252 research outputs found
Production of Paper Pulp Using Sisal Fiber Waste from Sisal Spinning Processes
Disposal of large volumes of textile waste is an escalating problem for textile industries. Sisal spinning industry is the one of the textile industries releasing large volumes of textile waste in the landfills. The rising costs, and reduction of available space together with increasing stringent environmental measures are making burying and land filling of textile waste, a declining option. This study therefore explores recycling options where the potential of using sisal fiber waste produced during sisal spinning processes as raw materials for the production of paper pulp was investigated. Sampling was done at 21stCentury Holdings Limited allocated at Chang’ombe industrial street Dar es Salaam mainly dealer of sisal yarns production. Materials were prepared and cut into small pieces of about ½ inches to reduce the fiber into unit lengths so as to achieve pulping required performance. Pulping process was achieved through Soda pulping techniques with two different effective alkali charges (EA-20% and EA-24%) for 240 minutes under maximum temperature 140 C, and liquor to fiber ratio 4:1by using Mathis Labomat dyeing Machine. The kappa number obtained was (25.5, 34.5) for material treated under EA 24% and EA 20% respectively, Percentage pulp yield were (47.1, 54.4) for EA 24% and EA20% pulp respectively. Freeness (630CFS, 555CSF) after refining at 4500rpm. Finally, the resulting pulp was used for hand sheet making and the sheets were tested for their mechanical properties; Grammage (61.1, 61.1) g/m2, Tensile index (9.9, 22.3) Nm/g, Tear index (13.3, 17.4) Nm2/g, burst index (1.7, 3.7 and 1.6) k.pa.m2/g and Elongation at break (2.02, 2.22) % for EA24% pulp, EA20% pulp respectively. The findings shows that sisal fiber wastes have a promising potential for paper pulp production compared to other non-wood raw material
Isotopic signatures of precent-day calcite and pyrite in low-temperature crystalline bedrock, Olkiluoto, SW Finland
Geochemical characteristics of precipitated fracture filling calcite and pyrite can provide much useful information about the deep bedrock environment at the time of their deposition. However, it has been difficult to identify fracture coatings precipitated from the present-day groundwater system. The aim of this study was to evaluate the relationship between the coexisting calcite and pyrite, and the groundwater present at the time of precipitation. Here we investigated fine-grained mineral precipitate deposited over a four-year period on the surface of groundwater monitoring equipment inserted into a drillhole at 530 m below sea level, at Olkiluoto, which is the planned site for a final repository of spent nuclear fuel. The experimental setting is also artificial in the sense that the drillholes have possibly affected groundwater circulation and a foreign object has been inserted into the drillhole. Combining the elemental and isotope geochemical composition of the precipitated calcite and pyrite with previously published compositional data on groundwater and evidence for microbial communities on this site, offered a possibility to get new insight of the precipitation and isotope fractionation processes taking place in deep crystalline bedrock. The concentration of the redox sensitive manganese in the precipitate gives supporting evidence for the influx of groundwater from overlying groundwater units. The delta C-13 (n = 13) and delta O-18 (n = 15) values of calcite vary from-13.2 to-9.7 parts per thousand and from-9.1 to-7.4 parts per thousand respectively. Comparison to the respective values in the local groundwater indicated that the precipitated calcite is in near isotopic equilibrium with its environment with respect to carbon and oxygen. The potential ultimate source of the carbon in the DIC and in the precipitate is likely in old fracture calcite coatings. The 834S values of pyrite (n = 9) show relatively small variation from-5.7 to 8.3 parts per thousand. This differs greatly from the huge span of 834S values from-50 to 80%o in fracture pyrites reported for the latest calcite fillings at Olkiluoto. The restricted range of 834S values is interpreted to result from open system conditions during precipitation, with new dissolved sulfate entering from the large brackish SO4-type groundwater unit above. The isotopic fractionation of sulfur between dissolved sulfate and sulfide is estimated to be 25 & PLUSMN; 10%o, which is in agreement with the results reported in laboratory experiments for bacterial sulfate reduction.Peer reviewe
Application of riverbed high-resolution mapping techniques in the Arno river (Florence, Italy)
Factors Influencing Preferences and Adoption of Improved Groundnut Varieties among Farmers in Tanzania
Access and use of seed of improved varieties of groundnut among farmers can improve
farmers’ livelihoods and contribute to the potential of crop production in Tanzania. This paper
analyzes factors underpinning the adoption of improved groundnut varieties among farmers to pave
the way for upscaling quality seed used for increased production and commodity business in farming
communities. A four-stage stratified sampling was used to collect data from 300 groundnut farmers
in seven agro-ecological zones through individual interviews. Secondary data were collected from
the literature and the Tanzania Agricultural Research Institute at Naliendele centre (TARI–Naliendele).
