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Sample records for bed net distribution

  1. Effect of permethrin-treated bed nets on the spatial distribution of malaria vectors in western Kenya

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    Gimnig, John E.; Kolczak, Margarette S.; Hightower, Allen W.; Vulule, John M.; Schoute, Erik; Kamau, Luna; Phillips-Howard, Penelope A.; ter Kuile, Feiko O.; Nahlen, Bernard L.; Hawley, William A.

    2003-01-01

    The effect of insecticide (permethrin)-treated bed nets (ITNs) on the spatial distribution of malaria vectors in neighboring villages lacking ITNs was studied during a randomized controlled trial of ITNs in western Kenya. There was a trend of decreased abundance of Anopheles gambiae with decreasing

  2. Health impact and cost-effectiveness of a private sector bed net distribution: experimental evidence from Zambia.

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    Sedlmayr, Richard; Fink, Günther; Miller, John M; Earle, Duncan; Steketee, Richard W

    2013-03-18

    Relatively few programmes have attempted to actively engage the private sector in national malaria control efforts. This paper evaluates the health impact of a large-scale distribution of insecticide-treated nets (ITNs) conducted in partnership with a Zambian agribusiness, and its cost-effectiveness from the perspective of the National Malaria Control Programme (NMCP). The study was designed as a cluster-randomized controlled trial. A list of 81,597 cotton farmers was obtained from Dunavant, a contract farming company in Zambia's cotton sector, in December 2010. 39,963 (49%) were randomly selected to obtain one ITN each. Follow-up interviews were conducted with 438 farmers in the treatment and 458 farmers in the control group in June and July 2011. Treatment and control households were compared with respect to bed net ownership, bed net usage, self-reported fever, and self-reported confirmed malaria. Cost data was collected throughout the programme. The distribution effectively reached target beneficiaries, with approximately 95% of households in the treatment group reporting that they had received an ITN through the programme. The average increase in the fraction of household members sleeping under an ITN the night prior to the interview was 14.6 percentage points (p-value US$ per ITN to Zambia's NMCP. The results illustrate that existing private sector networks can efficiently control malaria in remote rural regions. The intra-household allocation of ITNs distributed through this channel was comparable to that of ITNs received from other sources, and the health impact remained substantial.

  3. Assessing bed net damage: comparisons of three measurement methods for estimating the size, shape, and distribution of holes on bed nets.

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    Vanden Eng, Jodi L; Mathanga, Don P; Landman, Keren; Mwandama, Dyson; Minta, Anna A; Shah, Monica; Sutcliffe, James; Chisaka, Joseph; Lindblade, Kim A; Steinhardt, Laura

    2017-10-10

    Measuring the physical condition of long-lasting insecticidal nets (LLINs) under field conditions is of great importance for malaria control programmes to guide decisions on how frequently to replace LLINs. Current guidelines by the World Health Organization Pesticide Evaluation Scheme (WHOPES) propose a proportionate hole index (pHI) for assessing LLIN condition by counting the number of holes the size of a thumb, fist, head, and larger than a head. However, this method does not account for irregular hole shapes or exact hole sizes which could result in inaccurate decisions about when to replace LLINs. LLINs were collected during a 2013 health facility-based malaria case control study in Machinga District, Malawi. To evaluate the accuracy of the pHI, the physical condition of 277 LLINs was estimated by the WHOPES method and then compared with two more thorough measurement methods: image analysis of digital photographs of each LLIN side; and for 10 nets, ruler measurements of the length, width, and location of each hole. Total hole counts and areas per net were estimated by each method, and detailed results of hole shapes and composite pictures of hole locations were generated using image analysis. The WHOPES method and image analysis resulted in similar estimates of total hole counts, each with a median of 10 (inter-quartile range (IQR) 4-24 and 4-23, respectively; p = 0.004); however, estimated hole areas were significantly larger using the WHOPES method (median 162 cm 2 , IQR 28-793) than image analysis (median 13 cm 2 , IQR 3-101; p holes than image analysis did (p = 0.002) in 10 LLINs; however, total hole area was not significantly different (p = 0.16). Most holes were not circular but roughly 2-5 times longer in one direction. The lower quarter of LLIN sides was found to have the most holes. The WHOPES method overestimated total hole area, likely because holes are elongated rather than circular, suggesting further adjustments to the pHI formula may be

  4. Bed net ownership in Kenya: the impact of 3.4 million free bed nets

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    Vulule John

    2010-06-01

    Full Text Available Abstract Background In July and September 2006, 3.4 million long-lasting insecticide-treated bed nets (LLINs were distributed free in a campaign targeting children 0-59 months old (CU5s in the 46 districts with malaria in Kenya. A survey was conducted one month after the distribution to evaluate who received campaign LLINs, who owned insecticide-treated bed nets and other bed nets received through other channels, and how these nets were being used. The feasibility of a distribution strategy aimed at a high-risk target group to meet bed net ownership and usage targets is evaluated. Methods A stratified, two-stage cluster survey sampled districts and enumeration areas with probability proportional to size. Handheld computers (PDAs with attached global positioning systems (GPS were used to develop the sampling frame, guide interviewers back to chosen households, and collect survey data. Results In targeted areas, 67.5% (95% CI: 64.6, 70.3% of all households with CU5s received campaign LLINs. Including previously owned nets, 74.4% (95% CI: 71.8, 77.0% of all households with CU5s had an ITN. Over half of CU5s (51.7%, 95% CI: 48.8, 54.7% slept under an ITN during the previous evening. Nearly forty percent (39.1% of all households received a campaign net, elevating overall household ownership of ITNs to 50.7% (95% CI: 48.4, 52.9%. Conclusions The campaign was successful in reaching the target population, families with CU5s, the risk group most vulnerable to malaria. Targeted distribution strategies will help Kenya approach indicator targets, but will need to be combined with other strategies to achieve desired population coverage levels.

  5. Reconfiguration of distribution nets

    International Nuclear Information System (INIS)

    Latorre Bayona, Gerardo; Angarita Marquez, Jorge Luis

    2000-01-01

    Starting of the location of the reconfiguration problem inside the context of the operation of distribution nets, of the quality indicators definition and of the presentation of the alternatives more used for reduction of technical losses, they are related diverse reconfiguration methodologies proposed in the technical literature, pointing out their three principals limitations; also are presents the results of lost obtained starting from simulation works carried out in distribution circuits of the ESSA ESP, which permitting to postulate the reconfiguration of nets like an excellent alternative to reduce technical losses

  6. Use of bed nets and factors that influence bed net use among Jinuo Ethnic Minority in southern China.

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    Xu, Jian-wei; Liao, Yuan-mei; Liu, Hui; Nie, Ren-hua; Havumaki, Joshua

    2014-01-01

    Insecticide-treated nets (ITNs) are an integral part of vector control recommendations for malaria elimination in China. This study investigated the extent to which bed nets were used and which factors influence bed net use among Jinuo Ethnic Minority in China-Myanmar-Laos border areas. This study combined a quantitative household questionnaire survey and qualitative semi-structured in-depth interviews (SDI). Questionnaires were administered to 352 heads of households. SDIs were given to 20 key informants. The bed net to person ratio was 1∶2.1 (i.e., nearly one net for every two people), however only 169 (48.0%) households owned at least one net and 623 (47.2%) residents slept under bed nets the prior night. The percentages of residents who regularly slept under nets (RSUN) and slept under nets the prior night (SUNPN) were similar (48.0% vs. 47.2%, P>0.05), however the percentage correct use of nets (CUN) was significantly lower (34.5%, Pcash income per person (ACIP) was an independent factor that influenced bed net use (PHigh bed net availability does not necessarily mean higher coverage or bed net use. Household income, house type and knowledge of the ability of bed nets to prevent malaria are all independent factors that influence bed net use among Jinuo Ethnic Minority.

  7. Comparing ownership and use of bed nets at two sites with differential malaria transmission in western Kenya.

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    Ernst, Kacey C; Hayden, Mary H; Olsen, Heather; Cavanaugh, Jamie L; Ruberto, Irene; Agawo, Maurice; Munga, Stephen

    2016-04-14

    Challenges persist in ensuring access to and optimal use of long-lasting, insecticidal bed nets (LLINs). Factors associated with ownership and use may differ depending on the history of malaria and prevention control efforts in a specific region. Understanding how the cultural and social-environmental context of bed net use may differ between high- and low-risk regions is important when identifying solutions to improve uptake and appropriate use. Community forums and a household, cross-sectional survey were used to collect information on factors related to bed net ownership and use in western Kenya. Sites with disparate levels of transmission were selected, including an endemic lowland area, Miwani, and a highland epidemic-prone area, Kapkangani. Analysis of ownership was stratified by site. A combined site analysis was conducted to examine factors associated with use of all available bed nets. Logistic regression modelling was used to determine factors associated with ownership and use of owned bed nets. Access to bed nets as the leading barrier to their use was identified in community forums and cross-sectional surveys. While disuse of available bed nets was discussed in the forums, it was a relatively rare occurrence in both sites. Factors associated with ownership varied by site. Education, perceived risk of malaria and knowledge of individuals who had died of malaria were associated with higher bed net ownership in the highlands, while in the lowlands individuals reporting it was easy to get a bed net were more likely to own one. A combined site analysis indicated that not using an available bed net was associated with the attitudes that taking malaria drugs is easier than using a bed net and that use of a bed net will not prevent malaria. In addition, individuals with an unused bed net in the household were more likely to indicate that bed nets are difficult to use, that purchased bed nets are better than freely distributed ones, and that bed nets should only

  8. Free distribution of insecticidal bed nets improves possession and preferential use by households and is equitable: findings from two cross-sectional surveys in thirteen malaria endemic districts of Bangladesh

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    Ahmed Syed M

    2011-12-01

    Full Text Available Abstract Background BRAC, an indigenous non-governmental development organization (NGO, has been implementing a programme to prevent and control malaria in the 13 malaria-endemic districts of Bangladesh since 2007. One of the critical preventive interventions is the distribution of insecticidal bed nets (long-lasting insecticide-treated nets, LLINs and insecticide-treated ordinary nets, ITNs to the community free of cost. This study aimed to assess progress in the possession, preferential use, and knowledge on use of the LLIN/ITNs including the programme's avowed pro-poor inclination one and three and half years after intervention began. Methods A convenient sampling strategy based on malaria endemicity in the districts was adopted. First, thirty upazila (sub-district, with a population around 250,000s were selected at random, with high prevalent districts contributing more upazilas; second, from each upazila, one (2008 to two (2011 villages (covered by insecticidal bed net distribution programme were selected. From each village, households that had either one under-five child and/or a pregnant woman were included in the survey, one household being included only once. Data were collected using a pre-tested structured questionnaire. Results In all, 3,760 households in 2008 and 7,895 households in 2011 were surveyed for collecting relevant information. Proportion of households with at least one LLIN, and at least one LLIN/ITN increased (22-59 to 62-67% and 22-64% to 74-76% respectively over time, including increase in the mean number of LLIN/ITNs per household (≤ 1 to 1 +. The programme achieved > 80% coverage in sleeping under an LLIN/ITN in the case of under-five children and pregnant women, especially in the high-endemic districts. Knowledge regarding critical time of hanging the net also increased over time (7-22 to 44-54%, but remained low. The pro-poor inclination of the programme is reflected in the status of relevant indicators according

  9. Population preference of net texture prior to bed net trial in Kala-Azar-endemic areas.

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    Murari L Das

    Full Text Available Prior to a community-based efficacy trial of long-lasting insecticidal nets (LLINs in the prevention of visceral leishmaniasis (VL; also called kala-azar, a pilot study on preference of tools was held in endemic areas of India and Nepal in September 2005.LLINs made of polyester and polyethylene were distributed to 60 participants, who used the nets sequentially for 7 d. Acceptability and preference were evaluated via indirect indicators through questionnaires at three defined time points before and after use of the LLINs and through focus group discussions (FGDs. In the latter, preferences for color and size were also assessed. Untreated bed nets were owned by 87% of the households prior to the study. All users liked textures of both LLIN types after 7 d of use, but had a slight preference for those made of polyester if they were to recommend a LLIN to relatives or friends (p<0.05, mainly because of their relatively greater softness in comparison to polyethylene LLINs. Users reported that both net types reduced mosquito bites and number of insects, including sand fly (bhusana; genus Phlebotomus, inside the house. Side effects were minor and disappeared quickly.The large-scale intervention trial considered the preferences of the study population to decide on the best tool of intervention--light-blue, rectangular, polyester LLINs of different sizes.

  10. Long lasting insecticidal bed nets ownership, access and use in a high malaria transmission setting before and after a mass distribution campaign in Uganda.

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    Wanzira, Humphrey; Eganyu, Thomas; Mulebeke, Ronald; Bukenya, Fred; Echodu, Dorothy; Adoke, Yeka

    2018-01-01

    Uganda is conducting a second mass LLIN distribution campaign and Katakwi district recently received LLINs as part of this activity. This study was conducted to measure the success of the campaign in this setting, an area of high transmission, with the objectives to estimate LLIN ownership, access and use pre and post campaign implementation. Two identical cross sectional surveys, based on the Malaria Indicator Survey methodology, were conducted in three sub-counties in this district (Kapujan, Magoro and Toroma), six months apart, one before and another after the mass distribution campaign. Data on three main LLIN indicators including; household LLIN ownership, population with access to an LLIN and use were collected using a household and a women's questionnaire identical to the Malaria Indicator Survey. A total of 601 and 607 households were randomly selected in survey one and two respectively. At baseline, 60.57% (56.53-64.50) of households owned at least one net for every two persons who stayed in the household the night before the survey which significantly increased to 70.35% (66.54-73.96) after the campaign (p = 0.001). Similarly, the percentage of the household population with access to an LLIN significantly increased from 84.76% (82.99-86.52) to 91.57% (90.33-92.81), p = 0.001 and the percentage of household population that slept under an LLIN the night before the survey also significantly increased from 56.85% (55.06-58.82) to 81.72% (76.75-83.21), p = 0.001. The LLIN mass campaign successfully achieved the national target of over eighty-five percent of the population with access to an LLIN in this setting, however, universal household coverage and use were fourteen and three percent points less than the national target respectively. This is useful for malaria programs to consider during the planning of future campaigns by tailoring efforts around deficient areas like mechanisms to increase universal coverage and behavior change communication.

  11. Multiplex serology for impact evaluation of bed net distribution on burden of lymphatic filariasis and four species of human malaria in northern Mozambique.

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    Plucinski, Mateusz M; Candrinho, Baltazar; Chambe, Geraldo; Muchanga, João; Muguande, Olinda; Matsinhe, Graça; Mathe, Guidion; Rogier, Eric; Doyle, Timothy; Zulliger, Rose; Colborn, James; Saifodine, Abu; Lammie, Patrick; Priest, Jeffrey W

    2018-02-01

    Universal coverage with long-lasting insecticidal nets (LLINs) is a primary control strategy against Plasmodium falciparum malaria. However, its impact on the three other main species of human malaria and lymphatic filariasis (LF), which share the same vectors in many co-endemic areas, is not as well characterized. The recent development of multiplex antibody detection provides the opportunity for simultaneous evaluation of the impact of control measures on the burden of multiple diseases. Two cross-sectional household surveys at baseline and one year after a LLIN distribution campaign were implemented in Mecubúri and Nacala-a-Velha Districts in Nampula Province, Mozambique. Both districts were known to be endemic for LF; both received mass drug administration (MDA) with antifilarial drugs during the evaluation period. Access to and use of LLINs was recorded, and household members were tested with P. falciparum rapid diagnostic tests (RDTs). Dried blood spots were collected and analyzed for presence of antibodies to three P. falciparum antigens, P. vivax MSP-119, P. ovale MSP-119, P. malariae MSP-119, and three LF antigens. Seroconversion rates were calculated and the association between LLIN use and post-campaign seropositivity was estimated using multivariate regression. The campaign covered 68% (95% CI: 58-77) of the population in Nacala-a-Velha and 46% (37-56) in Mecubúri. There was no statistically significant change in P. falciparum RDT positivity between the two surveys. Population seropositivity at baseline ranged from 31-81% for the P. falciparum antigens, 3-4% for P. vivax MSP-119, 41-43% for P. ovale MSP-119, 46-56% for P. malariae MSP-119, and 37-76% for the LF antigens. The seroconversion rate to the LF Bm33 antigen decreased significantly in both districts. The seroconversion rate to P. malariae MSP-119 and the LF Wb123 and Bm14 antigens each decreased significantly in one of the two districts. Community LLIN use was associated with a decreased risk

  12. Household bed net ownership and use among under-5 children in Nigeria

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    Osuorah DC

    2013-07-01

    Full Text Available D Chidiebere Osuorah,1,2 Chijioke Elias Ezeudu,2 Stanley Kenechi Onah,2 Obinna Tochukwu Anyabolu31Child Survival Unit, Medical Research Council UK, The Gambia Unit, Banjul, The Gambia; 2Department of Pediatrics, Nnamdi Azikiwe University Teaching Hospital, Nnewi, Anambra, Nigeria; 3School of Health and Social Care, Oxford Brookes University, Oxford, UKBackground: Malaria remains the leading cause of morbidity and mortality in sub-Saharan Africa, with children under 5 years accounting for 86% of all malaria deaths. For effective control of malaria, WHO recommends rapid diagnosis and effective treatment, insecticide-treated bed nets, and indoor residual spraying. The use of insecticide-treated bed nets has been shown to be the most cost-effective strategy in preventing this infection. However, despite the Roll Back Malaria subsidized and free bed net distribution initiatives in some Africa countries, bed net uptake and usage still remains low in many households.Aim: This study aimed to investigate household characteristics and child factors that determine bed net ownership and use amongst under-5 children and the effect of its usage on malaria parasitemia in under-5 children in Nigeria.Methods: Data from a nationally representative sample of 5895 households was obtained from the 36 states and the Federal Capital Territory in the 2010 Nigeria demographic and health survey, with a minimum of 67 households enrolled per state. Appropriate statistical tools were used to identify the characteristics of households that owned a bed net and to examine the association between the households and child-level factors that predict the use of bed net and malaria prevalence among under-5 children within these households.Results: The rate of households bed net ownership in Nigeria is about 45.5%. About 48.5% of under-5 children in 33.9% of households surveyed, use a bed net during sleep. There was a strong correlation between households ownership and child

  13. Large-scale implementation of disease control programmes: a cost-effectiveness analysis of long-lasting insecticide-treated bed net distribution channels in a malaria-endemic area of western Kenya-a study protocol.

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    Gama, Elvis; Were, Vincent; Ouma, Peter; Desai, Meghna; Niessen, Louis; Buff, Ann M; Kariuki, Simon

    2016-11-21

    Historically, Kenya has used various distribution models for long-lasting insecticide-treated bed nets (LLINs) with variable results in population coverage. The models presently vary widely in scale, target population and strategy. There is limited information to determine the best combination of distribution models, which will lead to sustained high coverage and are operationally efficient and cost-effective. Standardised cost information is needed in combination with programme effectiveness estimates to judge the efficiency of LLIN distribution models and options for improvement in implementing malaria control programmes. The study aims to address the information gap, estimating distribution cost and the effectiveness of different LLIN distribution models, and comparing them in an economic evaluation. Evaluation of cost and coverage will be determined for 5 different distribution models in Busia County, an area of perennial malaria transmission in western Kenya. Cost data will be collected retrospectively from health facilities, the Ministry of Health, donors and distributors. Programme-effectiveness data, defined as the number of people with access to an LLIN per 1000 population, will be collected through triangulation of data from a nationally representative, cross-sectional malaria survey, a cross-sectional survey administered to a subsample of beneficiaries in Busia County and LLIN distributors' records. Descriptive statistics and regression analysis will be used for the evaluation. A cost-effectiveness analysis will be performed from a health-systems perspective, and cost-effectiveness ratios will be calculated using bootstrapping techniques. The study has been evaluated and approved by Kenya Medical Research Institute, Scientific and Ethical Review Unit (SERU number 2997). All participants will provide written informed consent. The findings of this economic evaluation will be disseminated through peer-reviewed publications. Published by the BMJ Publishing

  14. The importance of education to increase the use of bed nets in villages outside of Kinshasa, Democratic Republic of the Congo

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    Ndjinga Julie K

    2010-10-01

    Full Text Available Abstract Background Malaria is the most prominent disease in the Democratic Republic of the Congo (DRC, and long-lasting insecticide-treated nets (LLINs have been distributed free of charge since 2006 to combat the disease. However, the success of this bed net campaign depends on sufficient bed net use in all age groups. This study was designed to examine the factors affecting bed net use in villages outside of Kinshasa. Methods Two villages along the Congo River, totalling 142 households with 640 residents, were surveyed using a standard questionnaire. The interview determined the number, ages, and sexes of family members; the education level of the family head; the number, colour, and type of nets owned; and the number of nets used in the previous night. The size of house was also measured, and numbers of rooms and beds were recorded. These variables were examined to reveal important factors that affect bed net use. Results A total of 469 nets were counted, and nearly all nets were white LLINs. Of these nets, 229 (48.8% nets were used by 284 (44.4% residents. Bed nets were used by over 90% of children 5 to 15 years of age, whereas less than 50% of the residents in other age groups used bed nets. The important variables affecting bed net use were numbers of beds and rooms in the house and the education level of the family head of household. Conclusion Education was the most important factor affecting bed net use in the villages outside Kinshasa. Development of an educational programme, particularly one directed toward parents, is necessary to reduce misconceptions and increase prevalence of bed net use among all age groups.

  15. The effect of insecticide-treated bed net on malarial parasitaemia ...

    African Journals Online (AJOL)

    AFRICAN JOURNALS ONLINE (AJOL) · Journals · Advanced Search ... nets sold by a social marketing project were used as the intervention group. ... Keywords: Insecticide-treated bed net, Effectiveness, Malaria control, South-South Nigeria.

  16. Markets, voucher subsidies and free nets combine to achieve high bed net coverage in rural Tanzania

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    Gerrets Rene PM

    2008-06-01

    Full Text Available Abstract Background Tanzania has a well-developed network of commercial ITN retailers. In 2004, the government introduced a voucher subsidy for pregnant women and, in mid 2005, helped distribute free nets to under-fives in small number of districts, including Rufiji on the southern coast, during a child health campaign. Contributions of these multiple insecticide-treated net delivery strategies existing at the same time and place to coverage in a poor rural community were assessed. Methods Cross-sectional household survey in 6,331 members of randomly selected 1,752 households of 31 rural villages of Demographic Surveillance System in Rufiji district, Southern Tanzania was conducted in 2006. A questionnaire was administered to every consenting respondent about net use, treatment status and delivery mechanism. Findings Net use was 62.7% overall, 87.2% amongst infants (0 to1 year, 81.8% amongst young children (>1 to 5 years, 54.5% amongst older children (6 to 15 years and 59.6% amongst adults (>15 years. 30.2% of all nets had been treated six months prior to interview. The biggest source of nets used by infants was purchase from the private sector with a voucher subsidy (41.8%. Half of nets used by young children (50.0% and over a third of those used by older children (37.2% were obtained free of charge through the vaccination campaign. The largest source of nets amongst the population overall was commercial purchase (45.1% use and was the primary means for protecting adults (60.2% use. All delivery mechanisms, especially sale of nets at full market price, under-served the poorest but no difference in equity was observed between voucher-subsidized and freely distributed nets. Conclusion All three delivery strategies enabled a poor rural community to achieve net coverage high enough to yield both personal and community level protection for the entire population. Each of them reached their relevant target group and free nets only temporarily

  17. Bed nets for the prevention of malaria and anaemia in pregnancy

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    Dolan, G.; ter Kuile, F. O.; Jacoutot, V.; White, N. J.; Luxemburger, C.; Malankirii, L.; Chongsuphajaisiddhi, T.; Nosten, F.

    1993-01-01

    A prospective comparison of the antimalarial efficacy of bed nets was conducted with 341 pregnant women living in a mesoendemic malarious area of the Thai-Burmese border. Women in 3 adjacent study sites were allocated at random to receive either a single size permethrin-impregnated bed net (PIB), a

  18. Cost and cost effectiveness of long-lasting insecticide-treated bed nets - a model-based analysis

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    Pulkki-Brännström Anni-Maria

    2012-04-01

    Full Text Available Abstract Background The World Health Organization recommends that national malaria programmes universally distribute long-lasting insecticide-treated bed nets (LLINs. LLINs provide effective insecticide protection for at least three years while conventional nets must be retreated every 6-12 months. LLINs may also promise longer physical durability (lifespan, but at a higher unit price. No prospective data currently available is sufficient to calculate the comparative cost effectiveness of different net types. We thus constructed a model to explore the cost effectiveness of LLINs, asking how a longer lifespan affects the relative cost effectiveness of nets, and if, when and why LLINs might be preferred to conventional insecticide-treated nets. An innovation of our model is that we also considered the replenishment need i.e. loss of nets over time. Methods We modelled the choice of net over a 10-year period to facilitate the comparison of nets with different lifespan (and/or price and replenishment need over time. Our base case represents a large-scale programme which achieves high coverage and usage throughout the population by distributing either LLINs or conventional nets through existing health services, and retreats a large proportion of conventional nets regularly at low cost. We identified the determinants of bed net programme cost effectiveness and parameter values for usage rate, delivery and retreatment cost from the literature. One-way sensitivity analysis was conducted to explicitly compare the differential effect of changing parameters such as price, lifespan, usage and replenishment need. Results If conventional and long-lasting bed nets have the same physical lifespan (3 years, LLINs are more cost effective unless they are priced at more than USD 1.5 above the price of conventional nets. Because a longer lifespan brings delivery cost savings, each one year increase in lifespan can be accompanied by a USD 1 or more increase in price

  19. Factors affecting use of permethrin-treated bed nets during a randomized controlled trial in western Kenya

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    Alaii, Jane A.; Hawley, William A.; Kolczak, Margarette S.; ter Kuile, Feiko O.; Gimnig, John E.; Vulule, John M.; Odhacha, Amos; Oloo, Aggrey J.; Nahlen, Bernard L.; Phillips-Howard, Penelope A.

    2003-01-01

    Adherence with permethrin-treated bed net (ITN) use and their proper deployment was directly observed in 2,178 individuals (784 households) participating in a large-scale trial of ITNs on child mortality in western Kenya. The ITNs were distributed free of charge to ensure high coverage, resulting in

  20. Equity and coverage of insecticide-treated bed nets in an area of intense transmission of Plasmodium falciparum in Tanzania

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    Mtei Frank

    2009-04-01

    Full Text Available Abstract Background There is no clear consensus on the most sustainable and effective distribution strategy for insecticide treated bed nets (ITNs. Tanzania has been a leader in social marketing but it is still not clear if this can result in high and equitable levels of coverage. Methods A cluster-randomized survey of ITN and bed net ownership and use was conducted in a rural area exposed to intense Plasmodium falciparum transmission in NE Tanzania where ITN distribution had been subject to routine delivery of national strategies and episodic free distribution through local clinics. Data were collected on household assets to assess equity of ITN coverage and a rapid diagnostic test for malaria (RDT was performed in all ages. Results Among 598 households in four villages the use of any or insecticidal bed nets in children less than five years of age was 71% and 54% respectively. However there was a 19.8% increase in the number of bed nets per person (p Conclusion Marked inequity persists with the poorest households still experiencing the highest risk of malaria and the lowest ITN coverage. Abolition of this inequity within the foreseeable future is likely to require mass or targeted free distribution, but risks damaging what is otherwise an effective commercial market.

  1. The underlying reasons for very high levels of bed net use, and higher malaria infection prevalence among bed net users than non-users in the Tanzanian city of Dar es Salaam: a qualitative study.

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    Msellemu, Daniel; Shemdoe, Aloysia; Makungu, Christina; Mlacha, Yeromini; Kannady, Khadija; Dongus, Stefan; Killeen, Gerry F; Dillip, Angel

    2017-10-23

    Bed nets reduce malaria-related illness and deaths, by forming a protective barrier around people sleeping under them. When impregnated with long-lasting insecticide formulations they also repel or kill mosquitoes attempting to feed upon sleeping humans, and can even suppress entire populations of malaria vectors that feed predominantly upon humans. Nevertheless, an epidemiological study in 2012 demonstrated higher malaria prevalence among bed net users than non-users in urban Dar es Salaam, Tanzania. Focus group discussions were conducted with women from four selected wards of Dar es Salaam city, focusing on four major themes relating to bed net use behaviours: (1) reasons for bed net use, (2) reasons for not using bed nets, (3) stimuli or reminders for people to use a bed net (4) perceived reasons for catching malaria while using a bed net. An analytical method by framework grouping of relevant themes was used address key issues of relevance to the study objectives. Codes were reviewed and grouped into categories and themes. All groups said the main reason for bed net use was protection against malaria. Houses with well-screened windows, with doors that shut properly, and that use insecticidal sprays against mosquitoes, were said not to use bed nets, while frequent attacks from malaria was the main stimulus for people to use bed nets. Various reasons were mentioned as potential reasons that compromise bed net efficacy, the most common of which were: (1) bed net sharing by two or more people, especially if one occupant tends to come to bed late at night, and does not tuck in the net 71%; (2) one person shares the bed but does not use the net, moving it away from the side on which s/he sleeps 68%; (3) ineffective usage habits, called ulalavi, in which a sprawling sleeper either touches the net while sleeping up against it or leaves a limb hanging outside of it 68%. Less common reasons mentioned included: (1) Small bed nets which become un-tucked at night (31%); (2

  2. Bed net ownership, use and perceptions among women seeking antenatal care in Kinshasa, Democratic Republic of the Congo (DRC: Opportunities for improved maternal and child health

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    Tabala Martine

    2008-09-01

    Full Text Available Abstract Background To describe malaria knowledge, attitudes toward malaria and bed net use, levels of ownership and use of bed nets, and factors associated with ownership and use among pregnant women attending their first antenatal care (ANC visit in Kinshasa, DRC. Methods Women attending their first ANC visit at one maternity in Kinshasa were recruited to take part in a study where they were given free insecticide treated bed nets (ITNs and then followed up at delivery and 6 months post delivery to assess ITN use. This study describes the baseline levels of bed net ownership and use, attitudes towards net use and factors associated with net use Results Among 351 women interviewed at baseline, 115 (33% already owned a bed net and 86 (25% reported to have slept under the net the previous night. Cost was reported as the reason for not owning a net by 48% of the 236 women who did not own one. In multivariable analyses, women who had secondary school or higher education were 3.4 times more likely to own a net (95% CI 1.6–7.3 and 2.8 times more likely to have used a net (95% CI 1.3–6.0 compared to women with less education Conclusion Distribution of ITNs in antenatal clinics in this setting is needed and feasible. The potential for ITN use by this target population is high.

  3. Increasing coverage and decreasing inequity in insecticide-treated bed net use among rural Kenyan children.

    Directory of Open Access Journals (Sweden)

    Abdisalan M Noor

    2007-08-01

    Full Text Available Inexpensive and efficacious interventions that avert childhood deaths in sub-Saharan Africa have failed to reach effective coverage, especially among the poorest rural sectors. One particular example is insecticide-treated bed nets (ITNs. In this study, we present repeat observations of ITN coverage among rural Kenyan homesteads exposed at different times to a range of delivery models, and assess changes in coverage across socioeconomic groups.We undertook a study of annual changes in ITN coverage among a cohort of 3,700 children aged 0-4 y in four districts of Kenya (Bondo, Greater Kisii, Kwale, and Makueni annually between 2004 and 2006. Cross-sectional surveys of ITN coverage were undertaken coincidentally with the incremental availability of commercial sector nets (2004, the introduction of heavily subsidized nets through clinics (2005, and the introduction of free mass distributed ITNs (2006. The changing prevalence of ITN coverage was examined with special reference to the degree of equity in each delivery approach. ITN coverage was only 7.1% in 2004 when the predominant source of nets was the commercial retail sector. By the end of 2005, following the expansion of heavily subsidized clinic distribution system, ITN coverage rose to 23.5%. In 2006 a large-scale mass distribution of ITNs was mounted providing nets free of charge to children, resulting in a dramatic increase in ITN coverage to 67.3%. With each subsequent survey socioeconomic inequity in net coverage sequentially decreased: 2004 (most poor [2.9%] versus least poor [15.6%]; concentration index 0.281; 2005 (most poor [17.5%] versus least poor [37.9%]; concentration index 0.131, and 2006 with near-perfect equality (most poor [66.3%] versus least poor [66.6%]; concentration index 0.000. The free mass distribution method achieved highest coverage among the poorest children, the highly subsidised clinic nets programme was marginally in favour of the least poor, and the commercial

  4. Distributed evaluation of stochastic Petri nets

    NARCIS (Netherlands)

    Bell, A.; Buchholz, Peter; Lehnert, Ralf; Pioro, Micha

    2004-01-01

    In this paper we present on the distributed performance evaluation and model checking of systems specified by stochastic Petri nets. The approaches discussed rely on an explicit state-space generation and target at the usage of clusters of workstations. We present results for systems with several

  5. Airflow attenuation and bed net utilization: observations from Africa and Asia

    DEFF Research Database (Denmark)

    von Seidlein, Lorenz; Ikonomidis, Konstantin; Bruun, Rasmus

    2012-01-01

    Background/Methods Qualitative studies suggest that bed nets affect the thermal comfort of users. To understand and reduce this discomfort the effect of bed nets on temperature, humidity, and airflow was measured in rural homes in Asia and Africa, as well as in an experimental wind tunnel. Two...... discomfort is a factor limiting bed net use and open a range of architectural possibilities to overcome this limitation. Keywords: Malaria; Bed nets; Africa; Tanzania; The Gambia; Asia; Thailand; Philippines; Airflow; Temperature; Humidity; Climate...... investigators with architectural training selected 60 houses in The Gambia, Tanzania, Philippines, and Thailand. Data-loggers were used to measure indoor temperatures in hourly intervals over a 12 months period. In a subgroup of 20 houses airflow, temperature and humidity were measured at five-minute intervals...

  6. Mass distribution of free insecticide-treated nets do not interfere with continuous net distribution in Tanzania.

    Science.gov (United States)

    Eze, Ikenna C; Kramer, Karen; Msengwa, Amina; Mandike, Renata; Lengeler, Christian

    2014-05-27

    To protect the most vulnerable groups from malaria (pregnant women and infants) the Tanzanian Government introduced a subsidy (voucher) scheme in 2004, on the basis of a public-private partnership. These vouchers are provided to pregnant women at their first antenatal care visit and mothers of infants at first vaccination. The vouchers are redeemed at registered retailers for a long-lasting insecticidal net against the payment of a modest top-up price. The present work analysed a large body of data from the Tanzanian National Voucher Scheme, focusing on interactions with concurrent mass distribution campaigns of free nets. In an ecologic study involving all regions of Tanzania, voucher redemption data for the period 2007-2011, as well as data on potential determinants of voucher redemption were analysed. The four outcome variables were: pregnant woman and infant voucher redemption rates, use of treated bed nets by all household members and by under- five children. Each of the outcomes was regressed with selected determinants, using a generalized estimating equation model and accounting for regional data clustering. There was a consistent improvement in voucher redemption rates over the selected time period, with rates >80% in 2011. The major determinants of redemption rates were the top-up price paid by the voucher beneficiary, the retailer- clinic ratio, and socio-economic status. Improved redemption rates after 2009 were most likely due to reduced top-up prices (following a change in policy). Redemption rates were not affected by two major free net distribution campaigns. During this period, there was a consistent improvement in net use across all the regions, with rates of up to 75% in 2011. The key components of the National Treated Nets Programme (NATNETS) seem to work harmoniously, leading to a high level of net use in the entire population. This calls for the continuation of this effort in Tanzania and for emulation by other countries with endemic malaria.

  7. Determinants of household demand for bed nets in a rural area of southern Mozambique.

    Science.gov (United States)

    Chase, Claire; Sicuri, Elisa; Sacoor, Charfudin; Nhalungo, Delino; Nhacolo, Ariel; Alonso, Pedro L; Menéndez, Clara

    2009-06-15

    A key to making insecticide-treated nets (ITNs) a long-term, sustainable solution to the spread of malaria is understanding what drives their purchase and use. Few studies have analysed the determinants of demand for bed nets for malaria prevention at the household level, and in particular, how demand for nets compares with demand for other mosquito prevention methods. This study uses a household survey to assess the determinants of demand for bed nets in an area of endemic malaria transmission in rural, southern Mozambique. The study looks at willingness to pay (WTP) for bed nets, net ownership, usage, and past purchase behaviour, alongside expenditure and frequency of use of alternate methods for malaria prevention. While overall net ownership in the sample is low, the evidence fails to suggest that poorer households are less likely to own bed nets, when controlling for covariates, nor does the likelihood of receiving a free net depend on socioeconomic status (SES). Formal schooling and market knowledge seem to indicate higher average willingness to pay, while use of alternate methods for malaria prevention, and receipt of Indoor Residual Spraying (IRS) are found to decrease demand for bed nets. For long-term sustainability of ITNs to be realized, results suggest that either full or partial subsidies may be necessary in some contexts to encourage households to obtain and use nets. Given the possible substitution effects of combined malaria control interventions, and the danger of not taking into consideration household preferences for malaria prevention, successful malaria control campaigns should invest a portion of their funds towards educating recipients of IRS and users of other preventive methods on the importance of net use even in the absence of mosquitoes.

  8. Determinants of household demand for bed nets in a rural area of southern Mozambique

    Directory of Open Access Journals (Sweden)

    Nhacolo Ariel

    2009-06-01

    Full Text Available Abstract Background A key to making insecticide-treated nets (ITNs a long-term, sustainable solution to the spread of malaria is understanding what drives their purchase and use. Few studies have analysed the determinants of demand for bed nets for malaria prevention at the household level, and in particular, how demand for nets compares with demand for other mosquito prevention methods. Methods This study uses a household survey to assess the determinants of demand for bed nets in an area of endemic malaria transmission in rural, southern Mozambique. The study looks at willingness to pay (WTP for bed nets, net ownership, usage, and past purchase behaviour, alongside expenditure and frequency of use of alternate methods for malaria prevention. Results While overall net ownership in the sample is low, the evidence fails to suggest that poorer households are less likely to own bed nets, when controlling for covariates, nor does the likelihood of receiving a free net depend on socioeconomic status (SES. Formal schooling and market knowledge seem to indicate higher average willingness to pay, while use of alternate methods for malaria prevention, and receipt of Indoor Residual Spraying (IRS are found to decrease demand for bed nets. Conclusion For long-term sustainability of ITNs to be realized, results suggest that either full or partial subsidies may be necessary in some contexts to encourage households to obtain and use nets. Given the possible substitution effects of combined malaria control interventions, and the danger of not taking into consideration household preferences for malaria prevention, successful malaria control campaigns should invest a portion of their funds towards educating recipients of IRS and users of other preventive methods on the importance of net use even in the absence of mosquitoes.

  9. Social marketing of insecticide-treated bed net for malaria control ...

    African Journals Online (AJOL)

    Background: The effectiveness of the insecticide-treated bed net in reducing the morbidity and mortality associated with malaria has been proved at all levels of malaria transmission. Several models on how to achieve massive coverage have been suggested, but social marketing of the nets is highly favoured for its ...

  10. Knowledge, access and utilization of bed-nets among stable and seasonal migrants in an artemisinin resistance containment area of Myanmar.

    Science.gov (United States)

    Phyo Than, Wint; Oo, Tin; Wai, Khin Thet; Thi, Aung; Owiti, Philip; Kumar, Binay; Deepak Shewade, Hemant; Zachariah, Rony

    2017-09-14

    Myanmar lies in the Greater Mekong sub-region of South-East Asia faced with the challenge of emerging resistance to artemisinin combination therapies (ACT). Migrant populations are more likely than others to spread ACT resistance. A vital intervention to reduce malaria transmission, resistance spread and eliminate malaria is the use of bed nets. Among seasonal and stable migrants in an artemisinin resistance containment region of Myanmar, we compared a) their household characteristics, b) contact with health workers and information material, and c) household knowledge, access and utilization of bed nets. Secondary data from community-based surveys on 2484 migrant workers (2013 and 2014, Bago Region) were analyzed of which 37% were seasonal migrants. Bed net access and utilization were assessed using a) availability of at least one bed net per household, and b) one bed net per two persons, and c) proportion of household members who slept under abed net during the previous night (Indicator targets = 100%). Over 70% of all migrants were from unstable work settings with short transitory stays. Average household size was five (range 1-25) and almost half of all households had children under-five years. Roughly 10 % of migrants were night-time workers. Less than 40% of households had contact with health workers and less than 30% had exposure to information education and communication (IEC) materials, the latter being significantly lower among seasonal migrants. About 70% of households were aware of the importance of insecticide-treated bed-nets/long-lasting insecticidal nets (ITNs/LLINs), but knowledge on insecticide impregnation and retreatment of ITNs was poor (Myanmar. Possible ways forward include frequent distribution campaigns to compensate for short transitory stays, matching household distributions to household size, enhanced information campaigns and introducing legislation to make mosquito repellents available for night-time workers at plantations and farms

  11. Bed net use and associated factors in a rice farming community in Central Kenya

    Directory of Open Access Journals (Sweden)

    Kabuage Lucy

    2009-04-01

    Full Text Available Abstract Background Use of insecticide-treated nets (ITNs continues to offer potential strategy for malaria prevention in endemic areas. However their effectiveness, sustainability and massive scale up remain a factor of socio-economic and cultural variables of the local community which are indispensable during design and implementation stages. Methods An ethnographic household survey was conducted in four study villages which were purposefully selected to represent socio-economic and geographical diversity. In total, 400 households were randomly selected from the four study villages. Quantitative and qualitative information of the respondents were collected by use of semi-structured questionnaires and focus group discussions. Results Malaria was reported the most frequently occurring disease in the area (93% and its aetiology was attributed to other non-biomedical causes like stagnant water (16%, and long rains (13%. Factors which significantly caused variation in bed net use were occupant relationship to household head (χ2 = 105.705; df 14; P = 0.000, Age (χ2 = 74.483; df 14; P = 0.000, village (χ2 = 150.325; df 6; P = 0.000, occupation (χ2 = 7.955; df 3; P = 0.047, gender (χ2 = 4.254; df 1; P = 0.039 and education levels of the household head or spouse (χ2 = 33.622; df 6; P = 0.000. The same variables determined access and conditions of bed nets at household level. Protection against mosquito bite (95% was the main reason cited for using bed nets in most households while protection against malaria came second (54%. Colour, shape and affordability were some of the key potential factors which determined choice, use and acceptance of bed nets in the study area. Conclusion The study highlights potential social and economic variables important for effective and sustainable implementation of bed nets-related programmes in Sub-Saharan Africa.

  12. Entomological determinants of insecticide-treated bed net effectiveness in Western Myanmar

    NARCIS (Netherlands)

    Smithuis, Frank M.; Kyaw, Moe Kyaw; Phe, U. Ohn; van der Broek, Ingrid; Katterman, Nina; Rogers, Colin; Almeida, Patrick; Kager, Piet A.; Stepniewska, Kasia; Lubell, Yoel; Simpson, Julie A.; White, Nicholas J.

    2013-01-01

    In a large cluster randomized control trial of insecticide-treated bed nets (ITN) in Western Myanmar the malaria protective effect of ITN was found to be highly variable and, in aggregate, the effect was not statistically significant. A coincident entomological investigation measured malaria vector

  13. The phenomenon of diminishing –returns in the use of bed nets and ...

    African Journals Online (AJOL)

    2014-03-01

    Mar 1, 2014 ... treated bed nets and prompt malaria therapy in Tororo. Uganda, concluded the .... namely vaccination, cure and quarantine and yet cure for malaria actually ..... It is therefore the anti-malarial medicines given to their children that are .... his great assistance in the preparation of the electronic version of this ...

  14. Higher-moment measurements of net-kaon, net-charge and net-proton multiplicity distributions at STAR

    International Nuclear Information System (INIS)

    Sarkar, Amal

    2014-01-01

    In this paper, we report the measurements of the various moments, such as mean, standard deviation (σ), skewness (S) and kurtosis (κ) of the net-kaon, net-charge and net-proton multiplicity distributions at mid-rapidity in Au + Au collisions from √(s NN )=7.7 to 200 GeV with the STAR experiment at RHIC. This work has been done with the aim to locate the critical point on the QCD phase diagram. These moments and their products are related to the thermodynamic susceptibilities of conserved quantities such as net baryon number, net charge, and net strangeness as well as to the correlation length of the system which diverges in an ideal infinite thermodynamic system at the critical point. For a finite system, existing for a finite time, a non-monotonic behavior of these variables would indicate the presence of the critical point. Furthermore, we also present the moment products Sσ, κσ 2 of net-kaon, net-charge and net-proton multiplicity distributions as a function of collision centrality and energy. The energy and the centrality dependence of higher moments and their products have been compared with different models

  15. Distributed S-Net: design and implementation

    NARCIS (Netherlands)

    Grelck, C.; Julku, J.; Penczek, F.; Morazan, M.

    2009-01-01

    S-Net is a declarative coordination language and component technology aimed at modern multi-core/many-core architectures and systems-on-chip. It builds on the concept of stream processing to structure networks of communicating asynchronous components, which can be implemented using a conventional

  16. Which family members use the best nets? An analysis of the condition of mosquito nets and their distribution within households in Tanzania

    Directory of Open Access Journals (Sweden)

    Lines Jo

    2010-07-01

    Full Text Available Abstract Background Household ownership of insecticide-treated mosquito nets (ITNs is increasing, and coverage targets have been revised to address universal coverage with ITNs. However, many households do not have enough nets to cover everyone, and the nets available vary in physical condition and insecticide treatment status. Since 2004, the Government of Tanzania has been implementing the Tanzania National Voucher Scheme (TNVS, which distributes vouchers for ITNs through antenatal clinics to target pregnant women and their infants. This analysis aimed to determine the following: (1 coverage patterns of bed nets within households according to physical condition and treatment status; (2 who might be at risk if mosquitoes were diverted from occupants of untreated nets to those not using nets? (3 the degree to which those at highest risk of malaria use the most protective nets. Methods Data from the 2006 TNVS household survey were analysed to assess within-household distribution of net use. The associations between net characteristics and net user were also evaluated. Multivariate analysis was applied to the relationship between the number of holes per net and user characteristics while adjusting for confounders. Results In households with a net:person ratio better than 1:4 (one net for every four household members, more than 80% of the people in such households reported using a net the previous night. ITNs were most likely to be used by infants, young children (1-4 y, and women of childbearing age; they were least likely to be used by older women (≥50 y, older children (5-14 y, and adult men. The nets used by infants and women of childbearing age were in better-than-average physical condition; the nets used by older women and older children were in worse-than-average condition; while young children and adult men used nets in intermediate (average condition. When adjusted for confounders, the nets used by young and older children had more holes

  17. Modelling the impact of the long-term use of insecticide-treated bed nets on Anopheles mosquito biting time.

    Science.gov (United States)

    Ferreira, Claudia P; Lyra, Silas P; Azevedo, Franciane; Greenhalgh, David; Massad, Eduardo

    2017-09-15

    Evidence of changing in biting and resting behaviour of the main malaria vectors has been mounting up in recent years as a result of selective pressure by the widespread and long-term use of insecticide-treated bed nets (ITNs), and indoor residual spraying. The impact of resistance behaviour on malaria intervention efficacy has important implications for the epidemiology and malaria control programmes. In this context, a theoretical framework is presented to understand the mechanisms determining the evolution of feeding behaviour under the pressure of use of ITNs. An agent-based stochastic model simulates the impact of insecticide-treated bed nets on mosquito fitness by reducing the biting rates, as well as increasing mortality rates. The model also incorporates a heritability function that provides the necessary genetic plasticity upon which natural selection would act to maximize the fitness under the pressure of the control strategy. The asymptotic equilibrium distribution of mosquito population versus biting time is shown for several daily uses of ITNs, and the expected disruptive selection on this mosquito trait is observed in the simulations. The relative fitness of strains that bite at much earlier time with respect to the wild strains, when a threshold of about 50% of ITNs coverage highlights the hypothesis of a behaviour selection. A sensitivity analysis has shown that the top three parameters that play a dominant role on the mosquito fitness are the proportion of individuals using bed nets and its effectiveness, the impact of bed nets on mosquito oviposition, and the mosquito genetic plasticity related to changing in biting time. By taking the evolutionary aspect into account, the model was able to show that the long-term use of ITNs, although representing an undisputed success in reducing malaria incidence and mortality in many affected areas, is not free of undesirable side effects. From the evolutionary point of view of the parasite virulence, it

  18. Perceptions on the effect of small electric fans on comfort inside bed nets in southern Ghana: a qualitative study.

    Science.gov (United States)

    Jaeger, Mulako S; Briët, Olivier J T; Keating, Joseph; Ahorlu, Collins K; Yukich, Joshua O; Oppong, Samuel; Nardini, Peter; Pfeiffer, Constanze

    2016-12-01

    Long-lasting insecticidal nets (LLINs) are known to be highly effective in reducing malaria transmission, morbidity and mortality. However, among those owning an LLIN, use rates are often suboptimal. A reported barrier to bed net use is discomfort due to heat. This qualitative study was part of a larger evaluation conducted in communities without electricity in rural Ghana to assess whether 0.8 W solar powered net fans can increase net use. Twenty-three key informant interviews with household heads in the study communities in Shai-Osudoku District, southern Ghana, were conducted from July to August 2015. The purpose of the interviews was to obtain insight into perceptions of participants about the net fan system in relation to LLIN use. While all study participants reported using LLINs, with mosquito nuisance prevention as the prime motivation, heat was also mentioned as a key barrier to net use. Respondents appreciated the net fans because they improved comfort inside bed nets. The LED light on the fan stand became the main source of light at night and positively influenced the perception of the intervention as a whole. The general acceptance of the net fan system by the study participants highlights the potential of the intervention to improve comfort inside mosquito nets. This, therefore, has a potential to increase bed net use in areas with low access to electricity.

  19. System effectiveness of a targeted free mass distribution of long lasting insecticidal nets in Zanzibar, Tanzania

    Directory of Open Access Journals (Sweden)

    Abass Ali K

    2010-06-01

    Full Text Available Abstract Background Insecticide-treated nets (ITN and long-lasting insecticidal treated nets (LLIN are important means of malaria prevention. Although there is consensus regarding their importance, there is uncertainty as to which delivery strategies are optimal for dispensing these life saving interventions. A targeted mass distribution of free LLINs to children under five and pregnant women was implemented in Zanzibar between August 2005 and January 2006. The outcomes of this distribution among children under five were evaluated, four to nine months after implementation. Methods Two cross-sectional surveys were conducted in May 2006 in two districts of Zanzibar: Micheweni (MI on Pemba Island and North A (NA on Unguja Island. Household interviews were conducted with 509 caretakers of under-five children, who were surveyed for socio-economic status, the net distribution process, perceptions and use of bed nets. Each step in the distribution process was assessed in all children one to five years of age for unconditional and conditional proportion of success. System effectiveness (the accumulated proportion of success and equity effectiveness were calculated, and predictors for LLIN use were identified. Results The overall proportion of children under five sleeping under any type of treated net was 83.7% (318/380 in MI and 91.8% (357/389 in NA. The LLIN usage was 56.8% (216/380 in MI and 86.9% (338/389 in NA. Overall system effectiveness was 49% in MI and 87% in NA, and equity was found in the distribution scale-up in NA. In both districts, the predicting factor of a child sleeping under an LLIN was caretakers thinking that LLINs are better than conventional nets (OR = 2.8, p = 0.005 in MI and 2.5, p = 0.041 in NA, in addition to receiving an LLIN (OR = 4.9, p Conclusions Targeted free mass distribution of LLINs can result in high and equitable bed net coverage among children under five. However, in order to sustain high effective coverage, there

  20. Impact of promoting longer-lasting insecticide treatment of bed nets upon malaria transmission in a rural Tanzanian setting with pre-existing high coverage of untreated nets

    NARCIS (Netherlands)

    Russell, T.L.; Lwetoijera, D.W.; Maliti, D.; Chipwaza, B.; Kihonda, J.; Charlwood, J.D.; Smith, T.A.; Lengeler, C.; Mwanyangala, M.A.; Nathan, R.; Knols, B.G.J.; Takken, W.; Killeen, G.F.

    2010-01-01

    Background The communities of Namawala and Idete villages in southern Tanzania experienced extremely high malaria transmission in the 1990s. By 2001-03, following high usage rates (75% of all age groups) of untreated bed nets, a 4.2-fold reduction in malaria transmission intensity was achieved.

  1. Leveraging Microgrids for Capturing Uncertain Distribution Network Net Load Ramping

    OpenAIRE

    Majzoobi, Alireza; Khodaei, Amin

    2016-01-01

    In this paper, a flexibility-oriented microgrid optimal scheduling model is proposed to mitigate distribution network net load variability caused by large penetration distributed solar generation. The distributed solar generation variability, which is caused by increasing adoption of this technology by end-use consumers, is mainly addressed by electric utilities using grid reinforcement. Microgrids, however, provide viable and local solutions to this pressing challenge. The proposed model, wh...

  2. Temperature distribution in spouted bed and heat transfer

    International Nuclear Information System (INIS)

    Takeda, Hiroshi; Yamamoto, Yutaka

    1976-01-01

    Temperature distribution in spouted bed was measured by using brass and graphite spouted beds so as to investigate heat transfer characteristic of spouted bed applied to an apparatus of PyC coating. These spouted beds are batch type and are spouted by air or nitrogen gas of room temperature, and the outer wall of beds are heated by nichrome or graphite heater. Particles used for experiments are alumina spherical particles and the diameter is 0.80 -- 1.12 mm. Temperature condition is in the range of 400 -- 1,400 0 C. In the neighborhood of 400 0 C, the spouting condition is stable, while the spouting condition becomes unstable in the case of above 1,000 0 C. This is caused by abrupt temperature increase of spouting gas. It was found that heat transfer coefficient h sub(w) of our low temperature experiments was closer to the calculated from Malek et al.'s equation, h sub(p) of our experiments was several times greater than the calculated from Uemaki et al.'s equation. On the other hand, h sub(p) of high temperature experiments was compared with an experimental relation for convective heat transfer of fluidized bed, it was found that Nu sub(p) of our experiments was nearly equal to or greater than the calculated from the relation, this would be caused by radiant heat transfer. (auth.)

  3. Particle Distribution in a Fixed Bed Down Draft Wood Gasifier

    DEFF Research Database (Denmark)

    Hindsgaul, Claus

    2005-01-01

    Char particle samples were collected from six distances above the grate in a fixed bed of a down draft biomass gasifier. Each sample was separated into twelve size fractions by screening through standard sieves in order to determine the local particle size distribution. The ash contents of each...

  4. Video studies of passage by Anopheles gambiae mosquitoes through holes in a simulated bed net: effects of hole size, hole orientation and net environment.

    Science.gov (United States)

    Sutcliffe, James; Colborn, Kathryn L

    2015-05-13

    Holes in netting provide potential routes for mosquitoes to enter ITNs. Despite this, there is little information on how mosquitoes respond to holes in bed nets and how their responses are affected by hole size, shape and orientation or by ambient conditions around the net. Female Anopheles gambiae (G3) were recorded in a simulated bed net consisting of two sizes of untreated netting-covered behavioural arenas placed above and beside (to simulate the bed net roof and sides respectively) the experimenter who was a source of host cues from 'inside' the net. A round hole of 9 mm or 13 mm diameter was cut into the centre of the netting of each arena. Videos of unfed female mosquitoes in arenas were analysed for time spent flying, walking and standing still and for exit through the hole. The effects of the experimenter on temperature and relative humidity around the simulated net were also measured. Mosquitoes were significantly more active in overhead arenas than in arenas to the side. Hole passage was significantly more likely in smaller arenas than larger ones and for larger holes than smaller ones. In arenas to the side, hole passage rate through small holes was about 50% less likely than what could be explained by area alone. Passage rate through holes in overhead arenas was consistent with hole area. Temperature in arenas did not strongly reflect the experimenter's presence in the simulated net. Relative humidity and absolute humidity in overhead arenas, but not in arenas to the side, were immediately affected by experimenter presence. Higher levels of activity in overhead arenas than in arenas to the side were likely due to the rising heat and humidity plume from the experimenter. Lower than expected passage rates through smaller vertically oriented holes may have been be due to an edge effect that does not apply to horizontally oriented holes. Results suggest that current methods of assessing the importance of physical damage to ITNs may not accurately reflect

  5. Predicting the impact of insecticide-treated bed nets on malaria transmission: the devil is in the detail.

    Science.gov (United States)

    Gu, Weidong; Novak, Robert J

    2009-11-16

    Insecticide-treated bed nets (ITNs), including long-lasting insecticidal nets (LLINs), play a primary role in global campaigns to roll back malaria in tropical Africa. Effectiveness of treated nets depends on direct impacts on individual mosquitoes including killing and excite-repellency, which vary considerably among vector species due to variations in host-seeking behaviours. While monitoring and evaluation programmes of ITNs have focuses on morbidity and all-cause mortality in humans, local entomological context receives little attention. Without knowing the dynamics of local vector species and their responses to treated nets, it is difficult to predict clinical outcomes when ITN applications are scaled up across African continent. Sound model frameworks incorporating intricate interactions between mosquitoes and treated nets are needed to develop the predictive capacity for scale-up applications of ITNs. An established agent-based model was extended to incorporate the direct outcomes, e.g. killing and avoidance, of individual mosquitoes exposing to ITNs in a hypothetical village setting with 50 houses and 90 aquatic habitats. Individual mosquitoes were tracked throughout the life cycle across the landscape. Four levels of coverage, i.e. 40, 60, 80 and 100%, were applied at the household level with treated houses having only one bed net. By using Latin hypercube sampling scheme, parameters governing killing, diverting and personal protection of net users were evaluated for their relative roles in containing mosquito populations, entomological inoculation rates (EIRs) and malaria incidence. There were substantial gaps in coverage between households and individual persons, and 100% household coverage resulted in circa 50% coverage of the population. The results show that applications of ITNs could give rise to varying impacts on population-level metrics depending on values of parameters governing interactions of mosquitoes and treated nets at the individual level

  6. Predicting the impact of insecticide-treated bed nets on malaria transmission: the devil is in the detail

    Directory of Open Access Journals (Sweden)

    Novak Robert J

    2009-11-01

    Full Text Available Abstract Background Insecticide-treated bed nets (ITNs, including long-lasting insecticidal nets (LLINs, play a primary role in global campaigns to roll back malaria in tropical Africa. Effectiveness of treated nets depends on direct impacts on individual mosquitoes including killing and excite-repellency, which vary considerably among vector species due to variations in host-seeking behaviours. While monitoring and evaluation programmes of ITNs have focuses on morbidity and all-cause mortality in humans, local entomological context receives little attention. Without knowing the dynamics of local vector species and their responses to treated nets, it is difficult to predict clinical outcomes when ITN applications are scaled up across African continent. Sound model frameworks incorporating intricate interactions between mosquitoes and treated nets are needed to develop the predictive capacity for scale-up applications of ITNs. Methods An established agent-based model was extended to incorporate the direct outcomes, e.g. killing and avoidance, of individual mosquitoes exposing to ITNs in a hypothetical village setting with 50 houses and 90 aquatic habitats. Individual mosquitoes were tracked throughout the life cycle across the landscape. Four levels of coverage, i.e. 40, 60, 80 and 100%, were applied at the household level with treated houses having only one bed net. By using Latin hypercube sampling scheme, parameters governing killing, diverting and personal protection of net users were evaluated for their relative roles in containing mosquito populations, entomological inoculation rates (EIRs and malaria incidence. Results There were substantial gaps in coverage between households and individual persons, and 100% household coverage resulted in circa 50% coverage of the population. The results show that applications of ITNs could give rise to varying impacts on population-level metrics depending on values of parameters governing interactions of

  7. Impact of permethrin-treated bed nets on entomologic indices in an area of intense year-round malaria transmission

    NARCIS (Netherlands)

    Gimnig, John E.; Vulule, John M.; Lo, Terrence Q.; Kamau, Luna; Kolczak, Margarette S.; Phillips-Howard, Penelope A.; Mathenge, Evan M.; ter Kuile, Feiko O.; Nahlen, Bernard L.; Hightower, Allen W.; Hawley, William A.

    2003-01-01

    The effect of permethrin-treated bed nets (ITNs) on malaria vectors was studied as part of a large-scale, randomized, controlled trial in western Kenya. Indoor resting densities of fed Anopheles gambiae s.l. and An. funestus in intervention houses were 58.5% (P = 0.010) and 94.5% (P = 0.001) lower,

  8. Implications of the western Kenya permethrin-treated bed net study for policy, program implementation, and future research

    NARCIS (Netherlands)

    Hawley, William A.; ter Kuile, Feiko O.; Steketee, Richard S.; Nahlen, Bernard L.; Terlouw, Dianne J.; Gimnig, John E.; Shi, Ya Ping; Vulule, John M.; Alaii, Jane A.; Hightower, Allen W.; Kolczak, Margarette S.; Kariuki, Simon K.; Phillips-Howard, Penelope A.

    2003-01-01

    The fifth, and probably last, large-scale, group-randomized, controlled trial of insecticide (permethrin)-treated bed nets (ITNs) showed that ITNs are efficacious in reducing all-cause post-neonatal mortality in an area of intense, perennial malaria transmission. The trial helped to define pregnant

  9. Community-wide effects of permethrin-treated bed nets on child mortality and malaria morbidity in western Kenya

    NARCIS (Netherlands)

    Hawley, William A.; Phillips-Howard, Penelope A.; ter Kuile, Feiko O.; Terlouw, Dianne J.; Vulule, John M.; Ombok, Maurice; Nahlen, Bernard L.; Gimnig, John E.; Kariuki, Simon K.; Kolczak, Margarette S.; Hightower, Allen W.

    2003-01-01

    Spatial analyses of the effect of insecticide (permethrin)-treated bed nets (ITNs) on nearby households both with and without ITNs was performed in the context of a large-scale, group-randomized, controlled mortality trial in Asembo, western Kenya. Results illustrate a protective effect of ITNs on

  10. A good night's sleep and the habit of net use: perceptions of risk and reasons for bed net use in Bukoba and Zanzibar.

    Science.gov (United States)

    Koenker, Hannah M; Loll, Dana; Rweyemamu, Datius; Ali, Abdullah S

    2013-06-13

    Intensive malaria control interventions in the United Republic of Tanzania have contributed to reductions in malaria prevalence. Given that malaria control remains reliant upon continued use of long-lasting insecticidal bed nets (LLINs) even when the threat of malaria has been reduced, this qualitative study sought to understand how changes in perceived risk influence LLIN usage, and to explore in more detail the benefits of net use that are unrelated to malaria. Eleven focus group discussions were conducted in Bukoba Rural district and in Zanzibar Urban West district in late 2011. Participants were males aged 18 and over, females between the ages of 18 and 49, and females at least 50 years old. The perceived risk of malaria had decreased among the respondents, and malaria control interventions were credited for the decline. Participants cited reductions in both the severity of malaria and in their perceived susceptibility to malaria. However, malaria was still considered a significant threat. Participants' conceptualization of risk appeared to be an important consideration for net use. At the same time, comfort and aspects of comfort (getting a good night's sleep, avoiding biting pests) appeared to play a large role in personal decisions to use nets consistently or not. Barriers to comfort (feeling uncomfortable or trapped; perceived difficulty breathing, or itching/rashes) were frequently cited as reasons not to use a net consistently. While it was apparent that participants acknowledged the malaria-prevention benefits of net use, the exploration of the risk and comfort determinants of net use provides a richer understanding of net use behaviours, particularly in a setting where transmission has fallen and yet consistent net use is still crucial to maintaining those gains. Future behaviour change communication campaigns should capitalize on the non-malaria benefits of net use that provide a long-term rationale for consistent use even when the immediate threat of

  11. Host-seeking activity of a Tanzanian population of Anopheles arabiensis at an insecticide treated bed net.

    Science.gov (United States)

    Parker, Josephine E A; Angarita Jaimes, Natalia C; Gleave, Katherine; Mashauri, Fabian; Abe, Mayumi; Martine, Jackline; Towers, Catherine E; Towers, David; McCall, Philip J

    2017-07-04

    Understanding how mosquitoes respond to long lasting insecticide treated nets (LLINs) is fundamental to sustaining the effectiveness of this essential control tool. We report on studies with a tracking system to investigate behaviour of wild anophelines at an LLIN, in an experimental hut at a rural site in Mwanza, Tanzania. Groups of adult female mosquitoes (n = 10 per replicate) reared from larvae of a local population, identified as predominantly (95%) Anopheles arabiensis, were released in the hut. An infrared video tracking system recorded flight and net contact activity over 1 h as the mosquitoes attempted to reach a supine human volunteer within a bed net (either a deltamethrin-treated LLIN or an untreated control net). A range of activities, including flight path, position in relation to the bed net and duration of net contact, were quantified and compared between treatments. The total time that female An. arabiensis spent in flight around LLINs was significantly lower than at untreated nets [F(1,10) = 9.26, p = 0.012], primarily due to a substantial reduction in the time mosquitoes spent in persistent 'bouncing' flight [F(1,10) = 18.48, p = 0.002]. Most activity occurred at the net roof but significantly less so with LLINs (56.8% of total) than untreated nets [85.0%; Χ 2 (15) = 234.69, p Activity levels at the bed net directly above the host torso were significantly higher with untreated nets (74.2%) than LLINs [38.4%; Χ 2 (15) = 33.54, p = 0.004]. 'Visiting' and 'bouncing' rates were highest above the volunteer's chest in untreated nets (39.9 and 50.4%, respectively) and LLINs [29.9 and 42.4%; Χ 2 (13) = 89.91, p activity over 60 min was significantly more rapid for LLINs [F(1,10) = 6.81, p = 0.026], reiterating an 'attract and kill' rather than a repellent mode of action. The study has demonstrated the potential for detailed investigations of behaviour of wild mosquito populations under field conditions. The results validate

  12. Malaria in pregnant women in an area with sustained high coverage of insecticide-treated bed nets

    Directory of Open Access Journals (Sweden)

    Mshinda Hassan

    2008-07-01

    Full Text Available Abstract Background Since 2000, the World Health Organization has recommended a package of interventions to prevent malaria during pregnancy and its sequelae that includes the promotion of insecticide-treated bed nets (ITNs, intermittent preventive treatment in pregnancy (IPTp, and effective case management of malarial illness. It is recommended that pregnant women in malaria-endemic areas receive at least two doses of sulphadoxine-pyrimethamine in the second and third trimesters of pregnancy. This study assessed the prevalence of placental malaria at delivery in women during 1st or 2nd pregnancy, who did not receive intermittent preventive treatment for malaria (IPTp in a malaria-endemic area with high bed net coverage. Methods A hospital-based cross-sectional study was done in Ifakara, Tanzania, where bed net coverage is high. Primi- and secundigravid women, who presented to the labour ward and who reported not using IPTp were included in the study. Self-report data were collected by questionnaire; whereas neonatal birth weight and placenta parasitaemia were measured directly at the time of delivery. Results Overall, 413 pregnant women were enrolled of which 91% reported to have slept under a bed net at home the previous night, 43% reported history of fever and 62% were primigravid. Malaria parasites were detected in 8% of the placenta samples; the geometric mean (95%CI placental parasite density was 3,457 (1,060–11,271 parasites/μl in primigravid women and 2,178 (881–5,383 parasites/μl in secundigravid women. Fifteen percent of newborns weighed Conclusion The observed incidence of LBW and prevalence of placental parasitaemia at delivery suggests that malaria remains a problem in pregnancy in this area with high bed net coverage when eligible women do not receive IPTp. Delivery of IPTp should be emphasized at all levels of implementation to achieve maximum community coverage.

