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Sample records for evaluation cure system

  1. 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.

  2. Computerized Ultrasound Risk Evaluation (CURE) System: Development of Combined Transmission and Reflection Ultrasound with New Reconstruction Algorithms for Breast Imaging

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    Littrup, P J; Duric, N; Azevedo, S; Chambers, D; Candy, J V; Johnson, S; Auner, G; Rather, J; Holsapple, E T

    2001-09-07

    Our Computerized Ultrasound Risk Evaluation (CURE) system has been developed to the engineering prototype stage and generated unique data sets of both transmission and reflection ultrasound (US). This paper will help define the clinical underpinnings of the developmental process and interpret the imaging results from a similar perspective. The CURE project was designed to incorporate numerous diagnostic parameters to improve upon two major areas of early breast cancer detection. CURE may provide improved tissue characterization of breast masses and reliable detection of abnormal microcalcifications found in some breast cancers and ductal carcinoma in situ (DCIS). Current breast US is limited to mass evaluation, whereas mammography also detects and guides biopsy of malignant calcifications. Screening with CURE remains a distant goal, but improved follow-up of mammographic abnormalities may represent a feasible breakthrough. Improved tissue characterization could result in reduction of the estimated one million benign biopsies each year in the United States, costing up to several billion dollars. Most breast calcifications are benign and comprise-80% of stereotactic biopsies guided by mammography. Ultrasound has the capability of finding some groups of calcifications, but further improvements in resolution should also address tissue characterization to define the soft tissue filling of ducts by DCIS. In this manner, CURE may be able to more accurately identify the malignant calcifications associated with progression of DCIS or early cancers. Currently, high-resolution US images of the breast are performed in the reflection mode at higher frequencies, which also limits depth of penetration. Reconstruction of reflection ultrasound images relies upon acoustic impedance differences in the tissue and includes only direct backscatter of the ultrasound signal. Resolution and tissue contrast of current US continues to improve with denser transducer arrays and image

  3. Evaluating the efficacy of curing lights.

    Science.gov (United States)

    Solomon, C S; Osman, Y I

    1999-08-01

    The use of light curing units has increased tremendously over the past few years with the introduction of photoactivated composite restorative resins. The advantages of light-cured composites are well documented especially the ease of placement of restorations as a result of extended working time and control of setting. Many of the advantages of these composites are dependent on the adequate polymerisation and therefore the source of the visible light, especially the wavelength and the intensity of the light source. The aims of this study were (i) to determine the intensity output of curing lights in state clinics, private dental practices and dental clinics run by trade unions using a radiometer and (ii) to relate their output to various factors that may affect the intensity of the light produced by each unit. The light intensity of each light curing unit was measured using the Efos Cure Rite radiometer (Cure Rite, Efos model #8000; Efos Inc, Mississauga, Canada). Mean readings ranged from a high of 448 to a low of 22 mW/cm2 for curing lights at the time of evaluation. Nineteen (54.3%) of the light curing units were functioning at optimal intensities, followed by 10 (28.6%) functioning at levels between 150 and 300 mW/cm2 and 6 (17.1%) functioning at levels far below that required to achieve adequate photocuring. No statistically significant differences were found when comparing intensity readings with age, last maintenance service and bulb replacement (P > 0.05). All of the clinicians interviewed (100%) expressed subjective satisfaction with the performance of the light curing units, even though 45.7% functioned below optimal intensities (P > 0.05). Not one of the clinicians expressed dissatisfaction with the performance of any of the light curing units. The results of this study showed that the light intensities f light curing units used within private dental practices, state and trade union dental clinics were inadequate for optimum curing.

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

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    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. Evaluation of Degreasers as Brine Curing Additives

    Science.gov (United States)

    The length of time needed for brine curing of raw hides and skins, a minimum of 18 h, is a time-consuming and expensive process. In this paper we initially report the results of an investigation of the stratigraphic distribution of sodium chloride and water in fleshed hides cured for varying interv...

  6. Thermal Aging Behaviors of Rubber Vulcanizates Cured with Single and Binary Cure Systems

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    Choi, Sung Seen; Ha, Sung Ho [Sejong University, Seoul (Korea, Republic of); Woo, Chang Su [Korea Institute of Machinery and Materials, Daejeon (Korea, Republic of)

    2006-03-15

    In general, an accelerated sulfur cure system consists of elemental sulfur, one or two cure accelerators, and cure activators. Crosslink density of a rubber vulcanizate determines the physical properties. By increasing the crosslink density, the modulus, hardness, resilience, and abrasion resistance increase, whereas the elongation at break, heat build-up, and stress relaxation decrease. Sulfur linkages are composed of monosulfide, disulfide, and polysulfides. Sulfur linkages, especially polysulfides, are dissociated by heating and this brings about decrease of the crosslink density.

  7. Effect of curing modes of dual-curing core systems on microtensile bond strength to dentin and formation of an acid-base resistant zone.

    Science.gov (United States)

    Li, Na; Takagaki, Tomohiro; Sadr, Alireza; Waidyasekera, Kanchana; Ikeda, Masaomi; Chen, Jihua; Nikaido, Toru; Tagami, Junji

    2011-12-01

    To evaluate the microtensile bond strength (μTBS) and acid-base resistant zone (ABRZ) of two dualcuring core systems to dentin using four curing modes. Sixty-four caries-free human molars were randomly divided into two groups according to two dual-curing resin core systems: (1) Clearfil DC Core Automix; (2) Estelite Core Quick. For each core system, four different curing modes were applied to the adhesive and core resin: (1) dual-cured and dual-cured (DD); (2) chemically cured and dual-cured (CD); (3) dual-cured and chemically cured (DC); (4) chemically cured and chemically cured (CC). The specimens were sectioned into sticks (n = 20 for each group) for the microtensile bond test. μTBS data were analyzed using two-way ANOVA and the Dunnett T3 test. Failure patterns were examined with scanning electron microscopy (SEM) to determine the proportion of each mode. Dentin sandwiches were produced and subjected to an acid-base challenge. After argon-ion etching, the ultrastructure of ABRZ was observed using SEM. For Clearfil DC Core Automix, the μTBS values in MPa were as follows: DD: 29.1 ± 5.4, CD: 21.6 ± 5.6, DC: 17.9 ± 2.8, CC: 11.5 ± 3.2. For Estelite Core Quick, they were: DD: 48.9 ±5.7, CD: 20.5 ± 4.7, DC: 41.4 ± 8.3, CC: 19.1 ± 6.0. The bond strength was affected by both material and curing mode, and the interaction of the two factors was significant (p core systems affects bond strength to dentin, but has no significant effect on the formation of ABRZ.

  8. Creep measurements on curing epoxy systems

    DEFF Research Database (Denmark)

    Kammer, Charlotte; Szabo, Peter

    1998-01-01

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

  9. New curing system of urea-formaldehyde resind with polyhydrazides. I. Curing with dihydrazie compounds

    Science.gov (United States)

    Bunichiro Tomita; Hideaki Osawa; Chung-Yun Hse; George E. Myers

    1989-01-01

    A nonconventional curing system was developed using a simple mixing of urea-formaldehyde (UF) resins with polyfunctional hydrazide compounds under neutral contition. Several kinds of low molecular-weight dihydrazide compounds were investigated as hardners of the UF resins. Results were as follows: 1) As the minimum gelation times were observed in the range of molar...

  10. Hardness Evaluation of Composite Resins Cured with QTH and LED

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    Behnaz Esmaeili

    2014-03-01

    Full Text Available Background and aims. Today light cured composites are widely used. Physical and mechanical properties of composites are related to the degree of conversion. Light curing unit (LCU is an important factor for composite polymerization. Aim of this study is evaluation of composite resins hardness using halogen and LED light curing units. Materials and methods. In this study, 30 samples of Filtek Z250 and C-Fill composite resins were provided. Samples were light cured with Ultralume2, Valo and Astralis7. Vickers hardness number (VHN was measured in 0, 1, 2 mm depth. Statistical analysis used: Data were analysed by SPSS software and compared with each other by T-test, one-way and twoway ANOVA and Post-hoc Tukey test. Results. In Filtek Z250, at top surface, VHN of Ultralume2 was higher than VHN of Valo (P = 0.02 and Astralis7 (P = 0.04, but in depth of 1, 2 mm, VHN of Ultralume2 and Astralis7 were almost the same and both LCUs were more than Valo which the difference between Ultralume2 and Valo was significant in depth of 1mm (0.05 and 2mm (0.02. In C-Fill composite, at top surface, Astralis7 showed higher VHN, but in depth of 2 mm, performance of all devices were rather similar. Conclusion. In Z250, which contains camphorquinone initiator, light cure LED Ultra-lume2 with narrow wavelength showed higher hardness number than Valo. In C-fill, in top surface, Astralis7 with more exposure time, resulted higher VHN. But In depth of 2 mm, various light curing devices had rather similar hardness number.

  11. New curing system for urea-formaldehyde resins with polyhydrazides. I. Curing with poly(methycrylol hydrazide)

    Science.gov (United States)

    Katsumasa Miyake; Bunichiro Tomita; Chung-Yun Hse; George E. Myers

    1989-01-01

    A new curing system for urea-formaldehyde (UF) resins was investigated using poly(methacryloyl hydrazide) as the curing reagent. Results were as follows: 1) Gel time and the water-soluble part of cured resins were determined as function of pH and molar ratio [hydrazide group/(free formaldehyde+methylol group)]. It was found that the reaction in this system proceeds for...

  12. Shear bond strength of acidic primer, light-cure glass ionomer, light-cure and self cure composite adhesive systems - an in vitro study.

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    D, Krishnakanth Reddy; V, Kishore M S; Safeena, Safeena

    2013-06-01

    The purpose of this study was to determine shear bond strength and the effect on the bracket/ adhesive failure mode when an acidic primer and other etchants were used to condition the enamel surface before bonding. Group I: Brackets bonded with Ultimate cure-on-light Light-cure composite adhesive system. Group II: Brackets bonded with Ortho-one no-mix. Self-cure composite adhesive system. Group III: Brackets bonded with Light-cure glass ionomer adhesive system. Group IV: Brackets bonded with Transbond plus self etching primer. The results of this study indicated that the shear bond strength when using Transbond plus self etching primer showed the highest bond strength Group- IV(8.69 2.54 MPa) followed by Ultimate cure-on-light Group-I (8.62 1.84 MPa), Ortho-one no-mix (Bisco Inc. USA)Group-II (8.07 1.72 MPa), and least bond strength was seen in G.C. Fuji Ortho L.C. Group-III (6.01 1.6) MPa Conclusion: Use of self etching primer saves chairside time and satisfactory high bond strength was obtained. Care should be taken during debonding of ceramic brackets How to cite this article: Reddy K D, Kishore M S V, Safeena S. Shear Bond Strength of Acidic Primer, Light-Cure Glass Ionomer, Light-Cure and Self Cure Composite Adhesive Systems - An In Vitro Study. J Int Oral Health 2013; 5(3):73-78.

  13. Evaluation of wear rate of dental composites polymerized by halogen or LED light curing units

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    Alaghehmand H.

    2006-08-01

    Full Text Available Background and Aim: Sufficient polymerization is a critical factor to obtain optimum physical properties and clinical efficacy of resin restorations. The aim of this study was to evaluate wear rates of composite resins polymerized by two different systems Light Emitting Diodes (LED to and Halogen lamps. Materials and Methods: In this laboratory study, 20 specimens of A3 Tetric Ceram composite were placed in brass molds of 2*10*10 mm dimensions and cured for 40 seconds with 1 mm distance from surface. 10 specimens were cured with LED and the other 10 were cured with Halogen unit. A device with the ability to apply force was developed in order to test the wear of composites. After storage in distilled water for 10 days, the specimens were placed in the wear testing machine. A chrome cobalt stylus with 1.12 mm diameter was applied against the specimens surfaces with a load of 2 kg. The weight of each samples before and after 5000, 10000, 20000, 40000, 80000 and 120000 cycles was measured using an electronic balance with precision of 10-4 grams. Data were analyzed using t test and paired t test. P0.05. Conclusion: Based on the results of this study, LED and halogen light curing units resulted in a similar wear rate in composite resin restorations.

  14. 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

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    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

  15. Cytotoxicity and oxidative stress caused by dental adhesive systems cured with halogen and LED lights.

    Science.gov (United States)

    Spagnuolo, Gianrico; Annunziata, Marco; Rengo, Sandro

    2004-06-01

    The aim of the present study was to investigate the cytotoxicity of two "one bottle" adhesive systems after polymerization with a conventional halogen or a light emitting diode (LED) lamp. We hypothesized that different polymerization sources might enhance the intracellular production of reactive oxygen species (ROS), leading to reduced cell survival. Two "one bottle" adhesive systems (Optibond Solo and Scotchbond One) were cured with a commercial halogen (Optilux 500) and an LED source (Elipar Freelight, 3 M). The specimens were extracted for 24 h in complete cell culture medium or in phosphate-buffered saline (PBS). Endothelial cells (ECV 304) were exposed to the extracts for 24 h and survival rates were evaluated by the MTT assay. Then, ROS generation was monitored by the oxidation-sensitive fluorescent probe 2'7'-dichlorofluorescin diacetate (DCFH-DA). Extracts from all materials except for Optibond Solo polymerized with the halogen lamp were rated significantly cytotoxic. Scotchbond One cured with LED was the most toxic material, which reduced cell survival to about 23% compared with control cultures. Significantly higher amounts of ROS were produced in cell cultures treated with adhesives polymerized with the LED lamp compared with the materials cured with the commercial halogen light source. We demonstrated that the production of intracellular ROS by extracts of the adhesive systems depended on the light sources used for curing of the materials. These results suggested a possible link between ROS production and cytotoxic activity.

  16. Cured-in-place pipe reconstruction of existing underground systems

    Energy Technology Data Exchange (ETDEWEB)

    Knasel, J. [Kenny Construction Co., Wheeling, IL (United States)

    1995-09-01

    This paper describes InLiner USA{reg_sign} which is a cost effective process that allows pipes to be rebuilt without digging and avoids disturbing the area surrounding the pipe. This cured-in-place pipe (CIPP) technology is a unique process for reconstructing deteriorated pipe line systems in municipal and industry applications, which includes powerplants. The process uses a resin that coats and rebuilds th interior of the pipe to improve its structural integrity and corrosion resistance. CIPP creates continuous, seamless construction which increases flow capacities, stops infiltration, improves structural strength, resists long term corrosion and forms its own pipe within a pipe. It can be installed in a matter of hours or days and can be utilized in gravity and pressure pipes for storm sewers, sanitary sewers, combined sewers, water mains, gas mains and process piping.

  17. Development of a mathematical model of two-phase polymer curing systems

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    V. I. Molchanov

    2013-01-01

    Full Text Available The formation a heterogeneous structure in two-phase elastomer composites was studied. Computer modeling of curing system in a set of five reaction–diffusion equations was carried out. In numerical experiments it is shown that density of the crosslinking of the entire system increases slower than the cure in the absence of curative’s diffusion, and the cure rate and the total degree of crosslinking of the composite as a whole is reduced.

  18. Dual-cured etch-and-rinse adhesive systems increase the bond durability of direct coronal dentin restorations.

    Science.gov (United States)

    Borges, B C D; Vilela, A R R C; da Silva-Junior, C A; Souza-Junior, E J; Sinhoreti, M A C; Pinheiro, F H S L; Braz, R; Montes, M A J R

    2013-01-01

    This study aimed to evaluate the bond durability of dentin restorations bonded with light- or dual-cured etch-and-rinse adhesive systems. A three-step adhesive system (Scotchbond Multipurpose Plus), an acetone-based two-step adhesive system (Prime & Bond 2.1), and an ethanol-based two-step adhesive system (Excite) were tested. Both the light- and the dual-cured versions were evaluated. High C-factor dentin cavities were prepared on 120 bovine incisors, which were then restored with resin composite (n=10). The samples were stored in water for 24 hours, and half of them were subjected to additional degradation with 10% NaOCl for five hours. The push-out bond strength test was performed in a universal testing machine until failure. Failure modes were evaluated by scanning electron microscopy. Data were analyzed by three-way analysis of variance and Tukey tests (padhesive system presented a higher immediate bond strength and durability than those that were light cured. The three-step adhesive system produced the highest values, whereas the acetone-based adhesive system produced the lowest result. Therefore, the use of dual-cured etch-and-rinse adhesive systems can induce increased bond durability to direct coronal dentin restorations.

  19. Cytotoxicity evaluation of three light-cured dentin adhesive materials on human gingival fibroblasts, ex vivo.

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    Kierklo, A; Pawińska, M; Tokajuk, G; Popławska, B; Bielawska, A

    2012-01-01

    To evaluate the cytotoxic effects of three current light-cured dentin adhesives, in both uncured and post-cured conditions, on human gingival fibroblasts. The materials tested were Heliobond, Adper Single Bond 2 and Xeno V, which are characterized by various compositions and application procedures. Each agent, in volumes of 5 and 10 μL, was tested after polymerization, and those unpolymerized were diluted in DMEM to 10-3 and 10-5. The cytotoxicity of the adhesives was assessed on the basis of a test of cell viability in a culture of human gingival fibroblasts, with the use of tetrazolic salt (MTT assay). The results showed that, among the adhesive/bonding systems tested, Xeno V was the least cytotoxic. There were statistically significant differences in cell survival between polymerized Xeno V, Adper Single Bond 2 and Heliobond in the amount of 5 μL as well as between the Xeno V and Adper Single Bond 2 in 10-5 dilutions. The tested adhesives were more toxic in the polymerized form than in the dilutions. Samples of 10 μL resulted in a lower survival percentage of fibroblasts compared to 5 μL. All the tested adhesives demonstrated cytopathic effects towards human gingival fibroblasts, but varied in their cytotoxicity. This has clinical implications. Dentists should follow the rules of adhesive application, precisely dose them and not allow direct contact with the gums as, even after polymerization, adhesive agents exhibit potential cytotoxic activity.

  20. Evaluation of shear bond strength of orthodontic brackets using trans-illumination technique with different curing profiles of LED light-curing unit in posterior teeth.

    Science.gov (United States)

    Heravi, Farzin; Moazzami, Saied Mostafa; Ghaffari, Negin; Jalayer, Javad; Bozorgnia, Yasaman

    2013-11-21

    Although using light-cured composites for bonding orthodontic brackets has become increasingly popular, curing light cannot penetrate the metallic bulk of brackets and polymerization of composites is limited to the edges. Limited access and poor direct sight may be a problem in the posterior teeth. Meanwhile, effectiveness of the trans-illumination technique is questionable due to increased bucco-lingual thickness of the posterior teeth. Light-emitting diode (LED) light-curing units cause less temperature rise and lower risk to the pulpal tissue. The purpose of this study was to evaluate the clinical effectiveness of trans-illumination technique in bonding metallic brackets to premolars, using different light intensities and curing times of an LED light-curing unit. Sixty premolars were randomly divided into six groups. Bonding of brackets was done with 40- and 80-s light curing from the buccal or lingual aspect with different intensities. Shear bond strengths of brackets were measured using a universal testing machine. Data were analyzed by one-way analysis of variance test and Duncan's post hoc test. The highest shear bond belonged to group 2 (high intensity, 40 s, buccal) and the lowest belonged to group 3 (low intensity, 40 s, lingual). Bond strength means in control groups were significantly higher than those in experimental groups. In all experimental groups except group 6 (80 s, high intensity, lingual), shear bond strength was below the clinically accepted values. In clinical limitations where light curing from the same side of the bracket is not possible, doubling the curing time and increasing the light intensity during trans-illumination are recommended for achieving acceptable bond strengths.

  1. Effect of Curing Agent and Temperature on the Rheological Behavior of Epoxy Resin Systems

    OpenAIRE

    Lei Zhao; Chenhui Zhao; Guangcheng Zhang

    2012-01-01

    The effect of curing agent (6610) content and temperature on the rheological behavior of the epoxy resin CYD-128 was studied by DSC analysis and viscosity experiments. The results show that the resin system meets the requirements of processing technology. A complete reaction occurs when the curing agent content (40 parts per hundred resin, phr) is a little higher than the theoretical value (33.33 phr), while the degree of reaction of the resin system is reduced when the curing agent content i...

  2. EVALUATION OF BARRIERS TO THE USE OF RADIATION-CURED COATINGS IN SCREEN PRINTING

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    The report gives results of an evaluation of barriers to the use of radiation-cured coatings in screen printing. In support of the Source Reduction Review Project (SRRP), maximum achievable control technology (MACT) standards development, and the Pollution Prevention Act, EPA is ...

  3. Room Temperature Curing Resin Systems for Graphite/Epoxy Composite Repair.

    Science.gov (United States)

    1979-12-01

    SBy______ _____ Di st ribution/ iviliability Codes- 4- Di t Avail and/or D1 specj&I•iii ILLUSTRATIONS Fiu Page I uSC Analysis of Epon 828 /DETA after 72 Hour...Cure at 24C (75F) .........................................********** 8 2 DSC Analysis of Epon 828 /DETA after 72 Hour Cure at 24C (75F) and One Hour...illustrate this a DSC analysis (Figure 1) was made of room tempera- ture cured Epon 828 /DETA, a resin system which has been widely used as an ambient

  4. Microleakage of Resin Composite Restoration with Total-Etch and Self-Etch Systems at Various Curing Distances

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    Viona Diansari

    2013-06-01

    Full Text Available Microleakage still occurs between cavity wall and resin composite restoration, although bonding agent such as Total-etch (TE and Selfetch (SE systems had been used. One of the causes of microleakage was associated to improper polymerization affected by curing distances. The objective of this study was to evaluate the microleakage of resin composite restoration using TE and SE adhesive systems that were polymerized at various curing distances. A total of 120 human molars were prepared for class V cavity and were divided into 4 groups with bonded resin composite restoration: Group A (TE: Filtek Z350 + Adper Single Bond 2; Group B (TE: Tetric N Ceram + Tetric N Bond; Group C (SE: Clearfil APX + SE Bond; and Group D (SE: Ceram X + Xeno III. Each group were divided into 3 parts (10 teeth each which were restored at 0; 2 and 4 mm of curing distance respectively. After stored in aquadest at 37oC (24 hours, all specimens were immersed in 1% methylene blue solution (24 hours. Dye penetration at coronal site were observed under a stereomicroscope (Nikon SM 2800. The results showed that microleakage between 3 various curing distances of each group were not significantly different (Kruskall-Wallis test, p>0,05. Mann-Whitney U test (p<0,05 showed that microleakage between Group A-C; Group A-D and Group B-D were significantly different at 2 mm curing distance. Conclusion: microleakage of resin composite restoration with TE adhesive system were lower than SE at all curing distances.DOI: 10.14693/jdi.v15i2.68

  5. Evaluation of the Effect of Porcelain Laminate Thickness on Degree of Conversion of Light Cure and Dual Cure Resin Cements Using FTIR.

    Science.gov (United States)

    Hoorizad Ganjkar, Maryam; Heshmat, Haleh; Hassan Ahangari, Reza

    2017-03-01

    Increasing the thickness of the veneering porcelain may affect the polymerization of resin cements. Incomplete polymerization of resin cements can lead to compromised quality of restoration and decrease the longevity of indirect restorations. This study sought to assess the effect of IPS Empress porcelain thickness on the degree of conversion of light-cure and dual-cure resin cements using Fourier transform infrared spectroscopy. In this experimental study, IPS Empress porcelain discs (A2 shade) with 10mm diameter and 0.5, 1 and 1.5 mm thicknesses were fabricated. Choice2 (Bisco, USA) and Nexus3 (Kerr, USA) resin cements were light cured through the three porcelain thicknesses in two groups of 3 samples using a LED light-curing unit (LEDemetron II; Kerr, USA). The control group samples were cured individually with no porcelain disc. The degree of conversion of resin cements was determined using FTIR (Bruker; Equinox55, Germany). The data were analyzed using Dunn's test. The degree of conversion (in percent) beneath the 0.5, 1.5 and 2 mm thicknesses of IPS Empress was 68.67±0.88, 71.06±0.94 and 72.51±0.41 for Choice2 resin cement and 69.60±2.12, 69.64±1.63 and 69.24±2.12 for Nexus3, respectively. Porcelain thickness and type of resin cement had no significant effect on degree of conversion (p≥ 0.05). It seems that increasing the porcelain thickness by up to 1.5 mm has no adverse effect on degree of conversion of both dual cure and light cure resin cements evaluated in this study.

  6. High conversion self-curing sealer based on a novel injectable polyurethane system for root canal filling

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    Sun, Bin [Research Center for Nano-Biomaterials, Analytical and Testing Center, Sichuan University, Chengdu 610064 (China); Zuo, Yi, E-mail: zoae@scu.edu.cn [Research Center for Nano-Biomaterials, Analytical and Testing Center, Sichuan University, Chengdu 610064 (China); Li, Jidong; Wang, Li [Research Center for Nano-Biomaterials, Analytical and Testing Center, Sichuan University, Chengdu 610064 (China); Tang, Kuangyun [The State Key Laboratory of Oral Diseases and Orthognathic Surgery, Sichuan University West China College of Stomatology, Chengdu 610064 (China); Huang, Di; Du, Jingjing; Luo, Peipei; Li, Yubao [Research Center for Nano-Biomaterials, Analytical and Testing Center, Sichuan University, Chengdu 610064 (China)

    2013-08-01

    Low monomer–polymer conversion is the key factor leading to cytotoxicity for resin-containing restorative materials. This paper provides a new root canal filling system based on self-curing injectable polyurethane which can achieve high conversion in a short time. Traced FTIR spectra show more than 90% NCO group participated in the curing reaction after 4 h, and only about 5% remained after 24 h. The calculated data also testified the curing process supports a third-order reaction, and this efficient and sufficient reaction is postulated to weaken the toxic stimulation. By culturing with L929 murine fibroblasts, the PU sealer is shown to be favorable for cell attachment and proliferation. Then physicochemical properties of the injectable PU-based sealer were evaluated according to the Standard [ISO 6876:2001 (E)] for clinical application. A series of physicochemical properties of PU sealer have been tested comparing with AH Plus and Apexit Plus. And the results present that the self-curing PU sealer could not only match the clinic requirements, but even has better properties than the other two commercial sealers. We expect the high conversion PU sealer has a tremendous potential in the field of root canal filling after further biological evaluation. - Highlights: • A new root canal sealer based on self-curing injectable polyurethane was provided. • More than 90% NCO group reacted after 4h, and only about 5% remained after 24 h. • By culturing with L929 murine fibroblasts, the PU sealer showed perfect cytocompatibility. • Volumetric dilatancy after curing will make the sealer achieve a tight seal.

  7. New composite nitrite-free and low-nitrite meat-curing systems using natural colorants.

    Science.gov (United States)

    Eskandari, Mohammad H; Hosseinpour, Sara; Mesbahi, Gholamreza; Shekarforoush, Shahram

    2013-09-01

    Nitrite-free and low-nitrite meat-curing systems were developed to eliminate or reduce nitrite in frankfurter-type sausages. Different composite meat-curing mixtures were formulated using cochineal and paprika as natural colorants, sodium hypophosphite (SHP) as antimicrobial agent, butylated hydroxyanisole (BHA) as antioxidant and sodium nitrite. The treatment, which contained 0.015% cochineal, most closely resembled the 120 ppm NaNO2 in its ability to create cured-meat color. BHA was found to be a strong antioxidant at the 30 ppm level in cooked sausages during refrigerated storage for 5 weeks. All treatments containing 40 ppm sodium nitrite were successful in replicating sensory attributes of frankfurter samples. Our findings support the use of SHP as possible antibotulinal agent in nitrite-free meat-curing systems.

  8. Evaluation of light intensity output of QTH and LED curing devices in various governmental health institutions.

    Science.gov (United States)

    Al Shaafi, Mm; Maawadh, Am; Al Qahtani, Mq

    2011-01-01

    The purpose of this study was to evaluate the light intensity output of quartz-tungsten-halogen (QTH) and light emitting diode (LED) curing devices located at governmental health institutions in Riyadh, Saudi Arabia.Eight governmental institutions were involved in the study. The total number of evaluated curing devices was 210 (120 were QTH and 90 were LED). The reading of the light intensity output for each curing unit was achieved using a digital spectrometer; (Model USB4000 Spectrometer, Ocean Optics Inc, Dunedin, FL, USA). The reading procedure was performed by a single investigator; any recording of light intensity below 300 mW/cm2 was considered unsatisfactory.The result found that the recorded mean values of light intensity output for QTH and LED devices were 260 mW/cm2 and 598 mW/cm2, respectively. The percentage of QTH devices and LED devices considered unsatisfactory was 67.5% and 15.6%, respectively. Overall, the regular assessment of light curing devices using light meters is recommended to assure adequate output for clinical use.

  9. Clinical evaluation of a visible light-cured indirect composite for long-term provisionalization.

    Science.gov (United States)

    Ewoldsen, Nels; Sundar, Veeraraghavan; Bennett, William; Kanya, Kevin; Magyar, Karl

    2008-01-01

    To clinically evaluate a visible light-cured (VLC) resin composite system for long-term provisional and esthetic diagnostic restorations, fabricated using indirect techniques. One-hundred and nine teeth were restored in 31 patients. Preoperational impressions were used to create VLC resin composite restorations (Radica) using indirect techniques. Restorations were relined as necessary and placed using various provisional cements at a follow-up appointment, subsequent to preparation of the teeth. Both fabricating laboratory technicians and placing dentists rated the restorations for acceptability in esthetics, marginal fit, occlusion, and functionality in various stages of provisionalization. All restorations (100%) were rated acceptable for esthetics prior to relining. After relining, a majority (93-100%) of restorations were rated acceptable in esthetic and functional criteria. At the placement of the permanent restoration, a majority (96-100%) of restorations were rated acceptable in esthetic and functional criteria. Terms of service ranged from two to seventy-six days. In combination with in vitro results, the clinical performance of the Radica VLC system for provisionalization and esthetic diagnostic restorations was judged to be acceptable. The system offers esthetics that are superior to conventional provisional restorations, and should be a valuable option to practitioners considering longer-term provisionalization in complex cases.

  10. Effect of Curing Agent and Temperature on the Rheological Behavior of Epoxy Resin Systems

    Directory of Open Access Journals (Sweden)

    Lei Zhao

    2012-07-01

    Full Text Available The effect of curing agent (6610 content and temperature on the rheological behavior of the epoxy resin CYD-128 was studied by DSC analysis and viscosity experiments. The results show that the resin system meets the requirements of processing technology. A complete reaction occurs when the curing agent content (40 parts per hundred resin, phr is a little higher than the theoretical value (33.33 phr, while the degree of reaction of the resin system is reduced when the curing agent content is lower (25.00 phr than theoretical value. However, excessive curing agent (50.00 phr results in a lower reaction rate. Curing agent content has little influence on gel time when curing agent content exceeded 33.33 phr and the temperature was less than 70 °C. The isothermal viscosity-time curves shift towards the –x axis when the temperature rises from 50 °C to 80 °C. Meanwhile, higher temperature results in higher reaction rates.

  11. Effect of curing agent and temperature on the rheological behavior of epoxy resin systems.

    Science.gov (United States)

    Zhao, Chenhui; Zhang, Guangcheng; Zhao, Lei

    2012-07-17

    The effect of curing agent (6610) content and temperature on the rheological behavior of the epoxy resin CYD-128 was studied by DSC analysis and viscosity experiments. The results show that the resin system meets the requirements of processing technology. A complete reaction occurs when the curing agent content (40 parts per hundred resin, phr) is a little higher than the theoretical value (33.33 phr), while the degree of reaction of the resin system is reduced when the curing agent content is lower (25.00 phr) than theoretical value. However, excessive curing agent (50.00 phr) results in a lower reaction rate. Curing agent content has little influence on gel time when curing agent content exceeded 33.33 phr and the temperature was less than 70 °C. The isothermal viscosity-time curves shift towards the -x axis when the temperature rises from 50 °C to 80 °C. Meanwhile, higher temperature results in higher reaction rates.

  12. Evaluation of different types of dry-cured ham by Italian and French consumers.

    Science.gov (United States)

    Cannata, S; Ratti, S; Meteau, K; Mourot, J; Baldini, P; Corino, C

    2010-04-01

    The aim was to analyse the distribution of preferences between two group of consumers (100 consumers each) from different countries (Italy and France), in order to establish which type of dry-cured ham is most acceptable and to compare results across countries using preference mapping. A preference test was carried out on four types of dry-cured hams: Parma ham (P), Italian non-branded ham (I) and hams derived from pigs fed a diet containing sunflower oil (2.5%) (S) or extruded linseed (5%) (L). The consumers were requested to evaluate each single descriptor using a hedonic scale and assigning a score between 1 (dislike extremely) and 9 (like extremely). The four different dry-cured hams were sensorially well differentiated by the consumers of different nationalities. Italian consumers preferred P and S hams while French consumers preferred S, I and P hams in terms of overall acceptability and acceptability of aroma and flavour. L ham was negatively discriminated, compared to the other hams, by both consumer groups. A good differentiation between the dry-cured hams was obtained using the internal preference map method: P was discriminated from the other hams. 2009 Elsevier Ltd. All rights reserved.

  13. A Novel Scoring System to Measure Radiographic Abnormalities and Related Spirometric Values in Cured Pulmonary Tuberculosis

    Science.gov (United States)

    Báez-Saldaña, Renata; López-Arteaga, Yesenia; Bizarrón-Muro, Alma; Ferreira-Guerrero, Elizabeth; Ferreyra-Reyes, Leticia; Delgado-Sánchez, Guadalupe; Cruz-Hervert, Luis Pablo; Mongua-Rodríguez, Norma; García-García, Lourdes

    2013-01-01

    Background Despite chemotherapy, patients with cured pulmonary tuberculosis may result in lung functional impairment. Objective To evaluate a novel scoring system based on the degree of radiographic abnormalities and related spirometric values in patients with cured pulmonary tuberculosis. Methods One hundred and twenty seven patients with cured pulmonary tuberculosis were prospectively enrolled in a referral hospital specializing in respiratory diseases. Spirometry was performed and the extent of radiographic abnormalities was evaluated twice by each of two readers to generate a novel quantitative score. Scoring reproducibility was analyzed by the intra-class correlation coefficient (ICC) and the Bland-Altman method. Multiple linear regression models were performed to assess the association of the extent of radiographic abnormalities with spirometric values. Results The intra-observer agreement for scoring of radiographic abnormalities (SRA) showed an ICC of 0.81 (CI:95%, 0.67–0.95) and 0.78 (CI:95%, 0.65–0.92), for reader 1 and 2, respectively. Inter-observer reproducibility for the first measurement was 0.83 (CI:95%, 0.71–0.95), and for the second measurement was 0.74 (CI:95%, 0.58–0.90). The Bland-Altman analysis of the intra-observer agreement showed a mean bias of 0.87% and -0.55% and an inter-observer agreement of -0.35% and -1.78%, indicating a minor average systematic variability. After adjustment for age, gender, height, smoking status, pack-years of smoking, and degree of dyspnea, the scoring degree of radiographic abnormalities was significantly and negatively associated with absolute and percent predicted values of FVC: -0.07 (CI:95%, -0.01 to -0.04); -2.48 (CI:95%, -3.45 to -1.50); and FEV1 -0.07 (CI:95%, -0.10 to -0.05); -2.92 (CI:95%, -3.87 to -1.97) respectively, in the patients studied. Conclusion The extent of radiographic abnormalities, as evaluated through our novel scoring system, was inversely associated with spirometric values, and

  14. New epoxy/episulfide resin system for electronic and coating applications: Curing mechanisms and properties

    Science.gov (United States)

    Tsuchida, Katsuyuki

    This work involves research on a new resin system useful for printed circuit board and protective coating applications. The system provides excellent adhesion to copper and corrosion resistance for copper. The research involved detailed studies of the reaction mechanisms, and correlation of these mechanisms with the observed properties. The epoxy/episulfide system, when used with a dicyandiamide (DICY) curing agent, exhibits better adhesion to copper substrate, a better pot life and prepreg storage life, a lower thermal expansion coefficient, a lower heat of reaction, a lower degradation temperature, and higher water absorption as compared with the standard epoxy system. From model compound studies, the sulfur of the opened episulfide ring reacts with copper, resulting in a durable bond between the copper and matrix resin even after water boiling. Since the S- formed by the reaction of the episulfide with the curing agent easily reacts with both the episulfide and the epoxy, a C-S-C bond is formed and more unreacted curing agent remains as compared to the standard epoxy system. The new bond formation causes a lower thermal expansion coefficient and somewhat lower degradation temperature. The unreacted curing agent causes slightly higher water absorption. Since the episulfide ring has less stress than the epoxy ring the epoxy/episulfide system shows lower heat of reaction, i.e., a lower exotherm. and lower shrinkage. The epoxy/episuffide system, when used with a polyamide curing agent, exhibits better corrosion protection for copper substrates, a lower thermal expansion coefficient and a lower degradation temperature. From model compound studies, the curing reactions are changed by changing curing temperature and the presence of copper: the episulfide homopolymerization and the S--epoxy reactions increase in the case of room temperature curing or in the presence of copper. In the presence of copper, the sulfur of the episulfide also reacts with copper, although the

  15. The influence of tertiary amine accelerators on the curing behaviors of epoxy/anhydride systems

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Tao; Zhang, Chongfeng; Zhang, Junying, E-mail: zjybuct@gmail.com; Cheng, Jue

    2014-02-10

    Highlights: • The influences of two types of accelerators (BDMA and DMP-30) on curing reaction of DGEBF/MeHHPA systems were studied comparatively. • The activation energy and kinetic parameters of DGEBF/MeHHPA systems with accelerator content of 0.2 phr and 0.5 phr were calculated, respectively. • The dependence of autocatalytic and non-autocatalytic curing reaction on the loading of accelerators was discussed. • The non-catalytic curing reaction dominated absolutely in the curing process of DGEBF/MeHHPA systems when the accelerator contents were 0.2 phr. - Abstract: Accelerators have significant effects on the curing behaviors of epoxy/anhydride (diglycidyl ether of bisphenol-F/methylhexahydrophthalic anhydride, DGEBF/MeHHPA) systems. Non-isothermal DSC was used to investigate the influence of dimethyl benzylamine (BDMA, 0.2 phr/0.5 phr) and Tris-(dimethyl aminomethyl) phenol (DMP-30, 0.2 phr/0.5 phr) on the curing behaviors of DGEBF/MeHHPA systems, respectively. When the amount of accelerators was kept constant, the activation energy calculated by Kissinger method changed slightly in the presence of either BDMA or DMP-30. And, with increasing the accelerator content from 0.2 phr to 0.5 phr, the value of activation energy decreased from 115 kJ/mol to 85 kJ/mol. Furthermore, the calculation results of Málek method identified that all systems in this study fitted Sesták–Berggren (SB) model and the corresponding model parameters, m and n, were obtained. It was found that the contribution of autocatalytic reaction with low accelerator content (0.2 phr) was far less than that with high accelerator content (0.5 phr)

  16. Performance Based Evaluation of Concrete Strength under Various Curing Conditions to Investigate Climate Change Effects

    Directory of Open Access Journals (Sweden)

    Tae-Kyun Kim

    2015-07-01

    Full Text Available Recently, the manifestation of global warming-induced climate change has been observed through super typhoons, heavy snowfalls, torrential rains, and extended heat waves. These climate changes have been occurring all over the world and natural disasters have caused severe damage and deterioration of concrete structures and infrastructure. In an effort to deal with these problems due to extreme and abnormal climate changes, studies have been conducted to develop construction technologies and design guidelines. Nevertheless, study results applicable to construction sites continue to be ineffective and insufficient. Therefore, this study proposes ways to cope with climate change by considering the effect of concrete curing condition variations on concrete material performance. More specifically, the 3-, 7- and 28-day compressive and split tensile strength properties of concrete mix cured under various climatic factors including temperature, relative humidity, wind speed, and sunlight exposure time were evaluated to determine whether the concrete meets the current design requirements. Thereafter, a performance based evaluation (PBE was performed using satisfaction probabilities based on the test values to understand the problems associated with the current mix proportion design practice and to identify countermeasures to deal with climate change-induced curing conditions.

  17. Nitrosylation of myoglobin and nitrosation of cysteine by nitrite in a model system simulating meat curing.

    Science.gov (United States)

    Sullivan, Gary A; Sebranek, Joseph G

    2012-02-22

    Demand is growing for meat products cured without the addition of sodium nitrite. Instead of the direct addition of nitrite to meat in formulation, nitrite is supplied by bacterial reduction of natural nitrate often added as vegetable juice/powder. However, the rate of nitrite formation in this process is relatively slow, and the total ingoing nitrite is typically less than in conventional curing processes. The objective of this study was to determine the impact of the rate of addition of nitrite and the amount of nitrite added on nitrosylation/nitrosation reactions in a model meat curing system. Myoglobin was preferentially nitrosylated as no decrease in sulfhydryl groups was found until maximum nitrosylmyoglobin color was achieved. The cysteine-myoglobin model retained more sulfhydryl groups than the cysteine-only model (p 0.05). These data suggest that the amount of nitrite but not the rate of addition impacts the nitrosylation/nitrosation reactions this system.

  18. Comparative evaluation of sealing ability of light cure glass ionomer cement and light cure composite as coronal sealing material: An in vitro study

    Directory of Open Access Journals (Sweden)

    Pragya Jaiswal

    2017-01-01

    Full Text Available Aim: To compare and evaluate the sealing ability of light cure composite and light cure GIC as coronal sealing materials. Materials and Methods: 30 extracted human teeth were divided into three experimental groups of 10 teeth each. The teeth in group I are obturated without coronal seal, teeth in group II are obturated with light cure GIC (3M ESPE VITREMER as coronal seal and teeth in group III are obturated with light cure composite(3M ESPE filtek z250 as coronal seal, after removing 2mm of coronal gutta percha. These teeth (crown portion are then suspended in methylene blue, sealed and kept for 72 hours, to observe the amount of dye penetration. After 72 hours teeth were removed, washed under running water, dried and sectioned longitudinally, separating buccal and lingual halves. The linear extent of dye penetration was measured from cavosurface margin of the access cavity to the most apical extent of dye penetration point. The length from the cavosurface margin to the apex of the tooth was also measured and percentage linear micro leakage was estimated. Statistical Analysis: Data was statistically analyzed using one-way ANOVA followed by Post-Hoc Multiple comparison (Bonferroni. Results: In the present study specimens in group I showed the maximum percentage of linear microleakage of 31.51 percent. The specimens in group II showed the minimal amount of linear micro leakage of 6.49 percent. Conclusion: It can be concluded coronal seal reduces the micro leakage, and light cure GIC has better coronal sealing ability.

  19. Classification of the fragrant styles and evaluation of the aromatic quality of flue-cured tobacco leaves by machine-learning methods.

    Science.gov (United States)

    Gu, Li; Xue, Lichun; Song, Qi; Wang, Fengji; He, Huaqin; Zhang, Zhongyi

    2016-12-01

    During commercial transactions, the quality of flue-cured tobacco leaves must be characterized efficiently, and the evaluation system should be easily transferable across different traders. However, there are over 3000 chemical compounds in flue-cured tobacco leaves; thus, it is impossible to evaluate the quality of flue-cured tobacco leaves using all the chemical compounds. In this paper, we used Support Vector Machine (SVM) algorithm together with 22 chemical compounds selected by ReliefF-Particle Swarm Optimization (R-PSO) to classify the fragrant style of flue-cured tobacco leaves, where the Accuracy (ACC) and Matthews Correlation Coefficient (MCC) were 90.95% and 0.80, respectively. SVM algorithm combined with 19 chemical compounds selected by R-PSO achieved the best assessment performance of the aromatic quality of tobacco leaves, where the PCC and MSE were 0.594 and 0.263, respectively. Finally, we constructed two online tools to classify the fragrant style and evaluate the aromatic quality of flue-cured tobacco leaf samples. These tools can be accessed at http://bioinformatics.fafu.edu.cn/tobacco .

  20. 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.

  1. Acoustic Imaging of Microstructure and Evaluation of the Adhesive's Physical, Mechanical and Chemical Properties Changes at Different Cure States

    Science.gov (United States)

    Severina, I. A.; Fabre, A. J.; Maeva, E. Yu.

    Epoxy thermoset adhesives transform during cure from liquid state into the highly cross-linked solid. Cure state of the material depends on condition of the reaction (temperature, pressure, time etc.) and resin/hardener ratio. It is known that the cure degree of the adhesive correlates with adhesion strength, which is critical for structural adhesives used in automotive, aerospace and marine industries. In this work, characterization of cure process of the adhesive with acoustic methods is presented. Evolution of the acoustic and elastic properties (attenuation, sound velocity, density, elastic moduli) during cure reaction was monitored in relation to the substantial physical and chemical changes of the material. These macro parameters of the adhesive were compared with the material's microstructure obtained by high-resolution acoustic microscopy technique in frequencies range of 50-400 MHz. Development of the microstructure of the adhesive as it cures at different conditions has been investigated. Appearance and development of the granular structure on the adhesive interface during cure reaction has been demonstrated. Acoustic images were analyzed by mathematical method to quantitatively characterize distribution of the adhesive's components. Statistical analysis of such images provides an accurate quantitative measure of the degree of cure of such samples. Research results presented in this paper can be useful as a basis for non-destructive evaluation of the adhesive materials

  2. Evaluation of temperature rise with different curing methods and units in two composite resins

    Directory of Open Access Journals (Sweden)

    Tabatabaei M

    2006-01-01

    Full Text Available Background and Aim: The majority of commercial curing units in dentistry are of halogen lamp type. The new polymerizing units such as blue LED are introduced in recent years. One of the important side effects of light curing is the temperature rise in composite resin polymerization which can affect the vitality of tooth pulp. The purpose of this study was to evaluate the temperature rise in two different composite resins during polymerization with halogen lamps and blue LED. Materials and Methods: This experimental study investigated the temperature rise in two different composites (Hybrid, Tetric Ceram/Nanofilled, Filteke Supreme of A2 shade polymerized with two halogen lamps (Coltolux 50, 350 mW/cm2 and Optilux 501 in standard, 820 mW/cm2 and Ramp, 100-1030 mW/cm2 operating modes and one blue LED with the intensity of 620 mW/cm2. Five samples for each group were prepared and temperature rise was monitored using a k-type thermocouple. Data were analyzed by one-way ANOVA, two-way ANOVA and Tukey HSD tests with P<0.05 as the limit of significance. Results: Light curing units and composite resins had statistically significant influence on the temperature rise (p<0.05. Significantly, lower temperature rise occurred in case of illumination with Coltolux 50.There was no significant difference between Optilux 501 in standard curing mode and LED. Tetric Ceram showed higher temperature rise. Conclusion: According to the results of this study the high power halogen lamp and LED could produce significant heat which may be harmful to the dental pulp.

  3. Single Vacuum Bagging and Autoclave Curing System Influence on Physical and Mechanical Properties of Phenolic Composites

    Directory of Open Access Journals (Sweden)

    M.A. Mirzapour

    2010-12-01

    Full Text Available Industrial production of thermoset composite components involves the application of a vacuum bagging and autoclave pressure to minimize void percentage, usually to less than 5%. Phenolic resin systems generate water as a reaction byproduct via condensation reactions during curing at elevated temperatures. In this paper, vacuum bagging and simple manufactured autoclave curing systems are used for manufacturing of asbestos/phenolic composites and the effects of processing conditions on manufactured composites are investigated. The traditional single-vacuum-bag process is unable to manage the volatiles effectively, resulting in inferior laminates having voids. The autoclave process cure cycle (temperature/pressure profiles for the selected composite system is designed to emit volatiles during curing reactions effectively and produce composites with low void contents and excellent mechanical properties. Laminate consolidation quality is characterized by optical photomicrography for the cross-sections and measurements of void content and mechanical properties. The void content of phenolic composites as opposed to other composites increases as pressure increases up to 3 bar and it is then decreased beyond it. A product of 124% lower void content, 13% higher density, 24% higher flexural strength and 27% higher flexural modulus can be fabricated in composites obtainedby autoclave processing.

  4. In vitro evaluation of microleakage under ceramic and metal brackets bonded with LED and plasma arc curing.

    Science.gov (United States)

    Davari, Abdolrahim; Yassaei, Soghra; Karandish, Mariam; Zarghami, Fateme

    2012-09-01

    The aim of the present study was to evaluate these two high intensity light curing units regarding microleakage beneath metal and ceramic brackets. A total of 60 freshly extracted human premolar teeth were randomly divided into four groups of 15 samples; group I: Metal bracket + LED cured, group II: Ceramic bracket + LED cured, group III: Metal bracket + plasma arc cured, group IV: Ceramic bracket + plasma arc cured. After photopolymerization, the teeth were immersed in water and thermocycled (500 cycles between 5 and 55). Specimens were further sealed with nail varnish and stained with 5% basic fuchsin for 24 hours. All of the teeth were sectioned with two parallel longitudinal occlusogingival cuts and examined under a stereomicroscope. The microleakage was measured with a digital caliper and scored from 0 to 3 for marginal microleakage at the bracket-adhesive and adhesive-enamel interfaces from both the occlusal and gingival margins. Microleakage was detected in all groups. The plasma arc cured group showed less microleakage than light emitting diode (LED) cured in all samples at the enamel-adhesive interface at the gingival margin (ceramic brackets, p = 0.009 and metal brackets, p = 0.005). The plasma arc cured samples showed less microleakage than LED cured in metal brackets at the adhesive-brackets interface at the occlusal margin (p = 0.033). While curing with an LED unit, ceramic brackets displayed significantly less microleakage than metal ones at the gingival margin of adhesive-enamel interface (p = 0.013). The gingival margin in all groups exhibited higher microleakage compared with those observed in occlusal sides in all sample groups (p plasma arc units. 2. In all groups the microleakage at the gingival margin is greater than the occlusal margin. The microleakage formation permits the passage of bacteria and oral fluids initiating white spot lesions beneath the bracket base.

  5. Evaluation of Portland Cement Concrete with Internal Curing Capabilities : Research Project Capsule

    Science.gov (United States)

    2012-09-01

    Proper curing is the key to durable and sustainable concrete structures. When a concrete mixture : is designed, delivered, poured, and consolidated, curing is the last and the most critical part for : a fi nal product of great quality. Insuffi cient ...

  6. Diagnosing and curing system freeze-ups: Part II

    Energy Technology Data Exchange (ETDEWEB)

    Frey, R. [Heating and Plumbing Service, Sparta, NJ (United States)

    1996-02-01

    In our last article, we discussed determination and possible causes leading to frozen pipes in the heating system. We now turn to the matter of dealing with such freeze-ups. There are two major categories of frozen heating systems. The first and worst we can label the {open_quotes}Floridian Flew{close_quotes} type, when the usual occupants have taken off for warmer climates. The second is the {open_quotes}Howcudit {open_quote}B{close_quote} virus,{close_quotes} which occurs to normal people under an unusual Arctic Attack right while they are living there. Regarding the first, I never cease to be amazed how folks can just up and leave their house for three days to three months without making proper arrangements for monitoring the temperature of their home during their absence. There are a frightening number of humanoids out there, who either lack a minimal presence of common sense, or who are terrible gamblers. The amazing thing is that some of these folks wouldn`t even gamble a postage stamp on a magazine sweepstakes, but still will gamble the contents of their home by driving off for two weeks at Disneyland in the middle of January without ever making any provision for assuring that their house doesn`t freeze up while they are away. The {open_quotes}Howcudit {open_quote}B{close_quote}{close_quotes} type is not nearly as devasting as the {open_quotes}Floridian Flew.{close_quotes} Imagine coming home to an icy cold house after flying in from the sunny beaches of some tropical paradise. The oilburner switch is on. The thermostate is set at 60 where we left it, but the needle is buried somewhere down behind the cover, like it is cowering from guilt. {open_quotes}Oh Man! I just checked the bathroom; there is an icicle hanging from the vanity faucet and the toilet bowl is a block of ice.{close_quotes}

  7. Evaluation of the thermal resistance of different Salmonella serotypes in pork meat containing curing additives.

    Science.gov (United States)

    Quintavalla, S; Larini, S; Mutti, P; Barbuti, S

    2001-07-20

    The preliminary heat resistance evaluation of 94 Salmonella strains was carried out in culture medium (Trypticase soy broth, TSB). The heat resistance of three S. typhimurium strains (ATCC 14028, 133 and 1116), a strain each of S. derby B4373, S. potsdam 1133, S. menston 179. S. eppendorf 166, and S. kingston I124 was determined also in pork meat containing curing additives. As expected, the eight Salmonella strains showed greater heat resistance in pork meat than in TSB. At the lowest temperature (58 degrees C), the heat resistance increased 1.5-4 times, and it was most pronounced for the strains being most heat sensitive in TSB. S. potsdam 133 was the most resistant strain in pork meat, with D-values at 58 degrees C, 60 degrees C and 63 degrees C of 4.80, 1.57 and 0.30 min, respectively. The most sensitive strain turned out to be S. kingston 1124, with D-values of 2.79. 0.92 and 0.24 min, at the same temperatures. According to collected data, the heating processes, as applied to cured pork meat, providing an internal temperature of 60 degrees C for 9-10 min or of 63 degrees C for 3-4 min can be expected to provide a > or = 7 D kill of Salmonella belonging to the serotypes studied.

  8. Evaluation of changes in the taste of cooked meat products during curing using an artificial taste sensor.

    Science.gov (United States)

    Nodake, Kazumasa; Numata, Masahiro; Kosai, Kiichi; Kim, Yun-Jung; Nishiumi, Tadayuki

    2013-08-01

    The purpose of this study was to assess an evaluation method using an artificial taste sensor, in comparison with chemical analysis and sensory evaluation of the taste of meat during curing. Samples of Canadian pork were treated with salt, nitrite and phosphate. Curing time ranged from 0 to 168 h. In the sensory evaluation, there were no significant differences in the all characteristic items at 72-h cured sample compared to the 0-h sample. Some of the characteristic items for the 168-h sample (umami, overall taste, richness and overall palatability) showed significant difference (P curing time (R = 0.98 and 0.97, respectively), and total free amino acids (R = 0.91 and 0.96, respectively). The sensor output of bitterness was significantly correlated (R = 0.96) with the sum of amino acids corresponding to bitter taste. The increase in the chemical components contributing to bitterness and/or saltiness was indicated as the cause of the characteristic taste. Taste sensor analysis may be applicable as a qualitative method for evaluating taste characteristics generated during the curing of manufactured cooked meat products. © 2013 Japanese Society of Animal Science.

  9. Acrylic-phosphate glasses composites as self-curing controlled delivery systems of antibiotics.

    Science.gov (United States)

    Fernández, M; Méndez, J A; Vázquez, B; San Román, J; Ginebra, M P; Gil, F J; Manero, J M; Planell, J A

    2002-12-01

    New antibiotic delivery systems based on self-hardening methyl methacrylate (MMA)/polymethyl methacrylate (PMMA) systems and phosphate glasses (PG) in the system P(2)O(5)-CaO-Na(2)O have been developed. Self-curing formulations were prepared by mixing the solid component containing PMMA beads, different proportions of PG (30-70 wt %) and vancomycin (5 wt %) as antibiotic, with the liquid component made of MMA monomer. Dough and setting times increased with the content of PG but peak temperature decreased to values well below to guarantee the chemical stability of the antibiotic drug, gentamicin or vancomycin. Mechanical properties of the PMMA/PG composites were evaluated in compression test giving rise to values of compressive strength in the range of 100 MPa. The release of vancomycin was analyzed in vitro by immersion of samples in phosphate buffer of pH=7.4. Release profiles were influenced by the content of PG present in the cement. An initial burst of drug release was observed in all cases. The composites with 70 wt % PG released nearly the total amount of drug loaded in a period of 45 days, and those containing 60 wt % PG released the 70% of the vancomycin in the same period of time. However, either the control of the composite with 30 wt % PG released only the 30% of the drug in 10-15 days. The surface of the drug-loaded composites before and after release experiments was analyzed by ESEM. The deposition of some aggregates at certain points of the surface was detected for the specimens immersed in buffer phosphate after 45 days. This material was characterized by FTIR and Raman spectroscopy as an amorphous phosphate formed by calcium ortho and pyrophosphates, and indicates an interaction between the hydrated layer at the place of the glass and the surrounding medium.

  10. 24 hours and 3-months bond strength between dual-cured resin cements and simplified adhesive systems.

    Science.gov (United States)

    Aguiar, Thaiane R; Cavalcanti, Andrea N; Fontes, Céres M; Marchi, Giselle M; Muniz, Leonardo; Mathias, Paula

    2009-01-01

    This study evaluated the bonding compatibility between dual-cured resin cements and simplified adhesive systems (one-step self-etch and two-step etch & rinse), measured after 24 hours and 3 months. The occlusal dentin surfaces of 24 human third molars were exposed and flattened. Teeth were randomly assigned to 3 groups and treated with different combinations of adhesive system and resin cement [G1-Single Bond/Rely X ARC (SB/RX); G2-Excite DSC/Variolink II (EX/VR); G3-Adper Prompt/Rely X ARC (AD/RX)]. Indirect composite restorations were cemented on flattened surfaces, and sectioned to obtain multiple bonded beams for the microtensile bond strength test. The beams from each tooth were tested under tension after 24 hours and 3 months (ANOVA/ Tukey's test, alpha=5%). Failure patterns were evaluated with scanning electron microscopy. After 24h, AD/RX presented the lowest bond strength mean values. AD/RX specimens did not withstand three months storage. SB/RX and EX/VR presented similar bond strengths in both periods tested. The association AD/RX resulted in low bond strength mean values, especially after storage. Cementing indirect restorations using one-step self-etch adhesive systems and dual-cured resin cements would be clinically unreliable.

