100 research outputs found

    Modélisation des réactions de pyrolyse des coques de coco, des déchets de bois et de la paille : Application à la prévision de la composition molaire des gaz de gazéification

    Get PDF
    La prĂ©sente Ă©tude propose le couplage de mĂ©thodes numĂ©riques et expĂ©rimentales pour la prĂ©vision de la composition molaire du mĂ©lange gazeux issu de la gazĂ©ification de la biomasse. Elle prend en compte les diffĂ©rentes Ă©tapes de la gazĂ©ification Ă  savoir le sĂ©chage, la pyrolyse, la combustion et les principales rĂ©actions de rĂ©duction. La prĂ©sente mĂ©thode proposĂ©e repose sur plusieurs rĂ©sultats expĂ©rimentaux de la pyrolyse de trois diffĂ©rentes biomasses ayant des caractĂ©ristiques physico chimiques reprĂ©sentatives de multiples biomasses et sur la cinĂ©tique de rĂ©action des principales rĂ©actions de rĂ©duction Ă  savoir la rĂ©action de Boudouard et la rĂ©action du gaz Ă  l’eau. Les rĂ©sultats prĂ©vus par cette mĂ©thode se rapprochent correctement des rĂ©sultats expĂ©rimentaux obtenus dans la gazĂ©ification du bois Ă  l’oxygĂšne.Mots-clĂ©s : composition molaire,gazĂ©ification de la  biomasse, caractĂ©ristiques physico chimiques, bois, rĂ©action de pyrolyse

    Étude Ă©conomique des foyers domestiques par la technique d’ébullition de l’eau : cas du BĂ©nin

    Get PDF
    Les foyers font partie de la vie courante. Chaque mĂ©nage en utilise pour la cuisson de ses repas. Dans les pays en dĂ©veloppement, la plupart des populations utilisent surtout des foyers Ă  combustibles ligneux. Les effets nĂ©gatifs sur l’environnement sont aujourd’hui bien connus : poches de dĂ©sertification, Ă©rosion des sols, changements climatiques, etc. Ces effets peuvent se mesurer Ă  la consommation de ces foyers, laquelle dĂ©pend de la taille de la famille, des habitudes de repas et aussi du type de foyer utilisĂ©. La prĂ©sente Ă©tude, en utilisant la technique d’ébullition de l’eau, montre l’influence du type de foyer sur les performances, ainsi que l’économie qu’on peut atteindre avec les diffĂ©rents foyers. Les foyers Ă  combustibles fossiles ont les meilleures performances Ă©conomiques, mais le coĂ»t trĂšs bas des combustibles ligneux leur donne un avantage.Mots-clĂ©s : foyers, combustibles, performances, Ă©conomie d’énergie, environnement

    Need-Achievement And Career Preference Of In-School Adolescents In Anambra State, Nigeria: The Need To Reposition School Librarian/Library Roles

    Get PDF
    The relationship between need achievement and career preference of in-school adolescents were examined in this study. The need for the study was prompted by previous studies’ report that students make wrong career preferences due to poor information among other factors. The negative impact of these wrong preferences on the individual and the work place have become worrisome to all concerned. To achieve the main purpose of the research, a questionnaire was constructed through literature and was face validated by experts in the field of education. The instrument proved to be reliable (with a reliability index of .92.) to answer the research questions and also test the hypothesis at 0.5 level of significance. Participants were 380 (both male and female) in-schooling adolescents who supplied information to the questionnaires about need achievement and career preferences. Results revealed a heterogeneous pattern of career preference and a positive significant relationship between in-school adolescents’ need-achievement and career preference. Based on the findings, the paper made recommendations and highlights a significant need to reposition the roles of the school librarians and the services of the libraries to include career guidance services

