3,321 research outputs found

    Determination of design-related properties of selected Irish potatoes varieties

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    The aim of this study was to determine some design-related properties of Irish potatoes commonly grown in Nigeria that may be useful in designing, handling and processing equipment of the product. Two varieties were selected: Nicola and Diamant. The measured properties were length, width, thickness, bulk density, solid density and angle of repose. Other parameters were arithmetic mean, geometric mean, surface area, volume, porosity and kernel weight. The mean length, width and thickness obtained for Nicola variety were 66.5, 37.3 and 32.4 mm respectively; while 57.4, 35.2, and 31.7 mm were obtained for Diamant, respectively. The mean angle of repose of Nicola and Diamant varieties were 27.20 and 26.40°, respectively. Mean roundness of Nicola and Diamant varieties were also obtained as 0.6 and 0.7 respectively. The mean surface area and volume of Nicola variety was determined to be 58.55 cm2 and 42.61 cm³ while that of Diamant variety was 50.31 cm² and 34.08 cm³, respectively. Moisture contents of Nicola and Diamant varieties used were obtained as 76.3 and 85.9%, respectively. Mean hardness of Nicola and Diamant varieties was 1.52 and 1.7 HV, respectively; indicating that Diamant is a harder variety than Nicola. These properties may be useful and serve as a guide on major engineering design of handling and processing equipment

    IR optical fiber-based noncontact pyrometer for drop tube instrumentation

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    The design of a two color pyrometer with infrared optical fiber bundles for collection of the infrared radiation is described. The pyrometer design is engineered to facilitate its use for measurement of the temperature of small, falling samples in a microgravity materials processing experiment using a 100 meter long drop tube. Because the samples are small and move rapidly through the field of view of the pyrometer, the optical power budget of the detection system is severly limited. Strategies for overcoming this limitation are discussed

    Atomic clocks highly sensitive to the variation of the fine structure constant based on Hf II, Hf IV, and W VI ions

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    We demonstrate that several metastable excited states in Hf ~II, Hf ~IV and W ~VI ions may be good clock states since they are sufficiently long-living and are not sensitive to the perturbations. Cooling E1 transitions are available. Energy levels, Land\'{e} gg-factors, transition amplitudes for electric dipole (E1), electric quadrupole (E2), and magnetic dipole (M1) transitions, lifetimes, and electric quadrupole moments for Hf ~II, Hf ~IV, and W ~VI ions are investigated using a combination of several methods of relativistic many-body calculations including the configuration interaction (CI), linearized coupled-cluster single-doubles (SD) and many-body perturbation theory (CI+SD), and also the configuration interaction with perturbation theory (CIPT). Scalar polarizabilities of the ground states and the clock states have been calculated to determine the black body radiation (BBR) shifts. We have found that the relative BBR shifts for these transitions range between 10−16^{-16} −- 10−18^{-18}. A linear combination of two clock transition frequencies allows one to further suppress BBR. Several 5d5d - 6s6s single-electron clock transitions ensure high sensitivity of the transition frequencies to the variation of the fine structure constant α\alpha and may be used to search for dark matter producing this variation of α\alpha. The enhancement coefficient for α\alpha variation reaches K=8.3K=8.3. Six stable isotopes of Hf and 5 stable isotopes in W allow one to make King plots and search for new interactions mediated by scalar particles or other mechanisms.Comment: 9 page

    Serological Survey of Dengue Virus Immunoglobulin M Among Febrile Patients in Kaduna Metropolis, Nigeria

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    The purposes of this research were to determine the prevalence of dengue virus in the study population, to determine the relationship between the occurrence of dengue virus IgM and potential risk factors and to determine the association between the occurrence of dengue virus and some symptoms. In this study, blood specimen were collected from 340 subjects with febrile complaints attending hospitals in Kaduna metropolis, Nigeria and who gave their consent to participate. Serological determination of dengue virus IgM was carried out using enzyme linked immunosorbent assay technique. Structured questionnaires were also administered to obtain data on demographic, risk factors,  and symptoms of illness. A total of 6 subjects were positive for dengue virus IgM giving a prevalence of 1.8%. There was no statistically significant association between the occurrence of dengue virus IgM and potential risk factors, demographic factors and symptoms of the illness. The occurrence of dengue virus in the study population was confirmed

    Persistent X-Ray Photoconductivity and Percolation of Metallic Clusters in Charge-Ordered Manganites

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    Charge-ordered manganites of composition Pr1−x(Ca1−ySry)xMnO3\rm Pr_{1-x}(Ca_{1-y}Sr_{y})_{x}MnO_3 exhibit persistent photoconductivity upon exposure to x-rays. This is not always accompanied by a significant increase in the {\it number} of conduction electrons as predicted by conventional models of persistent photoconductivity. An analysis of the x-ray diffraction patterns and current-voltage characteristics shows that x-ray illumination results in a microscopically phase separated state in which charge-ordered insulating regions provide barriers against charge transport between metallic clusters. The dominant effect of x-ray illumination is to enhance the electron {\it mobility} by lowering or removing these barriers. A mechanism based on magnetic degrees of freedom is proposed.Comment: 8 pages, 4 figure

