WorldWideScience

Sample records for cure bioeconomic risk

  1. An ounce of prevention or a pound of cure: bioeconomic risk analysis of invasive species.

    Science.gov (United States)

    Leung, Brian; Lodge, David M; Finnoff, David; Shogren, Jason F; Lewis, Mark A; Lamberti, Gary

    2002-12-07

    Numbers of non-indigenous species--species introduced from elsewhere - are increasing rapidly worldwide, causing both environmental and economic damage. Rigorous quantitative risk-analysis frameworks, however, for invasive species are lacking. We need to evaluate the risks posed by invasive species and quantify the relative merits of different management strategies (e.g. allocation of resources between prevention and control). We present a quantitative bioeconomic modelling framework to analyse risks from non-indigenous species to economic activity and the environment. The model identifies the optimal allocation of resources to prevention versus control, acceptable invasion risks and consequences of invasion to optimal investments (e.g. labour and capital). We apply the model to zebra mussels (Dreissena polymorpha), and show that society could benefit by spending up to US$324 000 year(-1) to prevent invasions into a single lake with a power plant. By contrast, the US Fish and Wildlife Service spent US$825 000 in 2001 to manage all aquatic invaders in all US lakes. Thus, greater investment in prevention is warranted.

  2. Risk analysis and bioeconomics of invasive species to inform policy and management

    Science.gov (United States)

    David M. Lodge; Paul W. Simonin; Stanley W. Burgiel; Reuben P. Keller; Jonathan M. Bossenbroek; Christopher L. Jerde; Andrew M. Kramer; Edward S. Rutherford; Matthew A. Barnes; Marion E. Wittmann; W. Lindsay Chadderton; Jenny L. Apriesnig; Dmitry Beletsky; Roger M. Cooke; John M. Drake; Scott P. Egan; David C. Finnoff; Crysta A. Gantz; Erin K. Grey; Michael H. Hoff; Jennifer G. Howeth; Richard A. Jensen; Eric R. Larson; Nicholas E. Mandrak; Doran M. Mason; Felix A. Martinez; Tammy J. Newcomb; John D. Rothlisberger; Andrew J. Tucker; Travis W. Warziniack; Hongyan. Zhang

    2016-01-01

    Risk analysis of species invasions links biology and economics, is increasingly mandated by international and national policies, and enables improved management of invasive species. Biological invasions proceed through a series of transition probabilities (i.e., introduction, establishment, spread, and impact), and each of these presents opportunities for...

  3. Stepping stones for biological invasion: A bioeconomic model of transferable risk

    Science.gov (United States)

    Travis Warziniack; David Finnoff; Jonathan Bossenbroek; Jason F. Shogren; David. Lodge

    2011-01-01

    We investigate three sources of bias in valuation methods for ecosystem risk: failure to consider substitution possibilities between goods, failure to consider nonseparability of ecosystem services with market goods, and failure to consider substitution possibilities between ecosystems. The first two biases are known in the literature, and we offer insight on the size...

  4. From rainfall to farm incomes - transforming advice for managing climate risk in Australia. Part I: Development and testing of a bioeconomic modelling system

    NARCIS (Netherlands)

    Kokic, P.; Nelson, R.; Meinke, H.B.; Potgieter, A.; Carter, J.

    2007-01-01

    In this paper we report the development of a bioeconomic modelling system, AgFIRM, designed to help close a relevance gap between climate science and policy in Australia. We do this by making a simple econometric farm income model responsive to seasonal forecasts of crop and pasture growth for the

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

    Science.gov (United States)

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

    2016-08-01

    Powerful blue-light emitting dental curing lights are used in dental offices to photocure resins in the mouth. In addition, many dental personnel use magnification loupes. This study measured the effect of magnification loupes on the "blue light hazard" when the light from a dental curing light was reflected off a human tooth. Loupes with 3.5x magnification (Design for Vision, Carl Zeiss, and Quality Aspirator) and 2.5x magnification (Design for Vision and Quality Aspirator) were placed at the entrance of an integrating sphere connected to a spectrometer (USB 4000, Ocean Optics). A model with human teeth was placed 40 cm away and in line with this sphere. The light guide tip of a broad-spectrum Sapphire Plus (Den-Mat) curing light was positioned at a 45° angle from the facial surface of the central incisor. The spectral radiant power reflected from the teeth was recorded five times with the loupes over the entrance into the sphere. The maximum permissible cumulative exposure times in an 8-hr day were calculated using guidelines set by the ACGIH. It was concluded that at a 40 cm distance, the maximum permissible cumulative daily exposure time to light reflected from the tooth was approximately 11 min without loupes. The weighted blue irradiance values were significantly different for each brand of loupe (Fisher's PLSD p effective blue light hazard was reduced compared to without the loupes. Thus, although using magnification loupes increased the irradiance received at the pupil, the maximum cumulative daily exposure time to reflected light was increased up to 28 min. Further studies are required to determine the ocular hazards of a focused stare when using magnification loupes and the effects of other curing lights used in the dental office.

  6. Semiparametric accelerated failure time cure rate mixture models with competing risks.

    Science.gov (United States)

    Choi, Sangbum; Zhu, Liang; Huang, Xuelin

    2018-01-15

    Modern medical treatments have substantially improved survival rates for many chronic diseases and have generated considerable interest in developing cure fraction models for survival data with a non-ignorable cured proportion. Statistical analysis of such data may be further complicated by competing risks that involve multiple types of endpoints. Regression analysis of competing risks is typically undertaken via a proportional hazards model adapted on cause-specific hazard or subdistribution hazard. In this article, we propose an alternative approach that treats competing events as distinct outcomes in a mixture. We consider semiparametric accelerated failure time models for the cause-conditional survival function that are combined through a multinomial logistic model within the cure-mixture modeling framework. The cure-mixture approach to competing risks provides a means to determine the overall effect of a treatment and insights into how this treatment modifies the components of the mixture in the presence of a cure fraction. The regression and nonparametric parameters are estimated by a nonparametric kernel-based maximum likelihood estimation method. Variance estimation is achieved through resampling methods for the kernel-smoothed likelihood function. Simulation studies show that the procedures work well in practical settings. Application to a sarcoma study demonstrates the use of the proposed method for competing risk data with a cure fraction. Copyright © 2017 John Wiley & Sons, Ltd.

  7. IA of bio-economic projects in Region Zealand, Denmark

    DEFF Research Database (Denmark)

    Lybæk, Rikke; Kjær, Tyge; Palsberg, Aske

    Creating new pathways for sustainable ready-to-implement bio-economic projects within Region Zealand, Denmark, based on available biomass resources and existing and proven technology concepts.......Creating new pathways for sustainable ready-to-implement bio-economic projects within Region Zealand, Denmark, based on available biomass resources and existing and proven technology concepts....

  8. Terrestrial metapopulation dynamics: a nonlinear bioeconomic model analysis

    NARCIS (Netherlands)

    Groeneveld, R.A.; Weikard, H.P.

    2006-01-01

    This paper presents a spatially explicit bioeconomic analysis of species conservation in agricultural areas. Wild species in fragmented agricultural landscapes are best approached as metapopulations consisting of a finite number of local populations. Economic analysis of species conservation in

  9. 'Well, It's the Risk of the Unknown… Right?': A Qualitative Study of Perceived Risks and Benefits of HIV Cure Research in the United States.

    Directory of Open Access Journals (Sweden)

    Karine Dubé

    Full Text Available Biomedical research towards an HIV cure is advancing in the United States and elsewhere, yet little is known about perceptions of risks and benefits among potential study participants and other stakeholders. We conducted a qualitative study to explore perceived risks and benefits of investigational HIV cure research among people living with HIV (PLWHIV, biomedical HIV cure researchers, policy-makers and bioethicists.We conducted a qualitative research study using in-depth interviews with a purposive sample of PLWHIV, biomedical HIV cure researchers, policy-makers and bioethicists in 2015-2016. We analysed interview transcripts using thematic analysis anchored in grounded theory.We conducted and analyzed 36 key informant interviews. Qualitative analysis revealed four main findings. 1 Potential HIV cure study volunteers noted needing more information and education about the potential risks of HIV cure research. 2 Biomedical HIV cure researchers, policy-makers and bioethicists showed less awareness of social and financial risks of HIV cure research than PLWHIV. 3 Most respondents across the different categories of informants identified some risks that were too great to be acceptable in HIV cure research, although a subset of PLWHIV did not place an upper limit on acceptable risk. 4 PLWHIV showed a better awareness of potential psychological benefits of participating in HIV cure research than other groups of stakeholders.Our research suggests that PLWHIV have a variable understanding of the individual risks, sometimes substantial, associated with participating in biomedical HIV cure research studies. Community engagement and increased research literacy may help improve community understanding. Intensive informed consent procedures will be necessary for ethical study implementation. The current state of HIV cure research offers greater potential benefits to society than to participants. There is likely to be disagreement among regulators, researchers

  10. 'Well, It's the Risk of the Unknown… Right?': A Qualitative Study of Perceived Risks and Benefits of HIV Cure Research in the United States.

    Science.gov (United States)

    Dubé, Karine; Taylor, Jeff; Sylla, Laurie; Evans, David; Dee, Lynda; Burton, Alasdair; Willenberg, Loreen; Rennie, Stuart; Skinner, Asheley; Tucker, Joseph D; Weiner, Bryan J; Greene, Sandra B

    2017-01-01

    Biomedical research towards an HIV cure is advancing in the United States and elsewhere, yet little is known about perceptions of risks and benefits among potential study participants and other stakeholders. We conducted a qualitative study to explore perceived risks and benefits of investigational HIV cure research among people living with HIV (PLWHIV), biomedical HIV cure researchers, policy-makers and bioethicists. We conducted a qualitative research study using in-depth interviews with a purposive sample of PLWHIV, biomedical HIV cure researchers, policy-makers and bioethicists in 2015-2016. We analysed interview transcripts using thematic analysis anchored in grounded theory. We conducted and analyzed 36 key informant interviews. Qualitative analysis revealed four main findings. 1) Potential HIV cure study volunteers noted needing more information and education about the potential risks of HIV cure research. 2) Biomedical HIV cure researchers, policy-makers and bioethicists showed less awareness of social and financial risks of HIV cure research than PLWHIV. 3) Most respondents across the different categories of informants identified some risks that were too great to be acceptable in HIV cure research, although a subset of PLWHIV did not place an upper limit on acceptable risk. 4) PLWHIV showed a better awareness of potential psychological benefits of participating in HIV cure research than other groups of stakeholders. Our research suggests that PLWHIV have a variable understanding of the individual risks, sometimes substantial, associated with participating in biomedical HIV cure research studies. Community engagement and increased research literacy may help improve community understanding. Intensive informed consent procedures will be necessary for ethical study implementation. The current state of HIV cure research offers greater potential benefits to society than to participants. There is likely to be disagreement among regulators, researchers, clinicians

  11. Bioeconomic factors of natural resource transitions

    DEFF Research Database (Denmark)

    Kaiser, Brooks

    This paper uses bio-economic modeling and simulation to investigate the demise of the sperm whale industry in the mid-19th century. Petroleum is widely credited both contemporaneously and today with ‘saving the whales.’ We investigate the transition in illumination technologies from whale oil...... to petroleum as a stochastic dynamic process in which there is uncertainty over the parameters of the fishery and the timing of available substitutes for sperm oil in order to determine the effect on the whale population. Using new biological analysis of the sperm whale fishery (Whitehead, 2002) and insights...... from natural resource economics we show that under most economic conditions the dynamics, even without a substitute, would have prevented extinction; this result is notably different, for economic and biological reasons, than that usually determined for the better studied baleen whales. This research...

  12. Bioeconomic analysis supports the endangered species act.

    Science.gov (United States)

    Salau, Kehinde R; Fenichel, Eli P

    2015-10-01

    The United States Endangered Species Act (ESA) was enacted to protect and restore declining fish, wildlife, and plant populations. The ESA mandates endangered species protection irrespective of costs. This translates to the restriction of activities that harm endangered populations. We discuss criticisms of the ESA in the context of public land management and examine under what circumstance banning non-conservation activity on multiple use federal lands can be socially optimal. We develop a bioeconomic model to frame the species management problem under the ESA and identify scenarios where ESA-imposed regulations emerge as optimal strategies. Results suggest that banning harmful activities is a preferred strategy when valued endangered species are in decline or exposed to poor habitat quality. However, it is not optimal to sustain such a strategy in perpetuity. An optimal plan involves a switch to land-use practices characteristic of habitat conservation plans.

  13. Bioeconomic modeling of intervention against clinical mastitis caused by contagious pathogens

    DEFF Research Database (Denmark)

    Hisham Beshara Halasa, Tariq

    2012-01-01

    The objective of this study was to assess the epidemiologic and economic consequences of intervention against contagious clinical mastitis during lactation. A bioeconomic model of intramammary infections (IMI) was used to simulate contagious spread of Staphylococcus aureus, Streptococcus uberis...... was sensitive to changes to the cure rate of clinical IMI following treatment, but the ranking of the intervention scenarios did not change. The model was most sensitive to the changes to the transmission rate of Staph. aureus. The ranking of the intervention scenarios changed at low transmission rate...... transmission, number of IMI cases, and persistent subclinical IMI cases. Nonetheless, the high associated costs of culling bacteriologically unrecovered clinical IMI cows made the other scenarios with a long and intensive antibiotic treatment, but without culling, the most cost effective. The model...

  14. Conceptual framework for bioeconomic potential indicators in Danube Delta

    Directory of Open Access Journals (Sweden)

    Butu M.,

    2016-05-01

    Full Text Available The regional bioeconomic potential takes into consideration many sectors of the economy that use renewable biological resources. The plants are one of the main resources for the most sectors - food, health, environment, materials and energy. The assessment of bioeconomic potential involves the modeling of the biological and economical aspects. Establishing the indicators involved in the study of this aspect requires a “what we have and what we need” analysis. We started with the development of a database of plants to facilitate an easy access to information for all interested scientist from related research fields.

  15. Bioeconomic Approaches to Sustainable Management of Natural Tropical Forests

    Science.gov (United States)

    Tom Holmes; Erin O. Sills

    2016-01-01

    Bioeconomic models are idealized representations of human-nature interactions used to describe how the decisions that people make regarding the harvest of biological resources affect the future condition of resource stocks and the flow of net economic benefits. This modeling approach posits an assumed goal or objective that a decision-maker seeks to optimize subject to...

  16. Bio-economic household modelling for agricultural intensification

    NARCIS (Netherlands)

    Kruseman, G.

    2000-01-01

    This study contributes to the quest for sustainable agricultural intensification through the development of a quantitative bio-economic modelling framework that allows assessment of new technology and policy measures in terms of household welfare and sustainability indicators. The main aim

  17. Bioeconomic modelling of a prey predator system using differential ...

    African Journals Online (AJOL)

    Bioeconomic modelling of a prey predator system using differential algebraic equations. ... Through considering delay as a bifurcation parameter, the occurrence of Hopf bifurcation of the proposed model system with positive economic profit is shown in the neighborhood of the co-existing equilibrium point. Finally, some ...

  18. FISHRENT; Bio-economic simulation and optimisation model

    NARCIS (Netherlands)

    Salz, P.; Buisman, F.C.; Soma, K.; Frost, H.; Accadia, P.; Prellezo, R.

    2011-01-01

    Key findings: The FISHRENT model is a major step forward in bio-economic model-ling, combining features that have not been fully integrated in earlier models: 1- Incorporation of any number of species (or stock) and/or fleets 2- Integration of simulation and optimisation over a period of 25 years 3-

  19. The application of cure models in the presence of competing risks: a tool for improved risk communication in population-based cancer patient survival.

    Science.gov (United States)

    Eloranta, Sandra; Lambert, Paul C; Andersson, Therese M-L; Björkholm, Magnus; Dickman, Paul W

    2014-09-01

    Quantifying cancer patient survival from the perspective of cure is clinically relevant. However, most cure models estimate cure assuming no competing causes of death. We use a relative survival framework to demonstrate how flexible parametric cure models can be used in combination with competing-risks theory to incorporate noncancer deaths. Under a model that incorporates statistical cure, we present the probabilities that cancer patients (1) have died from their cancer, (2) have died from other causes, (3) will eventually die from their cancer, or (4) will eventually die from other causes, all as a function of time since diagnosis. We further demonstrate how conditional probabilities can be used to update the prognosis among survivors (eg, at 1 or 5 years after diagnosis) by summarizing the proportion of patients who will not die from their cancer. The proposed method is applied to Swedish population-based data for persons diagnosed with melanoma, colon cancer, or acute myeloid leukemia between 1973 and 2007.

  20. The evaluation of risk-benefit ratio for gut tissue sampling in HIV cure research.

    Science.gov (United States)

    Mehraj, Vikram; Ghali, Peter; Ramendra, Rayoun; Costiniuk, Cecilia; Lebouché, Bertrand; Ponte, Rosalie; Reinhard, Robert; Sousa, Jose; Chomont, Nicolas; Cohen, Eric A; Ancuta, Petronela; Routy, Jean-Pierre

    2017-10-01

    Antiretroviral therapy (ART) does not cure HIV infection due to the persistence of HIV reservoirs in long-lived memory CD4 T cells present in the blood, lymph nodes, intestinal tract, and other tissues. Interest grows in obtaining gut-tissue samples for HIV persistence studies, which poses an ethical challenge to provide study volunteers with adequate information on risks and benefits. Herein we assess the risks and benefits of undergoing gut biopsy procedures for HIV pathogenesis and reservoir studies. A group discussion was organised with physicians and community representatives on performing either a flexible sigmoidoscopy or a colonoscopy. Consensus was reached on conducting colonoscopy in persons ≥50 years. Thirty HIV-infected, ART-treated and nine uninfected participants were recruited. Colonoscopy was performed to collect 30 gut mucosal biopsies. When present, polyps were removed and abnormal mucosal findings were biopsied for pathological analysis. Participants were interviewed on potential discomfort following colonoscopic examination. The HIV-infected and uninfected groups were comparable in terms of age and gender with more men who have sex with men (MSM) in the former group. Abnormal colonoscopic findings were observed in 43.6% of all the participants and did not differ by HIV status. In total, 24 polyps were removed with a higher mean number of polyps removed in HIV-infected versus uninfected participants (1.7 vs 1.0, P =0.013). The number of polyps marginally correlated with inverted CD4:CD8 ratio. Based on our findings, colonoscopic examination was safe to use for gut biopsy procedures where almost half of the participants had polyps removed. Participation in the study provided colon cancer screening as an ancillary benefit that participants could have received in standard medical care, thus mitigating burdens of invasive procedures. Dialogue between community representatives and clinical researchers can increase participation and advance HIV cure

  1. Does radical cure of asymptomatic Plasmodium falciparum place adults in endemic areas at increased risk of recurrent symptomatic malaria?

    Science.gov (United States)

    Owusu-Agyei, Seth; Binka, Fred; Koram, Kwadwo; Anto, Francis; Adjuik, Martin; Nkrumah, Francis; Smith, Tom

    2002-07-01

    A cohort of 197 adults in Kassena-Nankana District (northern Ghana) was radically cured of malaria parasites to study subsequent incidence of malaria infection. During the following 20 weeks of the malaria transmission season, 49% experienced clinical attacks associated with Plasmodium falciparum parasitaemia. In a group of 202 adults identically followed-up 1 year later without being treated, only 38% experienced such episodes (log-rank test for equality of survivor functions, P=0.035). Clinical attacks in radically cured individuals presented with lower parasite densities but more symptoms. Randomized studies are needed to test the hypothesis that radical cure of P. falciparum enhances the risk and severity of subsequent clinical malaria attacks.

  2. Risk factors for non-cure among new sputum smear positive tuberculosis patients treated in tuberculosis dispensaries in Yunnan, China

    Directory of Open Access Journals (Sweden)

    Yubang Qiu

    2011-05-01

    Full Text Available Abstract Background Yunnan province in China has a high tuberculosis (TB burden. Cure rates in general are high, but they were below the target of 85% in 26 out of 129 counties in 2005. In these 26 counties we assessed which patient-related and treatment-related factors were associated with non-cure. Methods We conducted a prospective cohort study. Smear positive pulmonary TB patients treated at the local Center for Disease Control and Prevention (CDC were interviewed before start of treatment and during the fifth month of treatment using structured questionnaires. Information on treatment outcome was extracted from patient records. Patients cured at the end of treatment were compared to patients with unsuccessful treatment outcomes (failure, default, and death. Results A total of 841 patients were registered between January-June 2007 of which 792 (94% were cured. Independent risk factors for non-cure were having a low income (30 days, a positive smear test result two months after start of treatment, not being aware of the need to go to the CDC for medical follow up during treatment, and not seeing the need for treatment observation. Conclusion Reducing the financial burden of TB disease and providing health education to improve compliance with treatment could increase the proportion of patients with successful treatment outcomes.

  3. Bioeconomic Modelling of Wetlands and Waterfowl in Western Canada: Accounting for Amenity Values

    NARCIS (Netherlands)

    Kooten, van G.C.; Whitey, P.; Wong, L.

    2011-01-01

    This study reexamines and updates an original bioeconomic model of optimal duck harvest and wetland retention by Hammack and Brown (1974, Waterfowl and Wetlands: Toward Bioeconomic Analysis. Washington, DC: Resources for the Future). It then extends the model to include the nonmarket (in situ) value

  4. Update Treatment for HBV Infection and Persistent Risk for Hepatocellular Carcinoma: Prospect for an HBV Cure.

    Science.gov (United States)

    Yoo, Joseph; Hann, Hie-Won; Coben, Robert; Conn, Mitchell; DiMarino, Anthony J

    2018-04-20

    Since the discovery of the hepatitis B virus (HBV) by Blumberg et al. in 1965, its genome, sequence, epidemiology, and hepatocarcinogenesis have been elucidated. Globally, hepatitis B virus (HBV) is still responsible for the majority of hepatocellular carcinoma (HCC). HCC is the sixth-most common cancer in the world and the second-most common cancer death. The ultimate goal of treating HBV infection is the prevention of HCC. Fortunately, anti-HBV treatment with nucleos(t)ide analogues (NAs), which began with lamivudine in 1998, has resulted in remarkable improvements in the survival of patients with chronic hepatitis B and a reduced incidence of HCC. These results were documented with lamivudine, entecavir, and tenofovir. Nonetheless, as the duration of antiviral treatment increases, the risk for HCC still remains despite undetectable HBV DNA in serum, as reported by different investigators with observation up to 4⁻5 years. In our own experience, we are witnessing the development of HCC in patients who have received antiviral treatment. Some have enjoyed negative serum HBV DNA for over 12 years before developing HCC. Current treatment with NAs can effectively suppress the replication of the virus but cannot eradicate the covalently closed circular DNA (cccDNA) that is within the nucleus of hepatocytes. There still remains a great need for a cure for HBV. Fortunately, several compounds have been identified that have the potential to eradicate HBV, and there are ongoing clinical trials in progress in their early stages.

  5. Expanding risk consideration in integrated models - the role of downside risk aversion in irrigation decisions

    NARCIS (Netherlands)

    Finger, R.

    2013-01-01

    We present a bio-economic model that accounts for the effects of water and nitrogen use on the first three moments of profit margin distributions in Swiss maize production. We thus also account for downside risks in farmers’ decision making processes, which extents currently used bio-economic

  6. Approaches to Bioeconomic Modelling in correlation with Consumer Model and Biodiversity Indicators

    Directory of Open Access Journals (Sweden)

    Ipate Iudith

    2015-04-01

    Full Text Available In this study we analysed the characteristics of bio-economic models in agricultural systems and agro-biodiversity indicators. The classical bioeconomic models are used to analyze the human consumption of ecosystems for production. The analysis focuses on changes in a limited set of agrobiodiversity indicators that matter to human beings. In existing bioeconomic models incorporate ecological complexities and dynamics is limited. Although bioeconomic model provides useful methods to integrate economic values into environmental analyses, improved the dynamic interrelationships between natural processes and socio-economic systems is needed to allow an integrated assessment of multiple values. The overview will enable a more informed decision about whether and how bio-economic models/modeling can contribute to the development of integrated environmental decision support tools. The bio economic modeling it is important for evaluating the costs and benefits associated with environmental resource use.

  7. Willingness to participate and take risks in HIV cure research: survey results from 400 people living with HIV in the US.

    Science.gov (United States)

    Dubé, Karine; Evans, David; Sylla, Laurie; Taylor, Jeff; Weiner, Bryan J; Skinner, Asheley; Thirumurthy, Harsha; Tucker, Joseph D; Rennie, Stuart; Greene, Sandra B

    2017-01-01

    Participation in early-phase HIV cure studies includes clinical risks with little to no likelihood of clinical benefit. Examining the willingness of people living with HIV to participate is important to guide study design and informed consent. Our study examined the overall willingness of people living with HIV to participate in HIV cure research in the US, focusing on perceived risks and benefits of participation. We undertook an online survey of adults living with HIV in the US. Survey questions were developed based on previous research and a scoping review of the literature. We quantitatively assessed individuals' perceived risks and benefits of HIV cure-related research and respondents' willingness to participate in different modalities of HIV cure studies. We recruited 409 study participants of whom 400 were eligible for the study and were included in the analysis (nine were not eligible due to self-declared HIV-negative status). We found >50% willingness to participate in 14 different types of HIV cure studies. Perceived clinical benefits and social benefits were important motivators, while personal clinical risks appeared to deter potential participation. Roughly two-thirds of survey respondents (68%) indicated that they were somewhat willing to stop treatment as part of HIV cure research. In the bivariate models, females, African Americans/blacks, Hispanics, individuals in the lowest income bracket, people living with HIV for longer periods of their lives, and people who were self-perceived 'very healthy' were less willing to participate in certain types of HIV cure studies than others. Multivariate results showed the perceived benefits (adjusted odds ratios >1) and perceived risks (adjusted odds ratios HIV cure research in the US using perceived risks and benefits. The results offer guidance to HIV cure researchers and developers of interventions about the beneficial and detrimental characteristics of HIV cure strategies that are most meaningful to people

  8. Ethics of treatment interruption trials in HIV cure research: addressing the conundrum of risk/benefit assessment.

    Science.gov (United States)

    Henderson, Gail E; Peay, Holly L; Kroon, Eugene; Cadigan, Rosemary Jean; Meagher, Karen; Jupimai, Thidarat; Gilbertson, Adam; Fisher, Jill; Ormsby, Nuchanart Q; Chomchey, Nitiya; Phanuphak, Nittaya; Ananworanich, Jintanat; Rennie, Stuart

    2018-04-01

    Though antiretroviral therapy is the standard of care for people living with HIV, its treatment limitations, burdens, stigma and costs lead to continued interest in HIV cure research. Early-phase cure trials, particularly those that include analytic treatment interruption (ATI), involve uncertain and potentially high risk, with minimal chance of clinical benefit. Some question whether such trials should be offered, given the risk/benefit imbalance, and whether those who choose to participate are acting rationally. We address these questions through a longitudinal decision-making study nested in a Thai acute HIV research cohort.In-depth interviews revealed central themes about decisions to join. Participants felt they possessed an important identity as members of the acute cohort, viewing their bodies as uniquely suited to both testing and potentially benefiting from HIV cure approaches. While acknowledging risks of ATI, most perceived they were given an opportunity to interrupt treatment, to test their own bodies and increase normalcy in a safe, highly monitored circumstance. They were motivated by potential benefits to themselves, the investigators and larger acute cohort, and others with HIV. They believed their own trial experiences and being able to give back to the community were sufficient to offset participation risks.These decisions were driven by the specific circumstances experienced by our participants. Judging risk/benefit ratios without appreciating these lived experiences can lead to false determinations of irrational decision- making. While this does not minimise vital oversight considerations about risk reduction and protection from harm, it argues for inclusion of a more participant-centered approach. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  9. Bioeconomic study of a multispecies pest subjected to a pesticide

    International Nuclear Information System (INIS)

    Chaudhuri, K.

    1986-07-01

    The paper deals with a community of two ecologically independent insect species subjected to a combined spray of insecticides. The growth equations for the community are constructed taking breeding into account and assuming the presence of some sexually sterile males in the populations. The dynamical behaviour of the community is explained at length. A bioeconomic analysis of the spraying programme is undertaken and the existence of a bionomic equilibrium is proved. The optimal spraying policy is studied with the help of Pontryagin's maximum principle. Lastly, the principal results are summarized. (author)

  10. Combined-modality therapy for early-stage Hodgkin lymphoma: maintaining high cure rates while minimizing risks.

    Science.gov (United States)

    Kelsey, Chris R; Beaven, Anne W; Diehl, Louis F; Prosnitz, Leonard R

    2012-12-01

    Multiple randomized studies have demonstrated that chemotherapy, most commonly ABVD (doxorubicin [Adriamycin], bleomycin, vinblastine, dacarbazine), followed by consolidation radiation therapy is the most effective treatment program for early-stage Hodgkin lymphoma. With a combined-modality approach, the great majority of patients are cured of their disease. It is also apparent that both chemotherapy and radiation therapy can increase the risk of complications in the decades following treatment, with second cancers and cardiac disease being the most common. Most studies,evaluating such risks primarily include patients treated in decades past with what are now considered outdated approaches, including high-dose, wide-field radiation therapy. The treatment of Hodgkin lymphoma has evolved significantly, particularly in regard to radiation therapy. In combination with chemotherapy, much lower doses and smaller fields are employed, with success equivalent to that achieved using older methods. Many studies have shown a significant decline in both the rates of second cancers and the risk of cardiac disease with low-dose radiation confined to the original extent of disease. In favorable patients, as few as 2 cycles of ABVD have been shown to be effective. The current combined-modality approach seeks to maintain high cure rates but minimize risks by optimizing both chemotherapy and radiation therapy

  11. Bioeconomic modeling of lactational antimicrobial treatment of new bovine subclinical intramammary infections caused by contagious pathogens

    NARCIS (Netherlands)

    Borne, van den B.H.P.; Halasa, T.; Schaik, van G.; Hogeveen, H.; Nielen, M.

    2010-01-01

    This study determined the direct and indirect epidemiologic and economic effects of lactational treatment of new bovine subclinical intramammary infections (IMI) caused by contagious pathogens using an existing bioeconomic model. The dynamic and stochastic model simulated the dynamics of

  12. Bio-economic farm modelling to analyse agricultural land productivity in Rwanda

    NARCIS (Netherlands)

    Bidogeza, J.C.

    2011-01-01

    Keywords: Rwanda; farm household typology; sustainable technology adoption; multivariate analysis;
    land degradation; food security; bioeconomic model; crop simulation models; organic fertiliser; inorganic fertiliser; policy incentives

    In Rwanda, land degradation contributes to the

  13. Bio-economic farm modelling to analyse agricultural land productivity in Rwanda

    NARCIS (Netherlands)

    Bidogeza, J.C.

    2011-01-01

    Keywords: Rwanda; farm household typology; sustainable technology adoption; multivariate analysis;
    land degradation; food security; bioeconomic model; crop simulation models; organic fertiliser; inorganic fertiliser; policy incentives In Rwanda, land degradation contributes to the low and

  14. From CURE to MATCH: ADP receptor antagonists as the treatment of choice for high-risk atherothrombotic patients.

    Science.gov (United States)

    Hacke, Werner

    2002-01-01

    Patients with a clinical manifestation of atherothrombosis such as a recent ischaemic cerebrovascular event are at high risk of subsequent events. Atherothrombosis often reflects disseminated disease; thus, further events may occur not only in the same arterial distribution but also in other vascular beds. To achieve adequate secondary prevention in these patients, long-term antiplatelet therapy with consistent benefit across the atherothrombosis spectrum is required. In the CAPRIE (Clopidogrel versus Aspirin in Patients at Risk of Ischaemic Events) Trial, clopidogrel (clopidogrel bisulphate) was superior to acetylsalicylic acid (ASA) in reducing the combined risk of ischaemic stroke (IS), myocardial infarction (MI) or vascular death in patients with symptomatic atherosclerosis. Post hoc analyses demonstrated that the benefit of clopidogrel was amplified in high-risk patients, including patients with a history of previous ischaemic events, diabetic patients and patients with hypercholesterolaemia. The synergistic antiplatelet effect produced by using clopidogrel on top of ASA may be beneficial in high-risk patients. The benefit of dual antiplatelet therapy was recently examined in the CURE (Clopidogrel in Unstable Angina to Prevent Recurrent Events) Study, which demonstrated that long-term treatment with clopidogrel on top of standard therapy including ASA was superior to standard therapy alone in the prevention of major vascular ischaemic events in patients with unstable angina or non-Q-wave MI. The ongoing MATCH (Management of Atherothrombosis with Clopidogrel in High-risk Patients with Recent Transient Ischaemic Attack or Ischaemic Stroke) trial will evaluate the efficacy and safety of clopidogrel plus ASA versus clopidogrel alone in patients with recent transient ischaemic attack (TIA) or IS and with at least one additional risk factor. Approximately 7,600 patients will be enroled, with treatment and follow-up for each patient lasting 18 months. The primary

  15. Contractualist reasoning, HIV cure clinical trials, and the moral (ir)relevance of the risk/benefit ratio.

    Science.gov (United States)

    Kumar, Rahul

    2017-02-01

    Institutional review boards (IRB) normally require of a morally defensible clinical trial that any trial participant will benefit from the inquiry, or at least not be exposed to a significant risk of having their prospects worsened by participating. Stage 1 HIV cure trials tend not to meet this requirement. Does that show them to be morally indefensible? Utilitarian thinking about this question supports a negative answer. But one might reasonably expect a Kantian moral theory to support the conclusion that exposing trial participants to a significant risk of their prospects being worsened by their participation to be morally indefensible, on grounds that this would be a clear case of using a person as a mere means. In this paper, I argue, drawing on Kantian contractualist thinking, that requiring the risk/benefit ratio for participants be positive if a trial is to be morally defensible does not in fact gain any support from Kantian thinking about morality. 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/.

  16. Belief in a Cure for HIV Infection Associated with Greater HIV Risk Behaviour among HIV Positive Men Who Have Sex with Men.

    Science.gov (United States)

    Misovich, Stephen J.; Fisher, Jeffrey D.; Fisher, William A.

    1999-01-01

    Investigated the extent to which HIV seropositive men who have sex with men (MSM) believe that HIV is now, or will soon be, curable. Survey results indicate that belief in a cure for HIV is present among many seropositive MSM, and this belief relates to both recent risk behavior and intention to engage in risky behaviors. (SM)

  17. Bioeconomic model and selection indices in Aberdeen Angus cattle.

    Science.gov (United States)

    Campos, G S; Braccini Neto, J; Oaigen, R P; Cardoso, F F; Cobuci, J A; Kern, E L; Campos, L T; Bertoli, C D; McManus, C M

    2014-08-01

    A bioeconomic model was developed to calculate economic values for biological traits in full-cycle production systems and propose selection indices based on selection criteria used in the Brazilian Aberdeen Angus genetic breeding programme (PROMEBO). To assess the impact of changes in the performance of the traits on the profit of the production system, the initial values ​​of the traits were increased by 1%. The economic values for number of calves weaned (NCW) and slaughter weight (SW) were, respectively, R$ 6.65 and R$ 1.43/cow/year. The selection index at weaning showed a 44.77% emphasis on body weight, 14.24% for conformation, 30.36% for early maturing and 10.63% for muscle development. The eighteen-month index showed emphasis of 77.61% for body weight, 4.99% for conformation, 11.09% for early maturing, 6.10% for muscle development and 0.22% for scrotal circumference. NCW showed highest economic impact, and SW had important positive effect on the economics of the production system. The selection index proposed can be used by breeders and should contribute to greater profitability. © 2014 Blackwell Verlag GmbH.

  18. A Bioeconomic Analysis of Traditional Fisheries in the Red Sea

    KAUST Repository

    Jin, Di

    2012-06-15

    We undertake a bioeconomic analysis of the aggregate traditional fisheries in the Northern and Central areas of Red Sea off the coast of the Kingdom of Saudi Arabia (KSA). Results of our analysis using a Fox model and the Clarke-Yoshimoto-Pooley (CY&P) estimation procedure suggest that the aggregate traditional fisheries have been overfished since the early 1990s. The estimated stock size in recent years is as low as 6,400 MT, while the estimated stock size associated with the maximum economic yield (MEY) is 19,300 MT. The socially optimal level of fishing effort is about 139,000 days. Thus, the current effort level of 300,000 to 350,000 days constitutes a problem of overfishing. The estimated current total gross revenue from the traditional fisheries is Saudi Rials (SR) 147 million with zero net benefit. If total fishing effort is reduced to the socially optimal level, then we estimate gross revenue would be SR 167 million and the potential net benefit from the KSA Red Sea traditional fisheries could be as large as SR 111 million. Copyright © 2012 MRE Foundation, Inc.

  19. The time-dependent "cure-death" model investigating two equally important endpoints simultaneously in trials treating high-risk patients with resistant pathogens.

    Science.gov (United States)

    Sommer, Harriet; Wolkewitz, Martin; Schumacher, Martin

    2017-07-01

    A variety of primary endpoints are used in clinical trials treating patients with severe infectious diseases, and existing guidelines do not provide a consistent recommendation. We propose to study simultaneously two primary endpoints, cure and death, in a comprehensive multistate cure-death model as starting point for a treatment comparison. This technique enables us to study the temporal dynamic of the patient-relevant probability to be cured and alive. We describe and compare traditional and innovative methods suitable for a treatment comparison based on this model. Traditional analyses using risk differences focus on one prespecified timepoint only. A restricted logrank-based test of treatment effect is sensitive to ordered categories of responses and integrates information on duration of response. The pseudo-value regression provides a direct regression model for examination of treatment effect via difference in transition probabilities. Applied to a topical real data example and simulation scenarios, we demonstrate advantages and limitations and provide an insight into how these methods can handle different kinds of treatment imbalances. The cure-death model provides a suitable framework to gain a better understanding of how a new treatment influences the time-dynamic cure and death process. This might help the future planning of randomised clinical trials, sample size calculations, and data analyses. Copyright © 2017 John Wiley & Sons, Ltd.

  20. Long-term predictive value of postsurgical cortisol concentrations for cure and risk of recurrence in Cushing's disease

    NARCIS (Netherlands)

    Pereira, Alberto M.; van Aken, Maarten O.; van Dulken, Hans; Schutte, Pieter J.; Biermasz, Nienke R.; Smit, Jan W. A.; Roelfsema, Ferdinand; Romijn, Johannes A.

    2003-01-01

    We assessed the value of postoperative plasma cortisol concentrations to predict cure and recurrence of Cushing's disease after transsphenoidal surgery (TS). Seventy-eight of 80 consecutive patients treated by TS for Cushing's disease were evaluated. TS cured 72% (n = 56) of the patients. Two weeks

  1. Perceptions of Equipoise, Risk-Benefit Ratios, and "Otherwise Healthy Volunteers" in the Context of Early-Phase HIV Cure Research in the United States: A Qualitative Inquiry.

    Science.gov (United States)

    Dubé, Karine; Dee, Lynda; Evans, David; Sylla, Laurie; Taylor, Jeff; Brown, Brandon; Miller, Veronica; Corneli, Amy; Skinner, Asheley; Greene, Sandra B; Tucker, Joseph D; Rennie, Stuart

    2018-02-01

    Early-phase HIV cure research is conducted against a background of highly effective antiretroviral therapy, and involves risky interventions in individuals who enjoy an almost normal life expectancy. To explore perceptions of three ethical topics in the context of HIV cure research-(a) equipoise, (b) risk-benefit ratios, and (c) "otherwise healthy volunteers"-we conducted 36 in-depth interviews (IDIs) with three groups of purposively selected key informants: clinician-researchers ( n = 11), policy-makers and bioethicists ( n = 13), and people living with HIV (PLWHIV; n = 12). Our analysis revealed variability in perceptions of equipoise. Second, most key informants believed there was no clear measure of risk-benefit ratios in HIV cure research, due in part to the complexity of weighing (sometimes unknown) risks to participants and (sometimes speculative) benefits to science and society. Third, most clinician-researchers and policy-makers/bioethicists viewed potential HIV cure study participants as "otherwise healthy volunteers," but this perception was not shared among PLWHIV in our study.

  2. Modeling and bio-economic analysis of broilers' performance in Benin

    DEFF Research Database (Denmark)

    Houndonougbo, Mankpondji Frederic; Chwalibog, André; Chrysostome, C.A.A.M.

    2009-01-01

    The objective of this paper was to model bio-economic variables in broilers feeding. During 7 weeks, 120 broilers Red Bro were fed with diets containing soybean meals from solvent (Ss) or expeller (Se) processing. At grower phase (d 22 to d 49) the diets were switched for half of broilers in each...

  3. A multi-disciplinary framework for bio-economic modeling in aquaculture: a welfare case study

    NARCIS (Netherlands)

    Noble, C.; Berrill, I.K.; Waller, B.; Schneider, O.; Kole, A.P.W.

    2012-01-01

    This article summarizes the framework that translated data from multiple disciplines into a bio-economic decision tool for modeling the costs and benefits of improving fish welfare in commercial aquaculture. This decision tool formed the basis of a recent EU research project, BENEFISH which was

  4. Bioeconomic modelling of foot and mouth disease and its control in Ethiopia

    NARCIS (Netherlands)

    Jemberu, W.T.

    2016-01-01

    Keywords: Control, cost-benefit, economic impact, epidemiology, Ethiopia, Foot and mouth disease, intention, modelling, production system. Bioeconomic Modelling of Foot and Mouth Disease and Its control in Ethiopia Foot and mouth disease (FMD) is a highly contagious

  5. Bio-economic modeling of water quality improvements using a dynamic applied general equilibrium approach

    NARCIS (Netherlands)

    Dellink, R.; Brouwer, R.; Linderhof, V.G.M.; Stone, K.

    2011-01-01

    An integrated bio-economic model is developed to assess the impacts of pollution reduction policies on water quality and the economy. Emission levels of economic activities to water are determined based on existing environmental accounts. These emission levels are built into a dynamic economic model

  6. Protecting the African Elephant: A Dynamic Bioeconomic Model of Ivory Trade

    NARCIS (Netherlands)

    Kooten, van G.C.

    2008-01-01

    A dynamic bioeconomic model of ivory trade is used to investigate the efficacy of conservation payments, tourism benefits, quota regimes and a trade ban on the protection of the African elephant (Laxadonta africana). The model consists of four ivory exporting regions and one demand region. Results

  7. Radiation curing

    International Nuclear Information System (INIS)

    Wendrinsky, J.

    1987-04-01

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

  8. A bio-economic analysis of a shell fishery: The effects of recruitment and habitat in a meta population model

    NARCIS (Netherlands)

    Imeson, R.J.; van den Bergh, J.C.J.M.

    2004-01-01

    This paper presents a bioeconomic model where fishing effort exerted has multiple impacts on the recruitment process of a sedentary shellfish population. Recognizing that sedentary populations generally possess metapopulation characteristics at the recruitment stage, we show that fishing effort

  9. The Risk of Tuberculosis Reinfection Soon after Cure of a First Disease Episode Is Extremely High in a Hyperendemic Community.

    Directory of Open Access Journals (Sweden)

    Pieter Uys

    Full Text Available Elevated rates of reinfection tuberculosis in various hyperendemic regions have been reported and, in particular, it has been shown that in a high-incidence setting near Cape Town, South Africa, the rate of reinfection tuberculosis (TB disease after cure of a previous TB disease episode is about four times greater than the rate of first-time TB disease. It is not known whether this elevated rate is caused by a high reinfection rate due, for instance, to living circumstances, or a high rate of progress to disease specific to the patients, or both. In order to address that question we analysed an extensive data set from clinics attended by TB patients in the high-incidence setting near Cape Town, South Africa and found that, in fact, the (average rate of reinfection (as opposed to the rate of reinfection disease after cure of a previous TB disease episode is initially about 0.85 per annum. This rate diminishes rapidly over time and after about ten years this rate is similar to the rate of infection in the general population. Also, the rate of progress to disease after reinfection is initially high but declines in subsequent years down to the figure typical for the general population. These findings suggest that the first few months after cure of a TB disease episode form a critical period for controlling reinfection disease in a hyperendemic setting and that monitoring such cured patients could pre-empt a reinfection progressing to active disease.

  10. FLBEIA : A simulation model to conduct Bio-Economic evaluation of fisheries management strategies

    Directory of Open Access Journals (Sweden)

    Dorleta Garcia

    2017-01-01

    Here, we present FLBEIA, a flexible software to conduct bio-economic evaluation of fisheries management strategies. The model is multi-stock, multi-fleet, stochastic and seasonal. The fishery system is described as a sum of processes, which are internally assembled in a predetermined way. There are several functions available to describe the dynamic of each process and new functions can be added to satisfy specific requirements.

  11. A Bioeconomic Model of Cattle Stocking on Rangeland Threatened by Invasive Plants and Nitrogen Deposition

    OpenAIRE

    David Finnoff; Aaron Strong; John Tschirhart

    2008-01-01

    Across western North America, invasive plant species and elevated levels of nitrogen are threatening the productivity of rangelands. A bioeconomic model of stocking cattle on these rangelands is used to show that optimal stocking depends on the competition between native grasses and the invaders. However, nitrogen deposition is important in determining the ultimate rangeland species composition. Endogenous changes in plant successional thresholds are due to the interplay of nitrogen depositio...

  12. Hopf Bifurcation of a Differential-Algebraic Bioeconomic Model with Time Delay

    Directory of Open Access Journals (Sweden)

    Xiaojian Zhou

    2012-01-01

    Full Text Available We investigate the dynamics of a differential-algebraic bioeconomic model with two time delays. Regarding time delay as a bifurcation parameter, we show that a sequence of Hopf bifurcations occur at the positive equilibrium as the delay increases. Using the theories of normal form and center manifold, we also give the explicit algorithm for determining the direction of the Hopf bifurcations and the stability of the bifurcating periodic solutions. Numerical tests are provided to verify our theoretical analysis.

  13. Curing process

    International Nuclear Information System (INIS)

    Maruyama, Tsutomu; Watanabe, Tadashi.