  13. How many holes is too many? A prototype tool for estimating mosquito entry risk into damaged bed nets.

    Science.gov (United States)

    Sutcliffe, James; Ji, Xin; Yin, Shaoman

    2017-08-01

    Insecticide-treated bed nets (ITNs) have played an integral role in malaria reduction but how insecticide depletion and accumulating physical damage affect ITN performance is poorly understood. More accurate methods are needed to assess damage to bed nets so that they can be designed, deployed and replaced optimally. Video recordings of female Anopheles gambiae in near approach (1-½ cm) to occupied untreated rectangular bed nets in a laboratory study were used to quantify the amount of mosquito activity (appearances over time) around different parts of the net, the per-appearance probability of a mosquito coming close to holes of different sizes (hole encounter) and the per-encounter probability of mosquitoes passing through holes of different sizes (hole passage). Appearance frequency on different parts of the net reflected previously reported patterns: the area of the net under greatest mosquito pressure was the roof, followed by the bottom 30 cm of the sides, followed by the 30 cm area immediately above this, followed by the upper two-thirds of the sides. The ratio of activity in these areas was (respectively) 250:33:5:1. Per-appearance probability of hole encounter on all parts of the net was strongly predicted by a factor combining hole perimeter and area. Per-encounter probability of hole passage, in turn, was strongly predicted by hole width. For a given width, there was a 20% greater risk of passage through holes on the roof than holes on the sides. Appearance, encounter and passage predictors correspond to various mosquito behaviours that have previously been described and are combined into a prototype mosquito entry risk tool that predicts mosquito entry rates for nets with various amounts of damage. Scenarios that use the entry risk tool to test the recommendations of the WHOPES proportionate hole index (pHI) suggest that the pHI hole size categories and failure to account for hole location likely sometimes lead to incorrect conclusions about net

  14. Properties of Distributed Timed-Arc Petri Nets

    DEFF Research Database (Denmark)

    Nielsen, M.; Sassone, V.; Srba, J.

    2001-01-01

    In [12] we started a research on a distributed-timed extension of Petri nets where time parameters are associated with tokens and arcs carry constraints that qualify the age of tokens required for enabling. This formalism enables to model e.g. hardware architectures like GALS. We give a formal...... definition of process semantics for our model and investigate several properties of local versus global timing: expressiveness, reachability and coverability....

  15. A cluster randomized controlled cross-over bed net acceptability and preference trial in Solomon Islands: community participation in shaping policy for malaria elimination

    Directory of Open Access Journals (Sweden)

    Appleyard Bridget

    2009-12-01

    Full Text Available Abstract Background A key component of the malaria elimination strategy in Solomon Islands (SI is widespread coverage of long-lasting insecticidal nets (LLINs. The success of this strategy is dependent on LLIN acceptability and compliance. There has been unresolved debate among policy makers and donors as to which type of LLIN would be most appropriate for large-scale distribution in SI, and anecdotal reports of a lack of acceptability of certain brands of LLINs. A cluster randomized controlled crossover bed net acceptability and preference trial was therefore carried out from July to September, 2008 to inform policy and to facilitate community engagement and participation in the selection of the most appropriate LLIN for use in SI. Method A three-stage sampling method was used to randomly select the study population from Malaita Province, SI. Three brands of LLINs were assessed in this study: Olyset®, PermaNet® and DuraNet®. Bed net acceptability and preference were evaluated through surveys at three defined time points after short and longer-term trial of each LLIN. Results The acceptability of PermaNet® after short-term use (96.5% was significantly greater than Olyset® (67.3%, p and DuraNet® (69.8%, p . The acceptability of DuraNet® and Olyset® after short-term use was not significantly different at the 5% level. LLINs that were perceived not to prevent mosquito bites were significantly less acceptable than LLINs that were perceived to prevent mosquito bites (OR 0.15; 95%CI 0.03 to 0.6. LLINs that allow a pleasant night's sleep (OR 6.3; 95%CI:3.3-12.3 and have a soft texture (OR 5.7; 95%CI:1.9-20.5 were considered more acceptable than those that did not. Olyset®'s acceptability decreased over time and this was due to net wrinkling/shrinkage after washing resulting in reduced efficiency in preventing mosquito bites. The increase in DuraNet® acceptability was a result of a reduction in minor adverse events following longer-term use

  16. Global Distribution of Net Electron Acceptance in Subseafloor Sediment

    Science.gov (United States)

    Fulfer, V. M.; Pockalny, R. A.; D'Hondt, S.

    2017-12-01

    We quantified the global distribution of net electron acceptance rates (e-/m2/year) in subseafloor sediment (>1.5 meters below seafloor [mbsf]) using (i) a modified version of the chemical-reaction-rate algorithm by Wang et al. (2008), (ii) physical properties and dissolved oxygen and sulfate data from interstitial waters of sediment cores collected by the Ocean Drilling Program, Integrated Ocean Drilling Program, International Ocean Discovery Program, and U.S. coring expeditions, and (iii) correlation of net electron acceptance rates to global oceanographic properties. Calculated net rates vary from 4.8 x 1019 e-/m2/year for slowly accumulating abyssal clay to 1.2 x 1023 e-/m2/year for regions of high sedimentation rate. Net electron acceptance rate correlates strongly with mean sedimentation rate. Where sedimentation rate is very low (e.g., 1 m/Myr), dissolved oxygen penetrates more than 70 mbsf and is the primary terminal electron acceptor. Where sedimentation rate is moderate (e.g., 3 to 60 m/Myr), dissolved sulfate penetrates as far as 700 mbsf and is the principal terminal electron acceptor. Where sedimentation rate is high (e.g., > 60 m/Myr), dissolved sulfate penetrates only meters, but is the principal terminal electron acceptor in subseafloor sediment to the depth of sulfate penetration. Because microbial metabolism continues at greater depths than the depth of sulfate penetration in fast-accumulating sediment, complete quantification of subseafloor metabolic rates will require consideration of other chemical species.

  17. Impact of permethrin-treated bed nets on entomologic indices in an area of intense year-round malaria transmission.

    Science.gov (United States)

    Gimnig, John E; Vulule, John M; Lo, Terrence Q; Kamau, Luna; Kolczak, Margarette S; Phillips-Howard, Penelope A; Mathenge, Evan M; ter Kuile, Feiko O; Nahlen, Bernard L; Hightower, Allen W; Hawley, William A

    2003-04-01

    The effect of permethrin-treated bed nets (ITNs) on malaria vectors was studied as part of a large-scale, randomized, controlled trial in western Kenya. Indoor resting densities of fed Anopheles gambiae s.l. and An. funestus in intervention houses were 58.5% (P = 0.010) and 94.5% (P = 0.001) lower, respectively, compared with control houses. The sporozoite infection rate in An. gambiae s.l. was 0.8% in intervention areas compared with 3.4% (P = 0.026) in control areas, while the sporozoite infection rates in An. funestus were not significantly different between the two areas. We estimated the overall transmission of Plasmodium falciparum in intervention areas to be 90% lower than in control areas. Permethrin resistance was not detected during the study period. As measured by densities of An. gambiae s.l., the efficacy of bed nets decreased if one or more residents did not sleep under a net or if bed nets had not been re-treated within six months. These results indicate that ITNs are optimally effective if used every night and if permethrin is reapplied at least biannually.

  18. Towards a Notion of Distributed Time for Petri Nets

    DEFF Research Database (Denmark)

    Nielsen, Mogens; Sassone, Vladimiro; Srba, Jiří

    2001-01-01

    We set the ground for research on a timed extension of Petri nets where time parameters are associated with tokens and arcs carry constraints that qualify the age of tokens required for enabling. The novelty is that, rather than a single global clock, we use a set of unrelated clocks — possibly o...... per place — allowing a local timing as well as distributed time synchronisation. We give a formal definition of the model and investigate properties of local versus global timing, including decidability issues and notions of processes of the respective models.......We set the ground for research on a timed extension of Petri nets where time parameters are associated with tokens and arcs carry constraints that qualify the age of tokens required for enabling. The novelty is that, rather than a single global clock, we use a set of unrelated clocks — possibly one...

  19. Influence of kinematic cuts on the net charge distribution

    Energy Technology Data Exchange (ETDEWEB)

    Petersen, Hannah [Frankfurt Institute for Advanced Studies, Ruth-Moufang-Str. 1, 60438 Frankfurt am Main (Germany); Institut für Theoretische Physik, Goethe Universität, Max-von-Laue-Str. 1, 60438 Frankfurt am Main (Germany); GSI Helmholtzzentrum für Schwerionenforschung GmbH, Planckstr. 1, 64291 Darmstadt (Germany); Oliinychenko, Dmytro [Frankfurt Institute for Advanced Studies, Ruth-Moufang-Str. 1, 60438 Frankfurt am Main (Germany); Bogolyubov Institute for Theoretical Physics, Kiev 03680 (Ukraine); Steinheimer, Jan [Frankfurt Institute for Advanced Studies, Ruth-Moufang-Str. 1, 60438 Frankfurt am Main (Germany); Bleicher, Marcus [Frankfurt Institute for Advanced Studies, Ruth-Moufang-Str. 1, 60438 Frankfurt am Main (Germany); Institut für Theoretische Physik, Goethe Universität, Max-von-Laue-Str. 1, 60438 Frankfurt am Main (Germany)

    2016-12-15

    The higher moments of the net charge distributions, e.g. the skewness and kurtosis, are studied within an infinite hadronic matter calculation in a transport approach. By dividing the box into several parts, the volume dependence of the fluctuations is investigated. After confirming that the initial distributions follow the expectations from a binomial distribution, the influence of quantum number conservation in this case the net charge in the system on the higher moments is evaluated. For this purpose, the composition of the hadron gas is adjusted and only pions and ρ mesons are simulated to investigate the charge conservation effect. In addition, the effect of imposing kinematic cuts in momentum space is analysed. The role of resonance excitations and decays on the higher moments can also be studied within this model. This work is highly relevant to understand the experimental measurements of higher moments obtained in the RHIC beam energy scan and their comparison to lattice results and other theoretical calculations assuming infinite matter.

  20. Demand and willingness-to-pay for bed nets in Tanzania: results from a choice experiment.

    Science.gov (United States)

    Gingrich, Chris D; Ricotta, Emily; Kahwa, Amos; Kahabuka, Catherine; Koenker, Hannah

    2017-07-14

    Universal coverage campaigns for long-lasting insecticide-treated nets do not always reach the goal of one net for every two household members, and even when ownership of at least one net per household is high, many households may not own enough nets. The retail market provides these households options for replacing or increasing the number of nets they own with products that best fit their needs since a variety of net shapes, sizes, and colours are available. Hence, it is important to understand the factors affecting private net demand. This study explores private demand for nets in Tanzania using a discrete choice experiment. The experiment provides participants the option to buy nets with their own money, and thus should prove more accurate than a hypothetical survey of net preferences. Nearly 800 participants sampled in two regions showed an overall strong demand for nets, with 40% choosing to buy a net across all seven combinations of net prices and characteristics such as size, shape, and insecticide treatment. Only 8% of all participants chose not to buy a single net. A key factor influencing demand was whether a participant's household currently owned sufficient nets for all members, with rural participants showing lower net coverage and greater demand than urban participants. Both poor and less poor households showed strong evidence of making purchase decisions based on more than price alone. Mean willingness-to-pay values for a net started at US$1.10 and grew by US$0.50-1.40 for various attributes such as rectangular shape, large size, and insecticide treatment. The impact of price on demand was negative but small, with elasticity values between -0.25 and -0.45. The results suggest that private demand for nets in Tanzania could potentially supplement future coverage campaigns. Net manufacturers and retailers should advertise and promote consumers' preferred net attributes to improve sales and further expand net access and coverage. To overcome household

  1. The Effect of Mass Media Campaign on the Use of Insecticide-Treated Bed Nets among Pregnant Women in Nigeria

    Directory of Open Access Journals (Sweden)

    A. Ankomah

    2014-01-01

    Full Text Available Background. Malaria during pregnancy is a major public health problem in Nigeria especially in malaria-endemic areas. It increases the risk of low birth weight and child/maternal morbidity/mortality. This paper addresses the impact of radio campaigns on the use of insecticide-treated bed nets among pregnant women in Nigeria. Methods. A total of 2,348 pregnant women were interviewed during the survey across 21 of Nigeria’s 36 states. Respondents were selected through a multistage sampling technique. Analysis was based on multivariate logistic regression. Results. Respondents who knew that sleeping under ITN prevents malaria were 3.2 times more likely to sleep under net (OR: 3.15; 95% CI: 2.28 to 4.33; P<0.0001. Those who listened to radio are also about 1.6 times more likely to use ITN (OR: 1.56; 95% CI: 1.07 to 2.28; P=0.020, while respondents who had heard of a specific sponsored radio campaign on ITN are 1.53 times more likely to use a bed net (P=0.019. Conclusion. Pregnant women who listened to mass media campaigns were more likely to adopt strategies to protect themselves from malaria. Therefore, behavior change communication messages that are aimed at promoting net use and antenatal attendance are necessary in combating malaria.

  2. Liquid distribution in trickle-bed reactor; Distribution du liquide en reacteur a lit ruisselant

    Energy Technology Data Exchange (ETDEWEB)

    Marcandelli, C.; Wild, G. [Centre National de la Recherche Scientifique (CNRS-ENSIC), Lab. des Sciences du Genie Chimique, 54 - Nancy (France); Lamine, A.S. [CNRS-Universite de Paris-Nord, Lab. d' Ingenierie des Materiaux et des Hautes Pressions, 93 - Villetaneuse (France); Bernard, J.R. [Elf Antar France, Centre de Recherche Elf de Solaize, 69 - Solaize (France)

    2000-07-01

    The aim of this study is to develop techniques to qualify the efficiency of liquid distribution in trickle-bed reactors, using cold mockups. The experimental setup consists mainly in a 0.3-m-ID packed-bed column with three different plates used to vary the quality of inlet liquid distribution. Liquid distribution has been qualified using several techniques: global pressure drop measurements, global RTD (Residence-Time Distribution) of the liquid, local heat transfer probes, capacitance tomography, collector at the bottom of the reactor with nine equal zones. The bed pressure drop and the overall external liquid saturation decrease when the maldistribution increases; quantitative information is however difficult to obtain this way. Global RTD of the liquid allows quantifying of the average liquid distribution in the bed. The local thermal sensors give an indication of local liquid velocity and indicate possible local maldistribution of the liquid (scale mm) even when global distribution is good. Concerning the results obtained with the collector, a maldistribution index is defined ranging from 0 (ideal distribution) to 1 (worst possible distribution), and the influence of the different operating parameters (gas and liquid velocities, particle shape) is discussed. (authors)

  3. Bed shear stress distribution in straight channels with arbitrary cross section

    DEFF Research Database (Denmark)

    Christensen, Henrik Bo; Fredsøe, Jørgen

    1998-01-01

    The bed shear stress distribution in straight open channels is affected by mechanisms as bed curvature of the cross section profile, shear diffusion, and secondary currents. This paper compares some analytical and numerical methods to estimate the bed shear stress distribution. The methods...

  4. Multiscale probability distribution of pressure fluctuations in fluidized beds

    International Nuclear Information System (INIS)

    Ghasemi, Fatemeh; Sahimi, Muhammad; Reza Rahimi Tabar, M; Peinke, Joachim

    2012-01-01

    Analysis of flow in fluidized beds, a common chemical reactor, is of much current interest due to its fundamental as well as industrial importance. Experimental data for the successive increments of the pressure fluctuations time series in a fluidized bed are analyzed by computing a multiscale probability density function (PDF) of the increments. The results demonstrate the evolution of the shape of the PDF from the short to long time scales. The deformation of the PDF across time scales may be modeled by the log-normal cascade model. The results are also in contrast to the previously proposed PDFs for the pressure fluctuations that include a Gaussian distribution and a PDF with a power-law tail. To understand better the properties of the pressure fluctuations, we also construct the shuffled and surrogate time series for the data and analyze them with the same method. It turns out that long-range correlations play an important role in the structure of the time series that represent the pressure fluctuation. (paper)

  5. First study of the negative binomial distribution applied to higher moments of net-charge and net-proton multiplicity distributions

    International Nuclear Information System (INIS)

    Tarnowsky, Terence J.; Westfall, Gary D.

    2013-01-01

    A study of the first four moments (mean, variance, skewness, and kurtosis) and their products (κσ 2 and Sσ) of the net-charge and net-proton distributions in Au + Au collisions at √(s NN )=7.7–200 GeV from HIJING simulations has been carried out. The skewness and kurtosis and the collision volume independent products κσ 2 and Sσ have been proposed as sensitive probes for identifying the presence of a QCD critical point. A discrete probability distribution that effectively describes the separate positively and negatively charged particle (or proton and anti-proton) multiplicity distributions is the negative binomial (or binomial) distribution (NBD/BD). The NBD/BD has been used to characterize particle production in high-energy particle and nuclear physics. Their application to the higher moments of the net-charge and net-proton distributions is examined. Differences between κσ 2 and a statistical Poisson assumption of a factor of four (for net-charge) and 40% (for net-protons) can be accounted for by the NBD/BD. This is the first application of the properties of the NBD/BD to describe the behavior of the higher moments of net-charge and net-proton distributions in nucleus–nucleus collisions

  6. An exploratory study of treated-bed nets in Timor-Leste: patterns of intended and alternative usage

    Directory of Open Access Journals (Sweden)

    Wilder-Smith Annelies

    2011-07-01

    significantly decrease availability of nighttime sleeping space for all family members if distributed nets do not remain within the household. Conclusions Emphasizing that net usage is acceptable and important for all family members regardless of age or gender, and addressing the complex behavioural economics of alternative net usages could have significant impacts on malaria control efforts in Timor-Leste, as the country's programmes make progress towards universal net coverage.

  7. "Tazomoka Is Not a Problem". Local Perspectives on Malaria, Fever Case Management and Bed Net Use in Madagascar.

    Science.gov (United States)

    Mattern, Chiarella; Pourette, Dolorès; Raboanary, Emma; Kesteman, Thomas; Piola, Patrice; Randrianarivelojosia, Milijaona; Rogier, Christophe

    2016-01-01

    Although its incidence has been decreasing during the last decade, malaria is still a major public health issue in Madagascar. The use of Long Lasting Insecticidal Nets (LLIN) remains a key malaria control intervention strategy in Madagascar, however, it encounters some obstacles. The present study aimed to explore the local terminology related to malaria, information channels about malaria, attitude towards bed nets, and health care seeking practices in case of fever. This article presents novel qualitative findings about malaria. Until now, no such data has been published for Madagascar. A comparative qualitative study was carried out at four sites in Madagascar, each differing by malaria epidemiology and socio-cultural background of the populations. Seventy-one semi-structured interviews were conducted with biomedical and traditional caregivers, and members of the local population. In addition, observations of the living conditions and the uses of bed net were conducted. Due to the differences between local and biomedical perspectives on malaria, official messages did not have the expected impact on population in terms of prevention and care seeking behaviors. Rather, most information retained about malaria was spread through informal information circulation channels. Most interviewees perceived malaria as a disease that is simple to treat. Tazomoka ("mosquito fever"), the Malagasy biomedical word for malaria, was not used by populations. Tazo ("fever") and tazomahery ("strong fever") were the terms more commonly used by members of the local population to refer to malaria related symptoms. According to local perceptions in all areas, tazo and tazomahery were not caused by mosquitos. Each of these symptoms required specific health recourse. The usual fever management strategies consisted of self-medication or recourse to traditional and biomedical caregivers. Usage of bed nets was intermittent and was not directly linked to protection against malaria in the eyes

  8. Determinants of Ownership and Utilization of Insecticide-Treated Bed Nets for Malaria Control in Eastern Ethiopia

    Directory of Open Access Journals (Sweden)

    Sibhatu Biadgilign

    2012-01-01

    Full Text Available Background. Malaria remains a major cause of mortality and morbidity in the world, and particularly in sub-Saharan Africa. Objectives. The aim of this study was to determine ownership and utilization of ITNs among households with children under five in the previous night. Methods. A community based cross-sectional study was conducted in Gursum district in Eastern Ethiopia. A total of 335 households were surveyed using a pretested structured questionnaire administered though house-to-house interviews. Results. Household ownership for at least one mosquito net and use of nets were 62.4% (95% CI 57.2–67.6% and 21.5% (95% CI 17.1–25.9%, respectively. Households who received or were told about ITN in the last 6 months were three times more likely to have used it than those who were not (OR 3.25; 95% CI 1.5–7.10. Households whose heads were engaged as a farmer (adjusted OR 0.137; 95% CI: 0.04–0.50 and housewife (OR 0.26; 95% CI: 0.08–0.82 were less likely to use ITN than those of other occupations. Conclusion. The findings indicate low ITN ownership and utilization among the households. Intensive health education and community mobilization effort should be employed to increase the possession and proper utilization of insecticide treated bed nets.

  9. Temperature and pressure distributions in a 400 kW{sub t} fluidized bed straw gasifier

    Energy Technology Data Exchange (ETDEWEB)

    Erguedenler, A.; Ghaly, A.E.; Hamdullahpur, F. [Technical Univ. of Nova Scotia, Halifax (Canada)

    1993-12-31

    The temperature and pressure distribution characteristics of a 400 kW (thermal) dual-distributor type fluidized bed straw gasifier were investigated. The effects of the bed height, equivalence ratio (actual air-fuel ratio:stoichiometric air-fuel ratio) and fluidization velocity on the temperature and pressure variations in the gasifier were studied. Generally, the bed temperature reached the steady state condition within 15--20 minutes. The average temperature of the dense bed ranged from 649{degrees}C to 875{degrees}C depending on the levels of operating parameters used. The bed temperature increased linearly with increases in the equivalence ratio, higher bed temperatures were observed with lower bed height and no clear trend for the bed temperature with respect to variations in fluidization velocity was observed. The bed height, equivalence ratio and fluidization velocity affected the pressure drop in the fluidized bed gasifier. Increasing the fluidization velocity and/or decreasing the equivalence ratio resulted in higher pressure drops in the dense bed and the freeboard regions whereas increasing the bed height increased the pressure drop only in the dense bed.

  10. Comparing insecticide-treated bed net use to Plasmodium falciparum infection among schoolchildren living near Lake Victoria, Kenya.

    Science.gov (United States)

    Okoyo, Collins; Mwandawiro, Charles; Kihara, Jimmy; Simiyu, Elses; Gitonga, Caroline W; Noor, Abdisalan M; Njenga, Sammy M; Snow, Robert W

    2015-12-22

    Under trial conditions insecticide-treated nets have been shown to provide significant clinical and mortality protection under a range of malaria transmission intensity conditions. There are, however, few operational impact data, notably in very intense transmission conditions. This study, reports on malaria infection among Kenyan schoolchildren living in areas of intense malaria transmission and their reported use of insecticide-treated bed nets. 5188 children in 54 schools were randomly sampled from seven counties surrounding Lake Victoria between May and June 2014. A questionnaire was administered to schoolchildren in classes 2-6 on the use of a long-lasting, insecticide-treated net (LLIN) the night before the survey and provided a single blood sample for a rapid diagnostic test for malaria infection. Analysis of the impact of insecticide-treated net use on malaria prevalence was undertaken using a multivariable, mixed effects, logistic regression at 95% confidence interval (CI), taking into account hierarchical nature of the data and results adjusted for school clusters. The overall prevalence of malaria infection was 48.7%, two-thirds (67.9%) of the children reported using LLIN, 91.3% of the children reported that their households own at least one LLIN and the household LLIN coverage was 2.5 persons per one LLIN. The prevalence of infection showed variation across the counties, with prevalence being highest in Busia (66.9%) and Homabay (51.8%) counties, and lowest in Migori County (29.6%). Generally, malaria parasite prevalence differed between age groups and gender with the highest prevalence occurring in children below 7 years (50.6%) and males (52.2%). Adjusting for county and school, there was a significant reduction in odds of malaria infection among the schoolchildren who reported LLIN use the previous night by 14 % (aOR 0.86, 95% CI 0.74-0.98, P provide protection against infection among school-aged children.

  11. Effect of insecticide-treated bed nets on house-entry by malaria mosquitoes: The flight response recorded in a semi-field study in Kenya.

    Science.gov (United States)

    Spitzen, Jeroen; Koelewijn, Teun; Mukabana, W Richard; Takken, Willem

    2017-08-01

    Insecticide-treated nets are currently a major tool to reduce malaria transmission. Their level of repellency affects contact of the mosquito with the net, but may also influence the mosquito's entry into the house. The response of host-seeking malaria mosquitoes approaching the eave of an experimental house was recorded within a large screen house. We compared entry- and exit rates in relation to the presence in the house of different insecticide-treated bed nets (ITNs) with an untreated net. Mosquitoes were lured towards the house by dispensing a synthetic host-odour blend from within the net in the house. Complementary WHO bioassays revealed that the treated nets caused high knock-down- and mortality responses to the Anopheles gambiae sensu stricto strain tested. The proportion of mosquitoes that came into view of the cameras and subsequently entered the house did not differ between treated nets and the untreated net. Treated nets did not affect proportions of mosquitoes that exited the house and departed from view around the eave. However, the percentage of house-leaving and re-entering mosquitoes when an insecticide- treated net was present, was lower than in the presence of an untreated net. Our results indicated that there was no spatial repellent effect from pyrethroid-treated nets that influences house-entry at eave level. It is argued that the toxic effect of treated bed nets resulted in a reduced number of mosquitoes re-entering the house, which could thereby affect malaria transmission in neighbouring, unprotected houses. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

  12. Low Utilization of Insecticide-Treated Bed Net among Pregnant Women in the Middle Belt of Ghana

    Directory of Open Access Journals (Sweden)

    Grace Manu

    2017-01-01

    Full Text Available Background. Malaria in pregnancy leads to low birth weight, premature birth, anaemia, and maternal and neonatal mortality. Use of insecticide-treated nets (ITNs during pregnancy is one of the proven interventions to reduce the malaria burden. However, Ghana has not achieved its target for ITN use among pregnant women. Methods. A qualitative study was conducted in seven communities purposively selected from the middle belt of Ghana. Participants who had delivered in the six months prior to this study were selected. In all, seven focus group discussions and twenty-four in-depth interviews were conducted between June and August 2010. Results. Respondents knew of the importance of ITNs and other malaria-preventive strategies. Factors such as financial access and missed opportunities of free distribution denied some pregnant women the opportunity to own or use an ITN. Reasons for not using ITNs during pregnancy included discomfort resulting from heat, smell of the net, and difficulty in hanging the net. Participants maintained their ITNs by preventing holes in the nets, retreatment, and infrequent washing. Conclusion. Pregnant women know about the causes and prevention of malaria. However, this knowledge is not transformed into practice due to lack of access to ITNs and sleeping discomforts among other logistical constraints.

  13. Baseline for the cumulants of net-proton distributions at STAR

    International Nuclear Information System (INIS)

    Luo, Xiaofeng; Mohanty, Bedangadas; Xu, Nu

    2014-01-01

    We present a systematic comparison between the recently measured cumulants of the net-proton distributions by STAR for 0–5% central Au + Au collisions at √(s NN )=7.7–200 GeV and two kinds of possible baseline measure, the Poisson and Binomial baselines. These baseline measures are assuming that the proton and anti-proton distributions independently follow Poisson statistics or Binomial statistics. The higher order cumulant net-proton data are observed to deviate from all the baseline measures studied at 19.6 and 27 GeV. We also compare the net-proton with net-baryon fluctuations in UrQMD and AMPT model, and convert the net-proton fluctuations to net-baryon fluctuations in AMPT model by using a set of formula

  14. An exploratory qualitative study on perceptions about mosquito bed nets in the Niger Delta: what are the barriers to sustained use?

    Directory of Open Access Journals (Sweden)

    Galvin KT

    2011-04-01

    Full Text Available Kathleen T Galvin1, Nick Petford2, Frances Ajose3, Dai Davies41Bournemouth University, Talbot Campus, Fern Barrow, Poole, Dorset, UK; 2University of Northampton, Northampton, UK; 3Department of Medicine, Lagos State University and The Lagos State University Teaching Hospital, Ikeja, Lagos, Nigeria; 4Niger Delta Development Initiative, Poole, Dorset, UKBackground: The effectiveness of malaria control programs is determined by an array of complex factors, including the acceptability and sustained use of preventative measures such as the bed net. A small-scale exploratory study was conducted in several locations in the Niger Delta region, Nigeria, to discover barriers against the use of bed nets, in the context of a current drive to scale up net use in Nigeria.Methods: A qualitative approach with a convenience sample was used. One to one interviews with mostly male adult volunteers were undertaken which explored typical living and sleeping arrangements, and perceptions about and barriers against the use of the mosquito prevention bed net.Results: Several key issues emerged from the qualitative data. Bed nets were not reported as widely used in this small sample. The reasons reported for lack of use included issues of convenience, especially net set up and dismantling; potential hazard and safety concerns; issues related to typical family composition and nature of accommodation; humid weather conditions; and perceptions of cost and effectiveness. Most barriers to net use concerned issues about everyday practical living and sleeping arrangements and perceptions about comfort. Interviewees identified were aware of malaria infection risks, but several also indicated certain beliefs that were barriers to net use.Conclusions: Successful control of malaria and scale up of insecticide-treated net coverage relies on community perceptions and practice. This small study has illuminated a number of important everyday life issues, which remain barriers to

  15. The efficacy of permethrin-treated bed nets on child mortality and morbidity in western Kenya II. Study design and methods

    NARCIS (Netherlands)

    Phillips-Howard, Penelope A.; ter Kuile, Feiko O.; Nahlen, Bernard L.; Alaii, Jane A.; Gimnig, John E.; Kolczak, Margarette S.; Terlouw, Dianne J.; Kariuki, Simon K.; Shi, Ya Ping; Kachur, S. Patrick; Hightower, Allen W.; Vulule, John M.; Hawley, William A.

    2003-01-01

    This paper describes the study design and methods used in a large community-based, group-randomized, controlled trial of permethrin-treated bed nets (ITNs) in an area with intense, perennial malaria transmission in western Kenya conducted between 1996 and 1999. A multi-disciplinary framework was

  16. Impact of permethrin-treated bed nets on malaria, anemia, and growth in infants in an area of intense perennial malaria transmission in western Kenya

    NARCIS (Netherlands)

    ter Kuile, Feiko O.; Terlouw, Dianne J.; Kariuki, Simon K.; Phillips-Howard, Penelope A.; Mirel, Lisa B.; Hawley, William A.; Friedman, Jennifer F.; Shi, Ya Ping; Kolczak, Margarette S.; Lal, Altaf A.; Vulule, John M.; Nahlen, Bernard L.

    2003-01-01

    As part of a community-based, group-randomized, controlled trial of insecticide-treated bed nets (ITNs) in an area with intense malaria transmission in western Kenya, a birth cohort (n = 833) was followed monthly until the age of 24 months to determine the potential beneficial and adverse effects of

  17. Efficacy of permethrin-treated bed nets in the prevention of mortality in young children in an area of high perennial malaria transmission in western Kenya

    NARCIS (Netherlands)

    Phillips-Howard, Penelope A.; Nahlen, Bernard L.; Kolczak, Margarette S.; Hightower, Allen W.; ter Kuile, Feiko O.; Alaii, Jane A.; Gimnig, John E.; Arudo, John; Vulule, John M.; Odhacha, Amos; Kachur, S. Patrick; Schoute, Erik; Rosen, Daniel H.; Sexton, John D.; Oloo, Aggrey J.; Hawley, William A.

    2003-01-01

    A group-randomized controlled trial of insecticide (permethrin)-treated bed nets (ITNs) was conducted in an area of high perennial malaria transmission in western Kenya to test the effect of ITNs on all-cause mortality in children 1-59 months of age. Child deaths were monitored over a two-year

  18. The efficacy of permethrin-treated bed nets on child mortality and morbidity in western Kenya I. Development of infrastructure and description of study site

    NARCIS (Netherlands)

    Phillips-Howard, Penelope A.; Nahlen, Bernard L.; Alaii, Jane A.; ter Kuile, Feiko O.; Gimnig, John E.; Terlouw, Dianne J.; Kachur, S. Patrick; Hightower, Allen W.; Lal, Altaf A.; Schoute, Erik; Oloo, Aggrey J.; Hawley, William A.

    2003-01-01

    Randomized controlled trials in sub-Saharan Africa have shown that permethrin-treated bed nets and curtains reduce all-cause child mortality by 15-33% in areas with low or high but seasonal malaria transmission. This report describes the study site for a community-based, group-randomized, controlled

  19. Parents' perception on use of insecticide-treated bed net in Port ...

    African Journals Online (AJOL)

    It involved the distribution of 15-itemed questionnaires to 212 parents (with at least one under five aged child), who brought their children to the Paediatrics outpatient clinic of University of Port Harcourt Teaching Hospital. Questions asked covered: the awareness of ITN, the number of ITN owned by each participant and the ...

  20. Insecticide-treated nets ownership and utilization among under-five children following the 2010 mass distribution in Burkina Faso.

    Science.gov (United States)

    Diabaté, Souleymane; Druetz, Thomas; Bonnet, Emmanuel; Kouanda, Seni; Ridde, Valéry; Haddad, Slim

    2014-09-04

    Periodic mass distributions contribute significantly to universal access to insecticide-treated nets (ITNs). However, due to the limited number of nets distributed, needs remain unsatisfied, particularly in large households. This study was conducted in Kaya health district following the 2010 mass distribution of ITNs in Burkina Faso. Data were collected on the socio-economic and geo-spatial characteristics and ITN possession and utilization levels of 2,004 households. The study explored: 1) ITN access, in terms of intra-household saturation with ITNs (households with at least one ITN for every two members) correctly installed and in very good physical condition; and 2) factors influencing the decision to place under-five children under a net. Particular attention was given to vector control activities undertaken by mothers. Of the 2,004 households, 90% possessed at least one ITN. However, intra-household saturation with ITNs was below 60% in small households and below 20% in large ones (>6 members). Crude proportion ratios comparing possession and levels of intra-household saturation with ITNs varied between 1.5 (small households) and 7.8 (large households). The proportions of households with ITNs for every two members that were correctly hung or in very good physical condition ranged from 0% to 6.5% in large households and 27.8% to 40.7% in small ones. ITN use to protect under-five children was lower in large households; it was significantly higher when there was at least one ITN for every two members. In large households, it was significantly higher when a child had experienced an episode of any illness in the previous two weeks and when the mother had taken actions to control vector proliferation. In small households, ITN use was significantly higher in families with agricultural land and children aged 12-23 months. Ownership rates were high, but real access to bed nets remained limited. The allocation process disadvantages large families. Real access to bed

  1. Persistence of exponential bed thickness distributions in the stratigraphic record: Experiments and theory

    Science.gov (United States)

    Straub, K. M.; Ganti, V. K.; Paola, C.; Foufoula-Georgiou, E.

    2010-12-01

    Stratigraphy preserved in alluvial basins houses the most complete record of information necessary to reconstruct past environmental conditions. Indeed, the character of the sedimentary record is inextricably related to the surface processes that formed it. In this presentation we explore how the signals of surface processes are recorded in stratigraphy through the use of physical and numerical experiments. We focus on linking surface processes to stratigraphy in 1D by quantifying the probability distributions of processes that govern the evolution of depositional systems to the probability distribution of preserved bed thicknesses. In this study we define a bed as a package of sediment bounded above and below by erosional surfaces. In a companion presentation we document heavy-tailed statistics of erosion and deposition from high-resolution temporal elevation data recorded during a controlled physical experiment. However, the heavy tails in the magnitudes of erosional and depositional events are not preserved in the experimental stratigraphy. Similar to many bed thickness distributions reported in field studies we find that an exponential distribution adequately describes the thicknesses of beds preserved in our experiment. We explore the generation of exponential bed thickness distributions from heavy-tailed surface statistics using 1D numerical models. These models indicate that when the full distribution of elevation fluctuations (both erosional and depositional events) is symmetrical, the resulting distribution of bed thicknesses is exponential in form. Finally, we illustrate that a predictable relationship exists between the coefficient of variation of surface elevation fluctuations and the scale-parameter of the resulting exponential distribution of bed thicknesses.

  2. Determination of pressure distribution in an aerated bed in a controlled pilot-scale compost reactor

    Energy Technology Data Exchange (ETDEWEB)

    Solowiej, P. [Warmia and Mazury Univ., Olsztyn (Poland)

    2010-07-01

    This study investigated the effectiveness of dealing with biological waste by composting. In particular, it examined the feasibility of recovering excess thermal energy produced in the process of composting biological waste in terms of mass and energy transport parameters required in the aerated compost bed. An experiment was performed in which a 100 dm{sup 3} adiabatic, leak-tight reactor equipped with a controlled aeration system was constructed to study the temperature and pressure distribution in the bed. Sensors were used to determine the amount and humidity of emitted gases under variable external physical conditions. The perforated bottom of the reactor allowed for bed aeration. As such, the humidity and heat were transported upwards, forced by the air pumped in and by natural convection. In terms of pressure distribution inside the composted and aerated bed, the study results showed that there were considerable differences in pressure for the selected places of the bed of the composted biological material. An increase in upwards pressure was observed in the heap throughout the experiment. Pressure differences in the same plane of the bed were also noted. The study results should facilitate the development of a model of mass and energy transport in a bed of composted material.

  3. Petechiae: reproducible pattern of distribution and increased appearance after bed rest.

    Science.gov (United States)

    Ganse, Bergita; Limper, Ulrich; Bühlmeier, Judith; Rittweger, Jörn

    2013-08-01

    Exposure to acceleration can cause petechial hemorrhages, called G measles. Petechiae usually start to develop between 5 and 9 G with a high interindividual variance. Centrifuge training delays the onset to higher G levels. One might expect onset at lower G levels after bed rest; however, there is no evidence in the literature. A case of petechiae formation after bed rest is presented here. Orthostatic tolerance was tested using a tilt table and lower body negative pressure before and after bed rest in both campaigns of a 2 x 21-d bed rest study with 6 degrees head-down tilt. A 42-yr-old male Caucasian without any history of thrombosis, venous disease, hemorrhage, or petechiae, and with a negative thrombophilia screening, took part in the bed rest study as 1 out of 10 subjects. He was the only one to develop petechiae during the orthostatic tests after, but not before, bed rest in both campaigns. Petechiae were distributed throughout the lower legs and most pronounced at the shin in a stocking-like fashion, surprisingly reoccurring in an identical pattern of distribution. Petechiae appeared slowly over minutes during hyperemia. This case indicates that prolonged bed rest decreases the threshold for petechiae formation. A reproducible distribution pattern suggests that factors predisposing to petechiae formation keep their local distribution over time (possibly due to local vessel structures). Mechanisms of adaptation and interindividual variance are unclear. Findings are of clinical relevance as such cases might occur after prolonged bed rest in patients without need of expensive testing.

  4. Particle size distribution of main-channel-bed sediments along the upper Mississippi River, USA

    Science.gov (United States)

    Remo, Jonathan; Heine, Ruben A.; Ickes, Brian

    2016-01-01

    In this study, we compared pre-lock-and-dam (ca. 1925) with a modern longitudinal survey of main-channel-bed sediments along a 740-km segment of the upper Mississippi River (UMR) between Davenport, IA, and Cairo, IL. This comparison was undertaken to gain a better understanding of how bed sediments are distributed longitudinally and to assess change since the completion of the UMR lock and dam navigation system and Missouri River dams (i.e., mid-twentieth century). The comparison of the historic and modern longitudinal bed sediment surveys showed similar bed sediment sizes and distributions along the study segment with the majority (> 90%) of bed sediment samples having a median diameter (D50) of fine to coarse sand. The fine tail (≤ D10) of the sediment size distributions was very fine to medium sand, and the coarse tail (≥ D90) of sediment-size distribution was coarse sand to gravel. Coarsest sediments in both surveys were found within or immediately downstream of bedrock-floored reaches. Statistical analysis revealed that the particle-size distributions between the survey samples were statistically identical, suggesting no overall difference in main-channel-bed sediment-size distribution between 1925 and present. This was a surprising result given the magnitude of river engineering undertaken along the study segment over the past ~ 90 years. The absence of substantial differences in main-channel-bed-sediment size suggests that flow competencies within the highly engineered navigation channel today are similar to conditions within the less-engineered historic channel.

  5. Geographic distribution of hospital beds throughout China: a county-level econometric analysis.

    Science.gov (United States)

    Pan, Jay; Shallcross, David

    2016-11-08

    Geographical distribution of healthcare resources is an important dimension of healthcare access. Little work has been published on healthcare resource allocation patterns in China, despite public equity concerns. Using national data from 2043 counties, this paper investigates the geographic distribution of hospital beds at the county level in China. We performed Gini coefficient analysis to measure inequalities and ordinary least squares regression with fixed provincial effects and additional spatial specifications to assess key determinants. We found that provinces in west China have the least equitable resource distribution. We also found that the distribution of hospital beds is highly spatially clustered. Finally, we found that both county-level savings and government revenue show a strong positive relationship with county level hospital bed density. We argue for more widespread use of disaggregated, geographical data in health policy-making in China to support the rational allocation of healthcare resources, thus promoting efficiency and equity.

  6. Gender and willingness to pay for insecticides treated bed nets in a poor rural area in Tanzania.

    Science.gov (United States)

    Mujinja, P G M; Makwaya, C K; Sauerborn, R

    2004-12-01

    To examine socio-economic and malaria related differences between males and females that may cause gender differences in willingness to pay (WTP) for insecticide treated bed nets in a poor rural area. A two-week-interval (test re-test) cross-sectional study. Kisarawe District in coastal Tanzania. Two hundred and fifty one males and two hundred dollars females were interviewed. Females had about 50% of the males' income. The monthly average income was about US dollars 10.50 for females and US dollars 20.20 for males. The proportion of respondents willing to pay for an ITN, for both males and females, declined as the ITN prices increased (Pdifference between men and women, between both rounds were not statistically significant (p>0.05). Male respondents reported a higher mean number of own underfives living in the household compared to women, the difference was not statistically significant (P>0.8). Willingness to pay for ITN was found to be independent of having an under five child with recent history of malaria. Among both males and females, there was an association between a recent experience with malaria episode and WTP, p=0.05 and p=0.02 respectively. Among females, the proportion of those willing to pay for another person, at the lowest ITN price, was significantly higher in those with under five children in their households than in those with no underfives. This was not the case among the male respondents as the association was not statistically significant. Contrary to expectations were was no statistically significant difference in WTP for an ITN between females and males. Further studies that link willingness and ability to pay are required in rural poor population, such studies may be valuable inputs to government policy on and planning of ITN interventions in the public and private sector.

  7. Knowledge, access and utilization of bed-nets among stable and seasonal migrants in an artemisinin resistance containment area of Myanmar

    OpenAIRE

    Phyo Than, Wint; Oo, Tin; Wai, Khin Thet; Thi, Aung; Owiti, Philip; Kumar, Binay; Deepak Shewade, Hemant; Zachariah, Rony

    2017-01-01

    Background Myanmar lies in the Greater Mekong sub-region of South-East Asia faced with the challenge of emerging resistance to artemisinin combination therapies (ACT). Migrant populations are more likely than others to spread ACT resistance. A vital intervention to reduce malaria transmission, resistance spread and eliminate malaria is the use of bed nets. Among seasonal and stable migrants in an artemisinin resistance containment region of Myanmar, we compared a) their household characterist...

  8. Staff and bed distribution in public sector mental health services in ...

    African Journals Online (AJOL)

    Background. The Eastern Cape Province of South Africa is a resource-limited province with a fragmented mental health service. Objective. To determine the current context of public sector mental health services in terms of staff and bed distribution, and how this corresponds to the population distribution in the province.

  9. Software-Enabled Distributed Network Governance: The PopMedNet Experience.

    Science.gov (United States)

    Davies, Melanie; Erickson, Kyle; Wyner, Zachary; Malenfant, Jessica; Rosen, Rob; Brown, Jeffrey

    2016-01-01

    The expanded availability of electronic health information has led to increased interest in distributed health data research networks. The distributed research network model leaves data with and under the control of the data holder. Data holders, network coordinating centers, and researchers have distinct needs and challenges within this model. The concerns of network stakeholders are addressed in the design and governance models of the PopMedNet software platform. PopMedNet features include distributed querying, customizable workflows, and auditing and search capabilities. Its flexible role-based access control system enables the enforcement of varying governance policies. Four case studies describe how PopMedNet is used to enforce network governance models. Trust is an essential component of a distributed research network and must be built before data partners may be willing to participate further. The complexity of the PopMedNet system must be managed as networks grow and new data, analytic methods, and querying approaches are developed. The PopMedNet software platform supports a variety of network structures, governance models, and research activities through customizable features designed to meet the needs of network stakeholders.

  10. The Space Station Module Power Management and Distribution automation test bed

    Science.gov (United States)

    Lollar, Louis F.

    1991-01-01

    The Space Station Module Power Management And Distribution (SSM/PMAD) automation test bed project was begun at NASA/Marshall Space Flight Center (MSFC) in the mid-1980s to develop an autonomous, user-supportive power management and distribution test bed simulating the Space Station Freedom Hab/Lab modules. As the test bed has matured, many new technologies and projects have been added. The author focuses on three primary areas. The first area is the overall accomplishments of the test bed itself. These include a much-improved user interface, a more efficient expert system scheduler, improved communication among the three expert systems, and initial work on adding intermediate levels of autonomy. The second area is the addition of a more realistic power source to the SSM/PMAD test bed; this project is called the Large Autonomous Spacecraft Electrical Power System (LASEPS). The third area is the completion of a virtual link between the SSM/PMAD test bed at MSFC and the Autonomous Power Expert at Lewis Research Center.

  11. Effects of bed net use, female size, and plant abundance on the first meal choice (blood vs sugar of the malaria mosquito Anopheles gambiae

    Directory of Open Access Journals (Sweden)

    Stone Chris M

    2012-01-01

    Full Text Available Abstract Background The purpose of this study was to determine whether the sugar-or-blood meal choice of Anopheles gambiae females one day after emergence is influenced by blood-host presence and accessibility, nectariferous plant abundance, and female size. This tested the hypothesis that the initial meal of female An. gambiae is sugar, even when a blood host is available throughout the night, and, if not, whether the use of a bed net diverts mosquitoes to sugar sources. Methods Females and males Senna didymobotrya plants. Simultaneously they had access to a human blood host, either for 8 h or for only 30 min at dusk and dawn (the remainder of the night being excluded by an untreated bed net. In a third situation, the blood host was not present. All mosquitoes were collected in the morning. Their wing lengths, an indicator of pre-meal energetic state, were measured, and their meal choice was determined by the presence of midgut blood and of fructose. Results Female sugar feeding after emergence was facultative. When a blood host was accessible for 8 h per night, 92% contained blood, and only 3.7% contained sugar. Even with the use of a bed net, 78% managed to obtain a blood meal during the 30 min of accessibility at dusk or dawn, but 14% of females were now fructose-positive. In the absence of a blood host, and when either one or six plants were available, a total of 21.7% and 23.6% of females and 30.8% and 43.5% of males contained fructose, respectively. Feeding on both sugar and blood was more likely with bed net use and with greater plant abundance. Further, mosquitoes that fed on both resources were more often small and had taken a sugar meal earlier than the blood meal. The abundance of sugar hosts also affected the probability of sugar feeding by males and the amount of fructose obtained by both males and females. Conclusion Even in an abundance of potential sugar sources, female An. gambiae appear to prefer a nearby human source of blood

  12. Field-emission from parabolic tips: Current distributions, the net current, and effective emission area

    Science.gov (United States)

    Biswas, Debabrata

    2018-04-01

    Field emission from nano-structured emitters primarily takes place from the tips. Using recent results on the variation of the enhancement factor around the apex [Biswas et al., Ultramicroscopy 185, 1-4 (2018)], analytical expressions for the surface distribution of net emitted electrons, as well as the total and normal energy distributions are derived in terms of the apex radius Ra and the local electric field at the apex Ea. Formulae for the net emitted current and effective emission area in terms of these quantities are also obtained.

  13. Effects of random pebble distribution on the multiplication factor in HTR pebble bed reactors

    Energy Technology Data Exchange (ETDEWEB)

    Auwerda, G.J., E-mail: g.j.auwerda@tudelft.n [Department of Physics of Nuclear Reactors at the Delft University of Technology, Mekelweg 15, Delft (Netherlands); Kloosterman, J.L.; Lathouwers, D.; Hagen, T.H.J.J. van der [Department of Physics of Nuclear Reactors at the Delft University of Technology, Mekelweg 15, Delft (Netherlands)

    2010-08-15

    In pebble bed reactors the pebbles have a random distribution within the core. The usual approach in modeling the bed is homogenizing the entire bed. To quantify the errors arising in such a model, this article investigates the effect on k{sub eff} of three phenomena in random pebble distributions: non-uniform packing density, neutron streaming in between the pebbles, and variations in Dancoff factor. For a 100 cm high cylinder with reflective top and bottom boundary conditions 25 pebble beds were generated. Of each bed three core models were made: a homogeneous model, a zones model including density fluctuations, and an exact model with all pebbles modeled individually. The same was done for a model of the PROTEUS facility. k{sub eff} calculations were performed with three codes: Monte Carlo, diffusion, and finite element transport. By comparing k{sub eff} of the homogenized and zones model the effect of including density fluctuations in the pebble bed was found to increase k{sub eff} by 71 pcm for the infinite cylinder and 649 pcm for PROTEUS. The large value for PROTEUS is due to the low packing fraction near the top of the pebble bed, causing a significant lower packing fraction for the bulk of the pebble bed in the homogenized model. The effect of neutron streaming was calculated by comparing the zones model with the exact model, and was found to decrease k{sub eff} by 606 pcm for the infinite cylinder, and by 1240 pcm for PROTEUS. This was compared with the effect of using a streaming correction factor on the diffusion coefficient in the zones model, which resulted in {Delta}{sub streaming} values of 340 and 1085 pcm. From this we conclude neutron streaming is an important effect in pebble bed reactors, and is not accurately described by the correction factor on the diffusion coefficient. Changing the Dancoff factor in the outer part of the pebble bed to compensate for the lower probability of neutrons to enter other fuel pebbles caused no significant changes

  14. Distribution of physicians and hospital beds based on Gini coefficient and Lorenz curve: A national survey

    Directory of Open Access Journals (Sweden)

    Satar Rezaei

    2016-06-01

    Full Text Available Introduction: Inequality is prevalent in all sectors, particularly in distribution of and access to resources in the health sector. The aim of current study was to investigate the distribution of physicians and hospital beds in Iran in 2001, 2006 and 2011. Methods: This retrospective, cross-sectional study evaluated the distribution of physicians and hospital beds in 2001, 2006 and 2011 using Gini coefficient and Lorenz curve. The required data, including the number of physicians (general practitioners and specialists, number of hospital beds and number of hospitalized patients were obtained from the statistical yearbook of Iranian Statistical Center (ISC. The data analysis was performed by DASP software. Results: The Gini Coefficients for physicians and hospital beds based on population in 2001 were 0.19 and 0.16, and based on hospitalized patients, were 0.48 and 0.37, respectively. In 2006, these values were found to be 0.18 and 0.15 based on population, and 0.21 and 0.21 based on hospitalized patients, respectively. In 2011, however, the Gini coefficients were reported to be 0.16 and 0.13 based on population, and 0.47 and 0.37 based on hospitalized patients, respectively. Although distribution status had improved in 2011compared with 2001 in terms of population and number of hospitalized patients, there was more inequality in distribution based on the number of hospitalized patients than based on population. Conclusion: This study indicated that inequality in distribution of physicians and hospital beds was declined in 2011 compared with 2001. This distribution was based on the population, so it is suggested that, in allocation of resource, the health policymakers consider such need indices as the pattern of diseases and illness-prone areas, number of inpatients, and mortality.

  15. Experimentally determined distribution of granular-flow characteristics in collisional bed load transport

    Directory of Open Access Journals (Sweden)

    Matoušek Václav

    2018-01-01

    Full Text Available A series of laboratory experiments on turbulent open-channel two-phase flow in a form of intense bed load transport is reported. Measurements in a laboratory tilting flume included camera based imaging techniques to identify the structure of the flow at the local level. Obtained experimental distributions of two-phase flow related parameters - granular velocity, concentration, and temperature - across a collisional transport layer are discussed. The results are analysed together with additional measured quantities (discharges of mixture and grains, flow depth, bed slope etc. Our major goal is to evaluate the distribution of granular stresses across the transport layer with a special attention paid to the interface between the transport layer and the bed. Furthermore, comparisons are discussed between the experimental results and predictions produced by suitable kinetic-theory based models.

  16. "People will say that I am proud": a qualitative study of barriers to bed net use away from home in four Ugandan districts.

    Science.gov (United States)

    Monroe, April; Harvey, Steven A; Lam, Yukyan; Muhangi, Denis; Loll, Dana; Kabali, Asaph Turinde; Weber, Rachel

    2014-03-06

    Despite increased access and ownership, barriers to insecticide-treated bed net (ITN) use persist. While barriers within the home have been well documented, the challenges to net use when sleeping away from home remain relatively unexplored. This study examines common situations in which people sleep away from home and the barriers to ITN use in those situations. To explore these issues, a group of researchers conducted 28 in-depth interviews and four focus groups amongst adults from net-owning households in four Ugandan districts. In addition to sleeping outside during hot season, participants identified social events, livelihood activities, and times of difficulty as circumstances in which large numbers of people sleep away from home. Associated challenges to ITN use included social barriers such as fear of appearing proud, logistical barriers such as not having a place to hang a net, and resource limitations such as not having an extra net with which to travel. Social disapproval emerged as an important barrier to ITN use in public settings. Unique barriers to ITN use exist when people spend the night away from home. It is essential to identify and address these barriers in order to reduce malaria exposure in such situations. For events like funerals or religious "crusades" where large numbers of people sleep away from home, alternative approaches, such as spatial repellents may be more appropriate than ITNs. Additional research is required to identify the acceptability and feasibility of alternative prevention strategies in situations where ITNs are unlikely to be effective.

  17. Distributed embedded controller development with petri nets application to globally-asynchronous locally-synchronous systems

    CERN Document Server

    Moutinho, Filipe de Carvalho

    2016-01-01

    This book describes a model-based development approach for globally-asynchronous locally-synchronous distributed embedded controllers.  This approach uses Petri nets as modeling formalism to create platform and network independent models supporting the use of design automation tools.  To support this development approach, the Petri nets class in use is extended with time-domains and asynchronous-channels. The authors’ approach uses models not only providing a better understanding of the distributed controller and improving the communication among the stakeholders, but also to be ready to support the entire lifecycle, including the simulation, the verification (using model-checking tools), the implementation (relying on automatic code generators), and the deployment of the distributed controller into specific platforms. Uses a graphical and intuitive modeling formalism supported by design automation tools; Enables verification, ensuring that the distributed controller was correctly specified; Provides flex...

  18. On the Optimal Design of Distributed Generation Policies: Is Net Metering Ever Optimal?

    OpenAIRE

    Brown, David; Sappington, David

    2014-01-01

    Electricity customers who install solar panels often are paid the prevailing retail price for the electricity they generate. We show that this "net metering" policy typically is not optimal. A payment for distributed generation (w) that is below the retail price of electricity (r) will induce the welfare-maximizing level of distributed generation (DG) when centralized generation and DG produce similar (pollution) externalities. However, w can optimally exceed r when DG entails a substantial r...

  19. Comparing particle-size distributions in modern and ancient sand-bed rivers

    Science.gov (United States)

    Hajek, E. A.; Lynds, R. M.; Huzurbazar, S. V.

    2011-12-01

    Particle-size distributions yield valuable insight into processes controlling sediment supply, transport, and deposition in sedimentary systems. This is especially true in ancient deposits, where effects of changing boundary conditions and autogenic processes may be detected from deposited sediment. In order to improve interpretations in ancient deposits and constrain uncertainty associated with new methods for paleomorphodynamic reconstructions in ancient fluvial systems, we compare particle-size distributions in three active sand-bed rivers in central Nebraska (USA) to grain-size distributions from ancient sandy fluvial deposits. Within the modern rivers studied, particle-size distributions of active-layer, suspended-load, and slackwater deposits show consistent relationships despite some morphological and sediment-supply differences between the rivers. In particular, there is substantial and consistent overlap between bed-material and suspended-load distributions, and the coarsest material found in slackwater deposits is comparable to the coarse fraction of suspended-sediment samples. Proxy bed-load and slackwater-deposit samples from the Kayenta Formation (Lower Jurassic, Utah/Colorado, USA) show overlap similar to that seen in the modern rivers, suggesting that these deposits may be sampled for paleomorphodynamic reconstructions, including paleoslope estimation. We also compare grain-size distributions of channel, floodplain, and proximal-overbank deposits in the Willwood (Paleocene/Eocene, Bighorn Basin, Wyoming, USA), Wasatch (Paleocene/Eocene, Piceance Creek Basin, Colorado, USA), and Ferris (Cretaceous/Paleocene, Hanna Basin, Wyoming, USA) formations. Grain-size characteristics in these deposits reflect how suspended- and bed-load sediment is distributed across the floodplain during channel avulsion events. In order to constrain uncertainty inherent in such estimates, we evaluate uncertainty associated with sample collection, preparation, analytical

  20. Insecticide-treated bed nets reduce plasma antibody levels and limit the repertoire of antibodies to Plasmodium falciparum variant surface antigens

    DEFF Research Database (Denmark)

    Askjaer, N; Maxwell, C; Chambo, W

    2001-01-01

    The use of insecticide-treated bed nets (ITN) has been documented to reduce malaria morbidity and mortality in areas with endemic malaria, but concerns have been raised that ITN usage could affect the acquisition of malaria immunity. Several lines of evidence have indicated that antibodies against...... variant surface antigens (VSA) are important in the development of naturally acquired immunity to Plasmodium falciparum malaria and may thus be good indicators of immune status. We have compared the levels of VSA antibodies in plasma from children who have used ITN for 4 years to levels in plasma from...

  1. HYPERION NET - a distributed measurement system for monitoring background ionizing radiation

    International Nuclear Information System (INIS)

    Saponjic, Dj.; Zigic, A.; Arandjelovic, V.

    2003-01-01

    The distributed measurement system - HYPERION NET, based on the concept of FieldBus technology, has been developed, implemented, and tested as a pilot project, the first WEB enabled on-line networked ionizing radiation monitoring and measurement system. The Net has layered the structure, tree topology, and is based on the Internet infrastructure and TCP/IP communication protocol. The Net's core element is an intelligent GM transmitter, based on GM tube, used for measuring the absorbed dose in air, in the range of 0.087 to 720 μGy/h. The transmitter makes use of an advanced count rate measurement algorithm capable of suppressing the statistical fluctuations of the measured quantity, which significantly improves its measurement performance mailing it suitable for environmental radiation measurements. (author)

  2. Predicting the distribution of bed material accumulation using river network sediment budgets

    Science.gov (United States)

    Wilkinson, Scott N.; Prosser, Ian P.; Hughes, Andrew O.

    2006-10-01

    Assessing the spatial distribution of bed material accumulation in river networks is important for determining the impacts of erosion on downstream channel form and habitat and for planning erosion and sediment management. A model that constructs spatially distributed budgets of bed material sediment is developed to predict the locations of accumulation following land use change. For each link in the river network, GIS algorithms are used to predict bed material supply from gullies, river banks, and upstream tributaries and to compare total supply with transport capacity. The model is tested in the 29,000 km2 Murrumbidgee River catchment in southeast Australia. It correctly predicts the presence or absence of accumulation in 71% of river links, which is significantly better performance than previous models, which do not account for spatial variability in sediment supply and transport capacity. Representing transient sediment storage is important for predicting smaller accumulations. Bed material accumulation is predicted in 25% of the river network, indicating its importance as an environmental problem in Australia.

  3. Design and verification of distributed logic controllers with application of Petri nets

    Energy Technology Data Exchange (ETDEWEB)

    Wiśniewski, Remigiusz; Grobelna, Iwona; Grobelny, Michał; Wiśniewska, Monika [University of Zielona Góra, Licealna 9, 65-417 Zielona Góra (Poland)

    2015-12-31

    The paper deals with the designing and verification of distributed logic controllers. The control system is initially modelled with Petri nets and formally verified against structural and behavioral properties with the application of the temporal logic and model checking technique. After that it is decomposed into separate sequential automata that are working concurrently. Each of them is re-verified and if the validation is successful, the system can be finally implemented.

  4. The application of coloured Petri nets to verification of distributed systems specified by message Sequence Charts

    OpenAIRE

    CHERNENOK S.A.; NEPOMNIASCHY V.A.

    2015-01-01

    The language of message sequence charts (MSC) is a popular scenario-based specification language used to describe the interaction of components in distributed systems. However, the methods for validation of MSC diagrams are underdeveloped. This paper describes a method for translation of MSC diagrams into coloured Petri nets (CPN). The method is applied to the property verification of these diagrams. The considered set of diagram elements is extended by the elements of UML sequence diagrams a...

  5. 3D DEM simulation and analysis of void fraction distribution in a pebble bed high temperature reactor

    International Nuclear Information System (INIS)

    Yang, Xingtuan; Gui, Nan; Tu, Jiyuan; Jiang, Shengyao

    2014-01-01

    Highlights: • We show a detailed analysis of void fraction (VF) in HTR-10 of China using DEM. • Radial distribution (RD) of VF is uniform in the core and oscillated near the wall. • Axial distribution (AD) is linearly varied along height due to effect of gravity. • Steady RD of VF in the conical base is Gaussian-like, larger than packing bed. • Joint linear and normal distribution of VF is analyzed and explained. - Abstract: The current work analyzes the radial and axial distributions of void fraction of a pebble bed high temperature reactor. A three-dimensional pebble bed corresponding to our test facility of pebble bed type gas-cooled high temperature reactor (HTR-10) in Tsinghua University is simulated via discrete element method, and the radial and axial void fraction profiles are calculated. It validates the oscillating characteristics of radial void fraction near the wall. Detailed calculations show the differences of void fraction profiles between the stationary packing bed and the dynamically discharging bed. Based on the vertically and circumferentially averaged radial distribution and horizontally averaged axial distribution of void fraction, a fully three-dimensional analytical distribution of void fraction throughout the bed is established. The results show the combined effects of gravity and void variation in the pebble bed caused by the pebble discharging. It indicates the linearly increased packing effect caused by gravity in the vertical (axial) direction and the normal distribution of void in the horizontal (radial) direction by pebble drainage. These two effects coexist in the conical base of the bed whereas only the former effect exists in the cylindrical volume of the bed

  6. Low Utilization of Insecticide-Treated Bed Net among Pregnant Women in the Middle Belt of Ghana

    OpenAIRE

    Grace Manu; Ellen Abrafi Boamah-Kaali; Lawrence Gyabaa Febir; Emmanuel Ayipah; Seth Owusu-Agyei; Kwaku Poku Asante

    2017-01-01

    Background. Malaria in pregnancy leads to low birth weight, premature birth, anaemia, and maternal and neonatal mortality. Use of insecticide-treated nets (ITNs) during pregnancy is one of the proven interventions to reduce the malaria burden. However, Ghana has not achieved its target for ITN use among pregnant women. Methods. A qualitative study was conducted in seven communities purposively selected from the middle belt of Ghana. Participants who had delivered in the six months prior to th...