    Hepcidin and iron status in chronic kidney disease

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    Hepcidin is a critical inhibitor of iron export frommacrophages, enterocytes, and hepatocytes. Given that itis filtered and degraded by the kidney, its elevated levelsin renal failure have been suggested to play a role in thedisordered iron metabolism of uremia. It is a smalldefensin-like peptide whose production by hepatocytes ismodulated in response to anemia, hypoxia, orinflammation. Hepcidin could also act as an indicator offunctional iron deficiency (FID) in chronic kidneydisease (CKD) patients. This study was performed toassess hepcidin and its correlations with renal function,iron status parameters {serum iron, serum ferritin,transferrin saturation (TSAT) and soluble transferrinreceptor (sTfR)}, inflammatory cytokines (IL-6&IFN-?)and inflammatory markers (CRP) in patients with CKDeither on conservative treatment or on maintenancehemodialysis (HD). Serum prohepcidin was higher inHD patients compared to controls and CKD patients. Inthe whole patient group, serum hepcidin correlatedsignificantly with hemoglobin (Hb), IL-6, creatinine,CRP, sTfR and urinary hepcidin. In HD groupprohepcidin correlated significantly with creatinine.Multiple regression analysis showed that prohepcidinwas most predicted by serum creatinine and CRP.Elevated prohepcidin levels in HD patients studied couldmainly be due to its accumulation in impaired renalfunction in addition to low-grade inflammation,frequently encountered in this population

    Protective effect of garlic extract against maternal and foetal cerebellar damage induced by lead administration during pregnancy in rats

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    Background: In spite of its industrial usefulness and varied daily uses, lead (Pb) pollution is a widespread ecological problem that faces the humans in the 21th century. Pb was found to produces a wide range of toxic effects including neurotoxicity especially to the developing and young offspring. Recently, the utilisation of herbal plants has received a significant attention where there has been rising awareness in their therapeutic use; among these is the garlic. In light of the above, the current study is designed experimentally in female pregnant rats in order to investigate the beneficial role of garlic extract in the protection from the maternal and foetal cerebellar damage produced by administration of different doses of Pb during pregnancy. Materials and methods: Positively pregnant female rats were divided into five groups; one control group, two Pb-treated groups (exposed to 160 and 320 mg/kg b.w. of Pb, respectively) and two groups treated with both Pb and garlic (exposed to Pb as previous groups together with 250 mg/kg b.w./day of garlic extract). Treatments started from day 1 to day 20 of pregnancy, where the mother rats of different experimental groups were sacrificed to obtain the foetuses. Pb level in the maternal and foetal blood and cerebellum was estimated by spectrophotometry. Specimens of the cerebellum of different mother and foetal groups were processed to histological and immunohistochemical staining for microscopic examination. Results: The results showed that administration of Pb to pregnant rats resulted in a dose-dependent toxicity for both mothers and foetuses in the form of decrease in maternal weight gain, placental and foetal weights, brain weight and diminished foetal growth parameters, which were prominent in rat’s group treated with larger dose of Pb. In Pb-treated rats, Pb level in blood and cerebellum was high when compared with the control group. The histopathological examination of the cerebellum of treated dams and foetuses showed marked alterations mainly in the form of Purkinje cell degeneration and lack of development of foetal cerebellum. Co-treatment of garlic extract along with Pb resulted in a significant decrease in Pb levels as compared with those treated with Pb alone with improvement of the histopathological changes. Conclusions: This study was useful in evaluating the hazardous effects of uncontrolled use of Pb in general and in assessing the developmental and neurotoxicity of foetuses due to exposure during pregnancy in particular. Co-administration of garlic has beneficial effects in amelioration of Pb-induced neurotoxicity and reversing the histopathological changes of the cerebellum of mother rats and foetuses. (Folia Morphol 2018; 77, 1: 1–15

    Hydrogeochemical Characterization and Quality Assessment of Groundwater Based on Water Quality Index in Imo state, South Eastern Nigeria

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    Water Quality Index (WQI), Principal Component Analysis (PCA), Correlation matrix, Metal Pollution Index (MPI), Contamination Factor (CF), Pollution Load Index (PLI), Geoaccumulation Index (Igeo), Health Risk Assessment, and Hydrogeochemical facies were used to analyze statistical indexes and hydrogeochemical facies in groundwater resources in Imo state, Nigeria. All across the study area, twenty (20) groundwater samples were collected in a systematic manner. The samples were examined in accordance with the American Public Health Association standard (APHA) method. Findings from the study revealed that WQI, is of poor quality and should only be used for irrigation. Weathering and redox reactions are important in groundwater geochemistry, according to PCA results. TDS and Cl, HCO3 and  Zn, Cl; Mg and Ca, Ca and Na were all found to have a positive correlation in the correlation matrix while PH and K, HCO3 and Fe, Cl and SO4 are found to have a negative correlation in the correlation matrix. The findings show that the items have a weak correlation and that there is no relationship between the two variables. Further MPI, CF, and PLI findings revealed that groundwater is pure, the main source of pollution is geological and anthropogenic processes, and there is no pollution in sampled groundwater. Hydrogeochemical trend revealed that groundwater is Na++K+ > HCO3¯+CO3> Mg+ > SO4> Cl¯ > Ca+. Based on the finding, pre-use treatment of water resources is strongly advised
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