  11. Evaluation of cathepsin B levels in fresh thighs selected for cured raw ham production.

    Science.gov (United States)

    Conti, V; Ramoni, R; Parolari, G; Virgili, R; Grolli, S; Accornero, P; Fermi, P; Biffi, R; Bignetti, E

    1997-08-01

    Excessive meat tenderization in cured raw Parma ham has recently been correlated with abnormal levels of cathepsin B in freshly slaughtered thigh meat. We have developed a visual assay employing the substrate Z-Arg-Arg-NNapOMe for the quantitative detection of active cathepsin B levels in pork thigh muscle homogenates. The work was based on a kinetic characterization, in steady state condition, of pig muscle cathepsin B with several peptidyl chromophoric substrate analogs. This assay can easily and safely be performed by non-specialized personnel directly in the slaughterhouse or in the factory, for an early quality evaluation of thighs selected for Parma ham production. Our characterization has further indicated that the catalytic properties of porcine muscle cathepsin B and those of isoforms from other animal and plant species are practically identical. This is particularly evident in the commercially available bovine spleen isoform, which was employed as a model enzyme in most of the experiments.

  12. Effect of curing time on the bond strength of a bracket-bonding system cured with a light-emitting diode or plasma arc light.

    Science.gov (United States)

    Dall'Igna, Carine Maccarini; Marchioro, Ernani Menezes; Spohr, Ana Maria; Mota, Eduardo Gonçalves

    2011-02-01

    The purpose of this study was to assess the influence of two light units, a light-emitting diode (LED) and a plasma arc light (PAC), on the shear bond strength (SBS) of brackets bonded to enamel. Ninety bovine teeth were divided into six groups, according to the light-curing unit and exposure times used. In the LED (Ortholux; 3M-Unitek) group, the specimens were light cured for 5, 10, and 15 seconds. In the PAC (Apollo 95E; DenMed Technologies) group, the specimens were light cured for 3, 6, and 9 seconds. The brackets were bonded with Transbond XT (3M-Unitek), stored in distilled water at 37 °C for 24 hours and then submitted to SBS testing in a universal testing machine. The adhesive remnant index (ARI) was used to evaluate the amount of adhesive remaining on the teeth. According to analysis of variance and Tukey multiple comparisons test, the highest mean SBS was obtained with the LED at 15 seconds (16.68 MPa), which did not significantly differ from the LED 10 (14.76 MPa) or 5 (13.92 MPa) second groups (P > 0.05). The LED 10 and 5 second groups were not significantly different from the PAC 9 second group (12.66 MPa) or from the PAC 6 second group (9.96 MPa). The lowest mean SBS was obtained with the PAC 3 second group (8.29 MPa), which did not differ significantly from the PAC 6 second group. The method of light curing did not influence the ARI, with score 3 predominant. The LED at 5 seconds and the PAC at 3 seconds provided sufficient mean SBS to resist either orthodontic or masticatory forces.

  13. The cure: design and evaluation of a crowdsourcing game for gene selection for breast cancer survival prediction.

    Science.gov (United States)

    Good, Benjamin M; Loguercio, Salvatore; Griffith, Obi L; Nanis, Max; Wu, Chunlei; Su, Andrew I

    2014-07-29

    Molecular signatures for predicting breast cancer prognosis could greatly improve care through personalization of treatment. Computational analyses of genome-wide expression datasets have identified such signatures, but these signatures leave much to be desired in terms of accuracy, reproducibility, and biological interpretability. Methods that take advantage of structured prior knowledge (eg, protein interaction networks) show promise in helping to define better signatures, but most knowledge remains unstructured. Crowdsourcing via scientific discovery games is an emerging methodology that has the potential to tap into human intelligence at scales and in modes unheard of before. The main objective of this study was to test the hypothesis that knowledge linking expression patterns of specific genes to breast cancer outcomes could be captured from players of an open, Web-based game. We envisioned capturing knowledge both from the player's prior experience and from their ability to interpret text related to candidate genes presented to them in the context of the game. We developed and evaluated an online game called The Cure that captured information from players regarding genes for use as predictors of breast cancer survival. Information gathered from game play was aggregated using a voting approach, and used to create rankings of genes. The top genes from these rankings were evaluated using annotation enrichment analysis, comparison to prior predictor gene sets, and by using them to train and test machine learning systems for predicting 10 year survival. Between its launch in September 2012 and September 2013, The Cure attracted more than 1000 registered players, who collectively played nearly 10,000 games. Gene sets assembled through aggregation of the collected data showed significant enrichment for genes known to be related to key concepts such as cancer, disease progression, and recurrence. In terms of the predictive accuracy of models trained using this

  14. An Evaluation of Fracture Toughness of Vinyl Ester Composites Cured under Microwave Conditions

    Science.gov (United States)

    Ku, H.; Chan, W. L.; Trada, M.; Baddeley, D.

    2007-12-01

    The shrinkage of vinyl ester particulate composites has been reduced by curing the resins under microwave conditions. The reduction in the shrinkage of the resins by microwaves will enable the manufacture of large vinyl ester composite items possible (H.S. Ku, G. Van Erp, J.A.R. Ball, and S. Ayers, Shrinkage Reduction of Thermoset Fibre Composites during Hardening using Microwaves Irradiation for Curing, Proceedings, Second World Engineering Congress, Kuching, Malaysia, 2002a, 22-25 July, p 177-182; H.S. Ku, Risks Involved in Curing Vinyl Ester Resins Using Microwaves Irradiation. J. Mater. Synth. Proces. 2002b, 10(2), p 97-106; S.H. Ku, Curing Vinyl Ester Particle Reinforced Composites Using Microwaves. J. Comp. Mater., (2003a), 37(22), p 2027-2042; S.H. Ku and E. Siores, Shrinkage Reduction of Thermoset Matrix Particle Reinforced Composites During Hardening Using Microwaves Irradiation, Trans. Hong Kong Inst. Eng., 2004, 11(3), p 29-34). In tensile tests, the yield strengths of samples cured under microwave conditions obtained are within 5% of those obtained by ambient curing; it is also found that with 180 W microwave power, the tensile strengths obtained for all duration of exposure to microwaves are also within the 5% of those obtained by ambient curing. While, with 360 W microwave power, the tensile strengths obtained for all duration of exposure to microwaves are 5% higher than those obtained by ambient curing. Whereas, with 540 W microwave power, the tensile strengths obtained for most samples are 5% below those obtained by ambient curing (H. Ku, V.C. Puttgunta, and M. Trada, Young’s Modulus of Vinyl Ester Composites Cured by Microwave Irradiation: Preliminary Results, J. Electromagnet. Waves Appl., 2007, 20(14), p. 1911-1924). This project, using 33% by weight fly ash reinforced vinyl ester composite [VE/FLYSH (33%)], is to further investigate the difference in fracture toughness between microwave cured vinyl ester particulate composites and those cured

  15. Evaluation of Environmental Conditions on the Curing Of Commercial Fixative and Intumescent Coatings

    Energy Technology Data Exchange (ETDEWEB)

    Nicholson, J. C. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2017-01-10

    Performance metrics for evaluating commercial fixatives are often not readily available for important parameters that must be considered per the facility safety basis and the facility Basis for Interim Operations (BIO). One such parameter is the behavior of such materials in varied, “non-ideal” conditions where ideal is defined as 75 °F, 40% RH. Coupled with the inherent flammable nature of the fixative materials that can act to propagate flame along surfaces that are otherwise fireproof (concrete, sheet metal), much is left unknown when considering the safety basis implications for introducing these materials into nuclear facilities. Through SRNL’s efforts, three (3) fixatives, one (1) decontamination gel, and six (6) intumescent coatings were examined for their responses to environmental conditions to determine whether these materials were impervious to non-nominal temperatures and humidities that may be found in nuclear facilities. Characteristics that were examined included set-to-touch time, dust free time, and adhesion testing of the fully cured compounds. Of these ten materials, three were two-part epoxy materials while the other seven consisted of only one constituent. The results show that the epoxies tested are unable to cure in sub-freezing temperatures, with the low temperatures inhibiting crosslinking to a very significant degree. These efforts show significant inhibiting of performance for non-nominal environmental conditions, something that must be addressed both in the decision process for a fixative material to apply and per the safety basis to ensure the accurate flammability and material at risk is calculated.

  16. Evaluation of Environmental Conditions on the Curing Of Commercial Fixative and Intumescent Coatings

    Energy Technology Data Exchange (ETDEWEB)

    Nicholson, J. C. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2016-09-26

    Performance metrics for evaluating commercial fixatives are often not readily available for important parameters that must be considered per the facility safety basis and the facility Basis for Interim Operations (BIO). One such parameter is the behavior of such materials in varied, “non-ideal” conditions where ideal is defined as 75 °F, 40% RH. Coupled with the inherent flammable nature of the fixative materials that can act to propagate flame along surfaces that are otherwise fireproof (concrete, sheet metal), much is left unknown when considering the safety basis implications for introducing these materials into nuclear facilities. Through SRNL’s efforts, three (3) fixatives, one (1) decontamination gel, and six (6) intumescent coatings were examined for their responses to environmental conditions to determine whether these materials were impervious to non-nominal temperatures and humidities that may be found in nuclear facilities. Characteristics that were examined included set-to-touch time, dust free time, and adhesion testing of the fully cured compounds. Of these ten materials, three were two-part epoxy materials while the other seven consisted of only one constituent. The results show that the epoxies tested are unable to cure in sub-freezing temperatures, with the low temperatures inhibiting crosslinking to a very significant degree. These efforts show significant inhibiting of performance for non-nominal environmental conditions, something that must be addressed both in the decision process for a fixative material to apply and per the safety basis to ensure the accurate flammability and material at risk is calculated.

  17. Evaluation of light-curing units in rural and urban areas

    Science.gov (United States)

    AlShaafi, Maan M.

    2012-01-01

    Objectives To evaluate the distribution of light-curing units (LCU) used in an urban area (Riyadh) and a rural area (Kharj) of Saudi Arabia, and to compare their irradiance values. Methods The study involved three dental centers in urban areas and two in rural areas, all of which were parts of a single healthcare institution providing dental services. The light outputs (power mW) from 140 LCUs were measured by laboratory-grade spectrometry, and the irradiance (mW/cm2) was calculated from the tip area of each LCU. The minimum acceptable irradiance outputs for the quartz-tungsten-halogen (QTH) and light-emitting diode (LED) units were set at 300 and 600 mW/cm2, respectively. The ages of these units and the protocol used to light-cure the resins were also determined. Results The total number of LCUs was 140, 112 (78%) in urban areas, and 28 (22%) in rural areas. In rural areas, only 7 of the 22 (32%) QTH units delivered irradiances greater than 300 mW/cm2 and were therefore considered clinically acceptable, whereas 4 of the 6 (66.7%) LED units delivered values greater than 600 mW/cm2. In urban centers, 43 of 61 (70.5%) LED units and 25 of 61 (49%) QTH units were considered clinically acceptable. Irradiance values for both QTH (P < 0.01) and LED (P < 0.05) units were significantly better in urban than in rural areas. Conclusions Urban areas had a greater distribution of LCUs than rural areas. Overall, irradiance values were significantly higher in urban areas. PMID:23960546

  18. Evaluation of shear bond strength of orthodontic brackets using trans-illumination technique with different curing profiles of LED light-curing unit in posterior teeth

    OpenAIRE

    Heravi, Farzin; Moazzami, Saied Mostafa; Ghaffari, Negin; Jalayer, Javad; Bozorgnia, Yasaman

    2013-01-01

    Background Although using light-cured composites for bonding orthodontic brackets has become increasingly popular, curing light cannot penetrate the metallic bulk of brackets and polymerization of composites is limited to the edges. Limited access and poor direct sight may be a problem in the posterior teeth. Meanwhile, effectiveness of the trans-illumination technique is questionable due to increased bucco-lingual thickness of the posterior teeth. Light-emitting diode (LED) light-curing unit...

  19. Comparative evaluation of sorption, solubility and microhardness of heat cure polymethylmethacrylate denture base resin & flexible denture base resin.

    Science.gov (United States)

    Shah, Jay; Bulbule, Nilesh; Kulkarni, Shilpa; Shah, Riddhi; Kakade, Dilip

    2014-08-01

    The aim of the study was to evaluate and compare sorption, solubility and microhardness of heat cure polymethylmethacrylate (PMMA) denture base resin and flexible (thermoplastic polyamide nylon) denture base resin. Sorption, solubility and microhardness were assessed to determine compliance with ADA Specification no. 12. RESULTs were assessed using statistical and observational analyses. All materials satisfied ADA requirements for sorption, solubility and microhardness. Heat cure PMMA showed more sorption, solubility and microhardness than flexible (thermoplastic polyamide nylon). Flexible (thermoplastic polyamide nylon) resin absorbs less water, is less soluble and is more flexible than PMMA.

  20. Comparative bonding ability to dentin of a universal adhesive system and monomer conversion as functions of extended light curing times and storage.

    Science.gov (United States)

    Sampaio, Paula Costa Pinheiro; Kruly, Paula de Castro; Ribeiro, Clara Cabral; Hilgert, Leandro Augusto; Pereira, Patrícia Nóbrega Rodrigues; Scaffa, Polliana Mendes Candia; Di Hipólito, Vinicius; D'Alpino, Paulo Henrique Perlatti; Garcia, Fernanda Cristina Pimentel

    2017-11-01

    The purpose of this in vitro study was to evaluate the bonding ability and monomer conversion of a universal adhesive system applied to dentin as functions of different curing times and storage. The results were compared among a variety of commercial adhesives. Flat superficial dentin surfaces were exposed on human molars and assigned into one of the following adhesives (n = 15): total-etch Adper Single Bond 2 (SB) and Optibond Solo Plus (OS), self-etch Optibond All in One (OA) and Clearfil SE Bond (CSE), and Scotchbond Universal Adhesive in self-etch mode (SU). The adhesives were applied following the manufacturers' instructions and cured for 10, 20, or 40s. Specimens were processed for the microtensile bond strength (µTBS) test in accordance with the non-trimming technique and tested after 24h and 2 years. The fractured specimens were classified under scanning electron microscopy (SEM). Infrared (IR) spectra were obtained and monomer conversion (%) was calculated by comparing the aliphatic-to-aromatic IR absorption peak ratio before and after polymerization (n=5). Data were analyzed by 2-way ANOVA/Tukey's tests (α = 0.05). At 24-h evaluation, OA and CSE presented similar bond strength means irrespective of the curing time, whereas SB and SU exhibited significantly higher means when cured for 40s as did OS when cured for 20 or 40s (p adhesives tested exhibited significantly lower monomer conversion when photoactivated according to the manufacturers' instructions (10s). Higher monomer conversions obtained with longer light exposure allow only higher immediate bond strength for most of the adhesives tested. After 2-year storage, only the self-etching adhesive Optibond All-In-One exhibited the same bonding ability when cured for longer periods of time. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. Evaluation of thermal conductivity of heat-cured acrylic resin mixed with A1203

    Directory of Open Access Journals (Sweden)

    Ebadian B.

    2002-08-01

    Full Text Available One of the most important characteristics of denture base is thermal conductivity. This property has a major role in secretions of salivary glands and their enzymes, taste of the food and gustatory response. Polymethyl methacrylate used in prosthodontics is relatively an insulator. Different materials such as metal fillers and ceramics have been used to solve this problem. The aim of this study was the evaluation of AI2O3 effect on thermal conductivity of heat-cured acrylic resin. Acrylic resin was mixed with AI2O3 in two different weight rates (15 and 20 % of weight. So, group 1 and 2 were divided on this basis. Samples with pure acrylic resin were considered as control group. 18 cylindrical patterns were made in 9x9 mm dimensions and thermocouple wires embedded in each sample to act as conductor. The specimens were put in water with 70±1°C thermal range for 10 minutes. Then, thermal conductivity was measured. The results were analyzed with variance analysis and Dunken test. There was significant difference between thermal conductivity of all groups in all period times. It the first seconds, thermal conductivity in groups 1 and 2 were more than control group. Therefore, for developing of thermal conductivity of acrylic resin, A1203 can be used. Certainly, other characteristic of new resin should be evaluated.

  2. Toxoplasma gondii in raw and dry-cured ham: The influence of the curing process.

    Science.gov (United States)

    Herrero, Laura; Gracia, María Jesús; Pérez-Arquillué, Consuelo; Lázaro, Regina; Herrera, Antonio; Bayarri, Susana

    2017-08-01

    The aim of this work was to analyze Toxoplasma gondii in raw hams by mouse bioassay and to evaluate the effect of curing on the viability of the parasite to assess the risk of infection from eating dry-cured ham. After a serology study of 1200 pigs in Aragón (Spain), forty-one naturally infected pigs with different serological titers against T. gondii were selected. Two cured periods (9 and 12 months) were evaluated as well as the influence of the physicochemical composition of hams on T. gondii survival. Although the parasite burden was low, a high number of seropositive pigs with Toxoplasma tissues cysts in raw hams were found (31.6%). Viability of T. gondii was influenced by the curing, with statistically significant differences between fresh and cured hams (p < 0.001). The viability was higher in hams cured for 9 months compared to those cured for 12 months. However, this period of curing resulted in the reduction but not in a complete elimination of the risk. Thus, from a public health point of view, under the conditions of this study it is safer to consume dry-cured ham with periods of curing higher than 12 months. Analysis of physicochemical results did not identify any variable with significant influence on the presence and viability of T. gondii in cured ham, but loss of viability of T. gondii was observed in hams with a lower fat content. Further research is required to validate combinations of salts concentration and time of curing that can be used as preventive measures in the HACCP system of dry-cured ham industry. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Comparative Evaluation of Shear Bond Strength and Debonding Characteristics using Conventional Halogen Light Curing Unit and LED Light Curing Unit: An in vitro Study

    Directory of Open Access Journals (Sweden)

    Amit Bhardwaj

    2013-01-01

    Conclusion: The result of this study showed promise for the orthodontic application of LED as light curing units and 20 seconds of exposure time is adequate for both LED and Halogen light, since increasing the curing time to 40 seconds showed no significant difference.

  4. Evaluation of the mechanical properties of acetic-cure silicone with the addition of magnesium silicate

    Directory of Open Access Journals (Sweden)

    Ronald Vargas Orellana

    2015-06-01

    Full Text Available Current study evaluates the mechanical properties (tensile and tear strength of an acetic-cure silicone with the addition of 10 or 20% vol. magnesium silicate. Magnesium silicate was added to the silicone at concentrations of 10 (MS-10 and 20% (MS-20 volume, followed by the analysis of tensile strength, maximal elongation during tensile and tear strength. Results were compared to control group of silicone without additives (CG. Mean rates were determined and compared by analysis of variance and Tukey’s test (p < 0.05. Control group had the greatest elongation when subjected to tensile strength (650%, whereas the MS-10 group statistically showed a better tensile strength (8.8 MPa when compared to CG (7.5 MPa and MS-20 (7.5 MPa groups. Both magnesium silicate groups exhibited statistically similar tear strength, whereas MS-20 group demonstrated statistically greater tear strength. The addition of 10% magnesium silicate increased tensile strength, but tear strength and elongation were similar to control. The addition of 20% magnesium silicate did not affect tensile but increased tear strength.

  5. Evaluation of the flexural strength of dual-cure composite resin cements.

    Science.gov (United States)

    Duymus, Zeynep Yesil; Yanikoğlu, Nuran Dinckal; Alkurt, Murat

    2013-07-01

    The aim of this study was to evaluate of flexural strength of some adhesive resin cements. Three dual-cure composite resin cements (Nexus 3; Variolink II, Panavia F) were prepared. The manufacturer's mixing directions for the cements were followed. Adhesive resin cement was mixed, placed in the rectangular portion of the mold. Fifteen specimens were prepared for each cements. The cements were light-activated with light lamp for 40 s on both and top and bottom surfaces. The each cement specimens were divided into three groups according to time of storage and stored in distilled water for 24 h, 15, and 30 days. Total 45 specimens were stored at 37°C (98.6 0F) in distilled water for 24 h, 15, and 30 days prior to tests. The flexural strength was tested wıth a universal testing machine at a crosshead speed of 0.5 mm/min (0.02 in.) The maximum load was recorded as MPa. The results were analyzed by Analysis of Variance and Duncan test. The Panavia F resin cements content Bisphenol A was showed the highest flexural strength (80.80 MPa) (11.71 ksi) for 24 h. The lowest flexural strength was observed in Nexus 3 (51.00 MPa) (7.39 ksi). It was found significant interaction of material and time (p cement and time of storage was statistically significant on the flexural strengths (p < 0.001). Copyright © 2013 Wiley Periodicals, Inc.

  6. Evaluation of rat alveolar bone response to Angelus MTA or experimental light-cured mineral trioxide aggregate using fluorochromes.

    Science.gov (United States)

    Gomes-Filho, João Eduardo; de Moraes Costa, Mariana Machado Teixeira; Cintra, Luciano Tavares Angelo; Duarte, Paulo Carvalho Tobias; Takamiya, Aline Satie; Lodi, Carolina Simonetti; Bernabé, Pedro Felício Estrada

    2011-02-01

    The aim of this study was to evaluate the rat alveolar bone response after the implantation of experimental light-cured mineral trioxide aggregate (MTA) or Angelus MTA (Angelus, Londrina, Paraná, Brazil) by histological and fluorescence analysis. Thirty Wistar Albino rats were divided into three groups. In the control group, empty polyethylene tubes were inserted into the rat alveolar sockets immediately after extraction. In the other groups, the tubes were filled with light-cured MTA or Angelus MTA. Five animals from each group were injected with calcein on day 7, alizarin on day 14, and oxytetracycline on day 21. On day 30, these animals were killed, and the right hemimaxillas were removed and histologically processed. Half of the maxillas were processed and stained with hematoxylin and eosin. The remaining maxillas were processed for fluorescence analysis and stained with Stevenel blue and alizarin red. New bone was histomorphometrically evaluated using a Merz grid. The light-cured MTA presented a similar response when compared with Angelus MTA; it was characterized by a mild inflammatory response and complete bone healing. In the light-cured MTA group, the fluorescence areas were more evident at 21 days, showing an increase in bone formation. However, dystrophic mineralization was observed only with Angelus MTA. It was concluded that both materials present a similar inflammatory response and bone healing, but dystrophic mineralization was observed only with Angelus MTA. Copyright © 2011 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  7. Optimization of water curing for the preservation of chestnuts (Castanea sativa Mill.) and evaluation of microbial dynamics during process.

    Science.gov (United States)

    Blaiotta, Giuseppe; Di Capua, Marika; Romano, Annalisa; Coppola, Raffaele; Aponte, Maria

    2014-09-01

    Chestnuts are very perishable fruits, whose quality may be compromised during postharvest handling. Damage can be caused both by insects and fungi. Water curing, a commonly used postharvest method, is based on soaking fruits in water typically for about one week. Factors that affect effectiveness of water curing have only been explained partially. A decrease in pH, likely imputable to a light fermentation caused by lactic acid bacteria, may inhibit the growth of moulds. In this study a Lactobacillus pentosus strain was selected for its ability to inhibit fungi, and used as a starter culture during water curing. As second goal, a reduction of the environmental impact of the process was evaluated by using water that had been re-cycled from a previous curing treatment. Experiments were performed on pilot as well as on farm scale. In all trials, microbial dynamics were evaluated by means of a polyphasic approach including conventional and molecular-based analyses. According to results, the employment of an adjunct culture appears as a very promising opportunity. Even if no reduction in the duration of the process was achieved, waters exhibited a minor microbial complexity and fruits did not lose the natural lustre after the process. Copyright © 2014 Elsevier Ltd. All rights reserved.

  8. 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.

  9. Evaluation of the cohesive strength between resin composite and light-curing characterizing materials.

    Science.gov (United States)

    Pucci, César Rogério; Barcellos, Daphne Câmara; Palazon, Milena Traversa; Borges, Alessandra Bühler; da Silva, Melissa Aline; de Paiva Gonçalves, Sergio Eduardo

    2012-02-01

    To evaluate the cohesive strength between composite and different light-curing characterizing materials (LCCM), which were prepared using the intrinsic technique. One hundred composite specimens were made by using a prefabricated Teflon device, and a layer of LCCM was applied at the interface. The specimens were divided into 5 groups (n = 20): group 1 (control), no LCCM was used; group 2: application of White Kolor Plus Pigment (Kerr) LCCM; group 3: White Tetric Color Pigment (Ivoclar/Vivadent) LCCM; group 4: Brown Kolor Plus Pigment (Kerr) LCCM; group 5: Black Tetric Color Pigment (Ivoclar/Vivadent) LCCM. All materials were used according to the manufacturers' instructions. Specimens were submitted to a tensile test in a universal testing machine (EMIC DL-200MF) to evaluate the cohesive strength at the composite interface. Data were subjected to one-way ANOVA and Tukey's test (α = 5%). ANOVA showed a p-value = 0.0001, indicating that there were significant differences among the groups. The mean values in MPa (± standard deviation) obtained for the groups were: G1: 28.5 (± 2.74)a; G2: 23.5 (± 2.47)b; G3: 20.3 (± 2.49)b; G4: 10.5 (± 2.40)c; G5: 9.66 (± 3.06)c. The groups with the same letters presented no significant differences. The control group presented statistically significantly higher cohesive strengths when compared to the other groups. The groups in which Brown Kolor Plus Pigment and Black Tetric Color Pigment LCCM were used showed significantly lower cohesive strengths when compared to the groups in which White Kolor Plus Pigment and White Tetric Color Pigment LCMM were used. The use of LCCM produced with the intrinsic technique reduced the cohesive strength of composite.

  10. Water and Oil Repellent Finishing of Textiles by UV Curing: Evaluation of the Influence of Scaled-Up Process Parameters

    Directory of Open Access Journals (Sweden)

    Franco Ferrero

    2017-04-01

    Full Text Available In this work, various textile fabrics were coated with silicone and fluorocarbon-based resins by photo-curing using ultraviolet irradiation. A great number of large fabric samples were impregnated by padding with commercial finishing agents and then irradiated in air with a high power, semi-industrial UV source. The add-on of various finishing agents was kept low to reduce the treatment cost. White and dyed samples of different textile composition were treated and evaluated in terms of conferred repellency, yellowing, or color changes. Most relevant process parameters were investigated, utilizing the thermal process normally adopted at industrial level as reference. The results were statistically evaluated by ANOVA using Minitab 16 software, in order to identify the most influential parameters and to evaluate the real possibility of replacing the thermal treatment with UV curing.

  11. The effects of lactate on nitrosylmyoglobin formation from nitrite and metmyoglobin in a cured meat system.

    Science.gov (United States)

    McClure, Brooke N; Sebranek, Joseph G; Kim, Yuan H; Sullivan, Gary A

    2011-12-01

    Two experiments were conducted to determine the effects of lactate on nitrite during meat curing. In the first experiment, using a model system, eight reaction components including nitrite and lactate, were used to assess the effect of each component on metmyoglobin reducing activity by excluding one component at a time. Excluding lactate, nicotinamide adenine dinucleotide (NAD), l-lactate dehydrogenase (LDH) or phenazine methosulfate (PMS) resulted in no reducing activity. A second experiment, utilising a meat mixture, investigated the effects of lactate (0%, 2%, 4% or 6%), nitrite (0 or 156ppm), and packaging (oxygen-permeable or vacuum) on residual nitrite, meat colour and pH. Addition of lactate reduced residual nitrite in the meat mixtures. Both experiments support the hypothesis that lactate generates NADH which then reduces metmyoglobin to deoxymyoglobin. The resulting greater concentration of reduced myoglobin subsequently reacted with nitrite to produce more nitric oxide, reducing nitrite concentration and accelerating curing reactions. Copyright © 2011 Elsevier Ltd. All rights reserved.

  12. Evaluation and comparison of anti-Candida effect of heat cure polymethylmethacrylate resin enforced with silver nanoparticles and conventional heat cure resins: An in vitro study

    Directory of Open Access Journals (Sweden)

    S Suganya

    2014-01-01

    Full Text Available Recent years have been dominated by research in nano science. Dentistry is no exception and there is increased research on nanoparticles in dentistry. Complete dentures increase the carriage of Candida in healthy patients, and the proliferation of C. albicans can be associated with denture-induced stomatitis. Purpose: To evaluate the anti-Candida effect of heat cure denture base resins reinforced with Ag° in the ratio of 4:1, 3:1, 2:1 (Groups B, C, and D, respectively to the weight of denture base resins. Materials and Methods: Ag° were synthesized by chemical reduction method, incorporated into the polymer powder according to the ratio for each group, subjected to polymerization and microbial assay was calculated for the reference C. albicans strains by agar diffusion method for the incubation period of 24 h. Results: Group D showed multifold decrease in the colony-forming units. Conclusion: The antimicrobial effect of silver could be used vividly in the denture base for immunocompromised and geriatric patients.

  13. 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.

  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. Crosslinked bicontinuous biobased PLA/NR blends via dynamic vulcanization using different curing systems.

    Science.gov (United States)

    Yuan, Daosheng; Chen, Kunling; Xu, Chuanhui; Chen, Zhonghua; Chen, Yukun

    2014-11-26

    In this study, blends of entirely biosourced polymers, namely polylactide (PLA) and natural rubber (NR), were prepared through dynamic vulcanization using dicumyl peroxide (DCP), sulphur (S) and phenolic resin (2402) as curing agents, respectively. The crosslinked NR phase was found to be a continuous structure in all the prepared blends. The molecular weight changes of PLA were studied by gel permeation chromatography. Interfacial compatibilization between PLA and NR was investigated using Fourier transform infrared spectroscopy and scanning electron microscopy. The thermal properties of blends were evaluated by differential scanning calorimetry and thermogravimetric analysis instrument. It was found that the molecular weight of PLA and interfacial compatibilizaion between PLA and NR showed a significant influence on the mechanical and thermal properties of blends. The PLA/NR blend (60/40 w/w) by DCP-induced dynamic vulcanization owned the finest mechanical properties and thermal stability. Copyright © 2014 Elsevier Ltd. All rights reserved.

  16. Evaluation of adhesive bonding of lithium disilicate ceramic material with duel cured resin luting agents.

    Science.gov (United States)

    Lambade, Dipti Pravin; Gundawar, Sham M; Radke, Usha M

    2015-02-01

    The purpose of this vitro study was to comparatively evaluate the adhesive bonding of dual cured resin luting agents with lithium disilicate ceramic material. Porcelain laminate veneers were prepared with lithium disilicate ceramic material i.e. IPS Empress II( E-Max Press). These laminates were bonded with RelyX ARC, Panavia F 2.0, Variolink II, Duolink and Nexus NX3.The porcelain laminates were etched with 9.6% hydrofluoric acid (Pulpdent Corporation) for one minute, washed for 15 sec with three way syringe and dried for 15 sec with air syringe. The silane (Ultradent) was applied with the help of applicator tip in a single coat and kept undisturbed for one minute. The prepared surfaces of the premolars were treated with 37% phosphoric acid (Prime dent) for 15 sec, thoroughly rinsed and dried as per manufactures instructions. The shear bond test was carried out on all samples with the Universal testing machine (Instron U.S.A.) The scanning electron microscopic study was performed at the fractured interface of representative samples from each group of luting agents. In this study, the highest value of shear bond strength was obtained for NEXUS NX3 and the lowest for VARIOLINK II. The difference in bond strength can be interpreted as the difference in fracture resistance of luting agents, to which shearing load was applied during the shear bond strength test. It is inferred from this study that the composition of the luting agent determines the adhesive characteristics in addition to surface treatment and bonding surface area.

  17. An Evaluation of the Light Output from 22 Contemporary Light Curing Units

    OpenAIRE

    Soares, Carlos José; RODRIGUES, Monise de Paula; Oliveira, Laís Rani Sales; Braga, Stella Sueli Lourenço; Barcelos, Luciana Mendes; Silva,Gisele Rodrigues da; Giannini,Marcelo; Price,Richard Bengt

    2017-01-01

    Abstract This study measured the radiant power (mW), irradiance (mW/cm2) and emission spectra (mW/cm2/nm) of 22 new, or almost new, light curing units (LCUs): - Alt Lux II, BioLux Standard, Bluephase G2, Curing Light XL 3000, Demetron LC, DX Turbo LED 1200, EC450, EC500, Emitter C, Emitter D, KON-LUX, LED 3M ESPE, Led Lux II, Optilight Color, Optilight Max, Optilux 501, Poly Wireless, Radii cal, Radii plus, TL-01, VALO Cordless. These LCUs were either monowave or multiple peak light emitting ...

  18. Evaluation of light curing distance and mylar strips color on surface hardness of two different dental composite resins.

    Science.gov (United States)

    Mousavinasab, Seyed Mostafa; Barekatain, Mehrdad; Sadeghi, Elahe; Nourbakhshian, Farzaneh; Davoudi, Amin

    2014-01-01

    Hardness is one of the basic properties of dental materials, specially composite resins which is relevant to their polymerization. The aim of this study was to evaluate the effect of light curing distance and the color of clear Mylar strips on surface hardness of Silorane-based (SCR) and Methacrylate-based composite resins (MCR). 40 samples of MCRs (Filtek Z250) and SCRs (Filtek P90) were prepared in size of 5 mm×2 mm (80 samples in total). The samples divided into 8 groups (10 samples in each one) based on the color of clear Mylar strips (white or blue) and distance from light curing source (0 mm or 2 mm). All the samples cured for 40 second and stored in incubator for 24 hours in 37°C temperature. Surface hardness test was done by Vickers test machine and the collected data were analyzed by one-way ANOVA and paired T-test by using SPSS software version 13 at significant level of 0.05. MCRs cured with blue Mylar strips from 0 mm distance had the highest (114.5 kg/mm(2)) and SCRs cured with white Mylar strips from 2 mm distance had the lowest (42.2 kg/mm(2)) mean of surface hardness. Also, the results of comparison among SCRs and MCRs showed significant differences among all groups (all P values <0.01). The hardness decreased as the distance increased and the blue Mylar strips provided higher hardness than clear ones. Also, Filtek Z250 showed higher hardness compared to Filtek P90.

  19. Comparative evaluation of shear bond strength, between IPS-Empress2 ceramics and three dual-cured resin cements

    Directory of Open Access Journals (Sweden)

    Hajimiragha H

    2006-06-01

    Full Text Available Background and Aim: Cementation is one of the most critical steps of the porcelain restoration technique. However, limited information is available concerning the bond strength of current ceramic bonding systems. The aim of this study was to evaluate the shear bond strength of three dual-cure resin cements to IPS-Empress2 ceramics. Materials and Methods: In this experimental study, 30 pairs of IPS-Empress 2 ceramic discs were fabricated with 10 and 8 mm diameters and 2.5 mm thickness. After sandblasting and ultrasonic cleaning, the surfaces of all specimens were etched with 9% hydrofluoric acid for 60 seconds. Then, the three groups of 10 bonded specimens were prepared ceramic bonding resin systems including Panavia F2, Variolink II and Rely X ARC. After storage in 37±1c water for 24 hours and thermocycling in 5c and 55c water for 500 cycles with 1-minute dwell time, the shear bond strengths were determined using Instron machine at speed of 0.5mm/min. Data were analyzed by One Way ANOVA test. For multiple paired comparisons, the Tukey HSD method was used. The mode of failure was evaluated by scanning electro microscope (SEM. P<0.05 was considered as the limit of significance. Result: Significant differences were found between different cement types (P<0.05. Variolink II provided the highest bonding values with IPS-Empress2. A combination of different modes of failure was observed. Conclusion: Based on the results of this study, according to the highest mode of cohesive failure, Variolink II seems to have the strongest bond with IPS-Empress2 ceramics.

  20. Listening to people to cure people: the LpCp - tool, an instrument to evaluate hospital humanization.

    Science.gov (United States)

    Buffoli, M; Bellini, E; Bellagarda, A; Di Noia, M; Nickolova, M; Capolongo, S

    2014-01-01

    In the healthcare environment, nowadays, only a few among the available evaluation systems pay enough attention to certain social sustainability aspects. Among these, humanization plays a key role in an environment, like hospitals, where the mental and physical well-being of patients and healthcare operators is crucial. Our research project, known as 'SustHealth', is focused on the deficiencies of the evaluation methodology and aims at developing an assessment system related to a questionnaire-based investigation capable of revealing the most influential conditions and dynamics in people's hospital experience, while also recommending areas in hospitals where efforts can be made to sustain improvement strategies. The humanization of healthcare structures began with a significant investigation to assess all the major evaluation tools in both hospitals - to better understand the physical and emotional interactions in the structure-user ratio - and other areas. This helped understand the strengths and criticalities of the systems that were examined. This first step also allowed to shed light on the most important aspects to keep in mind when developing an evaluation system. During the operational steps an all-new LpCp - tool (Listening to people to Cure people) was created, which includes a questionnaire-based investigation and processing software, and its application for beta-testing in a 600-bed hospital in Milan. The LpCp - tool proved to be effective and capable of finding the deficiencies and potential in the examined hospital. Considering different themes through alternative viewpoints (staff, patients/visitors, technicians, etc.), the tool has allowed underlining different perceptions of the same place and also provided sound information to guide healthcare management in taking informed decisions about specific problems or users. Former interesting results show an inadequate appraisal about e.g. on-site facilities or recreational activities and a lack of

  1. Comparative evaluation of secondary caries formation around light-cured fluoride-releasing restorative materials

    Directory of Open Access Journals (Sweden)

    N Sathyajith Naik

    2017-01-01

    Full Text Available Aim: The aim of this study was to compare and evaluate secondary caries formation around light-cured fluoride-releasing restorative materials. Methodology: Standard Class V cavities were prepared on the buccal and lingual surfaces of forty extracted healthy premolars. The teeth were randomly divided into four groups of ten teeth each and labeled as Group I, II, III, and IV and restored with one of the following materials, namely, Fuji II LC (Group I, Vitremer (Group II, F-2000 (Group III, and Z-100 (Group IV; Control. The teeth were thermocycled and immersed in jars containing an acid gel for caries-like lesion formation. After 15 weeks, the samples were removed, washed, and sectioned buccolingually through the restoration. The sections were then grounded to a thickness of 80–100 µm. After imbibition in water, the sections were mounted on slides and lesions were examined, measured, and photographed with Leica DMRB Research Microscope. The observation recorded was subjected to (a analysis of variance, (b Studentized range test (Newman–Keuls, (c Snedecor's F-test. Results: The depth of the outer lesion in teeth restored with Z-100 (Group IV; Control was significantly higher than the teeth restored with F-2000 (Group III, Vitremer (Group II, and Fuji II LC (Group I (P < 0.01. The depth of the outer lesion in teeth restored with F-2000 (Group III was also significantly higher than the teeth restored with Vitremer (Group II and Fuji II LC (Group I (P < 0.01. However, there was no significant difference in depth of the outer lesions among the teeth restored with Vitremer (Group II and Fuji II LC (Group I. No wall lesion (WL was evident in teeth restored with Vitremer (Group II and Fuji II LC (Group I. The WL length and body depth in teeth restored with Z-100 (Group IV; Control were significantly higher than the teeth restored with F-2000 (Group III (P < 0.01. Conclusion: It was concluded that Fuji II LC and Vitremer had a inhibitory effect on the

  2. Examination of a Standardized Test for Evaluating the Degree of Cure of EVA Encapsulation: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Miller, D. C.; Gu, X.; Haldenman, S.; Hidalgo, M.; Malguth, E.; Reid, C. G.; Shioda, T.; Schulze, S. H.; Wang, Z. Y.; Wohlgemuth, J. H.

    2013-11-01

    The curing of cross-linkable encapsulation is a critical consideration for photovoltaic (PV) modules manufactured using a lamination process. Concerns related to ethylene-co-vinyl acetate (EVA) include the quality (e.g., expiration and uniformity) of the films or completion (duration) of the cross-linking of the EVA within a laminator. Because these issues are important to both EVA and module manufacturers, an international standard has recently been proposed by the Encapsulation Task-Group within the Working Group 2 (WG2) of the International Electrotechnical Commission (IEC) Technical Committee 82 (TC82) for the quantification of the degree of cure for EVA encapsulation. The present draft of the standard calls for the use of differential scanning calorimetry (DSC) as the rapid, enabling secondary (test) method. Both the residual enthalpy- and melt/freeze-DSC methods are identified. The DSC methods are calibrated against the gel content test, the primary (reference) method. Aspects of other established methods, including indentation and rotor cure metering, were considered by the group. Key details of the test procedure will be described.

  3. Examination of a Standardized Test for Evaluating the Degree of Cure of EVA Encapsulation (Presentation)

    Energy Technology Data Exchange (ETDEWEB)

    Miller, D.; Wohlgemuth, J.; Gu, X.; Haldeman, S.; Hidalgo, M.; Malguth, E.; Reid, C.; Shioda, T.; Schulze, S.; Wang, Z.

    2013-11-01

    The curing of cross-linkable encapsulation is a critical consideration for photovoltaic (PV) modules manufactured using a lamination process. Concerns related to ethylene-co-vinyl acetate (EVA) include the quality (e.g., expiration and uniformity) of the films or completion (duration) of the cross-linking of the EVA within a laminator. Because these issues are important to both EVA and module manufacturers, an international standard has recently been proposed by the Encapsulation Task-Group within the Working Group 2 (WG2) of the International Electrotechnical Commission (IEC) Technical Committee 82 (TC82) for the quantification of the degree of cure for EVA encapsulation. The present draft of the standard calls for the use of differential scanning calorimetry (DSC) as the rapid, enabling secondary (test) method. Both the residual enthalpy- and melt/freeze-DSC methods are identified. The DSC methods are calibrated against the gel content test, the primary (reference) method. Aspects of other established methods, including indentation and rotor cure metering, were considered by the group. Key details of the test procedure will be described.

  4. Water and saliva contamination effect on shear bond strength of brackets bonded with a moisture-tolerant light cure system.

    Science.gov (United States)

    Vicente, Ascensión; Mena, Ana; Ortiz, Antonio José; Bravo, Luis Alberto

    2009-01-01

    To evaluate the effects of water and saliva contamination on shear bond strength of brackets bonded with a moisture-tolerant light cure system. Brackets were bonded to 240 bovine lower incisors divided into 12 groups. Four bonding procedures were evaluated, including (1) TSEP/Transbond XT, (2) TMIP/ Transbond XT, (3) TSEP/Transbond PLUS, and (4) TMIP/Transbond PLUS, each under three different bonding conditions: without contamination, with water contamination, and with saliva contamination. Shear bond strength was measured with a universal testing machine. The adhesive remnant on the teeth was quantified with the use of image analyzing equipment. Without contamination, bond strengths for the four procedures were similar (P > .05). TSEP/Tranbond PLUS and TMIP/Transbond PLUS left significantly less adhesive on the teeth after debonding than TSEP/Transbond XT and TMIP/Transbond XT (P contaminated with water or saliva showed significantly worse performance than the other procedures evaluated (P Contamination (with water or saliva) did not affect either bond strength or adhesive remaining on the teeth for TSEP/ Transbond XT, TSEP/Transbond PLUS, or TMIP/Transbond PLUS (P > .017), although for TMIP/ Transbond XT, both variables showed significant reductions after contamination (P < .017). TSEP/Transbond PLUS, TMIP/Transbond PLUS, and TSEP/Transbond XT showed greater tolerance to wet conditions than was shown by TMIP/Transbond XT.

  5. Fiber Optic Systems for Light Curing Rigidization of Inflatable Structures Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Light (UV and visible) curing composite matrix resins are being explored as an attractive means for rigidizing inflatable spacecraft for large space-deployed...

  6. Evaluation of Out-of-Autoclave (OOA epoxy system

    Directory of Open Access Journals (Sweden)

    Fernanda Guilherme

    Full Text Available Abstract Epoxy resins (EP usually cure in autoclave to minimize resin voids and to achieve the desired resin/fiber ratio. Cure parameters such as temperature, vacuum and pressure levels are controlled and monitored. Aiming time and cost optimization, new out-of-autoclave (OOA cure processes have been developed lately. This study evaluated the cure cycle and the effect of non-programmed interruptions in an OOA process. Fourier Transform Infrared spectroscopy (FT-IR results show similarities between the resin used and diglycidyl ether of bisphenol A (DGEBA and also that the curing system is composed of cyan and sulfur hardeners, codified in industry, as Components of #2511 Resin System. The cure cycle and its interruptions were simulated by dynamic-mechanical analysis (DMA. The samples obtained were evaluated by FT-IR and differential scanning calorimetry (DSC, whose results show that the degree of cure varying between 0.8 to 0.85 was achieved at 120 °C.

  7. Printing and Curing of Conductive Ink Track on Fabric using Syringe Deposition System with DLP Projector and Hot Plate

    Directory of Open Access Journals (Sweden)

    Khirotdin Rd. Khairilhijra

    2017-01-01

    Full Text Available Printing is a technique to transfer ink onto substrates to create pattern and syringe deposition system has shown some great potential in printing due to its ability to produce filamentary bead tracks which is important concerning conductivity and easily adopted on conformal surfaces which could not be realized by conventional technique. Fabrics with integrated electrical features able to create intelligent articles and may potentially open up new perspective areas of application in textile printing. However, the applicability of this technique on fabrics remains unknown which the ink used has to meet certain requirements including high electrical conductivity, resistance to oxidation, dry out without clogging, good adhesion with suitable viscosity and surface tension. Thus, there is a need to do this study which is to determine the feasibility of syringe deposition system to print a conductive ink tracks using silver epoxy-based conductive ink on fabric substrate via lycra material. This study is also aim to investigate the feasibility of using DLP projector with hot plate as another source of heat to be used in curing the ink tracks on fabric. The effect of printing and curing parameters to the characteristics and conductivity of the ink track is investigated. Several mechanical and electrical tests were also administered to determine the cure, hardness, adhesion and resistance level of the ink tracks. The results obtained were as expected which higher printing speed and lower deposition height used, a narrower and thinner ink tracks were produced. Sample with 4 mm/s of printing speed and deposition height of 1 mm resulted in dimension closer to the targeted dimension. The longer curing time and higher temperature used, a lower resistance is produced. The lowest resistance achieved is 0.9 Ω cured at 150°C for 60 minutes. The conductivity of the ink track was affected by curing process and cross-sectional area of the ink track. It is proven

  8. Curing of Thick Thermoset Composite Laminates: Multiphysics Modeling and Experiments

    Science.gov (United States)

    Anandan, S.; Dhaliwal, G. S.; Huo, Z.; Chandrashekhara, K.; Apetre, N.; Iyyer, N.

    2017-11-01

    Fiber reinforced polymer composites are used in high-performance aerospace applications as they are resistant to fatigue, corrosion free and possess high specific strength. The mechanical properties of these composite components depend on the degree of cure and residual stresses developed during the curing process. While these parameters are difficult to determine experimentally in large and complex parts, they can be simulated using numerical models in a cost-effective manner. These simulations can be used to develop cure cycles and change processing parameters to obtain high-quality parts. In the current work, a numerical model was built in Comsol MultiPhysics to simulate the cure behavior of a carbon/epoxy prepreg system (IM7/Cycom 5320-1). A thermal spike was observed in thick laminates when the recommended cure cycle was used. The cure cycle was modified to reduce the thermal spike and maintain the degree of cure at the laminate center. A parametric study was performed to evaluate the effect of air flow in the oven, post cure cycles and cure temperatures on the thermal spike and the resultant degree of cure in the laminate.

  9. Chemical curing in alkyd paints: An evaluation via FT-IR and NMR spectroscopies

    Science.gov (United States)

    Bartolozzi, G.; Marchiafava, V.; Mirabello, V.; Peruzzini, M.; Picollo, M.

    2014-01-01

    A study aimed at determining the time necessary for an alkyd paint to attain chemical curing is presented. In particular, the object of our investigation was an oil paint made by Winsor & Newton, namely French ultramarine (PB29) in the Griffin Alkyd “fast drying oil colour” series. Using this paint, we prepared several mock-ups on glass. These were left in the laboratory at room temperature in a piece of furniture with glass doors for a total of 70 days. Samples were taken at different times, and the changes in their composition were monitored by means of FT-IR and multinuclear NMR spectroscopic analyses. Since the cross-linking reactions involved in the formation of the pictorial film mainly affect the amount of carbon-carbon double bonds, we monitored the decrease in allyl, diallyl and vinyl protons and carbons. The data obtained from the use of both techniques led us to conclude that, in our particular experimental conditions, the chemical curing of the paint layer is reached within the first 70 days, thus establishing the beginning of the ageing phenomena.

  10. Using a Chlorophyll Meter to Evaluate the Nitrogen Leaf Content in Flue-Cured Tobacco (Nicotiana tabacum L.

    Directory of Open Access Journals (Sweden)

    Renato Contillo

    2009-06-01

    Full Text Available In flue-cured tobacco N fertilizer is commonly applied during pre-planting, and very often applied again later as a growth-starter. It is generally held that the efficiency of N-fertilizer use can be improved by evaluating the leaf Nstatus after transplanting and until flowering stage. N use efficiency in this context does not refer merely to the yield but also to the quality, in the meanwhile minimizing the negative effects on the environment. To investigate these aspects, we evaluated the capacity of a Minolta model SPAD-502 chlorophyll meter to estimate the N-status in flue-cured tobacco. The aims was to verify if a relationship exists between SPAD readings and leaf N content, and if a single leaf, in a well defined stalk position, could represent the nitrogen content of the whole plant. During the years 1995 and 1996, a pot experiment was conducted using two flue-cured tobacco varieties. SPAD values, total chlorophyll, total N contents and leaf area were measured throughout the growing season, on each odd leaf stalk position. SPAD values were well-correlated with both total chlorophyll and total N leaf concentration, and the regression coefficients were higher when relationships were calculated on a leaf-area basis. For both relationships, SPAD-total chlorophyll and SPAD-total N, the best fittings were obtained with quadratic equations. One leaf stalk position alone is able to monitor the N-status of the whole plant during the first six weeks after transplanting, without distinction of year and variety effects. The SPAD measurement of one leaf per plant, throughout the vegetative growing season, is therefore a valid tool to test the N-status of the crop in a period when a required N supply is still effective.

  11. Curing kinetics, mechanism and chemorheological behavior of methanol etherified amino/novolac epoxy systems

    Directory of Open Access Journals (Sweden)

    S. F. Zhao

    2014-02-01

    Full Text Available The curing kinetics and mechanism of epoxy novolac resin (DEN and modified epoxy novolac resin (MDEN with methanol etherified amino resin were studied by means of differential scanning calorimetry (DSC, Fourier transforminfrared (FT-IR spectroscopy and chemorheological analysis. Their kinetics parameters and models of the curing were examined utilizing isoconversional methods, Flynn-Wall-Ozawa and Friedman methods. For the DEN mixture, its average activation energy (Ea was 71.05 kJ/mol and the autocatalytic model was established to describe the curing reaction. The MDEN mixture exhibited three dominant curing processes, termed as reaction 1, reaction 2 and reaction 3; and their Ea were 70.05, 106.55 and 101.91 kJ/mol, respectively. Besides, Ea of reaction 1 was similar to that of DEN mixture, while Ea of reactions 2 and 3 corresponded to that of the etherification reaction between hydroxyl and epoxide group. Moreover, these three dominant reactions were nth order in nature. Furthermore, their curing mechanisms were proposed from the results of DSC and FTIR. The chemorheological behavior was also investigated to obtain better plastics products via optimizing the processing schedules.

  12. Accumulation and evolution of tocopherols in dry-cured hams from Iberian pigs as affected by their feeding and rearing system

    DEFF Research Database (Denmark)

    Rey, A I; Lopez-Bote, C J; Daza, A

    2010-01-01

    The influence of feeding and rearing systems on the accumulation and evolution of α- and γ-tocopherols in relation to storage time in dry-cured ham slices and pieces was investigated. The accumulation of γ-tocopherol in Musculus Biceps femoris or fat of cured hams was lower in groups fed acorns i...

  13. Shear bond strength evaluation of chemically-cured and light-cured orthodontic adhesives after enamel deproteinization with 5.25% sodium hypochlorite

    Science.gov (United States)

    Salim, J. C.; Krisnawati; Purbiati, M.

    2017-08-01

    This study aimed to assess the effect of enamel deproteinization with 5.25% sodium hypochlorite (NaOCl) before etching on the shear bond strength (SBS) of Unite (UN; 3M Unitek) and Xihu-BIOM adhesive (XB). Fifty-two maxillary first premolars were divided into four groups: (1) UN and (2) XB according to manufacturer’s recommendation and (3) UN and (4) XB deproteinized with 5.25% NaOCl. Brackets were bonded, and a mechanical test was performed using a universal testing machine. The mean SBS value for groups A1, A2, B1, and B2 was 13.51 ± 2.552, 14.36 ± 2.902, 16.43 ± 2.615, and 13.05 ± 2.348 MPa, respectively. A statistically significant difference in SBSs was observed between chemically cured groups and between group B (p light-cured adhesive groups and between group A (p > 0.05). NaOCl enamel deproteinization before acid etching has a significant effect on the SBS of Unite adhesive, but not on that of the Xihu-BIOM adhesive. Furthermore, a significant difference in the SBS of Unite and Xihu-BIOM adhesives within the enamel deproteinization group was observed in this study.

  14. Evaluation Use in Evaluation Systems

    DEFF Research Database (Denmark)

    Højlund, Steven

    2014-01-01

    This article investigates the European Union’s evaluation system and its conduciveness to evaluation use. Taking the European Commission’s LIFE programme as its case, the article makes an empirical contribution to an emerging focus in the literature on the importance of organization...... and institutions when analyzing evaluation use. By focusing on the European Union’s evaluation system the article finds that evaluation use mainly takes place in the European Commission and less so in the European Parliament and the European Council. The main explanatory factors enabling evaluation use relate...... to the system’s formalization of evaluation implementation and use; these factors ensure evaluation quality, timeliness and capacity in the Commission. At the same time, however, the system’s formalization also impedes evaluation use, reducing the direct influence of evaluations on policy-making and effectively...

  15. 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.

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

    Science.gov (United States)

    Corcione, Carola Esposito; Freuli, Fabrizio; Frigione, Mariaenrica

    2014-09-22

    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. Effect of Dental Chair Light on Enamel Bonding of Orthodontic Brackets Using Light Cure Based Adhesive System: An In-Vitro Study.

    Science.gov (United States)

    Tiwari, Anil; Shyagali, Tarulatha; Kohli, Sarvraj; Joshi, Rishi; Gupta, Abhishek; Tiwari, Rana

    2016-10-01

    The aim of this in vitro study was to evaluate the influence of the Dental chair light on the bond strength of light cured composite resin. Sixty therapeutically extracted human premolar teeth were randomly allocated to two groups of 30 specimens each. In both groups light cured composite resin (Transbond XT) and MBT premolar metal brackets (3M Unitek) was used to bond brackets. In group I and II light curing was done using Light-emitting diode light curing units without and with the dental chair light respectively. After bonding, all samples were stored in distilled water at room temperature for 24 hours and subsequently tested for shear bond strength and Adhesive Remnant Index (ARI) scores. Data was subjected to Mann Whitney U statistical test. Results indicated that there was significantly higher shear bond strength (7.71 ± 1.90) for the Group II (composite cured with LED and dental chair light) compared with Group I (composite cured with LED LCU only) (5.74 ± 1.13).the obtained difference was statistically significant. There was no statistical significant difference between ARI scores in between the groups. light cure bonding with dental chair light switched on will produce greater bond strength than the conventional bonding. However, the ARI score were similar to both the groups. It is advised that the inexperienced orthodontist should always switch off the dental chair light while bonding for enough working time during the bracket placement.

  18. Detection of hydrothermal aging in Cured-In-Place Pipes (CIPP) based on microwave system

    OpenAIRE

    Manavipour, Maryam; Sklarczyk, Christoph; SZIELASKO, Klaus; Kurz, Jochen Horst; Boller, Christian

    2016-01-01

    Pipe rehabilitation by means of trenchless techniques has been performed for more than 40 years already. Cured-in-place pipe (CIPP) is a trenchless method to repair damaged pipelines by inserting a new liner of polymer composite inside the existing host pipe. Since these liners are exposed to water at different temperature after installation for a long time, the purpose of a study was to investigate the effect of hydrothermal aging on CIPP samples and how this effect can be assessed by means ...

  19. A comparative evaluation of the shear bond strength of five different orthodontic bonding agents polymerized using halogen and light-emitting diode curing lights: an in vitro investigation.