    1969-01-01

    A process for the rapid curing of an electrophoretically applied coating with either compositions of aqueous dispersion or aqueous coating compositions thereof is provided by irradiating with ionizing radiations. The process comprises the steps of (a) neutralizing an aqueous alkyd resin with a base, in which the alkyd resin contains a conjugated unsaturated fatty acid or oil as one of its constituents, (b) dispersing the neutralized resin in water, (c) applying to an electroconductive material the varnishes of the dispersed composition or the dispersed coating composition, and (d) irradiating the coatings with ionizing radiations so as to harden them. The alkyd resins have an acid value of 30 to 100 and the bases are equivalent to 0.7 to 1.2. the process is suitable for coil coating. In examples, a semi-esterified product of acid value 54 was diluted with 440 parts of ethylene glycol monobutyl ether and 110 parts of butanol. Next, they were neutralized with 87 parts of dimethyl amino ethanol. Thereafter, they were mixed with 1,013 parts of water to produce an aqueous dispersion of alkyd resin varnish at a concentration of 40%. To 325 parts of the varnish were added 1.3 parts of cobalt naphthenate- 60% toluene solution and then 675 parts of water to produce water soluble varnish containing 13% of a nonvolatile substance. The varnish was applied by electrophoresis for 10 seconds. The time required for the irradiation was about 1 second. The total radiation dose was 3 Mrad of electron beams at an acceleration energy of 300 kV and 25 mA of current. (Iwakiri, K.)

  14. Biomass supply from alternative cellulosic crops and crop residues: A spatially explicit bioeconomic modeling approach

    International Nuclear Information System (INIS)

    Egbendewe-Mondzozo, Aklesso; Swinton, Scott M.; Izaurralde, César R.; Manowitz, David H.; Zhang, Xuesong

    2011-01-01

    This paper introduces a spatially-explicit bioeconomic model for the study of potential cellulosic biomass supply. For biomass crops to begin to replace current crops, farmers must earn more from them than from current crops. Using weather, topographic and soil data, the terrestrial ecosystem model, EPIC, dynamically simulates multiple cropping systems that vary by crop rotation, tillage, fertilization and residue removal rate. EPIC generates predicted crop yield and environmental outcomes over multiple watersheds. These EPIC results are used to parameterize a regional profit-maximization mathematical programming model that identifies profitable cropping system choices. The bioeconomic model is calibrated to 2007–09 crop production in a 9-county region of southwest Michigan. A simulation of biomass supply in response to rising biomass prices shows that cellulosic residues from corn stover and wheat straw begin to be supplied at minimum delivered biomass:corn grain price ratios of 0.15 and 0.18, respectively. At the mean corn price of $162.6/Mg ($4.13 per bushel) at commercial moisture content during 2007–2009, these ratios correspond to stover and straw prices of $24 and $29 per dry Mg. Perennial bioenergy crops begin to be supplied at price levels 2–3 times higher. Average biomass transport costs to the biorefinery plant range from $6 to $20/Mg compared to conventional crop production practices in the area, biomass supply from annual crop residues increased greenhouse gas emissions and reduced water quality through increased nutrient loss. By contrast, perennial cellulosic biomass crop production reduced greenhouse gas emissions and improved water quality. -- Highlights: ► A new bioeconomic model predicts biomass supply and its environmental impacts. ► The model captures the opportunity cost of switching to new cellulosic crops. ► Biomass from crop residues is supplied at lower biomass price than cellulosic crops. ► Biomass from cellulosic crops has

  15. Methodology to predict long-term cancer survival from short-term data using Tobacco Cancer Risk and Absolute Cancer Cure models

    International Nuclear Information System (INIS)

    Mould, R F; Lederman, M; Tai, P; Wong, J K M

    2002-01-01

    Three parametric statistical models have been fully validated for cancer of the larynx for the prediction of long-term 15, 20 and 25 year cancer-specific survival fractions when short-term follow-up data was available for just 1-2 years after the end of treatment of the last patient. In all groups of cases the treatment period was only 5 years. Three disease stage groups were studied, T1N0, T2N0 and T3N0. The models are the Standard Lognormal (SLN) first proposed by Boag (1949 J. R. Stat. Soc. Series B 11 15-53) but only ever fully validated for cancer of the cervix, Mould and Boag (1975 Br. J. Cancer 32 529-50), and two new models which have been termed Tobacco Cancer Risk (TCR) and Absolute Cancer Cure (ACC). In each, the frequency distribution of survival times of defined groups of cancer deaths is lognormally distributed: larynx only (SLN), larynx and lung (TCR) and all cancers (ACC). All models each have three unknown parameters but it was possible to estimate a value for the lognormal parameter S a priori. By reduction to two unknown parameters the model stability has been improved. The material used to validate the methodology consisted of case histories of 965 patients, all treated during the period 1944-1968 by Dr Manuel Lederman of the Royal Marsden Hospital, London, with follow-up to 1988. This provided a follow-up range of 20- 44 years and enabled predicted long-term survival fractions to be compared with the actual survival fractions, calculated by the Kaplan and Meier (1958 J. Am. Stat. Assoc. 53 457-82) method. The TCR and ACC models are better than the SLN model and for a maximum short-term follow-up of 6 years, the 20 and 25 year survival fractions could be predicted. Therefore the numbers of follow-up years saved are respectively 14 years and 19 years. Clinical trial results using the TCR and ACC models can thus be analysed much earlier than currently possible. Absolute cure from cancer was also studied, using not only the prediction models which

  16. The Effect of Climate Change on Wetlands and Waterfowl in Western Canada: Incorporating Cropping Decisions into a Bioeconomic Model

    NARCIS (Netherlands)

    Whitey, P.; Kooten, van G.C.

    2011-01-01

    We extend an earlier bioeconomic model of optimal duck harvest and wetland retention in the Prairie Pothole Region of Western Canada to include cropping decisions. Instead of a single state equation, the model has two state equations representing the population dynamics of ducks and the amount of

  17. The Effect of Climate Change on Wetlands and Waterfowl in Western Canada: Incorporating Cropping Decisions into a Bioeconomic Model

    NARCIS (Netherlands)

    Withey, P.; Kooten, van G.C.

    2013-01-01

    We extend an earlier bioeconomic model of optimal duck harvest and wetland retention in the Prairie Pothole Region of Western Canada to include cropping decisions. Instead of a single state equation, the model has two state equations representing the population dynamics of ducks and the amount of

  18. Bioeconomic analysis of the environmental impact of a marine fish farm.

    Science.gov (United States)

    Rabassó, Miguel; Hernández, Juan M

    2015-08-01

    The evaluation of the environmental impact of aquaculture installations is nowadays a common social demand in many countries. The usual scientific approach to this question has been to assess the outcome from an ecological perspective, focussing on the effects produced on benthos or the water column and interactions with marine flora and fauna. In this paper, a bioeconomic model is developed to extend this traditional approach, to determine both the amount of total settled matter, its dispersion on the ocean floor and impacts on the marine ecosystem, while also taking into account other social considerations such as discounted net profits and investment returns. The model was applied to the case of off-shore gilthead seabream production in a coastal area of the Canary Isles archipelago, where the tidal current is predominant. Cage emissions and the degree of degradation of seagrass meadows on the seabed were taken as ecological impact indicators, while the net present value (NPV) for a specific time period was used as an economic indicator. By analysing the simulation results obtained by the bioeconomic model, we were able to determine the combination of production volume and harvest quantity which yields the greatest economic efficiency for different levels of degraded area. Copyright © 2015 Elsevier Ltd. All rights reserved.

  19. Radiation curing of polymers

    International Nuclear Information System (INIS)

    Randell, D.R.

    1987-01-01

    The contents of this book are: Areas of Application of UV Curing; Areas of Application of EB Curing; Laser Curing of Acrylic Coatings; A User's View of the Application of Radiation Curable Materials; Radiation Curable Offset Inks: A Technical and Marketing Overview; and UV Curable Screen Printing Inks

  20. Sustainable development and bioeconomic prosperity in Africa: Bio ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-06-03

    Jun 3, 2009 ... guidelines concerning significant issues like bio-risks, bio-safety, and bio-security that impinge on daily human existence and welfare. High–cost fossil fuel prices and national security concerns have sparked interest in bio-fuels in continental Africa. In brief, Africa is taking the lead in creating its own.

  1. 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 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.

  2. A bioeconomic approach to marriage and the sexual division of labor.

    Science.gov (United States)

    Gurven, Michael; Winking, Jeffrey; Kaplan, Hillard; von Rueden, Christopher; McAllister, Lisa

    2009-06-01

    Children may be viewed as public goods whereby both parents receive equal genetic benefits yet one parent often invests more heavily than the other. We introduce a microeconomic framework for understanding household investment decisions to address questions concerning conflicts of interest over types and amount of work effort among married men and women. Although gains and costs of marriage may not be spread equally among marriage partners, marriage is still a favorable, efficient outcome under a wide range of conditions. This bioeconomic framework subsumes both cooperative and conflictive views on the sexual division of labor. We test hypotheses concerning marriage markets, assortative mating, and men's labor motivations among Tsimane forager-horticulturalists of Bolivia and find that: (1) men and women both value work effort in marital partners, (2) marital labor contributions are complementary, (3) work effort is correlated between spouses, (4) total production is correlated with total reproduction, and (5) better hunters have higher fitness gains within marital unions.

  3. Bio-economic evaluation of implementing trawl fishing gear with different selectivity

    DEFF Research Database (Denmark)

    Grønbæk Kronbak, Lone; Nielsen, J. Rasmus; Jørgensen, Ole A.

    2009-01-01

    The paper develops a biological-economic evaluation tool to analyse the consequences for trawl fishers of implementing more selective fishing technologies. This is done by merging a dynamic biological population model and an economic cost-benefit evaluation framework to describe the consequences...... for the fish stocks, fishermen and society. The bio-economic evaluation is applied to the case of the Danish trawl fishery in Kattegat and Skagerrak, which experiences a high level of discards and byratches of several species. Four different kinds of selectivity scenarios are evaluated in comparison...... with a baseline. The results from the evaluation are indicators for the consequences on ecological and economic levels. The results show that implementation of different selective fishing gear in the Kattegat and Skagerrak mixed trawl fisheries generally implies a trade off over time between rebuilding the stocks...

  4. Bio-economic evaluation of implementing trawl fishing gear with different selectivity

    DEFF Research Database (Denmark)

    Kronbak, Lone Grønbæk; Nielsen, J. Rasmus; Jørgensen, Ole A.

    2009-01-01

    The paper develops a biological-economic evaluation tool to analyse the consequences for trawl fishers of implementing more selective fishing technologies. This is done by merging a dynamic biological population model and an economic cost-benefit evaluation framework to describe the consequences...... for the fish stocks, fishermen and society. The bio-economic evaluation is applied to the case of the Danish trawl fishery in Kattegat and Skagerrak, which experiences a high level of discards and bycatches of several species. Four different kinds of selectivity scenarios are evaluated in comparison...... with a baseline. The results from the evaluation are indicators for the consequences on ecological and economic levels. The results show that implementation of different selective fishing gear in the Kattegat and Skagerrak mixed trawl fisheries generally implies a trade off over time between rebuilding the stocks...

  5. Fuzzy Stochastic Optimal Guaranteed Cost Control of Bio-Economic Singular Markovian Jump Systems.

    Science.gov (United States)

    Li, Li; Zhang, Qingling; Zhu, Baoyan

    2015-11-01

    This paper establishes a bio-economic singular Markovian jump model by considering the price of the commodity as a Markov chain. The controller is designed for this system such that its biomass achieves the specified range with the least cost in a finite-time. Firstly, this system is described by Takagi-Sugeno fuzzy model. Secondly, a new design method of fuzzy state-feedback controllers is presented to ensure not only the regularity, nonimpulse, and stochastic singular finite-time boundedness of this kind of systems, but also an upper bound achieved for the cost function in the form of strict linear matrix inequalities. Finally, two examples including a practical example of eel seedling breeding are given to illustrate the merit and usability of the approach proposed in this paper.

  6. Ultrasonic cure monitoring

    Science.gov (United States)

    Djordjevic, B. Boro

    1999-12-01

    Fiber reinforced organic matrix composites applied to large structures require inexpensive cure process control. This paper reports on work to develop simple ultrasonic NDE sensors suitable for manufacturing and in-field use. This sensor is designed around a short wave-guide ultrasonic probe that is embedded in composite for in-situ cure monitoring applications. The sensor measures changes in resin density and sound velocity during cure and can be quantitatively calibrated for determination of the final cure. The cure monitoring is based on acoustic impedance variance across a material interface and can be utilized over the full cure cycle change of the resin in the composite. Significant advantage of this method is the simplicity of the measurement, low cost of the wave-guide probe and the adaptability of the sensor configuration to various composite-processing environments

  7. The bioeconomic impact of different management regulations on the Chesapeake Bay blue crab fishery

    Science.gov (United States)

    Bunnell, David B.; Lipton, Douglas W.; Miller, Thomas J.

    2010-01-01

    The harvest of blue crabs Callinectes sapidus in Chesapeake Bay declined 46% between 1993 and 2001 and remained low through 2008. Because the total market value of this fishery has declined by an average of US $ 3.3 million per year since 1993, the commercial fishery has been challenged to maintain profitability. We developed a bioeconomic simulation model of the Chesapeake Bay blue crab fishery to aid managers in determining which regulations will maximize revenues while ensuring a sustainable harvest. We compared 15 different management scenarios, including those implemented by Maryland and Virginia between 2007 and 2009, that sought to reduce female crab harvest and nine others that used seasonal closures, different size regulations, or the elimination of fishing for specific market categories. Six scenarios produced the highest revenues: the 2008 and 2009 Maryland regulations, spring and fall closures for female blue crabs, and 152- and 165-mm maximum size limits for females. Our most important finding was that for each state the 2008 and 2009 scenarios that implemented early closures of the female crab fishery produced higher revenues than the 2007 scenario, in which no early female closures were implemented. We conclude that the use of maximum size limits for female crabs would not be feasible despite their potentially high revenue, given the likelihood that the soft-shell and peeler fisheries cannot be expanded beyond their current capacity and the potentially high mortality rate for culled individuals that are the incorrect size. Our model results support the current use of seasonal closures for females, which permit relatively high exploitation of males and soft-shell and peeler blue crabs (which have high prices) while keeping the female crab harvest sustainable. Further, our bioeconomic model allows for the inclusion of an economic viewpoint along with biological data when target reference points are set by managers.

  8. TEMAS: fleet-based bio-economic simulation software to evaluate management strategies accounting for fleet behaviour

    DEFF Research Database (Denmark)

    Ulrich, Clara; Andersen, Bo Sølgaard; Sparre, Per Johan

    2007-01-01

    TEMAS (technical management measures) is a fleet-based bio-economic software for evaluating management strategies accounting for technical measures and fleet behaviour. It focuses on mixed fisheries in which several fleets can choose among several fishing activities to target different stocks...... in one or several areas. The software combines a management strategy evaluation framework, using a forward-running operating model and a management procedure with a fleet behaviour module simulating both short-term (effort allocation) and long-term (entry/exit) fleet dynamics. The suite of models behind...... TEMAS can be thought of as an extension of the traditional ICES forecast model. Alternative management scenarios can be compared and evaluated for their bio-economic consequences and robustness to parameter uncertainty. The software is generic and user-friendly, and can be run at several space and time...

  9. Curing light burns.

    Science.gov (United States)

    Spranley, Thomas J; Winkler, Mark; Dagate, John; Oncale, David; Strother, Elizabeth

    2012-01-01

    This study sought to reveal the potential heat generated by a light-emitting diode (LED) curing light, which has generally been considered to be relatively cool. It is likely that similarly designed curing lights will produce a similar level of heat and have the potential to cause damage to soft tissue.

  10. Grafting and curing

    International Nuclear Information System (INIS)

    Garnett, J.L.; Loo-Teck Ng; Visay Viengkhou

    1998-01-01

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

  11. When "The Cure" Is the Risk: Understanding How Substance Use Affects HIV and HCV in a Layered Risk Environment in San Juan, Puerto Rico

    Science.gov (United States)

    Hernández, Diana; Castellón, Pedro C.; Fernández, Yohansa; Torres-Cardona, Francisco A.; Parish, Carrigan; Gorshein, Danielle; Vargas Vidot, Jose; Miranda de Leon, Sandra; Rodriguez, Allan; Santana Bagur, Jorge; Feaster, Daniel J.; Schackman, Bruce R.; Metsch, Lisa R.

    2017-01-01

    Background: Substance use, particularly injection drug use, continues to fuel the HIV/HCV (hepatitis C virus) epidemics in San Juan, Puerto Rico (PR). Aim: This article examines individual and sociostructural factors that affect HIV/HCV risk among people who use drugs (PWUD) living with or at risk for HIV/HCV in San Juan, PR. Findings were used to…

  12. Quantifying the impact of weather extremes on global food security: A spatial bio-economic approach

    Directory of Open Access Journals (Sweden)

    Sika Gbegbelegbe

    2014-08-01

    Full Text Available This study uses a spatial bio-economic modelling framework to estimate the impact of the 2012 weather extreme in the USA on food security in the developing world. The study also quantifies the potential effects of a similar weather extreme occurring in 2050 under climate change. The study results indicate that weather extremes that affect maize productivity in key grain baskets can negatively affect food security in vulnerable countries. The 2012 weather extreme which occurred in the USA reduced US and global maize production by 29% compared to trend; maize consumption in the country decreased by 5% only and this resulted in less surplus maize for exports from the largest maize exporter in the world. Global maize production decreased by 6% compared to trend. The decrease in global maize production coupled with a reduction in the volume of global maize exports worsened food insecurity in eastern Africa, the Caribbean and Central America and India. The effects of the weather extreme on global food security would be worse, if the latter were to occur under climate change in 2050, assuming no climate change adaptation worldwide over the years. In addition, the hardest-hit regions would remain the same, whether the weather extreme occurs in 2012 instead of 2050: Sub-Saharan Africa (SSA, South Asia and the Latin America and Caribbean (LAC region. However, sustained growth in per capita income across world economies between 2000 and 2050 would allow few countries in SSA and the LAC region to virtually eliminate hunger within their borders. In these countries, per capita income would be high enough by 2050 to completely offset the negative effect of the weather extreme. The study results are also consistent with USDA׳s estimates on US and global maize production and consumption in 2012 after the weather extreme. Some discrepancy is found on the volume of global maize trade; this implies that the bio-economic model likely overestimates the effect of the

  13. Electron beam curing paint

    International Nuclear Information System (INIS)

    Maruyama, Tsutomu

    1991-04-01

    Electron beam curing (EBC) type paint is paint that is specially prepared so that it can be cured and dried by electron beam irradiation. Electron beam irradiation achieves hardly any curing and drying of ordinary normal-temperature drying type paint or heat-drying type paint. The main type of paint in which an electron beam produces a curing reaction is one in which a radical polymerization reaction takes place under irradiation. The use of this EBC painting - drying system has been considered for a variety of fields since it has a number of special features such as the fact that the paint dries instantaneously, no heat is applied and no solvent is used. (Author)

  14. A cure for HIV: is it in sight?

    Science.gov (United States)

    Pace, Matthew; Frater, John

    2014-07-01

    HIV is a devastating disease affecting millions of people worldwide despite the advent of successful antiretroviral therapy (ART). However, ART does not result in a cure and has to be taken for life. Accordingly, researchers are turning towards cure efforts, particularly in the light of two patients whose HIV has been seemingly eradicated. Numerous approaches and strategies have been considered for curing HIV, but no scalable and safe solution has yet been reached. With newly discovered difficulties in measuring the HIV reservoir, the main barrier to a cure, the only true test of cure is to stop ART and see whether the virus becomes detectable. However, it is possible that this treatment interruption may be associated with certain risks for patients. Here, we compare the current major approaches and recent advances for curing HIV, as well as discuss ways of evaluating HIV cure and the safety concerns involved.

  15. A simple Indian diabetes risk score could help identify nondiabetic individuals at high risk of non-alcoholic fatty liver disease (CURES-117).

    Science.gov (United States)

    Anbalagan, Viknesh Prabu; Venkataraman, Vijayachandrika; Vamsi, Mamilla; Deepa, Mohan; Mohan, Viswanathan

    2012-11-01

    We aim to determine whether a simple Indian diabetes risk score (IDRS) is associated with individuals with non-alcoholic fatty liver disease (NAFLD) among nondiabetic Asian Indians. Nondiabetic participants (n = 409) were selected from the Chennai Urban Rural Epidemiology Study. Mean age was 40 ± 11.9 years, mean body mass index was 23.2 ± 3.9 kg/m(2), and 224 (54.8%) were women. The IDRS was classified as high (≥60), medium (30-50), and low (<30) risk. Non-alcoholic fatty liver disease was assessed by high-resolution β mode ultrasonography. To determine the factors associated with NAFLD, a univariate analysis was first done and a stepwise logistic regression analysis was done based on the factors associated with NAFLD. Biochemical and anthropometric measurements were obtained using standardized procedures. The overall prevalence of NAFLD was 24.7% (101/409 participants), and it was significantly higher among those with a high (30.4%) and medium IDRS (21%) compared with the low IDRS group (15.8%; trend chi square; p = .022). In stepwise logistic regression, IDRS was associated with NAFLD with an adjusted odds ratio of 1.78 (95% confidence interval 1.04-3.06), even after adjusting for potential confounders. The IDRS can be used as the initial step to screen individuals at high risk of NAFLD in the community. © 2012 Diabetes Technology Society.

  16. Biofuel as an Integrated Farm Drainage Management crop: A bioeconomic analysis

    Science.gov (United States)

    Levers, L. R.; Schwabe, K. A.

    2017-04-01

    Irrigated agricultural lands in arid regions often suffer from soil salinization and lack of drainage, which affect environmental quality and productivity. Integrated Farm Drainage Management (IFDM) systems, where drainage water generated from higher-valued crops grown on high quality soils are used to irrigate salt-tolerant crops grown on marginal soils, is one possible strategy for managing salinity and drainage problems. If the IFDM crop were a biofuel crop, both environmental and private benefits may be generated; however, little is known about this possibility. As such, we develop a bioeconomic programming model of irrigated agricultural production to examine the role salt-tolerant biofuel crops might play within an IFDM system. Our results, generated by optimizing profits over land, water, and crop choice decisions subject to resource constraints, suggest that based on the private profits alone, biofuel crops can be a competitive alternative to the common practices of land retirement and nonbiofuel crop production under both low to high drainage water salinity. Yet IFDM biofuel crop production generates 30-35% fewer GHG emissions than the other strategies. The private market competitiveness coupled with the public good benefits may justify policy changes encouraging the growth of IFDM biofuel crops in arid agricultural areas globally.

  17. A welfare study into capture fisheries in cirata reservoir: a bio-economic model

    Science.gov (United States)

    Anna, Z.; Hindayani, P.

    2018-04-01

    Capture fishery in inland such as reservoirs can be a source of food security and even the economy and public welfare of the surrounding community. This research was conducted on Cirata reservoir fishery in West Java, to see how far reservoir capture fishery can contribute economically in the form of resource rents. The method used is the bioeconomic model Copes, which can analyze the demand and supply functions to calculate the optimization of stakeholders’ welfare in various management regimes. The results showed that the management of capture fishery using Maximum Economic Yield regime (MEY) gave the most efficient result, where fewer inputs would produce maximum profit. In the MEY management, the producer surplus obtained is IDR 2,610.203.099, - per quarter and IDR 273.885.400,- of consumer surplus per quarter. Furthermore, researches showed that sustainable management regime policy MEY result in the government rent/surplus ofIDR 217.891,345, - per quarter with the average price of fish per kg being IDR 13.929. In open access fishery, it was shown that the producer surplus becomesIDR 0. Thus the implementation of the MEY-based instrument policy becomes a necessity for Cirata reservoir capture fishery.

  18. Bioeconomic modeling for a small-scale sea cucumber fishery in Yucatan, Mexico.

    Science.gov (United States)

    Hernández-Flores, Alvaro; Cuevas-Jiménez, Alfonso; Poot-Salazar, Alicia; Condal, Alfonso; Espinoza-Méndez, Juan Carlos

    2018-01-01

    Due to the heavy exploitation of holothurians over the last few decades, it is necessary to implement fishing regulations aimed at reversing this situation. Holothurians require specific regulations that take into account their biology and ecology. Their behavior to group and form patches as a strategy for feeding, defense and reproduction, makes them vulnerable to overfishing. The higher the population density, the higher the catchability coefficient, and because they are sedentary organisms, the catchability does not change significantly until the density is very low. Hence, the stock assessment of holothurians can be improved by analyzing their spatial distribution. This paper proposes a stock assessment technique that considers the spatial distribution pattern of the sea cucumber Isostichopus badionotus from Yucatan, Mexico. A bioeconomic spatial model was developed to explain the interactions between fishing effort allocation, quasi-profits and the population in the short term. Because of the high price of the species and the low production costs, artisanal fishers preferred to maximize short-term quasi-profits, rather than the long-term benefits they could gain with low fishing mortality rates.

  19. Effort dynamics in a fisheries bioeconomic model: A vessel level approach through Game Theory

    Directory of Open Access Journals (Sweden)

    Gorka Merino

    2007-09-01

    Full Text Available Red shrimp, Aristeus antennatus (Risso, 1816 is one of the most important resources for the bottom-trawl fleets in the northwestern Mediterranean, in terms of both landings and economic value. A simple bioeconomic model introducing Game Theory for the prediction of effort dynamics at vessel level is proposed. The game is performed by the twelve vessels exploiting red shrimp in Blanes. Within the game, two solutions are performed: non-cooperation and cooperation. The first is proposed as a realistic method for the prediction of individual effort strategies and the second is used to illustrate the potential profitability of the analysed fishery. The effort strategy for each vessel is the number of fishing days per year and their objective is profit maximisation, individual profits for the non-cooperative solution and total profits for the cooperative one. In the present analysis, strategic conflicts arise from the differences between vessels in technical efficiency (catchability coefficient and economic efficiency (defined here. The ten-year and 1000-iteration stochastic simulations performed for the two effort solutions show that the best strategy from both an economic and a conservationist perspective is homogeneous effort cooperation. However, the results under non-cooperation are more similar to the observed data on effort strategies and landings.

  20. A bio-economic analysis of harvest control rules for the Northeast Arctic cod fishery.

    Science.gov (United States)

    Eikeset, Anne Maria; Richter, Andries P; Dankel, Dorothy J; Dunlop, Erin S; Heino, Mikko; Dieckmann, Ulf; Stenseth, Nils Chr

    2013-05-01

    Harvest control rules (HCRs) have been implemented for many fisheries worldwide. However, in most instances, those HCRs are not based on the explicit feedbacks between stock properties and economic considerations. This paper develops a bio-economic model that evaluates the HCR adopted in 2004 by the Joint Norwegian-Russian Fishery Commission to manage the world's largest cod stock, Northeast Arctic cod (NEA). The model considered here is biologically and economically detailed, and is the first to compare the performance of the stock's current HCR with that of alternative HCRs derived with optimality criteria. In particular, HCRs are optimized for economic objectives including fleet profits, economic welfare, and total yield and the emerging properties are analyzed. The performance of these optimal HCRs was compared with the currently used HCR. This paper show that the current HCR does in fact comes very close to maximizing profits. Furthermore, the results reveal that the HCR that maximizes profits is the most precautionary one among the considered HCRs. Finally, the HCR that maximizes yield leads to un-precautionary low levels of biomass. In these ways, the implementation of the HCR for NEA cod can be viewed as a success story that may provide valuable lessons for other fisheries.

  1. Radiation curing in the eighties

    International Nuclear Information System (INIS)

    Vrancken, A.

    1984-01-01

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

  2. Spatiotemporal bioeconomic performance of artificial shelters in a small-scale, rights-based managed Caribbean spiny lobster (Panulirus argus fishery

    Directory of Open Access Journals (Sweden)

    Maren Headley

    2017-03-01

    Full Text Available This study presents a bioeconomic analysis of artificial shelter performance in a fishery targeting a spiny lobster meta-population, with spatially allocated, individual exclusive benthic property rights for shelter introduction and harvest of species. Insights into fishers’ short-run decisions and fishing strategies are also provided. Spatiotemporal bioeconomic performance of shelters located in ten fishing areas during four seasons was compared using two-way ANOVAs and Pearson correlations. Results show that there was spatiotemporal heterogeneity in bioeconomic variables among fishing areas, with mean catch per unit effort (CPUE, kg shelter–1 ranging from 0.42 kg to 1.3 kg per trip, mean quasi-profits of variable costs per shelter harvested ranging from USD6.00 to USD19.57 per trip, and mean quasi-profits of variable costs ranging from USD338 to USD1069 per trip. Positive moderate correlations between shelter density and CPUE (kg shelter–1 km–2 were found. Bioeconomic performance of the shelters was influenced by spatiotemporal resource abundance and distribution, fishing area location in relation to the port, shelter density, heterogeneous fishing strategies and the management system. The results provide empirical information on the spatiotemporal performance of shelters and fishing strategies and can contribute to management at the local-scale of a meta-population distributed throughout the Caribbean Sea and Gulf of Mexico.

  3. Curing of Concrete

    African Journals Online (AJOL)

    surface coats, weak concrete blocks, leaky conduits and pipes illustrate defects frequently caused by improper curing .... Furthermore, water lost internally by self desiccation has to be replaced by water from outside, i.e. ... Other methods for preventing loss of moisture involve the use of liquid seal coat, or tight covers such as ...

  4. 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.

  5. Beam in on curing

    International Nuclear Information System (INIS)

    Holl, Dr.

    1981-01-01

    Electron beam curing of paints and allied materials is discussed. Examples of applications are: silicone papers; painting of metal; bonding of flake adhesives; bonding of grinding media (binders); paints for external uses; painting shaped parts; bi-reactive painting systems. An example is given of the calculation of the cost of irradiation. (U.K.)

  6. Management of Water and Fertilizer Consumption Using Bio-Economic Approach: A Case Study of Irrigation and Drainage Dorudzan

    International Nuclear Information System (INIS)

    Sheikhzeinoddin, A.; Esmaeili, A.; Zibaei, M.

    2016-01-01

    Today keep increasing the use of chemical fertilizer and water is an effort to improve yield, while overuse of fertilizer is making formerly arable land unusable but led to degrading the quality of water and serious problems for environmental. Hence, for accurate management, we require comprehensive and complete information on the economic and environmental impacts of different management methods. So, by using SWAT model were simulated the economic and environmental effects of each management strategies. Then, mathematical programming was used to determine the optimal cropping pattern subject to resources and environmental constraints in irrigation and Drainage Dorudzan. Based on the findings of this study, we can improve the economic and environmental benefits by moving from current status to economic or bio-economic pattern. Also, by moving from economic pattern to bio-economic pattern, 0.31 percent reduction of economic benefit is leading to improve nitrogen losses by 6.58 percent. In other words, we incur the cost equal to 64.5 thousand rials for reduction per kg nitrogen losses.

  7. Physician perceptions of HIV cure in China: A mixed methods review and implications for HIV cure research.

    Science.gov (United States)

    Rich, Zachary Clarke; Liu, Chuncheng; Ma, Qingyan; Hu, Fengyu; Cai, Weiping; Tang, Xiaoping; Tucker, Joseph David

    2015-09-01

    There are over 100 clinical trials worldwide focused on developing an HIV cure. Research participants will assume substantial individual risks while receiving little or no individual benefit. Physicians will have important dual roles of leading HIV cure research studies and guiding patient expectations. Many low and middle-income nations have started HIV cure trials, including China. The goal of this study was to better understand physician attitudes, behaviors, and perceptions of HIV cure research within the context of China. We conducted a quantitative and qualitative evidence review of published literature on physician perceptions of HIV cure in China. Quantitative survey data revealed that physicians rarely believed HIV was curable, but this perception may be more common compared to other countries. Qualitative data showed that inconsistent terminology used among physicians may contribute to the perception of HIV as curable. The belief that HIV is curable among some physicians in China may be related to the influence of traditional Chinese medicine beliefs. Rather than seeking elimination of pathogens, traditional Chinese medicine aims to achieve harmony between organs and a vital life force. In this context, HIV infection can be seen as a temporary state of imbalance rather than an irreversible change. There is a wide range of physician perceptions about HIV cure in China. Conflicting information about HIV cure from physicians and other sources could thwart the progress of HIV cure research. Enhancing patient-physician communication about ongoing HIV cure research trials will be important for developing an HIV cure.

  8. The cytotoxicity of resin composites cured with three light curing units at different curing distances

    OpenAIRE

    Ergün, Gülfem; Egilmez, Ferhan; Cekic Nagas, Isil

    2011-01-01

    Objective: The purpose of this study was to compare the effect of light curing distance on the cytotoxicity of five resin composites cured with three high-power light curing units. Study design: Seven cylindrical discs of each material (Grandio ®, Voco; Filtek ? Z250, 3M ESPE; Clearfil ? AP-X, Kuraray Co. Ltd.; Aelite ? LS, Bisco Inc. and Simile ®, Pentron) were cured. For curing, soft-up mode of quartz-tungsten-halogen, exponential mode of light emitting diode for 20 s, and ramp-curing m...

  9. The impact of climate and price risks on agricultural land use and crop management decisions

    NARCIS (Netherlands)

    Lehmann, N.; Finger, R.

    2013-01-01

    This article aims to investigate the impacts of climate change and of lower and more volatile crop price levels as currently observed in the European Union (EU) on optimal management decisions, average income and income risks in crop production in Western Switzerland. To this end, a bioeconomic

  10. Beam in on curing

    International Nuclear Information System (INIS)

    Holl, Dr.

    1981-01-01

    This third part of an article on the electron beam curing of paints covers the following aspects: inertising equipment; working without inert gas; increase in temperature when irradiating; irradiating plants; laboratory plants; plant operating from coil to coil; plant for shaped parts; possible applications; decorative films, paper, PVC; packaging material; metallisation of paper films; film bonding; strengthening of flock; coating; pressure sensitive adhesives. (U.K.)

  11. A bio-economic model to improve profitability in a large national beef cattle population

    Directory of Open Access Journals (Sweden)

    Javier López-Paredes

    2017-12-01

    Full Text Available A bio-economic model was developed for estimating economic values for use in improving profitability in a large national beef cattle population from birth to slaughter. Results were divided into fattening costs, production costs and income. Economic values were derived for 17 traits for two regions, mature weight (-0.43 € and -0.38 €/+1 kg of live weight, age at first calving (-0.13 € and -0.11 €/+1d, calving interval (-1.06 € and -1.02 €/+1d, age at last calving (0.03 € and 0.03 €/+1d, mortality 0-48 h (-5.86 € and -5.63 €/1% calves per cow and year, pre-weaning mortality (-5.96 € and -5.73 €/+1% calves per cow and year, fattening mortality (-8.23 € and -7.88 €/+1% calves per cow and year, adult mortality (-8.92 € and -7.34 €/+1% adult cows per cow and year, pre-weaning average daily gain (2.56 € and 2.84 €/+10g/d, fattening young animals average daily gain (2.65 € and 3.00 €/+10g/d, culled cow in fattening average daily gain (0.25 € and 0.16 €/+10g/d, culled cow dressing carcass percentage (3.09 € and 2.42 €/+1%, culled cow price (4.59 € and 3.59 €/+0.06 €/kg, carcass conformation score (16.39 € and 15.3 €/+1 SEUROP class, dressing carcass rate of calf (18.22 € and 18.23 €/+1%, carcass growth (9.00 € and 10.09 €/+10g of carcass weight/d and age at slaughter (0.27 € and 0.44 €/+1d. Two sample herds were used to show the economic impact of calving interval and age at first calving shortening in the profit per slaughtered young animal, which was 178 € and 111 € for Herds A and B, respectively. The economic values of functional traits were reduced and production traits were enhanced when fertility traits were improved. The model could be applied in a Spanish national program.

  12. 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...

  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. The cytotoxicity of resin composites cured with three light curing units at different curing distances.

    Science.gov (United States)

    Ergun, Gulfem; Egilmez, Ferhan; Cekic-Nagas, Isil

    2011-03-01

    The purpose of this study was to compare the effect of light curing distance on the cytotoxicity of five resin composites cured with three high-power light curing units. Seven cylindrical discs of each material (Grandio®, Voco; Filtek™ Z250, 3M ESPE; Clearfil™ AP-X, Kuraray Co. Ltd.; Aelite™ LS, Bisco Inc. and Simile®, Pentron) were cured. For curing, soft-up mode of quartz-tungsten-halogen, exponential mode of light emitting diode for 20 s, and ramp-curing mode of plasma arc light curing units for 6 s were used. The curing tip distances were determined as 2 and 9 mm and controlled via the use of metal rings. After ageing the samples for 24 and 72 hours in Dulbecco's Modified Eagle Medium/Ham's F12 (DMEM/F12), cytotoxicity of the extracts to cultured fibroblasts (L 929) was measured by using MTT (tetrazolium salt 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide) assay. The degree of cytotoxicity for each sample was determined according to the reference value represented by the cells in a pure culture medium. Statistical significance was determined using multifactorial analysis of variance. The type of resin composite (p light curing unit (p curing tip distance (p light emitting diode and plasma arc light curing units were used (p=0.184, F=1.448). The results of this study suggest that the light curing units and resin composites should be harmonized to one another and the curing distance between the tip of the light curing unit and the restoration surface should be as close as possible in order to achieve maximal biocompatibility.

  15. Modeling HIV Cure

    Science.gov (United States)

    Perelson, Alan; Conway, Jessica; Cao, Youfang

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

  16. Mixture proportioning for internal curing

    DEFF Research Database (Denmark)

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

    2005-01-01

    The concept of internal concrete curing is steadily progressing from the laboratory to field practice. In terminology currently being considered by ACI Committee 308, Curing Concrete, “internal curing refers to the process by which the hydration of cement occurs because of the availability...... 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...... hydration and strength development, reduced autogenous shrinkage and cracking, reduced permeability, and increased durability. The impact of internal curing begins immediately with the initial hydration of the cement, with benefits that are observed at ages as early as two days. Internal curing...

  17. The situation of radiation curing

    International Nuclear Information System (INIS)

    Chen Weixiu

    1988-01-01

    Radiation curing is a branch of radiation processing. It has developed significantly and its annual growth rate exceeds 10% in the nineteen eighties. Several products were manufactured by radiation curing, such as magnetic media, release coating, floor tile, printing flates, optical fiber, electronics, lithography and pressure sensitive adhesives etc. The chemistry of radiation curing is often considered ahead. The safe handling of UV/EB curable material, the regulation of industial and the patent protection for development in radiation curing were introduced. The equipment and processes of this field have got progress recently

  18. 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...... of external curing and novel methods of internal curing are described. It is stressed that proper curing is a key factor to achieve durable concrete.......It is known that some high-strength/high-performance concretes (HSC/HPC) are prone to cracking at an early age unless special precautions are taken. The paper deals with the methods of curing as one of the main strategies to ensure good performance of concrete. Curing by both external (conventional......) and internal methods is reviewed and analyzed, among other methods of mitigating shrinkage and cracking of concrete. The focus is on the mitigation of autogenous shrinkage of low water to binder ratio (w/b) concrete by means of internal curing. The concepts of internal curing are based on using lightweight...

  19. 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.

  20. Cure og giggle micturition..

    Science.gov (United States)

    Brocklebank, J T; Meadow, S R

    1981-01-01

    Two boys, aged 11 and 13, had involuntary, unstoppable, and complete emptying of the bladder on laughter. In one the wetting occurred only when standing and in company, but in the other occurred regardless of posture or company. One boy had a strong family history of wetting including a grandmother who had giggle micturition as a teenager. The symptoms had been present for between 1 and 2 years. However, unlike cases previously reported, each boy was cured--one within 6 weeks and the other within 6 months. It is not clear how much of the success was due to the general sympathetic and confidence-building measures used, advice about posture, or to the drug propantheline. PMID:7212764

  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. Curing efficiency of dual-cure resin cement under zirconia with two different light curing units.

    Science.gov (United States)

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

    2015-01-01

    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. 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. 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 (punit produced significantly greater VHN values compared to the QTH unit (pLight 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.

  3. 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.

  4. Excimer UV curing in printing

    International Nuclear Information System (INIS)

    Mehnert, R.

    1999-01-01

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

  5. The irradiation curing of coatings

    International Nuclear Information System (INIS)

    Autio, T.

    1974-01-01

    The electron beam irradiation curing of coatings has been technically feasible for over a decade. A brief description of the process is presented. The progress in this field has been astonishingly slow in comparison with the use of UV lamps as radiation source. The primary reason for this has been the great advantage in terms of capital cost of the UV curing lines and their ready adaptability to low or high production rates. A literature survey is given concerning basic and applied research in the electron curing area, patents, economics and existing installations around the world. (author)

  6. Self-curing concrete with different self-curing agents

    Science.gov (United States)

    Gopala krishna sastry, K. V. S.; manoj kumar, Putturu

    2018-03-01

    Concrete is recognised as a versatile construction material globally. Properties of concrete depend upon, to a greater extent, the hydration of cement and microstructure of hydrated cement. Congenial atmosphere would aid the hydration of cement and hence curing of concrete becomes essential, till a major portion of the hydration process is completed. But in areas of water inadequacy and concreting works at considerable heights, curing is problematic. Self-Curing or Internal Curing technique overcomes these problems. It supplies redundant moisture, for more than sufficient hydration of cement and diminish self-desiccation. Self-Curing agents substantially help in the conservation of water in concrete, by bringing down the evaporation during the hydration of Concrete. The present study focuses on the impact of self-curing agents such as Poly Ethylene Glycol (PEG), Poly Vinyl Alcohol (PVA) and Super Absorbent Polymer (SAP) on the concrete mix of M25 grade (reference mix). The effect of these agents on strength properties of Concrete such as compressive strength, split tensile strength and flexural strength was observed on a comparative basis which revealed that PEG 4000 was the most effective among all the agents.

  7. Increased risk of type 2 diabetes with ascending social class in urban South Indians is explained by obesity: The Chennai urban rural epidemiology study (CURES-116)

    DEFF Research Database (Denmark)

    Skar, Mette; Villumsen, Anne Berg; Christensen, Dirk Lund

    2013-01-01

    AIM: The aim of this study is to determine the factors responsible for differences in the prevalence of diabetes mellitus (DM) in subjects of different social class in an urban South Indian population. MATERIALS AND METHODS: Analyses were based on the cross-sectional data from the Chennai Urban...... measurements were performed and included in the analyses. Social class was classified based on income as low (Rs. social class, respectively (P ....001). A significant increase in the risk of diabetes was found with ascending social class (Intermediate class: Odds ratio [OR], 1.7 [confidence interval [CI], 1.2-2.3]; High class: OR, 2.0 [CI-1.4-2.9]). The multivariable adjusted logistic regression analysis revealed that the effect of social class on the risk...

  8. Industrial application of radiation curing

    International Nuclear Information System (INIS)

    Takashi Sasaki

    1993-01-01

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

  9. Bioeconomic modeling of lactational antimicrobial treatment of new bovine subclinical intramammary infections caused by contagious pathogens

    DEFF Research Database (Denmark)

    Van den Borne, B. H. P.; Hisham Beshara Halasa, Tariq; Van Schaik, G.

    2010-01-01

    of Staphylococcus aureus, Streptococcus uberis, Streptococcus dysgalactiae, and Escherichia coli during lactation and the dry period in a 100-cow dairy herd during 1 quota year. Input parameters on cure were obtained from recent Dutch field data. The costs of clinical IMI, subclinical IMI, and intervention were...... not limit the spread of Staph. aureus at high transmission rates, although the associated costs were lower compared with no intervention. To improve udder health in a dairy herd, lactational treatment of contagious subclinical IMI must therefore be preceded by management measures that lower the transmission...... of uncured cows after 2 mo of infection. Model behavior was observed for variation in parameter input values. Compared with no lactational intervention, lactational intervention of new subclinical IMI resulted in fewer clinical flare ups, less transmission within the herd, and much lower combined total...

  10. Paths to Change: Bio-Economic Factors, Geographical Gradients and the Land-Use Structure of Italy.

    Science.gov (United States)

    Masini, Emanuela; Barbati, Anna; Bencardino, Massimiliano; Carlucci, Margherita; Corona, Piermaria; Salvati, Luca

    2018-01-01

    This study introduces a bio-economic approach to evaluate the influence of local socioeconomic contexts on complex processes of landscape transformation (urbanization, withdrawal of farming with woodland creation and loss in crop mosaics) in a sustainable development perspective. Land-use and socioeconomic indicators (including shares of agriculture, industry and services in total product, per-worker value added, productivity by economic sector, distance from central cities, latitude and elevation) at the local district scale in Italy have been considered together in an exploratory approach based on multivariate statistics. The combined use of land-use and socioeconomic indicators was preferred to more traditional approaches based on single-variable analysis and allows identifying latent factors of landscape transformation at the local scale. Our approach sheds light in the intimate relationship between regional economic structures and land-use change in districts with varying socio-environmental attributes across Italy. Urban-rural divides, coastal-inland dichotomy and the elevation gradient were relevant factors shaping urbanization-driven landscape transformations at the country scale. Indicators of economic structure (and especially industrial production and per-worker productivity of industry and services) were also documented to influence greatly entity and direction of change in the use of land. Discontinuous and dispersed urbanization has been demonstrated to be spatially-decoupled from consolidated (continuous and compact) urbanization, expanding into undeveloped rural areas progressively far away from central cities and being spatially associated with forest land.

  11. Paths to Change: Bio-Economic Factors, Geographical Gradients and the Land-Use Structure of Italy

    Science.gov (United States)

    Masini, Emanuela; Barbati, Anna; Bencardino, Massimiliano; Carlucci, Margherita; Corona, Piermaria; Salvati, Luca

    2018-01-01

    This study introduces a bio-economic approach to evaluate the influence of local socioeconomic contexts on complex processes of landscape transformation (urbanization, withdrawal of farming with woodland creation and loss in crop mosaics) in a sustainable development perspective. Land-use and socioeconomic indicators (including shares of agriculture, industry and services in total product, per-worker value added, productivity by economic sector, distance from central cities, latitude and elevation) at the local district scale in Italy have been considered together in an exploratory approach based on multivariate statistics. The combined use of land-use and socioeconomic indicators was preferred to more traditional approaches based on single-variable analysis and allows identifying latent factors of landscape transformation at the local scale. Our approach sheds light in the intimate relationship between regional economic structures and land-use change in districts with varying socio-environmental attributes across Italy. Urban-rural divides, coastal-inland dichotomy and the elevation gradient were relevant factors shaping urbanization-driven landscape transformations at the country scale. Indicators of economic structure (and especially industrial production and per-worker productivity of industry and services) were also documented to influence greatly entity and direction of change in the use of land. Discontinuous and dispersed urbanization has been demonstrated to be spatially-decoupled from consolidated (continuous and compact) urbanization, expanding into undeveloped rural areas progressively far away from central cities and being spatially associated with forest land.

