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Sample records for autoclave curing

  1. 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.

  2. Mathematical Model For Autoclave Curing Of Unsaturated Polyester Based Composite Materials

    Directory of Open Access Journals (Sweden)

    Adnan A. Abdul Razak

    2013-05-01

    Full Text Available Heat transfer process involved in the autoclave curing of fiber-reinforced thermosetting composites is investigated numerically. A model for the prediction of the temperature and the extent of the reaction across the laminate thickness during curing process in the autoclave of unsaturated polyester based composite has been developed. The governing equation for one dimensional heat transfer, and accounting for the heat generation due to the exothermic cure reaction in the composites had been used.  It was found that the temperature at the central of the laminate increases up to the external imposed temperature, because of the thermal conductivity of the resin and fiber. The heat generated by the exothermic reaction of the resin is not adequately removed; the increase in the temperature at the center increases the resins rate reaction, which in turn generates more heat.

  3. Fourier transform infrared (FTIR) fiber optic monitoring of composites during cure in an autoclave

    Science.gov (United States)

    Druy, Mark A.; Elandjian, Lucy; Stevenson, William A.; Driver, Richard D.; Leskowitz, Garett M.

    1990-01-01

    Real-time in situ monitoring of the chemical states of epoxy resins was investigated during cure in an autoclave using infrared evanescent spectroscopy. Fiber evanescent sensors were developed which may be sandwiched between the plies of the prepreg sample. A short length of sapphire fiber was used as the sensor cell portion of the fiber probe. Heavy metal fluoride glass optical fiber cables were designed for connecting the FTIR spectrometer to the sensor fiber within the autoclave. The sapphire fibers have outstanding mechanical thermal properties which should permit their use as an embedded link in all thermoset composites. The system is capable of operation at a temperature of 250 C for periods up to 8 hours without major changes to the fiber transmission. A discussion of the selection of suitable sensor fibers, the construction of a fiber-optic interface, and the interpretation of in situ infrared spectra of the curing process is presented.

  4. Curing Pressure Influence of Out-of-Autoclave Processing on Structural Composites for Commercial Aviation

    Directory of Open Access Journals (Sweden)

    Vasileios M. Drakonakis

    2013-01-01

    Full Text Available Autoclaving is a process that ensures the highest quality of carbon fiber reinforced polymer (CFRP composite structures used in aviation. During the autoclave process, consolidation of prepreg laminas through simultaneous elevated pressure and temperature results in a uniform high-end material system. This work focuses on analyzing in a fundamental way the applications of pressure and temperature separately during prepreg consolidation. A controlled pressure vessel (press-clave has been designed that applies pressure during the curing process while the temperature is being applied locally by heat blankets. This vessel gives the ability to design manufacturing processes with different pressures while applying temperature at desired regions of the composite. The pressure role on the curing extent and its effect on the interlayer region are also tested in order to evaluate the consolidation of prepregs to a completely uniform material. Such studies may also be used to provide insight into the morphology of interlayer reinforcement concepts, which are widely used in the featherweight composites. Specimens manufactured by press-clave, which separates pressure from heat, are analytically tested and compared to autoclaved specimens in order to demonstrate the suitability of the press-clave to manufacture high-quality composites with excessively reduced cost.

  5. [Methods Used for Monitoring Cure Reactions in Real-time in an Autoclave

    Science.gov (United States)

    Cooper, John B.; Wise, Kent L.; Jensen, Brian J. (Technical Monitor)

    2000-01-01

    The goal of the research was to investigate methods for monitoring cure reactions in real-time in an autoclave. This is of particular importance to NASA Langley Research Center because polyimides were proposed for use in the High Speed Civil Transport (HSCT) program. Understanding the cure chemistry behind the polyimides would allow for intelligent processing of the composites made from their use. This work has led to two publications in peer-reviewed journals and a patent. The journal articles are listed as Appendix A which is on the instrument design of the research and Appendix B which is on the cure chemistry. Also, a patent has been awarded for the instrumental design developed under this grant which is given as Appendix C. There has been a significant amount of research directed at developing methods for monitoring cure reactions in real-time within the autoclave. The various research efforts can be categorized as methods providing either direct chemical bonding information or methods that provide indirect chemical bonding information. Methods falling into the latter category are fluorescence, dielectric loss, ultrasonic and similar type methods. Correlation of such measurements with the underlying chemistry is often quite difficult since these techniques do not allow monitoring of the curing chemistry which is ultimately responsible for material properties. Direct methods such as vibrational spectroscopy, however, can often be easily correlated with the underlying chemistry of a reaction. Such methods include Raman spectroscopy, mid-IR absorbance, and near-IR absorbance. With the recent advances in fiber-optics, these spectroscopic techniques can be applied to remote on-line monitoring.

  6. Monitoring cure properties of out-of-autoclave BMI composites using IFPI sensor

    Science.gov (United States)

    Kaur, Amardeep; Anandan, Sudharshan; Yuan, Lei; Watkins, Steve E.; Chandrashekhara, K.; Xiao, Hai; Phan, Nam

    2016-04-01

    A non-destructive technique for inspection of a Bismaleimide (BMI) composite is presented using an optical fiber sensor. High performance BMI composites are used for Aerospace application for their mechanical strength. They are also used as an alternative to toughened epoxy resins. A femtosecond-laser-inscribed Intrinsic Fabry-Perot Interferometer (IFPI) sensor is used to perform real time cure monitoring of a BMI composite. The composite is cured using the out-of-autoclave (OOA) process. The IFPI sensor was used for in-situ monitoring; different curing stages are analyzed throughout the curing process. Temperature-induced-strain was measured to analyze the cure properties. The IFPI structure comprises of two reflecting mirrors inscribed on the core of the fiber using a femtosecond-laser manufacturing process. The manufacturing process makes the sensor thermally stable and robust for embedded applications. The sensor can withstand very high temperatures of up to 850 °C. The temperature and strain sensitivities of embedded IFPI sensor were measured to be 1.4 pm/μepsilon and 0.6 pm/μepsilon respectively.

  7. An Investigation of Steam Curing Pressure Effect on Pozzolan Additive Autoclaved Aerated Concrete

    Directory of Open Access Journals (Sweden)

    Kadir Güçlüer

    2015-02-01

    Full Text Available Autoclaved Aerated Concrete (AAC is a porous light weight concrete obtained by adding a pore-forming material to a mixture made of finely pulverized siliceous aggregate and inorganic binder (lime and/or cement and hardened by steam cure. In this study fly ash was used instead of siliceous aggregate and experiment samples were obtained by adding 3%, 6%, 9%, 12% silica fume to the cement. Samples were cured under 1560C and 4 bars and 1770C and 8 bars, and were investigated for compressive strength, bulk density and ultrasound pulse velocity to determine their mechanical and physical properties. Microstructure of samples was observed by using SEM and XRD techniques. Samples’ bulk density values and compressive strengths are changing between 0.6-0.7 kg/dm3 and 2.5-4.4 MPa respectively.

  8. 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.

  9. Relationship between Structural Characteristics of Fly Ash and Reactivity under Autoclave Curing

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The reactivity of autoclaved materials is conventionally estimated by their chemical composition. In this paper, after determining the chemical composition of various types of fly ash, a series of new tests which included X-ray Diffraction (XRD), infrared spectral analysis (IR) and bound water testing, were applied to investigate the performance of autoclaved fly ash products. The relationship between the infrared spectral analysis of Si-O wavenumber (about 1 100 cm-1) and its autoclaved chemical reactivity, and compressive strength of its autoclaved samples, is analyzed. The results show that fly ash with a lower wavenumber will have stronger autoclaved chemical reactivity and higher compressive strength for its autoclaved sample. Thus, the Si-O stretching vibration wavelength can be used to estimate autoclaved chemical reactivity of fly ash, so as to control the quality of fly ash to be autoclaved, and to predict the compressive strength of autoclaved fly ash products.

  10. Long Out-time, Out-of-Autoclave Cure Composites Project

    Data.gov (United States)

    National Aeronautics and Space Administration — As the size of composite parts exceed that of even the largest autoclaves, new out-of-autoclave processes and materials are necessary to achieve the same level of...

  11. Mechanical Characterization of In and Out-of-Autoclave Cured Composite Panels for Large Launch Vehicles

    Science.gov (United States)

    Kellas, Sotiris; Lerch, Bradley A.; Wilmoth, Nathan

    2012-01-01

    Two manufacturing demonstration panels (1/16th-arc-segments of 10 m diameter cylinder) were fabricated under the composites part of the Lightweight Space Structures and Materials program. Both panels were of sandwich construction with aluminum core and 8-ply quasi-isotropic graphite/epoxy facesheets. One of the panels was constructed with in-autoclave curable unidirectional prepreg (IM7/977-3) and the second with out-of-autoclave unidirectional prepreg (T40-800B/5320-1). Following NDE inspection, each panel was divided into a number of small specimens for material property characterization and a large (0.914 m wide by 1.524 m long) panel for a buckling study. Results from the small specimen tests were used to (a) assess the fabrication quality of each 1/16th arc segment panel and (b) to develop and/or verify basic material property inputs to Finite Element analysis models. The mechanical performance of the two material systems is assessed at the coupon level by comparing average measured properties such as flatwise tension, edgewise compression, and facesheet tension. The buckling response of the 0.914 m wide by 1.524 m long panel provided a comparison between the in- and out-of autoclave systems at a larger scale.

  12. An Investigation of Stimulating the Autoclave Curing Process of Resin Matrix/Fiber Reinforced Composite Material,Ⅰ: Process model

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    A mathematical model is made which describes the curing process of composites constructed from continuous fiber-reinforced, thermosetting resin matrix prepreg materials, and the consolidation of the composite is developed. The model provides the variation of temperature distribution, the cure reaction process in the resin, the resin flow and fibers stress inside the composite, and the void variation and the residual stress distribution. It can be used to illustrate the mechanism of curing process and optimize the cure cycle of composite material in order to ensure the quality of a product.

  13. Effect of Steam-Autoclaved Curing on Chloride Permeability of High Strength Concrete%二次高温养护对高强混凝土抗 Cl-渗透性的影响

    Institute of Scientific and Technical Information of China (English)

    刘东升; 朱建舟; 谭克锋

    2014-01-01

    利用氯离子快速渗透法(RCM)研究了普通蒸汽养护后(80℃,0.1 MPa)再进行压蒸(180℃,1 MPa)养护,即二次高温养护,对不同胶凝材料体系的高强混凝土抗Cl-渗透性的影响。结果表明:对于纯水泥混凝土,与标养相比,“蒸养-压蒸”养护使混凝土抗Cl -渗透性能劣化。掺入粉煤灰、矿粉以及硅灰以等比例取代水泥时,“蒸养-压蒸”都较为充分地激发了上述混合材的火山灰活性,但不同掺合料对“蒸养-压蒸”后高强混凝土抗Cl-渗透性能影响差别较大。 XRD和SEM研究表明上述结果的产生与高温下水化产物的种类和分布有关。%Rapid choloride migration test (RCMT) was used to investigate the influence of curing methods and mineral admixtures on chloride ingress resistance of high strength concrete .The results indicate that steam cu-ring and autoclaving curing , especially autoclaving curing , considerably aggravated the chloride penetration through pure cement concrete when compared with normal curing .Incorporating silica fume can improve the chloride ingress resistance of steam curing concrete but degrades autoclaving curing concrete .Adding fly ash with low pozzolanic activity can increase chloride ingress resistance of autoclaving curing concrete , while chlo-ride penetration resistance of steam curing concrete becomes lower .The measure of multi-elements mineral admixtures mixing is propitious to improving the chloride ingress resistance of concrete compared with pure ce-ment concrete under same curing conditions .Results above was analyzed by XRD and SEM .

  14. Fast estimating concrete strength method applying microwave autoclave curing technology%应用微波蒸压技术的混凝土强度快速测定方法

    Institute of Scientific and Technical Information of China (English)

    蒋德稳; 田安国; 胡杰; 赵政

    2015-01-01

    为了快速测定混凝土强度,将微波技术应用到传统的蒸压养护工艺中,自行设计和制作了小型微波蒸压釜。通过试验得出了釜腔内温度压力大小、恒温恒压养护时间对混凝土早期强度的影响规律,进而总结出微波蒸压养护条件下混凝土快速养护制度。通过15批次(5种配合比)不同强度等级混凝土的微波蒸压养护和标准养护对比试验,建立了微波蒸压养护条件下的混凝土强度线性和非线性回归模型,模型中考虑了加速养护混凝土强度和混凝土水灰比,具有较好的相关关系。试验分析发现:运用微波技术,可以均匀、迅速地提高混凝土内部温度,减小温度应力,使混凝土1 h内获得较高(28 d强度40%~50%)、稳定的早期强度,可以作为预拌混凝土生产企业和施工现场进行强度控制和配合比调整时的依据。%In order to estimate concrete strength quickly,microwave was applied to the conditional autoclave curing. Small microwave autoclave suitable for the microwave autoclaved were self designed and made. By experiment research,the effect laws of temperature in autoclave and constant temperature curing time on the early strength of concrete were investigated,and rapid curing system was summa-rized on the condition of microwave and autoclave. By the contrast test of microwave autoclave curing and standard curing of 15 batches of different strength grade concrete,the linear and nonlinear regression model of concrete strength determination were established with better correlativity on the condition of microwave and autoclave. Concrete strength accelerated of curing and water-cement-ratio was considered in the model. It was found that the internal temperature of concrete would be uniformly,rapidly improved by microwave,and the temperature stress would be reduced.The high and stable early strength of concrete(40~50 percent of 28 d strength)was obtained

  15. Polimerização complementar em autoclave, microondas e estufa de um compósito restaurador direto = The effect of post-cure heating in autoclave, microwave oven and conventional oven on direct composite resin

    Directory of Open Access Journals (Sweden)

    Arossi, Guilherme Anziliero

    2007-01-01

    Full Text Available Com o objetivo de tornar o processo de confecção de restaurações indiretas mais acessível, reduzindo seus custos com a resina utilizada e os métodos de polimerização complementar, este estudo testou a possibilidade de se utilizar resinas diretas com métodos de polimerização complementar alternativos. Corpos de prova foram confeccionados com a resina Charisma e fotopolimerizados por 20 segundos. Em seguida as amostras foram submetidas à polimerização complementar em autoclave, microondas e estufa. Foram estabelecidos dois grupos controles: um controle negativo, que consistiu na utilização da resina Charisma fotopolimerizada convencionalmente (20s; e um grupo controle positivo, formado por amostras do compósito restaurador indireto Targis. O ensaio de microdureza Knoop foi realizado após uma semana de armazenagem e os resultados submetidos à análise estatística. Os três métodos de polimerização complementar propostos determinaram um aumento na microdureza do compósito restaurador direto quando comparado ao controle negativo (p 0,05. Conclui-se que, considerando o desenho experimental deste estudo, a polimerização complementar em autoclave, microondas ou estufa aumenta a microdureza da resina Charisma previamente fotopolimerizada

  16. Mechanical Properties of Autoclaved Shell-aggregate

    Institute of Scientific and Technical Information of China (English)

    MA Hailong; CUI Chong; LI Xing; Pierre Chevrier; Vanessa Bouchart; TANG Feng

    2011-01-01

    Waste solid propylene oxide sludge(POS)and fly ash were used as main raw material to prepare propylene oxide sludge aggregate(POSA)under the condition of autoclaved(180 ℃,1.0 MPa)curing.Three different test methods namely cylinder compressive strength(CCS),individual aggregate compressive strength(IACS)and strength contribution rate(SCR)proposed were used to characterize the mechanical properties of the autoclaved POSA.POS shell-aggregate with SCR of 94% were prepared under the hydrothermal synthesis and autoclaved curing.The experimental results indicate that CCS and IACS have good consistency in characterizing mechanical properties of POSA.It is suggested that SCR not only can characterize the strength of POSA core,but also can reflect the effect of shell on the performance of POSA.By means of least square method,relationships between CCS and IACS,CCS and SCR,IACS and SCR were deduced.

  17. Effect of Waterproofing Agent B and Curing Temperature on Properties of the Burning-free, Autoclave Curing-free and Non-cement Building Bricks Made from Iron Tailings%防水剂B和养护温度对铁尾矿三免砖性能的影响

    Institute of Scientific and Technical Information of China (English)

    徐民主; 雷国元; 宋均平; 罗文斌; 谭青; 李瑞杰

    2015-01-01

    Burning-free,autoclave curing-free and non-cement building bricks( three-free for short) were prepared with the fine low-silica iron ore tailing and the self-made non-cement curing agent as the raw material. The effect of the content of waterproofing agent B and curing temperature on the properties of the products such as the compressive strength,water resist-ance,frost resistance and anti-carbonization,and also its mechanisms were studied. The results showed that with the dosage of waterproofing agent B increase,compressive strength and 24 h water absorption of products decreased while saturated compres-sive strength and softening coefficient are increased first and then decreased. With the increase of initial curing temperature, water resistance,frost resistance and compressive strength in every curing time are improved significantly. According to the mechanism analysis by XRD and FI-TR,the results show that hydrated calcium silicate gel and ettringite are strength binder phase of three-free bricks. Meanwhile,the addition of waterproofing agent B does not affect the composition of binding phase. The increase of initial curing temperature and the addition of waterproofing agent B can inhibit the carbonation reaction within products and improve water resistance. The results of theoretical analysis can explain the effect of curing temperature and water-proofing agent B on performance of the products. It provides theory basis for the high-effect waterproofing agent and the optimi-zation of the curing conditions.%以某细粒低硅铁尾矿和无水泥固化剂为原料,制备免烧免蒸免水泥建材砖(简称“三免砖”)。研究了防水剂B和养护温度对制品抗压强度、耐水性和抗冻性的影响及其机制。试验结果表明:随着防水剂B掺量的增加,制品的干抗压强度和24 h吸水率均下降,饱和抗压强度和软化系数均先升后降;随着初期养护温度的升高,制品的耐水性、抗冻性和各龄期

  18. Autoclave nuclear criticality safety analysis

    Energy Technology Data Exchange (ETDEWEB)

    D`Aquila, D.M. [Martin Marietta Energy Systems, Inc., Piketon, OH (United States); Tayloe, R.W. Jr. [Battelle, Columbus, OH (United States)

    1991-12-31

    Steam-heated autoclaves are used in gaseous diffusion uranium enrichment plants to heat large cylinders of UF{sub 6}. Nuclear criticality safety for these autoclaves is evaluated. To enhance criticality safety, systems are incorporated into the design of autoclaves to limit the amount of water present. These safety systems also increase the likelihood that any UF{sub 6} inadvertently released from a cylinder into an autoclave is not released to the environment. Up to 140 pounds of water can be held up in large autoclaves. This mass of water is sufficient to support a nuclear criticality when optimally combined with 125 pounds of UF{sub 6} enriched to 5 percent U{sup 235}. However, water in autoclaves is widely dispersed as condensed droplets and vapor, and is extremely unlikely to form a critical configuration with released UF{sub 6}.

  19. Comparison of Autoclave and Out-of-Autoclave Composites

    Science.gov (United States)

    Sutter, James K.; Kenner, W. Scott; Pelham, Larry; Miller, Sandi G.; Polis, Danel L.; Nailadi, Chaitra; Zimmerman, Thomas J.; Lort, Richard D.; Hou, Tan-Hung; Quade, Derek J.; Lerch, Bradley A.; Walker, James; Fikes, John

    2010-01-01

    The National Aeronautics and Space Administration (NASA) Exploration Systems Mission Directorate initiated an Advanced Composite Technology Project through the Exploration Technology Development Program in order to support the polymer composite needs for future heavy lift launch architectures. As an example, the large composite dry structural applications on Ares V inspired the evaluation of autoclave and out-of-autoclave (OOA) composite materials. A NASA and industry team selected the most appropriate materials based on component requirements for a heavy lift launch vehicle. Autoclaved and OOA composites were fabricated and results will highlight differences in processing conditions, laminate quality, as well as initial room temperature thermal and mechanical performance. Results from this study compare solid laminates that were both fiber-placed and hand-laid. Due to the large size of heavy-lift launch vehicle composite structures, there is significant potential that the uncured composite material or prepreg will experience significant out-life during component fabrication. Therefore, prepreg out-life was a critical factor examined in this comparison. In order to rigorously test material suppliers recommended out-life, the NASA/Industry team extended the out-time of the uncured composite prepreg to values that were approximately 50% beyond the manufacturers out-time limits. Early results indicate that the OOA prepreg composite materials suffered in both composite quality and mechanical property performance from their extended out-time. However, the OOA materials performed similarly to the autoclaved composites when processed within a few days of exposure to ambient "shop" floor handling. Follow on studies evaluating autoclave and OOA aluminum honeycomb core sandwich composites are planned.

  20. Interface morphologic characteristics of articles in load-bearing autoclaved cellular concrete

    Energy Technology Data Exchange (ETDEWEB)

    Peng, S.; Wang, L. [China University of Mining and Technology (China)

    1999-06-01

    Using SEM-EDAX, the morphological characteristics within the interfacial zone between the fly ash particles and the lime-cement paste of load-bearing autoclaved cellular concrete is studied. The results shows that with autoclaved curing, the crystals of the hydration product are well developed. The microstructure of the interlocking needle and fibre shaped hydration products is denser than that of natural curing. Under natural curing, the crystallization of the hydration product is low, the particles mainly present in piles. Irregular dispersed grain-shaped hydration products are seen on the breaking face in the early stage of curing. Rod and sheet shaped AFt, AFm phases are seen later. The lack of connecting and interlocking of the hydration products is the main reason for the low strength of natural curing product. 4 refs., 6 figs., 1 tab.

  1. Volume of an Industrial Autoclave

    Directory of Open Access Journals (Sweden)

    Nicholas Madaffari

    2010-01-01

    Full Text Available We were able to determine the volume of an industrial autoclave sterilization tank using a technique learned in calculus. By measuring the dimensions of the tank and roughly estimating the equation of curvature at the ends of the tank, we were able to revolve half of the end of the tank around the x axis to get its fluid volume. Adding the two volumes of the ends and the volume of the cylindrical portion on the tank yielded the total volume.

  2. NON-AUTOCLAVE SILICATE BRICK

    Directory of Open Access Journals (Sweden)

    V. N. Yaglov

    2015-01-01

    Full Text Available The paper proposes a technology for obtaining bricks on the basis of lime-silica mixtures where chemical interactions are practically completely realized in dispersive state at the stage of preparation of binding contact maturing and raw mixture as a whole. The role of forming operation (moulding is changed in principle because in this case conversion of dispersive system into a rock-like solid occurs and due to this the solid obtains complete water-resistance in contact with water immediately after forming operation. Theoretical basis for the developed technology is capability of silicate dispersive substances (hydrated calcium silicate to transit in non-stable state, to form a rock-like water-resistant solid in the moment of mechanical load application during forming process. Specific feature of the proposed method is an exclusion of additional operations for autoclaving of products from the process of obtaining a silicate brick.Synthetic hydrated calcium silicate in contrast to natural ones are more uniform in composition and structure, they contain less impurities and they are characterized by dispersive composition and due to the mentioned advantages they find wider practical application. Contact-condensation binders permit to manipulate product properties on their basis and ensure maximum correspondence to the requirements of the concrete application. Raw material sources for obtaining synthetic hydrated calcium silicates are practically un-limited because calcium-silicon containing substances are found as in various technogenic wastes so in natural compounds as well. So the problem for obtaining hydrated calcium silicates having contact-condensation ability for structure formation becomes more and more actual one. This transition is considered as dependent principally on arrangement rate of substance particles which determined the level of its instability.

  3. A compensation approach to the tool used in autoclave based on FEA

    Institute of Scientific and Technical Information of China (English)

    Zhang Ji; Li Yingguang; Li Nanya; and Liao Wenhe

    2012-01-01

    Optimization of the curing process can not control the deformation of composite part prepared in autoclave accurately. And traditional "trial-and-error" tool surface compensation approach is low efficiency, high cost and can not control part deformation quantificationally. In order to address these issues, tool compensation approach based on FEA is presented. Model of multi-field coupling relationship in autoclave is realized. And finite element analysis model of composite part's curing process is developed to analyze part deformation. According to displacement of the part surface nodes after deformation, tool surface which compensated by the displacement of composite part which analyzed by FEA is used to control part deformation. A cylindrical composite part is ana- lyzed to verify the approach, and the result proves the correctness and validity of the approach.

  4. Intelligent sensor-model automated control of PMR-15 autoclave processing

    Science.gov (United States)

    Hart, S.; Kranbuehl, D.; Loos, A.; Hinds, B.; Koury, J.

    An intelligent sensor model system has been built and used for automated control of the PMR-15 cure process in the autoclave. The system uses frequency-dependent FM sensing (FDEMS), the Loos processing model, and the Air Force QPAL intelligent software shell. The Loos model is used to predict and optimize the cure process including the time-temperature dependence of the extent of reaction, flow, and part consolidation. The FDEMS sensing system in turn monitors, in situ, the removal of solvent, changes in the viscosity, reaction advancement and cure completion in the mold continuously throughout the processing cycle. The sensor information is compared with the optimum processing conditions from the model. The QPAL composite cure control system allows comparison of the sensor monitoring with the model predictions to be broken down into a series of discrete steps and provides a language for making decisions on what to do next regarding time-temperature and pressure.

  5. Shear reinforced beams in autoclaved aerated concrete

    DEFF Research Database (Denmark)

    Cornelius, Thomas

    2010-01-01

    Shear behaviour in concrete materials is very well documented, for normal density concrete materials. In this paper results of various tests on low density concrete materials like aerated autoclaved concrete (in the following denoted aircrete) will be presented and analyzed for different combinat......Shear behaviour in concrete materials is very well documented, for normal density concrete materials. In this paper results of various tests on low density concrete materials like aerated autoclaved concrete (in the following denoted aircrete) will be presented and analyzed for different...

  6. Vascular Cures

    Science.gov (United States)

    ... our CEO Board of Directors Scientific Advisory Board History of Vascular Cures Impact Contact Us Vascular Disease What is Vascular Disease? Education and Awareness Vascular Diseases Abdominal Aortic Aneurysm Aortic ...

  7. ANALYSIS OF MECHANICAL PROPERTIES OF HYDROTHERMALLY CURED HIGH STRENGTH CEMENT MATRIX FOR TEXTILE REINFORCED CONCRETE

    OpenAIRE

    Ondřej Holčapek; Filip Vogel; Petr Konvalinka

    2015-01-01

    The main objective of this article is to describe the influence of hydrothermal curing conditions in an autoclave device (different pressure and temperature), which took place at various ages of a fresh mixture (cement matrix – CM, and fibre-reinforced cement matrix – FRCM), on textile reinforced concrete production. The positive influence of autoclaving has been evaluated through the results of physical and mechanical testing – compressive strength, flexural strength, bulk density and dynami...

  8. Evaluation of dimensional stability of autoclavable elastomeric impression material.

    Science.gov (United States)

    Surendra, G P; Anjum, Ayesha; Satish Babu, C L; Shetty, Shilpa

    2011-03-01

    Impressions are important sources of cross contamination between patients and dental laboratories. As a part of infection control impressions contaminated with variety of micro-organisms via blood and oral secretions should be cleaned and disinfected or sterilized before being handled in dental laboratory. The purpose of this study was to determine the effect of autoclaving on dimensional stability of elastomeric impression material (polyvinyl siloxane-Affinis). In this in vitro study standardized stainless steel die as per ADA specification number 19 was fabricated. Polyvinyl siloxane (Affinis) light body and putty viscosity elastomeric impression materials were used. A total of 40 impressions of the stainless steel die were made and numeric coding system was used to identify the samples. Measurements were made using a measuring microscope. Distance between the cross lines CD and C'D' reproduced in the impression were measured before autoclaving, immediately after autoclaving and 24 hours after autoclaving and dimensional change was calculated. The data obtained was subjected to statistical analysis. The mean difference in dimensional change between the three groups was not statistically significant (P > 0.05). However the results revealed that there was higher mean dimensional change immediately after autoclaving when compared to the other 2 time intervals. It is desirable to delay the casting of an autoclavable elastomeric impression material by about 24 hours. Though disinfection of impression is routinely followed autoclaving of impression is an effective method of sterilization.

  9. No-Oven, No-Autoclave, Composite Processing Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Cornerstone Research Group Inc. (CRG) proposes to continue the efforts from the 2010 NASA SBIR Phase I topic X5.03, "No-Oven, No-Autoclave (NONA) Composite...

  10. Radiation curing

    International Nuclear Information System (INIS)

    In the beginning of the seventies the two types of radiation sources applied in industrial processes, electron radiation and UV, had been given rather optimistic forecasts. While UV could succeed in the field of panel and film coating, electron radiation curing seems to gain success in quite new fields of manufacturing. The listing of the suggested applications of radiation curing and a comparison of both advantages and disadvantages of this technology are followed by a number of case studies emphasizing the features of these processes and giving some examplary calculations. The data used for the calculations should provide an easy calculation of individual manufacturing costs if special production parameters, investment or energy costs are employed. (Author)

  11. Generating Autoclave-Level Mechanical Properties with Out-of-Autoclave Thermoplastic Placement of Large Composite Aerospace Structures Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Out-of-autoclave thermoplastic tape/tow placement (TP-ATP) is nearing commercialization but suffers a moderate gap in mechanical properties compared with laminates...

  12. Manufacturing of wind turbine blade by electron beam curing

    International Nuclear Information System (INIS)

    These materials have been fabricated by thermal curing process. However, thermal curing process has several disadvantages such as long curing time, large residual stresses. In order to avoid weakness of thermal process, the radiation curing process using UV, microwave, x-ray, y-ray and electron-beam is widely used in recent years. In comparison with the thermal-curing, radiation curing process does not need to thermal and autoclave equipment and have several advantages : dramatically reduced curing time : enhancement of part quality and performance : reduced environmental and health concerns : easy material treatment : significantly reduced overall manufacturing costs. This study describes novel synthesis of epoxy acrylate resin that was cured by electron-beam without photo-initiators. The effect of catalyst and synthetic temperature was investigated by molecular weight and chemical structure through GPC and NMR. E-beam cured resin showed significantly higher flexural strength and tensile strength than other commercial resins. The wind turbine wind turbine was fabricated by E-beam curing, using novel epoxy acrylate resin with fiber reinforced plastics (FRP). E-beam curable novel synthesized resin can be a good candidate in the wind turbine and in various industrial fields where high performance was required

  13. Anaerobic digestion of autoclaved and untreated food waste

    International Nuclear Information System (INIS)

    Highlights: • Autoclaving decreased the formation of NH4-N and H2S during food waste digestion. • Stable digestion was achieved with untreated and autoclaved FW at OLR 6 kg VS/m3day. • Use of acclimated inoculum allowed very rapid increases in OLR. • Highest CH4 yields were observed at OLR 3 kg VS/m3day with untreated FW. • Autoclaved FW produced highest CH4 yields during OLR 4 kgVS/m3day. - Abstract: Anaerobic digestion of autoclaved (160 °C, 6.2 bar) and untreated source segregated food waste (FW) was compared over 473 days in semi-continuously fed mesophilic reactors with trace elements supplementation, at organic loading rates (OLRs) of 2, 3, 4 and 6 kg volatile solids (VS)/m3 d. Methane yields at all OLR were 5–10% higher for untreated FW (maximum 0.483 ± 0.013 m3 CH4/kg VS at 3 kg VS/m3 d) than autoclaved FW (maximum 0.439 ± 0.020 m3 CH4/kg VS at 4 kg VS/m3 d). The residual methane potential of both digestates at all OLRs was less than 0.110 m3 CH4/kg VS, indicating efficient methanation in all cases. Use of acclimated inoculum allowed very rapid increases in OLR. Reactors fed on autoclaved FW showed lower ammonium and hydrogen sulphide concentrations, probably due to reduced protein hydrolysis as a result of formation of Maillard compounds. In the current study this reduced biodegradability appears to outweigh any benefit due to thermal hydrolysis of ligno-cellulosic components

  14. Anaerobic digestion of autoclaved and untreated food waste

    Energy Technology Data Exchange (ETDEWEB)

    Tampio, Elina, E-mail: elina.tampio@mtt.fi [Bioenergy and Environment, MTT Agrifood Research Finland, FI-31600 Jokioinen (Finland); Ervasti, Satu; Paavola, Teija [Bioenergy and Environment, MTT Agrifood Research Finland, FI-31600 Jokioinen (Finland); Heaven, Sonia; Banks, Charles [University of Southampton, Faculty of Engineering and the Environment, Southampton SO17 1BJ (United Kingdom); Rintala, Jukka [Bioenergy and Environment, MTT Agrifood Research Finland, FI-31600 Jokioinen (Finland)

    2014-02-15

    Highlights: • Autoclaving decreased the formation of NH4-N and H{sub 2}S during food waste digestion. • Stable digestion was achieved with untreated and autoclaved FW at OLR 6 kg VS/m{sup 3}day. • Use of acclimated inoculum allowed very rapid increases in OLR. • Highest CH{sub 4} yields were observed at OLR 3 kg VS/m{sup 3}day with untreated FW. • Autoclaved FW produced highest CH{sub 4} yields during OLR 4 kgVS/m{sup 3}day. - Abstract: Anaerobic digestion of autoclaved (160 °C, 6.2 bar) and untreated source segregated food waste (FW) was compared over 473 days in semi-continuously fed mesophilic reactors with trace elements supplementation, at organic loading rates (OLRs) of 2, 3, 4 and 6 kg volatile solids (VS)/m{sup 3} d. Methane yields at all OLR were 5–10% higher for untreated FW (maximum 0.483 ± 0.013 m{sup 3} CH{sub 4}/kg VS at 3 kg VS/m{sup 3} d) than autoclaved FW (maximum 0.439 ± 0.020 m{sup 3} CH{sub 4}/kg VS at 4 kg VS/m{sup 3} d). The residual methane potential of both digestates at all OLRs was less than 0.110 m{sup 3} CH{sub 4}/kg VS, indicating efficient methanation in all cases. Use of acclimated inoculum allowed very rapid increases in OLR. Reactors fed on autoclaved FW showed lower ammonium and hydrogen sulphide concentrations, probably due to reduced protein hydrolysis as a result of formation of Maillard compounds. In the current study this reduced biodegradability appears to outweigh any benefit due to thermal hydrolysis of ligno-cellulosic components.

  15. Development of autoclave moldable addition-type polyimides

    Science.gov (United States)

    Vaughan, R. W.; Jones, R. J.; Orell, M. K.; Zakrzewski, G. A.

    1976-01-01

    Chemistry and processing modifications of the poly(Diels Alder) polyimide (PDA) resin were performed to obtain structural composites suitable for 589 K (600 F) service. This work demonstrated that the PDA resin formulation is suitable for service at 589 K (600 F) for up to 125 hours when used in combination with Hercules HTS graphite fiber. Sandwich panels were autoclave molded using PDA/HTS skins and polyimide/glass honeycomb core. Excellent adhesion between honeycomb core and the facing skins was demonstrated. Fabrication ease was demonstrated by autoclave molding three-quarter scale YF-12 wing panels.

  16. Methane biofiltration using Autoclaved Aerated Concrete as the carrier material

    NARCIS (Netherlands)

    Ganendra, Giovanni; Mercado-Garcia, Daniel; Hernandez-Sanabria, Emma; Boeckx, P.; Ho, Adrian; Boon, N.

    2015-01-01

    The methane removal capacity of mixed methane-oxidizing bacteria (MOB) culture in a biofilter setup using autoclaved aerated concrete (AAC) as a highly porous carrier material was tested. Batch experiment was performed to optimize MOB immobilization on AAC specimens where optimum methane removal was

  17. 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.

  18. Porosity and Mechanical Strength of an Autoclaved Clayey Cellular Concrete

    Directory of Open Access Journals (Sweden)

    P. O. Guglielmi

    2010-01-01

    Full Text Available This paper investigates the porosity and the mechanical strength of an Autoclaved Clayey Cellular Concrete (ACCC with the binder produced with 75 wt% kaolinite clay and 25 wt% Portland cement. Aluminum powder was used as foaming agent, from 0.2 wt% to 0.8 wt%, producing specimens with different porosities. The results show that the specimens with higher content of aluminum presented pore coalescence, which can explain the lower porosity of these samples. The porosities obtained with the aluminum contents used in the study were high (approximately 80%, what accounts for the low mechanical strength of the investigated cellular concretes (maximum of 0.62 MPa. Nevertheless, comparing the results obtained in this study to the ones for low temperature clayey aerated concrete with similar compositions, it can be observed that autoclaving is effective for increasing the material mechanical strength.

  19. Non-autoclaved aerated concrete with mineral additives

    Science.gov (United States)

    Il'ina, L. V.; Rakov, M. A.

    2016-01-01

    We investigated the effect of joint grinding of Portland cement clinker, silica and carbonate components and mineral additives to specific surface of 280 - 300 m2/kg on the properties (strength, average density and thermal conductivity) of non-autoclaved aerated concrete, and the porosity of the hardened cement paste produced from Portland cement clinker with mineral additives. The joint grinding of the Portland cement clinker with silica and carbonate components and mineral additives reduces the energy consumption of non-autoclaved aerated concrete production. The efficiency of mineral additives (diopside, wollastonite) is due to the closeness the composition, the type of chemical bonds, physical and chemical characteristics (specific enthalpy of formation, specific entropy) to anhydrous clinker minerals and their hydration products. Considering the influence of these additions on hydration of clinker minerals and formation of hardened cement paste structure, dispersed wollastonite and diopside should be used as mineral additives. The hardness and, consequently, the elastic modulus of diopside are higher than that of hardened cement paste. As a result, there is a redistribution of stresses in the hardened cement paste interporous partitions and hardening, both the partitions and aerated concrete on the whole. The mineral additives introduction allowed to obtain the non-autoclaved aerated concrete with average density 580 kg/m3, compressive strength of 3.3 MPa and thermal conductivity of 0.131 W/(m.°C).

  20. Development of a Fully Automated Guided Wave System for In-Process Cure Monitoring of CFRP Composite Laminates

    Science.gov (United States)

    Hudson, Tyler B.; Hou, Tan-Hung; Grimsley, Brian W.; Yaun, Fuh-Gwo

    2016-01-01

    A guided wave-based in-process cure monitoring technique for carbon fiber reinforced polymer (CFRP) composites was investigated at NASA Langley Research Center. A key cure transition point (vitrification) was identified and the degree of cure was monitored using metrics such as amplitude and time of arrival (TOA) of guided waves. Using an automated system preliminarily developed in this work, high-temperature piezoelectric transducers were utilized to interrogate a twenty-four ply unidirectional composite panel fabricated from Hexcel (Registered Trademark) IM7/8552 prepreg during cure. It was shown that the amplitude of the guided wave increased sharply around vitrification and the TOA curve possessed an inverse relationship with degree of cure. The work is a first step in demonstrating the feasibility of transitioning the technique to perform in-process cure monitoring in an autoclave, defect detection during cure, and ultimately a closed-loop process control to maximize composite part quality and consistency.

  1. Carbon Foam Self-Heated Tooling for Out-of-Autoclave Composites Manufacturing Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Touchstone Research Laboratory, Ltd. (Touchstone) has developed a novel and innovative Out-of-Autoclave (OOA) composites manufacturing process with an electrically...

  2. Influence of post-cure treatments on hardness and marginal adaptation of composite resin inlay restorations: an in vitro study

    Directory of Open Access Journals (Sweden)

    Laiza Tatiana Poskus

    2009-12-01

    Full Text Available OBJECTIVES: The purpose of this study was to evaluate the Vickers hardness number (VHN and the in vitro marginal adaptation of inlay restorations of three hybrid composite resins (Filtek Z250, Opallis and Esthet-X subjected to two post-cure treatments. MATERIAL AND METHODS: For the microhardness test, three different groups were prepared in accordance with the post-cure treatments: control group (only light cure for 40 s, autoclave group (light cure for 40 s + autoclave for 15 min at 130ºC; and microwave group (light cure for 40 s + microwave for 3 min at 450 W. To assess the marginal adaptation, the composite resin was inserted incrementally into a mesial-occlusal-distal cavity brass mold and each increment light-cured for 40 s. A previous reading in micrometers was taken at the cervical wall, using a stereomicroscope magnifying glass equipped with a digital video camera and image-analysis software. Subsequently, the specimens were subjected to the post-cure treatments (autoclave and microwave and a reading was taken again at the cervical wall. Data were compared using ANOVA for the hardness test, split-plot ANOVA for the adaptation assessment and Tukey's test for multiple comparisons. A significance level of 5% was adopted for all analyses. RESULTS: The post-cure treatments increased the hardness of conventional composites (p<0.001 and the gap values of inlay restorations (p<0.01. Filtek Z250 showed higher hardness (p<0.001 and lower gap values than Opallis and Esthet-X (p<0.05. Gap values did not exceed 90 µm for any of the experimental conditions. CONCLUSION: The post-cure treatments increased the VHN and the gap values on the cervical floor of composite resin inlays. Moreover, Filtek Z250 showed the best results, with higher hardness and lower gap values.

  3. 加气混凝土制备工艺影响因素分析%Analysis of Influential Factors on Preparation of Autoclaved Aerated Concrete

    Institute of Scientific and Technical Information of China (English)

    罗立群; 程琪林

    2015-01-01

    Aimed at new requirements brought up by domestic building material market, autoclaved aerated concrete has been acclaimed owning to its several particular performance advantages such as lightweight, thermal insulation, acoustic insulation, anti-seismic, etc. After preparation process of auto-claved aerated concrete was briefly summarized, it focused on influence of material characteristics on the properties of the products such as siliceous material, calcareous material, vesicant, water-solid ratio and ad-ditives. Influence mechanism of curing conditions of green body, reaction process of preparation and prod-ucts microstructure on performance of autoclaved aerated concrete were introduced. Eventually, direction of development of autoclaved aerated concrete was prospected in the future.%针对建材市场节能环保产品的需求,加气混凝土制品以其独特的质轻节能、保温隔热、抗震隔音等综合性能优势而备受关注。简述了蒸压加气混凝土的制备过程,重点阐述了制备加气混凝土砌块的硅质材料、钙质材料、发气剂、水料比及添加物等物料特性对制品性能的影响,介绍了坯体养护条件、制备过程反应以及制品微观结构对加气混凝土性能的影响机理,展望了加气混凝土未来的发展方向。

  4. Study of Electron Beam Curing Process Using Epoxy Resin System

    International Nuclear Information System (INIS)

    The competition among industries in the current globalization system has required a systematic cost reduction without affecting the quality of the final product. This fact has encouraged the use of new technologies application on productive process, especially on polymeric composites, to assure the competitiveness. The possibility of producing a new type of carbon fiber reinforced composite by radiation process with excellent thermal and mechanical properties, has been researched since 90's and it can be a potential application in aerospace, marine and automobile industries. The polymeric composites cured by thermal process (furnace or autoclave) are an example of long curing cycles, which requires time and energy consumption. Electron beam curing technology allows the process at room temperature and reduces curing time; consequently, it becomes the main difference of this technology over thermal curing process. The aim of this work was to study electron beam curable epoxy formulation for filament winding process, as well as to investigate the electron beam curing process parameters using a DC 1500/25 - Job 188 Dynamitron model linear accelerator as radiation source, with 0.5 to 1.5 MeV, 0.1 to 25 mA and 60 to 120 cm scanning electron beam. The resin system consists of commercial epoxy resin (diglycidyl ether of bisphenol A - DGEBA) and cationic initiator (diaryliodonium hexafluoantimonate) and the polymerization carried out at room temperature with controlled dose rate. Thermal post cure took part of the process to improve the degree of cure and glass transition temperature (Tg) similar to thermal curable resin properties

  5. 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.