  7. Insecticidal, acaricidal and repellent effects of DEET- and IR3535-impregnated bed nets using a novel long-lasting polymer-coating technique.

    Science.gov (United States)

    Faulde, Michael K; Albiez, Gunther; Nehring, Oliver

    2010-03-01

    A novel long-lasting repellent-treated net (LLRTN) has been designed by binding the skin repellents N,N-diethyl-m-toluamide (DEET), or IR3535, onto the fibres of bed net fabric using a new polymer-coating technique. The repellent toxicological effectiveness and residual activity of a factory-based repellent-impregnated fabric has been evaluated by laboratory testing against adult Aedes aegypti mosquitoes and nymphal Ixodes ricinus ticks. By using this repellent-embedding impregnation technique, concentrations exceeding 10 g/m(2) could be achieved with one single polymer layer. Both DEET- and IR3535-impregnated fabrics revealed a dose-dependent insecticidal as well as acaricidal activity. One hundred percent knockdown times of DEET-treated bed nets ranged from 187.5 +/- 31.8 to 27.5 +/- 3.5 min against A. aegypti, and between 214 +/- 47 and 22.6 +/- 5 min against nymphal I. ricinus, linked to a DEET concentration of 1.08 and 10.58 g/m(2), respectively. With IR3535, A. aegypti produced dose-dependent 100% knockdown times varying from 87.5 +/- 10.6 to 57.5 +/- 3.5 min and between 131.4 +/- 6.5 and 33.8 +/- 5 min against nymphal I. ricinus, respectively, linked to concentrations between 1.59 and 10.02 g/m(2). One hundred percent repellency measured by complete landing and biting protection of impregnated fabric by using the arm-in-cage test could be achieved at DEET concentrations exceeding 3.7 to 3.9 g/m(2), and for IR3535 concentrations over 10 g/m(2). One hundred percent landing and biting protection could be preserved with DEET-treated fabrics for 29 weeks at an initial concentration of 4.66 g/m(2), 54 weeks at 8.8 g/m(2), 58 weeks at 9.96 g/m(2) and 61 weeks at 10.48 g/m(2) for DEET, and 23 weeks for IR3535-treated fabric at a concentration of 10.02 g/m(2). Unlike repellent-treated fabric, a brand of a commercially available long-lasting insecticide-treated net tested containing 500 mg permethrin/m(2) did not protect from mosquito bites. First results on

  8. Mosquito abundance, bed net coverage and other factors associated with variations in sporozoite infectivity rates in four villages of rural Tanzania

    DEFF Research Database (Denmark)

    Kweka, Eliningaya J; Nkya, Watoky M M; Mahande, Aneth M

    2008-01-01

    . Sporozoite infectivity rates, mosquito host blood meal source, bed net coverage and mosquito abundance were assessed in this study. METHODOLOGY: A longitudinal survey was conducted in four villages in two regions of Tanzania. Malaria vectors were sampled using the CDC light trap and pyrethrum spray catch...... methods. In each village, ten paired houses were selected for mosquitoes sampling. Sampling was done in fortnight case and study was undertaken for six months in both Kilimanjaro (Northern Tanzania) and Dodoma (Central Tanzania) regions. RESULTS: A total of 6,883 mosquitoes were collected including: 5......,628 (81.8%) Anopheles arabiensis, 1,100 (15.9%) Culex quinquefasciatus, 89 (1.4%) Anopheles funestus, and 66 (0.9%) Anopheles gambiae s.s. Of the total mosquitoes collected 3,861 were captured by CDC light trap and 3,022 by the pyrethrum spray catch method. The overall light trap: spray catch ratio was 1...

  9. Insecticide-treated nets mass distribution campaign: benefits and lessons in Zambia.

    Science.gov (United States)

    Masaninga, Freddie; Mukumbuta, Nawa; Ndhlovu, Ketty; Hamainza, Busiku; Wamulume, Pauline; Chanda, Emmanuel; Banda, John; Mwanza-Ingwe, Mercy; Miller, John M; Ameneshewa, Birkinesh; Mnzava, Abraham; Kawesha-Chizema, Elizabeth

    2018-04-24

    Zambia was an early adopter of insecticide-treated nets strategy in 2001, and policy for mass distribution with long-lasting insecticidal nets (LLINs) in 2005. Since then, the country has implemented mass distribution supplemented with routine delivery through antenatal care and under five clinics in health facilities. The national targets of universal (100%) coverage and 80% utilization of LLINs have not been attained. Free mass LLIN distribution campaign in Zambia offers important lessons to inform future campaigns in the African region. This study reviewed LLIN free mass distribution campaign information derived from Zambia's national and World Health Organization Global Malaria Programme annual reports and strategic plans published between 2001 and 2016. In 2014, a nationwide mass distribution campaign in Zambia delivered all the 6.0 million LLINs in 6 out of 10 provinces in 4 months between June and September before the onset of the rainy season. Compared with 235,800 LLINs and 2.9 million LLINs distributed on a rolling basis in 2008 and 2013, respectively, the 2014 mass campaign, which distributed 6 million LLINs represented the largest one-time-nationwide LLIN distribution in Zambia. The province (Luapula) with highest malaria transmission, mostly with rural settings recorded 98-100% sleeping spaces in homes covered with LLINs. The percentage of households owning at least 1 LLIN increased from 50.9% in 2006 to 77.7% in 2015. The 2014 mass campaign involved a coordinated response with substantial investments into macro (central) and micro (district) level planning, capacity building, tracking and logistics management supported by a new non-health sector partnership landscape. Coordination of LLIN distribution and logistics benefited from the mobile phone technology to transmit "real time" data on commodity tracking that facilitated timely delivery to districts. Free mass distribution of LLINs policy was adopted in 2005 in Zambia. Consistently implemented

  10. NetWall distributed firewall in the use of campus network

    Science.gov (United States)

    He, Junhua; Zhang, Pengshuai

    2011-10-01

    Internet provides a modern means of education but also non-mainstream consciousness and poor dissemination of information opens the door, network and moral issues have become prominent, poor dissemination of information and network spread rumors and negative effects of new problems, ideological and political education in schools had a huge impact, poses a severe challenge. This paper presents a distributed firewall will NetWall deployed in a campus network solution. The characteristics of the campus network, using technology to filter out bad information on the means of control, of sensitive information related to the record, establish a complete information security management platform for the campus network.

  11. Electromagnetic forces distribution and mechanical analysis in the first wall structure for INTOR/NET

    International Nuclear Information System (INIS)

    Coccorese, E.; Martone, R.; Rubinacci, G.; Biggio, M.; Inzaghi, A.; Turri, M.

    1984-01-01

    In the context of the studies performed at JRC-Ispra for NET/INTOR, a modular stainless steel first wall, and separated from the blanket which it envelops has been proposed. During plasma disruption the metallic structure of the first wall is inevitably subject to appreciable electromagnetic forces caused by induced eddy current-magnetic field interactions. The deformation and stress distributions in the first wall were quantified at various instants of time by three-dimensional calculations using the ICES-STRUDL code. (author)

  12. A new fluid distribution system for scale-flexible expanded bed adsorption

    DEFF Research Database (Denmark)

    Hubbuch, Jürgen; Heebøll-Nielsen, Anders; Hobley, Timothy John

    2002-01-01

    of axial dispersion was 6.1 x 10(-6) m(2) (.) s(-1) and 29 theoretical plates were measured. When the rotation rate was raised to 10 rpm, the coefficient of axial dispersion increased to 8.08 x 10(-6) m(2 .) s(-1) and the number of theoretical plates decreased to 22.......A new fluid distribution system designed for expanded bed adsorption was introduced and studied in a 150-cm diameter column. Based on fluid application through a rotating distributor, it eradicates the need for perforated plates, meshes, or local mixers. The effect of rotation rate on column...

  13. Synergistic insecticidal and repellent effects of combined pyrethroid and repellent-impregnated bed nets using a novel long-lasting polymer-coating multi-layer technique.

    Science.gov (United States)

    Faulde, Michael K; Nehring, Oliver

    2012-08-01

    New and improved strategies for malaria control and prevention are urgently needed. As a contribution to an optimized personal protection strategy, a novel long-lasting insecticide and repellent-treated net (LLIRN) has been designed by binding combinations of permethrin plus N,N-diethyl-m-toluamide (DEET), or insect repellent 3535 (IR3535), and etofenprox plus DEET, onto fibres of bed net fabric employing a new multi-layer polymer-coating technique. Protective repellent efficacy, toxicological effectiveness and residual activity of 12 LLIRN types have been evaluated by laboratory testing against adult Aedes aegypti. The novel multi-layer LLIRN design allowed simultaneous embedding at concentrations up to 5,930 mg/m(2) for DEET, 3,408 mg/m(2) for IR3535, 2,296 mg/m(2) for permethrin and 2,349 mg/m(2) for etofenprox, respectively. IR3535 layers prevented co-binding of additional pyrethroid-containing polymer layers, thus making pyrethroids plus DEET LLIRNs an ideal combination. All LLIRNs revealed synergistic insecticidal effects which, when measured against concentration controls of the isolated compounds, were significant in all LLIRN types designed. DEET in DEET plus permethrin LLIRNs significantly (p time from 55 to 75 %, the corresponding 100 % kill time (p time of etofenprox from 42 to 50 % (p = 0.004), the 100 % kill time from 25 to 38 % (p biting protection, even at low concentrations. One hundred percent biting and probing protection of stored LLIRNs was preserved for 83 weeks with the 5,930 mg/m(2) DEET and 2,139 mg/m(2) etofenprox LLIRN, for 72 weeks with the 5,002 mg/m(2) DEET and 2,349 mg/m(2) etofenprox LLIRN, for 63 weeks with the 3,590 mg/m(2) DEET and 1,208 mg/m(2) permethrin LLRN, and for 61 weeks with the 4,711 mg/m(2) DEET and 702 mg/m(2) etofenprox LLIRN. Because 100 % bite protection with up to 75 % quicker contact toxicity of pyrethroids were documented, synergistic toxicological and repellent effects of multi-layer polymer

  14. Ownership and usage of mosquito nets after four years of large-scale free distribution in Papua New Guinea

    Directory of Open Access Journals (Sweden)

    Hetzel Manuel W

    2012-06-01

    Full Text Available Abstract Background Papua New Guinea (PNG is a highly malaria endemic country in the South-West Pacific with a population of approximately 6.6 million (2009. In 2004, the country intensified its malaria control activities with support from the Global Fund. With the aim of achieving 80% ownership and usage, a country-wide campaign distributed two million free long-lasting insecticide-treated nets (LLINs. Methods In order to evaluate outcomes of the campaign against programme targets, a country-wide household survey based on stratified multi-stage random sampling was carried out in 17 of the 20 provinces after the campaign in 2008/09. In addition, a before-after assessment was carried out in six purposively selected sentinel sites. A structured questionnaire was administered to the heads of sampled households to elicit net ownership and usage information. Results After the campaign, 64.6% of households owned a LLIN, 80.1% any type of mosquito net. Overall usage by household members amounted to 32.5% for LLINs and 44.3% for nets in general. Amongst children under five years, 39.5% used a LLIN and 51.8% any type of net, whereas 41.3% of pregnant women used a LLIN and 56.1% any net. Accessibility of villages was the key determinant of net ownership, while usage was mainly determined by ownership. Most (99.5% of the household members who did not sleep under a net did not have access to a (unused net in their household. In the sentinel sites, LLIN ownership increased from 9.4% to 88.7%, ownership of any net from 52.7% to 94.1%. Usage of LLINs increased from 5.5% to 55.1%, usage of any net from 37.3% to 66.7%. Among children under five years, usage of LLINs and of nets in general increased from 8.2% to 67.0% and from 44.6% to 76.1%, respectively (all p ≤ 0.001. Conclusions While a single round of free distribution of LLINs significantly increased net ownership, an insufficient number of nets coupled with a heterogeneous distribution led to overall

  15. The stratigraphic distribution of large marine vertebrates and shell beds in the Pliocene of Tuscany

    Science.gov (United States)

    Dominici, Stefano; Benvenuti, Marco; Danise, Silvia

    2015-04-01

    The record of 337 shark fossils, 142 cetaceans and 10 sea cows from the Pliocene of Tuscany, mostly from historical museum collections, is revised. The majority of these fossils are concentrated at a few geographic sites from separated hinterland basins, on the South-Western side of the Northern Apennines. To better understand the meaning of these concentrations, the sequence stratigraphic distribution of more recent findings of large marine vertebrates is reconstructed against a high-resolution framework based on sedimentary facies analysis. These remains are usually covered by, or included in mudstones deposited far from the coast (N=12), skeletons being usually articulated, slightly displaced, and often bioeroded. A minor part of better preserved articulated skeletons is associated with sandstones from deltaic paleonenvironments (N=2). Marine mammal and shark remains may be associated with laterally-continuous shell accumulations, a type of concentration occurring at maximum flooding surfaces, separating relatively coarse-grained facies from open marine mudstones. Shell beds were bulk-sampled at 66 locations from six basins, covering a wide range of sedimentary facies, and spanning a chronologic interval of about 2.5 million years. A dataset of 62,655 mollusc specimens belonging to 496 species formed the basis of a statistical study to reconstruct the structure of the benthic communities, and to estimate paleodepths from intertidal to upper bathyal settings. Mollusc associations closely mirror the distribution of sedimentary facies, allowing for a fine tuning of the sequence stratigraphic architecture. Merging paleogeographic, stratigraphic and paleoecologic data, we conclude that the more abundant and diverse accumulations of large vertebrates took place in settings under the influence of coastal upwelling. A modern analogue occurs today in the Ligurian Sea, on the Tuscan offshore, where abundant nutrients carried by deep-marine currents of Western origin

  16. An approach to prospective consequential life cycle assessment and net energy analysis of distributed electricity generation

    International Nuclear Information System (INIS)

    Jones, Christopher; Gilbert, Paul; Raugei, Marco; Mander, Sarah; Leccisi, Enrica

    2017-01-01

    Increasing distributed renewable electricity generation is one of a number of technology pathways available to policy makers to meet environmental and other sustainability goals. Determining the efficacy of such a pathway for a national electricity system implies evaluating whole system change in future scenarios. Life cycle assessment (LCA) and net energy analysis (NEA) are two methodologies suitable for prospective and consequential analysis of energy performance and associated impacts. This paper discusses the benefits and limitations of prospective and consequential LCA and NEA analysis of distributed generation. It concludes that a combined LCA and NEA approach is a valuable tool for decision makers if a number of recommendations are addressed. Static and dynamic temporal allocation are both needed for a fair comparison of distributed renewables with thermal power stations to account for their different impact profiles over time. The trade-offs between comprehensiveness and uncertainty in consequential analysis should be acknowledged, with system boundary expansion and system simulation models limited to those clearly justified by the research goal. The results of this approach are explorative, rather than for accounting purposes; this interpretive remit, and the assumptions in scenarios and system models on which results are contingent, must be clear to end users. - Highlights: • A common LCA and NEA framework for prospective, consequential analysis is discussed. • Approach to combined LCA and NEA of distributed generation scenarios is proposed. • Static and dynamic temporal allocation needed to assess distributed generation uptake.

  17. Increasing prevalence of wildtypes in the dihydrofolate reductase gene of Plasmodium falciparum in an area with high levels of sulfadoxine/pyrimethamine resistance after introduction of treated bed nets

    DEFF Research Database (Denmark)

    Alifrangis, Michael; Lemnge, Martha M; Rønn, Anita M

    2003-01-01

    years old living in the villages from 1998 to 2000. In 2000, after two years of bed net use, the prevalence of wild types in codon 51, 59, and 108 of dhfr increased significantly in Magoda compared with previous years. Furthermore, the prevalence of dhfr wild types was significantly higher in Magoda...

  18. The use of mediation analysis to assess the effects of a behaviour change communication strategy on bed net ideation and household universal coverage in Tanzania.

    Science.gov (United States)

    Ricotta, Emily E; Boulay, Marc; Ainslie, Robert; Babalola, Stella; Fotheringham, Megan; Koenker, Hannah; Lynch, Matthew

    2015-01-21

    SBCC campaigns are designed to act on cognitive, social and emotional factors at the individual or community level. The combination of these factors, referred to as 'ideation', play a role in determining behaviour by reinforcing and confirming decisions about a particular health topic. This study introduces ideation theory and mediation analysis as a way to evaluate the impact of a malaria SBCC campaign in Tanzania, to determine whether exposure to a communication programme influenced universal coverage through mediating ideational variables. A household survey in three districts where community change agents (CCAs) were active was conducted to collect information on ITN use, number of ITNs in the household, and perceptions about ITN use and ownership. Variables relating to attitudes and beliefs were combined to make 'net ideation'. Using an ideational framework, a mediation analysis was conducted to see the impact exposure to a CCA only, mass media and community (M & C) messaging only, or exposure to both, had on household universal coverage, through the mediating variable net ideation. All three levels of exposure (CCA, M & C messaging, or exposure to both) were significantly associated with increased net ideation (CCA: 0.283, 95% CI: 0.136-0.429, p-value: mediation analysis is an applicable new tool to assess SBCC campaigns. Ideation as a mediator of the effects of communication exposure on household universal coverage has implications for designing SBCC to support both mass and continuous distribution efforts, since both heavily rely on consumer participation to obtain and maintain ITNs. Such systems can be strengthened by SBCC programming, generating demand through improving social norms about net ownership and use, perceived benefits of nets, and other behavioural constructs.

  19. Biodegradation of 2,4,6-trichlorophenol in a packed-bed biofilm reactor equipped with an internal net draft tube riser for aeration and liquid circulation

    Energy Technology Data Exchange (ETDEWEB)

    Gomez-De Jesus, A.; Romano-Baez, F.J.; Leyva-Amezcua, L.; Juarez-Ramirez, C.; Ruiz-Ordaz, N. [Departamento de Ingenieria Bioquimica, Escuela Nacional de Ciencias Biologicas, IPN. Prol. Carpio y Plan de Ayala, Colonia Santo Tomas, s/n. CP 11340, Mexico, D.F. (Mexico); Galindez-Mayer, J. [Departamento de Ingenieria Bioquimica, Escuela Nacional de Ciencias Biologicas, IPN. Prol. Carpio y Plan de Ayala, Colonia Santo Tomas, s/n. CP 11340, Mexico, D.F. (Mexico)], E-mail: cmayer@encb.ipn.mx

    2009-01-30

    For the aerobic biodegradation of the fungicide and defoliant 2,4,6-trichlorophenol (2,4,6-TCP), a bench-scale packed-bed bioreactor equipped with a net draft tube riser for liquid circulation and oxygenation (PB-ALR) was constructed. To obtain a high packed-bed volume relative to the whole bioreactor volume, a high A{sub D}/A{sub R} ratio was used. Reactor's downcomer was packed with a porous support of volcanic stone fragments. PB-ALR hydrodynamics and oxygen mass transfer behavior was evaluated and compared to the observed behavior of the unpacked reactor operating as an internal airlift reactor (ALR). Overall gas holdup values {epsilon}{sub G}, and zonal oxygen mass transfer coefficients determined at various airflow rates in the PB-ALR, were higher than those obtained with the ALR. When comparing mixing time values obtained in both cases, a slight increment in mixing time was observed when reactor was operated as a PB-ALR. By using a mixed microbial community, the biofilm reactor was used to evaluate the aerobic biodegradation of 2,4,6-TCP. Three bacterial strains identified as Burkholderia sp., Burkholderia kururiensis and Stenotrophomonas sp. constituted the microbial consortium able to cometabolically degrade the 2,4,6-TCP, using phenol as primary substrate. This consortium removed 100% of phenol and near 99% of 2,4,6-TCP. Mineralization and dehalogenation of 2,4,6-TCP was evidenced by high COD removal efficiencies ({approx}95%), and by the stoichiometric release of chloride ions from the halogenated compound ({approx}80%). Finally, it was observed that the microbial consortium was also capable to metabolize 2,4,6-TCP without phenol as primary substrate, with high removal efficiencies (near 100% for 2,4,6-TCP, 92% for COD and 88% for chloride ions)

  20. BigWig and BigBed: enabling browsing of large distributed datasets.

    Science.gov (United States)

    Kent, W J; Zweig, A S; Barber, G; Hinrichs, A S; Karolchik, D

    2010-09-01

    BigWig and BigBed files are compressed binary indexed files containing data at several resolutions that allow the high-performance display of next-generation sequencing experiment results in the UCSC Genome Browser. The visualization is implemented using a multi-layered software approach that takes advantage of specific capabilities of web-based protocols and Linux and UNIX operating systems files, R trees and various indexing and compression tricks. As a result, only the data needed to support the current browser view is transmitted rather than the entire file, enabling fast remote access to large distributed data sets. Binaries for the BigWig and BigBed creation and parsing utilities may be downloaded at http://hgdownload.cse.ucsc.edu/admin/exe/linux.x86_64/. Source code for the creation and visualization software is freely available for non-commercial use at http://hgdownload.cse.ucsc.edu/admin/jksrc.zip, implemented in C and supported on Linux. The UCSC Genome Browser is available at http://genome.ucsc.edu.

  1. Integration of the SSPM and STAGE with the MPACT Virtual Facility Distributed Test Bed.

    Energy Technology Data Exchange (ETDEWEB)

    Cipiti, Benjamin B. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Shoman, Nathan [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2017-08-01

    The Material Protection Accounting and Control Technologies (MPACT) program within DOE NE is working toward a 2020 milestone to demonstrate a Virtual Facility Distributed Test Bed. The goal of the Virtual Test Bed is to link all MPACT modeling tools, technology development, and experimental work to create a Safeguards and Security by Design capability for fuel cycle facilities. The Separation and Safeguards Performance Model (SSPM) forms the core safeguards analysis tool, and the Scenario Toolkit and Generation Environment (STAGE) code forms the core physical security tool. These models are used to design and analyze safeguards and security systems and generate performance metrics. Work over the past year has focused on how these models will integrate with the other capabilities in the MPACT program and specific model changes to enable more streamlined integration in the future. This report describes the model changes and plans for how the models will be used more collaboratively. The Virtual Facility is not designed to integrate all capabilities into one master code, but rather to maintain stand-alone capabilities that communicate results between codes more effectively.

  2. Exploration of probability distribution of velocities of saltating sand particles based on the stochastic particle-bed collisions

    International Nuclear Information System (INIS)

    Zheng Xiaojing; Xie Li; Zhou Youhe

    2005-01-01

    The wind-blown sand saltating movement is mainly categorized into two mechanical processes, that is, the interaction between the moving sand particles and the wind in the saltation layer, and the collisions of incident particles with sand bed, and the latter produces a lift-off velocity of a sand particle moving into saltation. In this Letter a methodology of phenomenological analysis is presented to get probability density (distribution) function (pdf) of the lift-off velocity of sand particles from sand bed based on the stochastic particle-bed collision. After the sand particles are dealt with by uniform circular disks and a 2D collision between an incident particle and the granular bed is employed, we get the analytical formulas of lift-off velocity of ejected and rebound particles in saltation, which are functions of some random parameters such as angle and magnitude of incident velocity of the impacting particles, impact and contact angles between the collision particles, and creeping velocity of sand particles, etc. By introducing the probability density functions (pdf's) of these parameters in communion with all possible patterns of sand bed and all possible particle-bed collisions, and using the essential arithmetic of multi-dimension random variables' pdf, the pdf's of lift-off velocities are deduced out and expressed by the pdf's of the random parameters in the collisions. The numerical results of the distributions of lift-off velocities display that they agree well with experimental ones

  3. Use of the RISK21 roadmap and matrix: human health risk assessment of the use of a pyrethroid in bed netting.

    Science.gov (United States)

    Doe, John E; Lander, Deborah R; Doerrer, Nancy G; Heard, Nina; Hines, Ronald N; Lowit, Anna B; Pastoor, Timothy; Phillips, Richard D; Sargent, Dana; Sherman, James H; Young Tanir, Jennifer; Embry, Michelle R

    2016-01-01

    The HESI-coordinated RISK21 roadmap and matrix are tools that provide a transparent method to compare exposure and toxicity information and assess whether additional refinement is required to obtain the necessary precision level for a decision regarding safety. A case study of the use of a pyrethroid, "pseudomethrin," in bed netting to control malaria is presented to demonstrate the application of the roadmap and matrix. The evaluation began with a problem formulation step. The first assessment utilized existing information pertaining to the use and the class of chemistry. At each stage of the step-wise approach, the precision of the toxicity and exposure estimates were refined as necessary by obtaining key data which enabled a decision on safety to be made efficiently and with confidence. The evaluation demonstrated the concept of using existing information within the RISK21 matrix to drive the generation of additional data using a value-of-information approach. The use of the matrix highlighted whether exposure or toxicity required further investigation and emphasized the need to address the default uncertainty factor of 100 at the highest tier of the evaluation. It also showed how new methodology such as the use of in vitro studies and assays could be used to answer the specific questions which arise through the use of the matrix. The matrix also serves as a useful means to communicate progress to stakeholders during an assessment of chemical use.

  4. Higher moments of net kaon multiplicity distributions at RHIC energies for the search of QCD Critical Point at STAR

    Directory of Open Access Journals (Sweden)

    Sarkar Amal

    2013-11-01

    Full Text Available In this paper we report the measurements of the various moments mean (M, standard deviation (σ skewness (S and kurtosis (κ of the net-Kaon multiplicity distribution at midrapidity from Au+Au collisions at √sNN = 7.7 to 200 GeV in the STAR experiment at RHIC in an effort to locate the critical point in the QCD phase diagram. These moments and their products are related to the thermodynamic susceptibilities of conserved quantities such as net baryon number, net charge, and net strangeness as also to the correlation length of the system. A non-monotonic behavior of these variable indicate the presence of the critical point. In this work we also present the moments products Sσ, κσ2 of net-Kaon multiplicity distribution as a function of collision centrality and energies. The energy and the centrality dependence of higher moments of net-Kaons and their products have been compared with it0s Poisson expectation and with simulations from AMPT which does not include the critical point. From the measurement at all seven available beam energies, we find no evidence for a critical point in the QCD phase diagram for √sNN below 200 GeV.

  5. Staff and bed distribution in public sector mental health services in the Eastern Cape Province, South Africa

    Directory of Open Access Journals (Sweden)

    Kiran Sukeri

    2014-11-01

    Full Text Available Background. The Eastern Cape Province of South Africa is a resource-limited province with a fragmented mental health service.  Objective. To determine the current context of public sector mental health services in terms of staff and bed distribution, and how this corresponds to the population distribution in the province. Method. In this descriptive cross-sectional study, an audit questionnaire was submitted to all public sector mental health facilities. Norms and indicators were calculated at provincial and district level. This article investigates staff and bed distribution only. Results. Results demonstrated that within the province, only three of its seven districts have acute beds above the national baseline norm requirement of 13/100 000. The private mental health sector provides approximately double the number of medium- to long-stay beds available in the public sector. Only two regions have staff/population ratios above the baseline norm of 20/100 000. However, there are significant differences in this ratio among specific staff categories. There is an inequitable distribution of resources between the eastern and western regions of the province. When compared with the western regions, the eastern regions have poorer access to mental health facilities, human resources and non-governmental organisations.  Conclusion. Owing to the inequitable distribution of resources, the provincial authorities urgently need to develop an equitable model of service delivery. The province has to address the absence of a reliable mental health information system.

  6. Preliminary estimates of spatially distributed net infiltration and recharge for the Death Valley region, Nevada-California

    International Nuclear Information System (INIS)

    Hevesi, J.A.; Flint, A.L.; Flint, L.E.

    2002-01-01

    A three-dimensional ground-water flow model has been developed to evaluate the Death Valley regional flow system, which includes ground water beneath the Nevada Test Site. Estimates of spatially distributed net infiltration and recharge are needed to define upper boundary conditions. This study presents a preliminary application of a conceptual and numerical model of net infiltration. The model was developed in studies at Yucca Mountain, Nevada, which is located in the approximate center of the Death Valley ground-water flow system. The conceptual model describes the effects of precipitation, runoff, evapotranspiration, and redistribution of water in the shallow unsaturated zone on predicted rates of net infiltration; precipitation and soil depth are the two most significant variables. The conceptual model was tested using a preliminary numerical model based on energy- and water-balance calculations. Daily precipitation for 1980 through 1995, averaging 202 millimeters per year over the 39,556 square kilometers area of the ground-water flow model, was input to the numerical model to simulate net infiltration ranging from zero for a soil thickness greater than 6 meters to over 350 millimeters per year for thin soils at high elevations in the Spring Mountains overlying permeable bedrock. Estimated average net infiltration over the entire ground-water flow model domain is 7.8 millimeters per year. To evaluate the application of the net-infiltration model developed on a local scale at Yucca Mountain, to net-infiltration estimates representing the magnitude and distribution of recharge on a regional scale, the net-infiltration results were compared with recharge estimates obtained using empirical methods. Comparison of model results with previous estimates of basinwide recharge suggests that the net-infiltration estimates obtained using this model may overestimate recharge because of uncertainty in modeled precipitation, bedrock permeability, and soil properties for

  7. Fluidization behavior in a circulating slugging fluidized bed reactor. Part I : residence time and residence time distribution of polyethylene solids

    NARCIS (Netherlands)

    Putten, van I.C.; Sint Annaland, van M.; Weickert, G.

    2007-01-01

    Square nosed slugging fluidization behavior in a circulating fluidized bed riser using a polyethylene powder with a very wide particle size distribution was studied. In square nosed slugging fluidization the extent of mixing of particles of different size depends on the riser diameter, gas velocity,

  8. Fluidization behavior in a circulating slugging fluidized bed reactor. Part I: Residence time and residence time distribution of polyethylene solids

    NARCIS (Netherlands)

    van Putten, I.C.; van Sint Annaland, M.; Weickert, G.

    2007-01-01

    Square nosed slugging fluidization behavior in a circulating fluidized bed riser using a polyethylene powder with a very wide particle size distribution was studied. In square nosed slugging fluidization the extent of mixing of particles of different size depends on the riser diameter, gas velocity,

  9. Baseline measures for net-proton distributions in high energy heavy-ion collisions

    International Nuclear Information System (INIS)

    Netrakanti, P.K.; Mishra, D.K.; Mohanty, A.K.; Mohanty, B.

    2014-01-01

    The STAR experiment at the Relativistic Heavy-Ion Collider facility has reported results for the cumulants and their ratios from the net-proton distributions upto the fourth order cumulants at various collision energies. These measurements were carried to look for the signatures of the possible critical point (CP) in the phase diagram for a system undertaking strong interactions. The results show an intriguing dependence of the cumulant ratios C 3 /C 2 and C 4 /C 2 as a function of beam energy. The beam energy dependence appears to be non-monotonic in nature. However the experiment also reports that the energy dependence is observed to be consistent with expectation from an approach based on the independent production of proton and anti-protons in the collisions. In this paper we emphasize the need to have a proper baseline for appropriate interpretation of the cumulant measurements and argue that the comparison to independent production approach needs to be done with extreme caution

  10. The Effect of Long Lasting Insecticide Bed Net Use on Malaria Prevalence in the Tombel Health District, South West Region-Cameroon

    Directory of Open Access Journals (Sweden)

    Eric B. Fokam

    2016-01-01

    Full Text Available Malaria remains a major public health problem in Africa, and its prevalence in Cameroon stands at 29%. Long Lasting Insecticide Nets (LLINs were distributed in 2011 to reduce malaria mortality and morbidity; however, assessment of this intervention is scanty. The present study in the Tombel health district (THD investigated the impact of this distribution on malaria prevalence. A total of 31,657 hospital records from 3 health facilities in 3 health areas for 2010–2013 were examined. Records for 2010 and 2011 provided predistribution baseline data, while those of 2012 and 2013 represented postdistribution data. 8,679 (27.4% patients were positive for malaria. Children below 5 years had the highest prevalence (40.7%. The number of confirmed cases was highest from June to August (peak rainy season. Malaria prevalence was higher in males (25.3% than in females (23.2%. Malaria prevalence increased in THD from 26.7% in 2010 to 30.7% in 2011 but dropped to 22.7% in 2012 and then increased in 2013 to 29.5%. There was an overall drop in the total number of confirmed malaria cases in 2012; this decrease was significant in Ebonji (p<0.001 and Nyasoso (p<0.015 health areas. The distribution of LLINs led to a short lived reduction in malaria prevalence in THD. LLIN distribution and other control activities should be reinforced to keep malaria prevalence low especially among the 0–5-year group.

  11. The impact of pyrethroid resistance on the efficacy of insecticide-treated bed nets against African anopheline mosquitoes: systematic review and meta-analysis.

    Directory of Open Access Journals (Sweden)

    Clare Strode

    2014-03-01

    Full Text Available Pyrethroid insecticide-treated bed nets (ITNs help contribute to reducing malaria deaths in Africa, but their efficacy is threatened by insecticide resistance in some malaria mosquito vectors. We therefore assessed the evidence that resistance is attenuating the effect of ITNs on entomological outcomes.We included laboratory and field studies of African malaria vectors that measured resistance at the time of the study and used World Health Organization-recommended impregnation regimens. We reported mosquito mortality, blood feeding, induced exophily (premature exit of mosquitoes from the hut, deterrence, time to 50% or 95% knock-down, and percentage knock-down at 60 min. Publications were searched from 1 January 1980 to 31 December 2013 using MEDLINE, Cochrane Central Register of Controlled Trials, Science Citation Index Expanded, Social Sciences Citation Index, African Index Medicus, and CAB Abstracts. We stratified studies into three levels of insecticide resistance, and ITNs were compared with untreated bed nets (UTNs using the risk difference (RD. Heterogeneity was explored visually and statistically. Included were 36 laboratory and 24 field studies, reported in 25 records. Studies tested and reported resistance inconsistently. Based on the meta-analytic results, the difference in mosquito mortality risk for ITNs compared to UTNs was lower in higher resistance categories. However, mortality risk was significantly higher for ITNs compared to UTNs regardless of resistance. For cone tests: low resistance, risk difference (RD 0.86 (95% CI 0.72 to 1.01; moderate resistance, RD 0.71 (95% CI 0.53 to 0.88; high resistance, RD 0.56 (95% CI 0.17 to 0.95. For tunnel tests: low resistance, RD 0.74 (95% CI 0.61 to 0.87; moderate resistance, RD 0.50 (95% CI 0.40 to 0.60; high resistance, RD 0.39 (95% CI 0.24 to 0.54. For hut studies: low resistance, RD 0.56 (95% CI 0.43 to 0.68; moderate resistance, RD 0.39 (95% CI 0.16 to 0.61; high resistance, RD 0

  12. Windows .NET Network Distributed Basic Local Alignment Search Toolkit (W.ND-BLAST

    Directory of Open Access Journals (Sweden)

    Oliver Melvin J

    2005-04-01

    Full Text Available Abstract Background BLAST is one of the most common and useful tools for Genetic Research. This paper describes a software application we have termed Windows .NET Distributed Basic Local Alignment Search Toolkit (W.ND-BLAST, which enhances the BLAST utility by improving usability, fault recovery, and scalability in a Windows desktop environment. Our goal was to develop an easy to use, fault tolerant, high-throughput BLAST solution that incorporates a comprehensive BLAST result viewer with curation and annotation functionality. Results W.ND-BLAST is a comprehensive Windows-based software toolkit that targets researchers, including those with minimal computer skills, and provides the ability increase the performance of BLAST by distributing BLAST queries to any number of Windows based machines across local area networks (LAN. W.ND-BLAST provides intuitive Graphic User Interfaces (GUI for BLAST database creation, BLAST execution, BLAST output evaluation and BLAST result exportation. This software also provides several layers of fault tolerance and fault recovery to prevent loss of data if nodes or master machines fail. This paper lays out the functionality of W.ND-BLAST. W.ND-BLAST displays close to 100% performance efficiency when distributing tasks to 12 remote computers of the same performance class. A high throughput BLAST job which took 662.68 minutes (11 hours on one average machine was completed in 44.97 minutes when distributed to 17 nodes, which included lower performance class machines. Finally, there is a comprehensive high-throughput BLAST Output Viewer (BOV and Annotation Engine components, which provides comprehensive exportation of BLAST hits to text files, annotated fasta files, tables, or association files. Conclusion W.ND-BLAST provides an interactive tool that allows scientists to easily utilizing their available computing resources for high throughput and comprehensive sequence analyses. The install package for W.ND-BLAST is

  13. The impact of rate design and net metering on the bill savings from distributed PV for residential customers in California

    International Nuclear Information System (INIS)

    Darghouth, Naim R.; Barbose, Galen; Wiser, Ryan

    2011-01-01

    Net metering has become a widespread mechanism in the U.S. for supporting customer adoption of distributed photovoltaics (PV), but has faced challenges as PV installations grow to a larger share of generation in a number of states. This paper examines the value of the bill savings that customers receive under net metering, and the associated role of retail rate design, based on a sample of approximately two hundred residential customers of California's two largest electric utilities. We find that the bill savings per kWh of PV electricity generated varies by more than a factor of four across the customers in the sample, which is largely attributable to the inclining block structure of the utilities' residential retail rates. We also compare the bill savings under net metering to that received under three potential alternative compensation mechanisms, based on California's Market Price Referent (MPR). We find that net metering provides significantly greater bill savings than a full MPR-based feed-in tariff, but only modestly greater savings than alternative mechanisms under which hourly or monthly net excess generation is compensated at the MPR rate. - Highlights: → We examine the value of bill savings under net metering to PV owners in California. → Bill savings per kWh of PV generation varies by a factor of four with net metering. The variation is attributable to rate design, the unique inclining block structure. → The median value of bill savings is reduced by 40-67% with MPR feed-in tariff. → The median value of bill savings is reduced by 6-12% with hourly netting.

  14. The Impacts of Changes to Nevada’s Net Metering Policy on the Financial Performance and Adoption of Distributed Photovoltaics

    Energy Technology Data Exchange (ETDEWEB)

    Gagnon, Pieter [National Renewable Energy Lab. (NREL), Golden, CO (United States); Sigrin, Ben [National Renewable Energy Lab. (NREL), Golden, CO (United States); Gleason, Mike [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2017-01-01

    Net energy metering (NEM) is a billing mechanism that has historically compensated owners of distributed generation systems at retail rates for any electricity that they export back to the grid rather than consume on-site. NEM can significantly enhance the financial performance of distributed generation systems from the owner’s perspective. The following analysis was designed to illustrate the potential impact of NEM policy and tariff changes implemented in early 2016 in Nevada.

  15. Sulfadoxine-Pyrimethamine-Based Intermittent Preventive Treatment, Bed Net Use, and Antenatal Care during Pregnancy: Demographic Trends and Impact on the Health of Newborns in the Kassena Nankana District, Northeastern Ghana

    Science.gov (United States)

    2010-01-01

    all children less than five years of age and for pregnant and nursing women. Design. This study was a prospective cohort study in which pregnant...during 2003.7 Similarly, bed net use during pregnancy, which was reported by 29% of 102 nursing and pregnant women sur- veyed in 2000, increased...malarious area of Malawi. Ann Trap Paediatr 24: 311-321. 27. Uneke CJ, I yare FE, Sunday-Adeoye H. Ajayi JA, 2008. Evalua- tion of maternal malaria at

  16. TosNet: An easy-to-use, real-time communications protocol for modular, distributed robot controllers

    DEFF Research Database (Denmark)

    Falsig, Simon; Sørensen, Anders Stengaard

    2009-01-01

    Net supports up to 15 nodes, with cycle-rates up to 25 kHz, depending on the configuration. The protocol stack is completely specified as VHDL code, implemented in an FPGA. The physical layer is implemented with Toslink fiberoptic links, offering a compact, robust and highly available link technology......This paper presents the TosNet network, created for robotics research, education, and prototyping, emphasizing ease of use, robustness, compactness, flexibility and fast hard realtime response, to allow distribution of all levels of the robot control system. The current implementation of Tos...

  17. Biomonitors and the assessment of ecological impacts: Distribution of herbivorous epifauna in contaminated macroalgal beds

    International Nuclear Information System (INIS)

    Roberts, David A.; Johnston, Emma L.; Poore, Alistair G.B.

    2008-01-01

    We determined metal contents of co-occurring algae Padina crassa and Sargassum sp. in Port Jackson (Australia), and relationships between metal levels and the abundance of epifaunal amphipods. Copper, lead and zinc concentrations were amongst the highest yet recorded in these algae. Copper, manganese and lead concentrations were far greater in P. crassa than Sargassum sp., possibly due to the low growth of P. crassa in proximity to contaminated sediments. However, in manipulative experiments the proximity of algae to sediments did not explain these differences. The abundance of herbivorous amphipods correlated negatively with the copper content of P. crassa, but not with the lower concentrations in Sargassum sp. The greater contamination of P. crassa led to patchy distributions of metals in algal beds and recolonisation experiments showed Sargassum sp. acts as a refuge from contaminants for epifauna. The contamination of macroalgae may pose threats to epifauna in harbours around the world. - The accumulation of metals by macroalgae may pose ecological threats to herbivorous epifauna in ports and harbours worldwide

  18. Bed turbulent kinetic energy boundary conditions for trapping efficiency and spatial distribution of sediments in basins.

    Science.gov (United States)

    Isenmann, Gilles; Dufresne, Matthieu; Vazquez, José; Mose, Robert

    2017-10-01

    The purpose of this study is to develop and validate a numerical tool for evaluating the performance of a settling basin regarding the trapping of suspended matter. The Euler-Lagrange approach was chosen to model the flow and sediment transport. The numerical model developed relies on the open source library OpenFOAM ® , enhanced with new particle/wall interaction conditions to limit sediment deposition in zones with favourable hydrodynamic conditions (shear stress, turbulent kinetic energy). In particular, a new relation is proposed for calculating the turbulent kinetic energy threshold as a function of the properties of each particle (diameter and density). The numerical model is compared to three experimental datasets taken from the literature and collected for scale models of basins. The comparison of the numerical and experimental results permits concluding on the model's capacity to predict the trapping of particles in a settling basin with an absolute error in the region of 5% when the sediment depositions occur over the entire bed. In the case of sediment depositions localised in preferential zones, their distribution is reproduced well by the model and trapping efficiency is evaluated with an absolute error in the region of 10% (excluding cases of particles with very low density).

  19. Probability distributions of bed load particle velocities, accelerations, hop distances, and travel times informed by Jaynes's principle of maximum entropy

    Science.gov (United States)

    Furbish, David; Schmeeckle, Mark; Schumer, Rina; Fathel, Siobhan

    2016-01-01

    We describe the most likely forms of the probability distributions of bed load particle velocities, accelerations, hop distances, and travel times, in a manner that formally appeals to inferential statistics while honoring mechanical and kinematic constraints imposed by equilibrium transport conditions. The analysis is based on E. Jaynes's elaboration of the implications of the similarity between the Gibbs entropy in statistical mechanics and the Shannon entropy in information theory. By maximizing the information entropy of a distribution subject to known constraints on its moments, our choice of the form of the distribution is unbiased. The analysis suggests that particle velocities and travel times are exponentially distributed and that particle accelerations follow a Laplace distribution with zero mean. Particle hop distances, viewed alone, ought to be distributed exponentially. However, the covariance between hop distances and travel times precludes this result. Instead, the covariance structure suggests that hop distances follow a Weibull distribution. These distributions are consistent with high-resolution measurements obtained from high-speed imaging of bed load particle motions. The analysis brings us closer to choosing distributions based on our mechanical insight.

  20. Spatial distribution of impacts to channel bed mobility due to flow regulation, Kootenai River, USA

    Science.gov (United States)

    Michael Burke; Klaus Jorde; John M. Buffington; Jeffrey H. Braatne; Rohan Benjakar

    2006-01-01

    The regulated hydrograph of the Kootenai River between Libby Dam and Kootenay Lake has altered the natural flow regime, resulting in a significant decrease in maximum flows (60% net reduction in median 1-day annual maximum, and 77%-84% net reductions in median monthly flows for the historic peak flow months of May and June, respectively). Other key hydrologic...

  1. A graphical user interface (GUI) toolkit for the calculation of three-dimensional (3D) multi-phase biological effective dose (BED) distributions including statistical analyses.

    Science.gov (United States)

    Kauweloa, Kevin I; Gutierrez, Alonso N; Stathakis, Sotirios; Papanikolaou, Niko; Mavroidis, Panayiotis

    2016-07-01

    A toolkit has been developed for calculating the 3-dimensional biological effective dose (BED) distributions in multi-phase, external beam radiotherapy treatments such as those applied in liver stereotactic body radiation therapy (SBRT) and in multi-prescription treatments. This toolkit also provides a wide range of statistical results related to dose and BED distributions. MATLAB 2010a, version 7.10 was used to create this GUI toolkit. The input data consist of the dose distribution matrices, organ contour coordinates, and treatment planning parameters from the treatment planning system (TPS). The toolkit has the capability of calculating the multi-phase BED distributions using different formulas (denoted as true and approximate). Following the calculations of the BED distributions, the dose and BED distributions can be viewed in different projections (e.g. coronal, sagittal and transverse). The different elements of this toolkit are presented and the important steps for the execution of its calculations are illustrated. The toolkit is applied on brain, head & neck and prostate cancer patients, who received primary and boost phases in order to demonstrate its capability in calculating BED distributions, as well as measuring the inaccuracy and imprecision of the approximate BED distributions. Finally, the clinical situations in which the use of the present toolkit would have a significant clinical impact are indicated. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  2. Atmospheric volatilization and distribution of (Z)- and (E)-1,3-dichloropropene in field beds with and without plastic covers.

    Science.gov (United States)

    Thomas, John E; Allen, L Hartwell; McCormack, Leslie A; Vu, Joseph C; Dickson, Donald W; Ou, Li-Tse

    2004-01-01

    The fumigant 1,3-dichloropropene (1,3-D) is considered to be a potential replacement for methyl bromide when methyl bromide is phased out in 2005. This study on surface emissions and subsurface diffusion of 1,3-D in a Florida sandy soil was conducted in field beds with or without plastic covers. After injection of the commercial fumigant Telone II by conventional chisels to field beds at 30cm depth which were covered with polyethylene film (PE), virtually impermeable film, or no cover (bare), (Z)- and (E)-1,3-D rapidly diffused upward. Twenty hours after injection, majority of (Z)- and (E)-1,3-D had moved upward from 30 cm depth to the layer of 5-20 cm depth. Downward movement of the two isomers in the beds with or without a plastic cover was not significant. (Z)-1,3-D diffused more rapidly than (E)-1,3-D. Virtually impermeable films (VIF) had a good capacity to retain (Z)- and (E)-1,3-D in soil pore air space. Vapor concentrations of the two isomers in the shallow subsurface of the field bed covered with VIF were greater than that in the two beds covered with polyethylene film (PE) or no cover (bare). In addition, VIF cover provided more uniform distribution of (Z)- and (E)-1,3-D in shallow subsurface than PE cover or no cover. Virtually impermeable film also had a better capability to retard surface emissions of the two isomers from soil in field beds than PE cover or no cover.

  3. Seasonal distribution of dissolved inorganic carbon and net community production on the Bering Sea shelf

    Directory of Open Access Journals (Sweden)

    J. T. Mathis

    2010-05-01

    Full Text Available In order to assess the current state of net community production (NCP in the southeastern Bering Sea, we measured the spatio-temporal distribution and controls on dissolved inorganic carbon (DIC concentrations in spring and summer of 2008 across six shelf domains defined by differing biogeochemical characteristics. DIC concentrations were tightly coupled to salinity in spring and ranged from ~1900 μmoles kg−1 over the inner shelf to ~2400 μmoles kg−1 in the deeper waters of the Bering Sea. In summer, DIC concentrations were lower due to dilution from sea ice melt, terrestrial inputs, and primary production. Concentrations were found to be as low ~1800 μmoles kg−1 over the inner shelf. We found that DIC concentrations were drawn down 30–150 μmoles kg−1 in the upper 30 m of the water column due to primary production and calcium carbonate formation between the spring and summer occupations. Using the seasonal drawdown of DIC, estimated rates of NCP on the inner, middle, and outer shelf averaged 28 ± 9 mmoles C m−2 d−1. However, higher rates of NCP (40–47 mmoles C m−2 d−1 were observed in the "Green Belt" where the greatest confluence of nutrient-rich basin water and iron-rich shelf water occurs. We estimated that in 2008, total NCP across the shelf was on the order of ~96 Tg C yr−1. Due to the paucity of consistent, comparable productivity data, it is impossible at this time to quantify whether the system is becoming more or less productive. However, as changing climate continues to modify the character of the Bering Sea, we have shown that NCP can be an important indicator of how the ecosystem is functioning.

  4. The Spatial Distribution of Bed Sediment on Fluvial System: A Mini Review of the Aceh Meandering River

    Directory of Open Access Journals (Sweden)

    Muhammad Irham

    2016-08-01

    Full Text Available Dynamic interactions of hydrological and geomorphological processes in the fluvial system result in accumulated deposit on the bed because the capacity to carry sediment has been exceeded. The bed load of the Aceh fluvial system is primarily generated by mechanical weathering resulting in boulders, pebbles, and sand, which roll or bounce along the river bed forming temporary deposits as bars on the insides of meander bends, as a result of a loss of transport energy in the system. This dynamic controls the style and range of deposits in the Aceh River. This study focuses on the spatial distribution of bed-load transport of the Aceh River. Understanding the spatial distribution of deposits facilitates the reconstruction of the changes in controlling factors during accumulation of deposits. One of the methods can be done by sieve analysis of sediment, where the method illuminates the distribution of sediment changes associated with channel morphology under different flow regimes. Hence, the purpose of this mini review is to investigate how the sediment along the river meander spatially dispersed. The results demonstrate that channel deposits in the Aceh River are formed from four different type of materials: pebble deposited along upstream left bank; sand located on the upstream, downstream, and along meander belts; and silt and clay located along the cut bank of meander bends. Because of different depositional pattern, the distribution of the sediment along the river can be used as a surrogate to identify bank stability, as well as to predict critical geometry for meander bend initiation

  5. Net Metering and Market Feedback Loops: Exploring the Impact of Retail Rate Design on Distributed PV Deployment

    Energy Technology Data Exchange (ETDEWEB)

    Darghouth, Naïm R. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Wiser, Ryan [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Barbose, Galen [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Mills, Andrew [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2015-01-13

    The substantial increase in deployment of customer-sited solar photovoltaics (PV) in the United States has been driven by a combination of steeply declining costs, financing innovations, and supportive policies. Among those supportive policies is net metering, which in most states effectively allows customers to receive compensation for distributed PV generation at the full retail electricity price. The current design of retail electricity rates and the presence of net metering have elicited concerns that the possible under-recovery of fixed utility costs from PV system owners may lead to a feedback loop of increasing retail prices that accelerate PV adoption and further rate increases. However, a separate and opposing feedback loop could offset this effect: increased PV deployment may lead to a shift in the timing of peak-period electricity prices that could reduce the bill savings received under net metering where time-varying retail electricity rates are used, thereby dampening further PV adoption. In this paper, we examine the impacts of these two competing feedback dynamics on U.S. distributed PV deployment through 2050 for both residential and commercial customers, across states. Our results indicate that, at the aggregate national level, the two feedback effects nearly offset one another and therefore produce a modest net effect, although their magnitude and direction vary by customer segment and by state. We also model aggregate PV deployment trends under various rate designs and net-metering rules, accounting for feedback dynamics. Our results demonstrate that future adoption of distributed PV is highly sensitive to retail rate structures. Whereas flat, time-invariant rates with net metering lead to higher aggregate national deployment levels than the current mix of rate structures (+5% in 2050), rate structures with higher monthly fixed customer charges or PV compensation at levels lower than the full retail rate can dramatically erode aggregate customer

  6. Sampling surface and subsurface particle-size distributions in wadable gravel-and cobble-bed streams for analyses in sediment transport, hydraulics, and streambed monitoring

    Science.gov (United States)

    Kristin Bunte; Steven R. Abt

    2001-01-01

    This document provides guidance for sampling surface and subsurface sediment from wadable gravel-and cobble-bed streams. After a short introduction to streams types and classifications in gravel-bed rivers, the document explains the field and laboratory measurement of particle sizes and the statistical analysis of particle-size distributions. Analysis of particle...

  7. Mathematical evaluation of community level impact of combining bed nets and indoor residual spraying upon malaria transmission in areas where the main vectors are Anopheles arabiensis mosquitoes

    Directory of Open Access Journals (Sweden)

    Okumu Fredros O

    2013-01-01

    Full Text Available Abstract Background Indoor residual insecticide spraying (IRS and long-lasting insecticide treated nets (LLINs are commonly used together even though evidence that such combinations confer greater protection against malaria than either method alone is inconsistent. Methods A deterministic model of mosquito life cycle processes was adapted to allow parameterization with results from experimental hut trials of various combinations of untreated nets or LLINs (Olyset®, PermaNet 2.0®, Icon Life® nets with IRS (pirimiphos methyl, lambda cyhalothrin, DDT, in a setting where vector populations are dominated by Anopheles arabiensis, so that community level impact upon malaria transmission at high coverage could be predicted. Results Intact untreated nets alone provide equivalent personal protection to all three LLINs. Relative to IRS plus untreated nets, community level protection is slightly higher when Olyset® or PermaNet 2.0® nets are added onto IRS with pirimiphos methyl or lambda cyhalothrin but not DDT, and when Icon Life® nets supplement any of the IRS insecticides. Adding IRS onto any net modestly enhances communal protection when pirimiphos methyl is sprayed, while spraying lambda cyhalothrin enhances protection for untreated nets but not LLINs. Addition of DDT reduces communal protection when added to LLINs. Conclusions Where transmission is mediated primarily by An. arabiensis, adding IRS to high LLIN coverage provides only modest incremental benefit (e.g. when an organophosphate like pirimiphos methyl is used, but can be redundant (e.g. when a pyrethroid like lambda cyhalothin is used or even regressive (e.g. when DDT is used for the IRS. Relative to IRS plus untreated nets, supplementing IRS with LLINs will only modestly improve community protection. Beyond the physical protection that intact nets provide, additional protection against transmission by An. arabiensis conferred by insecticides will be remarkably small, regardless of

  8. SeaDataNet - Pan-European infrastructure for marine and ocean data management: Unified access to distributed data sets

    Science.gov (United States)

    Schaap, D. M. A.; Maudire, G.

    2009-04-01

    SeaDataNet is an Integrated research Infrastructure Initiative (I3) in EU FP6 (2006 - 2011) to provide the data management system adapted both to the fragmented observation system and the users need for an integrated access to data, meta-data, products and services. Therefore SeaDataNet insures the long term archiving of the large number of multidisciplinary data (i.e. temperature, salinity current, sea level, chemical, physical and biological properties) collected by many different sensors installed on board of research vessels, satellite and the various platforms of the marine observing system. The SeaDataNet project started in 2006, but builds upon earlier data management infrastructure projects, undertaken over a period of 20 years by an expanding network of oceanographic data centres from the countries around all European seas. Its predecessor project Sea-Search had a strict focus on metadata. SeaDataNet maintains significant interest in the further development of the metadata infrastructure, but its primary objective is the provision of easy data access and generic data products. SeaDataNet is a distributed infrastructure that provides transnational access to marine data, meta-data, products and services through 40 interconnected Trans National Data Access Platforms (TAP) from 35 countries around the Black Sea, Mediterranean, North East Atlantic, North Sea, Baltic and Arctic regions. These include: National Oceanographic Data Centres (NODC's) Satellite Data Centres. Furthermore the SeaDataNet consortium comprises a number of expert modelling centres, SME's experts in IT, and 3 international bodies (ICES, IOC and JRC). Planning: The SeaDataNet project is delivering and operating the infrastructure in 3 versions: Version 0: maintenance and further development of the metadata systems developed by the Sea-Search project plus the development of a new metadata system for indexing and accessing to individual data objects managed by the SeaDataNet data centres. This

  9. MPL-Net Measurements of Aerosol and Cloud Vertical Distributions at Co-Located AERONET Sites

    Science.gov (United States)

    Welton, Ellsworth J.; Campbell, James R.; Berkoff, Timothy A.; Spinhirne, James D.; Tsay, Si-Chee; Holben, Brent; Starr, David OC. (Technical Monitor)

    2002-01-01

    In the early 1990s, the first small, eye-safe, and autonomous lidar system was developed, the Micropulse Lidar (MPL). The MPL acquires signal profiles of backscattered laser light from aerosols and clouds. The signals are analyzed to yield multiple layer heights, optical depths of each layer, average extinction-to-backscatter ratios for each layer, and profiles of extinction in each layer. In 2000, several MPL sites were organized into a coordinated network, called MPL-Net, by the Cloud and Aerosol Lidar Group at NASA Goddard Space Flight Center (GSFC) using funding provided by the NASA Earth Observing System. tn addition to the funding provided by NASA EOS, the NASA CERES Ground Validation Group supplied four MPL systems to the project, and the NASA TOMS group contributed their MPL for work at GSFC. The Atmospheric Radiation Measurement Program (ARM) also agreed to make their data available to the MPL-Net project for processing. In addition to the initial NASA and ARM operated sites, several other independent research groups have also expressed interest in joining the network using their own instruments. Finally, a limited amount of EOS funding was set aside to participate in various field experiments each year. The NASA Sensor Intercomparison and Merger for Biological and Interdisciplinary Oceanic Studies (SIMBIOS) project also provides funds to deploy their MPL during ocean research cruises. All together, the MPL-Net project has participated in four major field experiments since 2000. Most MPL-Net sites and field experiment locations are also co-located with sunphotometers in the NASA Aerosol Robotic Network. (AERONET). Therefore, at these locations data is collected on both aerosol and cloud vertical structure as well as column optical depth and sky radiance. Real-time data products are now available from most MPL-Net sites. Our real-time products are generated at times of AERONET aerosol optical depth (AOD) measurements. The AERONET AOD is used as input to our

  10. Distribution of volatile sulphur containing products during fixed bed pyrolysis and gasification of coals

    Energy Technology Data Exchange (ETDEWEB)

    Furimsky, E.

    1991-08-01

    Various coals were used to study the evolution of H{sub 2}S COS, and SO{sub 2} in a fixed bed reactor. For all types of coal, most of H{sub 2}S and SO{sub 2} were released during the devolatilization stage. COS was formed only during the gasification stage in the presence of CO{sub 2}.

  11. Malaria prevalence, anemia and baseline intervention coverage prior to mass net distributions in Abia and Plateau States, Nigeria.

    Science.gov (United States)

    Noland, Gregory S; Graves, Patricia M; Sallau, Adamu; Eigege, Abel; Emukah, Emmanuel; Patterson, Amy E; Ajiji, Joseph; Okorofor, Iheanyichi; Oji, Oji Uka; Umar, Mary; Alphonsus, Kal; Damen, James; Ngondi, Jeremiah; Ozaki, Masayo; Cromwell, Elizabeth; Obiezu, Josephine; Eneiramo, Solomon; Okoro, Chinyere; McClintic-Doyle, Renn; Oresanya, Olusola; Miri, Emmanuel; Emerson, Paul M; Richards, Frank O

    2014-03-26

    Nigeria suffers the world's largest malaria burden, with approximately 51 million cases and 207,000 deaths annually. As part of the country's aim to reduce by 50% malaria-related morbidity and mortality by 2013, it embarked on mass distribution of free long-lasting insecticidal nets (LLINs). Prior to net distribution campaigns in Abia and Plateau States, Nigeria, a modified malaria indicator survey was conducted in September 2010 to determine baseline state-level estimates of Plasmodium prevalence, childhood anemia, indoor residual spraying (IRS) coverage and bednet ownership and utilization. Overall age-adjusted prevalence of Plasmodium infection by microscopy was similar between Abia (36.1%, 95% CI: 32.3%-40.1%; n = 2,936) and Plateau (36.6%, 95% CI: 31.3%-42.3%; n = 4,209), with prevalence highest among children 5-9 years. P. malariae accounted for 32.0% of infections in Abia, but only 1.4% of infections in Plateau. More than half of children ≤10 years were anemic, with anemia significantly higher in Abia (76.9%, 95% CI: 72.1%-81.0%) versus Plateau (57.1%, 95% CI: 50.6%-63.4%). Less than 1% of households in Abia (n = 1,305) or Plateau (n = 1,335) received IRS in the 12 months prior to survey. Household ownership of at least one bednet of any type was 10.1% (95% CI: 7.5%-13.4%) in Abia and 35.1% (95% CI: 29.2%-41.5%) in Plateau. Ownership of two or more bednets was 2.1% (95% CI: 1.2%-3.7%) in Abia and 14.5% (95% CI: 10.2%-20.3%) in Plateau. Overall reported net use the night before the survey among all individuals, children Abia and 14.7%, 19.1% and 21.0%, respectively in Plateau. Among households owning nets, 34.4% of children Abia used a net, compared to 52.6% of children and 62.7% of pregnant women in Plateau. These results reveal high Plasmodium prevalence and childhood anemia in both states, low baseline coverage of IRS and LLINs, and sub-optimal net use-especially among age groups with highest observed malaria burden.

  12. The East Africa Oligocene intertrappean beds: Regional distribution, depositional environments and Afro/Arabian mammal dispersals

    Science.gov (United States)

    Abbate, Ernesto; Bruni, Piero; Ferretti, Marco Peter; Delmer, Cyrille; Laurenzi, Marinella Ada; Hagos, Miruts; Bedri, Omar; Rook, Lorenzo; Sagri, Mario; Libsekal, Yosief

    2014-11-01

    The extensive outpouring of the Oligocene Trap basalts over eastern Africa and western Arabia was interrupted by a period of quiescence marked by the deposition of terrestrial sediments. These so-called intertrappean beds are often lignitiferous and yield recurrent floras and faunas, sometimes represented by endemic mammals. We intended to highlight the peculiar features of these sedimentary intercalations using a large-scale approach including eastern Africa and the western Arabian peninsula. Starting from a new mapping in the Eritrean highland, the intertrappean beds resulted a continuous level that was a few tens of meters thick and traceable for some tens of kilometers. They consist of fluvial red, green and gray mudstones and siltstones with subordinate channelized pebbly sandstones, and lignite seams. Two new 40Ar-39Ar datings constraint the age of the intertrappean beds between 29.0 Ma and 23.6 Ma. The outcrops near Mendefera have yielded the remains of two proboscidean families, the Deinotheriidae and the Gomphoteriidae. The morphological grade of the two Mendefera proboscideans would suggest a more derived stage than that of representatives of the same families from other Oligocene African sites (e.g., Chilga, Ethiopia). An Oligocene age could be inferred for them. The occurrence of the genus Prodeinotherium at Mai Gobro possibly represents the first occurrence of this taxon, while the Gomphotheirum sp. might represent the oldest occurrence of this taxon in Africa before its dispersal towards Asia and Europe. Proboscideans have also been found in the lowland intertrappean beds of Dogali near Massawa. These sediments were contiguous with the Eritrean highland intertrappean beds during the Oligocene, but are now tectonically displaced from them by two thousand meters of vertical topographical distance. Dogali is also known for the occurrence of possible Deinotheriidae remains and the primitive elephantoid Eritreum. Entering the Ethiopian highland, an

  13. Use of antenatal care, maternity services, intermittent presumptive treatment and insecticide treated bed nets by pregnant women in Luwero district, Uganda

    Directory of Open Access Journals (Sweden)

    Mufubenga Patrobas

    2008-03-01

    Full Text Available Abstract Background To reduce the intolerable burden of malaria in pregnancy, the Ministry of Health in Uganda improved the antenatal care package by including a strong commitment to increase distribution of insecticide-treated nets (ITNs and introduction of intermittent preventive treatment with sulphadoxine-pyrimethamine for pregnant women (IPTp-SP as a national policy in 2000. This study assessed uptake of both ITNs and IPTp-SP by pregnant women as well as antenatal and maternity care use with the aim of optimizing their delivery. Methods 769 post-partum women were recruited from a rural area of central Uganda with perennial malaria transmission through a cross-sectional, community-based household survey in May 2005. Results Of the 769 women interviewed, antenatal clinic (ANC attendance was high (94.4%; 417 (57.7% visiting initially during the 2nd trimester, 242 (33.5% during the 3rd trimester and 266 (37.1% reporting ≥ 4 ANC visits. About 537 (71% and 272 (35.8% received one or ≥ 2 IPTp-SP doses respectively. Only 85 (15.8% received the first dose of IPTp-SP in the 3rd trimester. ITNs were used by 239 (31.3% of women during pregnancy and 314 (40.8% delivered their most recent pregnancy outside a health facility. Post-partum women who lacked post-primary education were more likely not to have attended four or more ANC visits (odds ratio [OR] 3.3, 95% confidence interval [CI] 1.2–9.3. Conclusion These findings illustrate the need to strengthen capacity of the district to further improve antenatal care and maternity services utilization and IPTp-SP uptake. More specific and effective community health strategies to improve effective ANC, maternity services utilization and IPTp-SP uptake in rural communities should be undertaken.