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

    Science.gov (United States)

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

    2014-01-01

    The curing reaction of a commercial cold-curing structural epoxy resin, specifically formulated for civil engineering applications, was analyzed by thermal analysis as a function of the curing time and the sample thickness. Original and remarkable results regarding the effects of curing time on the glass transition temperature and on the residual heat of reaction of the cold-cured epoxy were obtained. The influence of the sample thickness on the curing reaction of the cold-cured resin was 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. PMID:28788215

  13. 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.

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

    Directory of Open Access Journals (Sweden)

    Carola Esposito Corcione

    2014-09-01

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

  15. 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

  16. Participation in HIV cure-related research: a scoping review of the proxy literature and implications for future research.

    Science.gov (United States)

    Dubé, Karine; Ramirez, Catalina; Handibode, Jessica; Taylor, Jeffrey; Skinner, Asheley; Greene, Sandra; Tucker, Joseph D

    2015-10-01

    To identify the main types of HIV cure-related strategies and examine possible risks (and benefits) associated with participating in HIV cure-related research studies. We undertook a scoping review to first map out the landscape of HIV cure-related research and then examined the risks and potential benefits associated with participating in HIV cure research. Given the early stage of many HIV cure-related studies, we used proxy literatures from non-cure HIV research and cancer research in order to anticipate possible motivators and deterrents of participation in HIV cure-related studies. We discussed four main categories of HIV cure-related research: (1) early antiretroviral treatment (ART); (2) latency-reversing agents (LRAs); (3) therapeutic vaccinations and immune-based therapies (IBT); and (4) stem-cell transplantation and gene therapy. At this juncture, these categories of HIV cure-related research have substantial individual risks and negligible individual and clinical benefits. Non-cure HIV research (including HIV prevention and treatment) and cancer research have empirical similarities (and differences) to HIV cure research and may provide an opportunity to anticipate ethical and logistical challenges associated with HIV cure-related research participation and decision-making. Learning from the cancer field, a strong foundation of patient-participant and clinician-researcher trust will need to be established to facilitate recruitment of participants into HIV cure-related studies. Further empirical social science and ethics research will be necessary to inform clinical HIV cure-related research. The study of participation in HIV cure-related research can gain insights from proxy fields by incorporating study elements to clearly explain motivators and deterrents to participation and to inform the implementation of HIV cure-related studies. Study-specific contexts from the reviewed literature further demonstrate the importance of various types of research to

  17. Increased risk of type 2 diabetes with ascending social class in urban South Indians is explained by obesity: The Chennai urban rural epidemiology study (CURES-116

    Directory of Open Access Journals (Sweden)

    Mette Skar

    2013-01-01

    Full Text Available Aim: The aim of this study is to determine the factors responsible for differences in the prevalence of diabetes mellitus (DM in subjects of different social class in an urban South Indian population. Materials and Methods: Analyses were based on the cross-sectional data from the Chennai Urban Rural Epidemiology Study of 1989 individuals, aged ≥20 years. Entered in the analyses were information obtained by self-report on (1 household income; (2 family history of diabetes; (3 physical activity; (4 smoking status; (5 alcohol consumption. Biochemical, clinical and anthropometrical measurements were performed and included in the analyses. Social class was classified based on income as low (Rs. <2000 intermediate (Rs. 2000-5000` and high (Rs. 5000-20000. Results: The prevalence rates of DM were 12.0%, 18.4% and 21.7% in low, intermediate and high social class, respectively (P < 0.001. A significant increase in the risk of diabetes was found with ascending social class (Intermediate class: Odds ratio [OR], 1.7 [confidence interval [CI], 1.2-2.3]; High class: OR, 2.0 [CI-1.4-2.9]. The multivariable adjusted logistic regression analysis revealed that the effect of social class on the risk of diabetes remained significant (P = 0.016 when age, family history of diabetes and blood pressure were included. However, with the inclusion of abdominal obesity in the model, the significant effect of social class disappeared (P = 0.087. Conclusion: An increased prevalence of DM was found in the higher social class in this urban South Indian population, which is explained by obesity.

  18. 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).

  19. An Ultrasound Assessed Extraction Combined with Ion-Pair HPLC Method and Risk Assessment of Nitrite and Nitrate in Cured Meat

    Directory of Open Access Journals (Sweden)

    Babiker Yagoub Abdulkair

    2018-01-01

    Full Text Available An accurate IPC-UV method was developed and validated for the determination of nitrite (NI and nitrate (NA in meat products. The best separation was achieved on a phenyl-hexyl column (150 mm × 4.6 mm, 3 µm with a mobile phase composed of 25% acetonitrile and 75% buffer (2 mM disodium hydrogen phosphate and 3 mM tetrabutylammonium bromide, pH = 4. Eluents were monitored at 205 nm. Linearity ranges were 1.86 × 10−6–7.5 µg·ml−1 and 0.09–5.0 µg·ml−1 for NI and NA, respectively. The correlation coefficients were greater than 0.999 for NI and NA. This method was applied to a number of processed meat products in Riyadh (n = 155. NI ranged from 1.78 to 129.69 mg·kg−1, and NA ranged from 0.76 to 96.64 mg·kg−1. Results showed extensive use of NI and NA; however, concentrations were within the legal limit of Saudi Arabia except for one sample. Further, the risk assessment and dietary exposure have been estimated for both NI and NA.

  20. Increased risk of type 2 diabetes with ascending social class in urban South Indians is explained by obesity: The Chennai urban rural epidemiology study (CURES-116).

    Science.gov (United States)

    Skar, Mette; Villumsen, Anne Berg; Christensen, Dirk Lund; Petersen, Joergen Holm; Deepa, Mohan; Anjana, Ranjit Mohan; Pradeepa, Rajendra; Mohan, Viswanathan

    2013-11-01

    The aim of this study is to determine the factors responsible for differences in the prevalence of diabetes mellitus (DM) in subjects of different social class in an urban South Indian population. Analyses were based on the cross-sectional data from the Chennai Urban Rural Epidemiology Study of 1989 individuals, aged ≥20 years. Entered in the analyses were information obtained by self-report on (1) household income; (2) family history of diabetes; (3) physical activity; (4) smoking status; (5) alcohol consumption. Biochemical, clinical and anthropometrical measurements were performed and included in the analyses. Social class was classified based on income as low (Rs. social class, respectively (P social class (Intermediate class: Odds ratio [OR], 1.7 [confidence interval [CI], 1.2-2.3]; High class: OR, 2.0 [CI-1.4-2.9]). The multivariable adjusted logistic regression analysis revealed that the effect of social class on the risk of diabetes remained significant (P = 0.016) when age, family history of diabetes and blood pressure were included. However, with the inclusion of abdominal obesity in the model, the significant effect of social class disappeared (P = 0.087). An increased prevalence of DM was found in the higher social class in this urban South Indian population, which is explained by obesity.

  1. Dental light curing and its effects on color perception.

    Science.gov (United States)

    McCusker, Neil; Bailey, Clare; Robinson, Stephen; Patel, Naresh; Sandy, Jonathan R; Ireland, Anthony J

    2012-09-01

    Light curing has become increasingly popular for orthodontic bonding, partly as a result of improvements in light-curing unit technology and higher light intensities. The aim of this study was to determine orthodontists' knowledge of dental light-curing units, their safety aspects, and the possible effects on color perception. Questionnaires were administered to 120 specialists or trainees to assess their knowledge of light curing and safety issues. In addition, 15 orthodontists and 15 nonorthodontists were asked to complete the Farnsworth Munsell 100 hue test to assess color perception. One hundred four questionnaires were returned, giving a response rate of 86.6%. Light-emitting diode lights were the most popular (73.4%), followed by quartz-halogen (9.2%) and plasma lights (5.5%); 11.9% were unsure of the type of light used, 84% did not know the intensity, and 67% did not know the wavelength of the lights. Although most used safety equipment-eg, paddles-7% used no safety measures. Seventy-six percent were either unsure or took no precautions during light curing for staff or patients who had previous cataract surgery, and up to 99% were either unsure or took no precautions during light curing for staff or patients taking photosensitizing medications. With the Farnsworth Munsell test, 28 participants had average color discrimination, with 2 demonstrating superior discrimination. There were no differences between the orthodontists and the controls, or between men and women. Orthodontists' knowledge of dental light-curing units and hazards is poor. Although potential risks are associated with the long-term use of these light-curing units, no effect on color discrimination was detected. Copyright © 2012 American Association of Orthodontists. Published by Mosby, Inc. All rights reserved.

  2. Informed consent to HIV cure research.

    Science.gov (United States)

    Bromwich, Danielle; Millum, Joseph R

    2017-02-01

    Trials with highly unfavourable risk-benefit ratios for participants, like HIV cure trials, raise questions about the quality of the consent of research participants. Why, it may be asked, would a person with HIV who is doing well on antiretroviral therapy be willing to jeopardise his health by enrolling in such a trial? We distinguish three concerns: first, how information is communicated to potential participants; second, participants' motivations for enrolling in potentially high risk research with no prospect of direct benefit; and third, participants' understanding of the details of the trials in which they enrol. We argue that the communication concern is relevant to the validity of informed consent and the quality of decision making, that the motivation concern does not identify a genuine problem with either the validity of consent or the quality of decision making and that the understanding concern may not be relevant to the validity of consent but is relevant to the quality of decision making. In doing so, we derive guidance points for researchers recruiting and enrolling participants into their HIV cure trials, as well as the research ethics committees reviewing proposed studies. 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/.

  3. Advances in spot curing technology

    International Nuclear Information System (INIS)

    Burga, R.

    1999-01-01

    A brief review of spot curing technology was presented. The process which a spot of energy of a specific wavelength bandwidth and irradiance is used to cause a coating, encapsulant or adhesive to change from a liquid to a solid state

  4. Electron beam curing of coating

    International Nuclear Information System (INIS)

    Fujioka, S.; Fujikawa, Z.

    1974-01-01

    Electron beam curing (EBC) method, by which hardened coating film is obtained by polymerizing and cross-linking paint with electron beam, has finally reached industrialized stage. While about seven items such as short curing time, high efficiency of energy consumption, and homogeneous curing are enumerated as the advantages of EBC method, it has limitations of the isolation requirement from air needing the injection of inert gas, and considerable amount of initial investment. In the electron accelerators employed in EBC method, the accelerating voltage is 250 to 750 kV, and the tube current is several tens of mA to 200 mA. As an example of EBC applications, EBC ''Erio'' steel sheet was developed by the cooperative research of Nippon Steel Corp., Dai-Nippon Printing Co. and Toray Industries, Inc. It is a high-class pre-coated metal product made from galvanized steel sheets, and the flat sheets with cured coating are sold, and final products are fabricated by being worked in various shapes in users. It seems necessary to develop the paint which enables to raise added value by adopting the EBC method. (Wakatsuki, Y.)

  5. 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.

  6. Effects of environmental variability on recruitment and bioeconomic modelling in the Pacific sardine (Sardinops sagax caerulea fishery from Magdalena Bay, Baja California Sur, Mexico

    Directory of Open Access Journals (Sweden)

    Juan Antonio de Anda-Montañez

    2010-03-01

    Full Text Available Ricker's stock-recruitment equation, including the multivariate ENSO index (MEI as an environmental variable, was fitted to data of the Pacific sardine (Sardinops sagax caerulea fishery from Magdalena Bay, Baja California Sur, Mexico. The equation was then incorporated into an age-structured, bioeconomic model. Uncertainty was incorporated by using environmental fluctuations; seven-year projections, equivalent to one sardine generation, were computed. Five management options were considered in the projections: open access, effort at maximum sustainable economic yield (fMSE, catch at maximum sustainable yield (CMSY, equivalent effort level applied in the year 2004 (f2004, and an arbitrary catch quota of 40000 tons (CQ40000. Projection results were summarised by the indicator Net Present Value (NPV of the fishery for the modelled period. The strategies that involved some regulation in the effort level (fMSE and f2004 yielded the largest NPV. On the other hand, the strategies that involved regulation of the catch predicted—in addition to a lower NPV—a substantial increase in the effort to achieve the desired catch level. This study is the first bioeconomic approach for a sardine fishery management plan in this region.

  7. HIV cure research in South Africa: a preliminary exploration of stakeholder perspectives.

    Science.gov (United States)

    Moodley, Keymanthri; Staunton, Ciara; de Roubaix, Malcolm; Cotton, Mark

    2016-01-01

    Innovative strategies for HIV cure are in development and research studies are being designed and planned globally. South Africa is no exception. However, little is known about stakeholders' knowledge, understanding and expectations of future cure research. This study aimed to obtain in-depth qualitative insights into stakeholder perspectives at this formative stage of HIV cure research. Fifteen stakeholders were interviewed in an HIV research clinic in the Western Cape, South Africa with their consent. Interviews were transcribed verbatim and analysed using thematic content analysis. Broad themes that emerged included the meaning of cure, awareness of HIV cure research, risks and benefits of such research. General awareness and understanding of HIV cure research was lower than expected. Some participants expressed a fatalistic attitude to HIV and described it as an "end-time illness" with no prospect of cure. In general, HIV cure research was regarded as risky - biologically psychologically and socially. If study designs were to include treatment interruption, participants would comply only if success was guaranteed. Given these perceptions of HIV cure research, significant challenges to consent processes and participant recruitment can be anticipated. Authentic community engagement and intensive educational interventions will be necessary prior to future cure research in South Africa.

  8. 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

  9. Light curing in orthodontics; should we be concerned?

    Science.gov (United States)

    McCusker, Neil; Lee, Siu Man; Robinson, Stephen; Patel, Naresh; Sandy, Jonathan R; Ireland, Anthony J

    2013-06-01

    Light cured materials are increasingly used in orthodontic clinical practice and concurrent with developments in materials have been developments in light curing unit technology. In recent years the irradiances of these units have increased. The aim of this study was to determine the safe exposure times to both direct and reflected light. The weighted irradiance and safe exposure times of 11 dental curing lights (1 plasma arc, 2 halogen and 8 LED lights) were determined at 6 distances (2-60 cm) from the light guide tip using a spectroradiometer. In addition, using the single most powerful light, the same two parameters were determined for reflected light. This was done at a distance of 10 cm from the reflected light, but during simulated bonding of 8 different orthodontic brackets of three material types, namely stainless steel, ceramic and composite. The results indicate that the LED Fusion lamp had the highest weighted irradiance and the shortest safe exposure time. With this light the maximum safe exposure time without additional eye protection for the patient (at 10 cm), the operator (at 30 cm) and the assistant (at 60 cm) ranged from 2.5 min, 22.1 min and 88.8 min respectively. This indicates a relatively low short term risk during normal operation of dental curing lights. For reflected light at a distance of 10 cm the risk was even lower, but was affected by the material and shape of the orthodontic bracket under test. The short term risks associated with the use of dental curing lights, halogen, LED or plasma, appear to be low, particularly if as is the case adequate safety precautions are employed. The same is true for reflected light from orthodontic brackets during bonding. What is still unclear is the potential long term ocular effects of prolonged exposure to the blue light generated from dental curing lights. Copyright © 2013 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

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

    Science.gov (United States)

    ... also is possible that a person cured of Cushing disease might not recover their previous mental strength, including ... impairments in patients with long-term cure of Cushing’s disease. Journal of Clinical Endocrinology and Metabolism, 95 (6), ...

  11. Radiation sources EB and UV curing machines

    International Nuclear Information System (INIS)

    Takashi Sasaki

    1993-01-01

    This paper describes electron beam processors and related technologies for curing applications to facilitate those industrial personals who are trying to understand and evaluate the applicability and benefits of radiation curing to their products. 4 tabs., 10 figs

  12. Techniques for internal water curing of concrete

    DEFF Research Database (Denmark)

    Jensen, Ole Mejlhede; Pietro, Lura

    2003-01-01

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

  13. UV-cured polymer optics

    Science.gov (United States)

    Piñón, Victor; Santiago, Freddie; Vogelsberg, Ashten; Davenport, Amelia; Cramer, Neil

    2017-10-01

    Although many optical-quality glass materials are available for use in optical systems, the range of polymeric materials is limited. Polymeric materials have some advantages over glass when it comes to large-scale manufacturing and production. In smaller scale systems, they offer a reduction in weight when compared to glass counterparts. This is especially important when designing optical systems meant to be carried by hand. We aimed to expand the availability of polymeric materials by exploring both crown-like and flint-like polymers. In addition, rapid and facile production was also a goal. By using UV-cured thiolene-based polymers, we were able to produce optical materials within seconds. This enabled the rapid screening of a variety of polymers from which we down-selected to produce optical flats and lenses. We will discuss problems with production and mitigation strategies in using UV-cured polymers for optical components. Using UV-cured polymers present a different set of problems than traditional injection-molded polymers, and these issues are discussed in detail. Using these produced optics, we integrated them into a modified direct view optical system, with the end goal being the development of drop-in replacements for glass components. This optical production strategy shows promise for use in lab-scale systems, where low-cost methods and flexibility are of paramount importance.

  14. 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.

  15. Electron beam-cured coating

    International Nuclear Information System (INIS)

    Kishi, Naoyuki

    1976-01-01

    The method for hardening coatings by the irradiation with electron beams is reviewed. The report is divided into seven parts, namely 1) general description and characteristics of electron beam-cured coating, 2) radiation sources of curing, 3) hardening conditions and reaction behaviour, 4) uses and advantages, 5) latest trends of the industry, 6) practice in the field of construction materials, and 7) economy. The primary characteristics of the electron beam hardening is that graft reaction takes place between base resin and coating to produce strong adhesive coating without any pretreatment. A variety of base resins are developed. High class esters of acrylic acid monomers and methacrylic acid monomers are mainly used as dilutants recently. At present, scanning type accelerators are used, but the practical application of the system producing electron beam of curtain type is expected. The dose rate dependence, the repetitive irradiation and the irradiation atmosphere are briefly described. The filed patent applications on the electron beam hardening were analyzed by the officer of Japan Patent Agency. The production lines for coatings by the electron beam hardening in the world are listed. In the electron beam-cured coating, fifty percent of given energy is consumed effectively for the electron beam hardening, and the solvents discharged from ovens and polluting atmosphere are not used, because the paints of high solid type is used. The running costs of the electron beam process are one sixth of the thermal oven process. (Iwakiri, K.)

  16. 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.

  17. Photo-Curing: UV Radiation curing of polymers

    Science.gov (United States)

    Inman, Christina A.

    2004-01-01

    The Polymers Branch of the Materials Division is dedicated to the development of high-performance for a variety of applications. Areas of significant interest include high- temperature polymers, low density, and high strength insulating materials, conductive polymers, and high density polymer electrolytes. This summer our group is working diligently on a photo-curing project. There is interest in the medical community feel the need for a new and improved balloon that will be used for angioplasty (a form of heart surgery). This product should maintain flexibility but add many other properties. Like possibly further processability and resistance to infection. Our group intends on coming up with this product by using photo-enolization (or simply, photo-curing) by Diels-Alder trapping. The main objective was to synthesize a series of new polymers by Diels-Alder cycloaddition of photoenols with more elastomeric properties. Our group was responsible for performing the proper photo-curing techniques of the polymers with diacrylates and bismaleimides, synthesizing novel monomers, and evaluating experimental results. We attempted to use a diacrylate to synthesize the polymer because of previous research done within the Polymers Branch here at NASA. Most acrylates are commercially available, have more elastometric properties than a typical rigid aromatic structure has and they contain ethylene oxides in the middle of their structure that create extensive flexibility. The problem we encountered with the acrylates is that they photo chemically and thermally self polymerize and create diradicals at low temperatures; these constraints caused a lot of unnecessary side reactions. We want to promote solely, diketone polymerization because this type of polymerization has the ability to cause very elastic polymers. We chose to direct our attention towards the usage of maleimides because they are known for eliminating these unnecessary side reactions.

  18. Curing depth of composite resin light cured by LED and halogen light-curing units

    Science.gov (United States)

    Calixto, L. R.; Lima, D. M.; Queiroz, R. S.; Rastelli, A. N. S.; Bagnato, V. S.; Andrade, M. F.

    2008-11-01

    The purpose of this study was to evaluate the polymerization effectiveness of a composite resin (Z-250) utilizing microhardness testing. In total, 80 samples with thicknesses of 2 and 4 mm were made, which were photoactivated by a conventional halogen light-curing unit, and light-curing units based on LED. The samples were stored in water distilled for 24 h at 37°C. The Vickers microhardness was performed by the MMT-3 microhardness tester. The microhardness means obtained were as follows: G1, 72.88; G2, 69.35; G3, 67.66; G4, 69.71; G5, 70.95; G6, 75.19; G7, 72.96; and G8, 71.62. The data were submitted to an analysis of variance (ANOVA’s test), adopting a significance level of 5%. The results showed that, in general, there were no statistical differences between the halogen and LED light-curing units used with the same parameters.

  19. EXERT Yourself and Help in the Search for an Alzheimer's Cure

    Science.gov (United States)

    ... Yourself and Help in the Search for an Alzheimer’s Cure Can exercise slow or prevent cognitive decline in older people who are at increased risk for Alzheimer’s disease? The EXERT Study: Building Memories Through Exercise ...

  20. Incorporating Risks in Economic Values for Pigs in Smallholder Production Systems in Kenya

    DEFF Research Database (Denmark)

    Mbuthias, Jackson; Rewe, Thomas; Okeno, Tobias

    production systems in Kenya. In addition to traditional bio-economic profit model, a risk-rated model was used to derive risk-rated economic values. This model accounted for imperfect knowledge concerning risk attitude of farmers and variance of input and output prices. Positive economic values obtained...... for traits DP, LWg, LWs, PoSR, PrSR, SoSR and TNB indicate that targeting them in improvement would positively impact profitability in pig breeding programmes. Accounting for risks in the EVs did not yield errors greater than ±50%. Therefore both traditional and risk-rated models can be satisfactorily used...

  1. Radiation cured silicone rubber articles

    International Nuclear Information System (INIS)

    DuPont, J.G.; Goodwin, P.A.

    1984-01-01

    A process for making radiation cured silicone rubber articles is disclosed wherein a hydroxyl-terminated polysilaxane having a molecular weight from about 50,000 to about 2,000,000, optionally modified by mixing with up to 85% of an end-stopped silicone rubber, is mixed with from about 10 to about 70 parts per hundred of rubber of a finely divided silica filler with a particle size in the reinforcing range and other inert fillers as determined by desired final properties; the composition so prepared is formed into the desired shape at room temperature; the article so formed is precured to improve the mechanical properties of the material with which it is made by exposure to ammonia gas, ammonium hydroxide, or to the vapors or solutions of a volatile amine at room temperature; and the precured article is irradiated with high energy electrons or gamma radiation to effect a permanent cure of the material from which the article is formed

  2. 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.

  3. Microwave Cure of Phenol-Formaldehyde Adhesive

    OpenAIRE

    高谷, 政広; 田平, 英敏; 岡本, 忠

    2006-01-01

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

  4. How visible light curing came into dentistry.

    Science.gov (United States)

    Wilson, N H F

    2016-01-01

    The present paper details the history of the introduction of visible light curing into dentistry. This history provides an excellent example of 'out of the box', lateral thinking translation of innovative scientific technology into dentistry. Visible light curing is an important UK contribution to the recent history and current practice of dentistry, with several million visible light curing procedures being carried out globally on a daily basis.

  5. UV/EB curing market in Indonesia

    International Nuclear Information System (INIS)

    Hilmy, N.; Danu, S.

    1999-01-01

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

  6. Temperature rise induced by some light emitting diode and quartz-tungsten-halogen curing units.

    Science.gov (United States)

    Asmussen, Erik; Peutzfeldt, Anne

    2005-02-01

    Because of the risk of thermal damage to the pulp, the temperature rise induced by light-curing units should not be too high. LED (light emitting diode) curing units have the main part of their irradiation in the blue range and have been reported to generate less heat than QTH (quartz-tungsten-halogen) curing units. This study had two aims: first, to measure the temperature rise induced by ten LED and three QTH curing units; and, second, to relate the measured temperature rise to the power density of the curing units. The light-induced temperature rise was measured by means of a thermocouple embedded in a small cylinder of resin composite. The power density was measured by using a dental radiometer. For LED units, the temperature rise increased with increasing power density, in a statistically significant manner. Two of the three QTH curing units investigated resulted in a higher temperature rise than LED curing units of the same power density. Previous findings, that LED curing units induce less temperature rise than QTH units, does not hold true in general.

  7. 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

  8. 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.

  9. Pre-cure freezing affects proteolysis in dry-cured hams.

    Science.gov (United States)

    Bañón, S; Cayuela, J M; Granados, M V; Garrido, M D

    1999-01-01

    Several parameters (sodium chloride, moisture, intramuscular fat, total nitrogen, non-protein nitrogen, white precipitates, free tyrosine, L* a* b* values and acceptability) related with proteolysis during the curing were compared in dry-cured hams manufactured from refrigerated and frozen/thawed raw material. Pre-cure freezing increased the proteolysis levels significantly (pmeat, although it does not significantly affect the sensory quality of the dry-cured ham.

  10. Curing performance of a new-generation light-emitting diode dental curing unit.

    Science.gov (United States)

    Wiggins, Kim M; Hartung, Martin; Althoff, Olaf; Wastian, Christine; Mitra, Sumita B

    2004-10-01

    BACKGROUND; Recent technological advances have resulted in the marketing of high-powered, or HP, battery-operated light-emitting diode, or LED, dental curing lights. The authors examine the curing efficiency and peak polymerization temperature, or Tp, of a new HP LED curing light. The authors studied four visible light-curing, or VLC, units: HP LED (A), first-generation LED (B), conventional halogen (C) and high-intensity halogen (D). They determined the depth of cure, or DOC; adhesion; and Tp of three types of VLC resin-based composites after exposure to each light. The exposure times for units A and D were one-half those for units B and C. The power density of unit A was 1,000 milliwatts per square centimeter, which was comparable to that of unit D with turbo charge. The DOC and adhesion attained for all three resin-based composites after being light cured by unit A for a 10-second exposure time were equivalent to those after being light cured by unit D for a 10-second exposure time and to those after being light cured by units B and C for 20-second exposure times. The resin-based composites light cured by unit A attained significantly lower Tps than did those light cured by unit D at equivalent cure, or exposure, times and by unit C at twice the cure time. The authors found that Unit A effectively cured the resin-based composites at one-half the cure time of units B and C and at the same time as unit D, while maintaining low Tp. The battery-operated HP LED curing light might be an effective, time-saving alternative for clinicians to use in light curing resin-based composites.

  11. [Nonnius and the Spa cure].

    Science.gov (United States)

    Lecomte, J; Lemli, J; Marganne, M H; Melard, M

    1996-01-01

    The 12th of July 1635, Jan van Beverwyck wrote a letter from Dordrecht to his esteemed friend Luis Nunez, in Antwerp. He asked him for indications about the cure of kidney stones of which he was suffering. He had just passed two calculi very painfully. Nunez answered on July 31. His letter summarized his own experience with this disease. In such cases, temperate diuretics and emollients are well indicated: ingestion of light decoctions of Malva and Viola, Caerefolium and Parieteria as well as Marshmallow syrup. No purge and no 'chemicals'. However, the best remedy was drinking Spa water. Usually the best way to absorb it is to come to the springs, in the Ardennes, part of the independent Principality of Liège. However, considering the horrors of the war (the Thirty Years War) endangering the country, van Beverwyck would be wise to drink imported water during 40 or 50 days, while staying home quietly, in Dordrecht. The letter points out the importance of provoked diuresis in the treatment of kidney stones. On the other hand the letter is an illustration of the continuing contacts between the United Provinces and the Spanish territories and of the commercial traffic between Antwerp, Dordrecht and Spa. The exported water was bottled from many 'pouhons'. It was acid, ferruginous, sulfurous and saturated with carbon dioxide; no pathogen germs, at least at the spring. Nunez quoted the large number of his patients cured with Spa water in Antwerp. This is an illustration of its commercial expansion even during this critical period.

  12. Understanding bio-economics

    NARCIS (Netherlands)

    Patel, M.K.

    2008-01-01

    New plants for production of bio-based fuels, chemicals or plastics are being set up at an accelerating pace. However, this transition towards bio-based fuels, feedstocks and chemicals has not come without consequences. Increased demand has pushed up prices of key agricultural products such as maize

  13. 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.

  14. Animal models for HIV cure research

    Directory of Open Access Journals (Sweden)

    Ben Bruno Policicchio

    2016-01-01

    Full Text Available The HIV-1/AIDS pandemic continues to spread unabated worldwide and no vaccine exists within our grasp. Effective antiretroviral therapy (ART has been developed, but ART cannot clear the virus from the infected patient. A cure for HIV-1 is badly needed to stop both the spread of the virus in human populations and disease progression in infected individuals. A safe and effective cure strategy for HIV infection will require multiple tools and appropriate animal models are tools that are central to cure research. An ideal animal model should recapitulate the essential aspects of HIV pathogenesis and associated immune responses, while permitting invasive studies, thus allowing a thorough evaluation of strategies aimed at reducing the size of the reservoir (functional cure or eliminating the reservoir altogether (sterilizing cure. Since there is no perfect animal model for cure research, multiple models have been tailored and tested to address specific quintessential questions of virus persistence and eradication. The development of new nonhuman primate and mouse models, along with a certain interest in the feline model, have the potential to fuel cure research. In this review, we highlight the major animal models currently utilized for cure research and the contributions of each model to this goal.

  15. Animal Models for HIV Cure Research.

    Science.gov (United States)

    Policicchio, Benjamin B; Pandrea, Ivona; Apetrei, Cristian

    2016-01-01

    The HIV-1/AIDS pandemic continues to spread unabated worldwide, and no vaccine exists within our grasp. Effective antiretroviral therapy (ART) has been developed, but ART cannot clear the virus from the infected patient. A cure for HIV-1 is badly needed to stop both the spread of the virus in human populations and disease progression in infected individuals. A safe and effective cure strategy for human immunodeficiency virus (HIV) infection will require multiple tools, and appropriate animal models are tools that are central to cure research. An ideal animal model should recapitulate the essential aspects of HIV pathogenesis and associated immune responses, while permitting invasive studies, thus allowing a thorough evaluation of strategies aimed at reducing the size of the reservoir (functional cure) or eliminating the reservoir altogether (sterilizing cure). Since there is no perfect animal model for cure research, multiple models have been tailored and tested to address specific quintessential questions of virus persistence and eradication. The development of new non-human primate and mouse models, along with a certain interest in the feline model, has the potential to fuel cure research. In this review, we highlight the major animal models currently utilized for cure research and the contributions of each model to this goal.

  16. 7 CFR 29.6010 - Cured.

    Science.gov (United States)

    2010-01-01

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

  17. 9 CFR 319.103 - Cured beef tongue.

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 2 2010-01-01 2010-01-01 false Cured beef tongue. 319.103 Section 319... Cured beef tongue. In preparing “Cured Beef Tongue,” the application of curing solution to the fresh beef tongue shall not result in an increase in the weight of the cured beef tongue of more than 10...

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

    African Journals Online (AJOL)

    PROF. OLIVER OSUAGWA

    2015-12-01

    Dec 1, 2015 ... derived from therapy. This study was intended at determining the flexible Parametric Cure Fraction. Model for Gastric cancer Data. Suitability of four parametric mixture cure models were considered namely; Log Normal (LN) cure fraction model, Log Logistic (LL) cure fraction model, Weibull (W) cure fraction ...

  19. 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.

  20. EB/UV curing market in Malaysia

    International Nuclear Information System (INIS)

    Khairul Zaman Dahlan; Nik Ghazali Nik Salleh; Mohd Hilmi Mahmood

    1999-01-01

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

  1. Factors influencing EB curing of epoxy matrix

    International Nuclear Information System (INIS)

    Li Fengmei; Bao Jianwen; Chen Xiangbao; Bao Huaying; Wang Huiliang

    2002-01-01

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

  2. 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.

  3. Online monitoring method of degree of cure during non-isothermal microwave curing process

    Science.gov (United States)

    He, Yongxi; Li, Yingguang; Li, Nanya; Hao, Xiaozhong

    2018-02-01

    Curing rate is the variation rate of degree of cure with time, which is a crucial issue in the curing process of composite structures since it has a significant influence on the generation of voids and residual stresses. In this paper, an online monitoring method of degree of cure was presented based on refractive index measurement. The influence of cure and temperature variation on the refractive index of composite was separated in real time with a step-temperature refractive index separation method. Non-isothermal microwave curing process of carbon fiber/epoxy composite was monitored, and the degree of cure was obtained with a low measurement error of ±1.5% compared with that determined by off-line DSC measurement. The online monitoring method is a promising technology for smart manufacturing of composite structures.

  4. Managing dynamic epidemiological risks through trade

    Science.gov (United States)

    Horan, Richard D.; Fenichel, Eli P.; Finnoff, David; Wolf, Christopher A.

    2015-01-01

    There is growing concern that trade, by connecting geographically isolated regions, unintentionally facilitates the spread of invasive pathogens and pests – forms of biological pollution that pose significant risks to ecosystem and human health. We use a bioeconomic framework to examine whether trade always increases private risks, focusing specifically on pathogen risks from live animal trade. When the pathogens have already established and traders bear some private risk, we find two results that run counter to the conventional wisdom on trade. First, uncertainty about the disease status of individual animals held in inventory may increase the incentives to trade relative to the disease-free case. Second, trade may facilitate reduced long-run disease prevalence among buyers. These results arise because disease risks are endogenous due to dynamic feedback processes involving valuable inventories, and markets facilitate the management of private risks that producers face with or without trade. PMID:25914431

  5. A comparative evaluation of curing depth and compressive strength of dental composite cured with halogen light curing unit and blue light emitting diode: an in vitro study.

    Science.gov (United States)

    Kumar, C N Vijaya; Gururaj, M; Paul, Joseph

    2012-11-01

    To evaluate the curing depth and compressive strength of dental composite using halogen light curing unit and light emitting diode light curing unit. Eighty cylindrical composite specimens were prepared using posterior composite P60(3M). Forty specimens, out of which 20 samples (group A) cured with halogen light and 20 samples (group B) cured using light emitting diode (LED) light were checked for curing depth according to ISO 4049. Remaining 40 samples out of which 20 samples (group I) cured using halogen light and 20 samples (group II) cured using LED light were checked for compressive strength using Instron universal testing machine. Twenty samples (group A) cured with halogen light showed better curing depth than 20 samples (group B) cured with LED light. Twenty samples (group I) cured with halogen light showed almost similar results as 20 samples (group II) cured with LED light for compressive strength. Halogen light commonly used to cure composite resin have greater depth of cure, when compared to LED light, while both the lights produced compressive strength which is almost similar. Lower depth of cure with the LED unit, compared to the QTH unit, is associated with different light scattering due to differences in spectral emission. LED technology differs from QTH by the spectral emission that favorably matches the absorption spectrum of camphorquinone.

  6. Curing the stigma of leprosy.

    Science.gov (United States)

    Rafferty, Joy

    2005-06-01

    The stigma of leprosy is a real phenomenon in many people's lives that affects their physical, psychological, social and economical well-being. There are many causes for this damaging image of leprosy. There is no one easy answer to dispelling this image; it is something that has to be done in partnership with communities and patients. Many papers document the effects of stigma, but few discuss or trial solutions. Education and media campaigns counteract false beliefs about leprosy and raise awareness of new advances in the field. Leprosy care is increasingly provided in an integrated setting showing patients and their communities that leprosy is not a disease apart. Physical and socio-economic rehabilitation is worthwhile in restoring self worth and status in the community and helps patients to find employment. Group counselling can allow those with leprosy to talk about their feelings and experiences to empower one another. Gradually attitudes towards leprosy are changing, but there is still much to be done if the underlying menace of stigma is to be dealt with. We as health professionals must be prepared to make the first move and give that first touch. Certainly more research is needed. In the highly endemic countries the road to elimination may yet be long. Perhaps with effort we will one day be able not only to treat the disease, but also to cure the stigma of leprosy, and make that road an easier one.

  7. 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

  8. Curing of natural rubber and epoxy adhesive

    International Nuclear Information System (INIS)

    Matawie, A.M.; Sadek, E.M.

    2001-01-01

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

  9. Overview of UV and EB curing

    International Nuclear Information System (INIS)

    Garnett, J.L.

    2000-01-01

    Full text: UV and EB are complementary techniques in radiation curing. In the proposed paper, a brief review of both fields will be given. This will include principles of the process, the chemistry of the systems including monomers/oligomers/polymers used, additives required where necessary such as photoinitiators for UV, flow aids, adhesion promoters and the like. The types of equipment used in such processes will also be discussed including low energy electron beam utilisation and excimer curing. The advantages and disadvantages of both techniques will be examined. Mechanistic aspects of both curing systems will be discussed. Applications of the technology including developments in the banknote printing field will be summarised

  10. Radiation curing - twenty five years on

    International Nuclear Information System (INIS)

    Garnett, J.L.

    1995-01-01

    Progress in UV/EB curing during the past twenty five years is briefly reviewed. During this time developments in unique polymer chemistry, novel equipment design and the introduction of relevant educational programmes has enabled radiation curing to become an established technology with specific strengths in certain industries. Possible reasons for the emergence of the technology in these niche markets are discussed. Despite the worldwide recession, radiation curing is shown to be expanding at 5% per annum with the prospect of higher growth with improving economic conditions. (Author)

  11. [Is it possible to cure HIV infection?].

    Science.gov (United States)

    Gutiérrez, Carolina; Madrid, Nadia P; Moreno, Santiago

    2015-09-01

    Antiretroviral therapy has significantly improved the life expectancy in HIV-infected people, but it cannot cure the disease by itself. Several barriers have been identified for the cure of HIV infection, including a reservoir of latently infected cells, persistent viral replication in tissues, and anatomical sanctuaries. The main strategy proposed for the cure of HIV consists on the administration of drugs that, through the reactivation of latent HIV, would eliminate the cell reservoir. Ongoing clinical trials have shown the proof of concept, but the efficacy of these drugs in decreasing the reservoir size has not been proved so far.

  12. Traditional, complementary, and alternative medical cures for HIV: rationale and implications for HIV cure research.

    Science.gov (United States)

    Pan, Xin; Zhang, Alice; Henderson, Gail E; Rennie, Stuart; Liu, Chuncheng; Cai, Weiping; Wu, Feng; Tucker, Joseph D

    2017-12-13

    Traditional, complementary, and alternative medicine (TCAM) has been used by some people living with HIV (PLHIV) in an attempt to cure HIV. This article reviews the main factors influencing their decision to choose TCAM to cure HIV and discusses implications for HIV cure research. Those who decide to pursue traditional, complementary, and alternative medical cures may be influenced by the health system, cultural, and social dynamics, and their own individual beliefs and preferences. These same factors may impact participation in HIV cure research. People who search for traditional, complementary, and alternative medical cures may face special challenges as they are recruited, consented, and retained within HIV cure research studies. To address these potential challenges, we have suggested solutions focusing on culturally tailored communication and education, formative social science research, and community partnerships with key stakeholders. The social conditions that have promoted traditional, complementary and alternative medical cures will likely impact how PLHIV participate and experience HIV remission trials. Despite the potential challenges, it will be crucial to involve those who have previously sought out traditional cures for HIV in HIV cure research.

  13. 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.

  14. NONA Cure of Prepreg Structures, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — CRG's no-oven, no-autoclave (NONA) cure of OoA or autoclave prepreg materials allows the manufacture of large composite structures without the expensive and...

  15. 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...

  16. Radtech Asia'95 radiation curing conference proceedings

    International Nuclear Information System (INIS)

    1995-01-01

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

  17. Gamma and electron beam curing of polymers and composites

    International Nuclear Information System (INIS)

    Saunders, C.B.; Dickson, L.W.; Singh, A.

    1987-01-01

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

  18. 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.

  19. 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

  20. Application of a bioeconomic model for supporting the management process of the small pelagic fishery in the Veneto Region, northern Adriatic Sea, Italy

    Directory of Open Access Journals (Sweden)

    Silvia Silvestri

    2009-09-01

    Full Text Available We explore the sustainability of the small pelagics fishery in the northern Adriatic sea, northeastern Italy, by means of a bioeconomic simulation model. This model reproduces the biological and economic conditions in which the fisheries occur. Starting from an initial condition (2004, the simulation model incorporates the biological and economic processes of the resources and the fishing fleet and computes the most probable future trajectory of the system under different management conditions. We analysed the projection of selected indicators (biomass, recruitment, catches, profits under four different management scenarios based on effort control, and we assessed the performance of these management measures against the current situation. The four scenarios were: i increase in fuel price, ii reduction in fuel price, iii limiting the number of days at sea, and iv extending the fishing period. Each management event was introduced in the third year of the simulation. For each scenario a stochastic simulation was carried out. Our results show that the impact of each management measure tested was not homogeneous across the fleet. In particular, comparatively smaller vessels generally display narrower profit margins and tend to be more sensitive to negative shocks, reinforcing the idea that management measures should be calibrated by stratifying the fleet before implementation.

  1. A bio-economic evaluation of the potential for establishing a commercial fishery on two newly developed stocks: The Ionian red shrimp fishery

    Directory of Open Access Journals (Sweden)

    Jordi Guillen

    2012-05-01

    Full Text Available It has recently been shown that two deep-water red shrimp species (Aristeus antennatus and Aristaeomorpha foliacea have the potential to support a viable fishery in the Greek Ionian Sea (eastern Mediterranean. In this article, we investigate (i the evolution that this newly developed trawl shrimp fishery may undergo when subjected to different management measures, and (ii the most suitable extraction rates considering the uncertainties about the resource. We further analyse the effects that potential future fuel price increases and changes in the market may have on the fishery. Forecasting the biological and economic consequences of management actions, as well as the effects of market changes on inputs and outputs before they are applied, may help managers select the most suitable management options. We approach the problem by means of bio-economic simulation analysis. The results of this study show that fishing effort can increase by 50-100%, increasing the fleet’s profitability without jeopardizing the sustainability of the fishery.

  2. Radiation cured coatings for high performance products

    International Nuclear Information System (INIS)

    Parkins, J.C.; Teesdale, D.H.

    1984-01-01

    Development over the past ten years of radiation curable coating and lacquer systems and the means of curing them has led to new products in the packaging, flooring, furniture and other industries. Solventless lacquer systems formulated with acrylates and other resins enable high levels of durability, scuff resistance and gloss to be achieved. Ultra violet and electron beam radiation curing are used, the choice depending on the nature of the coating, the product and the scale of the operation. (author)

  3. Cycloaliphatic epoxide resins for cationic UV - cure

    International Nuclear Information System (INIS)

    Verschueren, K.; Balwant Kaur

    1999-01-01

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

  4. Additive effects in radiation grafting and curing

    International Nuclear Information System (INIS)

    Viengkhou, V.; Ng, L.

    1996-01-01

    Full text: Detailed studies on the accelerative effect of novel additives in radiation grafting and curing using acrylated monomer/oligomer systems have been performed in the presence of ionising radiation and UV as sources. Methyl methacrylate (MMA) is used as typical monomer for these grafting studies in the presence of the additives with model backbone polymers, cellulose and propropylene. Additives which have been found to accelerate these grafting processes are: mineral acid, occlusion compounds like urea, thermal initiators and photoinitiators as well as multifunctional monomers such as multifunctional acrylates. The results from irradiation with gamma rays have also been compared with irradiation from a 90W UV lamp. The role of the above additives in accelerating the analogous process of radiation curing has been investigated. Acrylated urethanes, epoxies and polyesters are used as oligomers together with acrylated monomers in this work with uv lamps of 300 watts/inch as radiation source. In the UV curing process bonding between film and substrate is usually due to physical forces. In the present work the presence of additives are shown to influence the occurrence of concurrent grafting during cure thus affecting the nature of the bonding of the cured film. The conditions under which concurrent grafting with UV can occur will be examined. A mechanism for accelerative effect of these additives in both grafting and curing processes has been proposed involving radiation effects and partitioning phenomena

  5. 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.

  6. Cure Cycle Optimization of Rapidly Cured Out-Of-Autoclave Composites

    Directory of Open Access Journals (Sweden)

    Anqi Dong

    2018-03-01

    Full Text Available Out-of-autoclave prepreg typically needs a long cure cycle to guarantee good properties as the result of low processing pressure applied. It is essential to reduce the manufacturing time, achieve real cost reduction, and take full advantage of out-of-autoclave process. The focus of this paper is to reduce the cure cycle time and production cost while maintaining high laminate quality. A rapidly cured out-of-autoclave resin and relative prepreg were independently developed. To determine a suitable rapid cure procedure for the developed prepreg, the effect of heating rate, initial cure temperature, dwelling time, and post-cure time on the final laminate quality were evaluated and the factors were then optimized. As a result, a rapid cure procedure was determined. The results showed that the resin infiltration could be completed at the end of the initial cure stage and no obvious void could be seen in the laminate at this time. The laminate could achieve good internal quality using the optimized cure procedure. The mechanical test results showed that the laminates had a fiber volume fraction of 59–60% with a final glass transition temperature of 205 °C and excellent mechanical strength especially the flexural properties.

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

    OpenAIRE

    Nurcan Ozakar Ilday; Yusuf Ziya Bayindir; Funda Bayindir; Aysel Gurpinar

    2013-01-01

    Background/purpose: Several factors may affects microhardness of resin cement under veneering materials. The aim of this study was to evaluate the effect of different veneering materials, light-curing units and curing times (20/3, 40/6) on the microhardness of dual-cured resin cement. Materials and methods: We pressed dual-cured resin cement specimens (Clearfil SA cement, 5 mm diameter, 1 mm thick) between two microscopic glass slides covered with transparent polystyrene matrix strips to r...

  8. Effect of curing agent type, cure treatment and organophilic clay on thermal properties of epoxy resin

    International Nuclear Information System (INIS)

    Leal, A.S.C.; Araujo, C.J. de; Silva, S.M.L.

