in modified flask when compare with other groups.

  6. Electron beam curing of acrylated epoxy resins for anisotropic conductive film application

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Tae gyu; Lee, Inhyuk; Lee, Jungmin [Department of Physics and Institute of Nanoscience and Nanotechnology, Hanyang University, Seoul, 133-791 (Korea, Republic of); Hwang, Jinyoung; Chung, Hoeil [Department of Chemistry, Hanyang University, Seoul, 133-791 (Korea, Republic of); Shin, Kwanwoo [Department of Chemistry and Interdisciplinary Program of Integrated Biotechnology, Institute of Biological Interfaces, Sogang University, Seoul 121-742 (Korea, Republic of); Seo, Young soo [Department of Nanoscience Technology, Sejong University, Seoul, 143-747 (Korea, Republic of); Kim, Jaeyong, E-mail: kimjy@hanyang.ac.kr [Department of Physics and Institute of Nanoscience and Nanotechnology, Hanyang University, Seoul, 133-791 (Korea, Republic of)

    2013-11-29

    Radiation curable acrylated epoxy oligomer was found to be an effective resin system for application to electron beams (EB) on curing of anisotropic conducting film. To study curing degree as a function of EB dosage, we irradiated bisphenol-A type acrylate epoxy oligomer samples with doses of 5 to 600 kGy of EB. To investigate the effect of a metal barrier for potential industrial application, a 3 mm thick Al plate was placed in front of the samples, and the curing parameters were compared with the ones irradiated without an Al plate. As the dosage of the EB irradiation was increased, the glass transition temperature of the sample ranged from 46.8 to 62.2 °C for the epoxy composites without placing an Al plate, and from 46.4 to 64.1 °C for their counterparts with a 3 mm thick Al plate. These results confirm that enhancement of the curing degree with increasing EB irradiation is possible even in the presence of a metal plate. The scanning electron microscope images of the fracture surfaces are presented as evidence of the morphological changes of the EB cured epoxy samples. - Highlights: ► Acrylated epoxy oligomer was cured by irradiation of the electron beam. ► Curing degree was increased with increasing dosage of the electron beam. ► Electron beam can be used for the bonding of anisotropic conducting films.

  7. Efficient composite fabrication using electron-beam rapidly cured polymers engineered for several manufacturing processes

    Energy Technology Data Exchange (ETDEWEB)

    Walton, T.C. [Aeroplas Corp. International, Nashua, NH (United States); Crivello, J.V. [Rensselaer Polytechnic Inst., Troy, NY (United States). Dept. of Chemistry

    1995-10-01

    Low cost, efficiently processed ultra high specific strength and stiffness graphite fiber reinforced polymeric composite materials are of great interest to commercial transportation, construction and aerospace industries for use in various components with enhanced degrees of weight reduction, corrosion/erosion resistance and fatigue resistance. 10 MeV Electron Beam cure processing has been found to increase the cure rate by an order of magnitude over thermally cured systems yet provide less molded in stresses and high T{sub g}s. However, a limited range of resins are available which are easily processed with low shrinkage and with performance properties equal or exceeding those of state of the art toughened epoxies and BMI`s. The technology, introduced by an academia-industry partnership sparked by Langley Research Center utilizes a cost effective, rapid curing polymeric composite processing technique which effectively reduces the need for expensive tooling and energy inefficient autoclave processing and can cure the laminate in seconds (compared to hours for thermal curing) in ambient or sub-ambient conditions. The process is based on electron beam (E-Beam) curing of a new series of (65 to 1,000,000 cPs.) specially formulated resins that have been shown to exhibit excellent mechanical and physical properties once cured. Fabrication processes utilizing these specially formulated and newly commercialized resins, (e.g. including Vacuum Assist Resin Transfer molding (VARTM), vacuum bag prepreg layup, pultrusion and filament winding grades) are engineered to cure with low shrinkage, provide excellent mechanical properties, be processed solventless (environmentally friendly) and are inherently non toxic.

  8. Physical properties of self-, dual-, and light-cured direct core materials.

    Science.gov (United States)

    Rüttermann, Stefan; Alberts, Ian; Raab, Wolfgang H M; Janda, Ralf R

    2011-08-01

    The objective of this study is to evaluate flexural strength, flexural modulus, compressive strength, curing temperature, curing depth, volumetric shrinkage, water sorption, and hygroscopic expansion of two self-, three dual-, and three light-curing resin-based core materials. Flexural strength and water sorption were measured according to ISO 4049, flexural modulus, compressive strength, curing temperature, and curing depth according to well-proven, literature-known methods, and the volumetric behavior was determined by the Archimedes' principle. ANOVA was calculated to find differences between the materials' properties, and correlation of water sorption and hygroscopic expansion was analysed according to Pearson (p < 0.05). Clearfil Photo Core demonstrated the highest flexural strength (125 ± 12 MPa) and curing depth (15.2 ± 0.1 mm) and had the highest flexural modulus (≈12.6 ± 1.2 GPa) concertedly with Multicore HB. The best compressive strength was measured for Voco Rebilda SC and Clearfil DC Core Auto (≈260 ± 10 MPa). Encore SuperCure Contrast had the lowest water sorption (11.8 ± 3.3 µg mm(-3)) and hygroscopic expansion (0.0 ± 0.2 vol.%). Clearfil Photo Core and Encore SuperCure Contrast demonstrated the lowest shrinkage (≈2.1 ± 0.1 vol.%). Water sorption and hygroscopic expansion had a very strong positive correlation. The investigated core materials significantly differed in the tested properties. The performance of the materials depended on their formulation, as well as on the respective curing process.