    Science.gov (United States)

    Banerjee, Sujoy; Banerjee, Rajlakshmi

    2011-01-01

    With the introduction of photosensitive (light-activated) restorative materials in orthodontics, various methods have been suggested to enhance the polymerization of the materials used, including use of more powerful light curing devices. Bond strength is an important property and determines the amount of force delivered and the treatment duration. Many light-cured bonding materials have become popular but it is the need of the hour to determine the bonding agent that is the most efficient and has the desired bond strength. To evaluate and compare the shear bond strengths of five different orthodontic light cure bonding materials cured with traditional halogen light and low-intensity light-emitting diode (LED) light curing unit. 100 human maxillary premolar teeth, extracted for orthodontic purpose, were used to prepare the samples. 100 maxillary stainless steel bicuspid brackets of 0.018 slot of Roth prescription, manufactured by D-tech Company, were bonded to the prepared tooth surfaces of the mounted samples using five different orthodontic bracket bonding light-cured materials, namely, Enlight, Fuji Ortho LC (resin-modified glass ionomer cement), Orthobond LC, Relybond, and Transbond XT. The bond strength was tested on an Instron Universal testing machine (model no. 5582). In Group 1 (halogen group), Enlight showed the highest shear bond strength (16.4 MPa) and Fuji Ortho LC showed the least bond strength (6.59 MPa) (P value 0.000). In Group 2 (LED group), Transbond showed the highest mean shear bond strength (14.6 MPa) and Orthobond LC showed the least mean shear bond strength (6.27 MPa) (P value 0.000). There was no statistically significant difference in the shear bond strength values of all samples cured using either halogen (mean 11.49 MPa) or LED (mean 11.20 MPa), as the P value was 0.713. Polymerization with both halogen and LED resulted in shear bond strength values which were above the clinically acceptable range given by Reynolds. The LED light curing

  20. A comparative evaluation of the shear bond strength of five different orthodontic bonding agents polymerized using halogen and light-emitting diode curing lights: An in vitro investigation

    Directory of Open Access Journals (Sweden)

    Sujoy Banerjee

    2011-01-01

    Full Text Available Purpose: With the introduction of photosensitive (light-activated restorative materials in orthodontics, various methods have been suggested to enhance the polymerization of the materials used, including use of more powerful light curing devices. Bond strength is an important property and determines the amount of force delivered and the treatment duration. Many light-cured bonding materials have become popular but it is the need of the hour to determine the bonding agent that is the most efficient and has the desired bond strength. Aim: To evaluate and compare the shear bond strengths of five different orthodontic light cure bonding materials cured with traditional halogen light and low-intensity light-emitting diode (LED light curing unit. Materials and Methods: 100 human maxillary premolar teeth, extracted for orthodontic purpose, were used to prepare the samples. 100 maxillary stainless steel bicuspid brackets of 0.018 slot of Roth prescription, manufactured by D-tech Company, were bonded to the prepared tooth surfaces of the mounted samples using five different orthodontic bracket bonding light-cured materials, namely, Enlight, Fuji Ortho LC (resin-modified glass ionomer cement, Orthobond LC, Relybond, and Transbond XT. The bond strength was tested on an Instron Universal testing machine (model no. 5582. Results: In Group 1 (halogen group, Enlight showed the highest shear bond strength (16.4 MPa and Fuji Ortho LC showed the least bond strength (6.59 MPa (P value 0.000. In Group 2 (LED group, Transbond showed the highest mean shear bond strength (14.6 MPa and Orthobond LC showed the least mean shear bond strength (6.27 MPa (P value 0.000. There was no statistically significant difference in the shear bond strength values of all samples cured using either halogen (mean 11.49 MPa or LED (mean 11.20 MPa, as the P value was 0.713. Conclusion: Polymerization with both halogen and LED resulted in shear bond strength values which were above the

  1. Comparative Evaluation of the Effects of Light Intensities and Curing Cycles of QTH, and LED Lights on Microleakage of Class V Composite Restorations.

    Science.gov (United States)

    Chandurkar, Anshu M; Metgud, Sandeep S; Yakub, Shaikh Shoeb; Kalburge, Vaishali J; Biradar, Basawaraj C

    2014-03-01

    The purpose of this study was to evaluate the effects of light intensity and curing cycles of QTH and LED lights on the microleakage of Class V composite restorations. Eighty freshly extracted human maxillary premolars were used for this study. Standardized Class V cavities were prepared and they were restored with microhybrid resin composite. According to the curing protocol, the teeth were then divided into 4 groups (n=20): QTH curing (standard and soft start modes), and LED (standard and soft start modes) irradiations. Microleakage was evaluated by immersion of the samples in 50% silver nitrate solution. The samples were then sectioned, evaluated under a stereomicroscope, and scored for microleakage. The results of the present in-vitro study showed mean dye leakage scores of 1.9, 1.2, 1.45 and 0.90 for Group I (QTH-Standard mode), Group II (QTH-Soft Start mode), Group III (LED-Standard mode) and Group IV (LED-Soft Start mode) respectively. It was thus concluded that the soft start polymerization showed a highly significant difference as compared to the standard curing modes of QTH and LED lights, respectively.

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

    Science.gov (United States)

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

    1997-01-01

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

  3. Influence of fresh date palm co-products on the ripening of a paprika added dry-cured sausage model system.

    Science.gov (United States)

    Martín-Sánchez, Ana María; Ciro-Gómez, Gelmy; Vilella-Esplá, José; Ben-Abda, Jamel; Pérez-Álvarez, José Ángel; Sayas-Barberá, Estrella

    2014-06-01

    Date palm co-products are a source of bioactive compounds that could be used as a new ingredient for the meat industry. An intermediate food product (IFP) from date palm co-products (5%) was incorporated into a paprika added dry-cured sausage (PADS) model system and was analysed for physicochemical parameters, lipid oxidation and sensory attributes during ripening. Addition of 5% IFP yielded a product with physicochemical properties similar to the traditional one. Instrumental colour differences were found, but were not detected visually by panellists, who also evaluated positively the sensory properties of the PADS with IFP. Therefore, the IFP from date palm co-products could be used as a natural ingredient in the formulation of PADS. Copyright © 2013 Elsevier Ltd. All rights reserved.

  4. Clinical evaluation on porcelain laminate veneers bonded with light-cured composite: results up to 7 years.

    Science.gov (United States)

    D'Arcangelo, Camillo; De Angelis, Francesco; Vadini, Mirco; D'Amario, Maurizio

    2012-08-01

    The purpose of this study was to evaluate the clinical performance of laminate porcelain veneers bonded with a light-cured composite. Thirty patients were restored with 119 porcelain laminate veneers. The veneers were studied for an observation time of 7 years. Marginal adaptation, marginal discoloration, secondary caries, color match, and anatomic form were clinically examined following modified United States Public Health Service (USPHS) criteria. Each restoration was also examined for cracks, fractures, and debonding. Pulp vitality was verified. In addition, plaque and gingival indexes and increase in gingival recession were recorded. Survival rate evaluating absolute failures and success rate describing relative failures were statistically determined, using both restoration and patient-related analyses. On the basis of the criteria used, most of the veneers rated Alfa. After 7 years, the results of the clinical investigation regarding marginal adaptation and marginal discoloration revealed only 2.5% and 4.2% Bravo ratings, respectively, among the 119 initially placed veneers. Using the restoration as the statistical unit, the survival rate was 97.5%, with a high estimated success probability of 0.843 after 7 years. Using the patient as the statistical unit, the survival rate was 90.0% and the estimated success probability after 7 years was 0.824. Gingival response to the veneers was all in the satisfactory range. Porcelain laminate veneers offer a predictable and successful treatment modality giving a maximum preservation of sound tooth. The preparation, cementation, and finishing procedures adopted are considered key factors for the long-term success and aesthetical result of the veneer restorations.

  5. An In vitro Comparative Evaluation of Disinfectants on Standard and Clinical Microbial Strains on Heat Cure Resins.

    Science.gov (United States)

    Pawashe, Karuna Gajanan; Tewary, Shivsagar; Sanyal, Pronob Kumar; Nilesh, Kumar

    2017-05-01

    Oral cavity is colonised by numerous micro-organisms that form a biofilm on the acrylic resin. Hence, routine hygiene is essential to prevent oral mucosal inflammation and lesions. Knowledge of appropriate disinfecting agents for acrylic resins is crucial in this context. To compare and evaluate the effectiveness of four commercially available disinfectants on heat cure acrylic resin specimens contaminated with standard and clinical strains of two micro-organisms commonly inhabiting the oral microflora. Two hundred acrylic resin specimens (n=200), 10 in each group were contaminated in vitro with 1x10 6 cells/ml suspensions of standard and clinical strains of micro-organisms (Candida albicans and Streptococcus mutans) and were immersed in four disinfectants (1% sodium hypochlorite, 2% chlorhexidine digluconate, 2% glutaraldehyde and 3.8% sodium perborate) for 10 minutes. The control group was not subjected to any disinfection process. For collection of clinical strains, oral swab was passed over the buccal mucosa and grown on blood agar culture media. Organism confirmation was done by growing them on selective culture media. Final counts of micro-organisms per ml were performed by plating method for evaluation of microbial level reduction. Results obtained were subjected to ANOVA and Tukey's test. Standard strains of Candida albicans (C) and Streptoccocus mutans (S) subjected to various disinfectants showed varied mean Colony Forming Units per ml (CFU/ml) from disinfectants showed varied mean CFU/ml from 10 5 ). All intergroup comparisons were highly significant (p0.05; NS). Almost 1% sodium hypochlorite was found to be the most effective disinfectant for both Candida albicans and Streptococcus mutans . The least effective disinfectant being: 3.8% sodium perborate.

  6. An In vitro Comparative Evaluation of Disinfectants on Standard and Clinical Microbial Strains on Heat Cure Resins

    Science.gov (United States)

    Tewary, Shivsagar; Sanyal, Pronob Kumar; Nilesh, Kumar

    2017-01-01

    Introduction Oral cavity is colonised by numerous micro-organisms that form a biofilm on the acrylic resin. Hence, routine hygiene is essential to prevent oral mucosal inflammation and lesions. Knowledge of appropriate disinfecting agents for acrylic resins is crucial in this context. Aim To compare and evaluate the effectiveness of four commercially available disinfectants on heat cure acrylic resin specimens contaminated with standard and clinical strains of two micro-organisms commonly inhabiting the oral microflora. Materials and Methods Two hundred acrylic resin specimens (n=200), 10 in each group were contaminated in vitro with 1x106 cells/ml suspensions of standard and clinical strains of micro-organisms (Candida albicans and Streptococcus mutans) and were immersed in four disinfectants (1% sodium hypochlorite, 2% chlorhexidine digluconate, 2% glutaraldehyde and 3.8% sodium perborate) for 10 minutes. The control group was not subjected to any disinfection process. For collection of clinical strains, oral swab was passed over the buccal mucosa and grown on blood agar culture media. Organism confirmation was done by growing them on selective culture media. Final counts of micro-organisms per ml were performed by plating method for evaluation of microbial level reduction. Results obtained were subjected to ANOVA and Tukey’s test. Results Standard strains of Candida albicans (C) and Streptoccocus mutans (S) subjected to various disinfectants showed varied mean Colony Forming Units per ml (CFU/ml) from disinfectants showed varied mean CFU/ml from 105). All intergroup comparisons were highly significant (p0.05; NS). Conclusion Almost 1% sodium hypochlorite was found to be the most effective disinfectant for both Candida albicans and Streptococcus mutans. The least effective disinfectant being: 3.8% sodium perborate. PMID:28658908

  7. SYSTEM CONTROL OF SMOKING PROCESS AND MEASURING BENZO[A]PYRENE IN TRADITIONAL PRODUCTION OF BOSNIAN DRY CURED HAM (BOSANSKI PRŠUT BY IMPLEMENTING HACCP SYSTEM

    Directory of Open Access Journals (Sweden)

    Almir Toroman

    2013-08-01

    Full Text Available As it is well known, traditional production of smoked meat products requires technological processes, which carry some food safety hazards (e.g. content of Benzo[a]pyrene. (B[a]P. “OMEGA COMERC Ltd.”, a member of the meat industry in Visoko region, has implemented food safety management system according to the recommendations from Codex Alimentarius CAC-RCP (9, recommended International Code of Practice - General Principles of Food Hygiene. By implementing HACCP system, the Company established adequate control measures in producing Bosnian dry cured ham (bosanski pršut on traditional way including the smoking process in the chambers. By doing this, they have created conditions to measure B[a]P content in the Bosnian dry cured ham and implement HACCP system without impairing traditional production and food safety of the final product.The aim of this study is to present the effect of the specific production process onto the meat smoking in order to preserve hygienic, nutritional and sensory values, and also to control B[a]P content in the final product.Key words: Bosnian dry cured ham, traditional production, smoking process, Benzo[a]pyrene, HACCP

  8. Comparison of shear bond strength of resin reinforced chemical cure glass ionomer, conventional chemical cure glass ionomer and chemical cure composite resin in direct bonding systems: an in vitro study.

    Science.gov (United States)

    Rao, Kolasani Srinivasa; Reddy, T Praveen Kumar; Yugandhar, Garlapati; Kumar, B Sunil; Reddy, S N Chandrasekhar; Babu, Devatha Ashok

    2013-01-01

    The acid pretreatment and use of composite resins as the bonding medium has disadvantages like scratching and loss of surface enamel, decalcification, etc. To overcome disadvantages of composite resins, glass ionomers and its modifications are being used for bonding. The study was conducted to evaluate the efficiency of resin reinforced glass ionomer as a direct bonding system with conventional glass ionomer cement and composite resin. The study showed that shear bond strength of composite resin has the higher value than both resin reinforced glass ionomer and conventional glass ionomer cement in both 1 and 24 hours duration and it increased from 1 to 24 hours in all groups. The shear bond strength of resin reinforced glass ionomer cement was higher than the conventional glass ionomer cement in both 1 and 24 hours duration. Conditioning with polyacrylic acid improved the bond strength of resin reinforced glass ionomer cement significantly but not statistically significant in the case of conventional glass ionomer cement.

  9. Effect of curing on the mechanical and healing behaviour of a hybrid dual network : A time resolved evaluation

    NARCIS (Netherlands)

    Abdolah Zadeh, M.; Grande, A.M.; van der Zwaag, S.; Garcia Espallargas, Santiago J.

    2016-01-01

    In the present work we show the effect of the crosslinking degree on the mechanical and healing behaviour of a healable thermoset dual-network polymer. A hyphenated rheological test (i.e. simultaneous rheology and FTIR) was used to follow the effect of the curing process on the mechanical

  10. Hardness evaluation of cured urea-formaldehyde resins with different formaldehyde/urea mole ratios using nanoindentation method

    Science.gov (United States)

    Byung-Dae Park; Charles R. Frihart; Yan Yu; Adya P. Singh

    2013-01-01

    To understand the influence of formaldehyde/urea (F/U) mole ratio on the properties of urea–formaldehyde (UF) resins, this study investigated hardness of cured UF resins with different F/U mole ratios using a nanoindentation method. The traditional Brinell hardness (HB) method was also used...

  11. Sensory evaluation of boar-taint-containing minced meat, dry-cured ham and dry fermented sausage by a trained expert panel and consumers.

    Science.gov (United States)

    Verplanken, Kaat; Wauters, Jella; Vercruysse, Vicky; Aluwé, Marijke; Vanhaecke, Lynn

    2017-10-15

    One of the main issues related to entire male pigs is the occurrence of boar taint, an off-odour, which compromises meat consumability. In this study, odour thresholds (indole: 24-65µgkg(-1), skatole: 44-89µgkg(-1), androstenone: 121-342µgkg(-1)) for the boar taint compounds were estimated in minced meat, dry fermented sausage and dry-cured ham. Afterwards, sensory evaluation of these products containing 10% tainted meat (minced meat and dry fermented sausage) or moderate boar taint compound levels (dry-cured ham) occurred. The beneficial effect of diluting tainted meat was demonstrated, as no significant difference in consumability was observed between gilts and 10% tainted meat by experts as well as consumers. Also dry-curing proved a promising technique for masking boar taint and preventing consumer dissatisfaction. The obtained results demonstrate the applicability of the estimated thresholds in meat as a tool for identifying masking and reducing strategies on the perception of boar taint. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Covariance evaluation system

    Energy Technology Data Exchange (ETDEWEB)

    Kawano, Toshihiko [Kyushu Univ., Fukuoka (Japan); Shibata, Keiichi

    1997-09-01

    A covariance evaluation system for the evaluated nuclear data library was established. The parameter estimation method and the least squares method with a spline function are used to generate the covariance data. Uncertainties of nuclear reaction model parameters are estimated from experimental data uncertainties, then the covariance of the evaluated cross sections is calculated by means of error propagation. Computer programs ELIESE-3, EGNASH4, ECIS, and CASTHY are used. Covariances of {sup 238}U reaction cross sections were calculated with this system. (author)

  13. The search for organizing principles as a cure against reductionism in systems medicine.

    Science.gov (United States)

    Wolkenhauer, Olaf; Green, Sara

    2013-12-01

    Biological complexity has forced scientists to develop highly reductive approaches, with an ever-increasing degree of specialization. As a consequence, research projects have become fragmented, and their results strongly dependent on the experimental context. The general research question, that originally motivated these projects, appears to have been forgotten in many highly specialized research programmes. We here investigate the prospects for use of an old regulative ideal from systems theory to describe the organization of cellular systems 'in general' by identifying key concepts, challenges and strategies to pursue the search for organizing principles. We argue that there is no tension between the complexity of biological systems and the search for organizing principles. On the contrary, it is the complexity of organisms and the current level of techniques and knowledge that urge us to renew the search for organizing principles in order to meet the challenges that are arise from reductive approaches in systems medicine. Reductive approaches, as important and inevitable as they are, should be complemented by an integrative strategy that de-contextualizes through abstractions, and thereby generalizes results. © 2013 FEBS.

  14. The search for organizing principles as a cure against reductionism in systems medicine

    DEFF Research Database (Denmark)

    Wolkenhauer, Olaf; Green, Sara

    2013-01-01

    Biological complexity has forced scientists to develop highly reductive approaches, with an ever-increasing degree of specialization. As a consequence, research projects have become fragmented, and their results strongly dependent on the experimental context. The general research question...... and strategies to pursue the search for organizing principles. We argue that there is no tension between the complexity of biological systems and the search for organizing principles. On the contrary, it is the complexity of organisms and the current level of techniques and knowledge that urge us to renew...... the search for organizing principles in order to meet the challenges that are arise from reductive approaches in systems medicine. Reductive approaches, as important and inevitable as they are, should be complemented by an integrative strategy that de-contextualizes through abstractions, and thereby...

  15. Evaluation de l'effet de la temperature de cure sur le comportement des materiaux bitumineux de type mr-5 traites a la mousse de bitume

    Science.gov (United States)

    Cardenas, Jose Alberto

    Cold recycling mixes and cold mixes with RAP are used in Quebec since 1991. However, this practice is not recommended at temperatures below 10 ° C. Very little research on this subject and the effects of low temperatures on the behavior of early mixes are being done. The present study compares the behavior of a MR-5 mix under different cure temperature, 0 ° C, 5 ° C, 10 ° C, and 23 ° C as the reference temperature. The cold curing conditions are explained in details. The research is based on two main aspects: the effect of curing temperature on the cold recycling materials with foamed asphalt and the comparison between two methods of testing the mechanical properties, there are the Marshall stability and the Indirect Tensile Strenght ITS. The study is divided into three stages. The first stage is the optimization of the foam properties and the mix design of test. The second stage is to prepare the specimens of MR-5 MB and the storage on the predefined cure conditions. Finally, the third stage consists of mechanical strength testing of briquettes at the curing time appointed. Meanwhile, at each stage, we evaluate the associated parameters, which are little known and highly useful in road construction. Firstly, we assess the foam index and the surface of contraction, which is used for formulating and optimization of the foam bitumen mixes. Secondly, we evaluate the index of fracture (IF) and the ductility index (ID) associated with the mechanical strength. At the end of the project, we compare the resistance of the MR-5 foamed bitumen used in this research with the MR-5 bitumen emulsion. The latter is more used in the road industry in Quebec and serves as a reference for the comparison. Both tests show that there is an increase in the resistance of the materials with time, even at temperature below 10 ° C. We notice that the percentage of increase in the resistance of the materials is significantly different in both tests. However, the ITS is highly effective

  16. The 'diagonal' approach to Global Fund financing: a cure for the broader malaise of health systems?

    Directory of Open Access Journals (Sweden)

    Baker Brook K

    2008-03-01

    Full Text Available Abstract Background The potentially destructive polarisation between 'vertical' financing (aiming for disease-specific results and 'horizontal' financing (aiming for improved health systems of health services in developing countries has found its way to the pages of Foreign Affairs and the Financial Times. The opportunity offered by 'diagonal' financing (aiming for disease-specific results through improved health systems seems to be obscured in this polarisation. In April 2007, the board of the Global Fund to fight AIDS, Tuberculosis and Malaria agreed to consider comprehensive country health programmes for financing. The new International Health Partnership Plus, launched in September 2007, will help low-income countries to develop such programmes. The combination could lead the Global Fund to fight AIDS, Tuberculosis and Malaria to a much broader financing scope. Discussion This evolution might be critical for the future of AIDS treatment in low-income countries, yet it is proposed at a time when the Global Fund to fight AIDS, Tuberculosis and Malaria is starved for resources. It might be unable to meet the needs of much broader and more expensive proposals. Furthermore, it might lose some of its exceptional features in the process: its aim for international sustainability, rather than in-country sustainability, and its capacity to circumvent spending restrictions imposed by the International Monetary Fund. Summary The authors believe that a transformation of the Global Fund to fight AIDS, Tuberculosis and Malaria into a Global Health Fund is feasible, but only if accompanied by a substantial increase of donor commitments to the Global Fund. The transformation of the Global Fund into a 'diagonal' and ultimately perhaps 'horizontal' financing approach should happen gradually and carefully, and be accompanied by measures to safeguard its exceptional features.

  17. ASRM test report: Autoclave cure process development

    Science.gov (United States)

    Nachbar, D. L.; Mitchell, Suzanne

    1992-01-01

    ASRM insulated segments will be autoclave cured following insulation pre-form installation and strip wind operations. Following competitive bidding, Aerojet ASRM Division (AAD) Purchase Order 100142 was awarded to American Fuel Cell and Coated Fabrics Company, Inc. (Amfuel), Magnolia, AR, for subcontracted insulation autoclave cure process development. Autoclave cure process development test requirements were included in Task 3 of TM05514, Manufacturing Process Development Specification for Integrated Insulation Characterization and Stripwind Process Development. The test objective was to establish autoclave cure process parameters for ASRM insulated segments. Six tasks were completed to: (1) evaluate cure parameters that control acceptable vulcanization of ASRM Kevlar-filled EPDM insulation material; (2) identify first and second order impact parameters on the autoclave cure process; and (3) evaluate insulation material flow-out characteristics to support pre-form configuration design.

  18. Systemic therapy with oncolytic myxoma virus cures established residual multiple myeloma in mice.

    Science.gov (United States)

    Bartee, Eric; Bartee, Mee Y; Bogen, Bjarne; Yu, Xue-Zhong

    2016-01-01

    Multiple myeloma is an incurable malignancy of plasma B-cells. Traditional chemotherapeutic regimes often induce initial tumor regression; however, virtually all patients eventually succumb to relapse caused by either reintroduction of disease during autologous transplant or expansion of chemotherapy resistant minimal residual disease. It has been previously demonstrated that an oncolytic virus known as myxoma can completely prevent myeloma relapse caused by reintroduction of malignant cells during autologous transplant. The ability of this virus to treat established residual disease in vivo, however, remained unknown. Here we demonstrate that intravenous administration of myxoma virus into mice bearing disseminated myeloma results in the elimination of 70-90% of malignant cells within 24 hours. This rapid debulking was dependent on direct contact of myxoma virus with residual myeloma and did not occur through destruction of the hematopoietic bone marrow niche. Importantly, systemic myxoma therapy also induced potent antimyeloma CD8(+) T cell responses which localized to the bone marrow and were capable of completely eradicating established myeloma in some animals. These results demonstrate that oncolytic myxoma virus is not only effective at preventing relapse caused by reinfusion of tumor cells during stem cell transplant, but is also potentially curative for patients bearing established minimal residual disease.

  19. Systemic therapy with oncolytic myxoma virus cures established residual multiple myeloma in mice

    Directory of Open Access Journals (Sweden)

    Eric Bartee

    2016-01-01

    Full Text Available Multiple myeloma is an incurable malignancy of plasma B-cells. Traditional chemotherapeutic regimes often induce initial tumor regression; however, virtually all patients eventually succumb to relapse caused by either reintroduction of disease during autologous transplant or expansion of chemotherapy resistant minimal residual disease. It has been previously demonstrated that an oncolytic virus known as myxoma can completely prevent myeloma relapse caused by reintroduction of malignant cells during autologous transplant. The ability of this virus to treat established residual disease in vivo, however, remained unknown. Here we demonstrate that intravenous administration of myxoma virus into mice bearing disseminated myeloma results in the elimination of 70–90% of malignant cells within 24 hours. This rapid debulking was dependent on direct contact of myxoma virus with residual myeloma and did not occur through destruction of the hematopoietic bone marrow niche. Importantly, systemic myxoma therapy also induced potent antimyeloma CD8+ T cell responses which localized to the bone marrow and were capable of completely eradicating established myeloma in some animals. These results demonstrate that oncolytic myxoma virus is not only effective at preventing relapse caused by reinfusion of tumor cells during stem cell transplant, but is also potentially curative for patients bearing established minimal residual disease.

  20. The 21st Century Cures Act Implications for the Reduction of Racial Health Disparities in the US Criminal Justice System: a Public Health Approach.

    Science.gov (United States)

    Cole, Donna M; Thomas, Dawna Marie; Field, Kelsi; Wool, Amelia; Lipiner, Taryn; Massenberg, Natalie; Guthrie, Barbara J

    2017-11-09

    Past drug epidemics have disproportionately criminalized drug addiction among African Americans, leading to disparate health outcomes, increased rates of HIV/AIDS, and mass incarceration. Conversely, the current opioid addiction crisis in the USA focuses primarily on white communities and is being addressed as a public health problem. The 21st Century Cures Act has the potential to reduce racial health disparities in the criminal justice system through the Act's public health approach to addiction and mental health issues. The 21st Century Cures Act is a progressive step in the right direction; however, given the historical context of segregation and the criminalization of drug addiction among African Americans, the goals of health equity are at risk of being compromised. This paper discusses the implications of this landmark legislation and its potential to decrease racial health disparities, highlighting the importance of ensuring that access to treatment and alternatives to incarceration must include communities of color. In this paper, the authors explain the key components of the 21st Century Cures Act that are specific to criminal justice reform, including a key objective, which is treatment over incarceration. We suggest that without proper attention to how, and where, funding mechanisms are distributed, the 21st Century Cures Act has the potential to increase racial health disparities rather than alleviate them.

  1. Influence of different curing systems on the physico-mechanical properties and stability of SBR and NR rubbers

    CERN Document Server

    Basfar, A A; Mofti, S

    2002-01-01

    The physical properties of radiation, sulfur and peroxide-cured styrene-butadiene rubber (SBR) and natural rubber (NR) were compared. The dependence of the mechanical properties of the radiation-vulcanized SBR and NR on the coagent concentration and radiation dose was studied. The effect of thermal aging on the mechanical properties of the different rubber formulations was discussed. The radiation-cured formulations of SBR have superior mechanical properties and thermal stability compared with those of the chemically vulcanized compounds. Whereas, the radiation-cured formulations of NR have similar mechanical properties but superior thermal stability (based on the % change in E after thermal aging), when compared with those of the sulfur-vulcanized compounds and slightly better than those of the peroxide-vulcanized compounds.

  2. Shear strength development of the phenol–formaldehyde adhesive bond during cure

    OpenAIRE

    Jost, Matej; Sernek, Milan

    2008-01-01

    The development of the shear strength of the phenol-formaldehyde (PF) adhesive bond during curing was investigated. Five different PF adhesive mixtures and 1.1 mm thick peeled beech (Fagus sylvatica L.) veneer were used to produce lap-shear specimens, which were cured at a pressing temperature of 160°C. Dielectric analysis (DEA) and modified ABES (automated bonding evaluation system) were used to evaluate the physical-chemical and mechanical aspects of PF adhesive cure in a miniature hot-pres...

  3. Can consumers cure healthcare?

    Science.gov (United States)

    Gruber, David

    2009-01-01

    The U.S. healthcare delivery system is in crises. Costs are too high and increasingly becoming unaffordable to federal and state governments, employers and consumers. Americans are dissatisfied with the current system and believe it should be fundamentally altered or rebuilt. A solution needs to be found, and it is not the single-payer system espoused by many in Washington and elsewhere. We believe consumers can cure healthcare if (a) professionals, providers and policy experts shift their mindset from treating diseases and conditions to taking a holistic approach to the caring of people, particularly Baby Boomers and their parents; (b) technology becomes widely available to increase engagement, personalize healthcare, share experiences, make better choices and embrace convenience and (c) a cost-effective and reimbursed primary care navigator (coordinator and/or health manager), consistent with the medical home concept espoused by the American Association of Family Practitioners (AAFP) becomes a central component of public policy.

  4. Processing-property relationships in autocalve-cured graphite-fiber/epoxy-resin composites

    Energy Technology Data Exchange (ETDEWEB)

    Wang, H.T.

    1988-01-01

    Research was conducted to model processing and investigate relationships between processing and physical/mechanical properties in autoclave-cured unidirectional graphite/epoxy composites. Particular attention was given to the cure kinetics, the temperature distribution inside the composite during cure, the chemorheology, the resin flow, and the physical/mechanical properties of the neat resin and its composites. The TGDDM/DDS epoxy system and unidirectional graphite fiber-reinforced composites were chosen for the study. The kinetics of neat resin and its prepreg were evaluated. Changes in temperature distribution in a composite during cure as a function of cure time and position were predicted by solving an energy-balance equation. A modified WLF equation was proposed as a theoretical model to predict changes of the chemoviscosity during cure; experimental data were generated from a cone-and-plate rheometer. Resin flow during cure was characterized by investigating the cross-section area of the composite. Finally, the effect of the curing process on the physical/mechanical properties of neat resin and composite was evaluated. Matrix-dominated failure mode was assessed. Both strength characterization and fracture mechanics test methods were performed.

  5. Drug release from kollicoat SR 30D-coated nonpareil beads: Evaluation of coating level, plasticizer type, and curing condition

    OpenAIRE

    Shao, Zezhi J.; Morales, Luis; Diaz, Steven; Muhammad, Nouman A.

    2002-01-01

    A newly available polyvinylacetate aqueous dispersion, Kollicoat SR 30D, was evaluated with respect to its ability to modulate the in vitro release of a highly water-soluble model compound (diphenhydramine hydrochloride) from nonpareil-based systems. Kollicoat SR 30D premixed with a selected plasticizer (10% wt/wt propylene glycol, 2.5% triethyl citrate, or 2.5% dibutyl sebacute), talc, and red #30 lake dye was coated onto the drug beads in an Aeromatic Strea I fluid-bed drier with a Wurster ...

  6. TECHNICAL DESIGN NOTE: A simple and low-cost cure monitoring system based on a side-polished plastic optical fibre

    Science.gov (United States)

    Bilro, L.; Alberto, N.; Pinto, J. L.; Nogueira, R. N.

    2010-11-01

    A novel cure monitoring system based on a side-polished interface on a plastic optical fibre is presented. Due to the mismatch of the refractive index of the fibre core and the external medium, part of the light beam is transmitted along the optical fibre by internal reflection and part is refracted in the sensitive zone. The phenomenon behind the principle of operation of the sensor is the reflection and transmission of light at an interface of two dielectric media traduced by Fresnel's equations. A good agreement between numerical and experimental results was achieved and real-time monitoring of the cure process was accomplished for a polyurethane resin and two different varnishes.

  7. Multibunch Instabilities and Cures

    Energy Technology Data Exchange (ETDEWEB)

    Fox, John D

    2003-05-23

    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.

  8. Cure shrinkage in casting resins

    Energy Technology Data Exchange (ETDEWEB)

    Spencer, J. Brock [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2015-02-01

    A method is described whereby the shrinkage of a casting resin can be determined. Values for the shrinkage of several resin systems in frequent use by Sandia have been measured. A discussion of possible methods for determining the stresses generated by cure shrinkage and thermal contraction is also included.

  9. Mechanical properties and degree of conversion of etch-and-rinse and self-etch adhesive systems cured by a quartz tungsten halogen lamp and a light-emitting diode.

    Science.gov (United States)

    Gaglianone, Lívia Aguilera; Lima, Adriano Fonseca; Gonçalves, Luciano Souza; Cavalcanti, Andrea Nóbrega; Aguiar, Flávio Henrique Baggio; Marchi, Giselle Maria

    2012-08-01

    The aim of the present study was to evaluate the degree of conversion (DC), elastic modulus (E), and flexural strength (FS) of five adhesive systems (only the bonding component of both Scotchbond MP-SBMP and Clearfil Protect Bond-CP; Single Bond 2-SB2; One-up Bond F Plus-OUP; and P90 System Adhesive: primer-P90P and bond-P90B) cured with a quartz tungsten halogen (QTH) lamp and a light-emitting diode (LED). Two groups per adhesive were formed (n=5), according to the light source (quartz tungsten halogen-QTH: Demetron LC; and light-emitting diode-LED: UltraLume 5). Bar-shaped specimens were evaluated using three-point bending. The DC was obtained by Fourier transform infrared spectroscopy (FTIR). SB2 and P90P exhibited better DC values for QTH curing. However, SB2 and P90P presented the worst results overall. The light source was statistically significant for all adhesives, except for P90B and OUP. Non-solvated adhesives presented the best E and FS values. It could be concluded that the DC and E values can be influenced by the light source; however, this interference is material dependent. Copyright © 2012 Elsevier Ltd. All rights reserved.

  10. Curing of Concrete

    African Journals Online (AJOL)

    use it economically. Curing of concrete involves the retention of sufficient free water in the cement paste so that the process of cement hydration may readily proceed. It also involves favorable temperature, humidity, and wind speed. No part of the process of making good concrete is more important than thorough curing.

  11. Cure Chemistry of Phenylethynyl Terminated Oligomers

    Science.gov (United States)

    Wood, Karen H.; Orwoll, Robert A.; Young, Philip R.; Jensen, Brian J.; McNair, Harold M.

    1997-01-01

    The ability to process high performance polymers into quality, void-free composites has been significantly advanced using oligomers terminated with reactive groups which cure or crosslink at elevated temperature without the evolution of volatile byproducts. Several matrix resin systems of considerable interest to the aerospace community utilize phenylethynyl-terminated imide (PETI) technology to achieve this advantage. The present paper addresses the cure chemistry of PETI oligomers. The thermal cure of a low molecular weight model compound was studied using a variety of analytical techniques including differential scanning calorimetry, Fourier transform infrared spectroscopy, and liquid chromatography-mass spectroscopy. The studies indicate an extremely complex cure process. Many stable products were isolated and this paper reports current work on identification of those products. The intent of this research is to provide fundamental insight into the molecular structure of the cured PETI engineering materials so that performance and durability can be more fully assessed.

  12. Technical and systems evaluations

    Energy Technology Data Exchange (ETDEWEB)

    Skolnik, E.G.; DiPietro, J.P. [Energetics, Inc., Washington, DC (United States)

    1998-08-01

    During FY 1998 Energetics performed a variety of technology-based evaluations for the Hydrogen Program. Three evaluations are summarized below: hydrogen bromine-based electricity storage, carbon-based hydrogen storage, and hydrogen-fueled buses.

  13. Acceleration of curing period of pastrami manufactured from buffalo meat: II-Fatty acids, amino acids, nutritional value and sensory evaluation

    Directory of Open Access Journals (Sweden)

    Ibrahim, Hayam M.A.

    2001-04-01

    Full Text Available Upon accelerating the curing period of pastrami (dry cured meat prepared from buffalo lean round muscles using heat treatment (~71ºC internally, the results indicated that: the peroxide and thiobarbituric acid (TBA values increased with increasing the aging period. Percentage of the released free fatty acids was 1.21 after heat treatment and increased gradually to reach 1.47 after hanging in air at room temperature for drying and complete curing up to 6 days. The major saturated and unsaturated fatty acids in all of the pastrami samples were palmitic (16:0, oleic (18:1 and linoleic (18:2 fatty acids. The main three identified polyunsaturated fatty acids (linoleic, linolenic and arachidonic were of high percentages in the accelerated cured samples than in the control one. The ratio of the unsaturated: saturated fatty acids was similar in either the heat treated (1.28:1 and the control (1.27: 1 pastrami samples. Similar findings were found for the ratio of total essential amino acids (EAAS: total amino acids (AAS. The Essential Amino Acids Index (EAAI that possesses higher percentage for the heat treated sample than that for the control one proved the higher biological acceptance of the heat accelerated cured pastrami sample. The predicted protein efficiency ratio (PER of all the investigated samples reached more than 2.42 of casein. Sensory evaluation of the pastrami sample processed to an internal temperature of ~71ºC proved by the panelists to be of attractive color, more tasty, of good characteristic odor and more tender than the control samples which were prepared and cured for 3 weeks without using heat treatment.En relación a la aceleración del período de cura del pastrami (carne curada en seco preparada a partir de carne magra de búfalo usando un tratamiento térmico (~71ºC internamente, los resultados indicaron que los valores de peróxido y ácido tiobarbitúrico (TBA aumentaron con el envejecimiento. El porcentaje de

  14. Demonstration and evaluation of an innovative water main rehabilitation technology: Cured-in-Place Pipe (CIPP) lining

    Science.gov (United States)

    As many water utilities are seeking new and innovative rehabilitation technologies to extend the life of their water distribution systems, information on the capabilities and applicability of new technologies is not always readily available from an independent source. The U.S. E...

  15. Hypoxanthine enhances the cured meat taste.

    Science.gov (United States)

    Ichimura, Sayaka; Nakamura, Yukinobu; Yoshida, Yuka; Hattori, Akihito

    2017-02-01

    We evaluated the enhancement of cured meat taste during maturation by sensory analysis. We focused on the heat-stable sarcoplasmic fraction (HSSF) to identify the factors related to cured meat taste. Because the dry matter of HSSF contained more than 30% nitrogen, nitrogen compounds such as free amino acids, small peptides and adenosine triphosphate-related compounds seemed to be the important components of HSSF. The samples cured with HSSF for 2 h exhibited the same taste profile as ones cured without HSSF for 168 h. Therefore, the changes in the amount and fractions of nitrogen compounds were examined in HSSF during incubation from 0 to 168 h. The concentration of hypoxanthine (Hx) gradually increased, while inosine-5'-monophosphate decreased during the incubation. The samples cured with pickles containing various concentrations of Hx were subjected to sensory analysis. The addition of Hx, in a dose-dependent fashion, enhanced cured meat taste by maturation for 2 h. It was concluded that Hx is essential for the enhancement of cured meat taste. © 2016 The Authors. Animal Science Journal published by John Wiley & Sons Australia, Ltd on behalf of Japanese Society of Animal Science.

  16. Hypoxanthine enhances the cured meat taste

    Science.gov (United States)

    Nakamura, Yukinobu; Yoshida, Yuka; Hattori, Akihito

    2016-01-01

    Abstract We evaluated the enhancement of cured meat taste during maturation by sensory analysis. We focused on the heat‐stable sarcoplasmic fraction (HSSF) to identify the factors related to cured meat taste. Because the dry matter of HSSF contained more than 30% nitrogen, nitrogen compounds such as free amino acids, small peptides and adenosine triphosphate‐related compounds seemed to be the important components of HSSF. The samples cured with HSSF for 2 h exhibited the same taste profile as ones cured without HSSF for 168 h. Therefore, the changes in the amount and fractions of nitrogen compounds were examined in HSSF during incubation from 0 to 168 h. The concentration of hypoxanthine (Hx) gradually increased, while inosine‐5′‐monophosphate decreased during the incubation. The samples cured with pickles containing various concentrations of Hx were subjected to sensory analysis. The addition of Hx, in a dose‐dependent fashion, enhanced cured meat taste by maturation for 2 h. It was concluded that Hx is essential for the enhancement of cured meat taste. PMID:27169902

  17. 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)

  18. Evaluation of shear bond strength of three different types of artificial teeth to heat cure denture base resin: An in vitro study

    Directory of Open Access Journals (Sweden)

    B Chittaranjan

    2013-01-01

    Conclusion: The results of this study suggest that there were significant differences in shear bond strength among control group and surface treatment groups of denture teeth bonded to heat cure denture base resin.

  19. In situ stabilization/solidification pilot testing of coal tar contaminated sediment focusing on mix uniformity, post-treatment curing and workability evaluation, Sydney Harbour, Nova Scotia

    Energy Technology Data Exchange (ETDEWEB)

    Carbonneau, K.; Flood, P.J.; Noble, B. [AECOM Environmental, Los Angeles, CA (United States)

    2010-07-01

    A study conducted by Environment Canada during the 1980s demonstrated the presence of polycyclic aromatic hydrocarbons (PAHs) above risk benchmarks for aquatic organisms in the sediments of estuarine ponds located in Sydney Harbour, Nova Scotia. This paper presented the results of pilot-scale demonstration conducted to determine post-treatment uniformity and workability of the solidification/stabilization (S/S) solution used to remove exposure pathways, reduce erodability, and improve sediment strength. Interlocking steel sheet pile (SSP) was driven through the sediment into the underlying natural soils in 6 distinct cells in order to evaluate multiple reagent mix designs. Grain size distribution, moisture content, and sediment bulk density were measured. Dynamic cone penetrometer tests were conducted after each cell was mixed. Samples were taken to assess unconfined compressive strength and hydraulic conductivity. The post-treatment curing and workability rate was also assessed. Results of the study showed consistent hardness with depth in each cell and increasing hardness with depth as a function of the cement content of the mix. The post-treated material did not exhibit a well-defined moisture density relationship. Moisture sensitivity was demonstrated by a rapid loss of strength upon a relatively small increase in moisture content. 5 refs., 3 tabs., 8 figs.

  20. Polymerization of a dual-cured cement through ceramic: LED curing light vs halogen lamp.

    Science.gov (United States)

    Lopes, Lawrence Gonzaga; Franco, Eduardo Batista; Name Neto, Abrão; Herrera, Francyle S; Kurachi, Cristina; Castañeda-Espinosa, Juan C; Lauris, José Roberto Pereira

    2004-12-01

    The aim of this study was to investigate the influence of light source, LED unit and halogen lamp (HL), on the effectiveness of Enforce dual-cured cement cured under a ceramic disc. Three exposure times (60, 80 and 120 s) were also evaluated. Two experimental groups, in which the polymerization of the dual-cured cement was performed through a ceramic disc, and two control groups, in which the polymerization of the dual-cured cement was performed directly without presence of ceramic disc were subdivided into three subgroups (three different exposure times), with five specimens each: G1A- HL 60s; G1B- HL 80s; G1C- HL 120s; G2A- LED 60s; G2B- LED 80s; G2C- LED 120s; and control groups: G3A- HL 60s; G3B- HL 80s; G3C- HL 120s; G4A- LED 60s; G4B- LED 80s and G4C- LED 120s. Cement was applied in a steel matrix (4mm diameter, 1.2mm thickness). In the experimental groups, a ceramic disc was placed on top. The cement was light-cured through the ceramic by a HL and LED, however, the control groups were cured without the ceramic disc. The specimens were stored in a light-proof container at 37ºC for 24 hours, then Vickers hardness was determined. A four-way ANOVA and Tukey test (p£ 0.05) were performed. All specimens cured by LED for 60s showed inferior values compared with the halogen groups. In general, light-curing by LED for 80s and 120s was comparable to halogen groups (60s and 80s) and their control groups. LED technology can be viable for light-curing through conventional ceramic indirect restorations, when curing time is increased in relation to HL curing time.

  1. Use of Gypsum as a Preventive Measure for Strength Deterioration during Curing in Class F Fly Ash Geopolymer System

    Science.gov (United States)

    Jun, Yubin; Oh, Jae Eun

    2015-01-01

    This study discusses strength deterioration during the curing process of fly ash geopolymer and the use of CaSO4·2H2O (gypsum) as a deterioration remedy when the ash was synthesized using a 10M NaOH and Na-silicate solution. The strength decline was mainly due to the widespread formation of nanometer-sized cracks that were related to excessive Na and Si concentrations at an early age. Use of 2 wt% CaSO4·2H2O resulted in the best measured strength by temporarily reducing Na and Si concentrations; Na was absorbed by SO42−, up to 11% in the matrix within one day, and formed Na2SO4 (thenardite), which gradually dissolved over time, slowly releasing Na ions. However, more than 4% gypsum suppressed overall strength development because too many Na ions were locked into Na2SO4 and could not participate in geopolymerization. The addition of gypsum impeded glass dissolution and even halted the process when more than 4% gypsum was used.

  2. Pervious Pavement System Evaluation

    Science.gov (United States)

    Pervious pavement is a low impact development stormwater control. The Urban Watershed Management Branch of the U.S. Environmental Protection Agency in Edison, NJ, is evaluating concrete pavers as a popular implementation. The pollutant removal of a bench-scale permeable interlo...

  3. Produce Sanitation System Evaluation

    Science.gov (United States)

    2011-05-01

    was also expected to improve food safety (i.e., reduce microbes) and reduce premature spoilage while minimizing environmental impact and unpleasant...PRECISION REDUCTION VEGETABLES CONTAMINATION TEST AND EVALUATION SAFETY PH FACTOR SANITATION FRESH FOODS MICROORGANISMS ...fruits and vegetables (FF&V) aboard Navy vessels, The sink saves labor associated with the washing of produce in food service operations by

  4. Polymerization and polymerization shrinkage stress: fast cure versus conventional cure.

    Science.gov (United States)

    Strydom, C

    2005-07-01

    Dentists nowadays have a choice of conventional halogen lights, halogen lights with more sophisticated curing cycles (step-cure, rapid-cure, ramp-cure & pulse-cure), fast halogen lights, laser lights, plasma arc lights (PAC) and, lately, LED lights. While the manufacturers of some of the curing units try to improve on the operational reliability of their lights with a slower initial rate of cure, other manufacturers simply wish to offer as fast a curing time as possible. The conventional approach to cure accepts that sufficient light intensity of at least 400 mW/cm2 at a wavelength of 400-500 nm, and an exposure time of at least 40 seconds is needed to cure a 2-mm layer of composite. When a halogen light with higher or very high intensity is used, alternative curing strategies provide for an initial slower cure to allow flow, and after that a higher-intensity cure to improve the degree of cure. In contrast, in the fast-cure or rapid-cure approach it is suggested that a layer of composite can be cured for only 5- 10 seconds at >2000 mW/cm2. Some go so far as to say that an exposure time of 3 seconds per layer may be enough. This contradictory approach is compounded by the fact that this support for fast cure does not seem to consider the negative consequences. Therefore, to address these concerns, this review discusses the possible effects of a fast cure approach compared to a more conventional approach in polymerization and polymerization shrinkage, and the consequences there-off. Other factors that play an influencing role in polymerization shrinkage stress are also included in the discussion.

  5. [To be cured of breast cancer].

    Science.gov (United States)

    Bobin, Jean-Yves; Guiochet, Nicole; Saez, Simone

    2002-06-01

    Can we say the magic word "cured", "cancer free" for breast cancer patients or can we say only survivors? This litterature review was focused on what mean cured of breast cancer with the long term effects on quality of life of locoregional and systemic therapies and the role of breast reconstruction. Finally changes in the intimacy, sex and love live and psychosocial live were stressed.

  6. 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.

  7. Evaluation of useful treatment which uses dual-energy when curing lung-cancer patient with stereotactic body radiation therapy

    Energy Technology Data Exchange (ETDEWEB)

    Jang, Hyeong Jun; Lee, Yeong Gyu; Kim, Yeong Jae; Park, Yeong Gyu [Dept. of Radiation Oncology, Catholic University Seoul St Mary' s hospital, Seoul (Korea, Republic of)

    2016-12-15

    This study will evaluate the clinical utility by applying clinical schematic that uses monoenergy or dual energy as according to the location of tumors to the stereotactic radiotherapy to compare the change in actual dose given to the real tumor and the dose that locates adjacent to the tumor. CT images from a total of 10 patients were obtained and the clinical planning were planned based on the volumetric modulated arc therapy on monoenergy and dual energy. To analyze the change factor in the tumor, Conformity Index(CI) and Homogeneity Index(HI) and maximum dose quantity were each calculated and comparing the dose distribution on normal tissues, v{sub 10} and v{sub 5}, first ⁓ fourth ribs closest to the tumor (1st ⁓ 4th Rib), Spinal Cord, Esophagus and Trachea were selected. Also, in order to confirm the accuracy on which the planned dose distribution is really measured, the 2-dimensional ion chamber array was used to measure the dose distribution. As of the tumor factor, CI and HI showed a number close to 1 when the two energies were used. As of the maximum dose, the front chest wall showed 2% and the dorsal tumor showed equivalent value. As of normal tissue, the front chest wall tumors were reduced by 4%, 5% when both energies were used in the adjacent rib and as of trachea, reduced by 11%, 17%. As of the dose in the lung, as of v{sub 10}, it reduced by 1.5%, v{sub 5} by 1%. As of the rear chest wall, when both energies were used, the ribs adjacent to the tumors showed 6%, 1%, 4%, 12% reduction, and in the lung dose distribution, v{sub 10} reduced by 3%, and v{sub 5} reduced by 3.1%. The dose measurement in all energies were in accordance to the results of Gamma Index 3mm/3%. Conclusion : It is considered that rather than using monoenergy, utilizing double energy in the clinical setting can be more effectively applied to the superficial tumors.

  8. The stability of new transparent polymeric materials: The epoxy trimethoxyboroxine system. Part 1: The preparation, characterization and curing of epoxy resins and their copolymers

    Science.gov (United States)

    Pearce, E.; Lin, S. C.

    1981-01-01

    The effects of resin composition, curing conditions fillers, and flame retardant additives on the flammability of diglycidyl ether of bisphenol-A (DGEBA) as measured by the oxygen index is examined. The oxygen index of DGEBA cured with various curing agents was between 0.198 to 0.238. Fillers and flame retardant additives can increase the oxygen index dependent on the material and the amount used. Changes in the basic cured resin properties can be anticipated with the addition of noncompatible additives. High flame resistant epoxy resins with good stability and mechanical properties are investigated.

  9. Polymerization efficiency of two dual-cure cements through dental ceramics.

    Science.gov (United States)

    Turp, Volkan; Ongul, Deger; Gultekin, Pınar; Bultan, Ozgur; Karataslı, Burcin; Pak Tunc, Elif

    2015-01-01

    The aim of this study was to evaluate the effect of thickness of zirconia on curing efficiency of resin cements. Four discs with 4.0 mm in diameter were prepared from non-HIP translucent zirconia blocks using a CAD/CAM system and feldspathic ceramic was layered onto discs. Thus, 4 ceramic disc samples were fabricated: (G) 0.5 mm zirconia- as a control group, (G1) 0.5 mm zirconia and 0.5 mm feldspathic, (G2) 1.0 mm zirconia and 0.5 mm feldspathic and (G3) 2.0 mm zirconia and 0.5 mm feldspathic ceramic layer. 2 different dual cure cements were polymerized using a LED curing unit. Degree of conversion was evaluated using Vickers Hardness Test and depths of cure of samples were measured. Data were analyzed statistically using One-way ANOVA and Tukey's HSD test (pceramic discs for two resin cements. As the thickness of the zirconia discs increased, the microhardness values and depth of cure decreased. Photocuring time cannot be the same for all clinical conditions, under thicker zirconia restorations (>2.0 mm), an extended period of light curing or a light unit with a high irradiance should be used.

  10. [Comparative evaluation of the marginal accuracy of single crowns fabricated computer using aided design/computer aided manufacturing methods, self-curing resin and Luxatemp].

    Science.gov (United States)

    Jianming, Yuan; Ying, Tang; Feng, Pan; Weixing, Xu

    2016-12-01

    This study aims to compare the marginal accuracy of single crowns fabricated using self-curing resin, Luxatemp, and computer aided design/computer aided manufacturing (CAD/CAM) methods in clinical application. A total of 30 working dies, which were obtained from 30 clinical teeth prepared with full crown as standard, were created and made into 30 self-curing resin, Luxatemp, and CAD/CAM single crowns. The restorations were seated on the working dies, and stereomicroscope was used to observe and measure the thickness of reference points. One-way analysis of variance, which was performed using SPSS 19.0 software package, compared the marginal gap widths of self-curing resin, Luxatemp, and CAD/CAM provisional crowns. The mean marginal gap widths of the fabricated self-curing resin, Luxatemp, and CAD/CAM were (179.06±33.24), (88.83±9.56), and (43.61±7.27) μm, respectively. A significant difference was observed among the three provisional crowns (Pcrown was lower than that of the self-curing resin and Luxatemp. Thus, the CAD/CAM provisional crown offers a better remediation effect in clinical application.

  11. MTA Computer Based Evaluation System.

    Science.gov (United States)

    Brenner, Lisa P.; And Others

    The MTA PLATO-based evaluation system, which has been implemented by a consortium of schools of medical technology, is designed to be general-purpose, modular, data-driven, and interactive, and to accommodate other national and local item banks. The system provides a comprehensive interactive item-banking system in conjunction with online student…

  12. 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.

  13. The Clay that Cures

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 6; Issue 2. Hydrotalcite - The Clay that Cures. N Bejoy. General Article Volume 6 Issue 2 February 2001 pp 57-61. Fulltext. Click here to view fulltext PDF. Permanent link: http://www.ias.ac.in/article/fulltext/reso/006/02/0057-0061. Author Affiliations.

  14. Miraculous cures in gynaecology

    NARCIS (Netherlands)

    Lammes, F. B.

    1988-01-01

    As a gynaecologist-oncologist one will quite often have been confronted with patients who have informed one of fairly impressive results of methods of alternative medicine. These convincing stories must have been impressive. Very often one may wonder about these 'cures'. There are, however, patients

  15. 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

  16. Curing Children's Cancer

    Science.gov (United States)

    ... Bar Home Current Issue Past Issues Cover Story: Leukemia/Lymphoma Curing Children's Cancer Past Issues / Summer 2008 Table of Contents ... transplants a blunt, toxic tool for fragile young children. "They represent ... high-risk leukemias, like Madelen's. But developments have not been fast ...

  17. 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. Copyright © 2014 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  18. Evaluation of intrapulpal temperature changes caused by bulk-fill composite resins cured with different light-source modes: ex vivo

    Directory of Open Access Journals (Sweden)

    Çiğdem Atalayın

    2017-05-01

    Full Text Available Objective: The aim was to evaluate the effects on intrapulpal temperature change of two different LED light-source modes used during the polymerization of bulk-fill composite resins placed in deep cavities. Materials and Method: Human extracted mandibular molar teeth (n=5 were used to create single-tooth model with an occlusal dentin-thickness of 0.5 mm. Filtek Bulk Fill Posterior (3M ESPE and SDR (Dentsply were applied according to manufacturers’ instructions. A conventional composite resin, Filtek Z250 (3M ESPE was used as control. The soft and turbo modes of LED (Bluephase 20i, Ivoclar Vivadent were used for polymerization. Intrapulpal temperature changes were determined by using a device simulating pulpal blood microcirculation. For each material, initial and maximum temperature was determined during the curing. Difference between the initial and the highest temperature value was considered as the maximum temperature change (Δt. The data were analyzed with two-way variance analysis and post-hoc Tukey test (p<0.05. Results: The turbo mode was found to cause significantly greater temperature rise than the soft mode (p<0.001; Tukey test. When the filling material was taken as the variable, the greatest temperature change was observed in the SDR, whereas the least temperature change was observed in the control (p<0.05; Tukey test. Conclusion: The polymerization of bulk-fill composite resins in the turbo mode of the LED light-source led to greater pulpal temperature rise. The materials’ content and structure also affected the temperature increase. Using the soft mode of a LED light-source for the polymerization of bulk-fill composite resins in deep cavities is preferable to keep the intrapulpal temperature rise minimum.

  19. Control Evaluation Information System Savings

    Directory of Open Access Journals (Sweden)

    Eddy Sutedjo

    2011-05-01

    Full Text Available The purpose of this research is to evaluate the control of information system savings in the banking and to identify the weaknesses and problem happened in those saving systems. Research method used are book studies by collecting data and information needed and field studies by interview, observation, questioner, and checklist using COBIT method as a standard to assess the information system control of the company. The expected result about the evaluation result that show in the problem happened and recommendation given as the evaluation report and to give a view about the control done by the company. Conclusion took from this research that this banking company has met standards although some weaknesses still exists in the system.Index Terms - Control Information System, Savings

  20. 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

  1. New Evaluation System Wins Approval

    Science.gov (United States)

    Barrett, Laura

    2011-01-01

    All Massachusetts school districts will have to adopt new evaluation systems based on a state framework that was approved by the Board of Elementary and Secondary Education on June 28. The new system will be phased in over three years, beginning with Level 4 schools--those designated "underperforming" by the state--in the 2011-12 school…

  2. Effect of curing protocol on the polymerization of dual-cured resin cements.

    Science.gov (United States)

    Pereira, Sónia G; Fulgêncio, Rogério; Nunes, Teresa G; Toledano, Manuel; Osorio, Raquel; Carvalho, Ricardo Marins

    2010-07-01

    The purpose of this study was to evaluate how curing protocol affects the extent of polymerization of dual-cured resin cements. Four commercial resin cements were used (DuoLink, Panavia F 2.0, Variolink II and Enforce). The extent of polymerization of the resin cements cured under different conditions was measured using a (1)H Stray-Field MRI method, which also enabled to probe molecular mobility in the kHz frequency range. Resin cements show well distinct behaviours concerning chemical cure. Immediate photo-activation appears to be the best choice for higher filler loaded resin cements (Panavia F 2.0 and Variolink). A photo-activation delay (5 min) did not induce any significant difference in the extent of polymerization of all cements. The extent of polymerization of dual-cured resin cements considerably changed among products under various curing protocols. Clinicians should optimize the materials choice taking into account the curing characteristics of the cements. Copyright 2010 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  3. Comparison of hardness of three temporary filling materials cured by two light-curing devices.