  6. Economic method of development of canned food sterilization regimes for industry autoclaves

    Directory of Open Access Journals (Sweden)

    Stolyanov A. V.

    2015-12-01

    Full Text Available Utilization of the sterilization equipment AVK-30M for development of sterilization regimes of canned food for industrial autoclaves, particularly for ASCAMAT 230, has been described. Energy consumption of autoclaves during stages of heating and sterilization has been compared as well

  7. PATI RESISTEN SAGU HASIL PROSES HIDROLISIS ASAM DAN AUTOCLAVING-COOLING [Resistant Starch of Sago from Acid Hydrolyzis and Autoclaving-Cooling Processes

    Directory of Open Access Journals (Sweden)

    Feri Kusnandar

    2015-07-01

    Full Text Available The aim of this study was to produce resistant starch (RS from a combination of acid hydrolysis and autoclaving-cooling processes of sago starch. This study compared two methods of starch modification to produce RS, i.e. (1 acid hydrolysis treatment followed by autoclaving-cooling cycles (AH-AC, and (2 autoclaving-cooling cycles followed by acid hydrolysis treatment (AC-AH. The acid hydrolysis used 1 and 2% HCl while autoclaving-cooling process consisted of three-cycle of autoclaving at 121°C for 30 min followed by cooling at 4°C for 72 hrs. Both AH-AC and AC-AH modification methods decreased starch content, altered amylose and amylopectin ratio, and increased RS contents. Both modification methods also yielded nearly flat pasting profiles at both heating and cooling phases as compared to that of native sago starch. At the same HCl concentration, the AH-AC process yielded a higher RS content than that of AC-AH. Among all treatments, the acid hydrolysis treatment using 1% HCl followed by three cycles of autoclaving-cooling process yielded the highest RS content (74.28%. The crystallinity of RS was also lower than of native sago starch, but its A crystalline type remained the same.

  8. Optimization of the Temperature-Time Curve for the Curing Process of Thermoset Matrix Composites

    Science.gov (United States)

    Aleksendrić, Dragan; Carlone, Pierpaolo; Ćirović, Velimir

    2016-10-01

    An intelligent optimization model aiming at off-line or pre-series optimization of the thermal curing cycle of polymer matrix composites is proposed and discussed. The computational procedure is based on the coupling of a finite element thermochemical process model, dynamic artificial neural networks and genetic algorithms. Objective of the optimization routine is the maximization of the composite degree of cure by the definition of the autoclave temperature. Obtained outcomes evidenced the capability of the method as well as its efficiency with respect to hard computing or experimental procedures.

  9. 煅烧磷石膏对蒸压硅酸盐制品水化过程的影响%Effect of calcined phosphogypsum on hydration process of autoclaved silicate products

    Institute of Scientific and Technical Information of China (English)

    陆金驰; 李东南; 陈凯; 黄金林

    2012-01-01

    磷石膏经高温煅烧改性后与粉煤灰、砂粉、石灰及水泥熟料等制备蒸压硅酸盐制品,研究了不同温度煅烧的磷石膏对蒸压硅酸盐制品水化过程的影响,用蒸压制品中未反应的Ca(OH)2量及结合水量分析它们的反应速率,用XRD测定蒸压硅酸盐制品的水化产物,并结合SEM分析,结果表明,经煅烧的磷石膏对蒸压硅酸盐制品的水化有明显的促进作用,托勃莫来石与C-S-H (1)等水化产物的迅速生长而形成密实的水化产物结构是其增强蒸压硅酸盐制品的根本原因.%The effects of calcined phosphogypsum on the hydration process of the autoclaved silicate products were investigated in this paper. The influence of adding phosphogypsum calcined at different temperatures on the hydration rate of autoclaved silicate products was analyzed for un-reacted Ca(OH)2 content and combined water. The hydrates were determined with XRD and SEM. It was found that the hydration of autoclaved silicate products with added phosphogypsum calcined over 500℃ was greatly improved. The hydrates of the autoclaved silicate products with added phosphogypsum calcined over 500℃ had more un-reacted Ca(OH)2 content and combined water in the same curing time, and the research indicated that adding phosphogypsum calcined over 500℃ could also reinforce the compressive strength of autoclaved silicate products. It was pointed out that the aluminate phase present in the raw materials cannot hydrate to form more ettringite during autoclaved curing, and rapid formation of such hydrates as calcium silicate hydrate (1) and tobermorite with a more compact structure is the main reason for strengthening autoclaved silicate products.

  10. Response of MICROTOX organisms to leachates of autoclaved cellular concrete

    Energy Technology Data Exchange (ETDEWEB)

    Latona, M.C.; Neufeld, R.D.; Hu, W.; Kelly, C.; Vallejo, L.E. [Univ. of Pittsburgh, PA (United States). Dept. of Civil and Environmental Engineering

    1997-08-01

    The MICROTOX bioassay, a toxicity test involving bioluminescent microorganisms, was conducted on aqueous leachates derived from a construction material made using coal fly ash as the key siliceous ingredient. The material is known as autoclaved cellular concrete (ACC). The test indicated an absence of toxic effects attributable to soluble species, which included the priority heavy metals in the filtered leachates. Toxic or inhibitive effects on the test bacteria were observed for the toxicity characteristic leaching procedure (TCLP) leachates, but this was probably due to acetic acid in the extractant rather than the solubilized metals. The ASTM (distilled-deionized water extractant) and simulated acid rain leachates, by comparison, produced a repeatable stimulative effect. Stimulation observed in the form of enhanced light output may be a manifestation of hormesis, a phenomenon reportedly caused by exposure to extremely low concentrations (part-per-billion range) of otherwise toxic agents such as heavy metals.

  11. Leachate and radon production from fly ash autoclaved cellular concrete

    Energy Technology Data Exchange (ETDEWEB)

    Latona, M.C.; Neufeld, R.D.; Vallejo, L.E.; Brandon, D.; Hu, W.; Kelly, C. [Univ. of Pittsburgh, PA (United States). Dept. of Civil and Environmental Engineering

    1997-08-01

    Environmental consequences and potential liabilities of autoclaved cellular concrete (ACC) use were assessed by aqueous leaching of crushed samples for metals and organic solvent extractions of solid ACC for polycyclic aromatic hydrocarbons (PAHs). Also, whole ACC blocks were tested for radon exhalation potential. Results show leachate concentrations were typically 10 times below, and always 100 times below the regulatory threshold of applicable drinking water standards. A Microtox bioassay procedure showed no toxic effects due to leached metals. Organic analysis of solvent extracts indicated no release of hazardous PAHs attributable to the fly ash ingredient of ACC. Measured rates of radon exhalation were too low to cause potentially dangerous buildups in confined air spaces. Fly ash ACC may be characterized as an environmentally green construction material based on these findings.

  12. Methane biofiltration using autoclaved aerated concrete as the carrier material.

    Science.gov (United States)

    Ganendra, Giovanni; Mercado-Garcia, Daniel; Hernandez-Sanabria, Emma; Boeckx, Pascal; Ho, Adrian; Boon, Nico

    2015-09-01

    The methane removal capacity of mixed methane-oxidizing bacteria (MOB) culture in a biofilter setup using autoclaved aerated concrete (AAC) as a highly porous carrier material was tested. Batch experiment was performed to optimize MOB immobilization on AAC specimens where optimum methane removal was obtained when calcium chloride was not added during bacterial inoculation step and 10-mm-thick AAC specimens were used. The immobilized MOB could remove methane at low concentration (~1000 ppmv) in a biofilter setup for 127 days at average removal efficiency (RE) of 28.7 %. Unlike a plug flow reactor, increasing the total volume of the filter by adding a biofilter in series did not result in higher total RE. MOB also exhibited a higher abundance at the bottom of the filter, in proximity with the methane gas inlet where a high methane concentration was found. Overall, an efficient methane biofilter performance could be obtained using AAC as the carrier material. PMID:25967655

  13. Grafting and curing

    International Nuclear Information System (INIS)

    Progress in radiation grafting and curing is briefly reviewed. The two processes are shown to be mechanistically related. The parameters influencing yields are examined particularly for grafting. For ionising radiation grafting systems (EB and gamma ray) these include solvents, substrate and monomer structure, dose and dose-rate, temperature and more recently role of additives. In addition, for UV grafting, the significance of photoinitiators is discussed. Current applications of radiation grafting and curing are outlined. The recent development of photoinitiator free grafting and curing is examined as well as the potential for the new excimer laser sources. The future application of both grafting and curing is considered, especially the significance of the occurrence of concurrent grafting during cure and its relevance in environmental considerations

  14. Numerical modelling of the strength of highly porous aerated autoclaved concrete

    Energy Technology Data Exchange (ETDEWEB)

    Schenider, T.; Greil, P. [Univ. of Erlangen-Nuernberg, Erlangen (Germany). Dept. of Materials Science; Schober, G. [Hebel AG, Fuerstenfeldbruck (Germany). Materialtechnische Entwicklung

    1998-12-31

    Highly porous building materials like aerated autoclaved concrete are characterized by low thermal conductivity and high mechanical strength, which both strongly depend on porosity. The influence of porosity distribution on the compressive strength of aerated autoclaved concrete was investigated by using finite element analysis and multiaxial Weibull theory. Calculations of failure probability of microstructures with ordered as well as random pore configurations show a dependence of compressive strength on the Weibull modulus of the matrix material and the size and arrangement of pores. The results of the calculations are compared to experimental data of aerated autoclaved concrete.

  15. Thermal Insulation and Strength of Autoclaved Light Concrete

    Institute of Scientific and Technical Information of China (English)

    YANG Ruochong; ZHU Jipeng; WU Zhishen; WU Zhiren; LI Min; PENG Changhai

    2011-01-01

    The primary objective of this study was to develop an autoclaved light concrete (ALC) material with ultra-thermal insulation property and to investigate the relationship between its physical characteristics and mechanical properties. Through tests of dry bulk density and compressive strength, relationship of physical characteristics and mechanical properties of samples were studied,resulting in a material with ultra-thermal insulation property. Scanning electron microscope (SEM) and energy-dispersive X-ray spectroscopy (EDX) were applied to analyze the micro-morphology and elemental composition of samples. To identify the product phases, X-ray diffraction (XRD) was engaged. The test results showed that compressive strength and thermal coefficient were reduced with the increasing of aluminum powder within the mixtures. As a result the optimal thermal coefficient and compressive strength of samples were improved to 0.061 W/(m · k) and 1.2 MPa, respectively. SEM,EDX and XRD analyses showed that calcium silicate hydrate and tobermorite crystal were main resultant phases.

  16. Curing metastatic testicular cancer

    OpenAIRE

    Einhorn, Lawrence H.

    2002-01-01

    Our initial studies with cisplatin + vinblastine + bleomycin began 27 years ago in 1974, changing the cure rate for disseminated disease from 5 to 60%. Subsequently, through random prospective clinical trials, we have modified the treatment regimen to reduce both the duration and dosages of the chemotherapy drugs. Cisplatin + etoposide was first used at Indiana University as salvage chemotherapy in 1978, representing the first time that a solid tumor had been cured with second-line chemothera...

  17. ANALYSIS OF MECHANICAL PROPERTIES OF HYDROTHERMALLY CURED HIGH STRENGTH CEMENT MATRIX FOR TEXTILE REINFORCED CONCRETE

    Directory of Open Access Journals (Sweden)

    Ondřej Holčapek

    2015-10-01

    Full Text Available The main objective of this article is to describe the influence of hydrothermal curing conditions in an autoclave device (different pressure and temperature, which took place at various ages of a fresh mixture (cement matrix – CM, and fibre-reinforced cement matrix – FRCM, on textile reinforced concrete production. The positive influence of autoclaving has been evaluated through the results of physical and mechanical testing – compressive strength, flexural strength, bulk density and dynamic modulus of elasticity, which have been measured on specimens with the following dimensions: 40×40×160mm3. In addition, it has been found that increasing the pressure and temperature resulted in higher values of measured characteristics. The results indicate that the most suitable surrounding conditions are 0.6MPa, and 165 °C at the age of 21 hours; the final compressive strength of cement matrix is 134.3MPa and its flexural strength is 25.9MPa (standard cured samples achieve 114.6MPa and 15.7MPa. Hydrothermal curing is even more effective for cement matrix reinforced by steel fibres (for example, the compressive strength can reach 177.5MPa, while laboratory-cured samples achieve a compressive strength of 108.5MPa.

  18. Carbon Foam Self-Heated Tooling for Out-of-Autoclave Composites Manufacturing Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This proposal addresses NASA's need for non-autoclave composites manufacture. The Constellation program, including the Ares V launch vehicle, will require very...

  19. Leaching of a copper flotation concentrate with ammonium persulfate in an autoclave system

    Institute of Scientific and Technical Information of China (English)

    M Deniz Turan; H Soner Altundoan

    2014-01-01

    The leaching behavior of a copper flotation concentrate was investigated using ammonium persulfate (APS) in an autoclave sys-tem. The decomposition products of APS, active oxygen, and acidic medium were used to extract metals from the concentrate. Leaching ex-periments were performed to compare the availability of APS as an oxidizing agent for leaching of the concentrate under atmospheric condi-tions and in an autoclave system. Leaching temperature and APS concentration were found to be important parameters in both leaching sys-tems. Atmospheric leaching studies showed that the metal extractions increased with the increase in APS concentration and temperature (up to 333 K). A similar tendency was determined in the autoclave studies up to 423 K. It was also determined that the metal extractions de-creased at temperatures above 423 K due to the passivation of the particle surface by molten elemental sulfur. The results showed that higher copper extractions could be achieved using an autoclave system.

  20. Effect of curing way on mechanical properties of PHC pipe piles%养护方式对PHC管桩力学性能的影响

    Institute of Scientific and Technical Information of China (English)

    王成启; 王春明; 周郁兵; 张宜兵

    2014-01-01

    The compressive strength and brittleness and modulus of elasticity of PHC pipe piles on standard curing and non-steam autoclaved and steam autoclaved are experimentally studied. The results show that the increase value of the compressive strength decreases continually according to the sequence of standard curing and non-steam autoclaved and steam autoclaved and circumstance humidity affects brittleness of PHC pipe piles and the brittleness of non-steam autoclaved concrete is less than steam autoclaved concrete’s. Moreover, circumstance humidity affects also modulus of elasticity of PHC pipe piles, cur-ing can increases modulus of elasticity of non-steam autoclaved piles concrete and modulus of elasticity of non-steam auto-claved piles concrete greater than steam autoclaved piles concrete’s.%文章开展标准养护、免压蒸养护和高压蒸汽养护3种养护方式对PHC管桩混凝土抗压强度、脆性和弹性模量的影响研究。结果表明,3种养护方式PHC管桩混凝土的抗压强度增幅按标准养护、免压蒸养护和高压蒸养的次序递减;环境湿度对免压蒸PHC管桩混凝土的脆性有一定的影响,免压蒸混凝土的脆性小于高压蒸养混凝土;环境湿度也对免压蒸PHC管桩混凝土的弹性模量产生一定的影响,适当后期养护可提高免压蒸混凝土的弹性模量,免压蒸养护混凝土的弹性模量大于高压蒸养混凝土。

  1. 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).

  2. Effects of surface treatments on the susceptibilities of low temperature degradation by autoclaving in zirconia.

    Science.gov (United States)

    Lee, Tae-Hoon; Lee, Sang-Hyuk; Her, Soo-Bok; Chang, Won-Gun; Lim, Bum-Soon

    2012-07-01

    The aim of this study was to investigate the effect of surface treatments on the aging susceptibilities by autoclaving in zirconia ceramics. Four commercially available tetragonal zirconia polycrystals and one zirconia-alumina composite were tested. Disk-shaped specimens were prepared and the grain sizes were analyzed using a scanning electron microscope and image analyzer. The specimens were divided into three groups based on surface treatments including heat treatment subsequent to mirror polishing, grinding, and sandblasting. Specimens in each group were autoclaved at 134°C for 1, 3, 5, 10, and 15 h. The phases of the specimens were analyzed using an X-ray diffractometer, and the relative amount of the monoclinic phase was calculated and analyzed using Student's t-test and Newman-Keuls multiple comparisons test. Single routine autoclave treatment for sterilization did not promote the phase transformation in zirconia. The phase transformations of all specimens by autoclaving were correlated with grain size, except for the zirconia-alumina composite. Grinding or sandblasting treatments gave rise to increased formation of the monoclinic phase, especially for the zirconia-alumina composite, which showed the highest fraction for the monoclinic phase. The effects of surface treatments on the aging susceptibilities by autoclaving were different in the experimental groups. It is notable that not all zirconia ceramics show similar phase transformation by autoclaving after surface treatments. PMID:22566390

  3. Morphological effects of autoclaved diet on the myenteric neurons of rats

    Institute of Scientific and Technical Information of China (English)

    Patrícia O Gon(c)alez; Naianne K Clebis; Renata B Mari; Karina M Gagliardo; Sandra R Stabille; Haroldo G Faria; Edson A Liberti; José Roberto Kfoury Jr

    2011-01-01

    AIM: To evaluate the effect of autoclaved diet on the jejunum neurons of the myenteric plexus of rats during their growth.METHODS: The experimental groups were made up of rats going through weaning whose mothers Received either an autoclaved or a non-autoclaved diet during gestation and lactation, and rats that were fed the same diet as their mothers during the post-weaning period. In order to measure the neurons' body pro-file and to quantify the number of neurons per area, preparations were stained by the nicotinamide adenine dinucleotide-diaphorase method.RESULTS: No significant changes were observed in rats' body weight or in the number of neurons regard-less of the diet used (P > 0.05). There was a decrease in the jejunum-ileum length in rats treated with an autoclaved diet (P < 0.05). An increase in the neuronal cross-sectional area was seen in rats that had Received the autoclaved diet, an effect that was significant for animals undergoing weaning. In addition, all observed factors showed significant differences when related to the age of the animals.CONCLUSION: The autoclaved diet did not alter the quantity of neurons, but increased their cell body area, suggesting changes similar to those observed in pro-tein deficiency.

  4. Effect of Sterilization by Dry Heat or Autoclaving on Bacterial Penetration through Berea Sandstone.

    Science.gov (United States)

    Jenneman, G E; McInerney, M J; Crocker, M E; Knapp, R M

    1986-01-01

    A study was undertaken to determine why bacteria could penetrate lengths of consolidated sandstone (Berea) faster when the sandstone was sterilized by autoclaving than when dry heat (150 degrees C, 3 h) was used. Changes in permeability, porosity, and pore entrance size of the rock as a result of autoclaving were not sufficient to explain the differences in penetration times observed, but electron dispersion spectroscopy and electron microscopy of the rock revealed changes in mineral composition and clay morphology. Autoclaved cores contained more chloride than dry-heated cores, and the clays of autoclaved cores were aggregated and irregularly shaped. Therefore, the decreases in bacterial penetration rates caused by autoclave sterilization were probably the result of a change in surface charge of the pores of the rock and of a reduction in surface area of clays available for adhesion. The results implied that dry-heat sterilization was preferable to autoclaving when examining biotic and abiotic interactions in a native-state rock model.

  5. Evaluation of dimensional stability and accuracy of autoclavable polyvinyl siloxane impression material.

    Science.gov (United States)

    Reddy, Subash M; Vijitha, D; Karthikeyan, S; Balasubramanian, R; Satish, A

    2013-12-01

    Dimensionally stable autoclavable impressions will be effective in controlling the cross-infection and contamination caused by patient's saliva and other oral secretions. The accuracy of newly introduced autoclavable polyvinyl siloxane impression material was assessed for its dimensional stability and accuracy. A standard metal model (Dentoform, U-501, Columbia) was customised for impression making. The impressions were made using the newly introduced polyvinyl siloxane impression materials (AFFINIS, Coltene/Whaledent AG, 9450 Alstalten, Switzerland). Fifty impressions were made and were divided into two groups A and B of 25 each. Group A was the control sample (non-autoclaved impressions) and group B was the test sample (autoclaved impressions), which was subjected to the steam autoclave procedure at 134 °C for 18 min, casts were poured in type IV gypsum products. The customised metal model, casts obtained from control and test group were subjected to laboratory evaluation with help of a travelling microscope (×10 magnification), and digital vernier calliper (0.01 mm/10 μm accuracy). Data analysis was done using one-way ANOVA and One-Sample t test to evaluate the overall accuracy (P polyvinyl siloxane impression material is accurate and dimensional stable for clinical use when steam autoclaved at 134 °C for 18 min.

  6. Gravity Effects of Curing Angle on Laminated Composite Structures: A Review on Novel Study

    Directory of Open Access Journals (Sweden)

    T. T. T. Jennise

    2013-01-01

    Full Text Available Composites manufactured by small and medium industries/entrepreneurs (SMI/E are conventionally cured in the horizontal position. Hence, the confined space restricts optimum productivity. Besides, SMI/E is unable to allocate high budget for high-end technology such as autoclave and vacuum mechanical oven which limits the development of SMI/E as a result of high capital cost. Through a series of literature review, the review confirmed that there is no similar scientific study has been conducted. Consequently, the review is carried out to facilitate the investigation of the feasibility of a gravity cured glass fiber laminated thermosetting composites via vacuum bagging at angle position from horizontal (0° to vertical (90° to enhance the curing space required.

  7. 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.

  8. 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

  9. Curing Efficacy of Light Emitting Diodes of Dental Curing Units

    OpenAIRE

    2009-01-01

    Background and aims The aim of the present study was to compare the efficacy of quartz tungsten halogen (QTH) and light emitting diode (LED) curing lights on polymerization of resin composite. Materials and methods A hybrid resin composite was used to prepare samples which were cured using two QTH and ten LED light curing sources. Twelve groups, each containing ten samples, were prepared using each light source. The cured depth of the resin was determined using ISO 4049 method and Vickers har...

  10. Some factors affecting the compressive strength of nickel slag autoclaved product%影响镍渣蒸压制品抗压强度的因素研究

    Institute of Scientific and Technical Information of China (English)

    余涛; 曹德光; 刘文威; 李浩璇; 陆石强

    2013-01-01

    试验利用镍渣、水泥熟料、熟石灰、电石渣等原料制备镍渣蒸压制品,探索了成型压力、增强剂加入量、加水量和蒸养制度等因素对镍渣蒸压制品抗压强度的影响规律.结果表明,本试验合适的成型压力为15~20 MPa,增强剂的最佳加入量为0.5%,合理的加水量为8.57%~10.00%,最佳的蒸压养护温度为180℃或190℃,对应的蒸压养护时间为8h或9h.此外,使用电石渣代替熟石灰利用相同工艺条件制备蒸压制品的抗压强度无明显差异.%Prepared from autoclaved product of nickel slag,cement clinker,slaked lime,carbide slag,the experiment studied some factors that affecting the compressive strength of nickel slag autoclaved product,such as molding pressure,content of enhancer,content of water added,steam curing system and so on.The results show that the suitable molding pressure is 15~20 MPa;the optimum enhancer content is 0.5%;the reasonable amount of water added is 8.57%~10.00%;the best autoclaving temperature is 180 ℃ or 190 ℃;autoclaving time is eight or nine hours.In addition,under the same process conditions,autoclaved product was successfully prepared if using carbide slag instead of slaked lime,and the compressive strength of autoclaved product had no significant difference.

  11. The release of 14C—chlorsulfuron bound residue by autoclaving method and its identification

    Institute of Scientific and Technical Information of China (English)

    GUOJiangfeng; PINGXiaofei; 等

    1999-01-01

    When individual microorganisms were used to release bound pesticide resdues,it was ussually not take into full account whether the autoclaving method could lead to the release of bound residues.The soil containing bound 14C-chlorsulfuron residues was treated with an autoclave in this study.The results reveal that the bound 14C-chlorsulfuron residue can be released from the soil when treated with the autoclave and the release rate can be remarkably enhanced by adding water into the soil when subjected to such treatment.A TLC analysis showed that the released 14C-residue was one of the degraded products of 14C-chlorsulfuron.After derivatization and analysis using the GC-MS,the released 14C-residue was tentatively identified as 2-amnino-4-hydroxyl-6-methyl-1,3,5-triazine.

  12. Modeling and simulation of high-pressure industrial autoclave polyethylene reactor

    Directory of Open Access Journals (Sweden)

    2008-01-01

    Full Text Available High-pressure technology for polyethylene production has been widely used by industries around the world. A good model for the reactor fluid dynamics is essential to set the operating conditions of an autoclave reactor. The high-pressure autoclave reactor model developed in this work was based on a non-isothermal dynamic model, where PID control equations are used to maintain the operation at the unstable steady state. The kinetic mechanism to describe the polymerization rate and molecular weight averages are presented. The model is capable of computing temperature, concentration gradients and polymer characteristics. The model was validated for an existing industrial reactor and data for production of homopolymer polyethylene and has represented well the behavior of the autoclave reactor used in ethylene homopolymerization.

  13. Distance to Cure

    OpenAIRE

    Capachi, Casey

    2013-01-01

    Distance to Cure A three-part television series by Casey Capachi www.distancetocure.com   Abstract   How far would you go for health care? This three-part television series, featuring two introductory segments between each piece, focuses on the physical, cultural, and political obstacles facing rural Native American patients and the potential of health technology to break down those barriers to care.   Part one,Telemedici...

  14. HANDLING ANISOTROPY AND STRENGTH OF FIBER-REINFORCED PLASTIC VIA LOCAL INHIBITION OF THE CURING PROCESS

    Directory of Open Access Journals (Sweden)

    Mr. Alexander E. Protsenko

    2016-06-01

    Full Text Available The authors study the possibility of increasing the polymer composite material strength, of reducing anisotropy of cross-breaking strength. The effect is achieved due to local inhibition of prepreg package. During the prepreg curing process by the vacuum-autoclave method, the inlay gelling action occurs later than in three-layer prepreg packets though they are located between them. The processes of increasing cross-breaking strength and of reducing the anisotropy are associated with the possibility of free shrinkage of three-layer prepreg packets.

  15. Efficient composite fabrication using electron-beam rapidly cured polymers engineered for several manufacturing processes

    International Nuclear Information System (INIS)

    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 Tgs. 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

  16. Bisphenol-A: an estrogenic substance is released from polycarbonate flasks during autoclaving.

    Science.gov (United States)

    Krishnan, A V; Stathis, P; Permuth, S F; Tokes, L; Feldman, D

    1993-06-01

    In studies to determine whether Saccharomyces cerevisiae produced estrogens, the organism was grown in culture media prepared using distilled water autoclaved in polycarbonate flasks. The yeast-conditioned media showed the presence of a substance that competed with [3H]estradiol for binding to estrogen receptors (ER) from rat uterus. However, it soon became clear that the estrogenic substance in the conditioned media was not a product of the yeast grown in culture, but was leached out of the polycarbonate flasks during the autoclaving procedure. [3H]Estradiol displacement activity was monitored by ER RRA, and the active substance was purified from autoclaved medium using a series of HPLC steps. The final purified product was identified as bisphenol-A (BPA) by nuclear magnetic resonance spectroscopy and mass spectrometry. BPA could also be identified in distilled water autoclaved in polycarbonate flasks without the requirement of either the organism or the constituents of the culture medium. Authentic BPA was active in competitive RRAs, demonstrating an affinity approximately 1:2000 that of estradiol for ER. In functional assays, BPA (10-25 nM) induced progesterone receptors in cultured human mammary cancer cells (MCF-7) at a potency of approximately 1:5000 compared to that of estradiol. The BPA effect on PR induction was blocked by tamoxifen. In addition, BPA (25 nM) increased the rate of proliferation of MCF-7 cells assessed by [3H]thymidine incorporation. Thus, BPA exhibited estrogenic activity by both RRA and two functional bioresponse assays. Finally, MCF-7 cells grown in media prepared with water autoclaved in polycarbonate exhibited higher progesterone receptor levels than cells.grown in media prepared with water autoclaved in glass, suggesting an estrogenic effect of the water autoclaved in polycarbonate. Our findings raise the possibility that unsuspected estrogenic activity in the form of BPA may have an impact on experiments employing media autoclaved in

  17. Composite Cure Process Modeling and Simulations using COMPRO(Registered Trademark) and Validation of Residual Strains using Fiber Optics Sensors

    Science.gov (United States)

    Sreekantamurthy, Thammaiah; Hudson, Tyler B.; Hou, Tan-Hung; Grimsley, Brian W.

    2016-01-01

    Composite cure process induced residual strains and warping deformations in composite components present significant challenges in the manufacturing of advanced composite structure. As a part of the Manufacturing Process and Simulation initiative of the NASA Advanced Composite Project (ACP), research is being conducted on the composite cure process by developing an understanding of the fundamental mechanisms by which the process induced factors influence the residual responses. In this regard, analytical studies have been conducted on the cure process modeling of composite structural parts with varied physical, thermal, and resin flow process characteristics. The cure process simulation results were analyzed to interpret the cure response predictions based on the underlying physics incorporated into the modeling tool. In the cure-kinetic analysis, the model predictions on the degree of cure, resin viscosity and modulus were interpreted with reference to the temperature distribution in the composite panel part and tool setup during autoclave or hot-press curing cycles. In the fiber-bed compaction simulation, the pore pressure and resin flow velocity in the porous media models, and the compaction strain responses under applied pressure were studied to interpret the fiber volume fraction distribution predictions. In the structural simulation, the effect of temperature on the resin and ply modulus, and thermal coefficient changes during curing on predicted mechanical strains and chemical cure shrinkage strains were studied to understand the residual strains and stress response predictions. In addition to computational analysis, experimental studies were conducted to measure strains during the curing of laminated panels by means of optical fiber Bragg grating sensors (FBGs) embedded in the resin impregnated panels. The residual strain measurements from laboratory tests were then compared with the analytical model predictions. The paper describes the cure process

  18. Curing Composite Materials Using Lower-Energy Electron Beams

    Science.gov (United States)

    Byrne, Catherine A.; Bykanov, Alexander

    2004-01-01

    In an improved method of fabricating composite-material structures by laying up prepreg tapes (tapes of fiber reinforcement impregnated by uncured matrix materials) and then curing them, one cures the layups by use of beams of electrons having kinetic energies in the range of 200 to 300 keV. In contrast, in a prior method, one used electron beams characterized by kinetic energies up to 20 MeV. The improved method was first suggested by an Italian group in 1993, but had not been demonstrated until recently. With respect to both the prior method and the present improved method, the impetus for the use of electron- beam curing is a desire to avoid the high costs of autoclaves large enough to effect thermal curing of large composite-material structures. Unfortunately, in the prior method, the advantages of electron-beam curing are offset by the need for special walls and ceilings on curing chambers to shield personnel from x rays generated by impacts of energetic electrons. These shields must be thick [typically 2 to 3 ft (about 0.6 to 0.9 m) if made of concrete] and are therefore expensive. They also make it difficult to bring large structures into and out of the curing chambers. Currently, all major companies that fabricate composite-material spacecraft and aircraft structures form their layups by use of automated tape placement (ATP) machines. In the present improved method, an electron-beam gun is attached to an ATP head and used to irradiate the tape as it is pressed onto the workpiece. The electron kinetic energy between 200 and 300 keV is sufficient for penetration of the ply being laid plus one or two of the plies underneath it. Provided that the electron-beam gun is properly positioned, it is possible to administer the required electron dose and, at the same time, to protect personnel with less shielding than is needed in the prior method. Adequate shielding can be provided by concrete walls 6 ft (approximately equal to 1.8 m) high and 16 in. (approximately

  19. Relaxed Poisson cure rate models.

    Science.gov (United States)

    Rodrigues, Josemar; Cordeiro, Gauss M; Cancho, Vicente G; Balakrishnan, N

    2016-03-01

    The purpose of this article is to make the standard promotion cure rate model (Yakovlev and Tsodikov, ) more flexible by assuming that the number of lesions or altered cells after a treatment follows a fractional Poisson distribution (Laskin, ). It is proved that the well-known Mittag-Leffler relaxation function (Berberan-Santos, ) is a simple way to obtain a new cure rate model that is a compromise between the promotion and geometric cure rate models allowing for superdispersion. So, the relaxed cure rate model developed here can be considered as a natural and less restrictive extension of the popular Poisson cure rate model at the cost of an additional parameter, but a competitor to negative-binomial cure rate models (Rodrigues et al., ). Some mathematical properties of a proper relaxed Poisson density are explored. A simulation study and an illustration of the proposed cure rate model from the Bayesian point of view are finally presented. PMID:26686485

  20. Cure og giggle micturition..

    OpenAIRE

    Brocklebank, J T; Meadow, S R

    1981-01-01

    Two boys, aged 11 and 13, had involuntary, unstoppable, and complete emptying of the bladder on laughter. In one the wetting occurred only when standing and in company, but in the other occurred regardless of posture or company. One boy had a strong family history of wetting including a grandmother who had giggle micturition as a teenager. The symptoms had been present for between 1 and 2 years. However, unlike cases previously reported, each boy was cured--one within 6 weeks and the other wi...

  1. Production technology of low silicon iron copper tailings autoclaved brick%低硅铜铁尾矿生产蒸压砖的技术研究

    Institute of Scientific and Technical Information of China (English)

    邓景明; 唐怀志

    2013-01-01

      以低硅铜铁尾矿为主要原料,掺入适量矿渣、铜渣、硅铝酸盐、硫酸盐、碳酸盐组成的固化剂经过加压成型后,在183℃温度的蒸压养护下制成标准砖,该砖平均抗压强度达到13.6 MPa,抗冻性能指标合格,固体废弃物利用率达到90%以上.%The paper introduces a kind of autoclaved brick, which is made of low silicon copper iron tailings as a main raw material, and appropriate mixture of amount of slag, copper slag, aluminosilicate, sulfates, carbonates as curing agent. The mixture is pressed into brick and cured at 183 ℃, which can reach 13.6 MPa of average compressive strength and qualified frost resistance index.

  2. Biochemical methane potential tests of different autoclaved and microwaved lignocellulosic organic fractions of municipal solid waste.

    Science.gov (United States)

    Pecorini, Isabella; Baldi, Francesco; Carnevale, Ennio Antonio; Corti, Andrea

    2016-10-01

    The aim of this research was to enhance the anaerobic biodegradability and methane production of two synthetic Organic Fractions of Municipal Solid Waste with different lignocellulosic contents by assessing microwave and autoclave pre-treatments. Biochemical Methane Potential assays were performed for 21days. Changes in the soluble fractions of the organic matter (measured by soluble chemical oxygen demand, carbohydrates and proteins), the first order hydrolysis constant kh and the cumulated methane production at 21days were used to evaluate the efficiency of microwaving and autoclaving pretreatments on substrates solubilization and anaerobic digestion. Microwave treatment led to a methane production increase of 8.5% for both the tested organic fractions while autoclave treatment had an increase ranging from 1.0% to 4.4%. Results showed an increase of the soluble fraction after pre-treatments for both the synthetic organic fractions. Soluble chemical oxygen demand observed significant increases for pretreated substrates (up to 219.8%). In this regard, the mediocre results of methane's production led to the conclusion that autoclaving and microwaving resulted in the hydrolysis of a significant fraction of non-biodegradable organic substances recalcitrant to anaerobic digestion.

  3. Synthesis and characterization of strontium carboxylates at room temperature and at high temperature in autoclave vessels

    DEFF Research Database (Denmark)

    Christgau, Stephan; Ståhl, Kenny; Andersen, Jens Enevold Thaulov

    2006-01-01

    -ray crystallography. Optimum conditions were found at T = 120-1400C, a base-to-acid ratio of 1.2 and 15 min. of reaction-time in an autoclave vessel. Large crystals were readily obtained within a time period of hours. The crystal structures of strontium D-glutamate hexahydrate (I) and strontium di-(hydrogen L...

  4. Moisture conditions of modern structures made of autoclaved aerated concrete in operation period

    Directory of Open Access Journals (Sweden)

    P.S. Zyryanov

    2011-03-01

    Full Text Available In St.-Petersburg and area six organizations making cellular concrete of autoclave hardening operate. At all enterprises the cellular concrete is made by the gas way of pore development by molding technology. The molding technology in practice means that the mass humidity of concrete on an exit from autoclaves will be at level of 35-45 % (great values of humidity correspond to smaller density. The similar situation is observed in other regions: more than 80 % of all autoclave cellular concrete in Russia are made by molding technology. The high humidity caused by presence of technological and constructional moisture in an initial stage of operation quickly decreases, reaching gradually operational level. The established humidity of cellular autoclave concrete as a part of protecting walls makes 3–6 % on weight. However the raised humidity of cellular concrete in an operation initial stage causes smaller settlement values of durability of concrete in a laying. Durability of concrete, in turn, influences on bearing capacity of anchorings for ventilated facades, if they are fastened in a body of cellular concrete. Thus, the information on dynamics of change of laying humidity in an operation initial stage allows to estimate terms of reach by designs calculated strength and thermophysical parameters.

  5. Biofiltration of Methane from Ruminants Gas Effluent Using Autoclaved Aerated Concrete as the Carrier Material

    NARCIS (Netherlands)

    Ganendra, Giovanni; Mercado-Garcia, Daniel; Hernandez-Sanabria, Emma; Peiren, Nico; De Campeneere, Sam; Ho, Adrian; Boon, Nico

    2015-01-01

    Abstract The performance of Methane-Oxidizing Bacteria (MOB) immobilized on Autoclaved Aerated Concrete (AAC) in a biofilter setup to remove methane from ruminants gas effluent was investigated. Two dairy cows were housed in respiration chambers for two days where the exhaust gas from the chambers w

  6. Autoclave reduction of jarosites and other metal sulfates : a new approach to major waste problems

    NARCIS (Netherlands)

    Hage, J.T.L.

    1999-01-01

    Industrial jarosite is a waste product of the zinc industry. It is considered a serious environmental problem, due to the quantity produced and the mobile hazardous metals it contains. Over 50 million tons are already stored worldwide. The jarosite sludge autoclave treatment process described in thi

  7. Autoclave reduction of jarosites and other metal sulfates : a new approach to major waste problems

    OpenAIRE

    Hage, J.L.T.

    1999-01-01

    Industrial jarosite is a waste product of the zinc industry. It is considered a serious environmental problem, due to the quantity produced and the mobile hazardous metals it contains. Over 50 million tons are already stored worldwide. The jarosite sludge autoclave treatment process described in this thesis is a technically and economically feasible alternative to storage, which is only a temporary solution.

  8. 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.

  9. Bacteria in crude oil survived autoclaving and stimulated differentially by exogenous bacteria.

    Science.gov (United States)

    Gong, Xiao-Cui; Liu, Ze-Shen; Guo, Peng; Chi, Chang-Qiao; Chen, Jian; Wang, Xing-Biao; Tang, Yue-Qin; Wu, Xiao-Lei; Liu, Chun-Zhong

    2012-01-01

    Autoclaving of crude oil is often used to evaluate the hydrocarbon-degrading abilities of bacteria. This may be potentially useful for bioaugmentation and microbial enhanced oil recovery (MEOR). However, it is not entirely clear if "endogenous" bacteria (e.g., spores) in/on crude oil survive the autoclaving process, or influence subsequent evaluation of the hydrocarbon-degradation abilities of the "exogenous" bacterial strains. To test this, we inoculated autoclaved crude oil medium with six exogenous bacterial strains (three Dietzia strains, two Acinetobacter strains, and one Pseudomonas strain). The survival of the spore-forming Bacillus and Paenibacillus and the non-spore-forming mesophilic Pseudomonas, Dietzia, Alcaligenes, and Microbacterium was detected using a 16S rRNA gene clone library and terminal restriction fragment length polymorphism (T-RFLP) analysis. However, neither bacteria nor bacterial activity was detected in three controls consisting of non-inoculated autoclaved crude oil medium. These results suggest that detection of endogenous bacteria was stimulated by the six inoculated strains. In addition, inoculation with Acinetobacter spp. stimulated detection of Bacillus, while inoculation with Dietzia spp. and Pseudomonas sp. stimulated the detection of more Pseudomonas. In contrast, similar exogenous bacteria stimulated similar endogenous bacteria at the genus level. Based on these results, special emphasis should be applied to evaluate the influence of bacteria capable of surviving autoclaving on the hydrocarbon-degrading abilities of exogenous bacteria, in particular, with regard to bioaugmentation and MEOR. Bioaugmentation and MEOR technologies could then be developed to more accurately direct the growth of specific endogenous bacteria that may then improve the efficiency of treatment or recovery of crude oil. PMID:23028421

  10. Bacteria in crude oil survived autoclaving and stimulated differentially by exogenous bacteria.

    Directory of Open Access Journals (Sweden)

    Xiao-Cui Gong

    Full Text Available Autoclaving of crude oil is often used to evaluate the hydrocarbon-degrading abilities of bacteria. This may be potentially useful for bioaugmentation and microbial enhanced oil recovery (MEOR. However, it is not entirely clear if "endogenous" bacteria (e.g., spores in/on crude oil survive the autoclaving process, or influence subsequent evaluation of the hydrocarbon-degradation abilities of the "exogenous" bacterial strains. To test this, we inoculated autoclaved crude oil medium with six exogenous bacterial strains (three Dietzia strains, two Acinetobacter strains, and one Pseudomonas strain. The survival of the spore-forming Bacillus and Paenibacillus and the non-spore-forming mesophilic Pseudomonas, Dietzia, Alcaligenes, and Microbacterium was detected using a 16S rRNA gene clone library and terminal restriction fragment length polymorphism (T-RFLP analysis. However, neither bacteria nor bacterial activity was detected in three controls consisting of non-inoculated autoclaved crude oil medium. These results suggest that detection of endogenous bacteria was stimulated by the six inoculated strains. In addition, inoculation with Acinetobacter spp. stimulated detection of Bacillus, while inoculation with Dietzia spp. and Pseudomonas sp. stimulated the detection of more Pseudomonas. In contrast, similar exogenous bacteria stimulated similar endogenous bacteria at the genus level. Based on these results, special emphasis should be applied to evaluate the influence of bacteria capable of surviving autoclaving on the hydrocarbon-degrading abilities of exogenous bacteria, in particular, with regard to bioaugmentation and MEOR. Bioaugmentation and MEOR technologies could then be developed to more accurately direct the growth of specific endogenous bacteria that may then improve the efficiency of treatment or recovery of crude oil.