    2010-01-01

    The effect of curing agent kind, curing conditions, and the incorporation of small amount of organoclay on the thermal properties of DGEBA epoxy resin was evaluated in order to develop an epoxy system for application as matrix in active composites (composites whose dispersed phase consists of shape memory alloy wires).The DGEBA resin was prepared using three amine derivatives as hardeners (TETA, DETA and DDS) under varied curing conditions, in the absence and presence of organoclay. Epoxy systems were characterized by dynamic mechanical analysis, optical microscopy and X-ray diffraction. According to results, the cured epoxy systems at elevated temperatures (DETA and DDS) showed higher glass transition temperature (T g ) and thermal stability values than the system cured at low temperature (TETA). In addition, when the post-cure treatment was used, the increases were superior. When 1 phr of organoclay was incorporated in DETA and DDS cured epoxy systems and post-cured, either the increase in the T g or thermal stability values were more significant, especially for the system cured with DDS. Hence, the epoxy/DDS/organoclay system (exfoliated nanocomposite) is the most appropriate to be used as matrix in the preparation of active composites since this matrix is thermally stable in the Ni-Ti shape memory alloy working range whose phase transformation occurs between 70-80 deg C. (author)

  9. Synergies, tensions and challenges in HIV prevention, treatment and cure research: exploratory conversations with HIV experts in South Africa.

    Science.gov (United States)

    Moodley, Keymanthri; Rossouw, Theresa; Staunton, Ciara; Colvin, Christopher J

    2016-04-30

    The ethical concerns associated with HIV prevention and treatment research have been widely explored in South Africa over the past 3 decades. However, HIV cure research is relatively new to the region and significant ethical and social challenges are anticipated. There has been no published empirical enquiry in Africa into key informant perspectives on HIV cure research. Consequently, this study was conducted to gain preliminary data from South African HIV clinicians, researchers and activists. In-depth interviews were conducted on a purposive sample of fourteen key informants in South Africa. Audiotaped interviews were transcribed verbatim with concurrent thematic analysis. The perspectives of HIV clinicians, researchers and activists were captured. Analyst triangulation occurred as the data were analysed by three authors independently. The rapid evolution of HIV cure research agendas was prominent with participants expressing some concern that the global North was driving the cure agenda. Participants described a symbiotic relationship between cure, treatment and prevention research necessitating collaboration. Assessing and managing knowledge and expectations around HIV cure research emerged as a central theme related to challenges to constructing 'cure' - how patients understand the idea of cure is important in explaining the complexity of cure research especially in the South African context where understanding of science is often challenging. Managing expectations and avoiding curative misconception will have implications for consent processes. Unique strategies in cure research could include treatment interruption, which has the potential to create therapeutic and ethical conflict and will be perceived as a significant risk. Ethical challenges in cure research will impact on informed consent and community engagement. It was encouraging to note the desire for synergy amongst researchers and clinicians working in the fields of prevention, treatment and cure

  10. 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 (Plight-cured temporary material exhibited the highest hardness 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.

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

    International Nuclear Information System (INIS)

    1993-01-01

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

  12. Recent advances in cured raw ham manufacture.

    Science.gov (United States)

    Bosse Née Danz, Ramona; Müller, Anne; Gibis, Monika; Weiss, Agnes; Schmidt, Herbert; Weiss, Jochen

    2018-03-04

    Cured raw hams are a valuable and popular group of meat products. The consumption and international trade have increased during the last years, therefore new technologies to accelerate the production process and to increase product quality and safety are needed. In the current review, an overview of European protected cured raw hams is presented. Furthermore, traditional methods for cured raw ham production together with recent advantages in the techniques for pretreatment (trimming, blade tenderization, and freeze-thawing), curing/salting (tumbling, vacuum impregnation, pulsed pressure, ultrasound, pulsed electric fields, simultaneous thawing/salting), drying/ripening (Quick-Dry-Slice-process, oil drop application, high temperature short time process) and postprocessing (vacuum and modified atmosphere packaging, high hydrostatic pressure, high pressure carbon dioxide, high pressure carbon dioxide with ultrasound) are described. Moreover, application techniques and effects of protective cultures and starter cultures, such as molds, yeasts, coagulase-negative staphylococci and lactic acid bacteria, on cured raw ham quality and safety are reviewed.

  13. Reply to Commentary: "Are HIV-Infected Candidates for Participation in Risky Cure-Related Studies Otherwise Healthy?"

    Science.gov (United States)

    Dubé, Karine; Sylla, Laurie; Dee, Lynda

    2018-02-01

    We respond to Eyal et al.'s commentary focusing on how people living with HIV participating in HIV cure-related studies are defined. We argue that the types of participants enrolled in research cannot be dissociated from the study interventions, the types of anticipated risks, and the background standard of care. As the field of HIV cure research advances, more nuance and granularity will be needed to define research criteria and acceptable risk/benefit ratios for cure study participants, as well as specific tiered protocol designs that serve to protect various participant populations from untoward risks, especially in very early phase research with interventions known to have potentially serious toxicities. We highlight key lessons from the ACTIVATE study involving a latency-reversing agent, Panobinostat, for HIV cure study design involving "otherwise healthy volunteers".

  14. Residual Stress Developed During the Cure of Thermosetting Polymers: Optimizing Cure Schedule to Minimize Stress.

    Energy Technology Data Exchange (ETDEWEB)

    Kropka, Jamie Michael; Stavig, Mark E.; Jaramillo, Rex

    2016-06-01

    When thermosetting polymers are used to bond or encapsulate electrical, mechanical or optical assemblies, residual stress, which often affects the performance and/or reliability of these devices, develops within the structure. The Thin-Disk-on-Cylinder structural response test is demonstrated as a powerful tool to design epoxy encapsulant cure schedules to reduce residual stress, even when all the details of the material evolution during cure are not explicitly known. The test's ability to (1) distinguish between cohesive and adhesive failure modes and (2) demonstrate methodologies to eliminate failure and reduce residual stress, make choices of cure schedules that optimize stress in the encapsulant unambiguous. For the 828/DEA/GMB material in the Thin-Disk-on-Cylinder geometry, the stress associated with cure is significant and outweighs that associated with cool down from the final cure temperature to room temperature (for measured lid strain, Scure I > I I e+h erma * II) * The difference between the final cure temperature and 1 1 -- the temperature at which the material gels, Tf-T ge i, was demonstrated to be a primary factor in determining the residual stress associated with cure. Increasing T f -T ge i leads to a reduction in cure stress that is described as being associated with balancing some of the 828/DEA/GMB cure shrinkage with thermal expansion. The ability to tune residual stress associated with cure by controlling T f -T ge i would be anticipated to translate to other thermosetting encapsulation materials, but the times and temperatures appropriate for a given material may vary widely.

  15. UV curing of nanoparticle reinforced acrylates

    Science.gov (United States)

    Bauer, F.; Flyunt, R.; Czihal, K.; Ernst, H.; Naumov, S.; Buchmeiser, M. R.

    2007-12-01

    To improve the surface hardness of radiation cured acrylate coatings, both silica nanoparticles and alumina particles with a few microns in size have been embedded into acrylate formulations. Regular mixing of nanoparticles into acrylate formulations, however, leads to highly viscous solutions inappropriate for coating procedures. The incompatibility of inorganic fillers and organic polymers can be avoided by surface modification of nanoparticles using trialkoxysilanes, which provide an interface between the two dissimilar materials. Nanoparticles modified by methacryloxypropyltrimethoxysilane (MEMO) and vinyltrimethoxysilane (VTMO), both having polymerisation-active groups, may be crosslinked with the acrylate resin. UV curing of the nanocomposites revealed an unexpected lower reactivity of the vinyl groups of VTMO modified silica compared to MEMO grafted on silica. For VTMO modification, DFT calculations showed a decrease of Mulliken atomic charge for the olefinic carbons pointing to a lower reactivity. For UV cured nano/microhybrid composites, a significant improvement of abrasion resistance was obtained.

  16. UV curing of nanoparticle reinforced acrylates

    Energy Technology Data Exchange (ETDEWEB)

    Bauer, F. [Leibniz-Institut fuer Oberflaechenmodifizierung, Permoserstr. 15, Leipzig D-04318 (Germany)], E-mail: frank.bauer@iom-leipzig.de; Flyunt, R.; Czihal, K. [Leibniz-Institut fuer Oberflaechenmodifizierung, Permoserstr. 15, Leipzig D-04318 (Germany); Ernst, H. [University of Leipzig, Department of Experimental Physics I, Leipzig D-04103 (Germany); Naumov, S. [Leibniz-Institut fuer Oberflaechenmodifizierung, Permoserstr. 15, Leipzig D-04318 (Germany); Buchmeiser, M.R. [Leibniz-Institut fuer Oberflaechenmodifizierung, Permoserstr. 15, Leipzig D-04318 (Germany); University of Leipzig, Institute of Technical Chemistry, Leipzig D-04103 (Germany)

    2007-12-15

    To improve the surface hardness of radiation cured acrylate coatings, both silica nanoparticles and alumina particles with a few microns in size have been embedded into acrylate formulations. Regular mixing of nanoparticles into acrylate formulations, however, leads to highly viscous solutions inappropriate for coating procedures. The incompatibility of inorganic fillers and organic polymers can be avoided by surface modification of nanoparticles using trialkoxysilanes, which provide an interface between the two dissimilar materials. Nanoparticles modified by methacryloxypropyltrimethoxysilane (MEMO) and vinyltrimethoxysilane (VTMO), both having polymerisation-active groups, may be crosslinked with the acrylate resin. UV curing of the nanocomposites revealed an unexpected lower reactivity of the vinyl groups of VTMO modified silica compared to MEMO grafted on silica. For VTMO modification, DFT calculations showed a decrease of Mulliken atomic charge for the olefinic carbons pointing to a lower reactivity. For UV cured nano/microhybrid composites, a significant improvement of abrasion resistance was obtained.

  17. Status of radiation curing in South America

    International Nuclear Information System (INIS)

    Machado, L.D.B.; Rotta, A.C.; Petrie, I.

    2007-01-01

    In August 2006, an agreement between the Rad tech International North America and the ATBCR, the Brazillian Technical Association for Radiation cure, turns ATCBR into RadTech South America. This new institution starts with already 10 years of history and pioneering technical experience and achievements in UV and EB radiation cure. Both RadTech institutions have asserted a whole cooperation and information exchange to continue with the initial ATBCR compromise in promoting UV and EB curing technology and to make it available to professionals, enterprise and other organizations. The RadTech South America has it's headquarter at the Energy and Nuclear Research Institute, IPEN, in Sao Paulo, Brazil, from whom also gets sponsorship. (Author)

  18. Influence of seawater mixing and curing on strength characteristics and porosity of ground granulated blast-furnace slag concrete

    Science.gov (United States)

    Adiwijaya; Hamada, H.; Sagawa, Y.; Yamamoto, D.

    2017-11-01

    Generally, in the concrete industry, several billion tons of fresh water are annually used for mixing water, curing water and cleaning water. Nevertheless, the utilization of seawater in the concrete industry is prohibited, because it increases the risk of corrosion of steel bars in concrete. This study presents strength characteristics and porosity of seawater mixed concrete and tap water mixed concrete incorporating Ground Granulated Blast-Furnace Slag (GGBS) with water-binder ratio (W/B) of 40%, 50% and 60%. The influence of seawater mixing, GGBS and curing conditions such as tap water curing (TC), seawater curing (SC) and air curing (AC) on the strength and porosity of concrete were evaluated. Based on investigation result, it was shown that there is no significant influence of seawater mixing in improving strength of GGBS concrete up to 365 days in TC and SC. Effectiveness of seawater-mixing on strength enhancement of GGBS concrete is larger in air curing than in water curing. Porosity of seawater-mixed concrete is decreased compared to tap water-mixed concrete in all curing conditions.

  19. BIOECONOMIC ANALYSIS OF CARBON FOREST SEQUESTRATION AND OF THE ECOLOGICAL DEBT: AN APPLICATION TO THE CASE OF RIO GRANDE DO SUL

    Directory of Open Access Journals (Sweden)

    Valny Giacomelli Sobrinho

    2009-09-01

    Full Text Available Though heavily criticized, the Kyoto Protocol has stood out as the key political tool in addressing climate change. However, one of the few instruments that allows industrialized and developing countries to cooperate towards mitigation of GHGs is CDM (Clean Development Mechanism. The underlying assumption of forestry CDM is that forest plantations (afforestation/ reforestation might help remove carbon dioxide (the most representative GHG emissions and compensate for the loss of natural forests. Therefore, this study focuses on this alleged trade-off. A bioeconomic analysis, which abstracts out money variables, is applied to assess carbon forest sequestration in Rio Grande do Sul. The state’s forest area is split up into natural and planted forests only. On one hand, this does not allow to check out for deforestation; on the other hand, such a phenomenon is not remarkable in Rio Grande do Sul. The land use is taken into account by a function that works as the emission removal demand. On the other hand, the emission supply function depends on the economic growth rates. The results show that, eventually, the sustainability of economic growth hinges on a region’s or country’s ecological situation – namely, equilibrium, credit or debt. The economic and environmental advantages of each mitigation strategy – CDM and natural forest conservation – are crosschecked. A nearly 40-year-long overshoot rate is, after all, estimated for the forest sector in Rio Grande do Sul. The estimates suggest that CDM might help to relieve environmental stress only where ecological credit is reported. Where ecological debt is already on, CDM was found unable to compensate for conservation disregard.

  20. SMART: a spatially explicit bio-economic model for assessing and managing demersal fisheries, with an application to italian trawlers in the strait of sicily.

    Directory of Open Access Journals (Sweden)

    Tommaso Russo

    Full Text Available Management of catches, effort and exploitation pattern are considered the most effective measures to control fishing mortality and ultimately ensure productivity and sustainability of fisheries. Despite the growing concerns about the spatial dimension of fisheries, the distribution of resources and fishing effort in space is seldom considered in assessment and management processes. Here we propose SMART (Spatial MAnagement of demersal Resources for Trawl fisheries, a tool for assessing bio-economic feedback in different management scenarios. SMART combines information from different tasks gathered within the European Data Collection Framework on fisheries and is composed of: 1 spatial models of fishing effort, environmental characteristics and distribution of demersal resources; 2 an Artificial Neural Network which captures the relationships among these aspects in a spatially explicit way and uses them to predict resources abundances; 3 a deterministic module which analyzes the size structure of catches and the associated revenues, according to different spatially-based management scenarios. SMART is applied to demersal fishery in the Strait of Sicily, one of the most productive fisheries of the Mediterranean Sea. Three of the main target species are used as proxies for the whole range exploited by trawlers. After training, SMART is used to evaluate different management scenarios, including spatial closures, using a simulation approach that mimics the recent exploitation patterns. Results evidence good model performance, with a noteworthy coherence and reliability of outputs for the different components. Among others, the main finding is that a partial improvement in resource conditions can be achieved by means of nursery closures, even if the overall fishing effort in the area remains stable. Accordingly, a series of strategically designed areas of trawling closures could significantly improve the resource conditions of demersal fisheries in

  1. SMART: a spatially explicit bio-economic model for assessing and managing demersal fisheries, with an application to italian trawlers in the strait of sicily.

    Science.gov (United States)

    Russo, Tommaso; Parisi, Antonio; Garofalo, Germana; Gristina, Michele; Cataudella, Stefano; Fiorentino, Fabio

    2014-01-01

    Management of catches, effort and exploitation pattern are considered the most effective measures to control fishing mortality and ultimately ensure productivity and sustainability of fisheries. Despite the growing concerns about the spatial dimension of fisheries, the distribution of resources and fishing effort in space is seldom considered in assessment and management processes. Here we propose SMART (Spatial MAnagement of demersal Resources for Trawl fisheries), a tool for assessing bio-economic feedback in different management scenarios. SMART combines information from different tasks gathered within the European Data Collection Framework on fisheries and is composed of: 1) spatial models of fishing effort, environmental characteristics and distribution of demersal resources; 2) an Artificial Neural Network which captures the relationships among these aspects in a spatially explicit way and uses them to predict resources abundances; 3) a deterministic module which analyzes the size structure of catches and the associated revenues, according to different spatially-based management scenarios. SMART is applied to demersal fishery in the Strait of Sicily, one of the most productive fisheries of the Mediterranean Sea. Three of the main target species are used as proxies for the whole range exploited by trawlers. After training, SMART is used to evaluate different management scenarios, including spatial closures, using a simulation approach that mimics the recent exploitation patterns. Results evidence good model performance, with a noteworthy coherence and reliability of outputs for the different components. Among others, the main finding is that a partial improvement in resource conditions can be achieved by means of nursery closures, even if the overall fishing effort in the area remains stable. Accordingly, a series of strategically designed areas of trawling closures could significantly improve the resource conditions of demersal fisheries in the Strait of

  2. Radiation curing applications of palm oil acrylates

    International Nuclear Information System (INIS)

    Mohd Hilmi Mahmood; Khairul Zaman; Rida, Anak Tajau; Mek Zah Salleh; Rosley Che Ismail

    2007-01-01

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

  3. UV/EB curing in Australia

    International Nuclear Information System (INIS)

    Woods, R.; Garnett, J.; Loo Teck Ng

    1999-01-01

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

  4. 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.

  5. 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.

  6. Why have we failed to cure Alzheimer's disease?

    Science.gov (United States)

    Korczyn, Amos D

    2012-01-01

    There is widespread recognition in the urgency to understand the causes and mechanisms of senile dementia. Attempts to find cures for Alzheimer's disease (AD) have, however, failed so far, in spite of enormous investments, intellectual and financial. We therefore have to reconsider the problem from new angles. AD is regarded as a disease because of its clinical manifestations and underlying pathology. However, this combination does not define a disease but rather a syndrome, just like hepatic cirrhosis in which liver pathology causes metabolic changes, but which can result from many different etiologies. It is unlikely that attacking a downstream phenomenon, like apoptosis or amyloid-β accumulation, can cure AD, or prevent the progression of the disease. It is probable that senile dementia is the result of a combination of several processes, working differently in each person. Epidemiological studies have identified many risk factors for "senile dementia of the Alzheimer type", some genetic but most environmental and therefore modifiable. Thus, a concerted action to fight the dementia epidemic must be made by aggressive action against its risk factors, and this battle must begin in midlife, not in old age.

  7. Stakeholder Engagement in HIV Cure Research: Lessons Learned from Other HIV Interventions and the Way Forward

    Science.gov (United States)

    Chu, Carissa; Ananworanich, Jintanat; Excler, Jean-Louis; Tucker, Joseph D.

    2015-01-01

    Abstract Clinical and basic science advances have raised considerable hope for achieving an HIV cure by accelerating research. This research is dominated primarily by issues about the nature and design of current and future clinical trials. Stakeholder engagement for HIV cure remains in its early stages. Our analysis examines timing and mechanisms of historical stakeholder engagement in other HIV research areas for HIV-uninfected individuals [vaccine development and pre-exposure prophylaxis (PrEP)], and HIV-infected individuals (treatment as prevention, prevention of mother-to-child transmission, and treatment of acute HIV infection) and articulate a plan for HIV cure stakeholder engagement. The experience from HIV vaccine development shows that early engagement of stakeholders helped manage expectations, mitigating the failure of several vaccine trials, while paving the way for subsequent trials. The relatively late engagement of HIV stakeholders in PrEP research may partly explain some of the implementation challenges. The treatment-related stakeholder engagement was strong and community-led from the onset and helped translation from research to implementation. We outline five steps to initiate and sustain stakeholder engagement in HIV cure research and conclude that stakeholder engagement represents a key investment in which stakeholders mutually agree to share knowledge, benefits, and risk of failure. Effective stakeholder engagement prevents misconceptions. As HIV cure research advances from early trials involving subjects with generally favorable prognosis to studies involving greater risk and uncertainty, success may depend on early and deliberate engagement of stakeholders. PMID:26061668

  8. Stakeholder Engagement in HIV Cure Research: Lessons Learned from Other HIV Interventions and the Way Forward.

    Science.gov (United States)

    Lo, Ying-Ru; Chu, Carissa; Ananworanich, Jintanat; Excler, Jean-Louis; Tucker, Joseph D

    2015-07-01

    Clinical and basic science advances have raised considerable hope for achieving an HIV cure by accelerating research. This research is dominated primarily by issues about the nature and design of current and future clinical trials. Stakeholder engagement for HIV cure remains in its early stages. Our analysis examines timing and mechanisms of historical stakeholder engagement in other HIV research areas for HIV-uninfected individuals [vaccine development and pre-exposure prophylaxis (PrEP)], and HIV-infected individuals (treatment as prevention, prevention of mother-to-child transmission, and treatment of acute HIV infection) and articulate a plan for HIV cure stakeholder engagement. The experience from HIV vaccine development shows that early engagement of stakeholders helped manage expectations, mitigating the failure of several vaccine trials, while paving the way for subsequent trials. The relatively late engagement of HIV stakeholders in PrEP research may partly explain some of the implementation challenges. The treatment-related stakeholder engagement was strong and community-led from the onset and helped translation from research to implementation. We outline five steps to initiate and sustain stakeholder engagement in HIV cure research and conclude that stakeholder engagement represents a key investment in which stakeholders mutually agree to share knowledge, benefits, and risk of failure. Effective stakeholder engagement prevents misconceptions. As HIV cure research advances from early trials involving subjects with generally favorable prognosis to studies involving greater risk and uncertainty, success may depend on early and deliberate engagement of stakeholders.

  9. 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 ...

  10. Curing reactions of palm oil alkyd enamels

    International Nuclear Information System (INIS)

    Tan Boon Yeow; Gan Seng Neon

    2000-01-01

    Amino resins are the most popularly used cross-linking agents for thermosetting coatings. The most common amino resins are those derived from melamine, 2,4,6-triamino-1,3,5-triazine and formaldehyde. They are attractive for developing high performance and low cost coatings to improve performances of other film-forming resins with reactive functional groups such as hydroxyl, carboxylic, and amide groups. Alkyds modified with melamine are mainly used in industrial baking enamels for metal surfaces. Short-oil alkyds containing 38-45% phthalic anhydride and a high proportion of hydroxyl values in the alkyd resins render good compatibility with melamine-formaldehyde resins. However, the actual mechanisms and pathways of the curing reactions involved are still not fully understood. This paper describes three palm oil alkyds, synthesized with high hydroxyl values. Clear coating enamels were made by mixing 4 parts; of alkyd resin with 1 part of a methylated melamine resin. The complex curing reactions of the clear enamel can be illustrated qualitatively by using DSC (Differential Scanning Calorimeter). Thermogravimetric analysis (TGA) was used to set suitable curing temperatures without degradation. The dry hard time with various curing temperatures was examined. Fourier transform infrared (FTIR) spectroscopy has been used to follow the changes in functional group concentrations as a function of time and temperature. (author)

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

    Indian Academy of Sciences (India)

    frequency is due to the hopping of charge carriers (Papa- thanassiou 2002). 5. Conclusions. Magnetoactive composites containing nickel in poly- chloroprene and nitrile matrices have been prepared. The cure characteristics reveal that the processability and flexibility of the matrix is not affected much even up to a maximum ...

  12. 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.

  13. Campus Violence: Kinds, Causes, and Cures.

    Science.gov (United States)

    Whitaker, Leighton C., Ed.; Pollard, Jeffrey W., Ed.

    This volume offers 14 papers on the types, sources, and possible cures of violence on college campuses from prominent workers in higher education. Following a preface the titles are: (1) "Conceptualizing Campus Violence: Definitions, Underlying Factors, and Effects" by Mary L. Roark; (2) "Administrative Perspectives on Disruptive…

  14. 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....

  15. 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 ...

  16. Electron-beam curing of epoxy resins

    Indian Academy of Sciences (India)

    Electron-beam (e-beam) induced polymerization of epoxy resins proceeds via cationic mechanism in presence of suitable photoinitiator. Despite good thermal properties and significant processing advantages, epoxy-based composites manufactured using e-beam curing suffer from low compressive strength, poor ...

  17. Salt intake, cured meat consumption, refrigerator use and stomach cancer incidence: A prospective cohort study (Netherlands)

    NARCIS (Netherlands)

    Brandt, P.A. van den; Botterweck, A.A.M.; Goldbohm, R.A.

    2003-01-01

    Objective: Many case-control studies have reported that salt and cured meat intake are positively, and refrigerator use is inversely, associated with stomach cancer risk. In the current prospective study these associations were evaluated. Methods: The Netherlands Cohort Study consisted of 120,852

  18. An emerging alternative to thermal curing: Electron curing of fiber-reinforced composites

    International Nuclear Information System (INIS)

    Singh, A.; Saunders, C.B.; Lopata, V.J.; Kremers, W.; Chung, M.

    1995-01-01

    Electron curing of fiber-reinforced composites to produce materials with good mechanical properties has been demonstrated by the authors' work, and by Aerospatiale. The attractions of this technology are the technical and processing advantages offered over thermal curing, and the projected cost benefits. Though the work so far has focused on the higher value composites for the aircraft and aerospace industries, the technology can also be used to produce composites for the higher volume industries, such as transportation and automotive

  19. Mechanical properties of provisional crown and bridge materials: chemical-curing versus dual-curing systems.

    Science.gov (United States)

    Balkenhol, Markus; Mautner, Meike Christina; Ferger, Paul; Wöstmann, Bernd

    2008-01-01

    This study aimed to investigate the flexural strength (FS) and flexural modulus (FM) of provisional crown and bridge materials at different storage times after mixing using materials with different curing mechanisms (dual-curing vs. self-curing). FS and FM of four proprietary materials (Trim, Luxatemp AM Plus, Luxatemp AM Plus Solar and Cool Temp Natural) were tested in a 3-point bending test according to EN ISO 4049:2000 at various times after mixing (37 degrees C dry/water) including thermocycling (5000x, 5-55 degrees C). Mean values of all measurements were calculated and subjected to the Games-Howell test (p=0.05) as well as a regression analysis (p=0.05). A two-way ANOVA (p=0.05) was used to identify the influence of the curing mechanism and chemical nature of the materials used. FS ranged between 11.1 and 24.0 MPa and FM between 82.5 and 548.2 MPa for all tested materials except for the dual-curing material (FS: 82.4 MPa; FM: 2060 MPa) 10 min after mixing. The r2-values, describing the goodness-of-fit of the regression curve for the relation between the mechanical properties and storage time, ranged from 0.701 to 0.979 for the composite based materials and 0.671 to 0.685 for the methacrylate resin. The chemical nature and curing mechanism significantly influenced (p<0.001) the mechanical properties, however, the influence of the curing mechanism disappeared at progressive points in time after mixing comparing Luxatemp AM Plus versus Luxatemp AM Plus Solar. FS and FM significantly depend on the time after mixing. Composite resin based materials are preferred versus methacrylate resins due to more favourable mechanical properties. If a high mechanical strength is indispensable directly after fabrication, a dual-curing provisional material is recommended.

  20. International cooperation for the cure and prevention of severe hemoglobinopathies.

    Science.gov (United States)

    Faulkner, Lawrence B; Uderzo, Cornelio; Masera, Giuseppe

    2013-08-01

    Thalassemia major (TM) is the most frequent life-threatening noninfectious disease of childhood in the Middle East, South Asia, and Pacific Islands where it accounts for a significant proportion of childhood mortality, morbidity, and related health care expenses. In spite of major advances in supportive care during the last decade, many patients in low-income and middle-income countries still fare poorly because of high treatment costs and lack of accessible multidisciplinary teams, not to consider the risk of blood-borne infections, primarily hepatitis C. In selected low-risk patients with a compatible sibling, TM is highly curable by bone marrow transplantation (BMT), which also improves the quality of life and is cost-effective. Starting in 2008, the Cure2Children Foundation (C2C), an Italian Non-Governmental Organization, has supported a BMT network in Pakistan, which during 2012 was extended to India. The primary aim of this project was to assess feasibility, outcomes, and costs of matched-related BMT for thalassemia in young low-risk children using a well-established and tolerable strategy. A total of 100 matched-related BMTs have been performed to date by partner institutions within this C2C-supported network; in the 50 low-risk cases with TM, over 90% disease-free survival was obtained with procedure expenses within 10,000 USD/BMT, that is, an outcome comparable to that obtained in affluent countries but with a fraction of the expenses. This cure rate was also obtained in start-up BMT centers (1 in Pakistan and 1 in India) within a structured and intensive cooperation program. Twinning and other international cooperation strategies based on shared principles and a common vision may substantially facilitate access to BMT.

  1. A global survey of HIV-positive people's attitudes towards cure research.

    Science.gov (United States)

    Simmons, R; Kall, M; Collins, S; Cairns, G; Taylor, S; Nelson, M; Fidler, S; Porter, K; Fox, J

    2017-02-01

    Involvement of people living with HIV (PLHIV) in the design of HIV cure studies is important, given the potential risks to participants. We present results of an international survey of PLHIV to define these issues and inform cure research. PLHIV were recruited in June-November 2014 through HIV websites, advocacy forums, social media and 12 UK HIV clinics. The survey included questions concerning demographics, HIV disease history, the desirability of types of cure and the patient's willingness to accept potential toxicity and treatment interruption (TI). We examined factors associated with TI and willingness to accept substantial risks. A total of 982 PLHIV completed the survey; 87% were male, 79% white and 81% men who have sex with men (MSM). Fifty-one per cent were aged 25-44 years and 69% were UK residents. The median time since diagnosis was 7 years [interquartile range (IQR) 2-17 years]. Eighty-eight per cent were receiving antiretrovirals (91% reported undetectable viral load). Health/wellbeing improvements (96%) and an inability to transmit HIV (90%) were more desirable cure characteristics than testing HIV-negative (69%). Ninety-five per cent were interested in participating in cure studies, and 59% were willing to accept substantial risks. PLHIV with a low CD4 count [201-350 cells/μL vs. ≥ 350 cells/μL; odds ratio (OR) 2.11; 95% confidence interval (CI) 1.11-4.00] were more likely to accept risks, whereas those with limited knowledge of HIV treatments vs. excellent/good knowledge and those aged ≥ 65 years vs. 45-64 years were less likely to accept risks [OR 0.58 (95% CI 0.37-0.90) and OR 0.18 (95% CI 0.07-0.45), respectively]. TI was acceptable for 62% of participants, with the main concerns being becoming unwell (82%), becoming infectious (76%) and HIV spreading through the body (76%). Cure research was highly acceptable to the PLHIV surveyed. Most individuals would accept risks, including TI, even in the absence of personal benefit. An optimal cure

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

    DEFF Research Database (Denmark)

    van Dijken, Jan WV; Pallesen, Ulla

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

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

    Directory of Open Access Journals (Sweden)

    Chean-Cheng Su

    2013-01-01

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

  4. Use of 'eradication' in HIV cure-related research: a public health debate.

    Science.gov (United States)

    Dubé, Karine; Luter, Stuart; Lesnar, Breanne; Newton, Luke; Galea, Jerome; Brown, Brandon; Gianella, Sara

    2018-02-13

    The landscape of Human Immunodeficiency Virus (HIV) research has changed drastically over the past three decades. With the remarkable success of antiretroviral treatment (ART) in decreasing AIDS-related mortality, some researchers have shifted their HIV research focus from treatment to cure research. The HIV cure research community often uses the term eradication to describe the science, and talks about eradicating the virus from the body. In public discourse, the term eradication could be conflated with disease eradication at the population level. In this paper, we call for a reframing of HIV cure research as control, as it is a more accurate descriptor and achievable goal in the foreseeable future. The properties of HIV are discordant with eradicability standards at both the individual level (as a clinical concept), and at the population level (as a public health concept). At the individual level, true eradication would necessitate absolute elimination of all latent HIV reservoirs from the body. Current HIV cure-related research strategies have proven unsuccessful at accurately quantifying, let alone eliminating these reservoirs. At the population level, eradication implies the permanent global reduction of HIV to zero new cases and to zero risk for future cases. Given the absence of an efficacious HIV vaccine and the impracticality and unethicality of eliminating animal reservoirs, global eradication of HIV is highly implausible. From a public health perspective, HIV eradication remains an elusive goal. The term 'eradication' is a misleading description of current HIV cure-related research. Instead, we call for the use of more realistic expressions such as 'sustained virologic HIV suppression (or control)' or 'management of HIV persistence' to describe HIV cure-related research. Using these terms reorients what HIV cure science can potentially achieve in the near future and avoids creating unrealistic expectations, particularly among the millions of people

  5. Ultrasonic and thermo-kinetic characterization of curing epoxy resin

    OpenAIRE

    Ali, Sheikh Mohammod

    2013-01-01

    This study combines cure kinetics modelling and thermal and ultrasonic cure monitoring to characterize the cure state of a complex commercial modified epoxy thermosetting system of industrial importance containing two epoxies, diethylene triamine hardener, external catalyst, aliphatic reactive diluent, and mica. Both catalyst and reactive diluent in the formulation of two epoxy resin mixture keep this complex system odd from others and to some extent a new one to report cure kinetics to the b...

  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. 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 internal curing water is in the approximate range 0.1–1 e/kg....

  8. 9 CFR 319.104 - Cured pork products.

    Science.gov (United States)

    2010-01-01

    ... INSPECTION AND CERTIFICATION DEFINITIONS AND STANDARDS OF IDENTITY OR COMPOSITION Cured Meats, Unsmoked and... in the following chart: Type of cured pork product Minimum meat PFF percentage 1 Product name and... 9 Animals and Animal Products 2 2010-01-01 2010-01-01 false Cured pork products. 319.104 Section...

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

    International Nuclear Information System (INIS)

    Ukachi, Takashi

    2003-01-01

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

  10. effect of light intensity on the cure characteristics of photo

    African Journals Online (AJOL)

    2012-05-05

    May 5, 2012 ... of material factors on the variables being measured. Light curing units in the sampled clinics were used to cure the composite specimens, which were all cylindrical. The one for micro-hardness evaluation measured eight millimetres in diameter and three millimetres in height while the other for depth of cure.

  11. Studying Room Temperature Curing of Phenolic Resin and their Composites

    Directory of Open Access Journals (Sweden)

    M.H. Beheshty

    2007-10-01

    Full Text Available Phenolic resins are synthetic low molecular weight thermoset resins which are polymerized and cured to higher molecular weights by condensation method. These resins have high weathering resistance, high oxidative thermal properties and good chemical resistance. Phenolic resins can be cured thermally or by acid curing. The most common method of curing phenolic resin is by thermal curing that takes place in the range of 130-180oC. At room temperature, however, phenolic resins are cured by acid catalysts. In this paper, room temperature curing of resol phenolic resin by para toluene sulphonic acid has been investigated. The acid quantity has been determined for room temperature curing of two types of resols to achieve a reasonable hardness and gelation time. Temperature curing and thermal stability of respective resins have been investigated by DSC and TGA, respectively. A glass-phenolic composite plate has been prepared and cured by these two methods. The results show that the optimum amount of acid is 20% by weight. Optimum mechanical properties, chemical resistance and thermal properties have been achieved for acid cured system. The hot cured resin, however, has better properties.

  12. 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...

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

    African Journals Online (AJOL)

    AIC, mean time to cure), variance and cure fraction (c) were used to determine the flexible Parametric Cure Fraction Model among the considered models. Gastric Cancer data from 76 patients received adjuvant CRT and 125 receiving resection (surgery) alone were used to confirm the suitability of the models. The data was ...

  14. Effect of curing time on microstructure and mechanical strength ...

    Indian Academy of Sciences (India)

    The aim of this paper is to study the influence of curing time on the microstructure and mechanical strength development of alkali activated binders based on vitreous calcium aluminosilicate (VCAS). Mechanical strength of alkali activated mortars cured at 65 °C was assessed for different curing times (4–168 h) using 10 ...

  15. Highly Conductive Carbon Fiber Reinforced Concrete for Icing Prevention and Curing

    Directory of Open Access Journals (Sweden)

    Oscar Galao

    2016-04-01

    Full Text Available This paper aims to study the feasibility of highly conductive carbon fiber reinforced concrete (CFRC as a self-heating material for ice formation prevention and curing in pavements. Tests were carried out in lab ambient conditions at different fixed voltages and then introduced in a freezer at −15 °C. The specimens inside the freezer were exposed to different fixed voltages when reaching +5 °C for prevention of icing and when reaching the temperature inside the freezer, i.e., −15 °C, for curing of icing. Results show that this concrete could act as a heating element in pavements with risk of ice formation, consuming a reasonable amount of energy for both anti-icing (prevention and deicing (curing, which could turn into an environmentally friendly and cost-effective deicing method.

  16. Virulence factor genotypes of Helicobacter pylori affect cure rates of eradication therapy.

    Science.gov (United States)

    Sugimoto, Mitsushige; Yamaoka, Yoshio

    2009-01-01

    The cure rates of Helicobacter pylori infection by using a combination of a proton pump inhibitor (PPI) and antimicrobial agents are mainly influenced by bacterial susceptibility to antimicrobial agents and the magnitude of acid inhibition during the treatment. Currently used empirical triple therapies do not reliably produce a > or =80% cure rate on an intention-to-treat basis. Therefore, tailored regimens based on relevant microbiological findings and pharmacogenomics are recommended for attaining an acceptable > or =95% cure rate. Recently, virulence factors of H. pylori, such as cagA and vacA, are reported to be major factors determining the cure rates. Individuals infected with strains with cagA-negative and vacA s2 genotypes have significantly increased risk of eradication failure of H. pylori infection. These virulence factors enhance gastric mucosal inflammation and are associated with the development of peptic ulcer and gastric cancer. H. pylori virulence factors induce proinflammatory cytokines, such as interleukin (IL)-1, IL-8, and tumor necrosis factor (TNF)- which influence mucosal inflammation and/or gastric acid secretion. When physicians select an H. pylori eradication regimen with an acceptable cure rate, they might need to consider H. pylori virulence factors, especially cagA and vacA.

  17. Greenhouse Gas Emission Mitigation And Agriculture, Trade-off Or Win-win Situation: Bioeconomic Farm Modelling In The Sudanian Area of Burkina Faso

    Science.gov (United States)

    Some, T. E.; Barbier, B.

    2015-12-01

    Climate changes talks regularly underline that developing countries' agriculture could play a stronger role in GHGs mitigation strategies and benefit from the Kyoto Protocol program of subsidies. Scientists explain that agriculture can contribute to carbon mitigation by storing more carbon in the soil through greener cropping systems. In this context, a growing number of research projects have started to investigate how developing countries agriculture can contribute to these objectives. The clean development mechanism (CDM) proposed in the Kyoto protocol is one particular policy instrument that can incite farmers to mitigate the GHG balance towards more sequestration and less emission. Some economists such as Michael Porter think that environmental regulation lead to a win-win outcome, in which case subsidies are not necessary. If it is a trade-off between incomes and the environment, subsidies are required. CDM can be mobilized to support the mitigation strategy. Agriculture implies the use of inputs. Reducing the emission implies the reduction of those inputs which will in turn imply a yield decrease. The study aims to assess whether this measure will imply a trade-off between environmental and economic objectives or a win-win situation. I apply this study to the case of small farmers in Burkina Faso through environmental instruments such as the emissions limits and agroforestry using a bioeconomic model, in which the farmers maximize their utility subject to constraints. The study finds that the limitation of emissions in annual crops production involves a trade-off. by impacting negatively their net cash come. By integrating perennial crops in the farming system, the farmers' utility increases. Around 6,118 kg are sequestrated individually. By computing the value on this carbon balance, farmers' net cash incomes go better. Then practicing agroforestry is a win-win situation, as they reach a higher level of income, and reduce emissions. Policymakers must

  18. Estimation of metastatic cure after radionuclide therapy.

    Science.gov (United States)

    Bernhardt, P; Forssell-Aronsson, E

    2007-12-01

    Targeted radionuclide therapy of disseminated tumor disease involves many factors that will affect the therapeutic outcome. For optimization of such therapy, it is important to know how these factors affect the therapeutic outcome. In this paper, the metastatic cure probability (MCP) model is described. The MCP model is a valuable tool for analyses of the various factors influencing the metastatic cure. The factors discussed are: 1) the physical parameters (the energy and range of emitted particles, absorbed dose-distributions, and cross-irradiation of tumors from the surrounding normal tissue) and 2) the biological parameters (radiosensitivity of tumors, tumor distributions, tumor growth rate, metastasis formation rate, variable tumor activity concentration and non-homogeneous tumor activity distributions).

  19. Environmental and conservation considerations for electron curing

    International Nuclear Information System (INIS)

    Nablo, S.V.; Fletcher, P.M.

    1992-01-01

    This paper reviews the more important features of electron curing pertaining to environmental protection and conservation. The high electrical conversion efficiencies of these devices measured at output power levels to 200 kilowatts are reviewed with attention to energy transport to the product. The comparative energetics of free radical initiated addition chemistry with that of the more conventional condensation polymerized systems are presented. Some details of recent studies of the repulpability and de-inkability of electron cured products are presented with mill scale trials showing successful recycling with up to 75 % EB processed material in the waste. The ability of energetic electrons to effectively replace toxic chemicals such as H 2 O 2 and ethylene oxide in product sterilization will be presented with a discussion of the regulatory aspects of this process for medical device applications. (author)

  20. 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.

  1. Coating and curing apparatus and methods

    Science.gov (United States)

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

    2015-02-24

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

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

    International Nuclear Information System (INIS)

    Cho, Donghwan; Cheon, Jinsil

    2013-01-01

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

  3. Curing profile of bulk-fill resin-based composites.

    Science.gov (United States)

    Li, Xin; Pongprueksa, Pong; Van Meerbeek, Bart; De Munck, Jan

    2015-06-01

    To evaluate the curing profile of bulk-fill resin-based composites (RBC) using micro-Raman spectroscopy (μRaman). Four bulk-fill RBCs were compared to a conventional RBC. RBC blocks were light-cured using a polywave LED light-curing unit. The 24-h degree of conversion (DC) was mapped along a longitudinal cross-section using μRaman. Curing profiles were constructed and 'effective' (>90% of maximum DC) curing parameters were calculated. A statistical linear mixed effects model was constructed to analyze the relative effect of the different curing parameters. Curing efficiency differed widely with the flowable bulk-fill RBCs presenting a significantly larger 'effective' curing area than the fibre-reinforced RBC, which on its turn revealed a significantly larger 'effective' curing area than the full-depth bulk-fill and conventional (control) RBC. A decrease in 'effective' curing depth within the light beam was found in the same order. Only the flowable bulk-fill RBCs were able to cure 'effectively' at a 4-mm depth for the whole specimen width (up to 4mm outside the light beam). All curing parameters were found to statistically influence the statistical model and thus the curing profile, except for the beam inhomogeneity (regarding the position of the 410-nm versus that of 470-nm LEDs) that did not significantly affect the model for all RBCs tested. Most of the bulk-fill RBCs could be cured up to at least a 4-mm depth, thereby validating the respective manufacturer's recommendations. According to the curing profiles, the orientation and position of the light guide is less critical for the bulk-fill RBCs than for the conventional RBC. Copyright © 2015 Elsevier Ltd. All rights reserved.

  4. Tools for Visualizing HIV in Cure Research.

    Science.gov (United States)

    Niessl, Julia; Baxter, Amy E; Kaufmann, Daniel E

    2018-02-01

    The long-lived HIV reservoir remains a major obstacle for an HIV cure. Current techniques to analyze this reservoir are generally population-based. We highlight recent developments in methods visualizing HIV, which offer a different, complementary view, and provide indispensable information for cure strategy development. Recent advances in fluorescence in situ hybridization techniques enabled key developments in reservoir visualization. Flow cytometric detection of HIV mRNAs, concurrently with proteins, provides a high-throughput approach to study the reservoir on a single-cell level. On a tissue level, key spatial information can be obtained detecting viral RNA and DNA in situ by fluorescence microscopy. At total-body level, advancements in non-invasive immuno-positron emission tomography (PET) detection of HIV proteins may allow an encompassing view of HIV reservoir sites. HIV imaging approaches provide important, complementary information regarding the size, phenotype, and localization of the HIV reservoir. Visualizing the reservoir may contribute to the design, assessment, and monitoring of HIV cure strategies in vitro and in vivo.

  5. Modeling fates and impacts for bio-economic analysis of hypothetical oil spill scenarios in San Francisco Bay

    International Nuclear Information System (INIS)

    French McCay, D.; Whittier, N.; Sankaranarayanan, S.; Jennings, J.; Etkin, D.S.

    2002-01-01

    The oil spill risks associated with four submerged rock pinnacles near Alcatraz Island in San Francisco Bay are being evaluated by the United States Army Corps of Engineers. Oil spill modeling has been conducted for a hypothetical oil spill to determine biological impacts, damages to natural resources and response costs. The scenarios are hypothetical vessel grounding on the pinnacles. The SIMAP modeling software by the Applied Science Associates was used to model 3 spill sizes (20, 50 and 95 percentile by volume) and 4 types of oil (gasoline, diesel, heavy fuel oil, and crude oil). The frequency distribution of oil fates and impacts was determined by first running each scenario in stochastic mode. The oil fates and biological effects of the spills were the focus of this paper. It was shown that diesel and crude oil spills would have greater impacts in the water column than heavy fuel or gasoline because gasoline is more volatile and less toxic and because heavy oil spills would be small in volume. It was determined that the major impacts and damage to birds would be low due to the high dilution potential of the bay. It was also noted that dispersants would be very effective in reducing impacts on wildlife and the shoreline. These results are being used to evaluate the cost-benefit analysis of removing the rocks versus the risk of an oil spill. The work demonstrates a statistically quantifiable method to estimate potential impacts that could be used in ecological risk assessment and cost-benefit analysis. 15 refs., 13 tabs., 11 figs

  6. Study on the heat-resistant EB curing composites

    International Nuclear Information System (INIS)

    Bao Jianwen; Li Yang; Li Fengmei

    2000-01-01

    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)

  7. 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.

  8. 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.

  9. Residual-based model diagnosis methods for mixture cure models.

    Science.gov (United States)

    Peng, Yingwei; Taylor, Jeremy M G

    2017-06-01

    Model diagnosis, an important issue in statistical modeling, has not yet been addressed adequately for cure models. We focus on mixture cure models in this work and propose some residual-based methods to examine the fit of the mixture cure model, particularly the fit of the latency part of the mixture cure model. The new methods extend the classical residual-based methods to the mixture cure model. Numerical work shows that the proposed methods are capable of detecting lack-of-fit of a mixture cure model, particularly in the latency part, such as outliers, improper covariate functional form, or nonproportionality in hazards if the proportional hazards assumption is employed in the latency part. The methods are illustrated with two real data sets that were previously analyzed with mixture cure models. © 2016, The International Biometric Society.