  9. Evaluation of microleakage in hybrid composite restoration with different intermediate layers and curing cycles

    Directory of Open Access Journals (Sweden)

    Mohan R Sakri

    2016-01-01

    Full Text Available Objective: To evaluate the impact of bulk or incremental curing of hybrid composite resin with different intermediate layers on interfacial microleakage. Materials and Methods: The recently extracted, sixty noncarious human mandibular molars were selected for the study. The standardized mesio-occluso-distal cavity with the occlusal cavity of 2 mm depth, 3 mm buccolingual width and proximal box dimension of 4 mm buccolingual width and 2 mm depth was prepared on all experimental teeth. The samples were divided into six groups of ten each. Group I was without an intermediate layer. Group II and III had 1 mm flowable composite liner, with incremental and bulk curing cycle, respectively. The Group IV, V, and VI had a self-cure composite liner with incremental and bulk curing. The teeth subjected to thermocycling and kept in 0.5% basic fuchsine dye for 24 h. The teeth were sectioned and observed under a stereomicroscope to grade them according to the extent of microleakage. The obtained data were statistically analyzed with Kruskal–Wallis and post hoc comparison test to understand the difference between the groups. Results: The Group II with flowable composite along incremental curing showed the least microleakage at both enamel (0.30 and cementum surface (0.50. The groups with self-cure composite liner were less effective than flowable composite. The microleakage at the enamel interface was less compared cementum interface across the groups. The groups with bulk curing were more prone to microleakage than incremental curing cycle. Conclusions: Within the limitation of the study, it was concluded that intermediate flowable composite with incremental curing was better suited to reduce microleakage.

  10. Influence of polymerization mode and C-factor on cohesive strength of dual-cured resin cements

    NARCIS (Netherlands)

    Jongsma, L.A.; Kleverlaan, C.J.; Pallav, P.; Feilzer, A.J.

    2012-01-01

    Objectives The aim of this study is to determine the influence of the C-factor and the mode of polymerization on the cohesive strength of various dual-cure resin cements. Methods Three curing conditions were tested; chemical curing with free shrinkage conditions (C = 0), and constraint shrinkage con

  11. Should we welcome a cure for autism? A survey of the arguments.

    Science.gov (United States)

    Barnes, R Eric; McCabe, Helen

    2012-08-01

    Substantial research efforts have been devoted to developing a cure for autism, but some advocates of people with autism claim that these efforts are misguided and even harmful. They claim that there is nothing wrong with people with autism, so there is nothing to cure. Others argue that autism is a serious and debilitating disorder and that a cure for autism would be a wonderful medical breakthrough. Our goal in this essay is to evaluate what assumptions underlie each of these positions. We evaluate the arguments made on each side, reject those that are implausible and then highlight the key assumptions of those that remain.

  12. Interfacial Interaction of Oxidatively Cured Hydrogen Silsesquioxane Spin-On-Glass Enamel with Stainless Steel Substrate

    DEFF Research Database (Denmark)

    Lampert, Felix; Kadkhodazadeh, Shima; Jensen, Annemette H.

    2017-01-01

    Thin film silica coatings have proven to be efficient barrier coatings to protect stainless steels from corrosion in aggressive environments. The deposition of sub-μm silica films from liquid hydrogen silsesquioxane precursor has previously been demonstrated on metallic substrates, whereby...... films were deposited on 316L grade austenitic stainless steel and oxidatively cured at 450◦C in ambient air. Oxidative curing yielded well adherent films which solely showed microscopic delamination after standardized adherence testing. Further, the oxidative curing led to the formation of a pronounced...

  13. ULTRASONIC BEHAVIOR OF EPOXY RESINS/POLY (ETHYLENE OXIDE)BLENDS CURED WITH PHTHALIC ANHYDRIDE

    Institute of Scientific and Technical Information of China (English)

    ZHENG Sixun; WANG Haiqian; LUO Xiaolie; ZHANG Naibin; MA Dezhu; ZHU Changfei; HU Jiankai

    1995-01-01

    By means of ultrasonic attenuation apparatus, the ultrasonic velocity and attenuation of anhydride-cured epoxy resins (EP)/poly(ethylene oxide)(PEO)blends were measured on the basis of pulse-echo method. It was found that the sonic velocity of the blends decreased as the temperature increased, but attenuation coefficient increased and possessed a peak value. Larger velocity and smaller attenuation coefficient(α)can be obtained from perfect crosslinking network structures of pure DGEBA cured with phthalic anhydride (PA). As for cured DGEBA/PEO blend systems,sonic velocity decreased as a function of PEO concentration,but attenuation coefficient (α) increased.

  14. Long-term effects of intragastric instillations of Sylgard 184 curing agent

    Energy Technology Data Exchange (ETDEWEB)

    Smith, D.M.; Drake, G.A.; London, J.E.

    1981-12-01

    Young male Sprague-Dawley rats (105 days old) were given a single dose (5 g/kg body weight (BW)) of Sylgard 184 curing agent intragastrically (IG), and young female Swiss-Webster mice (86 days old) were given a single dose (5 g/kg BW) IG, or a dose (1 g/kg BW) IG on each of 5 consecutive days, of Sylgard 184 curing agent. All animals were then maintained for the rest of their lives and autopsied at death. No significant effects were seen in any of the rats or mice receiving the Sylgard 184 curing agent compared to control animals.

  15. Curing mechanism of furan resin modified with different agents and their thermal strength

    Directory of Open Access Journals (Sweden)

    Huang Renhe

    2011-05-01

    Full Text Available The curing mechanism of furfuryl alcohol and urea-formaldehyde furan resins was investigated using infrared spectroscopy (IR technique. The curing productions of urea-formaldehyde furan resins modified with different agents (i.e. sorbitol, polyester polyol, phenol and acetone and the productions of incomplete curing were characterized by differential thermal analysis (DTA and thermal gravity analysis (TG. The results indicate that except for polyester polyol, the other modifiers have little effect on the thermal strength of urea-formaldehyde furan resin. Furthermore, the thermal strength can be improved at a temperature of higher than 550℃.