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

    OpenAIRE

    Carola Esposito Corcione; Fabrizio Freuli; Mariaenrica Frigione

    2014-01-01

    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 als...

  12. Composite Cryotank Technologies and Development 2.4 and 5.5M out of Autoclave Tank Test Results

    Science.gov (United States)

    Jackson, Justin R.; Vickers, John; Fikes, John

    2015-01-01

    The Composite Cryotank Technologies and Demonstration (CCTD) project substantially matured composite, cryogenic propellant tank technology. The project involved the design, analysis, fabrication, and testing of large-scale (2.4-m-diameter precursor and 5.5-m-diameter) composite cryotanks. Design features included a one-piece wall design that minimized tank weight, a Y-joint that incorporated an engineered material to alleviate stress concentration under combined loading, and a fluted core cylindrical section that inherently allows for venting and purging. The tanks used out-of-autoclave (OoA) cured graphite/epoxy material and processes to enable large (up to 10-m-diameter) cryotank fabrication, and thin-ply prepreg to minimize hydrogen permeation through tank walls. Both tanks were fabricated at Boeing using automated fiber placement on breakdown tooling. A fluted core skirt that efficiently carried axial loads and enabled hydrogen purging was included on the 5.5-m-diameter tank. Ultrasonic inspection was performed, and a structural health monitoring system was installed to identify any impact damage during ground processing. The precursor and 5.5-m-diameter tanks were tested in custom test fixtures at the National Aeronautics and Space Administration Marshall Space Flight Center. The testing, which consisted of a sequence of pressure and thermal cycles using liquid hydrogen, was successfully concluded and obtained valuable structural, thermal, and permeation performance data. This technology can be applied to a variety of aircraft and spacecraft applications that would benefit from 30 to 40% weight savings and substantial cost savings compared to aluminum lithium tanks.

  13. Multibunch Instabilities and Cures

    CERN Document Server

    Fox, J

    2003-01-01

    The common approach to achieve the high luminosity needed for high precision measurements adopted by the particle factories now under construction consists in storing high current e sup + e sup - beams distributed in many bunches in separate rings. The beams are brought together to collide at one interaction point. An inconvenience of this strategy is that the performances can be seriously limited by unstable coupled-bunch oscillations excited by transients or noise and sustained by long-lasting parasitic resonating modes (high order modes-HOM) in the vacuum chamber, mainly in the RF cavities. Minimization of the HOM content and broad-band feedback systems together with the reduction of the driving transients are the complementary cures to this kind of disease. This paper introduces the subject with some examples and special emphasis on bunch-by-bunch feedback systems.

  14. Elevated Temperature, Notched Compression Performance of Out of Autoclave Processed Composites

    Science.gov (United States)

    Grimsley, Brian W.; Sutter, James K.; Dixon, Genevieve D.; Smeltzer, Satn S.

    2013-01-01

    Curved honeycomb sandwich panels composed of carbon fiber reinforced toughened-epoxy polymer facesheets are being evaluated for potential use as payload fairing components on the NASA heavy-lift space launch system (HL-SLS). These proposed composite sandwich panels provide the most efficient aerospace launch structures, and offer mass and thermal advantages when compared with existing metallic payload fairing structures. NASA and industry are investigating recently developed carbon fiber epoxy prepreg systems which can be fabricated using out-of autoclave (OOA) processes. Specifically, OOA processes using vacuum pressure in an oven and thereby significantly reducing the cost associated with manufacturing large (up to 10 m diameter) composite structures when compared with autoclave. One of these OOA composite material systems, CYCOM(R) 5320-1, was selected for manufacture of a 1/16th scale barrel portion of the payload fairing; such that, the system could be compared with the well-characterized prepreg system, CYCOM(R) 977-3, typically processed in an autoclave. Notched compression coupons for each material were obtained from the minimum-gauge flat laminate [60/-60/0]S witness panels produced in this manufacturing study. The coupons were also conditioned to an effective moisture equilibrium point and tested according to ASTM D6484M-09 at temperatures ranging from 25 C up to 177 C. The results of this elevated temperature mechanical characterization study demonstrate that, for thin coupons, the OHC strength of the OOA laminate was equivalent to the flight certified autoclave processed composite laminates; the limitations on the elevated temperature range are hot-wet conditions up to 163 C and are only within the margins of testing error. At 25 C, both the wet and dry OOA material coupons demonstrated greater OHC failure strengths than the autoclave processed material laminates. These results indicate a substantial improvement in OOA material development and

  15. NONA Cure of Prepreg Structures Project

    Data.gov (United States)

    National Aeronautics and Space Administration — CRG's no-oven, no-autoclave (NONA) composite processing technology enables the fabrication of high-performance composite parts without the limitations imposed by...

  16. 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.

  17. Autoclave inactivation of infectious radioactive laboratory waste contained within a charcoal filtration system

    International Nuclear Information System (INIS)

    A model system was developed previously for disposal of solid laboratory waste that is both radioactive and heat sensitive, e.g., HIV. A double polypropylene bag with charcoal vent filter and absorbent was designed to meet requirements for both steam sterilization and disposal as solid radioactive waste. Earlier work demonstrated the effective containment of radioactive gases by the filter and inactivation of organisms as heat sensitive as HIV. The authors sought to broaden the application of this model to ensure inactivation of microorganisms that are more heat resistant than HIV. The efficacy of steam sterilization using water or solutions of iodophor, hypochlorite, or hydrogen peroxide was studied under constant temperature and time conditions. The systems were monitored with internal probes, physical, chemical, and biological indicators. Biological indicators documented inactivation when bags containing hydrogen peroxide (3%) were autoclaved for 60 min at 121C. Synergistic activity between hydrogen peroxide and autoclave conditions significantly reduced processing time

  18. THE INFLUENCE OF A HALLOYSITE ADDITIVE ON THE PERFORMANCE OF AUTOCLAVED AERATED CONCRETE

    Directory of Open Access Journals (Sweden)

    Z. Owsiak

    2015-03-01

    Full Text Available This paper presents the results from the tests of autoclaved aerated concrete with halloysite as a cement additive. Good pozzolanic properties make it a suitable material to be used as a partial replacement of a portion of cement. Basic physical and mechanical properties of the composites with various mineral content are discussed. The compressive strength test results indicate an increase in strength of the AAC containing 2.5 % and 5 % halloysite relative to the reference specimen. Thermal conductivity and density values remained at the same level. Observations of the microstructure in the scanning electron microscope confirmed the results from the XRD tests. Anhydrite was observed in addition to tobermorite. The results from the tests of the autoclaved aerated concretes in which halloysite was incorporated as 7.5 % and 10 % cement replacement showed an increase in compressive strength, density and thermal conductivity values.

  19. Dimensional stability of a polyvinylsiloxane impression material following ethylene oxide and steam autoclave sterilization.

    Science.gov (United States)

    Holtan, J R; Olin, P S; Rudney, J D

    1991-04-01

    Polyvinlsiloxane impressions were made from a stainless steel master die machined to stimulate five full veneer crown preparations symmetrically placed in an arch form. Three groups of 10 impressions each were made. Treatment groups were sterilized using an ethylene oxide gas and a conventional steam autoclave. Casts were poured and intrapreparation, height, and diameter measurements were made using a stereomicroscope, a digital electronic caliper, and a 1-inch travel dial indicator. Analysis of dimensional changes for the two groups showed that casts made from impressions sterilized by ethylene oxide are acceptable for use in the construction of fixed or removable prostheses. Casts made from impressions sterilized in a steam autoclave can be used for the fabrication of diagnostic casts and some transitional prostheses, but not for routine construction of crowns or fixed partial dentures.

  20. HYACE - a novel autoclave coring equipment for systematic offshore gashydrate sampling

    Energy Technology Data Exchange (ETDEWEB)

    Amann, H.; Hohnberg, H.J.; Reinelt, R. [Technische Univ. Berlin (Germany). Inst. fuer Schiffs- und Meerestechnik, Fachgebiet Maritime Technik

    1997-12-31

    HYACE, the acronym for hydrate autoclave coring equipment system, is a research and development project sponsored by the European Union`s Marine Science and Technology Programme MAST. The project was to have started in the fourth quarter of 1997 and is to last 30 months. The main activities of the project will be in the development and prototype testing of an innovative down-hole controlled autoclave coring system. This system will be designed to sample marine sediments at extended down-hole conditions maintaining as many parameters constant as possible. In general terms, the main aim of the project is to contribute to systematic ground truthing of a necessarily ephemeral phenomenon of growing global significance: sampling and analysis of gas hydrates in their natural environment. (MSK)

  1. Development and fabrication of an autoclave molded PES/Quartz sandwich radome

    Science.gov (United States)

    Stanton, Leonard E.; Levin, Stephen D.

    1993-04-01

    A cohesively bonded, thermoplastic composite sandwich radome for a leading edge supersonic aircraft has been built using autoclave processing with PES/Quartz prepreg and a PES coated honeycomb core. Processes were developed for solvent removal, thermoplastic laminate consolidation, surface etching to improve adhesion, honeycomb coating and forming, and ultrasound testing of bond integrity. Environmental testing was also conducted to verify the structural integrity of the radome for its intended application.

  2. Treatment of Clinical Solid Waste Using a Steam Autoclave as a Possible Alternative Technology to Incineration

    OpenAIRE

    Mohd Omar Ab Kadir; Nik Norulaini Nik Ab Rahman; Md. Sohrab Hossain; Md. Zaidul Islam Sarker; Venugopal Balakrishnan

    2012-01-01

    A steam autoclave was used to sterilize bacteria in clinical solid waste in order to determine an alternative to incineration technology in clinical solid waste management. The influence of contact time (0, 5, 15, 30 and 60 min) and temperature (111 °C, 121 °C and 131 °C) at automated saturated steam pressure was investigated. Results showed that with increasing contact time and temperature, the number of surviving bacteria decreased. The optimum experimental conditions as measured by degree ...

  3. Autoclaving and clinical recycling: Effects on mechanical properties of orthodontic wires

    OpenAIRE

    Oshagh, M.; M R Hematiyan; Y Mohandes; M R Oshagh; L Pishbin

    2012-01-01

    Background: About half of the orthodontists recycle and reuse orthodontic wires because of their costs. So when talking about reuse and sterilization of wires, their effects on mechanical properties of wires should be clarified. The purpose of this study was to assess the effects of sterilization and clinical use on mechanical properties of stainless steel wires. Materials and Methods: Thirty stainless steel orthodontic wires were divided into three equal groups of control, autoclave (ster...

  4. Autoclave leaching of molybdenite concentrates with catalytic additives of nitric acid

    Science.gov (United States)

    Smirnov, K. M.; Raspopov, N. A.; Shneerson, Ya. M.; Lapin, A. Yu.; Bitkov, G. A.; Men'shikov, Yu. A.; Paskhin, P. N.; Kirichenko, V. P.

    2010-07-01

    The scientific theoretical prerequisites for the use of small additives of nitric acid for the intensification of the autoclave oxidative leaching (AOL) of sulfide concentrates are checked in order to increase the degree of extraction of the base metal with a simultaneous decrease in the cost of the process. The technological parameters of the AOL conditions applied to molybdenite are also refined, and recommendations for a practical application of the apparatus of the process and for a decrease in its cost are made.

  5. Autoclaved Tumor Bone for Skeletal Reconstruction in Paediatric Patients: A Low Cost Alternative in Developing Countries

    Directory of Open Access Journals (Sweden)

    Masood Umer

    2013-01-01

    Full Text Available We reviewed in this series forty patients of pediatric age who underwent resection for malignant tumors of musculoskeletal system followed by biological reconstruction. Our surgical procedure for reconstruction included (1 wide en bloc resection of the tumor; (2 curettage of tumor from the resected bone; (3 autoclaving for 8 minutes (4 bone grafting from the fibula (both vascularized and nonvascularized fibular grafts used; (5 reimplantation of the autoclaved bone into the host bone defect and fixation with plates. Functional evaluation was done using MSTS scoring system. At final followup of at least 18 months (mean 29.2 months, 31 patients had recovered without any complications. Thirty-eight patients successfully achieved a solid bony union between the graft and recipient bone. Three patients had surgical site infection. They were managed with wound debridement and flap coverage of the defect. Local recurrence and nonunion occurred in two patients each. One patient underwent disarticulation at hip due to extensive local disease and one died of metastasis. For patients with non-union, revision procedure with bone graft and compression plates was successfully used. The use of autoclaved tumor grafts provides a limb salvage option that is inexpensive and independent of external resources and is a viable option for musculoskeletal tumor management in developing countries.

  6. Slide Rule For Calculating Curing Schedules

    Science.gov (United States)

    Heater, Don

    1995-01-01

    Special-purpose slide rule devised for calculating schedules for storing and curing adhesives, sealants, and other materials characterized by known curing times and shelf lives. Prevents mistakes commonly made in determining storage and curing schedules.

  7. Excimer UV curing in printing

    International Nuclear Information System (INIS)

    It is the aim of this study to investigate the potential of 308 run excimer UV curing in web and sheet fed offset printing and to discuss its present status. Using real-time FTIR-ATR and stationary or pulsed monochromatic (313 nm) irradiation chemical and physical factors affecting the curing speed of printing inks such as nature and concentration of photo-initiators, reactivity of the ink binding system, ink thickness and pigmentation, irradiance in the curing plane, oxygen concentration and nitrogen inerting, multiple pulse exposure, the photochemical dark reaction and temperature dependence were studied. The results were used to select optimum conditions for excimer UV curing in respect to ink reactivity, nitrogen inerting and UV exposure and to build an excimer UV curing unit consisting of two 50 W/cm 308 run excimer lamps, power supply, cooling and inerting unit. The excimer UV curing devices were tested under realistic conditions on a web offset press zirkon supra forte and a sheet fed press Heidelberg GTO 52. Maximum curing speeds of 300 m/min in web offset and 8000 sheets per hour in sheet fed offset were obtained

  8. Accelerated dry curing of hams.

    Science.gov (United States)

    Marriott, N G; Kelly, R F; Shaffer, C K; Graham, P P; Boling, J W

    1985-01-01

    Uncured pork legs from the right side of 18 carcasses were treated with a Ross Tenderizer and the left side were controls. All 36 samples were dry-cured for 40, 56 or 70 days and evaluated for appearance traits, cure penetration characteristics, microbial load, Kramer Shear force and taste attributes. The tenderization treatment had no effect (P > 0·05) on visual color or cure penetration rate, weight loss before curing, percentage moisture, nitrate level, nitrite level, total plate count, anaerobic counts, psychrotrophic counts, objective and subjective tenderness measurements or juiciness. However, the higher values of salt suggested a possible acceleration of the dry cure penetration process among the tenderized samples. Cure time had no effect (P > 0·05) on percentage moisture, percentage salt, nitrate content, nitrite content, shear force and juiciness. Results suggest a limited effect of the mechanical tenderization process on certain traits related to dry curing and that total process time should be at least 70 days if color stability during cooking is desired. PMID:22056076

  9. Implementing the concept of «sustainable development» in ukraine by use autoclaved aerated concrete.

    OpenAIRE

    Brynzin, I. V.; Paruta, V. А.

    2015-01-01

    Purpose. Implementation of the concept of "sustainable development" in Ukraine by the use of autoclaved aerated concrete, in the construction of low- and high-rise buildings and structures. The article describes the main characteristics of autoclaved aerated concrete, from the stage of extraction of raw materials and ending with recycling stage. Justified a broad introduction to the construction industry. Methodology. The results are obtained in the form of an expert opinion by comparing the ...

  10. West Angeles Community Development Corporation final technical report on export market feasibility planning and research for the solar medical autoclave

    Energy Technology Data Exchange (ETDEWEB)

    Power, G.D.

    1998-04-20

    This report summarizes core findings from an investigation performed by the staff of West Angeles Community Development Corporation (CDC) regarding the feasibility of marketing the Solar Medical Autoclave (``autoclave``) in South Africa. The investigation was completed during 1997, the period prescribed by the Grant Award made by the U.S. Department of Energy on January 1, 1997, and was monitored by the National Renewable Energy Laboratory.

  11. Industrial application of radiation curing

    International Nuclear Information System (INIS)

    The contents are advantages of radiation processes - a solvent-free system, less energy consumative, higher production rate, processability at ambient temperature; electron beams vs. ultraviolet curing; applications -broad spectrum of markets use radiation curable materials

  12. Mixture proportioning for internal curing

    DEFF Research Database (Denmark)

    Bentz, Dale P.; Pietro, Lura; Roberts, John W.

    2005-01-01

    is especially beneficial in low watercement ratio (w/c) concretes because of the chemical shrinkage that accompanies portland cement hydration and the low permeability of the calcium-silicate hydrates. Because the water that is chemically bound and adsorbed by the cement hydration products has a specific volume...... less than that of bulk water, a hydrating cement paste will imbibe water (about 0.07 g water/g cement) from an available source. While in higher w/c concretes, this water can be, and often is, supplied by external (surface) curing, in low w/c concretes, the permeability of the concrete quickly becomes......The concept of internal concrete curing is steadily progressing from the laboratory to field practice. In terminology currently being considered by ACI Committee 308, Curing Concrete, “internal curing refers to the process by which the hydration of cement occurs because of the availability...

  13. 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...

  14. Radiation curing: coatings and composites

    International Nuclear Information System (INIS)

    The initial experiments conducted in the late 1960's at Radiation Dynamics, Inc. (now IBA Industrial, Inc.) showed that by removing the pigment from a radiation curable coating formulation, the same binder system could be used as a matrix system for electron beam (EB) cured fiber reinforced composites. Recently, the binder systems used for EB curable coatings have also been successfully used (without pigments) as the matrices for EB and X-ray cured fiber composites. Insights gained from the development of coatings were translated into desirable properties for matrix materials. For example, understanding the surface wetting characteristics of a coating facilitated the development of a matrix that would wet fibers; the development of coatings that would adhere to rigid substrates as metal while being bent, as for coil coatings, and which would exhibit impact resistance when cured on a metal also imparted impact resistance to cured composite materials. Thermal analyses conducted on the coating binder cured at low energies were consistent with analyses performed on thick cross-sections as used for matrices. The configuration of the final product then dictated the modality of curing, be it low-energy EB for coatings or higher energy EB or X-ray curing for composites. In industrial radiation chemistry, one deals with monomers and oligomers (∼ 102 and ∼ 103 to 104 Daltons molecular weight, respectively). Thus, one can approach the development of coating binders or matrix systems as one would approach the synthesis of organic polymers. The desired final material is a fully cured and cross-linked polymer. In contrast, concepts involved in '' formulating '' are often derived from dealing with high molecular weight polymers (∼ 105 + Daltons) in which intense mechanical mixing is used to bring different ingredients together. When synthesizing a radiation curable coating or matrix system, greater attention is given to microphase compatibility as reflected in the

  15. 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

  16. 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.

  17. An autoclave study of zirconium alloys with and without a hydride rim

    OpenAIRE

    J. Wei, P. Frankel, M. Blat, A. Ambard, R. J. Comstock, Lars Hallstadius, S. Lyon, R.A. Cottis and M. Preuss

    2012-01-01

    Autoclave corrosion experiments were conducted on a number of zirconium alloys in different heat treatment conditions. The alloys tested in the present work were Zircaloy-4, ZIRLOH (ZIRLO is a registered trademark of Westinghouse Electric Company LLC in the USA and may be registered in other countries throughout the world. All rights reserved. Unauthorised use is strictly prohibited.) and two variants of ZIRLO with significantly lower Sn levels, referred to here as A-0·6Sn and A-0·0Sn. Typica...

  18. A New Kind of Curing

    Science.gov (United States)

    2001-01-01

    A new curing method using automated tape placement (ATP) with electron beam (EB), or e-beam, produces a combination known as in situ e-beam curing. Through a Small Business Innovation Research (SBIR) contract from NASA's Marshall Space Flight Center, Science Research Laboratory, Inc., created the in situ e-beam curing technique, which uses a low-energy electron beam gun to cure various composite materials. One important benefit is the technique's utilization of room temperature curing, which lessens the chance of mismatching the thermal expansion coefficients of different materials. For instance, metals and composites will expand at different rates when heated, but the low-energy e-beam gun reduces the expansion differential. Using a low-energy gun also results in less x-ray shielding, significantly reduced capital costs, reduced facility space, and increased processing capabilities for larger parts. However, using a low-energy gun also means that each tape layer is treated individually because the gun can penetrate only one layer at a time. The e-beam gun emits lower energy x-rays, which are more easily shielded than those emitted by previous guns. The low-energy system is relatively portable due to its light weight and small size. The gun weighs about 70 pounds and can be easily mounted on a robotic arm or an ATP head.

  19. Autoclave Fully Automatic Feeding and Discharging Can Trolley%杀菌釜全自动进出料台车

    Institute of Scientific and Technical Information of China (English)

    周东; 陈书琼; 陈凯; 林伟杰

    2013-01-01

    针对八宝粥罐头杀菌茏进出杀菌釜一直由人工完成,存在效率低,劳动强度大,可靠性差的问题,提出了一种杀菌釜全自动进出料台车设计方法.主要设计理念为装满八宝粥罐头的杀菌笼放置在台车轨道上,随台车运送到杀菌釜,杀菌釜内有与台车相对应的运送轨道,通过电机控制两端推块翻转,顺利实现将杀菌笼推进和拉出杀菌釜.%For the end of eight-treasure can bactericidal cage feeding and discharging autoclave had been done manuelly with low efficiency, high labor intensity and poor reliability. This paper put forward a kind of autoclave automatic feeding and discharging can trolley design method. The main design concept is the bactericidal cage full of eight-treasure porridge can be put on the tracks and sent to the autoclave with the trolley. There are tracks in the autoclave corresponding to the trolley with controlled the both ends ejector pads roll-over through the motor, push and pull out the bactericidal cage from autoclave smoothly.

  20. Effects of Autoclaving and Mercuric Chloride Sterilization on PAHs Dissipation in a Two-Liquid-Phase Soil Slurry

    Institute of Scientific and Technical Information of China (English)

    WANG Cong-Ying; WANG Fang; WANG Tao; YANG Xing-Lun; BIAN Yong-Rong; F.O.KENGARA; LI Zeng-Bo; JIANG Xin

    2011-01-01

    A two-liquid-phase (TLP) soil slurry system was employed to quantify the efficiencies of autoclaving and mercuric chloride sterilization in the dissipation of polycyclic aromatic hydrocarbons (PAHs). The fates of 11 PAHs (naphthalene, fluorene, phenanthrene, anthracene, fluoranthene, pyrene, benzo(a)anthracene, benzo(a)pyrene, benzo(b)fluoranthene, benzo(k)fluoranthene, dibenzo(a, h)anthracene) were recorded over 113 days of incubation. No microorganisms were detected in the HgCl2-sterilized soil slurries during the whole incubation period, indicating very effective sterilization. However, about 2%-36% losses of PAHs were observed in the HgCl2-sterilized slurry. In contrast to the HgCl2-sterilized soil slurry, some microorganisms survived in the autoclaved soil slurries. Moreover,significant biodegradation of 6 PAHs (naphthalene, fluorene, phenanthrene, anthracene, fluoranthene and pyrene) was observed in the autoclaved soil slurries. This indicated that biodegradation results of PAHs in the soil slurries, calculated on basis of the autoclaved control, would be underestimated. It could be concluded that the sterilization efficiency and effectiveness of HgCl2 on soil slurry was much higher than those of autoclaving at 121 ℃ for 45 min.

  1. Challenging Roadblocks to Cancer Cure.

    Science.gov (United States)

    Loda, Massimo

    2016-09-01

    The Pezcoller Symposium in Trento, Italy, June 2015, focused entirely on the question of why advanced cancer cure is so uncommon despite the extraordinarily rapid growth of invaluable therapeutic information. Participants were asked to define and to critically evaluate real and potential obstacles to permanent disease eradication. High-level concepts on potential road blocks to cures as well as opportunities for intervention in diverse areas of investigation ranging from genomic alterations to metabolism, microenvironment, immunity, and mechanotransduction were discussed. Provocative concepts and novel therapeutic avenues were proposed. What follows is a critical analysis of the highlights of this meeting. Cancer Res; 76(17); 4924-30. ©2016 AACR. PMID:27520451

  2. Stress Free Temperature Testing and Residual Stress Calculations on Out-of-Autoclave Composites

    Science.gov (United States)

    Cox, Sarah; Tate, LaNetra C.; Danley, Susan; Sampson, Jeff; Taylor, Brian; Miller, Sandi

    2012-01-01

    Future launch vehicles will require the incorporation large composite parts that will make up primary and secondary components of the vehicle. NASA has explored the feasibility of manufacturing these large components using Out-of-Autoclave impregnated carbon fiber composite systems through many composites development projects. Most recently, the Composites for Exploration Project has been looking at the development of a 10 meter diameter fairing structure, similar in size to what will be required for a heavy launch vehicle. The development of new material systems requires the investigation of the material properties and the stress in the parts. Residual stress is an important factor to incorporate when modeling the stresses that a part is undergoing. Testing was performed to verify the stress free temperature with two-ply asymmetric panels. A comparison was done between three newly developed out of autoclave IM7 /Bismalieimide (BMI) systems. This paper presents the testing results and the analysis performed to determine the residual stress of the materials.

  3. Stress Free Temperature Testing and Calculations on Out-of-Autoclave Composites

    Science.gov (United States)

    Cox, Sarah B.; Tate, LeNetra C.; Danley, Susan E.; Sampson, Jeffrey W.; Taylor, Brian J.; Sutter, James K.; Miller, Sandi G.

    2013-01-01

    Future launch vehicles will require the incorporation of large composite parts that will make up primary and secondary components of the vehicle. NASA has explored the feasibility of manufacturing these large components using Out-of-Autoclave impregnated carbon fiber composite systems through many composites development projects. Most recently, the Composites for Exploration Project has been looking at the development of a 10 meter diameter fairing structure, similar in size to what will be required for a heavy launch vehicle. The development of new material systems requires the investigation of the material properties and the stress in the parts. Residual stress is an important factor to incorporate when modeling the stresses that a part is undergoing. Testing was performed to verify the stress free temperature with two-ply asymmetric panels. A comparison was done between three newly developed out of autoclave IM7/Bismaleimide (BMI) systems. This paper presents the testing results and the analysis performed to determine the stress free temperature of the materials

  4. A compact and autoclavable system for acute extracellular neural recording and brain pressure monitoring for humans.

    Science.gov (United States)

    Angotzi, Gian Nicola; Baranauskas, Gytis; Vato, Alessandro; Bonfanti, Andrea; Zambra, Guido; Maggiolini, Emma; Semprini, Marianna; Ricci, Davide; Ansaldo, Alberto; Castagnola, Elisa; Ius, Tamara; Skrap, Miran; Fadiga, Luciano

    2015-02-01

    One of the most difficult tasks for the surgeon during the removal of low-grade gliomas is to identify as precisely as possible the borders between functional and non-functional brain tissue with the aim of obtaining the maximal possible resection which allows to the patient the longer survival. For this purpose, systems for acute extracellular recordings of single neuron and multi-unit activity are considered promising. Here we describe a system to be used with 16 microelectrodes arrays that consists of an autoclavable headstage, a built-in inserter for precise electrode positioning and a system that measures and controls the pressure exerted by the headstage on the brain with a twofold purpose: to increase recording stability and to avoid disturbance of local perfusion which would cause a degradation of the quality of the recording and, eventually, local ischemia. With respect to devices where only electrodes are autoclavable, our design permits the reduction of noise arising from long cable connections preserving at the same time the flexibility and avoiding long-lasting gas sterilization procedures. Finally, size is much smaller and set up time much shorter compared to commercial systems currently in use in surgery rooms, making it easy to consider our system very useful for intra-operatory mapping operations. PMID:25486648

  5. 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.

  6. Numeric model of the normative consumption of heat for the colour homogenisation of wood in pressure autoclaves

    Science.gov (United States)

    Dzurenda, Ladislav

    2016-06-01

    This paper presents a numeric model of the normative consumption of heat for the colour homogenisation of unfrozen wood using saturated steam in pressure autoclaves, in the form of a technically feasible standard. For more effective determination of the objectively necessary consumption of heat for steaming non-frozen wood in a steam autoclave, a program was prepared in EXCEL in the form of a numeric table. Based on the technical and technological data on machinery, the range of colour homogenised wood and the colour-homogenisation regime, the program provides information about normative - the consumption of heat per 1 mł - of colour homogenised wood as well as about the consumption of heat for individual items of the thermal balance off the process of colour homogenisation in a pressure autoclave.

  7. 压力蒸汽灭菌器的性能验证%The Performance Validation of Autoclave

    Institute of Scientific and Technical Information of China (English)

    吕恒源; 杨海军

    2014-01-01

    Autoclave is a common device of validation. By the performance validation of autoclave, we can confirm that the autoclave can reaches the performance requirements of equipment within the prescribed time, temperature and pressure conditions, reagents can be effective sterilization.%压力蒸汽灭菌器是一种常见的消毒灭菌装置。通过开展灭菌效果验证可确认压力蒸汽灭菌器是否能在规定的时间、温度和压力条件下达到设备性能指标要求,试剂是否能被有效灭菌。

  8. The Design of Autoclave Controlling System%发泡建材蒸压釜控制系统设计

    Institute of Scientific and Technical Information of China (English)

    吴滢

    2012-01-01

    发泡建材蒸压釜属大型压力容器,主要介绍了符合蒸压釜相关安全性能规定的控制器设计方法,以及规模蒸压釜群的能源管理系统的设计方法,从而可以实现设备与能源的最优利用.%The autoclave is a kind of large pressure vessel. The design method of autoclave controller, used in the production of aerated concrete, was mainly introduced, as well as the energy management system for scaled autoclave group by which the optimal utilization of facilities and energy could be realized.

  9. Treatment of infectious waste: development and testing of an add-on set for used gravity displacement autoclaves.

    Science.gov (United States)

    Stolze, René; Kühling, Jan-Gerd

    2009-06-01

    The safe management of potentially infectious healthcare waste is gaining increasing worldwide importance. In developing countries, simple incinerators are used for the treatment of this type of waste stream. However, as these incinerators produce high emissions and represent the main generators of dioxin and furans in these countries, alternative and cost-effective solutions are needed. As steam treatment systems do not produce persistent organic pollutants, the use of existing (older) medical autoclaves could represent a solution for the treatment of infectious waste. ETLog Health EnviroTech & Logistics, the German-based consulting and engineering company carried out the first research into whether gravity air displacement autoclaves can be used for the safe decontamination of infectious waste. The research showed that it is not possible to decontaminate waste using this type of autoclave. A subsequent research and development phase might, however, make it possible to develop a new process cycle. Tests carried out on the basis of international standards and norms showed that by applying this process cycle and using an add-on set, it is possible to treat healthcare waste using the existing stock of older medical autoclaves. The process cycle and the add-on set developed were tested under existing conditions in Hanoi, Vietnam using the treatment cycle developed for a 13-year-old autoclave. All the parameters for infectious waste decontamination were reached. As modified autoclaves prevent the emission of toxic substances, this approach presents an interim solution, which avoids the impacts on human health and the environment caused by the incineration of healthcare waste.

  10. Autoclaved, previously used intravaginal progesterone devices induces estrus and ovulation in anestrous Toggenburg goats.

    Science.gov (United States)

    Souza, J M G; Torres, C A A; Maia, A L R S; Brandão, F Z; Bruschi, J H; Viana, J H M; E Oba; Fonseca, J F

    2011-11-01

    Intravaginal progesterone devices are used worldwide for estrus induction in goats. Reused devices are able to induce estrus; however, this can be a health risk within a flock. The objective was to compare new and previously used (and autoclaved) progesterone-releasing intravaginal devices for induction of estrus and ovulation in seasonally anestrous Toggenburg goats. Anestrous goats (n=42) received new intravaginal devices containing 0.3g progesterone (CONTROL), or similar devices previously used for either 6 (USED6) or 12d (USED12) and subsequently autoclaved. All goats received 5mg dinoprost at device insertion and 200 IU eCG 5d later, and all devices were removed after 6d. After device removal, estrus was monitored and females displaying signs of estrus were mated by fertile bucks. Transrectal ovarian ultrasonography was performed after device removal until detection of ovulation. Blood samples were collected for determination of plasma progesterone concentration at different times. There was no difference (P>0.05) among groups CONTROL, USED6 or USED12 for: estrus response (87, 100 or 100%, respectively); duration of estrus (32.3±2.3, 25.2±3.4 or 27.3±4.1h); ovulation rate (100, 88 or 100%); number of ovulations (1.5±0.2, 1.9±0.3 or 1.7±0.3); and pregnancy rate (60, 58 or 67%). Plasma progesterone (P4) concentrations were greater (P<0.05) in CONTROL than in USED6-treated and USED12-treated goats (7.2±1.2, 4.7±0.7 and 4.3±0.6 ng/mL, respectively) at 6h after device insertion; these differences were maintained until 4d after device insertion (3.4±0.4, 2.3±0.2, and 2.5±0.2 ng/mL). Overall, plasma progesterone concentrations were greater (P<0.05) in nulliparous than in lactating goats (3.1±0.8 compared to 2.4±0.6 ng/mL, respectively). In conclusion, autoclaved, previously used intravaginal progesterone-releasing devices resulted in significant lesser plasma progesterone concentrations than new devices, but were similarly effective in inducing estrus

  11. Process test on five-autoclave linkage operation for autoclaved fly ash brick%蒸压粉煤灰砖“五釜联动操作”的工艺试验

    Institute of Scientific and Technical Information of China (English)

    王光建

    2012-01-01

    On the basis of the possibility analysis of five-autoclave linkage operation for autoclaving fly ash brick combine of the Tianyie building material company autoclaved fly ash brick production line, the paper describes the improvement on supply steam equipment of autoclave, so as to achieve energy conservation.%结合天业建材公司蒸压粉煤灰砖的生产实践,在对蒸压粉煤灰砖五釜联动操作的可行性分析、研究的基础上,提出了对蒸压釜供汽部分的设备改造方案和蒸压粉煤灰砖五釜联动操作的工艺试验方案,指出砖瓦企业实现节能减排、低碳发展必须抓好关键设备的技术改造、技术创新。

  12. 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 ...

  13. 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.

  14. Preparation of Slowly Digestible Starch by Citric Acid-hydrolysis with Autoclaving

    Directory of Open Access Journals (Sweden)

    Hansong Yu

    2015-03-01

    Full Text Available Aim of study is to produce Slowly Digestible Starch (SDS by a combination of citric acid-hydrolysis and autoclaving from raw corn starch. The effects of citric acid concentration, acid hydrolysis time, temperature and refrigeration and retro gradation time on the formation of SDS were investigated. The optimal process conditions optimized by Box-Benhnken’s central composite design and response surface analysis was as follows: concentration of citric acid is 0.08 M, acid hydrolyzed at 116°C for 14.5 min, and then stored at 0°C for 72 h. Under these optimal conditions, the content of SDS peaked at 19.38%.

  15. Strength properties of autoclaved cellular concrete with high volume fly ash

    Energy Technology Data Exchange (ETDEWEB)

    Hu, W.; Neufeld, R.D.; Vallejo, L.E.; Kelly, C.; Latona, M. [Univ. of Pittsburgh, PA (United States). Dept. of Civil and Environmental Engineering

    1997-08-01

    This paper presents the results of an investigation on the strength properties of autoclaved cellular concrete (ACC) blocks, a building material that can contain up to 70% w/w of electric utility fly ash. The scope of this investigation covers three phases: (1) a brief literature review; (2) a selection of optimum strength testing methods suitable for ACC materials; and (3) a determination of physical properties of ACC made with US electric utility fly ash, and comparison of such properties to European ACC materials made with sand as the silica source. Optimum laboratory testing methods were selected based on a comprehensive literature search that included American, European, and Chinese standards. The properties examined were compressive, tensile, and flexural strengths. Results showed that block recipe and density influence the compressive, tensile, and flexural strength values. The investigation indicated that the compressive strength of the blocks increases with dry weight density, and decreases as their moisture content increases.

  16. Properties of the wall structures made of autoclaved cellular concrete products on the polyurethane foam adhesive

    Directory of Open Access Journals (Sweden)

    A.S. Gorshkov

    2013-08-01

    Full Text Available The article presents information on a test experiment for the construction of masonry fragments made of autoclaved cellular concrete products (ААС blocks on the polyurethane adhesive and the ensuing structural, thermal and technological tests of this type of masonry in specialized laboratories and testing facilities. It is shown that the use of polyurethane foam adhesive to bond the concrete blocks in the masonry walls is technically and economically feasible. On the basis of the tests it was concluded that the laying of concrete blocks on the polyurethane adhesive may be used in the construction of non-load bearing interior and exterior walls of buildings, including the filling of the external frame openings of monolithic buildings with floor bearing of the masonry on load bearing monolithic floors (with appropriate justification of the settlement.

  17. HBV cure: why, how, when?

    Science.gov (United States)

    Levrero, Massimo; Testoni, Barbara; Zoulim, Fabien

    2016-06-01

    Current HBV treatments control replication and liver disease progression in the vast majority of treated patients. However, HBV patients often require lifelong therapies due to the persistence of transcriptionally active viral cccDNA mini-chromosome in the nucleus, which is not directly targeted by current antiviral therapies. A true complete cure of HBV would require clearance of intranuclear cccDNA from all infected hepatocytes. An intermediate but still relevant step forward that would allow treatment cessation would be reaching a functional cure, equivalent to resolved acute infection, with a durable HBsAg loss±anti-HBs seroconversion, undetectable serum DNA and persistence of cccDNA in a transcriptionally inactive status. Recent advances in technologies and pharmaceutical sciences, including the cloning of the mayor HBV receptor (i.e. the NTCP transporter) and the development in vitro HBV infection models, have heralded a new horizon of innovative antiviral and immune-therapeutic approaches. PMID:27447092

  18. 蒸压釜釜盖开裂失效分析%Failure Analysis on Cracking of Autoclave Cover

    Institute of Scientific and Technical Information of China (English)

    潘安霞; 师红旗; 丁毅; 马立群

    2011-01-01

    采用宏微观组织分析、化学成分分析、SEM断口形貌分析、EDS腐蚀产物化学成分分析等手段,分析了321不锈钢釜盖开裂的原因.结果表明,该釜盖的开裂属于氯化物应力腐蚀开裂,蒸压釜的工作介质和工作压力共同导致了釜盖的开裂,并提出了相应的改进措施.%The cracking of autoclave cover was analyzed by morphology and microstnicture analysis, SEM micro-morphology of fracture surface, EDS corrosion products analysis. The results show that the cracking of autoclave cover is attributed to stress corrosion cracking. Working stress and working fluid of the autoclave cover lead to the cracking of the autoclave cover jointly. Finally, the relative protection countermeasures are proposed.

  19. Comparative Evaluation of Dimensional Accuracy of Elastomeric Impression Materials when Treated with Autoclave, Microwave, and Chemical Disinfection

    OpenAIRE

    Kamble, Suresh S.; Khandeparker, Rakshit Vijay; Somasundaram, P; Raghav, Shweta; Babaji, Rashmi P; Varghese, T Joju

    2015-01-01

    Background: Impression materials during impression procedure often get infected with various infectious diseases. Hence, disinfection of impression materials with various disinfectants is advised to protect the dental team. Disinfection can alter the dimensional accuracy of impression materials. The present study was aimed to evaluate the dimensional accuracy of elastomeric impression materials when treated with different disinfectants; autoclave, chemical, and microwave method. Materials and...

  20. High Flow Addition Curing Polyimides

    Science.gov (United States)

    Chuang, Kathy C.; Vannucci, Raymond D.; Ansari, Irfan; Cerny, Lawrence L.; Scheiman, Daniel A.

    1994-01-01

    A new series of high flow PMR-type addition curing polyimides was developed, which employed the substitution of 2,2'-bis (trifluoromethyl) -4,4'-diaminobiphenyl (BTDB) for p-phenylenediamine (p -PDA) in a PMR-IL formulation. These thermoset polyimides, designated as 12F resins, were prepared from BTDB and the dimethyl ester of 4,4'- (hexafluo- roisopropylidene) -diphthalic acid (HFDE) with either nadic ester (NE) or p-aminostyrene (PAS) as the endcaps for addition curing. The 12F prepolymers displayed lower melting temperatures in DSC analysis, and higher melt flow in rheological studies than the cor- responding PMR-11 polyimides. Long-term isothermal aging studies showed that BTDB- based 12F resins exhibited comparable thermo-oxidative stability to P-PDA based PMR-11 polyimides. The noncoplanar 2- and 2'-disubstituted biphenyldiamine (BTDB) not only lowered the melt viscosities of 12F prepolymers, but also retained reasonable thermal sta- bility of the cured resins. The 12F polyimide resin with p-aminostyrene endcaps showed the best promise for long-term, high-temperature application at 343 C (650 F).