    Dataset on noise level measurement in Ota metropolis, Nigeria

    Get PDF
    Datasets contained in this article are noise level measurementcarried out at 41 different locations in Ota metropolis, Nigeria. Thenoise readings were measured at a time interval of 30 min for eachsite considered using a precision grade sound level meter. Theanalysis was based on the noise descriptors LAeq,L10,L90,LD, TNIand NEI. Results from the study reflects that the highest and lowestequivalent noise levels (LAeq) were recorded at commercial areas(96 dB (A)) and residential areas (52 dB (A)), respectively, thebackground noise level (L90) has the highest and lowest values atcommercial areas (77 dB (A)) and residential areas (44 dB (A)),respectively and the peak value (L10) has the highest value andlowest value at the commercial areas (96 dB (A)) and residentialareas (56 dB (A)). Based on the WHO recommendations and stan-dards, only 2 out of the 41 locations considered are under normallyacceptable situation while the noise levels of other areas are notacceptable. Noise map developed in this study provides enoughinformation for technical controls and interim legislation againstenvironmental noise pollution in the metropolis. Moreover, con-sidering the noise emission standards, planning and promoting thecitizens awareness about the high noise risk could help to mitigatethe effect of noise in Ota, Metropolis. The noise data in this study are useful as reference and guideline for future regulations onnoise limit to be implemented for urban areas in Nigeria anddeveloping countries at large

    Factors associated with delayed presentation to healthcare facilities for Lassa fever cases, Nigeria 2019: a retrospective cohort study.

    Get PDF
    BACKGROUND: Large outbreaks of Lassa fever (LF) occur annually in Nigeria. The case fatality rate among hospitalised cases is ~ 20%. The antiviral drug ribavirin along with supportive care and rehydration are the recommended treatments but must be administered early (within 6 days of symptom onset) for optimal results. We aimed to identify factors associated with late presentation of LF cases to a healthcare facility to inform interventions. METHODS: We undertook a retrospective cohort study of all laboratory confirmed LF cases reported in Nigeria from December 2018 to April 2019. We performed descriptive epidemiology and a univariate Cox proportional-hazards regression analysis to investigate the effect of clinical (symptom severity), epidemiological (age, sex, education, occupation, residential State) and exposure (travel, attendance at funeral, exposure to rodents or confirmed case) factors on time to presentation. RESULTS: Of 389 cases, median presentation time was 6 days (IQR 4-10 days), with 53% attending within 6 days. There were no differences in presentation times by sex but differences were noted by age-group; 60+ year-olds had the longest delays while 13-17 year-olds had the shortest. By sex and age, there were differences seen among the younger ages, with 0-4-year-old females presenting earlier than males (4 days and 73% vs. 10 days and 30%). For 5-12 and 13-17 year-olds, males presented sooner than females (males: 5 days, 65% and 3 days, 85% vs. females: 6 days, 50% and 5 days, 61%, respectively). Presentation times differed across occupations 4.5-9 days and 20-60%, transporters (people who drive informal public transport vehicles) had the longest delays. Other data were limited (41-95% missing). However, the Cox regression showed no factors were statistically associated with longer presentation time. CONCLUSIONS: Whilst we observed important differences in presentation delays across factors, our sample size was insufficient to show any statistically significant differences that might exist. However, almost half of cases presented after 6 days of onset, highlighting the need for more accurate and complete surveillance data to determine if there is a systemic or specific cause for delays, so to inform, monitor and evaluate public health strategies and improve outcomes

    HLA-DQA1*05 carriage associated with development of anti-drug antibodies to infliximab and adalimumab in patients with Crohn's Disease

    Get PDF
    Anti-tumor necrosis factor (anti-TNF) therapies are the most widely used biologic drugs for treating immune-mediated diseases, but repeated administration can induce the formation of anti-drug antibodies. The ability to identify patients at increased risk for development of anti-drug antibodies would facilitate selection of therapy and use of preventative strategies.This article is freely available via Open Access. Click on Publisher URL to access the full-text

    Mechanisms and management of loss of response to anti-TNF therapy for patients with Crohn's disease: 3-year data from the prospective, multicentre PANTS cohort study