Descriptive statistics and Probit regression model were used for data analysis. The empirical results
showed that Johari 1985, Pendo 1998, Naliendele 2009, Mnanje 2009, Mangaka 2009 and Nachi 2015,
are the main six improved groundnut varieties used by farmers, with Pendo 1998 having the highest
adoption rate (17.1%). In the grain market, four varieties, namely Pendo 1998, Mnanje 2009, Nachi
2015 and Johari 1985, were observed to be highly preferred by grain off-takers. Furthermore, among
the adopted improved varieties, Nachi 2015, is observed to be the most consistent high yielding
variety, ranging from 1100 kg/ha to 1500 kg/ha in all agro-ecological zones. A farmer’s decision to
adopt new varieties is affected by age and gender, farmer group membership, availability of improved
seed and seed cost. Overall, male farmers are more likely to adopt improved varieties of groundnut
than female farmers. The implications of these findings are also discussed, in particular in the area of
policy support
The use of 0.01M phosphate buffered saline as detection buffer for Alere Determine® HIV rapid test in resource limited settings
Insufficient supply of manufacture’s buffers/diluents in relation to the number of strips per kit has been found to have negative impact on patients’ results. Some laboratories personnel tend to use diluents from other rapid tests manufacturers such as Bioline, Unigold as well as malaria rapid diagnostic test (MRDT). This study aimed at evaluating the use of 0.01M phosphate buffered saline (PBS) as detection buffer for Alere Determine® HIV rapid test. This study was carried out at Bugando School of Medicine in Mwanza, Tanzania. A total of 300 whole blood specimens; 150 HIV positive specimens from patients attending Care and Treatment Centreand 150 HIV negative specimens were retested for HIV status using Alere Determine® HIV rapid test employing normal Alere buffer and 0.01M PBS as buffer.Of the total specimens tested; 150 (100%) of HIV positive were positive by using both Alere buffer and 0.01M PBS while 150(100%) of HIV negative samples were negative by both Alere Determine® and 0.01M PBS. The agreement between 0.01M PBS and Alere Determine® buffer was 100%. The value of kappa indicates perfect agreement between 0.01M PBS and Alere Determine® buffer (100%). A 0.01M PBS is recommended as alternative detection buffer for Alere Determine® in cases of insufficient supply. Further investigation to evaluate the suitable buffer for other rapid tests for HIV and other diseases is recommended especially in resource limited settings.