    Science.gov (United States)

    Bodrumlu, E; Koçak, M M; Hazar Bodrumlu, E; Ozcan, S; Koçak, S

    2014-01-01

    Polymerization ability of light-curing devices can affect the light-cured material hardness. The purpose of the present study was to evaluate and compare the hardness of three temporary filling materials that had been light-cured by either a light emitting diode (LED) or a halogen light-curing unit. The temporary filling materials, First Fill, Voco Clip and Bioplic, were placed in wells in a Teflon plate. The 24 specimens of each material were divided into two groups (N.=12/group) for photo-activation by either of the two light-curing units. The LED or halogen device was applied for 40s to the top surface of each specimen. A Knoop hardness test was performed on the top and bottom surface of each specimen, with five measurements per specimen. The highest hardness values for both the LED and halogen treated groups were observed for First Fill and the lowest values were for Voco Clip in top and bottom surfaces. The hardness obtained for the three materials with the halogen unit were significantly higher than the values obtained with the LED unit in both surfaces (Phardness values on the top and bottom surfaces than Voco Clip and Bioplic temporary materials. The hardness of light-cured temporary filling materials can be affected by the type of light-curing unit.

  4. Repair bond strength of dual-cured resin composite core buildup materials.

    Science.gov (United States)

    El-Deeb, Heba A; Ghalab, Radwa M; Elsayed Akah, Mai M; Mobarak, Enas H

    2016-03-01

    The reparability of dual-cured resin composite core buildup materials using a light-cured one following one week or three months storage, prior to repair was evaluated. Two different dual-cured resin composites; Cosmecore™ DC automix and Clearfil™ DC automix core buildup materials and a light-cured nanofilled resin composite; Filtek™ Z350 XT were used. Substrate specimens were prepared (n = 12/each substrate material) and stored in artificial saliva at 37 °C either for one week or three months. Afterward, all specimens were ground flat, etched using Scotchbond™ phosphoric acid etchant and received Single Bond Universal adhesive system according to the manufacturers' instructions. The light-cured nanofilled resin composite (Filtek™ Z350 XT) was used as a repair material buildup. To determine the cohesive strength of each solid substrate material, additional specimens from each core material (n = 12) were prepared and stored for the same periods. Five sticks (0.8 ± 0.01 mm(2)) were obtained from each specimen (30 sticks/group) for microtensile bond strength (μTBS) testing. Modes of failure were also determined. Two-way ANOVA revealed a significant effect for the core materials but not for the storage periods or their interaction. After one week, dual-cured resin composite core buildup materials (Cosmecore™ DC and Clearfil™ DC) achieved significantly higher repair μTBS than the light-cured nanofilled resin composite (Filtek™ Z350 XT). However, Clearfil™ DC revealed the highest value, then Cosmecore™ DC and Filtek™ Z350 XT, following storage for 3-month. Repair strength values recovered 64-86% of the cohesive strengths of solid substrate materials. The predominant mode of failure was the mixed type. Dual-cured resin composite core buildup materials revealed acceptable repair bond strength values even after 3-month storage.

  5. Research Progress on Microwave Curing of Epoxy Resin and Its Composites

    Directory of Open Access Journals (Sweden)

    XU Xue-hong

    2016-08-01

    Full Text Available Research progress of microwave curing on epoxy resin and its composites was summarized on the basis of introducing the principle of microwave curing technology and its advantages. The paper focused on the effect of microwave curing on the curing rate of epoxy resin and its composites as well as the mechanical and thermal properties of cured products. Two suitable composite systems for wave curing of powder-strengthened epoxy and fiber-strengthened epoxy and a few key technological problems for industrial application are introduced. The application prospect of microwave curing on epoxy resin and its composites was also presented.

  6. "System evaluates system": method for evaluating the efficiency of IS

    Directory of Open Access Journals (Sweden)

    Dita Blazkova

    2016-10-01

    Full Text Available In paper I deal with the possible solution of evaluating the efficiency of information systems in companies. The large number of existing methods used to address the efficiency of information systems is dependent on the subjective responses of the user that may distort output evaluation. Therefore, I propose a method that eliminates the subjective opinion of a user as the primary data source. Applications, which I suggests as part of the method, collects relevant data. In this paper I describe the application in detail. This is a follow-on program on any system that runs parallel with it. The program automatically collects data for evaluation. Data include mainly time data, positions the mouse cursor, printScreens, i-grams of previous, etc. I propose a method of evaluation of the data, which identifies the degree of the friendliness of the information system to the user. Thus, the output of the method is the conclusion whether users, who work with the information system, can handle effectively work with it.

  7. Bonding of dual-curing resin cements to dentin.

    Science.gov (United States)

    Asmussen, Erik; Peutzfeldt, Anne

    2006-10-01

    The purpose of the study was three-fold: 1) to determine the strength of the bond between a number of dual-curing resin cements and dentin treated with corresponding adhesive systems, 2) to determine the effect on bond strength of not light curing the cements, and 3) to investigate whether application of a solution of sodium sulfinate or ascorbic acid would increase the bond strength in the cases where the manufacturer's version of an adhesive system resulted in low bond strength with chemically cured cement, ie, cement cured without light. The adhesive systems comprised 5 simplified systems (Adper Scotchbond 1 XT, ED Primer II, Excite DSC, OptiBond Solo Plus, and Prime and Bond NT), and as controls, two three-step etch and rinse systems (Adper Scotchbond Multi-Purpose Plus and Gluma Solid Bond). The corresponding dual-curing resin cements were RelyX ARC, Panavia F 2.0, Variolink II, Nexus 2, Calibra, RelyX ARC, and 2Bond2. The cements were either light and chemically cured or only chemically cured. The adhesive systems were used as recommended by the manufacturers, which for some systems involved inclusion of a so-called activator or catalyst when used with chemically cured cement. Sodium sulfinate and ascorbic acid were applied as a 1% ethanol solution. The bond strengths were measured in shear after storing specimens for 24 h in 37 degree C water. When the dual-curing resin cements had been both light and chemically cured, the bond strengths increased in this order: Gluma Solid Bond cements decreased the bond strengths with OptiBond Solo Plus and Prime and Bond NT. The use of activator in conjunction with OptiBond Solo Plus and Prime and Bond NT increased the bond strength to chemically cured cement, but not to the level obtained when the cement was both light and chemically cured. The use of the catalyst of Adper Scotchbond Multi-Purpose Plus did not increase the bond strength with chemically cured cement. Pretreatment with a solution of sodium sulfinate or

  8. Evaluating a tobacco leaf humidification system involving nebulisation

    Directory of Open Access Journals (Sweden)

    Néstor Enrique Cerquera Peña

    2010-05-01

    Full Text Available A tobacco leaf humidifying system involving nebulisation was designned, implemented and evaluated; it had a system for monitoring and recording environmental conditions thereby producing an environment having more homogeneous relative humidity, ensuring better water use, better control of relative humidity and better control in managing cured tobacco leaf moisture content, thereby leading to a consequent improvement in final product quality. 55% to 75% relative humidity and 4 to 6 hour working ranges were obtained to en- sure leaf humidification reached 16% humidity on a wet basis. Two new designs are proposed for the conditioning stage regarding this conditioning chamber’s operational management, based on the results and field observations, which would allow better leaf management, thereby avoiding the risk of losses due to manipulation and over-humidification. This work strengthens research in the field of tobacco pos- tharvest technology, complementing other research projects which have been carried out in Colombia.

  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. © International & American Associations for Dental Research 2015.

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

    Science.gov (United States)

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

    2015-01-01

    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. PMID:26635279

  11. The effects of Exposure Times and Light Curing Sources on Surface Micro-Hardness of a Resin Modified Glass Ionomer

    Directory of Open Access Journals (Sweden)

    Iman Parisay

    2014-06-01

    Full Text Available Introduction: The aim of this study was to evaluate the influenceof different light curing systems and curing times on the micro-hardness of aresin modified glass ionomer. Methods: Forty two samples of ResinModified Glass Ionomer (RMGI were prepared using stainless steel cylindrical mold(8 × 2 mm and randomly divided into six groups of seven. Three groups werecured with a Quartz Tungsten Halogen (QTH light cure unit and the other threegroups were polymerized with LED unit for 20, 30 and 40 seconds. All sampleswere stored in distilled water for 24 hours. The micro-hardness was measured onthe top and bottom surfaces of the samples by Vickers hardness tester. Datawere analyzed by two–way ANOVA and Tukey’s post-hoc tests. Results: Two-wayANOVA showed that QTH light-cure unit had higher percentage in depth of curethan LED light-curing unit in both surfaces; whereas, the application time hasno significant effect on it. There was no interaction between two variables. Inboth light-curing groups, the values of top and bottom surfaces micro-hardnesswere increased as the application time increased, but there was not anystatistically significant difference among these groups except for 40-second groupof LED light-curing unit which was significantly higher than 20-second and30-second groups (P

  12. An evaluation of casein hydrolyzate in combination with antibiotic for bacterial cure and subsequent increase in milk yield in dairy cows

    Directory of Open Access Journals (Sweden)

    Silanikove Nissim

    2011-01-01

    Full Text Available Abstract Background A 3-yr study examined whether prepartum treatment with casein hydrolyzate in combination with antibiotic, as routinely used in Israel for dry cow therapy, improved bacterial cure and increased milk yield in subsequent lactations in comparison with treatment with antibiotic alone. The vast majority of bacterial isolates in samples collected prior to drying-off comprised coagulase-negative staphylococci, mostly as Staph. chromogenes. Results Bacterial cure associated with the combined treatment was 73.8% in cows, significantly higher than the 51.7% cure recorded when cows were treated only with antibiotic. During the study, the annual milk yield of non-casein hydrolyzate treated and treated control cows increased at ~2% per year, which is consistent with the national annual increase attributed to genetic selection. In cows treated with casein hydrolyzate the increase was 9% (above the 2% expected in the first lactation after the treatment, and 6.3% (above the 4% expected for 2 years in the second lactation after treatment. These increases were significantly higher than those in the controls and those expected through genetic improvement. Conclusions Treatment with casein hydrolyzate at dry-off was shown to be a viable mean to eliminate existing environmental bacterial infection, and to improve milk yield in the next lactation.

  13. Accounting for Cured Patients in Cost-Effectiveness Analysis.

    Science.gov (United States)

    Othus, Megan; Bansal, Aasthaa; Koepl, Lisel; Wagner, Samuel; Ramsey, Scott

    2017-04-01

    Economic evaluations often measure an intervention effect with mean overall survival (OS). Emerging types of cancer treatments offer the possibility of being "cured" in that patients can become long-term survivors whose risk of death is the same as that of a disease-free person. Describing cured and noncured patients with one shared mean value may provide a biased assessment of a therapy with a cured proportion. The purpose of this article is to explain how to incorporate the heterogeneity from cured patients into health economic evaluation. We analyzed clinical trial data from patients with advanced melanoma treated with ipilimumab (Ipi; n = 137) versus glycoprotein 100 (gp100; n = 136) with statistical methodology for mixture cure models. Both cured and noncured patients were subject to background mortality not related to cancer. When ignoring cured proportions, we found that patients treated with Ipi had an estimated mean OS that was 8 months longer than that of patients treated with gp100. Cure model analysis showed that the cured proportion drove this difference, with 21% cured on Ipi versus 6% cured on gp100. The mean OS among the noncured cohort patients was 10 and 9 months with Ipi and gp100, respectively. The mean OS among cured patients was 26 years on both arms. When ignoring cured proportions, we found that the incremental cost-effectiveness ratio (ICER) when comparing Ipi with gp100 was $324,000/quality-adjusted life-year (QALY) (95% confidence interval $254,000-$600,000). With a mixture cure model, the ICER when comparing Ipi with gp100 was $113,000/QALY (95% confidence interval $101,000-$154,000). This analysis supports using cure modeling in health economic evaluation in advanced melanoma. When a proportion of patients may be long-term survivors, using cure models may reduce bias in OS estimates and provide more accurate estimates of health economic measures, including QALYs and ICERs. Copyright © 2017 International Society for Pharmacoeconomics

  14. Avaliação térmica e reológica do ciclo de cura do pré-impregnado de carbono/epóxi Thermal and rheological evaluation of a carbon/epoxy prepreg cure cycle

    Directory of Open Access Journals (Sweden)

    Michelle L. Costa

    2003-07-01

    Full Text Available Parâmetros cinéticos e reológicos relacionados com o ciclo de cura de um sistema de pré-impregnado de resina epóxi (F584/fibra de carbono (prepreg foram determinados pelo uso de análises térmicas (DSC e DMA e reológicas. Os parâmetros determinados foram utilizados para avaliar o ciclo de cura hoje utilizado industrialmente no processamento de compósitos poliméricos pelo uso do prepreg em estudo.Baseando-se nos resultados das análises térmicas realizadas foi constatado para o sistema estudado que a cinética de cura é de ordem n = 1,3 e que a razão de aquecimento mais apropriada na obtenção de compósito polimérico é de 2,5 °C/min, pois esta razão de aquecimento proporciona um ciclo de cura a temperaturas mais baixas, quando comparada às demais razões estudadas, 5 e 10°C/min, favorecendo uma cura mais homogênea e melhor controlada.The kinetic and rheological parameters related to the cure cycle of an epoxy resin (F584/carbon fiber pre-impregnated (prepreg system were determined by thermal and rheological analysis. The results were used to evaluate the cure cycle nowadays used in the composite processing industry, with the same prepreg system. Based on thermal analyses results it was verified that the curing of the epoxy resin follows a polymerization kinetic of n = 1,3 order and that the heating rate more adequate for the composite processing is equal to 2,5 °C/min. This heating rate favors a cure cycle at lower temperatures, when compared to the other heating rates studied, 5 e 10 °C/min, allowing a more homogeneous and better controlled cure reactions.

  15. effect of curing methods on the compressive strength of concrete

    African Journals Online (AJOL)

    Abstract. Different curing methods are usually adopted to evaluate the compressive strength of concrete. This study reports the laboratory results of the effect of curing meth- ods on the compressive strength as well as the density of concrete. A total of 72 cubes of mix ratio 1:2:4 were investigated after subjecting them to ...

  16. Cure-dependent Viscoelastic Poisson’s Ratio of Epoxy

    Science.gov (United States)

    2007-01-26

    Poisson’s ratio in creep and stress relaxation of EPON 828 epoxy cured with tri- ethylenetriamine using geometric moiré with gratings of 20 lines per...cure kinetics [23] and cure-dependent viscoelastic properties [24] of this material. A second system was also investigated, EPON 828 /3274, a bisphenol...Table 1. The EPON 828 /3274 specimens were cured for 48 h at room temperature followed by 10 h at 75◦C to ensure the material was fully reacted. After

  17. Reliability evaluation of power systems

    CERN Document Server

    Billinton, Roy

    1996-01-01

    The Second Edition of this well-received textbook presents over a decade of new research in power system reliability-while maintaining the general concept, structure, and style of the original volume. This edition features new chapters on the growing areas of Monte Carlo simulation and reliability economics. In addition, chapters cover the latest developments in techniques and their application to real problems. The text also explores the progress occurring in the structure, planning, and operation of real power systems due to changing ownership, regulation, and access. This work serves as a companion volume to Reliability Evaluation of Engineering Systems: Second Edition (1992).

  18. Concurrent ultrasonic weld evaluation system

    Science.gov (United States)

    Hood, Donald W.; Johnson, John A.; Smartt, Herschel B.

    1987-01-01

    A system for concurrent, non-destructive evaluation of partially completed welds for use in conjunction with an automated welder. The system utilizes real time, automated ultrasonic inspection of a welding operation as the welds are being made by providing a transducer which follows a short distance behind the welding head. Reflected ultrasonic signals are analyzed utilizing computer based digital pattern recognition techniques to discriminate between good and flawed welds on a pass by pass basis. The system also distinguishes between types of weld flaws.

  19. POLYMERIZATION EFFICIENCY OF TWO DUAL-CURE CEMENTS THROUGH DENTAL CERAMICS

    Directory of Open Access Journals (Sweden)

    Volkan Turp

    2015-01-01

    Full Text Available Purpose: The aim of this study was to evaluate the effect of thickness of zirconia on curing efficiency of resin cements. Materials and Methods: 4 discs with 4.0 mm in diameter were prepared from non-HIP translucent zirconia blocks using a CAD/CAM system and feldspathic ceramic was layered onto discs. Thus, 4 ceramic disc samples were fabricated: (G 0.5 mm zirconia- as a control group, (G1 0.5 mm zirconia and 0.5 mm feldspathic, (G2 1.0 mm zirconia and 0.5 mm feldspathic and (G3 2.0 mm zirconia and 0.5 mm feldspathic ceramic layer. 2 different dual cure cements were polymerized using a LED curing unit. Degree of conversion was evaluated using Vickers Hardness Test and depths of cure of samples were measured. Data were analyzed statistically using One-way ANOVA and Tukey’s HSD test (p2.0 mm, an extended period of light curing or a light unit with a high irradiance should be used.

  20. Evaluating MT systems with BEER

    Directory of Open Access Journals (Sweden)

    Stanojević Miloš

    2015-10-01

    Full Text Available We present BEER, an open source implementation of a machine translation evaluation metric. BEER is a metric trained for high correlation with human ranking by using learning-to-rank training methods. For evaluation of lexical accuracy it uses sub-word units (character n-grams while for measuring word order it uses hierarchical representations based on PETs (permutation trees. During the last WMT metrics tasks, BEER has shown high correlation with human judgments both on the sentence and the corpus levels. In this paper we will show how BEER can be used for (i full evaluation of MT output, (ii isolated evaluation of word order and (iii tuning MT systems.

  1. Digital Identifier Systems: Comparative Evaluation

    Directory of Open Access Journals (Sweden)

    Hamid Reza Khedmatgozar

    2015-02-01

    Full Text Available Identifier is one of the main elements in identifying an object in digital environment. Digital identifier systems were developed followed by a lot of problems such as violation of persistency and uniqueness of physical identifiers and URL in digital environment. These identifiers try to guarantee uniqueness and persistency of hostnames by using indirect names for Domain Name System (DNS. The main objective of this research is to identify qualified digital identifier system among other systems. To achieve the research objective, researchers have considered two major steps: first, identifying main criteria for distinguishing digital identifier based on literature review and focus group interview; and second, performing a comparative evaluation on common identifier systems in the world. Findings of first step demonstrated seven main criteria in three domains for distinguishing digital identifier systems: identifier uniqueness and persistency in the identifier features domain, digital identification, digital uniqueness, digital persistency and digital actionability in the digital coverage domain, and globality in the comprehensiveness of scope domain. In the second step, results of the comparative evaluation on common identifier systems indicated that six identifier systems, included, DOI, Handle, UCI, URN, ARK and PURL, are appropriate choices for using as a digital identifier system. Also, according to these results, three identification systems Including NBN, MARIAM and ISNI were identified as suitable choices for digital identification in certain specialized fields. According to many benefits of using these identifiers in important applied fields, such as, digital content chains and networks integration, digital right management, cross referencing, digital libraries and citation analysis, results of this study can help digital environment experts to diagnose digital identifier and their effective use in applied fields.

  2. Effect of Lithium Disilicate Veneers of Different Thickness on the Degree of Conversion and Microhardness of a Light-Curing and a Dual-Curing Cement.

    Science.gov (United States)

    Scotti, Nicola; Comba, Allegra; Cadenaro, Milena; Fontanive, Luca; Breschi, Lorenzo; Monaco, Carlo; Scotti, Roberto

    2016-01-01

    Various materials and systems for bonding lithium disilicate to the tooth substrate are available to clinicians, who can adapt the materials to each clinical situation to maximize the performance of indirect esthetic restorations. This study aimed to evaluate the degree of conversion (DC) and the microhardness (MH) of a dual-curing and a light-curing cement under lithium disilicate discs of different thicknesses. A total of 48 lithium disilicate (IPS e.max CAD, Ivoclar Vivadent) samples were prepared and divided into three groups (n = 16) according to the thickness (group A was 0.6 mm; group B was 1.0 mm; group C was 1.5 mm). Each group was further divided into two subgroups (n = 8) according to the resin cement employed, NX3 (Kerr) or Choice 2 (Bisco). A standardized quantity of cement was placed on the sample, and DC was evaluated with an attenuated total reflectance Fourier transformed infrared spectrophotometer (Nicolet IS10, Thermo Scientific). Twenty-four hours after DC was established, Vickers test was performed on the cement with a microindentometer (Leica Microsystems). Results were statistically analyzed with analysis of variance test and significance set at P < .05. Statistical analysis showed cement type had a significant influence (P = .005) on DC. MH results were influenced by thicknesses only between 0.6 and 1.5 mm when light-cured cement was employed. The light-curing and the dual-curing cements reached comparable DCs between 0.6 and 1.5 mm. However, the light-curing resin showed a higher DC and MH.

  3. 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.

  4. Rubber composites cured with sulphur and peroxide and ...

    Indian Academy of Sciences (India)

    Besides classical applications of rubber products in tyres, conveyer belts and other products from technical rubber, ... application of sulphur curing systems leads to the forming of sulphidic bridges with various number of ... have advantages but also drawbacks, the main aim was to suppress the main negatives of both curing ...

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

    Directory of Open Access Journals (Sweden)

    Alireza Heidari

    2012-01-01

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

  6. Heat transfer properties and thermal cure of glass-ionomer dental cements.

    Science.gov (United States)

    Gavic, Lidia; Gorseta, Kristina; Glavina, Domagoj; Czarnecka, Beata; Nicholson, John W

    2015-10-01

    Under clinical conditions, conventional glass-ionomer dental cements can be cured by application of heat from dental cure lamps, which causes acceleration in the setting. In order for this to be successful, such heat must be able to spread sufficiently through the cement to enhance cure, but not transmit heat so effectively that the underlying dental pulp of the tooth is damaged. The current study was aimed at measuring heat transfer properties of modern restorative glass-ionomers to determine the extent to which they meet these twin requirements. Three commercial glass ionomer cements (Ionofil Molar, Ketac Molar and Equia™ Fill) were used in association with three different light emitting diode cure lamps designed for clinical use. In addition, for each cement, one set of specimens was allowed to cure without application of a lamp. Temperature changes were measured at three different depths (2, 3 and 4 mm) after cure times of 20, 40 and 60 s. The difference among the tested groups was evaluated by ANOVA (P lamp. However, temperature rises did not exceed 12.9 °C. Application of the cure lamp led to the establishment of a temperature gradient throughout each specimen. Differences were typically significant (P lamps, because those lamps have variable cooling systems, and are designed to optimize light output, not heating effect. Because the thermal conductivity of glass-ionomers is low, temperature rises at 4 mm depths were much lower than at 2 mm. At no time did the temperature rise sufficiently to cause concern about potential damage to the pulp.

  7. Quantification of γ- and α-tocopherol isomers in combination with pattern recognition model as a tool for differentiating dry-cured shoulders of Iberian pigs raised on different feeding systems.

    Science.gov (United States)

    Rey, Ana I; Amazan, Daniel; López-Bote, Clemente J; García-Casco, Juan M

    2014-10-01

    Quantification of γ- and α-tocopherol in dry-cured shoulders of Iberian pigs was evaluated as a tool for differentiating feeding backgrounds or regimens. Samples (n = 115) were obtained over two different seasons from the four categories of pigs described in the Industry Quality Policy, i.e. pigs fed in free-range conditions (FREE-RANGE), pigs fed in free-range conditions and provided feed supplements (FREE-FEED), pigs fed outdoors with feed and with access to grass (FEED-OUT) and pigs fed in intensive conditions with feed (FEED). Linear discriminant functions were calculated and validated. The validation results showed that 20% of the muscle samples were not correctly classified into the four feeding categories, giving an 80% success rate. The FEED group had the lowest proportion of errors, with 100% of samples correctly classified. For the FREE-RANGE group, 87% of samples were assigned to the correct feeding system by cross-validation; however, 13% were considered as FREE-FEED. A higher rate of correct classification can be obtained when using three categories or by calculating the weight gain in free-range conditions using regression equations. Taking into account the high variability of the samples and the high success in classification, these results are of interest and may be applied in practical situations. © 2014 Society of Chemical Industry.

  8. 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...

  9. Comparative evaluation of shear bond strength of three resin based dual-cure core build-up materials: An In-vitro study.

    Science.gov (United States)

    Jain, Gaurav; Narad, Aditi; Boruah, Lalit C; Rajkumar, Balakrishnan

    2015-01-01

    The in-vitro study compared the shear bond strength (SBS) of three recently introduced dual-cure resin based core build-up materials namely ParaCore, FluoroCore, and MultiCore. One hundred twenty extracted permanent human mandibular molar teeth were taken and sectioned horizontally beneath the dentinoenamel junction to expose the coronal dentin. The specimens obtained were divided into three main groups based on the materials used and then further divided into four sub-groups based on time interval with ten samples each. The dentin surface was treated with the respective adhesives of the groups and then bulk filled with core build-up materials. The attained samples were than subjected to shear loading in Instron Universal Testing Machine. The data were tabulated and statistically analyzed using analysis of variance (ANOVA), Tukey's HSD, and Levene's test. The mean SBS was highest in MultiCore at all time periods as compared to FluoroCore and ParaCore and was also higher at 48 h thermocycling in all three groups studied. MultiCore dual-cure resin based core build-up material showed the highest mean SBS as compared to FluoroCore and ParaCore. SBS was not negatively affected by thermocycling.

  10. Delayed cure bismaleimide resins

    Science.gov (United States)

    Adams, Johnnie E.; Jamieson, Donald R.

    1984-08-07

    Polybismaleimides prepared by delayed curing of bis-imides having the formula ##STR1## wherein R.sub.1 and R.sub.2 each independently is H, C.sub.1-4 -alkyl, C.sub.1-4 -alkoxy, Cl or Br, or R.sub.1 and R.sub.2 together form a fused 6-membered hydrocarbon aromatic ring, with the proviso that R.sub.1 and R.sub.2 are not t-butyl or t-butoxy; X is O, S or Se; n is 1-3; and the --(CH.sub.2).sub.n -- group, optionally, is substituted by 1-3 methyl groups or by fluorine.

  11. Effect of light curing modes on mechanical properties of direct and indirect composites.

    Science.gov (United States)

    Catelan, Anderson; Santo, Márcia Regina do Espírito; Menegazzo, Lívia Maluf; Moraes, João Carlos Silos; dos Santos, Paulo Henrique

    2013-01-01

    To evaluate the degree of conversion (DC), flexural strength (FS) and Knoop microhardness (KHN) of direct and indirect composite resins polymerized with different curing systems. Specimens of direct (Z250, 3M/Espe) and indirect (Sinfony, 3M/Espe) restorative materials were made and polymerized using two light curing units: XL2500 (3M/Espe) and Visio system (3M/Espe). Absorption spectra of both composites were obtained on a FTIR spectrometer in order to calculate the DC. FS was evaluated in a universal testing machine and surface microhardness was performed in a microhardness tester (50gf/15s). DC, FS and KHN data were submitted to two-way ANOVA and Tukey's test (α = 0.05). Z250 showed higher DC, FS and KHN compared with Sinfony when the polymerization was carried out with XL2500 (p Visio was used (p > 0.05). Visio showed higher DC and KHN for Z250 and Sinfony than the values obtained using XL2500 light curing (p 0.05). Even though the Visio system could increase DC and KHN for some direct and indirect composites, compared with the conventional halogen curing unit, a high number of monomers did not undergo conversion during the polymerization.

  12. Management information systems software evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Al-Tunisi, N.; Ghazzawi, A.; Gruyaert, F.; Clarke, D. [Saudi Aramco, Dhahran (Saudi Arabia). Process and Control Systems Dept.

    1995-11-01

    In November 1993, Saudi Aramco management endorsed a proposal to coordinate the development of the Management Information Systems (MISs) of four concurrent projects for its facilities Controls Modernization Program. The affected projects were the Ras Tanura Refinery Upgrade Project, the Abqaiq Plant Controls Modernization and the Shedgum and Uthmaniyah Gas plants Control Upgrade Projects. All of these projects had a significant requirement of MISs in their scope. Under the leadership of the Process and Control Systems Department, and MIS Coordination Team was formed with representatives of several departments. An MIS Applications Evaluation procedure was developed based on the Kepner Tregoe Decisions Analysis Process and general questionnaires were sent to over a hundred potential Vendors. The applications were divided into several categories, such as: Data Capture and Historization, Human User Interface, Trending, Reporting, Graphic Displays, Data Reconciliation, Statistical Analysis, Expert Systems, Maintenance Applications, Document Management and Operations Planning and Scheduling. For each of the MIS Application areas, detailed follow-up questionnaires were used to short list the candidate products. In May and June 1994, selected Vendors were invited to Saudi Arabia for an Exhibition which was open to all Saudi Aramco employees. In conjunction with this, the Vendors were subjected to a rigorous product testing exercise by independent teams of testers. The paper will describe the methods used and the lessons learned in this extensive software evaluation phase, which was a first for Saudi Aramco.

  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 (convention...

  14. Evaluating Storage Systems for Lustre

    Energy Technology Data Exchange (ETDEWEB)

    Oral, H. Sarp [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2015-08-20

    Storage systems are complex, including multiple subsystems and components. Sustained operations with top performance require all these subsystems and components working as expected. Having a detailed performance profile helps establishing a baseline. This baseline can be used for easier identification of possible future problems. A systematic bottom-to-top approach, starting with a detailed performance analysis of disks and moving up across layers and subsystems, provides a quantitative breakdown of each component's capabilities and bottlenecks. Coupling these low-level tests with Lustre-level evaluations will present a better understanding of performance expectations under different I/O workloads.

  15. Evaluation of the COGITO system

    DEFF Research Database (Denmark)

    Andersen, V.; Andersen, H.H.K.

    2002-01-01

    -site and for benefiting efficiently from the functionality of the site. In order to make the report a stand-alone report, it contains an introduction including 'Study of end-user needs and behaviour' exposing problemsconcerning e-commerce in general (taken from the D6.1), and a brief review of the objectives......This report covers the deliverable D7.2 of the COGITO project. It presents the evaluation of an 'intelligent' agent integrated into an e-commerce system. The aim of the agent is to support the user partly through direct communication and partly by guidinghim/her for navigating the web...

  16. Efficiency Evaluation of Energy Systems

    CERN Document Server

    Kanoğlu, Mehmet; Dinçer, İbrahim

    2012-01-01

    Efficiency is one of the most frequently used terms in thermodynamics, and it indicates how well an energy conversion or process is accomplished. Efficiency is also one of the most frequently misused terms in thermodynamics and is often a source of misunderstanding. This is because efficiency is often used without being properly defined first. This book intends to provide a comprehensive evaluation of various efficiencies used for energy transfer and conversion systems including steady-flow energy devices (turbines, compressors, pumps, nozzles, heat exchangers, etc.), various power plants, cogeneration plants, and refrigeration systems. The book will cover first-law (energy based) and second-law (exergy based) efficiencies and provide a comprehensive understanding of their implications. It will help minimize the widespread misuse of efficiencies among students and researchers in energy field by using an intuitive and unified approach for defining efficiencies. The book will be particularly useful for a clear ...

  17. Retrieval system evaluation: automatic evaluation versus incomplete judgments

    NARCIS (Netherlands)

    Hauff, C.; de Jong, Franciska M.G.

    In information retrieval (IR), research aiming to reduce the cost of retrieval system evaluations has been conducted along two lines: (i) the evaluation of IR systems with reduced amounts of manual relevance assessments, and (ii) the fully automatic evaluation of IR systems, thus foregoing the need

  18. Comparative evaluation for microleakage between Fuji-VII glass ionomer cement and light-cured unfilled resin: A combined in vivo in vitro study

    Directory of Open Access Journals (Sweden)

    Ashwin R

    2007-06-01

    Full Text Available Glass ionomer cement, besides being used as restorative material, can also be used as pit and fissure sealant. The use of glass ionomer cement as pit and fissure sealant has added benefit by its fluoride-releasing property that results in increased resistance of the fissures to demineralize. The capacity of a sealant to prevent microleakage into the fissure is important, since microleakage may initiate and support a carious lesion beneath the sealant. The study was carried out to compare marginal microleakage between Fuji-VII glass ionomer cement (G C Corporation, Tokyo, Japan and the conventional light-cured unfilled resin as pit and fissure sealants (3M Concise, 3M Dental Products, St. Paul, USA. The dye used was 2% methylene blue (Qualigens Fine Chemicals, Mumbai, India. The teeth were sectioned and studied under the stereomicroscope. The result revealed that there was no difference in microleakage ( P > 0.05 between the two materials.

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

    OpenAIRE

    Sujeong Lee; Arie van Riessen; Chul-Min Chon

    2016-01-01

    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...

  20. 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.

  1. The effect of light curing units, curing time, and veneering materials on resin cement microhardness

    Directory of Open Access Journals (Sweden)

    Nurcan Ozakar Ilday

    2013-06-01

    Conclusion: Light-curing units, curing time, and veneering materials are important factors for achieving adequate dual cure resin composite microhardness. High-intensity light and longer curing times resulted in the highest microhardness values.

  2. An Evaluation of the Adherence of Candida albicans on the Surface of Heat Cure Denture Base Material Subjected to Different Stages of Polishing.

    Science.gov (United States)

    Satpathy, Ashish; M R, Dhakshaini; Gujjari, Anil Kumar

    2013-10-01

    Candidiasis is common in denture wearers. Rough surfaces of dentures promote denture plaque formation and maturation, thus justifying the need for smooth surfaces. Proper finishing and polishing of dentures provide smooth surfaces. Thus, this study was done to assess the adherence of Candida to heat polymerized acrylic resin surfaces which were subjected to different stipulated polishing methods. A total of 48 acrylic resin specimens of dimension 10x10x3 mm(3) were fabricated and divided into four groups, A, B,C and D, with 12 specimens in each group, according to method of polishing step which was employed. Subsequently, they were subjected to an adherence assay. All the data was statistically analyzed by using One-way ANOVA and differences within the groups were analyzed by using independent sample t-test. RESULTS revealed that group A which was unpolished had a mean adherence of 2.92 and it was finished by using sand papers. Group B had a mean adherence of 0.5 and it was finished by using sand papers, followed by polishing with pumice. Group C had a mean adherence of 2.92 and finishing was done by using sandpaper which was followed by polishing with the use of pumice and rouge. Group D had a mean adherence of 37.1667. Finishing specimens of heat cure denture base resin with sand paper of progressive grits alone exhibited minimum Candidal adherence. Specimens which were finished by using sand papers of progressive grits, followed by polishing with pumice reduced Candidal adherence marginally as compared to that in control group. Finishing specimens of heat cure denture base resin by using above steps, followed by rouge, showed maximum Candidal adherence.

  3. Performance Evaluation of Strain Gauge Printed Using Automatic Fluid Dispensing System on Conformal Substrates

    Science.gov (United States)

    Khairilhijra Khirotdin, Rd.; Faridzuan Ngadiron, Mohamad; Adzeem Mahadzir, Muhammad; Hassan, Nurhafizzah

    2017-08-01

    Smart textiles require flexible electronics that can withstand daily stresses like bends and stretches. Printing using conductive inks provides the flexibility required but the current printing techniques suffered from ink incompatibility, limited of substrates to be printed with and incompatible with conformal substrates due to its rigidity and low flexibility. An alternate printing technique via automatic fluid dispensing system is proposed and its performances on printing strain gauge on conformal substrates were evaluated to determine its feasibility. Process parameters studied including printing speed, deposition height, curing time and curing temperature. It was found that the strain gauge is proven functional as expected since different strains were induced when bent on variation of bending angles and curvature radiuses from designated bending fixtures. The average change of resistances were doubled before the strain gauge starts to break. Printed strain gauges also exhibited some excellence elasticity as they were able to resist bending up to 70° angle and 3 mm of curvature radius.

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

    Directory of Open Access Journals (Sweden)

    Alexander Bernath

    2016-11-01

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

  5. 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. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Evaluating fractionated space systems - Status

    Science.gov (United States)

    Cornford, S.; Jenkins, S.; Wall, S.; Cole, B.; Bairstow, B.; Rouquette, N.; Dubos, G.; Ryan, T.; Zarifian, P.; Boutwell, J.

    DARPA has funded a number of teams to further refine its Fractionated Spacecraft vision. Several teams, including this team led by JPL, have been tasked to develop a tool for the evaluation of the Business case for a fractionated system architecture. This evaluation is to understand under what conditions and constraints the fractionated architecture make more sense (in a cost/benefit sense) than the traditional monolithic paradigm. Our approach to this evaluation is to generate and evaluate a variety of trade space options. These options include various sets of stimuli, various degrees of fractionation and various subsystem element properties. The stimuli include many not normally modeled such as technology obsolescence, funding profile changes and changes in mission objectives during the mission itself. The degrees of fractionation enable various traditional subsystem elements to be distributed across different free flyers which then act in concert as needed. This will enable key technologies to be updated as need dictates and availability allows. We have described our approach in a previous IEEE Aerospace conference paper but will briefly summarize here. Our approach to generate the Business Case evaluation is to explicitly model both the implementation and operation phases for the life cycle of a fractionated constellation. A variety of models are integrated into the Phoenix ModelCenter framework and are used to generate various intermediate data which is aggregated into the Present Strategic Value (PSV). The PSV is essentially the value (including the value of the embedded real options) minus the cost. These PSVs are calculated for a variety of configurations and scenarios including variations of various stimuli or uncertainties (e.g. supply chain delays, launch vehicle failures and orbital debris events). There are various decision options (e.g. delay, accelerate, cancel) which can now be exercised for each stimulus. We can compute the PSV for the various comb

  7. Java Mission Evaluation Workstation System

    Science.gov (United States)

    Pettinger, Ross; Watlington, Tim; Ryley, Richard; Harbour, Jeff

    2006-01-01

    The Java Mission Evaluation Workstation System (JMEWS) is a collection of applications designed to retrieve, display, and analyze both real-time and recorded telemetry data. This software is currently being used by both the Space Shuttle Program (SSP) and the International Space Station (ISS) program. JMEWS was written in the Java programming language to satisfy the requirement of platform independence. An object-oriented design was used to satisfy additional requirements and to make the software easily extendable. By virtue of its platform independence, JMEWS can be used on the UNIX workstations in the Mission Control Center (MCC) and on office computers. JMEWS includes an interactive editor that allows users to easily develop displays that meet their specific needs. The displays can be developed and modified while viewing data. By simply selecting a data source, the user can view real-time, recorded, or test data.

  8. Efficiency of dual-cured resin cement polymerization induced by high-intensity LED curing units through ceramic material.

    Science.gov (United States)

    Watanabe, H; Kazama, Re; Asai, T; Kanaya, F; Ishizaki, H; Fukushima, M; Okiji, T

    2015-01-01

    This study aimed to evaluate the ability of high-intensity light-emitting diode (LED) and other curing units to cure dual-cured resin cement through ceramic material. A halogen curing unit (Jetlite 3000, Morita), a second-generation LED curing unit (Demi, Kerr), and two high-intensity LED curing units (PenCure 2000, Morita; Valo, Ultradent) were tested. Feldspathic ceramic plates (VITABLOCS Mark II, A3; Vita Zahnfabrik) with thicknesses of 1.0, 2.0, and 3.0 mm were prepared. Dual-cured resin cement samples (Clearfil Esthetic Cement, Kuraray Noritake Dental) were irradiated directly or through one of the ceramic plates for different periods (5, 10, 15, or 20 seconds for the high-intensity LED units and 20, 40, 60, or 80 seconds for the others). The Knoop hardness test was used to determine the level of photopolymerization that had been induced in the resin cement. Data were analyzed by one-way analysis of variance and Dunnett's post-hoc test to identify test-control (maximum irradiation without a ceramic plate) differences for each curing unit (punits, the curing conditions had a statistically significant effect on the Knoop hardness numbers (KHNs) of the irradiated cement samples (punits (except for PenCure 2000 at 3.0 mm) were able to achieve control-level KHN values when the irradiation time was extended. At a plate thickness of 3.0 mm, irradiation for 20 seconds with the Valo or for 80 seconds with the Demi were the only methods that produced KHN values equivalent to those produced by direct irradiation. Regardless of the type of curing unit used, indirect irradiation of dual-cured resin cement through a ceramic plate resulted in decreased KHN values compared with direct irradiation. When the irradiation period was extended, only the LED units were able to achieve similar KHN values to those observed under direct irradiation in the presence of plates ≥2.0-mm thick. High-intensity LED units require a shorter irradiation period than halogen and second

  9. Effects of Curing Temperature and Pressure on the Chemical, Physical, and Mechanical Properties of Portland Cement

    Science.gov (United States)

    Pang, Xueyu

    a hydration kinetics curve is represented by an unknown function, the effect of curing condition on the curve can be modeled by incorporating a simple scale factor in this function. The relationship between this scale factor and curing condition is described by chemical kinetics laws. While the proposed new approach of modeling cement hydration kinetics has the advantage of being widely applicable to different types of cement, it only explains one influence factor of cement hydration (i.e. the curing condition). In order to take into account other influence factors and to further understand the fundamental mechanisms of cement hydration, a more complex particle-based numerical hydration model is developed by combining the two well-known cement hydration mechanisms, namely the nucleation and growth controlled mechanism and the diffusion controlled mechanism. The model is applied to experimental data of both C3S hydration in dilute suspensions and Class H cement paste hydration. Excellent agreement is observed between experimental and modeled results. Three rate-controlling parameters with clear physical meanings can be identified from the proposed model. Fitted model parameters are found to be in reasonable agreement with experimental observation. The dependencies of these parameters on particle size, cement composition, w/c ratio, and curing condition are also investigated. Finally, the importance of cement hydration kinetics is illustrated by showing their close correlations with the physical and mechanical properties. The various influence factors, including the curing temperature and pressure, of physical and mechanical property test results (particularly density and tensile strength) are evaluated. Potential damage mechanisms of cement paste specimens during depressurization are studied by analyzing the deformation behavior of the entire system consisting of the cement paste and pressurizing water.

  10. Accelerated Hazards Mixture Cure Model

    Science.gov (United States)

    Zhang, Jiajia; Peng, Yingwei

    2010-01-01

    We propose a new cure model for survival data with a surviving or cure fraction. The new model is a mixture cure model where the covariate effects on the proportion of cure and the distribution of the failure time of uncured patients are separately modeled. Unlike the existing mixture cure models, the new model allows covariate effects on the failure time distribution of uncured patients to be negligible at time zero and to increase as time goes by. Such a model is particularly useful in some cancer treatments when the treat effect increases gradually from zero, and the existing models usually cannot handle this situation properly. We develop a rank based semiparametric estimation method to obtain the maximum likelihood estimates of the parameters in the model. We compare it with existing models and methods via a simulation study, and apply the model to a breast cancer data set. The numerical studies show that the new model provides a useful addition to the cure model literature. PMID:19697127

  11. Comparative evaluation of effect of metal primer and sandblasting on the shear bond strength between heat cured acrylic denture base resin and cobalt-chromium alloy: An in vitrostudy

    Directory of Open Access Journals (Sweden)

    Sandeep Kalra

    2015-01-01

    Full Text Available Aims: The aim of this study was to evaluate the effect of metal primers and sandblasting on the shear bond strength (SBS of heat cured acrylic denture base resin to cobalt-chromium (Co-Cr alloy. Materials and Methods: A total number of 40 disk shaped wax patterns (10 mm in diameter and 2 mm in thickness were cast in Co-Cr alloy. Samples were divided into 4 groups depending on the surface treatment received. Group 1: No surface treatment was done and acts as control group. Group 2: Only sandblasting was done. Group 3: Only metal primer was applied. Group 4: Both metal primer and sandblasting were done. After surface treatment samples had been tested in Universal Testing Machine at crosshead speed of 0.5 mm/min in shear mode and scanning, electron microscope evaluation was done to observe the mode of failure. Statistical Analysis: All the observations obtained were analyzed statistically using software SPSS version 17; one-way analysis of variance (ANOVA and post-hoc Tukey test were applied. Results: The one-way ANOVA indicated that SBS values varied according to type of surface treatment done. The SBS was highest (18.70 ± 1.2 MPa when both sandblasting and metal primer was done when compared with no surface treatment (2.59 ± 0.32 MPa. Conclusions: It could be concluded that the use of metal primers along with sandblasting significantly improves the bonding of heat cured acrylic denture base resin with the Co-Cr alloy.

  12. Effect of self and dual-curing on degree of conversion and crosslink density of dual-cure core build-up materials.

    Science.gov (United States)

    Karakis, Duygu; Yıldırım-Bicer, Arzu Zeynep; Dogan, Arife; Koralay, Haluk; Cavdar, Sukru

    2017-04-01

    Dual-cure core build-up resins have been developed to take advantages of both self and light-cured resin. The aim of present study was to determine the polymerization characteristics of self and dual-cured modes of dual-cure core build-up composites evaluating degree of conversion (DC) and crosslink density by measurement of glass-transition temperature (Tg) and hardness decrease in ethanol. Clearfil Dc Core Automix (CLF) and Grandio Core Dc (GR) core build-up resins were selected. Twelve specimens for both composites were polymerized using quartz-halogen-tungsten light curing unit (QTH) and 12 specimens polymerized chemically. DC was determined by ATR-FTIR spectroscopy. TG/DTA analysis was performed to determine Tg. Microhardness value of specimens was determined by Vickers-tester before and after specimens stored in absolute ethanol for 24h. One-way ANOVA showed no different DC values between dual and self-cured mode of GR and dual-cured CLF composites had higher DC than self-cured mode. Tg and percentage of softening in ethanol values of GR and CLF revealed significant difference between self and dual-cured mode. In comparison of GR and CLF, DC showed no statistical difference in both curing modes. However, dual and self-cured GR has statistically higher Tg values and lower percentage of softening in ethanol than CLF. Polymerization characteristics of dual-cure core build-up composites have superiority in dual-cured mode than self-cured. Copyright © 2016. Published by Elsevier Ltd.

  13. 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.

  14. Cure Schedule for Stycast 2651/Catalyst 11.

    Energy Technology Data Exchange (ETDEWEB)

    Kropka, Jamie Michael [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); McCoy, John D. [New Mexico Inst. of Mining and Technology, Socorro, NM (United States)

    2017-11-01

    The Henkel technical data sheet (TDS) for Stycast 2651/Catalyst 11 lists three alternate cure schedules for the material, each of which would result in a different state of reaction and different material properties. Here, a cure schedule that attains full reaction of the material is defined. The use of this cure schedule will eliminate variance in material properties due to changes in the cure state of the material, and the cure schedule will serve as the method to make material prior to characterizing properties. The following recommendation was motivated by (1) a desire to cure at a single temperature for ease of manufacture and (2) a desire to keep the cure temperature low (to minimize residual stress build-up associated with the cooldown from the cure temperature to room temperature) without excessively limiting the cure reaction due to vitrification (i.e., material glass transition temperature, Tg, exceeding cure temperature).

  15. Culturally Responsive Evaluation Meets Systems-Oriented Evaluation

    Science.gov (United States)

    Thomas, Veronica G.; Parsons, Beverly A.

    2017-01-01

    The authors of this article each bring a different theoretical background to their evaluation practice. The first author has a background of attention to culturally responsive evaluation (CRE), while the second author has a background of attention to systems theories and their application to evaluation. Both have had their own evolution of…

  16. Evaluation of mobile systems: an integrative framework.

    NARCIS (Netherlands)

    Högler, T.; Versendaal, J.; Batenburg, R.

    2015-01-01

    This work presents an integrative framework for the evaluation of mobile systems. In comparison to stationary systems, mobile systems have a bundle of specific singularities that should be considered for evaluation. Further analysis of existing approaches clarifies that an integrative approach for

  17. Mixture proportioning for internal curing

    DEFF Research Database (Denmark)

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

    2005-01-01

    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...... of additional internal water that is not part of the mixing water.” The additional internal water is typically supplied by using relatively small amounts of saturated, lightweight, fine aggregates (LWA) or superabsorbent polymer (SAP) particles in the concrete. Benefits of internal curing include increased...... too low to allow the effective transfer of water from the external surface to the concrete interior. This is one justification for internal curing. Additional water that can be distributed somewhat uniformly throughout the concrete will be more readily able to reach unhydrated cement....

  18. Uninhabited Traffic Management System Evaluator (UTME) Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The key innovation of this effort is the development of an Uninhabited Aerial System (UAS) Traffic Manager Evaluator (UTME) specifically targeted at evaluating...

  19. Pervious Pavement System Evaluation- Abstract

    Science.gov (United States)

    Porous pavement is a low impact development stormwater control. The Urban Watershed Management Branch is evaluating interlocking concrete pavers as a popular implementation. The pavers themselves are impermeable, but the spaces between the pavers are backfilled with washed, gra...

  20. An Evaluation System for Foodservice Equipment

    Science.gov (United States)

    1985-10-01

    Saws Vertical Food Mixers Pressure Cookers Steam Jacketed Kettles Fundamentals of Steam Procedures to Clean Coffee Urns A List of Foodservice...Evaluation System for Pressure Cookers 90 Evaluation Form for Pressure Cookers 92 Pressure Cooker Evaluation Form Guide 93 Evaluation System for Steam...cleaned. Other tasks include maintenance of the gas jets , thermostat calibration, and cleaning of under burner area. Compare manufacture requirements

  1. Evaluating neural networks and artificial intelligence systems

    Science.gov (United States)

    Alberts, David S.

    1994-02-01

    Systems have no intrinsic value in and of themselves, but rather derive value from the contributions they make to the missions, decisions, and tasks they are intended to support. The estimation of the cost-effectiveness of systems is a prerequisite for rational planning, budgeting, and investment documents. Neural network and expert system applications, although similar in their incorporation of a significant amount of decision-making capability, differ from each other in ways that affect the manner in which they can be evaluated. Both these types of systems are, by definition, evolutionary systems, which also impacts their evaluation. This paper discusses key aspects of neural network and expert system applications and their impact on the evaluation process. A practical approach or methodology for evaluating a certain class of expert systems that are particularly difficult to measure using traditional evaluation approaches is presented.

  2. Failure to Diagnose Hyperparathyroidism in 10,432 Patients With Hypercalcemia: Opportunities for System-level Intervention to Increase Surgical Referrals and Cure.

    Science.gov (United States)

    Balentine, Courtney J; Xie, Rongbing; Kirklin, James K; Chen, Herbert

    2017-10-01

    To determine whether a significant number of patients with hyperparathyroidism remain undiagnosed and untreated. Failure to diagnose primary hyperparathyroidism and refer patients to surgeons leads to impaired quality of life and increased costs. We hypothesized that many patients with hyperparathyroidism would be untreated due to not considering the diagnosis, inadequate evaluation of hypercalcemia, and under-referral to surgeons. We reviewed administrative data on 682,704 patients from a tertiary referral center between 2011 and 2015, and identified hypercalcemia (>10.5 mg/dL) in 10,432 patients. We evaluated whether hypercalcemic patients underwent measurement of parathyroid hormone (PTH), had documentation of hypercalcemia/hyperparathyroidism, or were referred to surgeons. The mean age of our cohort was 54 years, with 61% females, and 56% whites. Only 3200 (31%) hypercalcemic patients had PTH levels measured, 2914 (28%) had a documented diagnosis of hypercalcemia, and 880 (8%) had a diagnosis of hyperparathyroidism in the medical record. Only 592 (22%) out of 2666 patients with classic hyperparathyroidism (abnormal calcium and PTH) were referred to surgeons. A significant proportion of patients with hyperparathyroidism do not undergo appropriate evaluation and surgical referral. System-level interventions which prompt further evaluation of hypercalcemia and raise physician awareness about hyperparathyroidism could improve outcomes and produce long-term cost savings.

  3. Evaluation of mechanical properties of Z250 composite resin light-cured by different methods Avaliação de propriedades mecânicas da resina composta Z250 fotoativada com diferentes métodos

    Directory of Open Access Journals (Sweden)

    Andresa Carla Obici

    2005-12-01

    Full Text Available This study evaluated some mechanical parameters of Z250 composite resin using different light-curing methods. Ten specimens were prepared for each mechanical test group with different dimensions according to the test. Light-curing was performed by: a. continuous light (800mW/cm²-40s; b. exponential light (0-800mW/cm²-40s; c. intermittent light (2s-600mW/cm²; 2s without light-80s; d. stepped light (10s-150mW/cm²; 30s-650mW/cm²; e. PAC (1320mW/cm²-3s; f. LED (350mW/cm²-40s. After 24 ± 1 h, the specimens were loaded at a crosshead speed of 0.5 mm/min until fracture. The mechanical properties were calculated and analyzed by ANOVA and Tukey test (5%. The results showed that the highest compressive strength values were found for the continuous, exponential, intermittent and stepped light methods, whereas PAC and LED obtained the lowest values. LED, stepped light, PAC, exponential and continuous light presented the highest values for diametral tensile strength. The intermittent light showed the lowest value, which was significantly lower than the value obtained for LED only. Flexural strength results were not significantly different between all light-curing methods. Finally, the highest modulus of elasticity values were obtained for LED, exponential, continuous and intermittent light, whereas PAC and stepped light showed the lowest values. The mechanical properties were affected by light-curing methods employed.Este estudo avaliou algumas propriedades mecânicas da resina composta Z250 usando diferentes métodos de fotoativação. Dez amostras foram preparadas para cada grupo, com diferentes dimensões de acordo com o ensaio. Os métodos de fotoativação foram: a luz contínua (800mW/cm²-40s; b luz exponencial (0-800mW/cm²-40s; c luz intermitente (2s-600mW/cm²; 2s sem luz-80s; d dupla intensidade (10s-150mW/cm²; 30s-650mW/cm²; e PAC (1320mW/cm²-3s; f LED (350mW/cm²-40s. Após 24 ± 1 h, as amostras foram carregadas até fraturar (v=0

  4. Effects of light intensity and curing time of the newest LED Curing units on the diametral tensile strength of microhybrid composite resins

    Science.gov (United States)

    Ariani, D.; Herda, E.; Eriwati, Y. K.

    2017-08-01

    The aim of this study was to evaluate the influence of light intensity and curing time of the latest LED curing units on the diametral tensile strength of microhybrid composite resins. Sixty-three specimens from three brands (Polofil Supra, Filtek Z250, and Solare X) were divided into two test groups and one control group. The test groups were polymerized with a Flashmax P3 LED curing unit for one or three seconds. The control group was polymerized with a Ledmax 450 curing unit with the curing time based on the resin manufacturer’s instructions. A higher light intensity and shorter curing time did not influence the diametral tensile strength of microhybrid composite resins.

  5. Toward 3D Printing of Medical Implants: Reduced Lateral Droplet Spreading of Silicone Rubber under Intense IR Curing.

    Science.gov (United States)

    Stieghorst, Jan; Majaura, Daniel; Wevering, Hendrik; Doll, Theodor

    2016-03-01

    The direct fabrication of silicone-rubber-based individually shaped active neural implants requires high-speed-curing systems in order to prevent extensive spreading of the viscous silicone rubber materials during vulcanization. Therefore, an infrared-laser-based test setup was developed to cure the silicone rubber materials rapidly and to evaluate the resulting spreading in relation to its initial viscosity, the absorbed infrared radiation, and the surface tensions of the fabrication bed's material. Different low-adhesion materials (polyimide, Parylene-C, polytetrafluoroethylene, and fluorinated ethylenepropylene) were used as bed materials to reduce the spreading of the silicone rubber materials by means of their well-known weak surface tensions. Further, O2-plasma treatment was performed on the bed materials to reduce the surface tensions. To calculate the absorbed radiation, the emittance of the laser was measured, and the absorptances of the materials were investigated with Fourier transform infrared spectroscopy in attenuated total reflection mode. A minimum silicone rubber spreading of 3.24% was achieved after 2 s curing time, indicating the potential usability of the presented high-speed-curing process for the direct fabrication of thermal-curing silicone rubbers.

  6. Evaluating Training and Development Systems.

    Science.gov (United States)

    Tracey, William R.