  1. Cancer: the consequences of cure

    International Nuclear Information System (INIS)

    The author considers the consequences of curing children treated for cancer in terms of their relation to society and society's responsibility to them. However serious the interruption of their schooling, these children achieve normal educational standards, and, despite adverse reports on central nervous system function, appear in practice to do as well as their peers. They deserve to be encouraged to succeed at school and later, an attitude not always shown by their teachers. For whatever reason, earlier maturity, earlier close contact with the adult world, these young people achieve well in work and at university. They deserve better of the public services, various professions, and even the armed services, who frequently reject them out of hand. Now that there are large numbers of these youngsters entering adulthood (it has been estimated, e.g., that by 1990 one in every two thousand individuals aged 20 will be a cured childhood cancer patient), it is necessary to see that these young people integrate satisfactorily with society and that cure produces no adverse consequences. (author)

  2. Comparative analysis of the effect of autoclaving and 10% formalin storage on extracted teeth: A microleakage evaluation

    Directory of Open Access Journals (Sweden)

    Attam Kanika

    2009-01-01

    Full Text Available Aim: This study compares the effect of formalin and autoclaving the tooth samples by evaluating microleakage in-vitro . Materials and Methods: Forty-five extracted human permanent incisor teeth were taken and randomly divided into three groups (with different methods of storage and disinfection with 15 teeth each: Group 1: Control-extracted teeth in this group were stored in normal saline, Group 2: the extracted teeth in this group were stored in 10 % formalin for two weeks and Group 3: the extracted teeth were Autoclaved at 121°C, at 15 psi pressure for 40 minutes. In all the groups after the specified storage period, class V cavities were prepared on the labial surface and restoration was performed with Z100 restorative. Finished and polished samples were subjected to 500 cycles of thermocycling. All specimens were immersed in methylene blue for 24 hours. After sectioning, the margins of restora-tion were evaluated for dye leakage at 10 X magnification, using an optical microscope. Data were subjected to nonparametric Kruskal Wallis one way analysis of variance. Inter-group comparisons were performed using the Mann Whitney test ( P < 0.05. Results: The authors found that the microleakage in the formalin group was considerably lower than that in the control group. The autoclave group showed slightly higher mean microleakage, but the difference was not statistically significant. Conclusion: Both autoclaving and formalin storage affect, to a varying degree, the microleakage values in vitro . The results in the autoclaving group matched those of the control group more closely, with only a slight difference.

  3. 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.

  4. Effect of high-dose irradiation and autoclave treatment on microbial safety and quality of ready-to-eat Bulgogi sauce

    International Nuclear Information System (INIS)

    In Korea, commercialized sauce for ready-to-eat (RTE) Bulgogi is usually manufactured using heat treatment to ensure that it has a long shelf-life. However, heat treatment may adversely affect the taste and flavor of the sauce, thus, the development of suitable sterilizing methods for RTE sauces is necessary to preserve the quality of the sauce during long storage periods. In this study, total bacterial growth, the viscosity, and the sensory properties of Bulgogi sauce were compared between sterilization with gamma irradiation (0–40 kGy) and autoclave treatment during storage at 35 °C for 90 days. No bacterial growth was observed following irradiation at more than 10 kGy or after autoclave treatment. However, the viscosity and sensory properties of samples gamma-irradiated at above 10 kGy or autoclave-treated were significantly changed, even though autoclave treatment induced a burnt taste and flavor. Therefore, a gamma irradiation of 10 kGy was effective to prepare ready-to-eat Bulgogi sauce with microbial safety and original sensory qualities. - Highlights: ► No bacterial growth in gamma-irradiated Bulgogi sauce ≥10 kGy or autoclaved sample was observed. ► Viscosity of irradiated sample at 40 kGy was similar to that of autoclaved sample. ► Sensory properties of irradiated sample >10 kGy or autoclaved sample deteriorated.

  5. Effects of Autoclaving Soy-Free and Soy-Containing Diets for Laboratory Rats on Protein and Energy Values Determined In Vitro and In Vivo

    OpenAIRE

    Taciak, Marcin; Tuśnio, Anna; Święch, Ewa; Barszcz, Marcin; Staśkiewicz, Łukasz; Skomiał, Jacek; Paradziej-Łukowicz, Jolanta; Pastuszewska, Barbara

    2015-01-01

    Autoclaving diminishes the nutritional value of rat diets, depending on the duration and temperature of the process and the type of dietary protein. We evaluated in vivo and in vitro the effects of autoclaving on the protein and energy values of soy-free and soy-containing rat diets. The true digestibility and biological value of the dietary protein were determined in a 10-d experiment involving 28-d-old Wistar Crl:WI(Han) male rats fed casein- or soy-containing diet that was autoclaved for 2...

  6. Preparation and characterization of PLGA nanospheres encapsulated with Autoclaved Leishmania Major (ALM) and Quillaja Saponin

    International Nuclear Information System (INIS)

    Several antigens, adjuvants and delivery systems have been evaluated for induction of protective immune responses against leishmaniasis, but have mostly been inefficient. In this study, poly (d,1-lactide-co-glycolide) (PLGA) nanospheres as antigen delivery system and Quillaja saponins (QS) as an immunoadjuvant have been used to increase the immune responses against Autoclaved Lieshmania major (ALM). PLGA nanospheres were prepared using a double emulsion (W/O/W) technique. The internal aqueous phase contained ALM and saponin, while the oily phase contained the solution of PLGA in dichloromethane and the external aqueous phase was polyvinylacohol (PVA) 7.5% (W/V) solution. Particulate characteristics were studied by scanning electron microscope and particle size analyzer. The encapsulation efficiency was determined by Lowry method and the release profile of antigen and saponin from nanospheres was evaluated for one week. Nanospheres were spherical in shape having smooth surfaces. Mean diameters for nanospheres loaded with ALM and ALM+QS were 300+-123 nm and 294+-106 nm respectively. Encapsulation efficiencies for ALM and QS were found 71+-14.8% and 55.8+- 23.1% respectively. Evaluation of the release profiles of ALM and QS from nanospheres in one week showed that 44.8 +-0.8% of ALM and 29.5+- 0.21% of QS had been released from naospheres. In conclusion, the prepared nanospheres with desirable size, encapsulation efficiency, and slow rate of release, had acceptable features for future in vivo studies. (author)

  7. Autoclaves for fatigue crack growth tests with unirradiated and irradiated specimens

    International Nuclear Information System (INIS)

    For about two years now, research programmes are being carried out in the USA with the purpose of investigating fatigue crack growth in steels for pressure vessels of LWRs under operating conditions, with main emphasis being placed on the determination of the effect of load increase time and constant load time, of the temperature, water chemistry, materials (basic materials and welds), of the stress intensity factor at the beginning of the test, as well as on the effect of irradiation. The results obtained during the first testing phase shall serve as a basis for a revision of the ASME Boiler and Pressure Vessel Code, Section XI, and also for a specification of new piping steels, including austenitic steels. The autoclaves for stationary and dynamic load used for the testing of unirradiated and irradiated specimens are described and details are given of the methods used for the crack growth measurements and water chemistry studies, along with a brief account of the data acquisition systems applied. The results obtained so far in the testing series are illustrated by means of selected examples. (orig.)

  8. Preparation of New Cementitious System using Fly Ash and Dehydrated Autoclaved Aerated Concrete

    Institute of Scientific and Technical Information of China (English)

    SHUI Zhonghe; LU Jianxin; TIAN Sufang; SHEN Peiliang; DING Sha

    2014-01-01

    We experimentally studied the interaction between pozzolanic material (fly ash) and dehydrated autoclaved aerated concrete (DAAC). The DAAC powder was obtained by grinding aerated concrete waste to particles finer than 75μm and was then heated to temperatures up to 900℃. New cementitious material was prepared by proportioning fly ash and DAAC, named as AF. X-ray diffraction (XRD) was employed to identify the crystalline phases of DAAC before and after rehydration. The hydration process of AF was analyzed by the heat of hydration and non-evaporable water content (Wn). The experimental results show that the highest reactivity of DAAC can be obtained by calcining the powder at 700℃and the dehydrated products are mainlyβ-C2S and CaO. The cumulative heat of hydration and Wn was found to be strongly dependent on the replacement level of fly ash, increasing the replacement level of fly ash lowered them in AF. The strength contribution rates on pozzolanic effect of fly ash in AF are always negative, showing a contrary tendency of that of cement-fly ash system.

  9. CO2 sequestration by carbonation of steelmaking slags in an autoclave reactor.

    Science.gov (United States)

    Chang, E-E; Pan, Shu-Yuan; Chen, Yi-Hung; Chu, Hsiao-Wen; Wang, Chu-Fang; Chiang, Pen-Chi

    2011-11-15

    Carbon dioxide (CO(2)) sequestration experiments using the accelerated carbonation of three types of steelmaking slags, i.e., ultra-fine (UF) slag, fly-ash (FA) slag, and blended hydraulic slag cement (BHC), were performed in an autoclave reactor. The effects of reaction time, liquid-to-solid ratio (L/S), temperature, CO(2) pressure, and initial pH on CO(2) sequestration were evaluated. Two different CO(2) pressures were chosen: the normal condition (700 psig) and the supercritical condition (1300 psig). The carbonation conversion was determined quantitatively by using thermo-gravimetric analysis (TGA). The major factors that affected the conversion were reaction time (5 min to 12h) and temperature (40-160°C). The BHC was found to have the highest carbonation conversion of approximately 68%, corresponding to a capacity of 0.283 kg CO(2)/kg BHC, in 12h at 700 psig and 160°C. In addition, the carbonation products were confirmed to be mainly in CaCO(3), which was determined by using scanning electron microscopy (SEM) and X-ray powder diffraction (XRD) to analyze samples before and after carbonation. Furthermore, reaction kinetics were expressed with a surface coverage model, and the carbon footprint of the developed technology in this investigation was calculated by a life cycle assessment (LCA). PMID:21889848

  10. Strain rate sensitivity of autoclaved aerated concrete from quasi-static regime to shock loading

    Directory of Open Access Journals (Sweden)

    Mespoulet Jérôme

    2015-01-01

    Full Text Available The quasi-static mechanical behavior of autoclaved aerated concrete is well-known and can be expressed as a function of its density. There are however not much studies dealing with its dynamic behavior and its damping ability when subjected to a mechanical shock or a blast. This study presents experimental results obtained at the Shock Physics Laboratory of THIOT INGENIERIE company. The test specimens are made of YTONG(TM cellular concrete with porosity in the range of 75 to 80%. Experimental tests cover a large strain rate amplitude (higher than 104 s−1 for specimens up to 250 mm. They were carried out with a small compression press and with two facilities dedicated to dynamic material characterization: JUPITER dynamic large press (2 MN, 3 ms rising time and TITAN multi-caliber single-stage gas gun. Results in un-confined conditions show an increase of the compressive strength when strain rate increases (45% increase at 5.102 s−1 but dynamic tests induce damage early in the experiment. This competition between dynamic strength raise and specimen fracture makes the complete compaction curve determination not to be done in unconfined dynamic condition. A 25% increase of the compressive strength has been observed between unconfined and confined condition in Q.S. regime.

  11. Characteristics of autoclave and in-reactor nodular corrosion of Zircaloys

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Y.H.; Rheem, K.S. (Korea Atomic Energy Research Inst., Daeduk (Republic of Korea)); Chung, H.M. (Argonne National Lab., IL (USA))

    1990-11-01

    Nodular corrosion characteristics of recrystallized Zircaloy-4 were investigated in static autoclave tests at 500{degree}C and 10.3 MPa. The roles of annealing temperature, cooling rate after beta-treating at 1050{degree}C, cold work, and surface treatment in corrosion tests were correlated with the results of microstructural characterization by scanning and transmission electron microscopies. A good correlation was obtained between average size of intermetallic precipitates and weight gain, in contrast to nodule coverage and nodule number density. These results could be best explained by the hypothesis that nodules nucleate in local regions that are depleted of Fe and Cr alloying elements. Some observations were inconsistent with the premise that nodules nucleate on or near intermetallic precipitates. Nodular corrosion characteristics and microstructures of commercial Zircaloy-2 cladding of fuel and gadolinia rods, obtained from several BWRs after burnup of 11--30 MWd/kgU, were also examined. Partial amorphization of intermetallic precipitates in BWR Zircaloy-2, and virtual dissolution and in an extreme case spinodal- like fluctuations of dissolved alloying elements in PWR Zircaloy-4 cladding were observed. Occurrence of nodular oxidation of Zircaloy-2 in BWRs could best be correlated to average size of intermetallic precipitates before irradiation and to fuel cladding operating temperature. For an intermetallic size range of 250--700 nm, nodular oxides were observed at 288{degree}C, but only thick uniform oxide was observed at 307{degree}C. 53 refs., 14 figs., 1 tab.

  12. Nonlinear Modeling of Autoclaved Aerated Concrete Masonry Wall Strengthened using Ferrocement Sandwich Structure

    KAUST Repository

    M., Abdel-Mooty

    2011-01-01

    Autoclaved Aerated Concrete (AAC) block are used mainly as non-load-bearing walls that provide heat insulation. This results in considerable saving in cooling energy particularly in hot desert environment with large variation of daily and seasonal temperatures. However, due to the relatively low strength there use load bearing walls is limited to single storey and low-rise construction. A system to enhance the strength of the AAC masonry wall in resisting both inplane vertical and combined vertical and lateral loads using ferrocement technology is proposed in this research. The proposed system significantly enhances the load carrying capacity and stiffness of the AAC wall without affecting its insulation characteristics. Ferrocement is made of cement mortar reinforced with closely spaced wire mesh. Full scale wall specimens with height of 2100mm and width of 1820mm were tested with different configuration of ferrocement. A finite elementmodel is developed and verified against the experimentalwork. The results of the finite element model correlates well with the experimental results.

  13. Irradiating or autoclaving chitosan/polyol solutions. Effect on thermogelling chitosan-β-glycerophosphate systems

    International Nuclear Information System (INIS)

    The effects of steam sterilization and γ-irradiation on chitosan and thermogelling chitosan-βglycerophosphate (GP) solutions containing polyol additives were investigated. The selected polyols were triethylene glycol, glycerol, sorbitol, glucose and poly(ethylene glycol) (PEG). They were incorporated to chitosan solutions prior to sterilization in a proportion ranging from 1 to 5% (w/v). The solutions were characterized with respect to their viscosity, thermogelling properties, compressive stress relaxation behavior and chitosan degradation. All polyols reduced the autoclaving-induced viscosity loss and had a positive impact on the solution thermogelling properties and compressive performance of the gels. Steam sterilization in the presence of glucose resulted in a substantial increase in the solution viscosity and gel strength. This was associated with a strong discoloration suggesting chemical alteration of the system. PEG was the most effective agent in preventing hydrolytic degradation of chitosan chains. Gamma-irradiation strongly decreased the chitosan solution viscosity regardless of the presence of additives, even when sterilization was carried out at -80 deg C. Moreover, the thermogelling properties were dramatically altered, and thus, γ-irradiation would not be an appropriate method to sterilize chitosan solutions. In conclusion, polyols are potentially useful additive to maximise the viscoelastic and mechanical properties of chitosan-GP after steam sterilization. (author)

  14. Comparative study and histomorphometric analysis of bone allografts lyophilized and sterilized by autoclaving, gamma irradiation and ethylene oxide in rats

    Directory of Open Access Journals (Sweden)

    Otavio Machado de Almeida

    2013-01-01

    Full Text Available PURPOSE: To compare three sterilization methods (autoclave, gamma irradiation and ethylene oxide over non demineralized lyophilized bone allografts. METHODS: Bone allografts were implanted on paravertebral muscles of 21 rats. After 30 days animals were sacrificed and grafts underwent comparative analysis regarding histomorphometric and macroscopic parameters. RESULTS: Allografts that underwent the three sterilization methods presents similar weight gain, cortical thickness similar to control group, and less fibrosis than the control group. Grafts that underwent sterilization in autoclave presented less presence of multinucleated giant cells, although not statistically significant. There was also no statistically significant difference regarding mineralization on the three groups. CONCLUSION: The three sterilization methods cause similar effects on bone allografts regarding macroscopic and histomorphometric parameters.

  15. Drying of Echinodorus macrophyllus and autoclaving and lyophilization of the fluid-extract: effects on the pharmacochemical composition

    Directory of Open Access Journals (Sweden)

    Ronam V. Flor

    2011-06-01

    Full Text Available Some pharmaceutical industries of phytomedicines are using conservation procedures (drying, autoclaving, in an attempt to avoid medicinal plants degradation, and of their fluid-extracts. Or, by adopting techniques adequate to foods, which not always are appropriate. On this sense, there is less research with Brazilian plants, causing some difficulties for their use as raw material by the domestic industry. Thus, the effects of drying at various temperatures or irradiation with microwaves, as well as autoclaving or lyophilization of the fluid-extract of samples collected in natura of Echinodorus macrophyllus (Kunth Micheli, Alismataceae, on the pharmacochemical composition were analyzed. At the research for chemical groups, the preponderating presence of flavones and coumarin derivatives was observed. The chromatographic profiles of the flavonic extracts were analyzed by TLC and HPLC and the levels of total flavonoids were determined. According to the results obtained, qualitative and quantitative changes were caused by the various processes employed.

  16. 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.

  17. UV/EB curing market in Indonesia

    International Nuclear Information System (INIS)

    The most application of UV curing of surface coating in Indonesia are on fancy plywood, furniture and wood flooring industry. Other application are on papers, printing ink/labelling, printed circuit board/PCB and dental materials. At present, application of EB curing coating is still in a pilot plant scale due to the high cost of production. Limited number of application of EB curing by using low energy electron beam machine are on wood panels, ceramics and marbles. This paper describes the market and the problem faced by the largest user of radiation curing systems such as the secondary process plywood, furniture and paper industries

  18. The Hydrothermal Autoclave Synthesis of the Nanopowders of the Refractory ZrO2 and HfO2 Oxides

    Directory of Open Access Journals (Sweden)

    N.F. Karpovich

    2015-12-01

    Full Text Available The nanopowders of the transition metal ZrO2 and HfO2 oxides were obtained by the hydrothermal autoclave synthesis. The nanoparticles possess a rounded shape and a size range of 40 to 80 nm (ZrO2, of 10 to 40 nm (HfO2. X-ray diffraction analysis and electron microscopy show that the structure of the nanoparticles is monoclinic.

  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. Induction of cellular and humoral responses by autoclaved and heat-killed antigen of Leishmania donovani in experimental visceral leishmaniasis.

    Science.gov (United States)

    Nagill, Rajeev; Mahajan, Raman; Sharma, Meenakshi; Kaur, Sukhbir

    2009-12-01

    The potential of autoclaved and heat-killed antigen of Leishmania donovani to induce cell-mediated and humoral response has been evaluated in the present study. The vaccines were delivered thrice subcutaneously at an interval of 2 weeks. Two weeks after second booster, BALB/c mice were challenged with 10(7) stationary phase promastigotes of L. donovani. Significant protection was achieved in immunized mice against L. donovani challenge with 69% to 76% and 59% to 64% reduction in parasite load in the liver and spleen respectively. Immunization induced significantly higher level of delayed type hypersensitivity (DTH) response in mice immunized with heat-killed antigen followed by autoclaved antigen. The immune response was assessed by quantifying Leishmania-specific antibodies and cytokine production. The antibody response was predominantly of IgG type with increased IgG2a production and lesser amount of IgM. The immunization preferentially stimulates the production of IFN-gamma and IL-2 in splenocytes which suggests a Th1 type response with a concomitant down-regulation of IL-10 and IL-4. These results indicate a potential for the heat-killed and autoclaved antigen as a vaccine which could trigger cell-mediated immune response.

  1. 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...

  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. Hard facts for radiation curing of elastomers

    International Nuclear Information System (INIS)

    The subject is covered under the headings: introduction; outline of chemistry (differences between conventional and radiation curing); compounding; green strength; response of rubbers to electron beam treatment; electron beam cured applications:(a) wire and cable applications;(b) rubber tyre components;(c) heat shrinkable materials;(d) roofing materials. (U.K.)

  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. Sorption and precipitation of Mn2+ by viable and autoclaved Shewanella putrefaciens: Effect of contact time

    KAUST Repository

    Chubar, Natalia

    2013-01-01

    The sorption of Mn(II) by viable and inactivated cells of Shewanella putrefaciens, a non-pathogenic, facultative anaerobic, gram-negative bacterium characterised as a Mn(IV) and Fe(III) reducer, was studied under aerobic conditions, as a function of pH, bacterial density and metal loading. During a short contact time (3-24h), the adsorptive behaviour of live and dead bacteria toward Mn(II) was sufficiently similar, an observation that was reflected in the studies on adsorption kinetics at various metal loadings, effects of pH, bacteria density, isotherms and drifting of pH during adsorption. Continuing the experiment for an additional 2-30days demonstrated that the Mn(II) sorption by suspensions of viable and autoclaved cells differed significantly from one another. The sorption to dead cells was characterised by a rapid equilibration and was described by an isotherm. In contrast, the sorption (uptake) to live bacteria exhibited a complex time-dependent uptake. This uptake began as adsorption and ion exchange processes followed by bioprecipitation, and it was accompanied by the formation of polymeric sugars (EPS) and the release of dissolved organic substances. FTIR, EXAFS/XANES and XPS demonstrated that manganese(II) phosphate was the main precipitate formed in 125ml batches, which is the first evidence of the ability of microbes to synthesise manganese phosphates. XPS and XANES spectra did not detect Mn(II) oxidation. Although the release of protein-like compounds by the viable bacteria increased in the presence of Mn2+ (and, by contrast, the release of carbohydrates did not change), electrochemical analyses did not indicate any aqueous complexation of Mn(II) by the organic ligands. © 2012 Elsevier Ltd.

  6. Factors influencing EB curing of epoxy matrix

    International Nuclear Information System (INIS)

    The effectiveness of electron beam (EB) curing of epoxy resins was found to be influenced by catalyst. In the presence of iodonium salt (diaryl iodonium hexafluoroantimonate, C3), the EB curing of epoxy resin is easier than in the presence of triaryl sulfonium hexafluoroantimonate (C1), or triaryl sulfonium hexafluorophosphate (C2), or iron arene containing cationic catalyst (Irgacure 261). The epoxy 616 (diglycidyl ether of bisphenol A) and 648 (diglycidyl ether of phenolic novolacs) can be cured by the above onium salts catalysts C1-C3. The epoxy with glycidyl amino epoxide group (such as AG 80; AFG 90) could not be cured by onium salts catalyst. The influence of irradiation dose, temperature and the effect of impurities on curing reaction were investigated

  7. Factors influencing EB curing of epoxy matrix

    Energy Technology Data Exchange (ETDEWEB)

    Li Fengmei E-mail: brc@bnu.edu.cn; Bao Jianwen; Chen Xiangbao; Bao Huaying; Wang Huiliang

    2002-03-01

    The effectiveness of electron beam (EB) curing of epoxy resins was found to be influenced by catalyst. In the presence of iodonium salt (diaryl iodonium hexafluoroantimonate, C3), the EB curing of epoxy resin is easier than in the presence of triaryl sulfonium hexafluoroantimonate (C1), or triaryl sulfonium hexafluorophosphate (C2), or iron arene containing cationic catalyst (Irgacure 261). The epoxy 616 (diglycidyl ether of bisphenol A) and 648 (diglycidyl ether of phenolic novolacs) can be cured by the above onium salts catalysts C1-C3. The epoxy with glycidyl amino epoxide group (such as AG 80; AFG 90) could not be cured by onium salts catalyst. The influence of irradiation dose, temperature and the effect of impurities on curing reaction were investigated.

  8. EB/UV curing market in Malaysia

    International Nuclear Information System (INIS)

    Radiation curing of coatings of wood based products is expanding and being used for curing of coatings of table tops, parquet, wood panel, furniture, curtain railing, etc. UV curing of over print varnish is still the main application of UV curing in printing industry. However, curing of printing ink has also been extended in the printing of CD and VCD in addition to other printing such as paper, magazine, label on bottles, metal-can, etc. In the electronic industry, the manufacturer of printed circuit board is still the main consumer of UV curable resins. On the other hand, low energy electron beam machine is used mainly for cross-linking of heat shrink films

  9. 7 CFR 29.2519 - Fire-cured.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Fire-cured. 29.2519 Section 29.2519 Agriculture... INSPECTION Standards Official Standard Grades for Kentucky and Tennessee Fire-Cured and Foreign-Grown Fire-Cured Tobacco (u.s. Types 22, 23, and Foreign Type 96) § 29.2519 Fire-cured. Tobacco cured...

  10. 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...

  11. Structure-Processing-Property Relationships at the Fiber-Matrix Interface in Electron-Beam Cured Composite Materials

    Energy Technology Data Exchange (ETDEWEB)

    Janke, C.J.

    1998-11-01

    The objective of this project was to characterize the properties of the resin and the fiber- resin interface in electron beam cured materials by evaluating several structural and processing parameters. The Oak Ridge National Laboratory (ORNL) has recently determined that the interlaminar shear strength properties of electron beam cured composites were 19-28% lower than for autoclave cured composites. Low interlaminar shear strength is widely acknowledged as the key barrier to the successfid acceptance and implementation of electron beam cured composites in industry. In this project we found that simple resin modification and process improvements are unlikely to substantially improve the interlaminar shear strength properties of electron beam cured composites. However, sizings and coatings were shown to improve these properties and there appears to be significant potential for further improvement. In this work we determined that the application of epoxy-based, electron beam compatible sizings or coatings onto surface- treated, unsized carbon fibers improved the composite interlaminar shear strength by as much as 55% compared to composites fabricated from surface-treated, unsized carbon fibers and 11 YO compared to composites made from surface-treated, GP sized carbon fibers. This work has identified many promising pathways for increasing the interlaminar shear strength of electron beam cured composites. As a result of these promising developments we have recently submitted a U.S. Department of Energy-Energy Research (DOE-ER) sponsored Laboratory Technical Research-Cooperative Research and Development Agreement (LTR- CRADA) proposal entitled, "Interracial Properties of Electron Beam Cured Composites", to continue this work. If funded, ORNL will lead a 3-year, $2.6 million effort involving eight industrial partners, NASA-Langley, and the U.S. Air Force. The principal objective of this CRADA is to significantly improve the interracial properties of carbon

  12. Prophage-Cured Derivatives of Streptococcus lactis and Streptococcus cremoris

    OpenAIRE

    Gasson, Michael J.; Davies, F. Lyndon

    1980-01-01

    Prophage curing was achieved in Streptococcus lactis and Streptococcus cremoris, and the cured derivatives were shown to be indicators for their temperate bacteriophages. Relysogenization of these cured derivatives completed the first formal demonstration of the lysogenic state in lactic streptococci.

  13. Curing of natural rubber and epoxy adhesive

    International Nuclear Information System (INIS)

    Low molecular weight epoxy resin based on diglycidyl ether of bisphenol A was synthesized and mixed at constant percentages with natural rubber. The rubber epoxy system was cured with various types of curing agents such as ethylene diamine, maleic anhydride as well as the prepared resole phenol formaldehyde. A study of the photo-induced crosslinking of the prepared elastic adhesives and film samples was carried out by exposure to ultraviolet lamp (300 w) for 2 weeks at 20 deg. C. Samples containing ethylene diamine were cured at 25 + - 1 deg. C. for 24 h while samples containing maleic anhydride or resole phenol formaldehyde resins were thermally cured at 150-170 deg. C. for 10 min. Cured adhesive compositions were tested mechanically and physically and evaluated as wood adhesives. While hardness, chemical resistance as well as heat stability of the prepared cured film sample were investigated. The obtained data indicate that the highest epoxy resin content and the presence of resole phenol formaldehyde resin in composition improve the tensile strength and adhesion properties on wood. While their cured film sample have the best hardness properties, chemical resistance and heat stability. (author)

  14. 蒸压膨胀珍珠岩保温板的研制及性能分析%Research on the preparation and properties of autoclaved insulation board made by expanded perlite

    Institute of Scientific and Technical Information of China (English)

    张宪圆; 林克辉; 谢红波; 杨军

    2012-01-01

    Expanded perlite insulation board was successfully prepared by autoclave curing method,which two kinds of expanded perlite with different packing densities were used as light-weight aggregate respectively,and Portland cement or self-made binder was used as cementing material. Hydrophobic treatment was also applied. The results indicate that the compressive and flexural strengths of insulation board made in this way are much higher than the requirement in national standard GB/T 10303-2001 "Expanded Perlite Thermal Insulation"; volume water absorption of EP insulation board is reduced significantly when the emulsion of silicone hydrophobic agent is used.%采用2种堆积密度不同的膨胀珍珠岩作轻骨料,以水泥和自制胶结料作为胶凝材料,通过蒸压养护方式制备成保温板,并进行了憎水处理.结果表明,采用该工艺制备的保温板其抗压及抗折强度优于GB/T10303-2001《膨胀珍珠岩绝热制品》标准要求;有机硅憎水剂乳液可显著降低保温板的体积吸水率.

  15. Fiber-Reinforced Epoxy Composites and Methods of Making Same Without the Use of Oven or Autoclave

    Science.gov (United States)

    Barnell, Thomas J. (Inventor); Rauscher, Michael D. (Inventor); Stienecker, Rick D. (Inventor); Nickerson, David M. (Inventor); Tong, Tat H. (Inventor)

    2016-01-01

    Method embodiments for producing a fiber-reinforced epoxy composite comprise providing a mold defining a shape for a composite, applying a fiber reinforcement over the mold, covering the mold and fiber reinforcement thereon in a vacuum enclosure, performing a vacuum on the vacuum enclosure to produce a pressure gradient, insulating at least a portion of the vacuum enclosure with thermal insulation, infusing the fiber reinforcement with a reactive mixture of uncured epoxy resin and curing agent under vacuum conditions, wherein the reactive mixture of uncured epoxy resin and curing agent generates exothermic heat, and producing the fiber-reinforced epoxy composite having a glass transition temperature of at least about 100.degree. C. by curing the fiber reinforcement infused with the reactive mixture of uncured epoxy resin and curing agent by utilizing the exothermically generated heat, wherein the curing is conducted inside the thermally insulated vacuum enclosure without utilization of an external heat source or an external radiation source.

  16. 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.

  17. Estabelecimento de ciclo de cura de pré-impregnados aeronáuticos Establishment of cure cycle of aeronautic prepregs

    Directory of Open Access Journals (Sweden)

    Michelle L. Costa

    2005-07-01

    Full Text Available Os compósitos poliméricos podem ser produzidos via moldagem em autoclave, onde as condições de processamento podem ser otimizadas a partir do conhecimento físico-químico da matriz polimérica. A evolução da cinética da reação de cura ocorre simultaneamente com as modificações no comportamento reológico do sistema polimérico, sendo comum denominar o fenômeno de comportamento reo-cinético. O presente trabalho tem como objetivo conhecer os parâmetros de cura, cinéticos e reológicos, de três diferentes sistemas de pré-impregnados de resina epóxi (cura a 177 °C, conhecidos como F161, F584 e 8552, hoje usados na indústria aeronáutica brasileira. Este estudo foi realizado com o auxílio das técnicas de DSC e reologia, utilizando-se análises dinâmicas e isotérmicas. Com isso, foi possível estabelecer a ordem de reação e a cinética de cura dos sistemas estudados. Neste estudo, foram utilizados como modelos matemáticos o de ordem n e o autocatalítico com ordem total de aproximadamente 2. A temperatura de gel foi de ~100 °C, e o tempo de gel correspondente foi de 135 segundos. A partir do conhecimento da cinética de cura e dos parâmetros reológicos dos sistemas de pré-impregnados foi possível estabelecer um ciclo de cura destinado à consolidação das peças aeronáuticas via moldagem em autoclave.Autoclave molding produces polymer composites, where the processing conditions can be optimized with physicochemical knowledge of the polymeric matrix. The cure reaction evolves simultaneously with changes in rheology, which is normally refered to as rheo-kinetic behavior. With the knowledge of the appropriate cure cycle one can identify the steps in which pressure should be applied and when to raise the temperature. This paper is aimed at investigating the cure, kinetics and rheological parameters of three prepreg epoxy systems, namely F161, F584 and 8552, which are currently used in the Brazilian aeronautic industry

  18. [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

  19. Autoclaved aerated concrete masonry with external insulation. Features of moisture conditions during the initial period of operation (rus

    Directory of Open Access Journals (Sweden)

    Kuptaraeva P.D.

    2011-12-01

    Full Text Available Building designs at the moment of commissioning include the initial (building and technological moisture. Thermal insulation systems influence on the yield of the initial moisture from the structures. However, there are no specific design requirements about determining initial moisture content in insulation systems.In this article the features of the initial period of operation on an example of aerated concrete are defined: the results of field surveys and calculations are shown and compared. On the basis of this comparison basic advice on the accounting features of the initial period of operation of autoclaved aerated concrete structures with external insulation are given.

  20. Radtech Asia'95 radiation curing conference proceedings

    International Nuclear Information System (INIS)

    The Radtech Asia'95 Radiation Curing Conference was held in November, 20-24, 1995 in Guilin, China. The subjects include chemistry, application, Measurement and Equipment, and Material modification. Out of 86 titles, some 30 papers are in INIS scope

  1. Financing cures in the United States.

    Science.gov (United States)

    Basu, Anirban

    2015-02-01

    True cures in health care are rare but likely not for long. The high price tag that accompanies a cure along with its rapid uptake create challenges in the financing of cures by public and private payers. In the US, the disaggregated nature of health insurance system adds to this challenge as patients frequently churn across multiple health plans. This creates a 'free-rider' problem, where no one health plan has the incentive to invest in cure since the returns will be scattered over many health plans. Here, a new health currency is proposed as a generalized version of a social impact bond that has the potential to solve this free-rider problem, as it can be traded not only between public and private payers but also within the private sector. An ensuing debate as to whether and how to develop such a currency can serve the US health care system well. PMID:25482146

  2. 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

  3. 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.

  4. 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.

  5. Measurement on Hydrate Products Crystallinity Degrees of Autoclaved Silicate Products%蒸压硅酸盐制品水化产物的结晶度分析

    Institute of Scientific and Technical Information of China (English)

    柯昌君; 王淑英; 王浩; 袁兵

    2012-01-01

    利用烧失量和酸溶法测定不同固体废物蒸压样品的结合水量和溶出差,研究固体废物蒸压样品中水化产物量、结晶度与其强度的关系.结果表明,粉煤灰、废玻璃、废混凝土蒸压样品的结晶度较低,钢渣蒸压样品的结晶度较高.蒸压样品的溶出差、结合水量和结晶度与水化产物种类有关.蒸压样品的结晶度可间接表达结晶良好的水化产物占总水化产物量的多少,并可用来确定不同蒸压制品的合理养护制度,指导蒸压制品的工艺优化.蒸压样品的结晶度存在合理范围.%The relationships of solid waste autoclaved samples compressive strength and their crystal-Unity degrees, hydrate amounts were studied with dissolved amount difference and bound water a-mount measured with loss on ignition and acid digestion method. The results showed that the crystal-linity degrees of autoclaved samples, such as fly ash, waste glass and waste concrete are in a low level except that the crystallinity degree of autoclaved steel slag sample is higher. The dissolved amount difference, bound water amount and crystallinity degree of the autoclaved samples were related to their hydrate types. The crystallinity degrees of autoclaved samples could be indirectly represented as the ratios of well-crystallized hydrate amounts to total hydrate amounts in the autoclaved samples, and used to determine the autoclaved schedule and guide the technology optimization for autoclaved products. There is a reasonable crystallinity degree range for the compressive strength of autoclaved samples.

  6. Cycloaliphatic epoxide resins for cationic UV - cure

    International Nuclear Information System (INIS)

    This paper introduces the cyclo - aliphatic epoxide resins used for the various applications of radiation curing and their comparison with acrylate chemistry. Radiation curable coatings and inks are pre - dominantly based on acrylate chemistry but over the last few years, cationic chemistry has emerged successfully with the unique properties inherent with cyclo - aliphatic epoxide ring structures. Wide variety of cationic resins and diluents, the formulation techniques to achieve the desired properties greatly contributes to the advancement of UV - curing technology

  7. Animal Models for HIV Cure Research

    OpenAIRE

    Benjamin B Policicchio; Pandrea, Ivona; Apetrei, Cristian

    2016-01-01

    The HIV-1/AIDS pandemic continues to spread unabated worldwide, and no vaccine exists within our grasp. Effective antiretroviral therapy (ART) has been developed, but ART cannot clear the virus from the infected patient. A cure for HIV-1 is badly needed to stop both the spread of the virus in human populations and disease progression in infected individuals. A safe and effective cure strategy for human immunodeficiency virus (HIV) infection will require multiple tools, and appropriate animal ...

  8. novel geopolymeric material cured at room temperature

    OpenAIRE

    Mitsuuchi Tashima, Mauro; Soriano Martinez, Lourdes; Monzó Balbuena, José Mª; Borrachero Rosado, María Victoria; Paya Bernabeu, Jorge Juan

    2013-01-01

    Alkali activated binders are a new class of binding material with comparable or enhanced performance to Portland cement. These binding materials are obtained by a chemical reaction between an aluminosilicate material and a highly alkaline solution. In most cases, the setting hardening process of this binder is performed at high curing temperatures. In this paper, alkali activated mortars based on vitreous calcium aluminosilicate (VCAS) cured at room temperature are evaluated. Mechanical stren...

  9. Tracking Polymer Cure Via Embedded Optical Fibers

    Science.gov (United States)

    Dean, David L.; Davidson, T. Fred

    1993-01-01

    Fourier-transform infrared spectroscopy applied in interior of specimen of material by bringing infrared light through specimen in optical fiber. Light interacts with material via evanescent-wave effect. Spectra obtained in this way at various times during curing process also combined with data from ultrasonic, thermographic, and dielectric-impedance monitoring, and other measurement techniques to obtain more complete characterization of progress of curing process.

  10. Gamma and electron beam curing of polymers and composites

    International Nuclear Information System (INIS)

    Radiation polymerization has helped us understand polymer chemistry, and is also playing an increasing role in the field of practical applications. Radiation curing has a present market share of about 5% of the total market for curing of polymers and composites and the annual growth rate of the radiation curing market is ≥20% per year. Advantages of radiation curing over thermal or chemical curing methods include: improved control of the curing rate, reduced curing times, curing at ambient temperatures, curing without the need for chemical initiators, and complete (100%) curing with minimal toxic chemical emissions. Radiation treatment may also be used to effect crosslinking and grafting of polymer and composite materials. The major advantage in these cases is the ability to process products in their final shape. Cable insulation, automotive and aircraft components, and improved construction materials are some of the current and near-future industrial applications of radiation curing and crosslinking. 19 refs

  11. Strength development, hydration reaction and pore structure of autoclaved slag cement with added silica fume

    Energy Technology Data Exchange (ETDEWEB)

    Xi, Y. [China Building Materials Academy, Beijing (China); Siemer, D.D. [LITCO, Idaho Falls, ID (United States); Scheetz, B.E. [Pennsylvania State Univ., University Park, PA (United States). Materials Research Lab.

    1997-01-01

    Under continuous hydrothermal treatment the strength of portland cement paste decreases with curing time and the pore structure coarsens. It was found in this study that the compressive strength of slag cement paste containing 67.5 wt.% ggbfs also decreases with time after 24 hour hydrothermal processing, but with a small addition of silica fume to the slag cement, the cement strength increases and the pore structure densifies when processed under comparable conditions. Based on observations XRD and SEM, these changes are attributed to: (1) changes in the hydration reactions and products by highly reactive silica fume, such that amorphous products dominate and the strength reducing phase {alpha}-C{sub 2}SH does not form; (2) slower hydration of slag, partially caused by the decreased pH of the pore solution, favors the formation of a dense pore structure; and (3) the space filling properties of the micro particles of silica fume.

  12. 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.

  13. 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.

  14. Solubility study of nickel ferrite in boric acid using a flow-through autoclave system under high temperature and high pressure

    Energy Technology Data Exchange (ETDEWEB)

    Park, Yong Joon; Choi, Ke Chon; Ha, Yeong Keong [Nuclear Chemistry Research Division, Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2016-04-15

    The solubility of nickel ferrite in an aqueous solution of boric acid was studied by varying the pH at the temperatures ranging from 25 .deg. C to 320 .deg. C. A flow-through autoclave system was specially designed and fabricated to measure the solubility of Fe in hydrothermal solutions under high temperature and pressure. The performance of this flow-through system was directly compared with the conventional static state technique using a batch-type autoclave system. The stability of fluid velocity for the flow-through autoclave system was verified prior to the solubility measurement. The influence of chemical additives, such as boric acid and H2, on the solubility of nickel ferrite was also evaluated.

  15. 7 CFR 29.2269 - Fire-cured.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Fire-cured. 29.2269 Section 29.2269 Agriculture... INSPECTION Standards Official Standard Grades for Virginia Fire-Cured Tobacco (u.s. Type 21) § 29.2269 Fire-cured. Tobacco cured under artificial atmospheric conditions by the use of open fires from which...

  16. Proceedings of workshop on surface finishing by radiation curing technology: radiation curing for better finishing

    International Nuclear Information System (INIS)

    This book compiled the paper presented at this workshop. The papers discussed are 1. Introduction to radiation curing, 2. Radiation sources -ultraviolet and electron beams, 3. UV/EB curing of surface coating - wood and nonwood substrates, 4. Development of EPOLA (epoxidised palm oil products acrylate) and its application, 5. Development of radiation-curable resin based natural rubber

  17. Production process and equipment selection of autoclaved brick%一种蒸压砖生产工艺流程及设备选型

    Institute of Scientific and Technical Information of China (English)

    周占霞

    2016-01-01

    The paper describes how to reduce the added proportion of calcium carbide slurry, improve the auto⁃claved brick quality, and reduce production costs of autoclaved brick by optimizing the production process and equipment selection to eliminate the mud clumping of calcium carbide slurry in autoclaved calcium carbide sludge brick.%通过优化生产工艺流程及设备选型消除电石泥蒸压砖中的电石泥结团,降低电石泥原料添加比例和提高蒸压砖质量,降低蒸压砖生产成本。

  18. 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.

  19. 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.

  20. Cure-in-place process for seals

    Science.gov (United States)

    Hirasuna, Alan R.

    1981-01-01

    A cure-in-place process which allows a rubber seal element to be deformed to its service configuration before it is cross-linked and, hence, is a plastic and does not build up internal stress as a result of the deformation. This provides maximum residual strength to resist the differential pressure. Furthermore, the process allows use of high modulus formulations of the rubber seal element which would otherwise crack if cured and then deformed to its service configuration, resulting in a seal which has better gap bridging capability. Basically, the process involves positioning an uncured seal element in place, deforming it to its service configuration, heating the seal element, curing it in place, and then fully seating the seal.

  1. Kinetic Analysis of Mica Tape Curing Process

    Directory of Open Access Journals (Sweden)

    Radek Polansky

    2008-01-01

    Full Text Available Curing program of thermoset insulating materials and its responsible setting has the key importance for assurance of high quality and reliability of electrical devices. It is possible to determine parameters of this program (temperature and time of curing by several ways in practise. There is mostly focused on methods based on kinetic analysis. The result comparison of selected methods of kinetic analysis and residual enthalpy measurement is the main aim of the paper. Two insulating tapes were chosen for the purpose of this study. These tapes correspond in their composition (glass fabric, mica and epoxy binder, but they differ in curing agent type. Simultaneous thermal analysis (STA was used during the measurements. Monitored results demonstrate the advantages and disadvantages of particular methods.