  16. Part of the Disease Or Part of the Cure? Chinese Investments in the Zambian Mining and Construction Sectors

    DEFF Research Database (Denmark)

    Kragelund, Peter

    2009-01-01

    China's role in African development is much debated among academics as well as among private sector organisations, trade unions and politicians. Notwithstanding the recent upsurge of interest, the lion's share of the current studies on ‘China in Africa’ is still based on a combination of aggregate...

  17. Optimal depth of cure for nanohybrid resin composite using quartz tungsten halogen and new high intensity light-emitting diode curing units.

    Science.gov (United States)

    Tanthanuch, Saijai; Ruengsri, Prapansri; Kukiattrakoon, Boonlert

    2013-08-01

    This study sought to evaluate the effects of quartz tungsten halogen (QTH) and light-emitting diode (LED) photocuring units on the degree of conversion (DC) and surface microhardness of a resin composite that had been cured for optimal depth of cure (DoC) assessment. Two hundred and forty cylindrical specimens (4.0 mm in diameter, 2.0-4.0 mm thick) of shade A2 resin composite were prepared and cured with either a QTH or an LED. The DC and top and bottom surface hardness were recorded, and data were analyzed using 2-way ANOVA, Tukey's test, t-test (α = 0.05) and linear regression analysis. The results showed that surface microhardness values and DC were affected by light intensity (P resin composite thickness (2, 3, and 4 mm) (P Resin composite polymerized by the QTH had an optimal DoC of 3 mm, compared to 4 mm for the LED.

  18. Silencing Huntington's chorea: Is RNA Interference a Potential Cure?

    Directory of Open Access Journals (Sweden)

    Gerlinde A. Metz

    2006-01-01

    Full Text Available In 1872, George Huntington described Huntington's disease as characterized by motor, cognitive and psychiatric impairments. Huntington's disease is a dominant and autosomal mutation on chromosome 4 featuring the insertion of numerous CAG repeats. CAG codes for the amino acid, glutmanine that forms part of the Huntingtin protein (htt. Excess glutamine attachments make htt prone to accumulate in neurons. Three genes can be considered when developing therapies for Huntington's disease. They include targeting the symptoms of the disease, the progression of the disease and the cause of the disease. By using RNA interference (RNAi, the cause of the disease can be targeted. RNAi is a method that could potentially silence the formation of abnormal htt. This paper will discuss how RNAi could potentially cure Huntington's disease, by describing the genetic and proteinomic basis of Huntington's disease, the function of RNAi in Huntington's disease and the problems of benefits of RNAi. Preliminary work using RNAi in transgenic mice has shown a decrease in the behavioural expression of the mutant Huntington gene. There are several limitations associated with using RNAi as a gene therapy. For example, the effects of RNAi are short lived. A transposition system such as Sleeping Beauty can be used to increase the integration of the gene, however, for patients who currently have Huntington's disease, RNAi may potentially be used in combination with drugs or other treatments to target both symptoms and the underlying cause of Huntington's disease. This combination could eventually alleviate many painful symptoms associated with Huntington's disease and could even stop the progressive neurodegeneration of Huntington's disease. This review concludes that a substantial amount of new research is still necessary before RNAi is directly applicable to human patients with Huntington's disease.

  19. Levofloxacin cures experimental pneumonic plague in African green monkeys.

    Directory of Open Access Journals (Sweden)

    Robert Colby Layton

    Full Text Available BACKGROUND: Yersinia pestis, the agent of plague, is considered a potential bioweapon due to rapid lethality when delivered as an aerosol. Levofloxacin was tested for primary pneumonic plague treatment in a nonhuman primate model mimicking human disease. METHODS AND RESULTS: Twenty-four African Green monkeys (AGMs, Chlorocebus aethiops were challenged via head-only aerosol inhalation with 3-145 (mean = 65 50% lethal (LD(50 doses of Y. pestis strain CO92. Telemetered body temperature >39 °C initiated intravenous infusions to seven 5% dextrose controls or 17 levofloxacin treated animals. Levofloxacin was administered as a "humanized" dose regimen of alternating 8 mg/kg and 2 mg/kg 30-min infusions every 24-h, continuing until animal death or 20 total infusions, followed by 14 days of observation. Fever appeared at 53-165 h and radiographs found multilobar pneumonia in all exposed animals. All control animals died of severe pneumonic plague within five days of aerosol exposure. All 16 animals infused with levofloxacin for 10 days survived. Levofloxacin treatment abolished bacteremia within 24 h in animals with confirmed pre-infusion bacteremia, and reduced tachypnea and leukocytosis but not fever during the first 2 days of infusions. CONCLUSION: Levofloxacin cures established pneumonic plague when treatment is initiated after the onset of fever in the lethal aerosol-challenged AGM nonhuman primate model, and can be considered for treatment of other forms of plague. Levofloxacin may also be considered for primary presumptive-use, multi-agent antibiotic in bioterrorism events prior to identification of the pathogen.

  20. Bacillus vanillea sp. nov., Isolated from the Cured Vanilla Bean.

    Science.gov (United States)

    Chen, Yong-gan; Gu, Feng-lin; Li, Ji-hua; Xu, Fei; He, Shu-zhen; Fang, Yi-ming

    2015-02-01

    A Gram-positive bacterium, designated strain XY18(T), was isolated from a cured vanilla bean in Hainan province, China. Cells were rod-shaped, endospore producing, and peritrichous flagella. Strain XY18(T) grew at salinities of 0-8 % (w/v) NaCl (optimally 1-4 %), pH 4.0-8.0 (optimally 5.0-7.0 %) and temperature range 20-45 °C (optimally 28-35 °C). The predominant menaquinone was MK-7. The major cellular fatty acids were anteiso-C15:0, iso-C15:0, anteiso-C17:0, and iso-C17:0. Phylogenetic analysis based on 16S rRNA gene sequence indicated that strain XY18(T) was a member of the genus Bacillus, and closely related to B. amyloliquefaciens NBRC 15535(T) and B. siamensis PD-A10(T), with 99.1 and 99.2 % sequence similarity, respectively. However, the DNA-DNA hybridization value between strain XY18(T) and B. amyloliquefaciens NBRC 15535(T) was 35.7 %. The genomic DNA G+C content of strain XY18(T) was 46.4 mol%, significantly differed from B. siamensis PD-A10(T) (41.4 %), which was higher than the range of 4 % indicative of species. On the basis of polyphasic taxonomic study, including phenotypic features, chemotaxonomy, and phylogenetic analyses, strain XY18(T) represents a novel species within the genus Bacillus, for which the name Bacillus vanillea sp. nov. is proposed. The type strain is XY18(T) (=CGMCC 8629 = NCCB 100507).