  14. Effect of untreated bed nets on blood-fed Phlebotomus argentipes in kala-azar endemic foci in Nepal and India.

    Science.gov (United States)

    Picado, Albert; Kumar, Vijay; Das, Murari; Burniston, Ian; Roy, Lalita; Suman, Rijal; Dinesh, Diwakar; Coosemans, Marc; Sundar, Shyam; Shreekant, Kesari; Boelaert, Marleen; Davies, Clive; Cameron, Mary

    2009-12-01

    Observational studies in the Indian subcontinent have shown that untreated nets may be protective against visceral leishmaniasis (VL). In this study, we evaluated the effect of untreated nets on the blood feeding rates of Phlebotomus argentipes as well as the human blood index (HBI) in VL endemic villages in India and Nepal. The study had a 'before and after intervention' design in 58 households in six clusters. The use of untreated nets reduced the blood feeding rate by 85% (95% CI 76.5-91.1%) and the HBI by 42.2% (95% CI 11.1-62.5%). These results provide circumstantial evidence that untreated nets may provide some degree of personal protection against sand fly bites.

  15. Simulation of distribution nets for natural gas, in stationary state considering the compressible effects

    International Nuclear Information System (INIS)

    Valbuena C, Javier

    1997-01-01

    The general method is presented to calculate the losses of pressure in a RTD starting from the geometry of the net (diameter and longitude), of the real behavior of the gas, of the ruggedness of the pipe and of the flow, considering the compressibility of the fluid so much as the influence of the compressible effects. The simulation method is derived of the principles of conservation of mass and energy for a gas that follows a reversible poly tropic process of stable state and stable flow - stationary regime

  16. Baixa aderência e alto custo como fatores de insucesso do uso de mosquiteiros impregnados com inseticida no controle da malária na Amazônia Brasileira Low adherence and high cost as failure factors of impregnated bed nets with insecticide for malaria control in the Brazilian Amazon

    Directory of Open Access Journals (Sweden)

    João Barberino Santos

    1999-08-01

    Full Text Available Em 1992, durante um ensaio com mosquiteiros impregnados com deltametrina, conduzido em Porto Murtinho, município de Costa Marques, Rondônia, na Amazônia Brasileira, analisou-se a aderência e os fatores econômicos capazes de reduzir o impacto do uso de mosquiteiros impregnados sobre a morbidade da malária. Os mosquiteiros impregnados tiveram excelente receptividade pela população local. No entanto, a aderência foi muito baixa, principalmente pelos adultos maiores de 15 anos de idade e, durante a estiagem. O preço do mosquiteiro impregnado foi calculado em US$18,83 para casal e, em US$13,82, para solteiro. Apesar das vantagens econômicas do emprego dos mosquiteiros impregnados em larga escala, desde que subsidiados pelas agências governamentais, a baixa aderência verificada, aliada aos fatores epidemiológicos locais, não permitem indicar o uso de mosquiteiros impregnados como medida de proteção em massa na Amazônia.In 1992 during a trial with deltamethrin-impregnated bed nets conducted in Porto Murtinho, municipality of Costa Marques, Rondonia, in the Brazilian Amazon, we investigated community compliance and the economic aspects capable of reducing the impact of this intervention on malaria morbidity. Impregnated bed nets were well accepted by the local population. However, compliance was found to be very low among adults over 15 years of age and mainly during the dry season. The cost of impregnated bed nets was US$18.83 for double-bed nets and US$13.82 for single bed nets. Despite the economic advantages of using impregnated bed nets subsidized by the government, the low compliance and local epidemiological factors do not allow to indicate the use of impregnated bed nets for mass malaria control in the Amazon region.

  17. The distribution over time of costs and social net benefits for pertussis immunization programs.

    Science.gov (United States)

    Girard, Dorota Zdanowska

    2010-03-01

    The cost of a six-dose pertussis immunization programs for children and adolescents is investigated in relation to estimators of the price of acellular vaccine, the value of a child's life, levels of vaccination rate and discount rates. We compare the cost of the program maintained over time at 90% with three alternative strategies, each involving a decrease in vaccination coverage. Data from England and Wales, 1966-2005, is used to formalize a delay in occurrence of pertussis cases as a result of a fall in coverage. We first apply the criterion of minimization of the total social cost of pertussis to identify the best cost saving immunization strategy. The results are also discussed in form of the discounted present value of the total social net benefits. We find that the discounted present value of the total social net benefit is maximized when a stable vaccination program at 90% is compared to a gradual decrease in vaccination coverage leading to the lowest vaccination rate. The benefits to society of providing sustained immunization strategy, vaccinating the highest proportion of children and adolescents, are systematically proved on the basis of the second optimisation criterion, independently of the level of estimators applied during economic evaluation for the cost variables.

  18. Netting the malaria menace: Distribution and utilization of long-lasting insecticidal net in a malaria endemic area in Bankura, West Bengal.

    Science.gov (United States)

    Mukhopadhyay, D K; Basu, S S; Roy, D; Das, N; Akbar, F; Sarkar, G N

    2016-03-01

    Long-lasting insecticidal net (LLIN) is considered to be a highly effective intervention against malaria under National Vector Borne Disease Control Programme in India. A cross-sectional study was undertaken to assess the coverage and utilization of LLIN and the factors related thereto. A survey of 1300 households was carried out in Ranibandh block of Bankura district in West Bengal, India, using lot quality assurance sampling (LQAS) method. Coverage/utilization of 80% was considered as minimum acceptable norm. The weighted sample size was calculated from each village of the block. The sociodemographic, economic information of the household along with the availability and use of LLIN was collected through interview and observation. In total, 7320 individuals including 840 children ≤ 5 yr were visited. Overall coverage of adequate LLIN was 65.4% (± 1.5%) and for children ≤ 5 yr, it was 60.5% (± 1.3%). Overall, 66.1% (± 1.4%) people of all ages and 63.7% (± 1.4%) children ≤ 5 yr slept under LLINs in the night before the survey. Out of 26 sub-centres, distribution of LLINs in 10 sub-centres was below the accepted norm, whereas utilization was sub-optimal in 19 sub-centres. In only 18.2% (± 0.5%) households, LLINs remained hanging during daytime. Poverty, caste, education, perception regarding malarial morbidity and preventive action of LLIN were associated significantly with the distribution of LLIN. Similarly, poverty (AOR = 2.14), threat perception regarding malarial morbidity (AOR = 1.51) and mortality (AOR = 2.52) were positively associated with the use of LLIN. Full utilization of bednets by under-fives of the households was higher in villages with sub-centres. Around two-third population of the study area was effectively covered with LLIN. Higher proportion of socially marginalized people received LLIN. Threat perception regarding malaria was directly associated with both receipt and use of LLIN. Behaviour change communication on utilization along

  19. RESTful NET

    CERN Document Server

    Flanders, Jon

    2008-01-01

    RESTful .NET is the first book that teaches Windows developers to build RESTful web services using the latest Microsoft tools. Written by Windows Communication Foundation (WFC) expert Jon Flanders, this hands-on tutorial demonstrates how you can use WCF and other components of the .NET 3.5 Framework to build, deploy and use REST-based web services in a variety of application scenarios. RESTful architecture offers a simpler approach to building web services than SOAP, SOA, and the cumbersome WS- stack. And WCF has proven to be a flexible technology for building distributed systems not necessa

  20. Comparison of net photosynthetic rate and 14C distribution between different cultural conditions on double cropping rice

    International Nuclear Information System (INIS)

    Huang Jianliang; Li Hesong; Zou Yingbin; Tu Naimei; Li Jianhui

    2002-01-01

    By applying the cultural method 'Vigorous Root-Strong Stem-Heavy Panicle Cultural Method' (VSHM), the yield of double cropping rice reached 18000 kg/hm 2 in large area at Liling county, Hunan province. The net photosynthetic rate and 14 C distribution of rice leaves between VSHM and traditional cultural methods (CK) were compared. The photosynthetic rate of the flag leaves at ripening stages under VSHM was higher than that of controls with both earlier rice or later rice. Regarding the net amount of 14 C-assimilate by a single flag leaf and the second top leaf, there were differences at the significant level of 0.01 and 0.05, respectively between VSHM and controls, and VSHM were 7.72%-35.05% higher. The percentage of distribution at panicles of 14 C-assimilate were 51.93%-61.40% when flag leaf was labelled, and 45.34%-54.25% when the second top leaf was labelled, that of earlier rice was higher than later rice respectively, but the differences were not significant between VSHM and CK. The actual yield of double cropping rice under the cultural condition of VSHM was 17710 kg/hm 2 , and increased by 18.33% when compared with controls

  1. Distributed Processing System for Restoration of Electric Power Distribution Network Using Two-Layered Contract Net Protocol

    Science.gov (United States)

    Kodama, Yu; Hamagami, Tomoki

    Distributed processing system for restoration of electric power distribution network using two-layered CNP is proposed. The goal of this study is to develop the restoration system which adjusts to the future power network with distributed generators. The state of the art of this study is that the two-layered CNP is applied for the distributed computing environment in practical use. The two-layered CNP has two classes of agents, named field agent and operating agent in the network. In order to avoid conflicts of tasks, operating agent controls privilege for managers to send the task announcement messages in CNP. This technique realizes the coordination between agents which work asynchronously in parallel with others. Moreover, this study implements the distributed processing system using a de-fact standard multi-agent framework, JADE(Java Agent DEvelopment framework). This study conducts the simulation experiments of power distribution network restoration and compares the proposed system with the previous system. We confirmed the results show effectiveness of the proposed system.

  2. Experimental study and simulation of mass distribution of the covering layer of soybean seeds coated in a spouted bed

    Directory of Open Access Journals (Sweden)

    Duarte C. R.

    2004-01-01

    Full Text Available In previous work, it was observed that the covering of soybean seeds with bacteria and micronutrients enhances vigorous growth of the plant thereby avoiding use of ammoniacal fertilizers. In the spouted bed covering can be done by pulverization of the coater slurry on the soybean seeds using a pneumatic atomizer. The optimum thickness of the cover allows the fundamental gaseous interchanges for germination and provides the ideal conditions for bacterium activity. The objective of this work was to study the influence of the process variables on thickness of the cover. A simulation of the mass distribution of seeds was obtained using a population balance model. Through the results obtained the operational conditions under which the coating layer distribution were determined has the greatest uniformity.

  3. Willingness to pay for small solar powered bed net fans: results of a Becker-DeGroot-Marschak auction in Ghana.

    Science.gov (United States)

    Yukich, Joshua O; Briët, Olivier J T; Ahorlu, Collins K; Nardini, Peter; Keating, Joseph

    2017-08-07

    Long-lasting insecticidal nets (LLINs) are one of the main interventions recommended by the World Health Organization for malaria vector control. LLINs are ineffective if they are not being used. Subsequent to the completion of a cluster randomized cross over trial conducted in rural Greater Accra where participants were provided with the 'Bɔkɔɔ System'-a set of solar powered net fan and light consoles with a solar panel and battery-or alternative household water filters, all trial participants were invited to participate in a Becker-DeGroot-Marschak auction to determine the mean willingness to pay (WTP) for the fan and light consoles and to estimate the demand curve for the units. Results demonstraed a mean WTP of approximately 55 Cedis (~13 USD). Demand results suggested that at a price which would support full manufacturing cost recovery, a majority of households in the area would be willing to purchase at least one such unit.

  4. Flow distribution of pebble bed high temperature gas cooled reactors using large eddy simulation

    International Nuclear Information System (INIS)

    Gokhan Yesilyurt; Hassan, Y.A.

    2003-01-01

    A High Temperature Gas-cooled Reactor (HTGR) is one of the renewed reactor designs to play a role in nuclear power generation. This reactor design concepts is currently under consideration and development worldwide. Since the HTGR concept offers inherent safety, has a very flexible fuel cycle with capability to achieve high burnup levels, and provides good thermal efficiency of power plant, it can be considered for further development and improvement as a reactor concept of generation IV. The combination of coated particle fuel, inert helium gas as coolant and graphite moderated reactor makes it possible to operate at high temperature yielding a high efficiency. In this study the simulation of turbulent transport for the gas through the gaps of the spherical fuel elements (fuel pebbles) will be performed. This will help in understanding the highly three-dimensional, complex flow phenomena in pebble bed caused by flow curvature. Under these conditions, heat transfer in both laminar and turbulent flows varies noticeably around curved surfaces. Curved flows would be present in the presence of contiguous curved surfaces. In the case of a laminar flow and of an appreciable effect of thermogravitional forces, the Nusselt (Nu) number depends significantly on the curvature shape of the surface. It changes with order of 10 times. The flow passages through the gap between the fuel balls have concave and convex configurations. Here the action of the centrifugal forces manifests itself differently on convex and concave parts of the flow path (suppression or stimulation of turbulence). The flow of this type has distinctive features. In such flow there is a pressure gradient, which strongly affects the boundary layer behavior. The transition from a laminar to turbulent flow around this curved flow occurs at deferent Reynolds (Re) numbers. Consequently, noncircular curved flows as in the pebble-bed situation, in detailed local sense, is interesting to be investigated. To the

  5. Analysis and Verification of Message Sequence Charts of Distributed Systems with the Help of Coloured Petri Nets

    Directory of Open Access Journals (Sweden)

    S. A. Chernenok

    2014-01-01

    Full Text Available The standard language of message sequence charts MSC is intended to describe scenarios of object interaction. Due to their expressiveness and simplicity MSC diagrams are widely used in practice at all stages of system design and development. In particular, the MSC language is used for describing communication behavior in distributed systems and communication protocols. In this paper the method for analysis and verification of MSC and HMSC diagrams is considered. The method is based on the translation of (HMSC into coloured Petri nets. The translation algorithms cover most standard elements of the MSC including data concepts. Size estimates of the CPN which is the result of the translation are given. Properties of the resulting CPN are analyzed and verified by using the known system CPN Tools and the CPN verifier based on the known tool SPIN. The translation method has been demonstrated by the example.

  6. Development of Ada language control software for the NASA power management and distribution test bed

    Science.gov (United States)

    Wright, Ted; Mackin, Michael; Gantose, Dave

    1989-01-01

    The Ada language software developed to control the NASA Lewis Research Center's Power Management and Distribution testbed is described. The testbed is a reduced-scale prototype of the electric power system to be used on space station Freedom. It is designed to develop and test hardware and software for a 20-kHz power distribution system. The distributed, multiprocessor, testbed control system has an easy-to-use operator interface with an understandable English-text format. A simple interface for algorithm writers that uses the same commands as the operator interface is provided, encouraging interactive exploration of the system.

  7. Netting the malaria menace: Distribution and utilization of long-lasting insecticidal net in a malaria endemic area in Bankura, West Bengal

    OpenAIRE

    D K Mukhopadhyay; S S Basu; D Roy; N Das; F Akbar; GN Sarkar

    2016-01-01

    Background & objectives: Long-lasting insecticidal net (LLIN) is considered to be a highly effective intervention against malaria under National Vector Borne Disease Control Programme in India. A cross-sectional study was undertaken to assess the coverage and utilization of LLIN and the factors related thereto. Methods: A survey of 1300 households was carried out in Ranibandh block of Bankura district in West Bengal, India, using lot quality assurance sampling (LQAS) method. Coverage/util...

  8. Limestone particle attrition and size distribution in a small circulating fluidized bed

    Energy Technology Data Exchange (ETDEWEB)

    Zhongxiang Chen; John R. Grace; C. Jim Lim [University of British Columbia, Vancouver, BC (Canada). Department of Chemical and Biological Engineering

    2008-06-15

    Limestone particle attrition was investigated in a small circulating fluidized bed reactor at temperatures from 25 to 850{sup o}C, 1 atm pressure and superficial gas velocities from 4.8 to 6.2 m/s. The effects of operating time, superficial gas velocity and temperature were studied with fresh limestone. No calcination or sulfation occurred at temperatures {le} 580{sup o}C, whereas calcination and sulfation affected attrition at 850{sup o}C. Increasing the temperature (while maintaining the same superficial gas velocity) reduced attrition if there was negligible calcination. Attrition was high initially, but after about 24 h, the rate of mass change became constant. The ratio of initial mean particle diameter to that at later times increased linearly with time and with (U{sub g} - U{sub mf}){sup 2}, while decreasing exponentially with temperature, with an activation energy for fresh limestone of -4.3 kJ/mol. The attrition followed Rittinger's surface theory. The change of surface area of limestone particles was proportional to the total excess kinetic energy consumed and to the total attrition time, whereas the change of surface area decreased exponentially with increasing temperature. At 850{sup o}C, the attrition rate of calcined lime was highest, whereas the attrition rate was lowest for sulfated particles. When online impact attrition was introduced, the attrition rate was about an order of magnitude higher than without impacts. 25 refs., 14 figs., 4 tabs.

  9. Centralized and Distributed Solutions for Fast Muting Adaptation in LTE-Advanced HetNets

    DEFF Research Database (Denmark)

    Soret, Beatriz; Pedersen, Klaus I.

    2015-01-01

    Enhanced Intercell Interference Coordination (eICIC) is known to provide promising performance benefits for LTE-Advanced Heterogeneous Networks. The use of eICIC facilitates more flexible inter-layer load balancing by means of small cell Range Extension (RE) and Almost Blank Subframes (ABS). Even...... though the eICIC configuration (RE and ABS) ideally should be instantaneously adapted to follow the fluctuations of the traffic and the channel conditions over time, previous studies have focused on slow intercell coordination. In this paper, we investigate fast dynamic eICIC solutions for centralized....... Two different fast muting adaptation algorithms are derived, and it is shown how those can be appplied to both the centralized and the distributed architecture. Performance results with bursty traffic show that the fast dynamic adaptation provides significant gains, both in 5%-ile and 50%-ile user...

  10. Downflow limestone beds for treatment of net-acidic, oxic, iron-laden drainage from a flooded anthracite mine, Pennsylvania, USA: 2. Laboratory evaluation

    Science.gov (United States)

    Cravotta, C.A.; Ward, S.J.; Hammarstrom, J.M.

    2008-01-01

    Acidic mine drainage (AMD) containing elevated concentrations of dissolved iron and other metals can be neutralized to varying degrees by reactions with limestone in passive treatment systems. We evaluated the chemical and mineralogical characteristics and the effectiveness of calcitic and dolomitic limestone for the neutralization of net-acidic, oxic, iron-laden AMD from a flooded anthracite mine. The calcitic limestone, with CaCO3 and MgCO3 contents of 99.8 and treatment system in 2003 at the Bell Mine, a large source of AMD and baseflow to the Schuylkill River in the Southern Anthracite Coalfield, in east-central Pennsylvania. In the winter of 2002-2003, laboratory neutralization-rate experiments evaluated the evolution of effluent quality during 2 weeks of continuous contact between AMD from the Bell Mine and the crushed calcitic or dolomitic limestone in closed, collapsible containers (cubitainers). The cubitainer tests showed that: (1) net-alkaline effluent could be achieved with detention times greater than 3 h, (2) effluent alkalinities and associated dissolution rates were equivalent for uncoated and Fe(OH)3-coated calcitic limestone, and (3) effluent alkalinities and associated dissolution rates for dolomitic limestone were about half those for calcitic limestone. The dissolution rate data for the cubitainer tests were used with data on the volume of effuent and surface area of limestone in the treatment system at the Bell Mine to evaluate the water-quality data for the first 1.5 years of operation of the treatment system. These rate models supported the interpretation of field results and indicated that treatment benefits were derived mainly from the dissolution of calcitic limestone, despite a greater quantity of dolomitic limestone within the treatment system. The dissolution-rate models were extrapolated on a decadal scale to indicate the expected decreases in the mass of limestone and associated alkalinities resulting from the long-term reaction of

  11. A Stochastic Theory for Deep Bed Filtration Accounting for Dispersion and Size Distributions

    DEFF Research Database (Denmark)

    Shapiro, Alexander; Bedrikovetsky, P. G.

    2010-01-01

    We develop a stochastic theory for filtration of suspensions in porous media. The theory takes into account particle and pore size distributions, as well as the random character of the particle motion, which is described in the framework of the theory of continuous-time random walks (CTRW...

  12. 3D Model Studies on the Effect of Bed and Powder Type Upon Radial Static Pressure and Powder Distribution in Metallurgical Shaft Furnaces

    Directory of Open Access Journals (Sweden)

    Panic B.

    2017-09-01

    Full Text Available The flow of gases in metallurgical shaft furnaces has a decisive influence on the course and process efficiency. Radial changes in porosity of the bed cause uneven flow of gas along the radius of the reactor, which sometimes is deliberate and intentional. However, holdup of solid particles in descending packed beds of metallurgical shaft furnaces can lead to unintentional changes in porosity of the bed along the radial reactor. Unintentional changes in porosity often disrupt the flow of gas causing poor performance of the furnace. Such disruptions of flow may occur in the blast furnace due to high level of powder content in gas caused by large amount of coal dust/powder insufflated as fuel substitute. The paper describes the model test results of radial distribution of static pressure and powder hold up within metallurgical reactor. The measurements were carried out with the use of 3D physical model of two-phase flow gas-powder in the moving (descending packed bed. Sinter or blast furnace pellets were used as packed bed while carbon powder or iron powder were used as the powder. Wide diversity within both static pressure distribution and powder distribution along the radius of the reactor were observed once the change in the type of powder occurred.

  13. Effects of application methods of metam sodium and plastic covers on horizontal and vertical distributions of methyl isothiocyanate in bedded field plots.

    Science.gov (United States)

    Ou, Li-Tse; Thomas, John E; Allen, L Hartwell; Vu, Joseph C; Dickson, Donald W

    2006-08-01

    This study was conducted to examine the effects of three application methods of metam sodium (broadcast, single irrigation drip tape delivery, and double irrigation drip tape delivery) and two plastic covers (polyethylene film and virtually impermeable film) on volatilization and on horizontal and vertical distributions of the biologically active product of metam sodium, methyl isothiocyanate (MITC), in field plots in a Florida sandy soil. Volatilization of MITC from field beds lasted for about 20 hours after completion of metam sodium application regardless of application methods. Virtually impermeable film (VIF) was a better barrier to reduce volatilization loss than polyethylene film (PE). Since water was not applied during broadcast application, MITC was mainly retained in the shallow soil layer (0- to 20-cm depth) and downward movement of MITC was limited to about 30 cm. Large values of standard deviation indicated that initial spatial distribution of MITC in the root zone (10- and 20-cm depths) of the two broadcast applied beds covered with PE or VIF was variable. Twice more water was delivered through the single drip tape than through individual tapes of double drip tape treatments during drip application of metam sodium. More water from the single drip tape likely facilitated downward movement of MITC to at least 60-cm depth, but MITC did not penetrate to this depth in the double drip tape beds. On the other hand, horizontal distribution of MITC in the root zone (10- and 20-cm depths) in the double drip tape beds was more uniform than in the single drip tape beds. More MITC was retained in the subsurface of the VIF-covered beds regardless of application methods than in the PE-covered beds.

  14. Critical evaluation and comparison of fluid distribution systems for industrial scale expanded bed adsorption chromatography columns

    DEFF Research Database (Denmark)

    Arpanaei, Ayyoob; Heebøll-Nielsen, Anders; Hubbuch, Jürgen

    2008-01-01

    distributor at large scale were apparent: dead zones were present which could not be removed by increasing rotation rates or flow rates, and such changes led to a deterioration in hydrodynamic properties. In contrast, during fluid introduction through a rotating distributor no dead zones were observed....... The results imply that further improvement in distributor design is needed and careful attention should be given to the trade off between turbulence and adequate fluid distribution....

  15. Heat and mass transfer in a reforming catalyst bed. Analytical prediction of distributions in the catalyst bed; Kaishitsu shokubaiso ni okeru netsu oyobi busshitsu ido. Suchi kaiseki ni yoru sonai bunpu no yosoku

    Energy Technology Data Exchange (ETDEWEB)

    Usami, Y [Tokyo Electric Power Co. Inc., Tokyo (Japan); Fukusako, S; Yamada, M [Hokkaido University, Sapporo (Japan)

    2000-01-25

    Heat and mass transfer characteristics within a reforming catalyst bed have been analytically investigated. A numerical analysis was carried out in a two-dimensional steady-state model of reforming catalyst layer. Reforming tube was filled with catalyst and the tube wall was uniformly heated, a mixture of steam and methane was reformed through the catalyst bed. Predicted temperature, formed gas composition, methane conversion rate, and heat transfer coefficient distributions in the catalyst layer showed good agreement with experimental data. The effects of space velocity, steam carbon molar ratio, and wall temperature on the heat transfer coefficient were analytically presented. From temperature and composition distributions simulated by two-dimensional analysis, the effects of these factors above mentioned and diffusion on the transport phenomena were qualitatively predicted. (author)

  16. Evaluation of power control concepts using the PMAD systems test bed. [Power Management and Distribution

    Science.gov (United States)

    Beach, R. F.; Kimnach, G. L.; Jett, T. A.; Trash, L. M.

    1989-01-01

    The Lewis Research Center's Power Management and Distribution (PMAD) System testbed and its use in the evaluation of control concepts applicable to the NASA Space Station Freedom electric power system (EPS) are described. The facility was constructed to allow testing of control hardware and software in an environment functionally similar to the space station electric power system. Control hardware and software have been developed to allow operation of the testbed power system in a manner similar to a supervisory control and data acquisition (SCADA) system employed by utility power systems for control. The system hardware and software are described.

  17. Distribution and stability of potential salmonid spawning gravels in steep boulder-bed streams of the eastern Sierra Nevada

    International Nuclear Information System (INIS)

    Kondolf, G.M.; Cada, G.F.; Sale, M.J.; Felando, T.

    1991-01-01

    Interest in small hydroelectric development (< 5 MW) has recently focused attention on steep streams and the resident trout populations they contain. High-gradient boulder-bed streams have been the sites of relatively few studies of salmonid spawning habitat, although they have geomorphic and hydraulic characteristics - and therefore gravel distributions - that are quite different from the more commonly described lower-gradient channels. The authors documented gravel distribution in seven high-gradient stream reaches in the eastern Sierra Nevada. Gravels occurred only in locations characterized by relatively low shear stress; they formed small pockets in sites of low divergence and larger deposits upstream of natural hydraulic controls. In 1986 (a wet year), all tracer gravels placed in gravel pockets at nine sites on four streams were completely swept away, and substantial scour, fill, and other channel changes occurred at many sites. In 1987 (a dry year), tracer gravels and the channel cross sections were generally stable. Periodic mobility of gravel may explain why brown trout Salmo trutta are more abundant than rainbow trout Oncorhychus mykiss in the study reaches, where high flows occur every May and June during snowmelt. Brown trout are fall spawners, and their fry emerge long before the high snowmelt flows, whereas rainbow trout are spring spawners whose eggs are in the gravel, and thus vulnerable to scour, during snowmelt flows

  18. An Experimental Study on Axial Temperature Distribution of Combustion of Dewatered Poultry Sludge in Fluidized bed combustor

    Directory of Open Access Journals (Sweden)

    Abbas A.H.

    2016-01-01

    Full Text Available A laboratory scale bubbling fluidized bed combustor was designed and fabricated to study the combustion of dewatered poultry sludge at different operational parameters. This paper present a study on the influence of equivalent ratio, secondary to primary air ratio and the fuel feed rate on the temperature distribution along the combustor. The equivalent ratio has been changed between 0.8 to 1.4% under poultry sludge feed rate of 10 kg/h and from 0.8 to 1 under poultry sludge feed rate of 15 kg/h. The secondary to primary air ratio was varied from 0.1 to 0.5 at 0.65 m injection height and 1.25 equivalent ratio. The results showed that these factors had a significant influence on the combustion characteristics of poultry sludge. The temperature distribution along the combustor was found to be strongly dependent on the fuel feed rate and the equivalent ratio and it increased when these two factors increased. However, the secondary air ratio increased the temperature in the lower region of the combustor while no significant effect was observed at the upper region of the combustor. The results suggested that the poultry sludge can be used as a fuel with high thermal combustor efficiency.

  19. Effectiveness and Cost of Insecticide-Treated Bed Nets and Indoor Residual Spraying for the Control of Cutaneous Leishmaniasis: A Cluster-Randomized Control Trial in Morocco

    Science.gov (United States)

    Faraj, Chafika; Yukich, Joshua; Adlaoui, El Bachir; Wahabi, Rachid; Mnzava, Abraham Peter; Kaddaf, Mustapha; El Idrissi, Abderrahmane Laamrani; Ameur, Btissam; Kleinschmidt, Immo

    2016-01-01

    Cutaneous leishmaniasis (CL) remains an important public health problem in Morocco. A cluster-randomized trial was conducted with the following three study arms: 1) long-lasting insecticide-treated nets (LLINs) plus standard of care environmental management (SoC-EM), 2) indoor residual spraying (IRS) with α-cypermethrin plus SoC-EM, and 3) SoC-EM alone. Incidence of new CL cases by passive and active case detection, sandfly abundance, and cost and cost-effectiveness was compared between study arms over 5 years. Incidence of CL and sandfly abundance were significantly lower in the IRS arm compared with SoC-EM (CL incidence rate ratio = 0.32, 95% confidence interval [CI] = 0.15–0.69, P = 0.005 and sandfly abundance ratio = 0.39, 95% CI = 0.18–0.85, P = 0.022). Reductions in the LLIN arm of the study were not significant, possibly due to poor compliance. IRS was effective and more cost-effective for the prevention of CL in Morocco. PMID:26811431

  20. Oxygen distribution in packed-bed membrane reactors for partial oxidations: effect of the radial porosity profiles on the product selectivity

    NARCIS (Netherlands)

    Kurten, U.; van Sint Annaland, M.; Kuipers, J.A.M.

    2004-01-01

    A two-dimensional, pseudohomogeneous reactor model was presented to describe the radial and axial concentration profiles in a packed-bed membrane reactor and the local velocity field while accounting for the influences due to the distributive membrane flow and the radial porosity profile. The effect

  1. Combustion of Biosolids in a Bubbling Fluidized Bed, Part 1: Main Ash-Forming Elements and Ash Distribution with a Focus on Phosphorus.

    Science.gov (United States)

    Skoglund, Nils; Grimm, Alejandro; Ohman, Marcus; Boström, Dan

    2014-02-20

    This is the first in a series of three papers describing combustion of biosolids in a 5-kW bubbling fluidized bed, the ash chemistry, and possible application of the ash produced as a fertilizing agent. This part of the study aims to clarify whether the distribution of main ash forming elements from biosolids can be changed by modifying the fuel matrix, the crystalline compounds of which can be identified in the raw materials and what role the total composition may play for which compounds are formed during combustion. The biosolids were subjected to low-temperature ashing to investigate which crystalline compounds that were present in the raw materials. Combustion experiments of two different types of biosolids were conducted in a 5-kW benchscale bubbling fluidized bed at two different bed temperatures and with two different additives. The additives were chosen to investigate whether the addition of alkali (K 2 CO 3 ) and alkaline-earth metal (CaCO 3 ) would affect the speciation of phosphorus, so the molar ratios targeted in modified fuels were P:K = 1:1 and P:K:Ca = 1:1:1, respectively. After combustion the ash fractions were collected, the ash distribution was determined and the ash fractions were analyzed with regards to elemental composition (ICP-AES and SEM-EDS) and part of the bed ash was also analyzed qualitatively using XRD. There was no evidence of zeolites in the unmodified fuels, based on low-temperature ashing. During combustion, the biosolid pellets formed large bed ash particles, ash pellets, which contained most of the total ash content (54%-95% (w/w)). This ash fraction contained most of the phosphorus found in the ash and the only phosphate that was identified was a whitlockite, Ca 9 (K,Mg,Fe)(PO 4 ) 7 , for all fuels and fuel mixtures. With the addition of potassium, cristobalite (SiO 2 ) could no longer be identified via X-ray diffraction (XRD) in the bed ash particles and leucite (KAlSi 2 O 6 ) was formed. Most of the alkaline-earth metals

  2. Characterising boiler ash from a circulating fluidised bed municipal solid waste incinerator and distribution of PCDD/F and PCB.

    Science.gov (United States)

    Zhang, Mengmei; Buekens, Alfons; Li, Xiaodong

    2018-05-31

    In this study, ash samples were collected from five locations situated in the boiler of a circulating fluidised bed municipal solid waste incinerator (high- and low-temperature superheater, evaporator tubes and upper and lower economiser). These samples represent a huge range of flue gas temperatures and were characterised for their particle size distribution, surface characteristics, elemental composition, chemical forms of carbon and chlorine and distribution of polychlorinated dibenzo-p-dioxins (PCDD), dibenzofurans (PCDF) and biphenyls (PCB). Enrichment of chlorine, one of the main elements of organochlorinated pollutants, and copper, zinc and lead, major catalytic metals for dioxin-like compounds, was observed in lower-temperature ash deposits. The speciation of carbon and chlorine on ash surfaces was established, showing a positive correlation between organic chlorine and oxygen-containing carbon functional groups. The load of PCDD/F and PCB (especially dioxin-like PCB) tends to rise rapidly with falling temperature of flue gas, reaching their highest value in economiser ashes. The formation of PCDD/F congeners through the chlorophenol precursor route apparently was enhanced downstream the boiler. Principal component analysis (PCA) was applied to study the links between the ash characteristics and distribution of chloro-aromatics. The primary purpose of this study is improving the understanding of any links between the characteristics of ash from waste heat systems and its potential to form PCDD/F and PCB. The question is raised whether further characterisation of fly ash may assist to establish a diagnosis of poor plant operation, inclusive the generation, destruction and eventual emission of persistent organic pollutants (POPs).

  3. Distributed medical services within the ATM-based Berlin regional test bed

    Science.gov (United States)

    Thiel, Andreas; Bernarding, Johannes; Krauss, Manfred; Schulz, Sandra; Tolxdorff, Thomas

    1996-05-01

    The ATM-based Metropolitan Area Network (MAN) of Berlin connects two university hospitals (Benjamin Franklin University Hospital and Charite) with the computer resources of the Technical University of Berlin (TUB). Distributed new medical services have been implemented and will be evaluated within the highspeed MAN of Berlin. The network with its data transmission rates of up to 155 Mbit/s renders these medical services externally available to practicing physicians. Resource and application sharing is demonstrated by the use of two software systems. The first software system is an interactive 3D reconstruction tool (3D- Medbild), based on a client-server mechanism. This structure allows the use of high- performance computers at the TUB from the low-level workstations in the hospitals. A second software system, RAMSES, utilizes a tissue database of Magnetic Resonance Images. For the remote control of the software, the developed applications use standards such as DICOM 3.0 and features of the World Wide Web. Data security concepts are being tested and integrated for the needs of the sensitive medical data. The highspeed network is the necessary prerequisite for the clinical evaluation of data in a joint teleconference. The transmission of digitized real-time sequences such as video and ultrasound and the interactive manipulation of data are made possible by Multi Media tools.

  4. Copyright Cartels or Legitimate Joint Ventures? What the MusicNet and Pressplay Litigation Means for the Entertainment Industry's New Distribution Models

    OpenAIRE

    Landy, Rachel

    2012-01-01

    Starr v. Sony BMG Music Entertainment illustrates the inherent tension between copyright holders seeking to enforce their exclusive rights and antitrust doctrine. In Starr, competing record labels pooled their copyrights into digital distribution joint ventures, MusicNet and Pressplay. Such collaboration toes a thin line between cartel-like ...

  5. Bed Bugs

    Science.gov (United States)

    Prevent, identify, and treat bed bug infestations using EPA’s step-by-step guides, based on IPM principles. Find pesticides approved for bed bug control, check out the information clearinghouse, and dispel bed bug myths.

  6. Explaining variation in adult Anopheles indoor resting abundance: the relative effects of larval habitat proximity and insecticide-treated bed net use.

    Science.gov (United States)

    McCann, Robert S; Messina, Joseph P; MacFarlane, David W; Bayoh, M Nabie; Gimnig, John E; Giorgi, Emanuele; Walker, Edward D

    2017-07-17

    Spatial determinants of malaria risk within communities are associated with heterogeneity of exposure to vector mosquitoes. The abundance of adult malaria vectors inside people's houses, where most transmission takes place, should be associated with several factors: proximity of houses to larval habitats, structural characteristics of houses, indoor use of vector control tools containing insecticides, and human behavioural and environmental factors in and near houses. While most previous studies have assessed the association of larval habitat proximity in landscapes with relatively low densities of larval habitats, in this study these relationships were analysed in a region of rural, lowland western Kenya with high larval habitat density. 525 houses were sampled for indoor-resting mosquitoes across an 8 by 8 km study area using the pyrethrum spray catch method. A predictive model of larval habitat location in this landscape, previously verified, provided derivations of indices of larval habitat proximity to houses. Using geostatistical regression models, the association of larval habitat proximity, long-lasting insecticidal nets (LLIN) use, house structural characteristics (wall type, roof type), and peridomestic variables (cooking in the house, cattle near the house, number of people sleeping in the house) with mosquito abundance in houses was quantified. Vector abundance was low (mean, 1.1 adult Anopheles per house). Proximity of larval habitats was a strong predictor of Anopheles abundance. Houses without an LLIN had more female Anopheles gambiae s.s., Anopheles arabiensis and Anopheles funestus than houses where some people used an LLIN (rate ratios, 95% CI 0.87, 0.85-0.89; 0.84, 0.82-0.86; 0.38, 0.37-0.40) and houses where everyone used an LLIN (RR, 95% CI 0.49, 0.48-0.50; 0.39, 0.39-0.40; 0.60, 0.58-0.61). Cooking in the house also reduced Anopheles abundance across all species. The number of people sleeping in the house, presence of cattle near the house

  7. Downflow limestone beds for treatment of net-acidic, oxic, iron-laden drainage from a flooded Anthracite Mine, Pennsylvania, USA: 1. Field evaluation

    Science.gov (United States)

    Cravotta, C.A.; Ward, S.J.

    2008-01-01

    Passive-treatment systems that route acidic mine drainage (AMD) through crushed limestone and/or organic-rich substrates have been used to remove the acidity and metals from various AMD sources, with a wide range of effects. This study evaluates treatment of net-acidic, oxic, iron-laden AMD with limestone alone, and with organic-rich compost layered with the limestone. In the fall of 2003, a treatment system consisting of two parallel, 500-m2 downflow cells followed by a 400-m2 aerobic settling pond and wetland was installed to neutralize the AMD from the Bell Mine, a large source of AMD and baseflow to the Schuylkill River in the Southern Anthracite Coalfield, in east-central Pennsylvania. Each downflow cell consisted of a lower substrate layer of 1,090 metric tons (t) of dolomitic limestone (60 wt% CaCO3) and an upper layer of 300 t of calcitic limestone (95 wt% CaCO3); one of the downflow cells also included a 0.3 m thick layer of mushroom compost over the limestone. AMD with pH of 3.5-4.3, dissolved oxygen of 6.6-9.9 mg/L, iron of 1.9-5.4 mg/L, and aluminum of 0.8-1.9 mg/L flooded each cell to a depth 0.65 m above the treatment substrates, percolated through the substrates to underlying, perforated outflow pipes, and then flowed through the aerobic pond and wetland before discharging to the Schuylkill River. Data on the flow rates and chemistry of the effluent for the treatment system indicated substantial neutralization by the calcitic limestone but only marginal effects from the dolomitic limestone or compost. Because of its higher transmissivity, the treatment cell containing only limestone neutralized greater quantities of acidity than the cell containing compost and limestone. On average, the treatment system removed 62% of the influent acidity, 47% of the dissolved iron, 34% of the dissolved aluminum, and 8% of the dissolved manganese. Prior to treatment of the Bell Discharge, the Schuylkill River immediately below its confluence with the discharge had p

  8. Distributed secondary gas injection via a fractal injector : A nature-inspired approach to improving conversion in fluidized bed reactors

    NARCIS (Netherlands)

    Christensen, D.O.

    2008-01-01

    The conversion in bubbling fluidized bed reactors is suppressed because the interphase mass transfer and gas-solid contact in bubbling fluidized bed reactors are often poor. Most of the gas is present in the form of bubbles, which have low surface-to-volume ratios and are nearly devoid of catalyst

  9. Experimental investigations of flow distribution in coolant system of Helium-Cooled-Pebble-Bed Test Blanket Module

    Energy Technology Data Exchange (ETDEWEB)

    Ilić, M.; Schlindwein, G., E-mail: georg.schlindwein@kit.edu; Meyder, R.; Kuhn, T.; Albrecht, O.; Zinn, K.

    2016-02-15

    Highlights: • Experimental investigations of flow distribution in HCPB TBM are presented. • Flow rates in channels close to the first wall are lower than nominal ones. • Flow distribution in central chambers of manifold 2 is close to the nominal one. • Flow distribution in the whole manifold 3 agrees well with the nominal one. - Abstract: This paper deals with investigations of flow distribution in the coolant system of the Helium-Cooled-Pebble-Bed Test Blanket Module (HCPB TBM) for ITER. The investigations have been performed by manufacturing and testing of an experimental facility named GRICAMAN. The facility involves the upper poloidal half of HCPB TBM bounded at outlets of the first wall channels, at outlet of by-pass pipe and at outlets of cooling channels in breeding units. In this way, the focus is placed on the flow distribution in two mid manifolds of the 4-manifold system: (i) manifold 2 to which outlets of the first wall channels and inlet of by-pass pipe are attached and (ii) manifold 3 which supplies channels in breeding units with helium coolant. These two manifolds are connected with cooling channels in vertical/horizontal grids and caps. The experimental facility has been built keeping the internal structure of manifold 2 and manifold 3 exactly as designed in HCPB TBM. The cooling channels in stiffening grids, caps and breeding units are substituted by so-called equivalent channels which provide the same hydraulic resistance and inlet/outlet conditions, but have significantly simpler geometry than the real channels. Using the conditions of flow similarity, the air pressurized at 0.3 MPa and at ambient temperature has been used as working fluid instead of HCPB TBM helium coolant at 8 MPa and an average temperature of 370 °C. The flow distribution has been determined by flow rate measurements at each of 28 equivalent channels, while the pressure distribution has been obtained measuring differential pressure at more than 250 positions. The

  10. Transverse mass and rapidity distributions and space dispersion plots of (net-)protons in Pb-Pb collisions at SPS energies

    International Nuclear Information System (INIS)

    Liu, Fu-Hu; Tian, Tian; Wen, Xin-Jian

    2014-01-01

    The transverse mass and rapidity distributions of (net-)protons produced in Pb-Pb collisions with different centrality intervals at 40A and 158A GeV have been analyzed by using the multisource thermal model in which the whole interacting system and then the sources are described by the Tsallis statistics. The modelling results are in agreement with the experimental data of the NA49 Collaboration. The dispersion plots (or scatter plots) of (net-)protons at the stage of freeze-out in the momentum space, velocity space, and transverse momentum and rapidity space in Pb-Pb collisions at 40A and 158A GeV in different centrality intervals are obtained. We see the differences in density distributions in the dispersion plots for different origins, centrality intervals, and incident energies for the considered collisions. (orig.)

  11. SeaDataNet - Pan-European infrastructure for marine and ocean data management: Unified access to distributed data sets (www.seadatanet.org)

    Science.gov (United States)

    Schaap, Dick M. A.; Maudire, Gilbert

    2010-05-01

    SeaDataNet is a leading infrastructure in Europe for marine & ocean data management. It is actively operating and further developing a Pan-European infrastructure for managing, indexing and providing access to ocean and marine data sets and data products, acquired via research cruises and other observational activities, in situ and remote sensing. The basis of SeaDataNet is interconnecting 40 National Oceanographic Data Centres and Marine Data Centers from 35 countries around European seas into a distributed network of data resources with common standards for metadata, vocabularies, data transport formats, quality control methods and flags, and access. Thereby most of the NODC's operate and/or are developing national networks to other institutes in their countries to ensure national coverage and long-term stewardship of available data sets. The majority of data managed by SeaDataNet partners concerns physical oceanography, marine chemistry, hydrography, and a substantial volume of marine biology and geology and geophysics. These are partly owned by the partner institutes themselves and for a major part also owned by other organizations from their countries. The SeaDataNet infrastructure is implemented with support of the EU via the EU FP6 SeaDataNet project to provide the Pan-European data management system adapted both to the fragmented observation system and the users need for an integrated access to data, meta-data, products and services. The SeaDataNet project has a duration of 5 years and started in 2006, but builds upon earlier data management infrastructure projects, undertaken over a period of 20 years by an expanding network of oceanographic data centres from the countries around all European seas. Its predecessor project Sea-Search had a strict focus on metadata. SeaDataNet maintains significant interest in the further development of the metadata infrastructure, extending its services with the provision of easy data access and generic data products

  12. Gross Mal distribution Identification and Effect of Inlet Distributor on the Phase Holdup in a Trickle Bed Reactor Using Gamma-Ray Densitometry (GRD)

    International Nuclear Information System (INIS)

    Mohd Fitri Abdul Rahman; Alexander, V.; Al-Dahhan, M.

    2016-01-01

    Local liquid and gas mal distribution and their holdups in a packed column are difficult to identify due to multiphase properties and other design factors. Good liquid and gas flow distribution important to determine to get high performance of Trickle Bed Reactor (TBR). Gross mal distribution indicates some faulty or bad flow distribution of liquid and gas. In this work, gross mal distribution of phases has been identified using Gamma Ray Densitometry (GRD) technique with three types of inlet distributors (single inlet towards the wall, single inlet at the center, and proper shower) by measuring line average diameter profile of phases (Liquid, Gas, and Solids) holdups. Gamma-ray densitometry is a non-invasive technique which can be implemented at the laboratory, pilot plant, and industrial scales reactors. Experiments were performed on 0.14 m diameter reactor made of Plexiglas filled with 0.003 m glass bead which acts as the solid. The superficial velocities for both gas and liquid were in the range 0.03 m/s to 0.27 m/s and 0.004 m/s to 0.014 m/s respectively. Proper shower distributor showed early liquid spreading than compared with other distributors. The effect of superficial gas velocity on liquid spread was seen to be non-significant, and liquid distribution is found to be almost uniform at the center region of the catalyst bed. (author)

  13. Simulation of net infiltration and potential recharge using a distributed-parameter watershed model of the Death Valley region, Nevada and California

    Science.gov (United States)

    Hevesi, Joseph A.; Flint, Alan L.; Flint, Lorraine E.

    2003-01-01

    This report presents the development and application of the distributed-parameter watershed model, INFILv3, for estimating the temporal and spatial distribution of net infiltration and potential recharge in the Death Valley region, Nevada and California. The estimates of net infiltration quantify the downward drainage of water across the lower boundary of the root zone and are used to indicate potential recharge under variable climate conditions and drainage basin characteristics. Spatial variability in recharge in the Death Valley region likely is high owing to large differences in precipitation, potential evapotranspiration, bedrock permeability, soil thickness, vegetation characteristics, and contributions to recharge along active stream channels. The quantity and spatial distribution of recharge representing the effects of variable climatic conditions and drainage basin characteristics on recharge are needed to reduce uncertainty in modeling ground-water flow. The U.S. Geological Survey, in cooperation with the Department of Energy, developed a regional saturated-zone ground-water flow model of the Death Valley regional ground-water flow system to help evaluate the current hydrogeologic system and the potential effects of natural or human-induced changes. Although previous estimates of recharge have been made for most areas of the Death Valley region, including the area defined by the boundary of the Death Valley regional ground-water flow system, the uncertainty of these estimates is high, and the spatial and temporal variability of the recharge in these basins has not been quantified. To estimate the magnitude and distribution of potential recharge in response to variable climate and spatially varying drainage basin characteristics, the INFILv3 model uses a daily water-balance model of the root zone with a primarily deterministic representation of the processes controlling net infiltration and potential recharge. The daily water balance includes precipitation

  14. Petri Nets

    Indian Academy of Sciences (India)

    In a computer system, for example, typical discrete events ... This project brought out a series of influential reports on Petri net theory in the mid and late ... Technology became a leading centre for Petri net research and from then on, Petri nets ...

  15. Simulation of the distribution of radionuclides in the reservoir bed for deep-well injection disposal of acid liquid radioactive waste

    International Nuclear Information System (INIS)

    Noskov, M.D.; Istomin, A.D.; Kesler, A.G.; Zubkov, A.A.; Zakharova, E.V.; Egorov, G.F.

    2007-01-01

    A mathematical model was developed for describing the changes in the state of the reservoir bed for dee-well injection disposal of acid liquid radioactive waste. The model considers the multicomponent filtration of the solution in the heterogeneous bed, sorption-desorption of radionuclides, taking into account the dependence of the distribution coefficient on the temperature and pH, as well as radioactive decay, interaction of acids with minerals, radiation-chemical and thermochemical decomposition of the acids, and dynamics of the temperature field, taking into account the convective heat transfer, thermal conductivity, and radiogenic heat release. The results of the simulation of the migration of radionuclides were reported, as well as of the distribution of the acids and the dynamics of the temperature field in the vicinity of the injection well of the site for deep-well injection disposal of the waste from Siberian Chemical Combine. A man-caused barrier is formed in the vicinity of the injection well, hindering the spread of radionuclides in the reservoir bed [ru

  16. Spatio-temporal distribution of Diaphanosoma brachyurum (Cladocera: Sididae in freshwater reservoir ecosystems: importance of maximum water depth and macrophyte beds for avoidance of fish predation

    Directory of Open Access Journals (Sweden)

    Jong-Yun Choi

    2014-10-01

    Full Text Available In empirical studies, Cladocera is commonly utilized as a primary food source for predators such as fish, thus, predator avoidance are important strategies to sustain their population in freshwater ecosystems. In this study, we tested the hypothesis that water depth is an important factor in determining the spatial distribution of Diaphanosoma brachyurum Liévin, 1848 in response to fish predation. Quarterly monitoring was implemented at three water layers (i.e., water surface and middle and bottom layers in 21 reservoirs located in the southeastern part of South Korea. D. brachyurum individuals were frequently observed at the study sites and exhibited different spatial patterns of distribution in accordance with the maximum depth of the reservoirs. In the reservoirs with a maximum depth of more than 6 m, high densities of D. brachyurum were observed in the bottom layers; however, in the shallower reservoirs (maximum depth <6 m, D. brachyurum were concentrated in the surface layer. Moreover, during additional surveys, we observed a trend in which D. brachyurum densities increased as the maximum depth or macrophyte biomass increased. Gut contents analysis revealed that predatory fishes in each reservoir frequently consumed D. brachyurum; however, the consumption rate abruptly decreased in reservoirs where the maximum depth was more than 11 m or in the shallow reservoirs supporting a macrophyte bed. Interestingly, the reservoirs more than 11-m depth supported high densities of D. brachyurum in the bottom layer and in the surface macrophyte bed. Based on these results, reservoirs with a maximum depth of more than 11 m or those with a macrophyte bed may provide a refuge for D. brachyurum to avoid fish predation. Compared with other cladoceran species, D. brachyurum readily exploits various types of refugia (in this study, the deep layer or surface macrophyte bed, which may help explain why this species is abundant in various types of reservoirs.

  17. Efficacy, Safety and Cost of Insecticide Treated Wall Lining, Insecticide Treated Bed Nets and Indoor Wall Wash with Lime for Visceral Leishmaniasis Vector Control in the Indian Sub-continent: A Multi-country Cluster Randomized Controlled Trial

    Science.gov (United States)

    Das, Pradeep; Ghosh, Debashis; Priyanka, Jyoti; Matlashewski, Greg; Kroeger, Axel; Upfill-Brown, Alexander

    2016-01-01

    Background We investigated the efficacy, safety and cost of lime wash of household walls plus treatment of sand fly breeding places with bleach (i.e. environmental management or EM), insecticide impregnated durable wall lining (DWL), and bed net impregnation with slow release insecticide (ITN) for sand fly control in the Indian sub-continent. Methods This multi-country cluster randomized controlled trial had 24 clusters in each three sites with eight clusters per high, medium or low sand fly density stratum. Every cluster included 45–50 households. Five households from each cluster were randomly selected for entomological measurements including sand fly density and mortality at one, three, nine and twelve months post intervention. Household interviews were conducted for socioeconomic information and intervention acceptability assessment. Cost for each intervention was calculated. There was a control group without intervention. Findings Sand fly mortality [mean and 95%CI] ranged from 84% (81%-87%) at one month to 74% (71%-78%) at 12 months for DWL, 75% (71%-79%) at one month to 49% (43%-55%) at twelve months for ITN, and 44% (34%-53%) at one month to 22% (14%-29%) at twelve months for EM. Adjusted intervention effect on sand fly density measured by incidence rate ratio ranged from 0.28 (0.23–0.34) at one month to 0.62 (0.51–0.75) at 12 months for DWL; 0.72 (0.62–0.85) at one month to 1.02 (0.86–1.22) at 12 months for ITN; and 0.89 (0.76–1.03) at one months to 1.49 (1.26–1.74) at 12 months for EM. Household acceptance of EM was 74% compared to 94% for both DWL and ITN. Operational cost per household in USD was about 5, 8, and 2 for EM, DWL and ITN, respectively. Minimal adverse reactions were reported for EM and ITN while 36% of households with DWL reported transient itching. Interpretation DWL is the most effective, durable and acceptable control method followed by ITN. The Visceral Leishmaniasis (VL) Elimination Program in the Indian sub

  18. The effect of household heads training about the use of treated bed nets on the burden of malaria and anaemia in under-five children: a cluster randomized trial in Ethiopia

    Directory of Open Access Journals (Sweden)

    Deribew Amare

    2012-01-01

    Full Text Available Abstract Background Long-lasting insecticide-treated bed nets (LLITN have demonstrated a significant effect in reducing malaria-related morbidity and mortality. However, barriers on the utilization of LLITN have hampered the desired outcomes. The aim of this study was to assess the effect of community empowerment on the burden of malaria and anaemia in under-five children in Ethiopia. Methods A cluster randomized trial was done in 22 (11 intervention and 11 control villages in south-west Ethiopia. The intervention consisted of tailored training of household heads about the proper use of LLITN and community network system. The burden of malaria and anaemia in under-five children was determined through mass blood investigation at baseline, six and 12 months of the project period. Cases of malaria and anaemia were treated based on the national protocol. The burden of malaria and anaemia between the intervention and control villages was compared using the complex logistic regression model by taking into account the clustering effect. Eight Focus group discussions were conducted to complement the quantitative findings. Results A total of 2,105 household heads received the intervention and the prevalence of malaria and anaemia was assessed among 2410, 2037 and 2612 under-five children at baseline, six and 12 months of the project period respectively. During the high transmission/epidemic season, children in the intervention arm were less likely to have malaria as compared to children in the control arm (OR = 0.42; 95%CI: 0.32, 0.57. Symptomatic malaria also steadily declined in the intervention villages compared to the control villages in the follow up periods. Children in the intervention arm were less likely to be anaemic compared to those in the control arm both at the high (OR = 0.84; 95%CI: 0.71, 0.99 and low (OR = 0.73; 95%CI: 0.60, 0.89 transmission seasons. Conclusion Training of household heads on the utilization of LLITN significantly

  19. Effect of malaria transmission reduction by insecticide-treated bed nets (ITNs) on the genetic diversity of Plasmodium falciparum merozoite surface protein (MSP-1) and circumsporozoite (CSP) in western Kenya.

    Science.gov (United States)

    Kariuki, Simon K; Njunge, James; Muia, Ann; Muluvi, Geofrey; Gatei, Wangeci; Ter Kuile, Feiko; Terlouw, Dianne J; Hawley, William A; Phillips-Howard, Penelope A; Nahlen, Bernard L; Lindblade, Kim A; Hamel, Mary J; Slutsker, Laurence; Shi, Ya Ping

    2013-08-27

    Although several studies have investigated the impact of reduced malaria transmission due to insecticide-treated bed nets (ITNs) on the patterns of morbidity and mortality, there is limited information on their effect on parasite diversity. Sequencing was used to investigate the effect of ITNs on polymorphisms in two genes encoding leading Plasmodium falciparum vaccine candidate antigens, the 19 kilodalton blood stage merozoite surface protein-1 (MSP-1(19kDa)) and the Th2R and Th3R T-cell epitopes of the pre-erythrocytic stage circumsporozoite protein (CSP) in a large community-based ITN trial site in western Kenya. The number and frequency of haplotypes as well as nucleotide and haplotype diversity were compared among parasites obtained from children diversity of > 0.7. No MSP-1(19kDa) 3D7 sequence-types were detected in 1996 and the frequency was less than 4% in 2001. The CSP Th2R and Th3R domains were highly polymorphic with a total of 26 and 14 haplotypes, respectively detected in 1996 and 34 and 13 haplotypes in 2001, with an overall haplotype diversity of > 0.9 and 0.75 respectively. The frequency of the most predominant Th2R and Th3R haplotypes was 14 and 36%, respectively. The frequency of Th2R and Th3R haplotypes corresponding to the 3D7 parasite strain was less than 4% at both time points. There was no significant difference in nucleotide and haplotype diversity in parasite isolates collected at both time points. High diversity in these two genes has been maintained overtime despite marked reductions in malaria transmission due to ITNs use. The frequency of 3D7 sequence-types was very low in this area. These findings provide information that could be useful in the design of future malaria vaccines for deployment in endemic areas with high ITN coverage and in interpretation of efficacy data for malaria vaccines based on 3D7 parasite strains.

  20. Decline in frequency of the 2La chromosomal inversion in Anopheles gambiae (s.s.) in Western Kenya: correlation with increase in ownership of insecticide-treated bed nets.

    Science.gov (United States)

    Matoke-Muhia, Damaris; Gimnig, John E; Kamau, Luna; Shililu, Josephat; Bayoh, M Nabie; Walker, Edward D

    2016-06-10

    The 2La chromosomal inversion, a genetic polymorphism in An. gambiae (sensu stricto) (s.s.), is associated with adaptation to microclimatic differences in humidity and desiccation resistance and mosquito behaviors. Ownership of insecticide-treated bed nets (ITNs) for malaria control has increased markedly in western Kenya in the last 20 years. An increase in the frequency of ITNs indoors could select against house entering or indoor resting of Anopheles mosquitoes. Thus, the frequency of the 2La inversion is postulated to change in An. gambiae (s.s.) with the increase of ITN ownership over time. Anopheles gambiae mosquitoes were sampled between 1994 and 2011 using pyrethrum knockdown, bednet traps and human landing catches (HLC) from Asembo and Seme, western Kenya. The 2La inversion was detected by a PCR assay with primers designed for proximal breakpoints of the 2La/a and 2L+(a)/+(a) chromosomal conformation. Mosquitoes were tested for malaria parasite infection by sporozoite ELISA. The frequency of the 2La chromosomal inversion declined from 100 % of all chromosomes in 1994 to 17 % in 2005 and remained low through 2011 (21 %). ITN ownership increased from 0 to > 90 % of houses in the study area during this interval. The decline in the frequency of the 2La chromosomal inversion was significantly, negatively correlated with year (r = -0.93) and with increase in ITN ownership (r = -0.96). The frequency of the homo- and heterokaryotypes departed significantly from Hardy-Weinberg equilibrium, suggesting that 2La/a karyotype was under selection, earlier in its favor and later, against it. Precipitation and maximum monthly temperature did not vary over time, therefore there was no trend in climate that could account for the decline. There was no significant difference in frequency of the 2La inversion in An. gambiae (s.s.) females sampled indoors or outdoors in HCL in 2011, nor was there an association between the 2La inversion and infection with Plasmodium

  1. Sewage impact on the composition and distribution of Polychaeta associated to intertidal mussel beds of the Mar del Plata rocky shore, Argentina

    Directory of Open Access Journals (Sweden)

    Elías Rodolfo

    2003-01-01

    Full Text Available The polychaete composition and distribution within mussel beds were studied in order to assess organic pollution due to domestic sewage in a rocky shore of Mar del Plata (Argentina during 1997. Four stations and a control site were randomly sampled around the local effluent. Quantitative data on polychaetes, as well as sediment accumulated among mussels and its organic carbon content were measured. Polychaete distribution patterns are related to the organic matter gradient, being Capitella cf. capitata, Neanthes succinea (Frey & Leuckart, 1847 and Boccardia polybranchia (Haswell, 1885 the dominant indicator species close to the effluent. At medial distances, the cirratulids Caulleriella alata (Southern, 1914 and Cirratulus cirratus (Müller, 1776 are very important in abundance. The syllids Syllis prolixa Ehlers, 1901 and S. gracilis Grube, 1840 are distributed along the study area, but dominate at the medial stations and at the control site. The orbiniid Protoariciella uncinata Hartmann-Schröder, 1962 is subdominant at the control station.

  2. Marine protected area and the spatial distribution of the gill net fishery in Copacabana, Rio de Janeiro, RJ, Brazil

    Directory of Open Access Journals (Sweden)

    R. B. Amorim

    Full Text Available Abstract This study characterizes the gill net fishery at Colônia de Pescadores Z13 (CPZ13, in Copacabana, Rio de Janeiro, and its relationship with the marine protected area ‘Monumento Natural do Arquipélago das Ilhas Cagarras – MoNa Cagarras’, describing the fleet and fishing gears, identifying fishing spots, species and their associations by gillnet type. From June 2012 to May 2013, every Tuesday to Sunday, gill net landings were monitored and fishers interviewed regarding their catch. Small boats (dory whaleboats are used to set three types of gillnets: “Corvineira” (target species – whitemouth croaker, “linguadeira” (target species – flounders and “rede-alta” (target species – bluefish. Fifty-nine species within 37 families were captured at 14 fishing spots, showing association with bottom type and distance from shore. The use of fisher’s local ecological knowledge defines gear placement at specific sites targeting fisheries resources. All fishing sites are not within the limits of MoNa Cagarras but would benefit from management plans including an MPA buffering zone.

  3. Net Neutrality

    DEFF Research Database (Denmark)

    Savin, Andrej

    2017-01-01

    Repealing “net neutrality” in the US will have no bearing on Internet freedom or security there or anywhere else.......Repealing “net neutrality” in the US will have no bearing on Internet freedom or security there or anywhere else....

  4. Net primary productivity distribution in the BOREAS region from a process model using satellite and surface data

    Science.gov (United States)

    Liu, J.; Chen, J. M.; Cihlar, J.; Chen, W.

    1999-11-01

    The purpose of this paper is to upscale tower measurements of net primary productivity (NPP) to the Boreal Ecosystem-Atmosphere Study (BOREAS) study region by means of remote sensing and modeling. The Boreal Ecosystem Productivity Simulator (BEPS) with a new daily canopy photosynthesis model was first tested in one coniferous and one deciduous site. The simultaneous CO2 flux measurements above and below the tree canopy made it possible to isolate daily net primary productivity of the tree canopy for model validation. Soil water holding capacity and gridded daily meteorological data for the region were used as inputs to BEPS, in addition to 1 km resolution land cover and leaf area index (LAI) maps derived from the advanced very high resolution radiometer (AVHRR) data. NPP statistics for the various cover types in the BOREAS region and in the southern study area (SSA) and the northern study area (NSA) are presented. Strong dependence of NPP on LAI was found for the three major cover types: coniferous forest, deciduous forest and cropland. Since BEPS can compute total photosynthetically active radiation absorbed by the canopy in each pixel, light use efficiencies for NPP and gross primary productivity could also be analyzed. From the model results, the following area-averaged statistics were obtained for 1994: (1) mean NPP for the BOREAS region of 217 g C m-2 yr-1; (2) mean NPP of forests (excluding burnt areas in the region) equal to 234 g C m-2 yr-1; (3) mean NPP for the SSA and the NSA of 297 and 238 g C m-2 yr-1, respectively; and (4) mean light use efficiency for NPP equal to 0.40, 0.20, and 0.33 g C (MJ APAR)-1 for deciduous forest, coniferous forest, and crops, respectively.

  5. Comparative cost analysis of insecticide-treated net delivery strategies: sales supported by social marketing and free distribution through antenatal care.