  10. 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.

  11. Modeling the curing process of thick-section autoclave cured composites

    Science.gov (United States)

    Loos, A. C.; Dara, P. H.

    1985-01-01

    Temperature gradients are significant during cure of large area, thick-section composites. Such temperature gradients result in nonuniformly cured parts with high void contents, poor ply compaction, and variations in the fiber/resin distribution. A model was developed to determine the temperature distribution in thick-section autoclave cured composites. Using the model, long with temperature measurements obtained from the thick-section composites, the effects of various processing parameters on the thermal response of the composites were examined. A one-dimensional heat transfer model was constructed for the composite-tool assembly. The governing differential equations and associated boundary conditions describing one-dimensional unsteady heat-conduction in the composite, tool plate, and pressure plate are given. Solution of the thermal model was obtained using an implicit finite difference technique.

  12. Vita ed economia nell’analisi sombartiana del capitalismo. Appunti per una interpretazione bioeconomica di Werner Sombart - The Life and The Economy in the Sombartian Analysis of Capitalism. Notes for a Bioeconomic Interpretation of Werner Sombart

    Directory of Open Access Journals (Sweden)

    Emiliano Bevilacqua

    2015-03-01

    Full Text Available The authors discuss the Sombartian analysis of capitalism from a bioeconomic perspective, paying attention to the relationship between people’s lives and economy. The paper focuses on the influence of individual behaviors and values on the genesis and the stabilization of capitalism. The Sombartian analysis is discussed stressing the point that it offers interesting insights to understand the relationship between economy and the everyday life of the people: the spirit of capitalism, luxury and religious beliefs are examples of cultural phenomena from which economy cannot be separated. The thesis of the authors is that the Sombartian analysis through a sociological interpretation of history able to avoid any psychological reductionism puts life at the center of economy.

  13. Curing efficiency of various resin-based materials polymerized through different ceramic thicknesses and curing time

    Science.gov (United States)

    Lee, Jung-Won; Cha, Hyun-Suk

    2011-01-01

    PURPOSE The aim of this in vitro study was to examine the curing efficiency of various resin-based materials polymerized through ceramic restorations with 3 different thicknesses. Curing efficiency was evaluated by determining the surface microhardness (VHN) of the resin specimens. MATERIALS AND METHODS Four kinds of resin materials were used. Z350 (3M ESPE Filtek™ Z350: A2 Shade), Z250 (3M ESPE Filtek™ Z250: A2 Shade) and Variolink® II (VL: Ivoclar vivadent, base: transparent) either with or without a self-curing catalyst (VLC: Ivoclar vivadent, catalyst: low viscosity/transparent) were filled into the silicone mold (10 mm diameter, 1 mm thick). They were cured through ceramic discs (IPS e.max Press MO-0 ingot ivoclar vivadent, 10 mm diameter, 0.5, 1 and 2 mm thicknesses) by LED light-curing units for 20 and 40 seconds. Vicker's microhardness numbers (VHNs) were measured on the bottom surfaces by a microhardness tester. Data were analyzed using a 3- way analysis of variance (ANOVA) at a significance level of 0.05. RESULTS The thickness of ceramic disc increased, the VHNs of all four resin types were decreased (Plight cured for 40 seconds were significantly higher than that of LED for 20 seconds in all four resin materials (Pcuring time resulted higher VHN values of all resin materials. The use of a catalyst produced a greater hardness with all polymerization methods. Restorative resin materials (Z350, Z250) showed higher VHN values than resin cement materials (VL, VLC). PMID:22053242

  14. Light curing through glass ceramics with a second- and a third-generation LED curing unit: effect of curing mode on the degree of conversion of dual-curing resin cements.

    Science.gov (United States)

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

    2013-12-01

    The aim of this study was to measure the degree of conversion (DC) of five dual-curing resin cements after different curing modes with a second- and a third-generation light-emitting diode (LED) curing unit. Additionally, irradiance of both light curing units was measured at increasing distances and through discs of two glass ceramics for computer-aided design/manufacturing (CAD/CAM). Irradiance and spectra of the Elipar FreeLight 2 (Standard Mode (SM)) and of the VALO light curing unit (High Power Mode (HPM) and Xtra Power Mode (XPM)) were measured with a MARC radiometer. Irradiance was measured at increasing distances (control) and through discs (1.5 to 6 mm thickness) of IPS Empress CAD and IPS e.max CAD. DC of Panavia F2.0, RelyX Unicem 2 Automix, SpeedCEM, BisCem, and BeautiCem SA was measured with an attenuated total reflectance-Fourier transform infrared spectrometer when self-cured (negative control) or light cured in SM for 40 s, HPM for 32 s, or XPM for 18 s. Light curing was performed directly (positive control) or through discs of either 1.5- or 3-mm thickness of IPS Empress CAD or IPS e.max CAD. DC was analysed with Kruskal-Wallis tests followed by pairwise Wilcoxon rank sum tests (α = 0.05). Maximum irradiances were 1,545 mW/cm(2) (SM), 2,179 mW/cm(2) (HPM), and 4,156 mW/cm(2) (XPM), and all irradiances decreased by >80 % through discs of 1.5 mm, ≥95 % through 3 mm, and up to >99 % through 6 mm. Generally, self-curing resulted in the lowest DC. For some cements, direct light curing did not result in higher DC compared to when light cured through ceramic discs. For other cements, light curing through ceramic discs of 3 mm generally reduced DC. Light curing was favourable for dual-curing cements. Some cements were more susceptible to variations in curing mode than others. When light curing a given cement, the higher irradiances of the third-generation LED curing unit resulted in similar DC compared to the second-generation one, though at shorter

  15. Electron beam curing of polymer matrix composites

    International Nuclear Information System (INIS)

    Janke, C.J.; Wheeler, D.; Saunders, C.

    1998-01-01

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

  16. A perspective on "cure" for Rett syndrome.

    Science.gov (United States)

    Clarke, Angus John; Abdala Sheikh, Ana Paula

    2018-04-02

    The reversal of the Rett syndrome disease process in the Mecp2 mouse model of Guy et al. (2007) has motivated families and researchers to work on this condition. The reversibility in adult mice suggests that there is potentially much to be gained from rational treatments applied to patients of any age. However, it may be difficult to strike the right balance between enthusiasm on the one hand and realism on the other. One effect of this has been a fragmentation of the "Rett syndrome community" with some groups giving priority to work aimed at a cure while fewer resources are devoted to medical or therapy-based interventions to enhance the quality of life of affected patients or provide support for their families.Several possible therapeutic approaches are under development that, it is claimed and hoped, may lead to a "cure" for patients with Rett syndrome. While all have a rationale, there are potential obstacles to each being both safe and effective. Furthermore, any strategy that succeeded in restoring normal levels of MECP2 gene expression throughout the brain carries potential pitfalls, so that it will be of crucial importance to introduce any clinical trials of such therapies with great care.Expectations of families for a radical, rational treatment should not be inflated beyond a cautious optimism. This is particularly because affected patients with us now may not be able to reap the full benefits of a "cure". Thus, interventions aimed at enhancing the quality of life of affected patients should not be forgone and their importance should not be minimised.

  17. 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.

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

    International Nuclear Information System (INIS)

    Janke, C.J.; Norris, R.E.; Yarborough, K.; Lopata, V.J.

    1997-01-01

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

  19. Pumice aggregates for internal water curing

    DEFF Research Database (Denmark)

    Pietro, Lura; Bentz, Dale P.; Lange, David A.

    2004-01-01

    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......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...... is saturation of the particles, which can be achieved only by immersion in boiling water or by vacuum saturation....

  20. HIV Infection: Advances Toward a Cure.

    Science.gov (United States)

    Douek, Daniel C

    2018-04-01

    Achieving cure of HIV infection requires eliminating all replication-competent virus from the reservoir of latently infected cells or completely inhibiting infected cells from emerging from latency. Strategies include very early use of antiretroviral therapy; hematopoietic stem cell transplantation; "shock-and-kill" approaches; immune therapy with immune checkpoint inhibitors; gene therapy, including use of CC chemokine receptor 5-modified CD4+ T cells; and broadly neutralizing antibody therapy. Success is likely to require a combination of approaches. This article summarizes a presentation by Daniel C. Douek, MD, PhD, at the IAS-USA continuing education program held in Berkeley, California, in May 2017.

  1. The cure for employee malaise--motivation.

    Science.gov (United States)

    Dawson, K M; Dawson, S N

    1991-01-01

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

  2. Turmeric: A condiment, cosmetic and cure

    Directory of Open Access Journals (Sweden)

    Hima Gopinath

    2018-01-01

    Full Text Available Turmeric (Curcuma longa L. is an integral part of Asian culture and cuisine. It has been used in traditional medicine since centuries. A myriad of health benefits have been attributed to it. Curcumin, the most biologically active curcuminoid in turmeric, is being investigated in pre-clinical and clinical trials for its role in disease prevention and cure. It has antioxidant, anti-inflammatory, antineoplastic, anti-proliferative and antimicrobial effects. We review the chemistry of this plant, its cultural relevance in Indian skin care, and its uses in dermatology.

  3. Curing and sociocultural separatism in South Thailand.

    Science.gov (United States)

    Golomb, L

    1985-01-01

    In much of Thailand animistic curing practices have lost ground to great tradition herbal medicine and modern scientific medicine as more people achieve literacy. Especially in urbanizing areas, Buddhist and Muslim Thais hold in the highest esteem traditional curers whose knowledge derives from patient experimentation and the study of ancient texts. However, among Malay-speaking Muslims in south Thailand, the most respected therapeutic knowledge is revelatory in nature. Southern Muslim curers are generally mystics or spirit-mediums whose direct channels of communication with the supernatural convey remedies for afflictions but also provide guidelines for maintaining sociocultural separatism.

  4. Effect of power density of curing unit, exposure duration, and light guide distance on composite depth of cure.

    Science.gov (United States)

    Lindberg, Anders; Peutzfeldt, Anne; van Dijken, Jan W V

    2005-06-01

    This in vitro study compared the depth of cure obtained with six quartz tungsten halogen and light-emitting diode curing units at different exposure times and light tip-resin composite distances. Resin composite specimens (Tetric Ceram, A3; diameter 4 mm, height 6 mm) were exposed from 0-, 3-, and 6-mm distance. The curing units (200-700 mW/cm2) were used for standard (20 and 40 s), pulse-delay mode (initial exposure of 3 s at 200 mW/cm2, followed by a resting period of 3 min and a final exposure of 10 or 30 s at 600 mW/cm2), or soft-start curing (40 s; exponential ramping). Curing depth was determined by measurement of Wallace hardness for each half millimeter starting at 0.5 mm from the top surface. For each specimen, a mean H(W) value was calculated from the H(W) values determined at the depths of 2.0 mm and less (0.5, 1.0, 1.5, and 2.0 mm, respectively). The depth of cure for each specimen was found by determining the greatest depth before an H(W) value exceeding the minimal H(W) value by 25% occurred. For all curing units, an increase in exposure time led to significantly higher depth of cure. Increasing the light tip-resin composite distance significantly reduced the depth of cure. With a light tip-resin composite distance of 6 mm, median values of depth of cure varied between 2.0 and 3.5 mm following a 20-s (or 3+10 s) exposure and between 3.0 and 4.5 mm following a 40-s (or 3+30 s) exposure. The composite situated above the depth of cure value cured equally well with all curing units. At both exposure times, Luxomax resulted in the significantly lowest depth of cure, and Astralis 7 yielded significantly higher depth. At both exposure times, a significant linear correlation was found between the determined power densities of the curing units and the pooled depth of cure values obtained. It seems that for the resin composite tested, the recommended exposure time of 40 s per 2-mm increment may be reduced to 20 s, or that increments may be increased from 2 to 3

  5. The Effect of Irradiation Distance on Microhardness of Resin Composites Cured with Different Light Curing Units

    Science.gov (United States)

    Cekic-Nagas, Isil; Egilmez, Ferhan; Ergun, Gulfem

    2010-01-01

    Objectives: The aim of this study was to compare the microhardness of five different resin composites at different irradiation distances (2 mm and 9 mm) by using three light curing units (quartz tungsten halogen, light emitting diodes and plasma arc). Methods: A total of 210 disc-shaped samples (2 mm height and 6 mm diameter) were prepared from different resin composites (Simile, Aelite Aesthetic Enamel, Clearfil AP-X, Grandio caps and Filtek Z250). Photoactivation was performed by using quartz tungsten halogen, light emitting diode and plasma arc curing units at two irradiation distances (2 mm and 9 mm). Then the samples (n=7/per group) were stored dry in dark at 37°C for 24 h. The Vickers hardness test was performed on the resin composite layer with a microhardness tester (Shimadzu HMV). Data were statistically analyzed using nonparametric Kruskal Wallis and Mann-Whitney U tests. Results: Statistical analysis revealed that the resin composite groups, the type of the light curing units and the irradiation distances have significant effects on the microhardness values (P<.05). Conclusions: Light curing unit and irradiation distance are important factors to be considered for obtaining adequate microhardness of different resin composite groups. PMID:20922164

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

    DEFF Research Database (Denmark)

    Dewaele, Magali; Asmussen, Erik; Peutzfeldt, Anne

    2009-01-01

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

  7. CURE: Clean use of reactor energy

    International Nuclear Information System (INIS)

    1990-05-01

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

  8. Strategies for the cure of HIV infection.

    Science.gov (United States)

    Rodríguez-Muñoz, Jesús; Moreno, Santiago

    2018-03-03

    The disadvantages of the long-term administration of antiretroviral therapy as well as the huge number of affected persons have placed the cure of HIV as a primary goal of Public Health. HIV may persist in the organism by at least four mechanisms: a latently infected cellular reservoir, the persistent replication of HIV in spite of ART, anatomic sanctuaries, and the immune dysfunction. Several strategies directed against these mechanisms have been developed. With all this, a complete eradication of HIV has been achieved in a patient using the transplantation of haemopoietic stem cells that were resistant to HIV-infection, and there are examples of functional cure either spontaneously (elite controllers) or after antiretroviral therapy (post-treatment controllers). However, no strategies have been successful in reducing the reservoir size, nor in achieving constant, uniform remissions. The failure of isolated strategies makes it likely that the combination of several of them may be the future solution. Copyright © 2018 Elsevier España, S.L.U. and Sociedad Española de Enfermedades Infecciosas y Microbiología Clínica. All rights reserved.

  9. 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.

  10. CURE: Clean use of reactor energy

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1990-05-01

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

  11. Effect of carbon nanoparticle addition on epoxy cure

    OpenAIRE

    Dimopoulos, Athanasios

    2007-01-01

    The thesis reports studies of cure kinetics and the glass transition temperature advancements of three commercial epoxy resin systems: MY 750 / HY 5922 (Vantico), MTM 44 -1 (ACG) and 8552 (Hexcel Composites). This investigation was conducted with the utilisation of Differential Scanning Calorimetry (DSC) and Temperature Modulated DSC (TMDSC). Appropriate phenomenological cure kinetics models were built to predict the degree of cure as a function of temperature/time profile. ...

  12. Variable selection for mixture and promotion time cure rate models.

    Science.gov (United States)

    Masud, Abdullah; Tu, Wanzhu; Yu, Zhangsheng

    2016-11-16

    Failure-time data with cured patients are common in clinical studies. Data from these studies are typically analyzed with cure rate models. Variable selection methods have not been well developed for cure rate models. In this research, we propose two least absolute shrinkage and selection operators based methods, for variable selection in mixture and promotion time cure models with parametric or nonparametric baseline hazards. We conduct an extensive simulation study to assess the operating characteristics of the proposed methods. We illustrate the use of the methods using data from a study of childhood wheezing. © The Author(s) 2016.

  13. Caesium diffusion through cement paste cured at different temperatures

    International Nuclear Information System (INIS)

    Peterson, V.K.; Ray, A.

    1999-01-01

    Cs + diffusivity through ordinary Portland cement (OPC) samples was investigated using Inductively Coupled Plasma Mass-Spectrometry (ICP-MS) and Secondary Ion Mass-Spectrometry (SIMS). Intrinsic diffusivities were calculated using modified diffusion equations. The intrinsic diffusivities of Cs + through OPC and cemented clinoptilolite samples cured at 25 deg C, 60 deg C and 150 deg C were compared. As expected, Cs + diffusivity was found to increase with increasing cure temperature of OPC. Cs + diffusivity through cemented clinoptilolite also varied with cure temperature. The addition of clinoptilolite to OPC reduced Cs + diffusivity through the sample, and this effect was more pronounced at greater cure temperatures

  14. Electron beam curing - taking good ideas to the manufacturing floor

    International Nuclear Information System (INIS)

    Saunders, C.; Lopata, V.; Barnard, J.; Stepanik, T.

    2000-01-01

    Acsion is exploiting several emerging electron beam EB applications ranging from composite curing and repair to viscose manufacturing. EB curing of composite structures offers several advantages: significantly reduced curing times; improvements in part quality and performance; reduced environmental and health concerns; improvements in material handling; and reduced overall manufacturing costs compared to thermal curing. The aerospace industry is developing EB technology in all of their market sectors, including military aviation and space products. Some specific products include cryogenic fuel tanks, improved canopy frames for jet aircraft, and the all-composite military aircraft. This paper discusses each of these opportunities. (author)

  15. Applications of mass spectrometry techniques to autoclave curing of materials

    Science.gov (United States)

    Smith, A. C.

    1983-01-01

    Mass spectrometer analysis of gases evolved from polymer materials during a cure cycle can provide a wealth of information useful for studying cure properties and procedures. In this paper data is presented for two materials to support the feasibility of using mass spectrometer gas analysis techniques to enhance the knowledge of autoclave curing of composite materials and provide additional information for process control evaluation. It is expected that this technique will also be useful in working out the details involved in determining the proper cure cycle for new or experimental materials.

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

    Directory of Open Access Journals (Sweden)

    H. Kimura

    2011-12-01

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

  17. Curing behavior and thermal properties of trifunctional epoxy resin cured by 4, 4’-diaminodiphenyl sulfone

    Directory of Open Access Journals (Sweden)

    2009-08-01

    Full Text Available A novel trifunctional epoxy resin 4-(3, 3-dihydro-7-hydroxy-2, 4, 4-trimethyl-2H-1-benzopyran-2-yl-1, 3-benzenediol glycidyl (shorted as TMBPBTH-EPOXY was synthesized in our lab to improve thermal performance. Its curing behavior and performance were studied by using 4, 4′-diaminodiphenyl sulfone (DDS as hardener with the mass ratio of 100:41 of TMBPBTH-EPOXY and DDS. The curing activation energy was investigated by differential scanning calorimetry (DSC to be 64.0 kJ/mol estimated by Kissinger’s method and 68.7 kJ/mol estimated by Flynn-Wall-Ozawa method respectively. Thermogravimetric analyzer (TGA was used to investigate the thermal decomposition of cured compounds. It was found that when curing temperature was lower than 180°C, the thermal decomposition temperature increased with the rise of curing temperature and curing time. On the other hand, when the curing temperature was higher than 180°C, the thermal decomposition temperature went down instead with the increase of curing time that might be the over-crosslinking of TMBPBTH-EPOXY and DDS hardener. The glass transition temperature (Tg of cured TMBPBTH-EPOXY/DDS compound determined by dynamic mechanical thermal analysis (DMTA is 290.1°C.

  18. Colour stability of heat and cold cure acrylic resins.

    Science.gov (United States)

    Bohra, Pavan Kumar; Ganesh, P R; Reddy, Madan Mohan; Ebenezar, A V Rajesh; Sivakumar, G

    2015-01-01

    To evaluate the colour stability of heat and cold cure acrylic resins under simulated oral conditions with different colorants. Three different brands of heat cure acrylic resin and two rapid cure auto polymerizing acrylic resin of commercial products such as Trevelon Heat Cure (THC), DPI Heat cure (DHC), Pyrax Heat Cure (PHC), DPI Cold cure (DCC) and Acralyn-R-Cold cure (ACC) have been evaluated for discoloration and colour variation on subjecting it to three different, commonly employed food colorants such as Erythrosine, Tartarizine and Sunset yellow. In order to simulate the oral condition the food colorants were diluted with artificial saliva to the samples taken up for the study. These were further kept in an incubator at 37°C ± 1°C. The UV-visible spectrophotometer has been utilized to evaluate the study on the basis of CIE L* a* b* system. The prepared samples for standard evaluation have been grouped as control group, which has been tested with a white as standard, which is applicable for testing the colour variants. The least colour changes was found to be with Sunset Yellow showing AE* value of 3.55 with heat cure acrylic resin branded as PHC material and the highest colour absorption with Tartarizine showing AE* value of 12.43 in rapid cure autopolymerzing acrylic resin material branded as ACC material. ACC which is a self cure acrylic resin shows a higher colour variation to the tartarizine food coloration. There were not much of discoloration values shown on the denture base resins as the food colorants are of organic azodyes.

  19. How do we value a cure?

    Science.gov (United States)

    Husereau, Don

    2015-01-01

    Future perceptions of the value of curative therapies will likely reflect debates happening today about preferences for funding of preventive versus treatment programs, as well as funding orphan drugs. Little is known about how society will value curative therapies versus standard treatments, and the significant role of a host of psychological factors compared to overarching concerns about opportunity costs will likely lead to significant tension between payers and the public. More research to clarify societal preferences and healthcare goals in regards to curative therapies and in light of the potential for significant opportunity costs will be required. Given what we know about preferences for the funding of prevention and treatment measures, we should expect that cures will not be held to a different measure.

  20. Ambient Cured Alkali Activated Flyash Masonry Units

    Science.gov (United States)

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

    2016-09-01

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

  1. Helicobacter pylori: Basic Mechanisms to Clinical Cure

    Directory of Open Access Journals (Sweden)

    ABR Thomson

    1995-01-01

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

  2. Internal water curing with Liapor aggregates

    DEFF Research Database (Denmark)

    Lura, Pietro

    2005-01-01

    Internal water curing is a very efficient way to counteract self-desiccation and autogenous shrinkage in high performance concrete, thereby reducing the likelihood of early-age cracking. This paper deals with early-age volume changes and moisture transport in lightweight aggregate concrete realized...... with wet lightweight aggregates. Lightweight aggregate concrete mixtures with different degree of saturation and different particle size of the lightweight aggregates were studied and compared to normal weight concrete. Autogenous deformations, selfinduced stresses in fully restrained conditions, elastic...... modulus and compressive strength were measured. Early-age expansion of the mixtures was greater the higher the degree of the saturation of the lightweight aggregates and the finer their particle size. The elastic properties and the earlyage expansion of the lightweight aggregate concrete were calculated...

  3. Thermographic analysis of the effect of composite type, layering method, and curing light on the temperature rise of photo-cured composites in tooth cavities.

    Science.gov (United States)

    Kim, Min-Jung; Kim, Ryan Jin-Young; Ferracane, Jack; Lee, In-Bog

    2017-10-01

    limitations of this in vitro study, when irradiation time is constant, a curing light with higher radiant power can induce relatively high thermal transfer, thereby increasing the risk of pulpal damage. Copyright © 2017 The Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  4. Electron beam curing of acrylic oligomers

    International Nuclear Information System (INIS)

    Seto, J.; Arakawa, S.; Ishimoto, C.; Miyashita, M.; Nagai, T.; Noguchi, T.; Shibata, A.

    1984-01-01

    The electron-beam curing process of acrylic oligomers, with and without γ-Fe 2 O 3 pigment filler and blended linear polymer, was investigated in terms of molecular structure and reaction mechanism. The polymerized fraction of trimethylolpropane-triacrylate (TMPTA) oligomers increases with increasing total dose, and is independent of the dose rate. Since the reaction rate is linearly dependent on the dose rate, the reaction mechanism involves monomolecular termination. The reaction rate does not depend on the number of functional groups of the oligomer at low doses, but above 0.3 Mrad the rate is slower for oligomers of higher functionality. A gel is formed more readily upon curing of a polyfunctional than a monofunctional oligomer, especially at high conversion to polymer; the resulting loss of flexibility of the polymer chains slows the reaction. Decrease of the molecular weight per functional group results in lower conversion; this is also due to the loss of chain flexibility, which is indicated as well by a higher glass-transition temperature. Modification of the acrylate oligomers with urethane results in more effective cross-linking reactions because of the more rigid molecular chains. Addition of γ-Fe 2 O 3 pigment reduces the reaction rate very little, but has the effect of providing added structural integrity, as indicated by the decrease of solvent-extractable material and the improvement of anti-abrasion properties. However, the flexibility of the coating and its adhesion to a PET base film are diminished. To increase the flexibility, linear polyvinylchloride and/or polyurethane were added to the acrylic oligomers. Final conversion to polymer was nearly 100 percent, and a higher elastic modulus and better antiabrasion properties were realized

  5. Stratospheric experiments on curing of composite materials

    Science.gov (United States)

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

    2016-07-01

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

  6. Nanomedicine applications towards the cure of HIV.

    Science.gov (United States)

    Lisziewicz, Julianna; Tőke, Enikő R

    2013-01-01

    Combination antiretroviral therapy (cART) successfully suppresses HIV replication. However, daily and lifelong treatment is necessary to manage patient illness because cART neither eradicates infected cells from reservoirs nor reconstitutes HIV-specific immunity that could kill infected cells. Toward the cure of HIV, different nanomedicine classes have been developed with the following disease-modifying properties: to eradicate the virus by activation of latently infected CD4+ T-cells and reservoirs flushing; to kill the infected cells in the reservoirs by boosting of HIV-specific T cells; and to prevent infection by the use of microbicides with improved epithelial penetration and drug half-life. Preclinical and clinical trials consistently demonstrated that DermaVir, the most advanced nanomedicine, induces long-lasting memory T-cell responses and reduces viral load in comparison with placebo. DermaVir and the nanomedicine pipelines have the potential to improve the health of HIV-infected people at lower costs, to decrease antiretroviral drug exposure, and to contribute to the cure of HIV/AIDS. Despite the leaps and bounds in the development of antiretroviral therapy, HIV remains a significant public health challenge. In this review, applications of nanomedicine- based technologies are discussed in the context of HIV treatment, including virus elimination by activation of latently infected CD4+ T-cells; infected cell elimination in the reservoirs by boosting HIV-specific T cells, and by preventing infection by the use of microbicides with improved epithelial penetration and drug half-life. Copyright © 2013 Elsevier Inc. All rights reserved.

  7. Using the canine genome to cure cancer and other diseases.

    Science.gov (United States)

    Olson, P N

    2007-08-01

    A high-quality draft genome sequence of the domestic dog (Canis familiaris), together with a dense map of single nucleotide polymorphisms, has been reported. Such new tools offer scientists amazing opportunities to define genetic, nutritional, environmental, and other risk factors for various canine diseases. Because many of the diseases that affect man's best friend also affect us, understanding a dog's disease may lead to new preventions and therapies for diseases that affect both dogs and people. Since a dog's life span is shorter than that for a human, monitoring potential risk factors in a well-controlled population of dogs is possible. Such a population should be one where dogs live in close relationship with their owners. Although longitudinal studies have been previously conducted on animals housed in laboratory environments, the natural environment offers a chance to study dogs in environments shared by their owners. If dogs are carefully monitored, and select exposures defined, considerable information could be collected in a dog's lifetime--the next 10-20 years. Such information could hold the clues for important discoveries, including causes and cures for cancer.

  8. 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

  9. 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.

  10. Comparison of the heat generation of light curing units.

    Science.gov (United States)

    Bagis, Bora; Bagis, Yildirim; Ertas, Ertan; Ustaomer, Seda

    2008-02-01

    The aim of this study was to evaluate the heat generation of three different types of light curing units. Temperature increases were recorded from a distance of 1 mm from a thermocouple to the tip of three different types of light curing units including one quartz-tungsten halogen (QTH), one plasma arc (PAC), and one light emitting diode (LED) unit. An experimental model was designed to fix the 1 mm distance between the tip of the light curing units and the thermocouple wire. Temperature changes were recorded in 10 second intervals up to 40 seconds. (10, 20, 30, and 40 seconds). Temperature measurements were repeated three times for every light curing unit after a one hour standby period. Statistical analysis of the results was performed using the analysis of variance (ANOVA) and the Bonferroni Test. The highest temperature rises (54.4+/-1.65 degrees C) occurred during activation of a PAC light curing unit for every test period (p<.05). The least temperature increase (11.8+/-1.3 degrees C) occurred with a LED curing unit for each tested period except for the measurement of the temperature rise using the QTH curing unit at the tenth second interval (p<.05). These results indicate the choice of light activation unit and curing time is important when polymerizing light activated resin based restorations to avoid any thermal damage to the pulp.

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

    International Nuclear Information System (INIS)

    Nakayama, Hiroshi; Kaetsu, Isao; Uchida, Kumao; Okuda, Jyunya; Kitami, Toshiaki; Matsubara, Yoshio

    2003-01-01

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

  12. Influence of site curing on bond properties of reinforced lightweight ...

    African Journals Online (AJOL)

    ... the requirements for structural lightweight concrete. The developed compressive strength and pull-out strength under both site curing conditions were relatively lower than full water curing condition but still were higher than minimum requirement as per standard. Journal of Civil Engineering Research and Practice Vol.

  13. Effect of Light Curing Unit Characteristics on Light Intensity Output ...

    African Journals Online (AJOL)

    Background: Modern dental composite restorations are wholly dependent on the use of Visible Light Curing devices. The characteristics of these devices may influence the quality of composite resin restorations. Objective: To determine the characteristics of light curing units (LCUs) in dental clinics in Nairobi and their effect ...

  14. Effect of light intensity on the cure characteristics of photo ...

    African Journals Online (AJOL)

    Objective: To determine the light intensity emitted by light curing units (LCUs) and its effect on the cure characteristics of composites polymerised with it. Design: A laboratory based cross sectional study. Setting: Public and private dental clinics in Nairobi, Kenya. Results: Thirty five (42.17%) LCUs produced light of intensity ...

  15. Influence of curing regimes on compressive strength of ultra high ...

    Indian Academy of Sciences (India)

    The bridges and highways are being constructed inlarge number all around the globe using. UHPC, there is ... The properties of UHPC are different from high performance concrete and normal concrete. The curing ... ture, elimination of coarse aggregate, microstructure enhancement by heat curing, addition of steel fibres for ...

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

    African Journals Online (AJOL)

    Department of Civil Engineering, Federal University of Technology Yola, Nigeria. aEmail: gadzymo@yahoo.com (corresponding author). Abstract. Different curing methods are .... ing materials are commonly used for concrete curing. [6] stated that as hydration progresses, the amount of water in mortar pores reduces and.

  17. Radiation curing of intelligent coating for controlled release and permeation

    International Nuclear Information System (INIS)

    Nakayama, Hiroshi; Kaetsu, Isao; Uchida, Kumao; Sakata, Shoei; Tougou, Kazuhide; Hara, Takamichi; Matsubara, Yoshio

    2002-01-01

    Intelligent membranes for pH and temperature-responsive drug releases were developed by coating and curing of polymer-drug composite film with electrolyte or N-isopropyl acrylamide curable mixture. It was proved that those intelligent membranes showed the stimule-sensitive and responsive release functions and could be produced efficiently by radiation curing processing with a conveyer system

  18. Degree of cure and viscosity of Hercules HBRF-55 resin

    Science.gov (United States)

    Bhi, S. T.; Hansen, R. Scott; Wilson, Brian A.; Calius, Emilo P.; Springer, George S.

    1987-01-01

    The rate of cure and viscosity were measured for Hercules HBRF-55 resin. The rate of cure was measured by differential scanning calorimetry, while the viscosity was measured by a parallel disk and plate type apparatus. The data were fitted to analytic expressions to make them suitable for use in numerical calculations.

  19. Shortest exposure time possible with LED curing lights

    NARCIS (Netherlands)

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

    2011-01-01

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

  20. HIV cure research: print and online media reporting in Australia.

    Science.gov (United States)

    Power, Jennifer; Fileborn, Bianca; Dowsett, Gary W; Lucke, Jayne; Brown, Graham; Ellard, Jeanne; Lewin, Sharon R; Tucker, Joseph D; Slavin, Sean; Sugarman, Jeremy; Hill, Sophie

    2017-10-01

    While still in its early stages, recent scientific research towards a cure for HIV has generated widespread media interest. The aim of this paper was to explore the ways in which this research has been represented in Australian print and online media and discuss implications of this. A search of databases from four selected media outlets was conducted to identify published articles that directly discussed HIV cure research. Content analysis was used to explore the discursive framing of HIV cure research and identify the presence or absence of people living with HIV in articles. In total, 95 articles were identified that had been published in print or online between 2007 and 2015. Media reports tended to focus on research breakthroughs or the future potential of HIV cure research, rather than more immediate implications of research findings. While not inaccurate, this focus often implied the field of HIV cure research was more advanced than was generally the case. There was a notable absence of commentary from people living with HIV or community advocates in media reporting. Media reporting may generate unrealistic expectations of HIV cure research. This raises ethical concerns that media reporting may inadvertently contribute to therapeutic or curative misconceptions among potential participants in HIV cure-related trials. To address this, scientists, HIV advocates and people living with HIV will need to work collaboratively to engage with reporters and media outlets to provide more consistent input and guidance into reporting about research towards a cure for HIV.

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

    Indian Academy of Sciences (India)

    Sulphur, peroxide and mixed sulphur/peroxide curing systems were introduced in cross-linking of rubber matrices. The aim was to investigate the influence of curing system composition on ... types of rubber compounds with incorporated untraditional fillers as .... ment is based on the analysis of time dependence of thermal.

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

    Indian Academy of Sciences (India)

    Tomalia et al.5 Though curing kinetics of bisphenol-A based epoxy resin with 1st to 4th generations of den- dritic poly(amido-amine) with different amines were studied by DSC,6 but performance of the thermosets was not reported. Thus a detail and systematic study on curing at room temperature of a hyperbranched epoxy.

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

    Directory of Open Access Journals (Sweden)

    S. Kumaravel

    2014-04-01

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

  4. Which therapeutic strategy will achieve a cure for HIV-1?

    Science.gov (United States)

    Cillo, Anthony R; Mellors, John W

    2016-06-01

    Strategies to achieve a cure for HIV-1 infection can be broadly classified into three categories: eradication cure (elimination of all viral reservoirs), functional cure (immune control without reservoir eradication), or a hybrid cure (reservoir reduction with improved immune control). The many HIV-1 cure strategies being investigated include modification of host cells to resist HIV-1, engineered T cells to eliminate HIV-infected cells, broadly HIV-1 neutralizing monoclonal antibodies, and therapeutic vaccination, but the 'kick and kill' strategy to expose latent HIV-1 with latency reversing agents (LRAs) and kill the exposed cells through immune effector functions is currently the most actively pursued. It is unknown, however, whether LRAs can deplete viral reservoirs in vivo or whether current LRAs are sufficiently safe for clinical use. Copyright © 2016. Published by Elsevier B.V.

  5. Bulk-Fill Composites: Effectiveness of Cure With Poly- and Monowave Curing Lights and Modes.

    Science.gov (United States)

    Gan, J K; Yap, A U; Cheong, J W; Arista, N; Tan, Cbk

    This study compared the effectiveness of cure of bulk-fill composites using polywave light-emitting diode (LED; with various curing modes), monowave LED, and conventional halogen curing lights. The bulk-fill composites evaluated were Tetric N-Ceram bulk-fill (TNC), which contained a novel germanium photoinitiator (Ivocerin), and Smart Dentin Replacement (SDR). The composites were placed into black polyvinyl molds with cylindrical recesses of 4-mm height and 3-mm diameter and photopolymerized as follows: Bluephase N Polywave High (NH), 1200 mW/cm 2 (10 seconds); Bluephase N Polywave Low (NL), 650 mW/cm 2 (18.5 seconds); Bluephase N Polywave soft-start (NS), 0-650 mW/cm 2 (5 seconds) → 1200 mW/cm 2 (10 seconds); Bluephase N Monowave (NM), 800 mW/cm 2 (15 seconds); QHL75 (QH), 550 mW/cm 2 (21.8 seconds). Total energy output was fixed at 12,000 mJ/cm 2 for all lights/modes, with the exception of NS. The cured specimens were stored in a light-proof container at 37°C for 24 hours, and hardness (Knoop Hardness Number) of the top and bottom surfaces of the specimens was determined using a Knoop microhardness tester (n=6). Hardness data and bottom-to-top hardness ratios were subjected to statistical analysis using one-way analysis of variance/Scheffe's post hoc test at a significance level of 0.05. Hardness ratios ranged from 38.43% ± 5.19% to 49.25% ± 6.38% for TNC and 50.67% ± 1.54% to 67.62% ± 6.96% for SDR. For both bulk-fill composites, the highest hardness ratios were obtained with NM and lowest hardness ratios with NL. While no significant difference in hardness ratios was observed between curing lights/modes for TNC, the hardness ratio obtained with NM was significantly higher than the hardness ratio obtained for NL for SDR.

  6. Effect of three types of light-curing units on 5-year colour changes of light-cured composite.

    Science.gov (United States)

    Tak, Onjen; Altintas, Subutay Han; Ozturk, Nilgun; Usumez, Aslihan

    2009-03-01

    The purpose of this study was to determine colour changes in a composite cured with tungsten-halogen, light-emitting diode (LED) or a plasma arc after 5 years. Five specimens 10 mm in diameter and 2 mm in height were prepared using Hybrid (Clearfil AP-X) composite for each test group. The corresponding specimens were cured with a tungsten-halogen curing light, a LED unit or with a plasma arc. Specimens were stored in light-proof boxes for 5 years after the curing procedure to avoid further exposure to light and stored in 37 degrees C in 100% humidity. Colorimetric values of the specimens immediately after curing and after 5 years were measured using colorimeter. The DeltaE*( ab ) values varied significantly depending on the curing unit used (p Curing time did not affect the colour changes of the specimens (p = 0.4). The results of this study suggest that composite materials undergo measurable changes due to the curing unit exposure.

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

    International Nuclear Information System (INIS)

    1993-01-01

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

  8. Influence of Curing-light Unit and Exposure Conditions on the Properties of Lightcured Resin Composite on Curing-light Units

    OpenAIRE

    岡田, 英俊; 石田, 喜紀; 野口, 博志; 長山, 克也; オカダ, ヒデトシ; イシダ, ヨシキ; ノグチ, ヒロシ; ナガヤマ, カツヤ; Hidetoshi, OKADA; Yoshiki, ISHIDA; Hiroshi, NOGUCHI; Katsuya, NAGAYAMA

    2003-01-01

    The purpose of this study was to examine the influence of curing light units and exposure conditions on the prperties of the polymerization of a lightcured resin composite. Lightfil was used as a resin composite. The curing light units used were a JETLITE, as a halogen lamp curing light source (HAL), a MICROWAVE, as a xenon lamp curing light source (XEN), and a AQUABLUE, as a light-emitting diode curing light source (LED). Each curing light unit was used to cure the resin composite with the i...

  9. The effect of curing conditions on the dentin bond strength of two dual-cure resin cements.

    Science.gov (United States)

    Tagami, Atsuko; Takahashi, Rena; Nikaido, Toru; Tagami, Junji

    2017-10-01

    The purpose of this study was to determine the effect of the curing condition (i.e., the curing mode and restoration thickness) on the tensile bond strength of a dual-cure resin cement applied to dentin. Indirect composite resin disks (1, 2, and 3mm in thickness) were prepared. The irradiance of a halogen light curing unit through each disk was measured by a curing radiometer. A measurement was also taken for the condition with no disk. Following this, two dual-cure resin cements, Panavia F2.0 and Panavia V5, were polymerized in either dual-cure mode or self-cure mode to bond the composite resin disk to the flat dentin surface. The specimens were sectioned and subjected to a microtensile bond strength (μTBS) test after 24h of water storage. The data were statistically analyzed by two-way ANOVA followed with multiple comparisons by post-hoc Tukey's test (α=0.05). The irradiance values [mW/cm 2 ] measured through indirect composite resin disks were 600 (0mm), 200 (1mm), 90 (2mm), and not detected (3mm). Two-way ANOVA indicated that both the curing condition and the type of resin cement affected the μTBS (pPanavia V5 bonded to dentin were significantly higher than those of Panavia F2.0 bonded to dentin (pPanavia V5, showed higher dentin bonding than Panavia F2.0 in both dual- and self-cure modes. Copyright © 2017 Japan Prosthodontic Society. Published by Elsevier Ltd. All rights reserved.

  10. 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 (presin 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-generation LED curing units to obtain KHN values similar to those observed during direct irradiation.

  11. Humanized mice: models for evaluating NeuroHIV and cure strategies.

    Science.gov (United States)

    Honeycutt, Jenna B; Garcia, J Victor

    2018-04-01

    While the human immunodeficiency virus (HIV) epidemic was initially characterized by a high prevalence of severe and widespread neurological pathologies, the development of better treatments to suppress viremia over years and even decades has mitigated many of the severe neurological pathologies previously observed. Despite effective treatment, mild neurocognitive impairment and premature cognitive aging are observed in HIV-infected individuals, suggesting a changing but ongoing role of HIV infection in the central nervous system (CNS). Although current therapies are effective in suppressing viremia, they are not curative and patients must remain on life-long treatment or risk recrudescence of virus. Important for the development and evaluation of a cure for HIV will be animal models that recapitulate critical aspects of infection in vivo. In the following, we seek to summarize some of the recent developments in humanized mouse models and their usefulness in modeling HIV infection of the CNS and HIV cure strategies.

  12. Development of Geopolymer Concrete with Different Curing Conditions

    Directory of Open Access Journals (Sweden)

    M.F. Nuruddin Nuruddin

    2011-02-01

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

  13. Efficiency of light curing units in a government dental school.

    Science.gov (United States)

    Nassar, Hani M; Ajaj, Reem; Hasanain, Fatin

    2018-01-01

    The light intensity of a light-curing unit is a crucial factor that affects the clinical longevity of resin composites. This study aimed to investigate the efficiency of light-curing units in use at a local governmental dental school for curing conventional and bulk-fill resin materials. A total of 166 light-curing units at three locations were examined, and the brand, type, clinic location, diameter of curing tip, tip cleanliness (using a visual score), and the output (in mW/cm 2 using a digital radiometer) were recorded. Only 23.5% of the units examined had clean tips, with the graduate student clinical area containing the highest percentage of clean tips. Further, tips with poor cleanliness score values were associated with significantly lower output intensities. A small percentage (9.4%) of units was capable of producing intensities higher than 1,200 mW/cm 2 and lower than 600 mW/cm 2 (7.6%). The majority of the low intensity units were located in the undergraduate student area, which also contained the highest number of units with intensities between 900 and 1,200 mW/cm 2 . The output of all the units in service was satisfactory for curing conventional resin composites, and most units were capable of curing bulk-fill resin materials.

  14. 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.

  15. The Modification of a Tetrafunctional Epoxy and Its Curing Reaction

    Directory of Open Access Journals (Sweden)

    Mingming Yu

    2015-06-01

    Full Text Available Recent experimental results showed that the Tg of cured resin scarcely decreased and the impact strength of resins increased by over 50% when a tetrafunctional epoxy named N,N,N',N'-tetraglycidyl-4,4'-diaminodiphenyl ether (TGDDE was introduced to an appropriate flexible chain from a dimer fatty acid (DFA. In order to understand the reason for this phenomenon, the modification and the chemical structure of the prepolymer together with the curing reaction and the viscoelasticity of the cured resins were studied in detail in the present work. The results indicated that the modification would help the prepolymer improve its molecular mobility. As a result, the resins could be further cured, resulting in the cross-linking density increasing. This is because the curing efficiency was increased, but the tetrafunctional epoxy was not cured completely due to its large steric hindrance. Moreover, the flexibility of some parts of the networks was improved, which was beneficial for the toughness of the cured resins. Therefore, the toughness of the tetrafunctional resin was improved with little influence on the thermal properties when the epoxies were modified with an appropriate content of DFA.

  16. Acceptability of HIV cure-related trials: the challenges for physicians and people living with HIV (ANRS-APSEC).

    Science.gov (United States)

    Preau, Marie; Doumergue, Marjolaine; Protiere, Christel; Goujard, Cécile; Mora, Marion; Meyer, Laurence; Lelievre, Jean-Daniel; Raffi, François; Spire, Bruno; Lambotte, Olivier; Suzan-Monti, Marie

    2018-01-18

    Essential HIV cure-related clinical trials (HCRCT) have a potentially high-risk profile in terms of participants' health, which could hinder enrollment by people living with HIV (PLWH) and healthcare professionals (HP). The ANRS-APSEC survey is part of the IAS "Towards an HIV cure" initiative, which promotes multidisciplinary research for a safe, affordable and scalable cure. The study objectives were to understand the psychosocial mechanisms underlying PLWH and HP viewpoints about future HCRCT. Six focus group discussions (three with PLWH (n = 21) and three with HP (n = 30)) were held in three French infectious disease units. From these, three perspectives on HCRCT were identified. The first involved beliefs and knowledge associating HCRCT with poorer health and quality of life for PLWH. The second concerned perceptions of HCRCT as a biological and epidemiological flashback to a situation when HIV infection was left uncontrolled. The third was characterized by aspects of historical HIV culture that embrace innovation.

  17. Effects of Degree of Curing on Fire Spread

    Science.gov (United States)

    Chaivaranont, W.; Evans, J. P.; Liu, Y.

    2016-12-01

    During extreme summer conditions in Australia, bushfire can become an uncontrollable natural hazard. Various factors, such as geographical and meteorological parameters greatly influence the magnitude of bushfire. In a grassland fire, there is an important factor that affects the severity of fire called the degree of curing. Degree of curing is a percentage measurement of the proportion of dead material in grassland where a 100% curing indicates a totally dead grass field. It is usually assumed constant due to the cost and difficulty in obtaining accurate field observations.To examine the importance of curing, the Phoenix RapidFire fire spread model was used to observe the magnitude and direction of grassland fire spread due to variations in the degree of curing. Idealised experiments and experiments based on 3 past fire events in Australia were conducted, where the 100 by 200 km study area is considered to be all grassland. In the idealised experiments, homogeneous curing data in various patterns were used along with extreme climate data and prescribed topography. In the past fire event experiments, satellite-derived estimated curing data, observed climate data from the nearest weather stations, and real elevation maps were used. A remotely sensed burned area map (MODIS MCD64A1 product) is also used to compare the simulated burned area of past fire events with the satellite observation.The results from both experiments showed that: 1) the rate of spread of grassland fire is significantly impeded when curing is below 75%, 2) topography has insignificant effect on fire spread direction and speed, 3) wind and curing both influence the direction and speed of spread, and 4) the model can only recreate the burned area in one out of three of the past fire events due to various causes including the fact that all past events used here were not exclusively grassland fire.