  1. MICROBIOLOGICAL EVOLUTION OF DACIA SAUSAGE, A DRY CURED ROMANIAN SAUSAGE

    Directory of Open Access Journals (Sweden)

    Ana Maria Simion Ciuciu

    2011-09-01

    Full Text Available Selected starter cultures were used to produce the traditional Romanian dry cured sausage, Dacia. A control sausage was produced without starter culture (sausage A, one with L. sakei CECT 5964 and S. equorum SA25 (sausage B and one with L. sakei CECT 5964, S. equorum SA25 and L. acidophilus CECT 903 (sausage C. Samples from each batch of sausages were taken at 0 (mix before stuffing, and after 2, 4, 7, 14, 21 and 28 days of ripening. Counts of total aerobic mesophilic flora, lactic acid bacteria, salt tolerant flora, and Enterobacteriaceae and some physical-chemical parameters (moisture, NaCl, pH and aw values were determined. High microbial counts (log CFU were observed with values at the end of ripening period: for lactic acid bacteria 9.77 (A, 11.47 (B and 11.19 (C; for total aerobic mesophilic flora 9.89 (A, 11.38 (B and 11.30 (C; for salt tolerant flora 4.45 (A, 5.31 (B and 5.27 (C. The starter cultures had a significant inhibitory effect on Enterobacteriaceae counts (log CFU, values at the end of ripening period being 1.32 (A, 0.33 (B and not detected (C. A significant decrease in the pH values is observed until the seventh day of ripening, showing a slight, but progressive increase after the 14th day of ripening. Results show that the production and ripening process in a pilot scale chamber under controlled conditions contributes in obtaining safe and homogeneous products.

  2. Modelling Chinese Smart Grid

    DEFF Research Database (Denmark)

    Yuksel, Ender; Nielson, Hanne Riis; Nielson, Flemming

    In this document, we consider a specific Chinese Smart Grid implementation and try to address the verification problem for certain quantitative properties including performance and battery consumption. We employ stochastic model checking approach and present our modelling and analysis study using...

  3. Chinese Commercial Negotiating Style.

    Science.gov (United States)

    1982-01-01

    the importance of whatever activities they are a part of-a form of Sinocentrism --and relations among all others belong to the periphery of the Chinese...Siemens, 22 73-74 "Silent Treatment," 68-69 Trade agreements, 4. See a/so Singapore, 32 Agreements; Compensatory Sinocentrism , 86 trade I----- Index / 105

  4. About Chinese Characters

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Some Chinese characters refer to natural phenomena andsubstances, such as "雨" yu (rain), "云" yun (clouds), "雪" xue (snow),"电" dian (lightning) and "雷" lei (thunder). The original form of "雨"was"(?)," in which"(?)" represents the cloud layer, and"(?)"symbolizes rain drops.

  5. Targeting the Chinese Consumer

    Institute of Scientific and Technical Information of China (English)

    MICHAEL O'NEILL

    2006-01-01

    @@ China's consumer markets have developed an almost mythic status in recent years; the Holy Grail for Western retailers and manufacturers desperate to carve a position in a market of such huge dimensions. But understanding the Chinese consumer is no easy task,as many overseas companies have found to their peril.

  6. Chinese Entrepreneurs Go Global

    Directory of Open Access Journals (Sweden)

    Daniel Zhou

    2012-02-01

    Full Text Available China may be on the tipping point of explosive global growth. In response to changes in the global economy and an economic slowdown domestically, hundreds of thousands of Chinese SMEs are being encouraged to “go global” by their central and local governments. To a Chinese company, going global requires the expansion of its existing business in other countries or the development of new ventures with partners operating in other countries. Explosive growth in China may be possible, but it will depend on an appropriate strategy for going global. For a country that has firmly established itself as an international manufacturing hub, going global requires a shift in its entrepreneurial capacity, which is the focus of this article. We first assess the current situation in China to understand its current entrepreneurial focus and capacity, as well as the impetus for change. Next, we contrast the Kirznerian and Schumpeterian views of entrepreneurship to illustrate that – to go global – Chinese entrepreneurs must shift from an emphasis on exploiting pricing inefficiencies (i.e., Kirznerian entrepreneurship to an emphasis on innovation (i.e., Schumpeterian entrepreneurship. Finally, we examine unique characteristics of the business environment and culture in China, which are likely to impact the ability of Chinese entrepreneurs to go global.

  7. Milestone for Chinese physicists

    CERN Multimedia

    2003-01-01

    Chinese scientists have discovered a new particle predicted decades ago but never observed before. It could be what was once called the "multi-quark state," tiny elementary particles with a strong interaction or force that serves as the source of nuclear energy (1/2 page).

  8. FROM THE CHINESE PRESS

    Institute of Scientific and Technical Information of China (English)

    1998-01-01

    China Plans to Stabilize Population Growth by the ’30s of the Next Century On November 19, 1997, China’s State Councilor, Song Jian, revealed that China should be able to achieve control of population growth about thirty years into the next century, when the Chinese population reaches 1.5 to 1.6 billion.