    Science.gov (United States)

    De Allegri, Manuela; Marschall, Paul; Flessa, Steffen; Tiendrebéogo, Justin; Kouyaté, Bocar; Jahn, Albrecht; Müller, Olaf

    2010-01-01

    Insecticide-treated nets (ITNs) are effective in substantially reducing malaria transmission. Still, ITN coverage in sub-Saharan Africa (SSA) remains extremely low. Policy makers are concerned with identifying the most suitable delivery mechanism to achieve rapid yet sustainable increases in ITN coverage. Little is known, however, on the comparative costs of alternative ITN distribution strategies. This paper aimed to fill this gap in knowledge by developing such a comparative cost analysis, looking at the cost per ITN distributed for two alternative interventions: subsidized sales supported by social marketing and free distribution to pregnant women through antenatal care (ANC). The study was conducted in rural Burkina Faso, where the two interventions were carried out alongside one another in 2006/07. Cost information was collected prospectively to derive both a financial analysis adopting a provider's perspective and an economic analysis adopting a societal perspective. The average financial cost per ITN distributed was US$8.08 and US$7.21 for sales supported by social marketing and free distribution through ANC, respectively. The average economic cost per ITN distributed was US$4.81 for both interventions. Contrary to common belief, costs did not differ substantially between the two interventions. Due to the district's ability to rely fully on the use of existing resources, financial costs associated with free ITN distribution through ANC were in fact even lower than those associated with the social marketing campaign. This represents an encouraging finding for SSA governments and points to the possibility to invest in programmes to favour free ITN distribution through existing health facilities. Given restricted budgets, however, free distribution programmes are unlikely to be feasible.

  6. Petri Nets

    Indian Academy of Sciences (India)

    GENERAL I ARTICLE ... In Part 1 of this two-part article, we have seen im- ..... mable logic controller and VLSI arrays, office automation systems, workflow management systems, ... complex discrete event and real-time systems; and Petri nets.

  7. Determining and addressing obstacles to the effective use of long-lasting insecticide-impregnated nets in rural Tanzania

    Directory of Open Access Journals (Sweden)

    Benziger Peter W

    2009-12-01

    Full Text Available Abstract Background The objective of this project was to achieve high, sustainable levels of net coverage in a village in rural Tanzania by combining free distribution of long-lasting insecticide-impregnated nets (LLINs with community-tailored education. In Tanzania, malaria is the leading cause of morbidity and mortality. Although malaria bed nets have a well-established role in reducing disease burden, few rural households have access to nets, and effective use depends on personal practices and attitudes. Methods Five practices and attitudes inconsistent with effective LLIN use were identified from household interviews (n = 10. A randomized survey of villagers (n = 132 verified local prevalence of these practices and attitudes. Community leaders held an educational session for two members of every household addressing these practice and attitudes, demonstrating proper LLIN use, and emphasizing behaviour modification. Attendees received one or two LLINs per household. Surveys distributed three weeks (n = 104 and 15 months (n = 104 post-intervention assessed corrected practices and attitudes. Project efficacy was defined by correction of baseline practices and attitudes as well as high rates of reported daily net use, with statistical significance determined by chi-square test. Results Baseline interviews and surveys revealed incorrect practices and attitudes regarding 1 use of nets in dry season, 2 need to retreat LLINs, 3 children napping under nets, 4 need to repair nets, and 5 net procurement as a priority, with 53- 88.6% incorrect responses (11.4-47% correct responses. A three-week follow-up demonstrated 83-95% correct responses. Fifteen-month follow-up showed statistically significant (p Conclusions Results suggest that addressing community-specific practices and attitudes prior to LLIN distribution promotes consistent and correct use, and helps change attitudes towards bed nets as a preventative health measure. Future LLIN distributions

  8. Experiments and simulation of a net closing mechanism for tether-net capture of space debris

    Science.gov (United States)

    Sharf, Inna; Thomsen, Benjamin; Botta, Eleonora M.; Misra, Arun K.

    2017-10-01

    This research addresses the design and testing of a debris containment system for use in a tether-net approach to space debris removal. The tether-net active debris removal involves the ejection of a net from a spacecraft by applying impulses to masses on the net, subsequent expansion of the net, the envelopment and capture of the debris target, and the de-orbiting of the debris via a tether to the chaser spacecraft. To ensure a debris removal mission's success, it is important that the debris be successfully captured and then, secured within the net. To this end, we present a concept for a net closing mechanism, which we believe will permit consistently successful debris capture via a simple and unobtrusive design. This net closing system functions by extending the main tether connecting the chaser spacecraft and the net vertex to the perimeter and around the perimeter of the net, allowing the tether to actuate closure of the net in a manner similar to a cinch cord. A particular embodiment of the design in a laboratory test-bed is described: the test-bed itself is comprised of a scaled-down tether-net, a supporting frame and a mock-up debris. Experiments conducted with the facility demonstrate the practicality of the net closing system. A model of the net closure concept has been integrated into the previously developed dynamics simulator of the chaser/tether-net/debris system. Simulations under tether tensioning conditions demonstrate the effectiveness of the closure concept for debris containment, in the gravity-free environment of space, for a realistic debris target. The on-ground experimental test-bed is also used to showcase its utility for validating the dynamics simulation of the net deployment, and a full-scale automated setup would make possible a range of validation studies of other aspects of a tether-net debris capture mission.

  9. The Impacts of Changes to Nevada's Net Metering Policy on the Financial Performance and Adoption of Distributed Photovoltaics

    Energy Technology Data Exchange (ETDEWEB)

    Gagnon, Pieter [National Renewable Energy Lab. (NREL), Golden, CO (United States); Sigrin, Ben [National Renewable Energy Lab. (NREL), Golden, CO (United States); Gleason, Mike [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2017-01-01

    As the adoption of distributed photovoltaics (DPV) has continued to rapidly increase, a national conversation has begun about the efficacy of full-retail net metering as a means of achieving the diverse objectives of electricity pricing. This conversation has prompted studies that have primarily focused on the total costs and benefits of DPV. To compliment those studies, we here characterize the potential impacts of tariff design on the customer-economics and adoption of DPV, where recent changes in Nevada are taken as a case study. We show that an increase in fixed charges more strongly impacts the payback period of small systems, and a decrease in credit for exported electricity more strongly impacts the payback period of large systems. We project that these combined changes will reduce DPV adoption in Nevada; total capacity in 2030 was projected to reach up to 363 MW, with 226 MW having already been installed at the end of the second quarter of 2016. In contrast, if full retail net metering had continued, DPV capacity was projected to reach up to 1,280 MW at the end of 2030, which would account for an estimated 6.5% of the total sales of electricity by NV Energy at that time. We project that the DPV systems will decrease the gross revenue from bill collection by $48 million per year under the new tariffs, whereas the decrease in gross revenue could have reached $255 million per year if full retail net metering had been continued. Although these results are given in the context of Nevada, the trends shown are intended to help information similar upcoming decisions in other states.

  10. Improved netting

    International Nuclear Information System (INIS)

    Bramley, A.; Clabburn, R.J.T.

    1976-01-01

    A method is described for producing netting composed of longitudinal and transverse threads of irradiation cross linked thermoplastic material, the threads being joined together at their crossings by moulded masses of cross linked thermoplastic material. The thread may be formed of polyethylene filaments, subjected to a radiation dose of 15 to 25 MR. The moulding can be conducted at 245 0 to 260 0 C or higher. The product is claimed to be an improved quality of netting, with bonds of increased strength between crossing threads. (U.K.)

  11. Power deposition profiles and Poynting vector distribution of phased antenna arrays in the ion-cyclotron resonance heating of a NET/INTOR-type tokamak

    International Nuclear Information System (INIS)

    Bhatnagar, V.P.; Koch, R.

    1986-01-01

    The heating produced by magnetosonic waves launched from phased antenna arrays in the ion-cyclotron range of frequencies is studied for a large tokamak with NET/INTOR-like parameters. The model used combines a 3-D planar, cold-plasma, antenna-plasma coupling code and a 3-D non-circular, toroidal, hot-plasma/ray-tracing code. First, the fractional power absorption of a ray during a single transit through the absorption layer is studied in a D-T plasma indicating total absorption in all INTOR cases except during the initial state characterized by low plasma temperature and density. However, in this case the single-pass wave absorption can be increased considerably by adding a few per cent of hydrogen. Further, complete power deposition profiles and Poynting vector distributions are presented for 'symmetric' and 'antisymmetric' 2x2 antenna array configurations with ksub(parallel)-shaping. Excitation of coaxial modes has, for the first time, been demonstrated explicitly by analysis of the Poynting vector distribution in real space. An antenna configuration with a π-phasing in the z-direction (such that the radiated power spectrum peaks at ksub(parallel) approx.= 5 m -1 ) and the choice of 3lambda/4 long antenna elements with 'symmetric' excitation in the y-direction, are found to produce central RF power deposition profiles in the second-harmonic and minority heating of INTOR. Finally, from a comparison of results for circular and non-circular NET/INTOR plasmas with elongation kappa=1.6, it is found that in the latter wave focusing is greatly reduced and that the power density figures are lower by approximately a factor of 1.9 for the case treated. (author)

  12. Application of Distributed Temperature Sensing for coupled mapping of sedimentation processes and spatio-temporal variability of groundwater discharge in soft-bedded streams

    DEFF Research Database (Denmark)

    Sebok, Eva; Duque, C; Engesgaard, Peter

    2015-01-01

    , maximum and mean streambed temperatures as well as the daily amplitude and standard deviation of temperatures. The identified potential high-discharge areas were mostly located near the channel banks, also showing temporal variability because of the scouring and redistribution of streambed sediments......The delineation of groundwater discharge areas based on Distributed Temperature Sensing (DTS) data of the streambed can be difficult in soft-bedded streams where sedimentation and scouring processes constantly change the position of the fibre optic cable relative to the streambed. Deposition...... variability in streambed temperatures between October 2011 and January 2012. Detailed monthly streambed elevation surveys were carried out to monitor the position of the fibre optic cable relative to the streambed and to quantify the effect of sedimentation processes on streambed temperatures. Based...

  13. Petri Nets

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 4; Issue 9. Petri Nets - Applications. Y Narahari. General Article Volume 4 Issue 9 September 1999 pp 44-52 ... Author Affiliations. Y Narahari1. Department of Computer Science and Automation, Indian Institute of Science, Bangalore 560 012, India.

  14. Net Gain

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

    Describing the effect of tax incentives for import, production, and sale of nets and insecticides; and ..... So far, China is the only country where a system for the routine treatment of ...... 1993), and the trials in Ecuador and Peru (Kroeger et al.

  15. On Dynamic Analysis, Optimal Distribution of Cable Tention and Experiment of Cable NET Structures in Large Radio Telescope

    International Nuclear Information System (INIS)

    Duan, Baoyan

    2002-01-01

    This paper presents the researching activities, in which the nonlinear dynamic analysis, optimization of the cables' tension distribution, real 50 meters model experiment are discussed. The long cable structure has been utilized in new generation large radio telescope with the diameter of 500 meters. In design, there are six high concrete towers form which are six computer controlled long cables about 250 meters long met at a cabin, which is a hemisphere with 6 meters diameter. The cabin can be moved three dimensional to track the target. Within the cabin, there is a stable platform. The positioning precision for the platform and cabin are 4mm and 50cm respectively. By which means, the poisoning accuracy can be received becomes a sensible and important problem. For the sake of this, study on vibration of cable with respect to random wind, such as nonlinear response, vortex and galloping, is investigated in this paper. Desirable design is that the tension forces among the six long cables are the same, at least as even as possible. This will be benefit to the control of the system, so that the higher dynamic positioning precision is easy to be obtained. To meet this kind of requirement, the optimal distribution of the cable tensions among cables is discussed and pretty good result is received. Before the real 500 meters diameters antenna is built, an experiment model with 50 meters diameter was built in Xidian University of China, shown in figure 2. The dynamic analysis on vibration (random wind response, vortex and galloping), optimization of the cable tensions' distribution is made with good result. Lots of 50-meter-model site experiments are carried out with useful and valuable results, form which the theory and simulation model has been improved repeatedly until both the model simulation and experiment results are very closed so that the difference can be accepted from the viewpoint of thoroughly, systematically and deeply in the paper. The conclusion

  16. Coloured Petri Nets

    CERN Document Server

    Jensen, Kurt

    2009-01-01

    Coloured Petri Nets (CPN) is a graphical language for modelling and validating concurrent and distributed systems, and other systems in which concurrency plays a major role. This book introduces the constructs of the CPN modelling language and presents the related analysis methods. It provides a comprehensive road map for the practical use of CPN.

  17. Coloured Petri Nets

    DEFF Research Database (Denmark)

    Jensen, Kurt; Kristensen, Lars Michael

    Coloured Petri Nets (CPN) is a graphical language for modelling and validating concurrent and distributed systems, and other systems in which concurrency plays a major role. The development of such systems is particularly challenging because of inherent intricacies like possible nondeterminism an...

  18. Direct deterministic method for neutronics analysis and computation of asymptotic burnup distribution in a recirculating pebble-bed reactor

    International Nuclear Information System (INIS)

    Terry, W.K.; Gougar, H.D.; Ougouag, A.M.

    2002-01-01

    A new deterministic method has been developed for the neutronics analysis of a pebble-bed reactor (PBR). The method accounts for the flow of pebbles explicitly and couples the flow to the neutronics. The method allows modeling of once-through cycles as well as cycles in which pebbles are recirculated through the core an arbitrary number of times. This new work is distinguished from older methods by the systematically semi-analytical approach it takes. In particular, whereas older methods use the finite-difference approach (or an equivalent one) for the discretization and the solution of the burnup equation, the present work integrates the relevant differential equation analytically in discrete and complementary sub-domains of the reactor. Like some of the finite-difference codes, the new method obtains the asymptotic fuel-loading pattern directly, without modeling any intermediate loading pattern. This is a significant advantage for the design and optimization of the asymptotic fuel-loading pattern. The new method is capable of modeling directly both the once-through-then-out fuel cycle and the pebble recirculating fuel cycle. Although it currently includes a finite-difference neutronics solver, the new method has been implemented into a modular code that incorporates the framework for the future coupling to an efficient solver such as a nodal method and to modern cross section preparation capabilities. In its current state, the deterministic method presented here is capable of quick and efficient design and optimization calculations for the in-core PBR fuel cycle. The method can also be used as a practical 'scoping' tool. It could, for example, be applied to determine the potential of the PBR for resisting nuclear-weapons proliferation and to optimize proliferation-resistant features. However, the purpose of this paper is to show that the method itself is viable. Refinements to the code are under way, with the objective of producing a powerful reactor physics

  19. Net neutrality and audiovisual services

    OpenAIRE

    van Eijk, N.; Nikoltchev, S.

    2011-01-01

    Net neutrality is high on the European agenda. New regulations for the communication sector provide a legal framework for net neutrality and need to be implemented on both a European and a national level. The key element is not just about blocking or slowing down traffic across communication networks: the control over the distribution of audiovisual services constitutes a vital part of the problem. In this contribution, the phenomenon of net neutrality is described first. Next, the European a...

  20. Traditional nets interfere with the uptake of long-lasting insecticidal nets in the Peruvian Amazon: the relevance of net preference for achieving high coverage and use.

    Directory of Open Access Journals (Sweden)

    Koen Peeters Grietens

    Full Text Available While coverage of long-lasting insecticide-treated nets (LLIN has steadily increased, a growing number of studies report gaps between net ownership and use. We conducted a mixed-methods social science study assessing the importance of net preference and use after Olyset® LLINs were distributed through a mass campaign in rural communities surrounding Iquitos, the capital city of the Amazonian region of Peru.The study was conducted in the catchment area of the Paujil and Cahuide Health Centres (San Juan district between July 2007 and November 2008. During a first qualitative phase, participant observation and in-depth interviews collected information on key determinants for net preference and use. In a second quantitative phase, a survey among recently confirmed malaria patients evaluated the acceptability and use of both LLINs and traditional nets, and a case control study assessed the association between net preference/use and housing structure (open vs. closed houses.A total of 10 communities were selected for the anthropological fieldwork and 228 households participated in the quantitative studies. In the study area, bed nets are considered part of the housing structure and are therefore required to fulfil specific architectural and social functions, such as providing privacy and shelter, which the newly distributed Olyset® LLINs ultimately did not. The LLINs' failure to meet these criteria could mainly be attributed to their large mesh size, transparency and perceived ineffectiveness to protect against mosquitoes and other insects, resulting in 63.3% of households not using any of the distributed LLINs. Notably, LLIN usage was significantly lower in houses with no interior or exterior walls (35.2% than in those with walls (73.8% (OR = 5.2, 95CI [2.2; 12.3], p<0.001.Net preference can interfere with optimal LLIN use. In order to improve the number of effective days of LLIN protection per dollar spent, appropriate quantitative and qualitative

  1. National assessment of Canadian pandemic preparedness: Employing InFluNet to identify high-risk areas for inter-wave vaccine distribution

    Directory of Open Access Journals (Sweden)

    Patrick Saunders-Hastings

    2017-08-01

    Full Text Available Background: Influenza pandemics emerge at irregular and unpredictable intervals to cause substantial health, economic and social burdens. Optimizing health-system response is vital to mitigating the consequences of future pandemics. Methods: We developed a mathematical model to assess the preparedness of Canadian health systems to accommodate pandemic-related increases in patient demand. We identify vulnerable areas, assess the potential of inter-wave vaccination to mitigate impacts and evaluate the association between demographic and health-system characteristics in order to identify predictors of pandemic consequences. Results: Modelled average attack rates were 23.7–37.2% with no intervention and 2.5–6.4% with pre-vaccination. Peak acute-care demand was 7.5–19.5% of capacity with no intervention and 0.6–2.6% with pre-vaccination. The peak ICU demand was 39.3–101.8% with no intervention and 2.9–13.3% with pre-vaccination. Total mortality was 2258–7944 with no intervention and 88–472 with pre-vaccination. Regions of Southern Ontario were identified as most vulnerable to surges in patient demand. The strongest predictors of peak acute-care demand and ICU demand were acute-care bed capacity (R = −0.8697; r2 = 0.7564 and ICU bed capacity (R = −0.8151; r2 = 0.6644, respectively. Demographic characteristics had mild associations with predicted pandemic consequences. Conclusion: Inter-wave vaccination provided adequate acute-care resource protection under all scenarios; ICU resource adequacy was protected under mild disease assumptions, but moderate and severe diseases caused demand to exceed expected availability in 21% and 49% of study areas, respectively. Our study informs priority vaccine distribution strategies for pandemic planning, emphasizing the need for targeted early vaccine distribution to high-risk individuals and areas. Keywords: Pandemic influenza, Vaccination

  2. Net Locality

    DEFF Research Database (Denmark)

    de Souza e Silva, Adriana Araujo; Gordon, Eric

    Provides an introduction to the new theory of Net Locality and the profound effect on individuals and societies when everything is located or locatable. Describes net locality as an emerging form of location awareness central to all aspects of digital media, from mobile phones, to Google Maps......, to location-based social networks and games, such as Foursquare and facebook. Warns of the threats these technologies, such as data surveillance, present to our sense of privacy, while also outlining the opportunities for pro-social developments. Provides a theory of the web in the context of the history...... of emerging technologies, from GeoCities to GPS, Wi-Fi, Wiki Me, and Google Android....

  3. The Uniframe .Net Web Service Discovery Service

    National Research Council Canada - National Science Library

    Berbeco, Robert W

    2003-01-01

    Microsoft .NET allows the creation of distributed systems in a seamless manner Within NET small, discrete applications, referred to as Web services, are utilized to connect to each other or larger applications...

  4. Numerical Simulations of the Effects of a Tidal Turbine Array on Near-Bed Velocity and Local Bed Shear Stress

    Directory of Open Access Journals (Sweden)

    Philip A. Gillibrand

    2016-10-01

    Full Text Available We apply a three-dimensional hydrodynamic model to consider the potential effects of energy extraction by an array of tidal turbines on the ambient near-bed velocity field and local bed shear stress in a coastal channel with strong tidal currents. Local bed shear stress plays a key role in local sediment dynamics. The model solves the Reynold-averaged Navier-Stokes (RANS equations on an unstructured mesh using mixed finite element and finite volume techniques. Tidal turbines are represented through an additional form drag in the momentum balance equation, with the thrust imparted and power generated by the turbines being velocity dependent with appropriate cut-in and cut-out velocities. Arrays of 1, 4 and 57 tidal turbines, each of 1.5 MW capacity, were simulated. Effects due to a single turbine and an array of four turbines were negligible. The main effect of the array of 57 turbines was to cause a shift in position of the jet through the tidal channel, as the flow was diverted around the tidal array. The net effect of this shift was to increase near-bed velocities and bed shear stress along the northern perimeter of the array by up to 0.8 m·s−1 and 5 Pa respectively. Within the array and directly downstream, near-bed velocities and bed shear stress were reduced by similar amounts. Changes of this magnitude have the potential to modify the known sand and shell banks in the region. Continued monitoring of the sediment distributions in the region will provide a valuable dataset on the impacts of tidal energy extraction on local sediment dynamics. Finally, the mean power generated per turbine is shown to decrease as the turbine array increased in size.

  5. Determination of concentration distribution and velocity of a catalyst in a model of a fluidized bed reactor using nuclear techniques

    International Nuclear Information System (INIS)

    Santos, V.A. dos.

    1981-09-01

    A simplified model of a cracking unit was construct. The gaseous phase consisted of air, the solid phase (zeolite catalyst cracking) and both the phases circulate at the ambiente temperature in the steady state with 500 g of catalyst and air flow of 1600 1/h. Measurements for the circulation time of the solid phase (catalyst), concentration and radial distribution of catalyst have been carried out. The reduced experimental model of the cracking reactor (FCC) was used and radioctive tracer and attenuation of γ-radiation techniques were employed. (E.G.) [pt

  6. Impact of mass distribution of free long-lasting insecticidal nets on childhood malaria morbidity: The Togo National Integrated Child Health Campaign

    Directory of Open Access Journals (Sweden)

    Sodahlon Yao K

    2010-07-01

    Full Text Available Abstract Background An evaluation of the short-term impact on childhood malaria morbidity of mass distribution of free long-lasting insecticidal nets (LLINs to households with children aged 9-59 months as part of the Togo National Integrated Child Health Campaign. Methods The prevalence of anaemia and malaria in children aged zero to 59 months was measured during two cross-sectional household cluster-sample surveys conducted during the peak malaria transmission, three months before (Sept 2004, n = 2521 and nine months after the campaign (Sept 2005, n = 2813 in three districts representative of Togo's three epidemiological malaria transmission regions: southern tropical coastal plains (Yoto, central fertile highlands (Ogou and northern semi-arid savannah (Tone. Results In households with children 65% in all 3 districts. Reported ITN use by children during the previous night was 35.9%, 43.8% and 80.6% in Yoto, Ogou and Tone, respectively. Rainfall patterns were comparable in both years. The overall prevalence of moderate to severe anaemia (Hb The effect was predominantly seen in children aged 18-59 months and in the two southern districts: PR (95% CI for moderate to severe anaemia and clinical malaria: Yoto 0.62 (0.44-0.88 and 0.49 (0.35-0.75; Ogou 0.54 (0.37-0.79 and 0.85 (0.57-1.27, respectively. Similar reductions occurred in children Conclusions A marked reduction in childhood malaria associated morbidity was observed in the year following mass distribution of free LLINs in two of the three districts in Togo. Sub-national level impact evaluations will contribute to a better understanding of the impact of expanding national malaria control efforts.

  7. Climate change and its impacts on vegetation distribution and net primary productivity of the alpine ecosystem in the Qinghai-Tibetan Plateau.

    Science.gov (United States)

    Gao, Qingzhu; Guo, Yaqi; Xu, Hongmei; Ganjurjav, Hasbagen; Li, Yue; Wan, Yunfan; Qin, Xiaobo; Ma, Xin; Liu, Shuo

    2016-06-01

    Changes in climate have caused impacts on ecosystems on all continents scale, and climate change is also projected to be a stressor on most ecosystems even at the rate of low- to medium-range warming scenarios. Alpine ecosystem in the Qinghai-Tibetan Plateau is vulnerable to climate change. To quantify the climate change impacts on alpine ecosystems, we simulated the vegetation distribution and net primary production in the Qinghai-Tibetan Plateau for three future periods (2020s, 2050s and 2080s) using climate projection for RCPs (Representative Concentration Pathways) RCP4.5 and RCP8.5 scenarios. The modified Lund-Potsdam-Jena Dynamic Global Vegetation Model (LPJ model) was parameter and test to make it applicable to the Qinghai-Tibetan Plateau. Climate projections that were applied to LPJ model in the Qinghai-Tibetan Plateau showed trends toward warmer and wetter conditions. Results based on climate projections indicated changes from 1.3°C to 4.2°C in annual temperature and changes from 2% to 5% in annual precipitation. The main impacts on vegetation distribution was increase in the area of forests and shrubs, decrease in alpine meadows which mainly replaced by shrubs which dominated the eastern plateau, and expanding in alpine steppes to the northwest dominated the western and northern plateau. The NPP was projected to increase by 79% and 134% under the RCP4.5 and RCP8.5. The projected NPP generally increased about 200gC·m(-2)·yr(-1) in most parts of the plateau with a gradual increase from the eastern to the western region of the Qinghai-Tibetan Plateau at the end of this century. Copyright © 2016 Elsevier B.V. All rights reserved.

  8. Intended and unintended effects of policy measures aimed at promoting net neutrality: an examination of the value chain for video distribution

    NARCIS (Netherlands)

    Nooren, P.; Leurdijk, A.; van Eijk, N.

    2012-01-01

    Net neutrality has, for a number of years, been a topic of often heated discussion in the Internet and telecom community. Net neutrality, in essence, requires that Internet users have open access to content and applications on the Internet, and, vice versa, that providers of applications can reach

  9. Bed diameter effects and incipient slugging in gas fluidized beds

    International Nuclear Information System (INIS)

    Agarwal, P.K.

    1986-01-01

    The coalescence and growth of bubble swarms formed at the distributor of a fluidized bed gives rise to lateral as well as vertical distributions of bubble properties. However, existing models employ average bubble properties obtained largely from semi-empirical considerations. In a recent Paper, the author developed a bubble growth model based on a population balance approach. Analytical expressions were derived for the bubble characteristic distributions and averages. However, the model, developed for unconstrained growth, did not take into account the effect of the bed diameter and the possibility of slugging. In this Paper, the model is extended to take these aspects into account. A slugging criterion is also developed which is expected to be valid for the regime where incipient slugging depends on the bed height as well as the region where bed height does not significantly affect minimum slugging conditions

  10. Dispersion of Bed Load Particles

    OpenAIRE

    SAWAI, Kenji

    1987-01-01

    The motion of bed load particles is so irregular that they disperse remarkably with time.In this study, some flume tests using painted tracer particles were carried out, in which thedispersive property of tracers changed variously with sediment feed rate.In analysing this process, a stochastic simulation model is proposed where it is discussedabout the degree of exposure of individual particle near the bed surface and about the variationof its pick up rate. The exponential distribution of ste...

  11. Distribution of discontinuous mudstone beds within wave-dominated shallow-marine deposits: Star Point Sandstone and Blackhawk Formation, Eastern Utah, USA

    OpenAIRE

    Eide, Christian; Buckley, Simon; Howell, John

    2017-01-01

    Deposits of wave-dominated shorelines are typically considered to act as relatively simple hydrocarbon reservoirs and are commonly modeled as “tanks of sand”. However, important heterogeneities that can act as barriers to fluid flow occur at the parasequence, bedset and bed scales, especially in viscous oil or low permeability oil fields. Heterogeneities at the parasequence and bedset scale have been well-studied, but discontinuous mudstone-beds occurring within the shoreface have received li...

  12. Art/Net/Work

    DEFF Research Database (Denmark)

    Andersen, Christian Ulrik; Lindstrøm, Hanne

    2006-01-01

    The seminar Art|Net|Work deals with two important changes in our culture. On one side, the network has become essential in the latest technological development. The Internet has entered a new phase, Web 2.0, including the occurrence of as ‘Wiki’s’, ‘Peer-2-Peer’ distribution, user controlled...... on the ‘network’ itself as a phenomenon and are often using technological networks as a mean of production and distribution. This changes the artistic practice and the distribution channels of art works – and the traditional notions of ‘work’, ‘origin’ and ‘rights’ are increasingly perceived as limiting...... the praxis of the artist. We see different kinds of interventions and activism (including ‘hacktivism’) using the network as a way of questioning the invisible rules that govern public and semi-public spaces. Who ‘owns’ them? What kind of social relationships do they generate? On what principle...

  13. Measures of Malaria Burden after Long-Lasting Insecticidal Net Distribution and Indoor Residual Spraying at Three Sites in Uganda: A Prospective Observational Study

    Science.gov (United States)

    Katureebe, Agaba; Zinszer, Kate; Arinaitwe, Emmanuel; Charland, Katia; Kigozi, Ruth; Kilama, Maxwell; Nankabirwa, Joaniter; Yeka, Adoke; Mawejje, Henry; Mpimbaza, Arthur; Donnelly, Martin J.; Rosenthal, Philip J.; Lindsay, Steve W.; Staedke, Sarah G.; Smith, David L.; Kamya, Moses R.; Dorsey, Grant

    2016-01-01

    Background Long-lasting insecticidal nets (LLINs) and indoor residual spraying of insecticide (IRS) are the primary vector control interventions used to prevent malaria in Africa. Although both interventions are effective in some settings, high-quality evidence is rarely available to evaluate their effectiveness following deployment by a national malaria control program. In Uganda, we measured changes in key malaria indicators following universal LLIN distribution in three sites, with the addition of IRS at one of these sites. Methods and Findings Comprehensive malaria surveillance was conducted from October 1, 2011, to March 31, 2016, in three sub-counties with relatively low (Walukuba), moderate (Kihihi), and high transmission (Nagongera). Between 2013 and 2014, universal LLIN distribution campaigns were conducted in all sites, and in December 2014, IRS with the carbamate bendiocarb was initiated in Nagongera. High-quality surveillance evaluated malaria metrics and mosquito exposure before and after interventions through (a) enhanced health-facility-based surveillance to estimate malaria test positivity rate (TPR), expressed as the number testing positive for malaria/number tested for malaria (number of children tested for malaria: Walukuba = 42,833, Kihihi = 28,790, and Nagongera = 38,690); (b) cohort studies to estimate the incidence of malaria, expressed as the number of episodes per person-year [PPY] at risk (number of children observed: Walukuba = 340, Kihihi = 380, and Nagongera = 361); and (c) entomology surveys to estimate household-level human biting rate (HBR), expressed as the number of female Anopheles mosquitoes collected per house-night of collection (number of households observed: Walukuba = 117, Kihihi = 107, and Nagongera = 107). The LLIN distribution campaign substantially increased LLIN coverage levels at the three sites to between 65.0% and 95.5% of households with at least one LLIN. In Walukuba, over the 28-mo post-intervention period

  14. Spatio-temporal distribution patterns of the invasive macroalga Sargassum muticum within a Danish Sargassum-bed

    DEFF Research Database (Denmark)

    Thomsen, M. S.; Wernberg, T.; Stæhr, P. A.

    2006-01-01

    Sargassum muticum was first observed in Scandinavia in Limfjorden (Denmark) in 1984, where it is now the most abundant and conspicuous macroalga. Despite the ecological importance of Sargassum, few studies have described seasonal patterns within Scandinavian Sargassum beds. We quantified the dyna...... and sediment stress limits Sargasum in shallow waters, and the presence of stable boulder substratum facilitate Sargassum. Competition for space from other macroalgae and herbivory are probably of minor importance.......Sargassum muticum was first observed in Scandinavia in Limfjorden (Denmark) in 1984, where it is now the most abundant and conspicuous macroalga. Despite the ecological importance of Sargassum, few studies have described seasonal patterns within Scandinavian Sargassum beds. We quantified...... the dynamics of macroalgae among years and seasons along a depth transect through a typical Sargassum bed in Limfjorden. The annual investigations (summer transects 1989-1999) showed a gradual increase in the dominance of Sargassum, especially at the 2-4-m depth interval. Significant seasonal dynamics...

  15. Gas distributor for fluidized bed coal gasifier

    Science.gov (United States)

    Worley, Arthur C.; Zboray, James A.

    1980-01-01

    A gas distributor for distributing high temperature reaction gases to a fluidized bed of coal particles in a coal gasification process. The distributor includes a pipe with a refractory reinforced lining and a plurality of openings in the lining through which gas is fed into the bed. These feed openings have an expanding tapered shape in the downstream or exhaust direction which aids in reducing the velocity of the gas jets as they enter the bed.

  16. Coloured Petri Nets

    DEFF Research Database (Denmark)

    Jensen, Kurt

    1987-01-01

    The author describes a Petri net model, called coloured Petri nets (CP-nets), by means of which it is possible to describe large systems without having to cope with unnecessary details. The author introduces CP-nets and provide a first impression of their modeling power and the suitability...

  17. Learning Visual Basic NET

    CERN Document Server

    Liberty, Jesse

    2009-01-01

    Learning Visual Basic .NET is a complete introduction to VB.NET and object-oriented programming. By using hundreds of examples, this book demonstrates how to develop various kinds of applications--including those that work with databases--and web services. Learning Visual Basic .NET will help you build a solid foundation in .NET.

  18. 1 The Effect of Camber Bed Drainage

    African Journals Online (AJOL)

    User

    The Effect of Camber Bed Drainage Landforms on Soil. Nutrient Distribution and Grain Yield of Maize on the Vertisols ... The Vertisols of the Accra Plains of Ghana are water logged after significant rainfall ... Excess application of 15-15-15 NPK and sulphate of ammonia fertilizers (150% .... beds, before planting and nutrient.

  19. Net metering in British Columbia : white paper

    International Nuclear Information System (INIS)

    Berry, T.

    2003-01-01

    Net metering was described as being the reverse registration of an electricity customer's revenue meter when interconnected with a utility's grid. It is a provincial policy designed to encourage small-distributed renewable power generation such as micro-hydro, solar energy, fuel cells, and larger-scale wind energy. It was noted that interconnection standards for small generation is an important issue that must be addressed. The British Columbia Utilities Commission has asked BC Hydro to prepare a report on the merits of net metering in order to support consultations on a potential net metering tariff application by the utility. This report provides information on net metering with reference to experience in other jurisdictions with net metering, and the possible costs and benefits associated with net metering from both a utility and consumer perspective. Some of the barriers and policy considerations for successful implementation of net metering were also discussed. refs., tabs., figs

  20. Reservoir evaluation of thin-bedded turbidites and hydrocarbon pore thickness estimation for an accurate quantification of resource

    Science.gov (United States)

    Omoniyi, Bayonle; Stow, Dorrik

    2016-04-01

    One of the major challenges in the assessment of and production from turbidite reservoirs is to take full account of thin and medium-bedded turbidites (succession, they can go unnoticed by conventional analysis and so negatively impact on reserve estimation, particularly in fields producing from prolific thick-bedded turbidite reservoirs. Field development plans often take little note of such thin beds, which are therefore bypassed by mainstream production. In fact, the trapped and bypassed fluids can be vital where maximising field value and optimising production are key business drivers. We have studied in detail, a succession of thin-bedded turbidites associated with thicker-bedded reservoir facies in the North Brae Field, UKCS, using a combination of conventional logs and cores to assess the significance of thin-bedded turbidites in computing hydrocarbon pore thickness (HPT). This quantity, being an indirect measure of thickness, is critical for an accurate estimation of original-oil-in-place (OOIP). By using a combination of conventional and unconventional logging analysis techniques, we obtain three different results for the reservoir intervals studied. These results include estimated net sand thickness, average sand thickness, and their distribution trend within a 3D structural grid. The net sand thickness varies from 205 to 380 ft, and HPT ranges from 21.53 to 39.90 ft. We observe that an integrated approach (neutron-density cross plots conditioned to cores) to HPT quantification reduces the associated uncertainties significantly, resulting in estimation of 96% of actual HPT. Further work will focus on assessing the 3D dynamic connectivity of the low-pay sands with the surrounding thick-bedded turbidite facies.

  1. Can the collection of expired long-lasting insecticidal nets reduce their coverage and use? Sociocultural aspects related to LLIN life cycle management and use in four districts in Madagascar.

    Science.gov (United States)

    Ramanantsoa, Ambinina; Wilson-Barthes, Marta; Rahenintsoa, Rindra; Hoibak, Sarah; Ranaivoharimina, Harilala; Rahelimalala, Martha Delphine; Rakotomanga, Avotiana; Finlay, Alyssa; Muela Ribera, Joan; Peeters Grietens, Koen

    2017-10-10

    There is growing awareness of the likely impact increased numbers of LLINs will have on the environment, if not disposed of or recycled appropriately. As part of a World Health Organization (WHO) and United Nations Environment Programme (UNEP) pilot study to assess environmentally-sound and cost-effective LLIN recycling strategies, the USAID-Deliver Project collected 22,559 used bed nets in Madagascar. A social science study was conducted to provide data on socio-cultural factors related to collection and replacement of LLINs, including impact on primary and other net uses. Ethnographic exploratory research was carried out following the pilot USAID-Deliver net collection and recycling campaign in Betioky, Tsihombe, Fenerive Est and Ambanja districts of Madagascar, triangulating participant observation, interviewing and group discussions. Sampling was theoretical and data analysis was a continuous and iterative process concurrent to data collection. Final analysis was conducted using NVivo10. The following themes emerged as contributing to the success of collecting expired LLINs in the community for recycling purposes: (i) net adequacy and preference: characteristic differences between collected and newly distributed nets lead to communities' reticence to relinquish old nets before confirming new nets were appropriate for intended use. Where newly distributed nets failed to meet local requirements, this was expected to increase alternative uses and decrease household turn over. (ii) Net collection strategies: the net collection campaign brought net use out of the private sphere and into the public arena. Net owners reported feeling ashamed when presenting damaged nets in public for collection, leading to reduced net relinquishment. (iii) Net lifecycle: communities perceived nets as being individually owned and economic value was attributed both to good-condition nets for sleeping and to worn nets for alternative/secondary purposes. Collecting nets at the stage of

  2. Long-lasting insecticidal net source, ownership and use in the context of universal coverage: a household survey in eastern Rwanda.

    Science.gov (United States)

    Kateera, Fredrick; Ingabire, Chantal M; Hakizimana, Emmanuel; Rulisa, Alexis; Karinda, Parfait; Grobusch, Martin P; Mutesa, Leon; van Vugt, Michèle; Mens, Petra F

    2015-10-06

    Universal long-lasting insecticidal net (LLIN) coverage (ULC) has reduced malaria morbidity and mortality across Africa. Although information is available on bed net use in specific groups, such as pregnant women and children under 5 years, there is paucity of data on their use among the general population. Bed net source, ownership and determinants of use among individuals from households in an eastern Rwanda community 8 months after a ULC were characterized. Using household-based, interviewer-administered questionnaires and interviewer-direct observations, data on bed net source, ownership and key determinants of net use, including demographics, socio-economic status indicators, house structure characteristics, as well as of bed net quantity, type and integrity, were collected from 1400 randomly selected households. Univariate and mixed effects logistic regression modelling was done to assess for determinants of bed net use. A total of 1410 households and 6598 individuals were included in the study. Overall, the proportion of households with at least one net was 92 % while bed net usage was reported among 72 % of household members. Of the households surveyed, a total ownership of 2768 nets was reported, of which about 96 % were reportedly LLINs received from the ULC. By interviewer-physical observation, 88 % of the nets owned were of the LLIN type with the remaining 12 % did not carry any mark to enable type recognition. The odds of bed net use were significantly lower among males and individuals: from households of low socio-economic status, from households with economic status, number of bed nets and type and number of sleeping spaces were key determinants of bed net use. To maximize impact of ULC, strategies that target males as well as those that ensure ITN coverage for all, address barriers to feasible and convenient bed net use including covering over all sleeping space types, and provide net hanging supports, are needed.

  3. The impact of benthic fauna on fluvial bed load transport: Challenges of upscaling laboratory experiments to river and landscape scales.

    Science.gov (United States)

    Rice, S. P.

    2012-04-01

    The impact on sediment transport processes and channel morphology of several relatively large, iconic animals including beaver and salmon is increasingly well understood. However, many other aquatic fauna are important zoogeomorphic agents and ecosystem engineers. These somewhat overlooked "Cinderella" species include benthic aquatic insect larvae, freshwater crustaceans and many species of fish. Despite relatively modest individual effects, the ubiquity, abundance and cumulative impact of these organisms makes them a potentially significant agency, with as yet undiscovered and unquantified impacts on channel morphology and sediment fluxes. Their actions (digging, foraging, moving, burrowing), constructions and secretions modify bed sediment characteristics (grain size distribution, interlock, imbrication, protrusion), alter bed topography (thence hydraulic roughness) and contribute to biogenic restraints on grain movement. In turn, they can affect the distribution of surface particle entrainment thresholds and bed shear stresses, with implications for bed load transport. Flume experiments have measured some of these impacts and provided direct observations of the mechanisms involved, but many of the most interesting research questions pertain to the impact of these animals at reach, catchment and even landscape scales: Not least, what is the impact of small aquatic animals on bed load flux and yield? This presentation will consider some of the challenges involved in answering this question; that is, of scaling up experimental understanding of how aquatic animals affect bed load transport processes to river scales. Pertinent themes include: (1) the potential impacts of experimental arrangements on the behaviours and activities that affect hydraulic or geomorphological processes; (2) field coincidence of the spatial and temporal distributions of (a) the animals and their behaviours with (b) the physical conditions (substrates, flows) under which those animals are

  4. Net4Care

    DEFF Research Database (Denmark)

    Christensen, Henrik Bærbak; Hansen, Klaus Marius

    2012-01-01

    , health centers are getting larger and more distributed, and the number of healthcare professionals does not follow the trend in chronic diseases. All of this leads to a need for telemedical and mobile health applications. In a Danish context, these applications are often developed through local...... (innovative) initiatives with little regards for national and global (standardization) initiatives. A reason for this discrepancy is that the software architecture for national (and global) systems and standards are hard to understand, hard to develop systems based on, and hard to deploy. To counter this, we...... propose a software ecosystem approach for telemedicine applications, providing a framework, Net4Care, encapsulating national/global design decisions with respect to standardization while allowing for local innovation. This paper presents an analysis of existing systems, of requirements for a software...

  5. The origin and distribution of HAPs elements in relation to maceral composition of the A1 lignite bed (Paleocene, Calvert Bluff Formation, Wilcox Group), Calvert mine area, east-central Texas

    Science.gov (United States)

    Crowley, Sharon S.; Warwick, Peter D.; Ruppert, Leslie F.; Pontolillo, James

    1997-01-01

    The origin and distribution of twelve potentially Hazardous Air Pollutants (HAPs; As, Be, Cd, Cr, Co, Hg, Mn, Ni, Pb, Sb, Se, and U) identified in the 1990 Clean Air Act Amendments were examined in relation to the maceral composition of the A1 bed (Paleocene, Calvert Bluff Formation, Wilcox Group) of the Calvert mine in east-central Texas. The 3.2 m-thick A1 bed was divided into nine incremental channel samples (7 lignite samples and 2 shaley coal samples) on the basis of megascopic characteristics. Results indicate that As, Cd, Cr, Ni, Pb, Sb, and U are strongly correlated with ash yield and are enriched in the shaley coal samples. We infer that these elements are associated with inorganic constituents in the coal bed and may be derived from a penecontemporaneous stream channel located several kilometers southeast of the mining block. Of the HAPs elements studied, Mn and Hg are the most poorly correlated to ash yield. We infer an organic association for Mn; Hg may be associated with pyrite. The rest of the trace elements (Be, Co, and Se) are weakly correlated with ash yield. Further analytical work is necessary to determine the mode of occurrence for these elements. Overall, concentrations of the HAPs elements are generally similar to or less than those reported in previous studies of lignites of the Wilcox Group, east-central region, Texas. Petrographic analysis indicates the following ranges in composition for the seven lignite samples: liptinites (5–8%), huminites (88–95%), and inertinites (trace amounts to 7%). Samples from the middle portion of the A1 bed contain abundant crypto-eugelinite compared to the rest of the samples; this relationship suggests that the degradation of plant material was an important process during the development of the peat mire. With the exception of Hg and Mn, relatively low levels of the HAPs elements studied are found in the samples containing abundant crypto-eugelinite. We infer that the peat-forming environment for this

  6. Using high-resolution suspended-sediment measurements to infer changes in the topographic distribution and grain size of bed sediment in the Colorado River downstream from Glen Canyon Dam

    Science.gov (United States)

    Topping, D. J.; Rubin, D. M.; Melis, T. S.; Wright, S. A.

    2004-12-01

    eddy bars. Thus, it is advantageous to analyze suspended-sediment concentration and grain-size data to infer changes in the topographic distribution and grain size of the upstream bed sediment. Rubin and Topping (2001) developed and tested a theory-based technique that can be used for this purpose. Their parameter "β " is a nondimensional measure of the average bed-surface grain-size that interacts with the suspended sediment in the flow. Analyses of the laser-acoustic datasets indicate that, when the Colorado River is relatively enriched with respect to finer sand, the discharge of water, and the concentration and grain size of the suspended sand are all positively correlated. During these periods, β is negatively correlated with discharge, indicating that the sand on the bed is finer at higher elevations along the banks. Although water discharge and the concentration of suspended sand remain positively correlated when the river is relatively depleted in finer sand, grain size of suspended sand then becomes negatively correlated with both the discharge of water and suspended-sand concentration. The greater decrease in β as a function of discharge demonstrates the decrease in the grain size of the bed sand as a function of elevation is much greater under sand-depleted conditions than under sand-enriched conditions. Thus, these analyses indicate that, during periods of erosion, sand is winnowed preferentially from lower elevations along the river.

  7. Planning of nets

    International Nuclear Information System (INIS)

    Carberry, M

    1996-01-01

    The paper is about the planning of nets in areas of low density like it is the case of the rural areas. The author includes economic and technological aspects, planning of nets, demands and management among others

  8. Annotating Coloured Petri Nets

    DEFF Research Database (Denmark)

    Lindstrøm, Bo; Wells, Lisa Marie

    2002-01-01

    Coloured Petri nets (CP-nets) can be used for several fundamentally different purposes like functional analysis, performance analysis, and visualisation. To be able to use the corresponding tool extensions and libraries it is sometimes necessary to include extra auxiliary information in the CP......-net. An example of such auxiliary information is a counter which is associated with a token to be able to do performance analysis. Modifying colour sets and arc inscriptions in a CP-net to support a specific use may lead to creation of several slightly different CP-nets – only to support the different uses...... of the same basic CP-net. One solution to this problem is that the auxiliary information is not integrated into colour sets and arc inscriptions of a CP-net, but is kept separately. This makes it easy to disable this auxiliary information if a CP-net is to be used for another purpose. This paper proposes...

  9. Providing insecticide treated bed nets in antiretroviral treatment ...

    African Journals Online (AJOL)

    HIV-replication.5-13 Mathematical models show that repeated ... antiretroviral treatment clinics in Malawi: a pilot ... related disease or AIDS.3 In addition, there are between 300 - ... and growing evidence of interactive pathology.1,2. HIV ..... by the HIV Unit and its partners. ... procurement and supply chain systems developed.

  10. Assessment of the Efficacy of Deltamethrin Impregnated Bed Nets ...

    African Journals Online (AJOL)

    The impact of deltamethrin treated bednets and walls were assessed on school children aged 12-18 years, in a community secondary school in Ono, Nigeria. Children with body weights of 45-60kg were given 2 tablets of fansidar to clear parasites in their system while those with body weights of 60kg and above were given ...

  11. Practice Hospital Bed Safety

    Science.gov (United States)

    ... Home For Consumers Consumer Updates Practice Hospital Bed Safety Share Tweet Linkedin Pin it More sharing options ... It depends on the complexity of the bed." Safety Tips CDRH offers the following safety tips for ...

  12. Bed Bugs and Schools

    Science.gov (United States)

    Bed bugs have long been a pest – feeding on blood, causing itchy bites and generally irritating their human hosts. They are successful hitchhikers, and can move from an infested site to furniture, bedding, baggage, boxes, and clothing.

  13. The Uniframe .Net Web Service Discovery Service

    National Research Council Canada - National Science Library

    Berbeco, Robert W

    2003-01-01

    ...) and registered with Internet Information Server (IIS), and can be applied in numerous fashions This project uses the NET capabilities to create a distributed discovery service (called as UNWSDS...

  14. A Lightweight TwiddleNet Portal

    National Research Council Canada - National Science Library

    Rimikis, Antonios M

    2008-01-01

    TwiddleNet is a distributed architecture of personal servers that harnesses the power of the mobile devices, enabling real time information and file sharing of multiple data types from commercial-off-the-shelf platforms...

  15. Control of Petri Nets by finite automata

    Energy Technology Data Exchange (ETDEWEB)

    Burkhard, H D

    1983-01-01

    Petri Nets are considered where the firings are controlled by finite automata. The control may be distributed to various automata working over disjoint sets of transitions. To avoid deadlocks and conflicts for the whole system the distribution of control must be organised in an appropriate manner. The existence of deadlocks and conflicts is shown to be undecidable in general, but conflict resolving and deadlock free controls can be constructed for given nets. 10 references.

  16. Effects of Educational Intervention on Long-Lasting Insecticidal Nets Use in a Malarious Area, Southeast Iran

    Directory of Open Access Journals (Sweden)

    Abdol Hossein Madani

    2012-04-01

    Full Text Available Long-lasting insecticidal nets (LLINs have been advocated as an effective tool against malaria transmission. However, success of this community based intervention largely depends on the knowledge and practice regarding malaria and its prevention. According to the national strategy plan on evaluation of LLINs (Olyset nets, this study was conducted to determine the perceptions and practices about malaria and to improve use of LLINs in Bashagard district, one of the important foci of malaria in southeast Iran. The study area comprised 14 villages that were randomized in two clusters and designated as LLINs and untreated nets. Each of households in both clusters received two bed nets by the free distribution and delivery. After one month quantitative data collection method was used to collect information regarding the objectives of the study. On the basis of this information, an educational program was carried out in both areas to increase motivation for use of bed nets. Community knowledge and practice regarding malaria and LLIN use assessed pre- and post-educational program. The data were analyzed using SPSS ver.16 software. At baseline, 77.5% of respondents in intervention and 69.4 % in control area mentioned mosquito bite as the cause of malaria, this awareness increased significantly in intervention (90.3% and control areas (87.9%, following the educational program. A significant increase also was seen in the proportion of households who used LLINs the previous night (92.5% compared with untreated nets (87.1%. Educational status was an important predictor of LLINs use. Regular use of LLIN was considerably higher than the targeted coverage (80% which recommended by World Heaths Organization. About 81.1% and 85.3% of respondents from LLIN and control areas reported that mosquito nuisance and subsequent malaria transmission were the main determinants of bed net use. These findings highlight a need for educational intervention in implementation of

  17. The effect of vibration on bed voidage behaviors in fluidized beds with large particles

    Directory of Open Access Journals (Sweden)

    H. Jin

    2007-09-01

    Full Text Available The effects of vibration parameters, operating conditions and material properties on bed voidage were investigated using an optical fiber probe approach in a vibrating fluidized bed with a diameter of 148 mm. Variables studied included frequency (0-282 s-1, amplitude (0 mm-1 mm, bed height (0.1 m-0.4 m as well as four kinds of particles (belonging to Geldart's B and D groups. The axial and radial voidage distribution with vibration is compared with that without vibration, which shows vibration can aid in the fluidization behaviors of particles. For a larger vibration amplitude, the vibration seriously affects bed voidage. The vibration energy can damp out for particle layers with increasing the bed height. According to analysis of experimental data, an empirical correlation for predicting bed voidage, giving good agreement with the experimental data and a deviation within ±15%, was proposed.

  18. Numerical investigation of the 3-dimensional steady-state temperature- and flow distribution in the core of a pebble bed high temperature reactor

    International Nuclear Information System (INIS)

    Verfondern, K.

    1983-01-01

    This work presents a computer model determining the steady-state temperature- and flow field in 3 dimensions in the core of a pebble bed high temperature reactor. The numerical sprinkler method, basind on the Thermix-model, allows to describe the thermo-hydraulics of a non-rotational-symmetric core-geometry. The AVR-reactor in Juelich, in operation since 1967, represents a suitable investigation-object for the computer model of Thermix-3D. It is in a 3D-mesh-structure to reproduce very precisely the so called ''graphite noses'', in which the shut-down rods are conducted as well as the filling cones in the inner and outer area. The results of the final calculation of the normal operation condition for the AVR-reactor unambiguously show, that within the core reproduced in 3 dimensions there are evident deviations in the flow profile and in the temperatures of the cooling gas in contrast to a 2D-handling. (orig.) [de

  19. Quantum net dynamics

    International Nuclear Information System (INIS)

    Finkelstein, D.

    1989-01-01

    The quantum net unifies the basic principles of quantum theory and relativity in a quantum spacetime having no ultraviolet infinities, supporting the Dirac equation, and having the usual vacuum as a quantum condensation. A correspondence principle connects nets to Schwinger sources and further unifies the vertical structure of the theory, so that the functions of the many hierarchic levels of quantum field theory (predicate algebra, set theory, topology,hor-ellipsis, quantum dynamics) are served by one in quantum net dynamics

  20. Programming NET Web Services

    CERN Document Server

    Ferrara, Alex

    2007-01-01

    Web services are poised to become a key technology for a wide range of Internet-enabled applications, spanning everything from straight B2B systems to mobile devices and proprietary in-house software. While there are several tools and platforms that can be used for building web services, developers are finding a powerful tool in Microsoft's .NET Framework and Visual Studio .NET. Designed from scratch to support the development of web services, the .NET Framework simplifies the process--programmers find that tasks that took an hour using the SOAP Toolkit take just minutes. Programming .NET

  1. Game Coloured Petri Nets

    DEFF Research Database (Denmark)

    Westergaard, Michael

    2006-01-01

    This paper introduces the notion of game coloured Petri nets. This allows the modeler to explicitly model what parts of the model comprise the modeled system and what parts are the environment of the modeled system. We give the formal definition of game coloured Petri nets, a means of reachability...... analysis of this net class, and an application of game coloured Petri nets to automatically generate easy-to-understand visualizations of the model by exploiting the knowledge that some parts of the model are not interesting from a visualization perspective (i.e. they are part of the environment...

  2. Flow characteristics of counter-current flow in debris bed

    International Nuclear Information System (INIS)

    Abe, Yutaka; Adachi, Hiromichi

    2004-01-01

    In the course of a severe accident, a damaged core would form a debris bed consisting of once-molten and fragmented fuel elements. It is necessary to evaluate the dryout heat flux for the judgment of the coolability of the debris bed during the severe accident. The dryout phenomena in the debris bed is dominated by the counter-current flow limitation (CCFL) in the debris bed. In this study, air-water counter-current flow behavior in the debris bed is experimentally investigated with glass particles simulating the debris beds. In this experiment, falling water flow rate and axial pressure distributions were experimentally measured. As the results, it is clarified that falling water flow rate becomes larger with the debris bed height and the pressure gradient in the upper region of the debris bed is different from that in the lower region of the debris bed. These results indicate that the dominant region for CCFL in the debris bed is identified near the top of the debris bed. Analytical results with annular flow model indicates that interfacial shear stress in the upper region of the debris bed is larger than that in the lower region of the debris bed. (author)

  3. Hydrodynamics of circulating and bubbling fluidized beds

    International Nuclear Information System (INIS)

    Gidaspow, D.P.; Tsuo, Y.P.; Ding, J.

    1991-01-01

    This paper reports that a review of modeling of the hydrodynamics of fluidization of bubbling beds showed that inviscid two-fluid models were able to predict a great deal of the behavior of bubbling beds because the dominant mechanism of energy dissipation is the drag between the particles and the fluid. The formation, the growth and the bursting of bubbles were predicted. Predicted wall-to-bed heat transfer coefficients and velocity profiles of jets agreed with measurements. Time average porosity distributions agreed with measurements done using gamma-ray densitometers without the use of any adjustable parameters. However, inviscid models could not correctly predict rates of erosion around tubes immersed into fluidized beds. To correctly model such behavior, granular stresses involving solids viscosity were added into the computer model. This viscosity arises due to random collision of particles. Several models fro this viscosity were investigated and the results compared to measurements of solids distributions in two-dimensional beds and to particle velocities reported in the literature. While in the case of bubbling beds the solids viscosity plays the role of a correction, modeling of a circulating fluidized bed (CFB) without a viscosity is not possible. Recent experimental data obtained at IIT and at IGT show that in CFB the solids viscous dissipation is responsible for as much as half of the pressure drop. From such measurement, solids viscosities were computed. These were used in the two fluid hydrodynamic model, to predict radial solids distributions and solids velocities which matched the experimental distributions. Most important, the model predicted cluster formation and transient internal circulation which is responsible for the favorable characteristics of CFBs, such as good wall-to-bed heat transfer. Video tape movies of computations compared favorably with high speed movies of the experiments

  4. Excitation functions of parameters extracted from three-source (net-)proton rapidity distributions in Au-Au and Pb-Pb collisions over an energy range from AGS to RHIC

    Energy Technology Data Exchange (ETDEWEB)

    Gao, Li-Na; Liu, Fu-Hu [Shanxi University, Institute of Theoretical Physics, Taiyuan, Shanxi (China); Sun, Yan; Sun, Zhu [Shanxi Datong University, Department of Physics, Datong, Shanxi (China); Lacey, Roy A. [Stony Brook University, Departments of Chemistry and Physics, Stony Brook, NY (United States)

    2017-03-15

    Experimental results of the rapidity spectra of protons and net-protons (protons minus antiprotons) emitted in gold-gold (Au-Au) and lead-lead (Pb-Pb) collisions, measured by a few collaborations at the alternating gradient synchrotron (AGS), super proton synchrotron (SPS), and relativistic heavy ion collider (RHIC), are described by a three-source distribution. The values of the distribution width σ{sub C} and fraction k{sub C} of the central rapidity region, and the distribution width σ{sub F} and rapidity shift Δy of the forward/backward rapidity regions, are then obtained. The excitation function of σ{sub C} increases generally with increase of the center-of-mass energy per nucleon pair √(s{sub NN}). The excitation function of σ{sub F} shows a saturation at √(s{sub NN}) = 8.8 GeV. The excitation function of k{sub C} shows a minimum at √(s{sub NN}) = 8.8 GeV and a saturation at √(s{sub NN}) ∼ 17 GeV. The excitation function of Δy increases linearly with ln(√(s{sub NN})) in the considered energy range. (orig.)

  5. Biodegradation of the herbicide Diuron in a packed bed channel and a double biobarrier with distribution of oxygenated liquid by airlift devices: influence of oxygen limitation.

    Science.gov (United States)

    Castañón-González, J Humberto; Galíndez-Mayer, Juvencio; Ruiz-Ordaz, Nora; Rocha-Martínez, Lizeth; Peña-Partida, José Carlos; Marrón-Montiel, Erick; Santoyo-Tepole, Fortunata

    2016-01-25

    From agricultural soils, where the herbicide Diuron has been frequently applied, a microbial community capable of degrading Diuron and 3,4-dichloroaniline was obtained. The volumetric rates and degradation efficiencies of Diuron and 3,4-DCA were evaluated in two distinct biofilm reactors, which differ in their operating conditions. One is a horizontal fixed bed reactor; plug-flow operated (PF-PBC) with severe limitation of oxygen. In this reactor, the air was supplied to an equalizer reservoir at the start of the PF-PBC reactor. The other is a compartmentalized aerobic biobarrier with internal recirculation of liquid aerated through airlift devices (ALB), continuously or intermittently operated. Both reactors were inoculated with a microbial community capable of degrading Diuron, isolated from a sugarcane field. In the oxygen-limited PF-PBC reactor, 3,4-DCA accumulation was detected, mainly in the middle zone of the packed channel. On the contrary, in the fully aerobic ALB reactor, minimal accumulation of catabolic byproducts was detected, and high Diuron removal efficiencies and removal rates were obtained when it was continuously operated in steady-state conditions. Additionally, the influence of oxygen limitation on the kinetic behavior of the PF-PBC reactor was determined, and a method to estimate the local removal rates of Diuron RV,CD along the plug-flow channel is described. It was observed that the local values of the instantaneous removal rate of Diuron dCD/dt are high in the aerobic region of the PF-PBC reactor; but, suddenly decay in the reactor zones limited by dissolved oxygen. Copyright © 2015 Elsevier B.V. All rights reserved.

  6. Fluid-bed combustion

    Energy Technology Data Exchange (ETDEWEB)

    Hunt, G.; Schoebotham, N.

    1981-02-01

    In Energy Equipment Company's two-stage fluidized bed system, partial combustion in a fluidized bed is followed by burn-off of the generated gases above the bed. The system can be retrofitted to existing boilers, and can burn small, high ash coal efficiently. It has advantages when used as a hot gas generator for process drying. Tests on a boiler at a Cadbury Schweppes plant are reported.

  7. Fluidised bed combustion system

    International Nuclear Information System (INIS)

    McKenzie, E.C.

    1976-01-01

    Fluidized bed combustion systems that facilitates the maintenance of the depth of the bed are described. A discharge pipe projects upwardly into the bed so that bed material can flow into its upper end and escape downwardly. The end of the pipe is surrounded by an enclosure and air is discharged into the enclosure so that material will enter the pipe from within the enclosure and have been cooled in the enclosure by the air discharged into it. The walls of the enclosure may themselves be cooled

  8. Effect of the Net Charge Distribution on the Aqueous Solution Properties of Polyampholytes Effet de la répartition de la charge nette sur les propriétés des solutions aqueuses de polyampholytes

    Directory of Open Access Journals (Sweden)

    Candau F.

    2006-12-01

    Full Text Available The zwitterion nature of ampholytic polymers provides features that are useful in environmental and industrial applications, e. g. ion-exchange membrane, as flocculants in sewage treatment and in oil recovery processes. In the latter case, the increase in viscosity which is observed in the presence of brine (anti -polyelectrolyte behavior make them ideal candidates for high salinity media. The aqueous solution properties of a series of ampholytic terpolymers based on sodium-2-acrylamido-2- rilethylpropanesulfonate (NaAMPS, Methacryloyloxyethyltrimethylammonium chloride (MADQUAT and acrylamide (AM, prepared in inverse micro emulsions have been investigated by viscometry and light scattering experiments. The distribution of the net charge among the chains was varied by adjusting the initial monomer composition and the degree of conversion. The effect of this distribution on the solubility of the samples and on the chain conformation was studied. It was found that samples with a narrow distribution of net charges were soluble in water even if the average net charge is small. Addition of salt produces a transition from an extended conformation to a more compact one in qualitative agreement with theoretical predictions. A practically alternated NaAMPS- MADQUAT copolymer prepared in homogeneous solution and with a small average net charge shows a behaviour quite similar to that of the terpolymers. La nature zwitterioniquedes polymères ampholytes présente des caractéristiques qui sont utiles dans les applications environnementales et industrielles, comme les membranes d'échange ionique, les floculants dans le traitement des eaux usées et dans les procédés de récupération de pétrole. Dans ce dernier cas, l'augmentation de viscosité qui est observée en présence de saumure (comportement antipolyélectrolyte en fait des candidats idéaux pour des milieux de salinité élevée. Les propriétés de la solution aqueuse d'une série de terpolym

  9. Coloured Petri Nets

    DEFF Research Database (Denmark)

    Jensen, Kurt

    1991-01-01

    This paper describes how Coloured Petri Nets (CP-nets) have been developed — from being a promising theoretical model to being a full-fledged language for the design, specification, simulation, validation and implementation of large software systems (and other systems in which human beings and...

  10. Net zero water

    CSIR Research Space (South Africa)

    Lindeque, M

    2013-01-01

    Full Text Available the national grid. The unfortunate situation with water is that there is no replacement technology for water. Water can be supplied from many different sources. A net zero energy development will move closer to a net zero water development by reducing...

  11. Construction of monophase nets

    International Nuclear Information System (INIS)

    Suarez A, Jose Antonio

    1996-01-01

    The paper refers to the use of monophase loads in commercial residential urbanizations and in small industries, for this reason it is considered unnecessary the construction of three-phase nets. The author makes a historical recount of these nets in Bogota, his capacities, uses and energy savings

  12. Effect of bed configuration on pebble flow uniformity and stagnation in the pebble bed reactor

    International Nuclear Information System (INIS)

    Gui, Nan; Yang, Xingtuan; Tu, Jiyuan; Jiang, Shengyao

    2014-01-01

    Highlights: • Pebble flow uniformity and stagnation characteristics are very important for HTR-PM. • Arc- and brachistochrone-shaped configuration effects are studied by DEM simulation. • Best bed configurations with uniform flow and no stagnated pebbles are suggested. • Detailed quantified characteristics of bed configuration effects are shown for explanation. - Abstract: Pebble flow uniformity and stagnation characteristics are very important for the design of pebble bed high temperature gas-cooled reactor. Pebble flows inside some specifically designed contraction configurations of pebble bed are studied by discrete element method. The results show the characteristics of stagnation rates, recycling rates, radial distribution of pebble velocity and residence time. It is demonstrated clearly that the bed with a brachistochrone-shaped configuration achieves optimum levels of flow uniformity and recycling rate concentration, and almost no pebbles are stagnated in the bed. Moreover, the optimum choice among the arc-shaped bed configurations is demonstrated too. Detailed information shows the quantified characteristics of bed configuration effects on flow uniformity. In addition, a good design of the pebble bed configuration is suggested

  13. Fusion through the NET

    International Nuclear Information System (INIS)

    Spears, B.