    This training and development manual discusses guiding principles and elements of evaluation: (1) philosophy and goals; (2) administrative planning, organization, staffing, direction, and control; (3) plant and facilities; (4) staff and faculty composition, qualifications, screening and selection, promotion, duties, compensation, and incentives;…

  7. Modular system design and evaluation

    CERN Document Server

    Levin, Mark Sh

    2015-01-01

    This book examines seven key combinatorial engineering frameworks (composite schemes consisting of algorithms and/or interactive procedures) for hierarchical modular (composite) systems. These frameworks are based on combinatorial optimization problems (e.g., knapsack problem, multiple choice problem, assignment problem, morphological clique problem), with the author’s version of morphological design approach – Hierarchical Morphological Multicritieria Design (HMMD) – providing a conceptual lens with which to elucidate the examples discussed. This approach is based on ordinal estimates of design alternatives for systems parts/components, however, the book also puts forward an original version of HMMD that is based on new interval multiset estimates for the design alternatives with special attention paid to the aggregation of modular solutions (system versions). The second part of ‘Modular System Design and Evaluation’ provides ten information technology case studies that enriches understanding of th...

  8. Cleaner Vacuum-Bag Curing

    Science.gov (United States)

    Clemons, J. M.; Penn, B. G.; Ledbetter, Frank E., III; Daniels, J. G.

    1987-01-01

    Improvement upon recommended procedures saves time and expense. Autoclave molding in vacuum bag cleaner if adhesive-backed covering placed around caul plate as well as on mold plate. Covering easy to remove after curing and leaves caul plate free of resin deposits.

  9. Evaluation of push-out bond strength of two endodontic post systems.

    Science.gov (United States)

    Mastoras, Konstantinos; Vasiliadis, Leonidas; Koulaouzidou, Elizabeth; Gogos, Christos

    2012-04-01

    The aim of this study was to evaluate the push-out bond strengths of a new polyfiber post system and a fiber post that were adhesively luted with a dual-cure resin cement. Forty single-rooted human maxillary teeth were sectioned below the cementoenamel junction, and the roots were endodontically treated. The roots were randomly divided into 2 groups of 20 specimens each according to the post type used: SpiraPost (group A; DMG, Englewood, NJ) and DT Light-Post Illusion X-RO (group B; Bisco Inc, Schaumburg, IL). All posts were cemented with dual-cure resin cement. Bonded specimens were cut into 1-mm-thick sections, and push-out tests were performed using a universal testing machine. All specimens were loaded until fracture, and the failure modes were evaluated with a stereomicroscope at 50× magnification. Representative specimens were analyzed by scanning electron microscopy. Push-out bond strength was significantly affected by the type of post (P Post Illusion X-RO (P post was the most frequent type of failure for the SpiraPost system. In all root segments, the SpiraPost system provided significantly increased post retention compared with the fiber post. Copyright © 2012 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  10. Mechanical properties of self-curing concrete (SCUC

    Directory of Open Access Journals (Sweden)

    Magda I. Mousa

    2015-12-01

    Full Text Available The mechanical properties of concrete containing self-curing agents are investigated in this paper. In this study, two materials were selected as self-curing agents with different amounts, and the addition of silica fume was studied. The self-curing agents were, pre-soaked lightweight aggregate (Leca; 0.0%, 10%, 15%, and 20% of volume of sand; or polyethylene-glycol (Ch.; 1%, 2%, and 3% by weight of cement. To carry out this study the cement content of 300, 400, 500 kg/m3, water/cement ratio of 0.5, 0.4, 0.3 and 0.0%, 15% silica fume of weight of cement as an additive were used in concrete mixes. The mechanical properties were evaluated while the concrete specimens were subjected to air curing regime (in the laboratory environment with 25 °C, 65% R.H. during the experiment. The results show that, the use of self-curing agents in concrete effectively improved the mechanical properties. The concrete used polyethylene-glycol as self-curing agent, attained higher values of mechanical properties than concrete with saturated Leca. In all cases, either 2% Ch. or 15% Leca was the optimum ratio compared with the other ratios. Higher cement content and/or lower water/cement ratio lead(s to more efficient performance of self-curing agents in concrete. Incorporation of silica fume into self-curing concrete mixture enhanced all mechanical properties, not only due to its pozzolanic reaction, but also due to its ability to retain water inside concrete.

  11. UNIX-based operating systems robustness evaluation

    Science.gov (United States)

    Chang, Yu-Ming

    1996-01-01

    Robust operating systems are required for reliable computing. Techniques for robustness evaluation of operating systems not only enhance the understanding of the reliability of computer systems, but also provide valuable feed- back to system designers. This thesis presents results from robustness evaluation experiments on five UNIX-based operating systems, which include Digital Equipment's OSF/l, Hewlett Packard's HP-UX, Sun Microsystems' Solaris and SunOS, and Silicon Graphics' IRIX. Three sets of experiments were performed. The methodology for evaluation tested (1) the exception handling mechanism, (2) system resource management, and (3) system capacity under high workload stress. An exception generator was used to evaluate the exception handling mechanism of the operating systems. Results included exit status of the exception generator and the system state. Resource management techniques used by individual operating systems were tested using programs designed to usurp system resources such as physical memory and process slots. Finally, the workload stress testing evaluated the effect of the workload on system performance by running a synthetic workload and recording the response time of local and remote user requests. Moderate to severe performance degradations were observed on the systems under stress.

  12. Solidifying process and flame retardancy of epoxy resin cured with boron-containing phenolic resin

    Science.gov (United States)

    Deng, Peng; Shi, Yan; Liu, Yuansen; Liu, Yuan; Wang, Qi

    2018-01-01

    For the sake of improving the charring performance and flame retardancy of epoxy resin (EP), boron-containing phenolic resin (BPR) instead of a conventional curing agent, linear phenolic resin (LPR) was employed to cure EP. Of several possible chemical structures for BPR, the existence of benzyl hydroxy groups in BPR chains has been confirmed using 1H nuclear magnetic resonance spectroscopy. The resonance of these groups may reasonably explain the higher curing reactivity of BPR-cured EP than that of LPR-cured EP. Thermogravimetric analysis, observation of the morphologies of the char residues and X-ray photoelectron spectroscopic were performed to characterize the charring process. Due to the presence of B2O3 produced on the char surface from decomposition of phenyl borates and the facile high self-crosslinking reaction of BPR, a more continuous and stronger char barrier was formed for BPR-cured EP compared to that for the LPR-cured EP system. Therefore the former exhibited much better flame retardancy. In addition, BPR-cured EP also displayed better dynamic mechanical properties, than those observed for LPR-cured EP. It is not subject to the significant lowering the glass transition temperature of the polymer which accompanies curing with LPR. This suggests that BPR cured resin may meet the requirement for utilization at high temperature.

  13. IDEA: A Unifying Theory for Evaluation Systems

    DEFF Research Database (Denmark)

    Bella, Giampaolo; Giustolisi, Rosario

    2017-01-01

    Secure systems for voting, exams, auctions and conference paper management are theorised to address the same problem, that of secure evaluations. In support of such a unifying theory comes a model for Secure Evaluation Systems (SES), which offers innovative common grounds to understand all four...

  14. Development of a School Leadership Evaluation System

    Science.gov (United States)

    Orlando, Nik

    2014-01-01

    This action research study examined the effectiveness of the process implemented by Partnerships to Uplift Communities (PUC) Schools Charter Management Organization to develop their school leader evaluation system in collaboration with current PUC school leaders. The development of the leadership evaluation system included the collective voices of…

  15. Overcoming barriers to evaluation of terminological systems

    NARCIS (Netherlands)

    Cornet, Ronald; de Keizer, Nicolette F.; Arts, Daniëlle G. T.

    2004-01-01

    Evaluation of terminological systems has been demonstrated to be a complicated task. This is due to the broad range of terminological systems, their application, and the clinical contexts in which they can be applied. We propose an evaluation framework that explicitly distinguishes an

  16. [Mineral water as a cure].

    Science.gov (United States)

    Nocco, Priska Binz

    2008-01-01

    resorts mentioned, especially regarding the quality and quantity aspects of the performed mineral water analyses, as well as in the reported written evidence and publications on the success of the therapies. Differences were also to be found in the conditions of the health resort facilities and in the medical support given. The therapy opportunities included mainly drinking and bath cures, which could occur alone or in combination. In the mentioned health resorts different clinical disease symptoms were treated. The most important baths were located in Acquarossa and Stabio, which were specialized in selected therapeutical domains, because of their particular water compositions. Numerous personalities from science and politics were concerned by the local springs and accepted to contribute to the promotion of these structures. Their engagement led to the integration of the native springs in the Farmacopea Ticinese. Since at that time it was extremely difficult to find experienced mineral water analysts in the region, the analyses of local native sources were assigned to qualified experts mainly coming from Italy. This scientific co-operation between the southern part of Switzerland and the northern part of Italy was, already at that time, active also in other work domains. The evaluation of the historical documentation available from the Farmacia Vantussi shows that this pharmacy supplied a considerable assortment of national and foreign spring waters, as well as foreign dried components. Of commercial interest was, to be noted, the free sale of the waters to hospitals, institutions, hotels, restaurants as well as to private households. The sales of waters and of their dried components upon prescription, however, constituted only the minor part. The introduction of the industrial bottling occurring in the first decades of the 20th century, led to a lowering price trend, through which the product 'mineral water' became accessible to a broader public. Henceforth its

  17. Light curing through glass ceramics: effect of curing mode on micromechanical properties of dual-curing resin cements.

    Science.gov (United States)

    Flury, Simon; Lussi, Adrian; Hickel, Reinhard; Ilie, Nicoleta

    2014-04-01

    The aim of this study was to investigate micromechanical properties of five dual-curing resin cements after different curing modes including light curing through glass ceramic materials. Vickers hardness (VH) and indentation modulus (Y HU) of Panavia F2.0, RelyX Unicem 2 Automix, SpeedCEM, BisCem, and BeautiCem SA were measured after 1 week of storage (37 °C, 100 % humidity). The resin cements were tested following self-curing or light curing with the second-generation light-emitting diode (LED) curing unit Elipar FreeLight 2 in Standard Mode (1,545 mW/cm(2)) or with the third-generation LED curing unit VALO in High Power Mode (1,869 mW/cm(2)) or in XtraPower Mode (3,505 mW/cm(2)). Light curing was performed directly or through glass ceramic discs of 1.5 or 3 mm thickness of IPS Empress CAD or IPS e.max CAD. VH and Y HU were analysed with Kruskal-Wallis tests followed by pairwise Wilcoxon rank sum tests (α = 0.05). RelyX Unicem 2 Automix resulted in the highest VH and Y HU followed by BeautiCem SA, BisCem, SpeedCEM, and finally Panavia F2.0. Self-curing of RelyX Unicem 2 Automix and SpeedCEM lowered VH and Y HU compared to light curing whereas self-curing of Panavia F2.0, BisCem, and BeautiCem SA led to similar or significantly higher VH and Y HU compared to light curing. Generally, direct light curing resulted in similar or lower VH and Y HU compared to light curing through 1.5-mm-thick ceramic discs. Light curing through 3-mm-thick discs of IPS e.max CAD generally reduced VH and Y HU for all resin cements except SpeedCEM, which was the least affected by light curing through ceramic discs. The resin cements responded heterogeneously to changes in curing mode. The applied irradiances and light curing times adequately cured the resin cements even through 1.5-mm-thick ceramic discs. When light curing resin cements through thick glass ceramic restorations, clinicians should consider to prolong the light curing times even with LED curing units providing high

  18. Evaluation Methods for Intelligent Tutoring Systems Revisited

    Science.gov (United States)

    Greer, Jim; Mark, Mary

    2016-01-01

    The 1993 paper in "IJAIED" on evaluation methods for Intelligent Tutoring Systems (ITS) still holds up well today. Basic evaluation techniques described in that paper remain in use. Approaches such as kappa scores, simulated learners and learning curves are refinements on past evaluation techniques. New approaches have also arisen, in…

  19. Development of a Sound Quality Evaluation System

    DEFF Research Database (Denmark)

    Kvist, Preben; Thomsen, Carsten; Lee, Sanjil

    2004-01-01

    This paper describes the development of the first version of the Sound Quality Evaluation System. The purpose of the system is to predict the subjective sound quality of home theater systems from objective measurements. 16 home theater systems were measured in an anechoic room. Several metrics...... expected to correlate w ith the subjective quality were proposed and tested. A model for the sound quality was created by mapping the subjective evaluations of the Home Theater System s with the metrics calculated for each system. Correlation between subjective listening test and the prediction is presente...

  20. Computerized ultrasound risk evaluation system

    Science.gov (United States)

    Duric, Nebojsa; Littrup, Peter J.; Holsapple, III, Earle; Barter, Robert Henry; Moore, Thomas L.; Azevedo, Stephen G.; Ferguson, Sidney W.

    2007-10-23

    A method and system for examining tissue are provided in which the tissue is maintained in a position so that it may be insonified with a plurality of pulsed spherical or cylindrical acoustic waves. The insonifying acoustic waves are scattered by the tissue so that scattered acoustic radiation including a mix of reflected and transmitted acoustic waves is received. A representation of a portion of the tissue is then derived from the received scattered acoustic radiation.

  1. Amygdalin, quackery or cure?

    Science.gov (United States)

    Blaheta, Roman A; Nelson, Karen; Haferkamp, Axel; Juengel, Eva

    2016-04-15

    The cyanogenic diglucoside, amygdalin, has gained high popularity among cancer patients together with, or in place of, conventional therapy. Still, evidence based research on amygdalin is sparse and its benefit controversial. Since so many cancer patients consume amygdalin, and many clinicians administer it without clear knowledge of its mode of action, current knowledge has been summarized and the pros and cons of its use weighed. A retrospective analysis was conducted for amygdalin relevant reports using the PubMed database with the main search term "Amygdalin" or "laetrile", at times combined with "cancer", "patient", "cyanide" or "toxic". We did not exclude any "unwanted" articles. Additionally, internet sources authorized by governmental or national institutions have also been included. Individual chapters summarize pharmacokinetics, preclinical and clinical studies and toxicity. No convincing evidence showing that amygdalin induces rapid, distinct tumor regression in cancer patients, particularly in those with late-stage disease, is apparent. However, there is also no evidence that purified amygdalin, administered in "therapeutic" dosage, causes toxicity. Multiple aspects of amygdalin administration have not yet been adequately explored, making further investigation necessary to evaluate its actual therapeutic potential. Copyright © 2016 Elsevier GmbH. All rights reserved.

  2. Analyses on curing process of electron beam radiation in epoxy resins

    Energy Technology Data Exchange (ETDEWEB)

    Sui Gang; Zhang Zuoguang; Chen Changqi; Zhong Weihong

    2003-02-17

    Epoxy resins have already been applied in electron beam (EB) curable composites structures extensively. The effects of different initiators and diluents on Shell Epon 828 radiation reaction were discussed in the paper, and the same radiation reaction systems were also explored using a heat treatment. The experimental results indicated cationic photoinitiator can initiate EB radiation curing of epoxy resin and traditionally heat-cured systems are not always suitable for the EB curing. The use of diluents would reduce the curing degree of resin and reactive diluents have less effect. The cationic ring-opening polymerization process including the decomposition of diaryliodonium salts under EB radiation at the initial stage and production of protonic acid that can initiate polyreaction was validated in the experiments. The characteristic of cured field and penetration process of EB in Shell Epon 828 system was also studied, and the whole cured area was found to be consisting of many lamellar structures.

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

    Science.gov (United States)

    Glouberman, S; Mintzberg, H

    2001-01-01

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

  4. Accelerated Cure Project for Multiple Sclerosis

    Science.gov (United States)

    ... content Accelerating research toward a cure for multiple sclerosis Toggle navigation Search form Search Connect Volunteer Donate ... to accelerate efforts toward a cure for multiple sclerosis by rapidly advancing research that determines its causes ...

  5. Factors Influencing the Cure Rate in the Corneal Graft Rejection with Survival Analysis

    Directory of Open Access Journals (Sweden)

    Feizi S.

    2009-11-01

    Full Text Available AbstractBackground and Objectives: Immunologic rejection of the transplanted cornea is the major cause of human allograft failure with several risk factors contributing to it. Since in the corneal graft, most individuals do not reject the graft, we used the survival analysis with cure rate for the assessment of the factors influencing the cure rate at the time of data analysis. The main aim of this study was to evaluate the cure rate and assess the risk factors for corneal graft rejection in the keratoconus disease in Labafinejad Hospital, Tehran, Iran. Methods: This was a routine data base study in which the data were gathered from keratoconus patients’ files that had undergone penetrating keratoplasty operation. In the survival analysis, individuals who didn’t reject corneal were considered cured. To study the factors influencing the cure rate, we used the Weibull distribution for survival function and the logistic link function for the cure rate because of their tractability and accuracy.Results: Out of 119 patients 31 patients (26% rejected grafts. Among the factors influencing cure rate, only in vascularization and in persons older than 25 years of age was ameaningful effect on decreasing cure rate. With this cure model, the expected cure rate in the non-vascularization and less than 25 year- old patients was 81, in non-vascularization and more than 25 year- olds it is 64, in the vascularization and less than 25 year- olds, the cure rate is 19 and in the vascularization and more than 25 years of age, the cure rate is 9 percent and the observed cure rate for Kaplan-Meier product limit estimator was 79, 61, 27 and 0 percent, respectively. The results showed that the estimate of cure rate in the survival analysis was near the Kaplan-Meier product-limits estimator.Conclusion: One of the benefits of modeling is its ability to generalize the results; using them in the prediction. According to the results obtained from the fitting cure model

  6. Relationship of Cure Temperature to Mechanical, Physical, and Dielectric Performance of PDMS Glass Composite for Electric Motor Insulation

    Science.gov (United States)

    Miller, Sandi G.; Becker, Kathleen; Williams, Tiffany S.; Scheiman, Daniel A.; McCorkle, Linda S.; Heimann, Paula J.; Ring, Andrew; Woodworth, Andrew

    2017-01-01

    Achieving NASAs aggressive fuel burn and emission reduction for N-plus-3 aircraft will require hybrid electric propulsion system in which electric motors driven by either power generated from turbine or energy storage system will power the fan for propulsion. Motors designed for hybrid electric aircraft are expected to operate at medium to high voltages over long durations in a high altitude service environment. Such conditions have driven research toward the development of wire insulation with improved mechanical strength, thermal stability and increased breakdown voltage. The silicone class of materials has been considered for electric wire insulation due to its inherent thermal stability, dielectric strength and mechanical integrity. This paper evaluates the dependence of these properties on the cure conditions of a polydimethyl-siloxane (PDMS) elastomer; where both cure temperature and base-to-catalyst ratio were varied. The PDMS elastomer was evaluated as a bulk material and an impregnation matrix within a lightweight glass veil support. The E-glass support was selected for mechanical stiffness and dielectric strength. This work has shown a correlation between cure conditions and material physical properties. Tensile strength increased with cure temperature whereas breakdown voltage tended to be independent of process variations. The results will be used to direct material formulation based on specific insulation requirements.

  7. How to Evaluate Integrated Library Automation Systems.

    Science.gov (United States)

    Powell, James R.; Slach, June E.

    1985-01-01

    This paper describes methodology used in compiling a list of candidate integrated library automation systems at a corporate technical library. Priorities for automation, identification of candidate systems, the filtering process, information for suppliers, software and hardware considerations, on-site evaluations, and final system selection are…

  8. Comparison of the effect of light-cure and dual-cure bondings on regional bond strength of fiber reinforced posts to root canal

    Directory of Open Access Journals (Sweden)

    Aminsalehi E.

    2008-04-01

    Full Text Available Background and Aim: The use of fiber reinforced posts in endodontically treated teeth has become increasingly common. But their retention in root canals must be considered seriously. The aim of this study was to evaluate the effect of light-cure and dual-cure bondings on regional bond strength of a fiber composite post.Materials and Methods: In this experimental in vitro study, 20 endodontically treated teeth were randomly divided into two groups. In the first group, a dual-cure bonding (Scotchbond Multi-Purpose Plus, 3M ESPE/USA [SBMP] was used and in the other group, a light-cure bonding (Single Bond, 3M ESPE/USA [SB] was applied according to the manufacturer's instructions. A dual-cure resin cement (Rely X ARC, 3M ESPE/USA was used to cement the post (Glassix, Harald Nordin SA,Switzerland. Coronal 8mm of cemented posts were sectioned in equal thirds using a 0.1mm diamond disc. Each slice was polished by a soft and wet abrasive paper in order to get a 2mm thickness. Loading was performed by a testing machine (Zwick/Germany at a speed of 1mm/min until the post was dislodged. Data were analyzed using one-sample Kolmogorov-Smirnov, T and ANOVA tests with P<0.05 as the level of significance.Results: There was a significant difference between the two adhesive systems in the middle third of the canal block with higher bond strength in SBMP group (p=0.02. In SB group the bond strength of the cervical region was higher than the middle and apical thirds (p<0.05. In SBMP group, there was no statistically difference between bond strength of the three regions (p=0.117.Conclusion: Based on the results of this study, dual-cure bonding could be recommended for composite post cementation into root canals, because its bond strength was more uniform in different regions of root and greater in the middle and third regions.

  9. Paclitaxel Release from Polyether-Anhydrides Prepared with UV-Curing Process

    Directory of Open Access Journals (Sweden)

    Anxin Dong

    2013-01-01

    Full Text Available Polyanhydrides have been used as drug delivery systems to achieve a long-term delivery due to its hydrophobicity and surface erosion degradation behavior. In order to develop a simple, economical, and rapid approach to synthesize polyanhydrides, we prepared a series of polyether-anhydride membranes composed of different mass fractions of sebacic acid, polyethylene glycol dimethacrylate, and poly(tetramethylene oxide dimethacrylate by ultraviolet curing process. The chemical structure and thermal properties of target polyanhydrides were characterized, while the paclitaxel releases from the polymer matrix were evaluated by HPLC. The results demonstrated that the UV-curing process is a good method to synthesize the target polymers in a short time, and the paclitaxel release procedure can be controlled by changing the component in the copolymers.

  10. 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.

  11. Effect of light-curing units on push-out fiber post bond strength in root canal dentin

    Science.gov (United States)

    Calixto, L. R.; Bandéca, M. C.; Silva, F. B.; Rastelli, A. N. S.; Porto-Neto, S. T.; Andrade, M. F.

    2009-08-01

    The purpose of this study was to evaluate the effectiveness of different light-curing units on the bond strength (push-out) of glass fiber posts in the different thirds of the root (cervical, middle and apical) with different adhesive luting resin systems (dual-cure total-etch; dual-cured and self-etch bonding system; and dual-cure self-adhesive cements), Disks of the samples ( n = 144) were used, with approximately 1 mm of thickness of 48 bovine roots restored with glass fiber posts, that were luted with resin cements photo-activated by halogen LCU (QTH, Optilux 501) and blue LED (Ultraled), with power densities of 600 and 550 mW/cm2, respectively. A universal testing machine (MTS 810 Material Test System) was used with a 1 mm diameter steel rod at cross-head speed of 0.5 mm/min until post extrusion, with load cell of 50 kg, for evaluation of the push-out strength in the different thirds of each sample. The push-out strength values in kgf were converted to MPa and analyzed through Analysis of Variance and Tukey’s test, at significance level of 5%. The results showed that there were no statistical differences between the QTH and LED LCUs. The self-adhesive resin cement had lower values of retention. The total-etch and self-adhesive system resin cements seem to be a possible alternative for glass fiber posts cementation into the radicular canal and the LED LCU can be applied as an alternative to halogen light on photo-activation of dual-cured resin cements.

  12. A Comparison of the Shear Bond Strength of Orthodontic Brackets Bonded With Light-Emitting Diode and Halogen Light-Curing Units

    Directory of Open Access Journals (Sweden)

    SM. Abtahi

    2006-09-01

    Full Text Available Statement of the problem: Various methods such as light emitting diode (LED have been used to enhance the polymerization of resin-based orthodontic adhesives. There is a lack of information on the advantages and disadvantages of different light curing systems.Purpose: The aim of this study was to compare the effect of LED and halogen light curing systems on the shear bond strength of orthodontic brackets.Materials and Methods: Forty extracted human premolars were etched with 37% phosphoric acid and cleansed with water spray and air dried. The sealant was applied on the tooth surface and the brackets were bonded using Transbond adhesive (3M Unitek,Monrovia, Calif. Adhesives were cured for 40 and 20 seconds with halogen (Blue Light, APOZA, Taiwan and LED (Blue dent, Smart, Yugoslavia light-curing systems,respectively. Specimens were thermocycled 2500 times (from 5 to 55 °C and the shear bond strength of the adhesive system was evaluated with an Universal testing machine (Zwick GmbH, Ulm, Germany at a crosshead speed of 1 mm/min until the bracketswere detached from the tooth. Adhesive remnant index (ARI scores were determined after bracket failure. The data were submitted to statistical analysis, using Mann-Whitney analysis and t-test.Results: No significant difference was found in bond strength between the LED and halogen groups (P=0.12. A significant difference was not observed in the adhesive remnant index scores between the two groups (P=0.97.Conclusion: Within the limitations of this in vitro study, the shear bond strength of resin-based orthodontic adhesives cured with a LED was statistically equivalent to those cured with a conventional halogen-based unit. LED light-curing units can be suggested for the polymerization of orthodontic bonding adhesives.

  13. The difference nanocomposite hardness level using LED photoactivation based on curing period variations

    Directory of Open Access Journals (Sweden)

    Hasiana Tatian

    2011-03-01

    Full Text Available Polimerizatian is the critical stage to determine the quality of composites resin, this involves isolated monomer carbon double bonds being converted to an extended network of single bonds. Physical and mechanical properties of composites are influenced by the level of conversion attained during polymerization. An adequate light intensity and light curing time are important to obtain the degree of polymerization. The objective of this study is to evaluate the difference of the hardness nanocomposites which activated by LED LCU based on the variation of curing times. This study is a true experimental research. The samples were made from nanocomposites material with cylinder form of 4 mm in depth, 6 mm in diameter. This samples divided into 3 groups of curing times. Group, I was cured for 20's curing time as a control due to manufactory recommended; Group II was cured for 30's, and Group III was cured for 40's and the hardness (Rebound hardness tester was determined using Rebound scale (RS and converted by Mohs scale (MS. There was a very significant level of hardness rate from each group using ANOVA test. The result of the study concludes that there were the differences on the nanocomposites hardness level cured under different curing times 20, 30 and 40 sec. The longer of curing times, the higher level of hardness.

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

    Science.gov (United States)

    Lee, Sujeong; van Riessen, Arie; Chon, Chul-Min

    2016-01-01

    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. PMID:28773720

  16. Freud's psychoanalysis: a moral cure.

    Science.gov (United States)

    Eriksson, Johan

    2014-08-01

    That psychoanalytical treatment in its classical Freudian sense is primarily a moral or ethical cure is not a very controversial claim. However, it is far from obvious how we are to understand precisely the moral character of psychoanalysis. It has frequently been proposed that this designation is valid because psychoanalysis strives neither to cure psychological symptoms pharmaceutically, nor to superficially modify the behaviour of the analysand, but to lead the analysand through an interpretive process during which he gradually gains knowledge of the unconscious motives that determine his behaviour, a process that might ideally liberate him to obtain, in relation to his inner desires, the status of a moral agent. There resides something appealing in these claims. But it is the author's belief that there is an even deeper moral dimension applying to psychoanalytical theory and praxis. Freudian psychoanalysis is a moral cure due to its way of thematizing psychological suffering as moral suffering. And this means that the moral subject - the being that can experience moral suffering - is not primarily something that the psychoanalytical treatment strives to realize, but rather the presupposition for the way in which psychoanalysis theorizes psychological problems as such. Copyright © 2014 Institute of Psychoanalysis.

  17. Concept Evaluation for Hydraulic Yaw System

    DEFF Research Database (Denmark)

    Stubkier, Søren; Pedersen, Henrik C.; Andersen, Torben Ole

    2013-01-01

    a suspension system on a car, leading the loads away from the turbine structure. However, to realize a soft hydraulic yaw system a new design concept must be found. As a part of the development of the new concept a preliminary concept evaluation has been conducted, evaluating seven different hydraulic yaw...... concepts, ranging from a one-to-one copy of the electrical drive (electrical drives replaced by hydraulic dittos), to floating suspension systems mounted on hydraulic cylinders. Rough calculations of size and consequences of the different systems are presented ending up with the final concept for further...

  18. Pervious Pavement System Evaluation-Poster

    Science.gov (United States)

    Pervious pavement is a low impact development stormwater control. The Environmental Protection Agency's Urban Watershed Management Branch is evaluating interlocking concrete pavingstone pervious pavement systems. The pavingstones themselves are impermeable, but the spaces between...

  19. Cure Schedule for Stycast 2651/Catalyst 9.

    Energy Technology Data Exchange (ETDEWEB)

    Kropka, Jamie Michael [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); McCoy, John D. [New Mexico Inst. of Mining and Technology, Socorro, NM (United States)

    2017-11-01

    The Emerson & Cuming technical data sheet (TDS) for Stycast 2651/Catalyst 9 lists three alternate cure schedules for the material, each of which would result in a different state of reaction and different material properties. Here, a cure schedule that attains full reaction of the material is defined. The use of this cure schedule will eliminate variance in material properties due to changes in the cure state of the material, and the cure schedule will serve as the method to make material prior to characterizing properties. The following recommendation uses one of the schedules within the TDS and adds a “post cure” to obtain full reaction.

  20. Survival of selected foodborne pathogens on dry cured pork loins.

    Science.gov (United States)

    Morales-Partera, Ángela M; Cardoso-Toset, Fernando; Jurado-Martos, Francisco; Astorga, Rafael J; Huerta, Belén; Luque, Inmaculada; Tarradas, Carmen; Gómez-Laguna, Jaime

    2017-10-03

    The safety of ready-to-eat products such as cured pork loins must be guaranteed by the food industry. In the present study, the efficacy of the dry curing process of pork loins obtained from free-range pigs in the reduction of three of the most important foodborne pathogens is analysed. A total of 28 pork loin segments, with an average weight of 0.57±0.12kg, were divided into four groups with three being inoculated by immersion with 7logCFU/ml of either Salmonella Typhimurium, Campylobacter coli or Listeria innocua and the last one inoculated by immersion with sterile medium (control group). The loin segments were treated with a seasoning mixture of curing agents and spices, packed in a synthetic sausage casing and cured for 64days. Microbiological analysis, pH and water activity (a w ) were assessed at four stages. The values of pH and a w decreased with curing time as expected. S. Typhimurium and C. coli dropped significantly (3.28 and 2.14 log units, respectively), but limited reduction of L. innocua (0.84 log unit) was observed along the curing process. In our study, three factors were considered critical: the initial concentration of the bacteria, the progressive reduction of pH and the reduction of a w values. Our results encourage performing periodic analysis at different stages of the manufacturing of dry cured pork loins to ensure the absence of the three evaluated foodborne pathogens. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. Multimodal Trip Planner System final evaluation report.

    Science.gov (United States)

    2011-05-01

    This evaluation of the Multimodal Trip Planning System (MMTPS) is the culmination of a multi-year project evaluating the development and deployment of a multimodal trip planner in the Chicagoland area between 2004 and 2010. The report includes an ove...

  2. Degree of cure of orthodontic adhesives with various polymerization initiation modes.

    Science.gov (United States)

    Eliades, T; Eliades, G; Bradley, T G; Watts, D C

    2000-08-01

    The purpose of this study was to estimate the degree of cure (DC) of a light-cured, and a two- and a one-phase (no-mix) chemically-cured, as well as a dual-cured commercially available orthodontic adhesive resin. Forty stainless steel brackets were divided into four groups of 10 brackets each, and the bracket bases were covered with a standardized volume of adhesive. They were then pressed firmly onto a yellowish background surface of 75 per cent reflectance covered with cellulose film to facilitate detachment of the system and recovery of the set material. The visible light- and dual-cured adhesives were photopolymerized by irradiation from the incisal and cervical edges of the bracket for 10 seconds each, while another group of ceramic brackets was used to assess the differential interference of transparent relative to opaque material in the DC. Micro-multiple internal reflectance Fourier transform infrared spectroscopy was employed for the estimation of the DC of the adhesives (alpha = 0.05, n = 10), utilizing a method proposed previously. The dual-cured product demonstrated the highest DC followed by the light-cured combined with the ceramic bracket, and the no-mix and the chemically-cured adhesives. The combination of the metallic bracket with the light-cured product resulted in a DC comparable with that of the chemically-cured material.

  3. Comparison of shear bond strength of orthodontic brackets bonded with halogen and plasma arc light curing

    Directory of Open Access Journals (Sweden)

    Mohammad Hossein IndianJPsychiatry

    2012-01-01

    Conclusion: Using the plasma arc system is superior to other methods due to reduced curing time. Also, since in using the halogen light system, an increase in curing periods from different angles resulted in a significant increase in shear bond strength; it is advisable to apply the halogen light from different angles.

  4. Setting shrinkage strains of chemical-cured glass ionomer-based ...

    African Journals Online (AJOL)

    Shrinkage strains are exhibited by the current formulations of chemical-cured dental restorative systems. In resin-modified glass ionomer systems, these have been linked to filler contents, types and quantity of monomer. Post-gelation rigid contraction that follows onset of cure leading to marginal defects is a clinically ...

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

    Science.gov (United States)

    SANTOS, Maria Jacinta Moraes Coelho; PASSOS, Sheila Pestana; da ENCARNAÇÃO, Monalisa Olga Lessa; SANTOS, Gildo Coelho; BOTTINO, Marco Antonio

    2010-01-01

    Objective This study evaluated the surface hardness of a resin cement (RelyX ARC) photoactivated through indirect composite resin (Cristobal) disks of different thicknesses using either a light-emitting diode (LED) or quartz tungsten halogen (QTH) light source. Material and Methods Eighteen resin cement specimens were prepared and divided into 6 groups according to the type of curing unit and the thickness of resin disks interposed between the cement surface and light source. Three indentations (50 g for 15 s) were performed on the top and bottom surface of each specimen and a mean Vickers hardness number (VHN) was calculated for each specimen. The data were analyzed using two-way ANOVA and Tukey-Kramer test was used for post-hoc pairwise comparisons. Results Increased indirect resin disk thickness resulted in decreased mean VHN values. Mean VHN values for the top surfaces of the resin cement specimens ranged from 23.2 to 46.1 (QTH) and 32.3 to 41.7 (LED). The LED curing light source produced higher hardness values compared to the QTH light source for 2- and 3-mm-thick indirect resin disks. The differences were clinically, but not statistically significant. Increased indirect resin disk thickness also resulted in decreased mean VHN values for the bottom surfaces of the resin cement: 5.8 to 19.1 (QTH) and 7.5 to 32.0 (LED). For the bottom surfaces, a statistically significant interaction was also found between the type of curing light source and the indirect resin disk thickness. Conclusions Mean surface hardness values of resin cement specimens decreased with the increase of indirect resin disk thickness. The LED curing light source generally produced higher surface hardness values. PMID:20485920

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

    Directory of Open Access Journals (Sweden)

    Maria Jacinta Moraes Coelho Santos

    2010-04-01

    Full Text Available OBJECTIVE: This study evaluated the surface hardness of a resin cement (RelyX ARC photoactivated through indirect composite resin (Cristobal disks of different thicknesses using either a light-emitting diode (LED or quartz tungsten halogen (QTH light source. MATERIAL AND METHODS: Eighteen resin cement specimens were prepared and divided into 6 groups according to the type of curing unit and the thickness of resin disks interposed between the cement surface and light source. Three indentations (50 g for 15 s were performed on the top and bottom surface of each specimen and a mean Vickers hardness number (VHN was calculated for each specimen. The data were analyzed using two-way ANOVA and Tukey-Kramer test was used for post-hoc pairwise comparisons. RESULTS: Increased indirect resin disk thickness resulted in decreased mean VHN values. Mean VHN values for the top surfaces of the resin cement specimens ranged from 23.2 to 46.1 (QTH and 32.3 to 41.7 (LED. The LED curing light source produced higher hardness values compared to the QTH light source for 2- and 3-mm-thick indirect resin disks. The differences were clinically, but not statistically significant. Increased indirect resin disk thickness also resulted in decreased mean VHN values for the bottom surfaces of the resin cement: 5.8 to 19.1 (QTH and 7.5 to 32.0 (LED. For the bottom surfaces, a statistically significant interaction was also found between the type of curing light source and the indirect resin disk thickness. CONCLUSION: Mean surface hardness values of resin cement specimens decreased with the increase of indirect resin disk thickness. The LED curing light source generally produced higher surface hardness values.

  7. Analysis of gap formation at tooth-composite resin interface: effect of C-factor and light-curing protocol

    Directory of Open Access Journals (Sweden)

    Gustavo Oliveira dos Santos

    2007-08-01

    Full Text Available OBJECTIVE: The aim of this study was to evaluate the effect of C-factor and light-curing protocol on gap formation in composite resin restorations. Material and METHODS: Cylindrical cavities with 5.0 mm diameter and three different depths (A=1.0, B=2.0 and C=3.0 mm were prepared on the occlusal surface of 30 human molars and restored in a single increment with P 60. The composite resin was light-cured according to two protocols: standard - 850 mW/cm² / 20 s and gradual - 100 up to 1000 mW/cm² / 10 s + 1000 mW/cm² / 10 s. After storage in distilled water (37°C/7 days, the restorations were cut into three slices in a buccolingual direction and the gap widths were analyzed using a 3D-scanning system. The data were submitted to ANOVA and Student-Newman-Keuls test (alpha=0.05. RESULTS: ANOVA detected a significant influence for the C-factor and light-curing protocol as independent factors, and for the double interaction C-factor vs. light-curing protocol. Cavities with higher C-factor presented the highest gap formation. The gradual light-curing protocol led to smaller gap formation at cavity interfaces. CONCLUSIONS: The findings of this study suggest that the C-factor played an essential role in gap formation. The gradual light-curing protocol may allow relaxation of composite resin restoration during polymerization reaction.

  8. Effect of light curing methods on microleakage and microhardness of different resin sealants.

    Science.gov (United States)

    Duangthip, Duangporn; Ballungpattama, Suda; Sitthisettapong, Thanya

    2011-07-01

    This study's purpose was to evaluate the effect of light curing methods on the microleakage and microhardness of sealants. The Elipar Free Light 2 light emitting diode (LED) with 10- and 20-second curing times, and the Elipar 2500 halogen light with a 20-second curing time were compared. Four different sealants were used: (1) Delton Clear; (2) Delton Opaque; (3) UltraSeal XT Clear; and (4) UltraSeal XT Opaque. Specimens were fabricated in a silicone mold (2-mm thick) and cured. Knoop hardness was measured at the bottom and top surfaces. For the microleakage evaluation, 120 human molars were divided into 12 groups and sealed with the sealants and curing methods, as stated previously. The teeth were thermocycled and immersed in 2% methylene blue for 24 hours. Each tooth was sectioned and examined for dye penetration. There were no statistically significant differences in the microleakage of sealants polymerized by either the halogen or LED curing methods. The microhardness of sealants varied according to the type of material and curing method. A 10-second polymerization time with light emitting diodes was not sufficient to cure the 2-mm-thick opaque or high filler loaded sealants. Decreasing the curing time, however, had no effect on the microleakage of the sealants.

  9. Effect of light-emitting diode and halogen light curing on the micro-hardness of dental composite and resin-modified glass ionomer cement: An in vitro study

    Directory of Open Access Journals (Sweden)

    M Bhalla

    2012-01-01

    Full Text Available Aims : This in vitro study was conducted to evaluate and compare the micro-hardness of composite resin and resin-modified glass ionomer cement using light-emitting diode (LED and halogen curing and also to inter-compare the effect of LED and halogen curing. Materials and Methods : The study sample comprised of 4 stainless steel plates with a thickness of 2 mm. For these stainless steel plates, holes were made to a diameter of 3 mm. The samples were divided into 4 groups of 8 each and labeled as group I, group II, group III, group IV, thus making provision for the two different modes of light exposure. In each group, the hole was restored with its respective restorative material and cured with light-curing unit according to manufacturer instructions. The results were statistically analyzed using Mann-Whitney test. Results and conclusion: It was concluded that the curing efficacy of the LED lamp was comparable to that of conventional halogen lamp, even with a 50% reduction in cure time, and resin composite (Filtek Z-250 presented the highest hardness values, whereas complete hardening of resin-modified glass ionomer cement (RMGIC (Vitremer was observed because of its self-curing system even after the removal of light source.

  10. Comparison of three Land Evaluation Systems in Evaluating the ...

    African Journals Online (AJOL)

    Three land evaluation system.(Land Capability Classification, Fertility Capability Classification and Land Suitability Classification) were compared for their practical relevance in terms of the accuracy of their predictive value on seven major soil types in the humid forest zone of south western Nigeria. The result showed that ...

  11. evaluation of municipal solid waste management system

    African Journals Online (AJOL)

    eobe

    This paper reports the evaluation of households' usage of the current solid waste management system (SWMS) within the city of Ilorin, ... respectively of the households were unsatisfied and moderately satisfied with the current waste management system. ..... collection, separation and willingness to pay”,. Kuwait Journal of ...

  12. Expected energy production evaluation for photovoltaic systems

    DEFF Research Database (Denmark)

    Ding, Yi; Østergaard, Jacob; Peng, Wang

    2011-01-01

    A photovoltaic (PV) system consists of many solar panels, which are connected in series, parallel or a combination of both. Energy production for the PV system with various configurations is different. In this paper, a methodology is developed to evaluate and analyze the expected energy production...

  13. Evaluation System Weighing down Tennessee Teachers

    Science.gov (United States)

    Heitin, Liana

    2011-01-01

    A state law, which helped Tennessee win Race to the Top money, pushed schools to implement a system that had limited pilot-testing. Education officials in Tennessee are taking flak from teachers and unions for rushing the implementation of the new teacher-evaluation system that will eventually undergird tenure decisions--a move, some worry, that…

  14. Advanced technology wind shear prediction system evaluation

    Science.gov (United States)

    Gering, Greg

    1992-01-01

    The program overviews: (1) American Airline (AA)/Turbulence Prediction Systems (TPS), which have installed forward looking infrared predictive windshear system on 3 MD-80 aircraft; (2) AA/TPS AWAS III evaluation, which is a joint effort and is installed in the noise landing gear (NLG) area and a data recorder installed in the E/E compartment.

  15. The simulation system of credit portfolio evaluation

    Directory of Open Access Journals (Sweden)

    G. Magariu

    1999-02-01

    Full Text Available A simulation system of evaluation of a portfolio of credits is presented. The system answers user's question from the list of possible questions. Design, execution and analysis of results of experiments needed for the answer are controlled by user question. Input and output data may be precise as well as probabilistic.

  16. System Modeling and Trust Evaluation of Distributed Systems

    OpenAIRE

    Alhadad, Nagham; Serrano-Alvarado, Patricia; Busnel, Yann; Lamarre, Philippe

    2015-01-01

    International audience; Nowadays, digital systems are connected through complex architectures. These systems involve persons, physical and digital resources such that we can consider that a system consists of elements from two worlds, the social world and the digital world, and their relations. Users perform activities like chatting, buying, sharing data, etc. Evaluating and choosing appropriate systems involve aspects like functionality, performance, QoS, ease of use, or price. Recently, tru...

  17. Automated Laser Seeker Performance Evaluation System (ALSPES)

    Science.gov (United States)

    Martin, Randal G.; Robinson, Elisa L.

    1988-01-01

    The Automated Laser Seeker Performance Evaluation System (ALSPES), which supports the Hellfire missile and Copperhead projectile laser seekers, is discussed. The ALSPES capabilities in manual and automatic operation are described, and the ALSPES test hardware is examined, including the computer system, the laser/attenuator, optics systems, seeker test fixture, and the measurement and test equipment. The calibration of laser energy and test signals in ALSPES is considered.

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

    NARCIS (Netherlands)

    de Vries, H.J.C.; 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

  19. Toxicity studies in rats fed nature cure bitters | Aniagu | African ...

    African Journals Online (AJOL)

    Graded doses of Nature Cure Bitters (NCB) were administered daily (100, 200 and 400 mg/kg p.o) to rats for 28 days and the effects on body weight, organ weight, clinical signs, gross pathology, haematology, histology and serum biochemical parameters were evaluated. The relative weights of the heart, liver and testes of ...

  20. A combinaison of UV curing technology with ATL process

    Science.gov (United States)

    Balbzioui, I.; Hasiaoui, B.; Barbier, G.; L'hostis, G.; Laurent, F.; Ibrahim, A.; Durand, B.

    2017-10-01

    In order to reduce the time and the cost of manufacturing composite, UV curing technology combined with automated tape placement process (ATL) based on reverse approach by working with a fixed head was studied in this article. First, a brief description of the developed head placement is presented. Mechanical properties are then evaluated by varying process parameters, including compaction force and tape placement speed. Finally, a parametric study is carried out to identify suitable materials and process parameters to manufacture a photo composite material with high mechanical performances. The obtained results show that UV curing is a very good alternative for thermal polymerization because of its fast cure speed due to less dependency on temperature.

  1. Modified Castor Oil as an Epoxy Resin Curing Agent

    Directory of Open Access Journals (Sweden)

    B. P. Patel

    2004-01-01

    Full Text Available 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 Brominated epoxy resin. The curing of epoxy resin by ACO was monitored on differential scanning calorimeter (DSC and based on the DSC study their glass fibre reinforced composites (GRC were fabricated. The cured samples (i.e. unreinforced were also subjected to thermo gravimetric analysis (TGA. The chemical, mechanical and electrical properties of the glass fibre reinforced composites (GRC were also evaluated.

  2. The effect of different adhesive types and curing methods on microleakage and the marginal adaptation of composite veneers.

    Science.gov (United States)

    Maleknejad, Fathemeh; Moosavi, Horieh; Shahriari, Resa; Sarabi, Nasrin; Shayankhah, Taybeh

    2009-05-01

    The aim of this in vitro study was to evaluate the influence of application techniques (with pre-curing vs without pre-curing) for dentin adhesive on microleakage and marginal adaptation of indirect composite veneer restorations. A total-etch bonding system, Excite/Variolink II (EXV), and a self-etching primer system, Panavia F2.0 (PF2), were used in the study. Forty-eight human central incisors were prepared for composite veneer restorations. The teeth were divided into two groups (n=24). For each resin cement, one half of each experimental group included an adhesive pre-cure (PC) with a halogen light source while the other half received no pre-cure (NPC) prior to resin cement insertion. Thus, four experimental groups were created: A (PC+EXV), B (NPC+EXV), C (PC+PF2), and D (NPC+PF2). Veneers made of Tetric Ceram resin composite were cemented using dual-cured resin luting agents. After storage in distilled water at 37 degrees C for 24 hours, the teeth were prepared for marginal leakage. Two samples of each group were selected at random for scanning electron microscopic (SEM) observation and evaluation of marginal adaptation at 1050x magnification. Data were analyzed using the Kruskal-Wallis and Mann-Whitney tests (a microleakage values were observed in dentinal margins of groups B and A, respectively. Dentin margins opposite to enamel margins had a significant difference in microleakage values of PC and NPC groups (Pmicroleakage and the marginal adaptation, especially dentin margins of indirect composite veneers.

  3. 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.

  4. Effect of different curing methods on the compressive strength development of pulverized copper slag concrete

    Directory of Open Access Journals (Sweden)

    Daniel Mensah Boakye

    2014-04-01

    Full Text Available The results of laboratory studies conducted to evaluate the effects of different curing conditions on the compressive strength development of concrete made with pulverized copper slag as partial replacement for ordinary Portland cement (OPC is presented. Concrete cube specimens were made with copper slag replacing cement in the following proportions; 2.5, 5, 10 and 15% compared to the control (0% specimen under normal laboratory conditions and cured in three different conditions, namely; water, solar chamber and ambient air up 90 days. Test performed included X-ray Fluorescence (XRF and sieve analysis respectively for the chemical oxide composition and fineness for both the pulverized copper slag and ordinary Portland cement. Specimens were tested for compressive strength up to 90 days of curing, with the temperature and humidity of the surrounding curing environment recorded for each of the three curing method used. The experimental results indicate a significant drop in the compressive strength as the copper slag content increases for all curing methods. Moreover, for the control samples, the percentage decrease in the compressive strength for the 3-day curing for water cured sample, compared to the solar chamber and ambient air were respectively 31% and 28%. However, beyond 28 up to 90 days of curing, the water cured samples yielded a higher compressive strength, followed by the solar chamber and ambient air. The percentage increase in the compressive strength up to 90 days of curing for water cured specimen, compared to the solar chamber and ambient air were respectively 8.5% and 12%. This trend was similar for all percentage replacement of cement with the pulverized copper slag

  5. Evaluation of Automated Yeast Identification System

    Science.gov (United States)

    McGinnis, M. R.

    1996-01-01

    One hundred and nine teleomorphic and anamorphic yeast isolates representing approximately 30 taxa were used to evaluate the accuracy of the Biolog yeast identification system. Isolates derived from nomenclatural types, environmental, and clinica isolates of known identity were tested in the Biolog system. Of the isolates tested, 81 were in the Biolog database. The system correctly identified 40, incorrectly identified 29, and was unable to identify 12. Of the 28 isolates not in the database, 18 were given names, whereas 10 were not. The Biolog yeast identification system is inadequate for the identification of yeasts originating from the environment during space program activities.

  6. Sensory and physicochemical characteristics of salamis added with vegetable-based curing ingredients

    Directory of Open Access Journals (Sweden)

    Vicky Lilge Kawski

    Full Text Available ABSTRACT: The aim of this study was to evaluate the sensory and physicochemical quality of colonial salamis added with vegetable-based curing ingredients as potential enhancers of quality products. Salamis were produced according to three treatments: (A Control: 0.1% curing salt; (B rosemary: 0.05% curing salt + 0.5% rosemary extract (RE; and (C RE+celery: 0.14% Veg 503 + 0.27% Veg 504 (sea salt plus celery, nitrate and nitrite supplies, respectively + 0.5% of RE. No significant differences were observed (P>0.05 among the three treatments for dry matter (DM, crude protein (CP, ash, ether extract (EE and gross energy (GE. Sensory analysis was performed by applying the preference test and multiple comparison between the three treatments. Salamis added with vegetable-based curing ingredients were sensory equivalent to conventional level of curing salts. Vegetable extracts allowed the development of the sensory features of salami and did not interfere in the fermentation process. Results suggested that the extracts can serve as effective natural curing ingredients for the ripening process and cured meat color as well as adequate shelf-life replacing the commercial curing salts in meat and meat products. After 30 days of ripening, salami from the control treatment (conventional levels of nitrite and nitrate and the treatments with added vegetable-based curing ingredients and low nitrite and nitrate content (RE and RE + celery were equivalent in sensory quality.

  7. Brayton isotope power system. Volume II. System evaluation attributes

    Energy Technology Data Exchange (ETDEWEB)

    1978-03-15

    This volume of the Brayton Isotope Power System, Phase II Plan, contains the self-evaluation by AiResearch, GE, and TECO, addressing Section 3 of The Dynamic Systems Evaluation Criteria and Procedures established by the Department of Energy. These evaluation criteria addresses: Component Feasibility; Flight System Design Performance; GDS Test Results; Reliability and Practicality; Safety; Spacecraft Integration; and Cost and Risk. Included in each of these general categories are several attributes, each of which addresses a separate component, feature, or area of interest related to the power system, its development status, degree of preparedness for proceeding into a flight program, and/or the contractors' performance during Phase I. The key elements which indicate the readiness of a radioisotope power system to progress into a flight qualification program are: an advanced state of development of the power conversion system; demonstrated or exhibited potential for space systems standards of reliability; evident capability of meeting system safety requirements; favorable cost/benefit tradeoff considering projected missions and technology advancement potential; and proven feasibility of fabricating and qualifying a flight system and integrating it with a candidate spacecraft and launch vehicle. As a result of considerable government investment in Brayton system component development, the MHW isotope heat source and the BIPS Phase I Ground Demonstration System, the BIPS is a more advanced state of development than any previous radioisotope power system technology. Evidence of this is presented along with a complete review of the attributes, the contractor recommended ratings, and the rationale for the self-evaluation.

  8. Mobile based optical form evaluation system

    Directory of Open Access Journals (Sweden)

    Asım Sinan YÜKSEL

    2016-05-01

    Full Text Available Optical forms that contain multiple-choice answers are widely used both for electing students and evaluating student achievements in education systems in our country and worldwide. Optical forms are evaluated by employing optical mark recognition techniques through optical readers. High cost of these machines, limited access to them, long waiting time for evaluation results make the process hard for educationists working in cities or countries. In this study, a mobile application was developed for the educationists who own mobile phones or tablets for the purpose of evaluating students' answer sheets quickly and independent of location and optical readers. Optical form recognition, reading and evaluation processes are done on the image of student's answer sheet that is taken with the mobile phone or tablet of educationist. The Android based mobile application that we developed has a user-friendly interface, high success rate and is the first of our knowledge application that operates on mobile platforms in this field.

  9. Evaluation of Explanation Interfaces in Recommender Systems

    Directory of Open Access Journals (Sweden)

    Sergio Cleger-Tamayo

    2017-05-01

    Full Text Available Explaining interfaces become a useful tool in systems that have a lot of content to evaluate by users. The different interfaces represent a help for the undecided users or those who consider systems as boxed black smart. These systems present recommendations to users based on different learning models. In this paper, we present the different objectives of the explanation interfaces and some of the criteria that you can evaluate, as well as a proposal of metrics to obtain results in the experiments. Finally, we showed the main results of a study with real users and their interaction with e-commerce systems. Among the main results, highlight the positive impact in relation to the time of interaction with the applications and acceptance of the recommendations received.

  10. A room temperature cured low dielectric hyperbranched epoxy ...

    Indian Academy of Sciences (India)

    The synthesized hyperbranched epoxy was cured by a combined hardener system consisting of a commercial poly(amido-amine) and a first generation aliphatic poly(amido-amine) dendrimer (PAD) prepared by Michael addition reaction of methyl acrylate and aliphatic amines. The thermoset exhibited high mechanical ...

  11. Evaluating Ventilation Systems for Existing Homes

    Energy Technology Data Exchange (ETDEWEB)

    Aldrich, Robb [Consortium for Advanced Residential Buildings (CARB), Norwalk, CT (United States); Arena, Lois [Consortium for Advanced Residential Buildings (CARB), Norwalk, CT (United States)

    2013-02-01

    In an effort to improve housing options near Las Vegas, Nevada, the Clark County Community Resources Division (CCCRD) performs substantial renovations to foreclosed homes. After dramatic energy, aesthetic, and health and safety improvements are made, homes are rented or sold to qualified residents. This report describes the evaluation and selection of ventilation systems for these homes, including key considerations when selecting an ideal system. The report then describes CCCRD’s decision process with respect to ventilation.

  12. ESPRE: Expert System for Platelet Request Evaluation

    OpenAIRE

    Sielaff, B H; Scott, E.; Connelly, D. P.

    1987-01-01

    ESPRE, a knowledge-based system designed to facilitate good platelet transfusion practices, is under development at the University of Minnesota Hospital and Clinic. This microcomputer based decision support system aids Blood Bank personnel in evaluating requests for platelet transfusions. Because of a direct link with the laboratory computers, most patient data need not be entered manually, but rather can be accessed directly. ESPRE uses a combination of frames and rules during its inference ...

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

    NARCIS (Netherlands)

    Alvarez Grima, M.M.

    2007-01-01

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

  14. CTBT integrated verification system evaluation model supplement

    Energy Technology Data Exchange (ETDEWEB)

    EDENBURN,MICHAEL W.; BUNTING,MARCUS; PAYNE JR.,ARTHUR C.; TROST,LAWRENCE C.

    2000-03-02

    Sandia National Laboratories has developed a computer based model called IVSEM (Integrated Verification System Evaluation Model) to estimate the performance of a nuclear detonation monitoring system. The IVSEM project was initiated in June 1994, by Sandia's Monitoring Systems and Technology Center and has been funded by the U.S. Department of Energy's Office of Nonproliferation and National Security (DOE/NN). IVSEM is a simple, ''top-level,'' modeling tool which estimates the performance of a Comprehensive Nuclear Test Ban Treaty (CTBT) monitoring system and can help explore the impact of various sensor system concepts and technology advancements on CTBT monitoring. One of IVSEM's unique features is that it integrates results from the various CTBT sensor technologies (seismic, in sound, radionuclide, and hydroacoustic) and allows the user to investigate synergy among the technologies. Specifically, IVSEM estimates the detection effectiveness (probability of detection), location accuracy, and identification capability of the integrated system and of each technology subsystem individually. The model attempts to accurately estimate the monitoring system's performance at medium interfaces (air-land, air-water) and for some evasive testing methods such as seismic decoupling. The original IVSEM report, CTBT Integrated Verification System Evaluation Model, SAND97-25 18, described version 1.2 of IVSEM. This report describes the changes made to IVSEM version 1.2 and the addition of identification capability estimates that have been incorporated into IVSEM version 2.0.

