16 research outputs found

    Thermal Pollution Mathematical Model

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    A one dimensional model for studying the thermal dynamics of cooling lakes was developed and verified. The model is essentially a set of partial differential equations which are solved by finite difference methods. The model includes the effects of variation of area with depth, surface heating due to solar radiation absorbed at the upper layer, and internal heating due to the transmission of solar radiation to the sub-surface layers. The exchange of mechanical energy between the lake and the atmosphere is included through the coupling of thermal diffusivity and wind speed. The effects of discharge and intake by power plants are also included. The numerical model was calibrated by applying it to Cayuga Lake. The model was then verified through a long term simulation using Lake Keowee data base. The comparison between measured and predicted vertical temperature profiles for the nine years is good. The physical limnology of Lake Keowee is presented through a set of graphical representations of the measured data base

    Verification and transfer of thermal pollution model. Volume 6: User's manual for 1-dimensional numerical model

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    The six-volume report: describes the theory of a three dimensional (3-D) mathematical thermal discharge model and a related one dimensional (1-D) model, includes model verification at two sites, and provides a separate user's manual for each model. The 3-D model has two forms: free surface and rigid lid. The former, verified at Anclote Anchorage (FL), allows a free air/water interface and is suited for significant surface wave heights compared to mean water depth; e.g., estuaries and coastal regions. The latter, verified at Lake Keowee (SC), is suited for small surface wave heights compared to depth (e.g., natural or man-made inland lakes) because surface elevation has been removed as a parameter

    Verification and transfer of thermal pollution model. Volume 4: User's manual for three-dimensional rigid-lid model

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    The theory of a three dimensional (3-D) mathematical thermal discharge model and a related one dimensional (1-D) model are described. Model verification at two sites, a separate user's manual for each model are included. The 3-D model has two forms: free surface and rigid lid. The former allows a free air/water interface and is suited for significant surface wave heights compared to mean water depth, estuaries and coastal regions. The latter is suited for small surface wave heights compared to depth because surface elevation was removed as a parameter. These models allow computation of time dependent velocity and temperature fields for given initial conditions and time-varying boundary conditions. The free surface model also provides surface height variations with time

    Thermal Pollution Mathematical Model. Volume 3: User's Manual for One-Dimensional Numerical Model for the Seasonal Thermocline

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    A user's manual for a one dimensional thermal model to predict the temperature profiles of a deep body of water for any number of annual cycles is presented. The model is essentially a set of partial differential equations which are solved by finite difference methods using a high speed digital computer. The model features the effects of area change with depth, nonlinear interaction of wind generated turbulence and buoyancy, adsorption of radiative heat flux below the surface, thermal discharges, and the effects of vertical convection caused by discharge. The main assumption in the formulation is horizontal homogeneity. The environmental impact of thermal discharges from power plants is emphasized. Although the model is applicable to most lakes, a specific site (Lake Keowee, S.C.) application is described in detail. The programs are written in FORTRAN 5

    Thermal Pollution Mathematical Model. Volume 5: User's Manual for Three-Dimensional Rigid-Lid Model

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    A user's manual for a three dimensional, rigid lid model used for hydrothermal predictions of closed basins subjected to a heated discharge together with various other inflows and outflows is presented. The model has the capability to predict (1) wind driven circulation; (2) the circulation caused by inflows and outflows to the domain; and (3) the thermal effects in the domain, and to combine the above processes. The calibration procedure consists of comparing ground truth corrected airborne radiometer data with surface isotherms predicted by the model. The model was verified for accuracy at various sites and results are found to be fairly accurate in all verification runs

    Verification and transfer of thermal pollution model. Volume 3: Verification of 3-dimensional rigid-lid model

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    The six-volume report: describes the theory of a three dimensional (3-D) mathematical thermal discharge model and a related one dimensional (1-D) model, includes model verification at two sites, and provides a separate user's manual for each model. The 3-D model has two forms: free surface and rigid lid. The former, verified at Anclote Anchorage (FL), allows a free air/water interface and is suited for significant surface wave heights compared to mean water depth; e.g., estuaries and coastal regions. The latter, verified at Lake Keowee (SC), is suited for small surface wave heights compared to depth (e.g., natural or man-made inland lakes) because surface elevation has been removed as a parameter. These models allow computation of time-dependent velocity and temperature fields for given initial conditions and time-varying boundary conditions. The free-surface model also provides surface height variations with time

    Thermal Pollution Mathematical Model. Volume 4: Verification of Three-Dimensional Rigid-Lid Model at Lake Keowee