    1987-01-01

    The paper concerns the next generation of fusion machines which are intended to demonstrate the technical viability of fusion. In Europe, the device that will follow on from JET is known as NET - the Next European Torus. If the design programme for NET proceeds, Europe could start to build the machine in 1994. The present JET programme hopes to achieve breakeven in the early 1990's. NET hopes to reach ignition in the next century, and so lay the foundation for a demonstration reactor. A description is given of the technical specifications of the components of NET, including: the first wall, the divertors to protect the wall, the array of magnets that provide the fields containing the plasma, the superconducting magnets, and the shield of the machine. NET's research programme is briefly outlined, including the testing programme to optimise conditions in the machine to achieve ignition, and its safety work. (U.K.)

  14. Fluidized bed incinerator development

    International Nuclear Information System (INIS)

    Ziegler, D.L.; Johnson, A.J.

    1976-01-01

    A fluidized bed incinerator is being developed for burning rad contaminated solid and liquid waste materials. In situ neutralization of acid gases by the bed material, catalytic afterburning, and gas filtration are used to produce a clean flue gas without the use of aqueous scrubbing

  15. Particle size distribution of ashes and the behaviour of metals when firing Salix in a circulating fluidized bed boiler (CFB); Askans partikelfraktionsfoerdelning och metallernas beteende vid eldning av Salix i en CFB-panna

    Energy Technology Data Exchange (ETDEWEB)

    Sfiris, G; Johansson, A [Vattenfall Utveckling AB, Stockholm (Sweden); Valmari, T; Kauppinen, E; Pyykoenen, J; Lyyraenen, J [VTT Technical Research Centre of Finland, Espoo (Finland)

    1999-07-01

    This project is part of the Ash Recovery Programme aimed at establishing the environmental, technical and financial preconditions for returning wood ash to the forest. The programme is funded jointly by NUTEK, Sydkraft and Vattenfall. This report summarises the results of the experimental and modelling work to study the behaviour of the metals (especially Cd and K), after burning Salix in a 3-12 MW Circulating Fluidized Bed (CFB) boiler. The purpose of the study was to determine, using the experimental data, where cadmium and potassium condense, on what size particles they condense, and the decisive parameters governing these processes. Measurements of the fly ash particle size distribution carried out with a Berner Low Pressure Impactor (BLPI), coupled to a pre-cyclone. Samples were collected from three points: in the convection path at 650 deg C, after the convection path but before the secondary cyclone (160 deg C), and after the bag house (150 deg C). Wet chemical sampling was made for Cd, K, Zn and Pb, with three types of sampling equipment: collection of both particles and gas, collection of particles only, and analysis of the gas phase only. Analysis was made of samples from two places in the convection path (650 deg C and 250 deg C). Samples of bed material, bottom ash and fly ash have been subjected to scanning electron microscopy (SEM), and in addition a few fly ash particles, sampled after the convection path, were subjected to energy dispersive X-ray analysis (EDX). Based on experimental results, modelling work was carried out with an equilibrium model and with a general aerosol computer model ABC (Aerosol Behaviour in Combustion)

  16. Net Zero Energy Buildings

    DEFF Research Database (Denmark)

    Marszal, Anna Joanna; Bourrelle, Julien S.; Gustavsen, Arild

    2010-01-01

    and identify possible renewable energy supply options which may be considered in calculations. Finally, the gap between the methodology proposed by each organisation and their respective national building code is assessed; providing an overview of the possible changes building codes will need to undergo......The international cooperation project IEA SHC Task 40 / ECBCS Annex 52 “Towards Net Zero Energy Solar Buildings”, attempts to develop a common understanding and to set up the basis for an international definition framework of Net Zero Energy Buildings (Net ZEBs). The understanding of such buildings...

  17. Getting to Net Zero

    Energy Technology Data Exchange (ETDEWEB)

    2016-09-01

    The technology necessary to build net zero energy buildings (NZEBs) is ready and available today, however, building to net zero energy performance levels can be challenging. Energy efficiency measures, onsite energy generation resources, load matching and grid interaction, climatic factors, and local policies vary from location to location and require unique methods of constructing NZEBs. It is recommended that Components start looking into how to construct and operate NZEBs now as there is a learning curve to net zero construction and FY 2020 is just around the corner.

  18. Pro NET Best Practices

    CERN Document Server

    Ritchie, Stephen D

    2011-01-01

    Pro .NET Best Practices is a practical reference to the best practices that you can apply to your .NET projects today. You will learn standards, techniques, and conventions that are sharply focused, realistic and helpful for achieving results, steering clear of unproven, idealistic, and impractical recommendations. Pro .NET Best Practices covers a broad range of practices and principles that development experts agree are the right ways to develop software, which includes continuous integration, automated testing, automated deployment, and code analysis. Whether the solution is from a free and

  19. Risk of Subclinical Micrometastatic Disease in the Supraclavicular Nodal Bed According to the Anatomic Distribution in Patients With Advanced Breast Cancer

    International Nuclear Information System (INIS)

    Reed, Valerie K.; Cavalcanti, Jose L.; Strom, Eric A.; Perkins, George H.; Oh, Julia L.; Tereffe, Welela; Yu, T.-K.; Yeung, Henry; Whitman, Gary J.; Bedrosian, Isabelle; Macapinlac, Homer A.; Buchholz, Thomas A.; Woodward, Wendy A.

    2008-01-01

    Purpose: To determine the anatomic distribution of gross supraclavicular nodes within the supraclavicular fossa using 2-deoxy-2-[F-18] fluoro-d-glucose (FDG) positron emission tomography/computed tomography (PET/CT) scans, and to evaluate likely coverage of specific regions of the supraclavicular fossa using standard radiation fields. Methods and Materials: We identified 33 patients with advanced or metastatic breast cancer who had a PET/CT scan demonstrating hypermetabolic supraclavicular lymph nodes in 2005. The locations of the involved lymph nodes were mapped onto a single CT set of images of the supraclavicular fossa. These lymph nodes were also mapped onto the treatment-planning CT dataset of 4 patients treated in our institution (2 patients with biopsy-proven supraclavicular nodes and 2 patients with clinically negative supraclavicular nodes). Results: We were able to determine the distribution of 52 supraclavicular lymph nodes in 32 patients. Of 32 patients, 28 (87%) had a history of metastatic disease, and 2 patients had isolated nodal recurrences. Five patients had supraclavicular nodes posterior to the vertebral body transverse process, and several lymph nodes were in close proximity to the medial field border, raising the possibility of geographic miss in these areas. Conclusions: In patients with locally advanced disease, increased coverage of the supraclavicular fossa medially and posteriorly may be warranted

  20. Net energy benefits of carbon nanotube applications

    International Nuclear Information System (INIS)

    Zhai, Pei; Isaacs, Jacqueline A.; Eckelman, Matthew J.

    2016-01-01

    Highlights: • Life cycle net energy benefits are examined. • CNT-enabled and the conventional technologies are compared. • Flash memory with CNT switches show significant positive net energy benefit. • Lithium-ion batteries with MWCNT cathodes show positive net energy benefit. • Lithium-ion batteries with SWCNT anodes tend to exhibit negative net energy benefit. - Abstract: Implementation of carbon nanotubes (CNTs) in various applications can reduce material and energy requirements of products, resulting in energy savings. However, processes for the production of carbon nanotubes (CNTs) are energy-intensive and can require extensive purification. In this study, we investigate the net energy benefits of three CNT-enabled technologies: multi-walled CNT (MWCNT) reinforced cement used as highway construction material, single-walled CNT (SWCNT) flash memory switches used in cell phones and CNT anodes and cathodes used in lithium-ion batteries used in electric vehicles. We explore the avoided or additional energy requirement in the manufacturing and use phases and estimate the life cycle net energy benefits for each application. Additional scenario analysis and Monte Carlo simulation of parameter uncertainties resulted in probability distributions of net energy benefits, indicating that net energy benefits are dependent on the application with confidence intervals straddling the breakeven line in some cases. Analysis of simulation results reveals that SWCNT switch flash memory and MWCNT Li-ion battery cathodes have statistically significant positive net energy benefits (α = 0.05) and SWCNT Li-ion battery anodes tend to have negative net energy benefits, while positive results for MWCNT-reinforced cement were significant only under an efficient CNT production scenario and a lower confidence level (α = 0.1).

  1. PhysioNet

    Data.gov (United States)

    U.S. Department of Health & Human Services — The PhysioNet Resource is intended to stimulate current research and new investigations in the study of complex biomedical and physiologic signals. It offers free...

  2. NetSig

    DEFF Research Database (Denmark)

    Horn, Heiko; Lawrence, Michael S; Chouinard, Candace R

    2018-01-01

    Methods that integrate molecular network information and tumor genome data could complement gene-based statistical tests to identify likely new cancer genes; but such approaches are challenging to validate at scale, and their predictive value remains unclear. We developed a robust statistic (Net......Sig) that integrates protein interaction networks with data from 4,742 tumor exomes. NetSig can accurately classify known driver genes in 60% of tested tumor types and predicts 62 new driver candidates. Using a quantitative experimental framework to determine in vivo tumorigenic potential in mice, we found that Net......Sig candidates induce tumors at rates that are comparable to those of known oncogenes and are ten-fold higher than those of random genes. By reanalyzing nine tumor-inducing NetSig candidates in 242 patients with oncogene-negative lung adenocarcinomas, we find that two (AKT2 and TFDP2) are significantly amplified...

  3. Blanket testing in NET

    International Nuclear Information System (INIS)

    Chazalon, M.; Daenner, W.; Libin, B.

    1989-01-01

    The testing stages in NET for the performance assessment of the various breeding blanket concepts developed at the present time in Europe for DEMO (LiPb and ceramic blankets) and the requirements upon NET to perform these tests are reviewed. Typical locations available in NET for blanket testing are the central outboard segments and the horizontal ports of in-vessel sectors. These test positions will be connectable with external test loops. The number of test loops (helium, water, liquid metal) will be such that each major class of blankets can be tested in NET. The test positions, the boundary conditions and the external test loops are identified and the requirements for test blankets are summarized (author). 6

  4. Vertical sorting and the morphodynamics of bed form-dominated rivers : a sorting evolution model

    NARCIS (Netherlands)

    Blom, Astrid; Ribberink, Jan S.; Parker, Gary

    2008-01-01

    Existing sediment continuity models for nonuniform sediment suffer from a number of shortcomings, as they fail to describe vertical sorting fluxes other than through net aggradation or degradation of the bed and are based on a discrete representation of the bed material interacting with the flow. We

  5. Programming NET 35

    CERN Document Server

    Liberty, Jesse

    2009-01-01

    Bestselling author Jesse Liberty and industry expert Alex Horovitz uncover the common threads that unite the .NET 3.5 technologies, so you can benefit from the best practices and architectural patterns baked into the new Microsoft frameworks. The book offers a Grand Tour" of .NET 3.5 that describes how the principal technologies can be used together, with Ajax, to build modern n-tier and service-oriented applications. "

  6. NET SALARY ADJUSTMENT

    CERN Multimedia

    Finance Division

    2001-01-01

    On 15 June 2001 the Council approved the correction of the discrepancy identified in the net salary adjustment implemented on 1st January 2001 by retroactively increasing the scale of basic salaries to achieve the 2.8% average net salary adjustment approved in December 2000. We should like to inform you that the corresponding adjustment will be made to your July salary. Full details of the retroactive adjustments will consequently be shown on your pay slip.

  7. Experimental study of flow field characteristics on bed configurations in the pebble bed reactor

    International Nuclear Information System (INIS)

    Jia, Xinlong; Gui, Nan; Yang, Xingtuan; Tu, Jiyuan; Jia, Haijun; Jiang, Shengyao

    2017-01-01

    Highlights: • PTV study of flow fields of pebble bed reactor with different configurations are carried out. • Some criteria are proposed to quantify vertical velocity field and flow uniformity. • The effect of different pebble bed configurations is also compared by the proposed criteria. • The displacement thickness is used analogically to analyze flow field characteristics. • The effect of mass flow variation in the stagnated region of the funnel flow is measured. - Abstract: The flow field characteristics are of fundamental importance in the design work of the pebble bed high temperature gas cooled reactor (HTGR). The different effects of bed configurations on the flow characteristics of pebble bed are studied through the PTV (Particle Tracking Velocimetry) experiment. Some criteria, e.g. flow uniformity (σ) and mass flow level (α), are proposed to estimate vertical velocity field and compare the bed configurations. The distribution of the Δθ (angle difference between the individual particle velocity and the velocity vector sum of all particles) is also used to estimate the resultant motion consistency level. Moreover, for each bed configuration, the thickness of displacement is analyzed to measure the effect of the funnel flow zone based on the boundary layer theory. Detailed information shows the quantified characteristics of bed configuration effects on flow uniformity and other characteristics; and the sequence of levels of each estimation criterion is obtained for all bed configurations. In addition, a good design of the pebble bed configuration is suggested and these estimation criteria can be also applied and adopted in testing other geometry designs of pebble bed.

  8. NET-2 Network Analysis Program

    International Nuclear Information System (INIS)

    Malmberg, A.F.

    1974-01-01

    The NET-2 Network Analysis Program is a general purpose digital computer program which solves the nonlinear time domain response and the linearized small signal frequency domain response of an arbitrary network of interconnected components. NET-2 is capable of handling a variety of components and has been applied to problems in several engineering fields, including electronic circuit design and analysis, missile flight simulation, control systems, heat flow, fluid flow, mechanical systems, structural dynamics, digital logic, communications network design, solid state device physics, fluidic systems, and nuclear vulnerability due to blast, thermal, gamma radiation, neutron damage, and EMP effects. Network components may be selected from a repertoire of built-in models or they may be constructed by the user through appropriate combinations of mathematical, empirical, and topological functions. Higher-level components may be defined by subnetworks composed of any combination of user-defined components and built-in models. The program provides a modeling capability to represent and intermix system components on many levels, e.g., from hole and electron spatial charge distributions in solid state devices through discrete and integrated electronic components to functional system blocks. NET-2 is capable of simultaneous computation in both the time and frequency domain, and has statistical and optimization capability. Network topology may be controlled as a function of the network solution. (U.S.)

  9. Bed Bugs FAQs

    Science.gov (United States)

    ... Europe. Bed bugs have been found in five-star hotels and resorts and their presence is not ... Health – Division of Parasitic Diseases Email Recommend Tweet YouTube Instagram Listen Watch RSS ABOUT About CDC Jobs ...

  10. Bed Bug Information Clearinghouse

    Science.gov (United States)

    Its purpose is to help states, communities, and consumers in efforts to prevent and control bed bug infestations. Currently includes only reviewed material from federal/state/local government agencies, extension services, and universities.

  11. Particle fuel bed tests

    International Nuclear Information System (INIS)

    Horn, F.L.; Powell, J.R.; Savino, J.M.

    1985-01-01

    Gas-cooled reactors, using packed beds of small diameter coated fuel particles have been proposed for compact, high-power systems. The particulate fuel used in the tests was 800 microns in diameter, consisting of a thoria kernel coated with 200 microns of pyrocarbon. Typically, the bed of fuel particles was contained in a ceramic cylinder with porous metallic frits at each end. A dc voltage was applied to the metallic frits and the resulting electric current heated the bed. Heat was removed by passing coolant (helium or hydrogen) through the bed. Candidate frit materials, rhenium, nickel, zirconium carbide, and zirconium oxide were unaffected, while tungsten and tungsten-rhenium lost weight and strength. Zirconium-carbide particles were tested at 2000 K in H 2 for 12 hours with no visible reaction or weight loss

  12. Vertical distribution of trace-element concentrations and occurrence of metallurgical slag particles in accumulated bed sediments of Lake Roosevelt, Washington, September 2002

    Science.gov (United States)

    Cox, S.E.; Bell, P.R.; Lowther, J.S.; Van Metre, P.C.

    2005-01-01

    Sediment cores were collected from six locations in Lake Roosevelt to determine the vertical distributions of trace-element concentrations in the accumulated sediments of Lake Roosevelt. Elevated concentrations of arsenic, cadmium, copper, lead, mercury, and zinc occurred throughout much of the accumulated sediments. Concentrations varied greatly within the sediment core profiles, often covering a range of 5 to 10 fold. Trace-element concentrations typically were largest below the surficial sediments in the lower one-half of each profile, with generally decreasing concentrations from the 1964 horizon to the surface of the core. The trace-element profiles reflect changes in historical discharges of trace elements to the Columbia River by an upstream smelter. All samples analyzed exceeded clean-up guidelines adopted by the Confederated Tribes of the Colville Reservation for cadmium, lead, and zinc and more than 70 percent of the samples exceeded cleanup guidelines for mercury, arsenic, and copper. Although 100 percent of the samples exceeded sediment guidelines for cadmium, lead, and zinc, surficial concentrations of arsenic, copper, and mercury in some cores were less than the sediment-quality guidelines. With the exception of copper, the trace-element profiles of the five cores collected along the pre-reservoir Columbia River channel typically showed trends of decreasing concentrations in sediments deposited after the 1964 time horizon. The decreasing concentrations of trace elements in the upper half of cores from along the pre-reservoir Columbia River showed a pattern of decreasing concentrations similar to reductions in trace-element loading in liquid effluent from an upstream smelter. Except for arsenic, trace-element concentrations typically were smaller at downstream reservoir locations along the pre-reservoir Columbia River. Trace-element concentration in sediments from the Spokane Arm of the reservoir showed distinct differences compared to the similarities

  13. An Apparatus for Bed Material Sediment Extraction From Coarse River Beds in Large Alluvial Rivers

    Science.gov (United States)

    Singer, M. B.; Adam, H.; Cooper, J.; Cepello, S.

    2005-12-01

    Grain size distributions of bed material sediment in large alluvial rivers are required in applications ranging from habitat mapping, calibration of sediment transport models, high resolution sediment routing, and testing of existing theories of longitudinal and cross steam sediment sorting. However, characterizing bed material sediment from coarse river beds is hampered by difficulties in sediment extraction, a challenge that is generally circumvented via pebble counts on point bars, even though it is unclear whether the bulk grain size distribution of bed sediments is well represented by pebble counts on bars. We have developed and tested a boat-based sampling apparatus and methodology for extracting bulk sediment from a wide range of riverbed materials. It involves the use of a 0.4 x 0.4 x 0.2 meter stainless steel toothed sampler, called the Cooper Scooper, which is deployed from and dragged downstream by the weight of a jet boat. The design is based on that of a river anchor such that a rotating center bar connected to a rope line in the boat aligns the sampler in the downstream direction, the teeth penetrate the bed surface, and the sampler digs into the bed. The sampler is fitted with lead weights to keep it from tipping over. The force of the sampler `biting' into the bed can be felt on the rope line held by a person in the boat at which point they let out slack. The boat then motors to the spot above the embedded sampler, which is hoisted to the water surface via a system of pulleys. The Cooper Scooper is then clipped into a winch and boom assembly by which it is brought aboard. This apparatus improves upon commonly used clamshell dredge samplers, which are unable to penetrate coarse or mixed bed surfaces. The Cooper Scooper, by contrast, extracts statistically representative bed material sediment samples of up to 30 kilograms. Not surprisingly, the sampler does not perform well in very coarse or armored beds (e.g. where surface material size is on the

  14. Biological Petri Nets

    CERN Document Server

    Wingender, E

    2011-01-01

    It was suggested some years ago that Petri nets might be well suited to modeling metabolic networks, overcoming some of the limitations encountered by the use of systems employing ODEs (ordinary differential equations). Much work has been done since then which confirms this and demonstrates the usefulness of this concept for systems biology. Petri net technology is not only intuitively understood by scientists trained in the life sciences, it also has a robust mathematical foundation and provides the required degree of flexibility. As a result it appears to be a very promising approach to mode

  15. NET system integration

    International Nuclear Information System (INIS)

    Farfaletti-Casali, F.; Mitchell, N.; Salpietro, E.; Buzzi, U.; Gritzmann, P.

    1985-01-01

    The NET system integration procedure is the process by which the requirements of the various Tokamak machine design areas are brought together to form a compatible machine layout. Each design area produces requirements which generally allow components to be built at minimum cost and operate with minimum technical risk, and the final machine assembly should be achieved with minimum departure from these optimum designs. This is carried out in NET by allowing flexibility in the maintenance and access methods to the machine internal components which must be regularly replaced by remote handling, in segmentation of these internal components and in the number of toroidal field coils

  16. Towards Self-Managed Executable Petri Nets

    DEFF Research Database (Denmark)

    Hansen, Klaus Marius; Zhang, Weishan; Ingstrup, Mads

    2008-01-01

    An issue in self-managed systems is that different abstractions and programming models are used on different architectural layers, leading to systems that are harder to build and understand. To alleviate this, we introduce a self-management approach which combines high-level Petri nets...... with the capability of distributed communication among nets. Organized in a three-layer goal management, change management, and component control architecture this allows for self-management in distributed systems. We validate the approach through the Flamenco/CPN middleware that allows for self-management of service......-oriented pervasive computing systems through the runtime interpretation of colored Petri nets. The current work focuses on the change management and component control layers....

  17. Incipient motion of gravel and coal beds

    Indian Academy of Sciences (India)

    R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

    2. 1Department of Civil Engineering, Indian Institute of Technology, ... the particle size distribution curve following the relationship by Christensen .... where f = friction factor, ρ = mass density of fluid, and V = mean velocity of flow. .... for the incipient motion of gravel and coal beds have been represented by simple empirical.

  18. River Bed Sediment Classification Using ADCP

    Science.gov (United States)

    Description of physical aquatic habitat in rivers often includes data describing distributions of water depth, velocity and bed material type. Water depth and velocity in streams deeper than about 1 m may be continuously mapped using an acoustic Doppler current profiler from a moving boat. Herein ...

  19. Coolability of volumetrically heated particle beds

    Energy Technology Data Exchange (ETDEWEB)

    Rashid, Muhammad

    2017-03-22

    In case of a severe nuclear reactor accident, with loss of coolant, a particle bed may be formed from the fragmentation of the molten core in the residual water at different stages of the accident. To avoid further propagation of the accident and maintain the integrity of the reactor pressure vessel, the decay heat of the particle bed must be removed. To better understand the various thermo-hydraulic processes within such heat-generating particle beds, the existing DEBRIS test facility at IKE has been modified to be able to perform novel boiling, dryout and quenching experiments. The essential experimental data includes the pressure gradients measured by 8 differential pressure transducers along the bed height as a function of liquid and vapour superficial velocities, the determination of local dryout heat fluxes for different system pressures as well as the local temperature distribution measured by a set of 51 thermocouples installed inside the particle bed. The experiments were carried out for two different particle beds: a polydispersed particle bed which consisted of stainless steel balls (2 mm, 3 mm and 6 mm diameters) and an irregular particle bed which consisted of a mixture of steel balls (3 mm and 6 mm) and irregularly shaped Al{sub 2}O{sub 3} particles. Additionally, all experiments were carried out for different flow conditions, such as the reference case of passive 1D top-flooding, 1D bottom flooding (driven by external pumps and different downcomer configurations) and 2D top-/bottom-/lateral flooding with a perforated downcomer. In this work, it has been observed that for both particle beds with downcomer configurations an open downcomer leads to the best coolability (dryout heat flux = 1560 kW/m{sup 2}, polydispersed particle bed, psys = 1 bar) of the particle bed, mainly due to bottom-flow with enhanced natural convection. It has also been shown that a potential lateral flow via a perforation of the downcomer does not bring any further improvements

  20. Coolability of volumetrically heated particle beds

    International Nuclear Information System (INIS)

    Rashid, Muhammad

    2017-01-01

    In case of a severe nuclear reactor accident, with loss of coolant, a particle bed may be formed from the fragmentation of the molten core in the residual water at different stages of the accident. To avoid further propagation of the accident and maintain the integrity of the reactor pressure vessel, the decay heat of the particle bed must be removed. To better understand the various thermo-hydraulic processes within such heat-generating particle beds, the existing DEBRIS test facility at IKE has been modified to be able to perform novel boiling, dryout and quenching experiments. The essential experimental data includes the pressure gradients measured by 8 differential pressure transducers along the bed height as a function of liquid and vapour superficial velocities, the determination of local dryout heat fluxes for different system pressures as well as the local temperature distribution measured by a set of 51 thermocouples installed inside the particle bed. The experiments were carried out for two different particle beds: a polydispersed particle bed which consisted of stainless steel balls (2 mm, 3 mm and 6 mm diameters) and an irregular particle bed which consisted of a mixture of steel balls (3 mm and 6 mm) and irregularly shaped Al 2 O 3 particles. Additionally, all experiments were carried out for different flow conditions, such as the reference case of passive 1D top-flooding, 1D bottom flooding (driven by external pumps and different downcomer configurations) and 2D top-/bottom-/lateral flooding with a perforated downcomer. In this work, it has been observed that for both particle beds with downcomer configurations an open downcomer leads to the best coolability (dryout heat flux = 1560 kW/m 2 , polydispersed particle bed, psys = 1 bar) of the particle bed, mainly due to bottom-flow with enhanced natural convection. It has also been shown that a potential lateral flow via a perforation of the downcomer does not bring any further improvements in

  1. Pebble-bed reactor

    International Nuclear Information System (INIS)

    Lohnert, G.; Mueller-Frank, U.; Heil, J.

    1976-01-01

    A pebble-bed nuclear reactor of large power rating comprises a container having a funnel-shaped bottom forming a pebble run-out having a centrally positioned outlet. A bed of downwardly-flowing substantially spherical nuclear fuel pebbles is positioned in the container and forms a reactive nuclear core maintained by feeding unused pebbles to the bed's top surface while used or burned-out pebbles run out and discharge through the outlet. A substantially conical body with its apex pointing upwardly and its periphery spaced from the periphery of the container spreads the bottom of the bed outwardly to provide an annular flow down the funnel-shaped bottom forming the runout, to the discharge outlet. This provides a largely constant downward velocity of the spheres throughout the diameter of the bed throughout a substantial portion of the down travel, so that all spheres reach about the same burned-out condition when they leave the core, after a single pass through the core area

  2. Fluidised bed heat exchangers

    International Nuclear Information System (INIS)

    Elliott, D.E.; Healey, E.M.; Roberts, A.G.

    1974-01-01

    Problems that have arisen during the initial stages of development of fluidised bed boilers in which heat transfer surfaces are immersed in fluidised solids are discussed. The very high heat transfer coefficients that are obtained under these conditions can be exploited to reduce the total heat transfer surface to a fraction of that in normal boilers. However, with the high heat flux levels involved, tube stressing becomes more important and it is advantageous to use smaller diameter tubes. One of the initial problems was that the pumping power absorbed by the fluidised bed appeared to be high. The relative influence of the fluidising velocity (and the corresponding bed area), tube diameter, tube spacing, heat transfer coefficient and bed temperature on pumping power and overall cost was determined. This showed the importance of close tube packing and research was undertaken to see if this would adversely affect the heat transfer coefficient. Pressure operation also reduces the pumping power. Fouling and corrosion tests in beds burning coal suggest that higher temperatures could be reached reliably and cost studies show that, provided the better refractory metals are used, the cost of achieving higher temperatures is not unduly high. It now remains to demonstrate at large scale that the proposed systems are viable and that the methods incorporated to overcome start up and part lead running problems are satisfactory. The promising role of these heat transfer techniques in other applications is briefly discussed

  3. Safety nets or straitjackets?

    DEFF Research Database (Denmark)

    Ilsøe, Anna

    2012-01-01

    Does regulation of working hours at national and sector level impose straitjackets, or offer safety nets to employees seeking working time flexibility? This article compares legislation and collective agreements in the metal industries of Denmark, Germany and the USA. The industry has historically...

  4. Neuronal nets in robotics

    International Nuclear Information System (INIS)

    Jimenez Sanchez, Raul

    1999-01-01

    The paper gives a generic idea of the solutions that the neuronal nets contribute to the robotics. The advantages and the inconveniences are exposed that have regarding the conventional techniques. It also describe the more excellent applications as the pursuit of trajectories, the positioning based on images, the force control or of the mobile robots management, among others

  5. Net4Care platform

    DEFF Research Database (Denmark)

    2012-01-01

    , that in turn enables general practitioners and clinical staff to view observations. Use the menus above to explore the site's information resources. To get started, follow the short Hello, World! tutorial. The Net4Care project is funded by The Central Denmark Region and EU via Caretech Innovation....

  6. Game Theory .net.

    Science.gov (United States)

    Shor, Mikhael

    2003-01-01

    States making game theory relevant and accessible to students is challenging. Describes the primary goal of GameTheory.net is to provide interactive teaching tools. Indicates the site strives to unite educators from economics, political and computer science, and ecology by providing a repository of lecture notes and tests for courses using…

  7. BacillusRegNet

    DEFF Research Database (Denmark)

    Misirli, Goksel; Hallinan, Jennifer; Röttger, Richard

    2014-01-01

    As high-throughput technologies become cheaper and easier to use, raw sequence data and corresponding annotations for many organisms are becoming available. However, sequence data alone is not sufficient to explain the biological behaviour of organisms, which arises largely from complex molecular...... the associated BacillusRegNet website (http://bacillus.ncl.ac.uk)....

  8. Boom Booom Net Radio

    DEFF Research Database (Denmark)

    Grimshaw, Mark Nicholas; Yong, Louisa; Dobie, Ian

    1999-01-01

    of an existing Internet radio station; Boom Booom Net Radio. Whilst necessity dictates some use of technology-related terminology, wherever possible we have endeavoured to keep such jargon to a minimum and to either explain it in the text or to provide further explanation in the appended glossary....

  9. 77 FR 72611 - Net Investment Income Tax

    Science.gov (United States)

    2012-12-05

    ... avoid double taxation of net investment income and the taxation of amounts distributed to charities. The.... The proposed regulations affect individuals, estates, and trusts. This document also contains a notice... calculated correctly. The likely respondents are individuals, estates, and trusts. Estimated total annual...

  10. 78 FR 72393 - Net Investment Income Tax

    Science.gov (United States)

    2013-12-02

    ... of Article 23 (Relief from Double Taxation) of the 2006 United States Model Income Tax Convention... taxation of ANSTs at the lowest individual tax rate. Furthermore, section 646 treats all distributions, to... of Net Investment Income. The regulations affect individuals, estates, and trusts whose incomes meet...

  11. Distribution

    Science.gov (United States)

    John R. Jones

    1985-01-01

    Quaking aspen is the most widely distributed native North American tree species (Little 1971, Sargent 1890). It grows in a great diversity of regions, environments, and communities (Harshberger 1911). Only one deciduous tree species in the world, the closely related Eurasian aspen (Populus tremula), has a wider range (Weigle and Frothingham 1911)....

  12. Neonatal and pediatric intensive care in Rio de Janeiro State, Brazil: an analysis of bed distribution, 1997 and 2007 Terapia intensiva neonatal e pediátrica no Rio de Janeiro, Brasil: distribuição de leitos e análise comparativa de equidade em 1997 e 2007

    Directory of Open Access Journals (Sweden)

    Arnaldo Prata Barbosa

    2011-01-01

    Full Text Available The objective of this study was to describe the characteristics of neonatal and pediatric intensive care units (ICU and beds in Rio de Janeiro, correlating with population demands in 1997 and 2007. All neonatal and pediatric ICUs were visited, identifying the availability and type of beds. Comparisons were made between: supply and demand using projected need for beds for the population; public and private ICUs; and geographical regions. In 2007, 95 units were included totaling 1,094 beds (74 units and 1,080 beds in 1997: 51% public and 48% private (47% and 52% in 1997; 47% neonatal, 18% pediatric and 35% mixed units. Most units were located in the metropolitan area. The distribution of public and private beds was similar in the metropolitan area in both periods; in the interior, public beds tripled. Access has improved, mainly in the interior, but there is still no equity in the distribution of and accessibility to the available beds, with a shortage in the public sector, an excess in the private sector, and a great concentration in the metropolitan area.Descrever as características das unidades de terapia intensiva (UTI neonatais e pediátricas e leitos no Rio de Janeiro, Brasil, correlacionando com demandas da população em 1997 e 2007. UTIs neonatais e pediátricas foram visitadas, identificando-se o tipo e disponibilidade de leitos. Foram feitas comparações entre: a oferta e a demanda projetada da necessidade de leitos para a população, a natureza pública ou privada das UTIs e regiões geográficas. Em 2007, 95 unidades foram incluídas, totalizando 1.094 leitos (74 e 1.080 leitos em 1997: 51% públicas e 48% privadas (47% e 52% em 1997; 47% neonatais, 18% pediátricas e 35% mistas. A maioria estava localizada na região metropolitana. A distribuição dos leitos públicos e privados foi semelhante na região metropolitana em ambos os períodos, no interior os públicos triplicaram. O acesso melhorou, principalmente no interior, mas

  13. in Spouted Bed

    Directory of Open Access Journals (Sweden)

    Bronislaw Buczek

    2013-01-01

    Full Text Available Samples of active coke, fresh and spent after cleaning flue gases from communal waste incinerators, were investigated. The outer layers of both coke particles were separately removed by comminution in a spouted bed. The samples of both active cokes were analysed by means of densities, mercury porosimetry, and adsorption technique. Remaining cores were examined to determine the degree of consumption of coke by the sorption of hazardous emissions (SO2, HCl, and heavy metals through its bed. Differences in contamination levels within the porous structure of the particles were estimated. The study demonstrated the effectiveness of commercial active coke in the cleaning of flue gases.

  14. The Safety of Hospital Beds

    Science.gov (United States)

    Gervais, Pierre; Pooler, Charlotte; Merryweather, Andrew; Doig, Alexa K.; Bloswick, Donald

    2015-01-01

    To explore the safety of the standard and the low hospital bed, we report on a microanalysis of 15 patients’ ability to ingress, move about the bed, and egress. The 15 participants were purposefully selected with various disabilities. Bed conditions were randomized with side rails up or down and one low bed with side rails down. We explored the patients’ use of the side rails, bed height, ability to lift their legs onto the mattress, and ability to turn, egress, and walk back to the chair. The standard bed was too high for some participants, both for ingress and egress. Side rails were used by most participants when entering, turning in bed, and exiting. We recommend that side rails be reconsidered as a means to facilitate in-bed movement, ingress, and egress. Furthermore, single deck height settings for all patients are not optimal. Low beds as a safety measure must be re-evaluated. PMID:28462302

  15. The Effect of Bedding Structure on Mechanical Property of Coal

    Directory of Open Access Journals (Sweden)

    Zetian Zhang

    2014-01-01

    Full Text Available The mechanical property of coal, influencing mining activity considerably, is significantly determined by the natural fracture distributed within coal mass. In order to study the effecting mechanism of bedding structure on mechanical property of coal, a series of uniaxial compression tests and mesoscopic tests have been conducted. The experimental results show that the distribution characteristic of calcite particles, which significantly influences the growth of cracks and the macroscopic mechanical properties of coal, is obviously affected by the bedding structure. Specifically, the uniaxial compression strength of coal sample is mainly controlled by bedding structure, and the average peak stress of specimens with axes perpendicular to the bedding planes is 20.00 MPa, which is 2.88 times the average amount of parallel ones. The test results also show a close relationship between the bedding structure and the whole deformation process under uniaxial loading.

  16. Apparatus for controlling fluidized beds

    Science.gov (United States)

    Rehmat, A.G.; Patel, J.G.

    1987-05-12

    An apparatus and process are disclosed for control and maintenance of fluidized beds under non-steady state conditions. An ash removal conduit is provided for removing solid particulates from a fluidized bed separate from an ash discharge conduit in the lower portion of the grate supporting such a bed. The apparatus and process of this invention is particularly suitable for use in ash agglomerating fluidized beds and provides control of the fluidized bed before ash agglomeration is initiated and during upset conditions resulting in stable, sinter-free fluidized bed maintenance. 2 figs.

  17. SolNet

    DEFF Research Database (Denmark)

    Jordan, Ulrike; Vajen, Klaus; Bales, Chris

    2014-01-01

    -accompanying Master courses, placements of internships, and PhD scholarship projects. A new scholarship project, “SHINE”, was launched in autumn 2013 in the frame work of the Marie Curie program of the European Union (Initial Training Network, ITN). 13 PhD-scholarships on solar district heating, solar heat......SolNet, founded in 2006, is the first coordinated International PhD education program on Solar Thermal Engineering. The SolNet network is coordinated by the Institute of Thermal Engineering at Kassel University, Germany. The network offers PhD courses on solar heating and cooling, conference...... for industrial processes, as well as sorption stores and materials started in December 2013. Additionally, the project comprises a training program with five PhD courses and several workshops on solar thermal engineering that will be open also for other PhD students working in the field. The research projects...

  18. Fluidized bed calciner

    International Nuclear Information System (INIS)

    Sheely, W.F.

    1986-01-01

    A unique way to convert radioactive scrap into useful nuclear fuel products was developed for the Department of Energy at Hanford. An advanced, fluidized bed calciner is used to convert metallic nitrate scrap or waste solutions into benign, solid and gaseous products. There are broad potential applications of this concept beyond those in the nuclear industry

  19. Nail Bed Injuries

    Science.gov (United States)

    ... All Topics A-Z Videos Infographics Symptom Picker Anatomy Bones Joints Muscles Nerves Vessels Tendons About Hand Surgery What is a Hand Surgeon? What is a Hand Therapist? Media Find a Hand Surgeon Home Anatomy Nail Bed Injuries Email to a friend * required ...

  20. Bed Bug Myths

    Science.gov (United States)

    Learn the truth about bed bugs, such as how easy they are to see with the naked eye, their preferred habitat, whether they transmit diseases, their public health effects, and whether pesticides are the best way to deal with an infestation.

  1. Seaweed beds support more juvenile reef fish than seagrass beds in a south-western Atlantic tropical seascape

    Science.gov (United States)

    Eggertsen, L.; Ferreira, C. E. L.; Fontoura, L.; Kautsky, N.; Gullström, M.; Berkström, C.

    2017-09-01

    Seascape connectivity is regarded essential for healthy reef fish communities in tropical shallow systems. A number of reef fish species use separate adult and nursery habitats, and hence contribute to nutrient and energy transfer between habitats. Seagrass beds and mangroves often constitute important nursery habitats, with high structural complexity and protection from predation. Here, we investigated if reef fish assemblages in the tropical south-western Atlantic demonstrate ontogenetic habitat connectivity and identify possible nurseries on three reef systems along the eastern Brazilian coast. Fish were surveyed in fore reef, back reef, Halodule wrightii seagrass beds and seaweed beds. Seagrass beds contained lower abundances and species richness of fish than expected, while Sargassum-dominated seaweed beds contained significantly more juveniles than all other habitats (average juvenile fish densities: 32.6 per 40 m2 in Sargassum beds, 11.2 per 40 m2 in back reef, 10.1 per 40 m2 in fore reef, and 5.04 per 40 m2 in seagrass beds), including several species that are found in the reef habitats as adults. Species that in other regions worldwide (e.g. the Caribbean) utilise seagrass beds as nursery habitats were here instead observed in Sargassum beds or back reef habitats. Coral cover was not correlated to adult fish distribution patterns; instead, type of turf was an important variable. Connectivity, and thus pathways of nutrient transfer, seems to function differently in east Brazil compared to many tropical regions. Sargassum-dominated beds might be more important as nurseries for a larger number of fish species than seagrass beds. Due to the low abundance of structurally complex seagrass beds we suggest that seaweed beds might influence adult reef fish abundances, being essential for several keystone species of reef fish in the tropical south-western Atlantic.

  2. Turkey's net energy consumption

    International Nuclear Information System (INIS)

    Soezen, Adnan; Arcaklioglu, Erol; Oezkaymak, Mehmet

    2005-01-01

    The main goal of this study is to develop the equations for forecasting net energy consumption (NEC) using an artificial neural-network (ANN) technique in order to determine the future level of energy consumption in Turkey. In this study, two different models were used in order to train the neural network. In one of them, population, gross generation, installed capacity and years are used in the input layer of the network (Model 1). Other energy sources are used in input layer of network (Model 2). The net energy consumption is in the output layer for two models. Data from 1975 to 2003 are used for the training. Three years (1981, 1994 and 2003) are used only as test data to confirm this method. The statistical coefficients of multiple determinations (R 2 -value) for training data are equal to 0.99944 and 0.99913 for Models 1 and 2, respectively. Similarly, R 2 values for testing data are equal to 0.997386 and 0.999558 for Models 1 and 2, respectively. According to the results, the net energy consumption using the ANN technique has been predicted with acceptable accuracy. Apart from reducing the whole time required, with the ANN approach, it is possible to find solutions that make energy applications more viable and thus more attractive to potential users. It is also expected that this study will be helpful in developing highly applicable energy policies

  3. Unlearning in feed-forward multi-nets

    NARCIS (Netherlands)

    Spaanenburg, L; Kurkova,; Steele, NC; Neruda, R; Karny, M

    2001-01-01

    Multi-nets promise an improved performance over monolithic neural networks by virtue of their distributed implementation. Modular neural networks are multi-nets based on an judicious assembly of functionally different parts. This can be viewed as again a monolithic network, but with more complex

  4. 7 CFR 2902.15 - Bedding, bed linens, and towels.

    Science.gov (United States)

    2010-01-01

    ... PROCUREMENT Designated Items § 2902.15 Bedding, bed linens, and towels. (a) Definition. (1) Bedding is that... minimum biobased content is 12 percent and shall be based on the amount of qualifying biobased carbon in..., and silk are not qualifying biobased feedstocks for the purpose of determining the biobased content of...

  5. Structures and scan strategies of software net models

    International Nuclear Information System (INIS)

    Puhr-Westerheide, P.; Sandbaek, H.

    1984-01-01

    The present paper deals with some aspects of plant control and monitoring systems as used in nuclear power plants. These aspects concern executable net models to run on computers. A short survey on the nets' environment and on some net scan strategies is given. Among the strategies are the 'topologically ordered scan' and the 'signal propagation scan'. A combined method 'topologically ordered signal propagation (TOSIP) scan' will be outlined as well as a net model data structure that allows the definition of subsystems for the use of clear structuration and dischargement to distributed systems. (author)

  6. VA National Bed Control System

    Data.gov (United States)

    Department of Veterans Affairs — The VA National Bed Control System records the levels of operating, unavailable and authorized beds at each VAMC, and it tracks requests for changes in these levels....

  7. Getting Rid of Bed Bugs

    Science.gov (United States)

    ... Directory Planning, Budget and Results Jobs and Internships Headquarters Offices Regional Offices Labs and Research Centers Bed ... to be careful in how you select a company. Related Information Collaborative Strategy on Bed Bugs - highlights ...

  8. Net one, net two: the primary care network income statement.

    Science.gov (United States)

    Halley, M D; Little, A W

    1999-10-01

    Although hospital-owned primary care practices have been unprofitable for most hospitals, some hospitals are achieving competitive advantage and sustainable practice operations. A key to the success of some has been a net income reporting tool that separates practice operating expenses from the costs of creating and operating a network of practices to help healthcare organization managers, physicians, and staff to identify opportunities to improve the network's financial performance. This "Net One, Net Two" reporting allows operations leadership to be held accountable for Net One expenses and strategic leadership to be held accountable for Net Two expenses.

  9. Proof Nets for Lambek Calculus

    NARCIS (Netherlands)

    Roorda, Dirk

    1992-01-01

    The proof nets of linear logic are adapted to the non-commutative Lambek calculus. A different criterion for soundness of proof nets is given, which gives rise to new algorithms for proof search. The order sensitiveness of the Lambek calculus is reflected by the planarity condition on proof nets;

  10. Net metering: zero electricity bill

    International Nuclear Information System (INIS)

    Mangi, A.; Khan, Z.

    2011-01-01

    Worldwide move towards renewable energy sources, environmental concerns and decentralization of the power sector have made net metering an attractive option for power generation at small scale. This paper discusses the net metering, economical issues of renewable sources in Pakistan, technical aspects, installation suitability according to varying terrain, existing utility rules and formulation of legislation for net metering making it economically attractive. (author)

  11. The Net Advance of Physics

    Science.gov (United States)

    THE NET ADVANCE OF PHYSICS Review Articles and Tutorials in an Encyclopædic Format Established 1995 [Link to MIT] Computer support for The Net Advance of Physics is furnished by The Massachusetts Newest Additions SPECIAL FEATURES: Net Advance RETRO: Nineteenth Century Physics History of Science

  12. Net-baryon-, net-proton-, and net-charge kurtosis in heavy-ion collisions within a relativistic transport approach

    International Nuclear Information System (INIS)

    Nahrgang, Marlene; Schuster, Tim; Stock, Reinhard; Mitrovski, Michael; Bleicher, Marcus

    2012-01-01

    We explore the potential of net-baryon, net-proton and net-charge kurtosis measurements to investigate the properties of hot and dense matter created in relativistic heavy-ion collisions. Contrary to calculations in a grand-canonical ensemble we explicitly take into account exact electric and baryon charge conservation on an event-by-event basis. This drastically limits the width of baryon fluctuations. A simple model to account for this is to assume a grand-canonical distribution with a sharp cut-off at the tails. We present baseline predictions of the energy dependence of the net-baryon, net-proton and net-charge kurtosis for central (b≤2.75 fm) Pb+Pb/Au+Au collisions from E lab =2A GeV to √(s NN )=200 GeV from the UrQMD model. While the net-charge kurtosis is compatible with values around zero, the net-baryon number decreases to large negative values with decreasing beam energy. The net-proton kurtosis becomes only slightly negative for low √(s NN ). (orig.)

  13. Horizontal ichthyoplankton tow-net system with unobstructed net opening

    Science.gov (United States)

    Nester, Robert T.

    1987-01-01

    The larval fish sampler described here consists of a modified bridle, frame, and net system with an obstruction-free net opening and is small enough for use on boats 10 m or less in length. The tow net features a square net frame attached to a 0.5-m-diameter cylinder-on-cone plankton net with a bridle designed to eliminate all obstructions forward of the net opening, significantly reducing currents and vibrations in the water directly preceding the net. This system was effective in collecting larvae representing more than 25 species of fish at sampling depths ranging from surface to 10 m and could easily be used at greater depths.

  14. MPL-net at ARM Sites

    Science.gov (United States)

    Spinhirne, J. D.; Welton, E. J.; Campbell, J. R.; Berkoff, T. A.; Starr, David OC. (Technical Monitor)

    2002-01-01

    The NASA MPL-net project goal is consistent data products of the vertical distribution of clouds and aerosol from globally distributed lidar observation sites. The four ARM micro pulse lidars are a basis of the network to consist of over twelve sites. The science objective is ground truth for global satellite retrievals and accurate vertical distribution information in combination with surface radiation measurements for aerosol and cloud models. The project involves improvement in instruments and data processing and cooperation with ARM and other partners.

  15. Master Robotic Net

    Directory of Open Access Journals (Sweden)

    Vladimir Lipunov

    2010-01-01

    Full Text Available The main goal of the MASTER-Net project is to produce a unique fast sky survey with all sky observed over a single night down to a limiting magnitude of 19-20. Such a survey will make it possible to address a number of fundamental problems: search for dark energy via the discovery and photometry of supernovae (including SNIa, search for exoplanets, microlensing effects, discovery of minor bodies in the Solar System, and space-junk monitoring. All MASTER telescopes can be guided by alerts, and we plan to observe prompt optical emission from gamma-ray bursts synchronously in several filters and in several polarization planes.

  16. Geomechanics of bedded salt

    International Nuclear Information System (INIS)

    Serata, S.; Milnor, S.W.

    1979-01-01

    Creep data from the literature search is reinterpreted by SGI, resulting in a better understanding of the temperature and stress state dependence of the octahedral creep rate and the octahedral shear strength. The concept of a transition strength between the elastic and the plastic states is in agreement with the data. The elastic and rheological properties of salt are described, and a set of constitutive equations is presented. The dependence of material properties on parameters such as temperature is considered. Findings on the permeability of salt are summarized, and the in-situ behavior of openings in bedded salt is described based on extensive engineering experience. A stress measuring system utilizing a finite element computer code is discussed. Geological factors affecting the stability of salt openings are considered, and the Stress Control Technique for designing stable openings in bedded salt formations is explained

  17. Report on the results of the FY 1998 hydrogen utilization international clean energy system technology (WE-NET). Subtask 5. Survey on the R and D of technologies for hydrogen transport and storage by hydrogen absorbing alloys (V. Development of the distributed transport/storage use hydrogen absorbing alloys); 1998 nendo suiso riyo kokusai clean energy system gijutsu (WE-NET). 5. Suiso yuso chozo gijutsu no kaihatsu (V. bunsan yuso chozoyo suiso kyuzo gokin no kaihatsu)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-03-01

    The paper described the FY 1998 results of the development of hydrogen distributed transport/storage use absorbing alloys in the WE-NET project. Study was made of improvement of hydrogen desorption characteristics by substituting Ca for part of Mg of Mg-Ni alloys and substituting Cr for part of Ni. It is necessary to shift the state of atomic bond by H atom and metal atom in alloys from the ionic bond to the metallic bond, and to change from the amorphous state to the BCC type crystal structure. It was found out that it was possible to do it by improving the composition and heat treatment. The addition of Cu to LaMg{sub 2} alloys shifts the bond with hydrogen to the bond with metal. Easy hydrogen desorption and large absorbing capacity can be expected. It was found out that LaMg{sub 2}Cu{sub 2} synthesized by the reaction sintering method has reversible hydrogen absorbing desorption characteristics. The absorbing amount is 2.4 wt%, the desorption amount 1.2 wt%, and the desorption temperature 190 degrees C. Those are still far from WE-NET targeted values, but a clue to the search was obtained. It was found out that by applying doping technology by Ti, etc. to NaAlH{sub 4}, characteristics can be expected of the desorption amount, 4.5 wt%, of the hydrogen desorption starting temperature from 100 degrees C to 200 degrees C. (NEDO)

  18. Limitations of shallow nets approximation.

    Science.gov (United States)

    Lin, Shao-Bo

    2017-10-01

    In this paper, we aim at analyzing the approximation abilities of shallow networks in reproducing kernel Hilbert spaces (RKHSs). We prove that there is a probability measure such that the achievable lower bound for approximating by shallow nets can be realized for all functions in balls of reproducing kernel Hilbert space with high probability, which is different with the classical minimax approximation error estimates. This result together with the existing approximation results for deep nets shows the limitations for shallow nets and provides a theoretical explanation on why deep nets perform better than shallow nets. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Effect of particle stratification on debris-bed dryout

    International Nuclear Information System (INIS)

    Gabor, J.D.; Cassulo, J.C.; Pederson, D.R.

    1982-01-01

    Significant work has been performed on debris-bed dryout on beds of either uniformly sized particles or particles of a wide size range which are well mixed. This work has provided an understanding of the mechanisms of dryout and an empirical basis for containment analysis. However, the debris bed resulting from a HCDA would not consist of uniformly sized particles and for certain scenarios the bed could be stratified rather than well mixed. Tests have been conducted on the effect of particle size distribution on dryout and concluded that not only is the mean particle size an important parameter but also the standard deviation of the distribution and change in porosity. The D6 in-pile test at Sandia with a 114-mm deep stratified bed resulted in a reduced dryout heat flux compared to a uniformly mixed bed. Because of the many questions concerning the dryout behavior of stratified beds of wide size distribution out-of-pile experiments in which metal particles in water pools are inductively heated were initiated at Argonne

  20. Shielding calculations for NET

    International Nuclear Information System (INIS)

    Verschuur, K.A.; Hogenbirk, A.

    1991-05-01

    In the European Fusion Technology Programme there is only a small activity on research and development for fusion neutronics. Never-the-less, looking further than blanket design now, as ECN is getting involved in design of radiation shields for the coils and biological shields, it becomes apparent that fusion neutronics as a whole still needs substantial development. Existing exact codes for calculation of complex geometries like MCNP and DORT/TORT are put over the limits of their numerical capabilities, whilst approximate codes for complex geometries like FURNACE and MERCURE4 are put over the limits of their modelling capabilities. The main objective of this study is just to find out how far we can get with existing codes in obtaining reliable values for the radiation levels inside and outside the cryostat/shield during operation and after shut-down. Starting with a 1D torus model for preliminary parametric studies, more dimensional approximation of the torus or parts of it including the main heterogeneities should follow. Regular contacts with the NET-Team are kept, to be aware of main changes in NET design that might affect our calculation models. Work on the contract started 1 July 1990. The technical description of the contract is given. (author). 14 refs.; 4 figs.; 1 tab

  1. Measurement of the bed material of gravel-bed rivers

    Science.gov (United States)

    Milhous, R.T.; ,

    2002-01-01

    The measurement of the physical properties of a gravel-bed river is important in the calculation of sediment transport and physical habitat values for aquatic animals. These properties are not always easy to measure. One recent report on flushing of fines from the Klamath River did not contain information on one location because the grain size distribution of the armour could not be measured on a dry river bar. The grain size distribution could have been measured using a barrel sampler and converting the measurements to the same as would have been measured if a dry bar existed at the site. In another recent paper the porosity was calculated from an average value relation from the literature. The results of that paper may be sensitive to the actual value of porosity. Using the bulk density sampling technique based on a water displacement process presented in this paper the porosity could have been calculated from the measured bulk density. The principle topics of this paper are the measurement of the size distribution of the armour, and measurement of the porosity of the substrate. The 'standard' method of sampling of the armour is to do a Wolman-type count of the armour on a dry section of the river bed. When a dry bar does not exist the armour in an area of the wet streambed is to sample and the measurements transformed analytically to the same type of results that would have been obtained from the standard Wolman procedure. A comparison of the results for the San Miguel River in Colorado shows significant differences in the median size of the armour. The method use to determine the porosity is not 'high-tech' and there is a need improve knowledge of the porosity because of the importance of porosity in the aquatic ecosystem. The technique is to measure the in-situ volume of a substrate sample by measuring the volume of a frame over the substrate and then repeated the volume measurement after the sample is obtained from within the frame. The difference in the

  2. High Maturity Is Not a Procrustean Bed

    Science.gov (United States)

    2014-07-01

    for public release; distribution unlimited 13. SUPPLEMENTARY NOTES 14. ABSTRACT In Greek mythology , Procrustes was a rogue smith and bandit who...Institute of Technology Jo Ann Lane, University of Southern California Supannika Koolmanojwong, University of Southern California Abstract. In Greek ... mythology , Procrustes was a rogue smith and bandit who invited travellers to rest in his “perfectly sized bed.” When they accepted, he forcibly bound

  3. The equivalency between logic Petri workflow nets and workflow nets.

    Science.gov (United States)

    Wang, Jing; Yu, ShuXia; Du, YuYue

    2015-01-01

    Logic Petri nets (LPNs) can describe and analyze batch processing functions and passing value indeterminacy in cooperative systems. Logic Petri workflow nets (LPWNs) are proposed based on LPNs in this paper. Process mining is regarded as an important bridge between modeling and analysis of data mining and business process. Workflow nets (WF-nets) are the extension to Petri nets (PNs), and have successfully been used to process mining. Some shortcomings cannot be avoided in process mining, such as duplicate tasks, invisible tasks, and the noise of logs. The online shop in electronic commerce in this paper is modeled to prove the equivalence between LPWNs and WF-nets, and advantages of LPWNs are presented.

  4. The Equivalency between Logic Petri Workflow Nets and Workflow Nets

    Science.gov (United States)

    Wang, Jing; Yu, ShuXia; Du, YuYue

    2015-01-01

    Logic Petri nets (LPNs) can describe and analyze batch processing functions and passing value indeterminacy in cooperative systems. Logic Petri workflow nets (LPWNs) are proposed based on LPNs in this paper. Process mining is regarded as an important bridge between modeling and analysis of data mining and business process. Workflow nets (WF-nets) are the extension to Petri nets (PNs), and have successfully been used to process mining. Some shortcomings cannot be avoided in process mining, such as duplicate tasks, invisible tasks, and the noise of logs. The online shop in electronic commerce in this paper is modeled to prove the equivalence between LPWNs and WF-nets, and advantages of LPWNs are presented. PMID:25821845

  5. Coal Bed Methane Primer

    Energy Technology Data Exchange (ETDEWEB)

    Dan Arthur; Bruce Langhus; Jon Seekins

    2005-05-25

    During the second half of the 1990's Coal Bed Methane (CBM) production increased dramatically nationwide to represent a significant new source of income and natural gas for many independent and established producers. Matching these soaring production rates during this period was a heightened public awareness of environmental concerns. These concerns left unexplained and under-addressed have created a significant growth in public involvement generating literally thousands of unfocused project comments for various regional NEPA efforts resulting in the delayed development of public and fee lands. The accelerating interest in CBM development coupled to the growth in public involvement has prompted the conceptualization of this project for the development of a CBM Primer. The Primer is designed to serve as a summary document, which introduces and encapsulates information pertinent to the development of Coal Bed Methane (CBM), including focused discussions of coal deposits, methane as a natural formed gas, split mineral estates, development techniques, operational issues, producing methods, applicable regulatory frameworks, land and resource management, mitigation measures, preparation of project plans, data availability, Indian Trust issues and relevant environmental technologies. An important aspect of gaining access to federal, state, tribal, or fee lands involves education of a broad array of stakeholders, including land and mineral owners, regulators, conservationists, tribal governments, special interest groups, and numerous others that could be impacted by the development of coal bed methane. Perhaps the most crucial aspect of successfully developing CBM resources is stakeholder education. Currently, an inconsistent picture of CBM exists. There is a significant lack of understanding on the parts of nearly all stakeholders, including industry, government, special interest groups, and land owners. It is envisioned the Primer would being used by a variety of

  6. Infant's bed climate and bedding in the Japanese home.

    Science.gov (United States)

    Nakamura Ikeda, Rie; Fukai, Kiyoko; Okamoto Mizuno, Kazue

    2012-06-01

    to assess the bed climate of infants in their homes in Japan. descriptive, exploratory, non-experimental research design. the data were collected at the participants' homes under normal circumstances. nineteen healthy infants between the ages of two and five months. Their mothers, who joined a parenting class organised by a maternity clinic in Okayama, Japan, consented to participate in this study. we visited the infants' homes and interviewed their mothers concerning the types and use of bedding. The temperature and relative humidity of the bed climate at the back and foot of the bedding, and in the room were measured every minute for four consecutive days. Differences among the bed climates measured during three seasons (spring, summer, and autumn) were assessed by one-way analysis of variance. The bed temperature was higher for infants than for adults. No significant difference in temperature was noted among the three seasons. The bed temperature was about 36.0°C when waterproof sheets and futon mattresses for children or adult were used. The average relative humidity of the bed climate at the back was highest in summer, followed by that in spring and autumn; the differences were significant. The use of waterproof sheets and futon mattresses for children in summer increased the relative humidity to 80% or more. The use of infant beds, sunoko drainboards, and cotton futon mattresses in summer was effective in reducing the bed humidity. these results suggest that nurse-midwives should advise the parents on comfortable bed climates for their infants, as well as how to select and use bedding for them. Copyright © 2010 Elsevier Ltd. All rights reserved.

  7. Particle bed reactor modeling

    Science.gov (United States)

    Sapyta, Joe; Reid, Hank; Walton, Lew

    The topics are presented in viewgraph form and include the following: particle bed reactor (PBR) core cross section; PBR bleed cycle; fuel and moderator flow paths; PBR modeling requirements; characteristics of PBR and nuclear thermal propulsion (NTP) modeling; challenges for PBR and NTP modeling; thermal hydraulic computer codes; capabilities for PBR/reactor application; thermal/hydralic codes; limitations; physical correlations; comparison of predicted friction factor and experimental data; frit pressure drop testing; cold frit mask factor; decay heat flow rate; startup transient simulation; and philosophy of systems modeling.

  8. Fluidised bed cereal cooking

    International Nuclear Information System (INIS)

    Jenkins, Simon Anthony

    2002-01-01

    Man has been cooking food for thousands of years for a number of reasons: to improve flavour and palatability, sterilise, increase digestibility, improve texture and colour. Increasingly more advanced techniques are employed today in food production plants to engineer foods with many different properties. With this in mind manufacturers are constantly seeking to improve processing techniques and apply new or different technologies (such as microwaves, RF and extrusion) to develop foods with new properties (like puffed texture starches) and to increase process efficiencies (energy efficiency, water reduction). This thesis reports on work undertaken to demonstrate the potential to achieve high temperature starch conversion of whole wheat grains in a fluidised bed, thereby reducing the amount of water required and processing time. Specifically, wheat from the farm at 14% water content is cooked in a fluidised bed. The fluidised bed heats the wheat quickly by convective heating. In addition, energy can be delivered directly to the grain by microwave heating during fluidisation. Degree of starch conversion is determined by measuring the reduction in size of endotherm of reaction as observed by Differential Scanning Calorimetry. The fluidising gas, processing temperature and starting moisture content were varied in order to investigate their effect on the cooking process. A mathematical model based on energy and species concentration equations was developed to help understand the internal grain processes. The model coupled the thermal energy equation with water diffusion. The effect of water evaporation was represented as a thermal sink in the energy equation. Popular kinetic models from literature were adapted to predict the degree of starch conversion. The model gives solutions consistent with experimental data and physical intuition. A commercial computational fluid dynamics package was used to study simple airflow and particle tracks in the fluidisation column. A

  9. Predicting fractional bed load transport rates: Application of the Wilcock‐Crowe equations to a regulated gravel bed river

    Science.gov (United States)

    Gaeuman, David; Andrews, E.D.; Krause, Andreas; Smith, Wes

    2009-01-01

    Bed load samples from four locations in the Trinity River of northern California are analyzed to evaluate the performance of the Wilcock‐Crowe bed load transport equations for predicting fractional bed load transport rates. Bed surface particles become smaller and the fraction of sand on the bed increases with distance downstream from Lewiston Dam. The dimensionless reference shear stress for the mean bed particle size (τ*rm) is largest near the dam, but varies relatively little between the more downstream locations. The relation between τ*rm and the reference shear stresses for other size fractions is constant across all locations. Total bed load transport rates predicted with the Wilcock‐Crowe equations are within a factor of 2 of sampled transport rates for 68% of all samples. The Wilcock‐Crowe equations nonetheless consistently under‐predict the transport of particles larger than 128 mm, frequently by more than an order of magnitude. Accurate prediction of the transport rates of the largest particles is important for models in which the evolution of the surface grain size distribution determines subsequent bed load transport rates. Values of τ*rm estimated from bed load samples are up to 50% larger than those predicted with the Wilcock‐Crowe equations, and sampled bed load transport approximates equal mobility across a wider range of grain sizes than is implied by the equations. Modifications to the Wilcock‐Crowe equation for determining τ*rm and the hiding function used to scale τ*rm to other grain size fractions are proposed to achieve the best fit to observed bed load transport in the Trinity River.

  10. Which nets are being used: factors associated with mosquito net use in Amhara, Oromia and Southern Nations, Nationalities and Peoples' Regions of Ethiopia.