  15. Light-emitting diode vs halogen light curing of orthodontic brackets: a 15-month clinical study of bond failures.

    Science.gov (United States)

    Krishnaswamy, N Rengarajan; Sunitha, Chakravarthi

    2007-10-01

    Previous in-vitro investigations reported no significant differences in the bond strength of brackets cured with conventional halogen lamps and those cured with light-emitting diodes (LED), even though LED curing times are much shorter. However, it is not known how LED curing performs in the oral cavity. The purpose of this randomized clinical trial was to evaluate the clinical performance of brackets cured with 2 light-curing units: a conventional halogen unit and an LED. Thirty patients treated with fixed appliances were included in this study. The bonding followed a contralateral quadrant pattern: in each patient, 2 quadrants were cured with the conventional halogen unit, and the other 2 quadrants were cured with the LED unit. The study had a single blind controlled design with a within-patient comparison of the 2 curing techniques, and the patients were allocated randomly. A total of 544 stainless steel brackets were examined for bracket failure. Location (tooth), cause, and date of failure were recorded over 15 months. Statistical analyses were performed with the Kaplan-Meier survival estimates and the log rank test. No statistically significant differences were found in total bond failure rate or in mean survival time between brackets cured with the halogen light and those cured with the LED. Neither were significant differences found between the 2 lights when the clinical performances of the maxillary and mandibular arches were compared, or when the posterior and anterior segments were compared. These results show that curing with an LED does not result in more bond failures or shorter time to failure when compared with conventional halogen light curing. Curing with an LED is an acceptable alternative to conventional halogen light curing.

  16. Cedar Avenue driver assist system evaluation report.

    Science.gov (United States)

    2011-12-01

    This paper summarizes an evaluation of the Driver Assist System (DAS) used by the Minnesota Valley Transit Authority (MTVA) for bus shoulder operations. The DAS is a GPS-based technology suite that provides lane-position feedback to the driver via a ...

  17. Distribution system reliability evaluation using credibility theory

    African Journals Online (AJOL)

    Xufeng Xu, Joydeep Mitra

    trapezoidal fuzzy numbers have been used to express uncertainties in Lei et al, 2005; Yuan et al, 2007 have used interval algorithm to deal with the uncertainty of component data to calculate the interval reliability indices. Most of fuzzy methods for reliability evaluation of distribution system are based on fuzzy set theory.

  18. A Case for Automatic System Evaluation

    NARCIS (Netherlands)

    Hauff, C.; Hiemstra, Djoerd; Azzopardi, Leif; de Jong, Franciska M.G.

    Ranking a set retrieval systems according to their retrieval effectiveness without relying on relevance judgments was first explored by Soboroff et al. [13]. Over the years, a number of alternative approaches have been proposed, all of which have been evaluated on early TREC test collections. In

  19. Pervious Pavement System Evaluation-Paper

    Science.gov (United States)

    The use of a pervious pavement can be effective as a low impact development stormwater control. The Urban Watershed Management Branch is evaluating interlocking concrete paver systems as a type of porous pavement. Although the pavers are impermeable, the spaces between the pave...

  20. EVALUATION OF INNOVATIVE PROJECTS IN CONTROLLING SYSTEM

    Directory of Open Access Journals (Sweden)

    Vladimir P. Bogko

    2013-01-01

    Full Text Available Implementation of the controlling system onto the high-tech enterprises requires the development of specific tools for their evaluation. The models of projects estimation are offered on the article on the basis of the methods of factor analysis, linear regression analysis and fuzzy logic of Mamdani’s algorithm.

  1. 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.

  2. Performance evaluation of a computed radiography system

    Energy Technology Data Exchange (ETDEWEB)

    Roussilhe, J.; Fallet, E. [Carestream Health France, 71 - Chalon/Saone (France); Mango, St.A. [Carestream Health, Inc. Rochester, New York (United States)

    2007-07-01

    Computed radiography (CR) standards have been formalized and published in Europe and in the US. The CR system classification is defined in those standards by - minimum normalized signal-to-noise ratio (SNRN), and - maximum basic spatial resolution (SRb). Both the signal-to-noise ratio (SNR) and the contrast sensitivity of a CR system depend on the dose (exposure time and conditions) at the detector. Because of their wide dynamic range, the same storage phosphor imaging plate can qualify for all six CR system classes. The exposure characteristics from 30 to 450 kV, the contrast sensitivity, and the spatial resolution of the KODAK INDUSTREX CR Digital System have been thoroughly evaluated. This paper will present some of the factors that determine the system's spatial resolution performance. (authors)

  3. Composite system reliability evaluation by stochastic calculation of system operation

    Energy Technology Data Exchange (ETDEWEB)

    Haubrick, H.-J.; Hinz, H.-J.; Landeck, E. [Dept. of Power Systems and Power Economics (Germany)

    1994-12-31

    This report describes a new developed probabilistic approach for steady-state composite system reliability evaluation and its exemplary application to a bulk power test system. The new computer program called PHOENIX takes into consideration transmission limitations, outages of lines and power stations and, as a central element, a highly sophisticated model to the dispatcher performing remedial actions after disturbances. The kernel of the new method is a procedure for optimal power flow calculation that has been specially adapted for the use in reliability evaluations under the above mentioned conditions. (author) 11 refs., 8 figs., 1 tab.

  4. Evaluation of a Data Messaging System Solution : Case: Evaluation of Apache Kafka™ at Accanto Systems

    OpenAIRE

    Nguyen, Huong

    2017-01-01

    This study aims to explore the process of adapting a new Data Messaging System Solution, i.e Apache Kafka™ (Kafka), and to evaluate whether it is suitable for the needs at Accanto Systems. The research follows the framework for Design Science research methodology. Evaluation of the artefact involves the use of a software quality model. The results of the study confirm that Kafka is satisfactory as a Data Messaging System solution. The results may also serve as an implementation guide...

  5. Fatty acid composition, oxidation status and volatile organic compounds in "Colonnata" lard from Large White or Cinta Senese pigs as affected by curing time.

    Science.gov (United States)

    Serra, A; Buccioni, A; Rodriguez-Estrada, M T; Conte, G; Cappucci, A; Mele, M

    2014-08-01

    The aim of the present paper was to evaluate the fatty acid composition, lipolysis, lipid oxidation and volatile organic compounds (VOCs) in Colonnata lard from Large White (LW) or Cinta Senese (CS) pigs during one-year of curing. CS lard contained higher amounts of unsaturated fatty acids than that from LW, due to the different rearing and feeding systems. Despite higher lipolysis in CS backfat during the curing period, the rate of fatty acid and cholesterol oxidation was higher in LW. The amount of cholesterol oxidation products (COPs) and thiobarbituric acid reactive substances (TBARs) significantly decreased after 3 months of curing, regardless of the type of lard. VOCs composition of lard was affected by curing time, but not by breed. While volatile fatty acid oxidation products (mainly aldehydes) were present at the beginning of curing, subsequently other volatile compounds (such as sulphur compounds and terpenes) that derived from ingredients used for lard production, increased in the samples. Copyright © 2014. Published by Elsevier Ltd.

  6. Cochlear implants: system design, integration, and evaluation.

    Science.gov (United States)

    Zeng, Fan-Gang; Rebscher, Stephen; Harrison, William; Sun, Xiaoan; Feng, Haihong

    2008-01-01

    As the most successful neural prosthesis, cochlear implants have provided partial hearing to more than 120000 persons worldwide; half of which being pediatric users who are able to develop nearly normal language. Biomedical engineers have played a central role in the design, integration and evaluation of the cochlear implant system, but the overall success is a result of collaborative work with physiologists, psychologists, physicians, educators, and entrepreneurs. This review presents broad yet in-depth academic and industrial perspectives on the underlying research and ongoing development of cochlear implants. The introduction accounts for major events and advances in cochlear implants, including dynamic interplays among engineers, scientists, physicians, and policy makers. The review takes a system approach to address critical issues in cochlear implant research and development. First, the cochlear implant system design and specifications are laid out. Second, the design goals, principles, and methods of the subsystem components are identified from the external speech processor and radio frequency transmission link to the internal receiver, stimulator and electrode arrays. Third, system integration and functional evaluation are presented with respect to safety, reliability, and challenges facing the present and future cochlear implant designers and users. Finally, issues beyond cochlear implants are discussed to address treatment options for the entire spectrum of hearing impairment as well as to use the cochlear implant as a model to design and evaluate other similar neural prostheses such as vestibular and retinal implants.

  7. Translating Genomic Discoveries to Cure Ultrahypermutant ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Translating Genomic Discoveries to Cure Ultrahypermutant Mismatch Repair Deficient Brain Tumours. Malignant brain tumours are the most common cause of death among children with cancer, but there is no known cure. This project will advance research in this important field. Inherited mutations and childhood cancer.

  8. Magnetoactive elastomeric composites: Cure, tensile, electrical and ...

    Indian Academy of Sciences (India)

    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 ...

  9. 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.

  10. Polymerization Mode of Self-Adhesive, Dual-Cured Dental Resin Cements Light Cured Through Various Restorative Materials.

    Science.gov (United States)

    Shim, Ji Suk; Kang, Jeong Kyung; Jha, Nayansi; Ryu, Jae Jun

    2017-05-06

    The aim of this study was to investigate the polymerization mode of self-adhesive, dual-cured resin cements light-cured through overlying materials with different degree of translucency by measuring the degree of conversion (DC). Three kinds of self-adhesive, dual-cured resin cements (G-CEM LinkAceTM , Maxcem EliteTM , and BisCem® ) were light-cured through three different restorative materials that included porcelain-fused metal (PFM), zirconia, and lithium disilicate. Polymerization kinetics were continuously evaluated using infrared spectroscopy after 0, 5, 10, and 30 min and 2 weeks of mixing. Data were statistically analyzed using two-way analysis of variance (ANOVA), one-way ANOVA, and Tukey's multiple-comparison test (α = 0.05). Regardless of the kind of resin cement, the light-cured groups showed higher DC than did the autopolymerization group under PFM at any point of time (p cements to achieve statistically similar DC between the zirconia and lithium disilicate groups increased in the following order: G-CEM LinkAceTM , BisCem® , and Maxcem EliteTM (p adhesive, dual-cured resin cements. The resin cements light-cured through lithium disilicate and zirconia showed higher DC than that shown by cements cured under PFM at any measurement time. The lithium disilicate and zirconia groups showed differences in the early stage of polymerization for G-CEM LinkAceTM and BisCem® ; however, the differences diminished at 2 weeks. Chemical polymerization is not sufficient to cause the resin cement to achieve the highest polymerization not only in early stage, but also in late stage of polymerization. The sensitivity to the intensity of the light was different for each resin cement. Special clinical steps to compensate for the attenuated light intensity seem to be necessary for the resin cements which are susceptible to light intensity. (J Esthet Restor Dent 29:209-214, 2017). © 2017 Wiley Periodicals, Inc.

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

    Science.gov (United States)

    Passos, Sheila Pestana; Souza, Rodrigo Othávio Assunção; Michida, Silvia Masae Araújo; Zamboni, Sandra Costa; Oliveira, Simone Helena Gonçalves de

    2013-01-01

    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 (6.40)ab; G2 - 12.02 (4.59)ab; G3 - 13.09 (5.62)ab; G4 - 15.96 (6.32)a; G5 - 6.22 (5.90)c; G6 - 9.48 (5.99)bc; G7 - 12.78 (11.30)ab; and G8 - 8.34 (5.98)bc. 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.

  12. CTBT Integrated Verification System Evaluation Model

    Energy Technology Data Exchange (ETDEWEB)

    Edenburn, M.W.; Bunting, M.L.; Payne, A.C. Jr.

    1997-10-01

    Sandia National Laboratories has developed a computer based model called IVSEM (Integrated Verification System Evaluation Model) to estimate the performance of a nuclear detonation monitoring system. The IVSEM project was initiated in June 1994, by Sandia`s Monitoring Systems and Technology Center and has been funded by the US Department of Energy`s Office of Nonproliferation and National Security (DOE/NN). IVSEM is a simple, top-level, modeling tool which estimates the performance of a Comprehensive Nuclear Test Ban Treaty (CTBT) monitoring system and can help explore the impact of various sensor system concepts and technology advancements on CTBT monitoring. One of IVSEM`s unique features is that it integrates results from the various CTBT sensor technologies (seismic, infrasound, radionuclide, and hydroacoustic) and allows the user to investigate synergy among the technologies. Specifically, IVSEM estimates the detection effectiveness (probability of detection) and location accuracy of the integrated system and of each technology subsystem individually. The model attempts to accurately estimate the monitoring system`s performance at medium interfaces (air-land, air-water) and for some evasive testing methods such as seismic decoupling. This report describes version 1.2 of IVSEM.

  13. Composite cements benefit from light-curing.

    Science.gov (United States)

    Lührs, Anne-Katrin; De Munck, Jan; Geurtsen, Werner; Van Meerbeek, Bart

    2014-03-01

    To investigate the effect of curing of composite cements and a new ceramic silanization pre-treatment on the micro-tensile bond strength (μTBS). Feldspathic ceramic blocks were luted onto dentin using either Optibond XTR/Nexus 3 (XTR/NX3; Kerr), the silane-incorporated 'universal' adhesive Scotchbond Universal/RelyX Ultimate (SBU/RXU; 3M ESPE), or ED Primer II/Panavia F2.0 (ED/PAF; Kuraray Noritake). Besides 'composite cement', experimental variables were 'curing mode' ('AA': complete auto-cure at 21°C; 'AA*': complete auto-cure at 37°C; 'LA': light-curing of adhesive and auto-cure of cement; 'LL': complete light-curing) and 'ceramic surface pre-treatment' ('HF/S/HB': hydrofluoric acid ('HF': IPS Ceramic Etching Gel, Ivoclar-Vivadent), silanization ('S': Monobond Plus, Ivoclar-Vivadent) and application of an adhesive resin ('HB': Heliobond, Ivoclar-Vivadent); 'HF/SBU': 'HF' and application of the 'universal' adhesive Scotchbond Universal ('SBU'; 3M ESPE, only for SBU/RXU)). After water storage (7 days at 37°C), ceramic-dentin sticks were subjected to μTBS testing. Regarding the 'composite cement', the significantly lowest μTBSs were measured for ED/PAF. Regarding 'curing mode', the significantly highest μTBS was recorded when at least the adhesive was light-cured ('LA' and 'LL'). Complete auto-cure ('AA') revealed the significantly lowest μTBS. The higher auto-curing temperature ('AA*') increased the μTBS only for ED/PAF. Regarding 'ceramic surface pre-treatment', only for 'LA' the μTBS was significantly higher for 'HF/S/HB' than for 'HF/SBU'. Complete auto-cure led to inferior μTBS than when either the adhesive (on dentin) or both adhesive and composite cement were light-cured. The use of a silane-incorporated adhesive did not decrease luting effectiveness when also the composite cement was light-cured. Copyright © 2013 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  14. Performance evaluation of the suggestion system.

    Science.gov (United States)

    Hadi, Mohammad; Sajjadi, Haniye Sadat; Baratpour, Sara; Toghiani, Ali

    2013-01-01

    This cross-sectional research evaluated the suggestion system of Isfahan University of Medical Sciences (IUMS) using CIPP model. The population consisted of all members of executive committee of suggestion system and the members of professional and general committee of IUMS; regarding to some limitations, sampling was not done. The tool of gathering data was a self-constructed questionnaire that its content validity approved by the professors' ideas, and calculating Cronbach's alpha confirmed its reliability. Collected data was analyzed using SPSS software. Analyzed data showed that the average score of the performance of the mentioned system was 50.47 +/- 14.8; based on this result it can be claimed that most of the participants (about 91%) evaluated the performance of the system moderate. The comparison of the average score of the four dimensions of CIPP model showed that the input dimension had the highest score and process, product and context dimensions were next on the hierarchy. Planning some programs for paying awards, facilitating and accelerating the personnel's and notifying the procedures of the suggestion system implementation are some useful strategy that could be used to increase the staff's participants.

  15. Comportamento de cura de adesivo epoxídico contendo grupo mercaptana avaliado por espectroscopia no infravermelho (MIR/NIR e calorimetria exploratória diferencial (DSC Cure behavior of epoxy adhesive containig mercaptan group evaluated by infrared spectroscopy (MIR/NIR and differential scanning calorimetry (DSC

    Directory of Open Access Journals (Sweden)

    Hilzette P. C. Andrade

    2008-01-01

    Full Text Available No presente trabalho, a flexibilidade de um adesivo epoxídico contendo diglicidiléter de bisfenol A (DGEBA e dietilenotriamina (DETA como agente de cura foi modificada pela adição de um segundo componente contendo grupos mercaptana (CAPCURE. A adição de amianto ao adesivo contendo CAPCURE também foi avaliada. As reações entre os grupos epoxídicos e os grupos amina, assim como entre os grupos epoxídicos e os grupos mercaptana, foram estudadas nas regiões espectrais do infravermelho médio (MIR e próximo (NIR. Observou-se que o amianto não interfere nas reações de cura e que a espectroscopia FT-NIR evidencia melhor as alterações espectrométricas ocorridas durante as reações em relação à análise FT-MIR. O tempo das reações de cura foi monitorado por calorimetria exploratória diferencial (DSC, observando-se que a introdução do CAPCURE acelerou a cura da resina. A energia de ativação (Ea das reações de cura foi obtida pelos métodos de Barrett e Borchardt-Daniels. Os adesivos contendo CAPCURE mostraram Ea em torno de 30 kJ.mol-1, enquanto o adesivo DGEBA/DETA apresentou Ea de 46 kJ.mol-1, ambas calculadas pelo método de Barrett.In the present work, the flexibility of an epoxy adhesive containing diglycidylether of bisphenol-A (DGEBA and diethylenetriamine (DETA as curing agent was changed by the addition of a second component containing mercaptan groups (CAPCURE. The addition of asbestos as a filler in the adhesive containing CAPCURE was also evaluated. Epoxy-amine and epoxy-mercaptan reactions were studied in NIR and MIR spectral regions. The filler addition did not cause influence on the cure reactions and spectrometric changes of cure reactions could be better observed by FT-NIR than FT-MIR analysis. The cure reaction time was monitored by DSC experiments and it was observed that the introduction of CAPCURE accelerated the cure reaction. The activation energies (Ea of curing reactions were obtained using Barrett

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

    Science.gov (United States)

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

    1981-01-01

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

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

    Directory of Open Access Journals (Sweden)

    E. Armellin

    2016-01-01

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

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

    Science.gov (United States)

    Parthasarathy, Deepa K; Bryan, Nathan S

    2012-11-01

    This process of "curing" food is a long practice that dates back thousands of years long before refrigeration or food safety regulations. Today food safety and mass manufacturing are dependent upon safe and effective means to cure and preserve foods including meats. Nitrite remains the most effective curing agent to prevent food spoilage and bacterial contamination. Despite decades of rigorous research on its safety and efficacy as a curing agent, it is still regarded by many as a toxic undesirable food additive. However, research within the biomedical science community has revealed enormous therapeutic benefits of nitrite that is currently being developed as novel therapies for conditions associated with nitric oxide (NO) insufficiency. Much of the same biochemistry that has been understood for decades in the meat industry has been rediscovered in human physiology. This review will highlight the fundamental biochemistry of nitrite in human physiology and highlight the risk benefit evaluation surrounding nitrite in food and meat products. Foods or diets enriched with nitrite can have profound positive health benefits. Copyright © 2012 Elsevier Ltd. All rights reserved.

  19. Zn-porphyrin formation in cured meat products: Effect of added salt and nitrite.

    Science.gov (United States)

    Adamsen, Christina E; Møller, Jens K S; Laursen, Kristoffer; Olsen, Karsten; Skibsted, Leif H

    2006-04-01

    Zn-porphyrin (Zn-pp) was quantified by fluorescence spectroscopy in the cured and dry cured meat products: Parma ham, Iberian ham, dry-cured ham with added nitrite, cooked ham with added nitrite, raw ham meat, raw bacon and Karree-Speck. The highest amount of Zn-pp was found in dry-cured Parma ham and Iberian ham, while the use of nitrite as curing agent was found to inhibit completely the formation of Zn-pp in meat products. A positive correlation between both Zn content and Fe content and the logarithmic transformed Zn-pp content (measured as fluorescence intensity I(fl)) was found for the different cured and dry cured meat products, with correlation coefficients of 0.79 (p<0.001) and 0.71 (p<0.01), respectively. Log I(fl) correlates best with the Zn content, indicating that the formation of Zn-pp is proportional to the Zn content. A model system with vacuum packed pork in brine with different added levels of sodium chloride with or without nitrite and Zn acetate was investigated in order to further elucidate the mechanism of Zn-pp formation. Zn-pp increased with time (up to 42 days investigated) in non-cured meat and for meat cured solely with NaCl lower than 9%. Addition of nitrite or Zn(II) in the curing brine was found to inhibit formation of Zn-pp confirming the observations from the various cured meat products. It is suggested that a chloride anion assisted dissociation of iron from myoglobin could be rate-determining for Zn-pp formation in meat products.

  20. Evaluating baghouse systems for energy efficiency

    Energy Technology Data Exchange (ETDEWEB)

    1982-02-01

    Energy efficiency of pulse jet baghouses may be evaluated by the magnitude of the pressure drop across the unit and the amount of cleaning energy it takes to properly clean the filter bags. The higher the pressure drop, the higher the energy consumption. Hints are given on optimum pressure drop specification, and efficient pulse system design. Proper insulation of the collector and proper flow control devices also help to conserve energy.

  1. Laboratory study of high performance curing compounds for concrete pavements : phase I.

    Science.gov (United States)

    2012-06-01

    Three emulsion-type and two sealing-type curing compounds were evaluated for their ability to impart freezethaw : scaling resistance, and restrict evaporation, carbonation and chloride penetration to concrete specimens : prepared to represent common ...

  2. Effect of Curing Mode on Shear Bond Strength of Self-Adhesive Cement to Composite Blocks

    National Research Council Canada - National Science Library

    Jin-Young Kim; Ga-Young Cho; Byoung-Duck Roh; Yooseok Shin

    2016-01-01

    .... The purpose of this study was to evaluate the shear bond strength and fracture pattern of indirect CAD/CAM composite blocks cemented with two self-etch adhesive cements with different curing modes...

  3. Implementation of curing, texturing, subbase, and compaction measurement alternatives for continuously reinforced concrete pavement.

    Science.gov (United States)

    2014-04-01

    This report evaluates four different subbase types, two different concrete mix designs (a standard Texas : Department of Transportation gradation and an optimized gradation), three different curing compounds, and : four different surface textures tha...

  4. A 7-year randomized prospective study of a one-step self-etching adhesive in non-carious cervical lesions. The effect of curing modes and restorative material

    DEFF Research Database (Denmark)

    van Dijken, Jan W V; Pallesen, Ulla

    2012-01-01

    Objective: The aim of this study was to evaluate the clinical retention of a one-step self-etching adhesive system (Xeno III) in Class V non-carious cervical lesions and the effect of restorative material and curing techniques on longevity of the restorations. Material and methods: A total of 139...... be evaluated. No post-operative sensitivity was reported by the participants. Overall relative cumulative loss rate frequencies for the adhesive system at 6, 18 and 7 years, independent of curing technique and restorative material, were 0.8%, 6.9% and 23.0%, respectively. The self-etching adhesive fulfilled...... Class V restorations were placed with the self-etching primer Xeno III and a resin composite (Tetric Ceram) or a poly-acid modified resin composite (Dyract AP) in non-carious cervical lesions without intentional enamel involvement. The materials were cured with a conventional continuous light, a soft...

  5. Evaluation of CDMA system capacity for mobile satellite system applications

    Science.gov (United States)

    Smith, Partrick O.; Geraniotis, Evaggelos A.

    1988-01-01

    A specific Direct-Sequence/Pseudo-Noise (DS/PN) Code-Division Multiple-Access (CDMA) mobile satellite system (MSAT) architecture is discussed. The performance of this system is evaluated in terms of the maximum number of active MSAT subscribers that can be supported at a given uncoded bit-error probability. The evaluation decouples the analysis of the multiple-access capability (i.e., the number of instantaneous user signals) from the analysis of the multiple-access mutliplier effect allowed by the use of CDMA with burst-modem operation. We combine the results of these two analyses and present numerical results for scenarios of interest to the mobile satellite system community.

  6. Comprehensive evaluation system of intelligent urban growth

    Science.gov (United States)

    Li, Lian-Yan; Ren, Xiao-Bin

    2017-06-01

    With the rapid urbanization of the world, urban planning has become increasingly important and necessary to ensure people have access to equitable and sustainable homes, resources and jobs.This article is to talk about building an intelligent city evaluation system.First,using System Analysis Model(SAM) which concludes literature data analysis and stepwise regression analysis to describe intelligent growth scientifically and obtain the evaluation index. Then,using the improved entropy method to obtain the weight of the evaluation index.Afterwards, establishing a complete Smart Growth Comprehensive Evaluation Model(SGCEM).Finally,testing the correctness of the model.Choosing Otago(New Zealand )and Yumen(China) as research object by data mining and SGCEM model,then we get Yumen and Otago’s rational degree’s values are 0.3485 and 0.5376 respectively. It’s believed that the Otago’s smart level is higher,and it is found that the estimated value of rationality is consistent with the reality.

  7. Establishment of a model experiment system to elucidate the mechanism by which Zn-protoporphyrin IX is formed in nitrite-free dry-cured ham.

    Science.gov (United States)

    Wakamatsu, J; Okui, J; Ikeda, Y; Nishimura, T; Hattori, A

    2004-10-01

    The aim of this study was to establish a model experiment system to elucidate the mechanism by which Zn-protoporphyrin IX (ZPP) is formed in Parma ham. The established model consisted of myoglobin, meat and antibiotics, and incubation under anaerobic conditions resulted in a greater yield of ZPP. Formation of ZPP was observed even in the presence of various antiseptics. The amount of ZPP formed increased as the period of incubation increased. ZPP formation was inhibited by heating meat homogenate depending on the heating temperature. Our results show that anaerobic conditions are suitable for the formation of ZPP in meat products without nitrate or nitrite and that endogenous enzymes as well as microorganisms may be involved in ZPP formation.

  8. Usability Evaluation of Laboratory Information Systems.

    Science.gov (United States)

    Mathews, Althea; Marc, David

    2017-01-01

    Numerous studies have revealed widespread clinician frustration with the usability of electronic health records (EHRs) that is counterproductive to adoption of EHR systems to meet the aims of health-care reform. With poor system usability comes increased risk of negative unintended consequences. Usability issues could lead to user error and workarounds that have the potential to compromise patient safety and negatively impact the quality of care.[1] While there is ample research on EHR usability, there is little information on the usability of laboratory information systems (LISs). Yet, LISs facilitate the timely provision of a great deal of the information needed by physicians to make patient care decisions.[2] Medical and technical advances in genomics that require processing of an increased volume of complex laboratory data further underscore the importance of developing user-friendly LISs. This study aims to add to the body of knowledge on LIS usability. A survey was distributed among LIS users at hospitals across the United States. The survey consisted of the ten-item System Usability Scale (SUS). In addition, participants were asked to rate the ease of performing 24 common tasks with a LIS. Finally, respondents provided comments on what they liked and disliked about using the LIS to provide diagnostic insight into LIS perceived usability. The overall mean SUS score of 59.7 for the LIS evaluated is significantly lower than the benchmark of 68 ( P effect of years of experience and LIS used did not account for the statistically significant difference in the mean SUS score between Orchard Harvest and each of the other LISs evaluated. The results of this study indicate that overall usability of LISs is poor. Usability lags that of systems evaluated across 446 usability surveys.

  9. Ultrasonic nondestructive evaluation systems industrial application issues

    CERN Document Server

    Callegari, Sergio; Montisci, Augusto; Ricci, Marco; Versaci, Mario

    2015-01-01

    This book covers the practical implementation of ultrasonic NDT techniques in an industrial environment, discussing several issues that may emerge and proposing strategies for addressing them successfully.  It aims to bridge advanced academic research results and their application to industrial procedures. The topics covered in the text range from the basic operation of an ultrasonic NDT system to the simulation of the measurement operations; from the choice and generation of the signals energizing the system to the different ways of exploiting the probes and their output signals; and from quality assessment evaluation to the use of soft computing techniques for classification. Throughout the text, an effort is made to embrace a system view where the physical and technological aspects of sensing are addressed together with higher abstraction levels, such as signal and information processing. Consequently, the book aims at guiding the reader through the various tasks requested for developing a complete ultras...

  10. Reducing, by pulse width modulation, the curing temperature of a prototype high-power LED light curing unit.

    Science.gov (United States)

    Huang, Ta-Ko; Hung, Chun-Cheng; Tsai, Chi-Cheng

    2006-06-01

    Third-generation LEDs have high irradiance and efficiency, but the associated temperature rise is potentially hazardous to the pulp of teeth. We evaluated, during composite polymerization, the irradiance and temperature rise of a prototype high-power LED light curing unit (LCU) with optimal pulse width modulation (PWM), and then compared the results with four off-the-shelf high-power LCUs. A cavity was prepared in a tooth, and a composite resin layer was applied and cured. For each LCU, the irradiance and temperature changes at the pulp-dentin junction were measured. Microhardness (Vickers hardness) of cured composite samples was measured for each LCU. Our prototype had a final temperature of 36.4 +/- 1.3 degrees C and irradiance of 1,182 +/- 1 mW/cm2. The unit with the highest temperature had a temperature of 48.7 +/- 1.2 degrees C and an irradiance of 1,194 +/- 1 mW/cm2. Based on the results of the present study, it was shown that PWM technology reduced the curing temperature while retaining the polymerization effectiveness of a high-power LED LCU.

  11. Perceived Usability Evaluation of Learning Management Systems: Empirical Evaluation of the System Usability Scale

    Science.gov (United States)

    Orfanou, Konstantina; Tselios, Nikolaos; Katsanos, Christos

    2015-01-01

    Perceived usability affects greatly student's learning effectiveness and overall learning experience, and thus is an important requirement of educational software. The System Usability Scale (SUS) is a well-researched and widely used questionnaire for perceived usability evaluation. However, surprisingly few studies have used SUS to evaluate the…

  12. Dielectric response of epoxy-amine compositions during isothermal curing

    Science.gov (United States)

    Rodin, D. L.; Stefanovich, S. Yu.; Yablokova, M. Yu.

    2017-04-01

    The change in electric conductivity and dielectric permittivity during the curing of epoxy-amine compositions in a mixture with the thermoplastic Ultem 1000 polyetherimide at 180°C is studied by means of dielectric spectroscopy. TGDDM epoxy resin and DADPS, MDEA, and MIPA amine curing agents are used as the epoxy-amine composition. The times of the gel and glass transition are determined from the time and frequency dependences of the dielectric response of the investigated mixtures. At a certain step of curing of epoxy-amine compositions, the separation of a new phase enriched with the thermoplastic is detected. This separation is accompanied by charge accumulation along the phase boundary and its interaction with the external electric field. In the dielectric spectrum, this effect of phase separation appears as an individual relaxation process with characteristic parameters of dielectric relaxation. It is found that at the final step of isothermal curing, there is a glass transition of the polymer, leading to a sharp drop in the reaction rate and stabilization of the dielectric response with respect to time. The detected steps of the reaction and the corresponding changes in the structure and rheology of the investigated polymer systems are characterized and confirmed by methods of viscometry and optical microscopy.

  13. Microdielectrometry: A new method for in situ cure monitoring

    Science.gov (United States)

    Sheppard, N. F.; Garverick, S. L.; Day, D. R.; Senturia, S. D.

    1980-12-01

    Integrated circuit technology has been used to develop a miniature dielectric cure monitor probe that combines small size with built in amplification to achieve good sensitivity down to 1 Hz, making the probe more sensitive to physical property changes than conventional dielectrometers operating at 1000 Hz. This paper describes the design and operation of the microdielectrometer chip, and the model used to determine the complex dielectric constant of the material under study. Two typical applications are illustrated by experiments. First, results of a postcure study of a Versamide 140, Epon 828 mixture are presented and compared to the results of a similar study using a conventional parallel plate capacitor. In a second experiment, several probes were placed in a 100 ml mold and used to monitor the cure of a sample of the same resin system. The data show the nonuniformity of cure within the sample, and can be explained on the basis of gelation and the temperature dependence of the dielectric properties as determined in the post-cure experiment.

  14. Evaluating Ventilation Systems for Existing Homes

    Energy Technology Data Exchange (ETDEWEB)

    Aldrich, R.; Arena, L.

    2013-02-01

    During the course of this project, an affordable and high performance ductwork system to directly address the problems of thermal losses, poor efficiency, and air leakage was designed. To save space and enable direct connections between different floors of the building, the ductwork system was designed in such a way that it occupied interior or exterior frame wall cavities. The ductwork system satisfied building regulations for structural support when bridging multiple floors, the spread of fire and smoke, and insulation to reduce the heat flow into or out of the building. Retrofits of urban residential buildings will be the main focus for the application of this ductwork system. Highly reflective foils and insulating materials were used to aid in the increase of the overall R-value of the ductwork itself and the wall assembly. It is expected that the proposed system will increase the efficiency of the HVAC system and the thermal resistance of the building envelope. The performance of the proposed ductwork design was numerically evaluated in a number of different ways. Our results indicate that the duct method is a very cost attractive alternative to the conventional method.

  15. Avaliação do processo de cura da borracha nitrílica (NBR pela resina fenólica através do cálculo da constante de cura Evaluation of phenolic resin vulcanization of nitrile rubber (NBR through determination of the cure constant

    Directory of Open Access Journals (Sweden)

    Ana Maria Furtado

    2001-03-01

    Full Text Available O processo de cura envolve reações de múltiplos mecanismos e sua investigação pode ser feita por meio de várias técnicas. Este trabalho apresenta a comparação entre dois métodos que utilizam parâmetros reométricos para o cálculo da constante cinética de cura (k relacionada com a cura da borracha nitrílica com a resina fenólica, tendo o policloropreno e o óxido de zinco como sistema ativador. Foi utilizado o planejamento de experimentos fatorial completo (2³ + ponto central como base para a preparação das formulações e análise dos resultados. Os resultados obtidos identificaram a influência da temperatura, da quantidade de cada um dos componentes das formulações e da adequação dos métodos de avaliação para o processo de cura da borracha nitrílica pela resina fenólica.The cure process involves reactions with multiple mechanisms and its investigation can be followed by using different techniques. This work compares two methods in which rheometric parameters are used to calculate the cure rate constant (k, related to the cure of nitrile rubber with phenolic resin and having polychloroprene and zinc oxide as the activators. A complete factorial (2³ + central point experimental design was used as base to prepare the formulations and to analyse the results. The results obtained identified the influence of the temperature, the amount of each component in the formulation and the suitability of the evaluation methods for the cure process of nitrile rubber with phenolic resin.

  16. Tocopherol content, weight loss and instrumental color analysis of Iberian dry-cured ham as affected by rearing and feeding systems

    Directory of Open Access Journals (Sweden)

    Daza, Argimiro

    2009-07-01

    Full Text Available The effects of rearing (outdoor vs indoor and feeding systems (acorn and grass vs mixed diets on ham quality from Duroc x Iberian pigs were studied. Seven groups of 5 females each were used. One group was reared under freerange conditions and fed with acorns and grass (outdoor pigs. Six group were fed mixed diets in confinement (indoor pigs under a factorial design 3 x 2 with three types of dietary fat: monounsaturated, polyunsaturated and medium (monounsaturated and polyunsaturated and two levels of α-tocopheryl-acetate. The α-and γ-tocopherol contents were higher (P Se ha estudiado el efecto del régimen de producción (en libertad vs estabulados y el sistema de alimentación (bellota y pasto vs piensos formulados en la calidad del jamón de cerdos Ibéricos cruzados con Duroc. Siete grupos de 5 hembras cada uno fueron usadas. Un grupo fue criado en condiciones de libertad y alimentado con bellotas y pasto (Cerdos en libertad. Seis grupos fueron alimentados con dietas formuladas en confinamiento (Cerdos estabulados usando un diseño factorial de 3 x 2 con tres tipos de grasa en la dieta: monoinsaturada, poliinsaturada y media (monoinsaturada y polinsaturada y dos niveles de acetato de α-tocoferol. Los contenidos de α- y γ-tocoferol fueron más altos (p < 0.05 en jamones de cerdos criados en libertad que en jamones de cerdos estabulados. Los jamones de cerdos estabulados pesaron menos que los jamones de cerdos en libertad y los valores de color rojo fueron mayores en jamones de cerdos en libertad que en cerdos estabulados. Después de 4 días de almacenamiento, la muestra de jamón de cerdos en libertad mostraron una menor tendencia (p < 0.10 a perder peso que aquellos de cerdos alimentados con un nivel basal de vitamina E. Estos resultados indican que cerdos Ibérico criados en libertad y alimentados con bellota y pasto incrementan su contenido en tocoferoles y mejoran el color y las pérdidas de peso de los jamones curados.

  17. Usability evaluation of laboratory information systems

    Directory of Open Access Journals (Sweden)

    Althea Mathews

    2017-01-01

    Full Text Available Background: Numerous studies have revealed widespread clinician frustration with the usability of electronic health records (EHRs that is counterproductive to adoption of EHR systems to meet the aims of health-care reform. With poor system usability comes increased risk of negative unintended consequences. Usability issues could lead to user error and workarounds that have the potential to compromise patient safety and negatively impact the quality of care.[1] While there is ample research on EHR usability, there is little information on the usability of laboratory information systems (LISs. Yet, LISs facilitate the timely provision of a great deal of the information needed by physicians to make patient care decisions.[2] Medical and technical advances in genomics that require processing of an increased volume of complex laboratory data further underscore the importance of developing user-friendly LISs. This study aims to add to the body of knowledge on LIS usability. Methods: A survey was distributed among LIS users at hospitals across the United States. The survey consisted of the ten-item System Usability Scale (SUS. In addition, participants were asked to rate the ease of performing 24 common tasks with a LIS. Finally, respondents provided comments on what they liked and disliked about using the LIS to provide diagnostic insight into LIS perceived usability. Results: The overall mean SUS score of 59.7 for the LIS evaluated is significantly lower than the benchmark of 68 (P < 0.001. All LISs evaluated received mean SUS scores below 68 except for Orchard Harvest (78.7. While the years of experience using the LIS was found to be a statistically significant influence on mean SUS scores, the combined effect of years of experience and LIS used did not account for the statistically significant difference in the mean SUS score between Orchard Harvest and each of the other LISs evaluated. Conclusions: The results of this study indicate that overall

  18. 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 (pSlim 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. Copyright © 2016 Elsevier B.V. All rights reserved.

  19. 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.

  20. [Systemic-psychodynamic model for family evaluation].

    Science.gov (United States)

    Salinas, J L; Pérez, M P; Viniegra, L; Armando Barriguete, J; Casillas, J; Valencia, A

    1992-01-01

    In this paper a family evaluation instrument called systemic-psychodynamic family evaluation model is described. Also, the second stage of the validation study of this instrument is presented (which deals with the inter-observers variation). Twenty families were studied. They were assessed always by the same interviewers designated as experts. They are all family therapy specialists and their assessment was used as the evaluation reference standard or "gold standard". The observers were psychiatrists without previous training in family therapy. For the purpose of the interview, both experts and observers were blind to the medical diagnosis of the patients. During the first stage of the validation study the observers did not have a reference guide which resulted in a low concordance rating. For the second stage, a 177 item guide was used and a considerable increase in the concordance rating was observed. Validation studies like the one used here are of considerable value to increase the reliability and further utilisation of evaluation instruments of this type.

  1. New method for evaluating composite reservoir systems

    Energy Technology Data Exchange (ETDEWEB)

    Benson, S.M.; Lai, C.H.

    1985-03-01

    A simple new technique has been developed for evaluating interference test data in radially symmetric composite reservoirs. The technique is based on the realization that systematic variations in the apparent storage coefficient (calculated from semi-log analysis of the late-time data are indicative of a two-mobility (k/..mu..) reservoir. By analyzing variations in the apparent storage coefficient, both the mobility and size of the inner region can be calculated. The technique is particularly useful for evaluating heterogeneous geothermal systems where the intersection of several faults, or hydrothermal alteration has created a high permeability region in the center of the geothermal field. The technique is applied to an extensive interference test in the geothermal reservoir at Klamath Falls, Oregon. 7 refs., 7 figs.

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

    Directory of Open Access Journals (Sweden)

    Alaghemand H

    2016-03-01

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

  3. In-Situ Cure Monitoring of Wind Turbine Blades by Using Fiber Bragg Grating Sensors and Fresnel Reflection Measurement.

    Science.gov (United States)

    Sampath, Umesh; Kim, Hyunjin; Kim, Dae-gil; Kim, Young-Chon; Song, Minho

    2015-07-27

    A fiber-optic cure monitoring system is proposed to measure curing status of composite structure such as a large scale wind turbine blade. The monitoring is based on the measurement of Fresnel reflectivity at the optical fiber/epoxy resin interface. The refractive index of epoxy resin varies throughout curing stages, changing the Fresnel reflectivity. The curing status is decided by monitoring the reflected intensity variation. The usage of fiber Bragg grating (FBG) sensor helps to separate the temperature-induced cross effects. A Gaussian curve fitting algorithm was applied to FBG spectra which were distorted in curing procedure. The substantial measurement errors could be minimized by locating the centroids of the Gaussian curve-fitted spectra. From the experiments performed in various isothermal conditions, the proposed system successfully identified the onset of gelation and the completion of curing of epoxy resins.

  4. Evaluation of mammographic screen-film systems.

    Science.gov (United States)

    Arnold, B A; Webster, E W; Kalisher, L

    1978-10-01

    Four screen-film systems were evaluated for their imaging properties in mammography, Modulation-transfer functions were measured at 40 kVp. Absolute screen-film sensitivities in mR and entrance exposures were measured with tungsten and molybdenum target tubes. Five radiologists viewed radiographs of a phantom containing microgranules of SiC ranging in diameter from 590 to 120 micrometer. The Rarex-B screen--composed of yttrium oxysulfide--performed best, allowing phantom radiographs at 185 mR with image quality sufficient to demonstrate microgranules greater than 330 micrometer in dimension.

  5. Fusion-fission energy systems evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Teofilo, V.L.; Aase, D.T.; Bickford, W.E.

    1980-01-01

    This report serves as the basis for comparing the fusion-fission (hybrid) energy system concept with other advanced technology fissile fuel breeding concepts evaluated in the Nonproliferation Alternative Systems Assessment Program (NASAP). As such, much of the information and data provided herein is in a form that meets the NASAP data requirements. Since the hybrid concept has not been studied as extensively as many of the other fission concepts being examined in NASAP, the provided data and information are sparse relative to these more developed concepts. Nevertheless, this report is intended to provide a perspective on hybrids and to summarize the findings of the rather limited analyses made to date on this concept.

  6. Distributed Impact Detector System (DIDS) Health Monitoring System Evaluation

    Science.gov (United States)

    Prosser, William H.; Madaras, Eric I.

    2010-01-01

    Damage due to impacts from micrometeoroids and orbital debris is one of the most significant on-orbit hazards for spacecraft. Impacts to thermal protection systems must be detected and the damage evaluated to determine if repairs are needed to allow safe re-entry. To address this issue for the International Space Station Program, Langley Research Center and Johnson Space Center technologists have been working to develop and implement advanced methods for detecting impacts and resultant leaks. LaRC funded a Small Business Innovative Research contract to Invocon, Inc. to develop special wireless sensor systems that are compact, light weight, and have long battery lifetimes to enable applications to long duration space structures. These sensor systems are known as distributed impact detection systems (DIDS). In an assessment, the NASA Engineering and Safety Center procured two prototype DIDS sensor units to evaluate their capabilities in laboratory testing and field testing in an ISS Node 1 structural test article. This document contains the findings of the assessment.

  7. An evaluation of classification systems for stillbirth

    Directory of Open Access Journals (Sweden)

    Pattinson Robert

    2009-06-01

    Full Text Available Abstract Background Audit and classification of stillbirths is an essential part of clinical practice and a crucial step towards stillbirth prevention. Due to the limitations of the ICD system and lack of an international approach to an acceptable solution, numerous disparate classification systems have emerged. We assessed the performance of six contemporary systems to inform the development of an internationally accepted approach. Methods We evaluated the following systems: Amended Aberdeen, Extended Wigglesworth; PSANZ-PDC, ReCoDe, Tulip and CODAC. Nine teams from 7 countries applied the classification systems to cohorts of stillbirths from their regions using 857 stillbirth cases. The main outcome measures were: the ability to retain the important information about the death using the InfoKeep rating; the ease of use according to the Ease rating (both measures used a five-point scale with a score Results InfoKeep scores were significantly different across the classifications (p ≤ 0.01 due to low scores for Wigglesworth and Aberdeen. CODAC received the highest mean (SD score of 3.40 (0.73 followed by PSANZ-PDC, ReCoDe and Tulip [2.77 (1.00, 2.36 (1.21, 1.92 (1.24 respectively]. Wigglesworth and Aberdeen resulted in a high proportion of unexplained stillbirths and CODAC and Tulip the lowest. While Ease scores were different (p ≤ 0.01, all systems received satisfactory scores; CODAC received the highest score. Aberdeen and Wigglesworth showed poor agreement with kappas of 0.35 and 0.25 respectively. Tulip performed best with a kappa of 0.74. The remainder had good to fair agreement. Conclusion The Extended Wigglesworth and Amended Aberdeen systems cannot be recommended for classification of stillbirths. Overall, CODAC performed best with PSANZ-PDC and ReCoDe performing well. Tulip was shown to have the best agreement and a low proportion of unexplained stillbirths. The virtues of these systems need to be considered in the development of an

  8. Information System Architectures: Representation, Planning and Evaluation

    Directory of Open Access Journals (Sweden)

    André Vasconcelos

    2003-12-01

    Full Text Available In recent years organizations have been faced with increasingly demanding business environments - pushed by factors like market globalization, need for product and service innovation and product life cycle reduction - and with new information technologies changes and opportunities- such as the Component-off-the-shelf paradigm, the telecommunications improvement or the Enterprise Systems off-the-shelf modules availability - all of which impose a continuous redraw and reorganization of business strategies and processes. Nowadays, Information Technology makes possible high-speed, efficient and low cost access to the enterprise information, providing the means for business processes automation and improvement. In spite of these important technological progresses, information systems that support business, do not usually answer efficiently enough to the continuous demands that organizations are faced with, causing non-alignment between business and information technologies (IT and therefore reducing organization competitive abilities. This article discusses the vital role that the definition of an Information System Architecture (ISA has in the development of Enterprise Information Systems that are capable of staying fully aligned with organization strategy and business needs. In this article the authors propose a restricted collection of founding and basis operations, which will provide the conceptual paradigm and tools for proper ISA handling. These tools are then used in order to represent, plan and evaluate an ISA of a Financial Group.

  9. Physicochemical Characteristics of Beef Jerky Cured with Salted-fermented Anchovy and Shrimp.

    Science.gov (United States)

    Kim, Gap-Don; Go, Gwang-Woong; Lim, Hyun-Jung; Jung, Eun-Young; Seo, Hyun-Woo; Jeong, Jin-Yeon; Joo, Seon-Tea; Yang, Han-Sul

    2014-01-01

    The aim of this study is to evaluate the availability of salted and fermented fish (SFF) including salted and fermented anchovy (SFA) and shrimp (SFS) as a marinade of beef jerky. In curing solutions, half (SFA 1 and SFS 1) or whole (SFA 2 and SFS 2) salt-water was replaced with SFF juices. Higher water activity (aw) was found in the beef jerky cured with SFFs than the control (C) (pbeef jerky. In particular, the SFS is a good ingredient for the curing solution. However, studies are still needed on improving the aw, pH, and surface color of the beef jerky to apply the SFFs for making beef jerky.

  10. Effect of different curing modes on the degree of conversion and the microhardness of different composite restorations

    Directory of Open Access Journals (Sweden)

    Reem Ali Ajaj

    2015-01-01

    Full Text Available Introduction: This study aims to evaluate the effects of different curing units and modes on the degree of conversion (DC and microhardness (MH of two different resin composites [ESTELITE ∑ QUICK (EQ, and Z350 XT (Z3]. Materials and Methods: One hundred (100 discs of each tested material were made and divided into two subgroups (n = 50 according to the discs′ dimensions: 5 mm diameter × 2 mm thickness, and 2 mm diameter × 2 mm thickness. Each subgroup was further subdivided into the following five classes (n = 10: I cured with halogen light curing-unit; II cured with light-emitting diode (LED unit; III cured with argon laser; IV cured with halogen light-curing unit for 5 s, 10 s rest followed by 20 s curing; and V cured with halogen light-curing unit for 10 s, then 10 s rest, followed by 10 s curing. The first subgroup was tested for MH using the Vickers Microhardness tester and the second subgroup was tested for DC using Fourier transform infrared spectroscopy (FTIR. Data were statistically analyzed using two-way analysis of variance (ANOVA and Tukey′s post hoc test P < 0.05. Results: Specimens in class IV showed the highest mean DC and MH, followed by class III, then class II. Class I showed significantly lower mean values for both DC and MH. On the other hand, Z3 showed statistically significantly higher mean DC and MH than EQ. Conclusion: Although the two tested composites did not perform similarly under the test conditions, curing with halogen unit for 5 s, then 10 s rest, followed by 10 s curing improved the DC and the MH of both the tested materials.

  11. Is There a Cure for Cushing's Syndrome?

    Science.gov (United States)

    ... Pinterest Email Print Is there a cure for Cushing syndrome? Untreated Cushing syndrome can be life-threatening—fortunately, most people ... their previous strength. People who no longer have Cushing syndrome might be more likely to develop diabetes, ...

  12. The prevention of losses in cured fish

    National Research Council Canada - National Science Library

    1981-01-01

    The paper reviews problems of the post-harvest losses in cured fish. The importance of this commodity in the tropics and existing methods of its handling, processing, storage and distribution are discussed...

  13. Fast Curing of Composite Wood Products

    Energy Technology Data Exchange (ETDEWEB)

    Dr. Arthur J. Ragauskas

    2006-04-26

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

  14. 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.

  15. Ionizing radiation induced curing of epoxy resin for advanced composites matrices

    Energy Technology Data Exchange (ETDEWEB)

    Alessi, S. [Dipartimento di Ingegneria Chimica dei Processi e dei Materiali, Universita di Palermo (Italy); Calderaro, E. [Dipartimento di Ingegneria Nucleare, Universita di Palermo (Italy); Centro Interdipartimentale di Ricerca sui Materiali Compositi (CIRMAC), Universita di Palermo Viale delle Scienze, 90128 Palermo (Italy); Parlato, A. [Dipartimento di Ingegneria Nucleare, Universita di Palermo (Italy); Fuochi, P. [Istituto per la Sintesi Organica e Fotoreattivita, CNR, Via P. Godetti 101, 40129 Bologna (Italy); Lavalle, M. [Istituto per la Sintesi Organica e Fotoreattivita, CNR, Via P. Godetti 101, 40129 Bologna (Italy); Corda, U. [Istituto per la Sintesi Organica e Fotoreattivita, CNR, Via P. Godetti 101, 40129 Bologna (Italy); Dispenza, C. [Dipartimento di Ingegneria Chimica dei Processi e dei Materiali, Universita di Palermo (Italy); Centro Interdipartimentale di Ricerca sui Materiali Compositi (CIRMAC), Universita di Palermo Viale delle Scienze, 90128 Palermo (Italy); Spadaro, G. [Dipartimento di Ingegneria Chimica dei Processi e dei Materiali, Universita di Palermo (Italy) and Centro Interdipartimentale di Ricerca sui Materiali Compositi (CIRMAC), Universita di Palermo Viale delle Scienze, 90128 Palermo (Italy)]. E-mail: spadaro@dicpm.unipa.it

    2005-07-01

    The radiation curing of an epoxy monomer in the presence of an iodonium salt, as photo initiator, is studied. Systems with different concentrations of photo initiators have been polymerized via both gamma rays and e-beam, at various dose rates. The aim of this work is to investigate how the photo initiator concentration and the irradiation dose rate affect the temperature of the systems during curing and how the different thermal histories influence the dynamic mechanical thermal properties of the obtained materials.

  16. Evaluating architecture impact on system energy efficiency.

    Science.gov (United States)

    Yu, Shijie; Yang, Hailong; Wang, Rui; Luan, Zhongzhi; Qian, Depei

    2017-01-01

    As the energy consumption has been surging in an unsustainable way, it is important to understand the impact of existing architecture designs from energy efficiency perspective, which is especially valuable for High Performance Computing (HPC) and datacenter environment hosting tens of thousands of servers. One obstacle hindering the advance of comprehensive evaluation on energy efficiency is the deficient power measuring approach. Most of the energy study relies on either external power meters or power models, both of these two methods contain intrinsic drawbacks in their practical adoption and measuring accuracy. Fortunately, the advent of Intel Running Average Power Limit (RAPL) interfaces has promoted the power measurement ability into next level, with higher accuracy and finer time resolution. Therefore, we argue it is the exact time to conduct an in-depth evaluation of the existing architecture designs to understand their impact on system energy efficiency. In this paper, we leverage representative benchmark suites including serial and parallel workloads from diverse domains to evaluate the architecture features such as Non Uniform Memory Access (NUMA), Simultaneous Multithreading (SMT) and Turbo Boost. The energy is tracked at subcomponent level such as Central Processing Unit (CPU) cores, uncore components and Dynamic Random-Access Memory (DRAM) through exploiting the power measurement ability exposed by RAPL. The experiments reveal non-intuitive results: 1) the mismatch between local compute and remote memory node caused by NUMA effect not only generates dramatic power and energy surge but also deteriorates the energy efficiency significantly; 2) for multithreaded application such as the Princeton Application Repository for Shared-Memory Computers (PARSEC), most of the workloads benefit a notable increase of energy efficiency using SMT, with more than 40% decline in average power consumption; 3) Turbo Boost is effective to accelerate the workload execution

  17. Evaluating architecture impact on system energy efficiency

    Science.gov (United States)

    Yu, Shijie; Wang, Rui; Luan, Zhongzhi; Qian, Depei

    2017-01-01

    As the energy consumption has been surging in an unsustainable way, it is important to understand the impact of existing architecture designs from energy efficiency perspective, which is especially valuable for High Performance Computing (HPC) and datacenter environment hosting tens of thousands of servers. One obstacle hindering the advance of comprehensive evaluation on energy efficiency is the deficient power measuring approach. Most of the energy study relies on either external power meters or power models, both of these two methods contain intrinsic drawbacks in their practical adoption and measuring accuracy. Fortunately, the advent of Intel Running Average Power Limit (RAPL) interfaces has promoted the power measurement ability into next level, with higher accuracy and finer time resolution. Therefore, we argue it is the exact time to conduct an in-depth evaluation of the existing architecture designs to understand their impact on system energy efficiency. In this paper, we leverage representative benchmark suites including serial and parallel workloads from diverse domains to evaluate the architecture features such as Non Uniform Memory Access (NUMA), Simultaneous Multithreading (SMT) and Turbo Boost. The energy is tracked at subcomponent level such as Central Processing Unit (CPU) cores, uncore components and Dynamic Random-Access Memory (DRAM) through exploiting the power measurement ability exposed by RAPL. The experiments reveal non-intuitive results: 1) the mismatch between local compute and remote memory node caused by NUMA effect not only generates dramatic power and energy surge but also deteriorates the energy efficiency significantly; 2) for multithreaded application such as the Princeton Application Repository for Shared-Memory Computers (PARSEC), most of the workloads benefit a notable increase of energy efficiency using SMT, with more than 40% decline in average power consumption; 3) Turbo Boost is effective to accelerate the workload execution

  18. Phthalocyanine Tetraamine Epoxy-Curing Agents

    Science.gov (United States)

    Fohlen, G. M.; Achar, B. N.; Parker, J. A.

    1986-01-01

    Tough fire- and chemical-resistant epoxies produced by using metalphthalocyanine tetraamines (MPT's) of copper, cobalt, or nickel as curing agents. Synthesis of MPT's commercially realizable and gives pure compounds with almost 90-percent yield. Synthesis applicable for metals with atomic radii of about 1.35 angstroms, including Cu, Co, Ni, Zn, Fe, Pt, Al, and V. Possible to use metal phthalocyanines to cure epoxy resins in homogeneous reaction.

  19. 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.

  20. HIV cure research: a formidable challenge

    OpenAIRE

    Ananworanich, Jintanat; Fauci, Anthony S.

    2015-01-01

    Abstract The ultimate goal of HIV cure research is to allow HIV-infected individuals to be free of disease in the absence of antiretroviral therapy. We discuss current directions and future opportunities aimed at achieving sustained virological remission, and possibly eradication. A multidisciplinary approach to HIV cure research will be important, and ethical, social and behavioural research should be conducted in parallel with basic and clinical research.

  1. Research on Full Data Planning Stimulation State of Smart Distribution Automation and Stimulation Evaluating System

    Directory of Open Access Journals (Sweden)

    Qiang Chang

    2014-05-01

    Full Text Available Smart distribution automation is an important part of smart grids. In our country, power distribution network is open looped and radial. To optimize the power distribution network, this paper aims to conduct full data planning in smart distribution automation from the perspective of annual total cost to explore efficient and practical planning algorithm, and provide fundamental basis for development and completion of smart power distribution system. In this paper, firstly, we analyze the proposal background and features of smart distribution automation to prepare for limits and targets in the process of distribution network planning. Then, according to regional characteristics of smart distribution automation, we provide with appliance strategies of multi ant colony algorithm in planning of smart distribution automation and figure out the stimulation branch circuit data of full data planning in certain power supply region after 500 iterations. It turns out that the convergence of algorithm and the result of optimization are good. At last, after evaluating the result of distribution network planning, we make out an index evaluating system and come up with evaluating process of the planning results as well as algorithm principle of AHP, and finally provide fundamental basis for self-cure of smart distribution automation.