  2. Integrative physicians and an herbal cancer "cure".

    Science.gov (United States)

    Ben-Arye, Eran; Rosenberg, Shoshana Keren; Samuels, Noah

    2016-08-01

    Oncologists are frequently asked about herbal remedies claiming to "cure" cancer, or at least delay its progression. While complementary and integrative medicine (CIM) should be aimed primarily at improving quality-of-life (QOL) related concerns, "wonder cures" are part of an alternative health belief model providing hope for a "miracle" where conventional treatment has failed. We describe a physician with extensive small-cell lung cancer (SCLC) undergoing chemotherapy, with significant toxicities and impaired daily function. He had come for an integrative physician (IP) consultation, provided by a medical doctor dually trained in CIM and supportive cancer care, taking place in a conventional supportive cancer care service. We describe the IP consultation in general and regarding an herbal remedy which was being promoted as a "cure" for cancer. The subsequent patient-tailored CIM treatment process, in which patients receive evidence-based guidance on treatments which address QOL-related concerns, are presented. PMID:27652207

  3. Characterization of electron beam cured epoxy acrylate

    International Nuclear Information System (INIS)

    Epoxy resin has wide application in various industrial fields because of their good mechanical strength, superiority adhesion and low shrinkage etc. And the typical curing method for epoxy resins is thermal and press compaction. However, a curing method was used electron beam process in this study. Epoxy acrylate was fabricated from mixture of epoxy, acrylic acid, tetraphenylporphyrin (TPP) and hydroquinone monomethyl ether (MEHQ) with mole ratios. Then electron beam irradiation effect on the curing of the epoxy acrylate resin was investigated various absorption dose in nitrogen atmospheres at room temperature. The dynamic mechanical and thermal properties of the irradiated epoxy acrylate resins were characterized using dynamic mechanical analysis (DMA) and thermogravimetric analyzer (TGA). And the tensile and flexural strength were measured by an universal tensile machine (UTM)

  4. UV/EB curing in Australia

    International Nuclear Information System (INIS)

    Progress in LTV/EB curing is reviewed in Australia. Generally the technology is used by those industries where curing is well developed in Europe and North America, however the scale is an order of magnitude lower due to the smaller market size. The Asian economic crisis does not appear to have affected expansion of the technology in Australia. EB continues to be successfully used in the packaging and foam fields whilst in UV, security devices, particularly banknotes are steadily expanding especially in export markets have been studied

  5. FTIR Monitoring Of Curing Of Composites

    Science.gov (United States)

    Druy, Mark A.; Stevenson, William A.; Young, Philip R.

    1990-01-01

    Infrared-sensing optical fiber system developed to monitor principal infrared absorption bands resulting from vibrations of atoms and molecules as chemical bonds form when resin cured. System monitors resin chemistry more directly. Used to obtain Fourier transform infrared (FTIR) spectrum from graphite fiber/polyimide matrix resin prepreg. Embedded fiber optic FTIR sensor used to indicate state of cure of thermosetting composite material. Developed primarily to improve quality of advanced composites, many additional potential applications exist because principal of operation applicable to all organic materials and most inorganic gases. Includes monitoring integrities of composite materials in service, remote sensing of hazardous materials, and examination of processes in industrial reactors and furnaces.

  6. Radiation curing applications of palm oil acrylates

    International Nuclear Information System (INIS)

    Various palm oil based urethan acrylate prepolymers (UP) were prepared from palm oil based polyols, diisocyanate compounds and hydroxyl terminated acrylate monomers by following procedure derived from established methods. The products were compared with each other in term of their molecular weights (MW), viscosities, curing speed by UV irradiation, gel contents and film hardness. The molecular structure of diisocyanate compounds and hydroxyl acrylate monomers were tend to determine the molecular weights and hence viscosities of the final products of urethan acrylate prepolymers (UP), whereas, the MW of the UP has no direct effects on the UV curing properties of the prepolymers. (author)

  7. Thermophysical characteristics of low density autoclaved aerated concrete and their influence on durability of exterior walls of buildings

    Directory of Open Access Journals (Sweden)

    A.B. Krutilin

    2015-03-01

    Full Text Available The paper presents the results of experimental studies of thermophysical characteristics of autoclaved aerated concrete with density of 400 and 500 kg/m3. The dependence of thermal conductivity on temperature and humidity was determined. The boundary humidities were set for which ice is either not formed or its amount is negligible in the pores of the materials at the temperature below zero. The new method of non-isothermal liquid transport coefficient determination was suggested. It was found that one of the basic mechanisms of moving water for cellular concrete samples with a moisture content over 30 % by weight is non-isothermal liquid transport. The effect of humidity on durability of exterior walls is estimated according to cellular concrete frost-resistance tests.

  8. 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.

  9. 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.

  10. 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....

  11. Internal water curing with Liapor aggregates

    DEFF Research Database (Denmark)

    Lura, Pietro

    2005-01-01

    Internal water curing is a very efficient way to counteract self-desiccation and autogenous shrinkage in high performance concrete, thereby reducing the likelihood of early-age cracking. This paper deals with early-age volume changes and moisture transport in lightweight aggregate concrete realized...... with simple composite models, showing good agreement with the experimental findings....

  12. Thermal and photochemical curing of filled resins

    International Nuclear Information System (INIS)

    Full text.UV-radiation curing has experienced a steady growth for the past 20 years because of its distinct advantages, namely, solvent-free formulations cured within a fraction of a second upon illumination at ambient temperature. But as the UV light hardly penetrates into pigmented resins and does not reach shadow areas of items presenting a complex shape, conventional UV-curable colored coatings cannot be used as protective varnishes for 3D items. Dual-cure systems have therefore been developed: the light induced polymerization of acrylic double bonds is combined with a thermally induced poly addition reaction between isocyanates and hydroxyl groups. the resulting polyurethane network was shown to exhibit satisfactory mechanical properties for a few millimeter thick pigmented samples. The influence of the hydrogen donor, the reaction temperature, the ambient humidity, as well as the importance of the UV step on the poly addition kinetics has been investigated by FTIR spectroscopy. the efficiency of this dual-cure processing has been demonstrated by ATR infrared spectroscopy investigations for composite materials containing carbon black. The mechanical properties of the resulting material have been evaluated by hardness and dynamic mechanical analysis measurements

  13. Development of carbon composites cured by radiation

    International Nuclear Information System (INIS)

    -Developments of the new process in the manufacture of composites - Developments of a necessary technics for the manufacture of an export embargo components - Developments of the green process in the manufacture of composites - Developments and applications of the radiation curing technics in the manufacture of various composites - Developments of the manufacturing process for carbon/carbon(carbon/silicon carbide) composites

  14. Development of Cooking Test Device with Bantam Autoclave Group%群锅蒸煮实验装置的研制

    Institute of Scientific and Technical Information of China (English)

    胡明辅; 李淑兰; 陈克利; 别玉

    2011-01-01

    A set of self-made cooking test device with bantam autoclave group is introduced including its principles, main structure, body design , and operation processes. The device is mainly composed of four parts; I is a box and rack supporting the box and two motion systems ; II is the lid movement system for smoothly opening the lid and closing it tightly; IK is a autoclave group base motion system for fixing the autoclaves in the shaft rotating disc supporter and driving axis of the supporter submerged in oil using for heating the autoclaves; IV is a heating measurement and control system to complete heating the oil, measuring, displaying and controlling temperature. Cooking wood or nonwood fibrous material under different conditions in 8 or more autoclaves can simultaneously carried out during one cooking cycle. The advantages of this device are efficient, precise and even temperature control, and reliable seal.%介绍了群锅蒸煮实验装置的基本原理、主要结构、锅体设计、实验过程等.该装置主要结构包括:箱体和机架、箱盖运动系统、蒸煮群锅运动系统、加热测量控制系统.该装置的优点是一次可同时进行8锅以上蒸煮实验,同时还具有加热均匀、温度控制精确、密封可靠、操作简单的特点.

  15. 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.

  16. 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.

  17. 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...

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

    Energy Technology Data Exchange (ETDEWEB)

    Janke, C. J. [ORNL; Howell, Dave [ORNL; Norris, Robert E. [ORNL

    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.

  19. Radiation curing technology progress and its industrial applications in Japan

    International Nuclear Information System (INIS)

    Optics, electronics and display industries are now the driving forces for the Japanese radiation curing technology. The purpose of this paper is to overview the newly developed radiation curing technology in Japan, in particular, its industrial applications, and to present the market figures in radiation curing applications, which were surveyed by RadTech Japan in 2002 afresh. (author)

  20. 7 CFR 30.12 - Fire-cure.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Fire-cure. 30.12 Section 30.12 Agriculture Regulations... AND STANDARDS Classification of Leaf Tobacco Covering Classes, Types and Groups of Grades § 30.12 Fire-cure. To cure tobacco under artificial atmospheric conditions by the use of open fires, the smoke...

  1. 7 CFR 30.13 - Air-cure.

    Science.gov (United States)

    2010-01-01

    ...-cure. To cure tobacco under natural atmospheric conditions without the use of fire, except for the... 7 Agriculture 2 2010-01-01 2010-01-01 false Air-cure. 30.13 Section 30.13 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections,...

  2. 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.

  3. 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.

  4. Environmental and conservation considerations for electron curing

    International Nuclear Information System (INIS)

    This paper reviews the more important features of electron curing pertaining to environmental protection and conservation. The high electrical conversion efficiencies of these devices measured at output power levels to 200 kilowatts are reviewed with attention to energy transport to the product. The comparative energetics of free radical initiated addition chemistry with that of the more conventional condensation polymerized systems are presented. Some details of recent studies of the repulpability and de-inkability of electron cured products are presented with mill scale trials showing successful recycling with up to 75 % EB processed material in the waste. The ability of energetic electrons to effectively replace toxic chemicals such as H2O2 and ethylene oxide in product sterilization will be presented with a discussion of the regulatory aspects of this process for medical device applications. (author)

  5. Antibiotics Cure Anthrax in Animal Models▿

    OpenAIRE

    Weiss, Shay; Kobiler, David; Levy, Haim; Pass, Avi; Ophir, Yakir; Rothschild, Nili; Tal, Arnon; Schlomovitz, Josef; Altboum, Zeev

    2011-01-01

    Respiratory anthrax, in the absence of early antibiotic treatment, is a fatal disease. This study aimed to test the efficiency of antibiotic therapy in curing infected animals and those sick with anthrax. Postexposure prophylaxis (24 h postinfection [p.i.]) of guinea pigs infected intranasally with Bacillus anthracis Vollum spores with doxycycline, ofloxacin, imipenem, and gentamicin conferred protection. However, upon termination of treatment, the animals died from respiratory anthrax. Combi...

  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. Coating and curing apparatus and methods

    Science.gov (United States)

    Brophy, Brenor L; Maghsoodi, Sina; Neyman, Patrick J; Gonsalves, Peter R; Hirsch, Jeffrey G; Yang, Yu S

    2015-02-24

    Disclosed are 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 skin curing sol-gel coatings deposited onto the surface of glass substrates using a high temperature air-knife are disclosed.

  8. 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.

  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

    International Nuclear Information System (INIS)

    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-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. 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.

  12. Thermal and photochemical curing of filled resins

    International Nuclear Information System (INIS)

    Full text.UV-radiation curing has experienced a steady growth for the past 20 years because of its distinct advantages, namely, solvent-free formulations cured within a fraction of a second upon illumination at ambient temperature. But as the UV light hardly penetrates into pigmented resins and does not reach shadow areas of items presenting a complex shape, conventional UV-curable colored coatings cannot be used as protective varnishes for 3D items. Dual-cure systems have therefore been developed: the light induced polymerization of acrylic double bonds is combined with a thermally induced poly addition reaction between isocyanates and hydroxyl groups. The resulting polyurethane network was shown to exhibit satisfactory mechanical properties for a few millimeter thick pigmented samples. The influence of the hydrogen donor, the reaction temperature, the ambient humidity, as well as the importance of the UV step on the poly addition kinetics has been investigated by FTIR spectroscopy. The efficiency of this dual-core processing has been demonstrated by ATR infrared spectroscopy investigations for composite materials containing carbon black. The mechanical properties of the resulting material have been evaluated by hardness and dynamic mechanical analysis measurements

  13. Study on the heat-resistant EB curing composites

    Energy Technology Data Exchange (ETDEWEB)

    Bao Jianwen; Li Yang [Institute of Aeronautical Materials, Beijing (China); Li Fengmei [Institute of Low Energy Nuclear Physics, Beijing Normal Univ., Beijing (China)

    2000-03-01

    There are many advantages in the EB-curing process of composites. Heat-resistant EB-curing composites could substitute for polyimide composites used in aeronautical engine. 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 thermal analysis (DMTA). The experiment result shows that the mechanical property of the composites cured by EB could meet the needs of the aeronautical engine in 250degC. (author)

  14. Technology and market of UV/EB curing in Indonesia

    International Nuclear Information System (INIS)

    Electron-beam (EB) and ultra-violet (UV) radiation are the types of irradiation systems which are being used in Indonesia for curing application. Ultra-violet curing is widely used commercially particularly in surface coating of wood and paper, printing, adhesives and electronic industries. Up to now, electron-beam curing is still in a pilot-scale step due to the economic reason. Although the equipment and chemicals tend to be more expensive than conventional systems, but radiation curing technology has been believed as an efficient and environmentally friendly technology in industrial application. This paper describes the technology and market of radiation curing in Indonesia. (author)

  15. 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.

  16. The problems of operational reliability exterior walls of a building based on the autoclaved aerated concrete blocks and possibility of their protection from moisture

    Directory of Open Access Journals (Sweden)

    N.S. Samofeev

    2010-12-01

    Full Text Available The basic mechanisms and factors that have destructive effect on the state of autoclaved aerocrete in the exterior walls of operated buildings are shown. These mechanisms are wetting the wall, the effect of moisture during freezing, carbonation hydrosilicate structure-phase of material. The possibilities of protection exterior walls with using hydrophobic multilayered vapor permeable stucco are estimated, which were accepted for protecting facades apartment buildings on the basis autoclaved aerocrete blocks in Bashkiriya.In the Republic of Bashkortostan in October 2010 was put into operation factory for production blocks with capaciry 225,000 m3 per year at OAO "GlavBashStroy" on equipment Masa-Henke, whose products are currently being investigated

  17. 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.

  18. 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.

  19. 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.

  20. INFLUENCE OF WATER-TO-CEMENT RATIO ON AIR ENTRAILMENT IN PRODUCTION OF NON-AUTOCLAVED FOAM CONCRETE USING TURBULENCE CAVITATION TECHNOLOGY

    OpenAIRE

    Gorshkov Pavel Vladimirovich

    2012-01-01

    Non-autoclaved foam concrete is an advanced thermal insulation material. Until recently, foam concrete production has been based on separate preparation of foam and solution, followed by their blending in a mixer. The situation changed when high-quality synthetic foaming agents and turbulence cavitation technology appeared on the market. Every model provides a dependence between the foam concrete strength and the water-to-cement ratio. According to the water-cement ratio we can distinguish st...

  1. 利用油页岩灰制备蒸压砖的试验研究%Study on preparation of autoclaved brick with oil shale ash

    Institute of Scientific and Technical Information of China (English)

    高子栋; 潘红

    2015-01-01

    The autoclaved brick is prepared with the oil shale ash, the fly ash, the calcium carbide residue, the gyp⁃sum and the stone chips. The effect on properties of autoclaved brick is studied by changing the ratio of oil shale ash and fly ash. When the ratio of oil shale ash increases, the compressive strength and the flexural strength of au⁃toclaved brick increase first, and then decrease, and the drying shrinkage value keep increasing. When the ratio of oil shale ash is 30%, the strength grade of autoclaved brick could achieves MU15. When the ratio of oil shale ash is 50%, the strength grade of autoclaved brick could also achieve MU10.%采用油页岩灰、粉煤灰、电石渣、石膏、石屑等作为原材料,制备了一种蒸压砖,研究了油页岩灰替代粉煤灰的比例对产品性能的影响。试验结果表明,随油页岩灰比例不断增大,蒸压砖的抗压强度、抗折强度均呈先提高后降低的变化趋势,干燥收缩值不断提高。当油页岩灰替代粉煤灰的比例为30%时,蒸压砖强度等级可达到标准JC239—2001《粉煤灰砖》中的MU15;当油页岩灰替代粉煤灰的比例为50%时,蒸压砖强度等级仍可达到MU10。

  2. An evaluation of corrosion characteristics of materials for cladding (Zr) and heat-exchanger tubes (Ti) of SMART in static autoclaves

    International Nuclear Information System (INIS)

    The corrosion characteristics of materials (Low-Sn Zircaloy-4, Zr-1.0Nb, PT-7M, ASTM Gr. 2 Ti, Inconel-600 alloys) for cladding and heat-exchanger tubes of SMART in pure water, ammonia aqueous solutions of pH 9.98 and pH 11.13 at 360 .deg. and in steam at 400 .deg. were evaluated by using static autoclaves

  3. Investigation of the use of fly-ash based autoclaved cellular concrete blocks in coal mines for air duct work. Final report, January 25, 1993--December 31, 1994

    Energy Technology Data Exchange (ETDEWEB)

    Horvath, M.L. [Ohio Edison Co., Akron, OH (United States)

    1995-06-19

    Coal mines are required to provide ventilation to occupied portions of underground mines. Concrete block is used in this process to construct air duct walls. However, normal concrete block is heavy and not easy to work with and eventually fails dramatically after being loaded due to mine ceiling convergence and/or floor heave. Autoclaved cellular concrete block made from (70{plus_minus}%) coal fly ash is lightweight and less rigid when loaded. It is lighter and easier to use than regular concrete block for underground mine applications. It has also been used in surface construction around the world for over 40 years. Ohio Edison along with eight other electric utility companies, the Electric Power Research Institute (EPRI), and North American Cellular Concrete constructed a mobile demonstration plant to produce autoclaved cellular concrete block from utility fly ash. To apply this research in Ohio, Ohio Edison also worked with the Ohio Coal Development Office and CONSOL Inc. to produce autoclaved cellular concrete block not only from coal ash but also from LIMB ash, SNRB ash, and PFBC ash from various clean coal technology projects sponsored by the Ohio Coal Development Office. The purpose of this project was to demonstrate the potential for beneficial use of fly ash and clean coal technology by-products in the production of lightweight block.

  4. The effect of multiple autoclave cycles on the surface of rotary nickel-titanium endodontic files: An in vitro atomic force microscopy investigation

    Directory of Open Access Journals (Sweden)

    Ashish Shashikant Nair

    2015-01-01

    Full Text Available Aims: To observe and study the effect of multiple autoclave sterilization cycles, on the surface of nickel-titanium (NiTi files. Materials and Methods: The file used for this study was the M two file (VDW and ProTaper (Dentsply. The apical 5 mm of the files were attached to a silicon wafer and subjected to autoclave cycles under standardized conditions. They were scanned with an AFM after 1, 5, and 10 cycles. The unsterilized files were used as control, before start of the study. Three vertical topographic parameters namely maximum height (MH, root mean square (RMS of surface roughness, and arithmetic mean roughness (AMRwere measured with the atomic force microscope (AFM. Analysis of variance along with Tukey′s test was used to test the differences. Results: The vertical topographic parameters were higher for both the files, right after the first cycle, when compared with the control (P < 0.01. The surface roughness increased sharply for M two when compared to ProTaper, though ProTaper had a rougher surface initially. Conclusions: The study confirmed that the irregularities present on the surface of the file became more prominent with multiple autoclave cycles, a fact that should be kept in mind during their reuse.

  5. Electron beam curing of polymer matrix composites

    Energy Technology Data Exchange (ETDEWEB)

    Janke, C.J. [Lockheed Martin Energy Systems, Inc., Oak Ridge, TN (United States); Wheeler, D. [Sandia National Lab., Albuquerque, NM (United States); Saunders, C. [AECL Technologies, Inc., Rockville, MD (United States)] [and others

    1998-01-08

    The purpose of the CRADA was to conduct research and development activities to better understand and utilize the electron beam PMC curing technology. This technology will be used to replace or supplement existing PMC thermal curing processes in Department of Energy (DOE) Defense Programs (DP) projects and American aircraft and aerospace industries. This effort involved Lockheed Martin Energy Systems, Inc./Lockheed Martin Energy Research Corp. (Contractor), Sandia National Laboratories, and ten industrial Participants including four major aircraft and aerospace companies, three advanced materials companies, and three electron beam processing organizations. The technical objective of the CRADA was to synthesize and/or modify high performance, electron beam curable materials that meet specific end-use application requirements. There were six tasks in this CRADA including: Electron beam materials development; Electron beam database development; Economic analysis; Low-cost Electron Beam tooling development; Electron beam curing systems integration; and Demonstration articles/prototype structures development. The contractor managed, participated and integrated all the tasks, and optimized the project efforts through the coordination, exchange, and dissemination of information to the project participants. Members of the Contractor team were also the principal inventors on several electron beam related patents and a 1997 R and D 100 Award winner on Electron-Beam-Curable Cationic Epoxy Resins. The CRADA achieved a major breakthrough for the composites industry by having successfully developed high-performance electron beam curable cationic epoxy resins for use in composites, adhesives, tooling compounds, potting compounds, syntactic foams, etc. UCB Chemicals, the world`s largest supplier of radiation-curable polymers, has acquired a license to produce and sell these resins worldwide.

  6. Electron beam curing of polymer matrix composites

    International Nuclear Information System (INIS)

    The purpose of the CRADA was to conduct research and development activities to better understand and utilize the electron beam PMC curing technology. This technology will be used to replace or supplement existing PMC thermal curing processes in Department of Energy (DOE) Defense Programs (DP) projects and American aircraft and aerospace industries. This effort involved Lockheed Martin Energy Systems, Inc./Lockheed Martin Energy Research Corp. (Contractor), Sandia National Laboratories, and ten industrial Participants including four major aircraft and aerospace companies, three advanced materials companies, and three electron beam processing organizations. The technical objective of the CRADA was to synthesize and/or modify high performance, electron beam curable materials that meet specific end-use application requirements. There were six tasks in this CRADA including: Electron beam materials development; Electron beam database development; Economic analysis; Low-cost Electron Beam tooling development; Electron beam curing systems integration; and Demonstration articles/prototype structures development. The contractor managed, participated and integrated all the tasks, and optimized the project efforts through the coordination, exchange, and dissemination of information to the project participants. Members of the Contractor team were also the principal inventors on several electron beam related patents and a 1997 R and D 100 Award winner on Electron-Beam-Curable Cationic Epoxy Resins. The CRADA achieved a major breakthrough for the composites industry by having successfully developed high-performance electron beam curable cationic epoxy resins for use in composites, adhesives, tooling compounds, potting compounds, syntactic foams, etc. UCB Chemicals, the world's largest supplier of radiation-curable polymers, has acquired a license to produce and sell these resins worldwide

  7. The cure for employee malaise--motivation.

    Science.gov (United States)

    Dawson, K M; Dawson, S N

    1991-01-01

    Although working conditions, hours, pay, and advancement opportunities are better now than in the 1950s--the "golden age" of American business--today's workers are significantly less satisfied. Why? The authors believe the cause of this malaise is lack of motivation. This article examines several techniques to cure employee malaise and discusses the long-term benefits of these techniques, which include empowerment, recognition, career development, the Pygmalion effect, incentives, and rewards. By making a commitment to these motivational techniques, managers will boost the morale and enthusiasm of their employees and their organization. This motivational process is not quick and easy; developing your employees is an ongoing process.

  8. 浅谈粉煤灰蒸压釜安装的几个要点%Talking about Several Key Points in the Installation of Fly-ash Autoclaved Kettle

    Institute of Scientific and Technical Information of China (English)

    周建锋

    2014-01-01

    详细介绍了粉煤灰蒸压釜安装过程中的几个要点,并提出了粉煤灰蒸压釜安装过程中需要注意的事项。%This paper introduces in detail several key points in the installation of fly-ash autoclaved kettle, and puts forward the matters needing attention in the installation of fly-ash autoclaved kettle.

  9. Heavy metal content in flue cured and air cured tobaccos from main production areas in Serbia

    Directory of Open Access Journals (Sweden)

    Radojičić Vesna

    2004-01-01

    Full Text Available The aim of this work was to examine the influence of growing conditions on heavy metal content in virginia (flue cured and burley (air cured tobacco type. Moreover, some of these metals could appear in the tobacco cigarette smoke. This fact may cause negative consequences for cigarette consumers. Examinations were carried out in five various production areas, for each tobacco type, during two years, 1998 and 1999; those were extreme years for production.Considering the results, it can be concluded: The most important factor for heavy metal content in tobacco leaves are weather conditions especially the amount of rainfall, since there is a direct correlation between the rainfall and size of roots, a dominant vegetation organ. It is inevitable that the metals content in flue cured and air cured tobaccos grown at different experimental lots, is still below the legally prescribed values. Tobacco leaves from Šabac production area have a little higher metal content than tobacco grown in other production areas, because a larger amount of copper was found. The metal content in plants can increase because of its absorption from soil, atmosphere, or mineral fertilizers and pesticides, and, what is very important, the content of metals can be high due to the vicinity of large industrial centers.

  10. 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....

  11. 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.

  12. 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.

  13. CURE: Clean use of reactor energy

    International Nuclear Information System (INIS)

    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

  14. Immunization against leishmaniasis by PLGA nanospheres encapsulated with autoclaved Leishmania major (ALM) and CpG-ODN.

    Science.gov (United States)

    Tafaghodi, Mohsen; Khamesipour, Ali; Jaafari, Mahmoud R

    2011-05-01

    Various adjuvants and delivery systems have been evaluated for increasing the protective immune responses against leishmaniasis and mostly have been shown not to be effective enough. In this study, poly(D,L-lactide-co-glycolide) (PLGA) nanospheres as an antigen delivery system and CpG-ODN as an immunoadjuvant have been used for the first time to enhance the immune response against autoclaved Leishmania major (ALM). PLGA nanospheres were prepared by a double-emulsion (W/O/W) technique. Particulate characteristics were studied by scanning electron microscopy and particle size analysis. Mean diameter of ALM + CpG-ODN-loaded nanospheres was 300 ± 128 nm. BALB/c mice were immunized three times in 3-week intervals using ALM plus CpG-ODN-loaded nanospheres [(ALM + CpG-ODN)(PLGA)], ALM encapsulated PLGA nanospheres [(ALM)(PLGA)], (ALM)(PLGA) + CpG, ALM + CpG, ALM alone, or phosphate buffer solution (PBS). The intensity of infection induced by L. major challenge was assessed by measuring size of footpad swelling. The strongest protection, showed by significantly (P<0.05) smaller footpad, was observed in mice immunized with (ALM + CpG-ODN)(PLGA). The (ALM)(PLGA), (ALM)(PLGA) + CpG, and ALM + CpG were also showed a significantly (P<0.05) smaller footpad swelling compared to the groups received either PBS or ALM alone. The mice immunized with (ALM + CpG-ODN)(PLGA), (ALM)(PLGA) + CpG, and ALM + CpG showed the highest IgG2a/IgG1 ratio, interferon-γ production, and lowest interleukin-4 production compared to the other groups. It is concluded that when both PLGA nanospheres and CpG-ODN adjuvants were used simultaneously, it induce stronger immune response and enhance protection rate against Leishmania infection.

  15. Immunization against leishmaniasis by PLGA nanospheres loaded with an experimental autoclaved Leishmania major (ALM) and Quillaja saponins.

    Science.gov (United States)

    Tafaghodi, M; Eskandari, M; Kharazizadeh, M; Khamesipour, A; Jaafari, M R

    2010-12-01

    Immune responses against the Leishmania antigens are not sufficient to protect against a leishmania challenge. Therefore these antigens need to be potentiated by various adjuvants and delivery systems. In this study, Poly (d,l-lactide-co-glycolide (PLGA) nanospheres as antigen delivery system and Quillaja saponins (QS) as immunoadjuvant have been used to enhance the immune response against autoclaved Leishmania major (ALM). PLGA nanospheres were prepared by a double-emulsion (W/O/W) technique. Particulate characteristics were studied by scanning electron microscopy and particle size analysis. Mean diameter for nanospheres loaded with ALM+QS was 294 ± 106 nm. BALB/c mice were immunized three times in 3-weeks intervals using ALM plus QS loaded nanospheres [(ALM+QS)PLGA], ALM encapsulated with PLGA nanospheres [(ALM)PLGA], (ALM)PLGA + QS, ALM + QS, ALM alone or PBS. The intensity of infection induced by L. major challenge was assessed by measuring size of footpad swelling. The strongest protection, showed by significantly (P < 0.05) smaller footpad, were observed in mice immunized with (ALM)PLGA. The (ALM+QS)PLGA group showed the least protection and highest swelling, while the (ALM)PLGA+QS, ALM+QS and ALM showed an intermediate protection with no significant difference. The mice immunized with ALM and ALM+QS showed the highest IgG2a/IgG1 ratio (P < 0.01), followed by (ALM)PLGA+QS. The highest IFN-γ and lowest IL-4 production was seen in (ALM)PLGA+QS, ALM+QS groups. The highest parasite burden was observed in (ALM)PLGA+QS and (ALM+QS)PLGA groups. It is concluded that PLGA nanospheres as a vaccine delivery system could increase the protective immune responses, but QS adjuvant has a reverse effect on protective immune responses and the least protective responses were seen in the presence of this adjuvant.

  16. A Study of Isothermal Curing of PMI Using DMA

    OpenAIRE

    Jing Zhang; Rui Ye; Jun Zou; Jijun Tang; Hongliang Wang

    2015-01-01

    The isothermal curing of polymethacrylimide (PMI) is studied through the use of dynamic mechanical analysis (DMA). Based on the growth rate of measured dynamic mechanical property, the relative conversion is defined to investigate the evolution of storage modulus E′ at different curing temperatures. Hsich’s nonequilibrium thermodynamic fluctuation theory, Avrami equation, and isoconversional methods are used to analyze isothermal cure kinetics of PMI. The results show that there are different...

  17. Curing reaction of bisphenol-A based benzoxazine with cyanate ester resin and the properties of the cured thermosetting resin

    Directory of Open Access Journals (Sweden)

    H. Kimura

    2011-12-01

    Full Text Available Curing reaction of bisphenol-A based benzoxazine with cyanate ester resin and the properties of the cured thermosetting resin were investigated. The cure behavior of benzoxazine with cyanate ester resin was monitored by model reaction using nuclear magnetic resonance (NMR. As a result of the model reaction, the ring opening reaction of benzoxazine ring and thermal self-cyclotrimerization of cyanate ester group occurred, and then the phenolic hydoroxyl group generated by the ring opening reaction of benzoxazine ring co-reacted with cyanate ester group. The properties of the cured thermosetting resin were estimated by mechanical properties, electrical resistivity, water resistance and heat resistance. The cured thermosetting resin from benzoxazine and cyanate ester resin showed good heat resistance, high electrical resistivity and high water resistance, compared with the cured thermosetting resin from benzoxazine and epoxy resin.

  18. Bending strength and depth of cure of light-cured composite resins irradiated using filters that simulate enamel.

    Science.gov (United States)

    Arikawa, H; Kanie, T; Fujii, K; Shinohara, N

    2004-01-01

    This study evaluates the light-attenuating effects of enamel on the properties of light-cured restorative resins using simple experimental filters. Three filters were designed to replicate the light transmittance characteristics of 0.5, 1.0 and 1.5 mm thick human enamel. The bending strength, depth of cure, and levels of residual monomer for 12 shades of three commercial light-cured composite resins were examined. These resins were cured either using direct irradiation from a light source or irradiation through one of the filters. For all materials, the bending strength and depth of cure of specimens irradiated through a filter were lower and the levels of residual monomer were higher than those found in specimens irradiated directly. The results indicate that the light-attenuating effect of enamel reduces the polymerization efficiency, resulting in poorer mechanical properties of light-cured composite resins. PMID:15125601

  19. Curing reaction of bisphenol-A based benzoxazine with cyanate ester resin and the properties of the cured thermosetting resin

    OpenAIRE

    Kimura, H.; Ohtsuka, K.; Matsumoto, A

    2011-01-01

    Curing reaction of bisphenol-A based benzoxazine with cyanate ester resin and the properties of the cured thermosetting resin were investigated. The cure behavior of benzoxazine with cyanate ester resin was monitored by model reaction using nuclear magnetic resonance (NMR). As a result of the model reaction, the ring opening reaction of benzoxazine ring and thermal self-cyclotrimerization of cyanate ester group occurred, and then the phenolic hydoroxyl group generated by the ring opening reac...

  20. 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.

  1. Patienthood in medieval Tuscany: beliefs and cures.

    Science.gov (United States)

    Lawless, Catherine

    2016-06-01

    This paper focuses on intersections of holy and sick bodies in the Tuscan Middle Ages to examine how the faithful accessed miraculous cures from contact with, or belief in, the relics of the saints. Rather than examine the relationship between the long dead martyrs (whose relics were abundant), however, it will look at the relationship between relatively recent saints and their devotees. The miracles discussed are traditional-that is, they are found in the lives of many saints and are not exceptional. It is hoped, however, that by concentrating on Tuscany, some insights can be secured on the relationship between Tuscan individuals of the late middle ages and those of their community who were recognised, either officially or through vox populi, as saints. PMID:27174846

  2. 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.

  3. 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.

  4. 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.

  5. Acoustic Monitoring of Adhesive Bond Curing in Wood Laminates.

    Science.gov (United States)

    Biernacki, Jacek Marek

    Challenges in manufacturing of wood products, such as glulam, include difficulty in controlling bonding variables and assessing bond quality. This dissertation investigates an ultrasonic method as a means of monitoring of curing and assessing bond quality in wood laminates. The effect of curing on ultrasonic transmission was studied using specimens of clear Douglas-fir, 100 x 200 x 600 mm, with the adhesive bond in the center of the specimen. Monitoring was performed simultaneously at normal and angular (5 ^circ nominal) incidence to the bond plane. Acoustic measurements were supplemented with destructive cure monitoring, standard bond strength measurement, monitoring of bulk viscosity curing, gel time measurement, and microscopic (SEM) examination. Angular incidence gave greater sensitivity to bond quality and curing status than did normal incidence. Analysis of wave propagation showed that displacement for transmission at a small angle (on the order of 5^circ ) was nearly parallel to the bond, which seems to explain greater sensitivity of angular incidence. Experimental results showed that this method was effective in detection of curing phases, such as spread, penetration, and hardening, defective bonds, and the effect of clamping pressure. An "unloading effect", measured as a relative transmission reduction after the clamping load was released, was sensitive to defective bonds, including uncured (kissing), underspread, and uneven spread bonds. Thick bonds (0.5 and 1.0 mm) caused the greatest increase in transmission, since waves at start of curing were highly attenuated. In angular transmission, thick-bond curing curves showed a characteristic inflection, which may be used to identify thick bonds and measure the curing rate. The results of this dissertation could be utilized to develop commercial systems in glulam manufacturing, which could evaluate: (a) phase of and completion of curing (b) bond quality (c) optimum clamping pressure. Similar systems could also

  6. Proportion cured models applied to 23 cancer sites in Norway.

    Science.gov (United States)

    Cvancarova, Milada; Aagnes, Bjarte; Fosså, Sophie D; Lambert, Paul C; Møller, Bjørn; Bray, Freddie

    2013-04-01

    Statistical cure is reached when a group of patients has the same mortality as cancer-free individuals. Cure models predict the cured proportion and the median survival of fatal cases. Cure models have seldom been applied and tested systematically across all major cancer sites. Incidence and follow-up data on 23 cancer sites recorded at the Cancer Registry of Norway 1963-2007 were obtained. Mixture cure models were fitted to obtain trends and up-to-date estimates (based on period approach) assuming cured and uncured groups exist. The model converged for cancers of the mouth and pharynx, oesophagus, stomach, colon, rectum, liver, gallbladder, pancreas, lung and trachea, ovary, kidney, bladder, CNS, non-Hodgkin lymphoma (only for males) and leukemia. The proportion of cured patients increased 1963-2002 for both sexes, with the largest changes (in percent) seen for leukemia (46.4 and 46.7) and CNS (35.9, 42.0), males given first. Median survival time for the uncured cases increased for colon and rectal cancer, and there was a three- fold increase in median survival time for patients with fatal ovarian cancers. Cancers of bladder and CNS had the highest up-to-date proportion cured (in percent), 67.4 and 64.0, respectively, pancreas and liver were amongst the lowest (5.7 and 9.9, respectively). Cure models are useful when monitoring progress in cancer care, but must be applied and interpreted with caution. The absolute estimates of the cure proportion are speculative and should not be calculated where cure is not medically anticipated. PMID:22927104

  7. 陶粒赤泥粉煤灰免烧砖性能研究%Research on properties of red mud fly ash from the burn exemption autoclaved brick

    Institute of Scientific and Technical Information of China (English)

    王敦强; 徐捷; 周国栋

    2012-01-01

    Based on the requirement of national energy conservation and environmental protection, we use the waste red mud and fly ash of Shandong Xinfa Aluminum and Electricity Group as the main raw material and with lime and cement as sharpened agent to produce red mud ceramsite fly ash from burn from autoclaved brick that is pressured molding by the pressure brick machine and natural curing. In order to make the industrialization production and substitute for clay brick, we make a quantitative analysis of the ratio of raw material and production process. Then, we get the reasonable ratio of raw materials and production process parameters, and discusse the influence of the ratio of raw material and production process parameters on the performance of the products. The results show; 1. When the composition is made up of 25% red mud, 18% fly ash, 45% ceramsite and 12% cement, brick products have the highest intensity; 2. When the composition is made up of 18% red mud, 21% fly ash, 50% ceramsite and 11% cement, the strength of the brick products meets the requirements, heat insulation performance is improved greatly and other physical properties also meet the requirement.%基于国家节能环保的要求,以山东信发铝电集团的废弃物赤泥、粉煤灰为主要原料,用石灰、水泥作为激化剂,经压砖机压制成型,自然养护来生产赤泥陶粒粉煤灰免烧免蒸压砖.为了使其工业化生产并能代替粘土砖,对原材料配比和生产工艺进行了定量分析,得出了合理的试验配方和生产工艺参数,探讨了原材料配比和生产工艺参数对砖制品性能的影响.结果表明:(1)当25%赤泥、18%粉煤灰、45%陶粒、12%水泥时,砖制品的强度最高.(2)当18%赤泥,21%粉煤灰,50%陶粒和11%水泥时,强度满足要求,保温性能大大提高,吸水率、冻融性和放射性等各方面物理特性符合要求.

  8. Technology status of autoclaved aerated concrete by utilizing mine tailings%利用矿山尾矿制备加气混凝土技术现状

    Institute of Scientific and Technical Information of China (English)

    罗立群; 舒伟

    2014-01-01

    根据发展循环经济和矿山清洁生产的开发思路,简述了矿山尾矿的产出和利用现状。针对尾矿堆存侵占土地、破坏生态环境、导致空气污染、易发生安全事故等危害,介绍了尾矿再选和大宗消纳等综合利用的两大途径。叙述了尾矿制备加气混凝土的技术特征,指出尾矿加气混凝土制品具有尾矿利用量大、节能降耗显著、保温隔热、质轻抗震、加工容易等综合优良性能,阐述了加气混凝土制备机理及其制品的性能表征,重点总结了利用铁尾矿、铜尾矿、黄金尾矿和其它矿山尾矿制备加气混凝土的技术现状。结合加气混凝土的生产和工程应用实际,提出尾矿制备加气混凝土应重点注意矿山尾矿粒度对建材原料的适应性、活化石灰的质量与原料中钙质矿物的影响、注重科学试验和人才培训、加强尾矿建材制品的力学性能研究等实际问题。%According to development idea on circular economy and clean production to exploiting mineral resources ,the present output and harm of producing on mine tailings were briefly reviewed .Tailings stockpiling have terrible effects on the expropriation of land ,the destruction of the ecological environment , causing air pollution ,easy to produce the safety accidents ,etc .Therefore ,two approaches of comprehensive utilization on tailings ,i .e .,recycling of useful components and bulk of consumption were introduced .On the basis of descriptions on the technical features of tailings ,related properties of autoclaved aerated concrete (AAC) with large amount of tailings utilization ,significant in energy saving ,thermal insulation ,light weight ,easy processing ,aseismatic performance were indicated respectively ,The technical status of utilizing iron tailings ,copper tailings ,gold tailings and other mine tailings to produce autoclaved aerated concrete was summarized intensively after the preparation mechanism

  9. 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.

  10. 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,

  11. 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.

  12. Thermal Study of Anhydrides Cured Tetrafunctional Cardo Epoxy Resin

    Directory of Open Access Journals (Sweden)

    Jignesh P. Patel

    2013-01-01

    Full Text Available Tetrafunctional cardo epoxy resin (EBCF was cured by using 10 wt% maleic anhydride (MA, pyromellitic dianhydride (PMDA, phthalic anhydride (PA, tetrahydrophthalic anhydride (THPA, tetrabromophthalic anhydride (TBPA, and tetrachlorophthalic anhydride (TCPA as hardeners at 120°C for 40–105 min (gel time and then postcured 1 h at 130°C. Gel time is found to depend on the structure of the anhydrides used. Cured samples were found insoluble in common solvents. Cured and uncured EBCF were characterized by FTIR, DSC, and TGA techniques. Cured and uncured resins followed multistep degradation reactions. Kinetic parameters, namely, order of degradation, energy of activation, frequency factor, and entropy change, were determined according to the Anderson-Freeman method and interpreted in light of the nature of hardeners used for curing purpose. The resins followed integral or fractional order degradation kinetics. Complex degradation reactions are due to different types of linkages in cured resins. Both nature and structure of resin and hardeners affected the curing behavior and the resultant thermal properties of the cured resins.

  13. Preparation of temperature responsive fragrance release membranes by UV curing

    International Nuclear Information System (INIS)

    The authors have studied the preparation and the function of intelligent drug release membranes by UV curing. Temperature responsive fragrance release membranes were prepared by UV curing process and the release functions were investigated as the function of thickness and composition of membrane. Microscopic observations were used to prove the postulated release mechanism

  14. Preparation of temperature responsive fragrance release membranes by UV curing

    Energy Technology Data Exchange (ETDEWEB)

    Nakayama, Hiroshi E-mail: nakayama@ned.kindai.ac.jp; Kaetsu, Isao; Uchida, Kumao; Okuda, Jyunya; Kitami, Toshiaki; Matsubara, Yoshio

    2003-06-01

    The authors have studied the preparation and the function of intelligent drug release membranes by UV curing. Temperature responsive fragrance release membranes were prepared by UV curing process and the release functions were investigated as the function of thickness and composition of membrane. Microscopic observations were used to prove the postulated release mechanism.