  9. Chinese court case fiction

    DEFF Research Database (Denmark)

    Hansen, Kim Toft

    2011-01-01

    established as early as the 6th Century AD, whereas the first substantial evidence of the tradition is from 13th Century and the first Chinese crime fiction novels were written during the 17th Century. This article is, then, a corrective for the international history of crime fiction based on numerous...

  10. Why I Learn Chinese

    Institute of Scientific and Technical Information of China (English)

    Benedicte; Corbiere

    2013-01-01

    <正>Even today, I still ask myself why I am so fascinated with Chinese language, history, culture, films, photos and economic development. My interest in China was not a spur-of-the-moment move; instead, all sorts of lucky chances since my childhood made me irresistibly interested in this great and impressive country. I was born in

  11. FROM THE CHINESE PRESS

    Institute of Scientific and Technical Information of China (English)

    1996-01-01

    Li Yiyi, an academician with the Chinese Academy of Sciences and director of Shenyang Metal Research Institute, has developed a new system for creating a low temperature and high pressure anti-hydrogen material in the research of engineering material. She has also been successful in her research of various types of steel.

  12. Chinese Students' Constructive Nationalism

    Science.gov (United States)

    Bell, Daniel A.

    2008-01-01

    Last June the author, a teacher of political theory at Tsinghua University, was asked by a Canadian television crew to get hold of some students for a special on modern China. During the discussion, the author observed that his Chinese students express a thoughtful and informed nationalism, and a distrust of Western-style democracy. Some of the…

  13. FROM THE CHINESE PRESS

    Institute of Scientific and Technical Information of China (English)

    1995-01-01

    The Chinese Ethnic Park, divided into two parts, occupies 45 hectares. The northern section, which opened first, occupies 20 hectares, featuring 16 ethnic villages where people can enjoy indigenous music and dance. About 200 performers working in the village represent a number of minority nationalities. Their performances are based on local custom, and mostly comprise greeting and bidding

  14. Chinese Borrowings in English

    Institute of Scientific and Technical Information of China (English)

    JU Li-li

    2014-01-01

    There are eight types of English word formation, which are widely used nowadays in English. Among them, Borrowings, as one of widely used types of English word formation, has drawn people's attention because many English words are borrowed from other languages, such as German, Latin. This article aims to demonstrate Chinese Borrowings in English from two aspects.

  15. Chinese Lacquer Art

    Institute of Scientific and Technical Information of China (English)

    ChengXiangjun

    2003-01-01

    Over the sweep of Chinese longstanding history,numerous treasures and heritages have been left over,among which the lacquer art is a brilliant one.China is the earliest country in the world using natural lacquer,In the early 1970s,archeologists unearthed a red lacquer wood bowl in an excavation in the

  16. Chinese Workers' Real Demand

    Institute of Scientific and Technical Information of China (English)

    Li Zhen

    2010-01-01

    @@ A new generation different from their elders Cheap labor has built Chinas economic miracle.As China's economy has bounced back,wages have followed suit.But,for the new generation of Chinese migrant workers,wages are not enough to meet their needs.

  17. Chinese Decorative Coatings Market

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    @@ Growth prospects The Chinese market for decorative coatings, excluding non-architectural products such as industrial varnishes,marine paint and other industrially applied coatings, has been growing byaround 10% annually and was estimated to be worth Eurol.3 billion a year, with an annual per capita consumption of just less than 1 liter ofpaint.

  18. SWOT analysis - Chinese Petroleum

    OpenAIRE

    Chunlan Wang; Lei Zhang; Qi Zhong

    2014-01-01

    This article was written in early December 2013, combined with the historical development and the latest data on the Chinese Petroleum carried SWOTanalysis. This paper discusses corporate resources, cost, management and external factors such as the political environment and the market supply and demand, conducted a comprehensive and profound analysis.

  19. Estimating and modelling cure in population-based cancer studies within the framework of flexible parametric survival models

    Directory of Open Access Journals (Sweden)

    Eloranta Sandra

    2011-06-01

    Full Text Available Abstract Background When the mortality among a cancer patient group returns to the same level as in the general population, that is, the patients no longer experience excess mortality, the patients still alive are considered "statistically cured". Cure models can be used to estimate the cure proportion as well as the survival function of the "uncured". One limitation of parametric cure models is that the functional form of the survival of the "uncured" has to be specified. It can sometimes be hard to find a survival function flexible enough to fit the observed data, for example, when there is high excess hazard within a few months from diagnosis, which is common among older age groups. This has led to the exclusion of older age groups in population-based cancer studies using cure models. Methods Here we have extended the flexible parametric survival model to incorporate cure as a special case to estimate the cure proportion and the survival of the "uncured". Flexible parametric survival models use splines to model the underlying hazard function, and therefore no parametric distribution has to be specified. Results We have compared the fit from standard cure models to our flexible cure model, using data on colon cancer patients in Finland. This new method gives similar results to a standard cure model, when it is reliable, and better fit when the standard cure model gives biased estimates. Conclusions Cure models within the framework of flexible parametric models enables cure modelling when standard models give biased estimates. These flexible cure models enable inclusion of older age groups and can give stage-specific estimates, which is not always possible from parametric cure models.

  20. 固化条件对热塑增韧环氧树脂的固化动力学和相分离的影响%Cure Kinetics and Phase Separation of Thermoplastic Toughened Epoxies Influenced by Curing Conditions

    Institute of Scientific and Technical Information of China (English)

    ZHANG Jin; Bronwyn Fox

    2008-01-01

    Thermoplastic toughened epoxy resins are widely used as matrices in modern prepreg systems.Different curing conditions play a great role in affecting the cure kinetics and phase behaviour of thermoplastic modified epoxies which further result in different mechanical properties of polymer matrix composites.Since the morphology of the cured thermoplastic/epoxy blends is directly related to the mechanical properties,it is essential to control processing conditions for obtaining desirable morphology.A polyethersulphone (PES) modified multifunctional epoxies,triglycidylaminophenol (TGAP) and tetraglycidyldiaminodiphenylmethane (TGDDM),was used for investigation.The cure kinetics and cured morphology of polymer blends heated at different heating rates and cured at different temperature were studied.It is shown that higher cure temperature and higher heating rate display similar effects in the epoxy conversion and the domain size of phase separated structure.