  18. Environmental and waste management issues, causes, characteristics, and cures

    International Nuclear Information System (INIS)

    Duffy, L.P.

    1992-01-01

    The department of Energy (DOE) views as one of its most challenging problems the minimization, management, and cleanup of waste materials generated from Departmental operations. The challenges for the DOE have striking similarities to the environmental restoration and waste management challenges associated with energy production and the mining and mineral processing industries. Their challenges relate to uranium mining and the resulting mill tailings; decontamination and decommissioning of facilities; processing of nuclear materials and production of weapons components. Add to this the challenge of environmental restoration solutions for waste disposal practices of the past. The fundamental goal of the DOE is to ensure that risks to human health and safety and to the environment posed by the department's past, present, and future operations are either eliminated to reduced to prescribed levels by the year 2019. To achieve this goal they must be able to assess environmental and health impacts resulting from the low concentrations of contaminants. This paper presents an overview of the causes, characteristics, and cures for these environmental restoration and waste management issues

  19. Red Wine and Pomegranate Extracts Suppress Cured Meat Promotion of Colonic Mucin-Depleted Foci in Carcinogen-Induced Rats.

    Science.gov (United States)

    Bastide, Nadia M; Naud, Nathalie; Nassy, Gilles; Vendeuvre, Jean-Luc; Taché, Sylviane; Guéraud, Françoise; Hobbs, Ditte A; Kuhnle, Gunter G; Corpet, Denis E; Pierre, Fabrice H F

    2017-01-01

    Processed meat intake is carcinogenic to humans. We have shown that intake of a workshop-made cured meat with erythorbate promotes colon carcinogenesis in rats. We speculated that polyphenols could inhibit this effect by limitation of endogenous lipid peroxidation and nitrosation. Polyphenol-rich plant extracts were added to the workshop-made cured meat and given for 14 days to rats and 100 days to azoxymethane-induced rats to evaluate the inhibition of preneoplastic lesions. Colons of 100-d study were scored for precancerous lesions (mucin-depleted foci, MDF), and biochemical end points of peroxidation and nitrosation were measured in urinary and fecal samples. In comparison with cured meat-fed rats, dried red wine, pomegranate extract, α-tocopherol added at one dose to cured meat and withdrawal of erythorbate significantly decreased the number of MDF per colon (but white grape and rosemary extracts did not). This protection was associated with the full suppression of fecal excretion of nitrosyl iron, suggesting that this nitroso compound might be a promoter of carcinogenesis. At optimized concentrations, the incorporation of these plant extracts in cured meat might reduce the risk of colorectal cancer associated with processed meat consumption.

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

    Science.gov (United States)

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

    2009-05-01

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

  1. Advanced composites--a new application of electron beam curing

    International Nuclear Information System (INIS)

    Sun Dakuan

    2007-01-01

    Consisting of a matrix phase of epoxy resin and reinforcement phase of high performance synthetic fiber, advanced composites have a number of engineering merits, such as high specific strength and specific modulus, light weight, fatigue resistance, corrosion resistance and dimensional stability, etc. Advanced composites have been applied in aerospace/aircraft industry, military industry, high pressure vessels, automobile industry and sports apparatus. Nowadays, advanced composites are produced by electron beam curing, an environment-friendly technology with greater safety and energy efficiency than conventional curing techniques. This paper gives a review on progresses of electron beam cured advanced composites. (authors)

  2. Experimental observation of internal water curing of concrete

    DEFF Research Database (Denmark)

    Lura, Pietro; Jensen, Ole Mejlhede

    2007-01-01

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

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

    Science.gov (United States)

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

    2014-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Zahra Bahrololoomi

    2014-12-01

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

  5. Effect of curing mode on the micro-mechanical properties of dual-cured self-adhesive resin cements.

    Science.gov (United States)

    Ilie, Nicoleta; Simon, Alexander

    2012-04-01

    Light supplying to luting resin cements is impeded in several clinical situations, causing us to question whether materials can properly be cured to achieve adequately (or adequate) mechanical properties. The aim of this study was therefore to analyse the effect of light on the micro-mechanical properties of eight popular dual-cured self-adhesive resin cements by comparing them with two conventional, also dual-cured, resin cements. Four different curing procedures were applied: auto-polymerisation (dark curing) and light curing (LED unit, Freelight 2, 20 s) by applying the unit directly on the samples' surface, at a distance of 5 and 10 mm. Twenty minutes after curing, the samples were stored for 1 week at 37°C in a water-saturated atmosphere. The micro-mechanical properties-Vickers hardness, modulus of elasticity, creep and elastic/plastic deformation-were measured. Data were analysed with multivariate ANOVA followed by Tukey's test and partial eta-squared statistics (p micro-mechanical properties was measured, whereas the influence of the curing procedure and type of cement-conventional or self-adhesive-was generally low. The influence of light on the polymerisation process was material dependent, with four different behaviour patterns to be distinguished. As a material category, significantly higher micro-mechanical properties were measured for the conventional compared to the self-adhesive resin cements, although this difference was low. Within the self-adhesive resin cements group, the variation in micro-mechanical properties was high. The selection of suitable resin cements should be done by considering, besides its adhesive properties, its micro-mechanical properties and curing behaviour also.

  6. Comparison of curing depth of a colored polyacid-modified composite resin with different light-curing units.

    Science.gov (United States)

    Vandenbulcke, Jeroen D E; Marks, Luc A M; Martens, Luc C; Verbeeck, Ronald M H

    2010-10-01

    To compare the depth of cure (DoC) of a colored polyacid-modified composite resin (PAM-C) with a traditional PAM-C and a fine hybrid composite resin using different light-curing units and different radiant energies. The DoC of the PAM-C Twinky Star (Voco, all shades), the PAM-C Glasiosite (Voco), and the composite resin Z100 (3M ESPE) shades A2 and A4 was determined using a penetrometer test method. The materials were cured in bulk using a halogen-based unit (Elipar Trilight, E = 18 J/cm2 and E = 32 J/cm2; 3M ESPE) and an LED curing unit (Elipar Freelight 2, E = 20 J/cm2; 3M ESPE) in split stainless steel molds. Immediately after curing, the height (mm) of the cured material was measured and taken as the DoC. Ranking of means was performed by Student-Newman-Keuls multiple comparison test, and statistically significant differences among mean values were detected with ANOVA. Mean DoC for all materials and shades varied as follows: 4.705 to 8.870 mm (E = 32 J/cm2); 3.672 to 8.050 mm (E = 20 J/cm2); and 4.090 to 7.357 mm (E = 18 J/cm2). Two-way ANOVA revealed that the DoC depended significantly (P curing device. Moreover, there was a significant interaction (P curing device with the highest energy density exhibited the highest curing depths.

  7. The role of spatial information in the preservation of the shrimp nursery function of mangroves: a spatially explicit bio-economic model for the assessment of land use trade-offs.

    Science.gov (United States)

    Zavalloni, Matteo; Groeneveld, Rolf A; van Zwieten, Paul A M

    2014-10-01

    Conversion to aquaculture affects the provision of important ecosystem services provided by mangrove ecosystems, and this effect depends strongly on the location of the conversion. We introduce in a bio-economic mathematical programming model relevant spatial elements that affect the provision of the nursery habitat service of mangroves: (1) direct or indirect connection of mangroves to watercourses; (2) the spatial allocation of aquaculture ponds; and (3) the presence of non-linear relations between mangrove extent and juvenile recruitment to wild shrimp populations. By tracing out the production possibilities frontier of wild and cultivated shrimp, the model assesses the role of spatial information in the trade-off between aquaculture and the nursery habitat function using spatial elements relevant to our model of a mangrove area in Ca Mau Province, Viet Nam. Results show that where mangrove forests have to coexist with shrimp aquaculture ponds, the inclusion of specific spatial information on ecosystem functions in considerations of land allocation can achieve aquaculture benefits while largely preserving the economic benefits generated by the nursery habitat function. However, if spatial criteria are ignored, ill-advised land allocation decisions can easily lead to a collapse of the mangrove's nursery function. Copyright © 2014 Elsevier Ltd. All rights reserved.

  8. Improvements in self-curing composites.

    Science.gov (United States)

    Raszewski, Zbigniew; Jałbrzykowski, Marek

    2017-09-01

    The purpose of this study was to test the influence of a barbituric acid derivative acting as a catalyst and small amounts of pyrolytic silica in acrylic resins on color stability, solubility and sorption of a composite. A series of two-component powder/liquid resin systems were prepared. Monomer-like mixtures (bis-GMA, TEGDMA, tertiary amine 60/40) and a quartz powder with additions of various silica and barbituric acid derivatives were used. Temperature of the material during polymerization was measured with the use of a thermometer. In addition, the material's flexural and compressive strength, sorption and solubility were tested pursuant to ISO4049:2009. The powder-based acrylic composition in a liquid mixed immediately before use, after an addition of a 0.5% barbituric acid derivative, has a lower temperature during the polymerization process (a reduction from 43°C to 37°C), whereas color stability over time is improved, with ΔE=1.81 for samples of powder mixtures containing between 0.45% of BPO and 0.15% of barbituric acid derivatives. For silanized quartz powder with 0.55% BPO and 0.1% BA+0.5% Aerosil R711, the obtained sorption value was 4.57±0.22μg/mm 3 , whereas solubility was 1.60±0.32μg/mm 3 . New catalytic system with barbituric acid derivative, improves color stability for samples stored at room condition and under light of high intensity. A two-phase composite (bis GMA TEGDMA/Quartz), with a new catalytic system with barbituric acid derivatives, has a lower self-cured temperature. Adding a small quantity of hydrophobic silica (0.5%) has a significant influence, with reduced sorption and solubility of the material. Copyright © 2017 Medical University of Bialystok. Published by Elsevier B.V. All rights reserved.

  9. Comparative study of sorption and solubility of heat-cure and self-cure acrylic resins in different solutions.

    Science.gov (United States)

    Saini, Rajesh; Kotian, Ravindra; Madhyastha, Prashanthi; Srikant, N

    2016-01-01

    The objective of this study was to compare the sorption and solubility of heat-cure and self-cure acrylic resins in different solutions. One heat-cure acrylic resin (Trevalon) and one self-cure acrylic resin (Rapid Repair) were studied. Five groups of square-shaped specimens (20 mm × 20 mm × 2 mm) were prepared for each acrylic resin and then immersed in five solutions: distilled water, artificial saliva, denture cleansing solution, distilled water, and denture cleaning solution for 12 h alternatively, artificial saliva and denture cleaning solution for 12 h alternatively at 37 ± 2°C, and tested sorption and solubility by weight gain/loss method, respectively, after 1, 6, and 11 weeks. The data were analyzed by one-way analysis of variance followed by post hoc Tukey's test. Water sorption mean values varied from 17.5 ± 0.88 to 27.25 ± 1.04 μg/mm 3 for heat cure and from 12.75 ± 0.55 to 19.75 ± 1.04 μg/mm 3 for self-cure in the different solutions after different interval periods of 1, 6, and 11 weeks. These values were statistically significant (Psolubility mean values varied from 0.25 ± 0.55 to 1.5 ± 0.55 μg/mm 3 for heat cure and from 1.5 ± 0.55 to 6.5 ± 0.55 μg/mm 3 for self-cure in the different solutions after different interval periods of 1, 6, and 11 weeks. These values were statistically not significant (P > 0.05). There was no linear correlation between sorption and solubility values. Overall, analysis of results showed the maximum sorption value in denture cleansing solution followed by alternative soaking in distilled water and artificial saliva. Least sorption was observed with artificial saliva followed by distilled water. Both heat-cure and self-cure acrylic resins showed varying water sorption and solubility. The results of both water sorption and solubility showed compliance with the International Standards Organization specification. No correlation was found between water sorption and solubility. Artificial saliva solution is a

  10. Isoconversional kinetic analysis of the alkyd/melamine resins curing

    Directory of Open Access Journals (Sweden)

    Jovičić Mirjana

    2013-01-01

    Full Text Available The curing reaction for the mixtures of alkyd resins based on ricinoleic acid, phthalic anhydride and three polyols (glycerin, trimethylolpropane or ethoxylated pentaerythritol with two different commercial melamine resins was investigated by differential scanning calorimetry (DSC. The curing kinetics analysis was performed using the isoconversional methods (Ozawa-Flynn-Wall, Kissinger-Akahira-Sunose and Friedman. Isoconversional methods were carried out with three heating rates (5, 10 and 20°C/min in a scanning temperature range from 40 to 250°C. It was found that the curing activation energy of resin mixtures is influenced by alkyd and melamine resin type due to the catalytic effect of hydroxyl group on the reactions. The dependence of apparent curing degree on time, which was obtained by mathematical transformations of dynamic DSC data using Ozawa-Flynn-Wall method, describes well the isothermal DSC experiments.

  11. Epoxy foams using multiple resins and curing agents

    Science.gov (United States)

    Russick, Edward M.; Rand, Peter B.

    2000-01-01

    An epoxy foam comprising a plurality of resins, a plurality of curing agents, at least one blowing agent, at least one surfactant and optionally at least one filler and the process for making. Preferred is an epoxy foam comprising two resins of different reactivities, two curing agents, a blowing agent, a surfactant, and a filler. According to the present invention, an epoxy foam is prepared with tailorable reactivity, exotherm, and pore size by a process of admixing a plurality of resins with a plurality of curing agents, a surfactant and blowing agent, whereby a foamable mixture is formed and heating said foamable mixture at a temperature greater than the boiling temperature of the blowing agent whereby said mixture is foamed and cured.

  12. If We Build It, Will They Come? Perceptions of HIV Cure-Related Research by People Living with HIV in Four U.S. Cities: A Qualitative Focus Group Study.

    Science.gov (United States)

    Sylla, Laurie; Evans, David; Taylor, Jeff; Gilbertson, Adam; Palm, David; Auerbach, Judith D; Dubé, Karine

    2018-01-01

    Global interest and investment in the search for an HIV cure has increased. Research has focused on what experts refer to as a sterilizing or eradicating cure, where HIV is eliminated from the body, and on what is often called a functional cure, where HIV remains, kept durably suppressed in the absence of antiretroviral treatment and therapy (ART). Many believe that a functional cure is likely to be found first. HIV cure studies will require active participation by people living with HIV (PLWHIV). Their desires and perceptions will be important to effectively recruit study participants and for the uptake of any future strategy that demonstrates safety and efficacy. The perspectives of PLWHIV are essential to advancing HIV cure research, and they should be taken into consideration as biomedical research advances. We conducted 10 focus groups in four U.S. cities, eliciting perspectives of PLWHIV on HIV cure and cure research. Most participants conceived of a cure as eradicating, and felt favorably toward it. In addition to the physical benefits of a potential cure, participants valued the possible de-stigmatization related to no longer living with HIV, liberation from concerns about transmitting HIV, and freedom from the burden of daily medication. Many participants did not regard a functional cure as an improvement over controlling HIV through ART, were distrustful about viral rebound potential, and noted concerns about medical complications and accompanying psychological distress. Some felt that the risks of HIV cure research were not worth taking. Many were skeptical about science's ability to eliminate HIV from the body.

  13. Optical Fibre Grating Refractometers for Resin Cure Monitoring.

    OpenAIRE

    Buggy, Stephen J.; Chehura, Edmon; James, Stephen W.; Tatam, Ralph P.

    2007-01-01

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

  14. Curing kinetics of alkyd/melamine resin mixtures

    OpenAIRE

    Jovičić Mirjana C.; Radičević Radmila Ž.

    2009-01-01

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

  15. Manufacturing prepainted steel sheet by electron beam curing

    International Nuclear Information System (INIS)

    Oka, Joji

    1987-01-01

    Several advantages are offered by electron beam curing. A formidably hard and stain resistant paint film which is difficult to obtain by heat curing paint is developed. As a result, a unique new prepainted steel is produced. Four technologies are involved: development high-quality paint, selection of optimum electron beam processor, technology to control electron beam processing atmosphere and secondary X-ray shield technology. These technologies are described in detail. (A.J.)

  16. Curing kinetics of alkyd/melamine resin mixtures

    Directory of Open Access Journals (Sweden)

    Jovičić Mirjana C.

    2009-01-01

    Full Text Available Alkyd resins are the most popular and useful synthetic resins applied as the binder in protective coatings. Frequently they are not used alone but are modified with other synthetic resins in the manufacture of the coatings. An alkyd/melamine resin mixture is the usual composition for the preparation of coating called 'baking enamel' and it is cured through functional groups of resins at high temperatures. In this paper, curing kinetics of alkyd resins based on castor oil and dehydrated castor oil with melamine resin, has been studied by DSC method with programmed heating and in isothermal mode. The results determined from dynamic DSC curves were mathematically transformed using the Ozawa isoconversional method for obtaining the isothermal data. These results, degree of curing versus time, are in good agreement with those determined by the isothermal DSC experiments. By applying the Ozawa method it is possible to calculate the isothermal kinetic parameters for the alkyd/melamine resin mixtures curing using only calorimetric data obtained by dynamic DSC runs. Depending on the alkyd resin type and ratio in mixtures the values of activation energies of curing process of resin mixtures are from 51.3 to 114 kJ mol-1. The rate constant of curing increases with increasing the content of melamine resin in the mixture and with curing temperature. The reaction order varies from 1.12 to 1.37 for alkyd based on dehydrated castor oil/melamine resin mixtures and from 1.74 to 2.03 for mixtures with alkyd based on castor oil. Based on the results obtained, we propose that dehydrated castor oil alkyd/melamine resin mixtures can be used in practice (curing temperatures from 120 to 160°C.

  17. Beliefs about the causes and cures of depression

    OpenAIRE

    Furnham, A.; Ritchie, W.; Lay, A.

    2016-01-01

    BACKGROUND: This study used attitude statement and vignette methodology to examine a mixed British sample’s belies about the causes and consequences of depression. AIMS: To test whether the group would recognise both vignettes with having depression and that the favoured cure would be Psychotherapy/Talking Cure. METHOD: In all, 320 adults completed a two-part questionnaire. In the first part, they were given two vignettes describing a 30-year-old female and a 45-year-old male...

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

    International Nuclear Information System (INIS)

    Nishitsuji, D. A.

    2006-01-01

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

  19. Monitoring the Cure State of Thermosetting Resins by Ultrasound

    Science.gov (United States)

    Lionetto, Francesca; Maffezzoli, Alfonso

    2013-01-01

    The propagation of low intensity ultrasound in a curing resin, acting as a high frequency oscillatory excitation, has been recently proposed as an ultrasonic dynamic mechanical analysis (UDMA) for cure monitoring. The technique measures sound velocity and attenuation, which are very sensitive to changes in the viscoelastic characteristics of the curing resin, since the velocity is related to the resin storage modulus and density, while the attenuation is related to the energy dissipation and scattering in the curing resin. The paper reviews the results obtained by the authors’ research group in the last decade by means of in-house made ultrasonic set-ups for both contact and air-coupled ultrasonic experiments. The basics of the ultrasonic wave propagation in polymers and examples of measurements of the time-evolution of ultrasonic longitudinal modulus and chemical conversion of different thermosetting resins are presented. The effect of temperature on the cure kinetics, the comparison with rheological, low frequency dynamic mechanical and calorimetric results, and the correlation between ultrasonic modulus and crosslinking density will be also discussed. The paper highlights the reliability of ultrasonic wave propagation for monitoring the physical changes taking place during curing and the potential for online monitoring during polymer and polymer matrix composite processing. PMID:28788306

  20. Monitoring the Cure State of Thermosetting Resins by Ultrasound

    Directory of Open Access Journals (Sweden)

    Alfonso Maffezzoli

    2013-09-01

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

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

    Science.gov (United States)

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

    2015-01-01

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

  2. Fight fire with fire: Gene therapy strategies to cure HIV.

    Science.gov (United States)

    Huyghe, Jon; Magdalena, Sips; Vandekerckhove, Linos

    2017-08-01

    Human Immunodeficiency Virus (HIV) to date remains one of the most notorious viruses mankind has ever faced. Despite enormous investments in HIV research for more than 30 years an effective cure for HIV has been elusive. Areas covered: Combination antiretroviral therapy (cART) suppresses active viral replication, but is not able to eliminate the virus completely due to stable integration of HIV inside the host genome of infected cells and the establishment of a latent reservoir, that is insensitive to cART. Nevertheless, this latent HIV reservoir is fully capable to refuel viral replication when treatment is stopped, creating a major obstacle towards a cure for HIV. Several gene therapy approaches ranging from the generation of HIV resistant CD4 + T cells to the eradication of HIV infected cells by immune cell engineering are currently under pre-clinical and clinical investigation and may present a promising road to a cure. In this review, we focus on the status and the prospects of gene therapy strategies to cure/eradicate HIV. Expert commentary: Recent advances in gene therapy for oncology and infectious diseases indicate that gene therapy may be a feasible and very potent cure strategy, and therefore a potential game changer in the search for an effective HIV cure.

  3. Employing human rights frameworks to realize access to an HIV cure.

    Science.gov (United States)

    Meier, Benjamin Mason; Gelpi, Adriane; Kavanagh, Matthew M; Forman, Lisa; Amon, Joseph J

    2015-01-01

    The scale of the HIV pandemic - and the stigma, discrimination and violence that surrounded its sudden emergence - catalyzed a public health response that expanded human rights in principle and practice. In the absence of effective treatment, human rights activists initially sought to protect individuals at high risk of HIV infection. With advances in antiretroviral therapy, activists expanded their efforts under international law, advocating under the human right to health for individual access to treatment. As a clinical cure comes within reach, human rights obligations will continue to play a key role in political and programmatic decision-making. Building upon the evolving development and implementation of the human right to health in the global response to HIV, we outline a human rights research agenda to prepare for HIV cure access, investigating the role of human rights law in framing 1) resource allocation, 2) international obligations, 3) intellectual property and 4) freedom from coercion. The right to health is widely recognized as central to governmental, intergovernmental and non-governmental responses to the pandemic and critical both to addressing vulnerability to infection and to ensuring universal access to HIV prevention, treatment, care and support. While the advent of an HIV cure will raise new obligations for policymakers in implementing the right to health, the resolution of past debates surrounding HIV prevention and treatment may inform claims for universal access.

  4. Employing human rights frameworks to realize access to an HIV cure

    Science.gov (United States)

    Meier, Benjamin Mason; Gelpi, Adriane; Kavanagh, Matthew M; Forman, Lisa; Amon, Joseph J

    2015-01-01

    Introduction The scale of the HIV pandemic – and the stigma, discrimination and violence that surrounded its sudden emergence – catalyzed a public health response that expanded human rights in principle and practice. In the absence of effective treatment, human rights activists initially sought to protect individuals at high risk of HIV infection. With advances in antiretroviral therapy, activists expanded their efforts under international law, advocating under the human right to health for individual access to treatment. Discussion As a clinical cure comes within reach, human rights obligations will continue to play a key role in political and programmatic decision-making. Building upon the evolving development and implementation of the human right to health in the global response to HIV, we outline a human rights research agenda to prepare for HIV cure access, investigating the role of human rights law in framing 1) resource allocation, 2) international obligations, 3) intellectual property and 4) freedom from coercion. Conclusions The right to health is widely recognized as central to governmental, intergovernmental and non-governmental responses to the pandemic and critical both to addressing vulnerability to infection and to ensuring universal access to HIV prevention, treatment, care and support. While the advent of an HIV cure will raise new obligations for policymakers in implementing the right to health, the resolution of past debates surrounding HIV prevention and treatment may inform claims for universal access. PMID:26568056

  5. Tinea capitis: predictive value of symptoms and time to cure with griseofulvin treatment.

    Science.gov (United States)

    Lorch Dauk, Kelly C; Comrov, Elana; Blumer, Jeffrey L; O'Riordan, Mary Ann; Furman, Lydia M

    2010-03-01

    To describe (a) the predictive value of symptoms for diagnosis of tinea capitis and (b) the rate and timing of cure with high-dose griseofulvin treatment. This prospective open-label study enrolled children aged 1 to 12 years with clinical tinea capitis. Participants with a positive dermatophyte culture received oral griseofulvin (20-25 mg/kg/day) and topical selenium sulfide shampoo for 6 weeks. Main outcome measures. The rate of symptoms of tinea capitis, and rates of mycologic and clinical cure. The positive predictive values of any 1, 2, 3, or 4 symptoms for a positive culture were 88%, 82%, 78%, and 77%, respectively. The observed rates of mycologic, clinical, and complete cure were 89%, 66%, and 49%, respectively. conclusion: In a high-risk population it is reasonable to diagnose tinea capitis using one or more cardinal symptoms. Oral griseofulvin at 20 to 25 mg/ kg/day with adjunctive shampooing for 6 weeks is moderately successful as treatment.

  6. Evaluation of the Ultraviolet-Curing Kinetics of Ultraviolet-Polymerized Oligomers Cured Using Poly (Ethylene Glycol Dimethacrylate

    Directory of Open Access Journals (Sweden)

    Ji-Won Park

    2018-03-01

    Full Text Available Ultraviolet (UV-curable oligomers are increasingly being used in various industries because they can be applied rapidly and have excellent physical properties. Ultraviolet polymerization is used for manufacturing such oligomers. Reactive diluents, which are employed during the secondary curing of UV-curable oligomers, can help elucidate the curing behaviors of these oligomers. In this study, poly (ethylene glycol dimethacrylate (PEGDMA was used as the reactive diluent for UV-curable oligomers. Photodifferential scanning calorimetry (photo-DSC and shrinkage measurements revealed that the curing behavior of the polymers was dependent on the size and number of molecules of PEGDMA. The effect of the small-size PEGDMA on curing behavior was greater than that of the larger molecules. Further, in most cases, the use of a larger amount of PEGDMA resulted in lower reactivity.

  7. Influence of curing time, overlay material and thickness on three light-curing composites used for luting indirect composite restorations.

    Science.gov (United States)

    D'Arcangelo, Camillo; De Angelis, Francesco; Vadini, Mirco; Carluccio, Fabio; Vitalone, Laura Merla; D'Amario, Maurizio

    2012-08-01

    To assess the microhardness of three resin composites employed in the adhesive luting of indirect composite restorations and examine the influence of the overlay material and thickness as well as the curing time on polymerization rate. Three commercially available resin composites were selected: Enamel Plus HRI (Micerium) (ENA), Saremco ELS (Saremco Dental) (SAR), Esthet-X HD (Dentsply/DeTrey) (EST-X). Post-polymerized cylinders of 6 different thicknesses were produced and used as overlays: 2 mm, 3 mm, 3.5 mm, 4 mm, 5 mm, and 6 mm. Two-mm-thick disks were produced and employed as underlays. A standardized amount of composite paste was placed between the underlay and the overlay surfaces which were maintained at a fixed distance of 0.5 mm. Light curing of the luting composite layer was performed through the overlays for 40, 80, or 120 s. For each specimen, the composite to be cured, the cured overlay, and the underlay were made out of the same batch of resin composite. All specimens were assigned to three experimental groups on the basis of the resin composite used, and to subgroups on the basis of the overlay thickness and the curing time, resulting in 54 experimental subgroups (n = 5). Forty-five additional specimens, 15 for each material under investigation, were produced and subjected to 40, 80, or 120 s of light curing using a microscope glass as an overlay; they were assigned to 9 control subgroups (n = 5). Three Vicker's hardness (VH) indentations were performed on each specimen. Means and standard deviations were calculated. Data were statistically analyzed using 3-way ANOVA. Within the same material, VH values lower than 55% of control were not considered acceptable. The used material, the overlay thickness, and the curing time significantly influenced VH values. In the ENA group, acceptable hardness values were achieved with 3.5-mm or thinner overlays after 120 or 80 s curing time (VH 41.75 and 39.32, respectively), and with 2-mm overlays after 40 s (VH 54

  8. Pengaruh Variasi Fraksi Volume, Temperatur, Waktu Curing dan Post-Curing Terhadap Karakteristik Tekan Komposit Polyester - Hollow Glass Microspheres

    Directory of Open Access Journals (Sweden)

    Chandra Prastyadi

    2017-03-01

    Full Text Available Dewasa ini penggunaan material komposit sudah sangat berkembang. Komposisi dari komposit juga sudah sangat beragam, namun penelitian tentang komposit Polyester – Hollow Glass Microspheres (HGM dengan variasi temperatur curing dan post-curing untuk karakteristik tekan masih sangat terbatas. Keunggulan yang dimiliki HGM antara lain memberikan bobot yang ringan, konduktivitas termal rendah, dan ketahanan terhadap tegangan kompresi yang tinggi. Komposit Polyester-HGM dapat diaplikasikan antara lain pada bemper atau body kendaraan sehingga dapat mereduksi berat total kendaraan dan meningkatkan efisiensi kendaraan. Penelitian dilakukan dengan mencampurkan polyester resin dan HGM. Spesimen uji tekan dibuat dengan dimensi sesuai ASTM D-695 dengan variasi fraksi volume HGM 10% hingga 17%. Spesimen menerima tiga perlakuan yang berbeda yaitu: (1 Spesimen I di-curing pada temperatur kamar (± 27°C ditahan selama 24 jam; (2 Spesimen II di-curing pada temperatur kamar (±27°C ditahan selama 24 jam lalu post-curing pada temperatur 90°C selama 5 jam; dan (3 Spesimen III di-curing pada temperatur 90°C ditahan selama 24 jam. Untuk mempelajari perbedaan sifat mekanik yang terjadi, dilakukan pengujian tekan. Pada penelitian ini dapat diketahui bahwa kekuatan tekan dan ketangguhan maksimum terjadi pada komposit dengan fraksi volume HGM 17%. Semakin tinggi temperatur curing akan meningkatkan nilai kekuatan tekan dan ketangguhan dari komposit polyester-HGM. Hal ini terjadi karena komposit yang di-curing pada temperatur tinggi memiliki ikatan crosslink lebih banyak sehingga ikatan polyester dan HGM lebih kuat dan nilai kekuatan tekan pada komposit akan meningkat.

  9. "We Need to Deploy Them Very Thoughtfully and Carefully": Perceptions of Analytical Treatment Interruptions in HIV Cure Research in the United States-A Qualitative Inquiry.

    Science.gov (United States)

    Dubé, Karine; Evans, David; Dee, Lynda; Sylla, Laurie; Taylor, Jeff; Skinner, Asheley; Weiner, Bryan J; Greene, Sandra B; Rennie, Stuart; Tucker, Joseph D

    2018-01-01

    Strategies to control HIV in the absence of antiretroviral therapy are needed to cure HIV. However, such strategies will require analytical treatment interruptions (ATIs) to determine their efficacy. We investigated how U.S. stakeholders involved in HIV cure research perceive ATIs. We conducted 36 in-depth interviews with three groups of stakeholders: 12 people living with HIV, 11 clinician-researchers, and 13 policy-makers/bioethicists. Qualitative data revealed several themes. First, there was little consensus on when ATIs would be ethically warranted. Second, the most frequent perceived hypothetical motivators for participating in research on ATIs were advancing science and contributing to society. Third, risks related to viral rebound were the most prevalent concerns related to ATIs. Stakeholders suggested ways to minimize the risks of ATIs in HIV cure research. Increased cooperation between scientists and local communities may be useful for minimizing risk. Further ethics research is necessary.

  10. Microhardness of composite resin cured through different primary tooth thicknesses with different light intensities and curing times: In vitro study.

    Science.gov (United States)

    Mazhari, Fatemeh; Ajami, Behjatolmolok; Moazzami, Saied Mostafa; Baghaee, Bahareh; Hafez, Bahareh

    2016-01-01

    The aim of this study was to evaluate the effect of increased exposure time and light intensity on microhardness of cured composite through different thicknesses of tooth structure in primary teeth. One hundred and seventy cylindrical resin composite specimens were prepared. All specimens were divided into 17 experimental and control groups. "Light-emitting diode" light curing unit (LCU) applied directly or through 1, 2, and 3 mm thicknesses tooth slices for experimental groups. The irradiation protocols were 25 and 50 s at 650 mW/cm(2) and 15 and 30 s at 1100 mW/cm(2). The "quartz-tungsten-halogen" LCU (400 mW/cm(2)) for 40 s was used in control group. Microhardness was measured by the Vickers hardness test. Indirectly cured specimens and those cured through a 1 mm thick tooth structure, an increase in intensity caused hardness drop. In the specimens cured through 2 and 3 mm thick tooth structures, increased intensity and/or exposure time did not show any appropriate changes on microhardness. Irradiation through a 1.0 mm thick tooth slice resulted in reduced microhardness although it was still within the clinically acceptable level. The hardness values of the specimens cured through 2 or 3 mm thick tooth slices fell below the clinically acceptable level even after doubling the exposure time and/or light intensity.

  11. Changes in the temperature of a dental light-cured composite resin by different light-curing units

    Science.gov (United States)

    Rastelli, A. N. S.; Jacomassi, D. P.; Bagnato, V. S.

    2008-08-01

    The purpose of this study was to evaluate the temperature increase during the polymerization process through the use of three different light-curing units with different irradiation times. One argon laser (Innova, Coherent), one halogen (Optilight 501, Demetron), and one blue LED (LEC 1000, MM Optics) LCU with 500 mW/cm2 during 5, 10, 20, 30, 40, 50, and 60 s of irradiation times were used in this study. The composite resin used was a microhybrid Filtek Z-250 (3M/ESPE) at color A2. The samples were made in a metallic mold 2 mm in thickness and 4 mm in diameter and previously light-cured during 40 s. A thermocouple (Model 120 202 EAJ, Fenwal Electronic, Milford, MA, USA) was introduced in the composite resin to measure the temperature increase during the curing process. The highest temperature increase was recorded with a Curing Light 2500 halogen LCU (5 and 31°C after 5 and 60 s, respectively), while the lowest temperature increase was recorded for the Innova LCU based on an argon laser (2 and 11°C after 5 and 60 s, respectively). The temperature recorded for LCU based on a blue LED was 3 and 22°C after 5 and 60 s, respectively. There was a quantifiable amount of heat generated during the visible light curing of a composite resin. The amount of heat generated was influenced by the characteristics of the light-curing units used and the irradiation times.

  12. Evaluation of microleakage of class II dental composite resin restorations cured with LED or QTH dental curing light; Blind, Cluster Randomized, In vitro cross sectional study.

    Science.gov (United States)

    Zakavi, Faramarz; Golpasand Hagh, Leila; Sadeghian, Soheila; Freckelton, Virginia; Daraeighadikolaei, Arash; Ghanatir, Elham; Zarnaghash, Najmeh

    2014-07-03

    The aim of this study is to compare the microleakage of Class II dental composite resin restorations which have been cured by three different LED (light emitting diode) light curing modes compared to control samples cured by QTH (quartz tungsten halogen) light curing units (LCUs), to determine the most effective light curing unit and mode of curing. In this experimental study, class II cavities were prepared on 100 sound human premolars which have been extracted for orthodontic treatment. The teeth were randomly divided into four groups; three experimental and one control group of 25 teeth each. Experimental groups were cured by either conventional, pulse-delay, or ramped curing modes of LED. The control group was cured for 20 seconds by QTH. The restorations were thermocycled (1000 times, between 5 and 55°C, for 5 seconds dwell time), dyed, sectioned mesio-distally and viewed under stereo-microscope (40×) magnification. Teeth were then scored on a 0 to 4 scale based on the amount of microleakage. The data were analyzed by Chi-square test.No significant difference was demonstrated between the different LCUs (light curing units), or modes of curing, at the enamel side (p > 0.05). At the dentin side, all modes of LED curing could significantly reduce microleakage (p curing improves marginal integrity and seal. High intense curing endangers those aims. Comparison between the three LED mode cured composite resin restorations and QTH curing showed LED curing in all modes is more effective than QTH for reducing microleakage. Both LED and QTH almost completely eliminate the microleakage on the enamel side, however none of them absolutely eliminated microleakage on the dentin side.

  13. We all need to know about HIV cure research:?a case report

    OpenAIRE

    Davies, Olubanke; Fox, Julie

    2015-01-01

    Abstract A cure for HIV is not near, yet publicity surrounding the possibility of cure is high. We present the case of an individual with acute HIV who delayed antiretroviral therapy due to misinformed expectations of availability of cure treatments. Researchers and the media need to be mindful of prematurely raising hope of a cure.

  14. 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.

  15. 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.

  16. Echinococcus granulosus: Cure for Cancer Revisited

    Directory of Open Access Journals (Sweden)

    Shiwanthi L. Ranasinghe

    2018-03-01

    Full Text Available Whereas a number of parasites are well recognized risk factors for a number of different cancers in mammalian hosts, there is limited information on the ability of parasitic organisms to induce anticancer effects. There are conflicting reports that echinococcosis, caused by the canine tapeworm Echinococcus granulosus, can decrease or increase cancer risk. This review considers both indirect anticancer effects as the result of adaptive immunity generated against certain echinococcal antigens and the direct effect of molecules released by E. granulosus whose activity directly inhibits cancer cell migration and growth. In conclusion, E. granulosus probably secretes molecules that can be developed as anticancer therapeutics in future.

  17. Dying after cure: A case of suicide in an adolescent treated for cancer

    Directory of Open Access Journals (Sweden)

    Laura Veneroni

    2015-01-01

    Full Text Available Although suicide among childhood cancer survivors is rare, there is still a significantly higher risk in this population than in healthy adolescents. A 17-year-old girl cured of Burkitt lymphoma committed suicide after completing her treatment. She had never previously shown signs of psychological suffering and was in good general health. This case made the operators wonder how this tragic possibility might be prevented. It is essential for the ongoing monitoring of the psychological and social suffering of young people during follow-up programs to be assured by a multidisciplinary team involved in the patient′s global care.

  18. Assessment of Salmonella survival in dry-cured Italian salami.

    Science.gov (United States)

    Bonardi, S; Bruini, I; Bolzoni, L; Cozzolino, P; Pierantoni, M; Brindani, F; Bellotti, P; Renzi, M; Pongolini, S

    2017-12-04

    The inactivation of Salmonella during curing of Italian traditional pork salami was investigated. A total of 150 batches of ground raw meat (GRM) used for salami manufacturing by four producers were tested for Salmonella by real-time PCR followed by ISO 6579 cultural confirmation and MPN enumeration. Salami produced with Salmonella positive GRMs were re-tested at the end of their curing period. Aw, pH and NaCl content were also measured. Detection of Salmonella was performed testing both 25 and 50g of the samples. By Real-Time PCR 37% of the GRMs resulted positive, but cultural detection of Salmonella was obtained in 14% of the samples only. Salmonella enumeration ranged from 31 MPN/g to Salmonella in 100% of all positive samples, vs. 62% of ISO-25g. Salami made of the contaminated GRMs were 29% Salmonella-positive, as most batches of salami produced with Salmonella-positive GRMs resulted negative after regular curing (20-48days). Overall, 13% of salami produced with Salmonella-contaminated GRMs were positive. They belonged to six batches, which turned out negative after prolonged curing ranging between 49 and 86days. Salmonella enumeration in salami ranged from 8.7 MPN/g to Salmonella in cured salami (p value: >0.05). The most common Salmonella serovars in GRMs were Derby (52%), Typhimurium monophasic variant 4, (Barbuti et al., 1993), 12:i:- (19%) and Stanley (10%). Salmonella Derby (56%), London, Branderup, Panama (13%, respectively) and Goldcoast (6%) were most frequent in cured salami. The study showed negative correlation between real-time CT values and cultural confirmation of Salmonella, as well as the importance of sample size for Salmonella detection. Among considered factors with possible effect on the occurrence of Salmonella in salami, statistical analysis revealed a role for aw in salami and for Salmonella load in GRMs, while pH and NaCl content did not significantly affect the probability of finding Salmonella in dry-cured salami in the context of

  19. Photothermal radiometry monitoring of light curing in resins

    Science.gov (United States)

    Zambrano-Arjona, M. A.; Medina-Esquivel, R.; Alvarado-Gil, J. J.

    2007-10-01

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

  20. Use of light-curing units in orthodontics.

    Science.gov (United States)

    Goyal, Amit; Hurkadle, Jyothikiran; Magegowda, Shivalinga; Bhatia, Pankaj

    2013-08-01

    Because of their wide field of applications, light-curing units are now indispensable for orthodontists and general dentists; thus, it is important to be familiar with the various types of light-curing units, their history, specifications, advantages, and disadvantages. For this review, a search of the PubMed database (from 1966 to March 2010) was conducted using the search term "curing lights orthodontics". Eligibility of the selected studies was determined by reading the abstracts of articles identified by the search. All the articles that met the inclusion criteria were selected, and the articles collected. The reference lists of the retrieved articles were also hand searched for any applicable studies that might have been missed in the database searches. When selecting curing lights for an office, many variables need to be considered. Armed with knowledge about each curing-light category, orthodontists can evaluate their unique practice style and select the appropriate light/lights. © 2013 Wiley Publishing Asia Pty Ltd.

  1. Mechanical properties of glass ionomer cements affected by curing methods.

    Science.gov (United States)

    Kleverlaan, Cornelis J; van Duinen, Raimond N B; Feilzer, Albert J

    2004-01-01

    The primary objective of the study was to assess the influence of externally applied 'command' set applications on the mechanical properties of several commercially available conventional glass ionomer cement (GIC). Four different restorative GICs cements (Fuji IX FAST, Fuji IX, Ketac Molar Quick, Ketac Molar) were cured using three different methods, e.g. standard curing conditions (SC), ultrasonic excitation (UC) and by an external heat source (HC). The compressive strength of these samples was measured and the groups were compared using one-way ANOVA. A standard thermocouple (K-type) measured the temperature in GIC during curing. In general all experiments showed an increase in strength going from SC, UC to HC. Especially, the compressive strength of Fuji IX FAST and Ketac Molar increased by UC and HC compared to the SC values. The compressive strength of Fuji IX FAST as a function of time showed an increase in strength during 28d. There was a clear relationship between the temperature in the sample (SCcuring time. Enhanced material properties at early curing time can improve the survival rate of GICs in the clinical situation. Ultrasonic excitation can be used as a 'command' set method and improves the properties of GIC at early setting time.

  2. Bio-economicity of the finishing phase on feedlot of crossbred young bulls slaughtered at different body weights Bioeconomicidade da fase de terminação em confinamento de bovinos mestiços abatidos com diferentes pesos

    Directory of Open Access Journals (Sweden)

    Renius Mello

    2009-01-01

    Full Text Available The objective in this work was to evaluate the economicity of the finishing phase on feedlot of F1 Red Angus × Nellore (½ RA ½ N and Blond D'Aquitaine × Nellore (½ BA ½ N crossbred young bulls slaughtered at 480, 520 and 560 kg of body weight. Thirty-six F1 crossbred young bull with 20 months of initial average age: 18 ½RA½ N and 18 ½N½ BA were allotted to a completely randomized design in a 2 × 3 factorial arrangement (genetic group × slaughter weight, with six replicates. The ½ BA ½ N young bulls slaughtered at 480 kg had the highest carcass gain (kg/day, feed efficiency, gross income (R$/day, gross profit of feed (R$/day, break-even cost of the diet (@/t DM and cost:benefit ratio. The ½ BA ½ N young bulls also had higher dressing percentage than ½ RA ½ N young bulls. As the slaughter weight rised the dressing percentage, feed:gain ratio, feed cost (R$/@ and R$/day and break-even point (kg/day increased; while the gross feed profit (R$/@ decreased. The bioeconomic multivariate nutritional index had better association with the profitability of the finishing phase of beef cattle on feedlot. Sensitivity analysis did not influence the results obtained. The benefit was lower than the feed cost from exchange relation of four (4 @/t DM of the diet. F1 Blond D'Aquitaine × Nellore crossbred young bulls slaughtered at 480 kg of body weight showed the best bioeconomic efficiency.Objetivou-se verificar a economicidade da fase de terminação em confinamento de tourinhos mestiços F1 Red Angus × Nelore (½ RA ½ N e F1 Blonde D'Aquitaine × Nelore (½ BA ½ N abatidos com 480, 520 e 560 kg de peso corporal. Trinta e seis bovinos mestiços F1, tourinhos, com 20 meses de idade média inicial: 18 ½ RA ½ N e 18 ½ BA ½ N foram distribuídos a um delineamento experimental inteiramente casualizado em arranjo fatorial 2 × 3 (grupos genético × peso de abate, com seis repetições. Os tourinhos ½ BA ½ N abatidos com 480 kg apresentaram

  3. Direct curing of composite material in free space environment

    Science.gov (United States)

    Kondyurin, Alexey

    The size and mass of modern space constructions (antenna, space satellite, space station or space base) sent to the Earth orbit are limited by capacity of a launch vehicle. A new approach enabling large-size constructions in space relies on the use of the technology of the polymerization of fiber-filled composites and a reactionable matrix applied in free space. The experimental and theoretical investigations on the curing process in high vacuum, space plasma and temperature variations indicate that the curing process can be realized under free space conditions. The curing process is sensitive to conditions of free space environment and to composition of polymer matrix. The selected compositions provide a bubble-free polymer matrix with crosslinking effect under the space irradiations. The results of laboratory experiments and stratospheric flight experiments are discussed. The investigations were supported by Alexander von Humboldt Foundation, ESA, NASA and RFBR (12-08-00970) grants.

  4. Comparative study of EB and UV cured polymer films

    International Nuclear Information System (INIS)

    Ali, M.A.; Akhtar, F.; Idriss Ali, K.M.

    1999-01-01

    A number of formulations were developed with urethane diacrylate oligomers in combination with several reactive diluent monomers of different functionalities in the presence of certain co-diluent co-monomers. Thin polymer films were prepared with these formulated solutions using either electron beam (EB) or ultraviolet (UV) radiation. Physical, mechanical and thermal properties of the radiation cured films were studied and correlated with the glass transition temperature (Tg) of the homopolymer of diluents and co-diluents. Tensile properties (strength and elongation) were almost double with the UV-cured films than those of the EB-cured films of the similar formulation. Thermal behavior was also found to be different in these two systems. The co-monomers played significant role to produce more shape recovery films than the oligomer/diluent system. The co-diluents also induced shape recovery character in the film whose Tg values are lower than 0 degree C. This is unique

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

    International Nuclear Information System (INIS)

    Ochi, Masafumi

    2003-01-01

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

  6. 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.