Marked reduction in fertility among African women with urogenital infections:A prospective cohort study
<div><p>Background</p><p>There is paucity of data on risk factors for reduced fertility in low-income countries.</p><p>Objective</p><p>To investigate factors associated with fertility among women in rural north eastern Tanzania.</p><p>Subjects and methods</p><p>A cohort of 1248 non-pregnant women was followed with urine pregnancy testing every third month or more regularly if they reported a missed menstrual period. Pregnancy was confirmed with trans-abdominal ultrasound. Information regarding general health, socioeconomic status and obstetric-gynaecological history was collected. Factors associated with conceiving within 180 days were identified using multivariate logistic regression analyses.</p><p>Results</p><p>Among the 1248 women, 736 were followed for 180 days and 209 of these had an ultrasound confirmed pregnancy. During the follow-up period, 169/736 women were diagnosed with urogenital infections, including suspected sexually transmitted or reproductive tract infections, urinary tract infection, and vaginal candidiasis. Urogenital infections were significantly associated with reduced odds of conceiving within 180 days (adjusted OR (AOR) 0.21, 95% CI 0.11–0.36). Being above 30 years of age was also negatively associated with odds of conceiving (AOR 0.45, 95% CI 0.26–0.77). In contrast, women who recently stopped using hormonal contraceptives (AOR 2.86, 95% CI 1.45–5.70) and women with low socioeconomic status (AOR 1.56, 95% CI 1.04–2.33) were significantly more likely to become pregnant within 180 days.</p><p>Conclusion</p><p>Urogenital infection seems to be a major health factor associated with reduced chances of conceiving. Considering the availability of effective treatment options for these diseases, public health authorities should increase awareness of diagnostic tools in settings with limited resources in order to improve fertility.</p></div
Diseases and pests of pigeonpea in eastern Africa: a review
Pigeonpea is one of the major legume crops grown in eastern Africa but has been relatively neglected in terms of research and development. The peas are a rich source of protein and the crop is nitrogen-fixing and drought tolerant. It is an ideal crop for the semi-arid areas of Africa and there is great potential for it to be more widely grown. The large number of pests and diseases which attack pigeonpea in Africa (and elsewhere) is perhaps the main constraint to increased production. The most important pest worldwide is the pod borer, Helicoverpa armigera, but the flowers and pods are attractive to a wide range of insect pests. The most important disease in eastern Africa is Fusarium wilt (Fusarium udum) and considerable effort has been devoted by ICRISAT to developing wilt-resistant pigeonpeas, adapted to cultivation in the region. This paper reviews the literature on pests and diseases of pigeonpea with special reference to eastern Africa and presents some new information on distribution and damage levels for the key pests and disease
Prevalence and risk factors for latent tuberculosis infection among household contacts of index cases in two South African provinces: Analysis of baseline data from a cluster-randomised trial.
INTRODUCTION: Household contacts of patients with active pulmonary tuberculosis (TB) often have latent TB infection, and are at risk of progression to disease. We set out to investigate whether index TB case HIV status was linked to a higher probability of latent TB infection among household contacts. MATERIALS AND METHODS: Data were collected prospectively from participants in the intervention arm of a household cluster-randomised trial in two South Africa provinces (Mangaung, Free State, and Capricorn, Limpopo). In intervention group households, TB contacts underwent HIV testing and tuberculin skin testing (TST). TST induration was estimated at two cut-offs (≥5mm, ≥10mm). Multilevel Bayesian regression models estimated posterior distributions of the percentage of household contacts with TST induration ≥5mm and ≥10mm by age group, and compared the odds of latent TB infection by key risk factors including HIV status index case age and study province. RESULTS: A total of 2,985 household contacts of 924 index cases were assessed, with most 2,725 (91.3%) undergoing TST. HIV prevalence in household contacts was 14% and 10% in Mangaung and Capricorn respectively. Overall, 16.8% (458/2,725) had TST induration of ≥5mm and 13.1% (359/2,725) ≥10mm. In Mangaung, children aged 0-4 years had a high TST positivity prevalence compared to their peers in Capricorn (22.0% vs. 7.6%, and 20.5% vs. 2.3%, using TST thresholds of ≥5mm and ≥10mm respectively). Compared to contacts from Capricorn, household contacts living in Mangaung were more likely to have TST induration ≥5mm (odds ratio [OR]: 3.08, 95% credibility interval [CI]: 2.13-4.58) and ≥10mm (OR: 4.52, 95% CI: 3.03-6.97). There was a 90% and 92% posterior probability that the odds of TST induration ≥5mm (OR: 0.79, 95% CI: 0.56-1.14) and ≥10mm (OR: 0.77, 95% CI: 0.53-1.10) respectively were lower in household contacts of HIV-positive compared to HIV-negative index cases. CONCLUSIONS: High TST induration positivity, especially among young children and people living in Mangaung indicates considerable TB transmission despite high antiretroviral therapy coverage. Household contact of HIV-positive index TB cases were less likely to have evidence of latent TB infection than contacts of HIV-negative index cases
Insect pests of pigeonpea in South Africa survey report
The incidence of pests in pigeon peas cultivated in South Africa was observed for the first time in surveys of field trials and plots undertaken in May 2000. The major insect pests observed were Clavigralla spp., Helicoverpa armigera and Callosobruchus spp
Risk factors of pre-hypertension and hypertension among non-pregnant women of reproductive age in northeastern Tanzania:a community based cross-sectional study
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