  1. STUDY ON PROPERTIES OF CURED COMPOUND IN CYANATE EATER AND EPOXY CO-CURING SYSTEM%环氧树脂与氰酸酯共固化产物性能的研究

    Institute of Scientific and Technical Information of China (English)

    陈平; 程子霞; 金镇镐; 雷清泉

    2001-01-01

    The influence of composition on the curing kinetic parameter,electrical,mechanical,thermal properties and the glass transition temperature of cured compound of epoxy and cyanate ester co-curing system catalyzed by transition metal acetylacetone was studied by means of DSC,dielectric and dynamic mechanical methods in this paper.The results showed that the reactive energy and frequency factor of co-curing is found to increase with enhanced concentrations of cyanate ester of co-curing system.The glass transition temperature and thermal stability of cyanate ester and epoxy cured system is found to increase with enhanced concentrations of the cyanate ester under the same cured condition,addition of the cyanate ester will decrease the loss factor and dielectrical constant value as well.

  2. Influence of the Light Source and Curing Parameters on Microhardness of a Silorane-Based Dental Composite Material

    OpenAIRE

    Malara P.; Czech Z.; Świderski W.

    2016-01-01

    The aim of the study was to determine the influence of the light source and the light-curing parameters (the distance of the material from the light source and time of light-curing) on microhardness of Flitek Silorane dental composite material. Standardized samples of Filtek Silorane material were cured using two types of Light Curing Units (LCUs) – halogen and LED. The distance of the light source and time of curing differed between samples. The Knoop’s microhardness was tested using microha...

  3. Experimental Study of Monitoring and Controlling of Composite Cure Process in Autoclave Featured with Fiber Optic Sensor

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    With the aid of the latest fiber optic sensing technology, parameters in the cure process of thermosetting resin-matrix composite, such as temperature, viscosity, void and residual stress, can be monitored entirely and efficiently. In this paper, experiment results of viscosity measurement in composite cure process in autoclave using fiber optic sensors are presented. Based on the sensed information, a computer program is utilized to control the cure process. With this technology,the cure process becomes more apparent and controllable, which will greatly improve the cured products and reduce the cost.

  4. Application of addition-cured silicone denture relining materials to adjust mouthguards.

    Science.gov (United States)

    Fukasawa, Shintaro; Churei, Hiroshi; Chowdhury, Ruman Uddin; Shirako, Takahiro; Shahrin, Sharika; Shrestha, Abhishekhi; Wada, Takahiro; Uo, Motohiro; Takahashi, Hidekazu; Ueno, Toshiaki

    2016-01-01

    The purposes of this study were to examine the shock absorption capability of addition-cured silicone denture relining materials and the bonding strength of addition-cured silicone denture relining materials and a commercial mouthguard material to determine its applicability to mouthguard adjustment. Two addition-cured silicone denture relining materials and eleven commercial mouthguard materials were selected as test materials. The impact test was applied by a free-falling steel ball. On the other hand, bonding strength was determined by a delamination test. After prepared surface treatments using acrylic resin on MG sheet surface, 2 types of addition-cured silicone denture relining materials were glued to MG surface. The peak intensity, the time to peak intensity from the onset of the transmitted force and bonding strength were statistically analyzed using ANOVA and Tukey's honest significant difference post hoc test (pmaterials could be clinically applicable as a mouthguard adjustment material.

  5. Cure modification of natural rubber containing benzothiazole accelerators by some modified thiocarbamyl sulfenamides

    NARCIS (Netherlands)

    Datta, R.N.; Debnath, S.C.; Noordermeer, J.W.M.

    2003-01-01

    The effects of N-cyclopentamethylene thiocarbamyl-N-(cyclohexyl,thiocyclohexyl)sulfenamide (CPCTS) and N-oxydiethylene thiocarbamyl-N-(cyclohexyl,thiocyclohexyl)sulfenamide (ODCTS) as cure modifiers on the vulcanization of natural rubber (NR) containing benzothiazole accelerators were studied. CPCTS

  6. DSC and curing kinetics study of epoxy grouting diluted with furfural -acetone slurry

    Science.gov (United States)

    Yin, H.; Sun, D. W.; Li, B.; Liu, Y. T.; Ran, Q. P.; Liu, J. P.

    2016-07-01

    The use of furfural-acetone slurry as active diluents of Bisphenol-A epoxy resin (DGEBA) groutings has been studied by dynamic and non-isothermal DSC for the first time. Curing kinetics study was investigated by non-isothermal differential scanning calorimetries at different heating rates. Activation enery (Ea) was calculated based on Kissinger and Ozawa Methods, and the results showed that Ea increased from 58.87 to 71.13KJ/mol after the diluents were added. The furfural-acetone epoxy matrix could cure completely at the theoretical curing temperature of 365.8K and the curing time of 139mins, which were determined by the kinetic model parameters.

  7. Polyurethane curing kinetics for polymer bonded explosives: HTPB/IPDI binder

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Sangmook; Hong, In-Kwon [Dankook University, Yongin (Korea, Republic of); Choi, Chong Han; Lee, Jae Wook [Sogang University, Seoul (Korea, Republic of)

    2015-08-15

    The kinetics of polyurethane reaction and the effect of catalysts on the curing behavior were studied. The mixtures of hydroxyl terminated polybutadiene and isophorone diisocyanate with different reaction catalysts were dynamically cured in a differential scanning calorimeter. The activation energies were evaluated by the Kissinger and the Ozawa methods. The Chang plot was also used to determine reaction order and rate constant. The results showed that the activation energies were influenced remarkably by the choice of catalysts. The degree of cure and the cure time at given temperatures were calculated by direct integration of modified auto-catalytic kinetic model. It would give valuable information like pot-life estimation during manufacturing polymer-bonded explosives.