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    The rigid lid model was developed to predict three dimensional temperature and velocity distributions in lakes. This model was verified at various sites (Lake Belews, Biscayne Bay, etc.) and th verification at Lake Keowee was the last of these series of verification runs. The verification at Lake Keowee included the following: (1) selecting the domain of interest, grid systems, and comparing the preliminary results with archival data; (2) obtaining actual ground truth and infrared scanner data both for summer and winter; and (3) using the model to predict the measured data for the above periods and comparing the predicted results with the actual data. The model results compared well with measured data. Thus, the model can be used as an effective predictive tool for future sites

    Age and sex prevalence of infectious dermatoses among primary school children in a rural South-Eastern Nigerian community

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    Introduction: Various dermatoses, due to their morbidity characteristics, have been shown to negatively impact on learning. The most epidemiologically important seem to be the infectious types because of their transmissibility and amenability to simple school-health measures. The aim of this study was to assess the prevalence and sex/age correlates of infectious dermatoses in a rural South-eastern Nigerian community.Methods: The pupils were proportionately recruited from the three primary schools based on school population. Stratified simple random samplingmethod was adopted and a table of random numbers was used to select required pupils from each arm. Clinical and laboratory examination wasdone to establish diagnoses of infectious skin disease. Data collected were analyzed using SPSS version 16. Results: The 400 pupils consisted of 153 males and 247 females. Age range was between 6 and 12 years. The prevalence of infectious聽 dermatoses was 72.3%. The five most prevalent clinical forms of infectious dermatoses, in order of decreasing prevalence, were tinea capitis (35.2%), scabies (10.5%), tinea corporis (5.8%), tinea pedis (5.5%), and impetigo (5.0%). More cases, generally, occurred among males than females聽 (80.4% vs 67.2%)); while some specific clinical types, pediculosis and seborrheic dermatitis, exhibited predilection for females. Pyodermas and scabies were significantly more prevalent in the 7-9 age-group; while tinea capitis, tinea corporis, seborrheic dermatitis and pediculosis were more associated with .10 age-group.Conclusion: Infectious dermatoses were highly prevalent in the surveyed population. Many of the clinical types exhibited sex- and age-specificity

    Sero-prevalence and risk factors for cytomegalovirus infection among pregnant women in a teaching hospital in Ogun state, Nigeria

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    Background: Infection with cytomegalo virus is usually asymptomatic however in pregnant women the risk of congenital infection and foetal  abnormalities makes antenatal screening for CMV infection necessary. The aim of this study was to determine the sero-prevalence and risk factors for  CMV infection among pregnant women in Babcock University Teaching Hospital (BUTH), Ilishan Remo, Ogun State, Nigeria.Methods: The study was a cross-sectional descriptive study conducted between January and May, 2017 on patients attending the antenatal clinic of  Babcock University Teaching Hospital. Enzyme Linked Immunosorbent Assay (ELISA) Kits were used to determine IgM and IgG anti CMV antibody titresinvenous blood samples obtained from study participants.Results: A total of 80 patients were recruited into the study. The mean age was 30 years.All (100%) respondents were sero-positive for anti CMV IgG  antibodies while 28.75% of respondents were seropositive for anti CMV IgM antibodies.Conclusion: There was a highsero-prevalence rate of CMV infection in the study. Screening of pregnant women for CMV infection is necessary due to the  risk of congenital infection and fetal defects

    HIV Non-Occupational Post-Exposure Prophylaxis Awareness Among Undergraduate Students of a Private University in South-West Nigeria

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    Objectives: The Human Immunodeficiency virus causes an infection of public health importance with about 71% of the global burden in Sub-Saharan Africa. In Nigeria, 3.2 million people are living with HIV, and 838,000 - 1.3 million of the cases are found among youths. Although Non- Occupational Human Immunodeficiency Virus (HIV) post-exposure prophylaxis (nPEP) is a safe and efficacious method of HIV prevention, it remains an underutilized prevention strategy in Nigeria.脗  This study aimed to determine the awareness level of nPEP after sexual and other non-occupational exposure to HIV among undergraduate students of a private University. Methods: A descriptive cross-sectional survey was conducted among 395 undergraduates芒鈧劉 students. Data was collected by pre-tested structured self-administered questionnaires. Data obtained from the study were analyzed using the IBM SPSS Statistics version 20 software program and Frequency distribution tables with percentages and cross-tables were used for data description. Results: About 42.8% were aware of nPEP. Most of the respondents 361 (91.4%) knew that PEP is to be given after HIV exposure risk following sexual intercourse. Although 79.5% of the respondents indicated that they will see their physician after unprotected sexual intercourse and other non-occupational exposure to HIV, the majority neither knows about nPEP initiation time, 247 (62.5%) nor its duration, 286 (72.4%). Conclusions: A low level of awareness was observed among our study participants, therefore, consistent health education and promotion of nPEP will improve its awareness, uptake, and possibly reduce the prevalence of HIV among our youths
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