    Science.gov (United States)

    Ngondi, Jeremiah M; Graves, Patricia M; Gebre, Teshome; Mosher, Aryc W; Shargie, Estifanos B; Emerson, Paul M; Richards, Frank O

    2011-04-17

    There has been recent large scale-up of malaria control interventions in Ethiopia where transmission is unstable. While household ownership of long-lasting insecticidal nets (LLIN) has increased greatly, there are concerns about inadequate net use. This study aimed to investigate factors associated with net use at two time points, before and after mass distribution of nets. Two cross sectional surveys were carried out in 2006 and 2007 in Amhara, Oromia and SNNP regions. The latter was a sub-sample of the national Malaria Indicator Survey (MIS 3R). Each survey wave used multi-stage cluster random sampling with 25 households per cluster (224 clusters with 5,730 households in Baseline 2006 and 245 clusters with 5,910 households in MIS 3R 2007). Net ownership was assessed by visual inspection while net utilization was reported as use of the net the previous night. This net level analysis was restricted to households owning at least one net of any type. Logistic regression models of association between net use and explanatory variables including net type, age, condition, cost and other household characteristics were undertaken using generalized linear latent and mixed models (GLLAMM). A total of 3,784 nets in 2,430 households were included in the baseline 2006 analysis while the MIS 3R 2007 analysis comprised 5,413 nets in 3,328 households. The proportion of nets used the previous night decreased from 85.1% to 56.0% between baseline 2006 and MIS 3R 2007, respectively. Factors independently associated with increased proportion of nets used were: LLIN net type (at baseline 2006); indoor residual spraying (at MIS 3R 2007); and increasing wealth index at both surveys. At both baseline 2006 and MIS 3R 2007, reduced proportion of nets used was independently associated with increasing net age, increasing damage of nets, increasing household net density, and increasing altitude (>2,000 m). This study identified modifiable factors affecting use of nets that were consistent

  11. Which nets are being used: factors associated with mosquito net use in Amhara, Oromia and Southern Nations, Nationalities and Peoples' Regions of Ethiopia

    Directory of Open Access Journals (Sweden)

    Mosher Aryc W

    2011-04-01

    Full Text Available Abstract Background There has been recent large scale-up of malaria control interventions in Ethiopia where transmission is unstable. While household ownership of long-lasting insecticidal nets (LLIN has increased greatly, there are concerns about inadequate net use. This study aimed to investigate factors associated with net use at two time points, before and after mass distribution of nets. Methods Two cross sectional surveys were carried out in 2006 and 2007 in Amhara, Oromia and SNNP regions. The latter was a sub-sample of the national Malaria Indicator Survey (MIS 3R. Each survey wave used multi-stage cluster random sampling with 25 households per cluster (224 clusters with 5,730 households in Baseline 2006 and 245 clusters with 5,910 households in MIS 3R 2007. Net ownership was assessed by visual inspection while net utilization was reported as use of the net the previous night. This net level analysis was restricted to households owning at least one net of any type. Logistic regression models of association between net use and explanatory variables including net type, age, condition, cost and other household characteristics were undertaken using generalized linear latent and mixed models (GLLAMM. Results A total of 3,784 nets in 2,430 households were included in the baseline 2006 analysis while the MIS 3R 2007 analysis comprised 5,413 nets in 3,328 households. The proportion of nets used the previous night decreased from 85.1% to 56.0% between baseline 2006 and MIS 3R 2007, respectively. Factors independently associated with increased proportion of nets used were: LLIN net type (at baseline 2006; indoor residual spraying (at MIS 3R 2007; and increasing wealth index at both surveys. At both baseline 2006 and MIS 3R 2007, reduced proportion of nets used was independently associated with increasing net age, increasing damage of nets, increasing household net density, and increasing altitude (>2,000 m. Conclusion This study identified

  12. High-level Petri Nets

    DEFF Research Database (Denmark)

    various journals and collections. As a result, much of this knowledge is not readily available to people who may be interested in using high-level nets. Within the Petri net community this problem has been discussed many times, and as an outcome this book has been compiled. The book contains reprints...... of some of the most important papers on the application and theory of high-level Petri nets. In this way it makes the relevant literature more available. It is our hope that the book will be a useful source of information and that, e.g., it can be used in the organization of Petri net courses. To make......High-level Petri nets are now widely used in both theoretical analysis and practical modelling of concurrent systems. The main reason for the success of this class of net models is that they make it possible to obtain much more succinct and manageable descriptions than can be obtained by means...

  13. NetView technical research

    Science.gov (United States)

    1993-01-01

    This is the Final Technical Report for the NetView Technical Research task. This report is prepared in accordance with Contract Data Requirements List (CDRL) item A002. NetView assistance was provided and details are presented under the following headings: NetView Management Systems (NMS) project tasks; WBAFB IBM 3090; WPAFB AMDAHL; WPAFB IBM 3084; Hill AFB; McClellan AFB AMDAHL; McClellan AFB IBM 3090; and Warner-Robins AFB.

  14. Statistical description of flume experiments on mixed-size bed-load transport and bed armoring processes

    Science.gov (United States)

    Chen, D.; Zhang, Y.

    2008-12-01

    The objective of this paper is to describe the statistical properties of experiments on non-uniform bed-load transport as well as the mechanism of bed armoring processes. Despite substantial effort made over the last two decades, the ability to compute the bed-load flux in a turbulent system remains poor. The major obstacles include the poor understanding of the formation of armor lays on bed surfaces. Such a layer is much flow-resistible than the underlying material and therefore significantly inhibits sediment transport from the reach. To study the problem, we conducted a flume study for mixed sand/gravel sediments. We observed that aggregated sediment blocks were the most common characters in armor layers - the largest sizes resist hydraulic forces, while the smaller sizes add interlocking support and prevent loss of fine material through gaps between the larger particles. Fractional transport rates with the existing of armor layers were measured with time by sediment trapping method at the end of flume. To address the intermittent and time-varying behavior of bed-load transport during bed armoring processes, we investigated the probability distribution of the fractional bed-load transport rates, and the underlying dynamic model derived from the continuous time random walk framework. Results indicate that it is critical to consider the impact of armor layers when a flow is sufficient to move some of the finer particles and yet insufficient to move all the larger particles on a channel bed.

  15. "We are supposed to take care of it": a qualitative examination of care and repair behaviour of long-lasting, insecticide-treated nets in Nasarawa State, Nigeria.

    Science.gov (United States)

    Hunter, Gabrielle C; Scandurra, Leah; Acosta, Angela; Koenker, Hannah; Obi, Emmanuel; Weber, Rachel

    2014-08-14

    The longevity of long-lasting insecticidal nets (LLIN) under field conditions has important implications for malaria vector control. The behaviour of bed net users, including net care and repair, may protect or damage bed nets and impact the physical integrity of nets. However, this behaviour, and the motivating and inhibiting factors, is not well understood. Qualitative research methods were used to examine behaviour, attitudes and norms around damage, care and repair of LLINs. Eighteen in-depth interviews (IDI) and six focus group discussions (FGD) were conducted with LLIN users in two local government areas of Nasarawa State, Nigeria. A brief background questionnaire with the 73 participants prior to IDIs or FGDs collected additional data on demographics, net use, and care and repair behaviour. Respondents cited that the major causes of damage to bed nets are primarily children, followed by rodents, everyday handling that is not gentle, and characteristics of sleeping spaces. Caring for nets was perceived as both preventing damage by careful handling and keeping the net clean, which may lead to over-washing of LLINs. Repairing a damaged net was considered something that net users should do and the responsibility of adults in the household. Despite this, reported frequency of net repair was low (18%). Motivations for taking care of and repairing nets centred around caring for one's family, avoiding mosquito bites, saving money, and maintaining the positive opinion of others by keeping a clean and intact net. Barriers to net care and repair related to time availability and low perceived value of bed nets or of one's health. This study provides novel and valuable insights on the perceptions and attitudes of LLIN users in Nasarawa, Nigeria on the durability of bed nets, how to care for and repair nets, and for what reasons. Communication around net care should stress proper daily storage of nets, regular net inspections, prompt repairs, and clarify misconceptions

  16. The bedding of laboratory animals as a source of airborne contaminants.

    Science.gov (United States)

    Kaliste, E; Linnainmaa, M; Meklin, T; Torvinen, E; Nevalainen, A

    2004-01-01

    In work environments with laboratory animals, the bedding of animals binds the excreta as well as other compounds originating from the animals and their environment. These may be generated into the ambient air when the personnel handle bedding in different procedures. This study compares the dustiness of different types of six clean and four soiled beddings from rat or mouse cages. The dust generation of clean bedding varied from beddings decreased, increased or stayed the same, depending on the type of bedding and animal species. A decrease in dustiness was, however, more common. The levels in the soiled beddings varied from bedding, the contents of bedding used in mouse, rat or rabbit cages were analysed for mesophilic bacteria and fungi, mycobacteria and endotoxins. All of these contaminants were variably found in the bedding samples, the maximal concentrations for bacteria were >6 500 000 colony-forming units (cfu)/g, for fungi 212 000 cfu/g, and for endotoxins 6500 ng/g (81 000 EU/g). The results showed that the bedding of laboratory animals may contain biologically effective compounds, and that these may be distributed into the ambient air depending on the characteristics of the bedding material. The dustiness of different bedding types is an important factor affecting the amount and quality of the occupational exposure of the personnel to airborne contaminants.

  17. Initial CAD investigations for NET

    International Nuclear Information System (INIS)

    Katz, F.; Leinemann, K.; Ludwig, A.; Marek, U.; Olbrich, W.; Schlechtendahl, E.G.

    1985-11-01

    This report summarizes the work done under contract no. 164/84-7/FU-D-/NET between the Commission of the European Communities and KfK during the period from June 1, 1984, through May 31, 1985. The following topics are covered in this report: Initial modelling of NET version NET2A, CAD system extension for remote handling studies, analysis of the CAD information structure, work related to the transfer of CAD information between KfK and the NET team. (orig.) [de

  18. Understanding Net Zero Energy Buildings

    DEFF Research Database (Denmark)

    Salom, Jaume; Widén, Joakim; Candanedo, José

    2011-01-01

    Although several alternative definitions exist, a Net-Zero Energy Building (Net ZEB) can be succinctly described as a grid-connected building that generates as much energy as it uses over a year. The “net-zero” balance is attained by applying energy conservation and efficiency measures...... and by incorporating renewable energy systems. While based on annual balances, a complete description of a Net ZEB requires examining the system at smaller time-scales. This assessment should address: (a) the relationship between power generation and building loads and (b) the resulting interaction with the power grid...

  19. BioNet Digital Communications Framework

    Science.gov (United States)

    Gifford, Kevin; Kuzminsky, Sebastian; Williams, Shea

    2010-01-01

    BioNet v2 is a peer-to-peer middleware that enables digital communication devices to talk to each other. It provides a software development framework, standardized application, network-transparent device integration services, a flexible messaging model, and network communications for distributed applications. BioNet is an implementation of the Constellation Program Command, Control, Communications and Information (C3I) Interoperability specification, given in CxP 70022-01. The system architecture provides the necessary infrastructure for the integration of heterogeneous wired and wireless sensing and control devices into a unified data system with a standardized application interface, providing plug-and-play operation for hardware and software systems. BioNet v2 features a naming schema for mobility and coarse-grained localization information, data normalization within a network-transparent device driver framework, enabling of network communications to non-IP devices, and fine-grained application control of data subscription band width usage. BioNet directly integrates Disruption Tolerant Networking (DTN) as a communications technology, enabling networked communications with assets that are only intermittently connected including orbiting relay satellites and planetary rover vehicles.

  20. Granular controls on the dispersion of bed load tracers

    Science.gov (United States)

    Jerolmack, D. J.; Martin, R. L.; Phillips, C. B.

    2014-12-01

    Coarse particles are transported in a river as bed load, i.e., they move in frequent contact with and are supported by the granular bed. This movement is typically intermittent and may be described by a series of steps are rests, the distributions of which determine particle dispersion. Laboratory and field studies of bed load tracer dispersion have reported sub- and super-diffusive behavior, both of which have been successfully reproduced with stochastic transport models. Although researchers have invoked heavy-tailed step lengths as the cause of anomalous dispersion, most observations report thin-tailed distributions. Little attention has been paid to rest periods, and stochastic transport models have not been connected to the underlying mechanics of particle motion. Based on theoretical and experimental evidence, we argue that step lengths are thin-tailed and do not control the longterm dispersion of bed load tracers; they are determined by momentum balance between the fluid and solid. Using laboratory experiments with both marbles and natural sediments, we demonstrate that the rest time distribution is power law, and argue that this distribution controls asymptotic dispersion. Observed rest times far exceed any hydrodynamic timescale. Experiments reveal that rest times of deposited particles are governed by fluctuations in river bed elevation; in particular, the return time for the bed to scour to the base of a deposited particle. Stochastic fluctuations in bed elevation are describable by an Ornstein-Uhlenbeck (mean-reverting random walk) model that contains two parameters, which we show are directly related to the granular shear rate and range of bed elevation fluctuations, respectively. Combining these results with the theory of asymmetric random walks (particles only move downstream), we predict superdiffusive behavior that is in quantitative agreement with our observations of tracer dispersion in a natural river.

  1. Fluidized bed boiler feed system

    Science.gov (United States)

    Jones, Brian C.

    1981-01-01

    A fluidized bed boiler feed system for the combustion of pulverized coal. Coal is first screened to separate large from small particles. Large particles of coal are fed directly to the top of the fluidized bed while fine particles are first mixed with recycled char, preheated, and then fed into the interior of the fluidized bed to promote char burnout and to avoid elutriation and carryover.

  2. Fluidized bed reactor for working up carbon coated particles

    International Nuclear Information System (INIS)

    Marschollek, M.; Simon, W.; Walter, C.

    1981-01-01

    A fluidized bed reactor is described for working up carbon coated particles, particularly nuclear fuel particles or fertile material particles consisting essentially of a cylindrical portion connected to a conical portion. Gas supply pipes, gas distribution space and gas distribution heads are provided within the conical reactor lower portion, the gas distribution members being arranged in at least two superimposed planes and distributed symmetrically over the cross-section of the reactor

  3. Rare, but challenging tumors: NET

    International Nuclear Information System (INIS)

    Ivanova, D.; Balev, B.

    2013-01-01

    Full text: Introduction: Gastroenteropancreatic Neuroendocrine Tumors (GEP - NET) are a heterogeneous group of tumors with different locations and many different clinical, histological, and imaging performance. In a part of them a secretion of various organic substances is present. The morbidity of GEP - NET in the EU is growing, and this leads to increase the attention to them. What you will learn: Imaging methods used for localization and staging of GEP - NET, characteristics of the study’s protocols; Classification of GEP - NET; Demonstration of typical and atypical imaging features of GEP - NET in patients registered at the NET Center at University Hospital ‘St. Marina’, Varna; Features of metastatic NET, The role of imaging in the evaluation of treatment response and follow-up of the patients. Discussion: The image semiotics analysis is based on 19 cases of GEP - NET registered NET Center at University Hospital ‘St. Marina’. The main imaging method is multidetector CT (MDCT), and magnetic resonance imaging (MRI ) has advantages in the evaluation of liver lesions and the local prevalence of anorectal tumors. In patients with advanced disease and liver lesions the assessment of skeletal involvement (MRI/ nuclear medical method) is mandatory. The majority of GEP - NET have not any specific imaging findings. Therefore it is extremely important proper planning and conducting of the study (MDCT and MR enterography; accurate assessment phase of scanning, positive and negative contrast). Conclusion: GEP - NET is a major diagnostic challenge due to the absence of typical imaging characteristics and often an overlap with those of the tumors of different origin can be observed. Therefore, a good knowledge of clinical and imaging changes occurring at different locations is needed. MDCT is the basis for the diagnosis, staging and follow-up of these neoplasms

  4. Management bedding : vrijloopstal met composterende bedding van houtsnippers

    NARCIS (Netherlands)

    Boer, de H.C.; Wiersma, M.; Galama, P.J.; Szanto, G.L.

    2015-01-01

    In de vrijloopstal liggen de koeien meestal op een organische bedding en scheiden daar mest (feces en urine) uit. Om de bedding voldoende droog en schoon te houden wordt er regelmatig nieuw strooisel aangevoerd en wordt de toplaag bewerkt. Op basis van onderzoek- en praktijkervaringen tot nu toe

  5. Shock Interaction with Random Spherical Particle Beds

    Science.gov (United States)

    Neal, Chris; Mehta, Yash; Salari, Kambiz; Jackson, Thomas L.; Balachandar, S. "Bala"; Thakur, Siddharth

    2016-11-01

    In this talk we present results on fully resolved simulations of shock interaction with randomly distributed bed of particles. Multiple simulations were carried out by varying the number of particles to isolate the effect of volume fraction. Major focus of these simulations was to understand 1) the effect of the shockwave and volume fraction on the forces experienced by the particles, 2) the effect of particles on the shock wave, and 3) fluid mediated particle-particle interactions. Peak drag force for particles at different volume fractions show a downward trend as the depth of the bed increased. This can be attributed to dissipation of energy as the shockwave travels through the bed of particles. One of the fascinating observations from these simulations was the fluctuations in different quantities due to presence of multiple particles and their random distribution. These are large simulations with hundreds of particles resulting in large amount of data. We present statistical analysis of the data and make relevant observations. Average pressure in the computational domain is computed to characterize the strengths of the reflected and transmitted waves. We also present flow field contour plots to support our observations. U.S. Department of Energy, National Nuclear Security Administration, Advanced Simulation and Computing Program, as a Cooperative Agreement under the Predictive Science Academic Alliance Program, under Contract No. DE-NA0002378.

  6. X-ray tomography investigations on pebble bed structures

    International Nuclear Information System (INIS)

    Reimann, J.; Rolli, R.; Pieritz, R.A.; Ferrero, C.; Di Michiel, M.

    2007-01-01

    Granular materials (pebbles) are used in present ceramic breeder blankets both for the ceramic breeder material and beryllium. The thermal-mechanical behaviour of these pebble beds strongly depends on the arrangement of the pebbles in the bed, their contacts and contact surfaces with other pebbles and with walls. The influence of these quantities is most pronounced for beryllium pebble beds because of the large thermal conductivity ratio of beryllium to helium gas atmosphere. At present, the data base for the pebble bed thermal conductivity (k) and heat transfer coefficient (h) is quite limited for compressed beds and significant discrepancies exist in respect to h. The detailed knowledge of the pebble bed topology is, therefore, essential to better understand the heat transfer mechanisms. In the present work, results from detailed X-ray tomography investigations are reported on pebble topology in i) the pebble bed bulk (which is relevant for k), and ii) the region close to walls with thicknesses of several pebble diameters (relevant for h). At Forschungszentrum Karlsruhe, pebble beds consisting of aluminium spheres with diameters of 2.3 and 5 mm, respectively, (simulating the blanket relevant 1 mm beryllium pebbles), were uniaxially compressed at different pressure levels. High resolution three-dimensional microtomography (MT) experiments were subsequently performed at the European Synchrotron Radiation Facility, Grenoble. Radial and axial void fraction distributions were found to be oscillatory next to the walls and non-oscillatory in the bulk. For non-compressed pebble beds, the bulk void fraction is fairly constant; for compressed beds, a gradient exists along the compression axis. In the bulk, the angular distribution of pebble contacts was found to be fairly constant, indicating that no regular packing structure is induced. In the wall region, the pebble layer touching the wall is composed of zones with hexagonal structures as shown clearly by MT images. This

  7. Linear Logic on Petri Nets

    DEFF Research Database (Denmark)

    Engberg, Uffe Henrik; Winskel, Glynn

    This article shows how individual Petri nets form models of Girard's intuitionistic linear logic. It explores questions of expressiveness and completeness of linear logic with respect to this interpretation. An aim is to use Petri nets to give an understanding of linear logic and give some apprai...

  8. Net neutrality and audiovisual services

    NARCIS (Netherlands)

    van Eijk, N.; Nikoltchev, S.

    2011-01-01

    Net neutrality is high on the European agenda. New regulations for the communication sector provide a legal framework for net neutrality and need to be implemented on both a European and a national level. The key element is not just about blocking or slowing down traffic across communication

  9. Properties of porous netted materials

    International Nuclear Information System (INIS)

    Daragan, V.D.; Drozdov, B.G.; Kotov, A.Yu.; Mel'nikov, G.N.; Pustogarov, A.V.

    1987-01-01

    Hydraulic and strength characteristics, efficient heat conduction and inner heat exchange coefficient are experimentally studied for porous netted materials on the base of the brass nets as dependent on porosity, cell size and method of net laying. Results of the studies are presented. It is shown that due to anisotropy of the material properties the hydraulic resistance in the direction parallel to the nets plane is 1.3-1.6 times higher than in the perpendicular one. Values of the effective heat conduction in the direction perpendicular to the nets plane at Π>0.45 agree with the data from literature, at Π<0.45 a deviation from the calculated values is marked in the direction of the heat conduction decrease

  10. NET remote workstation

    International Nuclear Information System (INIS)

    Leinemann, K.

    1990-10-01

    The goal of this NET study was to define the functionality of a remote handling workstation and its hardware and software architecture. The remote handling workstation has to fulfill two basic functions: (1) to provide the man-machine interface (MMI), that means the interface to the control system of the maintenance equipment and to the working environment (telepresence) and (2) to provide high level (task level) supporting functions (software tools) during the maintenance work and in the preparation phase. Concerning the man-machine interface, an important module of the remote handling workstation besides the standard components of man-machine interfacing is a module for graphical scene presentation supplementing viewing by TV. The technique of integrated viewing is well known from JET BOOM and TARM control using the GBsim and KISMET software. For integration of equipment dependent MMI functions the remote handling workstation provides a special software module interface. Task level support of the operator is based on (1) spatial (geometric/kinematic) models, (2) remote handling procedure models, and (3) functional models of the equipment. These models and the related simulation modules are used for planning, programming, execution monitoring, and training. The workstation provides an intelligent handbook guiding the operator through planned procedures illustrated by animated graphical sequences. For unplanned situations decision aids are available. A central point of the architectural design was to guarantee a high flexibility with respect to hardware and software. Therefore the remote handling workstation is designed as an open system based on widely accepted standards allowing the stepwise integration of the various modules starting with the basic MMI and the spatial simulation as standard components. (orig./HP) [de

  11. Net currents in the wave bottom boundary layer: on waveshape streaming and progressive wave streaming

    NARCIS (Netherlands)

    Kranenburg, Wouter; Ribberink, Jan S.; Uittenbogaard, R.E.; Hulscher, Suzanne J.M.H.

    2012-01-01

    The net current (streaming) in a turbulent bottom boundary layer under waves above a flat bed, identified as potentially relevant for sediment transport, is mainly determined by two competing mechanisms: an onshore streaming resulting from the horizontal non-uniformity of the velocity field under

  12. Net accumulation of the Greenland ice sheet

    DEFF Research Database (Denmark)

    Kiilsholm, Sissi; Christensen, Jens Hesselbjerg; Dethloff, Klaus

    2003-01-01

    High-resolution (50 km) climate change simulations for an area covering the entire Arctic have been conducted with the regional climate model (RCM) HIRHAM. The experiments were forced at the lateral boundary by large-scale atmospheric conditions from transient climate change scenario simulations...... with HIRHAM for periods representing present-day (1961-1990) and the future (2071-2100) in the two scenarios. We find that due to a much better representation of the surface topography in the RCM, the geographical distribution of present-day accumulation rates simulated by the RCM represents a substantial...... improvement compared to the driving OAGCM. Estimates of the regional net balance are also better represented by the RCM. In the future climate the net balance for the Greenland Ice Sheet is reduced in all the simulation, but discrepancies between the amounts when based on ECHAM4/OPYC3 and HIRHAM are found...

  13. Implementation strategies to increase access and demand of long-lasting insecticidal nets: a before-and-after study and scale-up process in Mozambique.

    Science.gov (United States)

    Arroz, Jorge A H; Mendis, Chandana; Pinto, Liliana; Candrinho, Baltazar; Pinto, João; Martins, Maria do Rosário O

    2017-10-25

    The universal coverage bed nets campaign is a proven health intervention promoting increased access, ownership, and use of bed nets to reduce malaria burden. This article describes the intervention and implementation strategies that Mozambique carried out recently in order to improve access and increase demand for long-lasting insecticidal nets (LLINs). A before-and-after study with a control group was used during Stage I of the implementation process. The following strategies were tested in Stage I: (1) use of coupons during household registration; (2) use of stickers to identify the registered households; (3) new LLIN ascription formula (one LLIN for every two people). In Stage II, the following additional strategies were implemented: (4) mapping and micro-planning; (5) training; and (6) supervision. Odds ratio (OR) and 95% confidence interval (CI) were used to compare and establish differences between intervened and control districts in Stage I. Main outcomes were: percentage of LLINs distributed, percentage of target households benefited. In Stage I, 87.8% (302,648) of planned LLINs were distributed in the intervention districts compared to 77.1% (219,613) in the control districts [OR: 2.14 (95% CI 2.11-2.16)]. Stage I results also showed that 80.6% (110,453) of households received at least one LLIN in the intervention districts compared to 72.8% (87,636) in the control districts [OR: 1.56 (95% CI 1.53-1.59)]. In Stage II, 98.4% (3,536,839) of the allocated LLINs were delivered, covering 98.6% (1,353,827) of the registered households. Stage I results achieved better LLINs and household coverage in districts with the newly implemented strategies. The results of stage II were also encouraging. Additional strategies adaptation is required for a wide-country LLIN campaign.

  14. Hydrogeological investigations of river bed clogging at a river bank filtration site along the River Warta, Poland

    Directory of Open Access Journals (Sweden)

    Przybyłek Jan

    2017-12-01

    Full Text Available River bank filtration (RBF is a system that enriches groundwater resources by induced infiltration of river water to an aquifer. Problematic during operation of RBF systems is the deterioration of infiltration effectiveness caused by river bed clogging. This situation was observed in the Krajkowo well field which supplies fresh water to the city of Poznań (Poland during and after the long hydrological drought between the years 1989 and 1992. The present note discusses results of specific hydrogeological research which included drilling of a net of boreholes to a depth of 10 m below river bottom (for sediment sampling as well as for hydrogeological measurements, analyses of grain size distribution and relative density studies. The results obtained have allowed the recognition of the origin of the clogging processes, as well as the documentation of the clogged parts of the river bottom designated for unclogging activities.

  15. Effectiveness of Bed Bug Pesticides

    Science.gov (United States)

    Before EPA allows a bed bug claim on a label, the product must be supported by data showing it will kill bed bugs when applied according to the label. Also consider factors such as extent of infestation, site preparation, and insect life stages.

  16. Temporal and spatial variability in thalweg profiles of a gravel-bed river

    Science.gov (United States)

    Madej, Mary Ann

    1999-01-01

    This study used successive longitudinal thalweg profiles in gravel-bed rivers to monitor changes in bed topography following floods and associated large sediment inputs. Variations in channel bed elevations, distributions of residual water depths, percentage of channel length occupied by riffles, and a spatial autocorrelation coefficient (Moran's I) were used to quantify changes in morphological diversity and spatial structure in Redwood Creek basin, northwestern California. Bed topography in Redwood Creek and its major tributaries consists primarily of a series of pools and riffles. The size, frequency and spatial distribution of the pools and riffles have changed significantly during the past 20 years. Following large floods and high sediment input in Redwood Creek and its tributaries in 1975, variation in channel bed elevations was low and the percentage of the channel length occupied by riffles was high. Over the next 20 years, variation in bed elevations increased while the length of channel occupied by riffles decreased. An index [(standard deviation of residual water depth/bankfull depth) × 100] was developed to compare variations in bed elevation over a range of stream sizes, with a higher index being indicative of greater morphological diversity. Spatial autocorrelation in the bed elevation data was apparent at both fine and coarse scales in many of the thalweg profiles and the observed spatial pattern of bed elevations was found to be related to the dominant channel material and the time since disturbance. River reaches in which forced pools dominated, and in which large woody debris and bed particles could not be easily mobilized, exhibited a random distribution of bed elevations. In contrast, in reaches where alternate bars dominated, and both wood and gravel were readily transported, regularly spaced bed topography developed at a spacing that increased with time since disturbance. This pattern of regularly spaced bed features was reversed

  17. Coevolution of bed surface patchiness and channel morphology: 2. Numerical experiments

    Science.gov (United States)

    Nelson, Peter A.; McDonald, Richard R.; Nelson, Jonathan M.; Dietrich, William E.

    2015-01-01

    In gravel bed rivers, bed topography and the bed surface grain size distribution evolve simultaneously, but it is not clear how feedbacks between topography and grain sorting affect channel morphology. In this, the second of a pair of papers examining interactions between bed topography and bed surface sorting in gravel bed rivers, we use a two-dimensional morphodynamic model to perform numerical experiments designed to explore the coevolution of both free and forced bars and bed surface patches. Model runs were carried out on a computational grid simulating a 200 m long, 2.75 m wide, straight, rectangular channel, with an initially flat bed at a slope of 0.0137. Over five numerical experiments, we varied (a) whether an obstruction was present, (b) whether the sediment was a gravel mixture or a single size, and (c) whether the bed surface grain size feeds back on the hydraulic roughness field. Experiments with channel obstructions developed a train of alternate bars that became stationary and were connected to the obstruction. Freely migrating alternate bars formed in the experiments without channel obstructions. Simulations incorporating roughness feedbacks between the bed surface and flow field produced flatter, broader, and longer bars than simulations using constant roughness or uniform sediment. Our findings suggest that patches are not simply a by-product of bed topography, but they interact with the evolving bed and influence morphologic evolution.

  18. Recovery of intertidal mussel beds in the Waddensea: use of habitat maps in the management of the fishery

    NARCIS (Netherlands)

    Dankers, N.M.J.A.; Brinkman, A.G.; Meijboom, A.; Dijkman, E.M.

    2001-01-01

    In the Waddensea, musselbed distribution and abundance has decreased. Management is aiming at increase of area of beds. Fisheries have been regulated. Mussel beds are slowly recovering, and localities where recovery occurs can be predicted reasonably well. Active restoration of beds has not been

  19. Maintenance of an obstruction-forced pool in a gravel-bed channel: streamflow, channel morphology, and sediment transport.

    Science.gov (United States)

    Richard D. Woodsmith; Marwan A. Hassan

    2005-01-01

    Maintenance of pool morphology in a stream channel with a mobile bed requires hydraulic conditions at moderate to high flows that route bed load through the pool as it is delivered from upstream. Through field measurements of discharge, vertical velocity profiles, bed load transport, and streambed scour, fill, and grain-size distribution, we found that maintenance of a...

  20. Conformal Nets II: Conformal Blocks

    Science.gov (United States)

    Bartels, Arthur; Douglas, Christopher L.; Henriques, André

    2017-08-01

    Conformal nets provide a mathematical formalism for conformal field theory. Associated to a conformal net with finite index, we give a construction of the `bundle of conformal blocks', a representation of the mapping class groupoid of closed topological surfaces into the category of finite-dimensional projective Hilbert spaces. We also construct infinite-dimensional spaces of conformal blocks for topological surfaces with smooth boundary. We prove that the conformal blocks satisfy a factorization formula for gluing surfaces along circles, and an analogous formula for gluing surfaces along intervals. We use this interval factorization property to give a new proof of the modularity of the category of representations of a conformal net.

  1. Pro asynchronous programming with .NET

    CERN Document Server

    Blewett, Richard; Ltd, Rock Solid Knowledge

    2014-01-01

    Pro Asynchronous Programming with .NET teaches the essential skill of asynchronous programming in .NET. It answers critical questions in .NET application development, such as: how do I keep my program responding at all times to keep my users happy how do I make the most of the available hardware how can I improve performanceIn the modern world, users expect more and more from their applications and devices, and multi-core hardware has the potential to provide it. But it takes carefully crafted code to turn that potential into responsive, scalable applications.With Pro Asynchronous Programming

  2. Turbulent water flow over rough bed - part I

    Energy Technology Data Exchange (ETDEWEB)

    Ksiazek, Leszek; Bartnik, Wojciech; Rumian, Jacek; Zagorowski, Pawel, E-mail: rmksiaze@cyf-kr.edu.pl [Department of Hydraulic Engineering and Geotechnics, University of Agriculture in Krakow, Mickiewicza Avenue 24/28, 30-059 Krakow (Poland)

    2011-12-22

    Restitution of diadromic fish requires restoration of ecological continuity of watercourses, e.g. by building fish ladders. Directions for fish ladders require that ichthyofauna is granted accurate conditions of water flow. To describe them, average values are used, that do not convey e.g. turbulence intensity or its spatial differentiation. The paper presents results of research on the turbulent water flow over the rough bed. The measurements were carried out with high sampling frequency probe for three velocity components. Bed configuration, distribution of average velocities and turbulence intensity were defined. The range of bed influence for the discussed water flow conditions was ascertained to reach the maximum of about 0.25 of height and decline at 0.35. The lowest turbulence and relatively lowest velocities near the bed may promote successive stages of ichthyofauna development.

  3. Protecting Your Home from Bed Bugs

    Science.gov (United States)

    ... your home: Inspect the luggage rack in your hotel room for bed bugs. Check secondhand furniture, beds, ... with Bed Bug Problems Discover. Accessibility EPA Administrator Budget & Performance Contracting Grants January 19, 2017 Web Snapshot ...

  4. Divertor plate concept with carbon based armour for NET

    International Nuclear Information System (INIS)

    Moons, F.; Howard, R.; Kneringer, G.; Stickler, R.

    1989-01-01

    A series of tests has been performed on simulated divertor elements for NET at the JET neutral beam injector test bed. The test section consisted of a water cooled main structure, the surface of which was protected with a carbon based armour in the form of tiles. The scope of these was to study the thermal behaviour of mechanically attached tiles with the use of an intermediate soft carbon layer to improve the thermal contact under divertor relevant conditions. (author). 4 refs.; 4 figs.; 1 tab

  5. Atlantic Ocean Acidification Test-Bed -- Net Ecosystem Calcification and Net Ecosystem Productivity, Flower Garden Banks, FY2015

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The AOAT project is engaged in monitoring/modeling efforts designed to: a) establish methodologies for monitoring, assessing, and modeling the impacts of Ocean...

  6. Atlantic Ocean Acidification Test-Bed -- Net Ecosystem Calcification and Net Ecosystem Productivity, Cheeca Rocks, Florida Reef Tract FY2013

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The AOAT project is engaged in monitoring/modeling efforts designed to: a) establish methodologies for monitoring, assessing, and modeling the impacts of Ocean...

  7. Gas fluidized bed reactor

    International Nuclear Information System (INIS)

    Bernardelli, H. da C.

    1976-03-01

    The equations of motion for both gas and particles in a gas fluidised system are stablished through general assumptions which are generally accepted on physical grounds. The resulting model is used to study the velocity fields of each phase in the case of an isolated bubble rising close to the flat distributor plate. A well posed problem results for the solution of Laplace's equation of the potential flow of the particles when consideration is given to the presence of the distributor as a boundary condition. The corresponding stream functions are also obtained which enable the drawing of the motion patterns using numerical techniques. The following two dimensional cases are analysed: S/b=1; S/b=1,5; S/b=2,5; S/b=5 and the limiting case S/b→αinfinite. The results for the interphase exchange between bubbles and particulate phases are applied to a gas fluidised bed reactor and its effect on the chemical conversion is studied for the simplest cases of piston flow and perfect mixing in the particulate phase [pt

  8. Chaotic hydrodynamics of fluidized beds

    Energy Technology Data Exchange (ETDEWEB)

    Van der Stappen, M.L.M. [Unit Process and Systems Engineering, Advanced Manufacturing Technology Group, Unilever Research Laboratorium, Vlaardingen (Netherlands)

    1996-12-31

    The major goals of this thesis are: (1) to develop and evaluate an analysis method based on techniques from non-linear chaos theory to characterize the nonlinear hydrodynamics of gas-solids fluidized beds quantitatively; and (2) to determine the dependence of the chaotic invariants on the operating conditions and investigate how the chaos analysis method can be profitably applied to improve scale-up and design of gas-solids fluidized bed reactors. Chaos theory is introduced in chapter 2 with emphasis on analysis techniques for (experimental) time series, known from literature at the start of this work (1990-1991). In chapter 3, the testing of existing and newly developed techniques on both model and fluidized bed data is described. This leads to the development of the chaos analysis method to analyze measured pressure fluctuations time series of a fluidized bed. Following, in chapter 4, this method is tested and all choices for the parameters are evaluated. The influence of the experimental parameters and external disturbances on the measurements and analysis results is discussed and quantified. The result is a chaos measurement and analysis protocol, which is further used in this work. In chapter 5, the applications to fluidized beds are discussed. It is shown that the entropy is a good measure for the characterization of the dynamical behavior of gas-solids bubbling/slugging fluidized beds. Entropy is applied to characterize the influence of the operating conditions, to assess regime transitions and to analyze dimensionless similar beds of different scale. Quantitative design correlations that relate entropy to the operating parameters (including the bed diameter) are described. Finally, it is discussed how the results of this work might be used in scaling up the chaotic dynamics of fluidized beds. The overall conclusions and outlook from this work are presented in chapter 6. 182 refs.

  9. KM3NeT

    CERN Multimedia

    KM3NeT is a large scale next-generation neutrino telescope located in the deep waters of the Mediterranean Sea, optimized for the discovery of galactic neutrino sources emitting in the TeV energy region.

  10. Pickering nuclear fish diversion net

    Energy Technology Data Exchange (ETDEWEB)

    Xiao, J.; Lew, A. [Ontario Power Generation, Toronto, Ontario (Canada)

    2013-07-01

    Pickering Fish Diversion Net - An Engineered Environmental Solution that has significantly reduced fish impingement at the Pickering Nuclear Facility. Note: As a recent urgent request/discussed by Mark Elliot, CNE-OPG and Jacques Plourde, CNS.

  11. PolicyNet Publication System

    Data.gov (United States)

    Social Security Administration — The PolicyNet Publication System project will merge the Oracle-based Policy Repository (POMS) and the SQL-Server CAMP system (MSOM) into a new system with an Oracle...

  12. Net Neutrality: Background and Issues

    National Research Council Canada - National Science Library

    Gilroy, Angele A

    2006-01-01

    .... The move to place restrictions on the owners of the networks that compose and provide access to the Internet, to ensure equal access and nondiscriminatory treatment, is referred to as "net neutrality...

  13. Bed retained products in swept fixed bed (SFB) coal hydropyrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Mastral, A.M.; Perez-Surio, M.J. [CSIC, Zaragosa (Spain). Inst. de Carboquimica

    1997-12-31

    The hydropyrolysis of a low rank coal in a swept fixed bed (SFB) reactor is carried out by fixing the hydrogen pressure (40 kg/cm{sup 2}), the hydrogen flow (2 l/min) and the residence time (10 min) at increasing temperatures (400 C, 500 C and 600 C) and coal bed heights (h, 1.5h, 2h, 2.5h and 3h). It is shown that the percentages of tars and char directly depend on the coal bed height and that there is not only a quantitative dependence, but also the height of the coal bed is very important and plays a relevant role on the nature of the conversion products. (orig.)

  14. Analisis Determinan Net Ekspor Indonesia

    OpenAIRE

    Daulay, Rahmawaty

    2010-01-01

    This study is to analyzing empirically among Indonesia GDP, trade partnership GDP (Malaysia, Singapore, US and Thailand) and real exchange rate toward Indonesia Net Export. To find out which one from those three variables is significant in order to fluctuating (increasing or decreasing) Indonesia Net Export either in the short run or in the long run. Data collection is obtained using secondary data, namely Indonesia GDP, Malaysia GDP, Singapura GDP, US GDP, Thailand GDP and real exchange rate...

  15. NetBeans GUI Builder

    OpenAIRE

    Pusiankova, Tatsiana

    2009-01-01

    This work aims at making readers familiar with the powerful tool NetBeans IDE GUI Builder and helping them make their first steps to creation of their own graphical user interface in the Java programming language. The work includes theoretical description of NetBeans IDE GUI Builder, its most important characteristics and peculiarities and also a set of practical instructions that will help readers in creation of their first GUI. The readers will be introduced to the environment of this tool ...

  16. The geographic diversity of nontuberculous mycobacteria isolated from pulmonary samples: an NTM-NET collaborative study

    NARCIS (Netherlands)

    Hoefsloot, W.; Ingen, J. van; Andrejak, C.; Angeby, K.; Bauriaud, R.; Bemer, P.; Beylis, N.; Boeree, M.J.; Cacho, J.; Chihota, V.; Chimara, E.; Churchyard, G.; Cias, R.; Daza, R.; Daley, C.L.; Dekhuijzen, P.N.R.; Domingo, D.; Drobniewski, F.; Esteban, J. De; Fauville-Dufaux, M.; Folkvardsen, D.B.; Gibbons, N.; Gomez-Mampaso, E.; Gonzalez, R.; Hoffmann, H.; Hsueh, P.R.; Indra, A.; Jagielski, T.; Jamieson, F.; Jankovic, M.; Jong, E. de; Keane, J.; Koh, W.J.; Lange, B. de; Leao, S.; Macedo, R.; Mannsaker, T.; Marras, T.K.; Maugein, J.; Milburn, H.J.; Mlinko, T.; Morcillo, N.; Morimoto, K.; Papaventsis, D.; Palenque, E.; Paez-Pena, M.; Piersimoni, C.; Polanova, M.; Rastogi, N.; Richter, E.; Ruiz-Serrano, M.J.; Silva, A.; Silva, M.P. da; Simsek, H.; Soolingen, D. van; Szabo, N.; Thomson, R.; Fernandez, T. Tortola; Tortoli, E.; Totten, S.E.; Tyrrell, G.; Vasankari, T.; Villar, M.; Walkiewicz, R.; Winthrop, K.L.; Wagner, D.; Trials, G. Nontuberculous

    2013-01-01

    A significant knowledge gap exists concerning the geographical distribution of nontuberculous mycobacteria (NTM) isolation worldwide. To provide a snapshot of NTM species distribution, global partners in the NTM-Network European Trials Group (NET) framework (www.ntm-net.org), a branch of the

  17. Net positive energy buildings

    International Nuclear Information System (INIS)

    Romero, A.; Barreiro, E.; Sanchez Zabala, V.

    2010-01-01

    Buildings are great consumers of energy, being responsible for almost 36% of CO2 emissions in Europe. Though there are many initiatives towards the reduction of energy consumption and CO2 emissions in buildings, many of the alternatives are diminished due to a lack of a unique and holistic approach to the problem. This paper reports a new innovative concept of Positive Energy Buildings (EB+), as well as an integral methodology that covers the overall design process for achieving them. The methodology evaluates energy efficiency solutions at different scales, from building site to generation systems. An educational building design in Navarra serves as a case study to check the feasibility of the proposed methodology. The study concludes that the key to achieve a Positive Energy Building is a minimized energy demand, complemented by efficient facilities and enhanced by distributed power generation from renewable sources. (Author).

  18. Terapia intensiva neonatal e pediátrica no Rio de Janeiro: distribuição de leitos e análise de eqüidade Neonatal and pediatric intensive care in Rio de Janeiro: distribution of beds and analysis of equity

    Directory of Open Access Journals (Sweden)

    ARNALDO PRATA BARBOSA

    2002-12-01

    Full Text Available OBJETIVOS: Identificar as UTIs pediátricas do Rio de Janeiro, número de leitos, distribuição geográfica, natureza pública ou privada, tipo de atendimento e de hospital, estudar a demanda da população e elaborar propostas de melhoria na eqüidade. MÉTODOS: Foram visitadas todas as UTIs do Estado, de julho de 97 a junho de 98, levantado o número de leitos e tempo médio de permanência. Com essas informações e dados do IBGE, estabeleceu-se a necessidade de leitos e a comparação entre oferta e demanda por regiões, formulando-se propostas de melhoria na eqüidade. RESULTADOS: Foram identificadas 80 UTIs (excluídas seis, totalizando 1.080 leitos; 60% intensivos e 40% semi-intensivos; 57% públicos e 43% privados; 52% em UTIs neonatais exclusivas, 14% em pediátricas e 34% em mistas (65% leitos neonatais, totalizando 791 leitos neonatais (73%. A maioria das UTIs (75% situava-se em hospitais gerais, 20% em maternidades ou hospitais materno-infantis e somente 5% eram centros universitários; a maioria na região metropolitana (89%, com 93% dos leitos para 74% da população infantil, dos quais a maioria na cidade do Rio de Janeiro (76%, com 73% dos leitos para 37% da população, enquanto que no interior existem apenas oito unidades (11% e 79 leitos (7% para 26% da população. CONCLUSÕES: Não há eqüidade na distribuição e no acesso aos leitos disponíveis, com carência no setor público e excesso no privado, grande concentração na região metropolitana e somente 5% das UTIs em hospitais universitários, propondo-se medidas de redistribuição e alocação de novos leitos em regiões mais carentes, associada à criação de uma central de vagas e sistema eficiente de transporte e referência.OBJECTIVES: To identify the pediatric ICUs at Rio de Janeiro, number of beds, geographical distribution, public or private nature, type of hospital and assistance, studying population demand and to propose measures for improving equity

  19. GOLD NETTING TO STRENGTHEN FINANCIAL SYSTEM STABILITY

    Directory of Open Access Journals (Sweden)

    Ahamed Kameel Mydin Meera

    2017-08-01

    Full Text Available Economic and financial crises seem to occur with increased frequency. Indeed now most countries, including several advanced economies like the US, Europe and Japan, are in serious economic recession. Employment and business opportunities have been much dampened. Inflation seems to be soaring globally and nations are witnessing widening gaps in income and wealth distribution. Many of these advanced economies are also facing shrinking population sizes that translate into aging problems and labor shortages. On top of those, there are environmental issues, including global warming. All these, in turn, have caused regional and global political conflicts and turmoil. The Arab Spring and the sovereign debt problems faced by some European countries like Greece are examples of this. Sustainability of economics and environment is thus of paramount concern of today. This paper considers those problems and suggests Interest-free Gold-based Electronic Netting System (IGENS as an effective way of injecting liquidity into the economy, practically free, that can spur business and employment while bringing about structural stability, inflation checked with both economic and environmental sustainability. Netting or muqassah is a transaction allowed in shari’ah and is practiced worldwide in different forms. Examples include the highly successful WIR Bank of Switzerland, various Local Exchange Trading Schemes (LETS and Bilateral and Multilateral Payment Arrangements between central banks.   Keywords:  Global crisis, Payment system, Gold, Netting, Muqassah, Liquidity, Sustainability, Financial system stability JEL Classification: E40, E42, E51

  20. Net Metering and Interconnection Procedures-- Incorporating Best Practices

    Energy Technology Data Exchange (ETDEWEB)

    Jason Keyes, Kevin Fox, Joseph Wiedman, Staff at North Carolina Solar Center

    2009-04-01

    State utility commissions and utilities themselves are actively developing and revising their procedures for the interconnection and net metering of distributed generation. However, the procedures most often used by regulators and utilities as models have not been updated in the past three years, in which time most of the distributed solar facilities in the United States have been installed. In that period, the Interstate Renewable Energy Council (IREC) has been a participant in more than thirty state utility commission rulemakings regarding interconnection and net metering of distributed generation. With the knowledge gained from this experience, IREC has updated its model procedures to incorporate current best practices. This paper presents the most significant changes made to IREC’s model interconnection and net metering procedures.

  1. Multiflavor string-net models

    Science.gov (United States)

    Lin, Chien-Hung

    2017-05-01

    We generalize the string-net construction to multiple flavors of strings, each of which is labeled by the elements of an Abelian group Gi. The same flavor of strings can branch, while different flavors of strings can cross one another and thus they form intersecting string nets. We systematically construct the exactly soluble lattice Hamiltonians and the ground-state wave functions for the intersecting string-net condensed phases. We analyze the braiding statistics of the low-energy quasiparticle excitations and find that our model can realize all the topological phases as the string-net model with group G =∏iGi . In this respect, our construction provides various ways of building lattice models which realize topological order G , corresponding to different partitions of G and thus different flavors of string nets. In fact, our construction concretely demonstrates the Künneth formula by constructing various lattice models with the same topological order. As an example, we construct the G =Z2×Z2×Z2 string-net model which realizes a non-Abelian topological phase by properly intersecting three copies of toric codes.

  2. Using multiple bed load measurements: Toward the identification of bed dilation and contraction in gravel-bed rivers

    Science.gov (United States)

    Marquis, G. A.; Roy, A. G.

    2012-02-01

    This study examines bed load transport processes in a small gravel-bed river (Béard Creek, Québec) using three complementary methods: bed elevation changes between successive floods, bed activity surveys using tags inserted into the bed, and bed load transport rates from bed load traps. The analysis of 20 flood events capable of mobilizing bed material led to the identification of divergent results among the methods. In particular, bed elevation changes were not consistent with the bed activity surveys. In many cases, bed elevation changes were significant (1 to 2 times the D50) even if the bed surface had not been activated during the flood, leading to the identification of processes of bed dilation and contraction that occurred over 10% to 40% of the bed surface. These dynamics of the river bed prevent accurate derivation of bed load transport rates from topographic changes, especially for low magnitude floods. This paper discusses the mechanisms that could explain the dilation and contraction of particles within the bed and their implications in fluvial dynamics. Bed contraction seems to be the result of the winnowing of the fine sediments under very low gravel transport. Bed dilation seems to occur on patches of the bed at the threshold of motion where various processes such as fine sediment infiltration lead to the maintenance of a larger sediment framework volume. Both processes are also influenced by flood history and the initial local bed state and in turn may have a significant impact on sediment transport and morphological changes in gravel-bed rivers.

  3. Army Net Zero Prove Out. Army Net Zero Training Report

    Science.gov (United States)

    2014-11-20

    economics  Strategies must evolve as technology, markets, incentives, and economics change (e.g. PV prices dropping~50% over the last few years... Food and Beverage -------------------------------> Mattresses/beds/furniture----------------------> Building Supplies/repair parts...352 16. PRICE CODE 17. SECURITY CLASSIFICATION OF REPORT Unclassified 18. SECURITY CLASSIFICATION OF THIS PAGE Unclassified 19

  4. Assessment of Appalachian basin oil and gas resources: Carboniferous Coal-bed Gas Total Petroleum System: Chapter G.1 in Coal and petroleum resources in the Appalachian basin: distribution, geologic framework, and geochemical character

    Science.gov (United States)

    Milici, Robert C.; Ruppert, Leslie F.; Ryder, Robert T.

    2014-01-01

    The Carboniferous Coal-bed Gas Total Petroleum System, which lies within the central and southern Appalachian basin, consists of the following five assessment units (AUs): (1) the Pocahontas Basin AU in southern West Virginia, eastern Kentucky, and southwestern Virginia; (2) the Central Appalachian Shelf AU in Tennessee, eastern Kentucky, and southern West Virginia; (3) the East Dunkard (Folded) AU in western Pennsylvania and northern West Virginia; (4) the West Dunkard (Unfolded) AU in Ohio and adjacent parts of Pennsylvania and West Virginia; and (5) the Appalachian Anthracite and Semi-Anthracite AU in Pennsylvania and Virginia. Only two of these assessment units were assessed quantitatively by the U.S. Geological Survey (USGS) in the National Oil and Gas Assessment in 2002. The USGS estimated the Pocahontas Basin AU and the East Dunkard (Folded) AU to contain a mean of about 3.6 and 4.8 trillion cubic feet (TCF) of undiscovered, technically recoverable gas, respectively.

  5. Controls on the variability of net infiltration to desert sandstone

    Science.gov (United States)

    Heilweil, Victor M.; McKinney, Tim S.; Zhdanov, Michael S.; Watt, Dennis E.

    2007-01-01

    As populations grow in arid climates and desert bedrock aquifers are increasingly targeted for future development, understanding and quantifying the spatial variability of net infiltration becomes critically important for accurately inventorying water resources and mapping contamination vulnerability. This paper presents a conceptual model of net infiltration to desert sandstone and then develops an empirical equation for its spatial quantification at the watershed scale using linear least squares inversion methods for evaluating controlling parameters (independent variables) based on estimated net infiltration rates (dependent variables). Net infiltration rates used for this regression analysis were calculated from environmental tracers in boreholes and more than 3000 linear meters of vadose zone excavations in an upland basin in southwestern Utah underlain by Navajo sandstone. Soil coarseness, distance to upgradient outcrop, and topographic slope were shown to be the primary physical parameters controlling the spatial variability of net infiltration. Although the method should be transferable to other desert sandstone settings for determining the relative spatial distribution of net infiltration, further study is needed to evaluate the effects of other potential parameters such as slope aspect, outcrop parameters, and climate on absolute net infiltration rates.

  6. Better backs by better beds?

    DEFF Research Database (Denmark)

    Bergholdt, Kim; Fabricius, Rasmus N; Bendix, Tom

    2008-01-01

    mattresses have a positive effect on LBP, and especially a hard mattress is commonly believed to have a positive effect. METHODS: One hundred sixty CLBP patients were randomized to 1 of 3 groups, having a mattress/bed mounted in their sleeping room for 1 month. The beds were: (1) waterbed (Akva), (2) body......-conforming foam mattress (Tempur), and (3) a hard mattress (Innovation Futon). At baseline and after 4 weeks, a blinded observer interviewed the patients on LBP levels (0-10), daily function (activities of daily living, 0-30), and on the amount of sleeping hours/night. RESULTS: Because of dropout of 19 patients...... using the probably most relevant "worst case" data. There were no relevant difference between the effects of the water bed and the foam bed. CONCLUSION: The Waterbed and foam mattress' did influence back symptoms, function and sleep more positively as apposed to the hard mattress, but the differences...

  7. Top Ten Bed Bug Tips

    Science.gov (United States)

    ... Directory Planning, Budget and Results Jobs and Internships Headquarters Offices Regional Offices Labs and Research Centers Bed ... you hire an expert, be sure it’s a company with a good reputation and request that it ...

  8. Torsion testing of bed joints

    DEFF Research Database (Denmark)

    Hansen, Klavs Feilberg; Pedersen, Carsten Mørk

    2008-01-01

    This paper describes a simple test method for determining the torsion strength of a single bed joint between two bricks and presents results from testing using this test method. The setup for the torsion test is well defined, require minimal preparation of the test specimen and the test can...... be carried out directly in a normal testing machine. The torsion strength is believed to be the most important parameter in out-of-plane resistance of masonry walls subjected to bending about an axis perpendicular to the bed joints. The paper also contains a few test results from bending of small walls about...... an axis perpendicular to the bed joints, which indicate the close connection between these results and results from torsion tests. These characteristics make the torsion strength well suited to act as substitute parameter for the bending strength of masonry about an axis perpendicular to the bed joints....

  9. Sea bed mapping and inspection

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2006-07-01

    The conference has 24 presentations on the topics: Sea bed mapping, inspection, positioning, hydrography, marine archaeology, remote operation vehicles and computerized simulation technologies, oil field activities and plans, technological experiences and problems. (tk)

  10. Estimating the opportunity costs of bed-days.

    Science.gov (United States)

    Sandmann, Frank G; Robotham, Julie V; Deeny, Sarah R; Edmunds, W John; Jit, Mark

    2018-03-01

    Opportunity costs of bed-days are fundamental to understanding the value of healthcare systems. They greatly influence burden of disease estimations and economic evaluations involving stays in healthcare facilities. However, different estimation techniques employ assumptions that differ crucially in whether to consider the value of the second-best alternative use forgone, of any available alternative use, or the value of the actually chosen alternative. Informed by economic theory, this paper provides a taxonomic framework of methodologies for estimating the opportunity costs of resources. This taxonomy is then applied to bed-days by classifying existing approaches accordingly. We highlight differences in valuation between approaches and the perspective adopted, and we use our framework to appraise the assumptions and biases underlying the standard approaches that have been widely adopted mostly unquestioned in the past, such as the conventional use of reference costs and administrative accounting data. Drawing on these findings, we present a novel approach for estimating the opportunity costs of bed-days in terms of health forgone for the second-best patient, but expressed monetarily. This alternative approach effectively re-connects to the concept of choice and explicitly considers net benefits. It is broadly applicable across settings and for other resources besides bed-days. © 2017 The Authors Health Economics published by John Wiley & Sons Ltd.

  11. Nonproliferation and safeguard considerations: Pebble Bed reactor fuel cycle evaluation

    International Nuclear Information System (INIS)

    1978-09-01

    Nuclear fuel cycles were evaluated for the Pebble Bed Gas Cooled Reactor under development in the Federal Republic of Germany. The basic fuel cycle specified for the HTR-K and PNP is well qualified and will meet the requirements of these reactors. Twenty alternate fuel cycles are described, including high-conversion cycles, net-breeding cycles, and proliferation-resistant cycles. High-conversion cycles, which have a high probability of being successfully developed, promise a significant improvement in resource utilization. Proliferation-resistant cycles, also with a high probability of successful development, conpare very favorably with those for other types of reactors. Most of the advanced cycles could be adapted to first-generation pebble bed reactors with no significant modifications

  12. Fluid-bed methane proposed

    Energy Technology Data Exchange (ETDEWEB)

    1981-05-01

    The first full scale plant for the production of methane from organic waste could be built in the next few years believes M.J. Nyns of the University of Louvain, Belgium, utilizing either expanded bed or fluidised bed systems, with more than one stage, in a continuous flow arrangement. Up to 8.0 m cubed gas/m cubed digester/day could be produced with residence times reduced to 34 hours.

  13. Application architecture for .NET designing applications and services

    CERN Document Server

    Microsoft. Redmond

    2003-01-01

    Get expert architectural and design-level guidance for building distributed solutions with the Microsoft® .NET Framework-learning how to synthesize your knowledge of application development, servers, and infrastructure and business requirements. This guide assumes you are familiar with .NET component development and the basic principles of a layered distributed application design. It examines architectural issues and solution design for a range of project stakeholders-whether you build and design applications and services, recommend appropriate technologies and products for applications and s

  14. Africa's largest long-lasting insecticide-treated net producer: lessons from A to Z Textiles.

    Science.gov (United States)

    Masum, Hassan; Shah, Ronak; Schroeder, Karl; Daar, Abdallah S; Singer, Peter A

    2010-12-13

    Field trials have demonstrated the efficacy of insecticide-treated nets, and the WHO has recently endorsed a shift toward Long-Lasting Insecticide Treated nets (LLINs) due to factors such as reduced distribution costs. However, the need for LLINs poses several challenges. Is it possible to manufacture LLINs in large quantities in the African continent, where malaria is most endemic? When production is located in low-income countries, what role is played by local funding and employment, scaling up manufacturing, and partnerships? What factors influence availability and pricing? A case study of A to Z Textiles was undertaken to answer the question of how large-scale production of LLINs can occur in a low income setting. One of the largest sources of bed nets for Africa, A to Z Textiles is Africa-based, and its Tanzanian operations have a production capacity of 30 million LLINs per year, along with full WHO recommendation for its nets. Our analysis is based on semi-structured interviews with key informants familiar with A to Z, site visits in Tanzania, and literature reviews.This paper discusses the history and current status of A to Z Textiles, identifies the factors that led to its success, and suggests policy considerations that could support similar initiatives in the future. Local funding, scaling up manufacturing, technology transfer, and partnerships all played important roles in A to Z's ascent, as did perceived benefits of local employment and capacity-building. Regulatory issues and procurement rules acted as barriers. A to Z cost-effectively manufactures high-quality LLINs where malaria is most endemic. With a production capacity of 30 million LLINs per year, and full WHOPES (WHO Pesticide Evaluation Scheme) certification, A to Z Textiles demonstrates how key health goods can be successfully produced in the low-income countries that use them. Its example may be instructive and of high interest to readers in the malaria community, especially in developing

  15. Africa's largest long-lasting insecticide-treated net producer: lessons from A to Z Textiles

    Directory of Open Access Journals (Sweden)

    Daar Abdallah S

    2010-12-01

    Full Text Available Abstract Background Field trials have demonstrated the efficacy of insecticide-treated nets, and the WHO has recently endorsed a shift toward Long-Lasting Insecticide Treated nets (LLINs due to factors such as reduced distribution costs. However, the need for LLINs poses several challenges. Is it possible to manufacture LLINs in large quantities in the African continent, where malaria is most endemic? When production is located in low-income countries, what role is played by local funding and employment, scaling up manufacturing, and partnerships? What factors influence availability and pricing? Discussion A case study of A to Z Textiles was undertaken to answer the question of how large-scale production of LLINs can occur in a low income setting. One of the largest sources of bed nets for Africa, A to Z Textiles is Africa-based, and its Tanzanian operations have a production capacity of 30 million LLINs per year, along with full WHO recommendation for its nets. Our analysis is based on semi-structured interviews with key informants familiar with A to Z, site visits in Tanzania, and literature reviews. This paper discusses the history and current status of A to Z Textiles, identifies the factors that led to its success, and suggests policy considerations that could support similar initiatives in the future. Local funding, scaling up manufacturing, technology transfer, and partnerships all played important roles in A to Z’s ascent, as did perceived benefits of local employment and capacity-building. Regulatory issues and procurement rules acted as barriers. A to Z cost-effectively manufactures high-quality LLINs where malaria is most endemic. Summary With a production capacity of 30 million LLINs per year, and full WHOPES (WHO Pesticide Evaluation Scheme certification, A to Z Textiles demonstrates how key health goods can be successfully produced in the low-income countries that use them. Its example may be instructive and of high interest to

  16. The SSM/PMAD automated test bed project

    Science.gov (United States)

    Lollar, Louis F.

    1991-01-01

    The Space Station Module/Power Management and Distribution (SSM/PMAD) autonomous subsystem project was initiated in 1984. The project's goal has been to design and develop an autonomous, user-supportive PMAD test bed simulating the SSF Hab/Lab module(s). An eighteen kilowatt SSM/PMAD test bed model with a high degree of automated operation has been developed. This advanced automation test bed contains three expert/knowledge based systems that interact with one another and with other more conventional software residing in up to eight distributed 386-based microcomputers to perform the necessary tasks of real-time and near real-time load scheduling, dynamic load prioritizing, and fault detection, isolation, and recovery (FDIR).

  17. Powder bed charging during electron-beam additive manufacturing

    International Nuclear Information System (INIS)

    Cordero, Zachary C.; Meyer, Harry M.; Nandwana, Peeyush; Dehoff, Ryan R.

    2017-01-01

    Electrons injected into the build envelope during powder bed electron-beam additive manufacturing can accumulate on the irradiated particles and cause them to repel each other. Under certain conditions, these electrostatic forces can grow so large that they drive the particles out of the build envelope in a process known as “smoking”. In the present work, we investigate the causes of powder bed charging and smoking during electron-beam additive manufacturing. In the first part of the paper, we characterize the surface chemistry of a common feedstock material—gas-atomized Ti-6Al-4V powder—and find that a thick, electrically insulating oxide overlayer encapsulates the particles. Based on these experimental results, we then formulate an analytical model of powder bed charging in which each particle is approximated as a capacitor, where the particle and its substrate are the electrodes and the oxide overlayer is the dielectric. Using this model, we estimate the charge distribution in the powder bed, the electrostatic forces acting on the particles, and the conditions under which the powder bed will smoke. It is found that the electrical resistivity of the oxide overlayer strongly influences the charging behavior of the powder bed and that a high resistivity promotes charge accumulation and consequent smoking. This analysis suggests new quality control and process design measures that can help suppress smoking.

  18. Colorectal Cancer Safety Net: Is It Catching Patients Appropriately?

    Science.gov (United States)

    Althans, Alison R; Brady, Justin T; Times, Melissa L; Keller, Deborah S; Harvey, Alexis R; Kelly, Molly E; Patel, Nilam D; Steele, Scott R

    2018-01-01

    Disparities in access to colorectal cancer care are multifactorial and are affected by socioeconomic elements. Uninsured and Medicaid patients present with advanced stage disease and have worse outcomes compared with similar privately insured patients. Safety net hospitals are a major care provider to this vulnerable population. Few studies have evaluated outcomes for safety net hospitals compared with private institutions in colorectal cancer. The purpose of this study was to compare demographics, screening rates, presentation stage, and survival rates between a safety net hospital and a tertiary care center. Comparative review of patients at 2 institutions in the same metropolitan area were conducted. The study included colorectal cancer care delivered either at 1 safety net hospital or 1 private tertiary care center in the same city from 2010 to 2016. A total of 350 patients with colorectal cancer from each hospital were evaluated. Overall survival across hospital systems was measured. The safety net hospital had significantly more uninsured and Medicaid patients (46% vs 13%; p presentation, a similar percentage of patients at each hospital presented with stage IV disease (26% vs 20%; p = 0.06). For those undergoing resection, final pathologic stage distribution was similar across groups (p = 0.10). After a comparable median follow-up period (26.6 mo for safety net hospital vs 29.2 mo for tertiary care center), log-rank test for overall survival favored the safety net hospital (p = 0.05); disease-free survival was similar between hospitals (p = 0.40). This was a retrospective review, reporting from medical charts. Our results support the value of safety net hospitals for providing quality colorectal cancer care, with survival and recurrence outcomes equivalent or improved compared with a local tertiary care center. Because safety net hospitals can provide equivalent outcomes despite socioeconomic inequalities and financial constraints, emphasis should be focused

  19. Internet application: production-technical information system MoNET

    International Nuclear Information System (INIS)

    Tomiga, J.

    2004-01-01

    MoNET is the production-technical information system supporting engineering, operational and maintenance processes of distribution network administrator. It utilizes the model of distribution network that is situated in the geo-space relational database. The geo-space database represents an information base of operational-technical processes. It contains elements and equipment s of the distribution network, failures, operational events, maintenance records, but also, parcels, reference planimetry, e.g. and other subjects for which is relevant the positional datum - geo-space information. MoNET is typically exploited in the fields: - evidence of the subjects and equipment of network, technical documentation; - property administration; - planning of network development, support of designing and construction; - technical calculation; - breakdown controller centre; - maintenance management. MoNET can be implemented as the desktop application, however its first benefit is derived from its usage as the intranet application MoNET WEB for the whole enterprise or organisation. This version enables an unrestricted number of end-users to enter this system. The end-users don't need any special software to enter the data of MoNet WEB application, the pre-installed Internet Explorer will do. (author)

  20. Advantages of forced non-steady operated trickle-bed reactors

    NARCIS (Netherlands)

    Boelhouwer, J.G.; Piepers, H.W.; Drinkenburg, A.A.H.