  15. Infinitistic and Non-infinitistic cures for nagging hangovers

    OpenAIRE

    Goldstein, Laurence

    2008-01-01

    Josh Parsons supplies a 'hair of the dog' cure for hangovers where diminishing bouts of drinking are supposed to mask the hangover and to stave it off permanently. The cure has the air of an infinitistic paradox but, disappointingly, it does not work

  16. Escherichia coli K-12 survives anaerobic exposure at pH 2 without RpoS, Gad, or hydrogenases, but shows sensitivity to autoclaved broth products.

    Directory of Open Access Journals (Sweden)

    Daniel P Riggins

    Full Text Available Escherichia coli and other enteric bacteria survive exposure to extreme acid (pH 2 or lower in gastric fluid. Aerated cultures survive via regulons expressing glutamate decarboxylase (Gad, activated by RpoS, cyclopropane fatty acid synthase (Cfa and others. But extreme-acid survival is rarely tested under low oxygen, a condition found in the stomach and the intestinal tract. We observed survival of E. coli K-12 W3110 at pH 1.2-pH 2.0, conducting all manipulations (overnight culture at pH 5.5, extreme-acid exposure, dilution and plating in a glove box excluding oxygen (10% H2, 5% CO2, balance N2. With dissolved O2 concentrations maintained below 6 µM, survival at pH 2 required Cfa but did not require GadC, RpoS, or hydrogenases. Extreme-acid survival in broth (containing tryptone and yeast extract was diminished in media that had been autoclaved compared to media that had been filtered. The effect of autoclaved media on extreme-acid survival was most pronounced when oxygen was excluded. Exposure to H2O2 during extreme-acid treatment increased the death rate slightly for W3110 and to a greater extent for the rpoS deletion strain. Survival at pH 2 was increased in strains lacking the anaerobic regulator fnr. During anaerobic growth at pH 5.5, strains deleted for fnr showed enhanced transcription of acid-survival genes gadB, cfa, and hdeA, as well as catalase (katE. We show that E. coli cultured under oxygen exclusion (<6 µM O2 requires mechanisms different from those of aerated cultures. Extreme acid survival is more sensitive to autoclave products under oxygen exclusion.

  17. Research on use of high calcium desulfurization ash in autoclaved brick%利用高钙固硫灰生产蒸压砖的研究

    Institute of Scientific and Technical Information of China (English)

    陈滨; 刘恒波; 万军

    2012-01-01

      The paper researches on the process of high calcium desulfurization ash autoclaved brick, and puts forward the ways to use the high calcium, high sulfur and low silicon of fly ash from the circulating fluidized bed boiler.%  对高钙固硫灰生产蒸压砖的生产工艺进行了研究,提出了重点解决循环流化床锅炉粉煤灰的高钙、高硫、低硅难题的有效途径

  18. 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.

  19. 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.

  20. Proceedings of national executive management seminar on surface finishing by radiation curing technology: radiation curing for better finishing

    International Nuclear Information System (INIS)

    This book compiled the paper presented at this seminar. The papers discussed are 1. Incentives for investment in the manufacturing sector (in Malaysia) 2.Trends and prospect of surface finishing by radiation curing technology in Malaysia 3. Industrial application of radiation curing

  1. 基于CATIA的半实物仿真用液压釜的设计与研究%Design and research of autoclave based on CATIA for hardware-in-the-loop simulation

    Institute of Scientific and Technical Information of China (English)

    陈江; 赵文纯; 鞠海洪

    2012-01-01

    For the design and research of an autoclave for hardware-in-loop simulation, a design method for autoclave based on the CATIA virtual prototype technology was proposed. The 3D modeling was carried out by using CATIA. Then, the weakness of the autoclave was checked and optimized by using CATIA-Analysis in order to improve the safety and reliability of autoclave. Finally, an autoclave which can meet the design requirements was designed.%针对半实物仿真用液压釜进行了设计与研究.提出了基于CATIA虚拟样机技术的的液压釜设计方法,通过CATIA进行三维实体建模,并通过CATIA-Analysis对液压釜薄弱处进行枝核优化,用以提高液压釜使用运行的安全性和可靠性,最终设计出满足要求的液压釜.

  2. Chemical modification of L-glutamine to alpha-amino glutarimide on autoclaving facilitates Agrobacterium infection of host and non-host plants: A new use of a known compound

    Directory of Open Access Journals (Sweden)

    Das Pralay

    2011-05-01

    Full Text Available Abstract Background Accidental autoclaving of L-glutamine was found to facilitate the Agrobacterium infection of a non host plant like tea in an earlier study. In the present communication, we elucidate the structural changes in L-glutamine due to autoclaving and also confirm the role of heat transformed L-glutamine in Agrobacterium mediated genetic transformation of host/non host plants. Results When autoclaved at 121°C and 15 psi for 20 or 40 min, L-glutamine was structurally modified into 5-oxo proline and 3-amino glutarimide (α-amino glutarimide, respectively. Of the two autoclaved products, only α-amino glutarimide facilitated Agrobacterium infection of a number of resistant to susceptible plants. However, the compound did not have any vir gene inducing property. Conclusions We report a one pot autoclave process for the synthesis of 5-oxo proline and α-amino glutarimide from L-glutamine. Xenobiotic detoxifying property of α-amino glutarimide is also proposed.

  3. 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.

  4. 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.

  5. 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.

  6. Cure kinetics and chemorheology of EPDM/graphene oxide nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Allahbakhsh, Ahmad [Department of Polymer Engineering, Islamic Azad University, South Tehran Branch, 17776-13651 Tehran (Iran, Islamic Republic of); Mazinani, Saeedeh, E-mail: s.mazinani@aut.ac.ir [Amirkabir Nanotechnology Research Institute (ANTRI), Amirkabir University of Technology, Tehran (Iran, Islamic Republic of); Kalaee, Mohammad Reza [Department of Polymer Engineering, Islamic Azad University, South Tehran Branch, 17776-13651 Tehran (Iran, Islamic Republic of); Sharif, Farhad [Department of Polymer Engineering and Color Technology, Amirkabir University of Technology, Tehran (Iran, Islamic Republic of)

    2013-07-10

    Graphical abstract: - Highlights: • Graphene oxide content and dispersion as effective parameters on cure kinetics. • Graphene oxide as an effective controlling factor of crosslink density. • Interaction of graphene oxide with curing system (ZnO) during curing process. - Abstract: In this study, the effect of graphene oxide on cure behavior of ethylene–propylene–diene rubber (EPDM) nanocomposite is studied. In this regard, the cure kinetics of nanocomposite is studied employing different empirical methods. The required activation energy of nth-order cure process shows about 160 kJ/mol increments upon 5 phr graphene oxide loading compared to 1 phr graphene oxide loading. However, the required activation energy is significantly reduced followed by incorporation of graphene oxide in nanocomposites compared to neat EPDM sample. Furthermore, the effect of graphene oxide on structural properties of nanocomposites during the cure process is studied using X-ray diffraction, scanning electron microscopy and Fourier transform infrared spectrometry techniques. As the results show, graphene oxide interestingly affects the structure of zinc oxide during the vulcanization process. This behavior could be probably related to high tendency of zinc oxide to react with oxidized surface of graphene oxide.

  7. A pilot-scale steam autoclave system for treating municipal solid waste for recovery of renewable organic content: Operational results and energy usage.

    Science.gov (United States)

    Holtman, Kevin M; Bozzi, David V; Franqui-Villanueva, Diana; Offeman, Richard D; Orts, William J

    2016-05-01

    A pilot-scale (1800 kg per batch capacity) autoclave used in this study reduces municipal solid waste to a debris contaminated pulp product that is efficiently separated into its renewable organic content and non-renewable organic content fractions using a rotary trommel screen. The renewable organic content can be recovered at nearly 90% efficiency and the trommel rejects are also much easier to sort for recovery. This study provides the evaluation of autoclave operation, including mass and energy balances for the purpose of integration into organic diversion systems. Several methods of cooking municipal solid waste were explored from indirect oil heating only, a combination of oil and direct steam during the same cooking cycle, and steam only. Gross energy requirements averaged 1290 kJ kg(-1) material in vessel, including the weight of free water and steam added during heating. On average, steam recovery can recoup 43% of the water added and 30% of the energy, supplying on average 40% of steam requirements for the next cook. Steam recycle from one vessel to the next can reduce gross energy requirements to an average of 790 kJ kg(-1).

  8. Preparation of boron-doped TiO{sub 2} films by autoclaved-sol method at low temperature and study on their photocatalytic activity

    Energy Technology Data Exchange (ETDEWEB)

    Lu Xiaona; Tian Baozhu; Chen Feng [Key Laboratory for Advanced Materials and Institute of Fine Chemicals, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237 (China); Zhang Jinlong, E-mail: jlzhang@ecust.edu.c [Key Laboratory for Advanced Materials and Institute of Fine Chemicals, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237 (China); School of Chemistry and Materials Science, Guizhou Normal University, Guiyang 550001 (China)

    2010-10-29

    A series of uniform and transparent boron-doped TiO{sub 2} films were synthesized from autoclaved-sol without organic solvent at low temperature. As-prepared B-TiO{sub 2} films with two layers were characterized by XRD, DRS, XPS and AFM. The photocatalytic characteristics were measured based on the degradation of Rhodamine B (RhB) solution under visible or UV light. The results indicated that the anatase phase was the main crystal form of the films, containing a small amount of brookite. The presence of boron caused a red shift in the absorption band of TiO{sub 2} films. The doped boron was mainly presented in the form of B{sub 2}O{sub 3}, O-Ti-B and O-Ti-B bonds, confirming that autoclaved-sol synthesis at low temperature allowed for incorporation of boron atoms into the TiO{sub 2} matrix. Transmission of the films was about 90% in the visible region. The 10% (atom) B-TiO{sub 2} film exhibited the best photocatalytic activity both in visible and UV light.

  9. Research on basic mechanical properties of autoclaved fly ash brick%蒸压粉煤灰砖基本力学性能研究

    Institute of Scientific and Technical Information of China (English)

    刘双龙; 闫欢欢

    2011-01-01

    按照《砌墙砖试验方法》(GB/T2542-2003)对蒸压粉煤灰砖进行砖的含水率、抗压强度、抗折强度试验。确定蒸压粉煤灰砖的基本力学指标,为编制辽宁省地方标准《蒸压粉煤灰砖建筑技术规范》提供试验依据。结果表明,蒸压粉煤灰砖含水率为2.96%,抗压强度为11.46MPa,抗折强度为1.68MPa,在实际工程上可替代普通烧结砖使用。%According to the GB/T 2542-2003 of masonry brick test method,the moisture content,compressive strength,transverse strength of the autoclaved fly ash brick are test.The results show that the autoclaved fly ash brick moisture content is 2.96 %,the compressive strength is 11.46 MPa,and the transverse strength is 1.68 MPa,so it can used as a substitute for the common fired brick in project.The mechanics index can provide a basis for the Liaoning standards of fly ash brick construction technical specifications.

  10. A pilot-scale steam autoclave system for treating municipal solid waste for recovery of renewable organic content: Operational results and energy usage.

    Science.gov (United States)

    Holtman, Kevin M; Bozzi, David V; Franqui-Villanueva, Diana; Offeman, Richard D; Orts, William J

    2016-05-01

    A pilot-scale (1800 kg per batch capacity) autoclave used in this study reduces municipal solid waste to a debris contaminated pulp product that is efficiently separated into its renewable organic content and non-renewable organic content fractions using a rotary trommel screen. The renewable organic content can be recovered at nearly 90% efficiency and the trommel rejects are also much easier to sort for recovery. This study provides the evaluation of autoclave operation, including mass and energy balances for the purpose of integration into organic diversion systems. Several methods of cooking municipal solid waste were explored from indirect oil heating only, a combination of oil and direct steam during the same cooking cycle, and steam only. Gross energy requirements averaged 1290 kJ kg(-1) material in vessel, including the weight of free water and steam added during heating. On average, steam recovery can recoup 43% of the water added and 30% of the energy, supplying on average 40% of steam requirements for the next cook. Steam recycle from one vessel to the next can reduce gross energy requirements to an average of 790 kJ kg(-1). PMID:26987737

  11. Clinical Application of Paper-plastic Package's Extension of Autoclave Pack%纸塑包装延长高压灭菌包的临床应用

    Institute of Scientific and Technical Information of China (English)

    冉成华

    2011-01-01

    目的:纸塑包装延长高压灭菌包的临床应用.方法:双层棉包布常规包装高压灭菌按要求存放7d,霉季5d,而纸塑包装可保存6个月.结果:纸塑包装大大延长无菌包的无菌时间.包装安全经济,可靠,并可预防院内感染.%Goal: clinical application of paper-plastic package’s extension of autoclave pack.Method: things regularly packed with double cotton and autoclaving can be stored for 7d, or 5d in mildew season; but thing packed with paper can be stored for 6 months.Result: paper pack greatly expands the asepsis time of sterility pack.The pack is safe and reliable, and can prevent infection in hospital.

  12. 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.

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

    DEFF Research Database (Denmark)

    Wistoft, Karen

    2014-01-01

    approaches within therapy, health promotion and education - but this is nothing new. By the early twentieth century, the Mind-Cure movement had been emphasizing the healing power of positive emotions and beliefs. William James (1842-1910)) defended the Mind-Cure through the debate around the scope...... of physicians' practice in the promotion of mental health. He saw the Mind-Cure as a typically American, pragmatic twist on mental health perceptions, through the religion of Healthy-Mindedness related to time. James was an advocate of carrying out empirical studies which could bring the effects of Healthy...

  14. On autoclaved aerated concrete block wall and plaster layer anti-crack%浅谈蒸压加气混凝土砌块墙体及粉刷层防裂

    Institute of Scientific and Technical Information of China (English)

    林恩凯

    2009-01-01

    According to the comparison on characteristics of the autoclaved aerated concrete block and traditional red brick, the author analyzes causes of wall crack quality common diseases, and provides corresponding control measures, so as to solve the crack problem of the autoclaved aerated concrete block wall and the plaster layer, thus promoting application of the autoclaved aerated concrete block.%通过比较蒸压加气混凝土砌块与传统红砖的特性,分析其墙体裂缝质量通病的原因,并提出相应的控制措施,以解决蒸压加气混凝土砌块墙体及粉刷层的开裂问题,从而推广蒸压加气混凝土砌块的应用.

  15. Optimization Study on Processing Conditions of Corn Resistant Starch by Autoclaving and Acid Hydrolysis Treatment%压热酸解法制备玉米抗性淀粉的工艺优化

    Institute of Scientific and Technical Information of China (English)

    冯铄涵; 阚建全

    2011-01-01

    The resistant starch was prepared with the High amylose corn starch by autoclaving-cooling cycles combined with acids hydrolysis treatment.The effects of concentration of starch solution,autoclaved temperature,autoclaved time and times of autoclaved-cooling cycles on the content of RS were studied in the autoclaved treatment.The type,concentration and treatment time of acids were also studied in the acid hydrolysis process.The results showed that the optimum conditions is: 30% starch solution was autoclaved at 125℃ for 45min,after repeated 2 times,0.15mol/L citric acid hydrolysised for 12h.The yield of resistant starch is up to 39.27%.%以高直链玉米淀粉为原料,研究压热-冷却循环结合酸解法制备抗性淀粉的最佳工艺条件。通过单因素实验和正交实验探讨了压热-冷却循环过程中淀粉溶液浓度、压热温度、压热时间、循环次数以及酸解处理过程中酸的种类、酸的浓度、酸解时间对抗性淀粉得率的影响。结果表明,在淀粉溶液浓度为30%、压热温度125℃、压热时间45min条件下,经过2次压热-冷却循环,然后0.15mol/L柠檬酸水解处理12h,在此条件下抗性淀粉得率可达39.27%。

  16. 7 CFR 29.3002 - Air-cured.

    Science.gov (United States)

    2010-01-01

    ... Practices), DEPARTMENT OF AGRICULTURE COMMODITY STANDARDS AND STANDARD CONTAINER REGULATIONS TOBACCO... control excess humidity during the curing period to prevent house-burn and barn-burn in damp weather....

  17. 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. PMID:23816516

  18. 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.

  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. 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.

  1. 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.

  2. Radiation curing of composites for vehicle component and vehicle manufacture

    International Nuclear Information System (INIS)

    Some ordinary uses of metals in vehicle components and vehicle manufacture, such as steel (specific gravity 7.8) or aluminum (specific gravity 2.7), can be replaced by carbon fiber composites (specific gravity 1.6) to provide significant weight savings while still maintaining structural integrity. The aircraft and aerospace industries have adopted this concept. The motor vehicle industry is using composite materials for some nonstructural components in automobiles, but have been reluctant to widely adopt this technology because of concerns about thermal curing times and other issues in high-volume manufacturing processes. A typical steel auto body weighing ∼750 kilograms would weigh only ∼155 kilograms if replaced with carbon fiber composites. Structural members, such as the vehicle chassis and body frame, could also be made out of carbon fiber composites. With only 20% of the typical body weight, smaller, lighter, less powerful and more fuel efficient engines could be used in such vehicles. Commercial aircraft manufacturers have adopted large carbon fiber structures in lieu of aluminum for a 40% weight reduction and estimate a 20% savings in fuel costs for large planes. These aircraft still use conventional materials for motors, tires and interior components. The fuel efficiency of an automobile could be doubled with an 80% weight reduction. As with aircraft, conventional motors, tires and interior components could be used in automobiles. Radiation curing can simplify the manufacture of carbon fiber composites. Penetrating X-rays generated with high-energy, high-power electron beam (EB) accelerators can cure structural composites while they are constrained within inexpensive molds; thus reducing cure times, eliminating heat transfer concerns and potentially hazardous volatile emissions during the curing process. Since X-rays can penetrate mold walls, the curing process is quite versatile, enabling diverse components with varying designs to be cured using a

  3. Some electroanalytical investigations into the cure chemistry of industrial sealants

    OpenAIRE

    Raftery, Declan Patrick

    1996-01-01

    This thesis represents a study of the cure chemistry of three contrasting adhesive technologies, applying a range of analytical approaches to gain further insight into the complex chemistry of adhesives. An introduction is given in chapter one into the general chemistry of adhesives and their analysis, with particular emphasis on anaerobic adhesives and the crucial role played by transition metals in the cure chemistry. In order to elucidate the role played by tertiary amines and saccahri...

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

    OpenAIRE

    Singh, Ajai R.

    2010-01-01

    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 vaccine...

  5. Curing kinetics of alkyd/melamine resin mixtures

    OpenAIRE

    Jovičić Mirjana C.; Radičević Radmila Ž.

    2009-01-01

    Alkyd resins are the most popular and useful synthetic resins applied as the binder in protective coatings. Frequently they are not used alone but are modified with other synthetic resins in the manufacture of the coatings. An alkyd/melamine resin mixture is the usual composition for the preparation of coating called 'baking enamel' and it is cured through functional groups of resins at high temperatures. In this paper, curing kinetics of alkyd resins based on castor oil and dehydrated castor...

  6. Electron beam curing of bisphenol A epoxy resins

    International Nuclear Information System (INIS)

    The effects of initiator type, concentration of initiator and molecular weight of oligomer were studied in the EB curing of bisphenol A diglycidyl ether type epoxy oligomer containing an onium initiator. Cured products of above 95 % of gel contents were obtained from liquid oligomers with an onium initiator content of 0.05 mol/kg. For solid oligomers the final levelling-off gel content decreased with increasing molecular weight of the original oligomer. However, unreacted epoxide bonds still remained in the cured system, although the gel content had almost reached its maximum. The post effect of curing was observed the present system. After irradiation, the decay of epoxide bonds continues following first order reaction kinetics and the apparent rate constant is directly proportional to the preirradiation dose. Dynamic mechanical studies show that heat-treatment after room temperature irradiation gives the cured product of higher glass transition temperature and crosslinking density than those of the product cured with tertiary amine at elevated temperature. (author)

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

    International Nuclear Information System (INIS)

    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 (Tg) 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 Tg

  10. DESTRUCTION OF TETRAPHENYLBORATE IN TANK 48H USING WET AIR OXIDATION BATCH BENCH SCALE AUTOCLAVE TESTING WITH ACTUAL RADIOACTIVE TANK 48H WASTE

    Energy Technology Data Exchange (ETDEWEB)

    Adu-Wusu, K; Paul Burket, P

    2009-03-31

    Wet Air Oxidation (WAO) is one of the two technologies being considered for the destruction of Tetraphenylborate (TPB) in Tank 48H. Batch bench-scale autoclave testing with radioactive (actual) Tank 48H waste is among the tests required in the WAO Technology Maturation Plan. The goal of the autoclave testing is to validate that the simulant being used for extensive WAO vendor testing adequately represents the Tank 48H waste. The test objective was to demonstrate comparable test results when running simulated waste and real waste under similar test conditions. Specifically: (1) Confirm the TPB destruction efficiency and rate (same reaction times) obtained from comparable simulant tests, (2) Determine the destruction efficiency of other organics including biphenyl, (3) Identify and quantify the reaction byproducts, and (4) Determine off-gas composition. Batch bench-scale stirred autoclave tests were conducted with simulated and actual Tank 48H wastes at SRNL. Experimental conditions were chosen based on continuous-flow pilot-scale simulant testing performed at Siemens Water Technologies Corporation (SWT) in Rothschild, Wisconsin. The following items were demonstrated as a result of this testing. (1) Tetraphenylborate was destroyed to below detection limits during the 1-hour reaction time at 280 C. Destruction efficiency of TPB was > 99.997%. (2) Other organics (TPB associated compounds), except biphenyl, were destroyed to below their respective detection limits. Biphenyl was partially destroyed in the process, mainly due to its propensity to reside in the vapor phase during the WAO reaction. Biphenyl is expected to be removed in the gas phase during the actual process, which is a continuous-flow system. (3) Reaction byproducts, remnants of MST, and the PUREX sludge, were characterized in this work. Radioactive species, such as Pu, Sr-90 and Cs-137 were quantified in the filtrate and slurry samples. Notably, Cs-137, boron and potassium were shown as soluble as a

  11. Radiation curing of composites for vehicle component and vehicle manufacture

    International Nuclear Information System (INIS)

    Some traditional uses of metals in vehicle component and vehicle manufacture, such as steel (specific gravity 7.8) or aluminum (specific gravity 2.7), can be replaced by carbon-fiber composites (specific gravity 1.6) to provide significant weight savings while maintaining structural integrity. The aerospace and aircraft industries have adopted this approach. The auto or motor vehicle industries have explored the use of composites, but have been reluctant to widely adopt this technology because of concerns over manufacturing processes. A typical steel auto body weighing ∼ 750 kilos would weigh only ∼ 155 kilos if replaced with carbon-fiber composites. Structural members, as the vehicle chassis, could also be fabricated out of carbon-fiber composites. With only 20% of the body weight, smaller, lower horse-power and more fuel efficient engines could be used to power such vehicles. Commercial aircraft manufacturers that have adopted carbon-fiber structures in lieu of aluminum (a 40% weight savings) estimate a 20% savings in fuel costs for large planes. These are still made with conventional materials being used for motors, tires, interiors, and the like. A fuel efficient auto now running at ∼ 10 kilometers/liter would more than double its fuel efficiency given the nearly 80% weight savings attainable by use of carbon-fiber composites just for the vehicle body. As with aircraft, conventional systems for propulsion (motors), braking, tires and interiors could still be used. Radiation curing can simplify the manufacture of carbon-fiber composite vehicle components. Highly penetrating X-rays derived from high current, high energy electron beam (EB) accelerators can be used to cure structural composites while they are constrained within inexpensive molds; thus reducing cure cycles, eliminating heat transfer concerns and concerns over potentially hazardous emissions during the curing process. Since X-rays can penetrate mold walls, the curing process is quite versatile

  12. Pretreatment of banana agricultural waste for bio-ethanol production: individual and interactive effects of acid and alkali pretreatments with autoclaving, microwave heating and ultrasonication.

    Science.gov (United States)

    Gabhane, Jagdish; William, S P M Prince; Gadhe, Abhijit; Rath, Ritika; Vaidya, Atul Narayan; Wate, Satish

    2014-02-01

    Banana agricultural waste is one of the potential lignocellulosic substrates which are mostly un-utilized but sufficiently available in many parts of the world. In the present study, suitability of banana waste for biofuel production with respect to pretreatment and reducing sugar yield was assessed. The effectiveness of both acid and alkali pretreatments along with autoclaving, microwave heating and ultrasonication on different morphological parts of banana (BMPs) was studied. The data were statistically analyzed using ANOVA and numerical point prediction tool of MINITAB RELEASE 14. Accordingly, the optimum cumulative conditions for maximum recovery of reducing sugar through acid pretreatment are: leaf (LF) as the substrate with 25 min of reaction time and 180°C of reaction temperature using microwave. Whereas, the optimum conditions for alkaline pretreatments are: pith (PH) as the substrate with 51 min of reaction time and 50°C of reaction temperature using ultrasonication (US).

  13. Cleavage of catalytic ally grown carbon nanofibers into hydrophilic segments by oxidation in a mixture of concentrated HNO3-H2SO4 in an autoclave

    Institute of Scientific and Technical Information of China (English)

    TENG Li-hua; WANG Zhi-jiang; TANG Tian-di

    2012-01-01

    The catalytically grown carbon nanofibers were treated by a mixture of concentrated nitric aid and sulfuric aid in an autoclave at temperature 333,363 and 423 K.It was found that the samples treated at 363 K and 423 K were still well dispersed in water 15 hours later,indicating that carbon nanofibers can be made hydrophilicy.It was also found that the dispersion was destroyed when the pH value was lowered by adding acid.The results are significant when the carbon nanofibers are used as enhancing component in polymer composite material because several hundreds of nm are perfect size and the hydrophilicity controls the dispersion of CNFs in the polymer media.It is concluded that the amount of the oxygen-containing groups on the surface and the hydrophilicity of the carbon nanofibers can be controlled by the treatment temperature,and that the carbon nanofibers can be cleaved into uniform segments.

  14. 金矿尾矿粉生产蒸压砖的研究%Use of gold mine tailings in autoclaved brick

    Institute of Scientific and Technical Information of China (English)

    袁善磊; 付强

    2013-01-01

    The paper introduces the raw material preparation of autoclaved gold mine tailings brick, which consists of gold mine tailings and fly ash as the main raw material, activated material and admixture as auxiliary materials, and the mixture is moistened and shaped according to the process requirements.%介绍了利用工业废弃物金矿尾矿粉和粉煤灰为主要原料,辅以激发材料、外加剂,混合均匀,加适量水湿拌,加压成型,按养护工艺要求,经蒸压养护后制成金矿尾矿粉蒸压砖。

  15. 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.

  16. 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.

  17. 环氧丙烷装置皂化电石渣处理方案%Feasibility scheme of epoxy propane saponification calcium carbide slag produce autoclaved fly ash brick

    Institute of Scientific and Technical Information of China (English)

    林盛海; 吴学亮

    2012-01-01

    本文介绍了皂化废电石渣用于生产蒸压粉煤灰砖的可行性。%The feasibility scheme of epoxy propane saponification Calcium carbide slag produce autoclaved fly ash brick was introduced.

  18. Pilot scale test on autoclaved brick production by semi-dry desulfurization by-products%半干法脱硫灰生产蒸压砖中试试验研究

    Institute of Scientific and Technical Information of China (English)

    刘松涛; 陈传敏; 赵毅; 卢林; 王涛; 杨艳芬

    2011-01-01

    The semi-dry desulfurization by-products are difficult to be utilized. Pilot scale study on the production technology of autoclaved brick which was mixed with semi-dry desulfurization by-products, slag and quicklime. The results show that autoclaved brick mixed with 50% semi-dry desulfurization ash and 10% quicklime dosage can meet the mechanical properties of MU20 strength grade. The mineral, such as hydrated calcium silicate, hydrated calcium aluminate and hydration sulphoaluminate, formed in autoclaved process can strengthen the strength of autoclaved brick.%为了解决半干法脱硫灰难以利用的问题,用脱硫灰、炉渣和CaO进行了蒸压砖生产的中试试验研究.研究表明:生产强度等级为MU20的脱硫灰蒸压砖,脱硫灰的掺量可控制在50%左右,CaO的掺量控制在10%左右.蒸压过程中形成的水化硅酸钙、水化铝酸钙和水化硫铝酸钙等矿物有利于增强蒸压砖强度.

  19. Application of a new type of electric appliance control mechanical safety interlock protection device in autoclaves%新型蒸压釜电器控制机械安全联锁保护装置

    Institute of Scientific and Technical Information of China (English)

    苏旭明; 李建华

    2016-01-01

    Autoclaves are widely used in industrial production. As a quick opening type pressure vessel, the safety interlock device is not perfect, which affects the safe operation of the autoclave. According to practical use, com⁃bines autoclaved reactor operating conditions, this paper introduces a electrical control mechanical safety interlock protection device which improves the autoclave safety coefficient, and prolongs service life of the interlock protec⁃tion device.%蒸压釜在工业生产中得到了广泛的使用,作为快开门式压力容器,安全联锁装置不完善,会对蒸压釜的安全运行造成影响。根据现场实际使用情况,结合蒸压釜的工作条件,介绍了一种电器控制机械安全联锁装置,提高了蒸压釜安全运行系数,也延长了联锁保护装置的使用寿命。

  20. Analysis on non-autoclave pipe pile concrete raw material and maintenance system%免压蒸管桩混凝土原材料及养护制度分析

    Institute of Scientific and Technical Information of China (English)

    蒋丽燕

    2016-01-01

    Combining with non-autoclave pipe pile concrete research status,starting from two aspects of raw material selection and maintenance system,the paper explores quality control measures of non-autoclave pipe pile concrete,analyzes the economy of non-autoclave pipe pile,and finally points out that:it not only reduces pipe pile producing energy consumption,but also improves pipe pile concrete durability through applying non-autoclave maintenance technology.%结合免压蒸管桩混凝土的研究现状,从原材料选用与养护制度两方面,探讨了免压蒸管桩混凝土的质量控制措施,并分析了免压蒸管桩的经济性,指出采用免压蒸养护生产工艺,既降低了管桩的生产能耗,又提高了管桩混凝土的耐久性。

  1. RC-加气混凝土砌块组合墙的抗震性能%Seismic performance of composite walls of RC-autoclaved aerated concrete blocks

    Institute of Scientific and Technical Information of China (English)

    刘佩; 袁泉; 郭猛; 李鹏飞

    2012-01-01

    Three composite wall specimens of RC-autoclaved aerated concrete blocks were tested under cyclic lateral loading to investigate their seismic performance. The damage processes and failure characters of the composite wall specimens were presented. And the load-bearing capacity, hysteresis behavior, stiffness and ductility capacity of the composite wall specimens were investigated, which were compared with those of the ordinary wall of autoclaved aerated concrete blocks. Test results show that the presence of constructional columns and beams constrained the propagation of cracks in the autoclaved aerate concrete blocks. And then the brittle behavior of the autoclaved aerated concrete blocks is changed, and the mechanical performance of the autoclaved aerated concrete blocks is improved. Composite walls of RC-autoclaved aerated concrete blocks with reasonable forms possess good seismic performance, and research on the composite walls provides a basis for the application of walls of autoclaved aerated concrete blocks in multi-storey buildings.%为了解RC-加气混凝土砌块组合墙的抗震性能,进行3片不同构造形式的RC-加气混凝土砌块墙的水平低周反复荷载试验.介绍组合墙试件的破坏过程和破坏特点,重点研究3片试件的承载力、滞回曲线、刚度和延性性能,并与已有普通加气混凝土砌块墙试验数据进行对比分析.研究结果表明:构造柱和系梁限制砌块裂缝的产生和发展,改善砌块的脆性性质,提高砌块的力学性能;通过合理构造措施将钢筋混凝土与加气混凝土砌块结合在一起形成的组合承重墙,具有较好的抗震性能,为加气混凝土砌块墙在多层房屋结构中的应用提供基础.

  2. Effect of Autoclaved Schedule for Compressive Strength of Hematite Tailing Bricks%蒸压制度对赤铁矿尾矿蒸压砖强度的影响

    Institute of Scientific and Technical Information of China (English)

    赵云良; 张一敏; 陈铁军

    2012-01-01

    Effect of autoclaved schedule for compressive strength of hematite tailing-lime-yellow sand system was studied. The suitable autoclaved schedule was that rise time, autoclave pressure, autoclave time, and decompression time were 2.1 h, 1. 2 MPa, 6 h and 3. 5 h, respectively, when the quality ratio of hematite tailings: lime: yellow sands was equal to 70:15:15 and forming pressure was 20 MPa. The mechanism of Effect of autoclaved schedule for compressive strength was discussed by XRD and DSC. The results show that in the hydration reaction process, hydrogarnet is firstly generated, and then CSH( 1) and high-strength tobermorite under the condition of 1. 2 MPa autoclaved pressure. With autoclave continuing, tobermorite is gradated into relative low-strength xonotlite.%研究了蒸压制度对赤铁矿尾矿-石灰-黄沙体系蒸压砖抗压强度的影响,确定了原料中尾矿、石灰、黄沙的质量比为70∶15∶15,成型压力为20 MPa的砖坯的适宜蒸压制度为∶升压时间2.1h,蒸汽压力1.2 MPa,恒压时间6h,降压时间3.5h.利用XRD 、DSC对蒸压砖抗压强度形成机理进行了探讨,结果表明,赤铁矿尾矿-石灰-黄沙体系在1.2MPa蒸汽压力下首先生成了水石榴石,而后生成CSH(Ⅰ)凝胶和高强度的托勃莫来石,随着蒸压时间的延长,托勃莫来石逐渐转化成强度相对较低的硬硅钙石.

  3. 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.

  4. Nature cure treatment in the context of India's epidemiological transition.

    Science.gov (United States)

    Alter, Joseph Stewart; Sharma, Chandrashekar

    2016-07-01

    Scholars have argued that theoretical insights of critical medical anthropology should be applied to the analysis of complementary and alternative medicine in order to develop more critically engaged integrative medicine. In this essay we focus on nature cure in the context of India's contemporary epidemiological transition as an example of why engaged integrative medicine is important for public health, and how the institutionalization of nature cure treatment in India provides a critical framework for the development of programs focused on holistic treatment and prevention. After providing an overview of the epidemiological transition in contemporary India, we develop this argument through an examination of illustrative cases in a clinic that operates within the structure of India's Central Council for Research on Yoga and Naturopathy. Based on a review of recent history and contemporary practice we describe how a system of medicine that makes use exclusively of air, earth, sunlight, water and food has been institutionalized and professionalized in India. Whereas biomedical treatment for chronic non-communicable diseases is focused on the problem of curing individual diseases, nature cure establishes a regimen of personalized public healthcare for the integrated management of symptoms. We argue that nature cure is based on an ecological understanding of health, thus providing treatment that reflects a broad appreciation for the risk factors that characterize India's current crises of public health. PMID:27417171

  5. 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.

  6. 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

  7. 用于热压浸出工艺的高压釜装备研究及工程放大%Application of Autoclave in Pilot Plant Test in Pressure Leaching Process

    Institute of Scientific and Technical Information of China (English)

    段东平; 周娥; 陈思明; 夏光祥

    2013-01-01

      热压浸出是湿法冶金领域发展至今非常有推广前景的高效工艺,高压釜是该工艺的核心装备与关键技术。系统回顾了中国科学院过程工程研究所多年来利用热压浸出工艺处理难冶金银精矿、高铁闪锌矿、氧化铜矿及红土矿等的研究历程,从实验室小试—扩试—示范工程直至工业生产的途径,分别采用了管式高压釜、空气搅拌高压釜、钛复合板高压釜以及100 m3生产型高压釜,实现了这些难处理矿产资源的高效清洁利用。%The pressure leaching is a very efficient hydrometallurgy process with autoclave being the key equipment and technology.This paper systematically reviewed gold and silver concentrate,high iron sphalerite, copper oxide ore and Laterite were treated by pressure leaching from laboratory test,expanded test to the industrial production of the demonstration project in IPE.Respectively,in a tubular autoclave,air stirred autoclave,titanium autoclave and industrial autoclave of 100 m3,these refractory mineral resources were extracted efficiently and cleanly.

  8. 响应面法优化压热法制备莲子抗性淀粉工艺的研究%Optimization of the Autoclaving Process for Preparation Lotus Seeds Resistant Starch by Response Surface Methods

    Institute of Scientific and Technical Information of China (English)

    汪颖; 郑宝东; 张怡; 林雨菲; 李淑婷

    2012-01-01

    以莲子淀粉为原料,采用压热法制备莲子抗性淀粉,通过单因素试验,研究淀粉乳浓度、压热温度、压热时间和淀粉乳pH值4个因素对莲子抗性淀粉得率的影响.利用响应面法进行分析,得到莲子抗性淀粉制备的最佳工艺条件.结果表明,所得的方程达到显著水平,压热法制备莲子抗性淀粉的最佳工艺条件为:淀粉乳浓度30%,压热温度111℃,压热时间10 min,淀粉乳pH值为6~7.实际测得的莲子抗性淀粉得率为41.89%±1.23%,与理论预测值基本一致.%Lotus seed resistant starch was prepared by autoclaving. On the basis of single factor tests, the effect of starch concentration, autoclaving temperature, autoclaving time and pH value on the yield of lotus seeds resistant starch were studied. The conditions of preparing resistant starch were optimized with response surface methods. Results revealed that the model was significant, and the optimal conditions were as follows: starch concentration of 30%, autoclaving temperature of 111 °C, autoclaving time of 10 min, pH6~7. With these optimized conditions, the yield of lotus seeds resistant starch reached 41.89%±1.23%, the same as the prediction value in the model.

  9. A study on the influence of curing on the strength of a standard grade concrete mix

    Directory of Open Access Journals (Sweden)

    Krishna Rao M.V.

    2010-01-01

    Full Text Available Curing is essential if concrete is to perform the intended function over the design life of the structure while excessive curing time may lead to the escalation of the construction cost of the project and unnecessary delays. Where there is a scarcity of water and on sloping surfaces where curing with water is difficult and in cases where large areas like pavements have to be cured, the use of curing compound may be resorted to. The parameters of the study include the curing period [1, 3, 7, 14 and 28 day], curing method [conventional wet curing, membrane forming compound curing and accelerated curing] and the type of cement [Ordinary Portland Cement(OPC 43 grade, Portland Pozzolana Cement(PPC 43 grade and Ordinary Portland Cement(OPC 43 grade +10% Silica Fume(SF replacement for cement]. In all a total of 99 cube specimens were cast and cured under different conditions before testing. Test results indicate a drop in strength at all ages for concretes with PPC and the one in which 10% OPC is replaced by silica Fume(SF in comparison with the concrete with OPC. Curing by membrane forming curing compound yielded nearly the same results as that of conventional wet curing for concrete with OPC and there was a marginal decrement in concrete with PPC. Predicted 28-day strength of concrete from the accelerated curing test was found to be on a conservative side compared to control concrete.

  10. 养护制度对富硅铁尾矿粉的活性及其浆体结构的影响%Influence of Curing System on the Activity of Silica-rich Iron Tailings and the Pore Structure of Iron Tailings-cement

    Institute of Scientific and Technical Information of China (English)

    李北星; 陈梦义; 王威; 朱志刚

    2013-01-01

    The influence of silica-rich iron tailings powders fineness and curing system on iron tailings activity and its cement mortar strength was studied.And the hydration products of iron tailings cement paste together with its pore structure under different curing system was tested by XRD,SEM and mercury porosimetry.The results show that the activity of iron tailings changes unobviously after reaching a certain fineness; Iron tailings with lower activity primarily have physical filling effect under standard curing,90 ℃ hot water conservation and 200 ℃dry heat conservation; Autoclave curing can greatly stimulate the activity of iron tailings and the main hydration product is C-S-H gel.90 ℃ hot water conservation and 200 ℃ dry heat conservation are able to decrease the number of harmful holes in iron tailings cement hardened paste but can increase the porosity of paste.Autoclave curing can refine slurry aperture and significantly reduce its porosity.%研究了富硅铁尾矿粉的细度和养护制度对铁尾矿活性及其水泥胶砂强度的影响,并通过X射线衍射(XRD)、扫描电镜(SEM)及压汞仪测试了铁尾矿水泥浆体在不同养护制度下的水化产物及孔结构分布.结果表明:铁尾矿粉磨至一定细度后其活性具有随细度增长变化不明显的特性;标准养护、90℃热水养护及200℃高温干热养护下,富硅铁尾矿粉的活性较低,主要起物理填充作用;蒸压养护激发了富硅铁尾矿粉的火山灰活性而形成大量C-S-H凝胶.90℃热水养护及200℃高温干热养护可降低铁尾矿水泥浆体中有害孔的数量,但增加浆体的孔隙率,而蒸压养护可细化浆体的孔径并显著降低孔隙率.

  11. Practical aspects of irradiance and energy in UV curing

    International Nuclear Information System (INIS)

    The physical properties of UV-cured materials are substantially affected by the lamp systems used to cure them. The development of the intended properties, whether a varnish, an ink, or an adhesive, can depend on how well these lamp factors are designed and managed. The four key factors of UV exposure are: UV irradiance (or intensity), spectral distribution (wavelengths) of UV, effective energy (time-integrated UV irradiance), and infrared radiation. Inks and varnishes will exhibit very different response to peak irradiance or energy, as well as to different UV spectra. The ability to identify the various lamp characteristics and match them to the optical properties of the curable materials, widens the range in which UV curing is a faster, more efficient production process. This paper explores the reasons for clearly identifying these factors for process optimization

  12. Cost analysis of low energy electron accelerator for film curing

    International Nuclear Information System (INIS)

    Low energy electron accelerators are recognized as one of the advanced curing means of converting processes for films and papers. In the last three years the price of the accelerator equipment has been greatly reduced. The targeted application areas are mainly processes of curing inks, coatings, and adhesives to make packaging materials. The operating cost analyses were made for electron beam (EB) processes over the conventional ones without EB. Then three new proposals for cost reduction of EB processes are introduced. Also being developed are new EB chemistries such as coatings, laminating adhesives and inks. EB processes give instantaneous cure and EB chemistries are basically non solvent causing less VOC emission to the environment. These developments of both equipment and chemistries might have a potential to change conventional packaging film industries. (author)

  13. 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.

