Structural and luminescence characterization of lithium-borosulfophosphate glasses containing dysprosium ions

Rare earth doped glasses have been a great deal of research interest due to their prominent applications in laser lighting technology. However, achieving highly efficient yellow light emission from these materials require the collective efforts of many researchers across the world. Hence, a series of high optical quality dysprosium doped lithium-borosulfophosphate glasses with chemical composition of 15Li2O-30B2O3-15SO3-(40-x)P2O5-xDy2O3 (where x = 0.1, 0.3, 0.5, 0.7 and 1.0 in mol%) were prepared by convectional melt quenching technique and characterized by X-Ray diffraction (XRD), Fourier Transform Infrared (FTIR) and Photoluminescence (PL) measurements. XRD pattern of the host glass confirms its amorphous nature while the results from FTIR spectra analysis indicates the presence of BO3, BO4, PO4 and SO42- groups in the host network structure. The photoluminescence spectral analysis revealed three emission bands at 494 nm, 585 nm and 673 nm attributed to the electronic transitions of 4F9/2→6H15/2, 4F9/2→6H13/2 and 4F9/2→6H15/2,respectively, under the excitation of 386 nm. Among all the prepared glass samples, 1.0 mol% Dy3+ contained glass sample exhibits an intense yellow emission at 585 nm which specifies its prospective suitability for yellow laser applications.Keywords: Borosulfophosphate glasses, Dysprosium ions, Fourier transform infrared spectroscopy, Photoluminescence analysi

Economic Impact of Galma Irrigation Scheme on the Farming Community in Dakaci, Zaria Area of Nigeria

Irrigation scheme is introduced for socioeconomic development of the community where it is based. One of such is the Galma Irrigation Fadama Project III around River Galma in Zaria Local Government Area of Kaduna State, Nigeria. The project provides water to surrounding communities for farming. This study was carried out with a view to determine the socioeconomic impact of the irrigation scheme on farming community in Dakaci, Zaria Area of Kaduna State. The study used data acquired from questionnaire survey, interviews and other secondary sources. Relevant data which include method of land acquisition, sources of capital, size of farmland, source of labor, major crops grown, average annual crop yield and average annual income were collected. The data were analyzed using simple descriptive statistics. The study revealed that the irrigation scheme to a large extent boosted crop yields and agricultural production in the area thereby improving the socioeconomic status of the farmers in the area. It is therefore recommended that more of such projects should be introduced to improve agricultural productivity. Moreover, there is the need for timely evaluation and assessment of such projects to maintain their proper functioning. In addition, government should refurbish the canals distributing the water to the farmlands, and also provide credit facilities to the farmers in order to improve their agricultural productivity which would help in ensuring food security for the nation at large

Economic Impact of Galma Irrigation Scheme on the Farming Community in Dakaci, Zaria Area of Nigeria

Irrigation scheme is introduced for socioeconomic development of the community where it is based. One of such is the Galma Irrigation Fadama Project III around River Galma in Zaria Local Government Area of Kaduna State, Nigeria. The project provides water to surrounding communities for farming. This study was carried out with a view to determine the socioeconomic impact of the irrigation scheme on farming community in Dakaci, Zaria Area of Kaduna State. The study used data acquired from questionnaire survey, interviews and other secondary sources. Relevant data which include method of land acquisition, sources of capital, size of farmland, source of labor, major crops grown, average annual crop yield and average annual income were collected. The data were analyzed using simple descriptive statistics. The study revealed that the irrigation scheme to a large extent boosted crop yields and agricultural production in the area thereby improving the socioeconomic status of the farmers in the area. It is therefore recommended that more of such projects should be introduced to improve agricultural productivity. Moreover, there is the need for timely evaluation and assessment of such projects to maintain their proper functioning. In addition, government should refurbish the canals distributing the water to the farmlands, and also provide credit facilities to the farmers in order to improve their agricultural productivity which would help in ensuring food security for the nation at large

Factors associated with interruption of treatment among Pulmonary Tuberculosis patients in Plateau State, Nigeria. 2011

Introduction: Nigeria has one of the highest tuberculosis (TB) burdens in the world with estimated  incidence of 133 per 100,000 populations. Multi-drug resistant TB (MDR-TB) is an emerging threat of the  TB control in Nigeria caused mainly by incomplete treatment. This study explored factors that affect  adherence to treatment among patients undergoing direct observation of TB treatment in Plateau state,  Nigeria.Methods: Between June and July 2011, we reviewed medical records and interviewed randomly selected pulmonary TB patients in their eighth month of treatment. Information on patients? clinical, socio- demographic and behavioral characteristics was collected using checklist and structured questionnaire for knowledge of treatment duration and reasons for interruption of treatment. We conducted focus group discussions with patients about barriers to treatment adherence. Data were analyzed with Epi Info  software. Results: Of 378 records reviewed, 229 (61%) patients were male; mean age 37.6 ±13.5 years and 71 (19%) interrupted their treatment. Interruption of treatment was associated with living > 5 km from TB treatment site (AOR: 11.3; CI 95%: 5.7-22.2), lack of knowledge of duration of treatment (AOR: 6.1; CI 95%: 2.8-13.2) and cigarette smoking (AOR: 3.4; CI 95%: 1.5- 8.0). Major reasons for the interruption were lack of transport fare (40%) and feeling well (25%). Focused group discussions revealed unfriendly attitudes of health care workers as barriers to adherence to treatment. Conclusion: This study revealed knowledge of the patients on the duration of treatment, distance and health workers  attitude as the major determinants of adherent to TB treatment. Training for health care workers on  patient education was conducted during routine supportive supervision.Key words: Interruption, treatment, Tuberculosis, Nigeri