  7. 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.

  8. Practical aspects of irradiance and energy in UV curing

    International Nuclear Information System (INIS)

    Stowe, R.W.

    1999-01-01

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

  9. Multifarious immunotherapeutic approaches to cure HIV-1 infection.

    Science.gov (United States)

    Imami, Nesrina; Herasimtschuk, Anna A

    2015-01-01

    Immunotherapy in the context of treated HIV-1 infection aims to improve immune responses to achieve better control of the virus. To date, multifaceted immunotherapeutic approaches have been shown to reduce immune activation and increase CD4 T-lymphocyte counts, further to the effects of antiretroviral therapy alone, in addition to improving HIV-1-specific T-cell responses. While sterilizing cure of HIV-1 would involve elimination of all replication-competent virus, a functional cure in which the host has long-lasting control of viral replication may be more feasible. In this commentary, we discuss novel strategies aimed at targeting the latent viral reservoir with cure of HIV-1 infection being the ultimate goal, an achievement that would have considerable impact on worldwide HIV-1 infection.

  10. Latency reversal and viral clearance to cure HIV-1.

    Science.gov (United States)

    Margolis, David M; Garcia, J Victor; Hazuda, Daria J; Haynes, Barton F

    2016-07-22

    Research toward a cure for human immunodeficiency virus type 1 (HIV-1) infection has joined prevention and treatment efforts in the global public health agenda. A major approach to HIV eradication envisions antiretroviral suppression, paired with targeted therapies to enforce the expression of viral antigen from quiescent HIV-1 genomes, and immunotherapies to clear latent infection. These strategies are targeted to lead to viral eradication--a cure for AIDS. Paired testing of latency reversal and clearance strategies has begun, but additional obstacles to HIV eradication may emerge. Nevertheless, there is reason for optimism that advances in long-acting antiretroviral therapy and HIV prevention strategies will contribute to efforts in HIV cure research and that the implementation of these efforts will synergize to markedly blunt the effect of the HIV pandemic on society. Copyright © 2016, American Association for the Advancement of Science.

  11. The Effect of Temperature Curing on Geopolymer Concrete

    Directory of Open Access Journals (Sweden)

    Triwulan

    2017-01-01

    Full Text Available This study presents curing temperature influences to behaviors of geopolymer concrete. The concrete was fly ash based, with the ratio of fly ash to alkaline activator was 65%:35%. Ratio coarse aggregate to fine aggregate was 60%:40%, ratios Na2SiO3/NaOH were 1.5:2 and 2.5. A polycarboxilate superplasticizer with ratio was 2% to fly ash weight. Form of the test specimens were cylinder with diameter of 10 cm and 20 cm high. Steam curing conducted were at 40°C, 60°C and 80°C for 24 hours. The control specimens were treated at normal moist curing. Tests conducted were compressive strength, tensile strength, porosity and elasticity modulus. The results indicated that at the elevated temperature the compressive strength increases as well as tensile strength but decreases the closed porosity of specimens. The elasticity modulus had a similar tendency.

  12. Optimum conditions for radiation curing of polyester/epoxy compositions

    International Nuclear Information System (INIS)

    Brzostowski, A.; Pietrzak, M.

    1982-01-01

    The effects of dose rate of γ 60 Co radiation, heat removal conditions and construction of polyester-epoxy compositions on the curing conditions of the latter were investigated. It was found that the optimum dose rate was within 0.1x10 4 Gy/h and 0.6x10 4 Gy/h for the following composition: 100 parts by weight of polyester resin, 10 to 15 parts by weight of an unsaturated epoxy resin and 100 parts by weight of silicon dioxide. The mixture was well cooled during the curing process. Curing is completed after the absorption of a dose from 0.3x10 4 Gy to 0.45x10 4 Gy. (author)

  13. Effect of saliva contamination prior to curing on microleakage of pit and fissure sealants, an in vitro study

    Directory of Open Access Journals (Sweden)

    Afshar H.

    2008-11-01

    Full Text Available "nBackground and Aim: Pit and fissure sealant therapy, is one of the most effective methods, in prevention of occlusal caries. Saliva contamination before curing the resin can increase the risk of failure in this method. The purpose of this study was to evaluate the effect of saliva contamination prior to curing on microleakage of pit and fissure sealants. "nMaterials and Methods: In this experimental in vitro study 21 sound human pre molars were selected and two standardized V-Shaped fissures were prepared on both buccal and lingual surfaces, then they were randomly divided into two equal groups. In the control group, the sealant was cured without any saliva contamination and in the case group, the sealed teeth were immersed in artificial saliva for ten seconds before curing. After thermocycling the samples were immersed in 2% fouchsin solution for 24 hours and then sectioned longitudinally in bucco - lingual direction. The specimens were then fixed and assessed under stereomicroscope to determine microleakage and dye penetration using paired student t. test. P<0.05 was considered as the level of significance. "nResults: Analysis of data showed no significant differences in microleakage, between the two groups (p=0.178. "nConclusion: According to the results of this study saliva contamination of uncured sealant had no influence on microleakage.

  14. Temperature and curing time affect composite sorption and solubility

    Directory of Open Access Journals (Sweden)

    Fabrício Luscino Alves de Castro

    2013-04-01

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

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

    Directory of Open Access Journals (Sweden)

    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.

  16. A Downside to Hepatitis C Virus Cure? Vigilance Is Needed Regarding Hepatitis B Virus Reactivation, Organ Rejection, or Hepatocellular Carcinoma Progression.

    Science.gov (United States)

    Sanaka, Sirish; Kasarala, George R; Tillmann, Hans L

    2018-03-05

    Cure of hepatitis C virus has become feasible in almost all patients. However, vigilance is needed in 3 scenarios: previous exposure to hepatitis B virus (HBV), history of organ transplantation, and history of cured hepatocellular carcinoma (HCC). The current data suggest that HBV reactivation occurs in about 10% of hepatitis B surface antigen (HBsAg)-positive patients and approximately 1% of hepatitis B core antibody-positive but HBsAg-negative patients. The risk of organ rejection is also around 1%, but can be fatal if not acted on immediately. Finally, the risk of early HCC recurrence may be increased but should not delay initiation of antiviral therapy in the setting of cured HCC; however, increased surveillance may be warranted.

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

    Directory of Open Access Journals (Sweden)

    Jovičić Mirjana C.

    2010-01-01

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

  18. Dynamic dielectric analysis for nondestructive cure monitoring and process control

    Science.gov (United States)

    Kranbuehl, D. E.; Delos, S. E.; Hoff, M. S.; Whitham, M. E.; Weller, L. W.

    1986-01-01

    Dynamic dielectric analysis (DDA) is an effective in situ NDE method that can monitor the reaction status in thermosets and the phase changes in thermoplastics, including slow reactions occuring late in the cure cycle and recrystallization during annealing. The effects of moisture and resin history on reaction rate can also be determined, as can ionic and dipolar contributions. The ionic mobility parameter is noted to be an excellent monitor of viscosity above the glass transition temperature. The ability of DDA to monitor cure rate variations in a thick section during autoclaving has been demonstrated.

  19. Electron beam curing polyurethane acrylate oligomer in air

    International Nuclear Information System (INIS)

    Zhu, Zhenkang; Chen, Xing; Zhou, Jichun; Ma, Zue-Teh

    1988-01-01

    It has been found according to our synthesis that a novel kind of polyurethane acrylate oligomer can be cured by electron beam in the presence of oxygen, even at normal atomospheric levels, without any additives. Irradiation of the oligomer with substantially complete cure to a solid non-tacky state is quite remarkable. It has the same gel content (90 %) in air as in nitrogen at dose of 33 kGy. Double bond conversion of the oligomer is about 50 % by I.R. (author)

  20. The chemistry of UV and EB radiation curing

    International Nuclear Information System (INIS)

    Garnett, J.L.

    1987-01-01

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

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

    International Nuclear Information System (INIS)

    Fisher, R.

    1999-01-01

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

  2. Mechanisms of atrial fibrillation: is a cure at hand?

    Science.gov (United States)

    Scheinman, M M

    2000-05-01

    The mechanisms of atrial fibrillation relate to the presence of random reentry involving multiple interatrial circuits. Triggers for development of atrial fibrillation include rapidly discharging atrial foci (mainly from pulmonary veins) or degeneration of atrial flutter or atrial tachycardia into fibrillation. Therapy for control of atrial fibrillation includes drugs, atrial pacing for those with sinus node dysfunction, or ablation of the atrioventricular junction. Therapeutic maneuvers for cure of atrial fibrillation include surgical or radiofrequency catheter induced linear lesions to reduce the atrial tissue and prevent the requisite number of reentrant wavelets. We need a much better understanding of basic mechanisms before a true cure is at hand.

  3. The chemistry of UV and BE radiation curing

    International Nuclear Information System (INIS)

    Garnett, J.L.

    1991-01-01

    The application of photopolymerisation (UV) and electron beams (EB) technologies in radiation rapid cure (PRC) processing is discussed. The chemistry associated with such reactions and the mechanisms of the processes are treated. The occurrence of concurrent grafting to substrate with radiation curing of films is shown to be an advantage in enhancing the properties of certain finished products. The parameters influencing the optimum grafting yield in such PRC processes are discussed. In many applications, the chemistry of such processes combined with the machine, specially for EB is shown. (author)

  4. Thermal and mechanical consequences of post-cure processing of DGEBA epoxy cured with diethanolamine

    Science.gov (United States)

    Arechederra, Gabriel; McCoy, John; Kropka, Jamie

    When diglycidyl ether of bisphenol A (DGEBA) resin is cured with diethanolamine (DEA), a cross-linked network epoxy that exhibits a glass transition temperature is obtained. This resin, when filled with glass microballoons, has been particularly useful as a potting material in high performance aerospace applications. In the present study, we post-process DGEBA/DEA by exposing it to isothermal temperatures, both below and above Tg, for long periods of time. This epoxy has residual reactive potential and is out of structural equilibrium, which leads to chemical and physical changes under these conditions. The relative contributions of the physical and chemical changes on the measured Tg and yield stress are distinguished by ``erasing'' physical aging contributions by annealing samples at temperatures above Tg. The sub-Tg aged and then annealed epoxies show an increase in yield stress with increasing Tg, but the super-Tg aged epoxies show little change in yield stress with increasing Tg. While this is evidence that the evolution of the network structure is different in the glassy, sub-Tg state than in the elastomeric, super-Tg environment, the detailed nature of the differences in the networks are yet to be explored.

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

    Science.gov (United States)

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

    2015-05-01

    Objectives were to compare belly, bacon processing, bacon slice, and sensory characteristics from pigs fed high protein canola meal (CM-HP) or conventional canola meal (CM-CV). Soybean meal was replaced with 0 (control), 33, 66, or 100% of both types of canola meal. Left side bellies from 70 carcasses were randomly assigned to conventional or dry cure treatment and matching right side bellies were assigned the opposite treatment. Secondary objectives were to test the existence of bilateral symmetry on fresh belly characteristics and fatty acid profiles of right and left side bellies originating from the same carcass. Bellies from pigs fed CM-HP were slightly lighter and thinner than bellies from pigs fed CM-CV, yet bacon processing, bacon slice, and sensory characteristics were unaffected by dietary treatment and did not differ from the control. Furthermore, testing the existence of bilateral symmetry on fresh belly characteristics revealed that bellies originating from the right side of the carcasses were slightly (P≤0.05) wider, thicker, heavier and firmer than bellies from the left side of the carcass. Copyright © 2015 Elsevier Ltd. All rights reserved.

  6. The curing behavior and properties of phthalonitrile resins using ionic liquids as a new class of curing agents

    Directory of Open Access Journals (Sweden)

    K. Cheng

    2017-11-01

    Full Text Available Binary blends composed of 1,3-bis (3,4-dicyanophenoxy benzene (3BOCN and ionic liquids (ILs with different molecular structures were prepared. The curing behavior of these 3BOCN/ILs blends were studied by thermogravimetric analysis (TGA, differential scanning calorimetry (DSC and rheological analysis. The study suggested that the blends possessed a wide processing window and the structures of ILs (anion, cation and alkyl chain length at cation had an effect on curing behavior. The 3BOCN/[EPy]BF4 resins were prepared at elevated temperature. IR spectra of the resins showed that there were triazine and isoindoline formed in curing process. The TGA and dynamic mechanical analysis (DMA revealed that the resins have excellent thermal stability together with high storage modulus and high glass transition temperature (Tg. Dielectric properties, long term oxidative aging and water uptake measurements of the resins suggested the IL brought some unique properties to the resins.

  7. 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.

  8. 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.

  9. Bilateral breast cancer after cured Hodgkin's disease

    International Nuclear Information System (INIS)

    Anderson, N.; Lokich, J.

    1990-01-01

    Three patients developed bilateral breast cancer at 10 to 24 years after mantle irradiation for locally or systemically advanced Hodgkin's disease (HD). Four of the six cancers in the three patients were detected only by mammography. Pathologically, five of the cancers were intraductal carcinomas (four with an invasive component) with one being a lobular carcinoma. Five of the six lesions were Stage I pathologically without evidence of axillary nodal involvement. It is recommended that female patients with Hodgkin's disease who have received mantle irradiation as part of the therapy for their Hodgkin's disease and who are observed for 10 or more years after completion of mantle irradiation be considered at risk for the development of breast cancer. Such patients should be monitored appropriately by routine bilateral mammograms to increase the early detection of early stage lesions

  10. Bacterial spoilage of meat and cured meat products

    NARCIS (Netherlands)

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

    1996-01-01

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

  11. Influence of curing regimes on compressive strength of ultra high ...

    Indian Academy of Sciences (India)

    The present paper is aimed to identify an efficient curing regime for ultra high performance concrete (UHPC), to achieve a target compressive strength more than 150 MPa, using indigenous materials. The thermal regime plays a vital role due to the limited fineness of ingredients and low water/binder ratio. By activation of the ...

  12. Effects of the different atmospheric steam curing processes on the ...

    Indian Academy of Sciences (India)

    In this paper an attempt has been made to study the use of microsilica on the properties of self-compacting-concrete (SCC) such as compressive strength, splitting tensile strength, flexural strength, ultrasonic pulse velocity (UPV) and micro-hardness when exposed to different atmospheric steam curing temperatures.

  13. Ultraviolet and electron beams: energy efficient methods of curing

    International Nuclear Information System (INIS)

    O'Hara, K.

    1982-01-01

    The use of ultraviolet or electron beam radiation for the curing of surface coatings is described. Examples are taken from a number of industries, particular attention being paid to the paper varnishing and printed circuit industries. The components of the coatings used in these processes and toxicology and safety aspects are considered. (author)

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

    Science.gov (United States)

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

    2007-04-18

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

  15. Recent developments in radiation curing in the USA

    Science.gov (United States)

    Nablo, Sam V.

    Radiation curing activities in the USA continue to focus strongly on the use of both UV and EB for the polymerization of silicone release coatings on paper and film. The high speeds of cure (200 m/minute) achievable at "room temperature" continue to make this the process of choice for the siliconization of both film and paper. Some of the process difficulties peculiar to this chemistry will be discussed. The success of the multi-color lithographic printing of web using single station electron curing has resulted in a major market for electron processors. The aesthetic and physical properties of the overprint varnishes used in this application are important and will be discussed. The relatively high costs of both the inks and varnishes will probably limit this application to folding carton use for foodstuffs and high quality products, with UV continuing to dominate in lower speed, less demanding applications. The application of electron initiated graft modification of polymer materials, particularly for biological/medical device application, is showing a good rate of development as is the use of selective treatment of materials for functional modification of packaging films, particularly for gas permeability control. Some examples of these applications will be reviewed. Continued work with "deep" curing or vulcanization of composite structures, particularly in the elastomers field, will be discussed with a brief review of the continuing growth of electron processing in this industry, particularly for tires and roofing products.

  16. Multiple imputation for cure rate quantile regression with censored data.

    Science.gov (United States)

    Wu, Yuanshan; Yin, Guosheng

    2017-03-01

    The main challenge in the context of cure rate analysis is that one never knows whether censored subjects are cured or uncured, or whether they are susceptible or insusceptible to the event of interest. Considering the susceptible indicator as missing data, we propose a multiple imputation approach to cure rate quantile regression for censored data with a survival fraction. We develop an iterative algorithm to estimate the conditionally uncured probability for each subject. By utilizing this estimated probability and Bernoulli sample imputation, we can classify each subject as cured or uncured, and then employ the locally weighted method to estimate the quantile regression coefficients with only the uncured subjects. Repeating the imputation procedure multiple times and taking an average over the resultant estimators, we obtain consistent estimators for the quantile regression coefficients. Our approach relaxes the usual global linearity assumption, so that we can apply quantile regression to any particular quantile of interest. We establish asymptotic properties for the proposed estimators, including both consistency and asymptotic normality. We conduct simulation studies to assess the finite-sample performance of the proposed multiple imputation method and apply it to a lung cancer study as an illustration. © 2016, The International Biometric Society.

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

    DEFF Research Database (Denmark)

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

    2004-01-01

    Eight pork loin samples were mounted in Plexiglas cylinders and cured for five days. Samples were scanned by computed tomography (CT) once every 24 h. At the end of the experiment, the cylinders were cut in 1 cm sections and analyzed for chloride. From image analysis of the CT images, concentration...

  18. Industrial potential for application of radiation curing in Pakistan

    International Nuclear Information System (INIS)

    Ahmed, S.

    1991-01-01

    Potential applications of radiation curing of coating are in the field of wood and wood products, drying of printing inks, ceramics (roof and floor tiles) and textiles. Pakistan a 'timber deficit' country needs to improve her wood, plywood, hardboard and particle board to make for shortage of quality wood. Imports of wood and wood products are in excess of 3000 million rupees. Radiation curing can be applied and itexcels over heat treatment. Whereas costs of high energy units (500 KeV) with scanning type are rather high, low energy (100-175 KeV) flat beam self-shielded units costing 200,000 US$ are available. For developing countries ultraviolet (UV) curing is ideally suited because of its low price, flexibility and simplicity in handling. Alternately, multipurpose bunker type facility such as 500 KeV current mA can be utilized in carrying out heat-shrinkables production, irradiation of cable and wire and curing of coatings on wood and wood products. (author)

  19. Effect of curing time on microstructure and mechanical strength ...

    Indian Academy of Sciences (India)

    Effect of curing time on microstructure and mechanical strength development of alkali activated binders based on vitreous calcium aluminosilicate (VCAS). M M TASHIMA, L SORIANO, M V BORRACHERO, J MONZÓ and J PAYÁ. ∗. Instituto de Ciencia y Tecnología del Hormigón, Universitat Politècnica de València, Camino ...

  20. 7 CFR 29.3502 - Air-cured.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Air-cured. 29.3502 Section 29.3502 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE COMMODITY STANDARDS AND STANDARD CONTAINER REGULATIONS TOBACCO INSPECTION Standards Official Standard Grade...

  1. 7 CFR 29.6002 - Air-cured.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Air-cured. 29.6002 Section 29.6002 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE COMMODITY STANDARDS AND STANDARD CONTAINER REGULATIONS TOBACCO INSPECTION Standards Definitions § 29.6002...

  2. 7 CFR 30.13 - Air-cure.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Air-cure. 30.13 Section 30.13 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE COMMODITY STANDARDS AND STANDARD CONTAINER REGULATIONS TOBACCO STOCKS AND STANDARDS Classification of Leaf...

  3. 7 CFR 29.3002 - Air-cured.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Air-cured. 29.3002 Section 29.3002 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE COMMODITY STANDARDS AND STANDARD CONTAINER REGULATIONS TOBACCO INSPECTION Standards Official Standard Grade...

  4. Cure Characteristics and Physico-Mechanical Properties of Natural ...

    African Journals Online (AJOL)

    MICHAEL

    Department of Chemistry, Delta State University, Abraka, Nigeria. ABSTRACT: The cure characteristics and the physico-mechanical properties of natural rubber, standard. Nigerian rubber, SNR10 filled with cherry seed shell (CSS) and standard carbon black CB (N330) were determined. The results showed that the scorch, ...

  5. The statistics of dose/cure relationships for irradiated tumours

    International Nuclear Information System (INIS)

    Porter, E.H.

    1980-01-01

    Attention is given to the statistical analysis of dose/cure experiments. The simplest possible theory is developed in detail with special attention to experimental design and to the range of validity of the methods advocated. Explanations are aimed at the mathematics-tolerant, not at the mathematician. (author)

  6. Recent developments in radiation curing in the USA

    International Nuclear Information System (INIS)

    Nablo, S.V.

    1990-01-01

    Radiation curing activities in the USA focus strongly on the use of both UV and EB for the polymerization of silicone release coatings on paper and film. The high speeds of cure (200 m/minute) achievable at ''room temperature'' continue to make this the process of choice for the siliconization of both film and paper. Some of the process difficulties peculiar to this chemistry will be discussed. The success of the multi-color lithographic printing of web using single station electron curing has resulted in a major market for electron processors. The aesthetic and physical properties of the overprint varnishes used in this application are important and will be discussed. The relatively high costs of both the inks and varnishes will probably limit this application to folding carton use for foodstuffs and high quality products, with UV continuing to dominate in lower speed, less demanding applications. The application of electron initiated graft modification of polymer materials, particularly for biological/medical device application, is showing a good rate of development as is the use of selective treatment of materials for functional modification of packaging films, particularly for gas permeability control. Some examples of these applications will be reviewed. Continued work with ''deep'' curing or vulcanization of composite structures, particularly in the elastomers field, will be discussed with a brief review of the continuing growth of electron processing in this industry, particularly for tyres and roofing products. (author)

  7. 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 ...

  8. Realtime 3D stress measurement in curing epoxy packaging

    DEFF Research Database (Denmark)

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

    2007-01-01

    This paper presents a novel method to characterize stress in microsystem packaging. A circular p-type piezoresistor is implemented on a (001) silicon chip. We use the circular stress sensor to determine the packaging induced stress in a polystyrene tube filled with epoxy. The epoxy curing process...

  9. The Era of HIV Cure Research | Michael | Annals of Ibadan ...

    African Journals Online (AJOL)

    Timothy Ray Brown is widely referred to as the first HIV patient to be cured of the disease. He received a CCR5 deficient bone marrow transplant as a treatment for Acute Myeloid Leukemia, with HAART controlled HIV-1 infection at the background. Seven years after the transplant, and discontinuation of HAART, he has been ...

  10. Towards an HIV cure: a global scientific strategy

    NARCIS (Netherlands)

    Deeks, Steven G.; Autran, Brigitte; Berkhout, Ben; Benkirane, Monsef; Cairns, Scott; Chomont, Nicolas; Chun, Tae-Wook; Churchill, Melissa; Di Mascio, Michele; Katlama, Christine; Lafeuillade, Alain; Landay, Alan; Lederman, Michael; Lewin, Sharon R.; Maldarelli, Frank; Margolis, David; Markowitz, Martin; Martinez-Picado, Javier; Mullins, James I.; Mellors, John; Moreno, Santiago; O'Doherty, Una; Palmer, Sarah; Penicaud, Marie-Capucine; Peterlin, Matija; Poli, Guido; Routy, Jean-Pierre; Rouzioux, Christine; Silvestri, Guido; Stevenson, Mario; Telenti, Amalio; van Lint, Carine; Verdin, Eric; Woolfrey, Ann; Zaia, John; Barré-Sinoussi, Françoise

    2012-01-01

    Given the limitations of antiretroviral therapy and recent advances in our understanding of HIV persistence during effective treatment, there is a growing recognition that a cure for HIV infection is both needed and feasible. The International AIDS Society convened a group of international experts

  11. Products Claiming to "Cure" Cancer Are a Cruel Deception

    Science.gov (United States)

    ... the fraudulent claims on their websites. If the companies don’t comply, the FDA may take further legal action to prevent their products from reaching consumers. Red Flags While some fraudulent products claim to cure a variety of diseases and conditions, fraudulent cancer products often ...

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

    DEFF Research Database (Denmark)

    Wistoft, Karen

    2014-01-01

    -Mindedness to light - but also criticized the Mind-Cure movement as being quasi-religious and having limited reach. His main criticism was its general rejection of the concepts of mental illness, suffering and basic human conflict. Today, many spiritual methods or practices of positive reflection go on to continue...

  13. Surgical cure ofthe Wolff-Parkinson-White syndrome a comparison ...

    African Journals Online (AJOL)

    Surgical cure ofthe Wolff-Parkinson-White syndrome a comparison oftwo techniques. u. o. VON OPPELL, R. N. SCOTT MILLAR, D. A. MILNE. TABLE!. Characteristics of WPW patients referred for surgical ablation of their aberrant atrioventricular pathways. Patient population and methods. We' retrospectively reviewed 19 ...

  14. Evaluation of curing compound application time on concrete surface durability.

    Science.gov (United States)

    2015-03-01

    The effect of curing compound application time after concrete finishing was examined in the study. Times of 30 minutes, 2 hours and 4 hours were considered and repeatability was evaluated with comparisons to a Phase I portion of the study. Scaling re...

  15. Influence of curing regimes on compressive strength of ultra high ...

    Indian Academy of Sciences (India)

    The Association Française de Génie Civil (AFGC) in its interim recommendations states UHPC to have ... participation of all materials in pozzolanic reaction. .... Influence of curing regimes on compressive strength of UHPC. 1425. Table 3. Mix proportion of mix A and mix B. Materials. C. SF. Q. QC. QF. ES-1. ES-3. W/C. SP.

  16. INTRODUCTION Curing is holding fruits at temperatures and ...

    African Journals Online (AJOL)

    toughens the outer layers and gives a total effect of prolonged shelf life. The agent used is warm or hot air. The level of curing depends on peel thickness and the length of time the fruit is to be stored (Zhang and Swingle, 2005; Perez et al. 2005). Orange fruits have a shelf life of about 14 days at ambient tropical conditions.

  17. Radiation cure technology used in inks and coatings

    International Nuclear Information System (INIS)

    Ravijst, J.-P.

    1995-01-01

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

  18. Could Switching to a Vegetarian Diet Cure My Diabetes?

    Science.gov (United States)

    ... control my diabetes? Could switching to a vegetarian diet cure my diabetes? Answers from M. Regina Castro, M.D. A ... Regina Castro, M.D. Meal planning for vegetarian diets. American Diabetes Association. http://www.diabetes.org/food-and-fitness/ ...

  19. 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.

  20. Curing A Large Composite Cylinder Without An Autoclave

    Science.gov (United States)

    Frazer, Robert E.

    1992-01-01

    Proposed technique provides application of heat and pressure to cure fiber-wound composite cylinder too large to fit in autoclave. Tube wound around cylinder applies pressure. Blanket distributes pressure. Pressure expels gas bubbles from material. Heat applied by conventional methods.

  1. Clinical Applications of Genome Editing to HIV Cure.

    Science.gov (United States)

    Wang, Cathy X; Cannon, Paula M

    2016-12-01

    Despite significant advances in HIV drug treatment regimens, which grant near-normal life expectancies to infected individuals who have good virological control, HIV infection itself remains incurable. In recent years, novel gene- and cell-based therapies have gained increasing attention due to their potential to provide a functional or even sterilizing cure for HIV infection with a one-shot treatment. A functional cure would keep the infection in check and prevent progression to AIDS, while a sterilizing cure would eradicate all HIV viruses from the patient. Genome editing is the most precise form of gene therapy, able to achieve permanent genetic disruption, modification, or insertion at a predesignated genetic locus. The most well-studied candidate for anti-HIV genome editing is CCR5, an essential coreceptor for the majority of HIV strains, and the lack of which confers HIV resistance in naturally occurring homozygous individuals. Genetic disruption of CCR5 to treat HIV has undergone clinical testing, with seven completed or ongoing trials in T cells and hematopoietic stem and progenitor cells, and has shown promising safety and potential efficacy profiles. Here we summarize clinical findings of CCR5 editing for HIV therapy, as well as other genome editing-based approaches under pre-clinical development. The anticipated development of more sophisticated genome editing technologies should continue to benefit HIV cure efforts.

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

    Indian Academy of Sciences (India)

    Hyperbranched epoxy; poly(amido-amine) dendrimer; curing agent; low dielectric constant; high performance. 1. Introduction. Epoxy resins have a broad range of applications includ- ing binder for coatings, high performance composites, adhesives, insulating materials, encapsulating and pack- aging materials for electronic ...

  3. Reproductive indices of Merino rams fed sun-cured Leucaena ...

    African Journals Online (AJOL)

    Reproductive indices of Merino rams fed sun-cured Leucaena leucocephala forage. I.V. Nsahlai, B.K. Byebwa, M.L.K. Bonsi. Abstract. (South African J of Animal Science, 2000, 30, Supplement 1: 111-112). Full Text: EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT.

  4. Application conditions for ester cured alkaline phenolic resin sand

    Directory of Open Access Journals (Sweden)

    Ren-he Huang

    2016-07-01

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

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

    International Nuclear Information System (INIS)

    Johnston, K.; Pavuluri, S.K.; Leonard, M.T.; Desmulliez, M.P.Y.; Arrighi, V.

    2015-01-01

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

  6. Factors associated with low cure rate of tuberculosis in remote poor areas of Shaanxi Province, China: a case control study

    Directory of Open Access Journals (Sweden)

    Zhang Hongwei

    2010-03-01

    Full Text Available Abstract Background The directly observed therapy-short course (DOTS strategy was introduced in Shaanxi province, China to improve tuberculosis (TB control by means of improved case detection (target: > = 70% and treatment success rates (target: > = 85% in new smear positive (SS+ TB patients. At a provincial level the targets were both reached in 2005. However in 30 (28% out of 107 counties of Shaanxi province the cure rate was below 85%. This study aimed to investigate patient and treatment characteristics associated with non-cure after tuberculosis (TB treatment in these counties. Methods In this case-control study, new smear positive TB cases in 30 counties with a cure rate Results Of the 659 patients included, 153 (23.2% did not have cure as treatment outcome. Interruption of treatment was most strongly associated with non-cure (OR = 8.7, 95% CI 3.9-18.4. Other independent risk factors were co-morbidity, low education level, lack of appetite as an initial symptom of TB disease, diagnosis of TB outside of the government TB control institutes, missing sputum re-examinations during treatment, and not having a treatment observer. Twenty-six percent of patients did not have a treatment observer. The non-cure rate was better for those with a doctor (odds ratio (OR 0.38, 95% confidence interval (CI 0.17-0.88 as treatment observer than for those with a family member (OR 0.62, 95%CI 0.37-1.03. The main reason for interrupted treatment mentioned by patients was presence of adverse effects during treatment (46.5%. Conclusions Interruption of treatment was most strongly associated with non-cure. Although treatment observation by medical staff is preferred, in order to diminish the proportion of patients who do not have a treatment observer and thereby reduce the proportion of patients who interrupt treatment, we suggest making it possible for family members, after sufficient training, to be treatment observers in remote areas where it is logistically

  7. Curing depth of (polyacid-modified) composite resins determined by scraping and a penetrometer.

    Science.gov (United States)

    Koupis, Nikolaos S; Vercruysse, Chris W J; Marks, Luc A M; Martens, Luc C; Verbeeck, Ronald M H

    2004-12-01

    The present study aimed to compare the curing depth of polyacid-modified composite resins (PAM-C) and some representative composite resins as a function of shade and post-cure using a scraping method and a penetrometer. The curing depth of the PAM-C Hytac, F2000, Glasiosite, Dyract, Dyract AP, and Compoglass F and of the composite resins Durafill VS and Z100 were determined for shade A2 and A4 using a scraping method based on ISO 4049:2000 and a digital penetrometer. Samples were light-cured (800 mW/cm2 at 40 s) in bulk in split stainless steel molds. Immediately after light-curing or after a 24 h post-cure, the height of the cylinder of cured material was measured and taken as the curing depth. For both test methods, the curing depth was independent of post-cure (P > or = 0.05) but differed significantly among materials and shade (Ppenetrometer give comparable curing depths for PAM-C. The curing depth greatly varies among the materials and can be considerably smaller than that of a microfilled composite resin. Shade A2 results in significantly greater values for the curing depth compared to shade A4, the effect depending quantitatively on the formulation of the material.

  8. Properties of ambient cured blended alkali activated cement concrete

    Science.gov (United States)

    Talha Junaid, M.

    2017-11-01

    This paper presents results of the development and strength properties of ambient-cured alkali activated geopolymer concrete (GPC). The study looks at the strength properties, such as compressive strength, splitting tensile strength, and elastic modulus of such concretes and its dependency on various parameters. The parameters studied in this work are the type and proportions of pre-cursor materials, type of activator and their respective ratios and the curing time. Two types of pre-cursor material; low calcium fly ash (FA) and ground granulated blast furnace slag (GGBFS) were activated using different proportions of sodium silicate and sodium hydroxide solutions. The results indicate that ambient cured geopolymer concrete can be manufactured to match strength properties of ordinary Portland cement concrete (OPC). The strength properties of GPC are dependent on the type and ratio of activator and the proportion of GGBFS used. Increasing the percentage of GGBFS increased the compressive and tensile strengths, while reducing the setting time of the mix. The effect of GGBFS on strength was more pronounced in mixes that contained sodium silicate as activator solution. Unlike OPC, ambient-cured GPC containing sodium silicate gain most of their strength in the first 7 days and there is no change in strength thereafter. However, GPC mixes not containing sodium silicate only achieve a fraction of their strength at 7 days and extended curing is required for such concretes to gain full strength. The results also indicate that the elastic modulus values of GPC mixes without sodium silicate are comparable to OPC while mixes with sodium silicate have elastic modulus values much lower than ordinary concrete.

  9. Economic evaluation of five curing processes for wood coatings

    International Nuclear Information System (INIS)

    Martinez M, I.

    1996-01-01

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

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

    Science.gov (United States)

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

    2016-12-01

    Light Curing Units (LCUs) are used daily in almost every dental office to photocure resins, but because the light is so bright, the user is unable to tell visually if there are any differences between different LCUs. This study evaluated the light output from six dental LCUs: Elipar Deep Cure-S (3M ESPE), Bluephase G2 (Ivoclar Vivadent), Translux 2Wave (Heraeus Kulzer), Optilight Prime (Gnatus), Slim Blast (First Medica) and Led.B (Guilin Woodpecker) with a fully charged battery, after 50, and again after 100, 20second light exposures. For each situation, the radiant power was measured 10 times with a laboratory-grade power meter. Then, the emission spectrum was measured using a fiber-optic spectrometer followed by an analysis of the light beam profile. It was found there were significant differences in the LCU power and the irradiance values between the LCUs (p<0.01). The Optilight Prime and Slim Blast LCUs showed a significant reduction in light output after a 50 and 100 exposures, while Bluephase G2 exhibited a significant reduction only after 100 exposures (p<0.01). The Bluephase G2 and Translux 2Wave delivered an emission spectrum that had two distinct wavelength emission peaks. Only the Elipar Deep Cure-S and Bluephase G2 LCUs displayed homogeneous light beam profiles, the other LCUs exhibited highly non-homogeneous light beam profiles. It was concluded that contemporary LCUs could have very different light output characteristics. Both manufacturers and researchers should provide more information about the light output from LCUs. Copyright © 2016 Elsevier B.V. All rights reserved.

  11. Helicobacter pylori: From Infection to Cure

    Directory of Open Access Journals (Sweden)

    ABR Thomson

    1996-01-01

    Full Text Available Over 380 abstracts, presentations and posters of recent advances were highlighted at the European and International Helicobacter pylori meeting held July 7 to 9, 1995 in Edinburgh, Scotland. New advances abound, with major interest focusing on the simple, safe, inexpensive new `gold standard’ for H pylori eradication therapy: a single week of tid omeprazole 20 mg, metronidazole 400 mg and clarithromycin 250 mg, or omeprazole 20 mg, amoxicillin 1000 mg and clarithromycin 500 mg. To avoid false negative results, two biopsies must be taken from the antrum and two from the gastric body at least four weeks after completion of eradication therapy, and ideally should be supplemented with at least one further H pylori test such as a biopsy for urease activity or culture, or a urea breath test. While most patients with a gastric or duodenal ulcer (DU who do not consume nonsteroidal anti-inflammatory drugs are infected with H pylori, the association is much less apparent in those with a DU who present with an upper gastrointestinal hemorrhage. H pylori eradication for nonulcer dyspepsia is not widely recommended, and the patient with a DU given effective H pylori eradication who presents with dyspepsia likely has erosive esophagitis rather than recurrent DU or H pylori. Gastroenterologists are at increased risk of H pylori infection, particularly older gastroenterologists who are very busy endoscopists.

  12. Risk aversion affects economic values of blue fox breeding scheme.

    Science.gov (United States)

    Peura, J; Kempe, R; Strandén, I; Rydhmer, L

    2016-12-01

    The profit and production of an average Finnish blue fox farm was simulated using a deterministic bio-economic farm model. Risk was included using Arrow-Prat absolute risk aversion coefficient and profit variance. Risk-rated economic values were calculated for pregnancy rate, litter loss, litter size, pelt size, pelt quality, pelt colour clarity, feed efficiency and eye infection. With high absolute risk aversion, economic values were lower than with low absolute risk aversion. Economic values were highest for litter loss (18.16 and 26.42 EUR), litter size (13.27 and 19.40 EUR), pregnancy (11.99 and 18.39 EUR) and eye infection (12.39 and 13.81 EUR). Sensitivity analysis showed that selection pressure for improved eye health depended strongly on proportion of culled animals among infected animals and much less on the proportion of infected animals. The economic value of feed efficiency was lower than expected (6.06 and 8.03 EUR). However, it was almost the same magnitude as pelt quality (7.30 and 7.30 EUR) and higher than the economic value of pelt size (3.37 and 5.26 EUR). Risk factors should be considered in blue fox breeding scheme because they change the relative importance of traits. © 2016 Blackwell Verlag GmbH.

  13. Effects of distance from tip of LED light-curing unit and curing time on surface hardness of nano-filled composite resin

    Science.gov (United States)

    Shafadilla, V. A.; Usman, M.; Margono, A.

    2017-08-01

    Polymerization process depends on several variables, including the hue, thickness, and translucency of the composite resin, the size of the filler particles, the duration of exposure to light (the curing time), the intensity of the light, and the distance from the light. This study aimed to analyze the effects of the distance from the tip of the light-emitting diode (LED) light-curing unit and of curing time on the surface hardness of nano-filled composite resin. 60 specimens were prepared in a mold and divided into 6 groups based on various curing distances and times: 2 mm, 5 mm, and 8 mm and 20 seconds and 40 seconds. The highest surface hardness was seen in the group both closest to the tip and having the longest curing time, while the lowest hardness was seen in the group both farthest from the tip and having the shortest curing time. Significant differences were seen among the various tip distances, except for in the two groups that had 8-mm tip distances, which had no significant differences due to curing time. Both decreased distance from the tip of the LED light-curing unit and increased curing time increase the surface hardness of nano-filled composite resin. However, curing time increases the surface hardness only if the tip distance is ≤ 5 mm.

  14. Light-curing considerations for resin-based composite materials: a review. Part II.

    Science.gov (United States)

    Malhotra, Neeraj; Mala, Kundabala

    2010-10-01

    As discussed in Part I, the type of curing light and curing mode impact the polymerization kinetics of resin-based composite (RBC) materials. Major changes in light-curing units and curing modes have occurred. The type of curing light and mode employed affects the polymerization shrinkage and associated stresses, microhardness, depth of cure, degree of conversion, and color change of RBCs. These factors also may influence the microleakage in an RBC restoration. Apart from the type of unit and mode used, the polymerization of RBCs is also affected by how a light-curing unit is used and handled, as well as the aspects associated with RBCs and the environment. Part II discusses the various clinical issues that should be considered while curing RBC restorations in order to achieve the best possible outcome.

  15. 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 ...

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

    International Nuclear Information System (INIS)

    Suda Kiatkamjornwong; Aran Hanseubsai

    1999-01-01

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

  17. E-Beam-Cured Layered-Silicate and Spherical Silica Epoxy Nanocomposites (Preprint)

    National Research Council Canada - National Science Library

    Chen, Chenggang; Anderson, David P

    2007-01-01

    .... The nanofillers can be two dimensional (layered-silicate) and zero dimensional (spherical silica). Both the spherical silica epoxy nanocomposite and the layered-silicate epoxy nanocomposite can be cured to a high degree of curing...

  18. Long-term survival, prevalence, and cure of cancer: a population-based estimation for 818 902 Italian patients and 26 cancer types

    Science.gov (United States)

    Dal Maso, L.; Guzzinati, S.; Buzzoni, C.; Capocaccia, R.; Serraino, D.; Caldarella, A.; Dei Tos, A. P.; Falcini, F.; Autelitano, M.; Masanotti, G.; Ferretti, S.; Tisano, F.; Tirelli, U.; Crocetti, E.; De Angelis, R.; Virdone, S.; Zucchetto, A.; Gigli, A.; Francisci, S.; Baili, P.; Gatta, G.; Castaing, M.; Zanetti, R.; Contiero, P.; Bidoli, E.; Vercelli, M.; Michiara, M.; Federico, M.; Senatore, G.; Pannozzo, F.; Vicentini, M.; Bulatko, A.; Pirino, D. R.; Gentilini, M.; Fusco, M.; Giacomin, A.; Fanetti, A. C.; Cusimano, R.

    2014-01-01

    Background Persons living after a cancer diagnosis represent 4% of the whole population in high-income countries. The aim of the study was to provide estimates of indicators of long-term survival and cure for 26 cancer types, presently lacking. Patients and methods Data on 818 902 Italian cancer patients diagnosed at age 15–74 years in 1985–2005 were included. Proportions of patients with the same death rates of the general population (cure fractions) and those of prevalent patients who were not at risk of dying as a result of cancer (cure prevalence) were calculated, using validated mixture cure models, by cancer type, sex, and age group. We also estimated complete prevalence, conditional relative survival (CRS), time to reach 5- and 10-year CRS >95%, and proportion of patients living longer than those thresholds. Results The cure fractions ranged from >90% for patients aged cancers to cancers of all ages. Five- or 10-year CRS >95% were both reached in cancers of the stomach, colon–rectum, pancreas, corpus and cervix uteri, brain, and Hodgkin lymphoma. For breast cancer patients, 5- and 10-year CRSs reached >95% after 19 and 25 years, respectively, and in 15 and 18 years for prostate cancer patients. Five-year CRS remained 25 years after cancer diagnosis in patients with liver and larynx cancers, non-Hodgkin lymphoma, myeloma, and leukaemia. Overall, the cure prevalence was 67% for men and 77% for women. Therefore, 21% of male and 31% of female patients had already reached 5-year CRS >95%, whereas 18% and 25% had reached 10-year CRS >95%. Conclusions A quarter of Italian cancer patients can be considered cured. This observation has a high potential impact on health planning, clinical practice, and patients' perspective. PMID:25149707

  19. Setting Performance Standards for a Cost-Effective Human Immunodeficiency Virus Cure Strategy in South Africa

    OpenAIRE

    Paltiel, A. David; Zheng, Amy; Weinstein, Milton C.; Gaynes, Melanie R.; Wood, Robin; Freedberg, Kenneth A.; Sax, Paul E.; Walensky, Rochelle P.

    2017-01-01

    Abstract Background. Reports of a single case of human immunodeficiency virus (HIV) eradication suggest that elimination of HIV from individuals is possible. Anticipating both increased research funding and the development of effective, durable cure technologies, we describe the circumstances under which a cure might improve survival and be cost-effective in South Africa. Methods. We adapted a simulation model comparing a hypothetical cure strategy (?Cure?) to the standard of care, lifetime a...

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

    Science.gov (United States)

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

    2000-01-01

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

  1. 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.

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

    OpenAIRE

    Tucker, Joseph D.; Gilbertson, Adam; Lo, Ying-Ru; Vit?ria, Marco

    2016-01-01

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

  3. The Effect of Rubber Mixing Process on The Curing Characteristics of Natural Rubber

    Directory of Open Access Journals (Sweden)

    Abu Hasan

    2013-04-01

    Full Text Available This research is aimed at studying the relationship between rubber mixing processes and curing characteristics of natural rubber. The curing characteristic analysis was carried out through a natural rubber formula having been masticated and mixed, followed by curing. As many as four mastication methods were finely applied; each respected four sequences of rubber mixing process. In the first method, rubber was masticated for 5 minutes and then rubber chemicals and carbon black N 330 were  simultaneously added. In the second and the third methods, rubber was masticated for 1 minute and then carbon blacks and rubber chemicals were also simultaneously added but using different type of fillers. In the fourth method, rubber was masticated for 3 minutes and then rubber chemicals and carbon black were subsequently added. The additions of rubber chemicals and carbon blacks to the masticated rubber were distinguished by the sequence and time allocated for each mixing process. The carbon blacks were added in two stages by which 10 phr was added first and the remaining 40 phr was added later along with oil. In another method, ratios of the carbon blacks addition (as done in the first  and the second stages were 20:30, 30:20, and 40:10. The examination results showed that rubber mixing process gave an impact on the changes of curing characteristics. They were much affected by the method of carbon black addition. The mixing temperature also had an effect on both curing time and curing rate in which the higher the mixing temperature, the lower the curing time and curing rate. Vulcanization temperature also affected the curing time and curing rate in which the higher the vulcanization temperature, the lower the curing time and the higher the curing rate. Lastly, particle size of carbon black also gave an impact on the curing time and curing rate in which the smaller the particle size, the lower the curing time and the higher the curing rate.

  4. Cellular effects of halogen blue light from dental curing unit

    International Nuclear Information System (INIS)

    Trosic, I.; Pavicic, I.; Jukic, S.