    2002-01-01

    Trickle-bed reactors are usually operated in the steady state trickle flow regime. Uneven liquid distribution and the formation of hot spots are the most serious problems experienced during trickle flow operation. In this paper, we advocate the use of non-steady state operation of trickle-bed

  1. Influence of decelerating flow on incipient motion of a gravel-bed ...

    Indian Academy of Sciences (India)

    2016-08-26

    Aug 26, 2016 ... From the observation of eleven fixed-bed and nine mobile-bed velocity profiles, it is revealed that the parabolic law method (PLM) and the Reynolds stress method are comparable for estimation of shear velocity in general. Also, the results show that the shear stress distribution adopts a convex form over ...

  2. Status of the in-pile test of HCPB pebble-bed assemblies in the HFR Petten

    Energy Technology Data Exchange (ETDEWEB)

    Laan, J.G. van der; Fokkens, J.H.; Hofmans, H.E.; Jong, M.; Magielsen, A.J.; Pijlgroms, B.J.; Stijkel, M.P. [NRG, Petten (Netherlands); Conrad, R. [JRC, Inst. for Energy, Petten (Netherlands); Malang, S.; Reimann, J. [FZK, Karlsruhe (Germany); Roux, N. [CEA Saclay (France)

    2002-06-01

    In the framework of developing the helium cooled pebble-bed (HCPB) blanket an irradiation test of pebble-bed assemblies is prepared at the HFR Petten. The test objective is to concentrate on the effect of neutron irradiation on the thermal-mechanical behaviour of the HCPB breeder pebble-bed at DEMO representative levels of temperature and defined thermal-mechanical loads. The basic test elements are EUROFER-97 cylinders with a horizontal bed of ceramic breeder pebbles sandwiched between two beryllium beds. The pebble beds are separated by EUROFER-97 steel plates. The heat flow is managed such as to have a radial temperature distribution in the ceramic breeder pebble-bed as flat as reasonably possible. The paper reports on the project status, and presents the results of pre-tests, material characteristics, the manufacturing of the pebble-bed assemblies, and the nuclear and thermo-mechanical loading parameters. (orig.)

  3. Status and threats on seagrass beds using GIS in Vietnam

    Science.gov (United States)

    Luong, Cao Van; Thao, Nguyen Van; Komatsu, Teruhisa; Ve, Nguyen Dac; Tien, Dam Duc

    2012-10-01

    Seagrasses, marine flowering plants, are widely distributed along temperate and tropical coastlines of the world. Seagrasses have key ecological roles in coastal ecosystems and can form extensive meadows supporting high biodiversity. Till now, fourteen seagrass species belonging to four families were found in Vietnam: Halophila beccarii, H. decipiens, H. ovalis, H. minor, Thalassia hemprichii, Enhalus acoroides, Ruppia maritima, Halodule pinifolia, H. uninervis, Syringodium isoetifolium, Cymadocea rotundata, C. serrulata and Thalassodendron ciliatum. A total area of seagrass beds in Vietnam is estimated to be approximately 17000 ha by satellite images and GIS technology. In recent years, the distribution areas and densities of seagrass beds in Vietnam have been serious decreased compared with those 10-15 years ago. The decline level depended on the impacts by the natural process, the economical activities and the conservation awareness of local people. Thus, it is different at each coastal area. Generally speaking, the distribution areas and densities of seagrass beds were decreased by more than 50%. Seagrasses on tidal flats in some areas such as Quang Ninh, Hai Phong, Phu Quoc seem to be nearly lost. The distribution areas of seagrass beds in 2009 at Tam Giang-Cau Hai lagoon and Cua Dai estuary was decreased by 50-70% of those in early 1990s.

  4. Stochastic models for transport in a fluidized bed

    NARCIS (Netherlands)

    Dehling, H.G; Hoffmann, A.C; Stuut, H.W.

    1999-01-01

    In this paper we study stochastic models for the transport of particles in a fluidized bed reactor and compute the associated residence time distribution (RTD). Our main model is basically a diffusion process in [0;A] with reflecting/absorbing boundary conditions, modified by allowing jumps to the

  5. MATT: Multi Agents Testing Tool Based Nets within Nets

    Directory of Open Access Journals (Sweden)

    Sara Kerraoui

    2016-12-01

    As part of this effort, we propose a model based testing approach for multi agent systems based on such a model called Reference net, where a tool, which aims to providing a uniform and automated approach is developed. The feasibility and the advantage of the proposed approach are shown through a short case study.

  6. Implementing NetScaler VPX

    CERN Document Server

    Sandbu, Marius

    2014-01-01

    An easy-to-follow guide with detailed step-by step-instructions on how to implement the different key components in NetScaler, with real-world examples and sample scenarios.If you are a Citrix or network administrator who needs to implement NetScaler in your virtual environment to gain an insight on its functionality, this book is ideal for you. A basic understanding of networking and familiarity with some of the different Citrix products such as XenApp or XenDesktop is a prerequisite.

  7. Net4Care PHMR Library

    DEFF Research Database (Denmark)

    2014-01-01

    The Net4Care PHMR library contains a) A GreenCDA approach for constructing a data object representing a PHMR document: SimpleClinicalDocument, and b) A Builder which can produce a XML document representing a valid Danish PHMR (following the MedCom profile) document from the SimpleClinicalDocument......The Net4Care PHMR library contains a) A GreenCDA approach for constructing a data object representing a PHMR document: SimpleClinicalDocument, and b) A Builder which can produce a XML document representing a valid Danish PHMR (following the MedCom profile) document from the Simple...

  8. The impact of structural development on near bed flow dynamics in gravel bed rivers: coupling flume experiments with numerical modelling

    Science.gov (United States)

    Ockelford, A.; Hardy, R. J.; Rice, S. P.; Powell, M.

    2017-12-01

    It is increasingly being recognised that gravel bed rivers develop a surface `texture' in response to changes in the flow and sediment regime. This textural response often takes the form of a bed structure which develops to ultimately stabilise the surface across a range of spatio-temporal scales and it is these topographical structures which determine the flow structures that develop over the river bed. However, our ability to measure and parameterise that structure in ways that are useful and meaningful for the prediction of flow dynamics, still remains inadequate; this paper uses a three dimensional numerical model to assess how the temporal development of structure influences the near bed flow dynamics. Using a suite of flume based experiments a unimodal grain size distribution (σg = 1.30, D50 = 8.8mm) was exposed to three different levels of constant bed shear that produced sediment transport conditions ranging from marginal transport to conditions approaching full mobility of all size fractions. Surface structuring characteristics were measured at a high spatio-temporal resolution such that the time evolution of the beds could be fully described. In total 54 surfaces were generated and run through a Reynolds averaged three dimensional numerical model with an Rng turbulence closure. The topography input included using an immersed boundary technique within a Cartesian framework. Discussion concentrates on the how the trajectory of structural evolution under the different treatments affects the near bed flow dynamics. Specifically links are made between how the scales of boundary topography influence the flow and discusses how the measured flow variability at any one point will contain both locally derived and upstream-inherited flow structures, according to the range of scales of bed topography present. Keywords: Graded, Sediment, Structure, Turbulence, Modelling

  9. Utility of Recycled Bedding for Laboratory Rodents

    OpenAIRE

    Miyamoto, Toru; Li, Zhixia; Kibushi, Tomomi; Okano, Shinya; Yamasaki, Nakamichi; Kasai, Noriyuki

    2009-01-01

    Animal facilities generate a large amount of used bedding containing excrement as medical waste. We developed a recycling system for used bedding that involves soft hydrothermal processing. In this study, we examined the effects of bedding type on growth, hematologic and serum biochemical values, and organ weights of female and male mice reared on either recycled or fresh bedding from 3 to 33 wk of age. Neither growth nor physiology differed between mice housed on recycled bedding compared wi...

  10. Fluid bed porosity equation for an inverse fluidized bed bioreactor with particles growing biofilm

    International Nuclear Information System (INIS)

    Campos-Diaz, K. E.; Limas-Ballesteros, R.

    2009-01-01

    Fluid Bed Bioreactor performance is strongly affected by bed void fraction or bed porosity fluctuations. Particle size enlargement due to biofilm growth is an important factor that is involved in these variations and until now there are no mathematical equations that consider biofilm growth. In this work a mathematical equation is proposed to calculate bed void fraction in an inverse fluid bed bioreactor. (Author)

  11. Chemical Characterization of Bed Material Coatingsby LA-ICP-MS and SEM-EDS

    Science.gov (United States)

    Piispanen, M. H.; Mustonen, A. J.; Tiainen, M. S.; Laitinen, R. S.

    Bed material coatings and the consequent agglomeration of bed material are main ash-related problems in FB-boilers. The bed agglomeration is a particular problem when combusting biofuels and waste materials. Whereas SEM-EDS together with automated image processing has proven to be a convenient method to study compositional distribution in coating layers and agglomerates, it is a relatively expensive technique and is not necessarily widely available. In this contribution, we explore the suitability of LA-ICP-MS to provide analogous information of the bed.

  12. Coloured Petri Nets and the Invariant Method

    DEFF Research Database (Denmark)

    Jensen, Kurt

    1981-01-01

    processes to be described by a common subnet, without losing the ability to distinguish between them. Our generalization, called coloured Petri nets, is heavily influenced by predicate transition-nets introduced by H.J. Genrich and K. Lautenbach. Moreover our paper shows how the invariant-method, introduced...... for Petri nets by K. Lautenbach, can be generalized to coloured Petri nets....

  13. Clinical physiology of bed rest

    Science.gov (United States)

    Greenleaf, John E.

    1993-01-01

    Maintenance of optimal health in humans requires the proper balance between exercise, rest, and sleep as well as time in the upright position. About one-third of a lifetime is spent sleeping; and it is no coincidence that sleeping is performed in the horizontal position, the position in which gravitational influence on the body is minimal. Although enforced bed rest is necessary for the treatment of some ailments, in some cases it has probably been used unwisely. In addition to the lower hydrostatic pressure with the normally dependent regions of the cardiovascular system, body fuid compartments during bed rest in the horizontal body position, and virtual elimination of compression on the long bones of the skeletal system during bed rest (hypogravia), there is often reduction in energy metabolism due to the relative confinement (hypodynamia) and alteration of ambulatory circadian variations in metabolism, body temperature, and many hormonal systems. If patients are also moved to unfamiliar surroundings, they probably experience some feelings of anxiety and some sociopsychological problems. Adaptive physiological responses during bed rest are normal for that environment. They are attempts by the body to reduce unnecessary energy expenditure, to optimize its function, and to enhance its survival potential. Many of the deconditioning responses begin within the first day or two of bed rest; these early responses have prompted physicians to insist upon early resumption of the upright posture and ambulation of bedridden patients.

  14. Simulant - water experiments to characterize the debris bed formed in severe core melt accidents

    International Nuclear Information System (INIS)

    Mathai, Amala M.; Anandan, J.; Sharma, Anil Kumar; Murthy, S.S.; Malarvizhi, B.; Lydia, G.; Das, Sanjay Kumar; Nashine, B.K.; Selvaraj, P.

    2015-01-01

    Molten Fuel Coolant Interaction (WO) and debris bed configuration on the core catcher plate assumes importance in assessing the Post Accident Heat Removal (PARR) of a heat generating debris bed. The key factors affecting the coolability of the debris bed are the bed porosity, morphology of the fragmented particles, degree of spreading/heaping of the debris on the core catcher and the fraction of lump formed. Experiments are conducted to understand the fragmentation kinetics and subsequent debris bed formation of molten woods metal in water at interface temperatures near the spontaneous nucleation temperature of water. Morphology of the debris particles is investigated to understand the fragmentation mechanisms involved. The spreading behavior of the debris on the catcher plate and the particle size distribution are presented for 5 kg and 10 kg melt inventories. Porosity of the undisturbed bed on the catcher plate is evaluated using a LASER sensor technique. (author)

  15. Efficacy of PermaNet® 3.0 and PermaNet® 2.0 nets against laboratory-reared and wild Anopheles gambiae sensu lato populations in northern Tanzania.

    Science.gov (United States)

    Kweka, Eliningaya J; Lyaruu, Lucile J; Mahande, Aneth M

    2017-01-18

    Mosquitoes have developed resistance against pyrethroids, the only class of insecticides approved for use on long-lasting insecticidal nets (LLINs). The present study sought to evaluate the efficacy of the pyrethroid synergist PermaNet® 3.0 LLIN versus the pyrethroid-only PermaNet® 2.0 LLIN, in an East African hut design in Lower Moshi, northern Tanzania. In this setting, resistance to pyrethroid insecticides has been identified in Anopheles gambiae mosquitoes. Standard World Health Organization bioefficacy evaluations were conducted in both laboratory and experimental huts. Experimental hut evaluations were conducted in an area where there was presence of a population of highly pyrethroid-resistant An. arabiensis mosquitoes. All nets used were subjected to cone bioassays and then to experimental hut trials. Mosquito mortality, blood-feeding inhibition and personal protection rate were compared between untreated nets, unwashed LLINs and LLINs that were washed 20 times. Both washed and unwashed PermaNet® 2.0 and PermaNet® 3.0 LLINs had knockdown and mortality rates of 100% against a susceptible strain of An. gambiae sensu stricto. The adjusted mortality rate of the wild mosquito population after use of the unwashed PermaNet® 3.0 and PermaNet® 2.0 nets was found to be higher than after use of the washed PermaNet® 2.0 and PermaNet® 3.0 nets. Given the increasing incidence of pyrethroid resistance in An. gambiae mosquitoes in Tanzania, we recommend that consideration is given to its distribution in areas with pyrethroid-resistant malaria vectors within the framework of a national insecticide-resistance management plan.

  16. D.NET case study

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

    lremy

    The mission was defined to build, “A society where information and ... innovative ideas and projects around different themes (using ICT), and piloting them to test .... like D.Net with several projects that had moved beyond their pilot phase.

  17. Petri Nets in Cryptographic Protocols

    DEFF Research Database (Denmark)

    Crazzolara, Federico; Winskel, Glynn

    2001-01-01

    A process language for security protocols is presented together with a semantics in terms of sets of events. The denotation of process is a set of events, and as each event specifies a set of pre and postconditions, this denotation can be viewed as a Petri net. By means of an example we illustrate...

  18. Complexity metrics for workflow nets

    NARCIS (Netherlands)

    Lassen, K.B.; Aalst, van der W.M.P.

    2009-01-01

    Process modeling languages such as EPCs, BPMN, flow charts, UML activity diagrams, Petri nets, etc., are used to model business processes and to configure process-aware information systems. It is known that users have problems understanding these diagrams. In fact, even process engineers and system

  19. Reference Guide Microsoft.NET

    NARCIS (Netherlands)

    Zee M van der; Verspaij GJ; Rosbergen S; IMP; NMD

    2003-01-01

    Met behulp van het rapport kunnen ontwikkelaars, beheerders en betrokken managers bij ICT projecten meer inzicht krijgen in de .NET technologie en een goede keuze maken in de inzetbaarheid van deze technologie. Het rapport geeft de bevindingen en conclusies van een verkennende studie naar het

  20. Complexity Metrics for Workflow Nets

    DEFF Research Database (Denmark)

    Lassen, Kristian Bisgaard; van der Aalst, Wil M.P.

    2009-01-01

    Process modeling languages such as EPCs, BPMN, flow charts, UML activity diagrams, Petri nets, etc.\\ are used to model business processes and to configure process-aware information systems. It is known that users have problems understanding these diagrams. In fact, even process engineers and system...

  1. Communicating with the Net Generation

    Science.gov (United States)

    2011-03-11

    resource investment is necessary to sustain a high quality all-volunteer force. 9 Leadership Technique for the Net Generation Army Regulation 600...Generations at Work, Millenials at Work, http://www.generationsatwork. com /articles_millennials_at_work.php (accessed November 21, 2010). 31 Thomas

  2. Net Neutrality in the Netherlands

    NARCIS (Netherlands)

    van Eijk, N.

    2014-01-01

    The Netherlands is among the first countries that have put specific net neutrality standards in place. The decision to implement specific regulation was influenced by at least three factors. The first was the prevailing social and academic debate, partly due to developments in the United States. The

  3. Surgery for GEP-NETs

    DEFF Research Database (Denmark)

    Knigge, Ulrich; Hansen, Carsten Palnæs

    2012-01-01

    Surgery is the only treatment that may cure the patient with gastroentero-pancreatic (GEP) neuroendocrine tumours (NET) and neuroendocrine carcinomas (NEC) and should always be considered as first line treatment if R0/R1 resection can be achieved. The surgical and interventional procedures for GEP...

  4. Net4Care PHMR Tutorial

    DEFF Research Database (Denmark)

    Christensen, Henrik Bærbak

    Goal To demonstrate how to use the Net4Care PHMR builder module to a) Create a SimpleClinicalDocument instance and populate it with relevant administrative and medical information to form a tele medical report of a set of measurements, b) Use the provided DanishPHMRBuilder to generate a correctly...

  5. Particle Bed Reactor scaling relationships

    International Nuclear Information System (INIS)

    Slovik, G.; Araj, K.; Horn, F.L.; Ludewig, H.; Benenati, R.

    1987-01-01

    Scaling relationships for Particle Bed Reactors (PBRs) are discussed. The particular applications are short duration systems, i.e., for propulsion or burst power. Particle Bed Reactors can use a wide selection of different moderators and reflectors and be designed for such a wide range of power and bed power densities. Additional design considerations include the effect of varying the number of fuel elements, outlet Mach number in hot gas channel, etc. All of these variables and options result in a wide range of reactor weights and performance. Extremely light weight reactors (approximately 1 kg/MW) are possible with the appropriate choice of moderator/reflector and power density. Such systems are very attractive for propulsion systems where parasitic weight has to be minimized

  6. Fluidized-bed nuclear reactor

    International Nuclear Information System (INIS)

    Grimmett, E.S.; Kunze, J.F.

    1975-01-01

    A reactor vessel containing a fluidized-bed region of particulate material including both a neutron-moderating and a fertile substance is described. A gas flow including fissile material passes through the vessel at a sufficient rate to fluidize the particulate material and at a sufficient density to support a thermal fission reaction within the fluidized-bed region. The high-temperature portion of a heat transfer system is located within the fluidized-bed region of the reactor vessel in direct contact with the fluidized particles. Heat released by fission is thereby transferred at an enhanced rate to a coolant circulating within the heat transfer system. Fission products are continuously removed from the gas flow and supplemental fissile material added during the reactor operation. (U.S.)

  7. Combined Opto-Acoustical sensor modules for KM3NeT

    International Nuclear Information System (INIS)

    Enzenhöfer, A.

    2013-01-01

    KM3NeT is a future multi-cubic-kilometre water Cherenkov neutrino telescope currently entering a first construction phase. It will be located in the Mediterranean Sea and comprise about 600 vertical structures called detection units. Each of these detection units has a length of several hundred metres and is anchored to the sea bed on one side and held taut by a buoy on the other side. The detection units are thus subject to permanent movement due to sea currents. Modules holding photosensors and additional equipment are equally distributed along the detection units. The relative positions of the photosensors has to be known with an uncertainty below 20 cm in order to achieve the necessary precision for neutrino astronomy. These positions can be determined with an acoustic positioning system: dedicated acoustic emitters located at known positions and acoustic receivers along each detection unit. This article describes the approach to combine an acoustic receiver with the photosensors inside one detection module using a common power supply and data readout. The advantage of this approach lies in a reduction of underwater connectors and module configurations as well as in the compactification of the detection units integrating the auxiliary devices necessary for their successful operation.

  8. Petri nets - part 1: concepts and application areas

    International Nuclear Information System (INIS)

    Sivertsen, Terje

    2004-03-01

    There exist a number of models, languages, methods, and tools that support the specification and analysis of system requirements. One important class comprises graphical methods based on the concept of Petri nets. Due to the wide variety of applications, these methods are relevant also in research and applications outside the digital systems safety domain. The present report constitutes the first of three parts of a unified exposition of graphical methods based on the concept of Petri nets. The report provides an introduction to basic concepts of Petri nets and an overview of a wide variety of application areas. The second part of the trilogy will present a number of techniques and tools. The third part will focus on analysis. Petri nets have been proposed for a wide variety of applications, and new areas are considered as new challenges emerge from scientific, technological, and social developments. The wide variety of application areas reflects a broad interest in Petri nets, coming from diverse directions. Empirically, as well as theoretically, there are good reasons to claim that Petri nets are applicable for many different kinds of problems. What is common to the different applications and problems addressed is the need for a formalism that allows adequate representation of important system characteristics like concurrency, asyncronicity, distribution, parallelism, and non-determinism. Several of the references in the report discuss NPP-related applications, or applications with great potentials for technology transfer from other areas to the nuclear domain. (Author)

  9. CSL model checking of deterministic and stochastic Petri nets

    NARCIS (Netherlands)

    Martinez Verdugo, J.M.; Haverkort, Boudewijn R.H.M.; German, R.; Heindl, A.

    2006-01-01

    Deterministic and Stochastic Petri Nets (DSPNs) are a widely used high-level formalism for modeling discrete-event systems where events may occur either without consuming time, after a deterministic time, or after an exponentially distributed time. The underlying process dened by DSPNs, under

  10. Net neutrality and the value chain for video

    NARCIS (Netherlands)

    Nooren, P.A.; Leurdijk, A.; Eijk, N. van

    2012-01-01

    Purpose: Video distribution over the internet leads to heated net-neutrality related debates between network operators and over-the-top application providers. The purpose of this paper is to analyze this debate from a new perspective that takes into account all of the assets that companies try to

  11. Potential migration of organic pollutants in pipes of polyethylene. Study in pipelines of distribution net of drinkable water; Migracion potential de contaminantes organicos en tubos de polietileno. Estudio en tuberias de red de distribuciond e agua potable

    Energy Technology Data Exchange (ETDEWEB)

    Ballel, X.; Ciurana de, C.; Caixach, J.; Cortina, M.; Om, M.

    2002-07-01

    Polyethylene pipes and connections are being widely used in treated water distribution services. Migration of low molecular weight compounds from the polyethylene into the water can change its final quality. This paper is about the concentrations and identification of the migration compounds found in treated water after staying in contact with low and high-density polyethylene. Identification and quantification were carried out using CLSA (Closed Loop Stripping Analysis) extraction technique and gas chromatography coupled to mass spectrometry (HRGC/HRMS). (Author) 12 refs.

  12. Prediction of bed level variations in nonuniform sediment bed channel

    Indian Academy of Sciences (India)

    B R Andharia

    2018-04-12

    Apr 12, 2018 ... A fully-coupled 1D mobile-bed model (CAR-. ICHAR) was introduced ...... for sediment trap, water level sensor, tail gate operated by lever arm at .... materials were brought back to upstream to feed the same through sediment ...

  13. Experimental study on evolution of bed structures of natural mountain rivers

    Directory of Open Access Journals (Sweden)

    Huai-xiang Liu

    2011-06-01

    Full Text Available Bed structures in many mountain rivers provide additional resistance to the flow. A field experiment was conducted on debris flow deposits in the valley of the Jiangjiagou Ravine, a tributary of the Yangtze River in southwestern China, to study the evolution and distribution of bed structures and their relationship with environmental conditions. Water and sediment from the Jiangjiagou main stream were diverted into the experimental channel. Several hydrological schemes were adopted to scour the channel until equilibrium was reached. During this process the evolutions of bed structures and channel configuration were investigated. The results indicate that stronger bed structures mean greater stream power consumption, greater resistance, and greater slope in a certain section when rivers are in dynamic equilibrium. Thus, to some extent the longitudinal profiles of channels can be determined by the distribution of bed structures. In natural cases, the strength and evolution of bed structures are under the influence of environmental conditions such as discharge and bed-load transportation rate. That is, given the same conditions, the same bed structure distribution and longitudinal profile can be predicted.

  14. Tritium recovery from helium purge stream of solid breeder blanket by cryogenic molecular sieve bed. 2. Regeneration operation of cryogenic molecular sieve bed

    Energy Technology Data Exchange (ETDEWEB)

    Kawamura, Yoshinori; Enoeda, Mikio; Nishi, Masataka [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1998-03-01

    Regeneration operation is a very important operation, because it is the most influential factor for deciding the net operation cycle time and the minimum dimension of Cryogenic Molecular Sieve Bed (CMSB). However, the experimental data of CMSB regeneration operation was not so sufficient that even the optimum regeneration procedure could not be decided yet. This work was focused on getting the primary information about various regeneration procedures. (author)

  15. .net

    Directory of Open Access Journals (Sweden)

    Le Comité de Rédaction d' EspacesTemps.net

    2002-06-01

    Full Text Available EspacesTemps lance aujourd'hui deux objets différents : un site internet et, sur ce site, Le Journal . Il s'agit donc de bien plus, et, au fond, de tout autre chose qu'un simple outil de communication destiné à informer nos lecteurs de nos parutions. Ce n'est pas non plus la « mise en ligne » de nos numéros-papier. L'internet nous donne au contraire l'occasion de réaliser, dans de meilleures conditions, ce que nous avons tenté de faire depuis quelques ...

  16. Caught in the Net: Perineuronal Nets and Addiction

    Directory of Open Access Journals (Sweden)

    Megan Slaker

    2016-01-01

    Full Text Available Exposure to drugs of abuse induces plasticity in the brain and creates persistent drug-related memories. These changes in plasticity and persistent drug memories are believed to produce aberrant motivation and reinforcement contributing to addiction. Most studies have explored the effect drugs of abuse have on pre- and postsynaptic cells and astrocytes; however, more recently, attention has shifted to explore the effect these drugs have on the extracellular matrix (ECM. Within the ECM are unique structures arranged in a net-like manner, surrounding a subset of neurons called perineuronal nets (PNNs. This review focuses on drug-induced changes in PNNs, the molecules that regulate PNNs, and the expression of PNNs within brain circuitry mediating motivation, reward, and reinforcement as it pertains to addiction.

  17. Army Net Zero Prove Out. Net Zero Energy Best Practices

    Science.gov (United States)

    2014-11-18

    recovery and cogeneration opportunities, offsetting the remaining demand with the production of renewable energy from onsite sources so that the Net...implementing energy recovery and cogeneration opportunities, and then offsetting the remaining demand with the production of renewable energy from on-site...they impact overall energy performance. The use of energy modeling in the design stage provides insights that can contribute to more effective design

  18. Net alkalinity and net acidity 2: Practical considerations

    Science.gov (United States)

    Kirby, C.S.; Cravotta, C.A.

    2005-01-01

    The pH, alkalinity, and acidity of mine drainage and associated waters can be misinterpreted because of the chemical instability of samples and possible misunderstandings of standard analytical method results. Synthetic and field samples of mine drainage having various initial pH values and concentrations of dissolved metals and alkalinity were titrated by several methods, and the results were compared to alkalinity and acidity calculated based on dissolved solutes. The pH, alkalinity, and acidity were compared between fresh, unoxidized and aged, oxidized samples. Data for Pennsylvania coal mine drainage indicates that the pH of fresh samples was predominantly acidic (pH 2.5-4) or near neutral (pH 6-7); ??? 25% of the samples had pH values between 5 and 6. Following oxidation, no samples had pH values between 5 and 6. The Standard Method Alkalinity titration is constrained to yield values >0. Most calculated and measured alkalinities for samples with positive alkalinities were in close agreement. However, for low-pH samples, the calculated alkalinity can be negative due to negative contributions by dissolved metals that may oxidize and hydrolyze. The Standard Method hot peroxide treatment titration for acidity determination (Hot Acidity) accurately indicates the potential for pH to decrease to acidic values after complete degassing of CO2 and oxidation of Fe and Mn, and it indicates either the excess alkalinity or that required for neutralization of the sample. The Hot Acidity directly measures net acidity (= -net alkalinity). Samples that had near-neutral pH after oxidation had negative Hot Acidity; samples that had pH mine drainage treatment can lead to systems with insufficient Alkalinity to neutralize metal and H+ acidity and is not recommended. The use of net alkalinity = -Hot Acidity titration is recommended for the planning of mine drainage treatment. The use of net alkalinity = (Alkalinitymeasured - Aciditycalculated) is recommended with some cautions

  19. Heat transfer between a fluidized bed and an immersed horizontal tube

    International Nuclear Information System (INIS)

    Beasley, D.E.; Figliola, R.S.

    1986-01-01

    Reliable predictions will require a better understanding of the heat transfer mechanisms and bed hydrodynamics in the neighborhood of the submerged surface. In this investigation measurements of the instantaneous heat transfer between a submerged surface and a gas fluidized bed operating in the bubbling regime are presented. The experimental results are compared to existing predictive models for the particle convective and the overall heat transfer coefficients. For the range of particle size and flow velocity studied, the particle convective component of heat transfer dominates the overall heat transfer between the bed and the submerged surface. Experimental studies into particle size distribution effects on heat transfer suggest that mixtures augment the bed to surface heat transfer. Documentation of bed particle size distribution is necessary if heat transfer data are to be compared or predicted

  20. Full Scale Drinking Water System Decontamination at the Water Security Test Bed

    Data.gov (United States)

    U.S. Environmental Protection Agency — The EPA’s Water Security Test Bed (WSTB) facility is a full-scale representation of a drinking water distribution system. In collaboration with the Idaho National...

  1. A parametric study of powder holdups in a packed bed under ...

    African Journals Online (AJOL)

    Nafiisah

    Packed bed, turbulent flow, mathematical modelling, decreasing ..... The vertical gauge pressure distribution, at a distance of 0.06 m away from the tuyere ... fines from these locations as the interactive forces are more than the drag forces. It.

  2. Apparatus and process for controlling fluidized beds

    Science.gov (United States)

    Rehmat, Amirali G.; Patel, Jitendra G.

    1985-10-01

    An apparatus and process for control and maintenance of fluidized beds under non-steady state conditions. An ash removal conduit is provided for removing solid particulates from a fluidized bed separate from an ash discharge conduit in the lower portion of the grate supporting such a bed. The apparatus and process of this invention is particularly suitable for use in ash agglomerating fluidized beds and provides control of the fluidized bed before ash agglomeration is initiated and during upset conditions resulting in stable, sinter-free fluidized bed maintenance.

  3. Net alkalinity and net acidity 1: Theoretical considerations

    International Nuclear Information System (INIS)

    Kirby, Carl S.; Cravotta, Charles A.

    2005-01-01

    Net acidity and net alkalinity are widely used, poorly defined, and commonly misunderstood parameters for the characterization of mine drainage. The authors explain theoretical expressions of 3 types of alkalinity (caustic, phenolphthalein, and total) and acidity (mineral, CO 2 , and total). Except for rarely-invoked negative alkalinity, theoretically defined total alkalinity is closely analogous to measured alkalinity and presents few practical interpretation problems. Theoretically defined 'CO 2 -acidity' is closely related to most standard titration methods with an endpoint pH of 8.3 used for determining acidity in mine drainage, but it is unfortunately named because CO 2 is intentionally driven off during titration of mine-drainage samples. Using the proton condition/mass-action approach and employing graphs to illustrate speciation with changes in pH, the authors explore the concept of principal components and how to assign acidity contributions to aqueous species commonly present in mine drainage. Acidity is defined in mine drainage based on aqueous speciation at the sample pH and on the capacity of these species to undergo hydrolysis to pH 8.3. Application of this definition shows that the computed acidity in mgL -1 as CaCO 3 (based on pH and analytical concentrations of dissolved Fe II , Fe III , Mn, and Al in mgL -1 ):acidity calculated =50{1000(10 -pH )+[2(Fe II )+3(Fe III )]/56+2(Mn) /55+3(Al)/27}underestimates contributions from HSO 4 - and H + , but overestimates the acidity due to Fe 3+ and Al 3+ . However, these errors tend to approximately cancel each other. It is demonstrated that 'net alkalinity' is a valid mathematical construction based on theoretical definitions of alkalinity and acidity. Further, it is shown that, for most mine-drainage solutions, a useful net alkalinity value can be derived from: (1) alkalinity and acidity values based on aqueous speciation (2) measured alkalinity minus calculated acidity, or (3) taking the negative of the

  4. Net alkalinity and net acidity 1: Theoretical considerations

    Science.gov (United States)

    Kirby, C.S.; Cravotta, C.A.

    2005-01-01

    Net acidity and net alkalinity are widely used, poorly defined, and commonly misunderstood parameters for the characterization of mine drainage. The authors explain theoretical expressions of 3 types of alkalinity (caustic, phenolphthalein, and total) and acidity (mineral, CO2, and total). Except for rarely-invoked negative alkalinity, theoretically defined total alkalinity is closely analogous to measured alkalinity and presents few practical interpretation problems. Theoretically defined "CO 2-acidity" is closely related to most standard titration methods with an endpoint pH of 8.3 used for determining acidity in mine drainage, but it is unfortunately named because CO2 is intentionally driven off during titration of mine-drainage samples. Using the proton condition/mass- action approach and employing graphs to illustrate speciation with changes in pH, the authors explore the concept of principal components and how to assign acidity contributions to aqueous species commonly present in mine drainage. Acidity is defined in mine drainage based on aqueous speciation at the sample pH and on the capacity of these species to undergo hydrolysis to pH 8.3. Application of this definition shows that the computed acidity in mg L -1 as CaCO3 (based on pH and analytical concentrations of dissolved FeII, FeIII, Mn, and Al in mg L -1):aciditycalculated=50{1000(10-pH)+[2(FeII)+3(FeIII)]/56+2(Mn)/ 55+3(Al)/27}underestimates contributions from HSO4- and H+, but overestimates the acidity due to Fe3+ and Al3+. However, these errors tend to approximately cancel each other. It is demonstrated that "net alkalinity" is a valid mathematical construction based on theoretical definitions of alkalinity and acidity. Further, it is shown that, for most mine-drainage solutions, a useful net alkalinity value can be derived from: (1) alkalinity and acidity values based on aqueous speciation, (2) measured alkalinity minus calculated acidity, or (3) taking the negative of the value obtained in a

  5. Physiology Of Prolonged Bed Rest

    Science.gov (United States)

    Greenleaf, John E.

    1991-01-01

    Report describes physiological effects of prolonged bed rest. Rest for periods of 24 hours or longer deconditions body to some extent; healing proceeds simultaneously with deconditioning. Report provides details on shifts in fluid electrolytes and loss of lean body mass, which comprises everything in body besides fat - that is, water, muscle, and bone. Based on published research.

  6. How to Find Bed Bugs

    Science.gov (United States)

    Find and correctly identify an infestation early before it becomes widespread. Look for rusty or reddish stains and pinpoint dark spots on bed sheets or mattresses, and search for bugs near the piping, seams and tags of the mattress and box spring.

  7. Sleeping arrangements and mosquito net use among under-fives: results from the Uganda Demographic and Health Survey

    Directory of Open Access Journals (Sweden)

    Arinaitwe Jacqueline

    2003-11-01

    Full Text Available Abstract Background The Roll Back Malaria Initiative has identified the under-fives as one of the high risk groups for malaria, and one of the strategies to fight malaria in this group is increasing mosquito net use. This implies that there must be selective targeting at the household level such that the children are protected. However, the Roll Back Malaria preferences must be reconciled with those at the household level to take into account household level preferences. Methods This paper is based on the 2000–2001 Uganda Demographic and Health Survey data in which information on mosquito net ownership and use was collected. The patterns of household mosquito net ownership and use for children under five years of age were examined using both bi-variate and multivariate analysis. Results The preferences at the household level seem to be different; children use mosquito nets primarily because they happen to share a bed with their parents. A child who shares a bed with the mother is 21 times more likely to use a mosquito net than his/her counterpart. Conclusion Increasing mosquito net coverage such that 60% (the target for the RBM of households have at least one mosquito net will not necessarily protect the under-fives. Either the coverage will have to be expanded or appropriate targeting strategies designed.

  8. WE-NET Hydrogen Energy Symposium proceedings; WE-NET suiso energy symposium koen yokoshu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-02-24

    The research and development of WE-NET (World Energy Network) was started in 1993 as a NEDO (New Energy and Industrial Technology Development Organization) project in the New Sunshine Program of Agency of Industrial Science and Technology, Ministry of International Trade and Industry, and aims to contribute to the improvement of global environment and to ease the difficult energy supply/demand situation. The ultimate goal of WE-NET is the construction of a global-scale clean energy network in which hydrogen will be produced from renewable energies such as water and sunshine for distribution to energy consuming locations. Experts are invited to the Symposium from the United States, Germany, and Canada. Information is collected from the participants on hydrogen energy technology development in the three countries, the result of the Phase I program of WE-NET is presented to hydrogen energy scientists in Japan, and views and opinions on the project are collected from them. Accommodated in the above-named publication are 30 essays and three special lectures delivered at the Symposium. (NEDO)

  9. Experimental study of self-leveling behavior in debris bed

    International Nuclear Information System (INIS)

    Zhang, Bin; Harada, Tetsushi; Hirahara, Daisuke; Matsumoto, Tatsuya; Morita, Koji; Fukuda, Kenji; Yamano, Hidemasa; Suzuki, Tohru; Tobita, Yoshiharu

    2008-01-01

    After a core disruptive accident in a sodium-cooled fast reactor, core debris may settle on locations such as within the core-support structure or in the lower inlet plenum of the reactor vessel as debris beds, as a consequence of rapid quenching and fragmentation of core materials in subcooled sodium. The particle beds that are initially of varying depth have been observed to undergo a process of self-leveling when sodium boiling occurs within the beds. The boiling is believed to provide the driven force with debris needed to overcome resisting forces. Self-leveling ability has much effect on heat-removal capability of debris beds. In the present study, characteristics of self-leveling behaviors were investigated experimentally with simulant materials. Although the decay heat from fuel debris drives the coolant boiling in reactor accident conditions, the present experiments employed depressurization boiling of water to simulate axially increasing void distribution in a debris bed, which consists of solid particles of alumina or lead with different density. The particle size (from 0.5 mm to 6 mm in diameter) and shape (spherical or non-spherical particles) were also taken as experimental parameters. A rough criteria for self-leveling occurrence is proposed and compared with the experimental results. Characteristics of the self-leveling behaviors observed are analyzed and extrapolate to reactor accident conditions. (author)

  10. Self-leveling onset criteria in debris beds

    International Nuclear Information System (INIS)

    Zhang, Bin; Harada, Tetsushi; Hirahara, Daisuke; Matsumoto, Tatsuya; Morita, Koji; Fukuda, Kenji; Yamano, Hidemasa; Suzuki, Tohru; Tobita, Yoshiharu

    2010-01-01

    In a core-disruptive accident of a sodium-cooled fast breeder reactor, core debris may settle on the core-support structure and/or in the lower inlet plenum of the reactor vessel because of rapid quenching and fragmentation of molten core materials in the subcooled sodium plenum. Coolant boiling is the mechanism driving the self-leveling of a debris bed that causes significant changes in the heat-removal capability of the beds. In the present study, we develop criteria establishing the onset of this self-leveling behavior that we base on a force balance model assuming a debris bed with a single-sized spherical particle. The model considers drag, buoyancy, and gravity acting on each particle. A series of experiments with simulant materials verified the applicability of this description of self-leveling. Particle size (between 0.5-6 mm), shape (spherical and nonspherical), density (namely of alumina, zirconia, lead, and stainless steel), along with boiling intensity, bed volume, and even experimental methods were taken into consideration to obtain general characteristics of the self-leveling process. We decided to use depressurization boiling to simulate an axially increasing void distribution in the debris bed, although bottom heating was also used to validate the use of the depressurization method. On the self-leveling onset issues, we obtained good agreement between model predictions and experimental results. Extrapolation of our model to actual reactor conditions is discussed. (author)

  11. The heat transfer mechanisms in fluidized beds; Laemmoensiirtomekanismit leijukerroksessa

    Energy Technology Data Exchange (ETDEWEB)

    Fogelholm, C.J.; Blomster, A.M.; Kojola, H. [Helsinki Univ. of Technology, Espoo (Finland)

    1996-12-01

    The goal of the research project is to improve the accuracy of the heat transfer correlation in circulating fluidized beds and to define how the heat transfer is distributed in radiation and convection in the different parts of the fluidized bed. This will be carried out by studying the behaviour and heat transfer of the fluidized bed in the boundary layer near the wall. The total and radiative heat transfer as well as the particle concentration will be measured. Based on the data a correlation will be created. Two different measurement systems are used. The particle concentration is measured by a image-analysis system. A video camera and a Super VHS recorder are used to capture live images from the bed. The images are digitized and stored on a PC. The system has been used in previous research projects at our laboratory. In earlier projects all measurements have been carried out in cold environments. In this project the system will be modified for hot environments. The radiative heat transfer is measured by a radiative heat transfer probe connected to a PC via an A/D converter. The probe consists of a heat flow detector which is isolated from the bed by a sapphire window so that only the radiative part of the heat transfer is detected. The probe will be calibrated in a black body oven so that the effect of the conduction and the sapphire window can be separated. (author)

  12. Fluidized bed combustion: mixing and pollutant limitation

    Energy Technology Data Exchange (ETDEWEB)

    Leckner, B. [Chalmers Univ. of Technology, Goeteborg (Sweden). Dept. of Energy Conversion

    1997-10-01

    Fluidized bed combustion (FBC) has been applied commercially during a few decades, and sufficient knowledge is gained to design boilers with sizes of up to several hundreds of megawatt thermal power (MW{sub th}). The knowledge of what goes on inside a large combustion chamber is still limited, however, and this impedes further optimization and efficient solution of problems that might occur. Despite this lack of knowledge the present survey deals with combustion chamber processes and discusses mixing and distribution of fuel and air in the combustion chamber and its importance for sulphur capture and reduction of emissions of nitrogen oxides. It is desirable to present the material in a general way and to cover the entire field of FBC. However, the scarce openly published information deals mostly with coal combustion in atmospheric circulating fluidized bed (CFB) combustors, and therefore this application will receive most attention, but reference is also made to pressurized combustion and to other fuels than coal. In this context the important work made in the LIEKKI project on the analysis of different fuels and on the influence of pressure should be especially pointed out. (orig.)

  13. Les dispositifs du Net art

    OpenAIRE

    Fourmentraux, Jean-Paul

    2010-01-01

    La pratique du Net art radicalise la question du potentiel communicationnel d’un média —Internet— qui constitue tout à la fois le support technique, l’outil créatif et le dispositif social de l’œuvre. Les technologies de l’information et de la communication (TIC) placent en effet l’œuvre d’art au cœur d’une négociation socialement distribuée entre l’artiste et le public. L’article est focalisé sur cette construction collective du Net art et sur ses mises en scènes. Il montre le travail artist...

  14. Complexity Metrics for Workflow Nets

    DEFF Research Database (Denmark)

    Lassen, Kristian Bisgaard; van der Aalst, Wil M.P.

    2009-01-01

    analysts have difficulties grasping the dynamics implied by a process model. Recent empirical studies show that people make numerous errors when modeling complex business processes, e.g., about 20 percent of the EPCs in the SAP reference model have design flaws resulting in potential deadlocks, livelocks......, etc. It seems obvious that the complexity of the model contributes to design errors and a lack of understanding. It is not easy to measure complexity, however. This paper presents three complexity metrics that have been implemented in the process analysis tool ProM. The metrics are defined...... for a subclass of Petri nets named Workflow nets, but the results can easily be applied to other languages. To demonstrate the applicability of these metrics, we have applied our approach and tool to 262 relatively complex Protos models made in the context of various student projects. This allows us to validate...

  15. The NASA Bed Rest Project

    Science.gov (United States)

    Rhodes, Bradley; Meck, Janice

    2005-01-01

    NASA s National Vision for Space Exploration includes human travel beyond low earth orbit and the ultimate safe return of the crews. Crucial to fulfilling the vision is the successful and timely development of countermeasures for the adverse physiological effects on human systems caused by long term exposure to the microgravity environment. Limited access to in-flight resources for the foreseeable future increases NASA s reliance on ground-based analogs to simulate these effects of microgravity. The primary analog for human based research will be head-down bed rest. By this approach NASA will be able to evaluate countermeasures in large sample sizes, perform preliminary evaluations of proposed in-flight protocols and assess the utility of individual or combined strategies before flight resources are requested. In response to this critical need, NASA has created the Bed Rest Project at the Johnson Space Center. The Project establishes the infrastructure and processes to provide a long term capability for standardized domestic bed rest studies and countermeasure development. The Bed Rest Project design takes a comprehensive, interdisciplinary, integrated approach that reduces the resource overhead of one investigator for one campaign. In addition to integrating studies operationally relevant for exploration, the Project addresses other new Vision objectives, namely: 1) interagency cooperation with the NIH allows for Clinical Research Center (CRC) facility sharing to the benefit of both agencies, 2) collaboration with our International Partners expands countermeasure development opportunities for foreign and domestic investigators as well as promotes consistency in approach and results, 3) to the greatest degree possible, the Project also advances research by clinicians and academia alike to encourage return to earth benefits. This paper will describe the Project s top level goals, organization and relationship to other Exploration Vision Projects, implementation

  16. Pebble bed blanket design for deuterium burning tandem mirror reactors

    International Nuclear Information System (INIS)

    Grotz, S.P.; Dhir, V.K.

    1983-01-01

    The UCLA tandem mirror reactor, SATYR, was developed around the capability of tandem mirrors with thermal barriers to burn deuterium at reasonable efficiency levels. The pebble bed concept has been incorporated into our blanket design for the following reasons: 1) Large area-to-volume ratio for purposes of heat removal; 2) Large volume of structure for high thermal capacity thus increasing the safety margin during off-normal incidents; 3) Relatively inexpensive manufacturing costs because of large acceptable tolerances and lack of exotic materials (i.e., lithium). A simplified stress analysis of the blanket module was performed to optimize and simplify the design. The pre-specified stress intensity limitations used were based upon a 30-year predicted lifetime for each module. Along with stress analysis of the vessel a detailed thermal hydraulic analysis of the pebble bed has been completed. Parameters affecting the pebble bed design are fluidization velocity, pressure drop, heat transfer coefficient, thermally induced stress in the spheres and spatial variation of the power density. Although reasonable gross thermal efficiencies of the 2 designs has been achieved (28% for H 2 O and 39% for He) the high net recirculating power fraction for heating and neutral beams results in relatively low net plant efficiencies (21% and 27%). The results show that a blanket can be designed with good thermal efficiency and a relative-ly simple configuration. However, application of this concept to the high Q deuterium-tritium fuel cycle would have difficulties resulting from the need for continuous removal of the tritium. (orig./HP)

  17. dotNet som multimediaplattform

    OpenAIRE

    Johansson, Glenn

    2008-01-01

    As the speed and complexity of computers have increased so have software and the expectations of users. Software development follows a straightforward evolution where complicated tasks are made easier by better tools; this repeats itself as those tasks in turn are automated. Software mechanics that were seen as revolutionary a decade ago are seen as obvious requirements that no multimedia application can be without. dotNet is the next step in line and makes it easier and faster to build softw...

  18. Distributed systems

    CERN Document Server

    Van Steen, Maarten

    2017-01-01

    For this third edition of "Distributed Systems," the material has been thoroughly revised and extended, integrating principles and paradigms into nine chapters: 1. Introduction 2. Architectures 3. Processes 4. Communication 5. Naming 6. Coordination 7. Replication 8. Fault tolerance 9. Security A separation has been made between basic material and more specific subjects. The latter have been organized into boxed sections, which may be skipped on first reading. To assist in understanding the more algorithmic parts, example programs in Python have been included. The examples in the book leave out many details for readability, but the complete code is available through the book's Website, hosted at www.distributed-systems.net.

  19. Contribution to the knowledge of spouted beds, including in particular an experimental study on the void fraction of the dense phase

    International Nuclear Information System (INIS)

    Eljas, Yves.

    1975-10-01

    The spouted bed is a gas-solid contact technique used to replace fluidisation when the solid particles are too large and too dense. Part one gives a bibliographical study on the aerodynamic aspect of spouted beds. Part two describes an experimental study of the void fraction distribution in a two-dimensional bed [fr

  20. NET model coil test possibilities

    International Nuclear Information System (INIS)

    Erb, J.; Gruenhagen, A.; Herz, W.; Jentzsch, K.; Komarek, P.; Lotz, E.; Malang, S.; Maurer, W.; Noether, G.; Ulbricht, A.; Vogt, A.; Zahn, G.; Horvath, I.; Kwasnitza, K.; Marinucci, C.; Pasztor, G.; Sborchia, C.; Weymuth, P.; Peters, A.; Roeterdink, A.

    1987-11-01

    A single full size coil for NET/INTOR represents an investment of the order of 40 MUC (Million Unit Costs). Before such an amount of money or even more for the 16 TF coils is invested as much risks as possible must be eliminated by a comprehensive development programme. In the course of such a programme a coil technology verification test should finally prove the feasibility of NET/INTOR TF coils. This study report is almost exclusively dealing with such a verification test by model coil testing. These coils will be built out of two Nb 3 Sn-conductors based on two concepts already under development and investigation. Two possible coil arrangements are discussed: A cluster facility, where two model coils out of the two Nb 3 TF-conductors are used, and the already tested LCT-coils producing a background field. A solenoid arrangement, where in addition to the two TF model coils another model coil out of a PF-conductor for the central PF-coils of NET/INTOR is used instead of LCT background coils. Technical advantages and disadvantages are worked out in order to compare and judge both facilities. Costs estimates and the time schedules broaden the base for a decision about the realisation of such a facility. (orig.) [de

  1. Market evaluation and investment planning in natural gas industry in Brazil: development of the net distribution pipeline; Avaliacao de mercado e planejamento de investimentos na industria de gas natural no Brasil: perspectivas de crescimento da malha de gasodutos de distribuicao

    Energy Technology Data Exchange (ETDEWEB)

    Avila, Pedro L.; Pamplona, Edson O. [Universidade Federal de Itajuba (UNIFEI), MG (Brazil)

    2008-07-01

    This paper proposes to develop a real options model to decision-making investments in flexible technologies. As a result, finding a closed-form solution, derived from the partial differential equation of the value of flexibility provided by alternative fuels. However, you can present and analysis the results of a practical application using the method to solve real options problems known as binomial model. Initially presents a brief explanation on the method of discounted cash flow, its failures and changes to the real options analysis. In the sequence chart an overview of the natural gas industry on Brazil, emphasizing the need for consistent investments evaluations in the sector. The next section shows the proposed development of mathematical model for assessing the flexibility to choose, obtained by the exchange of fuel for transport of gas pipeline distribution of natural gas. The model takes as the case scenario where the flexible pipeline can carry both natural gas and hydrogen, and the evaluation of the option of exchanging input gives more value to the investment opportunity, and consider the optimum conditions where the option to be exercised. Keywords: Decision Making, Real Options; Natural Gas, Flexible Technology. (author)

  2. A Science Cloud: OneSpaceNet

    Science.gov (United States)

    Morikawa, Y.; Murata, K. T.; Watari, S.; Kato, H.; Yamamoto, K.; Inoue, S.; Tsubouchi, K.; Fukazawa, K.; Kimura, E.; Tatebe, O.; Shimojo, S.

    2010-12-01

    Main methodologies of Solar-Terrestrial Physics (STP) so far are theoretical, experimental and observational, and computer simulation approaches. Recently "informatics" is expected as a new (fourth) approach to the STP studies. Informatics is a methodology to analyze large-scale data (observation data and computer simulation data) to obtain new findings using a variety of data processing techniques. At NICT (National Institute of Information and Communications Technology, Japan) we are now developing a new research environment named "OneSpaceNet". The OneSpaceNet is a cloud-computing environment specialized for science works, which connects many researchers with high-speed network (JGN: Japan Gigabit Network). The JGN is a wide-area back-born network operated by NICT; it provides 10G network and many access points (AP) over Japan. The OneSpaceNet also provides with rich computer resources for research studies, such as super-computers, large-scale data storage area, licensed applications, visualization devices (like tiled display wall: TDW), database/DBMS, cluster computers (4-8 nodes) for data processing and communication devices. What is amazing in use of the science cloud is that a user simply prepares a terminal (low-cost PC). Once connecting the PC to JGN2plus, the user can make full use of the rich resources of the science cloud. Using communication devices, such as video-conference system, streaming and reflector servers, and media-players, the users on the OneSpaceNet can make research communications as if they belong to a same (one) laboratory: they are members of a virtual laboratory. The specification of the computer resources on the OneSpaceNet is as follows: The size of data storage we have developed so far is almost 1PB. The number of the data files managed on the cloud storage is getting larger and now more than 40,000,000. What is notable is that the disks forming the large-scale storage are distributed to 5 data centers over Japan (but the storage

  3. Adult Bed-Wetting: A Concern?

    Science.gov (United States)

    Adult bed-wetting: A concern? My 24-year-old husband has started to wet the bed at ... of Privacy Practices Notice of Nondiscrimination Manage Cookies Advertising Mayo Clinic is a not-for-profit organization ...

  4. Find a Bed Bug Pesticide Product

    Science.gov (United States)

    Introduces the Bed Bug Product Search Tool, to help consumers find EPA-registered pesticides for bed bug infestation control. Inclusion in this database is not an endorsement. Always follow label directions carefully.

  5. EPA-Registered Bed Bug Products

    Science.gov (United States)

    ... rest or hide in hampers, bed frames, even furniture); Failing to treat adjacent areas where bed bugs ... to work (some pesticides, such as desiccators or growth regulators, may be very effective but take some ...

  6. Bed Bug Guidance for School Nurses

    Science.gov (United States)

    School nurses are often called upon to provide vital information to students, parents, teachers, and administrators. These tips on identifying, managing and preventing bed bugs will help you to effectively respond if bed bugs appear in your school.

  7. Bacillus cereus in free-stall bedding.

    Science.gov (United States)

    Magnusson, M; Svensson, B; Kolstrup, C; Christiansson, A

    2007-12-01

    To increase the understanding of how different factors affect the bacterial growth in deep sawdust beds for dairy cattle, the microbiological status of Bacillus cereus and coliforms in deep sawdust-bedded free stalls was investigated over two 14-d periods on one farm. High counts of B. cereus and coliforms were found in the entire beds. On average, 4.1 log(10) B. cereus spores, 5.5 log(10) B. cereus, and 6.7 log(10) coliforms per gram of bedding could be found in the upper layers of the sawdust likely to be in contact with the cows' udders. The highest counts of B. cereus spores, B. cereus, and coliforms were found in the bedding before fresh bedding was added, and the lowest immediately afterwards. Different factors of importance for the growth of B. cereus in the bedding material were explored in laboratory tests. These were found to be the type of bedding, pH, and the type and availability of nutrients. Alternative bedding material such as peat and mixtures of peat and sawdust inhibited the bacterial growth of B. cereus. The extent of growth of B. cereus in the sawdust was increased in a dose-dependent manner by the availability of feces. Urine added to different bedding material raised the pH and also led to bacterial growth of B. cereus in the peat. In sawdust, a dry matter content greater than 70% was needed to lower the water activity to 0.95, which is needed to inhibit the growth of B. cereus. In an attempt to reduce the bacterial growth of B. cereus and coliforms in deep sawdust beds on the farm, the effect of giving bedding daily or a full replacement of the beds was studied. The spore count of B. cereus in the back part of the free stalls before fresh bedding was added was 0.9 log units lower in stalls given daily bedding than in stalls given bedding twice weekly. No effect on coliform counts was found. Replacement of the entire sawdust bedding had an effect for a short period, but by 1 to 2 mo after replacement, the counts of B. cereus spores in the

  8. IntermIttent PreventIve treatment and Bed nets uPtake among ...

    African Journals Online (AJOL)

    2015, in the number of pregnant women in Kenya receiving recommended malaria prophylaxis in the ... recommended that at least three IPtp doses be provided to pregnant ..... operational research and training Initiative (sort. It), a global ...

  9. Effect of the use of insecticide-treated bed nets on birth outcomes ...

    African Journals Online (AJOL)

    Each year in sub-Saharan Africa, where 80 to 90% of the world's malaria cases occur, approximately 19 to 24 million .... in winning the battle against malaria.16 .... tion group and given ITNs prepared in ... two doses of tetanus toxoid vaccine.

  10. Sorting it out: bedding particle size and nesting material processing method affect nest complexity.

    Science.gov (United States)

    Robinson-Junker, Amy; Morin, Amelia; Pritchett-Corning, Kathleen; Gaskill, Brianna N

    2017-04-01

    As part of routine husbandry, an increasing number of laboratory mice receive nesting material in addition to standard bedding material in their cages. Nesting material improves health outcomes and physiological performance in mice that receive it. Providing usable nesting material uniformly and efficiently to various strains of mice remains a challenge. The aim of this study was to determine how bedding particle size, method of nesting material delivery, and processing of the nesting material before delivery affected nest building in mice of strong (BALB/cAnNCrl) and weak (C3H/HeNCrl) gathering abilities. Our data suggest that processing nesting material through a grinder in conjunction with bedding material, although convenient for provision of bedding with nesting material 'built-in', negatively affects the integrity of the nesting material and subsequent nest-building outcomes. We also found that C3H mice, previously thought to be poor nest builders, built similarly scored nests to those of BALB/c mice when provided with unprocessed nesting material. This was true even when nesting material was mixed into the bedding substrate. We also observed that when nesting material was mixed into the bedding substrate, mice of both strains would sort their bedding by particle size more often than if it were not mixed in. Our findings support the utility of the practice of distributing nesting material mixed in with bedding substrate, but not that of processing the nesting material with the bedding in order to mix them.

  11. Shaft placement in a bedded salt repository

    International Nuclear Information System (INIS)

    Klasi, M.L.

    1982-10-01

    Preferred shaft pillar sizes and shaft locations were determined with respect to the induced thermal stresses in a generic bedded salt repository at a depth of 610 m with a gross thermal loading of 14.8 W/m 2 . The model assumes isotropic material properties, plane strain and linear elastic behavior. Various shaft locations were analyzed over a 25 year period. The thermal results show that for this time span, the stratigraphy is unimportant except for the region immediately adjacent to the repository. The thermomechanical results show that for the given repository depth of 610 m, a minimum central shaft pillar radius of 244 m is required to equal the material strength in the barrier pillar. An assumed constant stress and constant temperature distribution creep model of the central shaft region adjacent to the repository conservatively overestimates a creep closure of 310 mm in a 6.1 m diameter centrally-located shaft

  12. Numerical simulation of the knotted nylon netting panel

    Directory of Open Access Journals (Sweden)

    Li Yuwei

    2016-01-01

    Full Text Available A piece of netting, consists of the 8 8 meshes, fixed on a square frame, was simulated and the tensions and their distribution, the positions of knots and netting shape were calculated by means of MATLAB in computer. The dynamic mathematic model was developed based on lumped mass method, the netting was treated as spring-mass system, the Runge-Kutta fifth-order and sixth-order method was used to solve the differential equations for every step, then the displacement and tension of each mass point were obtained. For verify this model, the tests have been carried out in a flume tank. The results of the numerical simulation fully agreed with the experiments.

  13. Long Term RadNet Quality Data

    Data.gov (United States)

    U.S. Environmental Protection Agency — This RadNet Quality Data Asset includes all data since initiation and when ERAMS was expanded to become RadNet, name changed to reflect new mission. This includes...

  14. Special Section on Coloured Petri Nets

    DEFF Research Database (Denmark)

    1998-01-01

    Special section on coloured Petri nets, their basic concepts, analysis methods, tool support and industrial applications.......Special section on coloured Petri nets, their basic concepts, analysis methods, tool support and industrial applications....

  15. Empirical closures for particulate debris bed spreading induced by gas–liquid flow

    Energy Technology Data Exchange (ETDEWEB)

    Basso, S., E-mail: simoneb@kth.se; Konovalenko, A.; Kudinov, P.

    2016-02-15

    Highlights: • Experimental study of the debris bed self-leveling phenomenon. • A scaling approach and a non-dimensional model to describe particle flow rate are proposed. • The model is validated against experiments with particles of different properties and at different gas injection conditions. - Abstract: Efficient removal of decay heat from the nuclear reactor core debris is paramount for termination of severe accident progression. One of the strategies is based on melt fragmentation, quenching and cooling in a deep pool of water under the reactor vessel. Geometrical configuration of the debris bed is among the important factors which determine possibility of removing the decay heat from the debris bed by natural circulation of the coolant. For instance, a tall mound-shape debris bed can be non-coolable, while the same debris can be coolable if spread uniformly. Decay heat generates a significant amount of thermal energy which goes to production of steam inside the debris bed. Two-phase flow escaping through the top layer of the bed becomes a source of mechanical energy which can move the particulate debris along the slope of the bed. The motion of the debris will lead to flattening of the bed. Such process is often called “self-leveling” phenomenon. Spreading of the debris bed by the self-leveling process can take significant time, depending on the initial debris bed configuration and other parameters. There is a competition between the time scales for reaching (i) a coolable configuration of the bed, and (ii) onset of dryout and re-melting of the debris. In the previous work we have demonstrated that the rate of particulate debris spreading is determined by local gas velocity and local slope angle of the bed. In this work we develop a scaling approach and a closure for prediction of debris spreading rate based on generalization of available experimental data. We demonstrate that introduced scaling criteria are universal for particles of different

  16. Fluidization quality analyzer for fluidized beds

    Science.gov (United States)

    Daw, C.S.; Hawk, J.A.

    1995-07-25

    A control loop and fluidization quality analyzer for a fluidized bed utilizes time varying pressure drop measurements. A fast-response pressure transducer measures the overall bed pressure drop, or over some segment of the bed, and the pressure drop signal is processed to produce an output voltage which changes with the degree of fluidization turbulence. 9 figs.

  17. Fluidized bed dry dense medium coal beneficiation

    CSIR Research Space (South Africa)

    North, Brian C

    2017-10-01

    Full Text Available medium beneficiation using a fluidized bed was investigated. Bed materials of sand, magnetite and ilmenite were used in a laboratory sized cylindrical fluidized bed. The materials were individually tested, as were mixes of sand and heavy minerals. Coal...

  18. The use of mosquito nets in fisheries: A global perspective.

    Directory of Open Access Journals (Sweden)

    Rebecca Short

    Full Text Available Free or subsidised mosquito net (MN distribution has been an increasingly important tool in efforts to combat malaria in recent decades throughout the developing world, making great strides towards eradicating this hugely detrimental disease. However, there has been increasing concern in the natural resource management and healthcare communities over alternative use of MNs, particularly in artisanal fisheries where it has been suggested they pose a threat to sustainability of fish stocks. So far, little evidence has been presented as to the global prevalence and characteristics of MN fishing, limiting global management initiatives and incentives for action across disciplines. We conducted a rapid global assessment of mosquito net fishing (MNF observations from expert witnesses living and/or working in malarial zones using an internet survey. MNF was found to be a broadly pan-tropical activity, particularly prevalent in sub-Saharan Africa. MNF is conducted using a variety of deployment methods and scales including seine nets, scoop/dip nets, set nets and traps. MNF was witnessed in a broad range of marine and freshwater habitats and was seen to exploit a wide range of taxa, with capture of juvenile fish reported in more than half of responses. Perceived drivers of MNF were closely related to poverty, revealing potentially complex and arguably detrimental livelihood and food security implications which we discuss in light of current literature and management paradigms. The key policies likely to influence future impacts of MNF are in health, regarding net distribution, and natural resource management regarding restrictions on use. We outline critical directions for research and highlight the need for a collaborative, interdisciplinary approach to development of both localised and broad-scale policy.

  19. Experimental Determination of Bed Conditions in Concentrated Pyroclastic Density Currents

    Science.gov (United States)

    Winner, A.; Ferrier, K.; Dufek, J.

    2016-12-01

    Pyroclastic density currents (PDCs) are ground-hugging mixtures of hot gas and rock that can reach temperatures > 800 oC and speeds of 200 m/s. These flows are capable of eroding and entraining the underlying bed material into the flow, which can strongly influence flow momentum, runout distance, and hazards associated with PDCs. However, the mechanism of erosion remains poorly constrained, with proposed mechanisms including under-pressure following the head of the fluidized current, force chain enhanced stresses at the bed, and discrete particle impacts and friction. The interactions between PDCs and the bed have been difficult to observe in the field, as their infrequent occurrence, opacity, and hostile environment make real-time measurement difficult. This study is aimed at obtaining a better understanding of the interactions between PDCs and the bed through a quantitative analysis of bed forces. Our experimental apparatus consists of a rotating cylindrical flume of radius 22 cm, within which gas-rich granular material flows along the interior of the cylinder as it rotates. By using a rotating cylinder, we are able to simulate long-duration flows, allowing us to observe impact forces at the bed over timescales comparable to the flow duration of natural PDCs. To measure the distribution and evolution of forces imparted by the flow on the bed, we constructed a cylindrical insert with a non-erodible bed in which we embedded force sensor arrays parallel and perpendicular to the direction of flow. To measure the forces felt by the particles in the flow, we added "smart particles" 25 to 50 mm in diameter to the flow. Each smart particle contains a three-axis accelerometer and a micro SD card enclosed in a spherical plastic casing, and possesses a density similar to that of the pumice in the experimental flow. Each smart particle also contains a three-axis magnetometer which permits its location to be tracked by means of a unique applied magnetic field. Ultimately

  20. NetBeans IDE 8 cookbook

    CERN Document Server

    Salter, David

    2014-01-01

    If you're a Java developer of any level using NetBeans and want to learn how to get the most out of NetBeans, then this book is for you. Learning how to utilize NetBeans will provide a firm foundation for your Java application development.