  8. Coil measurement data acquisition and curing press control system for SSC dipole magnet coils

    Energy Technology Data Exchange (ETDEWEB)

    Dickey, C.E.

    1989-03-01

    A coil matching program, similar in theory to the methods used to match Tevatron coils, is being developed at Fermilab. Modulus of elasticity and absolute coil size will be determined at 18-inch intervals along the coils while in the coil curing press immediately following the curing process. A data acquisition system is under construction to automatically acquire and manage the large quantities of data that result. Data files will be transferred to Fermilab's VAX Cluster for long-term storage and actual coil matching. The data acquisition system will also provide the control algorithm for the curing press hydraulic system. A description of the SSC Curing Press Data Acquisition and Controls System will be reported. 20 figs.

  9. Morphology and Cure Behavior of Multi-walled Carbon Nanotubes-based Thermally Conductive Adhesive

    Institute of Scientific and Technical Information of China (English)

    WANG Junxia; YAN Shilin; HE Yunban; YAN Fei; XIE Beiping

    2014-01-01

    We evaluated the cure behavior of multi-walled carbon nanotubes (MWCNTs) based thermally conductive adhesive by comprehensively thermal analysis, which presented extremely complicated variability of conversion ratioαas a function of temperature with synergistic action of positive effect and negative volume-blocking effect of MWCNTs and cross-linked network of cured polymer molecules. Due to the decomposition of MWCNTs and degradation of polymer, the mass drop is dramatically obvious over the temperature range of 330-370℃. Binary resins filled with acid-treated MWCNTs present similar reaction interval as neat epoxy and matrix resins, which is distinct from the material filled with raw MWCNTs. The alteration of the crystalline temperature and cure temperature of resins is attributed to heterogeneous nucleation of MWCNTs in matrix resins. The-COOH group of acid-treated MWCNTs reacts with epoxy groups and thus generates cross-linking, accelerates the reaction rate and reduces the cure temperature.

  10. Effects of graphene oxides on the cure behaviors of a tetrafunctional epoxy resin

    Directory of Open Access Journals (Sweden)

    2011-09-01

    Full Text Available The influence of graphene oxides (GOs on the cure behavior and thermal stability of a tetrafunctional tetraglycidyl-4,4’-diaminodiphenylmethane cured with 4,4’-diaminodiphenylsulfone was investigated by using dynamic differential scanning calorimetry (DSC and thermogravimetric analysis (TGA. The dynamic DSC results showed that the initial reaction temperature and exothermal peak temperature decreased with the increase of GO contents. Furthermore, the addition of GO increased the enthalpy of epoxy cure reaction. Results from activation energy method showed that activation energies of GO/epoxy nanocomposites greatly decreased with the GO content in the latter stage, indicating that GOs significantly hindered the occurrence of vitrification. The oxygen functionalities, such as hydroxyl and carboxyl groups, on the surface of GOs acted as catalysts and facilitated the curing reaction and the catalytic effect increased with the GO contents. TGA results revealed that the addition of GOs decreased the thermal stability of epoxy.

  11. Role of postpartum Kegel exercises in the prevention and cure of stress incontinence

    Directory of Open Access Journals (Sweden)

    Chitra Joshi

    2016-03-01

    Conclusions: The high cure rate depends on the factors like how correctly the Kegel exercises were instructed, how correctly the patients learned and performed them. [Int J Reprod Contracept Obstet Gynecol 2016; 5(3.000: 669-673

  12. Fiber Optic Systems for Light Curing Rigidization of Inflatable Structures Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Light (UV and visible) curing composite matrix resins are being explored as an attractive means for rigidizing inflatable spacecraft for large space-deployed...

  13. Constructing of cure monitoring system with piezoelectric ceramics for composite laminate

    Science.gov (United States)

    Oshima, Nobuo; Inoue, Kouichi; Motogi, Shinya; Fukuda, Takehito

    2003-08-01

    The cure monitoring system with piezoelectric ceramics is constructed. An embedded type piezoelectric ceramics sensor with flat lead wires is developed. And the piezoelectric ceramics is embedded into composite laminate. A dummy piezoelectric ceramics is set in the autoclave oven. The impedance of the piezoelectric ceramics which is embedded in the composite laminate and that of the dummy piezoelectric ceramics are measured by a LCR meter. The piezoelectric ceramics have strong temperature dependency. The temperature dependency of the impedance of piezoelectric ceramics is corrected by the information from the dummy piezoelectric ceramics. A dielectric sensor is also embedded in the composite laminate as a reference sensor for the degree of cure. The change in calculated cure index shows good correspondence with change in the log ion viscosity which is measured by the dielectric cure monitoring sensor.

  14. Influence of the curing cycles on the fatigue performance of unidirectional glass fiber reinforced epoxy composites

    DEFF Research Database (Denmark)

    Hüther, Jonas; Brøndsted, Povl

    2016-01-01

    stresses are built up and frozen, as residual stresses occur. In the present work, a glass fiber reinforced epoxy composite laminate with an unidirectional architecture based on non-crimp fabrics with backing fibers is investigated. Three different curing cycles (time-temperature cycles) are used, leading...... demonstrated that the resulting residual stresses barely influences the quasi-static mechanical properties of reinforced glass-fiber composites. It is found that the fatigue performance in the 0° direction is significantly influenced by the internal stresses, whereas the fatigue performance in the off axes......During the manufacturing process of fiber reinforced polymers the curing reaction of the resin results in shrinkage of the resin and introduces internal stresses in the composites. When curing at higher temperatures in order to shorten up the processing time, higher curing stresses and thermal...