  14. 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.

  15. Optimization of infrared radiation cure process parameters for glass fiber reinforced polymer composites

    International Nuclear Information System (INIS)

    Graphical abstract: Conventional thermal post curing process of polymer composites has the disadvantages of longer cure schedule, presence of thermal gradient between the core and outer layers and uncured resin patches within the composite laminate. Infrared radiation (IR) which is a part of electromagnetic spectrum, like other radiation curing methods, it is utilized for processing of food products, heating metals and other applications. The same technology is extended for curing of polymer composite laminates in this work. IR curing results in volumetric heating, hence it is faster and better compared to thermal curing. Considerable amount of time is saved as understood from the graph. Research highlights: → IR curing utilizes only 25% of total time as compared to conventional thermal curing method. → The optimized process parameters have been developed for Infrared radiation curing process. → Infrared radiation curing can be effectively employed for curing of polymer composite laminates. -- Abstract: Elevated temperature post curing is one of the most critical step in the processing of polymer composites. It ensures that the complete cross-linking takes place to produce the targeted properties of composites. In this work infrared radiation (IR) post curing process for glass fiber reinforced polymer composite laminates is studied as an alternative to conventional thermal cure. Distance from the IR source, curing schedule and volume of the composite were selected as the IR cure parameters for optimization. Design of experiments (DOE) approach was adopted for conducting the experiments. Tensile strength and flexural strength of the composite laminate were the responses measured to select the final cure parameters. Analysis of variance (ANOVA), surface plots and contour plots clearly demonstrate that the distance from the IR source and volume of the composite contribute nearly 70% to the response functions. This establishes that polymer composites cured using

  16. 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.

  17. Radiation cured polyester compositions containing metal-properties

    Science.gov (United States)

    Szalińska, H.; Pietrzak, M.; Gonerski, A.

    The subject of the studies was unsaturated polyester resin, Polimal-109 and its compositions containing acrylates of: sodium, potassium, calcium, magnesium, barium, manganese, iron, cobalt, copper and acrylic acid. Polyester resin modified with acrylic acid salts was cured with 60Co gamma radiation. Measurements of Vicat softening temperature, water absorption, creep current resistance, volume and surface resistivity, the tangent of dielectric loss angle and permittivity of radiation cured compositions were carried out. The results of the studies presented testify to the fact that the properties of cross-linked polymers alter after ionogenic compounds have been introduced into them.

  18. Trends in the wide web converting markets for UV curing

    International Nuclear Information System (INIS)

    As we prepare to enter a new decade, the use of ultraviolet (UV) energy to initiate the polymerization of coatings in the wide web segment of the Converting industry continues to increase. As is typical in the Converting industry, while many of the significant advances in technology have been developed around the world, they have been driven initially by the Western European markets. This was true with regards to the introduction of water-borne Pressure Sensitive Adhesives and thermal curing 100% solids silicone release coatings during the late 1970s and early 1980s, but this trend has changed with regards to the current state-of-the-art in UV curing

  19. 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.

  20. 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......) ultraviolet lithography, and (c) photolithography. We focus on hot embossing as it is one of the simplest, most cost-effective, and time-saving methods for replicating structures for thermoplasts. Addition curing silicones are shown to possess the ability to capture and retain an imprint made on it, 10–15 min...

  1. The chemistry of UV and EB radiation curing

    International Nuclear Information System (INIS)

    The application of photopolymerisation (UV) and electron beam (EB) technologies in radiation rapid cure (RRC) processing is discussed. The chemistry associated with such reactions and the mechanisms of the processes are treated. The occurrence of concurrent grafting to substrate with radiation curing of film is shown to be an advantage in enhancing the properties of certain finished products. The parameters influencing the optimum grafting yield in such RRC processes are discussed. In many applications, the chemistry of the process combined with the machine, expecially for EB, is shown a so-called ''turn-key'' operation. (author)

  2. 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.

  3. 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

  4. 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.

  5. Early-Age Strength of Ultra-High Performance Concrete in Various Curing Conditions

    Directory of Open Access Journals (Sweden)

    Jong-Sup Park

    2015-08-01

    Full Text Available The strength of Ultra-High Performance Concrete (UHPC can be sensitively affected by the curing method used. However, in contrast to the precast plant production of UHPC where a standard high-temperature steam curing is available, an optimum curing condition is rarely realized with cast-in-place UHPC. Therefore, the trend of the compressive strength development of UHPC was experimentally investigated in this study, with a focus on early-age strength by assuming the various curing conditions anticipated on site. Concrete specimens were cured under different conditions with variables including curing temperature, delay time before the initiation of curing, duration of curing, and moisture condition. Several conditions for curing are proposed that are required when the cast-in-place UHPC should gain a specified strength at an early age. It is expected that the practical use of UHPC on construction sites can be expedited through this study.

  6. 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.

  7. Radiation cure technology used in inks and coatings

    International Nuclear Information System (INIS)

    The radiation cure technology in inks and coatings by ultraviolet light (UV) and electron beam (EB) was introduced. The technology is the only one which meets the 3-E rules. An advantage of this technology is that a wide range of substrates can be printed such as paper, card, metal and even heat sensitive plastics

  8. 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

  9. 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...

  10. 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.

  11. Hypothalamic dysfunction in "cured" acromegaly is treatment modality dependent.

    Science.gov (United States)

    Peacey, S R; Toogood, A A; Shalet, S M

    1998-05-01

    The current definition of cure after treatment for acromegaly stipulates a reduction in GH levels to less than 2 ng/mL (acromegaly (mean 24-h GH concentration, 0.05; R vs. C, P 2 ng/mL) and who require SMS analog therapy. PMID:9589676

  12. Can advanced-stage ovarian cancer be cured?

    Science.gov (United States)

    Narod, Steven

    2016-04-01

    Approximately 20% of women with advanced-stage ovarian cancer survive beyond 12 years after treatment and are effectively cured. Initial therapy for ovarian cancer comprises surgery and chemotherapy, and is given with the goal of eradicating as many cancer cells as possible. Indeed, the three phases of therapy are as follows: debulking surgery to remove as much of the cancer as possible, preferably to a state of no visible residual disease; chemotherapy to eradicate any microscopic disease that remains present after surgery; and second-line or maintenance therapy, which is given to delay disease progression among patients with tumour recurrence. If no cancer cells remain after initial therapy is completed, a cure is expected. By contrast, if residual cancer cells are present after initial treatment, then disease recurrence is likely. Thus, the probability of cure is contingent on the combination of surgery and chemotherapy effectively eliminating all cancer cells. In this Perspectives article, I present the case that the probability of achieving a cancer-free state is maximized through a combination of maximal debulking surgery and intraperitoneal chemotherapy. I discuss the evidence indicating that by taking this approach, cures could be achieved in up to 50% of women with advanced-stage ovarian cancer. PMID:26787282

  13. 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

  14. Raman spectroscopic studies of the cure of dicyclopentadiene (DCPD)

    Science.gov (United States)

    Barnes, S. E.; Brown, E. C.; Corrigan, N.; Coates, P. D.; Harkin-Jones, E.; Edwards, H. G. M.

    2005-10-01

    The cure of polydicyclopentadiene conducted by ring-opening metathesis polymerisation in the presence of a Grubbs catalyst was studied using non-invasive Raman spectroscopy. The spectra of the monomer precursor and polymerised product were fully characterised and all stages of polymerisation monitored. Because of the monomer's high reactivity, the cure process is adaptable to reaction injection moulding and reactive rotational moulding. The viscosity of the dicyclopentadiene undergoes a rapid change at the beginning of the polymerisation process and it is critical that the induction time of the viscosity increase is determined and controlled for successful manufacturing. The results from this work show non-invasive Raman spectroscopic monitoring to be an effective method for monitoring the degree of cure, paving the way for possible implementation of the technique as a method of real-time analysis for control and optimisation during reactive processing. Agreement is shown between Raman measurements and ultrasonic time of flight data acquired during the initial induction period of the curing process.

  15. Antimony to Cure Visceral Leishmaniasis Unresponsive to Liposomal Amphotericin B.

    Directory of Open Access Journals (Sweden)

    Gloria Morizot

    2016-01-01

    Full Text Available We report on 4 patients (1 immunocompetent, 3 immunosuppressed in whom visceral leishmaniasis had become unresponsive to (or had relapsed after treatment with appropriate doses of liposomal amphotericin B. Under close follow-up, full courses of pentavalent antimony were administered without life-threatening adverse events and resulted in rapid and sustained clinical and parasitological cure.

  16. Antimony to Cure Visceral Leishmaniasis Unresponsive to Liposomal Amphotericin B.

    Science.gov (United States)

    Morizot, Gloria; Jouffroy, Romain; Faye, Albert; Chabert, Paul; Belhouari, Katia; Calin, Ruxandra; Charlier, Caroline; Miailhes, Patrick; Siriez, Jean-Yves; Mouri, Oussama; Yera, Hélène; Gilquin, Jacques; Tubiana, Roland; Lanternier, Fanny; Mamzer, Marie-France; Legendre, Christophe; Peyramond, Dominique; Caumes, Eric; Lortholary, Olivier; Buffet, Pierre

    2016-01-01

    We report on 4 patients (1 immunocompetent, 3 immunosuppressed) in whom visceral leishmaniasis had become unresponsive to (or had relapsed after) treatment with appropriate doses of liposomal amphotericin B. Under close follow-up, full courses of pentavalent antimony were administered without life-threatening adverse events and resulted in rapid and sustained clinical and parasitological cure.

  17. Pilot process waste assessment: Polyurethane foam mixing and curing

    International Nuclear Information System (INIS)

    This report represents a comprehensive assessment of the process waste streams for a polyurethane foam mixing and curing process in a rigid foam molding facility. The assessment includes profiles of waste streams, mass balances, pollution prevention options, benefit analysis of the options, and recommendations

  18. 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)

  19. Experimental study on shear property of autoclaved fly ash brick masonry in Xinjiang region%新疆地区蒸压粉煤灰实心砖砌体抗剪性能试验研究

    Institute of Scientific and Technical Information of China (English)

    袁康; 陈燕华; 常新军; 何志军

    2011-01-01

    Autoclaved fly ash brick is classified as one new wall material to replace fired brick, promoting the shear property of autoclaved fly ash brick masonry is very important for improving the earthquake resistance and crack resistance of masonry structure.Because of fluting the surface of brick,the shear property of ribbed autoclaved fly ash brick masonry would be improved. In the paper,the shear property of ribbed autoclaved fly ash brick masonry, common autoclaved fly ash brick masonry and fired brick have been comparative studied,and the earthquake resistance and crack resistance measures have been discussed under the premise of relative standard citations,in order to provide the theoretical basis for autoclaved fly ash brick's further promotion and application in Xinjiang which is located in seismic high-incidence area, while have climate characteristics of dry climate, high annual temperature difference,high diurnal temperature difference.%蒸压粉煤灰砖属于可以替代烧结普通砖的新型墙体材料,提高蒸压粉煤灰砖砌体的抗剪性能是改善此类砌体结构抗震、抗裂能力的关键.带肋蒸压粉煤灰砖通过改善砖的外形,在砖的表面开槽形成肋状,可提高砖砌体的抗剪能力.本文对带肋蒸压粉煤灰砖砌体、普通蒸压粉煤灰砖砌体和烧结普通砖砌体的抗剪性能进行了比较研究,并结合相关规范条文探讨了带肋蒸压粉煤灰砖的有关抗震、抗裂措施,为蒸压粉煤灰砖在地处地震高发区同时具备气候干燥,年温差、日温差大的新疆地区推广应用提供理论依据.

  20. 民营医疗美容机构压力蒸汽灭菌器使用现状调查%Investigation on usage status of autoclave of private medical cosmetology organization

    Institute of Scientific and Technical Information of China (English)

    孙惠惠; 王佳奇; 张流波; 李涛; 李炎; 沈瑾

    2015-01-01

    Objective To understand the status of autoclave using in private medical cosmetology organization and provide basis of disinfection and sterilization for standardizing private medical cosmetology institutions. Methods Date investiga-tion and on-the spot examination methods were used to carry out the investigation on the use of the autoclave status of 98 private medical cosmetology institutions of a city. Results There are a total of 101 sets of autoclave in 98 private medical cosmetology institutions,of which 67. 33% were under the exhaust autoclave. The rest were the pre-vacuum autoclave. These sterilizers were small and the sterilization chamber volume less than 60 L accounted for 71. 29%. Temperature detec-tion pass rate was 34. 65% and biological indicator pass rate was 96. 04%. Conclusion The private medical institutions of this city failed in temperature problems of the autoclave,the actual effect of sterilization far from the sterility assurance level requirements.%目的:了解民营医疗美容机构压力蒸汽灭菌器的使用现状,为规范民营医疗美容机构的消毒灭菌工作提供依据。方法采用资料调查和现场检测的方法,对某市98家民营医疗美容机构压力蒸汽灭菌器使用状况进行监测。结果共调查101台压力蒸汽灭菌器,其中有67.33%为下排气式压力蒸汽灭菌器,其余为预真空式压力蒸汽灭菌器。这些灭菌器均属微小型,灭菌腔体容积小于60 L的占71.29%。该城市医疗美容机构使用中的压力蒸汽灭菌器灭菌温度检测合格率为34.65%,生物指示物检测合格率为96.04%。结论该城市民营医疗美容机构压力蒸汽灭菌器温度不合格的问题突出,实际灭菌效果距离灭菌保证水平要求相差甚远。

  1. 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.

  2. Application conditions for ester cured alkaline phenolic resin sand

    Directory of Open Access Journals (Sweden)

    Ren-he Huang

    2016-07-01

    Full Text Available 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 following: (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 ìC, 35 ìC and 50 ìC, 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 (generally 45wt.%-65wt.% of resin, alkali content (generally 10wt.%-15wt.% of resin and viscosity of alkaline phenolic resin (generally 50-300 mPa≤s in the preparation of alkaline phenolic resin. Finally, the technique conditions of alkaline phenolic resin preparation and the application principles of organic ester were discussed.

  3. Economic evaluation of five curing processes for wood coatings

    International Nuclear Information System (INIS)

    In this work we study the economic feasibility of five methods for curing coatings over sheet wood products. Each year, Mexico is producing more than 40 millions of square meters of wood panels, but the demand is of the range of 58 millions of square meters of this product. Two millions are expended after they are coated, and 38 millions without coating, they are coated artisanilly when they are used to make pieces of furniture. The technical characteristics and the costs involved in each one of five methods of curing, are described. Investments involved with each method are processed to establish: fixed costs, variable costs, equilibrium point, and others. Initial investment, coasts and revenues are processed to determine the income statement pro-form, the projected statement of change in financial position, the projected working capital, the projected balance sheet, the cash-flow, and some economical and financial indicators for each one of the five curing methods. With this information, the internal rate of return (IRR) is determined, and used to compare the economic worth of each of the five methods. The five methods are profitable, because all they have a IRR greater than the opportunity cost of capital (15%) of projects with similar characteristics. Despite, with each one of the five methods, the capital invested is recoverable, and profits can be obtained; curing by ultraviolet light or by electron beam, let recover the investment in less than two years, require fewer dollars for investment, and have a IRR of 135% and 111% respectively. Besides ultraviolet light or electron beam curing processes, pollute less with volatile solvents, use the energy efficiently, have greater production rate, and the coating obtained have better quality than with the other three methods. (Author)

  4. Light output from six battery operated dental curing lights.

    Science.gov (United States)

    Shimokawa, Carlos Alberto Kenji; Turbino, Míriam Lacalle; Harlow, Jessie Eudora; Price, Hannah Louise; Price, Richard Bengt

    2016-12-01

    Light Curing Units (LCUs) are used daily in almost every dental office to photocure resins, but because the light is so bright, the user is unable to tell visually if there are any differences between different LCUs. This study evaluated the light output from six dental LCUs: Elipar Deep Cure-S (3M ESPE), Bluephase G2 (Ivoclar Vivadent), Translux 2Wave (Heraeus Kulzer), Optilight Prime (Gnatus), Slim Blast (First Medica) and Led.B (Guilin Woodpecker) with a fully charged battery, after 50, and again after 100, 20second light exposures. For each situation, the radiant power was measured 10 times with a laboratory-grade power meter. Then, the emission spectrum was measured using a fiber-optic spectrometer followed by an analysis of the light beam profile. It was found there were significant differences in the LCU power and the irradiance values between the LCUs (p<0.01). The Optilight Prime and Slim Blast LCUs showed a significant reduction in light output after a 50 and 100 exposures, while Bluephase G2 exhibited a significant reduction only after 100 exposures (p<0.01). The Bluephase G2 and Translux 2Wave delivered an emission spectrum that had two distinct wavelength emission peaks. Only the Elipar Deep Cure-S and Bluephase G2 LCUs displayed homogeneous light beam profiles, the other LCUs exhibited highly non-homogeneous light beam profiles. It was concluded that contemporary LCUs could have very different light output characteristics. Both manufacturers and researchers should provide more information about the light output from LCUs.

  5. 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}.

  6. Preparation and characterization of Fe-TiO 2 films with high visible photoactivity by autoclaved-sol method at low temperature

    Science.gov (United States)

    Lu, Xiaona; Ma, Yunfei; Tian, Baozhu; Zhang, Jinlong

    2011-03-01

    A series of uniform and transparent Fe-doped TiO 2 films were prepared by autoclaved-sol method at low temperature. The as-prepared films were characterized by XRD, DRS, EPR and AFM. The photocatalytic activity was evaluated based on the degradation of Rhodamine B solution under visible light. It was found that all the films were composed of mixed-phase crystal of anatase and brookite. Fe 3+ ions have been successfully doped into the TiO 2 crystal lattice by substituting Ti 4+, thus inducing significant absorption shift toward visible region compared with the pure TiO 2 films. EPR result further illustrated the doped Fe ions entered into the TiO 2 lattice. AFM reveals that doping of Fe ions increases the mean roughness and secondary particle size. The 0.5% Fe-TiO 2 films demonstrated the highest photocatalytic activity under visible light due to the interaction of active sites, impurity energy level and contact surface area.

  7. Hydrothermal interaction of crushed Topopah Spring tuff and J-13 water at 90, 150, and 2500C using Dickson-type, gold-bag rocking autoclaves

    International Nuclear Information System (INIS)

    As part of the Package Environment subtask of the Waste Package task within the Nevada Nuclear Waste Storage Investigations (NNWSI) Project, experiments were conducted to study the hydrothermal interaction of rock and water representative of a potential high-level waste repository in tuff. These experiments used crushed Topopah Spring tuff from both drillcore and outcrop samples. The data, when considered in conjunction with results from analogous experiments using solid wafers of tuff, define near-field repository conditions and can be used to assess the ability to use ''accelerated'' tests based on the surface area/volume (SA/V) parameter and temperature; allow the measurement of chemical changes due to reaction in phases present in the tuff before reaction; and permit the identification and chemical analysis of secondary phases resulting from hydrothermal reactions. Some of the results presented in this report have been used to demonstrate the usefulness of geochemical modeling in a repository environment using the EQ3/6 thermodynamic/kinetic geochemical modeling code. The tuff was reacted with a natural ground water in Dickson-type gold-bag rocking autoclaves that were periodically sampled under in situ conditions. Five short-term (0C and 50 to 100 bars. This report will focus on the results of experiments with crushed tuff, while a companion report will cover results of analogous short-term experiments run with solid waters of tuff

  8. Comparison of the Effects of Diet Sterilization by Irradiation and Autoclaving on the Equilibrium between Eleven Microbe Strains Seeded in the Alimentary Tracts of Axenic Mice

    International Nuclear Information System (INIS)

    Eleven obligate or facultative anaerobe strains were seeded successively in the alimentary tracts of 'gnotoxenic' mice. The animals were divided into four groups which received a commercially available diet sterilized by autoclaving or by irradiation (4 Mrad) or treated with the two methods in succession and supplemented or not supplemented in vitamins. A series of quantitative differential analyses carried out over a period of seven months on the faeces of the animals did not reveal any significant differences in the equilibrium that became established among the eleven strains in the faecal flora of the four groups of animals. At the end of the experiment quantitative differential analyses were performed of the stomachal and caecal flora of two animals from each group; again no differences were found in the equilibrium of the flora in the animals from the different groups. Any radiolytic products that may have been in the radiation-sterilized diet therefore had no detectable effect on the equilibrium of the microflora that the authors had chosen to establish in the alimentary tract of the 'gnotoxenic' animals. (author)

  9. 变电站蒸压粉煤灰砖砌体围墙裂缝分析与防治%Analysis and Prevention of Substation of Autoclaved Fly Ash Brick Masonry Wall Cracks

    Institute of Scientific and Technical Information of China (English)

    邵国华

    2014-01-01

    本文结合变电站工程实际,分析了变电站工程蒸压粉煤灰砖砌体清水围墙裂缝产生的原因,从蒸压粉煤灰砖的生产、构造设计及砌筑施工等几个方面提出了防治措施。%Combining with the actual substation engineering, Analyzed the causes of transformer substation project of autoclaved fly ash brick masonry wall cracks in water, Puts forward the prevention measures from the aspects of production, structure design and masonry construction of autoclaved fly ash brick.

  10. 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.

  11. Current and future market of UV/EB curing in Thailand

    International Nuclear Information System (INIS)

    Current status and future market of UV/EB curing in Thailand were presented. Included number of printing houses, export, main export market and the role of radiation curing in printing and packaging industries of Thailand

  12. 环境温度对蒸压粉煤灰砖混合料消化的影响%Effect of environmental temperature on slaking of autoclaved fly ash brick mixture

    Institute of Scientific and Technical Information of China (English)

    张建营

    2012-01-01

      The paper analyzes the effect of environmental temperature on slaking of autoclaved fly ash brick mixture, and the relationship between mixture and environmental temperature.%  分析了蒸压粉煤灰砖影响混合料消化的因素,分析了混合料与环境温度的关系,并对某企业存在的问题给出了解决办法。

  13. Research on autoclaved reaction activities of Si/Al -based industrial residues%硅铝质工业废弃物蒸压反应活性研究

    Institute of Scientific and Technical Information of China (English)

    陆金驰

    2011-01-01

    Mass fractions of active SiO2 and A12O3 ,and infrared spectrum (IR) were used to analyze the autoclaved reaction activities of Si/Al - based industrial residues, such as fly ash and coal dust slag etc. Results showed that autoclaved reaction activities of Si/Al - based industrial residues had an evident relationship with the mass fractions of active SiO2 and A12O3 ,and Si - O stretching vibration frequency about 1 100 cm-1 in strong absorption region of IR,that is the more mass fractions of active SiO2 and Al2 O3, and the lower Si-O stretching vibration frequency about 1 100 cm -1 in strong absorption region of IR, the stronger autoclaved reaction activities and the higher compressive strength of autoclaved products.%通过测定活性二氧化硅、氧化铝含量及红外光谱分析等方法研究粉煤灰、煤粉炉渣等硅铝质工业废弃物的蒸压反应活性.结果表明,硅铝质工业废弃物的蒸压反应活性与其活性二氧化硅、氧化铝含量及红外光谱1 100 cm-1附近强吸收区的Si-O伸缩振动频率存在明显的对应关系,即活性二氧化硅、氧化铝含量越高,红外光谱1 100 cm-1附近强吸收区的Si-O伸缩振动频率越低,蒸压反应活性越强,蒸压制晶强度越高.

  14. 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

  15. 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.

  16. Cure reaction and phase behavior of liquid crystalline epoxides-anhydride systems

    Institute of Scientific and Technical Information of China (English)

    Li Yan Liang; Shao Ping Ren; Yi Quan Zheng; Man Geng Lu

    2007-01-01

    A series of novel liquid crystalline epoxides with lateral substituents were cured with anhydrides and the cure kinetics was investigated by non-isothermal DSC technique. The results showed that the lengths of lateral substituents have great effect on the value of Ea. The curing reaction became less active, when the liquid crystalline epoxides have long lateral substituents and were controlled by diffusion at the late stage of cure. A nematic structure was observed by POM and XRD.

  17. 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.

  18. 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...

  19. 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 ...

  20. 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.

  1. Study on preparation of autoclaved brick by Yellow River silt and fly ash added waste papermaking liquor%利用造纸黑液和粉煤灰-泥砂制备蒸压砖的研究

    Institute of Scientific and Technical Information of China (English)

    张新爱; 关润伶

    2014-01-01

    以粉煤灰、黄河泥砂为主要原料,炉渣为骨料,石灰、石膏为激发剂,用造纸黑液代替水做拌和液制备黄河泥砂-粉煤灰蒸压砖。结果表明,造纸黑液代水制备蒸压砖是可行的,制备的蒸压砖可以达到JC 239-2001《粉煤灰砖》规定的MU25级的质量要求。%Autoclaved brick is prepared by fly ash and Yellow River silt as main materials, waste papermaking liquor as mixing liquid. The results show that it is feasible to make autoclaved brick by waste papermaking liquor as mixing liquid. The autoclaved brick meets the demand of MU25 grade in JC 239-2001 (fly ash bricks) standard.

  2. 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.

  3. 9 CFR 327.23 - Compliance procedure for cured pork products offered for entry.

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 2 2010-01-01 2010-01-01 false Compliance procedure for cured pork... procedure for cured pork products offered for entry. (a) Definitions. For the purposes of this section: (1) A Product is that cured pork article which is contained within one Group as defined in paragraph...

  4. Thermal stabilities of various rubber vulcanization cured by sulfur, peroxide and gamma radiation

    International Nuclear Information System (INIS)

    Sulfur and peroxide-cured rubber vulcanizates of NR and EPDM were obtained by blending the elastomers with fillers, antioxidants and appropriate accelerators, followed by vulcanization at 150 - 160 degree C. Blends of the same elastomers with appropriate co-agents and additives were also cured by gamma radiation at 150 and 200 kGy. A comparison of the thermal stabilities of these vulcanizates prepared by different curing techniques has been made by thermogravimetric analysis (TGA), assessed on the basis of comparison of DTG peak maxima, temperature for loss of 50% mass and actual thermal curves. The comparison reveals that the sulfur-cured vulcanizates are less thermally stable than their peroxide-cured counterparts. This may be attributed to the presence of a stronger C-C bond in case of peroxide-cured vulcanizates compared to weaker C-S sub x-C bond in case of sulfur-cured vulcanizates. However, compared to peroxide-cured vulcanizates, radiation-cured formulations demonstrated much improved thermal stability. This may originate from the existence of more uniformly distributed crosslinks and the enhanced rate of crosslink formation in the radiation process as compared to peroxide curing. In all the formulations whether sulfur, peroxide or radiation-cured, the natural rubber vulcanizates were found to be thermally much inferior to the synthetic contender, EPDM. Influence of variation of the amount of co-agent and other additives on the thermal stabilities of formulations of radiation cured NR and EPDM vulcanizates was also investigated

  5. 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.

  6. 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.

  7. Eradication of HIV and Cure of AIDS, Now and How?

    Directory of Open Access Journals (Sweden)

    Jie Lin eZhang

    2013-10-01

    Full Text Available Recent studies have highlighted the importance of eradication of human immunodeficiency virus (HIV and cure of acquired immunodeficiency syndrome (AIDS. However, a pivotal point that the patient immunity controls HIV reactivation after highly active anti-retroviral therapy (HAART, or combination anti-retroviral therapy, cART remains less well addressed. In spite of the fact that both innate and adaptive immunities are indispensable and numerous cells participate in the anti-HIV immunity, memory CD4 T-cells are indisputably the key cells organizing all immune actions against HIV while being the targets of HIV. Here we present a view and multidisciplinary approaches to HIV/AIDS eradication and cure. We aim at memory CD4 T-cells, utilizing the stem cell properties of these cells to reprogram an anti-HIV memory repertoire to eliminate the viral reservoir, toward achieving an AIDS-free world.

  8. Mixed Field Modification of Thermally Cured Castor Oil Based Polyurethanes

    International Nuclear Information System (INIS)

    Thermally cured polyurethanes were prepared from castor oil and hexamethylene diisocyanatee (HMDI). Due to the long aliphatic chain of the castor oil component of polyurethane, thermal curing of castor oil based polyurethane (COPU) is limited by increasing polymer viscosity. To enhance further crosslinking, COPUs were subjected to a range of accumulated doses (0.0-3.0 MGy) produced by the mixed ionizing field of the SLOWPOKE-2 research reactor. The physico-mechanical properties of COPU, unirradiated and irradiated, were characterized by mechanical tests. Increased bond formation resulting from radiation-induced crosslinking was confirmed by favorable increases in mechanical properties and by solid-state 13C-NMR and FTIR spectra

  9. Cure violence: a public health model to reduce gun violence.

    Science.gov (United States)

    Butts, Jeffrey A; Roman, Caterina Gouvis; Bostwick, Lindsay; Porter, Jeremy R

    2015-03-18

    Scholars and practitioners alike in recent years have suggested that real and lasting progress in the fight against gun violence requires changing the social norms and attitudes that perpetuate violence and the use of guns. The Cure Violence model is a public health approach to gun violence reduction that seeks to change individual and community attitudes and norms about gun violence. It considers gun violence to be analogous to a communicable disease that passes from person to person when left untreated. Cure Violence operates independently of, while hopefully not undermining, law enforcement. In this article, we describe the theoretical basis for the program, review existing program evaluations, identify several challenges facing evaluators, and offer directions for future research. PMID:25581151

  10. A consensus on criteria for cure of acromegaly

    OpenAIRE

    Giustina, Andrea; Chanson, Philippe; Bronstein, M D; Klibanski, A.; Lamberts, Steven; Casanueva, F.F. (Felipe F.); TRAINER, P; Ghigo, Ezio; Ho, K. K. Y.; 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 assays, biochemical measures, clinical outcomes, and definition of disease control were discussed, based on the available published evidence, and the strength of consensus statements was rated. Con...

  11. Child labour in the presence of agricultural dualism: possible cures

    OpenAIRE

    Dwibedi, Jayanta; Chaudhuri, Sarbajit

    2010-01-01

    The paper using a three-sector general equilibrium model with agricultural dualism and child labour shows that any fiscal measures designed to benefit backward agriculture cannot cure the problem of child labour in a developing economy although they raise the non-child labour income of the poor households. A policy of capital led growth through inflows of foreign capital, on the contrary, will be able to alleviate the problem by encouraging advanced agriculture and lowering the demand for c...

  12. 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.

  13. Cervical screening programme: HPV triage and test of cure protocol

    OpenAIRE

    Public Health Agency

    2013-01-01

    Testing for high-risk human papillomavirus (HR-HPV) as triage and test of cure was introduced into the Northern Ireland Cervical Screening Programme on Monday 28 January 2013. This policy change will significantly alter the screening pathway for women with a mild dyskaryosis or borderline smear result. The link between HR-HPV infection and the development of cervical cancer has now been clearly established, with almost 100% of cervical cancers containing HPV DNA. Women with no evidence of HR-...

  14. Acute Leukemia: Diagnosis, Management, and Potential for Cure

    OpenAIRE

    Stewart, Keith; Keating, Armand

    1988-01-01

    Acute leukemia is an uncommon malignant disorder resulting from the clonal proliferation of hematopoietic precursors of the myeloid or lymphoid lineages. Of the two major subgroups, acute lymphoblastic leukemia is more common in children, while acute myelogenous leukemia predominates in adults. With modern chemotherapy 60%-70% of all children with acute lymphoblastic leukemia can be long-term survivors and are potentially cured. Although the prognosis in acute myelogenous leukemia is less fav...

  15. Delayed Microbial Cure of Lymphogranuloma Venereum Proctitis with Doxycycline Treatment

    OpenAIRE

    De, Vries; Smelov, V.; Middelburg, J.G.; Pleijster, J.; Speksnijder, A.G.; Morré, S A

    2009-01-01

    Microbial cure of chlamydia proctitis (lymphogranuloma venereum [LGV] and non-LGV) with doxycycline treatment was evaluated by chlamydia DNA and RNA persistence in anal swab specimens. In LGV proctitis, RNA persisted for up to 16 days. In non-LGV chlamydia proctitis, DNA was undetectable after 7 days. These findings support the Centers for Disease Control and Prevention's treatment recommendation of a 21-day doxycycline regimen for LGV proctitis and a 7-day regimen for non-LGV chlamydia proct...

  16. Eradication of HIV and Cure of AIDS, Now and How?

    OpenAIRE

    Zhang, Jielin; Crumpacker, Clyde

    2013-01-01

    Recent studies have highlighted the importance of eradication of human immunodeficiency virus (HIV) and cure of acquired immunodeficiency syndrome (AIDS). However, a pivotal point that the patient immunity controls HIV reactivation after highly active anti-retroviral therapy [HAART or combination anti-retroviral therapy (cART)] remains less well addressed. In spite of the fact that both innate and adaptive immunities are indispensable and numerous cells participate in the anti-HIV immunity, m...

  17. Chronic Lymphocytic Leukemia: Inception to Cure: Are We There?

    OpenAIRE

    Lad, Deepesh P.; Malhotra, Pankaj; Varma, Subhash

    2012-01-01

    There have been remarkable advances in our understanding of the biology and therapeutics of chronic lymphocytic leukemia. B cell receptor signaling and micro-environment in CLL biology have been the most modern areas of research. In CLL therapeutics, we have come a long way from alkylating agents to chemo-immunotherapy. Despite this there remain significant lacunae in the disease biology that has hindered our quest to achieve the ultimate in CLL: Cure. This review aims to summarize the past, ...

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

    OpenAIRE

    Dr. Lilibeth A. Roxas; Nikko A. Roxas

    2015-01-01

    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 injectio...

  19. Emerging Concepts for Pelvic Organ Prolapse Surgery: What is Cure?

    OpenAIRE

    Lee, Una; Raz, Shlomo

    2010-01-01

    The objective of this review is to discuss emerging concepts in pelvic organ prolapse, in particular, “What is cure?” In a post-trial data analysis of the CARE (Colpopexy and Urinary Reduction Efforts) trial, treatment success varied tremendously depending on the definition used (19.2%–97.2%). Definitions that included the absence of vaginal bulge symptoms had the strongest relationships with the patients’ assessment of overall improvement and treatment success. As demonstrated by this study,...

  20. Curing preceramic polymers by exposure to nitrogen dioxide

    Science.gov (United States)

    Rabe, James A. (Inventor); Lipowitz, Jonathan (Inventor); Lu, Paul P. (Inventor)

    1991-01-01

    A rapid method of infusibilizing (curing) preceramic polymers comprising treatment said polymers with gaseous nitrogen dioxide. The infusibilized polymers may be pyrolyzed to temperatures in excess of about 800.degree. C. to yield ceramic materials with low oxygen content and, thus, good thermal stability. The methods are especially useful for the production of ceramic fibers and, more specifically, to the on-line production of ceramic fibers.

  1. Modified Castor Oil as an Epoxy Resin Curing Agent

    OpenAIRE

    Patel, B. P.; H. S. Patel; Patel, S R

    2004-01-01

    A castor oil, an agricultural product, is an unsaturated material. Hence the castor oil is brominated by bromine liquid. The brominated castor oil (BCO) was then reacted with excess of aliphatic diamines viz; ethylene diamine, 1,3-propane diamine and 1,6-hexane diamine. The resultant amino functionalized castor oil (ACO) samples were then characterized by elemental analysis, IR spectral study and number of amino groups. All the three ACO samples were then employed for the curing of commercial...

  2. 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...

  3. Bayesian Inference for Smoking Cessation with a Latent Cure State

    OpenAIRE

    Luo, Sheng; Crainiceanu, Ciprian M.; Thomas A Louis; Chatterjee, Nilanjan

    2009-01-01

    We present a Bayesian approach to modeling dynamic smoking addiction behavior processes when cure is not directly observed due to censoring. Subject-specific probabilities model the stochastic transitions among three behavioral states: smoking, transient quitting, and permanent quitting (absorbent state). A multivariate normal distribution for random effects is used to account for the potential correlation among the subject-specific transition probabilities. Inference is conducted using a Bay...

  4. Time course of isocyanate emission from curing polyurethane adhesives

    Science.gov (United States)

    Wirts, M.; Grunwald, D.; Schulze, D.; Uhde, E.; Salthammer, T.

    The time course of isocyanate emission from curing polyurethane (PUR) resins and adhesives was studied in two different emission test chambers. The measured emissions were strongly dependent on the type of experiment. The adhesives under investigation contained different types of diisocyanates and are used for different applications, e.g. for fixing of textile floor coverings. The influence of the curing mechanism on emission was studied by comparing the emission curves of one-component adhesives (OCA) and two-component adhesives (TCA). For TCA, the decrease in isocyanate emission was found to follow a two-step process during curing. In the first step, the emission is dominated by surface evaporation, and the decay of emission is mainly caused by the decrease in monomer content due to reaction. In the second step, the release is limited by internal diffusion. The influence of monomer reactivity on the emission profile could be demonstrated for 2,4'- and 4,4'-MDI. The less-reactive 2,4'-MDI caused prolonged emission. A strong dependence of emission rates on temperature and adhesive viscosity was also obvious. The evaluation of emission rates of different commercially available PUR adhesives showed the highest emission from systems that are applied at high temperatures. The high reactivity of diisocyanates requires special techniques for sampling and analysis. Therefore, an analytical method using HPLC-MS/MS was developed that enables limits of quantitation of <5 ng/m 3 with a sampling volume of 100 l.

  5. 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.

  6. 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

  7. Progress toward curing HIV infection with hematopoietic cell transplantation.

    Science.gov (United States)

    Petz, Lawrence D; Burnett, John C; Li, Haitang; Li, Shirley; Tonai, Richard; Bakalinskaya, Milena; Shpall, Elizabeth J; Armitage, Sue; Kurtzberg, Joanne; Regan, Donna M; Clark, Pamela; Querol, Sergio; Gutman, Jonathan A; Spellman, Stephen R; Gragert, Loren; Rossi, John J

    2015-01-01

    HIV-1 infection afflicts more than 35 million people worldwide, according to 2014 estimates from the World Health Organization. For those individuals who have access to antiretroviral therapy, these drugs can effectively suppress, but not cure, HIV-1 infection. Indeed, the only documented case for an HIV/AIDS cure was a patient with HIV-1 and acute myeloid leukemia who received allogeneic hematopoietic cell transplantation (HCT) from a graft that carried the HIV-resistant CCR5-∆32/∆32 mutation. Other attempts to establish a cure for HIV/AIDS using HCT in patients with HIV-1 and malignancy have yielded mixed results, as encouraging evidence for virus eradication in a few cases has been offset by poor clinical outcomes due to the underlying cancer or other complications. Such clinical strategies have relied on HIV-resistant hematopoietic stem and progenitor cells that harbor the natural CCR5-∆32/∆32 mutation or that have been genetically modified for HIV-resistance. Nevertheless, HCT with HIV-resistant cord blood remains a promising option, particularly with inventories of CCR5-∆32/∆32 units or with genetically modified, human leukocyte antigen-matched cord blood. PMID:26251620

  8. 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.

  9. 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

  10. 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.

  11. Tobacco, Microbes, and Carcinogens: Correlation Between Tobacco Cure Conditions, Tobacco-Specific Nitrosamine Content, and Cured Leaf Microbial Community.

    Science.gov (United States)

    Law, Audrey D; Fisher, Colin; Jack, Anne; Moe, Luke A

    2016-07-01

    Tobacco-specific nitrosamines are carcinogenic N-nitrosamine compounds present at very low levels in freshly harvested tobacco leaves that accumulate during leaf curing. Formation of N-nitrosamine compounds is associated with high nitrate levels in the leaf at harvest, and nitrate is presumed to be the source from which the N-nitrosation species originates. More specifically, nitrite is considered to be a direct precursor, and nitrite is linked with N-nitrosation in many environmental matrices where it occurs via microbial nitrate reduction. Here, we initiate work exploring the role of leaf microbial communities in formation of tobacco-specific nitrosamines. Leaves from burley tobacco line TN90H were air cured under various temperature and relative humidity levels, and 22 cured tobacco samples were analyzed for their microbial communities and leaf chemistry. Analysis of nitrate, nitrite, and total tobacco-specific nitrosamine levels revealed a strong positive correlation between the three variables, as well as a strong positive correlation with increasing relative humidity during cure conditions. 16S rRNA gene amplicon sequencing was used to assess microbial communities in each of the samples. In most samples, Proteobacteria predominated at the phylum level, accounting for >90 % of the OTUs. However, a distinct shift was noted among members of the high tobacco-specific nitrosamine group, with increases in Firmicutes and Actinobacteria. Several OTUs were identified that correlate strongly (positive and negative) with tobacco-specific nitrosamine content. Copy number of bacterial nitrate reductase genes, obtained using quantitative PCR, did not correlate strongly with tobacco-specific nitrosamine content. Incomplete denitrification is potentially implicated in tobacco-specific nitrosamine levels. PMID:27023797

  12. INFLUENCE OF WATER-TO-CEMENT RATIO ON AIR ENTRAILMENT IN PRODUCTION OF NON-AUTOCLAVED FOAM CONCRETE USING TURBULENCE CAVITATION TECHNOLOGY

    Directory of Open Access Journals (Sweden)

    Gorshkov Pavel Vladimirovich

    2012-10-01

    Full Text Available Non-autoclaved foam concrete is an advanced thermal insulation material. Until recently, foam concrete production has been based on separate preparation of foam and solution, followed by their blending in a mixer. The situation changed when high-quality synthetic foaming agents and turbulence cavitation technology appeared on the market. Every model provides a dependence between the foam concrete strength and the water-to-cement ratio. According to the water-cement ratio we can distinguish strong concrete mixtures (with the water-to-cement ratio equal to 0.3…0.4 and ductile ones (with the water-to-cement ratio equal to 0.5…0.7. Strong concrete mixtures are more durable. The lower the water-to-cement ratio, the higher the foam concrete strength. However super-plastic substances cannot be mixed by ordinary turbulent mixers. Foam concrete produced using the turbulence cavitation technology needs air-entraining, its intensity being dependent on several factors. One of the main factors is the amount of free water, if it is insufficient, the mixture will not be porous enough. A researcher needs to identify the optimal water-to-cement ratio based on the water consumption rate. Practical production of prefabricated concrete products and structures has proven that the reduction of the water-to-cement ratio improves the strength of the product. The task is to find the water-to-cement ratio for the foam concrete mixture to be plastic enough for air entraining. An increase in the ratio causes loss in the strength. The ratio shall vary within one hundredth points. Super-plasticizers are an alternative solution.

  13. Autoclave treatment of pig manure does not reduce the risk of transmission and transfer of tetracycline resistance genes in soil: successive determinations with soil column experiments.