Evaluation of Oxidant and Antioxidant Systems in Drought Response of Cowpea Varieties

Plant in their natural environment are exposed to several stresses such as the drought that affect their growth and productivity. Exposure of plant to drought leads to oxidative stresses as a result of increase in ROS, however plant counteract this effect by its antioxidant system. H2O2, malondialdehyde, membrane stability index, catalase and ascorbate peroxidase activities where evaluated in leaves of two cowpea varieties drought tolerant (Dan’ila) and drought susceptible (TVU 7778) during 2 weeks water deficit and 5days recovery. The result indicates significant increase in the H2O2, MDA, CAT and APX activities in both varieties during the stress period and significant decrease during recovery in drought tolerant variety compared to the drought susceptible variety. The membrane stability index decreases significantly during stress period in both varieties. Drought tolerant variety has the higher ability to counteract oxidant activity during the drought stress and recover faster than the drought susceptible variety. Keywords: Drought, antioxidant, cowpea DOI: 10.7176/JNSR/12-8-03 Publication date: April 30th 202

Structural and luminescent characteristic of Sm3+ doped magnesium sulfide borate orange-red phosphor for white LED

Polycrystalline compositions based on MgO, SO3 and B2O3 have both scientific and technological importance because of their useful applications. Doping with rare earth elements not only due to a rearrangement in the structure, but also to variation in the luminescence properties. Magnesium sulfide borate doped samarium oxide (MgSBO3:Sm3+) phosphors were prepared by solid state reaction and their structural and luminescence characteristic were studied and reported. IR and Raman spectral studies have been made to explore the presence of functional groups and various structural units in the prepared Polycrystalline. The formation of SO4, BO4, BO3, B-O-B and S-O-B structural units have been investigated. The emission and excitation properties were studied. And the results show that the emission and excitation spectra of these phosphors can be excited by ultraviolet (UV) 341, 370 and 403 nm light, and emit green, yellow and red light with intense peak at 601 nm, which are nicely in accordance with the widely applied near- UV LED chip. The emission spectral intensity of Sm3+ ions in the titled phosphors increases up to 1 mol% of Sm3+ ions and then decreases for 1.5 mol%. These results indicate that MgSBO3:Sm3+phosphor could be a potential suitable orange-red emitting phosphor candidate for white LEDs with excitation of a ~403 nm near UV LED chip

Estimation of public radiological dose from mining activities in some selected cities in Nigeria

Mining activities is one of the most significant sources of radiation exposure from long-lived naturally occurring radioactive materials (NORMs), and have resulted in unjustifiable public exposure doses which contravene radiation protection standards. As a result, estimating the extent of such exposure is essential for keeping the recommended public dose limit. This study therefore aims at estimating the public radiation dose around mining areas and its environs in some selected cities across Nigeria. Data on measured activity concentration of NORMs radionuclides comprising of U-238, Ra-226, Th-232 and K-40 from soil round mining areas in some selected cities in Nigeria were extracted from previous literatures and are used for public dose estimation using RESRAD computer code. From the calculated mean activity concentration, the results from each mining locations shows the maximum dose are lower than International Commission on Radiological Protection (ICRP), commended public dosage boundary of 1 mSv/yr with highest dose of 0.91 mSv/yr from Ra-226, Th-232 and K-40 over the period of 47.9 years reported from Gura Top mining site in Jos, Plateau State, while the lowest dose of 0.09 mSv/yr each over the period of 14.06 and 20.27 years occurred at Itagunmodi and Arufu sites for U-238, Th-232 and K-40. The highest dose recorded in Gura Top was due to numerous mining activities in the region. According to the ICRP, there is no safe level of radiation exposure. Therefore, there is need for competent authorities to conduct periodic assessment of radiation exposure from mining sites to ensure that all exposure emanating as a result of such activities are kept below the prescribed dose limit in accordance to the principle of As Low As Reasonably Achievable (ALARA), thereby ensuring public protection from unjustified radiation exposure

Structural characterization of sulphate borophosphate glasses containing calcium oxide