    2008-01-01

    Full text: Halogen curing lights are the most frequently used polymerization source in dental offices. Light-cured bonding systems have become increasingly popular among clinicians because they offer a number of advantages over self-cured adhesives. The effort to increase polymerization quality releases the commercially available high power light density dental curing units. Emitted visible blue light belongs to the range of nonionizing radiation. Common concern in both, patients and dentist grows with regard to the unfavorable effects on the pulp tissue. The aim of study was to evaluate the time and dose dependence effect of halogen light curing unit (Elipar TriLight, ESPE Dental AG, Germany) at the disposed condition modes in vitro. A quartz-tungsten-halogen light source emits radiation of the wavelengths between 400 and 515 nm. This halogen blue light source operates in the three illumination modes, medium (M), exponential (E) and standard (S), and five illumination times. The total irradiance or the light intensity was measured by the light intensity control area on the control panel of device and mean light intensity given by manufacturer was 800 m W/cm 2 . Continuous culture of V79 cells was illuminated in triplicate. The influence of medium mode (M), exponential (E) and standard (S) illumination during 20, 40 and 80 sec on the cell viability, colony forming ability and proliferation of V79 cell culture was investigated. Trypan blue exclusion test was used to determine cell viability, both, in the treated and control cell samples. Colony forming ability was assessed for each exposure time and mode by colony count on post-exposure day 7. Cell proliferation was determined by cell counts for each time and mode of exposure during five post-exposure days. Statistical difference were determined at p<0.05 (Statistica 7.0, StatSoft Inc., USA). Viability of cells was not affected by blue light in view of exposure time and modes. Regardless to exposure or illumination

  5. Light output from six battery operated dental curing lights

    International Nuclear Information System (INIS)

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

    2016-01-01

    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, 20 second light exposures. For each situation, the radiant power was measured 10 times with a laboratory-grade power meter. Then, the emission spectrum was measured using a fiber-optic spectrometer followed by an analysis of the light beam profile. It was found there were significant differences in the LCU power and the irradiance values between the LCUs (p < 0.01). The Optilight Prime and Slim Blast LCUs showed a significant reduction in light output after a 50 and 100 exposures, while Bluephase G2 exhibited a significant reduction only after 100 exposures (p < 0.01). The Bluephase G2 and Translux 2 Wave 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. - Highlights: • The six LCUs delivered significantly different light output characteristics. • The use of a single irradiance value does not adequately describe the light output from a curing light. • Small differences in the tip area, or how it is defined, will have a large effect on the calculated irradiance. • In some cases there were large portions of the light tip that emitted less than 400 mW/cm². • The radiant

  6. Page 1 s Curing of dental restorative composites 83 Average depth ...

    Indian Academy of Sciences (India)

    OCS is more than that of OCDY cured for 60 seconds. This indicates that increased cure time is not an alternative to an adequate level of intensity of light. Hardness values (figure 7), however, do show an increase in hardness for each material with curing time, although the increase is not significant for HLMU. The possible ...

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

    Directory of Open Access Journals (Sweden)

    Xiao Zhang

    2015-01-01

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

  8. Effect of curing conditions and ionic additives on properties of fly ash ...

    Indian Academy of Sciences (India)

    Administrator

    Ca(OH)2 and formed C–S–H (Farry et al 1989; Pietersen et al 1990). The hydrates formed possess cementitious ... to 325 kg/cm. 2. ). The test compacts were cured under two different conditions. In water curing the test specimens were immersed in water at ambient temperature. For steam curing the samples were kept in a.

  9. Effect of light-curing units on the thermal expansion of resin nanocomposites.

    Science.gov (United States)

    Park, Jeong-Kil; Hur, Bock; Ko, Ching-Chang; García-Godoy, Franklin; Kim, Hyung-Il; Kwon, Yong Hoon

    2010-12-01

    To examine the thermal expansion of resin nanocomposites after light-curing using different light-curing units. Four different resin nanocomposites and four different light-curing units [quartz-tungsten-halogen (QTH), light emitting diode (LED), laser, and plasma arc] were chosen. Metal dies were filled with resin to make specimens and light-cured. The light intensity and light-curing time of the QTH and LED light-curing units were 1000 mW/cm2 and 40 seconds, 700 mW/cm2 and 40 seconds for the laser, and 1600 mW/cm2 and 3 seconds for the plasma arc. The coefficient of thermal expansion (CTE) was evaluated using a thermomechanical analyzer (TMA) at temperatures ranging from 30-80 degrees C. The CTE of the resin nanocomposites tested ranged from 28.5 to 65.8 (x 10(-6)/ degrees C), depending on the product and type of light-curing unit used. Among the specimens, Grandio showed the lowest CTE. The specimens cured using the plasma arc unit (Apollo 95E) showed the highest CTE. There was a linear correlation between the CTE and filler content (vol%) (R: -0.94-0.99 depending on the light-curing unit). The results may suggest a careful selection of the light-curing unit because there was more expansion in the specimens cured using the plasma arc unit than those cured by the other units.

  10. Inhibition of ochratoxigenic moulds by Debaryomyces hansenii strains for biopreservation of dry-cured meat products.

    Science.gov (United States)

    Andrade, Maria J; Thorsen, Line; Rodríguez, Alicia; Córdoba, Juan J; Jespersen, Lene

    2014-01-17

    The ability of the osmotolerant yeast Debaryomyces hansenii to inhibit Penicillium nordicum, the most common ochratoxigenic mould encountered in dry-cured meat products, was evaluated. The antagonistic effect of ten D. hansenii strains isolated from dry-cured ham was screened in vitro using malt extract media and meat extract peptone media with the water activity (a(w)) adjusted to 0.97 and 0.90. A significant inhibition of the two tested P. nordicum strains by D. hansenii cells and cell-free supernatants was observed. At 0.97 a(w), increasing D. hansenii inoculum concentrations significantly improved the inhibition of mould growth on solid medium, whereas at 0.90 a(w) this was not always the case. As observed by bright field microscopy, most D. hansenii strains were able to delay P. nordicum spore germination when co-cultured in malt extract broth. D. hansenii FHSCC 253H showed the highest overall in vitro inhibition of ochratoxigenic mould growth, and was therefore chosen for co-cultivation assays in dry-cured ham slices incubated at 0.94 and 0.84 a(w) simulating ham ripening. Regardless of the experimental conditions tested, lower levels of the inoculated P. nordicum strain were detected in co-cultivation batches compared with batches without D. hansenii. The highest level of mould growth inhibition was observed in batches at 0.94 a(w). Ochratoxin A (OTA) production in ham samples was detected by HPLC-MS. Co-culturing of P. nordicum with D. hansenii FHSCC 253H resulted in lower OTA levels compared with control samples without D. hansenii. The decrease of the mycotoxin presence due to D. hansenii FHSCC 253H was more efficient at 0.94 a(w) (OTA was below the detection limit). In conclusion, D. hansenii is potentially suitable as a biopreservative agent for preventing ochratoxigenic mould growth and OTA accumulation in dry-cured meat products. The inoculation of D. hansenii should be made at the beginning of processing (at the end of post salting) when the a(w) of

  11. Effect of curing methods, packaging and gamma irradiation on the weight loss and dry matter percent of garlic during curing and storage

    International Nuclear Information System (INIS)

    Mahmoud, A.A.; El-Oksh, I.I.; Farag, S.E.A.

    1988-01-01

    The Egyptian garlic plants, showed higher percent of weight loss at 17 or 27 days from curing compared to those of Chinese plants. The curing period of 17 days seemed satisfactory for the Egyptian cultivar, whereas, 27 days seemed to be enough for the Chinese garlic. No significant differences were observed between common and shaded curing methods in weight loss per cent. The Chinese garlic contained higher dry matter percentage than those of the Egyptian cultivar. Shaded cured plants of the two cultivars contained higher dry matter percent than those subjected to the common curing methods. Irradiation of garlic bulbs, shaded curing method and sack packaging decreased, in general the weight loss during storage in comparison with other treatments

  12. 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.

  13. Hereditary angioedema as a metabolic liver disorder: novel therapeutic options and prospects for cure

    Directory of Open Access Journals (Sweden)

    Rohan Ameratuga

    2016-11-01

    Full Text Available Hereditary angioedema (HAE is a rare autosomal dominant disorder caused by mutations of the SERPING1 or the Factor 12 genes. It is potentially fatal, particularly if not identified at an early stage. Apart from androgens, which are contraindicated in children and in pregnant women, a range of effective, albeit very expensive treatments have recently become available for HAE patients. The cost of these new treatments is beyond the reach of most developing countries. At this time, there is no cure for the disorder. In spite of mutations of the SERPING1 gene, autoimmunity and infections are not prominent features of the condition. Here we present the argument that HAE should be viewed primarily as a metabolic liver disorder. This conceptual paradigm shift will stimulate basic research and may facilitate new therapeutic approaches to HAE outlined in this paper. We suggest several novel potential treatment options for HAE from the perspectives of clinical immunology, molecular biology and liver transplantation. Many of these offer the prospect of curing the disorder. The effectiveness of these options are rapidly improving in many cases and their risks are decreasing. Given the very high costs of treating HAE, some of these curative options may become feasible in the next decade.

  14. Semiparametric model and inference for spontaneous abortion data with a cured proportion and biased sampling.

    Science.gov (United States)

    Piao, Jin; Ning, Jing; Chambers, Christina D; Xu, Ronghui

    2018-01-01

    Evaluating and understanding the risk and safety of using medications for autoimmune disease in a woman during her pregnancy will help both clinicians and pregnant women to make better treatment decisions. However, utilizing spontaneous abortion (SAB) data collected in observational studies of pregnancy to derive valid inference poses two major challenges. First, the data from the observational cohort are not random samples of the target population due to the sampling mechanism. Pregnant women with early SAB are more likely to be excluded from the cohort, and there may be substantial differences between the observed SAB time and those in the target population. Second, the observed data are heterogeneous and contain a "cured" proportion. In this article, we consider semiparametric models to simultaneously estimate the probability of being cured and the distribution of time to SAB for the uncured subgroup. To derive the maximum likelihood estimators, we appropriately adjust the sampling bias in the likelihood function and develop an expectation-maximization algorithm to overcome the computational challenge. We apply the empirical process theory to prove the consistency and asymptotic normality of the estimators. We examine the finite sample performance of the proposed estimators in simulation studies and illustrate the proposed method through an application to SAB data from pregnant women. © The Author 2017. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  15. 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...

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

    Science.gov (United States)

    Zhang, Jielin; Crumpacker, Clyde

    2013-01-01

    Recent studies have highlighted the importance of eradication of human immunodeficiency virus (HIV) and cure of acquired immunodeficiency syndrome (AIDS). However, a pivotal point that the patient immunity controls HIV reactivation after highly active anti-retroviral therapy [HAART or combination anti-retroviral therapy (cART)] remains less well addressed. In spite of the fact that both innate and adaptive immunities are indispensable and numerous cells participate in the anti-HIV immunity, memory CD4 T-cells are indisputably the key cells organizing all immune actions against HIV while being the targets of HIV. Here we present a view and multidisciplinary approaches to HIV/AIDS eradication and cure. We aim at memory CD4 T-cells, utilizing the stem cell properties of these cells to reprogram an anti-HIV memory repertoire to eliminate the viral reservoir, toward achieving an AIDS-free world. PMID:24151495

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

    Directory of Open Access Journals (Sweden)

    Jie Lin eZhang

    2013-10-01

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

  18. A nonparametric mixture model for cure rate estimation.

    Science.gov (United States)

    Peng, Y; Dear, K B

    2000-03-01

    Nonparametric methods have attracted less attention than their parametric counterparts for cure rate analysis. In this paper, we study a general nonparametric mixture model. The proportional hazards assumption is employed in modeling the effect of covariates on the failure time of patients who are not cured. The EM algorithm, the marginal likelihood approach, and multiple imputations are employed to estimate parameters of interest in the model. This model extends models and improves estimation methods proposed by other researchers. It also extends Cox's proportional hazards regression model by allowing a proportion of event-free patients and investigating covariate effects on that proportion. The model and its estimation method are investigated by simulations. An application to breast cancer data, including comparisons with previous analyses using a parametric model and an existing nonparametric model by other researchers, confirms the conclusions from the parametric model but not those from the existing nonparametric model.

  19. THERMO-CURED GLASS IONOMER CEMENTS IN RESTORATIVE DENTISTRY

    Directory of Open Access Journals (Sweden)

    Kristina GORSETA

    2017-12-01

    Full Text Available Numerous positive properties of glass ionomer cements including biocompatibility, bioactivity, releasing of fluoride and good adhesion to hard dental tissue even under wet conditions and easy of handling are reasons for their wide use in paediatric and restorative dentistry. Their biggest drawbacks are the weaker mechanical properties. An important step forward in improving GIC’s features is thermo-curing with the dental polymerization unit during setting of the material. Due to their slow setting characteristics the GIC is vulnerable to early exposure to moisture. After thermo curing, cements retain all the benefits of GIC with developed better mechanical properties, improved marginal adaptation, increased microhardness and shear bond strength. Adding external energy through thermocuring or ultrasound during the setting of conventional GIC is crucial to achieve faster and better initial mechanical properties. Further clinical studies are needed to confirm these findings.

  20. Thermo-cured glass ionomer cements in restorative dentistry.

    Science.gov (United States)

    Gorseta, Kristina; Glavina, Domagoj

    2017-01-01

    Numerous positive properties of glass ionomer cements including biocompatibility, bioactivity, releasing of fluoride and good adhesion to hard dental tissue even under wet conditions and easy of handling are reasons for their wide use in paediatric and restorative dentistry. Their biggest drawbacks are the weaker mechanical properties. An important step forward in improving GIC's features is thermo-curing with the dental polymerization unit during setting of the material. Due to their slow setting characteristics the GIC is vulnerable to early exposure to moisture. After thermo curing, cements retain all the benefits of GIC with developed better mechanical properties, improved marginal adaptation, increased microhardness and shear bond strength. Adding external energy through thermocuring or ultrasound during the setting of conventional GIC is crucial to achieve faster and better initial mechanical properties. Further clinical studies are needed to confirm these findings.

  1. Delbruck Prize Award: Insights into HIV Dynamics and Cure

    Science.gov (United States)

    Perelson, Alan S.

    A large effort is being made to find a means to cure HIV infection. I will present a dynamical model of a phenomenon called post-treatment control (PTC) or functional cure of HIV-infection in which some patients treated with suppressive antiviral therapy have been taken off of therapy and then spontaneously control HIV infection. The model relies on an immune response and bistability to explain PTC. I will then generalize the model to explicitly include immunotherapy with monoclonal antibodies approved for use in cancer to show that one can induce PTC with a limited number of antibody infusions and compare model predictions with experiments in SIV infected macaques given immunotherapy. Lastly, I will argue that quantitative insights derived from models of HIV infection have and will continue to play an important role in medicine.

  2. Monolithic growth of partly cured polydimethylsiloxane thin film layers

    DEFF Research Database (Denmark)

    Yu, Liyun; Skov, Anne Ladegaard

    2014-01-01

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

  3. Arnica Tincture Cures Cutaneous Leishmaniasis in Golden Hamsters

    Directory of Open Access Journals (Sweden)

    Sara M. Robledo

    2018-01-01

    Full Text Available In search for potential therapeutic alternatives to existing treatments for cutaneous Leishmaniasis, we have investigated the effect of Arnica tincture Ph. Eur. (a 70% hydroethanolic tincture prepared from flowerheads of Arnica montana L. on the lesions caused by infection with Leishmania braziliensis in a model with golden hamsters. The animals were treated topically with a daily single dose of the preparation for 28 days. Subsequently, the healing process was monitored by recording the lesion size in intervals of 15 days up to day 90. As a result, Arnica tincture fully cured three out of five hamsters while one animal showed an improvement and another one suffered from a relapse. This result was slightly better than that obtained with the positive control, meglumine antimonate, which cured two of five hamsters while the other three showed a relapse after 90 days. This result encourages us to further investigate the potential of Arnica tincture in the treatment of cutaneous Leishmaniasis.

  4. Some Durability Aspects of Ambient Cured Bottom Ash Geopolymer Concrete

    Directory of Open Access Journals (Sweden)

    Saravanakumar R.

    2017-09-01

    Full Text Available The present study examines some durability aspects of ambient cured bottom ash geopolymer concrete (BA GPC due to accelerated corrosion, sorptivity, and water absorption. The bottom ash geopolymer concrete was prepared with sodium based alkaline activators under ambient curing temperatures. The sodium hydroxide used concentration was 8M. The performance of BA GPC was compared with conventional concrete. The test results indicate that BA GPC developes a strong passive layer against chloride ion diffusion and provides better protection against corrosion. Both the initial and final rates of water absorption of BA GPC were about two times less than those of conventional concrete. The BA GPC significantly enhanced performance over equivalent grade conventional concrete (CC.

  5. HIV Infection of Macrophages: Implications for Pathogenesis and Cure

    Directory of Open Access Journals (Sweden)

    Kiera Leigh Clayton

    2017-05-01

    Full Text Available Although CD4+ T cells represent the major reservoir of persistent HIV and SIV infection, accumulating evidence suggests that macrophages also contribute. However, investigations of the role of macrophages are often underrepresented at HIV pathogenesis and cure meetings. This was the impetus for a scientific workshop dedicated to this area of study, held in Cambridge, MA in January 2017. The workshop brought together experts in the fields of HIV/SIV immunology/virology, macrophage biology and immunology, and animal models of HIV/SIV infection to facilitate discussions regarding the role of macrophages as a physiologically relevant viral reservoir, and the implications of macrophage infection for HIV pathogenesis and cure strategies. An emerging consensus that infected macrophages likely persist in the setting of combination antiretroviral therapy, driving persistent inflammation and contributing to the viral reservoir, indicate the importance of addressing macrophages as well as CD4+ T cells with future therapeutic strategies.

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

    Science.gov (United States)

    Johnston, Rowena

    2016-12-01

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

  7. Targeted Immune Interventions for an HIV-1 Cure.

    Science.gov (United States)

    Perreau, Matthieu; Banga, Riddhima; Pantaleo, Giuseppe

    2017-10-01

    Combination antiretroviral therapy (cART) induces durable suppression of virus replication but is unable to eradicate HIV. Invariably, virus rebound follows treatment interruption and life-long cART is thus required. Advances have been made in our understanding of HIV latency, identification of HIV cell reservoirs, regulation of HIV-specific immune responses, as well as in the development of broad neutralizing antibodies and putative therapeutic vaccines. These have provided a scientific basis to explore alternative strategies that achieve durable suppression of viremia in the absence of cART, the so-called functional cure. Single intervention strategies have shown promise, albeit with limited efficacy. Consequently, a combination of interventions aiming to stimulate the immune response and prevent new rounds of viral infection and spreading may render the HIV functional cure a feasible goal. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Might dolutegravir be part of a functional cure for HIV?

    Science.gov (United States)

    Wainberg, Mark A; Han, Ying-Shan; Mesplède, Thibault

    2016-05-01

    Antiretroviral therapy (ART) has greatly decreased HIV-related morbidity and mortality. However, HIV can establish viral reservoirs that evade both the immune system and ART. Dolutegravir (DTG) is a second-generation integrase strand transfer inhibitor (INSTI) related to the first-generation INSTIs raltegravir (RAL) and elvitegravir (EVG). DTG shows a higher genetic barrier to the development of HIV-1 resistance than RAL and EVG. More interestingly, clinical resistance mutations to DTG in treatment-naïve patients have not been observed to date. This review summarizes recent studies on strategies toward a cure for HIV, explores resistance profiles of DTG, and discusses how DTG might help in finding a functional cure for HIV.

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

    OpenAIRE

    Jovičić Mirjana C.; Radičević Radmila Ž.; Simendić Vesna B.

    2010-01-01

    A combination of an alkyd resin with a melamine-formaldehyde resin gives a cured enamel film with the flexibility of the alkyd constituent and the high chemical resistance and hardness of the melamine resin at the same time. The melamine resin is a minor constituent and plays the role of a crosslinking agent. In this paper, alkyd resins of high hydroxyl numbers based on trimethylolpropane, ricinoleic acid and phthalic anhydride were synthesized. Two alkyds having 30 and 40 wt% of ricino...

  10. Depth of Cure of New Flowable Composite Resins

    Science.gov (United States)

    2012-03-30

    study. v ABSTRACT Objectives: This study evaluated the depth of cure of Surefil SDR Flow (Dentsply), Grandio Flow (VOCO) and Venus...bottom/maximum KHN or the scrape technique: Venus ≥ SDR ≥ Grandio ≥ Revolution. Conclusions: Venus Bulk Fill predictably exceeded the...composites are Surefil SDR Flow (Dentsply Caulk), Grandio Flow (VOCO) and Venus Bulk Fill (Heraeus Kulzer). 8 Surefil SDR (Stress Decreasing

  11. THERMO-CURED GLASS IONOMER CEMENTS IN RESTORATIVE DENTISTRY

    OpenAIRE

    Kristina GORSETA; Domagoj GLAVINA

    2017-01-01

    Numerous positive properties of glass ionomer cements including biocompatibility, bioactivity, releasing of fluoride and good adhesion to hard dental tissue even under wet conditions and easy of handling are reasons for their wide use in paediatric and restorative dentistry. Their biggest drawbacks are the weaker mechanical properties. An important step forward in improving GIC’s features is thermo-curing with the dental polymerization unit during setting of the material. Due to their slow se...

  12. Reducing Corrosion Control Costs with Rapid-Cure Coatings

    Science.gov (United States)

    2007-01-01

    manufacture its own alkyd or polyester resins has sufficient capital resources to manufacture the NRL resin systems. The novel resins are a series of amino...In addition to working with commercial partners, the Marine Coatings Section patented a new resin system and has formulated a new series of solvent...free, rapid- cure coatings designed specifically for shipboard use. These coatings, currently known as “novel resins ,” are cost-competi- tive with

  13. Effect of curing time on microstructure and mechanical strength ...

    Indian Academy of Sciences (India)

    showed an increase in the total weight loss (%) with the cur- ing time. After 72 h of curing, the total weight loss achieves a maximum value of 19·17%. The increase in weight loss is related to the progress of geopolymerization process. The dissolution process in alkaline medium implies that Si–O–. Si, Al–O–Al and Si–O–Al ...

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

    Science.gov (United States)

    Hanin, Leonid; Zaider, Marco

    2014-07-01

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

  15. Targeting the brain reservoirs: towards an HIV cure

    Directory of Open Access Journals (Sweden)

    Celine Marban

    2016-09-01

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

  16. Cure of Helicobacter pylori-associated ulcer disease through eradication.

    Science.gov (United States)

    Malfertheiner, P; Leodolter, A; Peitz, U

    2000-02-01

    The eradication of Helicobacter pylori (H. pylori) infection has led to a dramatic benefit for patients with gastroduodenal ulcer disease, as the majority of these patients receive a lifelong cure. Relapses after successful H. pylori cure may be caused by either recrudescence or reinfection, both rare events nowadays, or be attributed to non-steroidal anti-inflammatory drugs or aspirin intake. In certain geographical areas, H. pylori-negative relapses are proposed as a new, pathophysiological and not yet elucidated entity. The cure of H. pylori infection in uncomplicated duodenal ulcer diseases consists of 7 days of proton pump inhibitor (PPI) based triple therapy, containing two antibiotics from clarithromycin, amoxicillin and metronidazole. In gastric ulcer, it is recommended that the PPI is continued for a further 3 weeks as these ulcers have a prolonged healing time. Rescue therapies after failure need to take into consideration the resistance pattern of the micro-organism and are offered in the form of quadruple therapy or a high-dose PPI with amoxicillin.

  17. Use of alternative curing salts for processing salamis

    Directory of Open Access Journals (Sweden)

    Dong-Gyun Yim

    2018-01-01

    Full Text Available Objective This study was performed to determine effects of different curing salts on the quality of salamis and to assess feasibility of using NaCl-alternative salts. Methods Various types of curing salts (KCl or MgCl2 as well as NaCl (sun-dried or refined were incorporated for processing of salamis. The proximate composition, fatty acids, nucleotide-related compounds, and free amino acids of the salamis were analyzed during 40 days of ripening. Results The substitution of NaCl by KCl caused higher fat and ash content, but lower moisture content of the salami after 20 days of ripening (p<0.05. Compared with the sun-dried NaCl, use of KCl in salami also led to greater inosine 5′-monophosphate whereas refined NaCl had more inosine (p<0.05. KCl-added salami also had a higher C12:0, C17:1, and C20:0 than other types of salami (p<0.05. MgCl2-added salami had higher content of free amino acids compared to the other salamis (p<0.05. Conclusion Alternative curing salts such as KCl and MgCl2 could substitute NaCl in consideration of quality factor of a fermented meat product. Especially replacement of NaCl with KCl will be a suitable strategy for developing relatively low sodium salami products without compromising product quality.

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

    Science.gov (United States)

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

    2016-03-01

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

  19. Introduction: challenges to finding a cure for HIV infection

    Science.gov (United States)

    Richman, Douglas D.

    2011-01-01

    Purpose of review Renewed interest has emerged to address the latent reservoir of HIV to achieve a cure. Recent findings The integrated proviral genome is a fundamental component of the retroviral replication cycle. The establishment of latently infected CD4+ lymphocytes, and perhaps other as yet poorly characterized cells, represents a reservoir of HIV infection that is not appreciably affected by effective antiretroviral chemotherapy. Effective management of HIV infection thus will require lifelong treatment unless an approach to purging this reservoir is identified. Although substantial insights about the latent reservoir have been made, our understanding about the details of the reservoirs, the mechanisms of latency, and potential targets to eliminate latently infected cells is too primitive to achieve a cure without a great deal of basic research to elucidate some of these areas. Summary A resurgence of interest in latent infection and its treatment promises progress in addressing the challenge of a cure, although realistically this will require a prolonged period of investigation in many areas. PMID:21242886

  20. Study of electron beam curing process using epoxy resin system

    Science.gov (United States)

    Nishitsuji, Delmo A.; Marinucci, Gerson; Evora, Maria C.; de Andrade e Silva, Leonardo G.

    2007-12-01

    Polymeric matrix composite (PMC) has been used in engineering applications instead of metal in the last few years, due to its corrosion resistance and excellent relation between tensile strength/density and elastic modulus/density. However, PMC materials cured by thermal process require high temperature and are time-consuming. The electron beam (EB) curing technology allows its use at room temperature and reduced curing times, and this is one of the main advantages over thermal technology. The aim of this work is to investigate electron beam curable epoxy formulations to use in filament winding processes to produce composite material with similar or better properties than thermal curable composites. The study has been made with commercial epoxy resins and cationic initiators. The epoxy resin samples were irradiated for few minutes with total dose of 150 kGy. The glass transition temperatures ( Tg) were determined by dynamic mechanical analyzer (DMA) and the result was 137 °C. The thermal process was carried out in a furnace following three steps: 4 h at 90 °C, increasing temperature from 90 °C to 130 °C during 4 h and 12 h at 130 °C. The total process time was 20 h. The Tg of this sample was 102 °C.

  1. Study of electron beam curing process using epoxy resin system

    Energy Technology Data Exchange (ETDEWEB)

    Nishitsuji, Delmo A. [Centro Tecnologico da Marinha - CTMSP, Sao Paulo/SP (Brazil); Marinucci, Gerson [Instituto de Pesquisas Energeticas e Nucleares, Av. Prof. Lineu Prestes, 2242 Cidade Universitaria, 05508-000 Sao Paulo/SP (Brazil); Evora, Maria C. [Instituto de Estudos Avancados - IEAv/CTA, Sao Jose dos Campos/SP (Brazil); Andrade Silva, Leonardo G de e [Instituto de Pesquisas Energeticas e Nucleares, Av. Prof. Lineu Prestes, 2242 Cidade Universitaria, 05508-000 Sao Paulo/SP (Brazil)], E-mail: lgasilva@ipen.br

    2007-12-15

    Polymeric matrix composite (PMC) has been used in engineering applications instead of metal in the last few years, due to its corrosion resistance and excellent relation between tensile strength/density and elastic modulus/density. However, PMC materials cured by thermal process require high temperature and are time-consuming. The electron beam (EB) curing technology allows its use at room temperature and reduced curing times, and this is one of the main advantages over thermal technology. The aim of this work is to investigate electron beam curable epoxy formulations to use in filament winding processes to produce composite material with similar or better properties than thermal curable composites. The study has been made with commercial epoxy resins and cationic initiators. The epoxy resin samples were irradiated for few minutes with total dose of 150 kGy. The glass transition temperatures (T{sub g}) were determined by dynamic mechanical analyzer (DMA) and the result was 137 deg. C. The thermal process was carried out in a furnace following three steps: 4 h at 90 deg. C, increasing temperature from 90 deg. C to 130 deg. C during 4 h and 12 h at 130 deg. C. The total process time was 20 h. The T{sub g} of this sample was 102 deg. C.

  2. Controlling pests in dry-cured ham: A review.

    Science.gov (United States)

    Zhao, Y; Abbar, S; Amoah, B; Phillips, T W; Schilling, M W

    2016-01-01

    Dry-cured hams can become infested with ham mites, red-legged beetles, cheese skippers, and larder beetles during the aging process. Though other methods may be used for beetles and cheese skippers, methyl bromide is the only available fumigant that is effective at controlling ham mites in dry-cured ham plants in the United States. However, methyl bromide will be phased out of all industries by approximately 2015. This paper will review and explore potential alternatives that have been investigated to determine their feasibility for replacing methyl bromide to control pest infestations in dry-cured ham plants in the United States. Potential alternatives include: 1) fumigants such as phosphine and sulfuryl fluoride; 2) physical control approaches through cold treatment, modified atmosphere, inert dusts, etc.; 3) pesticides and bioactive compounds; 4) food-grade processing aids. The most promising potential alternatives to date include the use of propylene glycol on the ham surface, the exploration of alternative fumigants, and implementation of an integrated pest management plan. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. Electron beam curing of aramid fiber-reinforced composites

    International Nuclear Information System (INIS)

    Saunders, C.B.; Singh, A.; Lopata, V.J.; Boyer, G.D.; Kremers, W.; Mason, V.A.

    1990-01-01

    High strength- and stiffness-to-weight ratios have allowed fiber-reinforced composites to be used for many applications, including aircraft and aerospace products, sporting goods and automotive components. Electron beam (EB) processing involves using electrons to initiate polymerization and/or crosslinking reactions in suitable polymer substrates to enhance specific physical and chemical properties. The advantages of using EB processing rather than thermal curing techniques for composites, include reduced internal stresses, a result of curing at ambient temperature, greatly reduced curing times, and better control of energy absorption. The penetration limit for a 10-MeV electron beam is about 4 cm for one-sided treatment of unit-density material, making EB processing suitable for many applications. The penetration limit is inversely proportional to the density of the material. This paper reports on the authors' research program to study EB-curable aramid fiber-reinforced composites. The program objective is to design and manufacture EB-curable composites that meet mechanical and physical property specifications for selected applications. The suitability of standard fabrication methods, such as filament winding and hand lay-up, to EB processing is also discussed

  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. How far is cancer cured by radiation sensitization?

    International Nuclear Information System (INIS)

    Ando, Koichi; Sasaki, Takehito; Ikeda, Hiroshi

    1990-01-01

    Some types of cancer are not cured by radiation alone in view of histology, location, and size. In facing so-called radioresistant cancer, antineoplastic agents, hypoxic cell sensitizers, biological response modifiers, or hyperthermia are used in combination with radiation, with the aim of cancer cure. First of all, this chapter discusses the subject of 'what is tumor cure by radiation therapy'. Current conditions of the aforementioned combined modalities and the future perspectives are presented. The following subjects are covered: (1) tumor control - significance of the number of stem cells; (2) biological evaluation of chemo-radiotherapy with cisplatin; (3) clinical results and experience with combination of radiotherapy and radiosensitizers; (4) radiosensitization with hypoxic cell radiosensitizers - present status (5) hypoxic cell radiosensitizers - present status and problems from the viewpoint of clinical radiotherapy; (6) thermal radiosensitization in vitro and its implications for radiotherapy; (7) clinical assessment of thermoradiotherapy for breast cancer and cancer of the urinary bladder; (8) interactions of radiation and biological response modifiers in the treatment of malignant tumor; (9) improvement in the effects of radiation therapy with biological response modifiers. (N.K.)

  6. UV curing of teak veneers for decorative panel

    International Nuclear Information System (INIS)

    Gatot Trimulyadi Rekso; Darsono

    1999-01-01

    The radiation curing of surface coating of teak veneers for decorative panels has been conducted by using ultra violet (UV) as radiation source. In this experiment teak wood veneer was use as a substrate. Epoxy acrylate (import product,) and unsaturated polyester (locally product) were used as coating materials after being added with difunctional monomer TPGDA, and photo-initiator darocur 1173 or irgacure 184. Irradiation was conducted using 80 watt/cm LTV source at conveyor speed of 3,0 m/min. Parameters observed were viscosity of coating materials, hardness, adhesion, appearance, abrasion and chemical resistance of cured films. In general the results showed that viscosity of the formulations based on epoxy acrylate and unsaturated polyester resin were effected by the storage. Film cured by LTV made of epoxy acrylate and unsaturated polyester on the teak veneer wood have the same adhesion and abrasion resistant properties but the hardness and chemical resistant of epoxy acrylate are better than unsaturated polyester. From the experiment result it can be concluded the unsaturated polyester (locally product) can be used as radiation curable material for coating teak veneer panels

  7. Cancer-specific mortality, cure fraction, and noncancer causes of death among diffuse large B-cell lymphoma patients in the immunochemotherapy era.

    Science.gov (United States)

    Howlader, Nadia; Mariotto, Angela B; Besson, Caroline; Suneja, Gita; Robien, Kim; Younes, Naji; Engels, Eric A

    2017-09-01

    Survival after the diagnosis of diffuse large B-cell lymphoma (DLBCL) has been increasing since 2002 because of improved therapies; however, long-term outcomes for these patients in the modern treatment era are still unknown. Using Surveillance, Epidemiology, and End Results data, this study first assessed factors associated with DLBCL-specific mortality during 2002-2012. An epidemiologic risk profile, based on clinical and demographic characteristics, was used to stratify DLBCL cases into low-, medium-, and high-risk groups. The proportions of DLBCL cases that might be considered cured in these 3 risk groups was estimated. Risks of death due to various noncancer causes among DLBCL cases versus the general population were also calculated with standardized mortality ratios (SMRs). Overall, 8274 deaths were recorded among 18,047 DLBCL cases; 76% of the total deaths were attributed to DLBCL, and 24% were attributed to noncancer causes. The 10-year survival rates for the low-, medium-, and high-risk groups were 80%, 60%, and 36%, respectively. The estimated cure proportions for the low-, medium-, and high-risk groups were 73%, 49%, and 27%, respectively; however, these cure estimates were uncertain because of the need to extrapolate the survival curves beyond the follow-up time. Mortality risks calculated with SMRs were elevated for conditions including vascular diseases (SMR, 1.3), infections (SMR, 3.1), gastrointestinal diseases (SMR, 2.5), and blood diseases (SMR, 4.6). These mortality risks were especially high within the initial 5 years after the diagnosis and declined after 5 years. Some DLBCL patients may be cured of their cancer, but they continue to experience excess mortality from lymphoma and other noncancer causes. Cancer 2017;123:3326-34. © 2017 American Cancer Society. © 2017 American Cancer Society.

  8. Standardization of distance and angulation of light curing unit tip using distometer

    OpenAIRE

    Radzi, Z.; Abu Kasim, N.H.; Yahya, N. A.; Abu Osman, N.A.; Kassim, N.L.

    2017-01-01

    The purpose of this study was to investigate the light intensity of selected light curing unit with varying distance and angulation of the light curing tip and lightmeter. Four types of light units; Spectrum 800 (Dentsply), Coltulux 3 (Coltene), Elipar FreeLight 2 (3M Espe) and Starlight Pro (Mectron) were evaluated for light intensity at various distance between the light curing tip and the lightometer Cure Rite Denstply (0, 1, 3, 5, 10 and 15 mm). The light curing units were angulated ...

  9. Patterns of patient and healthcare provider viewpoints regarding participation in HIV cure-related clinical trials. Findings from a multicentre French survey using Q methodology (ANRS-APSEC).

    Science.gov (United States)

    Protière, Christel; Spire, Bruno; Mora, Marion; Poizot-Martin, Isabelle; Préau, Marie; Doumergue, Marjolaine; Morlat, Philippe; Zucman, David; Goujard, Cécile; Raffi, François; Lambotte, Olivier; Suzan-Monti, Marie

    2017-01-01

    Despite huge advances in the fight against HIV concerning diagnosis, clinical efficacy of antiretroviral treatments (ART), patient survival and quality of life, there is still no cure. Recent developments in HIV cure research have opened the way for clinical trials which could lead to a temporary or definitive end to ART. However, ethical questions exist about related trial-participation risks. The main goal of the ANRS-APSEC survey was, using Q-methodology, to investigate the viewpoints of people living with HIV (PLWH) and HIV healthcare providers (HHP) regarding motivations for and barriers to participation in HIV Cure-related clinical trials (HCRCT). Thirty-three statements were defined encompassing seven dimensions: treatment and follow-up; risks; benefits; patient-physician relationship; beliefs and attitudes; information; target population. Forty-one PLWH and 41 HHP from five French HIV services were asked to rank-order the statements. Five main viewpoints were elicited from "the most motivated" to "the most reluctant" vis-à-vis HCRCT participation. All placed importance on the wish to participate in HIV research. This result is in line with the HIV-specific culture of joint mobilization. For some viewpoints, the motivation to participate in/propose HCRCT was primarily conditioned by side-effects and/or by constraints, which overall were more accepted by PLWH than HHP. Some viewpoints placed particular importance on HCRCT recruitment strategies. Finally, some expressed a high acceptance of risks and constraints but emphasized the need for information. HIV cure research clinical trials (HCRCT) constitute a risky yet unavoidable step towards the goal of finding a cure. To improve future HCRCT and informed consent designs, based on PLWH and HHP preferences and expectations, we need greater knowledge about how these populations perceive the risks and the benefits of HCRCT. Our results confirmed the importance of careful, studied HCRCT design, management and

  10. Dimensional change of heat-cured acrylic resin dentures with three different cooling regimes following a standard curing cycle.

    Science.gov (United States)

    Moturi, Bhanodaya; Juszczyk, Andrzej S; Radford, David R; Clark, Robert K F

    2005-12-01

    The aim of the study was to compare dimensional changes in poly(methylmethacrylate) complete denture bases resulting from three different cooling regimens following a standard heating cycle. Changes in three separate dimensions were measured on ten dentures within each cooling regimen after curing, and before and after removing the denture from the cast using a computer imaging system. No consistent differences occurred as a result of removing the denture from the cast. The results indicated that there was greater change in dimension of dentures with the quenching cooling method than with either overnight cooling in the water bath or bench cooling. This was particularly evident after removal from the cast after curing (p<0.001). It is concluded that slow cooling results in less dimensional change.

  11. The applicability of DPSS laser for light curing of composite resins.

    Science.gov (United States)

    Kwon, Yong Hoon; Jang, Chang-Min; Shin, Dong-Hee; Seol, Hyo-Joung; Kim, Hyung-Il

    2008-10-01

    The applicability of diode-pumped solid state (DPSS) laser for light curing the composite resins was tested with a quartz-tungsten-halogen lamp-based unit and a light emitting diode unit. The emission spectra of the light-curing systems used match with the absorption spectrum of camphorquinone. Among the light-curing systems, DPSS laser showed the narrowest emission bandwidth. The light intensity of DPSS laser was approximately 64% of the other two light-curing units. In most specimens, DPSS laser showed the least attenuation of the number of incident photons. On the top surface, specimens cured with DPSS laser showed similar microhardness values compared to the specimens cured with the other two light-curing units. During the light curing, DPSS laser induced the lowest temperature rise (25.5-35.5 degrees C) in the specimens compared to the other two light-curing units (34.2-41.7 degrees C). In conclusion, DPSS laser has high potential to be an alternative to the other light-curing units or a new light-curing unit.

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

    Directory of Open Access Journals (Sweden)

    Tanvir Manzur

    2015-01-01

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

  13. 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.

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

    DEFF Research Database (Denmark)

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

    2011-01-01

    PURPOSE: To investigate the effect of curing rate on softening in ethanol, degree of conversion, and wear of resin composites. METHOD: With a given energy density and for each of two different light-curing units (QTH or LED), the curing rate was reduced by modulating the curing mode. Thus......, the irradiation of resin composite specimens (Filtek Z250, Tetric Ceram, Esthet-X) was performed in a continuous curing mode and in a pulse-delay curing mode. Wallace hardness was used to determine the softening of resin composite after storage in ethanol. Degree of conversion was determined by infrared...... spectroscopy (FTIR). Wear was assessed by a three-body test. Data were submitted to Levene's test, one and three-way ANOVA, and Tukey HSD test (alpha = 0.05). Results: Immersion in ethanol, curing mode, and material all had significant effects on Wallace hardness. After ethanol storage, resin composites...

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

    DEFF Research Database (Denmark)

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

    2007-01-01

    This study determined whether the strength with which resin composite bonds to dentin is influenced by variations in the curing rate of resin composites. Resin composites were bonded to the dentin of extracted human molars. Adhesive (AdheSE, Ivoclar Vivadent) was applied and cured (10 seconds...... @ 1000 mW/cm2) for all groups. A split Teflon mold was clamped to the treated dentin surface and filled with resin composite. The rate of cure was varied, using one of four LED-curing units of different power densities. The rate of cure was also varied using the continuous or pulse-delay mode...... of the four power densities was followed by a one-minute interval, after which light cure was completed (14, 29, 27 or 78 seconds), likewise, giving a total energy density of 16 J/cm2. The specimens produced for each of the eight curing protocols and two resin composites (Tetric EvoCeram, Ivoclar Vivadent...

  16. Pulp chamber temperature increase from curing light units: an in vitro study.

    Science.gov (United States)

    Cantekin, Kenan; Buyuk, Suleyman Kutalmis; Delikan, Ebru; Pedük, Kübra; Demirbuga, Sezer

    2014-01-01

    The purpose of this study was to compare temperature rises in the pulp chamber induced by halogen, plasma arc, and conventional light-emitting diode (LED) curing units with that induced via a new generation LED-curing unit (VALO) in extra power mode. A Class I cavity was prepared on the occlusal surface of 80 extracted caries- free mandibular third molars, which were filled with a microhybrid composite. A thermocouple wire was inserted into the pulp chamber of each tooth to measure temperature changes. The greatest temperature increases were observed during polymerization of composite resin with a halogen curing unit (3.2 degrees Celsius), followed by plasma arc curing (2.07 degrees Celsius) and VALO curing (1.44 degrees Celsius); the lowest temperature rise was with conventional LED curing (1.01 degrees Celsius). There were no statistically significant differences between conventional LED and VALO curing in extra power mode regarding pulp chamber temperature increases when polymerizing composite resin.

  17. 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 < 0.001). Within both systems, there were significant differences among groups, and the DD group showed the highest μTBS (p < 0.05). ABRZ morphology was not affected by curing mode, but it was highly adhesive-material dependent. The curing mode of dual-curing core systems affects bond strength to dentin, but has no significant effect on the formation of ABRZ.

  18. Sulfur amino acids in Cushing's disease: insight in homocysteine and taurine levels in patients with active and cured disease.

    Science.gov (United States)

    Faggiano, Antongiulio; Melis, Daniela; Alfieri, Raffaele; De Martino, MariaCristina; Filippella, Mariagiovanna; Milone, Francesco; Lombardi, Gaetano; Colao, Annamaria; Pivonello, Rosario

    2005-12-01

    Cushing's syndrome is associated with an increased cardiovascular risk. Although a series of cardiovascular risk factors have been identified, sulfur amino acids (SAAs), recently indicated as independent cardiovascular risk factors, have been poorly investigated in patients with Cushing's syndrome. The aim of this cross-sectional controlled study was to evaluate serum and urinary levels and urinary excretion rate (ER) of SAAs in patients with Cushing's disease (CD) during the active disease and after long-term disease remission. Forty patients with CD (20 with active disease and 20 with cured disease for at least 5 yr) and 40 controls entered the study. Serum and urinary concentrations and urinary ER of SAAs, namely methionine, cystine, homocysteine, and taurine, were measured by means of cationic exchange HPLC. Serum folic acid and vitamin B12 levels were also evaluated in patients and controls and correlated to SAA levels. CD patients with active disease had higher serum and urinary concentrations of cystine and homocysteine, and lower serum and higher urinary concentrations and ER of taurine than cured patients and controls. Vitamin B12 levels were significantly decreased in patients with active disease compared with cured patients and controls, whereas folic acid levels were slightly decreased in patients than in controls. In patients with active CD, urinary cortisol concentrations were significantly and inversely correlated to serum taurine and directly correlated to taurine urinary ER, and fasting serum glucose levels were significantly correlated to taurine urinary ER. At the multiple regression analysis, urinary cortisol concentrations were the best predictors of taurine ER. CD is associated with hyperhomocysteinemia and hypotaurinemia. Glucocorticoid excess, acting directly or indirectly, seems to be the most responsible for this imbalance in SAA levels. The long-term disease remission is accompanied by normalization of SAA levels. Hyperhomocysteinemia and

  19. Affordability Challenges to Value-Based Pricing: Mass Diseases, Orphan Diseases, and Cures.

    Science.gov (United States)

    Danzon, Patricia M

    2018-03-01

    To analyze how value-based pricing (VBP), which grounds the price paid for pharmaceuticals in their value, can manage "affordability" challenges, defined as drugs that meet cost-effectiveness thresholds but are "unaffordable" within the short-run budget. Three specific contexts are examined, drawing on recent experience. First, an effective new treatment for a chronic, progressive disease, such as hepatitis C, creates a budget spike that is transitory because initial prevalence is high, relative to current incidence. Second, "cures" that potentially provide lifetime benefits may claim abnormally high VBP prices, with high immediate budget impact potentially/partially offset by deferred cost savings. Third, although orphan drugs in principle target rare diseases, in aggregate they pose affordability concerns because of the growing number of orphan indications and increasingly high prices. For mass diseases, the transitory budget impact of treating the accumulated patient stock can be managed by stratified rollout that delays treatment of stable patients and prioritizes patients at high risk of deterioration. Delay spreads the budget impact and permits potential savings from launch of competing treatments. For cures, installment payments contingent on outcomes could align payment flows and appropriately shift risk to producers. This approach, however, entails high administrative and incentive costs, especially if applied across multiple payers in the United States. For orphan drugs, the available evidence on research and development trends and returns argues against the need for a higher VBP threshold to incentivize research and development in orphan drugs, given existing statutory benefits under orphan drug legislation. Copyright © 2018 International Society for Pharmacoeconomics and Outcomes Research (ISPOR). Published by Elsevier Inc. All rights reserved.

  20. 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.