    Science.gov (United States)

    Kang, Yijun; Gu, Xian; Hao, Yangyang; Hu, Jian

    2016-03-01

    The increasing use of antibiotics, especially tetracycline, in livestock feed adversely affects animal health and ecological integrity. Therefore, approaches to decrease this risk are urgently needed. High temperatures facilitate antibiotic degradation; whether this reduces transmission risk and transfer of tetracycline-resistant bacteria (TRBs) and tetracycline resistance genes (TRGs) in soil remains unknown. Successive experiments with soil columns evaluated the effects of autoclaving pig manure (APM) on soil TRB populations and TRGs over time at different soil depths. The data showed sharp increases in TRB populations and TRGs in each subsoil layer of PM (non-APM) and APM treatments within 30 days, indicating that TRBs and TRGs transferred rapidly. The level of TRBs in the upper soil layers was approximately 15-fold higher than in subsoils. TRBs were not dependent on PM and APM levels, especially in the late phase. Nevertheless, higher levels of APM led to rapid expansion of TRBs as compared to PM. Moreover, temporal changes in TRB frequencies in total culturable bacteria (TCBs) were similar to TRBs, indicating that the impact of PM or APM on TRBs was more obvious than for TCBs. TRBs were hypothesized to depend on the numbers of TRGs and indigenous recipient bacteria. In the plough layer, five TRGs (tetB, tetG, tetM, tetW, and tetB/P) existed in each treatment within 150 days. Selective pressure of TC may not be a necessary condition for the transfer and persistence of TRGs in soil. High temperatures might reduce TRBs in PM, which had minimal impact on the transmission and transfer of TRGs in soil. Identifying alternatives to decrease TRG transmission remains a major challenge. PMID:26517996

  14. Autoclave treatment of pig manure does not reduce the risk of transmission and transfer of tetracycline resistance genes in soil: successive determinations with soil column experiments.

    Science.gov (United States)

    Kang, Yijun; Gu, Xian; Hao, Yangyang; Hu, Jian

    2016-03-01

    The increasing use of antibiotics, especially tetracycline, in livestock feed adversely affects animal health and ecological integrity. Therefore, approaches to decrease this risk are urgently needed. High temperatures facilitate antibiotic degradation; whether this reduces transmission risk and transfer of tetracycline-resistant bacteria (TRBs) and tetracycline resistance genes (TRGs) in soil remains unknown. Successive experiments with soil columns evaluated the effects of autoclaving pig manure (APM) on soil TRB populations and TRGs over time at different soil depths. The data showed sharp increases in TRB populations and TRGs in each subsoil layer of PM (non-APM) and APM treatments within 30 days, indicating that TRBs and TRGs transferred rapidly. The level of TRBs in the upper soil layers was approximately 15-fold higher than in subsoils. TRBs were not dependent on PM and APM levels, especially in the late phase. Nevertheless, higher levels of APM led to rapid expansion of TRBs as compared to PM. Moreover, temporal changes in TRB frequencies in total culturable bacteria (TCBs) were similar to TRBs, indicating that the impact of PM or APM on TRBs was more obvious than for TCBs. TRBs were hypothesized to depend on the numbers of TRGs and indigenous recipient bacteria. In the plough layer, five TRGs (tetB, tetG, tetM, tetW, and tetB/P) existed in each treatment within 150 days. Selective pressure of TC may not be a necessary condition for the transfer and persistence of TRGs in soil. High temperatures might reduce TRBs in PM, which had minimal impact on the transmission and transfer of TRGs in soil. Identifying alternatives to decrease TRG transmission remains a major challenge.

  15. 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.

  16. 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.

  17. 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...... spectroscopy (FTIR). Wear was assessed by a three-body test. Data were submitted to Levene's test, one and three-way ANOVA, and Tukey HSD test (alpha = 0.05). Results: Immersion in ethanol, curing mode, and material all had significant effects on Wallace hardness. After ethanol storage, resin composites...

  18. 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

    This study determined whether the strength with which resin composite bonds to dentin is influenced by variations in the curing rate of resin composites. Resin composites were bonded to the dentin of extracted human molars. Adhesive (AdheSE, Ivoclar Vivadent) was applied and cured (10 seconds...... @ 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...... 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...

  19. 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.

  20. Modeling the intracellular pathogen-immune interaction with cure rate

    Science.gov (United States)

    Dubey, Balram; Dubey, Preeti; Dubey, Uma S.

    2016-09-01

    Many common and emergent infectious diseases like Influenza, SARS, Hepatitis, Ebola etc. are caused by viral pathogens. These infections can be controlled or prevented by understanding the dynamics of pathogen-immune interaction in vivo. In this paper, interaction of pathogens with uninfected and infected cells in presence or absence of immune response are considered in four different cases. In the first case, the model considers the saturated nonlinear infection rate and linear cure rate without absorption of pathogens into uninfected cells and without immune response. The next model considers the effect of absorption of pathogens into uninfected cells while all other terms are same as in the first case. The third model incorporates innate immune response, humoral immune response and Cytotoxic T lymphocytes (CTL) mediated immune response with cure rate and without absorption of pathogens into uninfected cells. The last model is an extension of the third model in which the effect of absorption of pathogens into uninfected cells has been considered. Positivity and boundedness of solutions are established to ensure the well-posedness of the problem. It has been found that all the four models have two equilibria, namely, pathogen-free equilibrium point and pathogen-present equilibrium point. In each case, stability analysis of each equilibrium point is investigated. Pathogen-free equilibrium is globally asymptotically stable when basic reproduction number is less or equal to unity. This implies that control or prevention of infection is independent of initial concentration of uninfected cells, infected cells, pathogens and immune responses in the body. The proposed models show that introduction of immune response and cure rate strongly affects the stability behavior of the system. Further, on computing basic reproduction number, it has been found to be minimum for the fourth model vis-a-vis other models. The analytical findings of each model have been exemplified by

  1. Avaliação dos comportamentos mecânico e térmico de laminados de PPS/fibra de carbono processados em autoclave sob diferentes ciclos de consolidação Evaluation of thermal and mechanical behaviors of PPS/carbon fiber laminates processed in autoclave under different consolidation cycles

    Directory of Open Access Journals (Sweden)

    Luciana S Marques

    2010-01-01

    Full Text Available Usualmente, um dos processos mais utilizados para fabricação de componentes em termoplásticos estruturais é a moldagem por compressão a quente, porém restringindo-se na obtenção de peças de pequeno e médio porte. Tal restrição deve-se à limitação do tamanho das prensas utilizadas, principalmente pelo custo envolvido. Procurando ampliar a aplicação de compósitos termoplásticos, possibilitando a fabricação de peças maiores e com maior potencial de integração, pelo uso de infra-estrutura já disponível em processadores de compósitos, este trabalho aborda o processamento de laminados de poli(sulfeto de fenileno (PPS reforçado com fibra de carbono em autoclave, pelo uso de quatro diferentes ciclos de consolidação. Os laminados obtidos foram caracterizados por inspeção por ultrassom, análises de DSC para a determinação da cristalinidade e avaliação das propriedades mecânicas em flexão, compressão e cisalhamento interlaminar. Os resultados mostram que laminados obtidos com taxas de resfriamento mais lentas apresentam menor resistência e módulo em compressão, uma vez que o maior grau de cristalinidade (~30% promove maior fragilização da matriz polimérica.One of the most used processes to obtain structural thermoplastic parts is the hot compression molding, which is limited to small and medium size parts because of the size of the press used, mainly related to its cost. This has hampered a wide use of thermoplastic composites in structural applications. In order to extend the application of thermoplastic composites, but still using available infrastructure in composite manufacturers, in this work we investigate the processing of carbon fiber reinforced polyphenylene sulfide (PPS in an autoclave, using four consolidation cycles. The processed laminates were characterized by ultrasound inspection, DSC analyses for the crystallinity determination and mechanical tests to evaluate the compression, flexure and

  2. The dental curing light: A potential health risk.

    Science.gov (United States)

    Price, Richard B T; Labrie, Daniel; Bruzell, Ellen M; Sliney, David H; Strassler, Howard E

    2016-08-01

    Powerful blue-light emitting dental curing lights are used in dental offices to photocure resins in the mouth. In addition, many dental personnel use magnification loupes. This study measured the effect of magnification loupes on the "blue light hazard" when the light from a dental curing light was reflected off a human tooth. Loupes with 3.5x magnification (Design for Vision, Carl Zeiss, and Quality Aspirator) and 2.5x magnification (Design for Vision and Quality Aspirator) were placed at the entrance of an integrating sphere connected to a spectrometer (USB 4000, Ocean Optics). A model with human teeth was placed 40 cm away and in line with this sphere. The light guide tip of a broad-spectrum Sapphire Plus (Den-Mat) curing light was positioned at a 45° angle from the facial surface of the central incisor. The spectral radiant power reflected from the teeth was recorded five times with the loupes over the entrance into the sphere. The maximum permissible cumulative exposure times in an 8-hr day were calculated using guidelines set by the ACGIH. It was concluded that at a 40 cm distance, the maximum permissible cumulative daily exposure time to light reflected from the tooth was approximately 11 min without loupes. The weighted blue irradiance values were significantly different for each brand of loupe (Fisher's PLSD p < 0.05) and were up to eight times greater at the pupil than when loupes were not used. However, since the linear dimensions of the resulting images would be 2.5 to 3.5x larger on the retina, the image area was increased by the square of the magnification and the effective blue light hazard was reduced compared to without the loupes. Thus, although using magnification loupes increased the irradiance received at the pupil, the maximum cumulative daily exposure time to reflected light was increased up to 28 min. Further studies are required to determine the ocular hazards of a focused stare when using magnification loupes and the effects of other

  3. Properties of modified anhydride hardener and its cured resin

    Science.gov (United States)

    Qiang, Chen; Bingjun, Gao; Jinglin, Chen; Tongzhao, Xu

    2000-01-01

    Methyl-nadic-tetrahydric-methylanhydride (MNA), nadic-tetrahydric-methylanhydride (NA), anhydride hardener was modified by solid diol molecule to improve the impregnation resin fracture toughness in cryogenic temperature. The lap-shear strength, transverse tension as well as the thermal shock test showed that the resin cured by the modified anhydride hardener had higher bond strength and more toughness at 77 K. After the experiment of vacuum pressure impregnation (VPI) processing, it was found that this resin had a longer usable life, better impregnating properties, but higher initial viscosity than the resin hybrid HY925 as hardener.

  4. Quantification of salt concentrations in cured pork by computed tomography

    DEFF Research Database (Denmark)

    Vestergaard, Christian Sylvest; Risum, Jørgen; Adler-Nissen, Jens

    2004-01-01

    Eight pork loin samples were mounted in Plexiglas cylinders and cured for five days. Samples were scanned by computed tomography (CT) once every 24 h. At the end of the experiment, the cylinders were cut in 1 cm sections and analyzed for chloride. From image analysis of the CT images, concentration...... profiles were extracted and fitted to a diffusion model which included a term to account for a non-negligible mass transfer coefficient. It was found that CT provides accurate estimates of salt gradients in meat and it was suggested that this analytical method could be valuable in scientific research and...

  5. [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.

  6. 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.

  7. 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).

  8. Demonstration of Mer-Cure Technology for Enhanced Mercury Control

    Energy Technology Data Exchange (ETDEWEB)

    John Marion; Dave O' Neill; Kevin Taugher; Shin Kang; Mark Johnson; Gerald Pargac; Jane Luedecke; Randy Gardiner; Mike Silvertooth; Jim Hicks; Carl Edberg; Ray Cournoyer; Stanley Bohdanowicz; Ken Peterson; Kurt Johnson; Steve Benson; Richard Schulz; Don McCollor; Mike Wuitshick

    2008-06-01

    Alstom Power Inc. has completed a DOE/NETL-sponsored program (under DOE Cooperative Agreement No. De-FC26-07NT42776) to demonstrate Mer-Cure{trademark}, one of Alstom's mercury control technologies for coal-fired boilers. The Mer-Cure{trademark}system utilizes a small amount of Mer-Clean{trademark} sorbent that is injected into the flue gas stream for oxidation and adsorption of gaseous mercury. Mer-Clean{trademark} sorbents are carbon-based and prepared with chemical additives that promote oxidation and capture of mercury. The Mer-Cure{trademark} system is unique in that the sorbent is injected into an environment where the mercury capture kinetics is accelerated. The full-scale demonstration program originally included test campaigns at two host sites: LCRA's 480-MW{sub e} Fayette Unit No.3 and Reliant Energy's 190-MW{sub e} Shawville Unit No.3. The only demonstration tests actually done were the short-term tests at LCRA due to budget constraints. This report gives a summary of the demonstration testing at Fayette Unit No.3. The goals for this Mercury Round 3 program, established by DOE/NETL under the original solicitation, were to reduce the uncontrolled mercury emissions by 90% at a cost significantly less than 50% of the previous target of $60,000/lb mercury removed. The results indicated that Mer-Cure{trademark} technology could achieve mercury removal of 90% based on uncontrolled stack emissions. The estimated costs for 90% mercury control, at a sorbent cost of $0.75 to $2.00/lb respectively, were $13,400 to $18,700/lb Hg removed. In summary, the results from demonstration testing show that the goals established by DOE/NETL were met during this test program. The goal of 90% mercury reduction was achieved. Estimated mercury removal costs were 69-78% lower than the benchmark of $60,000/lb mercury removed, significantly less than 50% of the baseline removal cost.

  9. Effect of curing temperatura on hydration process of different cement

    OpenAIRE

    Elkhadiri, I.; Palacios, M.; Puertas, F.

    2009-01-01

    [EN]Hydration was studied in two cements (CEM I 42.5R and CEM II/A-V 42.5R) cured at temperatures ranging from 4 to 85°C. Hydration was monitored with a number of instrumental techniques: X-Ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Backscattered Electron (BSE) imaging in conjunction with Energy Dispersive X-ray analysis (EDX) and Nuclear Magnetic Resonance (MAS NMR). The mechanical strength of the pastes was likewise determined at different ages, while mercury int...

  10. 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

  11. Developing the Manufacturing Process for Hylene MP Curing Agent

    Energy Technology Data Exchange (ETDEWEB)

    Eastwood, Eric

    2009-02-16

    This report details efforts to scale-up and re-establish the manufacturing process for the curing agent known as Hylene MP. First, small scale reactions were completed with varying conditions to determine key drivers for yielding high quality product. Once the optimum conditions were determined on the small scale, the scaled-up process conditions were determined. New equipment was incorporated into the manufacturing process to create a closed production system and improve chemical exposure controls and improve worker safety. A safe, efficient manufacturing process was developed to manufacture high quality Hylene MP in large quantities.

  12. 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.

  13. 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.

  14. 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.

  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. Non-autoclave silicate brick

    OpenAIRE

    V. N. Yaglov; Ya. N. Kovalev; V. N. Romaniuk; G. A. Burak

    2015-01-01

    The paper proposes a technology for obtaining bricks on the basis of lime-silica mixtures where chemical interactions are practically completely realized in dispersive state at the stage of preparation of binding contact maturing and raw mixture as a whole. The role of forming operation (moulding) is changed in principle because in this case conversion of dispersive system into a rock-like solid occurs and due to this the solid obtains complete water-resistance in contact with water immediate...

  17. Study on Autoclave Preparation Technology and Properties of Potato Resistant Starch%马铃薯抗性淀粉压热制备工艺与性质

    Institute of Scientific and Technical Information of China (English)

    王振强; 申森; 樊欣

    2012-01-01

    The autoclave preparation technology and properties of potato resistant starch(RS) were studied. Orthogonal experiment was adopted to optimize the preparation technology base on single factor tests of starch milk concentration, thermal - press temperature, thermal-press time and starch milk pH. The optimum extraction conditions were starch milk concentration, 200g/L; thermal-press temperature, 120℃ thermal-press time, 60 min; starch milk pH, 7, under which the RS yield was 4.66%. The enzyme resistance, water absorption and DSC profiles of potato RS were studied. The results showed that potato RS had strong anti-enzymatic ability; the water absorption of potato RS was higher than potato original starch; and the DSC profiles showed potato RS formed a variety of amylose structures which had tighter structure, thus had stronger heat resistance and anti-enzymatic ability.%对马铃薯抗性淀粉(RS)压热制备工艺及性质进行了研究.选择淀粉乳浓度、压热温度、压热时间和淀粉乳pH进行单因素试验,确定条件范围,再采用正交试验优化提取条件,得到最佳提取工艺条件为淀粉乳浓度200 g/L,压热温度120℃,压热时间75 min,淀粉乳pH7,按最佳工艺条件进行试验,马铃薯RS产率为4.66%.并研究了马铃薯RS抗酶解性、吸水性和DSC图谱,结果表明,马铃薯RS具有较强的抗酶解性;吸水率高于马铃薯精淀粉;DSC图谱显示马铃薯RS形成了多种结构更紧密的直链淀粉晶体,有较强的热稳定性和抗酶解性.

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

    International Nuclear Information System (INIS)

    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 Ea 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

  19. 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.

  20. 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

  1. EB-curing of coatings on wood composite boards

    International Nuclear Information System (INIS)

    The industrial radiation processing using low energy electron beam (EB) accelerators lower than 300 keV offers high speed, safe technologies for the chemical conversion of thin layer coatings. Because of the nonselective mode of initiating chain reaction polymerization involving free radicals in synthetic coating layers and suitable substrates, the EB curing of the coatings on woods and papers has particular advantage. Hungary decided to start an up-to-date EB line to process cement-bound (CB) wood chipboards with pigmented acrylic coatings. The CB wood chipboards contain more than 60 % of portland cement and up to 40 % of wood particles. They are produced as large boads of 6 - 16 mm thickness. In their fireproof character and other aspects, they are similar to asbestos-cement boards without containing carcinagenic asbestos, and are stable against moisture and atmospheric influences. EB-cured acrylate coating improved further those properties, and makes them valuable structural material. Oligomers and monomers as the main components of EB curable coatings, the irradiation with a Van de Graaff type electron accelerator of 2 MeV and the results are reported. The oligomers play the most important role in the formation of radiation curable coatings. (K.I.)

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

    Directory of Open Access Journals (Sweden)

    Ajai R Singh

    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.

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

    Science.gov (United States)

    Singh, Ajai R

    2010-01-01

    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. PMID:21327168

  4. Non-destructive monitoring of curing process in precast concrete

    International Nuclear Information System (INIS)

    Currently, the use of precast concrete elements has gained importance because it offers many advantages over site-cast concrete. A disadvantage of site-cast concrete is that its properties vary according to the manufacturing method, the environment and even the operator who carried out the mixing, pouring and implementation of the concrete. Precast concrete elements are manufactured in a controlled environment (typically referred to as a precast plant) and this reduces the shrinkage and creep. One of the key properties of precast concrete is the capability to gain compressive strength rapidly under the appropriate conditions. The compressive strength determines if the precast can be stripped from the form or manipulated. This parameter is measured using destructive testing over cylindrical or cubic samples. The quality control of precast is derived from the fracture suffered by these elements, resulting in a 'pass or fail' evaluation. In most cases, the solution to this problem is to allow the material to cure for a few hours until it acquires sufficient strength to handle the precast element. The focus of this paper is the description of the research project 'CUREND'. This project aims to design a non-destructive methodology to monitor the curing process in precast concrete. The monitoring will be performed using wireless sensor networks.

  5. 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.

  6. Non-destructive monitoring of curing process in precast concrete

    Science.gov (United States)

    Aparicio, S.; Ranz, J.; Fernández, R.; Albert, V.; Fuente, J. V.; Hernández, M. G.

    2012-12-01

    Currently, the use of precast concrete elements has gained importance because it offers many advantages over site-cast concrete. A disadvantage of site-cast concrete is that its properties vary according to the manufacturing method, the environment and even the operator who carried out the mixing, pouring and implementation of the concrete. Precast concrete elements are manufactured in a controlled environment (typically referred to as a precast plant) and this reduces the shrinkage and creep. One of the key properties of precast concrete is the capability to gain compressive strength rapidly under the appropriate conditions. The compressive strength determines if the precast can be stripped from the form or manipulated. This parameter is measured using destructive testing over cylindrical or cubic samples. The quality control of precast is derived from the fracture suffered by these elements, resulting in a "pass or fail" evaluation. In most cases, the solution to this problem is to allow the material to cure for a few hours until it acquires sufficient strength to handle the precast element. The focus of this paper is the description of the research project "CUREND". This project aims to design a non-destructive methodology to monitor the curing process in precast concrete. The monitoring will be performed using wireless sensor networks.

  7. Nanostructured magnesium oxide as cure activator for polychloroprene rubber.

    Science.gov (United States)

    Kar, Sritama; Bhowmick, Anil K

    2009-05-01

    The aim of this research was to synthesize magnesium oxide nanoparticles and to use them as cure activator for polychloroprene rubber (CR). The effects of counterions of magnesium salts on the homogeneous phase precipitation reaction to control size, monodispersity, crystallinity, and morphology of Mg(OH)2 nanoparticles were also investigated. Magnesium oxide nanoparticles were synthesized by optimizing the calcination temperature of Mg(OH)2 nanoparticles. Finally, the MgO nanoparticles were dispersed in polychloroprene rubber (CR) solution along with zinc oxide (ZnO) powder. The influence of MgO nanoparticles on the mechanical, dynamic mechanical and thermal properties of the resulting nanocomposites was quantified. The modulus and strength of ZnO-cured polychloroprene rubber with 4% MgO nanoparticles appeared to be superior to those with ZnO particles or ZnO with rubber grade MgO particles. These composites were further characterized by transmission electron microscopy and infrared spectroscopy in order to understand the morphology of the resulting system and the load transfer mechanism. PMID:19452982

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

    Science.gov (United States)

    Singh, Ajai R

    2010-01-01

    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.

  9. 蒸压粉煤灰砖砌体轴心受压性能试验研究%AN EXPERIMENTAL STUDY ON THE AXIAL COMPRESSIVE PROPERTIES OF AUTOCLAVED FLY ASH BRICK MASONRY

    Institute of Scientific and Technical Information of China (English)

    赵斐; 何晓雁; 乔建新

    2011-01-01

    36 autoclaved fly ash brick masonries are built for axial compressive tests.An experiment is carried out with the strength of both masonry and mortar serving as the basic parameters and the dial indicator used for measuring the deformation of masonries.Based on the experiment, the development features of cracks and the deformation patterns of masonries under compressure are analyzed.In light of the results of axial compressive tests of all the 36 masonries, a calculative formula of the compressive strength of autoclaved fly ash brick is established, which will supply experimental data for compiling regional technical codes.And, thus, the application of autoclaved fly ash brick will be extended.%试验以块体和砂浆强度为基本参数,砌筑36个蒸压粉煤灰砖砌体试件进行轴心受压试验,并配合百分表量测砌体变形.通过蒸压粉煤灰砖砌体轴心受压试验,分析了砌体受压时裂缝的发展特点和变形规律,根据36个试件的抗压试验结果,建立了蒸压粉煤灰砖砌体抗压强度的计算公式,为相关规范的编制提供试验数据,以利于蒸压粉煤灰砖的推广应用.

  10. Research on use of high calcium desulfurization ash in autoclaved brick CHEN Bin LIU Heng-bo WAN Jun%利用高钙固硫灰生产蒸压砖的研究

    Institute of Scientific and Technical Information of China (English)

    陈滨; 刘恒波; 万军

    2012-01-01

      The paper researches on the process of high calcium desulfurization ash autoclaved brick, and puts forward the ways to use the high calcium, high sulfur and low silicon of fly ash from the circulating fluidized bed boiler.%  对高钙固硫灰生产蒸压砖的生产工艺进行了研究,提出了重点解决循环流化床锅炉粉煤灰的高钙、高硫、低硅难题的有效途径。

  11. Autoclaved Sand-lime Bricks from Silica Tailings Powder and Stone Chips%用硅石尾矿粉和石屑制备蒸压灰砂砖

    Institute of Scientific and Technical Information of China (English)

    刘辉敏

    2013-01-01

    The influences of ingredients, molding pressures and autoclave temperatures on properties of autoclaved sand-lime bricks from silica tailings powder and stone chips were studied, and some samples were analyzed by XRD and SEM. The results show that high strength autoclaved sand-lime bricks can be prepared under appropriate conditions by silica tailings powder, stone chips and lime as the main components. When the mass ratio of lime powder to the silica tailings powder is less than 0.45, with the lime powder content increasing, the compressive strength of the samples gradually increases;but when the ratio further increases, the strength of the samples reduces. To improve the content of silica tailings powder and lime, molding pressure and the autoclave temperature can increase the strength of the sand-lime bricks. The stone chips are basically not involved in the hydrothermal reaction.%  研究了配合料组成、成型压力和蒸压温度对硅石尾矿粉(硅尾粉)-石屑蒸压灰砂砖抗压强度的影响,并用X射线衍射(XRD)和扫描电镜(SEM)对部分试样进行了分析。结果表明,以硅尾粉、石屑和石灰为主要组分,在适当条件下可制备强度较高的蒸压灰砂砖。当石灰粉与硅尾粉质量比小于0.45时,随着石灰粉掺量的增加,试样抗压强度逐渐提高;当质量比进一步增加时,试样强度降低。提高硅尾粉和石灰混合物含量、成型压力和蒸压温度,可提高灰砂砖强度。石屑基本上不参与水热反应。

  12. The Construction Technique of Autoclaved Lightweight Concrete (NALC)Masonry Free Plastering%轻质蒸压加气混凝土(NALC)砌块免抹灰式施工技术

    Institute of Scientific and Technical Information of China (English)

    孙国芳

    2011-01-01

    介绍了轻质蒸压加气混凝土(NALC)砌块的适用范围,论述了NALC砌块免抹灰施工的工艺流程及操作特点,质量标准及保证措施.%It introduces the applicable scope, and the process principle ot Autoclaved Lightweight Concrete( N ALC)Masonry.It tells the process and the operating characteristics of NALC Masonry Free Plastering, and the assurance measures.

  13. 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.

  14. 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.

  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. 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.

  17. 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.

  18. 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.

  19. Evaluation of Vickers hardness of bulk-fill composites cured by different light sources

    Science.gov (United States)

    Bakhsh, Turki A.; Yagmoor, Mohammed A.; Alsadi, Fahad M.; Jamleh, Ahmad

    2016-02-01

    [Objective] The current in vitro study was performed to evaluate Vickers hardness (VHN) of two different composite resins that were cured by using two different light curing units. [Materials and Methods] Porcelain tube samplers were used to fabricate composite cylinders from either Tetric Evoceram BulkFill (BF; Ivoclar/Vivadent, USA) or SonicFill composite (SF; Kerr, USA). Each composite type had 12 cylindrical specimens, and each specimen was cured with either Blue-phase N light-cure (Bp; Polywave, Ivoclar/Vivadent, USA) or Elipar S10 (El; Monowave, 3M ESPE, Germany). The VHN data were analyzed and tested by using Mann-Whitney U test at a significance level of 5%. [Results] Statistical analyses demonstrated an interaction between the type of composite and the type of light curing source. Significant differences (Pcomposite is not dependent on the type of light-cure. This research was supported by King Abdulaziz University.

  20. 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℃.

  1. 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.

  2. 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.

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

    OpenAIRE

    Tanvir Manzur; Shohana Iffat; Munaz Ahmed Noor

    2015-01-01

    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. Interna...

  5. Cancer Lung: Cure/Long Term Control Following Polyherbal Interventions- A Case Report

    OpenAIRE

    Verma, P.; B. R. Pandey; M. Bhalla; P. Raghuvanshi

    2012-01-01

    At present, there is no specific treatment aimed at cure of human lung cancer, a kind of most lethal cancers. Modern allopathy provides only temporary relief of symptoms or severity when used in the form of medicines, radiotherapy or chemotherapy at the cost of moderate to severe side-effects while long term survival or complete cures are anecdotal. It is also well known that surgical interventions, chemo and radiotherapies have failed consistently to cure many varieties of cancers. This hope...

  6. Cure and fabrication monitoring of composite materials with fibre-optic sensors

    Science.gov (United States)

    Roberts, S. S. J.; Davidson, R.

    The ultimate mechanical properties of composite materials are strongly dependent upon the chemical and rheological events occurring during the cure cycle. This review paper assesses the feasibility of using embedded fiber-optic sensors to conduct in situ measurements of cure states, cure kinetics, resin viscosity, and residual stress build-up during the manufacture of composite laminates. Several new techniques, some novel and some refinements of existing techniques are being developed to provide a basis for the eventual intelligent processing of composites.

  7. Food safety of salt-cured cod products : effects of salt-curing, rehydration and thermal treatmenton survival, growth and invasiveness of Listeria spp.

    OpenAIRE

    Lorentzen, Grete

    2010-01-01

    Salt-cured and dried salt-cured (klipfish) cod (Gadus morhua L.) are highly appreciated. Salt fish and klipfish are mainly prepared by rehydration to lower the level of salt. The rehydrated cod can be used in several dishes and consumption of these products has been considered safe due to the high level of salt. The overall aim of the thesis was to study the food safety of salt-cured fish products using Listeria spp. as an indicator. Initially, we studied the survival of Listeria spp. in m...

  8. Experimental Control of Curing & Structural Health Monitoring for Composite Patch Repairs

    Directory of Open Access Journals (Sweden)

    K.Kalkanis

    2014-01-01

    Full Text Available Unquestionably structural integrity of composite materials is of great importance and spans from production to service. The presented experimental investigation, supported initially by numerical analysis, addresses the capability of sensing during the curing cycle of Composite Patch Repair (CPR guaranteeing achievement of optimal cure levels. Results have exhibited identification and completion of cure leading to probable reduction of repair and downtime costs. The sensors were further used post curing for structural integrity where results proved that the optical fibres can render a general state of the strain field inside the patches and possible crack propagation (real time.

  9. Cure Kinetics of DGEBA/MDA System with Various Contents of NPG

    Energy Technology Data Exchange (ETDEWEB)

    Lee, H.K. [Woosuk Univerisity, Wanju (Korea, Republic of); Kim, Y.L.; Lee, J.Y.; Kim, S.W. [The University of Seoul, Seoul (Korea, Republic of)

    1999-05-01

    The isothermal cure behavior of diglycidyl ether of bisphenol A(DGEBA)/4,4`- methylene dianiline(MDA) system with various contents of neopentyl glycol(NPG) has been analyzed by differential scanning calorimetry(DSC). To increase the cure rate of DGEBA/MDA system, NPG was introduced as an accelerator. Regardless of the NPG content, the shape of the conversion curves showed sigmoid indicating that DGEBA/MDA/NPG system followed autocatalytic cure reaction. The cure reaction of DGEBA/MDA system increased with the increment of NPG content and it was due to the catalytic role of hydroxyl groups of NPG. (author). 21 refs., 6 figs., 2 tabs.

  10. 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

    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...... 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...

  11. 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.

  12. 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.

  13. The effects of cure temperature history on the stability of polyimide films

    Institute of Scientific and Technical Information of China (English)

    Ning Wenguo; Li Heng; Zhu Chunsheng; Luo Le; Chen Dong; Duan Zhenzhen

    2013-01-01

    The effects of cure temperature history on the stability of hinged structure poly (4,4-oxydiphenylene pyromellitimide) (PMDA-ODA) polyimide were studied by dynamic mechanical analysis.The polyimide films were cured under different curing conditions and peeled off by substrate etching.It was found that a proper cure time and temperature ramp rate improves the stability in terms of higher glass transition temperature.Ninety minutes at 375 ℃ or 200 ℃ is a beneficial high glass transition temperature.The temperature ramp rate should be between 2 ℃/min and 10 ℃/min,which is neither too high nor too low.

  14. 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

  15. Progress toward curing HIV infection with hematopoietic cell transplantation

    Directory of Open Access Journals (Sweden)

    Petz LD

    2015-07-01

    Full Text Available Lawrence D Petz,1 John C Burnett,2 Haitang Li,3 Shirley Li,3 Richard Tonai,1 Milena Bakalinskaya,4 Elizabeth J Shpall,5 Sue Armitage,6 Joanne Kurtzberg,7 Donna M Regan,8 Pamela Clark,9 Sergio Querol,10 Jonathan A Gutman,11 Stephen R Spellman,12 Loren Gragert,13 John J Rossi2 1StemCyte International Cord Blood Center, Baldwin Park, CA, USA; 2Department of Molecular and Cellular Biology, Irell and Manella Graduate School of Biological Sciences, 3Department of Molecular and Cellular Biology, Beckman Research Institute, City of Hope, Duarte, CA, USA; 4CCR5-Δ32/Δ32 Research Department, StemCyte International Cord Blood Center, Baldwin Park, CA, USA; 5Department of Stem Cell Transplantation, University of Texas MD Anderson Cancer Center, Houston, TX, USA; 6MD Anderson Cord Blood Bank, Department of Stem Cell Transplantation, University of Texas MD Anderson Cancer Center, Houston, TX, USA; 7Carolinas Cord Blood Bank, Duke University Medical Center, Durham, NC, USA; 8St Louis Cord Blood Bank, SSM Cardinal Glennon Children's Medical Center, St Louis, MO, USA; 9Enhance Quality Consulting Inc., Oviedo, FL, USA; 10Cell Therapy Service and Cord Blood Bank, Banc de Sang i Teixits, Barcelona, Spain; 11BMT/Hematologic Malignancies, University of Colorado, Aurora, CO, USA; 12Immunobiology and Observational Research, CIBMTR, Minneapolis, MN, USA; 13National Marrow Donor Program/Be The Match, Minneapolis, MN, USA Abstract: HIV-1 infection afflicts more than 35 million people worldwide, according to 2014 estimates from the World Health Organization. For those individuals who have access to antiretroviral therapy, these drugs can effectively suppress, but not cure, HIV-1 infection. Indeed, the only documented case for an HIV/AIDS cure was a patient with HIV-1 and acute myeloid leukemia who received allogeneic hematopoietic cell transplantation (HCT from a graft that carried the HIV-resistant CCR5-Δ32/Δ32 mutation. Other attempts to establish a cure for HIV

  16. 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.

  17. Monolithic growth of partly cured polydimethylsiloxane thin film layers

    DEFF Research Database (Denmark)

    Yu, Liyun; Skov, Anne Ladegaard

    2014-01-01

    The demand for monolithic structures in many applications has increased to enable more reliable and optimized performances such as for dielectric electroactive polymers (DEAPs). For the layers of the elements to grow efficiently together, it is first of all required that the layers adhere together...... 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...... 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...

  18. 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.

  19. Mechanistic aspects of polymer chemistry for radiation curing

    International Nuclear Information System (INIS)

    The chemistry of polymer production has been reviewed for the purpose of identifying suitable uses for high-energy electron accelerators in the plastics industry. High-energy radiation produces free radicals, electrons and ions in irradiated materials. These species initiate polymerization and cross-linking reactions in a manner analogous to that of chemical agents. The chemical mechanisms of radiation-induced polymerization, co-polymerization and cross-linking are compared with those of chemical and thermal initiation. Radiation polymerization can be a very fast process, but the polymerization reactions are quite exothermic, and temperature increases of up to 400 degrees Celcius may result if insufficient cooling is provided. Several approaches to reducing the temperature increase during radiation curing are presented. Chemical kinetic simulations of the radiation-induced cationic polymerization of styrene have shown that the effect of water inhibition on the rate of polymerization may be eliminated at the high dose rates available from high power accelerators. 25 refs

  20. 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.

  1. 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.

  2. 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...

  3. 依托住宅产业化开发蒸压砂加气混凝土成套体系技术%Exploitation of Complete Sets of Sand Autoclaved Aerated Concrete System Technology Relying on the Housing Industrialization

    Institute of Scientific and Technical Information of China (English)

    王超华

    2015-01-01

    Relying on the advantage of group industrialization to develop research and development and application of sand autoclaved aerated concrete materials for the maintenance system of the green, environmental protection,energy saving technology,formed sets of system technology of the sand autoclaved aerated insulation,exterior insulation,partition panel,steel structure within the envelope insulation panels etc.,then summarized the construction method of complete system.%依托集团产业化优势,大力开展以蒸压砂加气混凝土材料为建筑围护体系的绿色、环保、节能技术研发与应用,形成了蒸压砂加气自保温、外墙外保温、內隔墙板、钢结构外围护保温墙板等多项成套体系技术,进而总结提炼出成套体系施工工法。

  4. Evaluation of Alum-Naltrexone Adjuvant Activity, on Efficacy of Anti-Leishmania Immunization with Autoclaved Leishmania major (MRHO/IR/75/ER Antigens in BALB/C Mice.

    Directory of Open Access Journals (Sweden)

    Habib Mohammadzadeh Hajipirloo

    2014-09-01

    Full Text Available Naltrexone, an opioid receptor antagonist shifts the immune response toward a Th1 profile. In the current study, we evaluated the efficacy of the mixture of NTX and alum, as a new adjuvant, to enhance immune response and induce protection against Leishmania major in a mouse model.BALB/c mice were immunized three times either autoclaved L. major promastigotes' antigens alone or in combination with the adjuvant alum, naltrexone or the alum-naltrexone mixture. Both humoral and cellular immune responses were assessed two weeks after the last immunization and compared with control mice.The administration of alum- NTX in combination with the parasite antigen, significantly increased production of IFN-γ IFN-γ /IL-5 ratio, lymphocyte proliferation and improved DTH response against L. major. There was no significant difference in survival following challenge among groups.Immunization with the alum- naltrexone mixture as an adjuvant, in combination with the autoclaved L. major promastigotes antigens, can enhance cellular immunity and shift the immune responses to a Th1 pattern.

  5. 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.

  6. 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

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. Preparations and applications in UV curing coatings of epoxy acrylates containing carboxyl

    International Nuclear Information System (INIS)

    This paper introduces preparations of epoxy acrylates containing carboxyl through the reactions of epoxy acrylates with butanedioic anhydride, pentanedioic anhydride, cis-butenedioic anhydride, phthalic anhydride, tetrabromophthalic anhydride and -tetrahydrophthalic anhydride. These epoxy acrylates containing carboxyl have been applied to UV-curing coatings and their effects on properties of UV-curing coatings have been studied

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

    International Nuclear Information System (INIS)

    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 deg. C. The same epoxy resin, thermally cured for 16 h with an anhydride hardener, reached a Tg (tan δ) of 136 deg. C. So, the irradiated sample had its Tg increased approximately 20% and the curing process was much less time consuming.

  13. The curing behaviors of the epoxy/dicyanamide system modified with epoxidized natural rubber

    International Nuclear Information System (INIS)

    The effects of epoxidized natural rubber (ENR) on the curing behaviors and adhesive strengths of an epoxy (diglycidyl ether of bisphenol-A) and dicyandiamide/2-methyl imidazole system are studied with differential thermal calorimetry (DSC), scanning electron microscopy (SEM), and Instron tensile testing instrument. From DSC analyses of specimens prepared with unsealed aluminum pans, it is obtained that the reaction exotherm, the time to maximal curing rate, the glass transition temperature, the rate constant, and the reaction order of the epoxy system change with respect to the content of ENR added because of the reaction of ENR with the epoxy system. The results obtained from SEM micrographs indicate that the particle size of the rubber phase increases with increasing the curing temperature and the ENR content. The volume fraction of the separated rubber phase also follows the similar trend except at the high curing temperature which implying that the dissolution of epoxy resin in the ENR phase also depends on the curing temperature and the amount of ENR present. The lap shear strengths of specimens prepared with etched aluminum substrates increase with increasing the curing temperature because of a better cure at a higher temperature, but decrease with increasing the ENR content resulting from an adverse effect of ENR on the mechanical properties of the cured resins

  14. Effect of commercially available egg cures on the survival of juvenile salmonids.

    Directory of Open Access Journals (Sweden)

    Shaun Clements

    Full Text Available There is some concern that incidental consumption of eggs cured with commercially available cures for the purpose of sport fishing causes mortality in juvenile salmon. We evaluated this by feeding juvenile spring Chinook (Oncorhynchus tshawytscha and steelhead (O. mykiss with eggs cured with one of five commercially available cures. We observed significant levels of mortality in both pre-smolts and smolts. Depending on the experiment, 2, 3, or 4 of the cures were associated with mortality. Mortality tended to be higher in the smolts than in the parr, but there was no clear species effect. The majority of mortality occurred within the first 10 d of feeding. Removal of sodium sulfite from the cure significantly reduced the level of mortality. Soaking the eggs prior to feeding did not reduce mortality. We observed a clear relationship between the amount of cured egg consumed each day and the survival time. We conclude that consumption of eggs cured with sodium sulfite has the potential to cause mortality in juvenile steelhead and Chinook salmon in the wild.

  15. 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.

  16. 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.

  17. The curing behaviors of the epoxy/dicyanamide system modified with epoxidized natural rubber

    Energy Technology Data Exchange (ETDEWEB)

    Hong, S.-G.; Chan, C.-K

    2004-07-09

    The effects of epoxidized natural rubber (ENR) on the curing behaviors and adhesive strengths of an epoxy (diglycidyl ether of bisphenol-A) and dicyandiamide/2-methyl imidazole system are studied with differential thermal calorimetry (DSC), scanning electron microscopy (SEM), and Instron tensile testing instrument. From DSC analyses of specimens prepared with unsealed aluminum pans, it is obtained that the reaction exotherm, the time to maximal curing rate, the glass transition temperature, the rate constant, and the reaction order of the epoxy system change with respect to the content of ENR added because of the reaction of ENR with the epoxy system. The results obtained from SEM micrographs indicate that the particle size of the rubber phase increases with increasing the curing temperature and the ENR content. The volume fraction of the separated rubber phase also follows the similar trend except at the high curing temperature which implying that the dissolution of epoxy resin in the ENR phase also depends on the curing temperature and the amount of ENR present. The lap shear strengths of specimens prepared with etched aluminum substrates increase with increasing the curing temperature because of a better cure at a higher temperature, but decrease with increasing the ENR content resulting from an adverse effect of ENR on the mechanical properties of the cured resins.

  18. 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.

  19. 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.

  20. Kinetic Analysis and Characterization of Epoxy Resins Conventionally and Microwave Cured

    OpenAIRE

    Saccone, Guido

    2008-01-01

    Investigation about the advantages of the microwave curing process of epoxy resins. The reaction kinetic and the thermo-mechanical and spectroscopic properties of the epoxy systems microwave polymerized have been compared with those of samples conventionally cured. The specific microwave effect has also been studied. Finally the possible microwave heatability of non polar polymers, through incorporation of suitable sensitizers, has also been investigated.