  2. 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. Copyright 2004 John Wiley & Sons, Ltd.

  3. Disposal systems evaluations and tool development : Engineered Barrier System (EBS) evaluation.

    Energy Technology Data Exchange (ETDEWEB)

    Rutqvist, Jonny (LBNL); Liu, Hui-Hai (LBNL); Steefel, Carl I. (LBNL); Serrano de Caro, M. A. (LLNL); Caporuscio, Florie Andre (LANL); Birkholzer, Jens T. (LBNL); Blink, James A. (LLNL); Sutton, Mark A. (LLNL); Xu, Hongwu (LANL); Buscheck, Thomas A. (LLNL); Levy, Schon S. (LANL); Tsang, Chin-Fu (LBNL); Sonnenthal, Eric (LBNL); Halsey, William G. (LLNL); Jove-Colon, Carlos F.; Wolery, Thomas J. (LLNL)

    2011-01-01

    Key components of the nuclear fuel cycle are short-term storage and long-term disposal of nuclear waste. The latter encompasses the immobilization of used nuclear fuel (UNF) and radioactive waste streams generated by various phases of the nuclear fuel cycle, and the safe and permanent disposition of these waste forms in geological repository environments. The engineered barrier system (EBS) plays a very important role in the long-term isolation of nuclear waste in geological repository environments. EBS concepts and their interactions with the natural barrier are inherently important to the long-term performance assessment of the safety case where nuclear waste disposition needs to be evaluated for time periods of up to one million years. Making the safety case needed in the decision-making process for the recommendation and the eventual embracement of a disposal system concept requires a multi-faceted integration of knowledge and evidence-gathering to demonstrate the required confidence level in a deep geological disposal site and to evaluate long-term repository performance. The focus of this report is the following: (1) Evaluation of EBS in long-term disposal systems in deep geologic environments with emphasis on the multi-barrier concept; (2) Evaluation of key parameters in the characterization of EBS performance; (3) Identification of key knowledge gaps and uncertainties; and (4) Evaluation of tools and modeling approaches for EBS processes and performance. The above topics will be evaluated through the analysis of the following: (1) Overview of EBS concepts for various NW disposal systems; (2) Natural and man-made analogs, room chemistry, hydrochemistry of deep subsurface environments, and EBS material stability in near-field environments; (3) Reactive Transport and Coupled Thermal-Hydrological-Mechanical-Chemical (THMC) processes in EBS; and (4) Thermal analysis toolkit, metallic barrier degradation mode survey, and development of a Disposal Systems

  4. Microhardness of heat cure acrylic resin after treatment with disinfectants.

    Science.gov (United States)

    Amin, Faiza; Rehman, Abdur; Abbas, Muhammad

    2015-08-01

    To evaluate the effect of disinfectants and distilled water on the micro-hardness of heat cure acrylic resins. The case-control study was conducted at Dr. Ishrat-ul-Ebad Khan Institute of Oral Health Sciences, Dow University of Health Sciences, and Nadirshaw Edulji Dinshaw University of Engineering and Technology, Karachi, from April to October 2011. Specimens were fabricated from heat cure acrylic resin material and they were divided into four equal groups. Group 1 was evaluated at baseline and was taken as the control group. Group 2 was immersed in distilled water for 20 minutes, Group 3 in1% sodium hypochlorite for 20 minutes, and Group 4 in 2% alkaline gluteraldehyde for 10 minutes. All specimens were polished, stored in distilled water for 24 hours prior to experiment. All the specimens were immersed twice daily for a total of 60 days after which they were tested for Vickers micro-hardness test. Statistical analysis was conducted with one-way analysis of variance and Tukey post hoc test (a=0.05). There were 72 specimens divided into four groups of 18(25%) each. Statistically significant differences were found among all groups (pacrylic resins. Group 4 showed the most reduction in the hardness value which was followed by Group 3. The hardness of heat cure acrylic resin was affected by disinfectants.

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

    Science.gov (United States)

    Kostecki, Adam; Bilska, Agnieszka; Danyluk, Bożena

    2015-01-01

    The aim of this study was to determine the influence of the dried celeriac juice addition, as a nitrogenous compounds sources, on the quality of the experimental pork sausage. 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, flavour, 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 num. nd. The aim of this study was to determine the influence of the dried celeriac juice addition, as a nitrogenous

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

    Directory of Open Access Journals (Sweden)

    Cemil Dizman

    2010-06-01

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

  7. Evaluation of an adjustable epidemiologic information system.

    Directory of Open Access Journals (Sweden)

    Jiunn-Shyan Julian Wu

    Full Text Available BACKGROUND: In order to facilitate public health response and to achieve early control of infectious disease epidemics, an adjustable epidemiologic information system (AEIS was established in the Taiwan public health network in February 2006. METHODOLOGY/PRINCIPAL FINDINGS: The performance of AEIS for the period 2006 through 2008 was evaluated based on a number of response times (RT and the public health impact. After implementation of the system, the apparent overall shortened RT was mainly due to the shortening of personnel response time (PRT and the time needed to draft a new questionnaire that incurred as personnel-system interface (PSI; PRT dropped from a fluctuating range of 9.8 ∼28.8 days in the first four months to <10 days in the following months and remained low till 2008 (0.88±1.52 days. The PSIs for newly emerged infectious diseases were 2.6 and 3.4 person-hours for H5N1 in 2007 and chikungunya in 2008, respectively, a much improvement from 1142.5 person-hours for SARS in 2003. The duration of each rubella epidemic cluster was evaluated as public health impact and showed a shortening trend (p = 0.019 that concurred with the shortening of PRT from 64.8±47.3 to 25.2±38.2 hours per cluster (p<0.0001. CONCLUSIONS/SIGNIFICANCE: The first evaluation of the novel instrument AEIS that had been used to assist Taiwan's multi-level government for infectious diseases control demonstrated that it was well integrated into the existing public health infrastructure. It provided flexible tools and computer algorithms with friendly interface for timely data collection, integration, and analysis; as a result, it shortened RTs, filled in gaps of personnel lacking sufficient experiences, created a more efficient flow of response, and identified asymptomatic/mild cases early to minimize further spreading. With further development, AEIS is anticipated to be useful in the application of other acute public health events needing immediate

  8. Cytotoxicity of Light-Cured Dental Materials according to Different Sample Preparation Methods

    Directory of Open Access Journals (Sweden)

    Myung-Jin Lee

    2017-03-01

    Full Text Available Dental light-cured resins can undergo different degrees of polymerization when applied in vivo. When polymerization is incomplete, toxic monomers may be released into the oral cavity. The present study assessed the cytotoxicity of different materials, using sample preparation methods that mirror clinical conditions. Composite and bonding resins were used and divided into four groups according to sample preparation method: uncured; directly cured samples, which were cured after being placed on solidified agar; post-cured samples were polymerized before being placed on agar; and “removed unreacted layer” samples had their oxygen-inhibition layer removed after polymerization. Cytotoxicity was evaluated using an agar diffusion test, MTT assay, and confocal microscopy. Uncured samples were the most cytotoxic, while removed unreacted layer samples were the least cytotoxic (p < 0.05. In the MTT assay, cell viability increased significantly in every group as the concentration of the extracts decreased (p < 0.05. Extracts from post-cured and removed unreacted layer samples of bonding resin were less toxic than post-cured and removed unreacted layer samples of composite resin. Removal of the oxygen-inhibition layer resulted in the lowest cytotoxicity. Clinicians should remove unreacted monomers on the resin surface immediately after restoring teeth with light-curing resin to improve the restoration biocompatibility.

  9. Effect of different curing methods on the compressive strength development of pulverized copper slag concrete

    OpenAIRE

    Daniel Mensah Boakye; Herbert Chidozie Uzoegbo; Nonhlanhla Mojagotlhe; Moeti Malemona

    2014-01-01

    The results of laboratory studies conducted to evaluate the effects of different curing conditions on the compressive strength development of concrete made with pulverized copper slag as partial replacement for ordinary Portland cement (OPC) is presented. Concrete cube specimens were made with copper slag replacing cement in the following proportions; 2.5, 5, 10 and 15% compared to the control (0%) specimen under normal laboratory conditions and cured in three different conditions, namely; wa...

  10. Influence of Light-Curing Mode on the Erosion Preventive Effect of Three Different Resin-Based Surface Sealants

    Science.gov (United States)

    Wegehaupt, Florian J.; Tauböck, Tobias T.; Sener, Beatrice; Attin, Thomas

    2012-01-01

    Objectives. To investigate if reducing the light-curing time (while maintaining similar energy density) of resin-based surface sealants influences their erosion-preventive potential and mechanical stability after thermomechanical loading. Methods. Dentine samples were treated as follows: group 1—untreated, groups 2–4—Seal&Protect, groups 5–7—experimental sealer, and groups 8–10—Syntac Classic system. Groups 2, 5 and 8 were light-cured for 10 s (1000 mW/cm2), groups 3, 6 and 9 for 7 s (1400 mW/cm2), and groups 4, 7, and 10 for 3 s (3200 mW/cm2). After water storage (7 d), first measurement was performed to evaluate baseline permeability of the sealants. After a thermomechanical loading (5000 cycles, 50/5°C, 12000 brushing strokes) a second evaluation of permeability was conducted (measurement 2). Permeability was tested by storing the samples in HCl (pH 2.3; 24 h) and measuring the dentine calcium release by atomic absorption spectroscopy. Results. For the first and second measurements, no influence of light-exposure time on permeability was observed (ANOVA: P > 0.05). No significant difference in the stability of the respective sealants was observed when light-cured for different durations. Conclusion. Shortening the light-curing time, while maintaining energy density constant, has no influence on permeability and stability of the investigated sealants. PMID:22991513

  11. Influence of Light-Curing Mode on the Erosion Preventive Effect of Three Different Resin-Based Surface Sealants

    Directory of Open Access Journals (Sweden)

    Florian J. Wegehaupt

    2012-01-01

    Full Text Available Objectives. To investigate if reducing the light-curing time (while maintaining similar energy density of resin-based surface sealants influences their erosion-preventive potential and mechanical stability after thermomechanical loading. Methods. Dentine samples were treated as follows: group 1—untreated, groups 2–4—Seal&Protect, groups 5–7—experimental sealer, and groups 8–10—Syntac Classic system. Groups 2, 5 and 8 were light-cured for 10 s (1000 mW/cm2, groups 3, 6 and 9 for 7 s (1400 mW/cm2, and groups 4, 7, and 10 for 3 s (3200 mW/cm2. After water storage (7 d, first measurement was performed to evaluate baseline permeability of the sealants. After a thermomechanical loading (5000 cycles, 50/5°C, 12000 brushing strokes a second evaluation of permeability was conducted (measurement 2. Permeability was tested by storing the samples in HCl (pH 2.3; 24 h and measuring the dentine calcium release by atomic absorption spectroscopy. Results. For the first and second measurements, no influence of light-exposure time on permeability was observed (ANOVA: P>0.05. No significant difference in the stability of the respective sealants was observed when light-cured for different durations. Conclusion. Shortening the light-curing time, while maintaining energy density constant, has no influence on permeability and stability of the investigated sealants.

  12. Influence of aromatic amine hardeners in the cure kinetics of an epoxy resin used in advanced composites

    Directory of Open Access Journals (Sweden)

    Michelle Leali Costa

    2005-03-01

    Full Text Available Composite structures for aerospace applications are mainly made by the well-known prepreg technology. In order to achieve adequate prepreg processing schedules, and consequently maximum fiber strength utilization, one has to know in deep the cure kinetics of matrix, which held the fibers together. This work describes a procedure to study the cure kinetic and has as example how aromatic amine hardeners influence the cure kinetics of an epoxy resin used in advanced composites. The investigation was carried out by using the DSC technique and it was found that depending on the system used the cure kinetics of the formulation obeys order n or autocatalytic order.

  13. Determinant of flexible Parametric Estimation of Mixture Cure ...

    African Journals Online (AJOL)

    Cure models are survival models basically developed to estimate the proportion of patients cured in a clinical trial. These models estimate the cured proportion and also the probability of survival. Cure models are a special type of survival analysis model where it is assumed that there are a proportion of subjects who will ...

  14. Exploring the social meaning of curing HIV: a qualitative study of people who inject drugs in Guangzhou, China.

    Science.gov (United States)

    Chu, Carissa E; Wu, Feng; He, Xi; Ma, Qingyan; Cheng, Yu; Cai, Weiping; Volberding, Paul; Tucker, Joseph D

    2015-01-01

    Our objective was to explore the social meaning of HIV and perceptions of an HIV cure among people who inject drugs (PWID) in Guangzhou, China, which speaks to ethical and resource challenges to development in this field. We conducted a qualitative research study using in-depth interviews. We analyzed interview transcripts from 29 PWID, eight physicians, and three social workers from an outpatient HIV clinic and two methadone maintenance treatment centers. The social meaning of HIV infection and perceptions of an HIV cure reflected patients' relationships with society, health systems, and physicians. First, HIV infection decreased perceived social worth and disrupted peer relationships. The possibility of being cured renewed patient hope for regaining physical well-being and achieving social mobility. However, the existence of a cure may not alter the HIV-related stigma due to its association with stigmatized behaviors and marginalized groups. Second, although stigma was a significant barrier to engagement in health care, hope for a cure may outweigh fears of stigma and enhance linkage to HIV testing and treatment as well as methadone services. A cure may exacerbate perceived health disparities if inaccessible to key affected populations such as PWID. The social implications of an HIV cure among this key affected population may inform the design and implementation of cure clinical trials. Careful management of patient expectations, focusing research on key affected populations, expanding HIV testing and treatment systems, improving access to harm reduction programs, and ensuring post-trial access are important considerations for HIV cure research.

  15. Detection of Toxoplasma gondii in cured meats.

    Science.gov (United States)

    Warnekulasuriya, M R; Johnson, J D; Holliman, R E

    1998-12-22

    Congenital toxoplasmosis is associated with acute maternal infection acquired during or shortly before the pregnancy. The mother's infection is initiated by the ingestion of one of the life forms of the parasite but the relative importance of the different sources of toxoplasmosis are not established. Recent epidemiological studies have confirmed ingestion of raw meats as a risk factor but also identified consumption of cured meats as being associated with acute toxoplasmosis in pregnancy. There is little existing information concerning the efficiency of commercial curing processes for inactivating Toxoplasma gondii. We sought to detect the presence of T. gondii in ready-to-eat cured meat samples by amplification of the parasite's P30 gene using the polymerase chain reaction (PCR). In addition, tissue culture was used in order to isolate viable parasites. Laboratory inoculated specimens were used to assess the sensitivity of each method. PCR was able to detect parasite contamination down to a level of 5 x 10(3) trophozoites/g while viable toxoplasma could be detected in tissue culture at a level of 10(3) trophozoites/g cured meat. The high salt content of some cured meats limited sensitivity of the PCR assay by inhibition of the polymerase enzyme and reduced the sensitivity of tissue culture due to osmotic pressure causing cytopathic effect. However viable T. gondii was detected in one out of 67 ready-to-eat cured meat samples. Our results highlight the need for improved methods for detecting toxoplasma contamination of food. Health implications of consuming cured meats in pregnancy require careful consideration.

  16. Flexural Strength of Cold and Heat Cure Acrylic Resins Reinforced with Different Materials

    Directory of Open Access Journals (Sweden)

    Bijan Heidari

    2015-10-01

    Full Text Available Objectives: Heat-polymerized acrylic resin has been the most commonly used denture base material for over 60 years. However, the mechanical strength of acrylic resin is not adequate for long-term clinical performance of dentures. Consequently, fracture is a com- mon clinical occurrence, which often occurs in the midline of denture base.This study aimed to evaluate the efficacy of cold cure and heat cure acrylic resins, rein- forced with glass fibers, polyethylene fibers, and metal wire for denture base repair.Materials and Methods: Ninety specimens were prepared and allocated to nine groups. Ten specimens were included in the control group, and 80 were allocated to 8 experi- mental groups. In the experimental groups, the specimens were sectioned into two halves from the middle, and were then divided into two main groups: one group was repaired with heat cure acrylic resin, and the other with cold cure acrylic resin. Each group was di- vided into 4 subgroups: unreinforced, reinforced with glass fibers, polyethylene fibers, and metal wire. All specimens were then subjected to a 3-point bending test, and the flexural strength was calculated.Results: The group repaired with heat cure acrylic resin and reinforced with glass fiber showed the highest flexural strength; however, the group repaired with cold cure acrylic resin and reinforced with polyethylene fibers had the lowest flexural strength. There was no significant difference between the groups repaired with heat cure and cold cure acrylic resins without reinforcement.Conclusion: Repairing denture base with heat cure acrylic resin, reinforced with glass fi- bers increases the flexural strength of denture base.

  17. Effect of post-curing on thermal and mechanical behavior of GFRP composites

    Science.gov (United States)

    Kumar, D. S.; Shukla, M. J.; Mahato, K. K.; Rathore, D. K.; Prusty, R. K.; Ray, B. C.

    2015-02-01

    Curing cycle has a strong impact on the thermal and mechanical behavior of thermosetting polymers. The extent of cross-linking which is a strong function of curing temperature and time is directly linked to the glass transition temperature (Tg) of the thermosetting polymer. This transition temperature speaks about the transformation of the polymer from glassy state to rubbery state, hence decides the applicability of the material at certain temperature with certain degree of safety and reliability. Hence assessment of Tg and its possible improvement is quite essential from material point of view. The present study is emphasized on the impact of post curing parameters on thermal as well as mechanical behavior of glass fiber reinforced polymer (GFRP) composite. Post curing was carried out at 3 different temperatures (80°C, 110°C and 140°C) for different time periods (2h, 4h, 6h, 8h and 12h). Short beam Shear (SBS) test was performed on each of the post cured samples to determine the apparent Interlaminar Shear Strength (ILSS) and the corresponding Tg was also evaluated using differential scanning calorimetry (DSC) analysis. The results revealed that the ILSS and Tg are significantly affected with post curing parameters. No significant change in ILSS was obtained at 80°C over the entire curing time. In case of 110°C a smooth increment in ILSS was observed with time (even till 12 hrs). For samples post cured at 140°C a rapid improvement in ILSS takes place with time followed by saturation. With all the possible combinations of curing temperature and time, optimum values are noticed at 140°C for 6 hrs.

  18. 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

  19. Effect of hydrophilicity on the compatibility between a dual-curing resin cement and one-bottle simplified adhesives.

    Science.gov (United States)

    Chen, Liang; Suh, Byoung In

    2013-08-01

    To evaluate the effect of the hydrophilicity of adhesives on the compatibility between one-bottle simplified adhesives and a dual-curing resin cement. Three experimental and two commercial adhesives (All-Bond Universal, OptiBond Allin- One) with the same or similar pH and various degrees of hydrophilicity were tested in this study. Extracted human dentin was treated with each adhesive and bonded with a dual-curing resin cement (Duolink), which was either light cured or chemically (self) cured (n = 10). Shear bond strength was tested using the Ultradent jig method, and failure modes were determined using a stereomicroscope. Water contact angle (as a measure of hydrophilicity/-phobicity) was measured on a fully cured adhesive (n = 10). The data were analyzed statistically by ANOVA and Tukey's test. The quantitative relationship between the hydrophilicity and bond strength differences was analyzed (confidence level 95%). Among the experimental adhesives, differences in bond strengths between light-curing and self-curing modes were larger for the more hydrophilic adhesives. For the commercial adhesives, Optibond All-in-One had a lower contact angle than All-bond Universal (p Universal were 29.6 and 31.5, respectively (light cured), and 1.9 and 30.0, respectively (self-cured). Adhesive failure was a predominant mode for all adhesives except for All-Bond Universal. Regression analysis indicated a linear correlation between adhesives' hydrophilicity and bond strength differences (p adhesives were less compatible (larger bond strength differences between different curing modes) with this dual-curing resin cement. All-bond Universal is more hydrophobic than Optibond All-in-One and it is compatible with this self-/dual-curing resin cement.

  20. Influence of light transmittance and background reflectance on the light curing of adhesives used to bond esthetic brackets.

    Science.gov (United States)

    Lim, Yong-Kyu; Lee, Yong-Keun

    2007-07-01

    The objectives of this study were to determine the correlation between diffuse light transmittance (DLT) of esthetic brackets and the degree of cure (DC) of light-cured adhesives after direct irradiation, and to evaluate the influence of background reflectance. The influences of curing unit and irradiation time were also determined. The DLT of 4 ceramic and 4 plastic brackets was measured. Two reference light-curing protocols (cured over a glass slab; mean reflectance, 14.7%) and 4 experimental protocols (cured over bovine tooth slab; mean reflectance, 66.5%) were followed with 3 curing units: halogen, plasma arc, and light-emitting diode. The DC of 2 adhesives was calculated based on Fourier transform infrared spectroscopy. Two-way analysis of variance for the DC was performed (P = .05). The Pearson correlation between the DC and the DLT was determined. Mean DLTs were 44.9% to 75.9%. DC varied by bracket and curing protocol (P bracket. The interaction of the DLT and the reflectance of the background tooth on the light curing of adhesives should be studied further.

  1. Accelerated cure of phenol-formaldehyde by the addition of cure accelerators : studies with model compounds

    Science.gov (United States)

    Linda F. Lorenz; Anthony C. Conner

    2000-01-01

    Fast curing phenol-formaldehyde (PF) resins could potentially allow wood to be bonded at higher moisture contents and at lower press temperatures than those currently used commercially. Recent reports in the literature have shown that the addition of esters, lactones, or organic carbonates increased the curing rate of PF resins. Several mechanisms have been proposed to...

  2. Influence of different light curing units on the bond strength of indirect resin composite restorations

    Directory of Open Access Journals (Sweden)

    Veridiana Camilotti

    2008-06-01

    Full Text Available The aim of this study was to evaluate the influence of different light sources on the bond strength of indirect resin composite restorations cemented with a dual-cure resin cement. The superficial dentin of human third molars was exposed and acid-etched and an adhesive system was applied (Single Bond 2. Four-mm-thick indirect resin composite restorations (Gradia were fabricated and cemented using a dual-cure resin cement (Rely X. Four light sources were used to polymerize the cement: QTH - Optilux 401; LED1 - L.E.Demetron 1; LED2 - Optilight CL; and LED3 - Ultralume 5. The teeth were stored for 24 h and then sectioned, yielding stick-shaped specimens for each group with a bonded area of 1.0 mm². The specimens were then tested in a universal testing machine, at a crosshead speed of 1 mm/min. Data were analyzed using ANOVA. Bond strength mean values were: QTH: 22.5 (± 8.4; LED1: 22.7 (± 9.4; LED2: 21.4 (± 10.2; and LED3: 27.3 (± 13.8. No statistically significant difference was observed among the experimental groups. The bond strength values when the cement was polymerized using different LED lights were equivalent to the values when the QTH light was used. It can be concluded that the variety of light sources used in the present study did not influence the bond strength of indirect resin composite restorations cemented with a dual-cure resin cement.

  3. Disability Evaluation System Analysis and Research Annual Report 2017

    Science.gov (United States)

    2017-11-20

    Annual Report 2017 Disability Evaluation Systems Analysis and Research Prepared by Accession Medical Standards Analysis and Research Activity...Disabi l i ty Evaluation Systems Analysis and Research Annual Report 2017 Contributors Jan I. Maby, DO, MPH Paul O. Kwon, DO, MPH LTC...Disability Evaluation System ........................................................................... 3 Figure 1: Key Variables Collected at Each Stage

  4. Evaluation System for Pesticides (ESPE). 1. Agricultural pesticides

    NARCIS (Netherlands)

    Emans HJB; Beek MA; Linders JBHJ

    1992-01-01

    In this report a risk assessment or evaluation system for agricultural pesticides is presented, which estimates the hazards for man and environment resulting from the use of these pesticides. The evaluation system has also been placed within the context of the Uniform System for the Evaluation of

  5. Self-curing concrete types; water retention and durability

    Directory of Open Access Journals (Sweden)

    Magda I. Mousa

    2015-09-01

    This study was carried out to compare among concretes without or with silica fume (SF along with chemical type of shrinkage reducing admixture, polyethylene-glycol (Ch, and leca as self-curing agents for water retention even at elevated temperature (50 °C and their durability. The cement content of 400 kg/m3, silica fume of 15% by weight of cement, polyethylene-glycol of 2% by weight of cement, pre-saturated lightweight aggregate (leca 15% by volume of sand and water with Ch/binder ratio of 0.4 were selected in this study. Some of the physical and mechanical properties were determined periodically up to 28 days in case of exposure to air curing in temperature of (25 °C and (50 °C while up to 6 months of exposure to 5% of carbon dioxide and wet/dry cycles in 8% of sodium chloride for durability study. The concrete mass loss and the volumetric water absorption were measured, to evaluate the water retention of the investigated concretes. Silica fume concrete either without or with Ch gave the best results under all curing regimes; significant water retention and good durability properties.

  6. Light curing unit effectiveness assessed by dental radiometers.

    Science.gov (United States)

    Shortall, A C; Harrington, E; Wilson, H J

    1995-08-01

    The purpose of this investigation was to assess the effectiveness of five commercially available hand-held dental radiometers and a computer-based experimental radiometer. Light intensity of five visible light activation units was determined using the dental radiometers. The influence of curing light intensity on depth of cure of a hybrid composite material was determined using a digital penetrometer. The radiometers evaluated varied with respect to sensor aperture diameter, scale readings (analogue or digital) and the units of measurement (arbitrary or mW cm2). The experimental computer-based radiometer allowed continuous recording of intensity against time; thus the light output could be monitored over the entire irradiation period. When light intensity readings were normalized with regard to a standardized light sensing device aperture of 4 mm diameter, a linear relationship was found between depth of cure and the logarithm of the intensity of the light. The results of this investigation support the use of dental radiometers for periodically monitoring visible light activation units.

  7. A Comparative Study of Heat and Self-Cured Acrylic Resins on Color Stability of 5 Brands of Denture Teeth

    Directory of Open Access Journals (Sweden)

    Vafaee

    2016-03-01

    Full Text Available Background Denture teeth play a critical role in overall aesthetic outcomes of removable complete dentures, and long-term maintenance of these outcomes depends on the color stability of the prosthetic teeth. The characteristics of denture base resins play a significant role in prosthetic clinical performance and aesthetics. Objectives The purpose of this study was to assess the effect of two flasking materials on the color stability of five brands of denture teeth that were immersed in commonly consumed beverages. Materials and Methods In the present study 560 denture teeth (20 series were invested with heat- and cold-cured acrylic resin. All the specimens were thermo cycled between 4°C and 60°C, with 60 Seconds dwell times for 1000 cycles. Subsequently, the specimens in each group were divided into four subgroups based on the immersion medium: coffee, tea, cola, or distilled water. Digital images of the teeth were taken before immersion and 30 days after immersion. The color samples were measured using the CIE L* a* b* system, and color differences (ΔE were calculated. The data were evaluated by 3-way ANOVA and the Tukey HSD test. Results There were significant differences in color change between the cold-cured acrylic resins and the heat-cured acrylic resins, with a reduced amount of discoloration in the heat-cured group (ΔE = 10.12 ± 3.93, P = 0.001. The solutions showed significantly different amounts of discoloration on the teeth; distilled water had the least effect (ΔE = 8.49 ± 2.62, P = 0.001 and coffee had the maximum discoloration (ΔE = 14.14 ± 7.77, P = 0.001. A Tukey test showed that there was no significant difference between each brand of denture teeth. Conclusions Coffee caused the most color changes in the examined resin denture teeth. Tea and cola left less staining on the teeth, and distilled water caused the least discoloration. Generally, investing by heat- and cold-cured acrylic resins can significantly affect the

  8. Effect of prior refrigeration on botulinal outgrowth in perishable canned cured meat when temperature abused.

    Science.gov (United States)

    Tompkin, R B; Christiansen, L N; Shaparis, A B

    1978-01-01

    Perishable canned cured meat inoculated with Clostridium botulinum spores was placed at 4.4 or 10 degrees C after manufacture. Spore germination occurred at 10 degrees C. The germinated cell count remained stable over a period of 16 to 18 weeks. During that time period the inhibitory system and residual nitrite descreased. These factors combine to make perishable canned cured meats more prone to spoilage and potential hazard if they are temperature abused after a period of refrigerated storage. PMID:350155

  9. [How does we treat liver metastases from colorectal cancer by cure-intent surgery ?].

    Science.gov (United States)

    Takahashi, Keiichi; Yamaguchi, Tatsuro; Nakano, Daisuke; Nakayama, Yujiro; Oohinata, Ryouki; Yajima, Kazuhito; Iwasaki, Yoshiaki; Matsumoto, Hiroshi

    2013-08-01

    Surgery is the most optimal and curative intent strategy for liver recurrence from colorectal cancer. There are scoring systems and grade classification for liver resection. If we carry out preoperative imaging of liver metastases strictly following to liver resection, we can expect to get a cure state satisfactory. Early detection and repeated liver resection improve the outcome of residual liver recurrence after liver resection. The maximum number of liver metastases for cure intent liver resection is unclear. Further examination is necessary.

  10. Polyurethane curing kinetics for polymer bonded explosives: HTPB/IPDI binder

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Sangmook; Hong, In-Kwon [Dankook University, Yongin (Korea, Republic of); Choi, Chong Han; Lee, Jae Wook [Sogang University, Seoul (Korea, Republic of)

    2015-08-15

    The kinetics of polyurethane reaction and the effect of catalysts on the curing behavior were studied. The mixtures of hydroxyl terminated polybutadiene and isophorone diisocyanate with different reaction catalysts were dynamically cured in a differential scanning calorimeter. The activation energies were evaluated by the Kissinger and the Ozawa methods. The Chang plot was also used to determine reaction order and rate constant. The results showed that the activation energies were influenced remarkably by the choice of catalysts. The degree of cure and the cure time at given temperatures were calculated by direct integration of modified auto-catalytic kinetic model. It would give valuable information like pot-life estimation during manufacturing polymer-bonded explosives.

  11. Evaluation of the sustainability of contrasted pig farming systems: the procedure, the evaluated systems and the evaluation tools.

    Science.gov (United States)

    Bonneau, M; de Greef, K; Brinkman, D; Cinar, M U; Dourmad, J Y; Edge, H L; Fàbrega, E; Gonzàlez, J; Houwers, H W J; Hviid, M; Ilari-Antoine, E; Klauke, T N; Phatsara, C; Rydhmer, L; van der Oever, B; Zimmer, C; Edwards, S A

    2014-12-01

    Although a few studies consider the sustainability of animal farming systems along the three classical main pillars (economy, environment and society), most studies on pig farming systems address only one of these pillars. The present paper is the introduction to a series of companion papers presenting the results of a study undertaken within the EU-supported project Q-PorkChains, aiming at building a comprehensive tool for the evaluation of pig farming systems, which is robust to accommodate the large variability of systems existing in Europe. The tool is mostly based on questions to farmers and comprises a total of 37 dimensions distributed along eight themes: Animal Welfare, Animal Health, Breeding Programmes, Environmental Sustainability, Meat Safety, Market Conformity, Economy and Working Conditions. The paper describes the procedure that was used for building the tool, using it on 15 contrasted pig farming systems and analysing the results. The evaluated systems are briefly described and a short overview of the dimensions is provided. Detailed descriptions of the theme-wise tools and results, as well as the results of an integrated evaluation, are available in the companion papers.

  12. The effect of curing intensity on mechanical properties of different bulk-fill composite resins

    Directory of Open Access Journals (Sweden)

    Alkhudhairy FI

    2017-02-01

    Full Text Available Fahad I Alkhudhairy Restorative Dental Sciences Department, College of Dentistry, King Saud University, Riyadh, Kingdom of Saudi Arabia Objective: The purpose of this study was to investigate the effects of two curing light intensities on the mechanical properties (Vickers microhardness, compressive strength, and diametral tensile strength of bulk-fill resin-based composites (RBCs.Materials and methods: Four commercially available bulk-fill RBCs (Tetric® N-Ceram, SonicFill™, Smart Dentin Replacement (SDR™ Posterior Flowable Material, and Filtek™ Posterior Restorative were used in this study. A total of 72 cylindrical specimens of each RBC (n=288 were prepared and subjected to Vickers microhardness, compressive strength, and diametral tensile strength tests at high (1200 mW/cm2 and low (650 mW/cm2 curing light intensities (each n=12. Results were evaluated using independent and paired sample t-tests, one-way analysis of variance, and Tukey’s post hoc test. All tests were performed at a significance level of P<0.05.Results: The highest mean microhardness was observed for SonicFill (58.3 Vickers hardness number [VHN] cured using high-intensity light. Although having the least mean microhardness values, a significant difference was observed between SDR cured using high-intensity light and that cured using low-intensity light (P<0.05. In the total sample, the highest mean compressive strength was obtained for SonicFill (262.6 MPa, followed by SDR (253.2 MPa, both cured using high-intensity light, and the least was measured for Tetric N-Ceram cured using low-intensity light (214.3 MPa. At high and low curing light intensities, diametral tensile strength for all RBCs except SonicFill was significant (P<0.001.Conclusion: A higher curing light intensity (1200 mW/cm2 had a positive influence on the compressive and tensile strength of the four bulk-fill RBCs and microhardness of two materials tested compared with lower curing light intensity

  13. Cured in Place Pipe Repair

    OpenAIRE

    ECT Team, Purdue

    2007-01-01

    Insituform Technologies Inc. offers a pipe lining system called Paltem which uses a woven synthetic fiber covered with a polyester elastomer as the lining material. This system is used to rehabilitate pressure pipelines that have been damaged by corrosion or are experiencing leakage through joints, pinholes or other pipe defects.

  14. X-ray-cured carbon-fiber composites for vehicle use

    Science.gov (United States)

    Herer, Arnold; Galloway, Richard A.; Cleland, Marshall R.; Berejka, Anthony J.; Montoney, Daniel; Dispenza, Dan; Driscoll, Mark

    2009-07-01

    Carbon-fiber-reinforced composites were cured in molds using X-rays derived from a high-energy, high-current electron beam. X-rays could penetrate the mold walls as well as the fiber reinforcements and polymerize a matrix system. Matrix materials made from modified epoxy-acrylates were tailored to suitably low viscosity so that fiber wetting and adhesion could be attained. Techniques similar to vacuum-assisted resin transfer molding (VARTM) and conventional vacuum bagging of wet lay-ups were used. Inexpensive reinforced polyester molds were used to fabricate vehicle fenders. Moderately low-dose X-ray exposure was sufficient to attain functional properties, such as resistance to heat distortion at temperatures as high as 180 °C. The matrix system contained an impact additive which imparted toughness to the cured articles. "Class A" high gloss surfaces were achieved. Thermo-analytical techniques were used on small-sized samples of X-ray-cured matrix materials to facilitate selection of a system for use in making prototypes of vehicle components. X-rays-penetrated metal pieces that were placed within layers of carbon-fiber twill, which were cured and bonded into a structure that could be mechanically attached without concern over fracturing the composite. X-ray curing is a low temperature process that eliminates residual internal stresses which are imparted by conventional thermo-chemical curing processes.

  15. 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.

  16. Association of Surgical Treatment, Systemic Therapy, and Survival in Patients With Abdominal Visceral Melanoma Metastases, 1965-2014: Relevance of Surgical Cure in the Era of Modern Systemic Therapy.

    Science.gov (United States)

    Deutsch, Gary B; Flaherty, Devin C; Kirchoff, Daniel D; Bailey, Mariel; Vitug, Sarah; Foshag, Leland J; Faries, Mark B; Bilchik, Anton J

    2017-07-01

    Systemic therapy for metastatic melanoma has evolved rapidly during the last decade, and patient treatment has become more complex. To evaluate the survival benefit achieved through surgical resection of melanoma metastatic to the abdominal viscera in patients treated in the modern treatment environment. This retrospective review of the institutional melanoma database from the John Wayne Cancer Institute at Providence St Johns Health Center, a tertiary-level melanoma referral center, included 1623 patients with melanoma diagnosed as having potentially resectable abdominal metastases before (1969-2003) and after (2004-2014) advances in systemic therapy. Overall survival (OS). Of the 1623 patients identified in the database with abdominal melanoma metastases, 1097 were men (67.6%), and the mean (SD) age was 54.6 (14.6) years. Of the patients with metastatic melanoma, 1623 (320 [19.7%] in the 2004-2014 period) had abdominal metastases, including 336 (20.7%) with metastases in the gastrointestinal tract, 697 (42.9%) in the liver, 138 (8.5%) in the adrenal glands, 38 (2.3%) in the pancreas, 109 (6.7%) in the spleen, and 305 (18.8%) with multiple sites. Median OS was superior in surgical (n = 392; 18.0 months) vs nonsurgical (n = 1231; 7.0 months) patients (P < .001). The most favorable 1-year and 2-year OS was seen after surgery for gastrointestinal tract (52% and 41%) and liver (51% and 38%) metastases, respectively. Multivariable analysis found increasing age (hazard ratio [HR], 1.01; 95% CI, 1.00-1.01; P = .02) and the presence of ulceration (HR, 1.21; 95% CI, 1.01-1.45; P = .04) were associated with a worse OS. Alternatively, treatment with metastasectomy (HR, 0.59; 95% CI, 0.46-0.74; P < .001) and metastases involving the gastrointestinal tract (HR, 0.65; 95% CI, 0.48-0.87; P = .004) were associated with a better OS. The systemic treatment era did not significantly affect outcomes (HR, 0.82; 95% CI, 0.67-1.02; P = .15). Overall

  17. Developing a Formative Evaluation System for Distance Teaching.

    Science.gov (United States)

    Melton, Reginald F.

    1995-01-01

    Describes steps taken in developing an evaluation system for distance teaching at the Open Junior High School system in Indonesia. Reviews data collection techniques, and discusses advantages and disadvantages of evaluation studies. Presents a historical background of the system, and lists the system's strengths and weaknesses discovered via…

  18. Current views on HIV-1 latency, persistence, and cure.

    Science.gov (United States)

    Melkova, Zora; Shankaran, Prakash; Madlenakova, Michaela; Bodor, Josef

    2017-01-01

    HIV-1 infection cannot be cured as it persists in latently infected cells that are targeted neither by the immune system nor by available therapeutic approaches. Consequently, a lifelong therapy suppressing only the actively replicating virus is necessary. The latent reservoir has been defined and characterized in various experimental models and in human patients, allowing research and development of approaches targeting individual steps critical for HIV-1 latency establishment, maintenance, and reactivation. However, additional mechanisms and processes driving the remaining low-level HIV-1 replication in the presence of the suppressive therapy still remain to be identified and targeted. Current approaches toward HIV-1 cure involve namely attempts to reactivate and purge HIV latently infected cells (so-called "shock and kill" strategy), as well as approaches involving gene therapy and/or gene editing and stem cell transplantation aiming at generation of cells resistant to HIV-1. This review summarizes current views and concepts underlying different approaches aiming at functional or sterilizing cure of HIV-1 infection.

  19. Talking Cure Models: A Framework of Analysis.

    Science.gov (United States)

    Marx, Christopher; Benecke, Cord; Gumz, Antje

    2017-01-01

    Psychotherapy is commonly described as a "talking cure," a treatment method that operates through linguistic action and interaction. The operative specifics of therapeutic language use, however, are insufficiently understood, mainly due to a multitude of disparate approaches that advance different notions of what "talking" means and what "cure" implies in the respective context. Accordingly, a clarification of the basic theoretical structure of "talking cure models," i.e., models that describe therapeutic processes with a focus on language use, is a desideratum of language-oriented psychotherapy research. Against this background the present paper suggests a theoretical framework of analysis which distinguishes four basic components of "talking cure models": (1) a foundational theory (which suggests how linguistic activity can affect and transform human experience), (2) an experiential problem state (which defines the problem or pathology of the patient), (3) a curative linguistic activity (which defines linguistic activities that are supposed to effectuate a curative transformation of the experiential problem state), and (4) a change mechanism (which defines the processes and effects involved in such transformations). The purpose of the framework is to establish a terminological foundation that allows for systematically reconstructing basic properties and operative mechanisms of "talking cure models." To demonstrate the applicability and utility of the framework, five distinct "talking cure models" which spell out the details of curative "talking" processes in terms of (1) catharsis, (2) symbolization, (3) narrative, (4) metaphor, and (5) neurocognitive inhibition are introduced and discussed in terms of the framework components. In summary, we hope that our framework will prove useful for the objective of clarifying the theoretical underpinnings of language-oriented psychotherapy research and help to establish a more comprehensive understanding of how curative

  20. Evaluación de la tecnología sanitaria: Apósitos basados en la cura en ambiente húmedo para heridas crónicas Evaluation of Sanitary Technology: Dressings based on humid environment cure for chronic wounds

    Directory of Open Access Journals (Sweden)

    M. Gago Fornells

    2008-12-01

    Full Text Available El bombardeo constante en producción, diferenciación e idoneidad de tipos de apósitos al que se ha sometido en las dos últimas décadas el mundo de las heridas por parte de la industria hace necesario y obligatorio por parte del personal de la salud un conocimiento exhaustivo de la tecnología que tiene en sus manos. Los informes de Tecnología Sanitaria se han convertido en una buena herramienta para cubrir tanto la evaluación de los apósitos basados en cura en ambiente húmedo, como la precisión de sus indicaciones. En el presente trabajo analizamos la estructura de un Informe de Evaluación de Tecnología Sanitaria desde su marco general hasta su particularidad en el campo de los apósitos para el cuidado de heridas, las características básicas y estándar solicitadas por el profesional y el enfermo, manteniendo en todo momento unas visión integral desde el cuidado enfermero. Proponemos, al final, un informe ideal para hospital o centro de salud imaginario, que se ajuste a todas las premisas de calidad, las realidades de cada ámbito de salud y las posibilidades de cada sistema sanitario.In the last two decades the wounds sector has been subjected by the industry to a constant shelling in production, differentiation and suitability of types of dressings that requires necessarily and by imperative from the health staff an exhaustive knowledge of the technology that they have in their hands. The Sanitary Technology reports have become a good tool for covering both the evaluation of the dressings based on humid environment cure and their indications precision. In the present work we analyze the structure of a Sanitary Technology Evaluation report, from its general context to its special features in the field of dressings for wounds care, and the basic and standard characteristics requested by professionals and patients, always keeping an integral vision from the nurse care perspective. Finally, we propose an ideal report for a

  1. Curing mechanism of flexible aqueous polymeric coatings.

    Science.gov (United States)

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

    2017-06-01

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

  2. Effect of curing and drying on strength and absorption of concretes containing fly ash and silica fume

    Energy Technology Data Exchange (ETDEWEB)

    Saricimen, H.; Maslehuddin, M.; Shameem, M.; Al-Ghamdi, A. J.; Barry, M. S. [King Fahd Univ. of Petroleum and Minerals, Research Inst., Dhahran, (Saudi Arabia)

    2000-07-01

    The effects of curing and drying on the strength and absorption of plain and pozzolanic (i.e. containing finely ground clay or volcanic material) cement concretes are evaluated. Curing was carried out over a range of days ranging from one day to 60 days. At each testing period specimens were oven-dried at 70 degrees C for periods ranging from two hours to 24 hours, and the effect of curing and drying was evaluated by measuring 48-hour absorption and volume of permeable voids. Results showed an increase in compressive strength with increased curing and drying, with maximum increase occurring in fly-ash cement concrete specimens. There was a decrease in absorption with time of curing and an increase with drying period. Absorption capacity of fly-ash and silica-fume cements concrete specimens showed a significant decrease after three to seven days of curing. Absorption of pozzolanic cement concretes appeared unaffected especially after seven days of curing. Permeable voids decreased with curing. This characteristic was most evident in the case of fly-ash cement concrete specimens.25 refs., 14 tabs., 3 figs.

  3. Students Prefer Audience Response System for Lecture Evaluation

    OpenAIRE

    Turban, Joseph W

    2011-01-01

    Objectives: Student evaluation of courses is an important component of overall course evaluation. The extent of student participation in the evaluation may be related to the ease of the evaluation process. The standard evaluation format is a paper form. This study examines medical students preference of utilizing Audience Response System compared to a paper method. Methods: Following several medical school lectures, students were queried if they preferred Audience Response System versus a pap...

  4. Systems and methods for circuit lifetime evaluation

    Science.gov (United States)

    Heaps, Timothy L. (Inventor); Sheldon, Douglas J. (Inventor); Bowerman, Paul N. (Inventor); Everline, Chester J. (Inventor); Shalom, Eddy (Inventor); Rasmussen, Robert D. (Inventor)

    2013-01-01

    Systems and methods for estimating the lifetime of an electrical system in accordance with embodiments of the invention are disclosed. One embodiment of the invention includes iteratively performing Worst Case Analysis (WCA) on a system design with respect to different system lifetimes using a computer to determine the lifetime at which the worst case performance of the system indicates the system will pass with zero margin or fail within a predetermined margin for error given the environment experienced by the system during its lifetime. In addition, performing WCA on a system with respect to a specific system lifetime includes identifying subcircuits within the system, performing Extreme Value Analysis (EVA) with respect to each subcircuit to determine whether the subcircuit fails EVA for the specific system lifetime, when the subcircuit passes EVA, determining that the subcircuit does not fail WCA for the specified system lifetime, when a subcircuit fails EVA performing at least one additional WCA process that provides a tighter bound on the WCA than EVA to determine whether the subcircuit fails WCA for the specified system lifetime, determining that the system passes WCA with respect to the specific system lifetime when all subcircuits pass WCA, and determining that the system fails WCA when at least one subcircuit fails WCA.

  5. Multicentre evaluation of the Bayer DAX system.

    Science.gov (United States)

    Morosini, L; Rossetti, M; Berti, P; Pallotti, G; Fabbri, V; Mambelli, M C; Franceschin, A; Dell'Anna, L; Cappelletti, P; Brocco, G

    1993-12-01

    The analytical performance of the DAX, a high-throughput random access analyser, was studied according to ECCLS guidelines (ECCLS Document Vol. 3, No. 2, Beuth Verlag, Berlin, 1986) in a multicentre evaluation involving four laboratories. The trial took about 4 months. Determinations of 12 analytes produced more than 60,000 data. The imprecision study on 3 control sera for all analytes gave a within-run CV (median of 4 laboratories) which never exceeded 3% and was below 2% in 94% of the results. The median between-day CV was less than 3% in 92% of the results, with a highest value of 5.0%. No significant drift was detected during the 5-hour work period. No relevant sample- and cuvette-related carry-over was found. The manufacturer's claims concerning linearity were fulfilled or exceeded. The recovery of the assigned values for the control sera (median of 4 laboratories) ranged from 94 to 106%. In the method comparison on patients' samples, deviations were statistically significant in some cases, due to differences either in the methods used or in the calibration of the systems used for comparison; the regression lines, as inspected visually, and the coefficients of correlation were, however, generally acceptable. Imprecision and inaccuracy were within the acceptability limits as recommended by the Société Française de Biologie Clinique (SFBC) (Biochim. Clin. 12 (1988) 284-327) and the Deutsche Gesellschaft für Klinische Chemie (DGKC) (Dt. Arztebl. 85 (11) (1988) A697-A712). The limits of acceptance, proposed more recently by Fraser et al. (Eur. J. Clin. Chem. Clin. Biochem. 30 (1992) 311-317), were met in thirty-three of thirty-six cases. The alpha-amylase assay was significantly affected by bilirubin and haemolysis; interferences for the remaining analytes were predictable and well-known from the literature. The rate of sample throughput was found to be in agreement with that claimed by the manufacturer. The software did not present problems and was readily

  6. Evaluation of Galvanic Vestibular Stimulation System

    Science.gov (United States)

    Kofman, I. S.; Warren, E.; DeSoto, R.; Moroney, G.; Chastain, J.; De Dios, Y. E.; Gadd, N.; Taylor, L.; Peters, B. T.; Allen, E.; hide

    2017-01-01

    ) similar to what astronauts experience during transitions to new gravitational environments. Stochastic electrical stimulation can be applied to the vestibular system through electrodes placed over the mastoid process behind the ears in the binaural configuration resulting in stimulation in the mediolateral (side-to-side) plane. An additional electrode can be placed over the bony landmark of the tip of the c7 spinous process for the double monaural configuration, which will cause stimulation in the anteroposterior (forward-backward) plane. A portable constant current bipolar stimulator with subject isolation was designed and built to deliver the stimulus. The unit is powered using a 3.7 V battery pack and designed to produce currents up to 5 mA. The stimulator, controlled by a Raspberry Pi 3 computer, offers several stimulus signal generation options including a standalone mode, which uses onboard signal files stored on the flash memory card. Stochastic stimulation signals will be generated in 0-30 Hz frequency bandwidth. Stimulation amplitude can be increased incrementally to a maximum amplitude of 5.0 mA (e.g., 0, 0.5, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, 5.0 mA). In control trials, subjects will be experiencing vestibular stimulation with 0-mA current applied through the electrodes. The system will be evaluated at various levels of stimulation and in both the binaural and double monaural electrode configurations. One of the objectives is to identify stimulation levels producing effects most comparable to the post-flight disturbances. This is a pilot study that will set the stage for a larger, more comprehensive study that will investigate wider aspects of post-flight sensorimotor dysfunction and set sensorimotor standards for crew health.

  7. Strength of Geopolymer Cement Curing at Ambient Temperature by Non-Oven Curing Approaches: An Overview

    Science.gov (United States)

    Wattanachai, Pitiwat; Suwan, Teewara

    2017-06-01

    At the present day, a concept of environmentally friendly construction materials has been intensively studying to reduce the amount of releasing greenhouse gases. Geopolymer is one of the cementitious binders which can be produced by utilising pozzolanic wastes (e.g. fly ash or furnace slag) and also receiving much more attention as a low-CO2 emission material. However, to achieve excellent mechanical properties, heat curing process is needed to apply to geopolymer cement in a range of temperature around 40 to 90°C. To consume less oven-curing energy and be more convenience in practical work, the study on geopolymer curing at ambient temperature (around 20 to 25°C) is therefore widely investigated. In this paper, a core review of factors and approaches for non-oven curing geopolymer has been summarised. The performance, in term of strength, of each non-oven curing method, is also presented and analysed. The main aim of this review paper is to gather the latest study of ambient temperature curing geopolymer and to enlarge a feasibility of non-oven curing geopolymer development. Also, to extend the directions of research work, some approaches or techniques can be combined or applied to the specific properties for in-field applications and embankment stabilization by using soil-cement column.

  8. Curing characteristics of a composite - part 1: cure depth relationship to conversion, hardness and radiant exposure.

    Science.gov (United States)

    Erickson, Robert L; Barkmeier, Wayne W; Halvorson, Rolf H

    2014-06-01

    As the first part of a larger study on curing characteristics of a resin-based composite (RBC), the major objectives were to create an energy-hardness relationship (EHR) that relates Knoop hardness (KHN) with radiant exposure (H), and to do the same for degree of conversion (DC) in the form of an energy-conversion relationship (ECR). Both of these are meant to be universal relationships that satisfy reciprocity between irradiance and time for a given H value. RBC specimens were made by curing the material in 6mm diameter, stainless steel molds for 10-40s and allowing the material to cure for 24h. Cure depths were determined by a scrape-back method. KHN and DC values were determined along the central axis of the specimens, and these values were related to the internal H values using a measured transmission relationship, T(d), for the RBC. Suitable EHR and ECR relationships were developed for the RBC material that can be used to describe the curing characteristics under various curing conditions. However, predictive accuracy is affected for incident radiant exposures below about 12J/cm(2) to some extent. A relationship between KHN and DC was established. For the RBC examined, KHN measurements can be used as an alternate method or in conjunction with DC for describing the curing characteristics. Copyright © 2014 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  9. Standardized evaluation method for electromagnetic tracking systems

    Science.gov (United States)

    Hummel, Johann; Maurer, Calvin, Jr.; Figl, Michael; Bax, Michael; Bergmann, Helmar; Birkfellner, Wolfgang; Shahidi, Ramin

    2005-04-01

    The major aim of this work was to define a protocol for evaluation of electromagnetic tracking systems (EMTS). Using this protocol we compared two commercial EMTS: the Ascension microBIRD (B) and NDI Aurora (A). To enable reproducibility and comparability of the assessments a machined base plate was designed, in which a 50 mm grid of holes is precision drilled for position measurements. A circle of 32 equispaced holes in the center enables the assessment of rotation. A small mount which fits into pairs of grid holes on the base plate is used to mount the sensor in a defined and rigid way. Relative positional/orientational errors are found by subtracting the known distances/rotations between the machined locations from the differences of the mean observed positions/rotation. To measure the influence of metallic objects we inserted rods (made of SST 303, SST 416, aluminum, and bronze) into the sensitive volume between sensor and emitter. Additionally the dynamic behavior was tested by using an optical sensor mounted on a spacer in a distance of 150 mm to the EMTS sensors. We found a relative positional error of 0.96mm +/- 0.68mm, range -0.06mm;2.23mm (A) and 1.14mm +/- 0.78mm, range -3.72mm;1.57mm (B) for a give distance of 50 mm. The positional jitter amounted to 0.14 mm(A) / 0.20mm (B). The relative rotation error was found to be 1.81 degrees(A) / 0.63 degrees(B). For the dynamic behavior we calculated an error of 1.63mm(A)/1.93mm(B). The most relevant distortion caused by metallic objects results from SST 416. The maximum error 4.2mm(A)/41.9mm(B) occurs when the rod is close to the sensor(20mm).

  10. Alkali-activated fly ash: Effect of thermal curing conditions on mechanical and microstructural development - Part II

    Energy Technology Data Exchange (ETDEWEB)

    G. Kovalchuk; A. Fernandez-Jimenez; A. Palomo [V.D. Glukhovskiy Scientific Research Institute on Binders and Materials, Kiev (Ukraine)

    2007-02-15

    The development of mechanical strength and the mineral and microstructural characteristics of the alkali activated fly ash (AAFA), reveal the importance of the role played by the curing conditions prevailing during setting and hardening process: curing in a covered mould (CCM) at 95{sup o}C; dry curing (DC) at 150{sup o}C, or steam curing (ST) at 95{sup o}C. CCM yields the highest compressive strength (up to 102 MPa after 8 h of curing) and can be readily used in any AAFA system. DC is only recommended for NaOH-based systems (low SiO{sub 2}/Al{sub 2}O{sub 3} ratio), since waterglass-based mixes tend to retard reaction kinetics. SC, in turn, has an intermediate effect on strength development, between CCM and DC. 26 refs., 6 figs., 4 tabs.

  11. Water Pollution, Causes and Cures.

    Science.gov (United States)

    Manufacturing Chemists Association, Washington, DC.

    This commentary on sources of water pollution and water pollution treatment systems is accompanied by graphic illustrations. Sources of pollution such as lake bottom vegetation, synthetic organic pollutants, heat pollution, radioactive substance pollution, and human and industrial waste products are discussed. Several types of water purification…

  12. Improving system quality through software evaluation.

    Science.gov (United States)

    McDaniel, James G

    2002-05-01

    The role of evaluation is examined with respect to quality of software in healthcare. Of particular note is the failure of the Therac-25 radiation therapy machine. This example provides evidence of several types of defect which could have been detected and corrected using appropriate evaluation procedures. The field of software engineering has developed metrics and guidelines to assist in software evaluation but this example indicates that software evaluation must be extended beyond the formally defined interfaces of the software to its real-life operating context.

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

    OpenAIRE

    V.Sreevidya; Anuradha, R.; D. Dinakar; Dr. R.Venkatasubramani

    2012-01-01

    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...

  14. Making Sense of Alternative Assessment in a Qualitative Evaluation System

    Science.gov (United States)

    Rojas Serrano, Javier

    2017-01-01

    In a Colombian private English institution, a qualitative evaluation system has been incorporated. This type of evaluation poses challenges to students who have never been evaluated through a system that eliminates exams or quizzes and, as a consequence, these students have to start making sense of it. This study explores the way students face the…

  15. Evaluation Criteria for the Educational Web-Information System

    Science.gov (United States)

    Seok, Soonhwa; Meyen, Edward; Poggio, John C.; Semon, Sarah; Tillberg-Webb, Heather

    2008-01-01

    This article addresses how evaluation criteria improve educational Web-information system design, and the tangible and intangible benefits of using evaluation criteria, when implemented in an educational Web-information system design. The evaluation criteria were developed by the authors through a content validation study applicable to…

  16. Usability Evaluation of a Web-Based Learning System

    Science.gov (United States)

    Nguyen, Thao

    2012-01-01

    The paper proposes a contingent, learner-centred usability evaluation method and a prototype tool of such systems. This is a new usability evaluation method for web-based learning systems using a set of empirically-supported usability factors and can be done effectively with limited resources. During the evaluation process, the method allows for…

  17. An Analysis of Critical Issues in Korean Teacher Evaluation Systems

    Science.gov (United States)

    Choi, Hee Jun; Park, Ji-Hye

    2016-01-01

    Korea has used three different teacher evaluation systems since the 1960s: teacher performance rating, teacher performance-based pay and teacher evaluation for professional development. A number of studies have focused on an analysis of each evaluation system in terms of its advent, development, advantages and disadvantages, but these studies have…

  18. Translating genomic discoveries to cure ultrahypermutant mismatch ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Translating genomic discoveries to cure ultrahypermutant mismatch repair deficient brain tumours. Les tumeurs malignes au cerveau sont la cause la plus courante de décès chez les enfants atteints du cancer, mais il n'y a pas de traitement connu. Ce projet permettra de faire avancer la recherche dans ce domaine ...