Increasing demands for better perfoming glasses have lead to current investigating of the sturctural properties of glasses for optimum performances. Calcium sulphate borophosphate glasses of different compositions were prepared using melt quenching technique. The glass forming ability and stability were checked using Differential thermal analyzer (DTA). Density and molar volume had been evaluated and analyzed. From the results of XRD, the absent of discrete and continuous sharp peaks confirmed the amorphous nature of the glass compositions while the results from both IR and Raman revealed the existence of SO4, BO4, BO3, P-O-P and PO43-. Addition of CaSO4 to borophosphate influenced the conversion of the dominant BO3 groups to BO4 groups. The structure of the samples was mainly based on metaphosphate, diphosphate and BO4 units, which became depolymerized with addition of CaSO4 content. The glass forming ability and thermal stability were found to increase with an increase in the concentration of modifier content. Glass density and molar volume is found to be between 2.146 to 2.314 gcm-3 and 45.794 to 48.880 m3mol-1 respectively. It is observed that the density of glass increased while the molar volume also increased with respect to increase in concentration of CaSO4 in the glass compositions. We analysed our data using different mechanisms and compared the results with previous works. Our findings show that this glass could be beneficial and considered as a good candidate for optical devices applications

Technology in Massachusetts Schools, 2004-2005

BACKGROUND:ATCC HIV-1 drug resistance test kit was designed to detect HIV-1 drug resistance (HIVDR) mutations in the protease and reverse transcriptase genes for all HIV-1 group M subtypes and circulating recombinant forms. The test has been validated for both plasma and dried blood spot specimen types with viral load (VL) of ≥1000 copies/ml. We performed an in-country assessment on the kit to determine the genotyping sensitivity and its accuracy in detecting HIVDR mutations using plasma samples stored under suboptimal conditions. METHODS:Among 572 samples with VL ≥1000 copies/ml that had been genotyped by ViroSeq assay, 183 were randomly selected, including 85 successful genotyped and 98 unsuccessful genotyped samples. They were tested with ATCC kits following the manufacturer's instructions. Sequence identity and HIVDR patterns were analysed with Stanford University HIV Drug Resistance HIVdb program. RESULTS:Of the 183 samples, 127 (69.4%) were successfully genotyped by either method. While ViroSeq system genotyped 85/183 (46.5%) with median VL of 32,971 (IQR: 11,150-96,506) copies/ml, ATCC genotyped 115/183 (62.8%) samples with median VL of 23,068 (IQR: 7,397-86,086) copies/ml. Of the 98 unsuccessful genotyped samples with ViroSeq assay, 42 (42.9%) samples with lower median VL of 13,906 (IQR: 6,122-72,329) copies/ml were successfully genotyped using ATCC. Sequence identity analysis revealed that the sequences generated by both methods were >98% identical and yielded similar HIVDR profiles at individual patient level. CONCLUSION:This study confirms that ATCC kit showed greater sensitivity in genotyping plasma samples stored in suboptimal conditions experiencing frequent and prolonged power outage. Thus, it is more sensitive particularly for subtypes A and A/G HIV-1 in resource-limited settings

Seroprevalence of SARS-CoV-2 in four states of Nigeria in October 2020: A population-based household survey

The observed epidemiology of SARS-CoV-2 in sub-Saharan Africa has varied greatly from that in Europe and the United States, with much lower reported incidence. Population-based studies are needed to estimate true cumulative incidence of SARS-CoV-2 to inform public health interventions. This study estimated SARS-CoV-2 seroprevalence in four selected states in Nigeria in October 2020. We implemented a two-stage cluster sample household survey in four Nigerian states (Enugu, Gombe, Lagos, and Nasarawa) to estimate age-stratified prevalence of SARS-CoV-2 antibodies. All individuals in sampled households were eligible for interview, blood draw, and nasal/oropharyngeal swab collection. We additionally tested participants for current/recent malaria infection. Seroprevalence estimates were calculated accounting for the complex survey design. Across all four states, 10,629 (96·5%) of 11,015 interviewed individuals provided blood samples. The seroprevalence of SARS-CoV-2 antibodies was 25·2% (95% CI 21·8–28·6) in Enugu State, 9·3% (95% CI 7·0–11·5) in Gombe State, 23·3% (95% CI 20·5–26·4) in Lagos State, and 18·0% (95% CI 14·4–21·6) in Nasarawa State. Prevalence of current/recent malaria infection ranged from 2·8% in Lagos to 45·8% in Gombe and was not significantly related to SARS-CoV-2 seroprevalence. The prevalence of active SARS-CoV-2 infection in the four states during the survey period was 0·2% (95% CI 0·1–0·4). Approximately eight months after the first reported COVID-19 case in Nigeria, seroprevalence indicated infection levels 194 times higher than the 24,198 officially reported COVID-19 cases across the four states; however, most of the population remained susceptible to COVID-19 in October 2020