  15. Low Temperature Curing of Hydrogen Silsesquioxane Surface Coatings for Corrosion Protection of Aluminum

    DEFF Research Database (Denmark)

    Lampert, Felix; Jensen, Annemette Hindhede; Møller, Per

    2016-01-01

    Hydrogen Silsesquioxane (HSQ) has shown to be a promising precursor for corrosion protective glass coatings for metallic substrates due to the excellent barrier properties of the films, especially in the application of protective coatings for aluminum in the automotive industry where high chemical...... stability in alkaline environments is required. The coatings have been successfully applied to stainless steel substrates. However the traditional thermal curing of HSQ involves heating to elevated temperatures, which are beyond those applicable for most industrial applications of aluminum. In this study...... low temperature processes are tested and evaluated as possible alternatives to the traditional high temperature cure. Thin HSQ films are deposited onsilicon wafers to model the degree of curing induced by the low temperature methods in comparison to thermal curing.Furthermore, the coatings are applied...

  16. Study on Cure Behavior of a Model Epoxy System by Means of TTT Diagram

    Institute of Scientific and Technical Information of China (English)

    ZHANG Ming; AN Xue-feng; TANG Bang-ming; YI Xiao-su

    2006-01-01

    Curing behavior of a model epoxies system (E-54/AG-80) with DDS as hardener was studied in this paper.Round disk compression mode DMA was executed to study the gel behaviors at different temperatures to determine the relationship between gel-time (tgel) and temperature. The cure kinetics was studied by dynamic DSC analysis. Parameters were obtained for establishing a phenomenological cure reaction model.The relationship between glass transition temperature (Tg) and cure degree (α) was also analyzed by both isothermal and dynamic DSC method based on DiBenedetto equation, which gave a mathematical description of Tg as a function of both time and temperature. Consequently, characteristic temperatures such as Tg0, gel Tgand Tg∞ were determined. Finally, the Time-Temperature-Transition (TTT) diagram was designed based on the data and equations.

  17. Elite control of HIV: is this the right model for a functional cure?

    Science.gov (United States)

    Cockerham, Leslie R; Hatano, Hiroyu

    2015-02-01

    A cure for HIV is still greatly needed and has become a global research priority. A unique subset of HIV-infected individuals who spontaneously control HIV exists, and these are known as 'elite controllers'. They may represent a natural model for a 'functional cure' in which there is long term control of viral replication and remission from symptoms of HIV infection in the absence of antiretroviral therapy. However, controllers have evidence of ongoing inflammation, CD4(+) T cell depletion, and perhaps even inflammation-associated cardiovascular disease, suggesting that this natural long term virologic control may be coming at an immunologic and clinical cost. These individuals may continue to provide continued insights into mechanisms of host control; however, they may not represent the best model of a functional cure, if we believe that a cure should require a disease-free (and not just a treatment-free) state.

  18. Degradation of LIM domain-binding protein three during processing of Spanish dry-cured ham.

    Science.gov (United States)

    Gallego, Marta; Mora, Leticia; Fraser, Paul D; Aristoy, María-Concepción; Toldrá, Fidel

    2014-04-15

    Extensive proteolysis takes place during the processing of dry-cured ham due to the action of muscle peptidases. The aim of this work was to study the degradation of LIM domain binding protein 3 (LDB3), which is located at the Z-lines of the sarcomere, at different times during the Spanish dry-cured ham processing (2, 3.5, 5, 6.5, and 9 months). A total of 107 peptides have been identified by mass spectrometry, most of them generated from the first region of the protein sequence (position 1-90) providing evidence for the complexity and variability of proteolytic reactions throughout the whole process of dry-curing. Methionine oxidation has been observed in several peptides by the end of the process. The potential of some of the identified peptides to be used as biomarkers of dry-cured ham processing has also been considered.

  19. An Enhanced Vacuum Cure Technique for On-Aircraft Repair of Carbon-Bismaleimide Composites

    Science.gov (United States)

    Rider, Andrew N.; Baker, Alan A.; Wang, Chun H.; Smith, Graeme

    2011-06-01

    Carbon/bismaleimide (BMI) composite is increasingly employed in critical load carrying aircraft structures designed to operate at temperatures approaching 180°C. The high post-cure temperature (above 220°C) required to fully react the BMI resin, however, renders existing on-aircraft prepreg or wet layup repair methods invalid. This paper presents a new on-aircraft repair technique for carbon/BMI composites. The composite prepregs are first warm-staged to improve the ability to evacuate entrapped air. Then the patch is cured in the scarf cavity using the vacuum bag technique, followed by off-aircraft post-cure. The fully cured patch then can be bonded using a structural adhesive.

  20. The Curing Process of Epoxy/Amino-Functionalized MWCNTs: Calorimetry, Molecular Modelling, and Electron Microscopy

    Directory of Open Access Journals (Sweden)

    S. G. Prolongo

    2010-01-01

    Full Text Available Curing kinetic of an epoxy resin reinforced with amino-functionalized MWCNTs has been studied by DSC and the obtained results were explained through morphological studies carried out by SEM, TEM, FEG-SEM, and molecular simulation tools. The presence of MWCNTs in the curing reaction induces a retardation effect of curing reaction and a decrease of the reaction heat. Both are associated with the adsorption of curing agent molecules inside carbon nanotubes, which was proved through the application of electron microscopic techniques and molecular simulation tools. It has been also demonstrated that there is a chemical reaction between amine groups anchored to the nanotubes and oxirane rings of epoxy monomer, which improves the nanoreinforcement/matrix interfacial adhesion, appearing a chemical interphase. The glass transition temperature (Tg of epoxy matrix increases by the addition of MWCNTs due to the restriction of its mobility.