  19. Helping African American Males: The Cure.

    Science.gov (United States)

    Gill, Walter

    1992-01-01

    Looks at the current plight of the African-American male, exploring the role of the dominant culture, mass media, and low self-esteem. Describes a possible cure, citing five areas for action, calling for year-round school in some urban areas, exploring Afrocentric curricula, and considering rites of passage programs. (JB)

  20. Enhanced microactuation with magnetic field curing of ...

    Indian Academy of Sciences (India)

    The incorporation of nanoparticles of iron in a natural rubber matrix leads to flexible magnetorheolog- ical (MR) materials. Rod-shaped MR elastomers based on natural rubber and nanosized iron have been moulded both with and without the application of an external magnetic field during curing. These MR elastomer rods ...

  1. Enhanced microactuation with magnetic field curing of ...

    Indian Academy of Sciences (India)

    The incorporation of nanoparticles of iron in a natural rubber matrix leads to flexible magnetorheological (MR) materials. Rod-shaped MR elastomers based on natural rubber and nanosized iron have been moulded both with and without the application of an external magnetic field during curing. These MR elastomer rods ...

  2. Adhesive curing options for photonic packaging

    Science.gov (United States)

    Martin, Steven C.; Hubert, Manfred; Tam, Robin

    2002-06-01

    Varying the intensity of illumination used to cure photoactivated adhesives has been applied in medical and dental applications to improve the performance of polymer materials. For example, it has been observed that dental polymer composite materials express reduced shrinkage, important for durability of non-amalgam restorations, by introducing a phased time-intensity cure schedule. This work identified that curing conditions could influence the final properties of materials, and suggested the possibility of extending the characteristics that could be influenced beyond shrinkage to humidity resistance, Tg, outgassing and other important material properties. Obviously, these results have important ramifications for the photonic industry, with current efforts focused on improved manufacturing techniques. Improvement in low cost packaging solutions, including adhesives, will have to be made to bring the component cost down to address the needs of Metro and similar markets. However, there are perceived problems with the widespread use of adhesives, the most prevalent of these involving long term durability of the bond. Devices are typically aligned to sub-micron precision using active feedback and then must be locked in position to maintain performance. In contrast to traditional fastening methods, adhesive bonding is a highly attractive option due to the ease of deployment, lower equipment costs, and improved flexibility. Moreover, using methods analogous to those employed in dental applications, materials properties of photonic adhesives may be tailored using a programmed cure approach.

  3. Mechanical characterization and modeling of curing thermosets

    NARCIS (Netherlands)

    Van 't Hof, C.

    2006-01-01

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

  4. Color Developing Capacity of Plasma-treated Water as a Source of Nitrite for Meat Curing.

    Science.gov (United States)

    Jung, Samooel; Kim, Hyun Joo; Park, Sanghoo; Yong, Hae In; Choe, Jun Ho; Jeon, Hee-Joon; Choe, Wonho; Jo, Cheorun

    2015-01-01

    The interaction of plasma with liquid generates nitrogen species including nitrite (NO(-) 2). Therefore, the color developing capacity of plasma-treated water (PTW) as a nitrite source for meat curing was investigated in this study. PTW, which is generated by surface dielectric barrier discharge in air, and the increase of plasma treatment time resulted in increase of nitrite concentration in PTW. The PTW used in this study contains 46 ppm nitrite after plasma treatment for 30 min. To evaluate the effect of PTW on the cured meat color, meat batters were prepared under three different conditions (control, non-cured meat batter; PTW, meat batter cured with PTW; Sodium nitrite, meat batter cured with sodium nitrite). The meat batters were vacuum-packaged and cooked in a water-bath at 80℃ for 30 min. The typical color of cured meat developed in cooked meat batter treated with sodium nitrite or PTW. The lightness (L*) and yellowness (b*) values were similar in all conditions, whereas, the redness (a*) values of cooked meat batter with PTW and sodium nitrite (pcuring process of meat without addition of other nitrite sources.

  5. Temperature increase during orthodontic bonding with different curing units using an infrared camera.

    Science.gov (United States)

    Aksakalli, Sertac; Demir, Abdullah; Selek, Murat; Tasdemir, Sakir

    2014-01-01

    To evaluate the effects of different curing units and light-tip tooth surface distances on the temperature increase generated during orthodontic bonding, using an infrared camera (IR) and artificial neural networks (ANN). Fifty-two freshly extracted human premolar teeth were used. Metallic orthodontic brackets were bonded to the buccal surfaces of the teeth and thermal records were taken using an IR camera and ANN. Brackets were cured with a light-emitting diode (LED) and high intensity halogen (HQTH). Teeth were divided into four groups according to the curing units (LED and HQTH) and curing distances (from tooth surface and 10 mm away from tooth surface). The results were analyzed with analysis of variance (ANOVA) and the Tukey HSD test. The ANOVA and Tukey HSD tests revealed that temperature changes were influenced by the type of light source and exposure times. All groups revealed significant differences between each other (p < 0.001). The highest surface temperature increase was gained from curing with a LED unit from the tooth surface (11.35°C ± 0.91°C). The lowest surface temperature increase was gained from curing with a HQTH unit 10 mm away from the tooth surface (2.57°C ± 0.6°C). The LED unit induced significantly higher temperature changes than did the HQTH. The temperature increase during orthodontic bonding was increased with long exposure time. A shorter light-tip tooth surface distance leads to greater increases in temperature.

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

    Science.gov (United States)

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

    2016-05-01

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

  7. Applying Knowledge Management in Teacher Evaluation Systems

    Science.gov (United States)

    Essandoh, Albert

    2013-01-01

    Teacher evaluations are underused in public schools, resulting in the loss of knowledge critical to professional development. Knowledge management (KM) theory offers approaches that can lead to improvements in the effectiveness of evaluations and teacher performance. This multiple case study of 9 campuses in an exemplary school district…

  8. Sample evaluation of ontology-matching systems

    NARCIS (Netherlands)

    Hage, W.R. van; Isaac, A.; Aleksovski, Z.

    2007-01-01

    Ontology matching exists to solve practical problems. Hence, methodologies to find and evaluate solutions for ontology matching should be centered on practical problems. In this paper we propose two statistically-founded evaluation techniques to assess ontology-matching performance that are based on

  9. Razor UAS Test and Evaluation System Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Adsys Controls' Razor UAS Test System is a high fidelity simulation and Hardware-in-the-Loop (HIL) test system. Razor provides extensive existing capability for high...

  10. TASLIMAGE System #2 Technical Equivalence Evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Topper, J. D. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Stone, D. K. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2017-09-06

    In early 2017, a second TASLIMAGE system (TASL 2) was procured from Track Analysis Systems, Ltd. The new device is intended to complement the first system (TASL 1) and to provide redundancy to the original system which was acquired in 2009. The new system functions primarily the same as the earlier system, though with different X-Y stage hardware and a USB link from the camera to the host computer, both of which contribute to a reduction in CR-39 foil imaging time. The camera and image analysis software are identical between the two systems. Neutron dose calculations are performed externally and independent of the imaging system used to collect track data, relying only on the measured recoil proton track density per cm2 for a set of known-dose CR-39 foils processed in each etch.

  11. Depth of cure of resin composites: is the ISO 4049 method suitable for bulk fill materials?

    Science.gov (United States)

    Flury, Simon; Hayoz, Stefanie; Peutzfeldt, Anne; Hüsler, Jürg; Lussi, Adrian

    2012-05-01

    To evaluate if depth of cure D(ISO) determined by the ISO 4049 method is accurately reflected with bulk fill materials when compared to depth of cure D(new) determined by Vickers microhardness profiles. D(ISO) was determined according to "ISO 4049; Depth of cure" and resin composite specimens (n=6 per group) were prepared of two control materials (Filtek Supreme Plus, Filtek Silorane) and four bulk fill materials (Surefil SDR, Venus Bulk Fill, Quixfil, Tetric EvoCeram Bulk Fill) and light-cured for either 10s or 20s. For D(new), a mold was filled with one of the six resin composites and light-cured for either 10 s or 20 s (n=22 per group). The mold was placed under a microhardness indentation device and hardness measurements (Vickers hardness, VHN) were made at defined distances, beginning at the resin composite that had been closest to the light-curing unit (i.e. at the "top") and proceeding toward the uncured resin composite (i.e. toward the "bottom"). On the basis of the VHN measurements, Vickers hardness profiles were generated for each group. D(ISO) varied between 1.76 and 6.49 mm with the bulk fill materials showing the highest D(ISO). D(new) varied between 0.2 and 4.0 mm. D(new) was smaller than D(ISO) for all resin composites except Filtek Silorane. For bulk fill materials the ISO 4049 method overestimated depth of cure compared to depth of cure determined by Vickers hardness profiles. Copyright © 2012 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  12. Morphological study of fiber-reinforced post-bonding system-root dentin interface by evaluation of two bonding systems.

    Science.gov (United States)

    Esclassan Noirrit, Emmanuelle; Grégoire, Geneviève; Cournot, Maxime

    2008-03-01

    Morphological study of fiber post/bonding system/root dentin interface by evaluation of two bonding systems. The aim of the study was to analyze the interfaces, and thus the seal, between root dentin and bonded fiber-reinforced posts. The interfaces were obtained by applying two enamel-dentin adhesive systems, a one-bottle system used after application of phosphoric acid and a self-etch system, both used with an adhesive cement. The interface was evaluated by SEM observation of the continuity of the hybrid layer and the morphology of the resin tags, in terms of length, density and presence of side branches, at the interface between the fiber-reinforced post, the bonding system and the root dentin. Twenty-six anterior single-rooted teeth extracted for periodontal reasons were treated endodontically and then randomly separated into two groups of 13 teeth each: group 1: Excite DSC (Ivoclar Vivadent, Liechtenstein); group 2: AdheSE DC (Ivoclar Vivadent, Schaan, Liechtenstein). After preparation of the root canal and application of the adhesive, each specimen received a Postec translucent FRC post (Ivoclar Vivadent, Schaan, Liechtenstein) that was cemented in with Variolink II dual-curing luting composite (Ivoclar Vivadent, Schaan, Liechtenstein). The specimens were then prepared for SEM observation of the continuity of the hybrid layer and scoring of the morphology of the resin tags in each third of the root (at 1, 4.5 and 8mm from the coronal surface). There was no significant difference (at p<0.05) between the two groups in terms of continuity of the hybrid layer or morphology of the resin tags. The hybrid layer was present, unbroken and uniform in both the group where adhesive was used with a phosphoric acid total etch and the self-etch system group. Whatever the bonding system, the resin tags had side branches, and greater length and density in the cervical third than in the middle or apical thirds. Bubbles were found in the cement layer in most of the specimens

  13. Evaluating Performances of Solar-Energy Systems

    Science.gov (United States)

    Jaffe, L. D.

    1987-01-01

    CONC11 computer program calculates performances of dish-type solar thermal collectors and power systems. Solar thermal power system consists of one or more collectors, power-conversion subsystems, and powerprocessing subsystems. CONC11 intended to aid system designer in comparing performance of various design alternatives. Written in Athena FORTRAN and Assembler.

  14. Influence of end groups in hyperbranched polyesters used as modifiers in the characteristics of epoxy thermosets cured by adipic dihydrazide

    Directory of Open Access Journals (Sweden)

    A. Serra

    2013-07-01

    Full Text Available Mixtures of diglycidylether of bisphenol A (DGEBA resin and different ratios of aliphatic-aromatic hyperbranched polyester (HBP were cured by a latent curing agent, adipic dihydrazide (AH. The HBPs prepared have hydroxyl groups or 10-undecenoyl or allyl groups as chain ends. The curing mixtures were investigated by differential scanning calorimetry (DSC to study the curing process and to evaluate the kinetic parameters of the different formulations. These studies suggest that HBPs decrease the curing rate of epoxy/AH in the case of vinyl terminated HPB, whereas OH terminated HBP accelerates the first stages and delays the lasts. The thermosets obtained showed an improvement in microhardness and impact strength without any reduction of the Tg and thermal parameters. Microparticle phase separation was observed with the undecenoyl HBP derivatives or when a 10% of allyl HBP derivative was in the formulation.

  15. Talking Cure Models: A Framework of Analysis

    Directory of Open Access Journals (Sweden)

    Christopher Marx

    2017-09-01

    Full Text Available Psychotherapy is commonly described as a “talking cure,” a treatment method that operates through linguistic action and interaction. The operative specifics of therapeutic language use, however, are insufficiently understood, mainly due to a multitude of disparate approaches that advance different notions of what “talking” means and what “cure” implies in the respective context. Accordingly, a clarification of the basic theoretical structure of “talking cure models,” i.e., models that describe therapeutic processes with a focus on language use, is a desideratum of language-oriented psychotherapy research. Against this background the present paper suggests a theoretical framework of analysis which distinguishes four basic components of “talking cure models”: (1 a foundational theory (which suggests how linguistic activity can affect and transform human experience, (2 an experiential problem state (which defines the problem or pathology of the patient, (3 a curative linguistic activity (which defines linguistic activities that are supposed to effectuate a curative transformation of the experiential problem state, and (4 a change mechanism (which defines the processes and effects involved in such transformations. The purpose of the framework is to establish a terminological foundation that allows for systematically reconstructing basic properties and operative mechanisms of “talking cure models.” To demonstrate the applicability and utility of the framework, five distinct “talking cure models” which spell out the details of curative “talking” processes in terms of (1 catharsis, (2 symbolization, (3 narrative, (4 metaphor, and (5 neurocognitive inhibition are introduced and discussed in terms of the framework components. In summary, we hope that our framework will prove useful for the objective of clarifying the theoretical underpinnings of language-oriented psychotherapy research and help to establish a more

  16. Talking Cure Models: A Framework of Analysis

    Science.gov (United States)

    Marx, Christopher; Benecke, Cord; Gumz, Antje

    2017-01-01

    Psychotherapy is commonly described as a “talking cure,” a treatment method that operates through linguistic action and interaction. The operative specifics of therapeutic language use, however, are insufficiently understood, mainly due to a multitude of disparate approaches that advance different notions of what “talking” means and what “cure” implies in the respective context. Accordingly, a clarification of the basic theoretical structure of “talking cure models,” i.e., models that describe therapeutic processes with a focus on language use, is a desideratum of language-oriented psychotherapy research. Against this background the present paper suggests a theoretical framework of analysis which distinguishes four basic components of “talking cure models”: (1) a foundational theory (which suggests how linguistic activity can affect and transform human experience), (2) an experiential problem state (which defines the problem or pathology of the patient), (3) a curative linguistic activity (which defines linguistic activities that are supposed to effectuate a curative transformation of the experiential problem state), and (4) a change mechanism (which defines the processes and effects involved in such transformations). The purpose of the framework is to establish a terminological foundation that allows for systematically reconstructing basic properties and operative mechanisms of “talking cure models.” To demonstrate the applicability and utility of the framework, five distinct “talking cure models” which spell out the details of curative “talking” processes in terms of (1) catharsis, (2) symbolization, (3) narrative, (4) metaphor, and (5) neurocognitive inhibition are introduced and discussed in terms of the framework components. In summary, we hope that our framework will prove useful for the objective of clarifying the theoretical underpinnings of language-oriented psychotherapy research and help to establish a more comprehensive

  17. Curing efficiency of high-intensity light-emitting diode (LED) devices.

    Science.gov (United States)

    Rahiotis, Christos; Patsouri, Katerina; Silikas, Nick; Kakaboura, Afrodite

    2010-06-01

    We evaluated the curing efficiency of 4 high-intensity light-emitting diode (LED) devices by assessing percentage of residual C=C (%RDB), surface microhardness (SM), depth of cure (DC), percentage of linear shrinkage-strain (%LS), and percentage of wall-to-wall contraction (%WWC). The light-curing units tested were a QTH light, the Elipar TriLight (3M/ESPE), and 4 LED devices - the Allegro (Denmat), the Bluephase (Ivoclar/Vivadent), the FreeLight2 (3M/ESPE), and The Cure TC-01 (Spring Health Products). The %RDB was measured by microFTIR spectroscopy. Microhardness measurements (Vickers) were performed at the surface (H0) and at depths of 3 mm (H3) and 5 mm (H5) of cylindrical specimens. Depth of cure was expressed as the ratio of microhardness at each depth, relative to the corresponding surface value (H3/H0 and H5/H0). The bonded disc method was used to evaluate %LS. For the %WWC evaluation, cylindrical resin restorations were imaged by high resolution micro-CT and the %WWC was calculated at depths of 0 mm and 2 mm. There were no statistical differences among the LEDs in %RDB or %LS. The Bluephase and Allegro had the highest SM values. As compared with the other LEDs, the Bluephase and The Cure TC-01 had lower values for depth of cure at depths of 3 mm and 5 mm. There were no significant differences in %WWC among the LEDs at either depth, and the QTH had the lowest %WWC at both depths.

  18. Automated Information Systems for Evaluation of Social Service in ...

    African Journals Online (AJOL)

    This research developed information systems for evaluation of social services in Nigeria. The system is to be used by social workers in the long term care of children in the motherless babies' homes. The research has developed a system that evaluates the activities and operation of the motherless babies homes thereby ...

  19. Fire safety evaluation system for NASA office/laboratory buildings

    Science.gov (United States)

    Nelson, H. E.

    1986-11-01

    A fire safety evaluation system for office/laboratory buildings is developed. The system is a life safety grading system. The system scores building construction, hazardous areas, vertical openings, sprinklers, detectors, alarms, interior finish, smoke control, exit systems, compartmentation, and emergency preparedness.

  20. Categorization of Chinese Dry-Cured Ham Based on Three Sticks’ Method by Multiple Sensory Technologies

    Directory of Open Access Journals (Sweden)

    Dong Xia

    2017-01-01

    Full Text Available Odor profiles of three grades of Jinhua, Xuanwei, and Rugao dry-cured hams were analyzed and distinguished by both the electronic nose and the sensory evaluation. The odor was absorbed by bamboo sticks, which is the most traditional absorption method to classify different ham grades. Then data from electronic nose was analyzed by discriminant function analysis (DFA and cluster analysis (CA, compared with that from sensory evaluation by principal component analysis (PCA. Results showed that different grades of Jinhua, Xuanwei, and Rugao dry-cured hams could be distinguished effectively by the DFA results of electronic nose. However, sensory evaluation could not perform as well as electronic nose. It was demonstrated that intelligent sensory technology has higher sensitivity and reliability in classifying producing regions and grades of dry-cured ham.

  1. Effect of preheating resin composite and light-curing units on the microleakage of Class II restorations submitted to thermocycling

    National Research Council Canada - National Science Library

    dos Santos, R E Agostinho; Lima, A F; Soares, G P; Ambrosano, G M B; Marchi, G M; Lovadino, J R; Aguiar, F H B

    2011-01-01

    This in vitro study evaluated microleakage in Class II cavities restored with dental composite and varying light-curing units and the temperature of the composite when subjected to a thermocycling test...

  2. Evaluating operating system vulnerability to memory errors.

    Energy Technology Data Exchange (ETDEWEB)

    Ferreira, Kurt Brian; Bridges, Patrick G. (University of New Mexico); Pedretti, Kevin Thomas Tauke; Mueller, Frank (North Carolina State University); Fiala, David (North Carolina State University); Brightwell, Ronald Brian

    2012-05-01

    Reliability is of great concern to the scalability of extreme-scale systems. Of particular concern are soft errors in main memory, which are a leading cause of failures on current systems and are predicted to be the leading cause on future systems. While great effort has gone into designing algorithms and applications that can continue to make progress in the presence of these errors without restarting, the most critical software running on a node, the operating system (OS), is currently left relatively unprotected. OS resiliency is of particular importance because, though this software typically represents a small footprint of a compute node's physical memory, recent studies show more memory errors in this region of memory than the remainder of the system. In this paper, we investigate the soft error vulnerability of two operating systems used in current and future high-performance computing systems: Kitten, the lightweight kernel developed at Sandia National Laboratories, and CLE, a high-performance Linux-based operating system developed by Cray. For each of these platforms, we outline major structures and subsystems that are vulnerable to soft errors and describe methods that could be used to reconstruct damaged state. Our results show the Kitten lightweight operating system may be an easier target to harden against memory errors due to its smaller memory footprint, largely deterministic state, and simpler system structure.

  3. The influence of montmorillonite content on the kinetics of curing of epoxy nanocomposites

    Directory of Open Access Journals (Sweden)

    Jovičić Mirjana C.

    2012-01-01

    Full Text Available In this work, the attention was paid at the investigation of montmorillonite dispersion in epoxy/amine systems due to improved final properties of the nanocomposites. The influence of different montmorillonite content on the kinetics of curing of epoxy/Jeffamine D-230 systems was followed by differential scanning calorimetry (DSC. The curing of epoxy nanocomposites was performed using dynamic regime at three different heating rates: 5, 10 and 20°C/min. Three isoconversional methods were applied: two integral (Ozawa-Flynn-Wall and Kissinger-Akahira-Sunose methods and one differential (Friedman method. The presence of montmorillonite (MMT causes the beginning of curing at lower temperatures. The shape of the DSC curves has been changed by the addition of MMT, supporting the hypothesis of a change in the reaction mechanism. For hybrids with 3 and 5 wt.% of MMT, the Eα dependence is very similar to those found for the reference system (epoxy/Jeffamine D-230 for the curing degree less than 60%. The hybrid with 10 wt.% of MMT has lower energy activation in regard to the referent system without montmorillonite. Greater differences are observed in the second part of the reaction, where it is known that the curing process is more controlled by diffusion (α>0.60. The Ea value increases at the end of the reaction (α→1, which was observed for all systems, and is more pronounced in the presence of montmorillonite. [Projekat Ministarstva nauke Republike Srbije, br. III45022

  4. Performance evaluations and control system design

    NARCIS (Netherlands)

    S. Kramer (Stephan)

    2017-01-01

    markdownabstractThe accuracy of information available to managers about an employee's performance, combined with the transparency of performance evaluations based on that information, can help to motivate managers to reward good performance and highlight poor performance.

  5. Thermal Protection Systems Nondestructive Evaluation Tool Project

    Data.gov (United States)

    National Aeronautics and Space Administration — To address NASA's need for evaluation of bondline and in-depth integrity for lightweight rigid and/or flexible ablative materials, Physical Optics Corporation (POC)...

  6. Pervious Pavement System Evaluation- Abstract 1

    Science.gov (United States)

    Porous pavement is a low impact development stormwater control. The Urban Watershed Management Branch is evaluating interlocking concrete pavers as a popular implementation. The pavers themselves are impermeable, but the spaces between the pavers are backfilled with washed, gra...

  7. When to start paediatric testing of the adult HIV cure research agenda?

    Science.gov (United States)

    Shah, Seema K

    2017-02-01

    Ethical guidelines recommend that experimental interventions should be tested in adults first before they are tested and approved in children. Some challenge this paradigm, however, and recommend initiating paediatric testing after preliminary safety testing in adults in certain cases. For instance, commentators have argued for accelerated testing of HIV vaccines in children. Additionally, HIV cure research on the use of very early therapy (VET) in infants, prompted in part by the Mississippi baby case, is one example of a strategy that is currently being tested in infants before it has been well tested in adults. Because infants' immune systems are still developing, the timing of HIV transmission is easier to identify in infants than in adults, and infants who receive VET might never develop the viral reservoirs that make HIV so difficult to eradicate, infants may be uniquely situated to achieve HIV cure or sustained viral remission. Several commentators have now argued for earlier initiation of HIV cure interventions other than (or in addition to) VET in children. HIV cure research is therefore a good case for re-examining the important question of when to initiate paediatric research. I will argue that, despite the potential for HIV cure research to benefit children and the scientific value of involving children in this research, the HIV cure agenda should not accelerate the involvement of children for the following reasons: HIV cure research is highly speculative, risky, aimed at combination approaches and does not compare favourably with the available alternatives. I conclude by drawing general implications for the initiation of paediatric testing, including that interventions that have to be used in combination with others and cures for chronic diseases may not be valuable enough to justify early paediatric testing. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  8. Experimental Evaluation of Mountain Bike Suspension Systems

    Directory of Open Access Journals (Sweden)

    J. Titlestad

    2003-01-01

    Full Text Available A significant distinction between competitive mountain bikes is whether they have a suspension system. Research studies indicate that a suspension system gives advantages, but it is difficult to quantify the benefits because they depend on so many variables, including the physiology and psychology of the cyclist, the roughness of the track and the design of the suspension system. A laboratory based test rig has been built that allows the number of variables in the system to be reduced and test conditions to be controlled. The test rig simulates regular impacts of the rear wheel with bumps in a rolling road. The physiological variables of oxygen consumption and heart rate were measured, together with speeds and forces at various points in the system. Physiological and mechanical test results both confirm a significant benefit in using a suspension system on the simulated rough track, with oxygen consumption reduced by around 30 % and power transmitted through the pedals reduced by 30 % to 60 %.

  9. The effect of autoclaving and polishing techniques on energy transmission of light-curing tips.

    Science.gov (United States)

    Kofford, K R; Wakefield, C W; Nunn, M E

    1998-08-01

    The purpose of this study was to investigate if autoclaving light-curing tips in sterilization packages using a properly maintained autoclave filled with distilled water reduced the buildup of boiler scale and allowed the tips to maintain their ability to transmit energy. Thirty light-curing tips were divided into groups: control, never autoclaved; group 1, no light-curing tip treatment, autoclaved only; group 2, autoclaved and treated with the Demetron/Kerr Optics Maintenance Kit; group 3, autoclaved and treated with the EFOS Fiberoptic Cleaning Kit; group 4, autoclaved and treated with Shofu Brownie and Greenie polishing points; and group 5, autoclaved and treated with a standard rubber prophylaxis cup. The curing tips were packaged and subjected to 30 autoclave cycles in a clinical autoclave with standard loads of clinical instruments. The light transmission was measured with a curing radiometer. Results showed a 7% decrease in energy transmission for the untreated tips compared to the control. Both polishing system groups demonstrated a 4% decrease. There was no significant difference between the control and the first three groups. The polishing point and prophylaxis cup groups showed significantly decreased energy transmission (decreases of 11% and 25%, respectively). Light-curing tips can be autoclaved with routine packaged loads of clinical instruments and retain their ability to transmit light energy, provided that the tips are packaged and the autoclave is properly maintained and filled with distilled water. Commercially available optics maintenance kits are effective in removing deposits and restoring light energy transmission.

  10. About the cure kinetics in natural rubber/styrene Butadiene rubber blends at 433 K

    Energy Technology Data Exchange (ETDEWEB)

    Mansilla, M.A., E-mail: mmansilla@df.uba.ar [Laboratorio de Polimeros y Materiales Compuestos, Departamento de Fisica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Pabellon 1, C1428EGA Buenos Aires (Argentina); Marzocca, A.J. [Laboratorio de Polimeros y Materiales Compuestos, Departamento de Fisica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Pabellon 1, C1428EGA Buenos Aires (Argentina)

    2012-08-15

    Vulcanized blends of elastomers are employed in several goods mainly to improve physical properties and reduce costs. One of the most used blends of this kind is that composed by natural rubber (NR) and styrene butadiene rubber (SBR). The cure kinetic of these blends depends mainly on the compound formulation and the cure temperature and time. The preparation method of the blends can influence the mechanical properties of the vulcanized compounds. In this work the cure kinetic at 433 K of NR/SBR blends vulcanized with the system sulfur/TBBS (N-t-butyl-2-benzothiazole sulfenamide) is analyzed in samples prepared by mechanical mixing and solution blending. The two methods produce elastomer domains of NR and SBR, which present different microstructure due to the cure level attained during vulcanization. The cure kinetics is studied by means of rheometer tests and the model proposed by Kamal and Sourour. The analysis of the cure rate is presented and is related to the structure obtained during the vulcanization process.

  11. Biometric systems technology, design and performance evaluation

    CERN Document Server

    Wayman, James; Maltoni, Davide

    2005-01-01

    A reference book for anyone involved in the design, management or implementation of biometric systems, and provides all the information needed to a build reliable system. It focuses on the four most widely used types of biometric technology - speech, fingerprint, iris and face recognition.

  12. Reverse electrodialysis : evaluation of suitable electrode systems

    NARCIS (Netherlands)

    Veerman, J.; Saakes, M.; Metz, S. J.; Harmsen, G. J.

    Reverse electrodialysis (RED) is a method for directly extracting electrical energy from salinity gradients, especially from sea and river water. For the commercial implementation of RED, the electrode system is a key component. In this paper, novel electrode systems for RED were compared with

  13. Evaluation of an Automated Keywording System.

    Science.gov (United States)

    Malone, Linda C.; And Others

    1990-01-01

    Discussion of automated indexing techniques focuses on ways to statistically document improvements in the development of an automated keywording system over time. The system developed by the Joint Chiefs of Staff to automate the storage, categorization, and retrieval of information from military exercises is explained, and performance measures are…

  14. Advanced public transportation systems : evaluation guidelines

    Science.gov (United States)

    1994-01-01

    The Federal Transit Administration has developed the Advanced Public Transportation Systems (APTS) Program which is an integral part of the overall U.S. DOT Intelligent Vehicle Highway Systems (IVHS) effort. A major aim of the APTS Program is to prom...

  15. Could Switching to a Vegetarian Diet Cure My Diabetes?

    Science.gov (United States)

    ... my diabetes? Could switching to a vegetarian diet cure my diabetes? Answers from M. Regina Castro, M.D. A vegetarian diet probably won't cure your diabetes. But it may offer some benefits over a ...

  16. Economic evaluation for adoption of cogeneration system

    Energy Technology Data Exchange (ETDEWEB)

    Oh, Si-Doek [Hyosung Corporation, Bangbae-Dong, Seocho-Ku, Seoul 137-850 (Korea, Republic of); Oh, Hoo-Suk; Kwak, Ho-Young [Mechanical Engineering Department, Chung-Ang University, Seoul 156-756 (Korea, Republic of)

    2007-03-15

    An optimal planning for gas turbine cogeneration system was applied to find whether or not the adoption of the system to an office building or hotel in Seoul, Korea is profitable. The planning problem considered in this study is to determine the optimal configuration of the system equipment and optimal operational policy of the system when the annual energy demands of electric power, heat and cooling are given a priori. The optimal configuration of the system equipment has been determined based on annual cost method with proper choice of representative energy demand patterns obtained for the building and hotel in a 1-year period. A mixed-integer linear programming and the branch and bound algorithm have been used to obtain the optimal solution. The planning method employed here may be applied to making decision on the adoption of the cogeneration plant to any specific office building or hotel. (author)

  17. 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.

  18. Improved mechanical properties and ozone resistance of radiation-cured SBR. Final report, Dec 88-Jun 91. [Styrene Butadiene Rubber

    Energy Technology Data Exchange (ETDEWEB)

    Basfar, A.A.; Silverman, J.

    1991-08-01

    This report is a continuation and extension of the work of the earlier Army contract, where the superiority of the electron beam cured styrene butadiene rubber (SBR) tank pads to the sulfur cured pads was demonstrated. The focus of the present study is the investigation of the extraordinary ozone resistance of our radiation cured SBR, and also on possible alternatives for SBR, butadiene rubber (BR) in particular, as a tank pad compound. Base formulations of a fully sulfur cured system were established with 5% reproducibility, and results were confirmed by mechanical properties measurements on identical formulations from Belvoir Research Development and Engineering Center (BRDEC). Constant mechanical properties as a function of exposure to ozone indicate either competitive cross-linking and scissioning reactions or a 'protective' effect caused by higher terminal vinyl concentrations in the radiation cured formulations.

  19. Comparison of shear bond strength of orthodontic brackets bonded with halogen and plasma arc light curing.

    Science.gov (United States)

    Toodehzaeim, Mohammad Hossein; Kazemi, Alireza Danesh; Aghili, Hossein Agha; Barzegar, Kazem; Fallahtafti, Taranom

    2012-05-01

    Reduced time and appropriate bond strength of brackets is one of the most important aspects of orthodontic treatments. Prolonged halogen light curing for bonding of brackets is undesirable, so the purpose of this study was to compare the shear bond strength of brackets bonded with halogen light and plasma arc system. MATERIALS AND MEHODS: This was an experimental in vitro study. A total of 60 intact premolar teeth were collected and divided into four groups. Stainless steel orthodontic brackets were bonded to them. In groups 1 and 2, curing was done using halogen light given for 20 seconds from two and four angles. In groups 3 and 4, curing was carried out using the plasma arc system for 6 seconds from two and four angles. The shear bond strength was recorded by Instron. The statistics of ANOVA, Tukey's test, and T-test were used in data analysis. There was a statistically significant difference in shear bond strength among the four groups (P = 0.043) and between group 1 with group 2 (P = 0.035). Yet, there was no statistically significant difference between brackets bonded with plasma arc and those bonded with halogen light or between the two groups of plasma arc. Using the plasma arc system is superior to other methods due to reduced curing time. Also, since in using the halogen light system, an increase in curing periods from different angles resulted in a significant increase in shear bond strength; it is advisable to apply the halogen light from different angles.

  20. Evaluating the Software Design of a Complex System of Systems

    Science.gov (United States)

    2010-01-01

    shows the main claim, C1, is supported by three sub-claims C2, C3 , and C4. For purposes of illustration, each sub-claim is shown to be directly...Operational Capability IOT &E Initial Operational Test and Evaluation IOTE Initial Operational Test and Evaluation IPDR Initial Preliminary Design

  1. Process Modelling of Curing Process-Induced Internal Stress and Deformation of Composite Laminate Structure with Elastic and Viscoelastic Models

    Science.gov (United States)

    Li, Dongna; Li, Xudong; Dai, Jianfeng

    2017-08-01

    In this paper, two kinds of transient models, the viscoelastic model and the linear elastic model, are established to analyze the curing deformation of the thermosetting resin composites, and are calculated by COMSOL Multiphysics software. The two models consider the complicated coupling between physical and chemical changes during curing process of the composites and the time-variant characteristic of material performance parameters. Subsequently, the two proposed models are implemented respectively in a three-dimensional composite laminate structure, and a simple and convenient method of local coordinate system is used to calculate the development of residual stresses, curing shrinkage and curing deformation for the composite laminate. Researches show that the temperature, degree of curing (DOC) and residual stresses during curing process are consistent with the study in literature, so the curing shrinkage and curing deformation obtained on these basis have a certain referential value. Compared the differences between the two numerical results, it indicates that the residual stress and deformation calculated by the viscoelastic model are more close to the reference value than the linear elastic model.

  2. Resilience assessment and evaluation of computing systems

    CERN Document Server

    Wolter, Katinka; Vieira, Marco

    2012-01-01

    The resilience of computing systems includes their dependability as well as their fault tolerance and security. It defines the ability of a computing system to perform properly in the presence of various kinds of disturbances and to recover from any service degradation. These properties are immensely important in a world where many aspects of our daily life depend on the correct, reliable and secure operation of often large-scale distributed computing systems. Wolter and her co-editors grouped the 20 chapters from leading researchers into seven parts: an introduction and motivating examples,

  3. Global Positioning System receiver evaluation results

    Energy Technology Data Exchange (ETDEWEB)

    Byrne, R.H.

    1993-09-01

    A Sandia project currently uses an outdated Magnavox 6400 Global Positioning System (GPS) receiver as the core of its navigation system. The goal of this study was to analyze the performance of the current GPS receiver compared to newer, less expensive models and to make recommendations on how to improve the performance of the overall navigation system. This paper discusses the test methodology used to experimentally analyze the performance of different GPS receivers, the test results, and recommendations on how an upgrade should proceed. Appendices contain detailed information regarding the raw data, test hardware, and test software.

  4. Systems Evaluation at the Cool Energy House

    Energy Technology Data Exchange (ETDEWEB)

    Williamson, J. [Steven Winter Associates, Inc., Norwalk, CT (United States); Puttagunta, S. [Steven Winter Associates, Inc., Norwalk, CT (United States)

    2013-09-01

    Steven Winter Associates, Inc. (SWA) monitored several advanced mechanical systems within a 2012 deep energy retrofitted home in the small Orlando suburb of Windermere, FL. This report provides performance results of one of the home's heat pump water heaters (HPWH) and the whole-house dehumidifier (WHD) over a six month period. In addition to assessing the energy performance of these systems,this study sought to quantify potential comfort improvements over traditional systems. This information is applicable to researchers, designers, plumbers, and HVAC contractors. Though builders and homeowners can find useful information within this report, the corresponding case studies are a likely better reference for this audience.

  5. Systems Evaluation at the Cool Energy House

    Energy Technology Data Exchange (ETDEWEB)

    J. Williamson and S. Puttagunta

    2013-09-01

    Steven Winter Associates, Inc. (SWA) monitored several advanced mechanical systems within a 2012 deep energy retrofitted home in the small Orlando suburb of Windermere, FL. This report provides performance results of one of the home's heat pump water heaters (HPWH) and the whole-house dehumidifier (WHD) over a six month period. In addition to assessing the energy performance of these systems, this study sought to quantify potential comfort improvements over traditional systems. This information is applicable to researchers, designers, plumbers, and HVAC contractors. Though builders and homeowners can find useful information within this report, the corresponding case studies are a likely better reference for this audience.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-05-01

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

  7. Imbedded fiber optic pressure and temperature sensors enable cure monitoring of pultruded composite materials

    Science.gov (United States)

    Cable, David

    1990-05-01

    The application of fiberoptic multifunction sensing system for the measurement of temperature and pressure during the curing of fiberglass/epoxy composite structure is described. The system employs interferometric principles to measure temperature, pressure, and refractive index of liquids as well as other physical parameters. Fiberoptic pressure and temperature sensors have been employed in monitoring composites pultrusion and molding. The system is ideally suited for monitoring a variety of composite curing processes because of the sensor's microminiature size, tolerance of moderately high temperatures, non-metallic construction, and inherent immunity to electromagnetic and radio frequency signals.

  8. Evaluation of a Cyber Security System for Hospital Network.

    Science.gov (United States)

    Faysel, Mohammad A

    2015-01-01

    Most of the cyber security systems use simulated data in evaluating their detection capabilities. The proposed cyber security system utilizes real hospital network connections. It uses a probabilistic data mining algorithm to detect anomalous events and takes appropriate response in real-time. On an evaluation using real-world hospital network data consisting of incoming network connections collected for a 24-hour period, the proposed system detected 15 unusual connections which were undetected by a commercial intrusion prevention system for the same network connections. Evaluation of the proposed system shows a potential to secure protected patient health information on a hospital network.

  9. Evaluation of the Kloswall longwall mining system

    Science.gov (United States)

    Guay, P. J.

    1982-04-01

    A new longwal mining system specifically designed to extract a very deep web (48 inches or deeper) from a longwall panel was studied. Productivity and cost analysis comparing the new mining system with a conventional longwall operation taking a 30 inch wide web is presented. It is shown that the new system will increase annual production and return on investment in most cases. Conceptual drawings and specifications for a high capacity three drum shearer and a unique shield type of roof support specifically designed for very wide web operation are reported. The advantages and problems associated with wide web mining in general and as they relate specifically to the equipment selected for the new mining system are discussed.

  10. An Evaluation of Enhanced Geothermal Systems Technology

    Energy Technology Data Exchange (ETDEWEB)

    Jelacic, Allan [U.S. Dept. of Energy, Washington, DC (United States); Fortuna, Raymond [U.S. Dept. of Energy, Washington, DC (United States); LaSala, Raymond [U.S. Dept. of Energy, Washington, DC (United States); Nathwani, Jay [U.S. Dept. of Energy, Washington, DC (United States); Nix, Gerald [U.S. Dept. of Energy, Washington, DC (United States); Visser, Charles [National Renewable Energy Lab. (NREL), Golden, CO (United States); Green, Bruce [National Renewable Energy Lab. (NREL), Golden, CO (United States); Renner, Joel [Idaho National Lab. (INL), Idaho Falls, ID (United States); Blankenship, Douglas [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Kennedy, Mack [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Bruton, Carol [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2008-04-01

    This 2008 document presents the results of an eight-month study by the Department of Energy (DOE) and its support staff at the national laboratories concerning the technological requirements to commercialize a new geothermal technology, Enhanced Geothermal Systems (EGS).

  11. Automatic Tracking Evaluation and Development System (ATEDS)

    Data.gov (United States)

    Federal Laboratory Consortium — The heart of the ATEDS network consists of four SGI Octane computers running the IRIX operating system and equipped with V12 hardware graphics to support synthetic...

  12. PV System Energy Evaluation Method (Presentation)

    Energy Technology Data Exchange (ETDEWEB)

    Kurtz, S.

    2014-01-01

    This presentation describes a comparison of the "predicted" energy (based on historical weather data) with the "expected" energy (based on the measured weather data) to determine whether a PV system is performing as modeled in order to verify the accuracy of a model. A key factor in defining this energy test is determining the test boundary so that weather variations are not inadvertently included in what is considered to be PV system performance.

  13. Handling Qualities Evaluations of Unmanned Aircraft Systems

    Science.gov (United States)

    2015-05-04

    control power from the propulsion system, a two axis control stick to control pitch and roll, and a dual axis pedal system to control yaw and braking...cockpit in a GCS may consist of a throttle, control stick, and rudder pedals as well as any other hardware inputs benefi- cial to the pilot (landing gear...will consist of: a visual display, throttle, control stick, rudder pedals , and other appropriate hardware switches and levers. Removing the pilot from

  14. Interface Evaluation for Open System Architectures

    Science.gov (United States)

    2014-03-01

    information protection level ( IPL ) required for connected systems. Utilization of an open interface implies that a willingness to share information about...the interface exists. An inverse relationship between the IPL and the value of an open interface exists. As the IPL of connected systems increases...unclassified IPL . The minimum value is associated with a compartmentalized top secret IPL . The IPL scale is shown in Table 10. Information

  15. [Hepatitis C can be cured: will hepatitis B become next?

    Science.gov (United States)

    Chulanov, V P; Zueva, A P; Kostyushev, D S; Brezgin, S A; Volchkova, E V; Maleyev, V V

    2017-01-01

    Chronic hepatitis B (CHB) and C (CHC) are one of the leading causes of cirrhosis and liver cancer with over a million of people dying annually from their consequences. In Russia CHB and CHC morbidity and related mortality show an upward trend. As a result of recent breakthroughs in antiviral therapeutics CHC became a curable disease. Modern therapeutics effectively suppress viral replication in CHB patients, but withdrawal of antivirals usually results in disease relapse. Loss of HBsAg required for the so called 'functional cure' is a very rare event. Moreover, 'complete cure' when the virus is entirely eliminated from the body is not possible due to a persistent form of covalently closed circular DNA (cccDNA) of hepatitis B virus (HBV) in hepatocytes refractory to modern antivirals. Today, there is a plethora of new promising medications being at different stages of development that target different steps of viral life cycle, including inhibitors of interaction between HBV and its entry receptor NTCP, inhibitors of HBV cccDNA, inhibitors of nucleocapsid assembly, technologies of genome editing (TALENs, CRISPR/Cas etc) and RNA-interference. In addition to direct acting antivirals, there is a number of approaches aimed at enhancement of the innate and adaptive immune responses. In experimental conditions, some of these approaches or their combinations help to achieve functional cure. However, complete elimination of the virus is possible only using technologies of genome editing, capable of specific cccDNA degradation. Nuclease systems are currently at their early stages of development, and there is a long way to prove their efficacy and safety. Nevertheless, highly promising results of the recent years leave no doubt that CRISPR/Cas systems and similar technologies can become the basis of CHB therapy.

  16. 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 and...

  17. "A Roadmap for Flue-curing Tobacco Barns: Towards Developing ...

    African Journals Online (AJOL)

    The main conclusion was that there is urgent need for improving energy efficiency in tobacco curing. In the short term, high fuel consumption can be reduced by optimizing the thermal efficiency of curing structures, particularly for smallholder tobacco growers in Zimbabwe. Keywords: tobacco, flue-curing, smallholder farmers ...

  18. Techniques and materials for internal water curing of concrete

    DEFF Research Database (Denmark)

    Jensen, Ole Mejlhede; Lura, Pietro

    2006-01-01

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

  19. INTRODUCTION Curing is holding fruits at temperatures and ...

    African Journals Online (AJOL)

    The fruits are difficult to harvest without some minor damage, and most postharvest fungi are wound pathogens taking advantage of harvest injuries. Curing is presently used for ... Colour change to yellow was faster with sun curing and fruits initially cured to 7% weight ..... on green mold and stem-end rot of citrus fruit and its ...

  20. Evaluation of reliability worth in an electric power system

    Energy Technology Data Exchange (ETDEWEB)

    Billinton, Roy [Saskatchewan Univ., Saskatoon, SK (Canada). Power System Research Group

    1994-12-31

    This paper illustrates the application of basic power system reliability evaluation techniques to the quantification for reliability worth. The approach presented links customer interruption cost estimates with predictable indices of power system reliability. The technique is illustrated by application in the areas of generation, composite generation and transmission, and distribution system assessment using a hypothetical test system. (author)

  1. Pumice aggregates for internal water curing

    DEFF Research Database (Denmark)

    Pietro, Lura; Bentz, Dale P.; Lange, David A.

    2004-01-01

    A novel concept in internal curing of High Performance Concrete is based on dispersing very small, saturated lightweight aggregates (LWA) in the concrete, containing sufficient water to counteract self-desiccation. With this approach, the amount of water in the LWA can be minimized, thus economiz...... is saturation of the particles, which can be achieved only by immersion in boiling water or by vacuum saturation.......A novel concept in internal curing of High Performance Concrete is based on dispersing very small, saturated lightweight aggregates (LWA) in the concrete, containing sufficient water to counteract self-desiccation. With this approach, the amount of water in the LWA can be minimized, thus...... water absorption, but they release a greater percentage of their absorbed water at the equilibrium relative humidity of practical interest in early-age concrete, above 90%. Additionally, early-age properties of mortars with different contents of saturated pumice were investigated: a reference mix...

  2. Light-Curing Adhesive Repair Tapes

    Science.gov (United States)

    Allred, Ronald; Haight, Andrea Hoyt

    2009-01-01

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

  3. Aloe vera as cure for lichen planus.

    Science.gov (United States)

    Patil, Bharati A; Bhaskar, Hebbar Pragati; Pol, Jyoti S; Sodhi, Amandeep; Madhu, Asha V

    2013-01-01

    Oral lichen planus is a difficult condition to treat because of its chronic nature. Various treatment modalities have resulted in partial regression of symptoms but not a complete cure. Aloe vera, a product with minimal adverse effects, can be tried to treat this disorder. A 38-year-old male patient diagnosed with lichen planus of the skin and the oral mucosa was suffering from severe pain and a burning sensation intraorally and pruritus of the skin lesions. Considering the extensive involvement, an herbal alternative was considered. The patient was prescribed aloe vera juice and gel application for two months. At the nine-month follow-up, the patient was symptom-free and totally cured of the intraoral and skin lesions.

  4. Evaluation of surface roughness of three different composite resins with three different polishing systems.

    Science.gov (United States)

    Abzal, Mohammed S; Rathakrishnan, Mensudar; Prakash, Venkatachalam; Vivekanandhan, Paramasivam; Subbiya, Arunajatesan; Sukumaran, Vridhachalam Ganapathy

    2016-01-01

    The aim of this study was to evaluate the surface roughness of three composites with three different polishing systems. Composite specimens were made from the Teflon mold with a standardized cavity size (6 mm diameter and 3 mm height). Group I - Filtek Z350XT (Nano clusters), group II - T-Econom plus (Microhybrid), group III - G-aenial Flo (True Nano). The samples were cured for 30 s from both sides with the matrices in place. The 60 samples were divided into 3 groups (N = 20), which accounted for 40 surfaces, (n = 20 × 2 = 40) in each groups. Each group were subdivided into four subgroups based on the type polishing material, subgroup A - Control, subgroup B - Astrobrush, subgroup C - Astropol, and subgroup D - Soflex spiral wheel. The samples of all groups except group A (control) were finished and polished according to the manufacture's instruction. After polishing, the roughness (Ra) of the resin composite of all the specimens were measured using a profilometer. Soflex spiral wheel (group D) significantly had the least roughness (Ra) value as compared to the other groups. Among the three resin composites tested, G-aenial Flo exhibited least Ra value due to its reduced filler size and its uniform distribution.

  5. Effect of LED light-curing time for the adhesive resin on the modulus of elasticity.

    Science.gov (United States)

    Senawongse, Pisol; Harnirattisai, Choltacha; Otsuki, Masayuki; Tagami, Junji

    2007-06-01

    To evaluate the elastic modulus of successive layers where an adhesive resin was cured by different light-curing times. Eighty dentin discs which were 2 mm thick were prepared from 40 sound third molars. The dentin discs were further divided into four groups and bonded with 3M Single Bond 2 and cured with an LED for 5, 10, 15 and 20s. Bonded specimens were restored with a microhybrid resin composite. Specimens were cut perpendicular to the resin dentin interface, embedded in epoxy resin, and polished. Polished specimens were evaluated for the elastic modulus at the layer of dentin, hybrid layer, adhesive resin, and resin composite at 24 hours after preparation. Light-curing times influenced the elastic modulus of hybrid layer and adhesive resin. The significant differences of elastic modulus among successive layers were found. The results suggested that extension of light-curing times of adhesive resin from 5 to 20 seconds increased the mechanical properties of the resin dentin interface.

  6. Glass transition and degree of conversion of a light-cured orthodontic composite

    Directory of Open Access Journals (Sweden)

    Michela M. D. S. Sostena

    2009-12-01

    Full Text Available OBJECTIVE: This study evaluated the glass transition temperature (Tg and degree of conversion (DC of a light-cured (Fill Magic versus a chemically cured (Concise orthodontic composite. MATERIAL AND METHODS: Anelastic relaxation spectroscopy was used for the first time to determine the Tg of a dental composite, while the DC was evaluated by infrared spectroscopy. The light-cured composite specimens were irradiated with a commercial LED light-curing unit using different exposure times (40, 90 and 120 s. RESULTS: Fill Magic presented lower Tg than Concise (35-84ºC versus 135ºC, but reached a higher DC. CONCLUSIONS: The results of this study suggest that Fill Magic has lower Tg than Concise due to its higher organic phase content, and that when this light-cured composite is used to bond orthodontic brackets, a minimum energy density of 7.8 J/cm² is necessary to reach adequate conversion level and obtain satisfactory adhesion.

  7. Lipolysis in dry-cured ham maturation.

    Science.gov (United States)

    Vestergaard, C S; Schivazappa, C; Virgili, R

    2000-05-01

    Thirty light Parma hams were tested for muscle lipolytic activity (acid and neutral lipase activity) and free fatty acid (FFA) amounts in M. semimembranosus and biceps femoris, during progressive phases (0, 3, 6, 10 months) of dry-cured ham manufacturing. No correlation was found between the activities of acid and neutral lipases in fresh M. semimembranosus, while during processing the activities were positively related (pham, suggesting that FFA production could be influenced by both raw meat properties and muscle composition during processing.

  8. Evaluation of cassava-based systems for adaptation to climatic ...

    African Journals Online (AJOL)

    Evaluation of cassava-based systems for adaptation to climatic variations in eastern Nigeria. ... and Cassava + pigeon pea + maize were evaluated for five years using cassava root, shoot yields and their ratio as the index of adaptation to climatic variations. ... Keywords: Cassava, climate, cropping systems, Eastern Nigeria ...

  9. Sex Role Stereotyping and Evaluation: A Systems Approach.

    Science.gov (United States)

    McLure, Gail T.

    The usefulness of applying the Context, Input, Process, and Product (CIPP) Evaluation Model to school systems or projects where social change is needed is examined. The author introduces a systems approach to the examination of sex stereotyping, using the CIPP evaluation model, and sketches briefly the relationship between this model and the…

  10. Implementing, a sensory evaluation system in the manufacturing ...

    African Journals Online (AJOL)

    Often the people responsible for implementing sensory evaluation systems have had no formal training in sensory evaluation and the-task can seem quite ... This reliability can be assured through proper selection and training of panellists. .... results is a vehicle for lifting the profile of the sensory system. Ensure results are.

  11. Implementing a Sensory Evaluation System in the Manufacturing ...

    African Journals Online (AJOL)

    Often the people responsible for implementing sensory evaluation systems have had no formal training in sensory evaluation and the task can seem quite daunting. This paper presents some elements that are considered important when planning the design and implementation of a sensory system for process control.

  12. Application of computerized land evaluation systems in Tanzania: a ...

    African Journals Online (AJOL)

    Automated Land Evaluation System (ALES) and Land Evaluation Computer System (LECS) were applied in Kilosa District, Tanzania to test their applicability and adaptability in the area within the context of low-input rainfed maize farming. The study comprised physical land suitability classification of dominant soils ...

  13. Rhode Island Model Evaluation & Support System: Teacher. Edition III

    Science.gov (United States)

    Rhode Island Department of Education, 2015

    2015-01-01

    Rhode Island educators believe that implementing a fair, accurate, and meaningful educator evaluation and support system will help improve teaching and learning. The primary purpose of the Rhode Island Model Teacher Evaluation and Support System (Rhode Island Model) is to help all teachers improve. Through the Model, the goal is to help create a…

  14. Rhode Island Model Evaluation & Support System: Building Administrator. Edition III

    Science.gov (United States)

    Rhode Island Department of Education, 2015

    2015-01-01

    Rhode Island educators believe that implementing a fair, accurate, and meaningful educator evaluation and support system will help improve teaching, learning, and school leadership. The primary purpose of the Rhode Island Model Building Administrator Evaluation and Support System (Rhode Island Model) is to help all building administrators improve.…

  15. Rhode Island Model Evaluation & Support System: Support Professional. Edition II

    Science.gov (United States)

    Rhode Island Department of Education, 2015

    2015-01-01

    Rhode Island educators believe that implementing a fair, accurate, and meaningful evaluation and support system for support professionals will help improve student outcomes. The primary purpose of the Rhode Island Model Support Professional Evaluation and Support System (Rhode Island Model) is to help all support professionals do their best work…

  16. Document Level Assessment of Document Retrieval Systems in a Pairwise System Evaluation

    Science.gov (United States)

    Rajagopal, Prabha; Ravana, Sri Devi

    2017-01-01

    Introduction: The use of averaged topic-level scores can result in the loss of valuable data and can cause misinterpretation of the effectiveness of system performance. This study aims to use the scores of each document to evaluate document retrieval systems in a pairwise system evaluation. Method: The chosen evaluation metrics are document-level…

  17. IBM PC/IX operating system evaluation plan

    Science.gov (United States)

    Dominick, Wayne D. (Editor); Granier, Martin; Hall, Philip P.; Triantafyllopoulos, Spiros

    1984-01-01

    An evaluation plan for the IBM PC/IX Operating System designed for IBM PC/XT computers is discussed. The evaluation plan covers the areas of performance measurement and evaluation, software facilities available, man-machine interface considerations, networking, and the suitability of PC/IX as a development environment within the University of Southwestern Louisiana NASA PC Research and Development project. In order to compare and evaluate the PC/IX system, comparisons with other available UNIX-based systems are also included.

  18. STAR Network Distributed Computer Systems Evaluation Results.

    Science.gov (United States)

    1981-02-12

    image processing systems. Further, because of the small data require- ments a segment of TOTT is a good candidate for VLSI. It can attain the...broadcast capabilities of the distributed architecture to isolate the overhead of accounting and enhacing of fault isolation (see Figure B-1). B-1 The

  19. A new evaluation platform for Navigation systems

    DEFF Research Database (Denmark)

    Sejerøe, Thomas Hanefeld; Poulsen, Niels Kjølstad; Ravn, Ole

    2005-01-01

    The KALMTOOL 2 toolbox is a set of MATLAB tools for state estimation for nonlinear systems. The toolbox contains functions for extended Kalman filtering as well as for two new filters called the DD1 filter and the DD2 filter. It also contains function for Uncented Kalman filters as well as three...

  20. A self-evaluation token system versus an external evaluation token system alone in a residential setting with predelinquent youth.

    Science.gov (United States)

    Wood, R; Flynn, J M

    1978-01-01

    This study compared the effects of self-evaluation and adult-dispensed tokens on room-cleaning behavior of six predelinquent youths in a residential token-economy setting. The self-evaluation token system proved to be as effective as the external adult-administered system in increasing room-cleaning behavior and was more effective in maintaining performance after contingencies were withdrawn. The self-evaluation token system increased resistance to extinction, compared to the external token system, and appeared to be a useful component for a traditional token-economy system.