    Get PDF
    This is the final version. Available from Elsevier via the DOI in this record. Background We sought to report the effectiveness of infliximab and adalimumab over the first 3 years of treatment and to define the factors that predict anti-TNF treatment failure and the strategies that prevent or mitigate loss of response. Methods Personalised Anti-TNF therapy in Crohn’s disease (PANTS) is a UK-wide, multicentre, prospective observational cohort study reporting the rates of effectiveness of infliximab and adalimumab in anti-TNF-naive patients with active luminal Crohn’s disease aged 6 years and older. At the end of the first year, sites were invited to enrol participants still receiving study drug into the 2-year PANTS-extension study. We estimated rates of remission across the whole cohort at the end of years 1, 2, and 3 of the study using a modified survival technique with permutation testing. Multivariable regression and survival analyses were used to identify factors associated with loss of response in patients who had initially responded to anti-TNF therapy and with immunogenicity. Loss of response was defined in patients who initially responded to anti-TNF therapy at the end of induction and who subsequently developed symptomatic activity that warranted an escalation of steroid, immunomodulatory, or anti-TNF therapy, resectional surgery, or exit from study due to treatment failure. This study was registered with ClinicalTrials.gov, NCT03088449, and is now complete. Findings Between March 19, 2014, and Sept 21, 2017, 389 (41%) of 955 patients treated with infliximab and 209 (32%) of 655 treated with adalimumab in the PANTS study entered the PANTS-extension study (median age 32·5 years [IQR 22·1–46·8], 307 [51%] of 598 were female, and 291 [49%] were male). The estimated proportion of patients in remission at the end of years 1, 2, and 3 were, for infliximab 40·2% (95% CI 36·7–43·7), 34·4% (29·9–39·0), and 34·7% (29·8–39·5), and for adalimumab 35·9% (95% CI 31·2–40·5), 32·9% (26·8–39·2), and 28·9% (21·9–36·3), respectively. Optimal drug concentrations at week 14 to predict remission at any later timepoints were 6·1–10·0 mg/L for infliximab and 10·1–12·0 mg/L for adalimumab. After excluding patients who had primary non-response, the estimated proportions of patients who had loss of response by years 1, 2, and 3 were, for infliximab 34·4% (95% CI 30·4–38·2), 54·5% (49·4–59·0), and 60·0% (54·1–65·2), and for adalimumab 32·1% (26·7–37·1), 47·2% (40·2–53·4), and 68·4% (50·9–79·7), respectively. In multivariable analysis, loss of response at year 2 and 3 for patients treated with infliximab and adalimumab was predicted by low anti-TNF drug concentrations at week 14 (infliximab: hazard ratio [HR] for each ten-fold increase in drug concentration 0·45 [95% CI 0·30–0·67], adalimumab: 0·39 [0·22–0·70]). For patients treated with infliximab, loss of response was also associated with female sex (vs male sex; HR 1·47 [95% CI 1·11–1·95]), obesity (vs not obese 1·62 [1·08–2·42]), baseline white cell count (1·06 [1·02–1·11) per 1 × 10âč increase in cells per L), and thiopurine dose quartile. Among patients treated with adalimumab, carriage of the HLA-DQA1*05 risk variant was associated with loss of response (HR 1·95 [95% CI 1·17–3·25]). By the end of year 3, the estimated proportion of patients who developed anti-drug antibodies associated with undetectable drug concentrations was 44·0% (95% CI 38·1–49·4) among patients treated with infliximab and 20·3% (13·8–26·2) among those treated with adalimumab. The development of antidrug antibodies associated with undetectable drug concentrations was significantly associated with treatment without concomitant immunomodulator use for both groups (HR for immunomodulator use: infliximab 0·40 [95% CI 0·31–0·52], adalimumab 0·42 [95% CI 0·24–0·75]), and with carriage of HLA-DQA1*05 risk variant for infliximab (HR for carriage of risk variant: infliximab 1·46 [1·13–1·88]) but not for adalimumab (HR 1·60 [0·92–2·77]). Concomitant use of an immunomodulator before or on the day of starting infliximab was associated with increased time without the development of anti-drug antibodies associated with undetectable drug concentrations compared with use of infliximab alone (HR 2·87 [95% CI 2·20–3·74]) or introduction of an immunomodulator after anti-TNF initiation (1·70 [1·11–2·59]). In years 2 and 3, 16 (4%) of 389 patients treated with infliximab and 11 (5%) of 209 treated with adalimumab had adverse events leading to treatment withdrawal. Nine (2%) patients treated with infliximab and two (1%) of those treated with adalimumab had serious infections in years 2 and 3. Interpretation Only around a third of patients with active luminal Crohn’s disease treated with an anti-TNF drug were in remission at the end of 3 years of treatment. Low drug concentrations at the end of the induction period predict loss of response by year 3 of treatment, suggesting higher drug concentrations during the first year of treatment, particularly during induction, might lead to better long-term outcomes. Anti-drug antibodies associated with undetectable drug concentrations of infliximab, but not adalimumab, can be predicted by carriage of HLA-DQA1*05 and mitigated by concomitant immunomodulator use for both drugs.Guts UKCrohn’s and Colitis UKCure Crohn’s ColitisAbbVieMerck Sharp and DohmeNapp PharmaceuticalsPfizerCelltrion Healthcar
    • 

    corecore